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Sample records for activator inhibitor-1 regulates

  1. Effect of histone acetylate modification on the plasminogen activator inhibitor 1 gene regulation in mesangial cells

    Institute of Scientific and Technical Information of China (English)

    刘念

    2013-01-01

    Objective To investigate the effect of histone acetylation change on the transforming growth factor β1(TGF-β1)-associated plasminogen activator inhibitor 1(PAI-1)regulation in mesangial cells(MCs). Methods MCs were

  2. Plasminogen Activator Inhibitor-1 Controls Vascular Integrity by Regulating VE-Cadherin Trafficking.

    Directory of Open Access Journals (Sweden)

    Anna E Daniel

    Full Text Available Plasminogen activator inhibitor-1 (PAI-1, a serine protease inhibitor, is expressed and secreted by endothelial cells. Patients with PAI-1 deficiency show a mild to moderate bleeding diathesis, which has been exclusively ascribed to the function of PAI-1 in down-regulating fibrinolysis. We tested the hypothesis that PAI-1 function plays a direct role in controlling vascular integrity and permeability by keeping endothelial cell-cell junctions intact.We utilized PAI-039, a specific small molecule inhibitor of PAI-1, to investigate the role of PAI-1 in protecting endothelial integrity. In vivo inhibition of PAI-1 resulted in vascular leakage from intersegmental vessels and in the hindbrain of zebrafish embryos. In addition PAI-1 inhibition in human umbilical vein endothelial cell (HUVEC monolayers leads to a marked decrease of transendothelial resistance and disrupted endothelial junctions. The total level of the endothelial junction regulator VE-cadherin was reduced, whereas surface VE-cadherin expression was unaltered. Moreover, PAI-1 inhibition reduced the shedding of VE-cadherin. Finally, we detected an accumulation of VE-cadherin at the Golgi apparatus.Our findings indicate that PAI-1 function is important for the maintenance of endothelial monolayer and vascular integrity by controlling VE-cadherin trafficking to and from the plasma membrane. Our data further suggest that therapies using PAI-1 antagonists like PAI-039 ought to be used with caution to avoid disruption of the vessel wall.

  3. Regulation of Plasminogen Activator Inhibitor-1 Expression by Tumor Suppressor Protein p53*

    OpenAIRE

    Shetty, Sreerama; Shetty, Praveenkumar; Idell, Steven; Velusamy, Thirunavukkarasu; Bhandary, Yashodhar P.; Shetty, Rashmi S.

    2008-01-01

    H1299 lung carcinoma cells lacking p53 (p53-/-) express minimal amounts of plasminogen activator inhibitor-1 (PAI-1) protein as well as mRNA. p53-/- cells express highly unstable PAI-1 mRNA. Transfection of p53 in p53-/- cells enhanced PAI-1 expression and stabilized PAI-1 mRNA. On the contrary, inhibition of p53 expression by RNA silencing in non-malignant human lung epithelial (Beas2B) cells decreased basal as well as urokinase-type plasminogen activator-induced PAI-...

  4. Plasminogen activator inhibitor 1: Mechanisms of its synergistic regulation by growth factors

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiaoling

    2011-12-01

    My research is on the synergistic regulation of PAI-1 by EGF and TGF-β. The mechanism of synergistic regulation of PAI-1 by EGF and TGF-β are addressed. Methods are described for effective identification of RNA accessible sites for antisense oligodexoxynucleotides (ODNs) and siRNA. In this study effective AS-ODN sequences for both Lcn2 and Bcl2 were identified by in vitro tiled microarray studies. Our results suggest that hybridization of ODN arrays to a target mRNA under physiological conditions might be used as a rapid and reliable in vitro method to accurately identify targets on mRNA molecules for effective antisense and potential siRNA activity in vivo.

  5. Plasminogen activator inhibitor 1: Mechanisms of its synergistic regulation by growth factors

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiaoling [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    My research is on the synergistic regulation of PAI-1 by EGF and TGF-β. The mechanism of synergistic regulation of PAI-1 by EGF and TGF-β are addressed. Methods are described for effective identification of RNA accessible sites for antisense oligodexoxynucleotides (ODNs) and siRNA. In this study effective AS-ODN sequences for both Lcn2 and Bcl2 were identified by in vitro tiled microarray studies. Our results suggest that hybridization of ODN arrays to a target mRNA under physiological conditions might be used as a rapid and reliable in vitro method to accurately identify targets on mRNA molecules for effective antisense and potential siRNA activity in vivo.

  6. Does plasminogen activator inhibitor-1 drive lymphangiogenesis?

    DEFF Research Database (Denmark)

    Bruyère, Françoise; Melen-Lamalle, Laurence; Blacher, Silvia;

    2010-01-01

    The purpose of this study is to explore the function of plasminogen activator inhibitor-1 (PAI-1) during pathological lymphangiogenesis. PAI-1, the main physiological inhibitor of plasminogen activators is involved in pathological angiogenesis at least by controlling extracellular proteolysis and...

  7. Functional Stability of Plasminogen Activator Inhibitor-1

    Directory of Open Access Journals (Sweden)

    Songul Yasar Yildiz

    2014-01-01

    Full Text Available Plasminogen activator inhibitor-1 (PAI-1 is the main inhibitor of plasminogen activators, such as tissue-type plasminogen activator (t-PA and urokinase-type plasminogen activator (u-PA, and a major regulator of the fibrinolytic system. PAI-1 plays a pivotal role in acute thrombotic events such as deep vein thrombosis (DVT and myocardial infarction (MI. The biological effects of PAI-1 extend far beyond thrombosis including its critical role in fibrotic disorders, atherosclerosis, renal and pulmonary fibrosis, type-2 diabetes, and cancer. The conversion of PAI-1 from the active to the latent conformation appears to be unique among serpins in that it occurs spontaneously at a relatively rapid rate. Latency transition is believed to represent a regulatory mechanism, reducing the risk of thrombosis from a prolonged antifibrinolytic action of PAI-1. Thus, relying solely on plasma concentrations of PAI-1 without assessing its function may be misleading in interpreting the role of PAI-1 in many complex diseases. Environmental conditions, interaction with other proteins, mutations, and glycosylation are the main factors that have a significant impact on the stability of the PAI-1 structure. This review provides an overview on the current knowledge on PAI-1 especially importance of PAI-1 level and stability and highlights the potential use of PAI-1 inhibitors for treating cardiovascular disease.

  8. Phospholemman-dependent regulation of the cardiac Na/K-ATPase activity is modulated by inhibitor-1 sensitive type-1 phosphatase.

    Science.gov (United States)

    El-Armouche, Ali; Wittköpper, Katrin; Fuller, William; Howie, Jacqueline; Shattock, Michael J; Pavlovic, Davor

    2011-12-01

    Cardiac Na/K-ATPase (NKA) is regulated by its accessory protein phospholemman (PLM). Whereas kinase-induced PLM phosphorylation has been shown to mediate NKA stimulation, the role of endogenous phosphatases is presently unknown. We investigated the role of protein phosphatase-1 (PP-1) on PLM phosphorylation and NKA activity in rat cardiomyocytes and failing human hearts. Incubation of rat cardiomyocytes with the chemical PP-1/PP-2A inhibitor okadaic acid or the specific PP-1-inhibitor peptide (I-1ct) identified PLM phosphorylation at Ser-68 as the main substrate for PP-1. Moreover, myocytes adenovirally overexpressing PP-1 inhibitor-1 protein (I-1,Ad-I-1/eGFP) showed a 70% increase in PLM Ser-68 phosphorylation and 65% increase in NKA current, compared with enhanced green fluorescence protein (eGFP)-infected controls (Ad-eGFP), using Western blotting and voltage clamping, respectively. Notably, in left ventricular myocardium from patients with heart failure, PLM Ser-68 phosphorylation was ≈ 50% lower (n=7) than in nonfailing controls (n=7). We provide the first physiological and biochemical evidence that PLM phosphorylation and cardiac Na/K-ATPase activity are negatively regulated by PP-1 and that this regulatory mechanism could be counteracted by I-1. This novel mechanism is markedly perturbed in failing hearts favoring PLM dephosphorylation and NKA deactivation and thus may contribute to maladaptive hypertrophy and arrhythmogenesis via chronically higher intracellular Na and Ca concentrations.

  9. Hepatocyte growth factor activator inhibitor-1 is induced by bone morphogenetic proteins and regulates proliferation and cell fate of neural progenitor cells.

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    Raili Koivuniemi

    Full Text Available BACKGROUND: Neural progenitor cells (NPCs in the developing neuroepithelium are regulated by intrinsic and extrinsic factors. There is evidence that NPCs form a self-supporting niche for cell maintenance and proliferation. However, molecular interactions and cell-cell contacts and the microenvironment within the neuroepithelium are largely unknown. We hypothesized that cellular proteases especially those associated with the cell surface of NPCs play a role in regulation of progenitor cells in the brain. METHODOLOGY/PRINCIPAL FINDINGS: In this work, we show that NPCs, isolated from striatal anlage of developing rat brain, express hepatocyte growth factor activator inhibitor-1 and -2 (HAI-1 and HAI-2 that are cell surface-linked serine protease inhibitors. In addition, radial glia cells derived from mouse embryonic stem cells also express HAI-1 and HAI-2. To study the functional significance of HAI-1 and HAI-2 in progenitor cells, we modulated their levels using expression plasmids or silencing RNA (siRNA transfected into the NPCs. Data showed that overexpression of HAI-1 or HAI-2 decreased cell proliferation of cultured NPCs, whilst their siRNAs had opposite effects. HAI-1 also influenced NPC differentiation by increasing the number of glial fibrillary acidic protein (GFAP expressing cells in the culture. Expression of HAI-1 in vivo decreased cell proliferation in developing neuroepithelium in E15 old animals and promoted astrocyte cell differentiation in neonatal animals. Studying the regulation of HAI-1, we observed that Bone morphogenetic protein-2 (BMP-2 and BMP-4 increased HAI-1 levels in the NPCs. Experiments using HAI-1-siRNA showed that these BMPs act on the NPCs partly in a HAI-1-dependent manner. CONCLUSIONS: This study shows that the cell-surface serine protease inhibitors, HAI-1 and HAI-2 influence proliferation and cell fate of NPCs and their expression levels are linked to BMP signaling. Modulation of the levels and actions of HAI-1

  10. Plasminogen activator inhibitor-1 in sputum and nasal fluids increases in asthmatics during common colds

    Science.gov (United States)

    Cho, Seong H.; Hong, Seung J.; Chen, Haimei; Habib, Ali; Cho, David; Lee, Sun H.; Kang, Joseph; Ward, Theresa; Boushey, Homer A.; Schleimer, Robert P.; Avila, Pedro C.

    2014-01-01

    Capsule Summary This study showed that sputum and nasal lavage levels of plasminogen activator inhibitor-1 (PAI-1) rise during a common cold in asthmatic patients. This rise may contribute to the progression of airway remodeling. PMID:24373352

  11. Biochemical mechanism of action of a diketopiperazine inactivator of plasminogen activator inhibitor-1

    DEFF Research Database (Denmark)

    Einholm, Anja P; Pedersen, Katrine E; Wind, Troels;

    2003-01-01

    XR5118 [(3 Z,6 Z )-6-benzylidine-3-(5-(2-dimethylaminoethyl-thio-))-2-(thienyl)methylene-2,5-dipiperazinedione hydrochloride] can inactivate the anti-proteolytic activity of the serpin plasminogen activator inhibitor-1 (PAI-1), a potential therapeutic target in cancer and cardiovascular diseases....

  12. Modulation of plasminogen activator inhibitor-1 (PAI-1) by the naphthoquinone shikonin.

    Science.gov (United States)

    Han, Tingting; Zhang, Guangping; Yan, Dong; Yang, Hong; Ma, Tonghui; Ye, Zuguang

    2016-09-01

    Plasminogen activator inhibitor-1 (PAI-1) is a key negative regulator of the fibrinolytic system. Elevated levels of PAI-1 are associated with thrombosis and cardiovascular and metabolic diseases. Inhibition of PAI-1 activity represents a new strategy for antithrombotic and antifibrinolysis therapies. In this study, we systematically investigated the inhibitory effect of shikonin on PAI-1 activity. In the chromogenic substrate-based urokinase (uPA)/PAI-1 assay, we found that shikonin inhibited human PAI-1 activity with IC50 values of 30.68±2.32μM. This result was further confirmed by urokinase-type plasminogen activator (uPA)-mediated clot lysis assay. Mechanistic studies indicated that shikonin directly could bind to PAI-1 and prevent the binding of PAI-1 to uPA in a dose-dependent manner. Shikonin also blocked the formation of PAI-1/uPA complex, as shown by SDS/PAGE analysis. In the mouse arterial thrombosis model, intraperitoneal injection of shikonin at 1mgkg(-1) dose significantly prolonged tail bleeding time from 12.956±4.457min to 26.576±2.443min. It also reduced arterial thrombus weight from 0.01±0.001g to 0.006±0.001g (p<0.05). In a liver fibrosis treatment model, when shikonin was continuously injected intraperitoneally at a dose of 1mgkg(-1) over a two-week period, the hydroxyproline content in the mice plasma was significantly reduced and the degree of liver fibrosis was decreased significantly. Thus, shikonin may represent a novel small molecule inhibitor of PAI-1 that could have become a lead drug the treatment of thrombus and fibrosis. PMID:27476618

  13. IMD-4690, a novel specific inhibitor for plasminogen activator inhibitor-1, reduces allergic airway remodeling in a mouse model of chronic asthma via regulating angiogenesis and remodeling-related mediators.

    Science.gov (United States)

    Tezuka, Toshifumi; Ogawa, Hirohisa; Azuma, Masahiko; Goto, Hisatsugu; Uehara, Hisanori; Aono, Yoshinori; Hanibuchi, Masaki; Yamaguchi, Yoichi; Fujikawa, Tomoyuki; Itai, Akiko; Nishioka, Yasuhiko

    2015-01-01

    Plasminogen activator inhibitor (PAI)-1 is the principal inhibitor of plasminogen activators, and is responsible for the degradation of fibrin and extracellular matrix. IMD-4690 is a newly synthesized inhibitor for PAI-1, whereas the effect on allergic airway inflammation and remodeling is still unclear. We examined the in vivo effects by using a chronic allergen exposure model of bronchial asthma in mice. The model was generated by an immune challenge for 8 weeks with house dust mite antigen, Dermatophagoides pteronyssinus (Dp). IMD-4690 was intraperitoneally administered during the challenge. Lung histopathology, hyperresponsiveness and the concentrations of mediators in lung homogenates were analyzed. The amount of active PAI-1 in the lungs was increased in mice treated with Dp. Administration with IMD-4690 reduced an active/total PAI-1 ratio. IMD-4690 also reduced the number of bronchial eosinophils in accordance with the decreased expressions of Th2 cytokines in the lung homogenates. Airway remodeling was inhibited by reducing subepithelial collagen deposition, smooth muscle hypertrophy, and angiogenesis. The effects of IMD-4690 were partly mediated by the regulation of TGF-β, HGF and matrix metalloproteinase. These results suggest that PAI-1 plays crucial roles in airway inflammation and remodeling, and IMD-4690, a specific PAI-1 inhibitor, may have therapeutic potential for patients with refractory asthma due to airway remodeling. PMID:25785861

  14. IMD-4690, a novel specific inhibitor for plasminogen activator inhibitor-1, reduces allergic airway remodeling in a mouse model of chronic asthma via regulating angiogenesis and remodeling-related mediators.

    Directory of Open Access Journals (Sweden)

    Toshifumi Tezuka

    Full Text Available Plasminogen activator inhibitor (PAI-1 is the principal inhibitor of plasminogen activators, and is responsible for the degradation of fibrin and extracellular matrix. IMD-4690 is a newly synthesized inhibitor for PAI-1, whereas the effect on allergic airway inflammation and remodeling is still unclear. We examined the in vivo effects by using a chronic allergen exposure model of bronchial asthma in mice. The model was generated by an immune challenge for 8 weeks with house dust mite antigen, Dermatophagoides pteronyssinus (Dp. IMD-4690 was intraperitoneally administered during the challenge. Lung histopathology, hyperresponsiveness and the concentrations of mediators in lung homogenates were analyzed. The amount of active PAI-1 in the lungs was increased in mice treated with Dp. Administration with IMD-4690 reduced an active/total PAI-1 ratio. IMD-4690 also reduced the number of bronchial eosinophils in accordance with the decreased expressions of Th2 cytokines in the lung homogenates. Airway remodeling was inhibited by reducing subepithelial collagen deposition, smooth muscle hypertrophy, and angiogenesis. The effects of IMD-4690 were partly mediated by the regulation of TGF-β, HGF and matrix metalloproteinase. These results suggest that PAI-1 plays crucial roles in airway inflammation and remodeling, and IMD-4690, a specific PAI-1 inhibitor, may have therapeutic potential for patients with refractory asthma due to airway remodeling.

  15. Plasminogen Activator Inhibitor-1 and Susceptibility to Lung Cancer: A Population Genetics Perspective

    OpenAIRE

    Bayramoglu, Aysegul; Gunes, Hasan Veysi; Metintas, Muzaffer; Degirmenci, Irfan; Guler, Halil Ibrahim; Ustuner, Cengiz; Musmul, Ahmet

    2014-01-01

    Aim: The aim of this study was to investigate the polymorphism frequency of plasminogen activator inhibitor-1 (PAI-1) (rs1799889) 4G/5G in patients with lung cancer. Methods: In this study, 286 genomic DNAs (154 lung cancer patients+132 subjects without lung cancer) were analyzed. Polymorphisms were determined by using the polymerase chain reaction (PCR) method, with 4G and 5G allele-specific primers. PCR products were assessed by a charge-coupled device camera and exposed to 2% agarose gel e...

  16. Triglyceride concentration and waist circumference influence alcohol-related plasminogen activator inhibitor-1 activity increase in black South Africans

    NARCIS (Netherlands)

    Pieters, Marlien; de Lange, Zelda; Hoekstra, Tiny; Ellis, Suria M.; Kruger, Annamarie

    2010-01-01

    We investigated the association between alcohol consumption and plasminogen activator inhibitor-1 activity (PAI-1(act)) and fibrinogen concentration in a black South African population presenting with lower PAI-1(act) and higher fibrinogen than what is typically observed in white populations. We, fu

  17. IMD-4690, a Novel Specific Inhibitor for Plasminogen Activator Inhibitor-1, Reduces Allergic Airway Remodeling in a Mouse Model of Chronic Asthma via Regulating Angiogenesis and Remodeling-Related Mediators

    OpenAIRE

    Tezuka, Toshifumi; Ogawa, Hirohisa; AZUMA, MASAHIKO; GOTO, HISATSUGU; Uehara, Hisanori; Aono, Yoshinori; Hanibuchi, Masaki; Yamaguchi, Yoichi; Fujikawa, Tomoyuki; Itai, Akiko; Nishioka, Yasuhiko

    2015-01-01

    Plasminogen activator inhibitor (PAI)-1 is the principal inhibitor of plasminogen activators, and is responsible for the degradation of fibrin and extracellular matrix. IMD-4690 is a newly synthesized inhibitor for PAI-1, whereas the effect on allergic airway inflammation and remodeling is still unclear. We examined the in vivo effects by using a chronic allergen exposure model of bronchial asthma in mice. The model was generated by an immune challenge for 8 weeks with house dust mite antigen...

  18. Plasminogen Activator Inhibitor-1 in depression: Results from Animal and Clinical Studies.

    Science.gov (United States)

    Jiang, Haitang; Li, Xiaoli; Chen, Suzhen; Lu, Na; Yue, Yingying; Liang, Jinfeng; Zhang, Zhijun; Yuan, Yonggui

    2016-01-01

    Evidence suggests that plasminogen activator inhibitor-1 (PAI-1) is a stress-related factor, and serum PAI-1 levels are increased in patients with major depressive disorders (MDD). Herein, we analysed PAI-1 protein levels in the brain, cerebrospinal fluid (CSF) and serum of rodents exposed to chronic unpredictable mild stress or treated with escitalopram. In addition, we examined PAI-1 concentrations in serum obtained from 17 drug-free depressed patients before and after escitalopram treatment. We found that PAI-1 expression was increased in area 1 of the cingulate cortex and prelimbic cortex of the medial prefrontal cortex as well as in the hippocampal cornu ammonis 3 and dentate gyrus in stressed rats. A downregulation of PAI-1 following chronic escitalopram treatment was also found. PAI-1 levels were higher in the CSF and serum in stressed rats than in controls, although the difference did not reach statistical significance in the serum. Escitalopram treatment significantly decreased PAI-1 levels in the serum, but not in the CSF. MDD patients had significantly greater serum PAI-1 concentrations than controls. Our results suggest that PAI-1 is implicated in the pathophysiology of depression. PMID:27456456

  19. Increased concentration of plasminogen activator inhibitor-1 and fibrinogen in individuals with metabolic syndrome.

    Science.gov (United States)

    Palomo, Iván G; Gutiérrez, César L; Alarcón, Marcelo L; Jaramillo, Julio C; Segovia, Fabián M; Leiva, Elba M; Mujica, Verónica E; Icaza, Gloria N; Díaz, Nora S; Moore-Carrasco, Rodrigo

    2009-01-01

    Metabolic syndrome (MS) is closely linked to a generalized metabolic disorder referred to as insulin resistance. Disturbances in the hemostasis and fibrinolytic systems are a feature of MS. The aim of this study was to determine the concentration levels of fibrinogen and plasminogen activator inhibitor-1 (PAI-1) in a group of patients with MS with respect to a non-MS group, and to evaluate their possible relation with other risk factors in MS. The study was carried out in a total of 186 male and female non-smoking individuals aged 45-64 years, 93 with MS (ATP III criteria) and 93 without MS. Plasmatic levels of PAI-1 were measured by ELISA, and those of fibrinogen by the Claus method. The plasmatic levels of PAI-1 (men 49.2±19.8 vs. 35.0±12.2 ng/ml and women 42.0±19.7 vs. 31.6±14.6 ng/ml; p=0.0026) and fibrinogen (274.0±82.1 vs. 232.7±66.6 ng/ml; p=0.0002) were significantly higher in the MS group than in the non-MS group. PAI-1 was significantly associated with diastolic blood pressure, triglycerides and waist circumference. Fibrinogen was negatively associated with HDL-c. High plasmatic levels of PAI-1 and fibrinogen contribute to the cardiovascular risk that characterizes individuals with MS. PMID:21475821

  20. Enhancing the function of CD34(+ cells by targeting plasminogen activator inhibitor-1.

    Directory of Open Access Journals (Sweden)

    Sugata Hazra

    Full Text Available Previously, we showed that transient inhibition of TGF- β1 resulted in correction of key aspects of diabetes-induced CD34(+ cell dysfunction. In this report, we examine the effect of transient inhibition of plasminogen activator inhibitor-1 (PAI-1, a major gene target of TGF-β1 activation. Using gene array studies, we examined CD34(+ cells isolated from a cohort of longstanding diabetic individuals, free of microvascular complications despite suboptimal glycemic control, and found that the cells exhibited reduced transcripts of both TGF-β1 and PAI-1 compared to age, sex, and degree of glycemic control-matched diabetic individuals with microvascular complications. CD34(+ cells from diabetic subjects with microvascular complications consistently exhibited higher PAI-1 mRNA than age-matched non-diabetic controls. TGF- β1 phosphorodiamidate morpholino oligo (PMO reduced PAI-1 mRNA in diabetic (p<0.01 and non-diabetic (p=0.05 CD34(+ cells. To reduce PAI-1 in human CD34(+ cells, we utilized PAI-1 siRNA, lentivirus expressing PAI-1 shRNA or PAI-1 PMO. We found that inhibition of PAI-1 promoted CD34(+ cell proliferation and migration in vitro, likely through increased PI3(K activity and increased cGMP production. Using a retinal ischemia reperfusion injury model in mice, we observed that recruitment of diabetic CD34(+ cells to injured acellular retinal capillaries was greater after PAI-1-PMO treatment compared with control PMO-treated cells. Targeting PAI-1 offers a promising therapeutic strategy for restoring vascular reparative function in defective diabetic progenitors.

  1. The 4G/4G plasminogen activator inhibitor-1 genotype is associated with frequent recurrence of acute otitis media.

    NARCIS (Netherlands)

    Emonts, M.; Wiertsema, S.P.; Veenhoven, R.H.; Houwing-Duistermaat, J.J.; Walraven, V.; Groot, R. de; Hermans, P.W.M.; Sanders, E.A.M.

    2007-01-01

    OBJECTIVES: Plasminogen activator inhibitor-1 counterregulates cell migration, adhesion, and tissue repair. The PAI1 4G/5G promoter polymorphism has an effect on expression levels of PAI1. After a first acute otitis media episode, children are at increased risk for a next episode. Because the PAI1 4

  2. Distal hinge of plasminogen activator inhibitor-1 involves its latency transition and specificities toward serine proteases

    Directory of Open Access Journals (Sweden)

    Shaltiel Shmuel

    2003-07-01

    Full Text Available Abstract Background The plasminogen activator inhibitor-1 (PAI-1 spontaneously converts from an inhibitory into a latent form. Specificity of PAI-1 is mainly determined by its reactive site (Arg346-Met347, which interacts with serine residue of tissue-type plasminogen activator (tPA with concomitant formation of SDS-stable complex. Other sites may also play roles in determining the specificity of PAI-1 toward serine proteases. Results To understand more about the role of distal hinge for PAI-1 specificities towards serine proteases and for its conformational transition, wild type PAI-1 and its mutants were expressed in baculovirus system. WtPAI-1 was found to be about 12 fold more active than the fibrosarcoma PAI-1. Single site mutants within the Asp355-Arg356-Pro357 segment of PAI-1 yield guanidine activatable inhibitors (a that can still form SDS stable complexes with tPA and urokinase plasminogen activator (uPA, and (b that have inhibition rate constants towards plasminogen activators which resemble those of the fibrosarcoma inhibitor. More importantly, latency conversion rate of these mutants was found to be ~3–4 fold faster than that of wtPAI-1. We also tested if Glu351 is important for serine protease specificity. The functional stability of wtPAI-1, Glu351Ala, Glu351Arg was about 18 ± 5, 90 ± 8 and 14 ± 3 minutes, respectively, which correlated well with both their corresponding specific activities (84 ± 15 U/ug, 112 ± 18 U/ug and 68 ± 9 U/ug, respectively and amount of SDS-stable complex formed with tPA after denatured by Guanidine-HCl and dialyzed against 50 mM sodium acetate at 4°C. The second-order rate constants of inhibition for uPA, plasmin and thrombin by Glu351Ala and Glu351Arg were increased about 2–10 folds compared to wtPAI-1, but there was no change for tPA. Conclusion The Asp355-Pro357 segment and Glu351 in distal hinge are involved in maintaining the inhibitory conformation of PAI-1. Glu351 is a specificity

  3. Two distinct expression patterns of urokinase, urokinase receptor and plasminogen activator inhibitor-1 in colon cancer liver metastases

    DEFF Research Database (Denmark)

    Illemann, Martin; Bird, Nigel; Majeed, Ali;

    2009-01-01

    Metastatic growth and invasion by colon cancer cells in the liver requires the ability of the cancer cells to interact with the new tissue environment. Plasmin(ogen) is activated on cell surfaces by urokinase-type PA (uPA), and is regulated by uPAR and plasminogen activator inhibitor-1 (PAI-1......). To compare the expression patterns of uPA, uPAR and PAI-1 in colon cancer with that in their liver metastases, we analysed matched samples from 14 patients. In all 14 primary colon cancers, we found upregulation of uPAR, uPA mRNA and PAI-1 in primarily stromal cells at the invasive front. In 5 of the 14......, whereas 8 of the remaining 9 showed direct contact between the cancer cells and the liver parenchyma. We conclude that there are 2 distinct patterns of expression of uPAR, uPA and PAI-1 in colon cancer liver metastases and that these correlate closely with 2 morphological growth patterns. These findings...

  4. Plasminogen activator inhibitor-1 4G/5G gene polymorphism in patients with myocardial or cerebrovascular infarction in Tianjin, China

    Institute of Scientific and Technical Information of China (English)

    战梅; 周玉玲; 韩忠朝

    2003-01-01

    Objective To investigate the association between the plasminogen activator inhibitor-1 (PAI-1) 4G/5G gene polymorphism and the occurrence of myocardial and cerebrovascular infarctions in individuals from Tianjin, China.Methods The PAI-1 genotype was determined using allele-specific polymerase chain reaction (AS-PCR) in 56 myocardial infarction (MI) patients, 54 cerebrovascular infarction(CI) patients and 83 unrelated healthy controls. All subjects ' clinical features and plasma PAI-1 activity levels were determined.Results The PAI-1 genotype distribution frequency of the single guanine deletion/insertion 4G/5G polymorphism (located -675 bp upstream from the start of transcription) significantly differed between the patients and healthy controls. In the MI group, the 4G/4G-genotype frequency was increased, but the 4G/5G-genotype is decreased when compared to the control group. In the CI group, both the 4G/4G- and 4G/5G -genotypes occurred at a lower frequency than those in the control group (P<0.001). The plasma PAI-1 activity level in the MI group was lowered as the presence of the 4G allele decreases. In the CI group, the frequency of 5G/5G was much higher than that of the control group (P<0.001). The plasma PAI-1 activity level in the CI group was elevated as the presence of the 5G allele increased. Furthermore, positive correlation between triglyceride, glucose levels and PAI-1 activity were found in all three groups (P<0.001).Conclusions The PAI-1 4G/5G gene polymorphism is associated with a higher risk of MI and CI in individuals in Tianjin, China. The deletion/insertion polymorphism is probably an important hereditary risk factor for heart diseases. Moreover, triglyceride and glucose levels of plasma have functional importance in regulating PAI-1 activity.

  5. Plasminogen activator inhibitor-1 removal using dextran sulphate columns. Evidence of PAI-1 homeostasis.

    LENUS (Irish Health Repository)

    Maher, Vincent M G

    2009-08-01

    Patients with high plasma plasminogen activator inhibitor-1 (PAI-1) antigen levels are prone to develop thrombosis. Lowering PAI-1 levels may offer a therapeutic option and help to better understand PAI-1 metabolism. We examined the effect on plasma PAI-1 levels of LDL-apheresis using dextran sulphate (DS) columns in 12 patients (9 male, 3 female, 49 +\\/- 10 years) with heterozygous familial hypercholesterolaemia and coronary artery disease. One plasma volume equivalent (2.3-4.0 l) was treated during each procedure (at flow rates of 23 +\\/- 2 ml\\/min). Lipids and PAI-1 antigen levels were measured in plasma before and immediately after 19 aphereses (once in 7 patients, twice in 3 patients and three times in 2 patients) and also at 3 and 7 days post apheresis in five of these patients and in the column eluates from 8 of these patients. DS-apheresis reduced plasma cholesterol (50 +\\/- 8%), triglyceride (45 +\\/- 27%), apolipoprotein B (59 +\\/- 10%) and PAI-1 antigen levels from 10.2 +\\/- 5.2 to 6.0 +\\/- 3.1 ng\\/ml (P = 0.005). The PAI-I changes were independent of circadian variation. PAI-I bound to the DS-columns (3.51 +\\/- 1.03 ng\\/ml filtered plasma) and the percent of filtered PAI-1 that was bound correlated inversely (r = -0.81, P < 0.02) with basal PAI-1 levels indicating a high affinity saturable binding process. In four patients, plasma PAI-1 levels post-apheresis were higher than expected based on the amount of PAI-removed by the DS columns. The difference between the expected and actual PAI-1 level post apheresis, reflecting PAI-1 secretion or extracellular redistribution, correlated inversely with basal PAI-1 levels (r = -0.83, P = 0.01). PAI-1 levels returned to baseline pre-apheresis values 7 days post apheresis. PAI-1 antigen may be removed from plasma without adverse effect, resulting temporarily in its extracellular redistribution and restoration to baseline levels over one week. PAI-1 redistribution particularly when baseline pre

  6. Plasminogen activator inhibitor-1 4G/5G polymorphism and retinopathy risk in type 2 diabetes: a meta-analysis

    OpenAIRE

    Zhang Tengyue; Pang Chong; Li Ningdong; Zhou Elaine; Zhao Kanxing

    2013-01-01

    Abstract Background Mounting evidence has suggested that plasminogen activator inhibitor-1 (PAI-1) is a candidate for increased risk of diabetic retinopathy. Studies have reported that insertion/deletion polymorphism in the PAI-1 gene may influence the risk of this disease. To comprehensively address this issue, we performed a meta-analysis to evaluate the association of PAI-1 4G/5G polymorphism with diabetic retinopathy in type 2 diabetes. Methods Data were retrieved in a systematic manner a...

  7. Temporal changes in circulating P-selectin, plasminogen activator inhibitor-1, magnesium, and creatine kinase after percutaneous coronary intervention*

    OpenAIRE

    Ying, Shu-qin; Xiang, Mei-xiang; Fang, Lu; Wang, Jian-an

    2010-01-01

    Objective: This study aims to determine the mechanisms underlying restenosis and ischemia-reperfusion injury of the myocardium after percutaneous coronary intervention (PCI). Methods: The present study examined serial changes (5 min, 30 min, 2 h, 6 h, and 24 h after PCI) in circulating P-selectin, plasminogen activator inhibitor-1 (PAI-1), magnesium (Mg), and creatine kinase-myocardial band fraction (CK-MB) levels, which may be associated with restenosis and myocardial injury in patients unde...

  8. Effect of Plasminogen Activator Inhibitor-1 and Tissue Plasminogen Activator Polymorphisms on Susceptibility to Type 2 Diabetes in Malaysian Subjects

    Directory of Open Access Journals (Sweden)

    Zaid Al-Hamodi

    2012-01-01

    Full Text Available Elevated activity of plasminogen activator inhibitor-1 (PAI-1 and decreased tissue plasminogen activator (tPA activity are considered to be important risk factors for type 2 diabetes mellitus (T2DM and metabolic syndrome (MetS. The aim of this study was to investigate the association of the PAI-1 4G/5G and tPA Alu-repeat I/D polymorphisms with T2DM in Malaysian subjects. Serum insulin, coronary risk panel, plasma glucose, and PAI-1 4G/5G and tPA Alu-repeat I/D polymorphisms were studied in 303 T2DM subjects (227 with MetS and 76 without MetS and 131 normal subjects without diabetes and MetS. Statistical analysis showed that the dominant and additive models of PAI-1 4G/5G polymorphism showed a weak association with T2DM without MetS (OR=2.35, P=0.045; OR=1.67, P=0.058. On the other hand, the recessive model of the tPA Alu-repeat I/D polymorphism showed an association with T2DM with MetS (OR=3.32, P=0.013 whereas the dominant and additive models of the tPA Alu-repeat I/D polymorphism were not associated with T2DM either with or without MetS.

  9. Elevated plasma levels of vascular endothelial growth factor and plasminogen activator inhibitor-1 decrease during improvement of psoriasis

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Christensen, Ib Jarle; Svendsen, M N;

    2002-01-01

    OBJECTIVE AND DESIGN: An evaluation of angiogenesis related molecules during open treatment of psoriasis. MATERIALS AND SUBJECTS: Plasma samples and skin biopsies from 16 patients with psoriasis and plasma samples from 13 healthy controls. TREATMENT: Ranitidine 300 mg orally twice daily for 6...... months. METHODS: Vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) were determined by ELISA methods in plasma collected from the patients before treatment and after 1, 3 and 6 months. Vessel counts were performed in biopsies from affected skin areas taken before...... improvement of the disease suggest that the two molecules may play a role in pathogenesis of psoriasis....

  10. Angiotensin II induces secretion of plasminogen activator inhibitor 1 and a tissue metalloprotease inhibitor-related protein from rat brain astrocytes

    International Nuclear Information System (INIS)

    The present study investigates angiotensin (Ang) II effects on secretory protein synthesis in brain astrocytes cultured from neonatal and 21-day-old rats. Ang II-induced changes in the de novo synthesis of [35S]methionine-labeled secretory proteins were visualized using two-dimensional NaDodSO4/PAGE. Astrocytes from 21-day-old rat brain possess specific high-affinity receptors for Ang II. These cells express two Ang II-induced secretory proteins with Mr 55,000 (AISP-55K) and Mr 30,000 (AISP-30K), which were time- and dose-dependent (EC50, 1 nM). [Sar1, Ile8]Ang II (where Sar is sarcosine) inhibited Ang II-induced secretion of AISP-55K but not AISP-30K. N-terminal amino acid sequencing indicates that AISP-55K is identical to rat plasminogen activator inhibitor 1, whereas AISP-30K exhibits 72-81% identity to three closely related proteins: human tissue inhibitor of metalloproteases, a rat phorbol ester-induced protein, and the murine growth-responsive protein 16C8. Immunofluorescent staining with rat plasminogen activator inhibitor 1 antibody was induced in the majority of cells in culture after Ang II treatment of astrocytes from 21-day-old rat brains. Absence of this response to Ang II in astrocytes from neonatal rat brain provides evidence that this action of Ang II on astrocytes is developmentally regulated

  11. Hepatocyte growth factor activator inhibitor-1 has a complex subcellular itinerary

    DEFF Research Database (Denmark)

    Godiksen, Sine; Selzer-Plon, Joanna; Pedersen, Esben D K;

    2008-01-01

    it is a key regulator of carcinogenesis. HAI-1 is expressed in polarized epithelial cells, which have the plasma membrane divided by tight junctions into an apical and a basolateral domain. In the present study we show that HAI-1 at steady-state is mainly located on the basolateral membrane of both Madin......-Darby canine kidney cells and mammary gland epithelial cells. After biosynthesis, HAI-1 is exocytosed mainly to the basolateral plasma membrane from where 15% of the HAI-1 molecules are proteolytically cleaved and released into the basolateral medium. The remaining membrane-associated HAI-1 is endocytosed...... and then recycles between the basolateral plasma membrane and endosomes for hours until it is transcytosed to the apical plasma membrane. Minor amounts of HAI-1 present at the apical plasma membrane are proteolytically cleaved and released into the apical medium. Full-length membrane-bound HAI-1 has a half...

  12. Plasminogen activator inhibitor-1 polymers, induced by inactivating amphipathic organochemical ligands

    DEFF Research Database (Denmark)

    Pedersen, Katrine E; Einholm, Anja P; Christensen, Anni;

    2003-01-01

    . As compared with native PAI-1, the polymers exhibited an increased resistance to temperature-induced unfolding. Polymerization was associated with specific changes in patterns of digestion with non-target proteases. During incubation with urokinase-type plasminogen activator, the polymers were slowly...

  13. A plasminogen activator inhibitor-1 inhibitor reduces airway remodeling in a murine model of chronic asthma.

    Science.gov (United States)

    Lee, Sun H; Eren, Mesut; Vaughan, Douglas E; Schleimer, Robert P; Cho, Seong H

    2012-06-01

    We previously reported that plasminogen activator inhibitor (PAI)-1 deficiency prevents collagen deposition in the airways of ovalbumin (OVA)-challenged mice. In this study, we explored the therapeutic utility of blocking PAI-1 in preventing airway remodeling, using a specific PAI-1 inhibitor, tiplaxtinin. C57BL/6J mice were immunized with intraperitoneal injections of OVA on Days 0, 3, and 6. Starting on Day 11, mice were challenged with phosphate-buffered saline or OVA by nebulization three times per week for 4 weeks. Tiplaxtinin was mixed with chow and administered orally from 1 day before the phosphate-buffered saline or OVA challenge. Lung tissues were harvested after challenge and characterized histologically for infiltrating inflammatory cells, mucus-secreting goblet cells, and collagen deposition. Airway hyperresponsiveness was measured using whole-body plethysmography. Tiplaxtinin treatment significantly decreased levels of PAI-1 activity in bronchoalveolar lavage fluids, which indicates successful blockage of PAI-1 activity in the airways. The number of infiltrated inflammatory cells was reduced by tiplaxtinin treatment in the lungs of the OVA-challenged mice. Furthermore, oral administration of tiplaxtinin significantly attenuated the degree of goblet cell hyperplasia and collagen deposition in the airways of the OVA-challenged mice, and methacholine-induced airway hyperresponsiveness was effectively reduced by tiplaxtinin in these animals. This study supports our previous findings that PAI-1 promotes airway remodeling in a murine model of chronic asthma, and suggests that PAI-1 may be a novel target of treatment of airway remodeling in asthma. PMID:22323366

  14. Gene expression of fibrinolytic factors urokinase plasminogen activator and plasminogen activator inhibitor-1 in rabbit temporo-mandibular joint cartilage with disc displacement

    Institute of Scientific and Technical Information of China (English)

    ZHAN Jing; GU Zhi-yuan; WU Li-qun; ZHANG Yin-kai; HU Ji-an

    2005-01-01

    Background The urokinase plasminogen activator system is believed to play an important role in degradation of the extracellular matrix associated with cartilage and bone destruction; however its precise roles in temporomandibular disorders have not yet been clarified. The aims of this study were to investigate the gene expression of fibrinolytic factors urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) in the articular cartilage of rabbit temporomandibular joint (TMJ) with disc displacement (DD) and to probe the relationship between fibrinolytic activity and cartilage remodeling. Methods Disc displacement of right joints was performed in 36 of 78 rabbits under investigation. The animals were sacrificed at 4 days and 1, 2, 4, 8 and 12 weeks after surgery, respectively. The right joints of these animals were harvested and processed for the examination of mRNA expression of uPA and PAI-1 in articular cartilage using in situ hybridization techniques. Results The expression of uPA and PAI-1 was co-expressed weakly in the chondrocytes from transitive zone to hypertrophic zone and mineralized zone, while no hybridizing signals were shown in proliferative zone and superficial zone in control rabbits. The most striking was the up-regulation of uPA and PAI-1 mRNA in 4-day rabbits postoperatively at the onset of cartilage degeneration. The strongest hybridizing signals for uPA and PAI-1 were seen in 2-week rabbits postoperatively. After 2 weeks, the expression of uPA and PAI-1 began to decrease and reached nearly normal level at 12 weeks. Conclusions The expression of the uPA/PAI-1 system coincides with the pathological changes in condylar cartilage after DD. The uPA/PAI-1 system may be one of the essential mediators in articular cartilage remodeling.

  15. Signal Transducer and Activator of Transcription (Stat)-Induced Stat Inhibitor 1 (Ssi-1)/Suppressor of Cytokine Signaling 1 (Socs1) Inhibits Insulin Signal Transduction Pathway through Modulating Insulin Receptor Substrate 1 (Irs-1) Phosphorylation

    OpenAIRE

    Kawazoe, Yoshinori; Naka, Tetsuji; Fujimoto, Minoru; Kohzaki, Hidetsugu; Morita, Yoshiaki; Narazaki, Masashi; Okumura, Kohichi; Saitoh, Hiroshi; Nakagawa, Reiko; Uchiyama, Yasuo; Akira, Shizuo; Kishimoto, Tadamitsu

    2001-01-01

    Signal transducer and activator of transcription (STAT)-induced STAT inhibitor 1 (SSI-1) is known to function as a negative feedback regulator of cytokine signaling, but it is unclear whether it is involved in other biological events. Here, we show that SSI-1 participates and plays an important role in the insulin signal transduction pathway. SSI-1–deficient mice showed a significantly low level of blood sugar. While the forced expression of SSI-1 reduced the phosphorylation level of insulin ...

  16. Evaluation of 12-Lipoxygenase (12-LOX and Plasminogen Activator Inhibitor 1 (PAI-1 as Prognostic Markers in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Tomasz Gondek

    2014-01-01

    Full Text Available In carcinoma of prostate, a causative role of platelet 12-lipoxygenase (12-LOX and plasminogen activator inhibitor 1 (PAI-1 for tumor progression has been firmly established in tumor and/or adjacent tissue. Our goal was to investigate if 12-LOX and/or PAI-1 in patient’s plasma could be used to predict outcome of the disease. The study comprised 149 patients (age 70±9 divided into two groups: a study group with carcinoma confirmed by positive biopsy of prostate (n=116 and a reference group (n=33 with benign prostatic hyperplasia (BPH. The following parameters were determined by the laboratory test in plasma or platelet-rich plasma: protein level of 12-LOX, PAI-1, thromboglobulin (TGB, prostate specific antigen (PSA, C-reactive protein (CRP, hemoglobin (HGB, and hematocrit (HCT, as well as red (RBC and white blood cells (WBC, number of platelets (PLT, international normalized ratio of blood clotting (INR, and activated partial thromboplastin time (APTT. The only difference of significance was noticed in the concentration of 12-LOX in platelet rich plasma, which was lower in cancer than in BPH group. Standardization to TGB and platelet count increases the sensitivity of the test that might be used as a biomarker to assess risk for prostate cancer in periodically monitored patients.

  17. Increase of plasminogen activator inhibitor-1 and decrease of transforming growth factor-b1 in children with dengue haemorrhagic fever in Indonesia.

    NARCIS (Netherlands)

    Djamiatun, K.; Faradz, S.M.; Setiati, T.E.; Netea, M.G.; Ven, A.J.A.M. van der; Dolmans, W.M.V.

    2011-01-01

    Mortality in children with severe dengue haemorrhagic fever (DHF) in Indonesia is high. The origin of the elevated plasminogen activator inhibitor-1 (PAI-1) levels in these children is unclear. We measured PAI-1, transforming growth factor-beta1 (TGF-beta1), platelet counts, plasma leakage and liver

  18. Relationship of plasminogen activator inhibitor 1 gene 4G/5G polymorphisms to hypertension in Korean women

    Institute of Scientific and Technical Information of China (English)

    Kyu-nam Kim; Kwang-min Kim; Bom-taeck Kim; Nam-seok Joo; Doo-yeoun Cho; Duck-joo Lee

    2012-01-01

    Background Hypertension (HTN) is a major determinant of various cardiovascular events.Plasma levels of plasminogen activator inhibitor 1 (PAl-1) modulate this risk.A deletion/insertion polymorphism within the PAl-1 loci (4G/4G,4G/5G,5G/5G) affects the expression of this gene.The present study investigated the association between PAl-1 loci polymorphisms and HTN in Korean women.@@Methods Korean women (n=1312) were enrolled in this study to evaluate the association between PAl-1 4G/5G gene polymorphisms and HTN as well as other metabolic risk factors.PAl-1 loci polymorphisms were investigated using polymerase chain reaction amplification and single-strand conformation polymorphism analysis.@@Results The three genotype groups differed with respect to systolic blood pressure (P=0.043),and diastolic blood pressure (P=0.009) but not with respect to age,body mass index,total cholesterol,low or high density lipoprotein cholesterol,triglycerides,or fasting blood glucose.Carriers of the PAl-1 4G allele had more hypertension significantly (PAl-1 4G/5G vs.PAl-1 5G/5G,P=0.032; PAl-1 4G/4G vs.PAl-1 5G/5G,P=0.034).When stratified according to PAl-1 4G/5G polymorphism,there was no significant difference in all metabolic parameters among PAl-1 genotype groups in patients with HTN as well as subjects with normal blood pressure.The estimated odds ratio of the 4G/4G genotype and 4G/5G for HTN was 1.7 (P=0.005),and 1.6 (P=0.015),respectively.@@Conclusion These findings might indicate that PAl-1 loci polymorphisms independently contribute to HTN and that gene-environmental interaction may be not associated in Korean women.

  19. Plasminogen Activator Inhibitor-1 Antagonist TM5484 Attenuates Demyelination and Axonal Degeneration in a Mice Model of Multiple Sclerosis.

    Directory of Open Access Journals (Sweden)

    Nicolas Pelisch

    Full Text Available Multiple sclerosis (MS is characterized by inflammatory demyelination and deposition of fibrinogen in the central nervous system (CNS. Elevated levels of a critical inhibitor of the mammalian fibrinolitic system, plasminogen activator inhibitor 1 (PAI-1 have been demonstrated in human and animal models of MS. In experimental studies that resemble neuroinflammatory disease, PAI-1 deficient mice display preserved neurological structure and function compared to wild type mice, suggesting a link between the fibrinolytic pathway and MS. We previously identified a series of PAI-1 inhibitors on the basis of the 3-dimensional structure of PAI-1 and on virtual screening. These compounds have been reported to provide a number of in vitro and in vivo benefits but none was tested in CNS disease models because of their limited capacity to penetrate the blood-brain barrier (BBB. The existing candidates were therefore optimized to obtain CNS-penetrant compounds. We performed an in vitro screening using a model of BBB and were able to identify a novel, low molecular PAI-1 inhibitor, TM5484, with the highest penetration ratio among all other candidates. Next, we tested the effects on inflammation and demyelination in an experimental allergic encephalomyelitis mice model. Results were compared to either fingolimod or 6α-methylprednisolone. Oral administration of TM5484 from the onset of signs, ameliorates paralysis, attenuated demyelination, and axonal degeneration in the spinal cord of mice. Furthermore, it modulated the expression of brain-derived neurotrophic factor, which plays a protective role in neurons against various pathological insults, and choline acetyltransferase, a marker of neuronal density. Taken together, these results demonstrate the potential benefits of a novel PAI-1 inhibitor, TM5484, in the treatment of MS.

  20. Idiopathic pulmonary fibrosis in relation to gene polymorphisms of transforming growth factor-β1 and plasminogen activator inhibitor 1

    Institute of Scientific and Technical Information of China (English)

    LI Xin-xia; LI Ning; BAN Cheng-jun; ZHU Min; XIAO Bai; DAI Hua-ping

    2011-01-01

    Background Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal fibrotic lung disease of unknown etiology.Host susceptibility or genetic factors may be important for the predisposition to it. Transforming growth factor-pi (TGF-β1,a potent profibrotic cytokine) and plasminogen activator inhibitor 1 (PAI-1) play important roles in the development of pulmonary fibrosis. The objective of the study was to investigate the association between the gene polymorphisms of TGF-β1 869 T>C and PAI-1 4G/5G and the susceptibility to IPF in Han ethnicity.Methods Polymerase chain reaction (PCR) and restriction fragment length polymorphism were performed to analyse the gene polymorphisms of TGF-β1 in 869T>C and PAI-1 4G/5G in 85 IPF patients and 85 healthy controls matched in age, gender, race and smoker status.Results There was a significant difference in 869T>Cgenotype distribution of TGF-β1 between IPF cases and controls,a significant negative association between TC genotype and the development of IPF (OR=0.508, 95% Cl: 0.275-0.941)and a positive association between CC genotype and the development of IPF (OR=1.967, 95% Cl: 1.063-3.641). There was a significant positive association between PAI-1 5G/SG genotype and the development of IPF (OH=0.418, 95% Cl:0.193-0.904).Conclusions Gene polymorphisms of TGF-pi in 869T<C and PAI-1 4G/SG may affect the susceptibility to IPF in Han ethnicity. Further investigations are needed to confirm these findings and assess their biological significance in the development of the disease in this ethnic population.

  1. Association of plasminogen activator inhibitor-1 and angiotensin converting enzyme polymorphisms with recurrent pregnancy loss in Iranian women

    Directory of Open Access Journals (Sweden)

    Fatemeh Shakarami

    2015-10-01

    Full Text Available Background: Recurrent pregnancy loss (RPL defined by two or more failed pregnancies before 20 weeks of gestation. Several factors play a role in RPL including thrombophilic conditions which can be influenced by gene polymorphisms. Plasminogen activator inhibitor-1 (PAI-1 and angiotensin converting enzyme (ACE genes are closely related to fibrinolytic process, embryonic development and pregnancy success. Objective: The aim of this study was to investigate the relationship between RPL and common polymorphisms in ACE and PAI-1 genes. Materials and Methods: In this case control study, 100 women with recurrent abortions (at least two were selected as cases and 100 healthy women with two or more normal term deliveries without a history of abortion as controls. Total genomic DNA was isolated from blood leukocytes. The status of the PAI-1 4G/5G and ACE (D/I polymorphism was determined by PCR-RFLP. Results: Homozygosity for PAI-1 4G polymorphism was seen in 17 cases (17%, and 5 controls (5% (p=0.006 so patients with homozygote 4G mutation were significantly more prone to RPL in contrast to control group (OR: 4.63, % 95 CI: 1.55-13.84. In addition, 7 patients (7 %, and no one from the control group, were homozygote (I/I for ACE polymorphism (p=0.034, suggesting no significant associations between ACE D allele or DD genotype and RPL. Conclusion: Considering these results, because 4G/4G polymorphism for PAI-1 gene could be a thrombophilic variant leading to abortion, analysis of this mutation and other susceptibility factors are recommended in patients with RPL.

  2. Immobilization of the distal hinge in the labile serpin plasminogen activator inhibitor 1: identification of a transition state with distinct conformational and functional properties.

    Science.gov (United States)

    De Taeye, Bart; Compernolle, Griet; Dewilde, Maarten; Biesemans, Wouter; Declerck, Paul J

    2003-06-27

    The serpin plasminogen activator inhibitor-1 (PAI-1) plays an important role in the regulation of the fibrinolytic activity in blood. In plasma, PAI-1 circulates mainly in the active conformation. However, PAI-1 spontaneously converts to a latent conformation. This conversion comprises drastic conformational changes in both the distal and the proximal hinge region of the reactive center loop. To study the functional and conformational rearrangements associated solely with the mobility of the proximal hinge, disulfide bonds were introduced to immobilize the distal hinge region. These mutants exhibited specific activities comparable with that of PAI-1-wt. However, the engineered disulfide bond had a major effect on the conformational and associated functional transitions. Strikingly, in contrast to PAI-1-wt, inactivation of these mutants yielded a virtually complete conversion to a substrate-like conformation. Comparison of the digestion pattern (with trypsin and elastase) of the mutants and PAI-1-wt revealed that the inactivated mutants have a conformation differing from that of latent and active PAI-1-wt. Unique trypsin-susceptible cleavage sites arose upon inactivation of these mutants. The localization of these exposed residues provides evidence that a displacement of alphahF has occurred, indicating that the proximal hinge is partly inserted between s3A and s5A. In conclusion, immobilization of the distal hinge region in PAI-1 allowed the identification of an "intermediate" conformation characterized by a partial insertion of the proximal hinge region. We hypothesize that locking PAI-1 in this transition state between active and latent conformations is associated with a displacement of alphahF, subsequently resulting in substrate behavior.

  3. Plasminogen activator inhibitor-1 4G/5G polymorphism and retinopathy risk in type 2 diabetes: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Zhang Tengyue

    2013-01-01

    Full Text Available Abstract Background Mounting evidence has suggested that plasminogen activator inhibitor-1 (PAI-1 is a candidate for increased risk of diabetic retinopathy. Studies have reported that insertion/deletion polymorphism in the PAI-1 gene may influence the risk of this disease. To comprehensively address this issue, we performed a meta-analysis to evaluate the association of PAI-1 4G/5G polymorphism with diabetic retinopathy in type 2 diabetes. Methods Data were retrieved in a systematic manner and analyzed using Review Manager and STATA Statistical Software. Crude odds ratios (ORs with 95% confidence intervals (CIs were used to assess the strength of associations. Results Nine studies with 1, 217 cases and 1, 459 controls were included. Allelic and genotypic comparisons between cases and controls were evaluated. Overall analysis suggests a marginal association of the 4G/5G polymorphism with diabetic retinopathy (for 4G versus 5G: OR 1.13, 95%CI 1.01 to 1.26; for 4G/4G versus 5G/5G: OR 1.30, 95%CI 1.04 to 1.64; for 4G/4G versus 5G/5G + 4G/5G: OR 1.26, 95%CI 1.05 to 1.52. In subgroup analysis by ethnicity, we found an association among the Caucasian population (for 4G versus 5G: OR 1.14, 95% CI 1.00 to 1.30; for 4G/4G versus 5G/5G: OR 1.33, 95%CI 1.02 to 1.74; for 4G/4G versus 5G/5G + 4G/5G: OR 1.41, 95%CI 1.13 to 1.77. When stratified by the average duration of diabetes, patients with diabetes histories longer than 10 years have an elevated susceptibility to diabetic retinopathy than those with shorter histories (for 4G/4G versus 5G/5G: OR 1.47, 95%CI 1.08 to 2.00. We also detected a higher risk in hospital-based studies (for 4G/4G versus 5G/5G+4G/5G: OR 1.27, 95%CI 1.02 to 1.57. Conclusions The present meta-analysis suggested that 4G/5G polymorphism in the PAI-1 gene potentially increased the risk of diabetic retinopathy in type 2 diabetes and showed a discrepancy in different ethnicities. A higher susceptibility in patients with longer duration of

  4. Association of the 4 g/5 g polymorphism of plasminogen activator inhibitor-1 gene with sudden sensorineural hearing loss. A case control study

    OpenAIRE

    Cho Seong; Chen Haimei; Kim Il; Yokose Chio; Kang Joseph; Cho David; Cai Chun; Palma Silvia; Busi Micol; Martini Alessandro; Yoo Tae J

    2012-01-01

    Abstract Background The 5 G/5 G genotype of PAI-1 polymorphism is linked to decreased plasminogen activator inhibitor-1 (PAI-1) levels and it has been suggested that lower PAI-1 levels may provide protective effects on inflammation, local microcirculatory disturbance, and fibrotic changes, which are likely associated with development of sudden sensorineural hearing loss (SSNHL). Methods The association of the 4 G/5 G PAI-1 polymorphism with the development and clinical outcome of SSNHL is eva...

  5. Signals transducers and activators of transcription (STAT)-induced STAT inhibitor-1 (SSI-1)/suppressor of cytokine signaling-1 (SOCS-1) suppresses tumor necrosis factor α-induced cell death in fibroblasts

    OpenAIRE

    Morita, Yoshiaki; Naka, Tetsuji; Kawazoe, Yoshinori; Fujimoto, Minoru; Narazaki, Masashi; Nakagawa, Reiko; Fukuyama, Hidehiro; Nagata, Shigekazu; Kishimoto, Tadamitsu

    2000-01-01

    Signal transducers and activators of transcription (STAT)-induced STAT inhibitor-1 [SSI-1; also known as suppressor of cytokine signaling-1 (SOCS-1)] was identified as a negative feedback regulator of Janus kinase-STAT signaling. We previously generated mice lacking the SSI-1 gene (SSI-1 −/−) and showed that thymocytes and splenocytes in SSI-1 −/− mice underwent accelerated apoptosis. In this paper, we show that murine embryonic fibroblasts lacking the SSI-1 gene are more sensitive than their...

  6. Plasminogen activator inhibitor-1 (PAI-1 and urokinase plasminogen activator (uPA in sputum of allergic asthma patients.

    Directory of Open Access Journals (Sweden)

    Sebastian Zukowski

    2008-06-01

    Full Text Available Urokinase plasminogen activator (uPA and its inhibitor (PAI-1 have been associated with asthma. The aim of this study was to evaluate concentration of uPA and PAI-1 in induced sputum of house dust mite allergic asthmatics (HDM-AAs. The study was performed on 19 HDM-AAs and 8 healthy nonatopic controls (HCs. Concentration of uPA and PAI-1 was evaluated in induced sputum supernatants using ELISA method. In HDM-AAs the median sputum concentration of uPA (128 pg/ml; 95% CI 99 to 183 pg/ml and PAI-1 (4063 pg/ml; 95%CI 3319 to 4784 pg/ml were significantly greater than in HCs (17 pg/ml; 95%CI 12 to 32 pg/ml; p<0.001 and 626 pg/ml; 95%CI 357 to 961 pg/ml; p<0.001 for uPA and PAI-1 respectively. The sputum concentration of uPA correlated with sputum total cell count (r=0.781; p=0.0001 and with logarithmically transformed exhaled nitric oxide concentration (eNO (r=0.486; p=0.035 but not with FEV1 or bronchial reactivity to histamine. On the contrary, the sputum PAI-1 concentration correlated with FEV1 (r=-0,718; p=0.0005 and bronchial reactivity to histamine expressed as log(PC20 (r=-0.824; p<0.0001 but did not correlate with sputum total cell count or eNO. The results of this study support previous observations linking PAI-1 with airway remodeling and uPA with cellular inflammation. Moreover, the observed effect of uPA seems to be independent of its fibrynolytic activity.

  7. Dissecting the effect of RNA aptamer binding on the dynamics of plasminogen activator inhibitor 1 using hydrogen/deuterium exchange mass spectrometry

    DEFF Research Database (Denmark)

    Trelle, Morten B; Dupont, Daniel Miotto; Madsen, Jeppe Buur;

    2014-01-01

    , about their effects on protein conformation and dynamics. We have employed hydrogen/deuterium exchange (HDX) mass spectrometry to study the effect of RNA aptamers on the structural flexibility of the serpin plasminogen activator inhibitor-1 (PAI-1). The aptamers have characteristic effects...... on the biochemical properties of PAI-1. In particular, they are potent inhibitors of the structural transition of PAI-1 from the active state to the inactive, so-called latent state. This transition is one of the largest conformational changes of a folded protein domain without covalent modification. Binding...

  8. Study on Effect of Different Dosages of Ligustrazine on Level of Plasminogen Activator Inhibitor-1 Activity in Type 2 Diabetes Mellitus Patients

    Institute of Scientific and Technical Information of China (English)

    薛现中; 张兆华; 邢小燕

    2003-01-01

    Objective: To observe the effect of different dosages of ligustrazine (LG) on the level of plasminogen activator inhibitor-1 (PAI-1) activity in patients with type 2 diabetes mellitus. Methods:Ninety cases of type 2 diabetes mellitus inpatients were selected, and randomly divided into LG small dosage group (SDG), LG large dosage group (LDG) and control group. The 120 mg LG, 400 mg LG and normal saline 250 ml were given through intravenous dripping respectively, once daily, 20 days as one treatment course. Before and after treatment, all the patients had their fasting blood taken for PAI-1 and tissue plasminogen activator (t-PA) assessment test to perform the comparative study. Results: Seventythree out of the 90 patients completed the observation course, the PAI-1 activity of three groups after treatment all lowered compared with that before treatment, and the difference between groups was also significant (all P<0.01). After treatment the PAI-1 level of SDG and LDG of LG were all markedly lowered (all P<0. 01), the LDG′s lowering was more evident than that of SDG, and comparison between these two groups of patients showed significant difference (P<0.01). Although in the control group there was some difference between before and after treatment, it was not so significant like the above-mentioned two groups (P= 0. 0140). No adverse reaction occurred in the 3 groups during the observation period.Conclusion: LG could safely and effectively lower type 2 diabetes mellitus patient′s plasma PAI-1 activity level, and LDG of LG proved to be particularly effective.

  9. Plasminogen Activator Inhibitor-1 Mitigates Brain Injury in a Rat Model of Infection-Sensitized Neonatal Hypoxia–Ischemia

    OpenAIRE

    Yang, Dianer; Sun, Yu-Yo; Nemkul, Niza; Baumann, Jessica M.; Shereen, Ahmed; Dunn, R. Scott; Wills-Karp, Marsha; Lawrence, Daniel A.; Lindquist, Diana M.; Kuan, Chia-Yi

    2012-01-01

    Intrauterine infection exacerbates neonatal hypoxic–ischemic (HI) brain injury and impairs the development of cerebral cortex. Here we used low-dose lipopolysaccharide (LPS) pre-exposure followed by unilateral cerebral HI insult in 7-day-old rats to study the pathogenic mechanisms. We found that LPS pre-exposure blocked the HI-induced proteolytic activity of tissue-type plasminogen activator (tPA), but significantly enhanced NF-κB signaling, microglia activation, and the production of pro-inf...

  10. Amelioration of glomerulosclerosis with all-trans retinoic acid is linked to decreased plasminogen activator inhibitor-1 and α-smooth muscle actin

    Institute of Scientific and Technical Information of China (English)

    Xia LIU; Lei L(U); Bei-bei TAO; Ai-ling ZHOU; Yi-chun ZHU

    2011-01-01

    Aim:To examine the effects of all-trans retinoic acid (atRA) on renal morphology and function as well as on renal plasminogen activator inhibitor-1 (PAI-1) expression and plasmin activity in rats with 5/6 nephrectomy.Methods:Adult male Sprague Dawley rats were given 5/6 nephrectomy or sham operation. Renal function was measured 2 weeks later. The nephrectomized rats were assigned to groups matched for proteinuria and treated with vehicle or atRA (5 or 10 mg/kg by gastric gavage once daily) for the next 12 weeks. Rats with sham operation were treated with vehicle. At the end of the treatments,kidneys were collected for histological examination, Western blot analysis, and enzymatic activity measurements.Results:The 5/6 nephrectomy promoted hypertension, renal dysfunction, and glomerulosclerosis. These changes were significantly reduced in the atRA-treated group. The expressions of PAI-1 and α-smooth muscle actin (α-SMA) were significantly increased in the vehicle-treated nephrectomized rats. Treatment with atRA significantly reduced the expressions of PAI-1 and α-SMA. However, piasmin activity remained unchanged following atRA treatment.Conclusion:Treatment with atRA ameliorates glomerulosclerosis and improves renal function in rats with 5/6 nephrectomy. This is associated with a decrease in PAI-1 and α-SMA, but not with a change in plasmin activity.

  11. Lack of association between level of Plasminogen Activator Inhibitor-1 and estimates of tumor angiogenesis in early breast cancer

    DEFF Research Database (Denmark)

    Offersen, Birgitte Vrou; Riisbro, Rikke; Knoop, Ann;

    2007-01-01

    Plasminogen Activator Inhibitor type-1 (PAI-1) is involved in tumor invasion and progression. High levels of PAI-1 are associated with poor prognosis in breast cancer, and PAI-1 has been shown to play a role in angiogenic processes. Since estimates of tumor angiogenesis may predict poor prognosis...... we studied the relationship between PAI-1 and estimates of angiogenesis in breast cancer. Tumor tissue specimens from 438 breast cancer patients were included. Median follow-up was 10.3 years. Protein levels of PAI-1 were measured using an ELISA. Angiogenesis scores were performed using a Chalkley.......009) were independent markers of death from breast cancer. This study confirms high PAI-1 or high Chalkley counts as markers of poor prognosis in breast cancer patients, and suggests that the prognostic impact of PAI-1 is independent of its supposed involvement in tumor angiogenesis. Udgivelsesdato: 2007...

  12. Hypoxia dysregulates the production of adiponectin and plasminogen activator inhibitor-1 independent of reactive oxygen species in adipocytes

    International Nuclear Information System (INIS)

    Low plasma levels of adiponectin (hypoadiponectinemia) and elevated circulating concentrations of plasminogen activator inhibitor (PAI)-1 are causally associated with obesity-related insulin resistance and cardiovascular disease. However, the mechanism that mediates the aberrant production of these two adipokines in obesity remains poorly understood. In this study, we investigated the effects of hypoxia and reactive oxygen species (ROS) on production of adiponectin and PAI-1 in 3T3-L1 adipocytes. Quantitative PCR and immunoassays showed that ambient hypoxia markedly suppressed adiponectin mRNA expression and its protein secretion, and increased PAI-1 production in mature adipocytes. Dimethyloxallyl glycine, a stabilizer of hypoxia-inducible factor 1α (HIF-1α), mimicked the hypoxia-mediated modulations of these two adipokines. Hypoxia caused a modest elevation of ROS in adipocytes. However, ablation of intracellular ROS by antioxidants failed to alleviate hypoxia-induced aberrant production of adiponectin and PAI-1. On the other hand, the antioxidants could reverse hydrogen peroxide (H2O2)-induced dysregulation of adiponectin and PAI-1 production. H2O2 treatment decreased the expression levels of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein (C/EBPα), but had no effect on HIF-1α, whereas hypoxia stabilized HIF-1α and decreased expression of C/EBPα, but not PPARγ. Taken together, these data suggest that hypoxia and ROS decrease adiponectin production and augment PAI-1 expression in adipocytes via distinct signaling pathways. These effects may contribute to hypoadiponectinemia and elevated PAI-1 levels in obesity, type 2 diabetes, and cardiovascular diseases

  13. Effects of a diet containing Brazilian propolis on lipopolysaccharide-induced increases in plasma plasminogen activator inhibitor-1 levels in mice

    Science.gov (United States)

    Ohkura, Naoki; Oishi, Katsutaka; Kihara-Negishi, Fumiko; Atsumi, Gen-ichi; Tatefuji, Tomoki

    2016-01-01

    Background: Brazilian propolis has many biological activities including the ability to help prevent thrombotic diseases, but this particular effect has not been proven. Plasma levels of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of fibrinolysis, increase under inflammatory conditions such as infection, obesity and atherosclerosis and such elevated levels predispose individuals to a risk of developing thrombotic diseases. Aim: This study aimed to determine the effects of a diet containing Brazilian propolis on lipopolysaccharide (LPS)-induced increases in plasma PAI-1 levels. Materials and Methods: Mice were fed with a diet containing 0.5% (w/w) Brazilian propolis for 8 weeks. Thereafter, the mice were subcutaneously injected with saline containing 0.015 mg/kg of LPS and sacrificed 4 h later. Results: Orally administered Brazilian propolis significantly suppressed the LPS-induced increase in PAI-1 antigen and its activity in mouse plasma. Conclusion: This study indicated that Brazilian propolis contains natural products that can decrease thrombotic tendencies in mice.

  14. Cross-talk between human mast cells and bronchial epithelial cells in plasminogen activator inhibitor-1 production via transforming growth factor-β1.

    Science.gov (United States)

    Cho, Seong H; Lee, Sun H; Kato, Atsushi; Takabayashi, Tetsuji; Kulka, Marianna; Shin, Soon C; Schleimer, Robert P

    2015-01-01

    Previous reports suggest that plasminogen activator inhibitor-1 (PAI-1) promotes airway remodeling and that human and mouse mast cells (MCs) are an important source of PAI-1. In the present study we investigated MC-epithelial cell (EC) interactions in the production of PAI-1. We stimulated the human MC line LAD2 with IgE-receptor cross-linking and collected the supernatants. We incubated the human bronchial EC line BEAS-2B with the LAD2 supernatants and measured the level of PAI-1. When the supernatants from IgE-stimulated LAD2 were added to BEAS-2B, there was a significant enhancement of PAI-1 production by BEAS-2B. When we treated the MC supernatants with a transforming growth factor (TGF)-β1 neutralizing antibody, the MC-derived induction of PAI-1 from BEAS-2B was completely abrogated. Although TGF-β1 mRNA was constitutively expressed in resting LAD2, it was not highly induced by IgE-mediated stimulation. Nonetheless, active TGF-β1 protein was significantly increased in LAD2 after IgE-mediated stimulation. Active TGF-β1 produced by primary cultured human MCs was significantly reduced in the presence of a chymase inhibitor, suggesting a role of MC chymase as an activator of latent TGF-β1. This study indicates that stimulation of human MCs by IgE receptor cross-linking triggers activation of TGF-β1, at least in part via chymase, which in turn induces the production of PAI-1 by bronchial ECs. Our data suggest that human MCs may play an important role in airway remodeling in asthma as a direct source of PAI-1 and by activating bronchial ECs to produce further PAI-1 via a TGF-β1-mediated activation pathway. PMID:24987792

  15. NGF upregulates the plasminogen activation inhibitor-1 in neurons via the calcineurin/NFAT pathway and the Down syndrome-related proteins DYRK1A and RCAN1 attenuate this effect.

    Directory of Open Access Journals (Sweden)

    Georgios C Stefos

    Full Text Available BACKGROUND: Plasminogen activator inhibitor 1 (PAI-1 is a key regulator of the plasminogen activation system. Although several lines of evidence support a significant role of PAI-1 in the brain, the regulation of its expression in neurons is poorly understood. In the present study we tested the hypothesis that NGF induces the upregulation of PAI-1 via the calcineurin/nuclear factor of activated T cells (NFAT pathway and analysed whether the overexpression of the Down syndrome-related proteins DYRK1A and RCAN1 modulated the effect of NGF on PAI-1 expression. RESULTS: NGF upregulated PAI-1 mRNA levels in primary mouse hippocampal neurons cultured for 3 days in vitro and in the rat pheochromocytoma cell line PC12. Reporter gene assays revealed that NGF activated the calcineurin/NFAT pathway in PC12 cells. Induction of PAI-1 by NGF was sensitive to the calcineurin inhibitor FK506 and the specific inhibition of NFAT activation by the cell permeable VIVIT peptide. Activation of calcineurin/NFAT signalling through other stimuli resulted in a much weaker induction of PAI-1 expression, suggesting that other NGF-induced pathways are involved in PAI-1 upregulation. Overexpression of either DYRK1A or RCAN1 negatively regulated NFAT-dependent transcriptional activity and reduced the upregulation of PAI-1 levels by NGF. CONCLUSION: The present results show that the calcineurin/NFAT pathway mediates the upregulation of PAI-1 by NGF. The negative effect of DYRK1A and RCAN1 overexpression on NGF signal transduction in neural cells may contribute to the altered neurodevelopment and brain function in Down syndrome.

  16. Sunflower trypsin inhibitor-1.

    Science.gov (United States)

    Korsinczky, Michael L J; Schirra, Horst Joachim; Craik, David J

    2004-10-01

    SFTI-1 is a bicyclic 14 amino acid peptide that was originally isolated from the seeds of the sunflower Helianthus annuus. It is a potent inhibitor of trypsin, with a sub-nanomolar K(i) value and is homologous to the active site region of the well-known family of serine protease inhibitors known as the Bowman-Birk trypsin inhibitors. It has a cyclic backbone that is cross-braced by a single disulfide bridge and a network of hydrogen bonds that result in a well-defined structure. SFTI-1 is amenable to chemical synthesis, allowing for the creation of synthetic variants. Alterations to the structure such as linearising the backbone or removing the disulfide bridge do not reduce the potency of SFTI-1 significantly, and minimising the peptide to as few as nine residues results in only a small decrease in reactivity. The creation of linear variants of SFTI-1 also provides a tool for investigating putative linear precursor peptides. The mechanism of biosynthesis of SFTI-1 is not yet known but it seems likely that it is a gene-coded product that has arisen from a precursor protein that may be evolutionarily related to classic Bowman-Birk inhibitors. PMID:15544530

  17. Role of connective growth factor in plasminogen activator inhibitor-1 and fibronectin expression induced by transforming growth factor β1 in renal tubular cells

    Institute of Scientific and Technical Information of China (English)

    张春; 孟宪芳; 朱忠华; 杨晓; 邓安国

    2004-01-01

    Background Connective tissue growth factor (CTGF) contributes greatly to renal tubulointerstitial fibrosis, which is the final event leading to end-stage renal failure. This study was designed to investigate the effects of CTGF antisense oligodeoxynucleotides (ODNs) on the expressions of plasminogen activator inhibitor-1 (PAI-1) and fibronectin in renal tubular cells induced by transforming growth factor β1 (TGF-β1) in addition to the role of CTGF in the accumulation and degradation of renal extracellular matrix (ECM).Methods A human proximal tubular epithelial cell line (HKC) was cultured in vitro. Cationic lipid-mediated CTGF antisense ODNs were transfected into HKC cells. After HKC cells were stimulated with TGF-β1 (5 μg/L), the mRNA levels of PAI-1 and fibronectin were measured by RT-PCR. Intracellular PAI-1 protein synthesis was assessed by flow cytometry. The secreted PAI-1 and fibronectin in the medium were determined by Western blot and ELISA, respectively.Results TGF-β1 was found to induce tubular CTGF, PAI-1, and fibronectin mRNA expression. PAI-1 and fibronectin mRNA expression induced by TGF-β1 was significantly inhibited by CTGF antisense ODNs. CTGF antisense ODNs also inhibited intracellular PAI-1 protein synthesis and lowered the levels of PAI-1 and fibronectin protein secreted into the medium.Conclusions CTGF may play a crucial role in the accumulation and degradation of excessive ECM during tubulointerstitial fibrosis, and transfecting CTGF antisense ODNs may be an effective way to prevent renal fibrosis.

  18. Impact of statin therapy on plasma levels of plasminogen activator inhibitor-1. A systematic review and meta-analysis of randomised controlled trials.

    Science.gov (United States)

    Sahebkar, Amirhossein; Catena, Cristiana; Ray, Kausik K; Vallejo-Vaz, Antonio J; Reiner, Željko; Sechi, Leonardo A; Colussi, GianLuca

    2016-07-01

    Elevated plasma levels of the pro-thrombotic and pro-inflammatory factor plasminogen activator inhibitor-1 (PAI-1) may contribute to the pathogenesis of atherosclerotic cardiovascular disease. Beyond their lipid-lowering effect, statins have been shown to modulate plasma PAI-1 levels but evidence from individual randomised controlled trials (RCTs) is controversial. Therefore, we aimed to assess the potential effects of statin therapy on plasma PAI-1 concentration through a meta-analysis of RCTs. We searched Medline and SCOPUS databases (up to October 3, 2014) to identify RCTs investigating the effect of statin therapy on plasma PAI-1 concentrations. We performed random-effects meta-analysis and assessed heterogeneity (I² test, subgroup and sensitivity analyses) and publication bias (funnel plot, Egger and "trim and fill" tests). Sixteen RCTs (comprising 19 treatment arms) were included and pooled analyses showed a significant effect of statins in reducing plasma PAI-1 concentrations (weighted mean difference WMD: -15.72 ng/ml, 95 % confidence interval [CI]: -25.01, -6.43,). In subgroup analysis, this effect remained significant in with lipophilic statins (atorvastatin and simvastatin) (WMD: -21.32 ng/ml, 95 % CI: -32.73, -9.91, I²=99 %) and particularly atorvastatin (WMD: -20.88 ng/mL, 95 % CI: -28.79, -12.97, I2=97 %). In the meta-regression analysis, the impact of statins on PAI-1 did not correlate with the administered dose, duration of treatment and changes in plasma LDL-cholesterol concentrations. Finally, evidence of publication bias was observed. In conclusion, taking into account the limit of heterogeneity between studies, the present meta-analysis suggests that statin therapy (mainly atorvastatin) significantly lowers plasma PAI-1 concentrations. PMID:27009446

  19. Association of the 4 g/5 g polymorphism of plasminogen activator inhibitor-1 gene with sudden sensorineural hearing loss. A case control study

    Directory of Open Access Journals (Sweden)

    Cho Seong

    2012-06-01

    Full Text Available Abstract Background The 5 G/5 G genotype of PAI-1 polymorphism is linked to decreased plasminogen activator inhibitor-1 (PAI-1 levels and it has been suggested that lower PAI-1 levels may provide protective effects on inflammation, local microcirculatory disturbance, and fibrotic changes, which are likely associated with development of sudden sensorineural hearing loss (SSNHL. Methods The association of the 4 G/5 G PAI-1 polymorphism with the development and clinical outcome of SSNHL is evaluated via a case control study. 103 patients with SSNHL and 113 age and sex-matched controls were enrolled at University of Ferrara, Italy and hearing loss outcome was measured at least 3 months after the onset of hearing loss. DNA was isolated from peripheral blood using the QIAamp kit and the 4 G/5 G polymorphism in the −675 promoter region was genotyped with an allele-specific PCR. Genotype distribution was tested in patients and compared to controls by chi-square and odd-ratio analysis. The codominant and recessive models were used for the multiple logistic regression analyses of the PAI-1 gene allele. Results In this population, 5 G/5 G genotype had a two-time lower frequency in SSNHL patients compared to healthy controls (15.5% vs 30.1% and was associated with decreased odds compared to 4 G/5 G genotype (OR 0.37, 95% CI 0.19-0.75, p = 0.005. In addition, the patients with 5 G/5 G genotype showed a trend of more than 2 times higher ratio of hearing recovery (> 20 dB after systemic corticosteroid treatment compared to 4 G/5 G genotype (OR 2.3, 95% CI 0.32 - 16.83, p = 0.39, suggesting a better clinical outcome. Conclusions The 5 G/5 G genotype of PAI-1 may be associated with a reduced risk of SSNHL in the Italian population.

  20. A regulatory hydrophobic area in the flexible joint region of plasminogen activator inhibitor-1, defined with fluorescent activity-neutralizing ligands. Ligand-induced serpin polymerization

    DEFF Research Database (Denmark)

    Egelund, R; Einholm, A P; Pedersen, K E;

    2001-01-01

    by all tested nonfluorescent neutralizers, indicating that all neutralizers bind to a common hydrophobic area preferentially accessible in active PAI-1. Activity neutralization proceeded through two consecutive steps as follows: first step is conversion to forms displaying substrate behavior toward u...

  1. Human telomerase activity regulation

    OpenAIRE

    Wojtyla, Aneta; Gladych, Marta; Rubis, Blazej

    2010-01-01

    Telomerase has been recognized as a relevant factor distinguishing cancer cells from normal cells. Thus, it has become a very promising target for anticancer therapy. The cell proliferative potential can be limited by replication end problem, due to telomeres shortening, which is overcome in cancer cells by telomerase activity or by alternative telomeres lengthening (ALT) mechanism. However, this multisubunit enzymatic complex can be regulated at various levels, including expression control b...

  2. Concentrations of plasminogen activator inhibitor-1 (PAI-1 and urokinase plasminogen activator (uPA in induced sputum of asthma patients after allergen challenge

    Directory of Open Access Journals (Sweden)

    Krzysztof Kowal,

    2010-04-01

    Full Text Available Urokinase plasminogen activator (uPA and its inhibitor (PAI-1 are involved in tiisue remodeling and repairprocesses associated with acute and chronic inflammation. The aim of the study was to evaluate the effect of allergen challengeon concentration of uPA and PAI-1 in induced sputum of house dust mite allergic asthmatics (HDM-AAs. ThirtyHDM-AAs and ten healthy persons (HCswere recruited for the study. In 24 HDM-AAs bronchial challenge with Dermatophagoidespteronyssinus (Dp and in 6 HDM-AAs sham challenege with saline were performed. In HDM-AAs sputumwas induced 24 hours before (T0 and 24 hours (T24 after the challenge. Concentration of uPA and PAI-1 in induced sputumwere determined using immunoenzymatic assays. At T0 in HDM-AAs mean sputum uPA (151±96 pg/ml and PAI-1(4341±1262 pg/ml concentrations were higher than in HC (18.8±6.7 pg/ml; p=0.0002 and 596±180 pg/ml; p<0.0001; foruPA and PAI-1 respectively. After allergen challenge further increase in sputum uPA (187±144 pg/ml; p=0.03 and PAI-1(6252±2323 pg/ml; p<0.0001 concentrations were observed. Moreover, in Dp challenged, but not in saline challengedHDM-AAs the mean uPA/PAI-1 ratio decreased significantly at T24. No significant increase in the studied parameters werefound in sham challenged patients. In HDM-AAs allergen exposure leads to activation of the plasmin system in the airways.Greater increase of the PAI-1 concentration than uPA concentration after allergen challenge may promote airway remodelingand play an important role in the development of bronchial hyperreactivity.

  3. Concentrations of plasminogen activator inhibitor-1 (PAI-1 and urokinase plasminogen activator (uPA in induced sputum of asthma patients after allergen challenge.

    Directory of Open Access Journals (Sweden)

    Marcin Moniuszko

    2011-04-01

    Full Text Available Urokinase plasminogen activator (uPA and its inhibitor (PAI-1 are involved in tiisue remodeling and repair processes associated with acute and chronic inflammation. The aim of the study was to evaluate the effect of allergen challenge on concentration of uPA and PAI-1 in induced sputum of house dust mite allergic asthmatics (HDM-AAs. Thirty HDM-AAs and ten healthy persons (HCswere recruited for the study. In 24 HDM-AAs bronchial challenge with Dermatophagoides pteronyssinus (Dp and in 6 HDM-AAs sham challenege with saline were performed. In HDM-AAs sputum was induced 24 hours before (T0 and 24 hours (T24 after the challenge. Concentration of uPA and PAI-1 in induced sputum were determined using immunoenzymatic assays. At T0 in HDM-AAs mean sputum uPA (151 Âą 96 pg/ml and PAI-1 (4341 Âą 1262 pg/ml concentrations were higher than in HC (18.8 Âą 6.7 pg/ml; p=0.0002 and 596 Âą 180 pg/ml; p<0.0001; for uPA and PAI-1 respectively. After allergen challenge further increase in sputum uPA (187 Âą 144 pg/ml; p=0.03 and PAI-1 (6252 Âą 2323 pg/ml; p<0.0001 concentrations were observed. Moreover, in Dp challenged, but not in saline challenged HDM-AAs the mean uPA/PAI-1 ratio decreased significantly at T24. No significant increase in the studied parameters were found in sham challenged patients. In HDM-AAs allergen exposure leads to activation of the plasmin system in the airways. Greater increase of the PAI-1 concentration than uPA concentration after allergen challenge may promote airway remodeling and play an important role in the development of bronchial hyperreactivity.

  4. Regulating prefrontal cortex activation

    DEFF Research Database (Denmark)

    Aznar, Susana; Klein, Anders Bue

    2013-01-01

    pharmacological effect of elevating serotonin levels in anxiety regulation. Recent animal and human functional magnetic resonance studies have pointed to a specific involvement of the 5-hydroxytryptamine (5-HT)2A serotonin receptor in the PFC feedback regulatory projection onto the amygdala. This receptor...... of emotion-based actions, such as addiction and other impulse-related behaviors. In this review, we give an overview of the 5-HT2A receptor distribution (neuronal, intracellular, and anatomical) along with its functional and physiological effect on PFC activation, and how that relates to more recent findings...... of a regulatory effect of the PFC on the emotional control of our actions....

  5. Small Interfering RNA-mediated Caveolin-1 Knockout on Plasminogen Activator Inhibitor-1 Expression in Insulin-stimulated Human Vascular Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    Huiling YANG; Gebo WEN; Weixin HU; Shuya HE; Zhihua QUAN; Weixia PENG; Bin YAN; Jianghua LIU; Fang WEN; Renxian CAO; Yangyan XU

    2007-01-01

    Using human vascular endothelial cells (ECV304) as the target,we studied the effect of caveolin(CAV)-1 in the course of insulin-stimulated expression of plasminogen activator inhibitor(PAI)-1.The appropriate single-stranded oligonucleotides representing the RNAi CAV-1 gene were analyzed by Ambion software.After annealing to generate double-stranded oligonucleotides (ds oligo),it was cloned into the pENTR/U6 entry vector containing RNA polymerase Ⅲ expression element by T4 DNA ligase.The short hairpin (shRNA) sequences transferred from the pENTR/U6 entry were cloned into the pLenti6/BLOCK-iTDEST vector with an LR recombination reaction.After identification by sequencing,we successfully constructed the CAV-1 RNAi lentiviral expression system using Gateway technology.Silencing efficiency was assayed by real-time reverse transcription-polymerase chain reaction,immunofluorescence staining and Western blotting.ECV304 cells were cultured in the medium containing different concentrations of insulin(1×10-9 to 1×10-7M)with the CAV-1 gene silenced or not.The expression level and subcellular localization of PAI-1 and CAV-1 were compared using reverse transcription-polymerase chain reaction,immunofluorescence staining and Western blot assay.The results showed that the potent inhibition of CAV-1 expression could reach 85%,and it was specific to the CAV-1-derived shRNA,not the S100A13-derived shRNA.There was no dramatic difference in PAI-1 expression between the RNAi+ and RNAi-ECV304 cells incubated with physiological insulin,but PAI-1 protein did accumulate under the cell membrane.As the concentration of insulin increased,the expression of PAI-1 was up-regulated,whereas the expression of CAV-1 attenuated.Furthermore,PAl-1 clearly augmented after CAV-1 knockdown.These results indicated that hyperinsulinism could promote PAI-1 expression by inhibiting CAV-1,and stabilizing or up-regulating CAV-1 expression in endothelial cells might reduce complications of the great vessels

  6. The −675 4G/5G Polymorphism in Plasminogen Activator Inhibitor-1 Gene Is Associated with Risk of Asthma: A Meta-Analysis

    OpenAIRE

    Wei Nie; Bing Li; Qing-Yu Xiu

    2012-01-01

    BACKGROUND: A number of studies assessed the association of -675 4G/5G polymorphism in the promoter region of plasminogen activator inhibitor (PAI)-1 gene with asthma in different populations. However, most studies reported inconclusive results. A meta-analysis was conducted to investigate the association between polymorphism in the PAI-1 gene and asthma susceptibility. METHODS: Databases including Pubmed, EMBASE, HuGE Literature Finder, Wanfang Database, China National Knowledge Infrastructu...

  7. Identification of a peroxisome proliferator responsive element (PPRE)-like cis-element in mouse plasminogen activator inhibitor-1 gene promoter

    International Nuclear Information System (INIS)

    PAI-1 is expressed and secreted by adipose tissue which may mediate the pathogenesis of obesity-associated cardiovascular complications. Evidence is presented in this report that PAI-1 is not expressed by preadipocyte, but significantly induced during 3T3-L1 adipocyte differentiation and the PAI-1 expression correlates with the induction of peroxisome proliferator-activated receptor γ (PPARγ). A peroxisome proliferator responsive element (PPRE)-like cis-element (-206TCCCCCATGCCCT-194) is identified in the mouse PAI-1 gene promoter by electrophoretic mobility shift assay (EMSA) combined with transient transfection experiments; the PPRE-like cis-element forms a specific DNA-protein complex only with adipocyte nuclear extracts, not with preadipocyte nuclear extracts; the DNA-protein complex can be totally competed away by non-labeled consensus PPRE, and can be supershifted with PPARγ antibody. Mutation of this PPRE-like cis-element can abolish the transactivation of mouse PAI-1 promoter mediated by PPARγ. Specific PPARγ ligand Pioglitazone can significantly induce the PAI-1 expression, and stimulate the secretion of PAI-1 into medium

  8. The -675 4G/5G polymorphism in plasminogen activator inhibitor-1 gene is associated with risk of asthma: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Wei Nie

    Full Text Available BACKGROUND: A number of studies assessed the association of -675 4G/5G polymorphism in the promoter region of plasminogen activator inhibitor (PAI-1 gene with asthma in different populations. However, most studies reported inconclusive results. A meta-analysis was conducted to investigate the association between polymorphism in the PAI-1 gene and asthma susceptibility. METHODS: Databases including Pubmed, EMBASE, HuGE Literature Finder, Wanfang Database, China National Knowledge Infrastructure (CNKI and Weipu Database were searched to find relevant studies. Odds ratios (ORs with 95% confidence intervals (CIs were used to assess the strength of association in the dominant model, recessive model, codominant model, and additive model. RESULTS: Eight studies involving 1817 cases and 2327 controls were included. Overall, significant association between 4G/5G polymorphism and asthma susceptibility was observed for 4G4G+4G5G vs. 5G5G (OR = 1.56, 95% CI 1.12-2.18, P = 0.008, 4G/4G vs. 4G/5G+5G/5G (OR = 1.38, 95% CI 1.06-1.80, P = 0.02, 4G/4G vs. 5G/5G (OR = 1.80, 95% CI 1.17-2.76, P = 0.007, 4G/5G vs. 5G/5G (OR = 1.40, 95% CI 1.07-1.84, P = 0.02, and 4G vs. 5G (OR = 1.35, 95% CI 1.08-1.68, P = 0.008. CONCLUSIONS: This meta-analysis suggested that the -675 4G/5G polymorphism of PAI-1 gene was a risk factor of asthma.

  9. The Glycosylation of Plasminogen Activator Inhibitor-1

    DEFF Research Database (Denmark)

    Skottrup, Peter Durand; Pedersen, Katrine Egelund; Christensen, Anni;

    of these sequences. Analyses of these mutants for the content of N-acetyl glucosamine showed that Asn209 and Asn265, but not Asn329, are glycosylated, in agreement with previous suggestions made on the basis of X-ray crystal structure analysis of PAI-1 expressed in CHO cells (Xue et al. (1998) Structure 6, 627...

  10. The Glycosylation of Plasminogen Activator Inhibitor-1

    DEFF Research Database (Denmark)

    Skottrup, Peter; Pedersen, Katrine Egelund; Christensen, Anni;

    2002-01-01

    of these sequences. Analyses of these mutants for the content of N-acetyl glucosamine showed that Asn209 and Asn265, but not Asn329, are glycosylated, in agreement with previous suggestions made on the basis of X-ray crystal structure analysis of PAI-1 expressed in CHO cells (Xue et al. (1998) Structure 6, 627...

  11. The Glycosylation of Plasminogen Activator Inhibitor-1

    DEFF Research Database (Denmark)

    Skottrup, Peter; Pedersen, Katrine Egelund; Christensen, Anni;

    spectrometry and monosaccharide composition analysis and compared to that of natural and recombinant PAI-1 from other sources. These results contribute to a structural basis for previous observations of a different functional importance of the N-linked glycosylation at each of the 2 sequences....

  12. The High Affinity Binding Site on Plasminogen Activator Inhibitor-1 (PAI-1) for the Low Density Lipoprotein Receptor-related Protein (LRP1) Is Composed of Four Basic Residues.

    Science.gov (United States)

    Gettins, Peter G W; Dolmer, Klavs

    2016-01-01

    Plasminogen activator inhibitor 1 (PAI-1) is a serpin inhibitor of the plasminogen activators urokinase-type plasminogen activator (uPA) and tissue plasminogen activator, which binds tightly to the clearance and signaling receptor low density lipoprotein receptor-related protein 1 (LRP1) in both proteinase-complexed and uncomplexed forms. Binding sites for PAI-1 within LRP1 have been localized to CR clusters II and IV. Within cluster II, there is a strong preference for the triple CR domain fragment CR456. Previous mutagenesis studies to identify the binding site on PAI-1 for LRP1 have given conflicting results or implied small binding contributions incompatible with the high affinity PAI-1/LRP1 interaction. Using a highly sensitive solution fluorescence assay, we have examined binding of CR456 to arginine and lysine variants of PAI-1 and definitively identified the binding site as composed of four basic residues, Lys-69, Arg-76, Lys-80, and Lys-88. These are highly conserved among mammalian PAI-1s. Individual mutations result in a 13-800-fold increase in Kd values. We present evidence that binding involves engagement of CR4 by Lys-88, CR5 by Arg-76 and Lys-80, and CR6 by Lys-69, with the strongest interactions to CR5 and CR6. Collectively, the individual binding contributions account quantitatively for the overall PAI-1/LRP1 affinity. We propose that the greater efficiency of PAI-1·uPA complex binding and clearance by LRP1, compared with PAI-1 alone, is due solely to simultaneous binding of the uPA moiety in the complex to its receptor, thereby making binding of the PAI-1 moiety to LRP1 a two-dimensional surface-localized association. PMID:26555266

  13. Molecular regulation of osteoclast activity.

    Science.gov (United States)

    Bruzzaniti, Angela; Baron, Roland

    2006-06-01

    Osteoclasts are multinucleated cells derived from hematopoietic precursors that are primarily responsible for the degradation of mineralized bone during bone development, homeostasis and repair. In various skeletal disorders such as osteoporosis, hypercalcemia of malignancy, tumor metastases and Paget's disease, bone resorption by osteoclasts exceeds bone formation by osteoblasts leading to decreased bone mass, skeletal fragility and bone fracture. The overall rate of osteoclastic bone resorption is regulated either at the level of differentiation of osteoclasts from their monocytic/macrophage precursor pool or through the regulation of key functional proteins whose specific activities in the mature osteoclast control its attachment, migration and resorption. Thus, reducing osteoclast numbers and/or decreasing the bone resorbing activity of osteoclasts are two common therapeutic approaches for the treatment of hyper-resorptive skeletal diseases. In this review, several of the key functional players involved in the regulation of osteoclast activity will be discussed. PMID:16951988

  14. Proteinase activity regulation by glycosaminoglycans

    Directory of Open Access Journals (Sweden)

    Tersariol I.L.S.

    2002-01-01

    Full Text Available There are few reports concerning the biological role and the mechanisms of interaction between proteinases and carbohydrates other than those involved in clotting. It has been shown that the interplay of enzymes and glycosaminoglycans is able to modulate the activity of different proteases and also to affect their structures. From the large number of proteases belonging to the well-known protease families and also the variety of carbohydrates described as widely distributed, only few events have been analyzed more deeply. The term "family" is used to describe a group of proteases in which every member shows an evolutionary relationship to at least one other protease. This relationship may be evident throughout the entire sequence, or at least in that part of the sequence responsible for catalytic activity. The majority of proteases belong to the serine, cysteine, aspartic or metalloprotease families. By considering the existing limited proteolysis process, in addition to the initial idea that the proteinases participate only in digestive processes, it is possible to conclude that the function of the enzymes is strictly limited to the cleavage of intended substrates since the destruction of functional proteins would result in normal tissue damage. In addition, the location as well as the eventual regulation of protease activity promoted by glycosaminoglycans can play an essential role in the development of several physiopathological conditions.

  15. Prognostic Importance of Cell Cycle Regulators Cyclin D1 (CCND1) and Cyclin-Dependent Kinase Inhibitor 1B (CDKN1B/p27) in Sporadic Gastric Cancers

    Science.gov (United States)

    Minarikova, Petra; Halkova, Tereza; Belsanova, Barbora; Tuckova, Inna; Belina, Frantisek; Dusek, Ladislav; Zavoral, Miroslav

    2016-01-01

    Background. Gastric cancer is known for a notable variety in the course of the disease. Clinical factors, such as tumor stage, grade, and localization, are key in patient survival. It is expected that molecular factors such as somatic mutations and gene amplifications are also underlying tumor biological behavior and may serve as factors for prognosis estimation. Aim. The purpose of this study was to examine gene amplifications from a panel of genes to uncover potential prognostic marker candidates. Methods. A panel of gene amplifications including 71 genes was tested by multiplex ligation-dependent probe amplification (MLPA) technique in 76 gastric cancer samples from a Caucasian population. The correlation of gene amplification status with patient survival was determined by the Kaplan-Meier method. Results. The amplification of two cell cycle regulators, CCND1 and CDKN1B, was identified to have a negative prognostic role. The medial survival of patients with gastric cancer displaying amplification compared to patients without amplification was 192 versus 725 days for CCND1 (P = 0.0012) and 165 versus 611 days for CDKN1B (P = 0.0098). Conclusion. Gene amplifications of CCND1 and CDKN1B are potential candidates to serve as prognostic markers for the stratification of patients based on the estimate of survival in the management of gastric cancer patients.

  16. Platelets actively sequester angiogenesis regulators

    OpenAIRE

    Lakka Klement, Giannoula; Yip, Tai-Tung; Cassiola, Flavia; Kikuchi, Lena; Cervi, David; Podust, Vladimir; Italiano, Joseph E.; Wheatley, Erin; Abou-Slaybi, Abdo; Bender, Elise; Almog, Nava; Kieran, Mark W.; Folkman, Judah

    2009-01-01

    Clinical trials with antiangiogenic agents have not been able to validate plasma or serum levels of angiogenesis regulators as reliable markers of cancer presence or therapeutic response. We recently reported that platelets contain numerous proteins that regulate angiogenesis. We now show that accumulation of angiogenesis regulators in platelets of animals bearing malignant tumors exceeds significantly their concentration in plasma or serum, as well as their levels in platelets from non–tumor...

  17. Low levels of Bax inhibitor-1 gene expression increase tunicamycin-induced apoptosis in human neuroblastoma SY5Y cells

    Institute of Scientific and Technical Information of China (English)

    Dan Wu; Peirong Wang; Shiyao Wang

    2012-01-01

    A human SH-SY5Y neuroblastoma cell line with a low level of Bax inhibitor-1 expression was established by lentivirus-mediated RNA interference and fluorescence-activated cell sorting. In control SH-SY5Y cells, tunicamycin treatment induced endoplasmic reticulum stress-mediated apoptosis; however, after Bax inhibitor-1 gene knockdown, cell survival rates were significantly decreased and the degree of apoptosis was significantly increased following tunicamycin treatment. In addition, chromatin condensation and apparent apoptotic phenomena, such as marginalization and cytoplasmic vesicles, were observed. Our findings indicate that Bax inhibitor-1 can delay apoptosis induced by endoplasmic reticulum stress.

  18. Regulation of p21ras activity

    DEFF Research Database (Denmark)

    Lowy, D R; Zhang, K; DeClue, J E;

    1992-01-01

    The ras genes encode GTP/GDP-binding proteins that participate in mediating mitogenic signals from membrane tyrosine kinases to downstream targets. The activity of p21ras is determined by the concentration of GTP-p21ras, which is tightly regulated by a complex array of positive and negative control...... mechanisms. GAP and NF1 can negatively regulate p21ras activity by stimulating hydrolysis of GTP bound to p21ras. Other cellular factors can positively regulate p21ras by stimulating GDP/GTP exchange....

  19. [Molecular mechanisms regulating the activity of macrophages].

    Science.gov (United States)

    Onoprienko, L V

    2011-01-01

    This article reviews modern concepts of the most common types of macrophage activation: classical, alternative, and type II. Molecular mechanisms of induction and regulation of these three types of activation are discussed. Any population of macrophages was shown to change its properties depending on its microenvironment and concrete biological situation (the "functional plasticity of macrophages"). Many intermediate states of macrophages were described along with the most pronounced and well-known activation types (classical activation, alternative activation, and type II activation). These intermediate states are characterized by a variety of combinations of their biological properties, including elements of the three afore mentioned types of activation. Macrophage activity is regulated by a complex network of interrelated cascade mechanisms.

  20. Regulation of ROCK Activity in Cancer

    DEFF Research Database (Denmark)

    Morgan-Fisher, Marie; Wewer, Ulla M; Yoneda, Atsuko

    2013-01-01

    , these findings demonstrate additional modes to regulate ROCK activity. This review describes the molecular mechanisms of ROCK activity regulation in cancer, with emphasis on ROCK isoform-specific regulation and interaction partners, and discusses the potential of ROCKs as therapeutic targets in cancer.......Cancer-associated changes in cellular behavior, such as modified cell-cell contact, increased migratory potential, and generation of cellular force, all require alteration of the cytoskeleton. Two homologous mammalian serine/threonine kinases, Rho-associated protein kinases (ROCK I and II), are key...... regulators of the actin cytoskeleton acting downstream of the small GTPase Rho. ROCK is associated with cancer progression, and ROCK protein expression is elevated in several types of cancer. ROCKs exist in a closed, inactive conformation under quiescent conditions, which is changed to an open, active...

  1. Influence of ACE I/D Polymorphism on Circulating Levels of Plasminogen Activator Inhibitor 1, D-Dimer, Ultrasensitive C-Reactive Protein and Transforming Growth Factor β1 in Patients Undergoing Hemodialysis.

    Directory of Open Access Journals (Sweden)

    Sara Santos de Carvalho

    Full Text Available There is substantial evidence that chronic renal and cardiovascular diseases are associated with coagulation disorders, endothelial dysfunction, inflammation and fibrosis. Angiotensin-Converting Enzyme Insertion/Deletion polymorphism (ACE I/D polymorphism has also be linked to cardiovascular diseases. Therefore, this study aimed to compare plasma levels of ultrassensible C-reactive protein (usCRP, PAI-1, D-dimer and TGF-β1 in patients undergoing HD with different ACE I/D polymorphisms.The study was performed in 138 patients at ESRD under hemodialysis therapy for more than six months. The patients were divided into three groups according to the genotype. Genomic DNA was extracted from blood cells (leukocytes. ACE I/D polymorphism was investigated by single polymerase chain reaction (PCR. Plasma levels of D-dimer, PAI-1 and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA, and the determination of plasma levels of usCRP was performed by immunonephelometry. Data were analyzed by the software SigmaStat 2.03.Clinical characteristics were similar in patients with these three ACE I/D polymorphisms, except for interdialytic weight gain. I allele could be associated with higher interdialytic weight gain (P = 0.017. Patients genotyped as DD and as ID had significantly higher levels of PAI-1 than those with II genotype. Other laboratory parameters did not significantly differ among the three subgroups (P = 0.033. Despite not reaching statistical significance, plasma levels of usCRP were higher in patients carrying the D allele.ACE I/D polymorphisms could be associated with changes in the regulation of sodium, fibrinolytic system, and possibly, inflammation. Our data showed that high levels of PAI-1 are detected when D allele is present, whereas greater interdialytic gain is associated with the presence of I allele. However, further studies with different experimental designs are necessary to elucidate the mechanisms involved in these

  2. Molecular regulation of telomerase activity in aging

    Institute of Scientific and Technical Information of China (English)

    Craig Nicholls; He Li; Jian-Qiu Wang; Jun-Ping Liu

    2011-01-01

    The process of aging is mitigated by the maintenance and repair of chromosome ends (telomeres),resulting in extended lifespan.This review examines the molecular mechanisms underlying the actions and regulation of the enzyme telomerase reverse transcriptase (TERT),which functions as the primary mechanism of telomere maintenance and regulates cellular life expectancy.Underpinning increased cell proliferation,telomerase is also a key factor in facilitating cancer cell immortalization.The review focuses on aspects of hormonal regulations of telomerase,and the intraceilular pathways that converge to regulate telomerase activity with an emphasis on molecular interactions at protein and gene levels.In addition,the basic structure and function of two key telomerase enzyme components-the catalytic subunit TERT and the template RNA (TERC) are discussed briefly.

  3. Commission of energy regulation. 2004 activity report

    International Nuclear Information System (INIS)

    The commission of energy regulation (CRE) is an independent administrative authority in charge of the control of the operation of gas and electricity markets. This document is the fifth activity report of CRE and covers the July 1, 2003 - June 30, 2004 period, which corresponds to the era of opening of energy markets as a consequence of the enforcement of the June 26, 2003 European directive. In the framework of the stakes made by energy markets liberalization, this document presents the situation of the gas and electricity markets during this period (European framework, regulation of both markets, public utility mission..) and describes CRE's means for the monitoring of these markets. (J.S.)

  4. Biochemical Importance of Glycosylation of Plasminogen Activator Inhibitor-1

    DEFF Research Database (Denmark)

    Gils, Ann; Pedersen, Katrine Egelund; Skottrup, Peter Durand;

    2003-01-01

    glycosylation pattern of the sites at N209 and N265, while that at N329 is not utilised. The IC(50)-values for inactivation of PAI-1 by 4 monoclonal antibodies differed strongly between glycosylated PAI-1 and non-glycosylated PAI-1 expressed in E. coli. For 3 antibodies, an overlap of the epitopes...... specifically on glycosylation of either one or the other of the utilised sites. The PAI-1-binding protein vitronectin reversed the changes associated with the lack of glycosylation at one of the sites. Our results stress the importance of the source of PAI-1 when studying the mechanisms of action of PAI-1......-inactivating compounds of potential clinical importance....

  5. Biochemical Importance of Glycosylation of Plasminogen Activator Inhibitor-1

    DEFF Research Database (Denmark)

    Gils, Ann; Pedersen, Katrine Egelund; Skottrup, Peter;

    2003-01-01

    specifically on glycosylation of either one or the other of the utilised sites. The PAI-1-binding protein vitronectin reversed the changes associated with the lack of glycosylation at one of the sites. Our results stress the importance of the source of PAI-1 when studying the mechanisms of action of PAI-1...

  6. Regulators of Slc4 bicarbonate transporter activity

    Directory of Open Access Journals (Sweden)

    Ian M. Thornell

    2015-06-01

    Full Text Available The Slc4 family of transporters is comprised of anion exchangers (AE1-4, Na-coupled bicarbonate transporters (NCBTs including electrogenic Na/bicarbonate cotransporters (NBCe1 and NBCe2, electroneutral Na/bicarbonate cotransporters (NBCn1 and NBCn2, and the electroneutral Na-driven Cl-bicarbonate exchanger (NDCBE, as well as a borate transporter (BTR1. These transporters regulate intracellular pH (pHi and contribute to steady-state pHi, but are also involved in other physiological processes including CO2 carriage by red blood cells and solute secretion/reabsorption across epithelia. Acid-base transporters function as either acid extruders or acid loaders, with the Slc4 proteins moving HCO3– either into or out of cells. According to results from both molecular and functional studies, multiple Slc4 proteins and/or associated splice variants with similar expected effects on pHi are often found in the same tissue or cell. Such apparent redundancy is likely to be physiologically important. In addition to regulating pHi, a HCO3– transporter contributes to a cell’s ability to fine tune the intracellular regulation of the cotransported/exchanged ion(s (e.g., Na+ or Cl–. In addition, functionally similar transporters or splice variants with different regulatory profiles will optimize pH physiology and solute transport under various conditions or within subcellular domains. Such optimization will depend on activated signaling pathways and transporter expression profiles. In this review, we will summarize and discuss both classical and more recently identified regulators of the Slc4 proteins. Some of these regulators include traditional second messengers, lipids, binding proteins, autoregulatory domains, and less conventional regulators. The material presented will provide insight into the diversity and physiological significance of multiple members within the Slc4 gene family.

  7. Ack1: activation and regulation by allostery.

    Directory of Open Access Journals (Sweden)

    Ketan S Gajiwala

    Full Text Available The non-receptor tyrosine kinase Ack1 belongs to a unique multi-domain protein kinase family, Ack. Ack is the only family of SH3 domain containing kinases to have an SH3 domain following the kinase domain; others have their SH3 domains preceding the kinase domain. Previous reports have suggested that Ack1 does not require phosphorylation for activation and the enzyme activity of the isolated kinase domain is low relative to other kinases. It has been shown to dimerize in the cellular environment, which augments its enzyme activity. The molecular mechanism of activation, however, remains unknown. Here we present structural and biochemical data on Ack1 kinase domain, and kinase domain+SH3 domain that suggest that Ack1 in its monomeric state is autoinhibited, like EGFR and CDK. The activation of the kinase domain may require N-lobe mediated symmetric dimerization, which may be facilitated by the N-terminal SAM domain. Results presented here show that SH3 domain, unlike in Src family tyrosine kinases, does not directly control the activation state of the enzyme. Instead we speculate that the SH3 domain may play a regulatory role by facilitating binding of the MIG6 homologous region to the kinase domain. We postulate that features of Ack1 activation and regulation parallel those of receptor tyrosine kinase EGFR with some interesting differences.

  8. Effects of Chronic Mild Stress in Female Bax Inhibitor-1-Gene Knockout Mice

    OpenAIRE

    Sui, Zhi-Yan; Chae, Han-Jung; Huang, Guang-Biao; Zhao, Tong; Shrestha Muna, Sushma; Chung, Young-Chul

    2012-01-01

    Objective The anti-apoptotic protein Bax inhibitor-1 (BI-1) is a regulator of apoptosis linked to endoplasmic reticulum (ER) stress, and BI-1-/- mice exhibit increased sensitivity to tissue damage. The purpose of this study was to investigate the role of BI-1 in the pathogenesis of chronic mild stress (CMS)-induced depression-like behaviors in BI-1-/- mice. Methods We delivered CMS for 2 or 6 weeks in BI-1-knockout and wild-type mice. Control groups of BI-1-knockout and wild-type mice were le...

  9. Localization and regulation of the tissue plasminogen activator-plasmin system in the hippocampus.

    Science.gov (United States)

    Salles, Fernando J; Strickland, Sidney

    2002-03-15

    The extracellular protease cascade of tissue plasminogen activator (tPA) and plasminogen has been implicated in neuronal plasticity and degeneration. We show here that unstimulated expression of tPA in the mouse hippocampus is concentrated in the mossy fiber pathway, with little or no expression within the perforant path, the Schaffer collaterals, or neuronal cell bodies. tPA protein is also expressed in vascular endothelial cells throughout the brain parenchyma. Four hours after excitotoxic injury, tPA protein is transiently induced within CA1 pyramidal neurons. The induced CA1 tPA is localized to neurons that survive the injury and is enzymatically active. Within the mossy fiber pathway, injury resulted in decreased tPA protein. In contrast, mossy fiber tPA activity displayed a biphasic character: transient increase at 8 hr, then a decrease by 24 hr after injury. Analysis of plasminogen activator inhibitor-1 (PAI-1) expression showed that PAI-1 antigen is upregulated by 24 hr and could account for the tPA activity downregulation seen at this time point. Plasminogen immunohistochemistry suggested an increase within the mossy fiber pathway after injury. Finally, hippocampal tPA expression among various mammalian species was strikingly different. These results indicate a complex control of tPA protein and enzymatic activity in the hippocampus that may help regulate neuronal plasticity.

  10. Regulation of pokemon 1 activity by sumoylation.

    Science.gov (United States)

    Roh, Hee-Eun; Lee, Min-Nyung; Jeon, Bu-Nam; Choi, Won-Il; Kim, Yoo-Jin; Yu, Mi-Young; Hur, Man-Wook

    2007-01-01

    Pokemon 1 is a proto-oncogenic transcriptional regulator that contains a POZ domain at the N-terminus and four Kruppel-like zinc fingers at the C-terminus. Pokemon 1 plays an important role in adipogenesis, osteogenesis, oncogenesis, and transcription of NF-kB responsive genes. Recent reports have shown that biological activities of transcription factors are regulated by sumolylation. We investigated whether Pokemon 1 is post-translationally modified by sumoylation and whether the modification affects Pokemon 1's transcriptional properties. We found that Pokemon 1 is sumoylated in vitro and in vivo. Upon careful analysis of the amino acid sequence of Pokemon 1, we found ten potential sumoylation sites located at lysines 61, 354, 371, 379, 383, 396, 486, 487, 536 and 539. We mutated each of these amino acids into arginine and tested whether the mutation could affect the transcriptional properties of Pokemon 1 on the Pokemon 1 responsive genes, such as ADH5/FDH and pG5-FRE-Luc. Wild-type Pokemon 1 potently represses transcription of ADH5/FDH. Most of the mutants, however, were weaker transcription repressors and repressed transcription 1.3-3.3 fold less effective. Although potential sumoylation sites were located close to the DNA binding domain or the nuclear localization sequence, the mutations did not alter nuclear localization or DNA binding activity. In addition, on the pG5-FRE-Luc test promoter construct, ectopic SUMO-1 repressed transcription in the presence of Pokemon 1. The sumoylation target lysine residue at amino acid 61, which is located in the middle of the POZ-domain, is important because K61R mutation resulted in a much weaker molecular interaction with corepressors. Our data suggest that Pokemon 1's activity as a transcription factor may involve sumoylation, and that sumoylation might be important in the regulation of transcription by Pokemon 1. PMID:17595526

  11. Regulation of Aicda expression and AID activity.

    Science.gov (United States)

    Zan, Hong; Casali, Paolo

    2013-03-01

    Activation-induced cytidine deaminase (AID) is expressed in a B cell differentiation stage-specific fashion and is essential for immunoglobulin (Ig) gene class switch DNA recombination (CSR) and somatic hypermutation (SHM). CSR and SHM play a central role in the maturation of antibody and autoantibody responses. AID displays a mutagenic activity by catalyzing targeted deamination of deoxycytidine (dC) residues in DNA resulting in dU:dG mismatches, which are processed into point-mutations in SHM or double-strand breaks (DSBs) in CSR. Although AID specifically targets the Ig gene loci (IgH, Igκ and Igλ), it can also home into a wide array of non-Ig genes in B-and non-B-cell backgrounds. Aberrant expression of AID is associated with multiple diseases such as allergy, inflammation, autoimmunity and cancer. In autoimmune systemic lupus erythematosus, dysregulated AID expression underpins increased CSR, SHM and autoantibody production. As a potent mutator, AID is under stringent transcriptional, post-transcriptional and post-translational regulation. AID is also regulated in its targeting and enzymatic function. In resting naïve or memory B cells, AID transcripts and protein are undetectable. These, however, are readily and significantly up-regulated in B cells induced to undergo CSR and/or SHM. Transcription factors, such as HoxC4 and NF-κB, which are up-regulated in a B cell lineage-and/or differentiation stage-specific manner, regulate the induction of AID. HoxC4 induces AID expression by directly binding to the AID gene promoter through an evolutionarily conserved 5'-ATTT-3' motif. HoxC4 is induced by the same stimuli that induce AID and CSR. It is further up-regulated by estrogen through three estrogen responsive elements in its promoter region. The targeting of AID to switch (S) regions is mediated by 14-3-3 adaptor proteins, which specifically bind to 5'-AGCT-3' repeats that are exist at high frequency in S region cores. Like HoxC4, 14-3-3 adaptors are induced

  12. Regulation of Aicda expression and AID activity.

    Science.gov (United States)

    Zan, Hong; Casali, Paolo

    2013-03-01

    Activation-induced cytidine deaminase (AID) is expressed in a B cell differentiation stage-specific fashion and is essential for immunoglobulin (Ig) gene class switch DNA recombination (CSR) and somatic hypermutation (SHM). CSR and SHM play a central role in the maturation of antibody and autoantibody responses. AID displays a mutagenic activity by catalyzing targeted deamination of deoxycytidine (dC) residues in DNA resulting in dU:dG mismatches, which are processed into point-mutations in SHM or double-strand breaks (DSBs) in CSR. Although AID specifically targets the Ig gene loci (IgH, Igκ and Igλ), it can also home into a wide array of non-Ig genes in B-and non-B-cell backgrounds. Aberrant expression of AID is associated with multiple diseases such as allergy, inflammation, autoimmunity and cancer. In autoimmune systemic lupus erythematosus, dysregulated AID expression underpins increased CSR, SHM and autoantibody production. As a potent mutator, AID is under stringent transcriptional, post-transcriptional and post-translational regulation. AID is also regulated in its targeting and enzymatic function. In resting naïve or memory B cells, AID transcripts and protein are undetectable. These, however, are readily and significantly up-regulated in B cells induced to undergo CSR and/or SHM. Transcription factors, such as HoxC4 and NF-κB, which are up-regulated in a B cell lineage-and/or differentiation stage-specific manner, regulate the induction of AID. HoxC4 induces AID expression by directly binding to the AID gene promoter through an evolutionarily conserved 5'-ATTT-3' motif. HoxC4 is induced by the same stimuli that induce AID and CSR. It is further up-regulated by estrogen through three estrogen responsive elements in its promoter region. The targeting of AID to switch (S) regions is mediated by 14-3-3 adaptor proteins, which specifically bind to 5'-AGCT-3' repeats that are exist at high frequency in S region cores. Like HoxC4, 14-3-3 adaptors are induced

  13. Phosphorylation regulates coilin activity and RNA association

    Directory of Open Access Journals (Sweden)

    Hanna J. Broome

    2013-02-01

    The Cajal body (CB is a domain of concentrated components found within the nucleus of cells in an array of species that is functionally important for the biogenesis of telomerase and small nuclear ribonucleoproteins. The CB is a dynamic structure whose number and size change during the cell cycle and is associated with other nuclear structures and gene loci. Coilin, also known as the marker protein for the CB, is a phosphoprotein widely accepted for its role in maintaining CB integrity. Recent studies have been done to further elucidate functional activities of coilin apart from its structural role in the CB in an attempt to explore the rationale for coilin expression in cells that have few CBs or lack them altogether. Here we show that the RNA association profile of coilin changes in mitosis with respect to that during interphase. We provide evidence of transcriptional and/or processing dysregulation of several CB-related RNA transcripts as a result of ectopic expression of both wild-type and phosphomutant coilin proteins. We also show apparent changes in transcription and/or processing of these transcripts upon coilin knockdown in both transformed and primary cell lines. Additionally, we provide evidence of specific coilin RNase activity regulation, on both U2 and hTR transcripts, by phosphorylation of a single residue, serine 489. Collectively, these results point to additional functions for coilin that are regulated by phosphorylation.

  14. Endoglin regulates cyclooxygenase-2 expression and activity.

    Science.gov (United States)

    Jerkic, Mirjana; Rivas-Elena, Juan V; Santibanez, Juan F; Prieto, Marta; Rodríguez-Barbero, Alicia; Perez-Barriocanal, Fernando; Pericacho, Miguel; Arévalo, Miguel; Vary, Calvin P H; Letarte, Michelle; Bernabeu, Carmelo; López-Novoa, Jose M

    2006-08-01

    The endoglin heterozygous (Eng(+/-)) mouse, which serves as a model of hereditary hemorrhagic telangiectasia (HHT), was shown to express reduced levels of endothelial NO synthase (eNOS) with impaired activity. Because of intricate changes in vasomotor function in the Eng(+/-) mice and the potential interactions between the NO- and prostaglandin-producing pathways, we assessed the expression and function of cyclooxygenase (COX) isoforms. A specific upregulation of COX-2 in the vascular endothelium and increased urinary excretion of prostaglandin E(2) were observed in the Eng(+/-) mice. Specific COX-2 inhibition with parecoxib transiently increased arterial pressure in Eng(+/-) but not in Eng(+/+) mice. Transfection of endoglin in L6E9 myoblasts, shown previously to stimulate eNOS expression, led to downregulation of COX-2 with no change in COX-1. In addition, COX-2 promoter activity and protein levels were inversely correlated with endoglin levels, in doxycyclin-inducible endothelial cells. Chronic NO synthesis inhibition with N(omega)-nitro-l-arginine methyl ester induced a marked increase in COX-2 only in the normal Eng(+/+) mice. N(omega)-nitro-l-arginine methyl ester also increased COX-2 expression and promoter activity in doxycyclin-inducible endoglin expressing endothelial cells, but not in control cells. The level of COX-2 expression following transforming growth factor-beta1 treatment was less in endoglin than in mock transfected L6E9 myoblasts and was higher in human endothelial cells silenced for endoglin expression. Our results indicate that endoglin is involved in the regulation of COX-2 activity. Furthermore, reduced endoglin levels and associated impaired NO production may be responsible, at least in part, for augmented COX-2 expression and activity in the Eng(+/-) mice. PMID:16840721

  15. Structural Basis for Plexin Activation and Regulation.

    Science.gov (United States)

    Kong, Youxin; Janssen, Bert J C; Malinauskas, Tomas; Vangoor, Vamshidhar R; Coles, Charlotte H; Kaufmann, Rainer; Ni, Tao; Gilbert, Robert J C; Padilla-Parra, Sergi; Pasterkamp, R Jeroen; Jones, E Yvonne

    2016-08-01

    Class A plexins (PlxnAs) act as semaphorin receptors and control diverse aspects of nervous system development and plasticity, ranging from axon guidance and neuron migration to synaptic organization. PlxnA signaling requires cytoplasmic domain dimerization, but extracellular regulation and activation mechanisms remain unclear. Here we present crystal structures of PlxnA (PlxnA1, PlxnA2, and PlxnA4) full ectodomains. Domains 1-9 form a ring-like conformation from which the C-terminal domain 10 points away. All our PlxnA ectodomain structures show autoinhibitory, intermolecular "head-to-stalk" (domain 1 to domain 4-5) interactions, which are confirmed by biophysical assays, live cell fluorescence microscopy, and cell-based and neuronal growth cone collapse assays. This work reveals a 2-fold role of the PlxnA ectodomains: imposing a pre-signaling autoinhibitory separation for the cytoplasmic domains via intermolecular head-to-stalk interactions and supporting dimerization-based PlxnA activation upon ligand binding. More generally, our data identify a novel molecular mechanism for preventing premature activation of axon guidance receptors. PMID:27397516

  16. An epidemiological investigation on serum levels of leptin, adiponectin, interleukin-6and plasminogen activator inhibitor-1 in middle aged and elderly people%中老年血清瘦素、脂联素、白介素-6及纤溶酶原激活物抑制物-1的流行病学调查

    Institute of Scientific and Technical Information of China (English)

    鲍蓓; 李志海; 陈卫文; 王立; 靳玉凤; 王晓燕

    2012-01-01

    目的 对广州市中老年人血清瘦素( leptin)、脂联素(adiponectin)、白介素-6(interleukin-6,IL-6)及纤溶酶原激活物抑制物-1(plasminogen activator inhibitor-1,PAI-1)进行流行病学调查.方法 在广州市生物库第三期注册登记的10 027名中老年人中随机抽取1996名中老年人进行问卷调查和健康体检.以酶联免疫吸附双抗夹心( ELISA)法测定leptin、adiponectin、IL-6、PAI-1.结果 广州市中老年人leptin、adiponectin、IL-6、PAI-1分别为( 10.46±9.75) μg/L、(9115.5±9812.91) μg/L、(13.13±6.50) pg/mL和(163.71±110.04)μg/L.校正年龄因素后,男、女性别间leptin、adiponectin、IL-6和PAI-1差异均有显著性(P<0.05).结论 本次大样本的中老年leptin、adiponectin、IL-6、PAI -1的流行病学调查数据可靠,为后期的生活方式与慢性心、脑血管和代谢性疾病关系的研究和公共卫生干预提供了依据.%Objective To conduct an epidemiological investigation on leptin,adiponectin,interleukin-6 ( IL-6 ),and plasminogen activator inhibitor-1 ( PAI-1 ) in the middle aged and elderly people in Guangzhou.Methods 1996 of 10 027 middle aged and elderly people registered at Guangzhou Database were randomly selected to be surveyed by questionnaires and to have physical examination.Levels of leptin,adiponectin,IL-6,and PAI-1 were determined by enzyme-linked immunosorbent assay ( ELISA ).Results Leptin was ( 10.46 ± 9.75 ) μg/L, adiponectin was ( 9115.5 ± 9812.91 ) μg/L,IL-6 was ( 13.13 ± 6.50 ) pg/mL,and PAI-1 was ( 163.71 ± 110.04 ) μg/L in Guangzhou middle aged and elderly people.There were significant differences in levels of leptin,adiponectin,IL-6,and PAI-1 between male and female after age adjustment.Conclusions Reliable data of leptin,adiponectin,IL-6,and PAI-1 in this large-scale epidemiological investigation provides support for the future research on the relationship between lifestyle and chronic cardiovascular,cardiocerebrovascular diseases

  17. Emi1 is needed to couple DNA replication with mitosis but does not regulate activation of the mitotic APC/C

    OpenAIRE

    Di Fiore, Barbara; Pines, Jonathon

    2007-01-01

    Ubiquitin-mediated proteolysis is critical for the alternation between DNA replication and mitosis and for the key regulatory events in mitosis. The anaphase-promoting complex/cyclosome (APC/C) is a conserved ubiquitin ligase that has a fundamental role in regulating mitosis and the cell cycle in all eukaryotes. In vertebrate cells, early mitotic inhibitor 1 (Emi1) has been proposed as an important APC/C inhibitor whose destruction may trigger activation of the APC/C at mitosis. However, in t...

  18. 76 FR 12364 - Agency Information Collection Activities: Bonded Warehouse Regulations

    Science.gov (United States)

    2011-03-07

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Bonded Warehouse... Bonded Warehouse Regulations. This request for comment is being made pursuant to the Paperwork Reduction... concerning the following information collection: Title: Bonded Warehouse Regulations. OMB Number:...

  19. Effects of urokinase type plasminogen activator and plasminogen activator inhibitor-1 expressions on the formation of aneurysm of perimembranous ventricular septal defect%尿激酶型纤溶酶原激活物及其抑制物表达在膜周型室间隔缺损自发闭合中的作用

    Institute of Scientific and Technical Information of China (English)

    钱娟; 李本尚; 殷敏智; 沈萍; 孙锟

    2015-01-01

    0.05).结论 uPA及抑制物系统在VSA形成过程中起重要作用,参与瘤体的形成和纤维增殖过程.%Objective The exact mechanisms of defect closure in patients with perimembranous ventricular septal defect (PMVSD) remain unknown.We hypothesized that the expression of urokinase type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) may mediate extracellular matrix (ECM) remodeling in aneurysms.Method Seven normal heart tricuspid septal leaflet and 33 aneurysms were collected in Shanghai Renji Hospital and Shanghai Children's Medical Center from January 2008 to June 2010.Immunohistochemical expression of uPA and PAI-1 in 4 normal heart valvular tissues and 15 aneurysms was detected with immunohistochemical methods.The expression of uPA and PAI-1 mRNA in 3 normal heart valvular tissues and 7 aneurysms was studied by real time fluorescent PCR;the protein expression of uPA and PAI-1 in 4 normal heart valvular tissues and 11 aneurysms was tested with Western blotting.Result The surface of the aneurysms were completely covered by endothelial cells.Two types of granulation tissue,myxoid and fibrous,were associated with the aneurismal formation.uPA were recognized predominantly in valvar interstitial cells (VICs) which located mainly in regions adjacent to the endothelium and smooth muscle cells of blood vessels.PAI-1 was found in both VICs which located mainly in granulation tissue and endothelial cells.Nine aneurysms expressed a higher uPA activity than 4 normal valvular tissues ((74.6 ± 11.8) % vs.(49.5 ± 7.4) %;t =3.87,P =0.003) and six aneurysms expressed a low uPA activity ((10.3±3.1)% vs.(49.5±7.4)%;t=11.78,P=0.000) andahighPAI-1 activity ((55.2±1.7) % vs.(50.8 ± 3.8) %;t =2.55,P =0.034) using immunohistochemical methods.uPA / PAI-1 ratio of protein expression tested by Western blot was 0.88 ± 0.22 in four normal heart vavular tissues;five aneurysms expressed high uPA activity and low PAI-1 activity and u

  20. Activation and Regulation of Cellular Eicosanoid Biosynthesis

    Directory of Open Access Journals (Sweden)

    Thomas G. Brock

    2007-01-01

    Full Text Available There is a growing appreciation for the wide variety of physiological responses that are regulated by lipid messengers. One particular group of lipid messengers, the eicosanoids, plays a central role in regulating immune and inflammatory responses in a receptor-mediated fashion. These mediators are related in that they are all derived from one polyunsaturated fatty acid, arachidonic acid. However, the various eicosanoids are synthesized by a wide variety of cell types by distinct enzymatic pathways, and have diverse roles in immunity and inflammation. In this review, the major pathways involved in the synthesis of eicosanoids, as well as key points of regulation, are presented.

  1. THE EUROPEAN MODEL OF STATE REGULATION OF TOURISM ACTIVITIES

    OpenAIRE

    О. Davydova

    2013-01-01

    In the article the existing model of state regulation of the development of tourism. Expediency of the European model of state regulation of tourism development in Ukraine. It is noted that the European model of state regulation of tourism activities based on the coordination of marketing activities and the development of cooperation between the public and private sectors. The basic forms of public-private partnerships and the advantages of using cluster model of development of tourism, namel...

  2. 50 CFR 404.7 - Regulated activities.

    Science.gov (United States)

    2010-10-01

    ... vessel engine cooling water, weather deck runoff, and vessel engine exhaust; (f) Discharging or... effluent, cooling water, and engine exhaust; (g) Touching coral, living or dead; (h) Possessing fishing... Wildlife and Fisheries JOINT REGULATIONS (UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF...

  3. Aging, Physical Activity, and Energy Intake Regulation

    OpenAIRE

    Van Walleghen, Emily Lynn

    2006-01-01

    More than seventy percent of Americans over the age of sixty are classified as overweight or obese, and the future incidence of these conditions is expected to rise. Although it is unclear why older adults are predisposed to weight gain, decreased total energy expenditure may contribute to positive energy balance. It is also possible that age-related impairments in energy intake regulation result in the inability to appropriately adjust food intake to meet energy requirements with advancing a...

  4. Active Power Regulation based on Droop for AC Microgrid

    DEFF Research Database (Denmark)

    Li, Chendan; Coelho, Ernane A. A.; Firoozabadi, Mehdi Savaghebi;

    2015-01-01

    In this paper, two different control strategies are proposed to address the active power regulation issue in AC microgrids. The principle of power regulation in the droop controller is firstly introduced. Frequency scheduling and droop gain scheduling on top of droop control is proposed to succes......In this paper, two different control strategies are proposed to address the active power regulation issue in AC microgrids. The principle of power regulation in the droop controller is firstly introduced. Frequency scheduling and droop gain scheduling on top of droop control is proposed...

  5. Modern aspects of tax regulation of investment activity

    Directory of Open Access Journals (Sweden)

    E.S. Podakov

    2016-03-01

    Full Text Available The article investigates the tax regulation of investment activity in modern conditions. Scientists studied different views about the impact of tax regulations on the investment activity in the country. The author determines that the tax regulation of investment activity involves the use of state mechanisms taxation of certain measures to improve investment conditions. The subject is the state tax regulations, and the object is the investment activity of individual and institutional investors of any form of ownership including organizational and legal forms. Such regulation is performed by using complex special tools. The possible methods of tax stimulation of investment processes are described. The article deals with the current results of tax reform in Ukraine and predicts its possible consequences for agricultural producers. The rating positions of Ukraine according to international organizations are showed. The systematic analysis has been carried out and the impact of differential tax rates, tax exemption for a specified period, reducing the tax base, elimination of double taxation on investment activity in certain areas have been researched. The special instruments of investment activity tax regulation are considered. The options for improving investment activity by introducing effective tax regulation are determined.

  6. Activity Dependent Regulation of Inhibitory Circuitry

    OpenAIRE

    Sharma, Nikhil

    2015-01-01

    Inhibition controls information flow through a neural circuit by modulating synaptic integration, restricting action potentials, and coordinating the activity of ensembles of neurons. These functions are mediated by a diverse array of inhibitory neuron subtypes that synapse on defined domains of a postsynaptic neuron. Activity-dependent transcription controls inhibitory synapse number and function, but how this transcription program affects the inhibitory inputs that form on di...

  7. Commission for energy regulation - 2012 Activity Report

    International Nuclear Information System (INIS)

    After a presentation of the organisation, role and missions of the French Commission for Energy Regulation (CRE), and of its relationship with other institutional actors, this report describes and comments the action of the CRE in the fields of dialogue and transparency. It presents and comments key figures regarding the electricity and gas retail markets. It reports and comments the European reaction to the cold peak of February 2012 (historical peak for consumption and prices, inquiry on the causes of these price peaks, need of a European market). The next part addresses the relationship between electricity grids and territories (solidarity between electricity grids as the basis of the Europe of energy, evolution of French grids to face new needs and to take regional and local dimensions into account). Another part addresses gas infrastructures which are considered as the cornerstone of a good operation for the French market and for the integration of the European energy market (gas world market in 2012, definition of a target model for the gas market by European regulators, evolution of the French market in compliance with the European target model, new tariffs for the use of natural gas transport networks). The report then addresses the development of renewable energies: actions of CRE (bidding, opinion of tariffs), influence of renewable energy development on electricity prices on gross markets, needed evolution of electricity grids. A last part addresses the issues of energy cost, demand management, and struggle against energy poverty

  8. Dietary methanol regulates human gene activity.

    Directory of Open Access Journals (Sweden)

    Anastasia V Shindyapina

    Full Text Available Methanol (MeOH is considered to be a poison in humans because of the alcohol dehydrogenase (ADH-mediated conversion of MeOH to formaldehyde (FA, which is toxic. Our recent genome-wide analysis of the mouse brain demonstrated that an increase in endogenous MeOH after ADH inhibition led to a significant increase in the plasma MeOH concentration and a modification of mRNA synthesis. These findings suggest endogenous MeOH involvement in homeostasis regulation by controlling mRNA levels. Here, we demonstrate directly that study volunteers displayed increasing concentrations of MeOH and FA in their blood plasma when consuming citrus pectin, ethanol and red wine. A microarray analysis of white blood cells (WBC from volunteers after pectin intake showed various responses for 30 significantly differentially regulated mRNAs, most of which were somehow involved in the pathogenesis of Alzheimer's disease (AD. There was also a decreased synthesis of hemoglobin mRNA, HBA and HBB, the presence of which in WBC RNA was not a result of red blood cells contamination because erythrocyte-specific marker genes were not significantly expressed. A qRT-PCR analysis of volunteer WBCs after pectin and red wine intake confirmed the complicated relationship between the plasma MeOH content and the mRNA accumulation of both genes that were previously identified, namely, GAPDH and SNX27, and genes revealed in this study, including MME, SORL1, DDIT4, HBA and HBB. We hypothesized that human plasma MeOH has an impact on the WBC mRNA levels of genes involved in cell signaling.

  9. Physical Activity and Self-Regulation Strategy Use in Adolescents

    Science.gov (United States)

    Matthews, James; Moran, Aidan

    2011-01-01

    Objective: To examine the degree to which the use of selected theoretically derived self-regulation strategies (eg, goal setting) could predict adolescents' self-reported leisure-time physical activity behavior. Method: Two hundred thirty-three (M age = 15.88) high school students completed measures assessing their self-regulation strategy use and…

  10. The protective role of Bax Inhibitor-1 against chronic mild stress through the inhibition of monoamine oxidase A

    OpenAIRE

    Hwa-Young Lee; Geum-Hwa Lee; Anu Marahatta; Shun-Mei Lin; Mi-Rin Lee; Kyu Yun Jang; Kyung Min Kim; Hee Jae Lee; Jae-Won Lee; Tarique Rajasaheb Bagalkot; Young-Chul Chung; Yong-Chul Lee; Hyung-Ryong Kim; Han-Jung Chae

    2013-01-01

    The anti-apoptotic protein Bax inhibitor-1 (BI-1) is a regulator of apoptosis linked to endoplasmic reticulum (ER) stress. It has been hypothesized that BI-1 protects against neuron degenerative diseases. In this study, BI-1−/− mice showed increased vulnerability to chronic mild stress accompanied by alterations in the size and morphology of the hippocampi, enhanced ROS accumulation and an ER stress response compared with BI-1+/+ mice. BI-1−/− mice exposed to chronic mild stress showed signif...

  11. Regulation of nuclear activities in Canada

    International Nuclear Information System (INIS)

    This review was initiated by the OECD Nuclear Energy Agency for its series of analytical studies on nuclear legislation. It looks at the historic background and general overview of the use and handling of nuclear energy; the governmental framework controlling nuclear activities; and the agencies involved in its research and industrial applications. The regulatory power and structure of the Atomic Energy Control Board are highlighted

  12. Hormonal Regulation of Hepatic Drug Metabolizing Enzyme Activity During Adolescence

    OpenAIRE

    Kennedy, M J

    2008-01-01

    Activities of drug metabolizing enzymes (DME) are known to change throughout the course of physical and sexual maturation with the greatest variability noted during infancy and adolescence. The mechanisms responsible for developmental regulation of DME are currently unknown. However, the hormonal changes of puberty/adolescence provide a theoretical framework for understanding biochemical regulation of DME activity during growth and maturation. Important information regarding potential influen...

  13. A Small Group Activity About Bacterial Regulation And Complementation

    Directory of Open Access Journals (Sweden)

    Susan M. Merkel

    2010-11-01

    Full Text Available As teachers, we well understand the need for activities that help develop critical-thinking skills in microbiology. In our experience, one concept that students have difficulty understanding is transcriptional regulation of bacterial genes. To help with this, we developed and evaluated a paper-based activity to help students understand and apply the concepts of bacterial transcriptional regulation. While we don't identify it as such, we use a complementation experiment to assess student understanding of how regulation changes when new DNA is introduced. In Part 1 of this activity, students complete an open book, take-home assignment that asks them to define common terminology related to regulation, and draw the regulatory components of different scenarios involving positive and negative regulation. In Part 2, students work in small groups of 3-4 to depict the regulatory components for a different scenario. They are asked to explain the results of a complementation experiment based on this scenario. They then predict the results of a slightly different experiment. Students who completed the Regulation Activity did significantly better on post-test questions related to regulation, compared to pre-test questions.

  14. Kinase active Misshapen regulates Notch signaling in Drosophila melanogaster.

    Science.gov (United States)

    Mishra, Abhinava K; Sachan, Nalani; Mutsuddi, Mousumi; Mukherjee, Ashim

    2015-11-15

    Notch signaling pathway represents a principal cellular communication system that plays a pivotal role during development of metazoans. Drosophila misshapen (msn) encodes a protein kinase, which is related to the budding yeast Ste20p (sterile 20 protein) kinase. In a genetic screen, using candidate gene approach to identify novel kinases involved in Notch signaling, we identified msn as a novel regulator of Notch signaling. Data presented here suggest that overexpression of kinase active form of Msn exhibits phenotypes similar to Notch loss-of-function condition and msn genetically interacts with components of Notch signaling pathway. Kinase active form of Msn associates with Notch receptor and regulate its signaling activity. We further show that kinase active Misshapen leads to accumulation of membrane-tethered form of Notch. Moreover, activated Msn also depletes Armadillo and DE-Cadherin from adherens junctions. Thus, this study provides a yet unknown mode of regulation of Notch signaling by Misshapen. PMID:26431585

  15. Correlation of plasminogen activator inhibitor-1 and transforming growth factor-beta with diabetic nephropathy in type 2 diabetes mellitus%血浆纤溶酶原激活物抑制物1及血清转化生长因子β与2型糖尿病肾病的相关性研究

    Institute of Scientific and Technical Information of China (English)

    徐丰博; 刘惠兰; 孙懿

    2012-01-01

    目的 研究2型糖尿病肾病(DN)及单纯2型糖尿病(T2DM)患者血浆纤溶酶原激活物抑制物1(PAI-1)及血清转化生长因子β(TGF-β)水平的变化.并进一步探讨在T2DM患者中血浆PAI-1和血清TGF-β的关系.方法 T2DM患者93例,其中T2DM无蛋白尿患者(DM组)37例;微量蛋白尿患者(DN 1组)27例,尿白蛋白/肌酐(A/C)20~200 mg/g;显著蛋白尿患者(DN 2组)29例,A/C>200 mg/g.选取正常对照组32例,均为健康体检者.所有检测对象过夜禁食10~12小时后,于清晨空腹抽取肘静脉血4 ml,其中2 ml不抗凝血用于生化指标检测.酶联免疫吸附试验(ELISA)测定血浆PAI-1、TGF-β水平.结果 ①血浆PAI-1水平DN1、DN2组显著高于正常对照组,(69.28±18.61) ng/L、(69.43±17.86) ng/L vs (51.97±30.11) ng/L(P<0.05).②血清TGF-β水平DM、DN1、DN2组显著高于正常对照组,分别为(137.99±21.47) ng/L、(180.36±40.45) ng/L、(298.92±77.37) ng/L vs(100.65±24.21) ng/L(均P<0.01).③血清TGF-β和血浆PAI-1水平无明显相关性.④血浆PAI-1水平及血清TGF-β水平升高是T2DM并发肾病的危险因素.结论 T2DM合并肾病患者血浆PAI-1水平、血清TGF-β水平升高,两项指标可以预测T2DM合并肾病的危险.%Objective Plasma plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-beta (TGF-fj) level of type 2 diabetes patients were studied for exploring the pathophysiological mechanism. Methods According to the standards of diabetic diagnosis and typing put forward by ADA in 1997,a total of 93 unrelated patients with type 2 diabetes were randomly recruited in the study. These patients were further divided into type 2 diabetes with nephropathy (DN1,DN2) and without nephropathy (DN) according to their urinary albumin to creatinine ratio (A/C). At the same time,32 healthy controls were selected from population for regular physical examination in the hospital. The levels of PAI-1 and TGF-β were measured by enzyme

  16. PAI-1基因4G/5G多态性与肥胖型多囊卵巢综合征的相关性研究*%Correlations between 4G/5G Polymorphism in Plasminogen Activator Inhibitor-1(PAI-1)Gene and Obese Polycystic Ovarian Syndrome

    Institute of Scientific and Technical Information of China (English)

    庄朝辉; 沈宗姬; 黄亚珍; 徐文新

    2013-01-01

    Objective:To investigate the prevalence of 4G/5G polymorphism of plasminogen activator inhibitor-1(PAI-1)gene in obese polycystic ovary syndrome(PCOS)and their relationships between insulin sensitivity and plasma fibrinolysis function,to find a new way to prevent obesity and insulin resistance of obese PCOS.Method:135 patients and 124 controls were selected.Body mass index(BMI)and waist-to-hip(WHR) ratio were determined.Based on the BMI,the PCOS patients were divided into two groups:74 patients without obesity and 61 patients with obesity.Blood samples were obtained for DNA analysis.PAI-1 plasma levels,fasting insulin and fasting glucose were measured by the ELISA in all subjects.The 4G/5G polymorphic site of the PAI-1 gene promoter region was amplified by the polymerase chain reaction(PCR).We evaluate insulin resistance with Homa-IR and measure insulin sensitivityindex(ISI).Result:Comparison of the clinical data:BMI,WHR,fasting insulin,Homa-IR in patients with obesity were significant greater than those in patients without obesity,the difference was statistically significant between the groups(P<0.05);The PCOS group had significantly higher 4G/4G than the control group,whereas there were significantly less 5G/5G.PCOS women have higher levels of PAI-1 compared with the control group(P<0.05).There was no statistical difference of genotype distribution between patients with obesity and patients without obesity, whereas there was a statistically significant difference in the PAI-1 levels among the groups(P<0.05).Conclusion:The presence of the 4G allele in PAI-1 promoter region of the gene further increases the PAI-1 levels.PAI-1 gene polymorphism 4G genetype may be correlated with PCOS in Chinese women.PAI-1 gene polymorphism 4G genetype may be not correlated with obesity of PCOS in Chinese women.Anti-PAI-1 study may be a new way to prevent obesity and insulin resistance of obese PCOS.%  目的:通过研究肥胖型多囊卵巢综合征(PCOS)纤

  17. Regulation of Activation Induced Deaminase (AID) by Estrogen.

    Science.gov (United States)

    Pauklin, Siim

    2016-01-01

    Regulation of Activation Induced Deaminase (AID) by the hormone estrogen has important implications for understanding adaptive immune responses as well as the involvement of AID in autoimmune diseases and tumorigenesis. This chapter describes the general laboratory techniques for analyzing AID expression and activity induced by estrogen, focusing on the isolation and preparation of cells for hormone treatment and the subsequent analysis of AID responsiveness to estrogen at the RNA level and for determining the regulation of AID activity via estrogen by analyzing Ig switch circle transcripts and mutations in switch region loci.

  18. Absence of canonical active chromatin marks in developmentally regulated genes

    Science.gov (United States)

    Ruiz-Romero, Marina; Corominas, Montserrat; Guigó, Roderic

    2015-01-01

    The interplay of active and repressive histone modifications is assumed to play a key role in the regulation of gene expression. In contrast to this generally accepted view, we show that transcription of genes temporally regulated during fly and worm development occurs in the absence of canonically active histone modifications. Conversely, strong chromatin marking is related to transcriptional and post-transcriptional stability, an association that we also observe in mammals. Our results support a model in which chromatin marking is associated to stable production of RNA, while unmarked chromatin would permit rapid gene activation and de-activation during development. In this case, regulation by transcription factors would play a comparatively more important regulatory role. PMID:26280901

  19. Developmental regulation of aromatase activity in the rat hypothalamus

    Energy Technology Data Exchange (ETDEWEB)

    Lephart, E.D.

    1989-01-01

    The brain of all mammalian species studied thus far contain an enzymatic activity (aromatase) that catalyzes the conversion of androgens to estrogens. The activity is highest during prenatal development and contributes to the establishment of sex differences which determine adult gonadotropin secretion patterns and reproductive behavior. The studies presented in this dissertation represent a systematic effort to elucidate the mechanism(s) that control the initiation of and contribute to maintaining rat hypothalamic aromatase activity during pre- and postnatal development. Aromatase enzyme activity was measured by the {sup 3}H{sub 2}O release assay or by traditional estrogen product isolation. Brain aromatase mRNA was detected by hybridization to a cDNA encoding rat aromatase cytochrome P-450. In both males and females the time of puberty was associated with a decline in hypothalamic aromatase activity. This decline may represent a factor underlying the peri-pubertal decrease in the sensitivity to gonadal steroid feedback that accompanies completion of puberty. The results also indicate that androgens regulate brain aromatase levels during both the prepubertal and peri-pubertal stages of sexual development and that this regulation is transiently lost in young adults. Utilizing a hypothalamic organotypic culture system, aromatase activity in vitro was maintained for as long as two days. The results of studies of a variety of hormonal and metabolic regulators suggest that prenatal aromatase activity is regulated by factor(s) that function independently from the classical cyclic AMP and protein kinase C trans-membrane signaling pathways.

  20. Post-translational regulation of Oct4 transcriptional activity.

    Directory of Open Access Journals (Sweden)

    Jonathan P Saxe

    Full Text Available Oct4 is a key component of the molecular circuitry which regulates embryonic stem cell proliferation and differentiation. It is essential for maintenance of undifferentiated, pluripotent cell populations, and accomplishes these tasks by binding DNA in multiple heterodimer and homodimer configurations. Very little is known about how formation of these complexes is regulated, or the mechanisms through which Oct4 proteins respond to complex extracellular stimuli which regulate pluripotency. Here, we provide evidence for a phosphorylation-based mechanism which regulates specific Oct4 homodimer conformations. Point mutations of a putative phosphorylation site can specifically abrogate transcriptional activity of a specific homodimer assembly, with little effect on other configurations. Moreover, we performed bioinformatic predictions to identify a subset of Oct4 target genes which may be regulated by this specific assembly, and show that altering Oct4 protein levels affects transcription of Oct4 target genes which are regulated by this assembly but not others. Finally, we identified several signaling pathways which may mediate this phosphorylation and act in combination to regulate Oct4 transcriptional activity and protein stability. These results provide a mechanism for rapid and reversible alteration of Oct4 transactivation potential in response to extracellular signals.

  1. Physiological roles of mitogen-activated-protein-kinase-activated p38-regulated/activated protein kinase

    Institute of Scientific and Technical Information of China (English)

    Sergiy; Kostenko; Gianina; Dumitriu; Kari; Jenssen; Lgreid; Ugo; Moens

    2011-01-01

    Mitogen-activated protein kinases(MAPKs)are a family of proteins that constitute signaling pathways involved in processes that control gene expression,cell division, cell survival,apoptosis,metabolism,differentiation and motility.The MAPK pathways can be divided into conventional and atypical MAPK pathways.The first group converts a signal into a cellular response through a relay of three consecutive phosphorylation events exerted by MAPK kinase kinases,MAPK kinase,and MAPK.Atypical MAPK pathways are not organized into this three-tiered cascade.MAPK that belongs to both conventional and atypical MAPK pathways can phosphorylate both non-protein kinase substrates and other protein kinases.The latter are referred to as MAPK-activated protein kinases.This review focuses on one such MAPK-activated protein kinase,MAPK-activated protein kinase 5(MK5)or p38-regulated/activated protein kinase(PRAK).This protein is highly conserved throughout the animal kingdom and seems to be the target of both conventional and atypical MAPK pathways.Recent findings on the regulation of the activity and subcellular localization,bona fide interaction partners and physiological roles of MK5/PRAK are discussed.

  2. Structure of catalytic domain of Matriptase in complex with Sunflower trypsin inhibitor-1

    Directory of Open Access Journals (Sweden)

    Huang Mingdong

    2011-06-01

    Full Text Available Abstract Background Matriptase is a type II transmembrane serine protease that is found on the surfaces of epithelial cells and certain cancer cells. Matriptase has been implicated in the degradation of certain extracellular matrix components as well as the activation of various cellular proteins and proteases, including hepatocyte growth factor and urokinase. Sunflower trypsin inhibitor-1 (SFTI-1, a cyclic peptide inhibitor originally isolated from sunflower seeds, exhibits potent inhibitory activity toward matriptase. Results We have engineered and produced recombinant proteins of the matriptase protease domain, and have determined the crystal structures of the protease:SFTI-1 complex at 2.0 Å as well as the protease:benzamidine complex at 1.2 Å. These structures elaborate the structural basis of substrate selectivity of matriptase, and show that the matriptase S1 substrate specificity pocket is larger enough to allow movement of benzamidine inside the S1 pocket. Our study also reveals that SFTI-1 binds to matriptase in a way similar to its binding to trypsin despite the significantly different isoelectric points of the two proteins (5.6 vs. 8.2. Conclusions This work helps to define the structural basis of substrate specificity of matriptase and the interactions between the inhibitor and protease. The complex structure also provides a structural template for designing new SFTI-1 derivatives with better potency and selectivity against matriptase and other proteases.

  3. Epigenetic regulator Lid maintains germline stem cells through regulating JAK-STAT signaling pathway activity

    Directory of Open Access Journals (Sweden)

    Lama Tarayrah

    2015-11-01

    Full Text Available Signaling pathways and epigenetic mechanisms have both been shown to play essential roles in regulating stem cell activity. While the role of either mechanism in this regulation is well established in multiple stem cell lineages, how the two mechanisms interact to regulate stem cell activity is not as well understood. Here we report that in the Drosophila testis, an H3K4me3-specific histone demethylase encoded by little imaginal discs (lid maintains germline stem cell (GSC mitotic index and prevents GSC premature differentiation. Lid is required in germ cells for proper expression of the Stat92E transcription factor, the downstream effector of the Janus kinase signal transducer and activator of transcription (JAK-STAT signaling pathway. Our findings support a germ cell autonomous role for the JAK-STAT pathway in maintaining GSCs and place Lid as an upstream regulator of this pathway. Our study provides new insights into the biological functions of a histone demethylase in vivo and sheds light on the interaction between epigenetic mechanisms and signaling pathways in regulating stem cell activities.

  4. Extracellular Matrix Stiffness Regulates Osteogenic Differentiation through MAPK Activation.

    Directory of Open Access Journals (Sweden)

    Jun-Ha Hwang

    Full Text Available Mesenchymal stem cell (MSC differentiation is regulated by the extracellular matrix (ECM through activation of intracellular signaling mediators. The stiffness of the ECM was shown to be an important regulatory factor for MSC differentiation, and transcriptional coactivator with PDZ-binding motif (TAZ was identified as an effector protein for MSC differentiation. However, the detailed underlying mechanism regarding the role of ECM stiffness and TAZ in MSC differentiation is not yet fully understood. In this report, we showed that ECM stiffness regulates MSC fate through ERK or JNK activation. Specifically, a stiff hydrogel matrix stimulates osteogenic differentiation concomitant with increased nuclear localization of TAZ, but inhibits adipogenic differentiation. ERK and JNK activity was significantly increased in cells cultured on a stiff hydrogel. TAZ activation was induced by ERK or JNK activation on a stiff hydrogel because exposure to an ERK or JNK inhibitor significantly decreased the nuclear localization of TAZ, indicating that ECM stiffness-induced ERK or JNK activation is important for TAZ-driven osteogenic differentiation. Taken together, these results suggest that ECM stiffness regulates MSC differentiation through ERK or JNK activation.

  5. Extracellular Matrix Stiffness Regulates Osteogenic Differentiation through MAPK Activation.

    Science.gov (United States)

    Hwang, Jun-Ha; Byun, Mi Ran; Kim, A Rum; Kim, Kyung Min; Cho, Hang Jun; Lee, Yo Han; Kim, Juwon; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

    2015-01-01

    Mesenchymal stem cell (MSC) differentiation is regulated by the extracellular matrix (ECM) through activation of intracellular signaling mediators. The stiffness of the ECM was shown to be an important regulatory factor for MSC differentiation, and transcriptional coactivator with PDZ-binding motif (TAZ) was identified as an effector protein for MSC differentiation. However, the detailed underlying mechanism regarding the role of ECM stiffness and TAZ in MSC differentiation is not yet fully understood. In this report, we showed that ECM stiffness regulates MSC fate through ERK or JNK activation. Specifically, a stiff hydrogel matrix stimulates osteogenic differentiation concomitant with increased nuclear localization of TAZ, but inhibits adipogenic differentiation. ERK and JNK activity was significantly increased in cells cultured on a stiff hydrogel. TAZ activation was induced by ERK or JNK activation on a stiff hydrogel because exposure to an ERK or JNK inhibitor significantly decreased the nuclear localization of TAZ, indicating that ECM stiffness-induced ERK or JNK activation is important for TAZ-driven osteogenic differentiation. Taken together, these results suggest that ECM stiffness regulates MSC differentiation through ERK or JNK activation.

  6. Energy Regulation Commission. Activity report. 1 July - 31 December 2008

    International Nuclear Information System (INIS)

    After a description of the scope of activities, organisation and operation of the CRE (Commission de Regulation de l'Energie, Energy regulation commission) and of the CorDIS (Comite de reglement des differents et des sanctions de la CRE, CRE's Committee for settlements of controversies and sanctions), this report outlines the importance of the grid manager independence and of the regulation reinforcement for the building up of a domestic energy market. It discusses the role of the regulation authority in the interconnection of European grids, their operation security and supply security, but also in pricing and in investments. It highlights the relationship between the reduction of carbon emission, energy demand management, strengthening of electric grids, financial incentives, and advanced metering systems. It describes how the CRE ensures a good operation of electricity and natural gas markets

  7. THE EUROPEAN MODEL OF STATE REGULATION OF TOURISM ACTIVITIES

    Directory of Open Access Journals (Sweden)

    О. Davydova

    2013-11-01

    Full Text Available In the article the existing model of state regulation of the development of tourism. Expediency of the European model of state regulation of tourism development in Ukraine. It is noted that the European model of state regulation of tourism activities based on the coordination of marketing activities and the development of cooperation between the public and private sectors. The basic forms of public-private partnerships and the advantages of using cluster model of development of tourism, namely, contracts, production sharing agreement, lease, joint venture. Promising areas of application of the PPP identified the transport sector, housing and utilities, energy and tourism sector. The features of cluster formations in the country and the prospects for tourism clusters.

  8. The Immune System as a Regulator of Thyroid Hormone Activity

    OpenAIRE

    Klein, John R.

    2006-01-01

    It has been known for decades that the neuroendocrine system can both directly and indirectly influence the developmental and functional activity of the immune system. In contrast, far less is known about the extent to which the immune system collaborates in the regulation of endocrine activity. This is particularly true for immune-endocrine interactions of the hypothalamus-pituitary-thyroid axis. Although thyroid stimulating hormone (TSH) can be produced by many types of extra-pituitary cell...

  9. Neural progenitor cells regulate microglia functions and activity.

    Science.gov (United States)

    Mosher, Kira I; Andres, Robert H; Fukuhara, Takeshi; Bieri, Gregor; Hasegawa-Moriyama, Maiko; He, Yingbo; Guzman, Raphael; Wyss-Coray, Tony

    2012-11-01

    We found mouse neural progenitor cells (NPCs) to have a secretory protein profile distinct from other brain cells and to modulate microglial activation, proliferation and phagocytosis. NPC-derived vascular endothelial growth factor was necessary and sufficient to exert at least some of these effects in mice. Thus, neural precursor cells may not only be shaped by microglia, but also regulate microglia functions and activity.

  10. Regulation of eNOS Enzyme Activity by Posttranslational Modification

    OpenAIRE

    Heiss, Elke H.; Dirsch, Verena M.

    2014-01-01

    The regulation of endothelial NO synthase (eNOS) employs multiple different cellular control mechanisms impinging on level and activity of the enzyme. This review aims at summarizing the current knowledge on the posttranslational modifications of eNOS, including acylation, nitrosylation, phosphorylation, acetylation, glycosylation and glutathionylation. Sites, mediators and impact on enzyme localization and activity of the single modifications will be discussed. Moreover, interdependence, coo...

  11. Active Inference, homeostatic regulation and adaptive behavioural control

    OpenAIRE

    Pezzulo, G; Rigoli, F.; Friston, K.

    2015-01-01

    We review a theory of homeostatic regulation and adaptive behavioural control within the Active Inference framework. Our aim is to connect two research streams that are usually considered independently; namely, Active Inference and associative learning theories of animal behaviour. The former uses a probabilistic (Bayesian) formulation of perception and action, while the latter calls on multiple (Pavlovian, habitual, goal-directed) processes for homeostatic and behavioural control. We offer a...

  12. How is AMPK activity regulated in skeletal muscles during exercise?

    DEFF Research Database (Denmark)

    Jørgensen, Sebastian Beck; Rose, Adam John

    2008-01-01

    discuss the influence of reactive oxygen species produced within the muscle as well as muscle glycogen and TAK1 in regulating AMPK during exercise. Currently, during intensive contraction, activation of alpha2-AMPK seems mainly to rely on AMP accumulating from ATP-hydrolysis whereas calcium signaling may...

  13. Regulation of Enzyme Activity through Interactions with Nanoparticles

    OpenAIRE

    Bin Zhang; Bing Yan; Zhaochun Wu

    2009-01-01

    The structure and function of an enzyme can be altered by nanoparticles (NPs). The interaction between enzyme and NPs is governed by the key properties of NPs, such as structure, size, surface chemistry, charge and surface shape. Recent representative studies on the NP-enzyme interactions and the regulation of enzyme activity by NPs with different size, composition and surface modification are reviewed.

  14. 76 FR 28801 - Agency Information Collection Activities: Bonded Warehouse Regulations

    Science.gov (United States)

    2011-05-18

    ... Federal Register (76 FR 11254) on March 1, 2011, allowing for a 60-day comment period. This notice allows... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Bonded Warehouse... approval in accordance with the Paperwork Reduction Act: Bonded Warehouse Regulations. This is a...

  15. Signal integration by Ca2+ regulates intestinal stem cell activity

    Science.gov (United States)

    Deng, Hansong; Gerencser, Akos A.; Jasper, Heinrich

    2015-01-01

    Summary Somatic stem cells (SCs) maintain tissue homeostasis by dynamically adjusting proliferation and differentiation in response to stress and metabolic cues. Here, we identify Ca2+ signaling as a central regulator of intestinal SC (ISC) activity in Drosophila. We find that dietary L-glutamate stimulates ISC division and gut growth. The metabotropic glutamate receptor (mGluR) is required in ISCs for this response and for an associated modulation of cytosolic Ca2+ oscillations that results in sustained high cytosolic Ca2+ concentrations. High cytosolic Ca2+ induces ISC proliferation by regulating Calcineurin and CREB - regulated transcriptional co-activator (CRTC). In response to a wide range of dietary and stress stimuli, ISCs reversibly transition between Ca2+ oscillation states that represent poised or activated modes of proliferation, respectively. We propose that the dynamic regulation of intracellular Ca2+ levels allows effective integration of diverse mitogenic signals in ISCs to tailor their proliferative activity to the needs of the tissue. PMID:26633624

  16. Commission for Energy regulation (CRE) - Activity report June 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2004 activity report of CRE. Content: A - Opening of the gas and electricity markets for professional customers on 1 July 2004; B - Regulation of the gas market: Gas markets and players (The European environment, The French gas market); Regulation of the gas market (Implementing regulation, Works planned for the coming year; C - Regulation of the electricity market: The electricity markets and players (The European electricity markets, The French electricity market, Monitoring the electricity market); Regulation of the French electricity market (Access to public grid, Cross-border exchanges, Un-bundled accounting principles); The public electricity service in the regulated market (Content of the public service, Public service charges, Electricity production public service financing, Electricity sales tariffs) D - The working of CRE: How CRE exercises its jurisdiction, Tools; E - Appendices: Glossary, Units and conversions, Council of European Energy Regulators, Index of tables and figures.

  17. Commission for Energy regulation (CRE) - Activity report June 2004

    International Nuclear Information System (INIS)

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2004 activity report of CRE. Content: A - Opening of the gas and electricity markets for professional customers on 1 July 2004; B - Regulation of the gas market: Gas markets and players (The European environment, The French gas market); Regulation of the gas market (Implementing regulation, Works planned for the coming year; C - Regulation of the electricity market: The electricity markets and players (The European electricity markets, The French electricity market, Monitoring the electricity market); Regulation of the French electricity market (Access to public grid, Cross-border exchanges, Un-bundled accounting principles); The public electricity service in the regulated market (Content of the public service, Public service charges, Electricity production public service financing, Electricity sales tariffs) D - The working of CRE: How CRE exercises its jurisdiction, Tools; E - Appendices: Glossary, Units and conversions, Council of European Energy Regulators, Index of tables and figures

  18. Commission for Energy regulation (CRE) - Activity report june 2008

    International Nuclear Information System (INIS)

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2008 activity report of CRE. Content: A - How CRE works: CRE regulatory authority and organisation: Powers, Organisation; Budget resources; Personnel; B - The Standing Committee for Dispute Settlement and Sanctions (CoRDiS) activity: Admissibility, Authority; C - Building a single European energy market: Overview; Organisation and coordination of the main European regulators (Work carried out collectively by European regulators, Regulator organisation and development, CRE's relations with European Community institutions, Development of CEER activities outside the European Union); CRE's European activities (The contribution of European regulators to the Third Energy Package, Integration of gas markets, Integration of electricity markets, Operation of the European interconnected electricity grid and security of supply, Opening up markets to benefit consumers); European Community activities (The European Commission's proposals for the internal energy market: the Third Energy Package, The European Commission's proposals for fighting climate change: the Climate Package, Infringement

  19. Complement system part I - molecular mechanisms of activation and regulation

    Directory of Open Access Journals (Sweden)

    Nicolas eMerle

    2015-06-01

    Full Text Available Complement is a complex innate immune surveillance system, playing a key role in defense against pathogens and in host homeostasis. The complement system is initiated by conformational changes in recognition molecular complexes upon sensing danger signals. The subsequent cascade of enzymatic reactions is tightly regulated to assure that complement is activated only at specific locations requiring defense against pathogens, thus avoiding host tissue damage. Here we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and pathology. This article will review the mechanisms of activation of alternative, classical and lectin pathways, the formation of C3 and C5 convertases, the action of anaphylatoxins and the membrane attack complex. We will also discuss the importance of structure-function relationships using the example of atypical hemolytic uremic syndrome. Lastly we will discuss the development and benefits of therapies using complement inhibitors.

  20. Cbl negatively regulates JNK activation and cell death

    Institute of Scientific and Technical Information of China (English)

    Andrew A Sproul; Zhiheng Xu; Michael Wilhelm; Stephen Gire; Lloyd A Greene

    2009-01-01

    Here, we explore the role of Cbl proteins in regulation of neuronal apoptosis. In two paradigms of neuron apopto-sis--nerve growth factor (NGF) deprivation and DNA damage--cellular levels of c-Cbl and Cbl-b fell well before the onset of cell death. NGF deprivation also induced rapid loss of tyrosine phosphorylation (and most likely, activa-tion) of c-Cbl. Targeting e-Cbl and Cbl-b with siRNAs to mimic their loss/inactivation sensitized neuronal cells to death promoted by NGF deprivation or DNA damage. One potential mechanism by which Cbl proteins might affect neuronal death is by regulation of apoptotic c-Jun N-terminal kinase (JNK) signaling. We demonstrate that Cbl pro-teins interact with the JNK pathway components mixed lineage kinase (MLK) 3 and POSH and that knockdown of Cbl proteins is sufficient to increase JNK pathway activity. Furthermore, expression of c-Cbl blocks the ability of MLKs to signal to downstream components of the kinase cascade leading to JNK activation and protects neuronal cells from death induced by MLKs, but not from downstream JNK activators. On the basis of these findings, we propose that Cbls suppress cell death in healthy neurons at least in part by inhibiting the ability of MLKs to activate JNK signaling. Apoptotic stimuli lead to loss of Cbl protein/activity, thereby removing a critical brake on JNK acti-vation and on cell death.

  1. Commission for Energy regulation (CRE) - Activity report June 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2007 activity report of CRE. Content: A - Towards a single European energy market: Birth of a single European energy market (Origins of Europe of Energy, Emergence of a European energy policy); Main European Community guiding lines (European governance as regards energy, Guiding principles for the internal energy market); European Community activities (European Commission reports, Electricity and gas Regional Initiatives); Organisation and coordination of European regulators (Joint organisation of European regulators, CRE's relations with European Community institutions); CRE's European activities (Regional integration of gas markets, Regional integration of electricity markets, Operation of the European interconnected electricity grid and security of supply, CRE's other European activities); B - CRE action at national level: Grids/networks and infrastructures (General information, Electricity grids, Regulation of gas networks and infrastructures); Markets (Changes in the regulatory and legislative contexts of electricity and natural gas markets, Electricity markets

  2. Commission for Energy regulation (CRE) - Activity report June 2007

    International Nuclear Information System (INIS)

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2007 activity report of CRE. Content: A - Towards a single European energy market: Birth of a single European energy market (Origins of Europe of Energy, Emergence of a European energy policy); Main European Community guiding lines (European governance as regards energy, Guiding principles for the internal energy market); European Community activities (European Commission reports, Electricity and gas Regional Initiatives); Organisation and coordination of European regulators (Joint organisation of European regulators, CRE's relations with European Community institutions); CRE's European activities (Regional integration of gas markets, Regional integration of electricity markets, Operation of the European interconnected electricity grid and security of supply, CRE's other European activities); B - CRE action at national level: Grids/networks and infrastructures (General information, Electricity grids, Regulation of gas networks and infrastructures); Markets (Changes in the regulatory and legislative contexts of electricity and natural gas markets, Electricity markets, Natural gas

  3. Shape regulation generates elastic interaction between active force dipoles

    CERN Document Server

    Golkov, Roman

    2016-01-01

    The organization of live cells to tissues is associated with the mechanical interaction between cells, which is mediated through their mechanical environment. We model live cells as spherical active force dipoles surrounded by an infinite elastic matrix, and analytically evaluate their elastic interaction energy for different scenarios of their regulatory behavior. For purely dilational eigenstrains the elastic interaction energy between any two bodies vanishes. We identify mechanical interactions between active cells applying non isotropic displacements with a regulation mechanism designed so that they will preserve their spherical shape. We express the resultant non-isotropic deformation field by a multipole expansion in terms of spherical harmonics. Mechanical self-regulation of live cells is not fully understood, and we compare homeostatic (set point) force applied by the cells on their environment versus homeostatic displacements on their surface. By including or excluding the first term of the expansion...

  4. Regulation of burstiness by network-driven activation

    CERN Document Server

    García-Pérez, Guillermo; Serrano, M Ángeles

    2014-01-01

    We prove that complex networks of interactions have the capacity to regulate and buffer unpredictable fluctuations in production events. We show that non-bursty network-driven activation dynamics can effectively regulate the level of burstiness in the production of nodes, which can be enhanced or reduced. Burstiness can be induced even when the endogenous inter-event time distribution of nodes' production is non-bursty. We found that hubs tend to be less controllable than low degree nodes, which are more susceptible to the networked regulatory effects. Our results have important implications for the analysis and engineering of bursty activity in a range of systems, from telecommunication networks to transcription and translation of genes into proteins in cells.

  5. Commission for Energy regulation (CRE) - Activity report June 2005

    International Nuclear Information System (INIS)

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2005 activity report of CRE. Content: A - The opening of the markets in France and in Europe: The opening of the markets one year after 1 July 2004 (An especially important step, Electricity and gas: a common framework with structural differences, The coexistence of market prices and regulated tariffs); The European texts of 26 June 2003 (Texts to give new impetus, Texts to harmonize the role and powers of national regulators, Texts to guarantee the independence of system operators, Texts to ensure transparent and non-discriminatory access to networks, Texts providing for strengthening of interconnections); The outlook for 2007, a fully open market (1 July 2007: a date set by the directives, Priority given to informing and protecting consumers); B - Regulation of the natural gas market: The gas market in the European context (Europe's dependency on imports is increasing, Gas prices increased considerably across the whole of Europe in 2004, The European gas scene continues to be dominated by a small number of players, Gas infrastructures need to be developed in Europe, The new European

  6. Activation and Regulation of DNA-Driven Immune Responses

    OpenAIRE

    Paludan, Søren R

    2015-01-01

    The innate immune system provides early defense against infections and also plays a key role in monitoring alterations of homeostasis in the body. DNA is highly immunostimulatory, and recent advances in this field have led to the identification of the innate immune sensors responsible for the recognition of DNA as well as the downstream pathways that are activated. Moreover, information on how cells regulate DNA-driven immune responses to avoid excessive inflammation is now emerging. Finally,...

  7. Harvester ants use interactions to regulate forager activation and availability.

    Science.gov (United States)

    Pinter-Wollman, Noa; Bala, Ashwin; Merrell, Andrew; Queirolo, Jovel; Stumpe, Martin C; Holmes, Susan; Gordon, Deborah M

    2013-07-01

    Social groups balance flexibility and robustness in their collective response to environmental changes using feedback between behavioural processes that operate at different timescales. Here we examine how behavioural processes operating at two timescales regulate the foraging activity of colonies of the harvester ant, Pogonomyrmex barbatus, allowing them to balance their response to food availability and predation. Previous work showed that the rate at which foragers return to the nest with food influences the rate at which foragers leave the nest. To investigate how interactions inside the nest link the rates of returning and outgoing foragers, we observed outgoing foragers inside the nest in field colonies using a novel observation method. We found that the interaction rate experienced by outgoing foragers inside the nest corresponded to forager return rate, and that the interactions of outgoing foragers were spatially clustered. Activation of a forager occurred on the timescale of seconds: a forager left the nest 3-8 s after a substantial increase in interactions with returning foragers. The availability of outgoing foragers to become activated was adjusted on the timescale of minutes: when forager return was interrupted for more than 4-5 min, available foragers waiting near the nest entrance went deeper into the nest. Thus, forager activation and forager availability both increased with the rate at which foragers returned to the nest. This process was checked by negative feedback between forager activation and forager availability. Regulation of foraging activation on the timescale of seconds provides flexibility in response to fluctuations in food abundance, whereas regulation of forager availability on the timescale of minutes provides robustness in response to sustained disturbance such as predation.

  8. Disorders of regulation of cognitive activity in autistic children.

    Science.gov (United States)

    Adrien, J L; Martineau, J; Barthélémy, C; Bruneau, N; Garreau, B; Sauvage, D

    1995-06-01

    Infantile autism is a pervasive developmental disorder characterized by disturbances concerning not only the areas of socialization and communication ("aloneness") but also the ability to modify and change behavior ("need for sameness"). In most recent studies, various abnormal and deviant cognitive activities, such as the ability to regulate one's behavior, were considered as accounting for these signs. In this report, we examined the regulation of cognitive activity, from a developmental perspective in comparing autistic with mentally retarded children matched in a pairwise manner by global, verbal, and nonverbal developmental ages. All children were tested with tasks adapted from the Object Permanence Test which corresponds to Piaget's sensorimotor development Stages IV to VI. Results showed that autistic children had a pervasive difficulty in maintenance set, made more perseverative errors when the abstraction degree of task was higher, and were more variable in their behavioral strategies. Discussion is focused on the interests and limits of these tasks for the examination of regulation activity from diagnostic and developmental perspectives. Finally, interpretations about recent neuropsychological and neurophysiological works, and additional interdisciplinary studies are suggested. PMID:7559291

  9. Raf activation is regulated by tyrosine 510 phosphorylation in Drosophila.

    Directory of Open Access Journals (Sweden)

    Fan Xia

    2008-05-01

    Full Text Available The proto-oncoprotein Raf is pivotal for mitogen-activated protein kinase (MAPK signaling, and its aberrant activation has been implicated in multiple human cancers. However, the precise molecular mechanism of Raf activation, especially for B-Raf, remains unresolved. By genetic and biochemical studies, we demonstrate that phosphorylation of tyrosine 510 is essential for activation of Drosophila Raf (Draf, which is an ortholog of mammalian B-Raf. Y510 of Draf is phosphorylated by the c-src homolog Src64B. Acidic substitution of Y510 promotes and phenylalanine substitution impairs Draf activation without affecting its enzymatic activity, suggesting that Y510 plays a purely regulatory role. We further show that Y510 regulates Draf activation by affecting the autoinhibitory interaction between the N- and C-terminal fragments of the protein. Finally, we show that Src64B is required for Draf activation in several developmental processes. Together, these results suggest a novel mechanism of Raf activation via Src-mediated tyrosine phosphorylation. Since Y510 is a conserved residue in the kinase domain of all Raf proteins, this mechanism is likely evolutionarily conserved.

  10. Regulation of Akt/PKB activity by P21-activated Kinase in Cardiomyocytes

    OpenAIRE

    Mao, Kai; Kobayashi, Satoru; Jaffer, Zahara M.; Huang, Yuan; Volden, Paul; Chernoff, Jonathan; Liang, Qiangrong

    2007-01-01

    Akt/PKB is a critical regulator of cardiac function and morphology, and its activity is governed by dual phosphorylation at active loop (Thr308) by phosphoinositide-dependent protein kinase-1 (PDK1) and at carboxyl-terminal hydrophobic motif (Ser473) by a putative PDK2. P21-activated kinase-1 (Pak1) is a serine/threonine protein kinase implicated in the regulation of cardiac hypertrophy and contractility, and was shown previously to activate Akt through an undefined mechanism. Here we report ...

  11. p53 regulation and activity in mouse embryonic stem cells

    OpenAIRE

    Solozobova, Valeriya

    2010-01-01

    P53 is a tumour development p53. The aim of this work was to study the regulation of p53 in embryonic stem cells and its activation in response to DNA damage. p53 was found that p53 becomes transcriptionally active in ES cells after DNA damage. Embryonic stem cells contain a relatively high amount of p53 protein and p53 RNA. After differentiation p53 level is rapidly downregulated. The high abundance of p53 in undifferentiated ES cells is a result of enhanced translation.

  12. The molecular regulation of Janus kinase (JAK) activation.

    Science.gov (United States)

    Babon, Jeffrey J; Lucet, Isabelle S; Murphy, James M; Nicola, Nicos A; Varghese, Leila N

    2014-08-15

    The JAK (Janus kinase) family members serve essential roles as the intracellular signalling effectors of cytokine receptors. This family, comprising JAK1, JAK2, JAK3 and TYK2 (tyrosine kinase 2), was first described more than 20 years ago, but the complexities underlying their activation, regulation and pleiotropic signalling functions are still being explored. Here, we review the current knowledge of their physiological functions and the causative role of activating and inactivating JAK mutations in human diseases, including haemopoietic malignancies, immunodeficiency and inflammatory diseases. At the molecular level, recent studies have greatly advanced our knowledge of the structures and organization of the component FERM (4.1/ezrin/radixin/moesin)-SH2 (Src homology 2), pseudokinase and kinase domains within the JAKs, the mechanism of JAK activation and, in particular, the role of the pseudokinase domain as a suppressor of the adjacent tyrosine kinase domain's catalytic activity. We also review recent advances in our understanding of the mechanisms of negative regulation exerted by the SH2 domain-containing proteins, SOCS (suppressors of cytokine signalling) proteins and LNK. These recent studies highlight the diversity of regulatory mechanisms utilized by the JAK family to maintain signalling fidelity, and suggest alternative therapeutic strategies to complement existing ATP-competitive kinase inhibitors. PMID:25057888

  13. Regulation of transcription and activity of Rhizobium etli glutaminase A.

    Science.gov (United States)

    Huerta-Saquero, Alejandro; Calderón-Flores, Arturo; Díaz-Villaseñor, Andrea; Du Pont, Gisela; Durán, Socorro

    2004-08-01

    The present study determines the regulatory mechanisms that operate on Rhizobium etli glutaminase A. glsA gene expression levels were evaluated under several metabolic conditions by fusions of the glsA gene promoter and the transcriptional reporter cassette uidA2-aad. glsA expression was directly correlated to the glutaminase A activity found under the tested growth conditions, reaching its maximum level in the presence of glutamine and during exponential growth phase. Glutamine induces glsA expression. The influence of allosteric metabolites on glutaminase A activity was also determined. The purified enzyme was inhibited by 2-oxoglutarate and pyruvate, whereas oxaloacetate and glyoxylate modulate it positively. Glutaminase A is not inhibited by glutamate and is activated by ammonium. Glutaminase A participates in an ATP-consuming cycle where glutamine is continually degraded and resynthesized by glutamine synthetase (GS). GS and glutaminase A activities appear simultaneously during bacterial growth under different metabolic conditions and their control mechanisms are not reciprocal. Slight overproduction in glutaminase A expression causes a reduction in growth yield and a dramatic decrease in bacterial growth. We propose a model for regulation of glutaminase A, and discuss its contribution to glutamine cycle regulation. PMID:15279892

  14. Calcium and cargoes as regulators of myosin 5a activity

    International Nuclear Information System (INIS)

    Myosin 5a is a two-headed actin-dependent motor that transports various cargoes in cells. Its enzymology and mechanochemistry have been extensively studied in vitro. It is a processive motor that takes multiple 36 nm steps on actin. The enzymatic activity of myosin 5 is regulated by an intramolecular folding mechanism whereby its lever arms fold back against the coiled-coil tail such that the motor domains directly bind the globular tail domains. We show that the structure seen in individual folded molecules is consistent with electron density map of two-dimensional crystals of the molecule. In this compact state, the actin-activated MgATPase activity of the molecule is markedly inhibited and the molecule cannot move processively on surface bound actin filaments. The actin-activated MgATPase activity of myosin 5a is activated by increasing the calcium concentration or by binding of a cargo-receptor molecule, melanophilin, in vitro. However, calcium binding to the calmodulin light chains results in dissociation of some of the calmodulin which disrupts the ability of myosin 5a to move on actin filaments in vitro. Thus we propose that the physiologically relevant activation pathway in vivo involves binding of cargo-receptor proteins

  15. Commission for Energy regulation (CRE) - Activity report june 2006

    International Nuclear Information System (INIS)

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2006 activity report of CRE. Content: A - Opening of the electricity and natural gas markets to household consumers on 1 July 2007: CRE at the service of eligible customers (Information for eligible customers, Improved knowledge of non-household customers); Monitoring of the non-discrimination, transparency and independence of system operators (Drafting and distribution of codes of good conduct for system operators, The necessary improvement of system operator independence); Preparing the practical methods of opening: GTE 2007 and GTG 2007 (The necessary simplification of relations between operators and customers, Achieving a greater level of consumer information and protection, The clearly defined stages of the 'customer pathway', Profiling and settlement mechanisms: turning experience feedback from 2004 to good account); Persisting uncertainties and hurdles (The need for a suitable regulatory and legislative platform, Hurdles to the opening of the household market); B - Regulation of the natural gas market: The gas market in the European context (Increasing weight of imports in gas

  16. Commission for Energy regulation (CRE) - Activity report june 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    CRE is the French commission for energy regulation. CRE's remit is to assist in ensuring the proper operation of the electricity and natural gas markets for the benefit of the end-user. In particular, CRE ensures that the conditions of access to electricity and natural gas transmission and distribution systems do not hinder the development of competition. It monitors, for the electricity and natural gas sectors, all transactions made between suppliers, traders and producers, all transactions made on the organised markets and cross-border trading. It ensures that suppliers, traders and producers propose offers that are consistent with their financial and technical constraints. It monitors the implementation of and compliance with regulations giving consumers the right to choose their supplier in a competitive market, and allowing new suppliers to enter the market. This document is the 2006 activity report of CRE. Content: A - Opening of the electricity and natural gas markets to household consumers on 1 July 2007: CRE at the service of eligible customers (Information for eligible customers, Improved knowledge of non-household customers); Monitoring of the non-discrimination, transparency and independence of system operators (Drafting and distribution of codes of good conduct for system operators, The necessary improvement of system operator independence); Preparing the practical methods of opening: GTE 2007 and GTG 2007 (The necessary simplification of relations between operators and customers, Achieving a greater level of consumer information and protection, The clearly defined stages of the 'customer pathway', Profiling and settlement mechanisms: turning experience feedback from 2004 to good account); Persisting uncertainties and hurdles (The need for a suitable regulatory and legislative platform, Hurdles to the opening of the household market); B - Regulation of the natural gas market: The gas market in the European context (Increasing weight of

  17. AMP-activated protein kinase (AMPK) activation regulates in vitro bone formation and bone mass

    OpenAIRE

    Shah, M; Kola, B; Bataveljic, A.; Arnett, T. R.; Viollet, B.; Saxon, L.; Korbonits, M.; C. Chenu

    2010-01-01

    Adenosine 5′-monophosphate-activated protein kinase (AMPK), a regulator of energy homeostasis, has a central role in mediating the appetite-modulating and metabolic effects of many hormones and antidiabetic drugs metformin and glitazones. The objective of this study was to determine if AMPK can be activated in osteoblasts by known AMPK modulators and if AMPK activity is involved in osteoblast function in vitro and regulation of bone mass in vivo. ROS 17/2.8 rat osteoblast-like cells were cult...

  18. Inhibitory neurotransmission regulates vagal efferent activity and gastric motility.

    Science.gov (United States)

    McMenamin, Caitlin A; Travagli, R Alberto; Browning, Kirsteen N

    2016-06-01

    The gastrointestinal tract receives extrinsic innervation from both the sympathetic and parasympathetic nervous systems, which regulate and modulate the function of the intrinsic (enteric) nervous system. The stomach and upper gastrointestinal tract in particular are heavily influenced by the parasympathetic nervous system, supplied by the vagus nerve, and disruption of vagal sensory or motor functions results in disorganized motility patterns, disrupted receptive relaxation and accommodation, and delayed gastric emptying, amongst others. Studies from several laboratories have shown that the activity of vagal efferent motoneurons innervating the upper GI tract is inhibited tonically by GABAergic synaptic inputs from the adjacent nucleus tractus solitarius. Disruption of this influential central GABA input impacts vagal efferent output, hence gastric functions, significantly. The purpose of this review is to describe the development, physiology, and pathophysiology of this functionally dominant inhibitory synapse and its role in regulating vagally determined gastric functions. PMID:27302177

  19. [Polymethoxylated flavonoids activate cystic fibrosis transmembrane conductance regulator chloride channel].

    Science.gov (United States)

    Cao, Huan-Huan; Fang, Fang; Yu, Bo; Luan, Jian; Jiang, Yu; Yang, Hong

    2015-04-25

    Cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent chloride channel, plays key roles in fluid secretion in serous epithelial cells. Previously, we identified two polymethoxylated flavonoids, 3',4',5,5',6,7-hexamethoxyflavone (HMF) and 5-hydroxy-6,7,3',4'-tetramethoxyflavone (HTF) which could potentiate CFTR chloride channel activities. The present study was aimed to investigate the potentiation effects of HMF and HTF on CFTR Cl(-) channel activities by using a cell-based fluorescence assay and the short circuit Ussing chamber assay. The results of cell-based fluorescence assay showed that both HMF and HTF could dose-dependently potentiate CFTR Cl(-) channel activities in rapid and reversible ways, and the activations could be reversed by the CFTR blocker CFTRinh-172. Notably, HMF showed the highest affinity (EC50 = 2 μmol/L) to CFTR protein among the flavonoid CFTR activators identified so far. The activation of CFTR by HMF or HTF was forskolin (FSK) dependent. Both compounds showed additive effect with FSK and 3-Isobutyl-1-methylx (IBMX) in the activation of CFTR, while had no additive effect with genistein (GEN). In ex vivo studies, HMF and HTF could stimulate transepithelial Cl(-) secretion in rat colonic mucosa and enhance fluid secretion in mouse trachea submucosal glands. These results suggest that HMF and HTF may potentiate CFTR Cl(-) channel activities through both elevation of cAMP level and binding to CFTR protein pathways. The results provide new clues in elucidating structure and activity relationship of flavonoid CFTR activators. HMF might be developed as a new drug in the therapy of CFTR-related diseases such as bronchiectasis and habitual constipation. PMID:25896054

  20. Negative regulation of lymphocyte activation by the adaptor protein LAX.

    Science.gov (United States)

    Zhu, Minghua; Granillo, Olivia; Wen, Renren; Yang, Kaiyong; Dai, Xuezhi; Wang, Demin; Zhang, Weiguo

    2005-05-01

    The membrane-associated adaptor protein LAX is a linker for activation of T cells (LAT)-like molecule that is expressed in lymphoid tissues. Upon stimulation of T or B cells, it is phosphorylated and interacts with Grb2 and the p85 subunit of PI3K. LAX, however, is not capable of replacing LAT in the TCR signaling pathway. In this study we report that upon T or B cell activation, the LAX protein was up-regulated dramatically. Although disruption of the LAX gene by homologous recombination had no major impact on lymphocyte development, it caused a significant reduction in CD23 expression on mature B cells. Interestingly, naive LAX(-/-) mice had spontaneous germinal center formation. Compared with normal T and B cells, LAX(-/-) T and B cells were hyperresponsive and had enhanced calcium flux, protein tyrosine phosphorylation, MAPK and Akt activation, and cell survival upon engagement of the T or B AgRs. Our data demonstrate that LAX functions as a negative regulator in lymphocyte signaling.

  1. How Phosphorylation and ATPase Activity Regulate Anion Flux though the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR).

    Science.gov (United States)

    Zwick, Matthias; Esposito, Cinzia; Hellstern, Manuel; Seelig, Anna

    2016-07-01

    The cystic fibrosis transmembrane conductance regulator (CFTR, ABCC7), mutations of which cause cystic fibrosis, belongs to the ATP-binding cassette (ABC) transporter family and works as a channel for small anions, such as chloride and bicarbonate. Anion channel activity is known to depend on phosphorylation by cAMP-dependent protein kinase A (PKA) and CFTR-ATPase activity. Whereas anion channel activity has been extensively investigated, phosphorylation and CFTR-ATPase activity are still poorly understood. Here, we show that the two processes can be measured in a label-free and non-invasive manner in real time in live cells, stably transfected with CFTR. This study reveals three key findings. (i) The major contribution (≥90%) to the total CFTR-related ATP hydrolysis rate is due to phosphorylation by PKA and the minor contribution (≤10%) to CFTR-ATPase activity. (ii) The mutant CFTR-E1371S that is still conductive, but defective in ATP hydrolysis, is not phosphorylated, suggesting that phosphorylation requires a functional nucleotide binding domain and occurs in the post-hydrolysis transition state. (iii) CFTR-ATPase activity is inversely related to CFTR anion flux. The present data are consistent with a model in which CFTR is in a closed conformation with two ATPs bound. The open conformation is induced by ATP hydrolysis and corresponds to the post-hydrolysis transition state that is stabilized by phosphorylation and binding of chloride channel potentiators. PMID:27226582

  2. Dynamic regulation of Polycomb group activity during plant development.

    Science.gov (United States)

    Bemer, Marian; Grossniklaus, Ueli

    2012-11-01

    Polycomb group (PcG) complexes play important roles in phase transitions and cell fate determination in plants and animals, by epigenetically repressing sets of genes that promote either proliferation or differentiation. The continuous differentiation of new organs in plants, such as leaves or flowers, requires a highly dynamic PcG function, which can be induced, modulated, or repressed when necessary. In this review, we discuss the recent advance in understanding PcG function in plants and focus on the diverse molecular mechanisms that have been described to regulate and counteract PcG activity in Arabidopsis.

  3. Regulation of dopamine transporter activity by carboxypeptidase E

    Directory of Open Access Journals (Sweden)

    Zhang Heping

    2009-05-01

    Full Text Available Abstract Background The dopamine transporter (DAT plays a critical role in terminating the action of dopamine by rapid reuptake into the presynaptic neuron. Previous studies have revealed that the DAT carboxyl terminus (DAT-CT can directly interact with other cellular proteins and regulate DAT function and trafficking. Results Here, we have identified that carboxypeptidase E (CPE, a prohormone processing exopeptidase and sorting receptor for the regulated secretory pathway, interacts with the DAT-CT and affects DAT function. Mammalian cell lines coexpressing CPE and DAT exhibited increased DAT-mediated dopamine uptake activity compared to cells expressing DAT alone. Moreover, coexpression of an interfering DAT-CT minigene inhibited the effects of CPE on DAT. Functional changes caused by CPE could be attributed to enhanced DAT expression and subsequent increase in DAT cell surface localization, due to decreased DAT degradation. In addition, CPE association could reduce the phosphorylation state of DAT on serine residues, potentially leading to reduced internalization, thus stabilizing plasmalemmal DAT localization. Conclusion Taken together, our results reveal a novel role for CPE in the regulation of DAT trafficking and DAT-mediated DA uptake, which may provide a novel target in the treatment of dopamine-governed diseases such as drug addiction and obesity.

  4. Regulation of seasonal reproduction by hypothalamic activation of thyroid hormone

    Directory of Open Access Journals (Sweden)

    Ai eShinomiya

    2014-02-01

    Full Text Available Organisms living outside the tropics measure the changes in the length of the day to adapt to seasonal changes in the environment. Animals that breed during spring and summer are called long-day breeders, while those that breed during fall are called short-day breeders. Although the influence of thyroid hormone in the regulation of seasonal reproduction has been known for several decades, its precise mechanism remained unknown. Recent studies revealed that the activation of thyroid hormone within the mediobasal hypothalamus (MBH plays a key role in this phenomenon. This localized activation of the thyroid hormone is controlled by thyrotropin (thyroid-stimulating hormone, TSH secreted from the pars tuberalis of the pituitary gland. Although seasonal reproduction is a rate-limiting factor in animal production, genes involved in photoperiodic signal transduction pathway could emerge as potential targets to facilitate domestication.

  5. Osteoblast differentiation and migration are regulated by dynamin GTPase activity.

    Science.gov (United States)

    Eleniste, Pierre P; Huang, Su; Wayakanon, Kornchanok; Largura, Heather W; Bruzzaniti, Angela

    2014-01-01

    Bone formation is controlled by osteoblasts, but the signaling proteins that control osteoblast differentiation and function are still unclear. We examined if the dynamin GTPase, which is associated with actin remodeling and migration in other cells, plays a role in osteoblast differentiation and migration. Dynamin mRNA was expressed in primary osteoblasts throughout differentiation (0-21 days). However, alkaline phosphatase (ALP) activity, a marker of osteoblast differentiation, was decreased in osteoblasts over-expressing dynamin. Conversely, ALP activity was increased following shRNA-mediated knockdown of dynamin and in osteoblasts treated with the dynamin inhibitor, dynasore. Dynasore also reduced c-fos and osterix expression, markers of early osteoblasts, suggesting a role for dynamin in pre-osteoblast to osteoblast differentiation. Since dynamin GTPase activity is regulated by tyrosine phosphorylation, we examined the mechanism of dynamin dephosphorylation in osteoblasts. Dynamin formed a protein complex with the tyrosine phosphatase PTP-PEST and inhibition of phosphatase activity increased the level of phosphorylated dynamin. Further, PTP-PEST blocked the Src-mediated increase in the phosphorylation and GTPase activity of wild-type dynamin but not the phosphorylation mutant dynY231F/Y597F. Although ALP activity was increased in osteoblasts expressing GTPase-defective dynK44A, and to a lesser extent dynY231F/Y597F, osteoblast migration was significantly inhibited by dynK44A and dynY231F/Y597F. These studies demonstrate a novel role for dynamin GTPase activity and phosphorylation in osteoblast differentiation and migration, which may be important for bone formation. PMID:24387844

  6. Legal Instruments of Regulation of Development of Banking Activity in Ukraine

    OpenAIRE

    Senyshch Pavlo M.

    2014-01-01

    The article considers main approaches to identification of essence of legal instruments of regulation of development of the banking activity, identifies the mechanism of legal regulation of the banking activity and its elements and justifies the system and form of legal regulation of the banking activity in Ukraine. It describes subjects of legal regulation of the banking activity at the international level, which are the Basel Committee on Banking Supervision, European Central Bank, IMF, Int...

  7. Regulation of TLR3 Activation by S100A9.

    Science.gov (United States)

    Tsai, Su-Yu; Segovia, Jesus A; Chang, Te-Hung; Shil, Niraj K; Pokharel, Swechha M; Kannan, T R; Baseman, Joel B; Defrêne, Joan; Pagé, Nathalie; Cesaro, Annabelle; Tessier, Philippe A; Bose, Santanu

    2015-11-01

    Recognition of viral dsRNA by endosomal TLR3 activates innate immune response during virus infection. Trafficking of TLR3 to the endolysosomal compartment arising from fusion of late endosome (LE) with lysosome is required for recognition and detection of pathogen associated molecular patterns, which results in activation of the TLR3-dependent signaling cascade. Existing knowledge about the mechanism(s) and cellular factor(s) governing TLR3 trafficking is limited. In the current study, we identified intracellular S100A9 protein as a critical regulator of TLR3 trafficking. S100A9 was required for maturation of TLR3 containing early endosome (EE) into LE, the compartment that fuses with lysosome to form the endolysosomal compartment. A drastic reduction in cytokine production was observed in S100A9-knockout (KO) primary macrophages following RNA virus infection and treatment of cells with polyinosinic-polycytidylic acid (polyIC; a dsRNA mimetic that acts as a TLR3 agonist). Mechanistic studies revealed colocalization and interaction of S100A9 with TLR3 following polyIC treatment. S100A9-TLR3 interaction was critical for maturation of TLR3 containing EE into LE because TLR3 could not be detected in the LE of polyIC-treated S100A9-KO macrophages. Subsequently, TLR3 failed to colocalize with its agonist (i.e., biotin-labeled polyIC) in S100A9-deficient macrophages. The in vivo physiological role of S100A9 was evident from loss of cytokine production in polyIC-treated S100A9-KO mice. Thus, we identified intracellular S100A9 as a regulator of TLR3 signaling and demonstrated that S100A9 functions during pre-TLR3 activation stages by facilitating maturation of TLR3 containing EE into LE. PMID:26385519

  8. DMPD: Receptor tyrosine kinases and the regulation of macrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14726496 Receptor tyrosine kinases and the regulation of macrophage activation. Cor...(.csml) Show Receptor tyrosine kinases and the regulation of macrophage activation. PubmedID 14726496 Title ...Receptor tyrosine kinases and the regulation of macrophage activation. Authors Co

  9. Drug Discovery against Psoriasis: Identification of a New Potent FMS-like Tyrosine Kinase 3 (FLT3) Inhibitor, 1-(4-((1H-Pyrazolo[3,4-d]pyrimidin-4-yl)oxy)-3-fluorophenyl)-3-(5-(tert-butyl)isoxazol-3-yl)urea, That Showed Potent Activity in a Psoriatic Animal Model.

    Science.gov (United States)

    Li, Guo-Bo; Ma, Shuang; Yang, Ling-Ling; Ji, Sen; Fang, Zhen; Zhang, Guo; Wang, Li-Jiao; Zhong, Jie-Min; Xiong, Yu; Wang, Jiang-Hong; Huang, Shen-Zhen; Li, Lin-Li; Xiang, Rong; Niu, Dawen; Chen, Ying-Chun; Yang, Sheng-Yong

    2016-09-22

    Psoriasis is a chronic T-cell-mediated autoimmune disease, and FMS-like tyrosine kinase 3 (FLT3) has been considered as a potential molecular target for the treatment of psoriasis. In this investigation, structural optimization was performed on a lead compound, 1-(4-(1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)phenyl)-3-(4-chloro-3-(trifluoromethyl)phenyl)urea (1), which showed a moderate inhibitory activity againt FLT3. A series of pyrazolo[3,4-d]pyrimidine derivatives were synthesized, and structure-activity relationship analysis led to the discovery of a number of potent FLT3 inhibitors. One of the most active compounds, 1-(4-(1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-3-fluorophenyl)-3-(5-tert-butylisoxazol-3-yl)urea (18b), was then chosen for in-depth antipsoriasis studies because this compound displayed the highest potency in a preliminary antipsoriasis test. Compound 18b exhibited significant antipsoriatic effects in the K14-VEGF transgenic mouse model of psoriasis, and no recurrence was found 15 days later after the last administration. Detailed mechanisms of action of compound 18b were also investigated. Collectively, compound 18b could be a potential drug candidate for psoriasis treatment.

  10. Regulation of Akt/PKB activity by P21-activated kinase in cardiomyocytes.

    Science.gov (United States)

    Mao, Kai; Kobayashi, Satoru; Jaffer, Zahara M; Huang, Yuan; Volden, Paul; Chernoff, Jonathan; Liang, Qiangrong

    2008-02-01

    Akt/PKB is a critical regulator of cardiac function and morphology, and its activity is governed by dual phosphorylation at active loop (Thr308) by phosphoinositide-dependent protein kinase-1 (PDK1) and at carboxyl-terminal hydrophobic motif (Ser473) by a putative PDK2. P21-activated kinase-1 (Pak1) is a serine/threonine protein kinase implicated in the regulation of cardiac hypertrophy and contractility and was shown previously to activate Akt through an undefined mechanism. Here we report Pak1 as a potential PDK2 that is essential for Akt activity in cardiomyocytes. Both Pak1 and Akt can be activated by multiple hypertrophic stimuli or growth factors in a phosphatidylinositol-3-kinase (PI3K)-dependent manner. Pak1 overexpression induces Akt phosphorylation at both Ser473 and Thr308 in cardiomyocytes. Conversely, silencing or inactivating Pak1 gene diminishes Akt phosphorylation in vitro and in vivo. Purified Pak1 can directly phosphorylate Akt only at Ser473, suggesting that Pak1 may be a relevant PDK2 responsible for AKT Ser473 phosphorylation in cardiomyocytes. In addition, Pak1 protects cardiomyocytes from cell death, which is blocked by Akt inhibition. Our results connect two important regulators of cellular physiological functions and provide a potential mechanism for Pak1 signaling in cardiomyocytes. PMID:18054038

  11. Vimentin regulates activation of the NLRP3 inflammasome

    Science.gov (United States)

    Dos Santos, Gimena; Rogel, Micah R.; Baker, Margaret A.; Troken, James R.; Urich, Daniela; Morales-Nebreda, Luisa; Sennello, Joseph A.; Kutuzov, Mikhail A.; Sitikov, Albert; Davis, Jennifer M.; Lam, Anna P.; Cheresh, Paul; Kamp, David; Shumaker, Dale K.; Budinger, G. R. Scott; Ridge, Karen M.

    2015-03-01

    Activation of the NLRP3 inflammasome and subsequent maturation of IL-1β have been implicated in acute lung injury (ALI), resulting in inflammation and fibrosis. We investigated the role of vimentin, a type III intermediate filament, in this process using three well-characterized murine models of ALI known to require NLRP3 inflammasome activation. We demonstrate that central pathophysiologic events in ALI (inflammation, IL-1β levels, endothelial and alveolar epithelial barrier permeability, remodelling and fibrosis) are attenuated in the lungs of Vim-/- mice challenged with LPS, bleomycin and asbestos. Bone marrow chimeric mice lacking vimentin have reduced IL-1β levels and attenuated lung injury and fibrosis following bleomycin exposure. Furthermore, decreased active caspase-1 and IL-1β levels are observed in vitro in Vim-/- and vimentin-knockdown macrophages. Importantly, we show direct protein-protein interaction between NLRP3 and vimentin. This study provides insights into lung inflammation and fibrosis and suggests that vimentin may be a key regulator of the NLRP3 inflammasome.

  12. Substrate regulation of ascorbate transport activity in astrocytes

    International Nuclear Information System (INIS)

    Astrocytes possess a concentrative L-ascorbate (vitamin C) uptake mechanism involving a Na(+)-dependent L-ascorbate transporter located in the plasma membrane. The present experiments examined the effects of deprivation and supplementation of extracellular L-ascorbate on the activity of this transport system. Initial rates of L-ascorbate uptake were measured by incubating primary cultures of rat astrocytes with L-[14C]ascorbate for 1 min at 37 degrees C. We observed that the apparent maximal rate of uptake (Vmax) increased rapidly (less than 1 h) when cultured cells were deprived of L-ascorbate. In contrast, there was no change in the apparent affinity of the transport system for L-[14C]ascorbate. The increase in Vmax was reversed by addition of L-ascorbate, but not D-isoascorbate, to the medium. The effects of external ascorbate on ascorbate transport activity were specific in that preincubation of cultures with L-ascorbate did not affect uptake of 2-deoxy-D-[3H(G)]glucose. We conclude that the astroglial ascorbate transport system is modulated by changes in substrate availability. Regulation of transport activity may play a role in intracellular ascorbate homeostasis by compensating for regional differences and temporal fluctuations in external ascorbate levels

  13. Parkin Regulates the Activity of Pyruvate Kinase M2.

    Science.gov (United States)

    Liu, Kun; Li, Fanzhou; Han, Haichao; Chen, Yue; Mao, Zebin; Luo, Jianyuan; Zhao, Yingming; Zheng, Bin; Gu, Wei; Zhao, Wenhui

    2016-05-01

    Parkin, a ubiquitin E3 ligase, is mutated in most cases of autosomal recessive early onset Parkinson disease. It was discovered that Parkin is also mutated in glioblastoma and other human malignancies and that it inhibits tumor cell growth. Here, we identified pyruvate kinase M2 (PKM2) as a unique substrate for parkin through biochemical purification. We found that parkin interacts with PKM2 both in vitro and in vivo, and this interaction dramatically increases during glucose starvation. Ubiquitylation of PKM2 by parkin does not affect its stability but decreases its enzymatic activity. Parkin regulates the glycolysis pathway and affects the cell metabolism. Our studies revealed the novel important roles of parkin in tumor cell metabolism and provided new insight for therapy of Parkinson disease. PMID:26975375

  14. Effects of Online Self-Regulation Activities on Physical Activity Among Pregnant and Early Postpartum Women.

    Science.gov (United States)

    Kim, Hye Kyung; Niederdeppe, Jeff; Graham, Meredith; Olson, Christine; Gay, Geri

    2015-01-01

    Physical and psychological changes that occur during pregnancy present a unique challenge for women's physical activity. Using a theory-based prospective design, this study examines the effects of pregnant women's (a) physical activity cognitions (self-efficacy, outcome expectancy, and safety beliefs) and (b) online self-regulation activities (goal-setting and self-monitoring) on subsequent changes in their physical activity intentions and behavior during pregnancy and immediately postpartum. The authors used data from three panel surveys administered to pregnant women enrolled in a web-based intervention to promote healthy pregnancy and postpartum weight, as well as log data on their use of self-regulatory features on the intervention website. Perceived self-efficacy and perceived safety of physical activity in pregnancy enhanced subsequent intentions to be physically active. Repeated goal-setting and monitoring of those goals helped to maintain positive intentions during pregnancy, but only repeated self-monitoring transferred positive intentions into actual behavior. Theoretically, this study offers a better understanding of the roles of self-regulation activities in the processes of goal-striving. The authors also discuss practical implications for encouraging physical activity among pregnant and early postpartum women.

  15. Regulation of sucrose metabolism in higher plants: localization and regulation of activity of key enzymes

    Science.gov (United States)

    Winter, H.; Huber, S. C.; Brown, C. S. (Principal Investigator)

    2000-01-01

    Sucrose (Suc) plays a central role in plant growth and development. It is a major end product of photosynthesis and functions as a primary transport sugar and in some cases as a direct or indirect regulator of gene expression. Research during the last 2 decades has identified the pathways involved and which enzymes contribute to the control of flux. Availability of metabolites for Suc synthesis and 'demand' for products of sucrose degradation are important factors, but this review specifically focuses on the biosynthetic enzyme sucrose-phosphate synthase (SPS), and the degradative enzymes, sucrose synthase (SuSy), and the invertases. Recent progress has included the cloning of genes encoding these enzymes and the elucidation of posttranslational regulatory mechanisms. Protein phosphorylation is emerging as an important mechanism controlling SPS activity in response to various environmental and endogenous signals. In terms of Suc degradation, invertase-catalyzed hydrolysis generally has been associated with cell expansion, whereas SuSy-catalyzed metabolism has been linked with biosynthetic processes (e.g., cell wall or storage products). Recent results indicate that SuSy may be localized in multiple cellular compartments: (1) as a soluble enzyme in the cytosol (as traditionally assumed); (2) associated with the plasma membrane; and (3) associated with the actin cytoskeleton. Phosphorylation of SuSy has been shown to occur and may be one of the factors controlling localization of the enzyme. The purpose of this review is to summarize some of the recent developments relating to regulation of activity and localization of key enzymes involved in sucrose metabolism in plants.

  16. Regulation of ALF promoter activity in Xenopus oocytes.

    Directory of Open Access Journals (Sweden)

    Dan Li

    Full Text Available BACKGROUND: In this report we evaluate the use of Xenopus laevis oocytes as a matched germ cell system for characterizing the organization and transcriptional activity of a germ cell-specific X. laevis promoter. PRINCIPAL FINDINGS: The promoter from the ALF transcription factor gene was cloned from X. laevis genomic DNA using a PCR-based genomic walking approach. The endogenous ALF gene was characterized by RACE and RT-PCR for transcription start site usage, and by sodium bisulfite sequencing to determine its methylation status in somatic and oocyte tissues. Homology between the X. laevis ALF promoter sequence and those from human, chimpanzee, macaque, mouse, rat, cow, pig, horse, dog, chicken and X. tropicalis was relatively low, making it difficult to use such comparisons to identify putative regulatory elements. However, microinjected promoter constructs were very active in oocytes and the minimal promoter could be narrowed by PCR-mediated deletion to a region as short as 63 base pairs. Additional experiments using a series of site-specific promoter mutants identified two cis-elements within the 63 base pair minimal promoter that were critical for activity. Both elements (A and B were specifically recognized by proteins present in crude oocyte extracts based on oligonucleotide competition assays. The activity of promoter constructs in oocytes and in transfected somatic Xenopus XLK-WG kidney epithelial cells was quite different, indicating that the two cell types are not functionally equivalent and are not interchangeable as assay systems. CONCLUSIONS: Overall the results provide the first detailed characterization of the organization of a germ cell-specific Xenopus promoter and demonstrate the feasibility of using immature frog oocytes as an assay system for dissecting the biochemistry of germ cell gene regulation.

  17. Enzymatic Regulation of Steroidogenesis and Nuclear Receptor Activation : Special Focus on Vitamin D and Sex Hormones

    OpenAIRE

    LUNDQVIST, JOHAN

    2011-01-01

    Enzyme-catalyzed reactions are important to regulate steroidogenesis and nuclear receptor activation. The present investigation examines the role of steroid metabolism catalyzed by CYP7B1 for regulation of hormone receptor activation and the effects of vitamin D on enzymatic regulation of steroidogenesis. The study reports data indicating that CYP7B1 can regulate estrogenic signaling by converting estrogens into inactive or less active metabolites. Similar results were obtained for CYP7B1-med...

  18. Sucking pump activity in feeding behaviour regulation in carpenter ants.

    Science.gov (United States)

    Falibene, Agustina; Gontijo, Alberto de Figueiredo; Josens, Roxana

    2009-06-01

    Modulation of liquid feeding-rate would allow insects to ingest more food in the same time when this was required. Ants can vary nectar intake rate by increasing sucking pump frequency according to colony requirements. We analysed electrical signals generated by sucking pump activity of ants during drinking solutions of different sucrose concentrations and under different carbohydrate-deprivation levels. Our aim was to define parameters that characterize the recordings and analyse their relationship with feeding behaviour. Signals showed that the initial and final frequencies of sucking pump activity, as well as the difference between them were higher in sugar-deprived ants. However, these parameters were not influenced by sucrose solution concentration, which affected the number of pump contractions and the volume per contraction. Unexpectedly, we found two different responses in feeding behaviour of starved and non-starved ants depending on concentration. Starved ants drank dilute solutions for the same length of time as non-starved ants but ingested higher volumes. While drinking the concentrated solutions, starved ants drank the same volume, but did so in a shorter time than the non-starved ones. Despite these differences, for each analysed concentration the total number of pump contractions remained constant independently of sugar-deprivation level. These results are discussed in the frame of feeding regulation and decision making in ant foraging behaviour. PMID:19217950

  19. Sucking pump activity in feeding behaviour regulation in carpenter ants.

    Science.gov (United States)

    Falibene, Agustina; Gontijo, Alberto de Figueiredo; Josens, Roxana

    2009-06-01

    Modulation of liquid feeding-rate would allow insects to ingest more food in the same time when this was required. Ants can vary nectar intake rate by increasing sucking pump frequency according to colony requirements. We analysed electrical signals generated by sucking pump activity of ants during drinking solutions of different sucrose concentrations and under different carbohydrate-deprivation levels. Our aim was to define parameters that characterize the recordings and analyse their relationship with feeding behaviour. Signals showed that the initial and final frequencies of sucking pump activity, as well as the difference between them were higher in sugar-deprived ants. However, these parameters were not influenced by sucrose solution concentration, which affected the number of pump contractions and the volume per contraction. Unexpectedly, we found two different responses in feeding behaviour of starved and non-starved ants depending on concentration. Starved ants drank dilute solutions for the same length of time as non-starved ants but ingested higher volumes. While drinking the concentrated solutions, starved ants drank the same volume, but did so in a shorter time than the non-starved ones. Despite these differences, for each analysed concentration the total number of pump contractions remained constant independently of sugar-deprivation level. These results are discussed in the frame of feeding regulation and decision making in ant foraging behaviour.

  20. Notch1 regulated autophagy controls survival and suppressor activity of activated murine T-regulatory cells

    Science.gov (United States)

    Marcel, Nimi; Sarin, Apurva

    2016-01-01

    Cell survival is one of several processes regulated by the Notch pathway in mammalian cells. Here we report functional outcomes of non-nuclear Notch signaling to activate autophagy, a conserved cellular response to nutrient stress, regulating survival in murine natural T-regulatory cells (Tregs), an immune subset controlling tolerance and inflammation. Induction of autophagy required ligand-dependent, Notch intracellular domain (NIC) activity, which controlled mitochondrial organization and survival of activated Tregs. Consistently, NIC immune-precipitated Beclin and Atg14, constituents of the autophagy initiation complex. Further, ectopic expression of an effector of autophagy (Atg3) or recombinant NIC tagged to a nuclear export signal (NIC-NES), restored autophagy and suppressor function in Notch1-/- Tregs. Furthermore, Notch1 deficiency in the Treg lineage resulted in immune hyperactivity, implicating Notch activity in Treg homeostasis. Notch1 integration with autophagy, revealed in these experiments, holds implications for Notch regulated cell-fate decisions governing differentiation. DOI: http://dx.doi.org/10.7554/eLife.14023.001 PMID:27267497

  1. Regulation of prolactin in mice with altered hypothalamic melanocortin activity.

    Science.gov (United States)

    Dutia, Roxanne; Kim, Andrea J; Mosharov, Eugene; Savontaus, Eriika; Chua, Streamson C; Wardlaw, Sharon L

    2012-09-01

    This study used two mouse models with genetic manipulation of the melanocortin system to investigate prolactin regulation. Mice with overexpression of the melanocortin receptor (MC-R) agonist, α-melanocyte-stimulating hormone (Tg-MSH) or deletion of the MC-R antagonist agouti-related protein (AgRP KO) were studied. Male Tg-MSH mice had lower blood prolactin levels at baseline (2.9±0.3 vs. 4.7±0.7ng/ml) and after restraint stress (68±6.5 vs. 117±22ng/ml) vs. WT (pprolactin content was not different. Blood prolactin was also decreased in male AgRP KO mice at baseline (4.2±0.5 vs. 7.6±1.3ng/ml) and after stress (60±4.5 vs. 86.1±5.7ng/ml) vs. WT (pprolactin content was lower in male AgRP KO mice (4.3±0.3 vs. 6.7±0.5μg/pituitary, pprolactin levels were observed in female AgRP KO mice vs. WT. Hypothalamic dopamine activity was assessed as the potential mechanism responsible for changes in prolactin levels. Hypothalamic tyrosine hydroxylase mRNA was measured in both genetic models vs. WT mice and hypothalamic dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) content were measured in male AgRP KO and WT mice but neither were significantly different. However, these results do not preclude changes in dopamine activity as dopamine turnover was not directly investigated. This is the first study to show that baseline and stress-induced prolactin release and pituitary prolactin content are reduced in mice with genetic alterations of the melanocortin system and suggests that changes in hypothalamic melanocortin activity may be reflected in measurements of serum prolactin levels.

  2. Effects of angiotensin Ⅱ receptor antagonist on expression of plasminogen activator inhibitor-1 in the renal biopsy of patients with chronic kidney disease%血管紧张素Ⅱ受体拮抗剂对慢性肾脏病患者肾组织中纤溶酶原激活物抑制物-1表达的影响

    Institute of Scientific and Technical Information of China (English)

    王文革; 李侠

    2010-01-01

    Objective To evaluate the effects of angiotensin Ⅱreceptor antagonist (ARB) on expression of plasminogen activator inhibitor(PAI)-1 in the human renal biopsy of patients with chronic kidney disease(CKD)and analyse its clinical significance.Methods PAI-1 expression of 63 specimens with CKD was detected by immunohistochemistry and quantitative analysis was achieved by image analysis system. meanwhile, the patients'clinical data were collected,and PAI-1 expression of 63 specimens with CKD was compared with that of normal renal tissue(19 cases).Results Compared with the normal renal tissue,the expression of PAI-1 in CKD 1,2 and 3 stage wag respectively drastically increased(P<0.05).The expression of PAI-1 in CKD 3 stage was higher than that in CKD 1 and 2 stage(P<0.05).The expression of PAI-1 in the patients treated by valsartan[renal corpuscle(4.73±1.18)%,renal tubule(37.16±6.81)%]was lower than that with no treatment[renal corpuscle(5.81±1.95)%,renal tubule(43.22 ±10.25)%](P<0.05).Conclusions It suggests that the abnormal expression of PAI-1 in CKD play an important role in the progression of glomerular and tubulointerstitiai sclerosis in patients with CKD.ARB may prevent the development of renal inflammation and sclerosis by inhibiting the production of PAI-1.ARB may contribute to the prevention and therapy of CKD.%目的 探讨血管紧张索Ⅱ受体拮抗剂(ARB)对慢性肾脏病(CKD)患者肾组织中纤溶酶原激活物抑制物(PAI)-1表达的影响及临床意义.方法 采用免疫组化法检测63例CKD患者肾穿刺标本中PAI-1的表达水平,用图像分析法对PAI-1进行定量测定,同时收集患者的相关临床资料,并与因肾肿瘤切除肾脏的远离肿瘤部分的正常肾组织19例比较.结果 CKD 1、2、3期患者PAI-1在肾组织中的表达均较正常肾组织显著增多(P<0.05);而CKD 3期患者PAI-1在肾组织中的表达明显高于CKDI期和2期患者(P<0.05).应用缬沙坦治疗的CKD 16例患者肾组织中PAI-1

  3. Proteomic Profiling of Differentially Expressed Proteins from Bax inhibitor-1 Knockout and Wild Type Mice

    OpenAIRE

    Li, Bo; John C Reed; Kim, Hyung-Ryong; Chae, Han-Jung

    2012-01-01

    Bax inhibitor-1 (BI-1) is an anti-apoptotic protein located in the endoplasmic reticulum (ER). The role of BI-1 has been studied in different physiopathological models including ischemia, diabetes, liver regeneration and cancer. However, fundamental knowledge about the effects of BI-1 deletion on the proteome is lacking. To further explore this protein, we compared the levels of different proteins in bi-1−/− and bi-1+/+ mouse tissues by two-dimensional electrophoresis (2-DE) and mass spectrom...

  4. German National Galileo Public Regulated Service (PRS) Testing Activities

    Science.gov (United States)

    Habrich, Heinz; Söhne, Wolfgang

    2013-04-01

    The European Global Navigation System (GNSS) Galileo is going to be established in the near future. Currently, four satellites are in place forming the In-Orbit-Testing (IOT) phase. Within the next years, the constellation will be filled. Full Operational Capability (FOC) will be reached 2019. Beside the Open Service (OS) which is comparable to other OS of existing GNSS, e.g., GPS C/A, there is a so-called Public Regulated Service (PRS) included in the IOT satellites already. The PRS will have improved robustness, i.e. robust signals which will be resistant against involuntary interferences, jamming and spoofing. The PRS signal is encrypted and there will be a restricted access to authorized users, e.g. safety and emergency services, authorities with security task, critical infrastructure organizations etc. The access to the PRS which will be controlled through a special key management will be managed and supervised within the European Union (EU) Member States (MS) by national authorities, the Competent PRS Authority (CPA). But a set of Common Minimum Standards (CMS) will define the minimum requirements applicable to each PRS participant. Nevertheless, each MS is responsible for its national key management. This presentation will inform about the testing activities for Galileo PRS in Germany. The coarse concept for the testing is explained, the schedule is outlined. Finally, the paper will formulate some expectations to the Galileo PRS, e.g. for international cooperation.

  5. Plasma plasminogen activator inhibitor-1 predicts myocardial infarction in HIV-1-infected individuals

    DEFF Research Database (Denmark)

    Knudsen, Andreas; Katzenstein, Terese L; Benfield, Thomas;

    2014-01-01

    (PAI-1) were measured using a Luminex assay in plasma samples from routine visits both 12 and 2 months prior to the case patient's MI. RESULTS: The two groups had similar HIV characteristics and traditional cardiovascular risk factors. In univariate analysis, PAI-1 levels were associated with MI......OBJECTIVES: Biomarkers of endothelial dysfunction, inflammation and coagulation are associated with atherosclerosis and cardiovascular disease, but their association and possible predictive value remain controversial among HIV-1-infected individuals. We sought to investigate the association of...... seven biomarkers with first-time myocardial infarction (MI) in an HIV-1-infected population. DESIGN: A matched case-control study of 54 cases and 54 controls. METHODS: We compared 54 HIV-1-infected patients with verified first-time MI and 54 HIV-1-infected controls matched for age, duration of...

  6. Plasminogen activator inhibitor-1 deficient mice are protected from angiotensin II-induced fibrosis

    OpenAIRE

    Beier, Juliane I.; Kaiser, J. Phillip; Guo, Luping; Martínez-Maldonado, Manuel; Arteel, Gavin E.

    2011-01-01

    PAI-1 has been shown to be both profibrotic and antifibrotic in animal models of hepatic fibrosis. Although these models have similarities to human fibrotic liver disease, no rodent model completely recapitulates the clinical situation; indeed, transaminase values in most models of hepatic fibrosis are much higher than in chronic liver diseases in humans. Here, wild-type and PAI-1−/− mice were administered AngII (500 ng/kg/min) for 4 weeks. ECM accumulation was evaluated by Sirius red stainin...

  7. Cystatin F regulates proteinase activity in IL-2-activated natural killer cells.

    Science.gov (United States)

    Maher, Katarina; Konjar, Spela; Watts, Colin; Turk, Boris; Kopitar-Jerala, Natasa

    2014-01-01

    Cystatin F is a unique member of the cystatin family of cysteine protease inhibitors, which is synthesized as an inactive dimer and it is activated by N-terminal cleavage in the endolysosomes. It is expressed in the cells of the immune system: myeloid cells and the cells involved in target cell killing: natural killer (NK) cells and cytotoxic T cells (CTLs). Upon activation of the NK cells with interleukin 2 (IL-2), cystatin F was found upregulated and co-localized in cytotoxic granules with cathepsin C (CatC) and CatV. However, cystatin F inhibits the CatC in cells only when its N-terminal part is processed. Although cystatin F could inhibit both CatV and CatC, the IL-2 stimulation of the YT cells resulted in an increased CatV activity, while the CatC activity was unchanged. The incubation of IL-2 activated NK cells with a cysteine proteinase inhibitor E-64d increased the cystatin F dimer formation. Our results suggest that cystatin F not only inhibits CatV, but it is processed by the CatV in order to inhibit the CatC activity in cytotoxic granules. The regulation of the CatC activity in the cytotoxic granules of the NK cells by the cystatin F could be important for the processing and activation of granule-associated serine proteases - granzymes.

  8. NMDA receptor activation regulates sociability by its effect on mTOR signaling activity.

    Science.gov (United States)

    Burket, Jessica A; Benson, Andrew D; Tang, Amy H; Deutsch, Stephen I

    2015-07-01

    Tuberous Sclerosis Complex is one example of a syndromic form of autism spectrum disorder associated with disinhibited activity of mTORC1 in neurons (e.g., cerebellar Purkinje cells). mTORC1 is a complex protein possessing serine/threonine kinase activity and a key downstream molecule in a signaling cascade beginning at the cell surface with the transduction of neurotransmitters (e.g., glutamate and acetylcholine) and nerve growth factors (e.g., Brain-Derived Neurotrophic Factor). Interestingly, the severity of the intellectual disability in Tuberous Sclerosis Complex may relate more to this metabolic disturbance (i.e., overactivity of mTOR signaling) than the density of cortical tubers. Several recent reports showed that rapamycin, an inhibitor of mTORC1, improved sociability and other symptoms in mouse models of Tuberous Sclerosis Complex and autism spectrum disorder, consistent with mTORC1 overactivity playing an important pathogenic role. NMDA receptor activation may also dampen mTORC1 activity by at least two possible mechanisms: regulating intraneuronal accumulation of arginine and the phosphorylation status of a specific extracellular signal regulating kinase (i.e., ERK1/2), both of which are "drivers" of mTORC1 activity. Conceivably, the prosocial effects of targeting the NMDA receptor with agonists in mouse models of autism spectrum disorders result from their ability to dampen mTORC1 activity in neurons. Strategies for dampening mTORC1 overactivity by NMDA receptor activation may be preferred to its direct inhibition in chronic neurodevelopmental disorders, such as autism spectrum disorders.

  9. Collagen I-induced dendritic cells activation is regulated by TNF- production through down-regulation of IRF4

    Indian Academy of Sciences (India)

    Barun Poudel; Hyeon-Hui Ki; Young-Mi Lee; Dae-Ki Kim

    2015-03-01

    Previously we have shown that collagen I enhances the maturation and function of dendritic cells (DCs). Inflammatory mediators such as tumour necrosis factor (TNF)-, interleukin (IL)-1 and lipopolysaccharide (LPS) are also known to activate DCs. Here we investigated the involvement of TNF- on the collagen I-induced DCs activation. TNF-a neutralization inhibited collagen I-induced IL-12 secretions by DCs. Additionally, we observed suppression of collagen I-induced costimulatory molecules expression along with down-regulation of genes involved in DCs activation pathway. Furthermore, TNF- inhibition upon collagen Istimulation up-regulated the expression of interferon regulatory transcription factor IRF4, when compared to collagen I only treated cells. Collectively, our data demonstrate that collagen I induce TNF- production, which is crucial for the activation and function of DCs, through down-regulation of IRF4, and implicates the importance in development of anti- TNF- therapeutics for several inflammatory diseases.

  10. Adoption Activities on the Internet: A Call for Regulation

    Science.gov (United States)

    Roby, Jini L.; White, Holly

    2010-01-01

    There is a growing practice of adoption services on the Internet with varying degrees of regulation, depending on whether it is domestic infant adoption, public foster care adoption, or international adoption. Regulation is particularly lacking in domestic infant adoptions, with Web sites connecting prospective birth and adoptive parents,…

  11. Cutaneous Human Papillomaviruses Down-regulate AKT1, whereas AKT2 Up-regulation and Activation Associates with Tumors

    OpenAIRE

    O'Shaughnessy, Ryan F L; Akgũl, Baki; Storey, Alan; Pfister, Herbert; Harwood, Catherine A; Byrne, Carolyn

    2007-01-01

    Epithelial tumorigenesis has been linked to AKT up-regulation. Human papillomaviruses (HPV) cause anogenital cancers and anogenital HPV infection up-regulates AKT activity. Mounting evidence points to a role for cutaneous HPVs as etiologic factors in skin tumorigenesis. High-risk cutaneous β HPVs have been linked to carcinogenesis in immunosuppressed patients, and high-risk cutaneous HPV8 genes enhance tumorigenesis in transgenic mice. We find that, in contrast to anogenital HPVs, cutaneous H...

  12. AMP-activated protein kinase (AMPK) activation regulates in vitro bone formation and bone mass.

    Science.gov (United States)

    Shah, M; Kola, B; Bataveljic, A; Arnett, T R; Viollet, B; Saxon, L; Korbonits, M; Chenu, C

    2010-08-01

    Adenosine 5'-monophosphate-activated protein kinase (AMPK), a regulator of energy homeostasis, has a central role in mediating the appetite-modulating and metabolic effects of many hormones and antidiabetic drugs metformin and glitazones. The objective of this study was to determine if AMPK can be activated in osteoblasts by known AMPK modulators and if AMPK activity is involved in osteoblast function in vitro and regulation of bone mass in vivo. ROS 17/2.8 rat osteoblast-like cells were cultured in the presence of AMPK activators (AICAR and metformin), AMPK inhibitor (compound C), the gastric peptide hormone ghrelin and the beta-adrenergic blocker propranolol. AMPK activity was measured in cell lysates by a functional kinase assay and AMPK protein phosphorylation was studied by Western Blotting using an antibody recognizing AMPK Thr-172 residue. We demonstrated that treatment of ROS 17/2.8 cells with AICAR and metformin stimulates Thr-172 phosphorylation of AMPK and dose-dependently increases its activity. In contrast, treatment of ROS 17/2.8 cells with compound C inhibited AMPK phosphorylation. Ghrelin and propranolol dose-dependently increased AMPK phosphorylation and activity. Cell proliferation and alkaline phosphatase activity were not affected by metformin treatment while AICAR significantly inhibited ROS 17/2.8 cell proliferation and alkaline phosphatase activity at high concentrations. To study the effect of AMPK activation on bone formation in vitro, primary osteoblasts obtained from rat calvaria were cultured for 14-17days in the presence of AICAR, metformin and compound C. Formation of 'trabecular-shaped' bone nodules was evaluated following alizarin red staining. We demonstrated that both AICAR and metformin dose-dependently increase trabecular bone nodule formation, while compound C inhibits bone formation. When primary osteoblasts were co-treated with AICAR and compound C, compound C suppressed the stimulatory effect of AICAR on bone nodule formation

  13. A specific, transmembrane interface regulates fibroblast activation protein (FAP) homodimerization, trafficking and exopeptidase activity.

    Science.gov (United States)

    Wonganu, Benjamaporn; Berger, Bryan W

    2016-08-01

    Fibroblast activation protein (FAP) is a cell-surface serine protease which promotes invasiveness of certain epithelial cancers and is therefore a potential target for cancer drug development and delivery. Unlike dipeptidyl peptidase IV (DPPIV), FAP exhibits prolyl endopeptidase activity and is active as a homodimer with specificity for type I collagen. The mechanism that regulates FAP homodimerization and its relation to prolyl endopeptidase activity is not completely understood. Here, we investigate key residues in the FAP TM domain that may be significant for FAP homodimerization. Mutations to predicted TM interfacial residues (G10L, S14L, and A18L) comprising a small-X3-small motif reduced FAP TM-CYTO dimerization relative to wild type as measured using the AraTM assay, whereas predicted off-interface residues showed no significant change from wild type. The results implied that the predicted small-X3-small dimer interface affect stabilization of FAP TM-CYTO homodimerization. Compared with FAPwild-type, the interfacial TM residue G10L significantly decreased FAP endopeptidase activity more than 25%, and also reduced cell-surface versus intracellular expression relative to other interfacial residues S14L and A18L. Thus, our results suggest FAP dimerization is important for both trafficking and protease activity, and is dependent on a specific TM interface. PMID:27155568

  14. Arabidopsis PROTEASOME REGULATOR1 is required for auxin-mediated suppression of proteasome activity and regulates auxin signalling.

    Science.gov (United States)

    Yang, Bao-Jun; Han, Xin-Xin; Yin, Lin-Lin; Xing, Mei-Qing; Xu, Zhi-Hong; Xue, Hong-Wei

    2016-01-01

    The plant hormone auxin is perceived by the nuclear F-box protein TIR1 receptor family and regulates gene expression through degradation of Aux/IAA transcriptional repressors. Several studies have revealed the importance of the proteasome in auxin signalling, but details on how the proteolytic machinery is regulated and how this relates to degradation of Aux/IAA proteins remains unclear. Here we show that an Arabidopsis homologue of the proteasome inhibitor PI31, which we name PROTEASOME REGULATOR1 (PTRE1), is a positive regulator of the 26S proteasome. Loss-of-function ptre1 mutants are insensitive to auxin-mediated suppression of proteasome activity, show diminished auxin-induced degradation of Aux/IAA proteins and display auxin-related phenotypes. We found that auxin alters the subcellular localization of PTRE1, suggesting this may be part of the mechanism by which it reduces proteasome activity. Based on these results, we propose that auxin regulates proteasome activity via PTRE1 to fine-tune the homoeostasis of Aux/IAA repressor proteins thus modifying auxin activity. PMID:27109828

  15. Robust, synergistic regulation of human gene expression using TALE activators.

    Science.gov (United States)

    Maeder, Morgan L; Linder, Samantha J; Reyon, Deepak; Angstman, James F; Fu, Yanfang; Sander, Jeffry D; Joung, J Keith

    2013-03-01

    Artificial activators designed using transcription activator-like effector (TALE) technology have broad utility, but previous studies suggest that these monomeric proteins often exhibit low activities. Here we demonstrate that TALE activators can robustly function individually or in synergistic combinations to increase expression of endogenous human genes over wide dynamic ranges. These findings will encourage applications of TALE activators for research and therapy, and guide design of monomeric TALE-based fusion proteins.

  16. Regulation of p53 Localization and Activity by Ubc13▿ †

    OpenAIRE

    Laine, Aaron; Topisirovic, Ivan; Zhai, Dayong; John C Reed; Borden, Katherine L. B.; Ronai, Ze'ev

    2006-01-01

    The abundance and activity of p53 are regulated largely by ubiquitin ligases. Here we demonstrate a previously undisclosed regulation of p53 localization and activity by Ubc13, an E2 ubiquitin-conjugating enzyme. While increasing p53 stability, Ubc13 decreases p53 transcriptional activity and increases its localization to the cytoplasm, changes that require its ubiquitin-conjugating activity. Ubc13 elicits K63-dependent ubiquitination of p53, which attenuates Hdm2-induced polyubiquitination o...

  17. Physical Activity, Self-Regulation, and Early Academic Achievement in Preschool Children

    Science.gov (United States)

    Becker, Derek R.; McClelland, Megan M.; Loprinzi, Paul; Trost, Stewart G.

    2014-01-01

    Research Findings: The present study investigated whether active play during recess was associated with self-regulation and academic achievement in a prekindergarten sample. A total of 51 children in classes containing approximately half Head Start children were assessed on self-regulation, active play, and early academic achievement. Path…

  18. Self-Regulated Learning and Perceived Health among University Students Participating in Physical Activity Classes

    Science.gov (United States)

    McBride, Ron E.; Altunsöz, Irmak Hürmeriç; Su, Xiaoxia; Xiang, Ping; Demirhan, Giyasettin

    2016-01-01

    The purpose of this study was to explore motivational indicators of self-regulated learning (SRL) and the relationship between self-regulation (SR) and perceived health among university students enrolled in physical activity (PA) classes. One hundred thirty-one Turkish students participating in physical education activity classes at two…

  19. Structural plasticity of GABAergic axons is regulated by network activity and GABAA receptor activation

    Directory of Open Access Journals (Sweden)

    Anne eSchuemann

    2013-06-01

    Full Text Available Coordinated changes at excitatory and inhibitory synapses are essential for normal brain development and function. It is well established that excitatory neurons undergo structural changes, but our knowledge about inhibitory structural plasticity is rather scarce. Here we present a quantitative analysis of the dynamics of GABAergic boutons in the dendritic region of the hippocampal CA1 area using time-lapse two-photon imaging in organotypic hippocampal cultures from GAD65-GFP mice. We show that ~20% of inhibitory boutons are not stable. They are appearing, disappearing and reappearing at specific locations along the inhibitory axon and reflect immature or incomplete synapses. Furthermore, we observed that persistent boutons show large volume fluctuations over several hours, suggesting that presynaptic content of inhibitory synapses is not constant. Our data show that inhibitory boutons are highly dynamic structures and suggest that inhibitory axons are continuously probing potential locations for inhibitory synapse formation by redistributing presynaptic material along the axon.In addition, we found that neuronal activity affects the exploratory dynamics of inhibitory axons. Blocking network activity rapidly reduces the number of transient boutons, whereas enhancing activity reduces the number of persistent inhibitory boutons, possibly reflecting enhanced competition between boutons along the axon. The latter effect requires signaling through GABAA receptors. We propose that activity-dependent regulation of bouton dynamics contributes to inhibitory synaptic plasticity.

  20. Phosphorylation networks regulating JNK activity in diverse genetic backgrounds

    DEFF Research Database (Denmark)

    Bakal, Chris; Linding, Rune; Llense, Flora;

    2008-01-01

    Cellular signaling networks have evolved to enable swift and accurate responses, even in the face of genetic or environmental perturbation. Thus, genetic screens may not identify all the genes that regulate different biological processes. Moreover, although classical screening approaches have suc...

  1. Polyphosphate - an ancient energy source and active metabolic regulator

    Directory of Open Access Journals (Sweden)

    Achbergerová Lucia

    2011-08-01

    Full Text Available Abstract There are a several molecules on Earth that effectively store energy within their covalent bonds, and one of these energy-rich molecules is polyphosphate. In microbial cells, polyphosphate granules are synthesised for both energy and phosphate storage and are degraded to produce nucleotide triphosphate or phosphate. Energy released from these energetic carriers is used by the cell for production of all vital molecules such as amino acids, nucleobases, sugars and lipids. Polyphosphate chains directly regulate some processes in the cell and are used as phosphate donors in gene regulation. These two processes, energetic metabolism and regulation, are orchestrated by polyphosphate kinases. Polyphosphate kinases (PPKs can currently be categorized into three groups (PPK1, PPK2 and PPK3 according their functionality; they can also be divided into three groups according their homology (EcPPK1, PaPPK2 and ScVTC. This review discusses historical information, similarities and differences, biochemical characteristics, roles in stress response regulation and possible applications in the biotechnology industry of these enzymes. At the end of the review, a hypothesis is discussed in view of synthetic biology applications that states polyphosphate and calcium-rich organelles have endosymbiotic origins from ancient protocells that metabolized polyphosphate.

  2. 15 CFR 922.82 - Prohibited or otherwise regulated activities.

    Science.gov (United States)

    2010-01-01

    ... classification) that is approved in accordance with section 312 of the Federal Water Pollution Control Act, as... COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Gulf of the Farallones National... cooling water, clean vessel generator cooling water, clean bilge water, or anchor wash; or (iv)...

  3. Membrane lipids regulate ganglioside GM2 catabolism and GM2 activator protein activity[S

    Science.gov (United States)

    Anheuser, Susi; Breiden, Bernadette; Schwarzmann, Günter; Sandhoff, Konrad

    2015-01-01

    Ganglioside GM2 is the major lysosomal storage compound of Tay-Sachs disease. It also accumulates in Niemann-Pick disease types A and B with primary storage of SM and with cholesterol in type C. Reconstitution of GM2 catabolism with β-hexosaminidase A and GM2 activator protein (GM2AP) at uncharged liposomal surfaces carrying GM2 as substrate generated only a physiologically irrelevant catabolic rate, even at pH 4.2. However, incorporation of anionic phospholipids into the GM2 carrying liposomes stimulated GM2 hydrolysis more than 10-fold, while the incorporation of plasma membrane stabilizing lipids (SM and cholesterol) generated a strong inhibition of GM2 hydrolysis, even in the presence of anionic phospholipids. Mobilization of membrane lipids by GM2AP was also inhibited in the presence of cholesterol or SM, as revealed by surface plasmon resonance studies. These lipids also reduced the interliposomal transfer rate of 2-NBD-GM1 by GM2AP, as observed in assays using Förster resonance energy transfer. Our data raise major concerns about the usage of recombinant His-tagged GM2AP compared with untagged protein. The former binds more strongly to anionic GM2-carrying liposomal surfaces, increases GM2 hydrolysis, and accelerates intermembrane transfer of 2-NBD-GM1, but does not mobilize membrane lipids. PMID:26175473

  4. Redox Regulation of the AMP-Activated Protein Kinase

    OpenAIRE

    Yingying Han; Qilong Wang; Ping Song; Yi Zhu; Ming-Hui Zou

    2010-01-01

    Redox state is a critical determinant of cell function, and any major imbalances can cause severe damage or death. Objectives The aim of this study is to determine if AMP-activated protein kinase (AMPK), a cellular energy sensor, is activated by oxidants generated by Berberine in endothelial cells (EC). Methods Bovine aortic endothelial cells (BAEC) were exposed to Berberine. AMPK activity and reactive oxygen species were monitored after the incubation. Results In BAEC, Berberine caused a dos...

  5. Redox Regulation of Protein Tyrosine Phosphatase Activity by Hydroxyl Radical

    OpenAIRE

    Meng, Fan-Guo; Zhang, Zhong-Yin

    2012-01-01

    Substantial evidence suggests that transient production of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) is an important signaling event triggered by the activation of various cell surface receptors. Major targets of H2O2 include protein tyrosine phosphatases (PTPs). Oxidation of the active site Cys by H2O2 abrogates PTP catalytic activity, thereby potentially furnishing a mechanism to ensure optimal tyrosine phosphorylation in response to a variety of physiological stimuli. ...

  6. Astragaloside Ⅱ triggers T cell activation through regulation of CD45 protein tyrosine phosphatase activity

    Institute of Scientific and Technical Information of China (English)

    Chun-ping WAN; Li-xin GAO; Li-fei HOU; Xiao-qian YANG; Pei-lan HE; Yi-fu YANG; Wei TANG

    2013-01-01

    Aim:To investigate the immunomodulating activity of astragalosides,the active compounds from a traditional tonic herb Astragalus membranaceus Bge,and to explore the molecular mechanisms underlying the actions,focusing on CD45 protein tyrosine phosphatase (CD45 PTPase),which plays a critical role in T lymphocyte activation.Methods:Primary splenocytes and T cells were prepared from mice.CD45 PTPase activity was assessed using a colorimetric assay.Cell proliferation was measured using a [3H]-thymidine incorporation assay.Cytokine proteins and mRNAs were examined with ELISA and RT-PCR,respectively.Activation markers,including CD25 and CD69,were analyzed using flow cytometry.Activation of LCK (Tyr505) was detected using Western blot analysis.Mice were injected with the immunosuppressant cyclophosphamide (CTX,80 mg/kg),and administered astragaloside Ⅱ (50 mg/kg).Results:Astragaloside Ⅰ,Ⅱ,Ⅲ,and Ⅳ concentration-dependently increased the CD45-mediated of pNPP/OMFP hydrolysis with the EC50 values ranged from 3.33 to 10.42 μg/mL.Astragaloside Ⅱ (10 and 30 μg/mL) significantly enhanced the proliferation of primary splenocytes induced by ConA,alloantigen or anti-CD3.Astragaloside Ⅱ (30 μg/mL) significantly increased IL-2 and IFN-y secretion,upregulated the mRNA levels of IFN-y and T-bet in primary splenocytes,and promoted CD25 and CD69 expression on primary CD4+T cells upon TCR stimulation.Furthermore,astragaloside Ⅱ (100 ng/mL) promoted CD45-mediated dephosphorylation of LCK (Tyr505) in primary T cells,which could be blocked by a specific CD45 PTPase inhibitor.In CTX-induced immunosuppressed mice,oral administration of astragaloside Ⅱ restored the proliferation of splenic T cells and the production of IFN-Y and IL-2.However,astragaloside Ⅱ had no apparent effects on B cell proliferation.Conclusion:Astragaloside Ⅱ enhances T cell activation by regulating the activity of CD45 PTPase,which may explain why Astragalus membranaceus Bge is used as a tonic

  7. Cyclic dermal BMP signalling regulates stem cell activation during hair regeneration

    OpenAIRE

    Plikus, M. V.; Mayer, J. A.; de La Cruz, D.; Baker, Ruth E.; Maini, P.K.; Maxson, R.; Chuong, C M

    2008-01-01

    In the age of stem cell engineering it is critical to understand how stem cell activity is regulated during regeneration. Hairs are mini-organs that undergo cyclic regeneration throughout adult life1, and are an important model for organ regeneration. Hair stem cells located in the follicle bulge2 are regulated by the surrounding microenvironment, or niche3. The activation of such stem cells is cyclic, involving periodic -catenin activity4, 5, 6, 7. In the adult mouse, regeneration occurs in ...

  8. Examining "Active" Procrastination from a Self-Regulated Learning Perspective

    Science.gov (United States)

    Cao, Li

    2012-01-01

    This study examined the notion that active procrastinators are a positive type of procrastinators who possess desirable characteristics similar to non-procrastinators, but different from the traditional passive procrastinators. A two-step procedure was followed to categorise university students (N = 125) as active procrastinators, passive…

  9. Substrate stiffness regulates filopodial activities in lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Yu-Ren Liou

    Full Text Available Microenvironment stiffening plays a crucial role in tumorigenesis. While filopodia are generally thought to be one of the cellular mechanosensors for probing environmental stiffness, the effects of environmental stiffness on filopodial activities of cancer cells remain unclear. In this work, we investigated the filopodial activities of human lung adenocarcinoma cells CL1-5 cultured on substrates of tunable stiffness using a novel platform. The platform consists of an optical system called structured illumination nano-profilometry, which allows time-lapsed visualization of filopodial activities without fluorescence labeling. The culturing substrates were composed of polyvinyl chloride mixed with an environmentally friendly plasticizer to yield Young's modulus ranging from 20 to 60 kPa. Cell viability studies showed that the viability of cells cultured on the substrates was similar to those cultured on commonly used elastomers such as polydimethylsiloxane. Time-lapsed live cell images were acquired and the filopodial activities in response to substrates with varying degrees of stiffness were analyzed. Statistical analyses revealed that lung cancer cells cultured on softer substrates appeared to have longer filopodia, higher filopodial densities with respect to the cellular perimeter, and slower filopodial retraction rates. Nonetheless, the temporal analysis of filopodial activities revealed that whether a filopodium decides to extend or retract is purely a stochastic process without dependency on substrate stiffness. The discrepancy of the filopodial activities between lung cancer cells cultured on substrates with different degrees of stiffness vanished when the myosin II activities were inhibited by treating the cells with blebbistatin, which suggests that the filopodial activities are closely modulated by the adhesion strength of the cells. Our data quantitatively relate filopodial activities of lung cancer cells with environmental stiffness and

  10. Regulation of Prolactin in Mice with Altered Hypothalamic Melanocortin Activity

    OpenAIRE

    Dutia, Roxanne; Kim, Andrea J.; Mosharov, Eugene; Savontaus, Eriika; Chua, Streamson C.; Wardlaw, Sharon L.

    2012-01-01

    This study used two mouse models with genetic manipulation of the melanocortin system to investigate prolactin regulation. Mice with overexpression of the melanocortin receptor (MC-R) agonist, α-melanocyte-stimulating hormone (Tg-MSH) or deletion of the MC-R antagonist agouti-related protein (AgRP KO) were studied. Male Tg-MSH mice had lower blood prolactin levels at baseline (2.9±0.3 vs 4.7±0.7 ng/ml) and after restraint stress(68 ±6.5 vs 117±22 ng/ml) versus WT (p

  11. [Studies on regulation of glutamine synthetase activity from Streptomyces lincolnensis].

    Science.gov (United States)

    Jin, Z; Jiao, R; Mao, Y

    2001-08-01

    Glutamine synthetase in crude extracts from Streptomyces lincolnensis growing under different nitrogen sources were studied. The results showed that NH4+ in high concentration repressed the biosynthesis of the enzyme. To determine whether Streptomyces lincolnensis has undergone covalent modification, a comparison of the glutamine synthetase isolated from cells grown on different nitrogen sources was made. No significant difference was observed in specific activity, pH optima, divalent cation response, and ultraviolet absorption spectra. Glutamine synthetase activity was not influenced by ammonia shock or snake venom phosphodiesterase treatment. Under these conditions, the activity of glutamine synthetase from K. aerogenes was markedly changed. There was therefore no evidence for enzymatic adenylylation of glutamine synthetase from Streptomyces lincolnensis. Glutamine synthetase was subject to feedback inhibition by end products of glutamine metabolism. Cumulative feedback inhibition of the Mn(2+)-dependent glutamine synthetase activity was demonstrated. These results suggest that glutamine synthetase from Streptomyces lincolnensis is an allosteric enzyme. PMID:12552916

  12. Expression of Arabidopsis Bax Inhibitor-1 in transgenic sugarcane confers drought tolerance.

    Science.gov (United States)

    Ramiro, Daniel Alves; Melotto-Passarin, Danila Montewka; Barbosa, Mariana de Almeida; Santos, Flavio Dos; Gomez, Sergio Gregorio Perez; Massola Júnior, Nelson Sidnei; Lam, Eric; Carrer, Helaine

    2016-09-01

    The sustainability of global crop production is critically dependent on improving tolerance of crop plants to various types of environmental stress. Thus, identification of genes that confer stress tolerance in crops has become a top priority especially in view of expected changes in global climatic patterns. Drought stress is one of the abiotic stresses that can result in dramatic loss of crop productivity. In this work, we show that transgenic expression of a highly conserved cell death suppressor, Bax Inhibitor-1 from Arabidopsis thaliana (AtBI-1), can confer increased tolerance of sugarcane plants to long-term (>20 days) water stress conditions. This robust trait is correlated with an increased tolerance of the transgenic sugarcane plants, especially in the roots, to induction of endoplasmic reticulum (ER) stress by the protein glycosylation inhibitor tunicamycin. Our findings suggest that suppression of ER stress in C4 grasses, which include important crops such as sorghum and maize, can be an effective means of conferring improved tolerance to long-term water deficit. This result could potentially lead to improved resilience and yield of major crops in the world. PMID:26872943

  13. Deubiquitylating enzyme USP9x regulates hippo pathway activity by controlling angiomotin protein turnover

    DEFF Research Database (Denmark)

    Nguyen, Thanh Hung; Andrejeva, Diana; Gupta, Rajat;

    2016-01-01

    The Hippo pathway has been identified as a key barrier for tumorigenesis, acting through downregulation of YAP/TAZ activity. Elevated YAP/TAZ activity has been documented in many human cancers. Ubiquitylation has been shown to play a key role in regulating YAP/TAZ activity through downregulation....../TAZ activity. We demonstrate that USPx regulates ubiquitin-mediated turnover of the YAP inhibitor, Angiomotin. USP9x acts to deubiquitylate Angiomotin at lysine 496, resulting in stabilization of Angiomotin and lower YAP/TAZ activity. USP9x mRNA levels were reduced in several cancers. Clinically, USP9x m...

  14. REGULATION AND SUPERVISION OF BANKING ACTIVITY IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Anisoara Niculina APETRI

    2015-04-01

    Full Text Available The main challenges currently faced by most central banks are generated by the effects of the economic and financial crisis. Thus, at the national, European and international level there is a trend of changing the economic governance structures and improving the regulatory and supervisory policies, focusing on macro-prudential oversight. In the context of changes at the European Union level, the central banks of the Member States become also subject to changes in their carried out actions. The objectives of this research aim mainly at: highlighting the role of the National Bank of Romania in regulating and supervising the banking system in Romania and analyzing the measures implemented by the National Bank of Romania after the crisis so far; identifying the challenges of the National Bank of Romania on the basis of changes operated by European Union at the supervisory framework level.

  15. Serum thymus and activation-regulated chemokine as disease activity and response biomarker in alopecia areata.

    Science.gov (United States)

    Inui, Shigeki; Noguchi, Fumihito; Nakajima, Takeshi; Itami, Satoshi

    2013-11-01

    Serum thymus and activation-regulated chemokine/CCL17 (sTARC) is known as a good indicator for atopic dermatitis severity. Herein, we investigate whether sTARC correlates with severity and therapeutic response for alopecia areata (AA) in our 121 patients. The sTARC mean of AA totalis and universalis was significantly higher than mild AA. Next, we compared sTARC of diffuse AA (n = 14) and severity-controlled patchy AA (n = 32) and found that sTARC in diffuse AA (564.2 ± 400.0 pg/mL) was significantly higher than that of the patchy type (344.0 ± 239.8 pg/mL), suggesting a potential role of TARC in active progression of diffuse AA. Ten patients with diffuse AA were treated with i.v. corticosteroid pulse therapy. Then, we tested whether sTARC can predict prognosis after the pulse therapy and found that baseline sTARC in the poor responders (1025.5 ± 484.8 pg/mL) was significantly higher than that in the good responders (complete remission at 24 months after the pulse therapy, 347.8 ± 135.7 pg/mL), indicating sTARC as a response biomarker in the corticosteroid pulse therapy for diffuse AA. Finally, to investigate TARC production in the affected hair follicles, we performed immunohistochemical double staining of TARC and CD68 using scalp skin specimens of diffuse AA with high titers of sTARC. The results showed their co-localization in the infiltrating cells around the AA hair follicles, suggesting that TARC is mainly produced from CD68(+) histiocytes. In conclusion, sTARC is a disease activity and response biomarker in AA, providing new insight beyond the T-helper 1/2 paradigm to solve the immunological pathogenesis of AA.

  16. Regulation of Proteolytic Enzyme Activity in Lactococcus lactis

    OpenAIRE

    Meijer, W.; Marugg, J D; Hugenholtz, J

    1996-01-01

    Two different Lactococcus lactis host strains, L. lactis subsp. lactis MG1363 and L. lactis subsp. cremoris SK1128, both containing plasmid pNZ521, which encodes the extracellular serine proteinase (PrtP) from strain SK110, were used to study the medium and growth-rate-dependent activity of three different enzymes involved in the proteolytic system of lactococci. The activity levels of PrtP and both the intracellular aminopeptidase PepN and the X-prolyl-dipeptidyl aminopeptidase PepXP were st...

  17. Hormonal Regulation of chicken intestinal NHE and SGLT-1 activities

    OpenAIRE

    Ilundáin Larrañeta, María Anunciación; De la Horra, Maria del Carmen; Cano Rodríguez, María Mercedes; Peral Rubio, María José; Calonge Castrillo, María Luisa

    2001-01-01

    The effects of aldosterone and arginine vasotocin (AVT) on intestinal Na/Hexchange (NHE) and Na-sugar cotransport (SGLT-1) activi-ties have been investigated using brush-border membrane ves-icles isolated from Hubbard chicken small and large intestines, and they were compared with those induced by either Nadepletion or dehydration. Na depletion was induced by feeding the chickens with either a low- or a high-Na diet for either 0.5, 1, 2, 4, or 8 days. Ileal and colonic NHE2 activity inc...

  18. The role of AMP-activated protein kinase in regulation of skeletal muscle metabolism

    OpenAIRE

    Anna Dziewulska; Paweł Dobrzyń; Agnieszka Dobrzyń

    2010-01-01

    AMP-activated protein kinase (AMPK) is a conserved, ubiquitously expressed eukaryotic enzyme that is activated in response to increasing AMP level. Regulation of AMPK activity in skeletal muscle is coordinated by contraction and phosphorylation by upstream kinases and a growing number of hormones and cytokines. Once activated, AMPK turns on catabolic, ATP-generating pathways, and turns off ATP-consuming metabolic processes such as biosynthesis and proliferation. Activation of AMPK promotes gl...

  19. Protease-activated receptor 2 activation of myeloid dendritic cells regulates allergic airway inflammation

    Directory of Open Access Journals (Sweden)

    Dienger Krista

    2011-09-01

    Full Text Available Abstract Background A common characteristic of allergens is that they contain proteases that can activate protease-activated receptor (PAR-2; however the mechanism by which PAR-2 regulates allergic airway inflammation is unclear. Methods Mice (wild type and PAR-2-deficient were sensitized using German cockroach (GC feces (frass, the isolated protease from GC frass, or through adoptive transfer of GC frass-treated bone marrow-derived dendritic cells (BMDC and measurements of airway inflammation (cellular infiltration, cytokine expression, and mucin production, serum IgE levels and airway hyperresponsiveness (AHR were assessed. BMDC were cultured, treated with GC frass and assessed for cytokine production. PAR-2 expression on pulmonary mDCs was determined by flow cytometry. Results Exposure to GC frass induced AHR and airway inflammation in wild type mice; however PAR-2-deficient mice had significantly attenuated responses. To directly investigate the role of the protease, we isolated the protease from GC frass and administered the endotoxin-free protease into the airways of mice in the presence of OVA. GC frass proteases were sufficient to promote the development of AHR, serum IgE, and Th2 cytokine production. PAR-2 expression on mDC was upregulated following GC frass exposure, but the presence of a functional PAR-2 did not alter antigen uptake. To determine if PAR-2 activation led to differential cytokine production, we cultured BMDC in the presence of GM-CSF and treated these cells ex vivo with GC frass. PAR-2-deficient BMDC released significantly less IL-6, IL-23 and TNFα compared to BMDC from wild type mice, suggesting PAR-2 activation was important in Th2/Th17 skewing cytokine production. To determine the role for PAR-2 on mDCs on the initiation of allergic airway inflammation, BMDCs from wild type and PAR-2-deficient mice were treated in the presence or absence of GC frass and then adoptively transferred into the airway of wild type mice

  20. Regulation of AMP-activated protein kinase by LKB1 and CaMKK in adipocytes

    DEFF Research Database (Denmark)

    Gormand, Amélie; Henriksson, Emma; Ström, Kristoffer;

    2011-01-01

    AMP-activated protein kinase (AMPK) is a serine/threonine kinase that regulates cellular and whole body energy homeostasis. In adipose tissue, activation of AMPK has been demonstrated in response to a variety of extracellular stimuli. However, the upstream kinase that activates AMPK in adipocytes...

  1. Prostaglandin E2 Regulation of Cystic Fibrosis Transmembrane Conductance Regulator Activity and Airway Surface Liquid Volume Requires Gap Junctional Communication

    OpenAIRE

    Scheckenbach, K E Ludwig; Losa, Davide; Dudez, Tecla; Bacchetta, Marc; O'Grady, Scott; Crespin, Sophie; Chanson, Marc

    2010-01-01

    Stimulation of the cystic fibrosis transmembrane conductance regulator (CFTR) by protease-activated receptors (PARs) at the basolateral membranes and by adenosine receptors (ADO-Rs) at the apical membrane maintain airway surface liquid (ASL) volume, which is required to ensure hydrated and clearable mucus. Both pathways involve the release of prostaglandin E2 (PGE2) and the stimulation of their basolateral receptors (EP-Rs). We sought to determine whether gap junctions contribute to the coord...

  2. Prostaglandin E₂regulation of cystic fibrosis transmembrane conductance regulator activity and airway surface liquid volume requires gap junctional communication

    OpenAIRE

    Scheckenbach, K E Ludwig; Losa, Davide; Dudez, Tecla; Bacchetta, Marc; O'Grady, Scott; Crespin, Sophie; Chanson, Marc

    2011-01-01

    Stimulation of the cystic fibrosis transmembrane conductance regulator (CFTR) by protease-activated receptors (PARs) at the basolateral membranes and by adenosine receptors (ADO-Rs) at the apical membrane maintain airway surface liquid (ASL) volume, which is required to ensure hydrated and clearable mucus. Both pathways involve the release of prostaglandin E₂ (PGE₂) and the stimulation of their basolateral receptors (EP-Rs). We sought to determine whether gap junctions contribute to the coord...

  3. 76 FR 28852 - Agency Information Collection (Regulation for Submission of Evidence); Activity Under OMB Review

    Science.gov (United States)

    2011-05-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Regulation for Submission of Evidence); Activity Under OMB Review... INFORMATION: Title: Regulation for Submission of Evidence--Title 38 CFR 17.101(a)(4). OMB Control Number:...

  4. Design for mood: Twenty activity-based opportunities to design for mood regulation

    NARCIS (Netherlands)

    Desmet, P.M.A.

    2015-01-01

    This paper introduces a theory-based approach to design for mood regulation. The main proposition is that design can best influence mood by enabling and stimulating people to engage in a broad range of mood-regulating activities. The first part of the manuscript reviews state-of-the art mood-focused

  5. 78 FR 76851 - Agency Information Collection Activities: BP Regulations Pertaining to Customs Brokers

    Science.gov (United States)

    2013-12-19

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: BP Regulations Pertaining to Customs Brokers AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland... requirement concerning the CBP Regulations Pertaining to Customs Brokers (19 CFR Part 111). This request...

  6. 75 FR 67094 - Agency Information Collection Activities: CBP Regulations Pertaining to Customs Brokers

    Science.gov (United States)

    2010-11-01

    ... SECURITY Customs and Border Protection Agency Information Collection Activities: CBP Regulations Pertaining to Customs Brokers AGENCY: U.S. Customs and Border Protection, Department of Homeland Security... concerning the: CBP Regulations Pertaining to Customs Brokers (19 CFR Part 111). This request for comment...

  7. 77 FR 477 - Agency Information Collection Activities: Rules Relating to Regulation of Domestic Exchange...

    Science.gov (United States)

    2012-01-05

    ... COMMISSION Agency Information Collection Activities: Rules Relating to Regulation of Domestic Exchange-Traded...., permitting electronic submission of responses. Rules Relating to Regulation of Domestic Exchange-Traded... solicits comments on rules related to risk disclosure concerning exchange traded commodity options....

  8. Study on the Model for Regulation of the Allosteric Enzyme Activity

    Institute of Scientific and Technical Information of China (English)

    LI,Qian-Zhong(李前忠); LUO,Liao-Fu(罗辽复); ZHANG,Li-Rong(张利绒)

    2002-01-01

    The effects of activator molecule and repressive molecule on binding process between allosteric enzyme and substrate are disused by considering the heterotropic effect of the regulating molecule that binds to allosteric enzyme. A model of allosteric enzyme with heterotropic effect is presented. The cooperativity and anticooperativity in the regulation process are studied.

  9. 15 CFR 922.112 - Prohibited or otherwise regulated activities.

    Science.gov (United States)

    2010-01-01

    ... CFR part 660 (Fisheries off West Coast States). The coordinates for the line representing the 50... used during fishing activities, which is prohibited pursuant to 50 CFR part 660 (Fisheries off West... remove, take, or injure benthic invertebrates or algae located on Cordell Bank. This prohibition does...

  10. Molecular mechanisms of complement activation, regulation and evasion

    NARCIS (Netherlands)

    Wu, J.

    2012-01-01

    The complement system of our immune defense can rapidly recognize and eliminate pathogens in blood. Activation of complement depends on enzymatic complexes, known as C3 convertases, which are short lived and dissociate irreversibly. Staphylococcus aureus secretes a small protein (named SCIN) that su

  11. After the Slippery Slope: Dutch Experiences on Regulating Active Euthanasia

    NARCIS (Netherlands)

    Boer, Th.A.

    2003-01-01

    “When a country legalizes active euthanasia, it puts itself on a slippery slope from where it may well go further downward.” If true, this is a forceful argument in the battle of those who try to prevent euthanasia from becoming legal. The force of any slippery-slope argument, however, is by definit

  12. Endothelial PI 3-kinase activity regulates lymphocyte diapedesis.

    Science.gov (United States)

    Nakhaei-Nejad, Maryam; Hussain, Amer M; Zhang, Qiu-Xia; Murray, Allan G

    2007-12-01

    Lymphocyte recruitment to sites of inflammation involves a bidirectional series of cues between the endothelial cell (EC) and the leukocyte that culminate in lymphocyte migration into the tissue. Remodeling of the EC F-actin cytoskeleton has been observed after leukocyte adhesion, but the signals to the EC remain poorly defined. We studied the dependence of peripheral blood lymphocyte transendothelial migration (TEM) through an EC monolayer in vitro on EC phosphatidylinositol 3-kinase (PI 3-kinase) activity. Lymphocytes were perfused over cytokine-activated EC using a parallel-plate laminar flow chamber. Inhibition of EC PI 3-kinase activity using LY-294002 or wortmannin decreased lymphocyte TEM (48 +/- 6 or 34 +/- 7%, respectively, vs. control; mean +/- SE; P structure" after intercellular adhesion molecule-1 ligation, whereas this was inhibited by jasplakinolide treatment. A similar fraction of lymphocytes migrated on control or LY-294002-treated EC and localized to interendothelial junctions. However, lymphocytes failed to extend processes below the level of vascular endothelial (VE)-cadherin on LY-294002-treated EC. Together these observations indicate that EC PI 3-kinase activity and F-actin remodeling are required during lymphocyte diapedesis and identify a PI 3-kinase-dependent step following initial separation of the VE-cadherin barrier.

  13. Mechanisms regulating regional cerebral activation during dynamic handgrip in humans

    DEFF Research Database (Denmark)

    Williamson, James; Friedman, D B; Mitchell, J H;

    1996-01-01

    type of afferent input required for this cerebral activation. The rCBF was measured at +5.0 and +9.0 cm above the orbitomeatal (OM) plane in 13 subjects during 1) rest; 2) dynamic left-hand contractions; 3) postcontraction ischemia (metaboreceptor afferents); and 4) biceps brachii tendon vibration...

  14. Aptamer and PNIPAAm co-conjugated nanoparticles regulate activity of enzyme with different temperature.

    Science.gov (United States)

    Yu, Jiemiao; Yang, Liangrong; Liang, Xiangfeng; Dong, Tingting; Qu, Hongnan; Rong, Meng; Liu, Huizhou

    2016-10-01

    In this paper, we described a temperature responsive nano-system that can regulate activity of enzyme with different temperature. Temperature responsive polymer poly(N-isopropylacrylamide) (PNIPAAm), with low critical solution temperature of 32°C, was synthesized with thiol modification. PNIPAAm and thrombin aptamer were co-functionalized on the surface of gold nanoparticles for effective regulation of thrombin activity with different temperature. On the one hand, we studied the thermal responsive properties of this inhibitor via UV-visible spectroscopy. On the other hand, we investigated the regulation of thrombin activity by this platform with different temperature. The PNIPAAm chains could extend and shrink with different temperature, which suggested that PNIPAAm on the surface of gold nanoparticles could regulate interaction between thrombin and aptamer according to temperature changing. At 25°C, PNIPAAm was hydrophilic extended state, which blocked the interaction between thrombin and aptamer on the surface of gold nanoparticles, therefore thrombin activity had no change. On the contrary, at 37°C, PNIPAAm transformed from hydrophilic extended state to hydrophobic shrank state, allowing the aptamer to capture thrombin, inhibiting the activity of thrombin. More interestingly, this regulation was reverse to normal condition, where 37°C was always the optimum reaction temperature for most of human enzymes. This system we prepared was opposite, which was capable of inhibiting the thrombin activity at 37°C. Furthermore, this was the first report of regulation of thrombin activity using this temperature responsive platform. PMID:27474278

  15. Redox regulation of the AMP-activated protein kinase.

    Directory of Open Access Journals (Sweden)

    Yingying Han

    Full Text Available Redox state is a critical determinant of cell function, and any major imbalances can cause severe damage or death.The aim of this study is to determine if AMP-activated protein kinase (AMPK, a cellular energy sensor, is activated by oxidants generated by Berberine in endothelial cells (EC.Bovine aortic endothelial cells (BAEC were exposed to Berberine. AMPK activity and reactive oxygen species were monitored after the incubation.In BAEC, Berberine caused a dose- and time-dependent increase in the phosphorylation of AMPK at Thr172 and acetyl CoA carboxylase (ACC at Ser79, a well characterized downstream target of AMPK. Concomitantly, Berberine increased peroxynitrite, a potent oxidant formed by simultaneous generation of superoxide and nitric oxide. Pre-incubation of BAEC with anti-oxidants markedly attenuated Berberine-enhanced phosphorylation of both AMPK and ACC. Consistently, adenoviral expression of superoxide dismutase and pretreatment of L-N(G-Nitroarginine methyl ester (L-NAME; a non-selective NOS inhibitor blunted Berberine-induced phosphorylation of AMPK. Furthermore, mitochondria-targeted tempol (mito-tempol pretreatment or expression of uncoupling protein attenuated AMPK activation caused by Berberine. Depletion of mitochondria abolished the effects of Berberine on AMPK in EC. Finally, Berberine significantly increased the phosphorylation of LKB1 at Ser307 and gene silencing of LKB1 attenuated Berberine-enhanced AMPK Thr172 phosphorylation in BAEC.Our results suggest that mitochondria-derived superoxide anions and peroxynitrite are required for Berberine-induced AMPK activation in endothelial cells.

  16. The chitinolytic activity of Listeria monocytogenes EGD is regulated by carbohydrates but also by the virulence regulator PrfA

    DEFF Research Database (Denmark)

    Larsen, Marianne Halberg; Leisner, Jørgen; Ingmer, Hanne

    2010-01-01

    for nutrient acquisition and environmental survival but also for infecting animals and humans. Interestingly, the central L. monocytogenes virulence gene regulator, PrfA, is required for the chitinolytic phenotype, as chitinase activity was significantly reduced in prfA mutant cells compared to its level...... in wild-type cells. In agreement with this, Northern blot analysis showed that the amounts of chiA and chiB transcripts upon induction by chitin were significantly lower in the prfA mutant than in the wild type. The chitinolytic activity and chiA and chiB expression were reduced in the absence of the sig...

  17. Signal integration by Ca(2+) regulates intestinal stem-cell activity.

    Science.gov (United States)

    Deng, Hansong; Gerencser, Akos A; Jasper, Heinrich

    2015-12-10

    Somatic stem cells maintain tissue homeostasis by dynamically adjusting proliferation and differentiation in response to stress and metabolic cues. Here we identify Ca(2+) signalling as a central regulator of intestinal stem cell (ISC) activity in Drosophila. We show that dietary L-glutamate stimulates ISC division and gut growth. The metabotropic glutamate receptor (mGluR) is required in ISCs for this response, and for an associated modulation of cytosolic Ca(2+) oscillations that results in sustained high cytosolic Ca(2+) concentrations. High cytosolic Ca(2+) concentrations induce ISC proliferation by regulating Calcineurin and CREB-regulated transcriptional co-activator (Crtc). In response to a wide range of dietary and stress stimuli, ISCs reversibly transition between Ca(2+) oscillation states that represent poised or activated modes of proliferation, respectively. We propose that the dynamic regulation of intracellular Ca(2+) levels allows effective integration of diverse mitogenic signals in ISCs to adapt their proliferative activity to the needs of the tissue.

  18. Nuclear factor Y regulates ancient budgerigar hepadnavirus core promoter activity.

    Science.gov (United States)

    Shen, Zhongliang; Liu, Yanfeng; Luo, Mengjun; Wang, Wei; Liu, Jing; Liu, Wei; Pan, Shaokun; Xie, Youhua

    2016-09-16

    Endogenous viral elements (EVE) in animal genomes are the fossil records of ancient viruses and provide invaluable information on the origin and evolution of extant viruses. Extant hepadnaviruses include avihepadnaviruses of birds and orthohepadnaviruses of mammals. The core promoter (Cp) of hepadnaviruses is vital for viral gene expression and replication. We previously identified in the budgerigar genome two EVEs that contain the full-length genome of an ancient budgerigar hepadnavirus (eBHBV1 and eBHBV2). Here, we found eBHBV1 Cp and eBHBV2 Cp were active in several human and chicken cell lines. A region from nt -85 to -11 in eBHBV1 Cp was critical for the promoter activity. Bioinformatic analysis revealed a putative binding site of nuclear factor Y (NF-Y), a ubiquitous transcription factor, at nt -64 to -50 in eBHBV1 Cp. The NF-Y core binding site (ATTGG, nt -58 to -54) was essential for eBHBV1 Cp activity. The same results were obtained with eBHBV2 Cp and duck hepatitis B virus Cp. The subunit A of NF-Y (NF-YA) was recruited via the NF-Y core binding site to eBHBV1 Cp and upregulated the promoter activity. Finally, the NF-Y core binding site is conserved in the Cps of all the extant avihepadnaviruses but not of orthohepadnaviruses. Interestingly, a putative and functionally important NF-Y core binding site is located at nt -21 to -17 in the Cp of human hepatitis B virus. In conclusion, our findings have pinpointed an evolutionary conserved and functionally critical NF-Y binding element in the Cps of avihepadnaviruses.

  19. Osteoblast differentiation and migration are regulated by Dynamin GTPase activity

    OpenAIRE

    Pierre P. Eleniste; Huang, Su; Wayakanon, Kornchanok; Largura, Heather W.; Bruzzaniti, Angela

    2013-01-01

    Bone formation is controlled by osteoblasts but the signaling proteins that control osteoblast differentiation and function are still unclear. We examined if the dynamin GTPase, which is associated with actin remodeling and migration in other cells, plays a role in osteoblast differentiation and migration. Dynamin mRNA was expressed in primary osteoblasts throughout differentiation (0–21 days). However, alkaline phosphatase (ALP) activity, a marker of osteoblast differentiation, was decreased...

  20. Subcellular localization of PUMA regulates its pro-apoptotic activity in Burkitt's lymphoma B cells

    OpenAIRE

    Ambroise, Gorbatchev; Portier, Alain; Roders, Nathalie; Arnoult, Damien; Vazquez, Aimé

    2015-01-01

    The BH3-only protein PUMA (p53-upregulated modulator of apoptosis) is a major regulator of apoptosis. It belongs to the Bcl-2 family of proteins responsible for maintaining mitochondrial outer membrane integrity by controlling the intrinsic (mitochondrial) apoptotic pathway. We describe here a new pathway regulating PUMA activation through the control of its subcellular distribution. Surprisingly, neither PUMA upregulation in normal activated human B lymphocytes nor high levels of PUMA in Bur...

  1. Application of the Positive International Experience of Tax Regulation of Investment and Innovation Activity in Ukraine

    OpenAIRE

    Krisovatyy Ihor A.

    2013-01-01

    The goal of the article is to study the positive international experience in the sphere of tax regulation of investment and innovation activity and a possibility of its use in modern practice. It analyses application of basic instruments of stimulation of investment and innovation activity in foreign countries. Namely: change of the taxation base, tax rate, use of the innovation loan and investment oriented depreciation policy. Using the study of experience of tax regulation in foreign countr...

  2. Diacylglycerol kinase theta and zeta isoforms: regulation of activity, protein binding partners and physiological functions

    OpenAIRE

    Los, Alrik Pieter

    2007-01-01

    Diacylglycerol kinases (DGKs) phosphorylate the second messenger diacylglycerol (DAG) yielding phosphatidic acid (PA). In this thesis, we investigated which structural domains of DGKtheta are required for DGK activity. Furthermore, we showed that DGKzeta binds to and is activated by the Retinoblastoma tumour suppressor protein (pRB) and the pRB-related proteins p107 and p130, key regulators of the cell-cycle, differentiation and apoptosis. The interaction between pRB and DGKzeta is regulated ...

  3. GITR Activation Positively Regulates Immune Responses against Toxoplasma gondii

    Science.gov (United States)

    Costa, Frederico R. C.; Mota, Caroline M.; Santiago, Fernanda M.; Silva, Murilo V.; Ferreira, Marcela D.; Fonseca, Denise M.; Silva, João S.; Mineo, José R.; Mineo, Tiago W. P.

    2016-01-01

    Toxoplasma gondii is a widespread parasite responsible for causing clinical diseases especially in pregnant and immunosuppressed individuals. Glucocorticoid-induced TNF receptor (GITR), which is also known as TNFRS18 and belongs to the TNF receptor superfamily, is found to be expressed in various cell types of the immune system and provides an important costimulatory signal for T cells and myeloid cells. However, the precise role of this receptor in the context of T. gondii infection remains elusive. Therefore, the current study investigated the role of GITR activation in the immunoregulation mechanisms induced during the experimental infection of mice with T. gondii. Our data show that T. gondii infection slightly upregulates GITR expression in Treg cells and B cells, but the most robust increment in expression was observed in macrophages and dendritic cells. Interestingly, mice infected and treated with an agonistic antibody anti-GITR (DTA-1) presented a robust increase in pro-inflammatory cytokine production at preferential sites of parasite replication, which was associated with the decrease in latent brain parasitism of mice under treatment with DTA-1. Several in vivo and in vitro analysis were performed to identify the cellular mechanisms involved in GITR activation upon infection, however no clear alterations were detected in the phenotype/function of macrophages, Tregs and B cells under treatment with DTA-1. Therefore, GITR appears as a potential target for intervention during infection by the parasite Toxoplasma gondii, even though further studies are still necessary to better characterize the immune response triggered by GITR activation during T. gondii infection. PMID:27027302

  4. Tonic activity of Gα-gustducin regulates taste cell responsivity

    OpenAIRE

    Clapp, Tod R.; Trubey, Kristina R.; Vandenbeuch, Aurelie; Stone, Leslie M; Margolskee, Robert F.; Chaudhari, Nirupa; Kinnamon, Sue C.

    2008-01-01

    The taste-selective G protein, α-gustducin (α-gus) is homologous to α-transducin and activates phosphodiesterase in vitro. α-Gustducin-knockout mice are compromised to bitter, sweet and umami taste stimuli, suggesting a central role in taste transduction. Here, we suggest a different role for Gα-gustducin. In taste buds of α-gustducin knockout mice, basal (unstimulated) cAMP levels are high compared to those of wild-type mice. Further, H-89, a cAMP-dependent Protein Kinase inhibitor, dramatic...

  5. SUMO modification regulates the transcriptional activity of FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Alm-Kristiansen, Anne Hege; Norman, Ingrid Louise; Matre, Vilborg [Department of Molecular Biosciences, University of Oslo, N-0316 Oslo (Norway); Gabrielsen, Odd Stokke, E-mail: o.s.gabrielsen@imbv.uio.no [Department of Molecular Biosciences, University of Oslo, N-0316 Oslo (Norway)

    2009-09-25

    FLASH is a huge multifunctional nuclear protein that has been linked to apoptotic signalling, transcriptional control and Cajal body function. To gain further insight into the functions of the FLASH protein, we performed a yeast two-hybrid screening with FLASH as bait and identified the SUMO-conjugating enzyme Ubc9 as an interaction partner. The main interaction surface for Ubc9 was found in the C-terminal part of FLASH, which is also a target for sumoylation. We identified K1813 as the major sumoylation site in FLASH, being enhanced by the SUMO E3 ligases Pc2 and PIASy. Disruption of this SUMO-conjugation site did not change the speckled subnuclear localization of FLASH, but it caused a reduction in FLASH activity as measured in a Gal4-tethering assay. Interestingly, the SUMO-specific protease SENP1 activated FLASH in the same assay. Overall, our results point to a complex involvement of sumoylation in modulating the function of FLASH.

  6. Xanthine oxidase activity regulates human embryonic brain cells growth

    Directory of Open Access Journals (Sweden)

    Kevorkian G. A.

    2011-10-01

    Full Text Available Aim. Involvement of Xanthine Oxidase (XO; EC1.1.3.22 in cellular proliferation and differentiation has been suggested by the numerous investigations. We have proposed that XO might have undoubtedly important role during the development, maturation as well as the death of human embryos brain cells. Methods. Human abortion material was utilized for the cultivation of brain cells (E90. XO activity was measured by the formation of uric acid in tissue. Cell death was detected by the utility of Trypan Blue dye. Results. Allopurinol suppressed the XO activity in the brain tissue (0.12 ± 0.02; 0.20 ± 0.03 resp., p < 0.05. On day 12th the number of cells in the culture treated with the Allopurinol at the early stage of development was higher in comparison with the Control (2350.1 ± 199.0 vs 2123 ± 96 and higher in comparison with the late period of treatment (1479.6 ± 103.8, p < < 0.05. In all groups, the number of the dead cells was less than in Control, indicating the protective nature of Allopurinol as an inhibitor of XO. Conclusions. Allopurinol initiates cells proliferation in case of the early treatment of the human brain derived cell culture whereas at the late stages it has an opposite effect.

  7. AMP-Activated Protein Kinase Regulates Oxidative Metabolism in Caenorhabditis elegans through the NHR-49 and MDT-15 Transcriptional Regulators.

    Science.gov (United States)

    Moreno-Arriola, Elizabeth; El Hafidi, Mohammed; Ortega-Cuéllar, Daniel; Carvajal, Karla

    2016-01-01

    Cellular energy regulation relies on complex signaling pathways that respond to fuel availability and metabolic demands. Dysregulation of these networks is implicated in the development of human metabolic diseases such as obesity and metabolic syndrome. In Caenorhabditis elegans the AMP-activated protein kinase, AAK, has been associated with longevity and stress resistance; nevertheless its precise role in energy metabolism remains elusive. In the present study, we find an evolutionary conserved role of AAK in oxidative metabolism. Similar to mammals, AAK is activated by AICAR and metformin and leads to increased glycolytic and oxidative metabolic fluxes evidenced by an increase in lactate levels and mitochondrial oxygen consumption and a decrease in total fatty acids and lipid storage, whereas augmented glucose availability has the opposite effects. We found that these changes were largely dependent on the catalytic subunit AAK-2, since the aak-2 null strain lost the observed metabolic actions. Further results demonstrate that the effects due to AAK activation are associated to SBP-1 and NHR-49 transcriptional factors and MDT-15 transcriptional co-activator, suggesting a regulatory pathway that controls oxidative metabolism. Our findings establish C. elegans as a tractable model system to dissect the relationship between distinct molecules that play a critical role in the regulation of energy metabolism in human metabolic diseases.

  8. RKIP regulates MAP kinase signaling in cells with defective B-Raf activity.

    Science.gov (United States)

    Zeng, Lingchun; Ehrenreiter, Karin; Menon, Jyotsana; Menard, Ray; Kern, Florian; Nakazawa, Yoko; Bevilacqua, Elena; Imamoto, Akira; Baccarini, Manuela; Rosner, Marsha Rich

    2013-05-01

    MAP kinase (MAPK) signaling results from activation of Raf kinases in response to external or internal stimuli. Here, we demonstrate that Raf kinase inhibitory protein (RKIP) regulates the activation of MAPK when B-Raf signaling is defective. We used multiple models including mouse embryonic fibroblasts (MEFs) and primary keratinocytes from RKIP- or Raf-deficient mice as well as allografts in mice to investigate the mechanism. Loss of B-Raf protein or activity significantly reduces MAPK activation in these cells. We show that RKIP depletion can rescue the compromised ERK activation and promote proliferation, and this rescue occurs through a Raf-1 dependent mechanism. These results provide formal evidence that RKIP is a bona fide regulator of Raf-1. We propose a new model in which RKIP plays a key role in regulating the ability of cells to signal through Raf-1 to ERK in B-Raf compromised cells.

  9. PKCζ regulates Notch receptor routing and activity in a Notch signaling-dependent manner.

    Science.gov (United States)

    Sjöqvist, Marika; Antfolk, Daniel; Ferraris, Saima; Rraklli, Vilma; Haga, Cecilia; Antila, Christian; Mutvei, Anders; Imanishi, Susumu Y; Holmberg, Johan; Jin, Shaobo; Eriksson, John E; Lendahl, Urban; Sahlgren, Cecilia

    2014-04-01

    Activation of Notch signaling requires intracellular routing of the receptor, but the mechanisms controlling the distinct steps in the routing process is poorly understood. We identify PKCζ as a key regulator of Notch receptor intracellular routing. When PKCζ was inhibited in the developing chick central nervous system and in cultured myoblasts, Notch-stimulated cells were allowed to undergo differentiation. PKCζ phosphorylates membrane-tethered forms of Notch and regulates two distinct routing steps, depending on the Notch activation state. When Notch is activated, PKCζ promotes re-localization of Notch from late endosomes to the nucleus and enhances production of the Notch intracellular domain, which leads to increased Notch activity. In the non-activated state, PKCζ instead facilitates Notch receptor internalization, accompanied with increased ubiquitylation and interaction with the endosomal sorting protein Hrs. Collectively, these data identify PKCζ as a key regulator of Notch trafficking and demonstrate that distinct steps in intracellular routing are differentially modulated depending on Notch signaling status.

  10. Regulation of the activity of the Bacillus licheniformis A5 glutamine synthetase.

    OpenAIRE

    Donohue, T J; Bernlohr, R W

    1981-01-01

    The regulation of glutamine synthetase activity by positive and negative effectors of enzyme activity singularly and in combinations was studied by using a homogeneous enzyme preparation from Bacillus licheniformis A5. Phosphorylribosyl pyrophosphate at concentrations greater than 2mM stimulated glutamine synthetase activity by approximately 70%. The concentration of phosphorylribosyl pyrophosphate required for half-maximal stimulation of enzyme activity was 0.4 mM. Results obtained from stud...

  11. Legal Instruments of Regulation of Development of Banking Activity in Ukraine

    Directory of Open Access Journals (Sweden)

    Senyshch Pavlo M.

    2014-03-01

    Full Text Available The article considers main approaches to identification of essence of legal instruments of regulation of development of the banking activity, identifies the mechanism of legal regulation of the banking activity and its elements and justifies the system and form of legal regulation of the banking activity in Ukraine. It describes subjects of legal regulation of the banking activity at the international level, which are the Basel Committee on Banking Supervision, European Central Bank, IMF, International Financial Reporting Standards Foundation and others. The article considers specific features of the regulatory requirements of Basel II and Basel III and specific features of their introduction into the banking activity. It describes anti-cyclic measures offered by the Basel Committee, which should facilitate formation of such conditions, under which the banking sector could have a lower level of leverage and stability with respect to influence of system risks. Significant attention is paid to international instruments of regulation of the banking activity, which include the following legal acts: Uniform Rules for Collections, Uniform Customs and Practice for Documentary Credits, and Unified Rules for Loan Guarantees. The article shows that the share of subordinate legal acts is significant in the Ukrainian system of banking regulatory and legal acts since the state cannot operatively react to the changing processes in banking at the legislative level and, that is why, basic provisions on carrying out banking activity should be fixed in law.

  12. DMPD: Genetic regulation of macrophage priming/activation: the Lsh gene story. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 1757110 Genetic regulation of macrophage priming/activation: the Lsh gene story. Bl... (.svg) (.html) (.csml) Show Genetic regulation of macrophage priming/activation: the Lsh gene story. Pubmed...ID 1757110 Title Genetic regulation of macrophage priming/activation: the Lsh gen

  13. Reciprocal regulation of LXRα activity by ASXL1 and ASXL2 in lipogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ui-Hyun; Seong, Mi-ran [Department of Bioscience and Biotechnology, Institute of Bioscience, BK21 Graduate Program, Sejong University, Seoul 143-747 (Korea, Republic of); Kim, Eun-Joo; Hur, Wonhee; Kim, Sung Woo [Department of Molecular Biology, BK21 Graduate Program, Dankook University, Gyeonggi-do 448-701 (Korea, Republic of); Yoon, Seung Kew [The Catholic University Liver Research Center and WHO Collaborating Center of Viral Hepatitis, The Catholic University, College of Medicine, Seoul 137-701 (Korea, Republic of); Um, Soo-Jong, E-mail: umsj@sejong.ac.kr [Department of Bioscience and Biotechnology, Institute of Bioscience, BK21 Graduate Program, Sejong University, Seoul 143-747 (Korea, Republic of)

    2014-01-10

    Highlights: •ASXL1 and ASXL2 directly interact with ligand-bound LXRα. •Ligand-induced LXRα activity is repressed by ASXL1 and activated by ASXL2. •ASXL1 and ASXL2 bind to the LXRE of the LXRα target promoter. •ASXL1 and ASXL2 reciprocally regulate lipogenesis in liver cells. -- Abstract: Liver X receptor alpha (LXRα), a member of the nuclear receptor superfamily, plays a pivotal role in hepatic cholesterol and lipid metabolism, regulating the expression of genes associated with hepatic lipogenesis. The additional sex comb-like (ASXL) family was postulated to regulate chromatin function. Here, we investigate the roles of ASXL1 and ASXL2 in regulating LXRα activity. We found that ASXL1 suppressed ligand-induced LXRα transcriptional activity, whereas ASXL2 increased LXRα activity through direct interaction in the presence of the ligand. Chromatin immunoprecipitation (ChIP) assays showed ligand-dependent recruitment of ASXLs to ABCA1 promoters, like LXRα. Knockdown studies indicated that ASXL1 inhibits, while ASXL2 increases, lipid accumulation in H4IIE cells, similar to their roles in transcriptional regulation. We also found that ASXL1 expression increases under fasting conditions, and decreases in insulin-treated H4IIE cells and the livers of high-fat diet-fed mice. Overall, these results support the reciprocal role of the ASXL family in lipid homeostasis through the opposite regulation of LXRα.

  14. Regulation and activity of secretory leukoprotease inhibitor (SLPI) is altered in smokers.

    Science.gov (United States)

    Meyer, Megan; Bauer, Rebecca N; Letang, Blanche D; Brighton, Luisa; Thompson, Elizabeth; Simmen, Rosalia C M; Bonner, James; Jaspers, Ilona

    2014-02-01

    A hallmark of cigarette smoking is a shift in the protease/antiprotease balance, in favor of protease activity. However, it has recently been shown that smokers have increased expression of a key antiprotease, secretory leukoprotease inhibitor (SLPI), yet the mechanisms involved in SLPI transcriptional regulation and functional activity of SLPI remain unclear. We examined SLPI mRNA and protein secretion in differentiated nasal epithelial cells (NECs) and nasal lavage fluid (NLF) from nonsmokers and smokers and demonstrated that SLPI expression is increased in NECs and NLF from smokers. Transcriptional regulation of SLPI expression was confirmed using SLPI promoter reporter assays followed by chromatin immunoprecipitation. The role of STAT1 in regulating SLPI expression was further elucidated using WT and stat1(-/-) mice. Our data demonstrate that STAT1 regulates SLPI transcription in epithelial cells and slpi protein in the lungs of mice. Additionally, we reveal that NECs from smokers have increased STAT1 mRNA/protein expression. Finally, we demonstrate that SLPI contained in the nasal mucosa of smokers is proteolytically cleaved but retains functional activity against neutrophil elastase. These results demonstrate that smoking enhances expression of SLPI in NECs in vitro and in vivo, and that this response is regulated by STAT1. In addition, despite posttranslational cleavage of SLPI, antiprotease activity against neutrophil elastase is enhanced in smokers. Together, our findings show that SLPI regulation and activity is altered in the nasal mucosa of smokers, which could have broad implications in the context of respiratory inflammation and infection.

  15. The protease inhibitor HAI-2, but not HAI-1, regulates matriptase activation and shedding through prostasin.

    Science.gov (United States)

    Friis, Stine; Sales, Katiuchia Uzzun; Schafer, Jeffrey Martin; Vogel, Lotte K; Kataoka, Hiroaki; Bugge, Thomas H

    2014-08-01

    The membrane-anchored serine proteases, matriptase and prostasin, and the membrane-anchored serine protease inhibitors, hepatocyte growth factor activator inhibitor (HAI)-1 and HAI-2, are critical effectors of epithelial development and postnatal epithelial homeostasis. Matriptase and prostasin form a reciprocal zymogen activation complex that results in the formation of active matriptase and prostasin that are targets for inhibition by HAI-1 and HAI-2. Conflicting data, however, have accumulated as to the existence of auxiliary functions for both HAI-1 and HAI-2 in regulating the intracellular trafficking and activation of matriptase. In this study, we, therefore, used genetically engineered mice to determine the effect of ablation of endogenous HAI-1 and endogenous HAI-2 on endogenous matriptase expression, subcellular localization, and activation in polarized intestinal epithelial cells. Whereas ablation of HAI-1 did not affect matriptase in epithelial cells of the small or large intestine, ablation of HAI-2 resulted in the loss of matriptase from both tissues. Gene silencing studies in intestinal Caco-2 cell monolayers revealed that this loss of cell-associated matriptase was mechanistically linked to accelerated activation and shedding of the protease caused by loss of prostasin regulation by HAI-2. Taken together, these data indicate that HAI-1 regulates the activity of activated matriptase, whereas HAI-2 has an essential role in regulating prostasin-dependent matriptase zymogen activation.

  16. Unimpeded skin carcinogenesis in K14-HPV16 transgenic mice deficient for plasminogen activator inhibitor

    OpenAIRE

    Masset, Anne; Maillard, Catherine; Sounni, Nor Eddine; Jacobs, Nathalie; Bruyére, Françoise; Delvenne, Philippe; Tacke, Marlene; Reinheckel, Thomas; Foidart, Jean-Michel; Coussens, Lisa M.; Noël, Agnès

    2011-01-01

    Angiogenesis, extracellular matrix remodeling and cell migration are associated with cancer progression and involve at least, the plasminogen activating system and its main physiological inhibitor, the plasminogen activator inhibitor-1 (PAI-1). Considering the recognized importance of PAI-1 in the regulation of tumor angiogenesis and invasion in murine models of skin tumor transplantation, we explored the functional significance of PAI-1 during early stages of neoplastic progression in the tr...

  17. Rubisco activity and regulation as targets for crop improvement.

    Science.gov (United States)

    Parry, Martin A J; Andralojc, P John; Scales, Joanna C; Salvucci, Michael E; Carmo-Silva, A Elizabete; Alonso, Hernan; Whitney, Spencer M

    2013-01-01

    Rubisco (ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase) enables net carbon fixation through the carboxylation of RuBP. However, some characteristics of Rubisco make it surprisingly inefficient and compromise photosynthetic productivity. For example, Rubisco catalyses a wasteful reaction with oxygen that leads to the release of previously fixed CO(2) and NH(3) and the consumption of energy during photorespiration. Furthermore, Rubisco is slow and large amounts are needed to support adequate photosynthetic rates. Consequently, Rubisco has been studied intensively as a prime target for manipulations to 'supercharge' photosynthesis and improve both productivity and resource use efficiency. The catalytic properties of Rubiscos from diverse sources vary considerably, suggesting that changes in turnover rate, affinity, or specificity for CO(2) can be introduced to improve Rubisco performance in specific crops and environments. While attempts to manipulate plant Rubisco by nuclear transformation have had limited success, modifying its catalysis by targeted changes to its catalytic large subunit via chloroplast transformation have been much more successful. However, this technique is still in need of development for most major food crops including maize, wheat, and rice. Other bioengineering approaches for improving Rubisco performance include improving the activity of its ancillary protein, Rubisco activase, in addition to modulating the synthesis and degradation of Rubisco's inhibitory sugar phosphate ligands. As the rate-limiting step in carbon assimilation, even modest improvements in the overall performance of Rubisco pose a viable pathway for obtaining significant gains in plant yield, particularly under stressful environmental conditions.

  18. Emotion Regulation and Excess Weight: Impaired Affective Processing Characterized by Dysfunctional Insula Activation and Connectivity.

    Science.gov (United States)

    Steward, Trevor; Picó-Pérez, Maria; Mata, Fernanda; Martínez-Zalacaín, Ignacio; Cano, Marta; Contreras-Rodríguez, Oren; Fernández-Aranda, Fernando; Yucel, Murat; Soriano-Mas, Carles; Verdejo-García, Antonio

    2016-01-01

    Emotion-regulation strategies are understood to influence food intake. This study examined the neurophysiological underpinnings of negative emotion processing and emotion regulation in individuals with excess weight compared to normal-weight controls. Fifteen participants with excess-weight (body mass index >25) and sixteen normal-weight controls (body mass index 18-25) performed an emotion-regulation task during functional magnetic resonance imaging. Participants were exposed to 24 negative affective or neutral pictures that they were instructed to Observe (neutral pictures), Maintain (sustain the emotion elicited by negative pictures) or Regulate (down-regulate the emotion provoked by negative pictures through previously trained reappraisal techniques). When instructed to regulate negative emotions by means of cognitive reappraisal, participants with excess weight displayed persistently heightened activation in the right anterior insula. Decreased responsivity was also found in right anterior insula, the orbitofrontal cortex and cerebellum during negative emotion experience in participants with excess weight. Psycho-physiological interaction analyses showed that excess-weight participants had decreased negative functional coupling between the right anterior insula and the right dlPFC, and the bilateral dmPFC during cognitive reappraisal. Our findings support contentions that excess weight is linked to an abnormal pattern of neural activation and connectivity during the experience and regulation of negative emotions, with the insula playing a key role in these alterations. We posit that ineffective regulation of emotional states contributes to the acquisition and preservation of excess weight. PMID:27003840

  19. Emotion Regulation and Excess Weight: Impaired Affective Processing Characterized by Dysfunctional Insula Activation and Connectivity

    Science.gov (United States)

    Mata, Fernanda; Martínez-Zalacaín, Ignacio; Cano, Marta; Contreras-Rodríguez, Oren; Fernández-Aranda, Fernando; Yucel, Murat; Soriano-Mas, Carles; Verdejo-García, Antonio

    2016-01-01

    Emotion-regulation strategies are understood to influence food intake. This study examined the neurophysiological underpinnings of negative emotion processing and emotion regulation in individuals with excess weight compared to normal-weight controls. Fifteen participants with excess-weight (body mass index >25) and sixteen normal-weight controls (body mass index 18–25) performed an emotion-regulation task during functional magnetic resonance imaging. Participants were exposed to 24 negative affective or neutral pictures that they were instructed to Observe (neutral pictures), Maintain (sustain the emotion elicited by negative pictures) or Regulate (down-regulate the emotion provoked by negative pictures through previously trained reappraisal techniques). When instructed to regulate negative emotions by means of cognitive reappraisal, participants with excess weight displayed persistently heightened activation in the right anterior insula. Decreased responsivity was also found in right anterior insula, the orbitofrontal cortex and cerebellum during negative emotion experience in participants with excess weight. Psycho-physiological interaction analyses showed that excess-weight participants had decreased negative functional coupling between the right anterior insula and the right dlPFC, and the bilateral dmPFC during cognitive reappraisal. Our findings support contentions that excess weight is linked to an abnormal pattern of neural activation and connectivity during the experience and regulation of negative emotions, with the insula playing a key role in these alterations. We posit that ineffective regulation of emotional states contributes to the acquisition and preservation of excess weight. PMID:27003840

  20. Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids

    Directory of Open Access Journals (Sweden)

    Azevedo R.B.

    2001-01-01

    Full Text Available Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%. Removal of the gonads in both males and females (comparison between castrated groups increased the difference in SOD activity from 83 to 138% and reduced the difference in CAT activity from 180 to 86%. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48% CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.

  1. Na,K-ATPase activity in mouse muscle is regulated by AMPK and PGC-1a

    DEFF Research Database (Denmark)

    Ingwersen, Maria S; Kristensen, Michael; Pilegaard, Henriette;

    2011-01-01

    Na,K-ATPase activity, which is crucial for skeletal muscle function, undergoes acute and long-term regulation in response to muscle activity. The aim of the present study was to test the hypothesis that AMP kinase (AMPK) and the transcriptional coactivator PGC-1a are underlying factors in long...

  2. An activator of transcription regulates phage TP901-1 late gene expression

    DEFF Research Database (Denmark)

    Brøndsted, Lone; Pedersen, Margit; Hammer, Karin

    2001-01-01

    A promoter active in the late phase of the lytic cycle of lactococcal bacteriophage TP901-1 has been identified. The promoter is tightly regulated and requires the product of the phage TP901-1 orf29 for activity. A deletion analysis of the late promoter region showed that a fragment as small as 9...

  3. Comparing Models for Generating a System of Activation and Inhibition of Self-Regulated Learning

    Science.gov (United States)

    Magno, Carlo

    2008-01-01

    The study investigated the effect of activation and negative affect on self-regulation. The activation factors are self-determination, disengagement, initiative, and persistence while negative affect is composed of worry, anxiety, thought suppression, and fear of negative evaluation. Separate measures were used for each factor and administered to…

  4. Cyclic dermal BMP signaling regulates stem cell activation during hair regeneration

    OpenAIRE

    Plikus, Maksim V; Mayer, Julie; de la Cruz, Damon; Baker, Ruth E.; Maini, Philip K.; Maxson, Robert; Chuong, Cheng-ming

    2008-01-01

    In the age of stem cell engineering, it is critical to understand how stem cell activity is regulated during regeneration. Hairs are mini-organs that undergo cyclic regeneration throughout adult life,1 and are an important model for organ regeneration. Hair stem cells located in the follicle bulge2 are regulated by the surrounding micro-environment, or niche3. The activation of such stem cells is cyclic, involving periodic β-catenin activity4–7. In adult mouse, regeneration occurs in waves in...

  5. The cell biology of inflammasomes: Mechanisms of inflammasome activation and regulation.

    Science.gov (United States)

    Sharma, Deepika; Kanneganti, Thirumala-Devi

    2016-06-20

    Over the past decade, numerous advances have been made in the role and regulation of inflammasomes during pathogenic and sterile insults. An inflammasome complex comprises a sensor, an adaptor, and a zymogen procaspase-1. The functional output of inflammasome activation includes secretion of cytokines, IL-1β and IL-18, and induction of an inflammatory form of cell death called pyroptosis. Recent studies have highlighted the intersection of this inflammatory response with fundamental cellular processes. Novel modulators and functions of inflammasome activation conventionally associated with the maintenance of homeostatic biological functions have been uncovered. In this review, we discuss the biological processes involved in the activation and regulation of the inflammasome.

  6. Post-translational Control of the Temporal Dynamics of Transcription Factor Activity Regulates Neurogenesis.

    Science.gov (United States)

    Quan, Xiao-Jiang; Yuan, Liqun; Tiberi, Luca; Claeys, Annelies; De Geest, Natalie; Yan, Jiekun; van der Kant, Rob; Xie, Wei R; Klisch, Tiemo J; Shymkowitz, Joost; Rousseau, Frederic; Bollen, Mathieu; Beullens, Monique; Zoghbi, Huda Y; Vanderhaeghen, Pierre; Hassan, Bassem A

    2016-01-28

    Neurogenesis is initiated by the transient expression of the highly conserved proneural proteins, bHLH transcriptional regulators. Here, we discover a conserved post-translational switch governing the duration of proneural protein activity that is required for proper neuronal development. Phosphorylation of a single Serine at the same position in Scute and Atonal proneural proteins governs the transition from active to inactive forms by regulating DNA binding. The equivalent Neurogenin2 Threonine also regulates DNA binding and proneural activity in the developing mammalian neocortex. Using genome editing in Drosophila, we show that Atonal outlives its mRNA but is inactivated by phosphorylation. Inhibiting the phosphorylation of the conserved proneural Serine causes quantitative changes in expression dynamics and target gene expression resulting in neuronal number and fate defects. Strikingly, even a subtle change from Serine to Threonine appears to shift the duration of Atonal activity in vivo, resulting in neuronal fate defects. PMID:26824657

  7. Characterization of Adapter Protein NRBP as a Negative Regulator of T Cell Activation

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; LIN Zhi-xin; WU Jun

    2008-01-01

    Adapter proteins can regulate the gene transcriptions in disparate signaling pathway by interacting with multiple signaling molecules, including T cell activation signaling. Nuclear receptor binding protein (NRBP), a novel adapter protein, represents a small family of evolutionarily conserved proteins with homologs in Caenorhabditis elegans (C. elegans), Drosophila melanogaster (D.melanogaster), mouse and human. Here, we demonstrated that overexpression of NRBP in Jurkat TAg cells specifically impairs T cell receptor (TCR) or phorbol myristate acetate (PMA)/ionomycin-mediated signaling leading to nuclear factor of activated T cells (NFAT) promoter activation. Furthermore, the N-terminal of NRBP is necessary for its regulation of NFAT activation. Finally, we showed that NRBP has minimal effect on both TCR- and PMA-induced CD69 up-regulation in Jurkat TAg cells, which suggests that NRBP may function downstream of protein kinase C (PKC)/Ras pathway.

  8. Structural mechanism of GAF-regulated σ(54) activators from Aquifex aeolicus.

    Science.gov (United States)

    Batchelor, Joseph D; Lee, Peter S; Wang, Andrew C; Doucleff, Michaeleen; Wemmer, David E

    2013-01-01

    The σ subunits of bacterial RNA polymerase occur in many variant forms and confer promoter specificity to the holopolymerase. Members of the σ(54) family of σ subunits require the action of a 'transcriptional activator' protein to open the promoter and initiate transcription. The activator proteins undergo regulated assembly from inactive dimers to hexamers that are active ATPases. These contact σ(54) directly and, through ATP hydrolysis, drive a conformational change that enables promoter opening. σ(54) activators use several different kinds of regulatory domains to respond to a wide variety of intracellular signals. One common regulatory module, the GAF domain, is used by σ(54) activators to sense small-molecule ligands. The structural basis for GAF domain regulation in σ(54) activators has not previously been reported. Here, we present crystal structures of GAF regulatory domains for Aquifex aeolicus σ(54) activators NifA-like homolog (Nlh)2 and Nlh1 in three functional states-an 'open', ATPase-inactive state; a 'closed', ATPase-inactive state; and a 'closed', ligand-bound, ATPase-active state. We also present small-angle X-ray scattering data for Nlh2-linked GAF-ATPase domains in the inactive state. These GAF domain dimers regulate σ(54) activator proteins by holding the ATPase domains in an inactive dimer conformation. Ligand binding of Nlh1 dramatically remodels the GAF domain dimer interface, disrupting the contacts with the ATPase domains. This mechanism has strong parallels to the response to phosphorylation in some two-component regulated σ(54) activators. We describe a structural mechanism of GAF-mediated enzyme regulation that appears to be conserved among humans, plants, and bacteria. PMID:23123379

  9. NLRP3 Activation Was Regulated by DNA Methylation Modification during Mycobacterium tuberculosis Infection

    Science.gov (United States)

    Wei, Meili; Wang, Lu; Wu, Tao; Xi, Jun; Han, Yuze; Yang, Xingxiang; Zhang, Ding; Fang, Qiang

    2016-01-01

    Mycobacterium tuberculosis (Mtb) infection activates the NLRP3 inflammasome in macrophages and dendritic cells. Much attention has been paid to the mechanisms for regulation of NLRP3 against Mtb. However, whether epigenetic mechanisms participated in NLRP3 activation is still little known. Here we showed that NLRP3 activation was regulated by DNA methylation modification. Mtb infection promoted NLRP3 activation and inflammatory cytokines expression. NLRP3 promoter was cloned and subsequently identified by Dual-Luciferase Reporter System. The results showed that NLRP3 promoter activity was decreased after methylation by DNA methylase Sss I in vitro. Meanwhile, DNA methyltransferases inhibitor DAC could upregulate the expression of NLRP3. Furthermore, promoter region of NLRP3 gene was demethylated after Mtb H37Rv strain infection. These data revealed that DNA methylation was involved in NLRP3 inflammasome activation during Mtb infection and provided a new insight into the relationship between host and pathogens. PMID:27366746

  10. Control of antioxidative response by the tumor suppressor protein PML through regulating Nrf2 activity

    Science.gov (United States)

    Guo, Shuang; Cheng, Xiwen; Lim, Jun-Hee; Liu, Yu; Kao, Hung-Ying

    2014-01-01

    Oxidative stress is a consequence of an imbalance between reactive oxygen species (ROS) production and the ability of the cytoprotective system to detoxify the reactive intermediates. The tumor suppressor promyelocytic leukemia protein (PML) functions as a stress sensor. Loss of PML results in impaired mitochondrial complex II activity, increased ROS, and subsequent activation of nuclear factor erythroid 2–related factor 2 (Nrf2) antioxidative pathway. We also demonstrate that sulforaphane (SFN), an antioxidant, regulates Nrf2 activity by controlling abundance and subcellular distribution of PML and that PML is essential for SFN-mediated ROS increase, Nrf2 activation, antiproliferation, antimigration, and antiangiogenesis. Taking the results together, we have uncovered a novel antioxidative mechanism by which PML regulates cellular oxidant homeostasis by controlling complex II integrity and Nrf2 activity and identified PML as an indispensable mediator of SFN activity. PMID:24943846

  11. Truncating PREX2 mutations activate its GEF activity and alter gene expression regulation in NRAS-mutant melanoma

    KAUST Repository

    Lissanu Deribe, Yonathan

    2016-03-01

    PREX2 (phosphatidylinositol-3,4,5-triphosphate-dependent Rac-exchange factor 2) is a PTEN (phosphatase and tensin homolog deleted on chromosome 10) binding protein that is significantly mutated in cutaneous melanoma and pancreatic ductal adenocarcinoma. Here, genetic and biochemical analyses were conducted to elucidate the nature and mechanistic basis of PREX2 mutation in melanoma development. By generating an inducible transgenic mouse model we showed an oncogenic role for a truncating PREX2 mutation (PREX2E824*) in vivo in the context of mutant NRAS. Using integrative cross-species gene expression analysis, we identified deregulated cell cycle and cytoskeleton organization as significantly perturbed biological pathways in PREX2 mutant tumors. Mechanistically, truncation of PREX2 activated its Rac1 guanine nucleotide exchange factor activity, abolished binding to PTEN and activated the PI3K (phosphatidyl inositol 3 kinase)/Akt signaling pathway. We further showed that PREX2 truncating mutations or PTEN deletion induces down-regulation of the tumor suppressor and cell cycle regulator CDKN1C (also known as p57KIP2). This down-regulation occurs, at least partially, through DNA hypomethylation of a differentially methylated region in chromosome 11 that is a known regulatory region for expression of the CDKN1C gene. Together, these findings identify PREX2 as a mediator of NRAS-mutant melanoma development that acts through the PI3K/PTEN/Akt pathway to regulate gene expression of a cell cycle regulator.

  12. Neuronal MHC Class I Expression Is Regulated by Activity Driven Calcium Signaling.

    Directory of Open Access Journals (Sweden)

    Dan Lv

    Full Text Available MHC class I (MHC-I molecules are important components of the immune system. Recently MHC-I have been reported to also play important roles in brain development and synaptic plasticity. In this study, we examine the molecular mechanism(s underlying activity-dependent MHC-I expression using hippocampal neurons. Here we report that neuronal expression level of MHC-I is dynamically regulated during hippocampal development after birth in vivo. Kainic acid (KA treatment significantly increases the expression of MHC-I in cultured hippocampal neurons in vitro, suggesting that MHC-I expression is regulated by neuronal activity. In addition, KA stimulation decreased the expression of pre- and post-synaptic proteins. This down-regulation is prevented by addition of an MHC-I antibody to KA treated neurons. Further studies demonstrate that calcium-dependent protein kinase C (PKC is important in relaying KA simulation activation signals to up-regulated MHC-I expression. This signaling cascade relies on activation of the MAPK pathway, which leads to increased phosphorylation of CREB and NF-κB p65 while also enhancing the expression of IRF-1. Together, these results suggest that expression of MHC-I in hippocampal neurons is driven by Ca2+ regulated activation of the MAPK signaling transduction cascade.

  13. Regulation and function of signal transducer and activator of transcription 3

    Institute of Scientific and Technical Information of China (English)

    Qian-Rong; Qi; Zeng-Ming; Yang

    2014-01-01

    Signal transducer and activator of transcription 3(STAT3), a member of the STAT family, is a key regulator of many physiological and pathological processes. Significant progress has been made in understanding the transcriptional control, posttranslational modification, cellular localization and functional regulation of STAT3. STAT3 can translocate into the nucleus and bind to specific promoter sequences, thereby exerting transcriptional regulation. Recent studies have shown that STAT3 can also translocate into mitochondria, participating in aerobic respiration and apoptosis. In addition, STAT3 plays an important role in inflammation and tumorigenesis by regulating cell proliferation, differentiation and metabolism. Conditional knockout mouse models make it possible to study the physiological function of STAT3 in specific tissues and organs. This review summarizes the latest advances in the understanding of the expression, regulation and function of STAT3 in physiological and tumorigenic processes.

  14. Effects of Environmental Regulation on Economic Activity and Pollution in Commercial Agriculture

    OpenAIRE

    Sneeringer, Stacy E.

    2009-01-01

    Research on environmental regulation’s effects on economic activity has largely focused on manufacturing, ignoring one of the major polluters in the U.S. – commercial agriculture. As livestock production has become increasingly mobile, regulation has become an important criterion in firm location. This article extends the literature on environmental regulation’s economic effects to commercial agriculture by exploiting a series of regulations adopted in North Carolina in the 1990s. During this...

  15. Casein Kinase 2 Regulates the mRNA-destabilizing Activity of Tristetraprolin*

    OpenAIRE

    Lee, Won Hyeok; Lee, Hyun Hee; Vo, Mai-Tram; Kim, Hyo Jeong; Ko, Myoung Seok; Im, Yeong-Cheol; Min, Young Joo; Lee, Byung Ju; Cho, Wha Ja; Park, Jeong Woo

    2011-01-01

    Tristetraprolin (TTP) is an AU-rich element-binding protein that regulates mRNA stability. We previously showed that TTP acts as a negative regulator of VEGF gene expression in colon cancer cells. The p38 MAPK pathway is known to suppress the TTP activity. However, until now the signaling pathway to enhance TTP function is not well known. Here, we show that casein kinase 2 (CK2) enhances the TTP function in the regulation of the VEGF expression in colon cancer cells. CK2 increased TTP protein...

  16. Cellular contractility and extracellular matrix stiffness regulate matrix metalloproteinase activity in pancreatic cancer cells.

    Science.gov (United States)

    Haage, Amanda; Schneider, Ian C

    2014-08-01

    The pathogenesis of cancer is often driven by local invasion and metastasis. Recently, mechanical properties of the tumor microenvironment have been identified as potent regulators of invasion and metastasis, while matrix metalloproteinases (MMPs) are classically known as significant enhancers of cancer cell migration and invasion. Here we have been able to sensitively measure MMP activity changes in response to specific extracellular matrix (ECM) environments and cell contractility states. Cells of a pancreatic cancer cell line, Panc-1, up-regulate MMP activities between 3- and 10-fold with increased cell contractility. Conversely, they down-regulate MMP activities when contractility is blocked to levels seen with pan-MMP activity inhibitors. Similar, albeit attenuated, responses are seen in other pancreatic cancer cell lines, BxPC-3 and AsPC-1. In addition, MMP activity was modulated by substrate stiffness, collagen gel concentration, and the degree of collagen cross-linking, when cells were plated on collagen gels ranging from 0.5 to 5 mg/ml that span the physiological range of substrate stiffness (50-2000 Pa). Panc-1 cells showed enhanced MMP activity on stiffer substrates, whereas BxPC-3 and AsPC-1 cells showed diminished MMP activity. In addition, eliminating heparan sulfate proteoglycans using heparinase completely abrogated the mechanical induction of MMP activity. These results demonstrate the first functional link between MMP activity, contractility, and ECM stiffness and provide an explanation as to why stiffer environments result in enhanced cell migration and invasion.

  17. Nutritional conditions regulate transcriptional activity of SF-1 by controlling sumoylation and ubiquitination.

    Science.gov (United States)

    Lee, Jiwon; Yang, Dong Joo; Lee, Syann; Hammer, Gary D; Kim, Ki Woo; Elmquist, Joel K

    2016-01-11

    Steroidogenic factor 1 (SF-1) is a transcription factor expressed in the ventral medial nucleus of the hypothalamus that regulates energy homeostasis. However, the molecular mechanisms of SF-1 in the control of energy balance are largely unknown. Here, we show that nutritional conditions, such as the presence or absence of serum, affect SF-1 action. Serum starvation significantly decreased hypothalamic SF-1 levels by promoting ubiquitin-dependent degradation, and sumoylation was required for this process. SF-1 transcriptional activity was also differentially regulated by nutritional status. Under normal conditions, the transcriptional activity of hypothalamic SF-1 was activated by SUMO, but this was attenuated during starvation. Taken together, these results indicate that sumoylation and ubiquitination play crucial roles in the regulation of SF-1 function and that these effects are dependent on nutritional conditions, further supporting the importance of SF-1 in the control of energy homeostasis.

  18. Phosphatidylinositol 4-phosphate 5-kinases in the regulation of T cell activation

    Directory of Open Access Journals (Sweden)

    Loretta eTuosto

    2016-05-01

    Full Text Available Phosphatidylinositol 4,5-biphosphate kinases (PIP5K are critical regulators of T cell activation being the main enzymes involved in the synthesis of phosphatidylinositol 4,5-biphosphate (PIP2. PIP2 is indeed a pivotal regulator of the actin cytoskeleton, thus controlling T cell polarization and migration, stable adhesion to antigen presenting cells (APC, spatial organization of the immunological synapse (IS, and costimulation. Moreover, PIP2 serves also as a precursor for the second messengers inositol triphosphate (IP3, diacylglycerol (DAG and phosphatidylinositol 3,4,5-triphosphate (PIP3, which are essential for the activation of signalling pathways regulating cytokine production, cell cycle progression, survival, metabolism and differentiation. Here, we discuss the impact of PIP5Ks on several T lymphocyte functions with a specific focus on the role of CD28 co-stimulation in PIP5K compartimentalization and activation.

  19. Signal transducer and activator of transcription 3 regulation by novel binding partners

    Institute of Scientific and Technical Information of China (English)

    Tadashi; Matsuda; Ryuta; Muromoto; Yuichi; Sekine; Sumihito; Togi; Yuichi; Kitai; Shigeyuki; Kon; Kenji; Oritani

    2015-01-01

    Signal transducers and activators of transcription(STATs) mediate essential signals for various biological processes,including immune responses,hematopoiesis,and neurogenesis. STAT3,for example,is involved in the pathogenesis of various human diseases,including cancers,autoimmune and inflammatory disorders. STAT3 activation is therefore tightly regulated at multiple levels to prevent these pathological conditions. A number of proteins have been reported to associate with STAT3 and regulate its activity. These STAT3-interacting proteins function to modulate STAT3-mediated signaling at various steps and mediate the crosstalk of STAT3 with other cellular signaling pathways. This article reviews the roles of novel STAT3 binding partners such as DAXX,zipperinteracting protein kinase,Krüppel-associated box-associated protein 1,Y14,PDZ and LIM domain 2 and signal transducing adaptor protein-2,in the regulation of STAT3-mediated signaling.

  20. Absence of canonical marks of active chromatin in developmentally regulated genes.

    Science.gov (United States)

    Pérez-Lluch, Sílvia; Blanco, Enrique; Tilgner, Hagen; Curado, Joao; Ruiz-Romero, Marina; Corominas, Montserrat; Guigó, Roderic

    2015-10-01

    The interplay of active and repressive histone modifications is assumed to have a key role in the regulation of gene expression. In contrast to this generally accepted view, we show that the transcription of genes temporally regulated during fly and worm development occurs in the absence of canonically active histone modifications. Conversely, strong chromatin marking is related to transcriptional and post-transcriptional stability, an association that we also observe in mammals. Our results support a model in which chromatin marking is associated with the stable production of RNA, whereas unmarked chromatin would permit rapid gene activation and deactivation during development. In the latter case, regulation by transcription factors would have a comparatively more important regulatory role than chromatin marks.

  1. Regulation of Peroxisome Proliferator-Activated Receptors by E6-Associated Protein

    Directory of Open Access Journals (Sweden)

    Lakshmi Gopinathan

    2008-01-01

    Full Text Available Peroxisome proliferator-activated receptors (PPARs are nuclear receptors (NRs that regulate genes involved in lipid and glucose metabolism. PPAR activity is regulated by interactions with cofactors and of interest are cofactors with ubiquitin ligase activity. The E6-associated protein (E6-AP is an E3 ubiquitin ligase that affects the activity of other NRs, although its effects on PPARs have not been examined. E6-AP inhibited the ligand-independent transcriptional activity of PPARα and PPARβ, with marginal effects on PPARγ, and decreased basal mRNA levels of PPARα target genes. Inhibition of PPARα activity required the ubiquitin ligase function of E6-AP, but occurred in a proteasome-independent manner. PPARα interacted with E6-AP, and in mice treated with PPARα agonist clofibrate, mRNA and protein levels of E6-AP were increased in wildtype, but not in PPARα null mice, indicating a PPARα-dependent regulation. These studies suggest coordinate regulation of E6-AP and PPARα, and contribute to our understanding of the role of PPARs in cellular metabolism.

  2. Regulation of pH in human skeletal muscle: adaptations to physical activity

    DEFF Research Database (Denmark)

    Juel, C

    2008-01-01

    resonance technique to exercise experiments including blood sampling and muscle biopsies. The present review characterizes the cellular buffering system as well as the most important membrane transport systems involved (Na(+)/H(+) exchange, Na-bicarbonate co-transport and lactate/H(+) co......-transport) and describes the contribution of each transport system in pH regulation at rest and during muscle activity. It is reported that the mechanisms involved in pH regulation can undergo adaptational changes in association with physical activity and that these changes are of functional importance....

  3. AMP-activated protein kinase-regulated activation of the PGC-1alpha promoter in skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Isabella Irrcher

    Full Text Available The mechanisms by which PGC-1alpha gene expression is controlled in skeletal muscle remains largely undefined. Thus, we sought to investigate the transcriptional regulation of PGC-1alpha using AICAR, an activator of AMPK, that is known to increase PGC-1alpha expression. A 2.2 kb fragment of the human PGC-1alpha promoter was cloned and sequence analysis revealed that this TATA-less sequence houses putative consensus sites including a GC-box, a CRE, several IRSs, a SRE, binding sites for GATA, MEF2, p 53, NF-kappaB, and EBox binding proteins. AMPK activation for 24 hours increased PGC-1alpha promoter activity with concomitant increases in mRNA expression. The effect of AICAR on transcriptional activation was mediated by an overlapping GATA/EBox binding site at -495 within the PGC-1alpha promoter based on gel shift analyses that revealed increases in GATA/EBox DNA binding. Mutation of the EBox within the GATA/EBox binding site in the promoter reduced basal promoter activity and completely abolished the AICAR effect. Supershift analyses identified USF-1 as a DNA binding transcription factor potentially involved in regulating PGC-1alpha promoter activity, which was confirmed in vivo by ChIP. Overexpression of either GATA-4 or USF-1 alone increased the p851 PGC-1alpha promoter activity by 1.7- and 2.0-fold respectively, while co-expression of GATA-4 and USF-1 led to an additive increase in PGC-1alpha promoter activity. The USF-1-mediated increase in PGC-1alpha promoter activation led to similar increases at the mRNA level. Our data identify a novel AMPK-mediated regulatory pathway that regulates PGC-1alpha gene expression. This could represent a potential therapeutic target to control PGC-1alpha expression in skeletal muscle.

  4. All-trans retinoic acid negatively regulates cytotoxic activities of nature killer cell line 92

    International Nuclear Information System (INIS)

    NK cells are key components of innate immune systems and their activities are regulated by cytokines and hormones. All-trans retinoic acid (ATRA), as a metabolite of vitamin A and an immunomodulatory hormone, plays an important role in regulating immune responses. In the present study, we investigated the effect of ATRA on human NK cell line NK92. We found that ATRA dose-dependently suppressed cytotoxic activities of NK92 cells without affecting their proliferation. To explore the mechanisms underlying the ATRA influence on NK92 cells, we examined the production of cytokines (TNF-α, IFN-γ), gene expression of cytotoxic-associated molecules (perforin, granzyme B, nature killer receptors (NCRs), and NKG2D), and the activation of NF-κB pathways related with immune response. Our results demonstrated that ATRA suppressed NF-κB activity and prevented IκBα degradation in a dose-dependent way, inhibited IFN-γ production and gene expression of granzyme B and NKp46. Our findings suggest that ATRA is a negative regulator of NK92 cell activation and may act as a potential regulator of anti-inflammatory functions in vivo

  5. AMP-activated protein kinase regulates nicotinamide phosphoribosyl transferase expression in skeletal muscle

    DEFF Research Database (Denmark)

    Brandauer, Josef; Vienberg, Sara Gry; Andersen, Marianne Agerholm;

    2013-01-01

    -activated protein kinase (AMPK) increases sirtuin activity by elevating NAD levels. As NAM directly inhibits sirtuins, increased Nampt activation or expression could be a metabolic stress response. Evidence suggests that AMPK regulates Nampt mRNA content, but whether repeated AMPK activation is necessary for...... increasing Nampt protein levels is unknown. To this end, we assessed whether exercise training- or 5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide (AICAR)-mediated increases in skeletal muscle Nampt abundance are AMPK dependant. One-legged knee-extensor exercise training in humans increased Nampt protein...

  6. Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem.

    Energy Technology Data Exchange (ETDEWEB)

    Matt Vaughn Greg Harrington Daniel R Bush

    2002-08-06

    This project was based on our discovery that sucrose acts as a signaling molecule that regulates the activity of a proton-sucrose symporter in sugar beet leaf tissue. A major objective here was determining how sucrose transporter activity is being regulated. When sucrose accumulates in the phloem sucrose transport activity drops dramatically. Western blots of plasma membrane proteins isolated from sucrose treated leaves showed that the loss of sucrose transport activity was proportional to a decline in symporter abundance, demonstrating that sucrose transport is regulated by changes in the amount of BvSUT1 protein. BvSUT1 transcript levels decreased in parallel with the loss of sucrose transport activity. Nuclear run-on experiments demonstrated that BvSUT1 gene transcription was repressed significantly in nuclei from leaves fed 100 mM exogenous sucrose, showing that sucrose-dependent modulation of BvSUT1 mRNA levels is mediated by changes in transcription. To identify which secondary messenger systems might be involved in regulating symporter activity, we used a variety of pharmacological agents to probe for a role of calcium or protein phosphorylation in sucrose signaling. In a detailed analysis, only okadaic acid altered sucrose transport activity. These results suggest a protein phosphatase is involved. We hypothesized that protein kinase inhibitors would have a neutral affect or increase symporter transcription. Transpirational feeding of the protein kinase inhibitor staurosporine had no impact on sucrose transport while calphostin C, an inhibitor of protein kinase C, caused a 60% increase. These data provided good evidence that protein phosphorylation plays a central role in regulating sucrose symporter expression and sucrose transport activity. To determine whether protein phosphorylation is involved in sucrose regulation of proton-sucrose symporter activity, we pre-fed leaves with staurosporine for 4 h and then fed the treated leaves water or 100 mM sucrose

  7. Activity-dependent brain-derived neurotrophic factor expression regulates cortistatin-interneurons and sleep behavior

    Directory of Open Access Journals (Sweden)

    Martinowich Keri

    2011-03-01

    Full Text Available Abstract Background Sleep homeostasis is characterized by a positive correlation between sleep length and intensity with the duration of the prior waking period. A causal role for brain-derived neurotrophic factor (BDNF in sleep homeostasis has been suggested, but the underlying mechanisms remain unclear. Cortistatin, a neuropeptide expressed primarily in a subset of cortical GABAergic interneurons, is another molecule implicated in sleep homeostasis. Results We confirmed that sleep deprivation leads to an increase in cortical cortistatin mRNA expression. Disruption of activity-dependent BDNF expression in a genetically modified mouse line impairs both baseline levels of cortistatin mRNA as well as its levels following sleep deprivation. Disruption of activity-dependent BDNF also leads to a decrease in sleep time during the active (dark phase. Conclusion Our studies suggest that regulation of cortistatin-expressing interneurons by activity-dependent BDNF expression may contribute to regulation of sleep behavior.

  8. CYLD Regulates Noscapine Activity in Acute Lymphoblastic Leukemia via a Microtubule-Dependent Mechanism

    Science.gov (United States)

    Yang, Yunfan; Ran, Jie; Sun, Lei; Sun, Xiaodong; Luo, Youguang; Yan, Bing; Tala; Liu, Min; Li, Dengwen; Zhang, Lei; Bao, Gang; Zhou, Jun

    2015-01-01

    Noscapine is an orally administrable drug used worldwide for cough suppression and has recently been demonstrated to disrupt microtubule dynamics and possess anticancer activity. However, the molecular mechanisms regulating noscapine activity remain poorly defined. Here we demonstrate that cylindromatosis (CYLD), a microtubule-associated tumor suppressor protein, modulates the activity of noscapine both in cell lines and in primary cells of acute lymphoblastic leukemia (ALL). Flow cytometry and immunofluorescence microscopy reveal that CYLD increases the ability of noscapine to induce mitotic arrest and apoptosis. Examination of cellular microtubules as well as in vitro assembled microtubules shows that CYLD enhances the effect of noscapine on microtubule polymerization. Microtubule cosedimentation and fluorescence titration assays further reveal that CYLD interacts with microtubule outer surface and promotes noscapine binding to microtubules. These findings thus demonstrate CYLD as a critical regulator of noscapine activity and have important implications for ALL treatment. PMID:25897332

  9. Regulation of aflatoxin biosynthesis: effect of glucose on activities of various glycolytic enzymes.

    Science.gov (United States)

    Buchanan, R L; Lewis, D F

    1984-08-01

    Catabolism of carbohydrates has been implicated in the regulation of aflatoxin synthesis. To characterize this effect further, the activities of various enzymes associated with glucose catabolism were determined in Aspergillus parasiticus organisms that were initially cultured in peptone-mineral salts medium and then transferred to glucose-mineral salts and peptone-mineral salts media. After an initial increase in activity, the levels of glucose 6-phosphate dehydrogenase, mannitol dehydrogenase, and malate dehydrogenase were lowered in the presence of glucose. Phosphofructokinase activity was greater in the peptone-grown mycelium, but fructose diphosphatase was largely unaffected by carbon source. Likewise, carbon source had relatively little effect on the activities of pyruvate kinase, malic enzyme, isocitrate-NADP dehydrogenase, and isocitrate-NAD dehydrogenase. The results suggest that glucose may, in part, regulate aflatoxin synthesis via a carbon catabolite repression of NADPH-generating and tricarboxylic acid cycle enzymes.

  10. [Effect of plant growth regulators on physiological activity of Bradyrhizobium japonicum ].

    Science.gov (United States)

    Leonova, N O; Tytova, L V; Tantsiurenko, O V; Antypchuk, A F

    2005-01-01

    Influence of plant growth regulators Ivin, Emistim C, Eney and Agrostimulin on the biomass production and exopolymers synthesis of soybean nodule bacteria, which have contrasting symbiotic properties, and glutamine synthetase activity of their cell-free extracts were studied. It was shown that the processes of the biomass and exopolymers accumulation had an opposite direction. Of all preparations only Ivin and Agrostimulin intensificol growth activity of the microorganisms under study. The level of glutamine synthetase activity and this enzymatic reaction specificity to the bivalent metal ions were determined by the special features of Bradyrhizobium strains and nature of the plant growth regulators. Only in the presence of Eney the increase of glutamine synthetase activity of both cultures of Bradyrhizobium japonicum was established.

  11. Mechanisms underlying regulation of the expression and activities of the mammalian pyruvate dehydrogenase kinases.

    Science.gov (United States)

    Sugden, Mary C; Holness, Mark J

    2006-07-01

    The mechanisms that control mammalian pyruvate dehydrogenase complex (PDC) activity include its phosphorylation (inactivation) by a family of pyruvate dehydrogenase kinases (PDKs 1 - 4). Here we review new developments in the regulation of the activities and expression of the PDKs, in particular PDK2 and PDK4, in relation to glucose and lipid homeostasis. This review describes recent advances relating to the acute and long-term modes of regulation of the PDKs, with particular emphasis on the regulatory roles of nuclear receptors including peroxisome proliferator-activated receptor (PPAR) alpha and Liver X receptor (LXR), PPAR gamma coactivator alpha (PGC-1alpha) and insulin, and the impact of changes in PDK activity and expression in glucose and lipid homeostasis. Since PDK4 may assist in lipid clearance when there is an imbalance between lipid delivery and oxidation, it may represent an attractive target for interventions aimed at rectifying abnormal lipid as well as glucose homeostasis in disease states. PMID:17132539

  12. Somatostatin modulates insulin-degrading-enzyme metabolism: implications for the regulation of microglia activity in AD.

    Directory of Open Access Journals (Sweden)

    Grazia Tundo

    Full Text Available The deposition of β-amyloid (Aβ into senile plaques and the impairment of somatostatin-mediated neurotransmission are key pathological events in the onset of Alzheimer's disease (AD. Insulin-degrading-enzyme (IDE is one of the main extracellular protease targeting Aβ, and thus it represents an interesting pharmacological target for AD therapy. We show that the active form of somatostatin-14 regulates IDE activity by affecting its expression and secretion in microglia cells. A similar effect can also be observed when adding octreotide. Following a previous observation where somatostatin directly interacts with IDE, here we demonstrate that somatostatin regulates Aβ catabolism by modulating IDE proteolytic activity in IDE gene-silencing experiments. As a whole, these data indicate the relevant role played by somatostatin and, potentially, by analogue octreotide, in preventing Aβ accumulation by partially restoring IDE activity.

  13. Regulation of Mutagenic DNA Polymerase V Activation in Space and Time.

    Science.gov (United States)

    Robinson, Andrew; McDonald, John P; Caldas, Victor E A; Patel, Meghna; Wood, Elizabeth A; Punter, Christiaan M; Ghodke, Harshad; Cox, Michael M; Woodgate, Roger; Goodman, Myron F; van Oijen, Antoine M

    2015-08-01

    Spatial regulation is often encountered as a component of multi-tiered regulatory systems in eukaryotes, where processes are readily segregated by organelle boundaries. Well-characterized examples of spatial regulation are less common in bacteria. Low-fidelity DNA polymerase V (UmuD'2C) is produced in Escherichia coli as part of the bacterial SOS response to DNA damage. Due to the mutagenic potential of this enzyme, pol V activity is controlled by means of an elaborate regulatory system at transcriptional and posttranslational levels. Using single-molecule fluorescence microscopy to visualize UmuC inside living cells in space and time, we now show that pol V is also subject to a novel form of spatial regulation. After an initial delay (~ 45 min) post UV irradiation, UmuC is synthesized, but is not immediately activated. Instead, it is sequestered at the inner cell membrane. The release of UmuC into the cytosol requires the RecA* nucleoprotein filament-mediated cleavage of UmuD→UmuD'. Classic SOS damage response mutants either block [umuD(K97A)] or constitutively stimulate [recA(E38K)] UmuC release from the membrane. Foci of mutagenically active pol V Mut (UmuD'2C-RecA-ATP) formed in the cytosol after UV irradiation do not co-localize with pol III replisomes, suggesting a capacity to promote translesion DNA synthesis at lesions skipped over by DNA polymerase III. In effect, at least three molecular mechanisms limit the amount of time that pol V has to access DNA: (1) transcriptional and posttranslational regulation that initially keep the intracellular levels of pol V to a minimum; (2) spatial regulation via transient sequestration of UmuC at the membrane, which further delays pol V activation; and (3) the hydrolytic activity of a recently discovered pol V Mut ATPase function that limits active polymerase time on the chromosomal template.

  14. Heat Shock Protein 90 Indirectly Regulates ERK Activity by Affecting Raf Protein Metabolism

    Institute of Scientific and Technical Information of China (English)

    Fei DOU; Liu-Di YUAN; Jing-Jing ZHU

    2005-01-01

    Extracellular signal-regulated protein kinase (ERK) has been implicated in the pathogenesis of several nerve system diseases. As more and more kinases have been discovered to be the client proteins of the molecular chaperone Hsp90, the use of Hsp90 inhibitors to reduce abnormal kinase activity is a new treatment strategy for nerve system diseases. This study investigated the regulation of the ERK pathway by Hsp90. We showed that Hsp90 inhibitors reduce ERK phosphorylation without affecting the total ERK protein level. Further investigation showed that Raf, the upstream kinase in the Ras-Raf-MEK-ERK pathway,forms a complex with Hsp90 and Hsp70. Treating cells with Hsp90 inhibitors facilitates Raf degradation,thereby down-regulating the activity of ERK.

  15. Licensing and safety regulation on units engaged in civilian nuclear pressure retaining component's activities

    International Nuclear Information System (INIS)

    The NNSA convened a meeting for granting the first batch of 25 units engaged in the activities of civilian nuclear pressure retaining components with 45 qualificatory licenses in 1995, and will conduct surveillance and inspection pursuant to requirements of regulations on the associated implementing activities by units that had obtained a qualificatory license. At present, the NNSA has prepared part of inspection procedures of nuclear pressure retaining components

  16. Structural mechanism of GAF-regulated σ54 activators from Aquifex aeolicus

    OpenAIRE

    Batchelor, Joseph D.; Lee, Peter S.; Wang, Andrew C.; Doucleff, Michaeleen; Wemmer, David E.

    2012-01-01

    The σ subunits of bacterial RNA polymerase occur in many variant forms, and confer promoter specificity to the holopolymerase. Members of the σ54 family of σ subunits require the action of a ‘transcriptional activator’ protein to open the promoter and initiate transcription. The activator proteins undergo regulated assembly from inactive dimers to hexamers that are active ATPases. These contact σ54 directly and, through ATP hydrolysis, drive a conformational change that enables promoter openi...

  17. The role of class I histocompatibility antigens in the regulation of T-cell activation.

    OpenAIRE

    Dasgupta, J D; Cemach, K; Dubey, D P; Yunis, E J; Amos, D. B.

    1987-01-01

    Class I major histocompatibility antigens in humans (HLA antigens) were found to participate in the regulation of T-cell activation and proliferation induced by phytohemagglutinin. W6/32, a monomorphic antibody directed against class I HLA-A,B,C antigens, significantly inhibited the phytohemagglutinin-induced cell proliferation of peripheral blood lymphocytes. Almost complete suppression of cell activation was achieved on a subfraction of peripheral blood lymphocytes enriched in Mo1+ monocyte...

  18. Sphingomyelin synthase 1 activity is regulated by the BCR-ABL oncogene[S

    OpenAIRE

    Burns, Tara Ann; Subathra, Marimuthu; signorelli, Paola; Choi, Young; Yang, Xiaofeng; Wang, Yong; Villani, Maristella; Bhalla, Kapil; Zhou, Daohong; Luberto, Chiara

    2013-01-01

    Sphingomyelin synthase (SMS) produces sphingomyelin while consuming ceramide (a negative regulator of cell proliferation) and forming diacylglycerol (DAG) (a mitogenic factor). Therefore, enhanced SMS activity could favor cell proliferation. To examine if dysregulated SMS contributes to leukemogenesis, we measured SMS activity in several leukemic cell lines and found that it is highly elevated in K562 chronic myelogenous leukemia (CML) cells. The increased SMS in K562 cells was caused by the ...

  19. Identification of Caspase-6 as a New Regulator of Alternatively Activated Macrophages.

    Science.gov (United States)

    Yao, Yongfang; Shi, Qian; Chen, Bing; Wang, Qingsong; Li, Xinda; Li, Long; Huang, Yahong; Ji, Jianguo; Shen, Pingping

    2016-08-12

    Alternatively activated macrophages (AAMs) play essential roles in the promotion of tissue remodeling, vasculogenesis, and tumor progression; however, the detailed mechanisms underlying the activation of AAMs remain largely unknown. Here, by using quantitative proteomic analysis, we identified 62 proteins that were up-regulated in IL-4-induced macrophages. Among these, Caspase-6 was increased significantly. Caspase-6 is important in the apoptotic signaling pathway; however, its role in non-apoptosis is also reported. Here, we first examined the non-apoptotic role of Caspase-6 in the alternative activation of macrophages after administration of IL-4, 4T1 tumor conditional medium, or co-culture with 4T1 cells. Both treatments promoted alternative activation of RAW264.7 cells and primary macrophages, whereas disruption of caspase-6 expression and activity could markedly suppress the biomarker levels of AAMs. Overexpression of Caspase-6 could significantly promote the activation of AAMs. Importantly, we further present evidence that caspase-6 could regulate breast cancer cell invasion by modulating MMP-2 and MMP-9 expression in 4T1 tumor-associated macrophages, as ablation of protein levels or activity of caspase-6 suppressed tumor cell invasion in vitro In conclusion, the observed results markedly expanded our views of the dynamic changes in protein composition during alternative activation of macrophages, and they revealed a critical new role of caspase-6 in regulating this cellular biological process, which suggested that caspase-6 might be a key nod molecule to regulate immunological steady-state and be a therapeutic candidate for tumor immunotherapy. PMID:27325699

  20. Temporal self-regulation theory: a neurobiologically informed model for physical activity behavior

    OpenAIRE

    Peter eHall; Geoffrey eFong

    2015-01-01

    Dominant explanatory models for physical activity behavior are limited by the exclusion of several important components, including temporal dynamics, ecological forces, and neurobiological factors. The latter may be a critical omission, given the relevance of several aspects of cognitive function for the self-regulatory processes that are likely required for consistent implementation of physical activity behavior in everyday life. This narrative review introduces temporal self-regulation theo...

  1. Energy Conservation Analysis and Control of Hybrid Active Semiactive Suspension with Three Regulating Damping Levels

    OpenAIRE

    Long Chen; Dehua Shi; Ruochen Wang; Huawei Zhou

    2016-01-01

    Active suspension has not been popularized for high energy consumption. To address this issue, this paper introduces the concept of a new kind of suspension. The linear motor is considered to be integrated into an adjustable shock absorber to form the hybrid active semiactive suspension (HASAS). To realize the superiority of HASAS, its energy consumption and regeneration mechanisms are revealed. And the system controller which is composed of linear quadratic regulator (LQR) controller, mode d...

  2. Negative regulation of glial engulfment activity by Draper terminates glial responses to axon injury

    OpenAIRE

    Logan, Mary A.; Hackett, Rachel; Doherty, Johnna; Sheehan, Amy; Speese, Sean D.; Freeman, Marc R

    2012-01-01

    Neuronal injury elicits potent cellular responses from glia, but molecular pathways modulating glial activation, phagocytic function, and termination of reactive responses remain poorly defined. Here we show that positive or negative regulation of glial reponses to axon injury are molecularly encoded by unique isoforms of the Drosophila engulfment receptor Draper. Draper-I promotes engulfment of axonal debris through an immunoreceptor tyrosine-based activation motif (ITAM). In contrast, Drape...

  3. Regulation and practices regarding the management of very low activity radioactive wastes. Report nr 309

    International Nuclear Information System (INIS)

    This document reports a study which aims at analysing the recommendations made by international bodies (IAEA, Euratom) and the regulations of several countries (Germany, United States, United Kingdom, Sweden, Spain, Canada, Slovakia, Belgium, Japan and France) regarding the management of low activity radioactive wastes, with a focus on practices in releasing and recycling very low activity materials and the French national program for radioactive waste management

  4. Extracellular-regulated kinase 2 is activated by the enhancement of hinge flexibility.

    OpenAIRE

    Sours, Kevin M.; Xiao,Yao; Ahn, Natalie G.

    2014-01-01

    Protein motions underlie conformational and entropic contributions to enzyme catalysis; however, relatively little is known about the ways in which this occurs. Studies of the mitogen-activated protein kinase ERK2 (extracellular-regulated protein kinase 2) by hydrogen-exchange mass spectrometry suggest that activation enhances backbone flexibility at the linker between N- and C-terminal domains while altering nucleotide binding mode. Here, we address the hypothesis that enhanced backbone flex...

  5. Cln3-associated kinase activity in Saccharomyces cerevisiae is regulated by the mating factor pathway.

    Science.gov (United States)

    Jeoung, D I; Oehlen, L J; Cross, F R

    1998-01-01

    The Saccharomyces cerevisiae cell cycle is arrested in G1 phase by the mating factor pathway. Genetic evidence has suggested that the G1 cyclins Cln1, Cln2, and Cln3 are targets of this pathway whose inhibition results in G1 arrest. Inhibition of Cln1- and Cln2-associated kinase activity by the mating factor pathway acting through Far1 has been described. Here we report that Cln3-associated kinase activity is inhibited by mating factor treatment, with dose response and timing consistent with involvement in cell cycle arrest. No regulation of Cln3-associated kinase was observed in a fus3 kss1 strain deficient in mating factor pathway mitogen-activated protein (MAP) kinases. Inhibition occurs mainly at the level of specific activity of Cln3-Cdc28 complexes. Inhibition of the C-terminally truncated Cln3-1-associated kinase is not observed; such truncations were previously identified genetically as causing resistance to mating factor-induced cell cycle arrest. Regulation of Cln3-associated kinase specific activity by mating factor treatment requires Far1. Overexpression of Far1 restores inhibition of C-terminally truncated Cln3-1-associated kinase activity. G2/M-arrested cells are unable to regulate Cln3-associated kinase, possibly because of cell cycle regulation of Far1 abundance. Inhibition of Cln3-associated kinase activity by the mating factor pathway may allow this pathway to block the earliest step in normal cell cycle initiation, since Cln3 functions as the most upstream G1-acting cyclin, activating transcription of the G1 cyclins CLN1 and CLN2 as well as of the S-phase cyclins CLB5 and CLB6. PMID:9418890

  6. Acidosis-induced p38 MAPK activation and its implication in regulation of cardiac contractility

    Institute of Scientific and Technical Information of China (English)

    Ming ZHENG; Rong HOU; Rui-ping XIAO

    2004-01-01

    AIM: To determine the possible role of pH in mediating activation of p38 mitogen-activated protein kinase (MAPK) and the consequent function of activated p38 MAPK in regulating cardiac contractility. METHODS: Adult rat cardiomyocytes were isolated and cultured. Low pH media was used to induce intracellular acidosis and contraction of single cardiomyocyte was measured. RESULTS: Phosphorylation of p38 MAPK was increased during ischemia, and pHi was decreased. Intracellular acidosis activated p38 MAPK to a similar level as ischemia. Inhibition of p38 MAPK activation by SB203580, a specific inhibitor of p38 MAPK, reversed acidosis-mediated reduction of myocyte contractility. CONCLUSION: In adult rat cardiomyocytes, intracellular acidification activated p38 MAPK and decreased cardiac contractility. Pretreatment of cardiomyocytes with SB203580 completely blocked p38 MAPK activation and partially reversed acidosis-mediated decline of cardiac contractility.

  7. GROWTH-REGULATING ACTIVITY OF SOME SALTS OF 1-NAPHTHALENACETIC ACID AND 2-NAPHTHOXYACETIC ACID

    Directory of Open Access Journals (Sweden)

    Maria Laichici

    2001-01-01

    Full Text Available The salts of 1-naphthalene acetic acid and 2-naphthoxyacetic acid with ethanolamine have been synthetized. The two salts have been assessed using Tsibulskaya-Vassiliev biological test using agar-agar as the medium. Statistical processing of the data has been carried out. The good results of the bioassay indicate an auxinic growth-regulating activity of the two salts.

  8. Cycling for Students with ASD: Self-Regulation Promotes Sustained Physical Activity

    Science.gov (United States)

    Todd, Teri; Reid, Greg; Butler-Kisber, Lynn

    2010-01-01

    Individuals with autism often lack motivation to engage in sustained physical activity. Three adolescents with severe autism participated in a 16-week program and each regularly completed 30 min of cycling at the end of program. This study investigated the effect of a self-regulation instructional strategy on sustained cycling, which included…

  9. Cationic amino acid transporter-2 regulates immunity by modulating arginase activity.

    Directory of Open Access Journals (Sweden)

    Robert W Thompson

    2008-03-01

    Full Text Available Cationic amino acid transporters (CAT are important regulators of NOS2 and ARG1 activity because they regulate L-arginine availability. However, their role in the development of Th1/Th2 effector functions following infection has not been investigated. Here we dissect the function of CAT2 by studying two infectious disease models characterized by the development of polarized Th1 or Th2-type responses. We show that CAT2(-/- mice are significantly more susceptible to the Th1-inducing pathogen Toxoplasma gondii. Although T. gondii infected CAT2(-/- mice developed stronger IFN-gamma responses, nitric oxide (NO production was significantly impaired, which contributed to their enhanced susceptibility. In contrast, CAT2(-/- mice infected with the Th2-inducing pathogen Schistosoma mansoni displayed no change in susceptibility to infection, although they succumbed to schistosomiasis at an accelerated rate. Granuloma formation and fibrosis, pathological features regulated by Th2 cytokines, were also exacerbated even though their Th2 response was reduced. Finally, while IL-13 blockade was highly efficacious in wild-type mice, the development of fibrosis in CAT2(-/- mice was largely IL-13-independent. Instead, the exacerbated pathology was associated with increased arginase activity in fibroblasts and alternatively activated macrophages, both in vitro and in vivo. Thus, by controlling NOS2 and arginase activity, CAT2 functions as a potent regulator of immunity.

  10. Cu,Zn Superoxide Dismutase Maturation and Activity Are Regulated by COMMD1

    NARCIS (Netherlands)

    Vonk, Willianne I. M.; Wijmenga, Cisca; Berger, Ruud; van de Sluis, Bart; Klomp, Leo W. J.

    2010-01-01

    The maturation and activation of the anti-oxidant Cu, Zn superoxide dismutase (SOD1) are highly regulated processes that require several post-translational modifications. The maturation of SOD1 is initiated by incorporation of zinc and copper ions followed by disulfide oxidation leading to the forma

  11. Effects of ethanol feeding on the activity and regulation of hepatic carnitine palmitoyltransferase I

    NARCIS (Netherlands)

    Guzman, M.; Geelen, M.J.H.

    1988-01-01

    The effects of ethanol administration on activity and regulation of carnitine palmitoyltransferase I (CPT-I) were studied in hepatocytes isolated from rats fed a liquid, high-fat diet containing 36% of total calories as ethanol or an isocaloric amount of sucrose. Cells were isolated at several time

  12. Diacylglycerol kinase ζ regulates RhoA activation via a kinase-independent scaffolding mechanism

    DEFF Research Database (Denmark)

    Ard, Ryan; Mulatz, Kirk; Abramovici, Hanan;

    2012-01-01

    Rho GTPases share a common inhibitor, Rho guanine nucleotide dissociation inhibitor (RhoGDI), which regulates their expression levels, membrane localization, and activation state. The selective dissociation of individual Rho GTPases from RhoGDI ensures appropriate responses to cellular signals, b...

  13. AGC kinases regulate phosphorylation and activation of eukaryotic translation initiation factor 4B

    NARCIS (Netherlands)

    van Gorp, A. G. M.; van der Vos, K. E.; Brenkman, A. B.; Bremer, A.; van den Broek, N.; Zwartkruis, F.; Hershey, J. W.; Burgering, B. M. T.; Calkhoven, C. F.; Coffer, P. J.

    2009-01-01

    Eukaryotic translation initiation factor 4B (eIF4B) plays a critical role during the initiation of protein synthesis and its activity can be regulated by multiple phosphorylation events. In a search for novel protein kinase B (PKB/c-akt) substrates, we identified eIF4B as a potential target. Using a

  14. A Kinesthetic Activity Using LEGO Bricks and Buckets for Illustrating the Regulation of Blood Sugar

    Science.gov (United States)

    Urschler, Margaret; Meidl, Katherine; Browning, Samantha; Khan, Basima; Milanick, Mark

    2015-01-01

    This article describes how, when first faced with understanding blood sugar regulation, students often resort to simple memorization.Many students would like to get more involved with the conceptual framework but do not know how to start. The authors have developed an activity based on the Modell approach, a "view from the inside." This…

  15. 78 FR 78375 - Agency Information Collection Activities: CBP Regulations Pertaining to Customs Brokers

    Science.gov (United States)

    2013-12-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: CBP Regulations Pertaining to Customs Brokers Correction In notice document 2013-30220 appearing on page 76851 of the...

  16. 76 FR 163 - Agency Information Collection Activities: CBP Regulations Pertaining to Customs Brokers

    Science.gov (United States)

    2011-01-03

    ... Register (75 FR 67094) on November 1, 2010, allowing for a 60-day comment period. This notice allows for an... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: CBP Regulations Pertaining to Customs Brokers AGENCY: U.S. Customs and Border Protection, Department of Homeland...

  17. 77 FR 5778 - Agency Information Collection Activities: Rules Relating to Regulation of Domestic Exchange...

    Science.gov (United States)

    2012-02-06

    ... COMMISSION Agency Information Collection Activities: Rules Relating to Regulation of Domestic Exchange-Traded... extension of the collection. The collection covers rules related to risk disclosure concerning exchange... INFORMATION: In the notice of Extension of an Existing Collection, FR Doc. 2011-33841, on page 477 in...

  18. 76 FR 10384 - Agency Information Collection Activities: Regulation on Agency Protests

    Science.gov (United States)

    2011-02-24

    ... published this information collection request (ICR) in the Federal Register on November 15, 2010 at 75 FR... SECURITY Agency Information Collection Activities: Regulation on Agency Protests AGENCY: Office of Chief Procurement Officer, Acquisition Policy and Legislation Office, DHS. ACTION: 30-Day Notice and request...

  19. Bias in the assessment of regulation activities in studying at the level of higher education

    NARCIS (Netherlands)

    Minnaert, A; Janssen, PJ

    1997-01-01

    This article presents the results of a comparison between two questionnaires about regulation activities related to studying in higher education. The questionnaire developed within a different educational setting appears to be less discriminative and predictive than an equally developed local versio

  20. 14 CFR 1204.1503 - Programs and activities subject to these regulations.

    Science.gov (United States)

    2010-01-01

    ... regulations. 1204.1503 Section 1204.1503 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION ADMINISTRATIVE AUTHORITY AND POLICY Intergovernmental Review of National Aeronautics and Space Administration... publishes in the Federal Register a description of the Agency's programs and activities that are subject...

  1. Neuroanatomy of cardiac activity-regulating circuitry : A transneuronal retrograde viral labelling study in the rat

    NARCIS (Netherlands)

    TerHorst, GJ; Hautvast, RWM; DeJongste, MJL; Korf, J

    1996-01-01

    The anatomy of cardiac activity-regulating circuitry was studied with retrograde transneuronal viral labelling after pseudorabies virus injections into different parts of the rat heart. Transection of the spinal cord at Th1 was used to reveal selectively the parasympathetic neuronal networks. Virus-

  2. Protein Kinase C Regulates the Cell Surface Activity of Endothelin-Converting Enzyme-1.

    Science.gov (United States)

    Smith, A Ian; Lew, Rebecca A; Thomas, Walter G; Tochon-Danguy, Nathalie

    2006-09-01

    The potent vasoconstrictor endothelin is a 21 amino acid peptide whose principal physiological function is to regulate vascular tone. The generation of endothelin is crucially dependent on the local presence and activity of endothelin converting enzyme-1 (ECE-1) expressed on the surface of vascular endothelial cells. In this study, we have shown in endothelial cells that the enzyme is phosphorylated, and that phosphorylation is increased by phorbol ester stimulation of protein kinase C (PKC). Furthermore, by monitoring specific ECE-1 activity on the surface of live cells, we also show that following PKC activation, enzyme activity is significantly increased at the cell surface, where it is positioned to catalyse the generation of active endothelin. We believe this novel finding is unprecedented for a peptide processing enzyme. Indeed, this new knowledge regarding the control of endothelin production by regulating ECE-1 activity at the cell surface opens up a new area of endothelin biology and will provide novel insights into the physiology and pathophysiology of endothelin and endothelin-associated diseases. In addition, the information generated in these studies may provide valuable new insights into potential extra- and intracellular targets for the pharmacological and perhaps even therapeutic regulation of endothelin production and thus vascular tone. PMID:19617920

  3. Revisiting the mechanism of coagulation factor XIII activation and regulation from a structure/functional perspective.

    Science.gov (United States)

    Gupta, Sneha; Biswas, Arijit; Akhter, Mohammad Suhail; Krettler, Christoph; Reinhart, Christoph; Dodt, Johannes; Reuter, Andreas; Philippou, Helen; Ivaskevicius, Vytautas; Oldenburg, Johannes

    2016-01-01

    The activation and regulation of coagulation Factor XIII (FXIII) protein has been the subject of active research for the past three decades. Although discrete evidence exists on various aspects of FXIII activation and regulation a combinatorial structure/functional view in this regard is lacking. In this study, we present results of a structure/function study of the functional chain of events for FXIII. Our study shows how subtle chronological submolecular changes within calcium binding sites can bring about the detailed transformation of the zymogenic FXIII to its activated form especially in the context of FXIIIA and FXIIIB subunit interactions. We demonstrate what aspects of FXIII are important for the stabilization (first calcium binding site) of its zymogenic form and the possible modes of deactivation (thrombin mediated secondary cleavage) of the activated form. Our study for the first time provides a structural outlook of the FXIIIA2B2 heterotetramer assembly, its association and dissociation. The FXIIIB subunits regulatory role in the overall process has also been elaborated upon. In summary, this study provides detailed structural insight into the mechanisms of FXIII activation and regulation that can be used as a template for the development of future highly specific therapeutic inhibitors targeting FXIII in pathological conditions like thrombosis. PMID:27453290

  4. An Arabidopsis SUMO E3 Ligase, SIZ1, Negatively Regulates Photomorphogenesis by Promoting COP1 Activity

    KAUST Repository

    Lin, Xiao-Li

    2016-04-29

    COP1 (CONSTITUTIVE PHOTOMORPHOGENIC 1), a ubiquitin E3 ligase, is a central negative regulator of photomorphogenesis. However, how COP1 activity is regulated by post-translational modifications remains largely unknown. Here we show that SUMO (small ubiquitin-like modifier) modification enhances COP1 activity. Loss-of-function siz1 mutant seedlings exhibit a weak constitutive photomorphogenic phenotype. SIZ1 physically interacts with COP1 and mediates the sumoylation of COP1. A K193R substitution in COP1 blocks its SUMO modification and reduces COP1 activity in vitro and in planta. Consistently, COP1 activity is reduced in siz1 and the level of HY5, a COP1 target protein, is increased in siz1. Sumoylated COP1 may exhibits higher transubiquitination activity than does non-sumoylated COP1, but SIZ1-mediated SUMO modification does not affect COP1 dimerization, COP1-HY5 interaction, and nuclear accumulation of COP1. Interestingly, prolonged light exposure reduces the sumoylation level of COP1, and COP1 mediates the ubiquitination and degradation of SIZ1. These regulatory mechanisms may maintain the homeostasis of COP1 activity, ensuing proper photomorphogenic development in changing light environment. Our genetic and biochemical studies identify a function for SIZ1 in photomorphogenesis and reveal a novel SUMO-regulated ubiquitin ligase, COP1, in plants.

  5. Effectiveness and Student Perceptions of an Active Learning Activity Using a Headline News Story to Enhance In-Class Learning of Cell Cycle Regulation

    Science.gov (United States)

    Dirks-Naylor, Amie J.

    2016-01-01

    An active learning activity was used to engage students and enhance in-class learning of cell cycle regulation in a PharmD level integrated biological sciences course. The aim of the present study was to determine the effectiveness and perception of the in-class activity. After completion of a lecture on the topic of cell cycle regulation,…

  6. Cyclic nucleotides and mitogen-activated protein kinases: regulation of simvastatin in platelet activation

    Directory of Open Access Journals (Sweden)

    Hou Ssu-Yu

    2010-06-01

    Full Text Available Abstract Background 3-Hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA reductase inhibitors (statins have been widely used to reduce cardiovascular risk. These statins (i.e., simvastatin may exert other effects besides from their cholesterol-lowering actions, including inhibition of platelet activation. Platelet activation is relevant to a variety of coronary heart diseases. Although the inhibitory effect of simvastatin in platelet activation has been studied; the detailed signal transductions by which simvastatin inhibit platelet activation has not yet been completely resolved. Methods The aim of this study was to systematically examine the detailed mechanisms of simvastatin in preventing platelet activation. Platelet aggregation, flow cytometric analysis, immunoblotting, and electron spin resonance studies were used to assess the antiplatelet activity of simvastatin. Results Simvastatin (20-50 μM exhibited more-potent activity of inhibiting platelet aggregation stimulated by collagen than other agonists (i.e., thrombin. Simvastatin inhibited collagen-stimulated platelet activation accompanied by [Ca2+]i mobilization, thromboxane A2 (TxA2 formation, and phospholipase C (PLCγ2, protein kinase C (PKC, and mitogen-activated protein kinases (i.e., p38 MAPK, JNKs phosphorylation in washed platelets. Simvastatin obviously increased both cyclic AMP and cyclic GMP levels. Simvastatin markedly increased NO release, vasodilator-stimulated phosphoprotein (VASP phosphorylation, and endothelial nitric oxide synthase (eNOS expression. SQ22536, an inhibitor of adenylate cyclase, markedly reversed the simvastatin-mediated inhibitory effects on platelet aggregation, PLCγ2 and p38 MAPK phosphorylation, and simvastatin-mediated stimulatory effects on VASP and eNOS phosphorylation. Conclusion The most important findings of this study demonstrate for the first time that inhibitory effect of simvastatin in platelet activation may involve activation of the cyclic AMP

  7. nifH Promoter Activity Is Regulated by DNA Supercoiling in Sinorhizobium meliloti

    Institute of Scientific and Technical Information of China (English)

    Yan-Jie LIU; Biao HU; Jia-Bi ZHU; Shan-Jiong SHEN; Guan-Qiao YU

    2005-01-01

    In prokaryotes, DNA supercoiling regulates the expression of many genes; for example, the expression of Klebsiella pneumoniae nifLA operon depends on DNA negative supercoiling in anaerobically grown cells, which indicates that DNA supercoiling might play a role in gene regulation of the anaerobic response. Since the expression of the nifH promoter in Sinorhizobium meliloti is not repressed by oxygen, it is proposed that the status of DNA supercoiling may not affect the expression of the nifH promoter. We tested this hypothesis by analyzing nifH promoter activity in wild-type and gyr- Escherichia coli in the presence and absence of DNA gyrase inhibitors. Our results show that gene expression driven by the S.meliloti nifH promoter requires the presence of active DNA gyrase. Because DNA gyrase increases the number of negative superhelical turns in DNA in the presence of ATP, our data indicate that negative supercoiling is also important for nifH promoter activity. Our study also shows that the DNA supercoilingdependent S. meliloti nifH promoter activity is related to the trans-acting factors NtrC and NifA that activate it. DNA supercoiling appeared to have a stronger effect on NtrC-activated nifH promoter activity than on NifA-activated promoter activity. Collectively, these results from the S. meliloti nifH promoter model system seem to indicate that, in addition to regulating gene expression during anaerobic signaling, DNA supercoiling may also provide a favorable topology for trans-acting factor binding and promoter activation regardless of oxygen status.

  8. Negative regulation of caspase 3-cleaved PAK2 activity by protein phosphatase 1

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The p21-activated kinase 2 (PAK2) is activated by binding of small G proteins, Cdc42 and Rac, or through proteolytic cleavage by caspases or caspase-like proteases. Activation by both small G protein and caspase requires autophosphorylation at Thr-402 of PAK2. Although activation of PAK2 has been investigated for nearly a decade, the mechanism of PAK2 downregulation is unclear. In this study, we have applied the kinetic theory of substrate reaction during modification of enzyme activity to study the regulation mechanism of PAK2 activity by the catalytic subunit of protein phosphatase 1 (PP1α). On the basis of the kinetic equation of the substrate reaction during the reversible phosphorylation of PAK2, all microscopic kinetic constants for the free enzyme and enzyme-substrate(s) complexes have been determined. The results indicate that (1) PP1α can act directly on phosphorylated Thr-402 in the activation loop of PAK2 and down-regulate its kinase activity; (2) binding of the exogenous protein/peptide substrates at the active site of PAK2 decreases both the rates of PAK2 autoactivation and inactivation. The present method provides a novel approach for studying reversible phosphorylation reactions. The advantage of this method is not only its usefulness in study of substrate effects on enzyme modification but also its convenience in study of modification reaction directly involved in regulation of enzyme activity. This initial study should provide a foundation for future structural and mechanistic work of protein kinases and phosphatases.

  9. Negative regulation of caspase 3-cleaved PAK2 activity by protein phosphatase 1

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The p21-activated kinase 2 (PAK2) is activated by binding of small G proteins, Cdc42 and Rac, or through proteolytic cleavage by caspases or caspase-like proteases. Activation by both small G protein and caspase requires autophosphorylation at Thr-402 of PAK2. Although activation of PAK2 has been investigated for nearly a decade, the mechanism of PAK2 downregulation is unclear. In this study, we have applied the kinetic theory of substrate reaction during modification of enzyme activity to study the regulation mechanism of PAK2 activity by the catalytic subunit of protein phosphatase 1 (PP1α). On the basis of the kinetic equation of the substrate reaction during the reversible phosphorylation of PAK2, all microscopic kinetic constants for the free enzyme and enzyme-substrate(s) complexes have been determined. The results indicate that (1) PP1α can act directly on phosphorylated Thr-402 in the acti-vation loop of PAK2 and down-regulate its kinase activity; (2) binding of the exogenous protein/peptide substrates at the active site of PAK2 decreases both the rates of PAK2 autoactivation and inactivation. The present method provides a novel approach for studying reversible phosphorylation reactions. The advantage of this method is not only its usefulness in study of substrate effects on enzyme modifica-tion but also its convenience in study of modification reaction directly involved in regulation of enzyme activity. This initial study should provide a foundation for future structural and mechanistic work of protein kinases and phosphatases.

  10. Epidermis-type lipoxygenase 3 regulates adipocyte differentiation and peroxisome proliferator-activated receptor gamma activity

    DEFF Research Database (Denmark)

    Hallenborg, Philip; Jørgensen, Claus; Petersen, Rasmus K;

    2010-01-01

    The nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR gamma) is essential for adipogenesis. Although several fatty acids and their derivatives are known to bind and activate PPAR gamma, the nature of the endogenous ligand(s) promoting the early stages of adipocyte differenti...

  11. PPARβ/δ regulates glucocorticoid- and sepsis-induced FOXO1 activation and muscle wasting.

    Directory of Open Access Journals (Sweden)

    Estibaliz Castillero

    Full Text Available FOXO1 is involved in glucocorticoid- and sepsis-induced muscle wasting, in part reflecting regulation of atrogin-1 and MuRF1. Mechanisms influencing FOXO1 expression in muscle wasting are poorly understood. We hypothesized that the transcription factor peroxisome proliferator-activated receptor β/δ (PPARβ/δ upregulates muscle FOXO1 expression and activity with a downstream upregulation of atrogin-1 and MuRF1 expression during sepsis and glucocorticoid treatment and that inhibition of PPARβ/δ activity can prevent muscle wasting. We found that activation of PPARβ/δ in cultured myotubes increased FOXO1 activity, atrogin-1 and MuRF1 expression, protein degradation and myotube atrophy. Treatment of myotubes with dexamethasone increased PPARβ/δ expression and activity. Dexamethasone-induced FOXO1 activation and atrogin-1 and MuRF1 expression, protein degradation, and myotube atrophy were inhibited by PPARβ/δ blocker or siRNA. Importantly, muscle wasting induced in rats by dexamethasone or sepsis was prevented by treatment with a PPARβ/δ inhibitor. The present results suggest that PPARβ/δ regulates FOXO1 activation in glucocorticoid- and sepsis-induced muscle wasting and that treatment with a PPARβ/δ inhibitor may ameliorate loss of muscle mass in these conditions.

  12. TALE activators regulate gene expression in a position- and strand-dependent manner in mammalian cells.

    Science.gov (United States)

    Uhde-Stone, Claudia; Cheung, Edna; Lu, Biao

    2014-01-24

    Transcription activator-like effectors (TALEs) are a class of transcription factors that are readily programmable to regulate gene expression. Despite their growing popularity, little is known about binding site parameters that influence TALE-mediated gene activation in mammalian cells. We demonstrate that TALE activators modulate gene expression in mammalian cells in a position- and strand-dependent manner. To study the effects of binding site location, we engineered TALEs customized to recognize specific DNA sequences located in either the promoter or the transcribed region of reporter genes. We found that TALE activators robustly activated reporter genes when their binding sites were located within the promoter region. In contrast, TALE activators inhibited the expression of reporter genes when their binding sites were located on the sense strand of the transcribed region. Notably, this repression was independent of the effector domain utilized, suggesting a simple blockage mechanism. We conclude that TALE activators in mammalian cells regulate genes in a position- and strand-dependent manner that is substantially different from gene activation by native TALEs in plants. These findings have implications for optimizing the design of custom TALEs for genetic manipulation in mammalian cells.

  13. Regulating the nitrite reductase activity of myoglobin by redesigning the heme active center.

    Science.gov (United States)

    Wu, Lei-Bin; Yuan, Hong; Gao, Shu-Qin; You, Yong; Nie, Chang-Ming; Wen, Ge-Bo; Lin, Ying-Wu; Tan, Xiangshi

    2016-07-01

    Heme proteins perform diverse functions in living systems, of which nitrite reductase (NIR) activity receives much attention recently. In this study, to better understand the structural elements responsible for the NIR activity, we used myoglobin (Mb) as a model heme protein and redesigned the heme active center, by introducing one or two distal histidines, and by creating a channel to the heme center with removal of the native distal His64 gate (His to Ala mutation). UV-Vis kinetic studies, combined with EPR studies, showed that a single distal histidine with a suitable position to the heme iron, i.e., His43, is crucial for nitrite (NO2(-)) to nitric oxide (NO) reduction. Moreover, creation of a water channel to the heme center significantly enhanced the NIR activity compared to the corresponding mutant without the channel. In addition, X-ray crystallographic studies of F43H/H64A Mb and its complexes with NO2(-) or NO revealed a unique hydrogen-bonding network in the heme active center, as well as unique substrate and product binding models, providing valuable structural information for the enhanced NIR activity. These findings enriched our understanding of the structure and NIR activity relationship of heme proteins. The approach of creating a channel in this study is also useful for rational design of other functional heme proteins. PMID:27108710

  14. Heat Shock Proteins Regulate Activation-induced Proteasomal Degradation of the Mature Phosphorylated Form of Protein Kinase C*

    OpenAIRE

    Lum, Michelle A.; Balaburski, Gregor M; Murphy, Maureen E.; Black, Adrian R.; Black, Jennifer D.

    2013-01-01

    Background: Mechanisms of activation-induced PKC down-regulation are poorly understood. A characterized pathway involves priming site dephosphorylation and degradation of the dephosphorylated species.

  15. Ostrinia furnacalis serpin-3 regulates melanization cascade by inhibiting a prophenoloxidase-activating protease.

    Science.gov (United States)

    Chu, Yuan; Zhou, Fan; Liu, Yang; Hong, Fang; Wang, Guirong; An, Chunju

    2015-06-01

    Serine protease cascade-mediated prophenolxidase activation is a prominent innate immune response in insect defense against the invading pathogens. Serpins regulate this reaction to avoid excessive activation. However, the function of serpins in most insect species, especially in some non-model agriculture insect pests, is largely unknown. We here cloned a full-length cDNA for a serpin, named as serpin-3, from Asian corn borer, Ostrinia furnacalis (Guenée). The open reading frame of serpin-3 encodes 462-amino acid residue protein with a 19-residue signal peptide. It contains a reactive center loop strikingly similar to the proteolytic activation site in prophenoloxidase. Sequence comparison indicates that O. furnacalis serpin-3 is an apparent ortholog of Manduca sexta serpin-3, a defined negative regulator of melanization reaction. Serpin-3 mRNA and protein levels significantly increase after a bacterial or fungal injection. Recombinant serpin-3 efficiently blocks prophenoloxidase activation in larval plasma in a concentration-dependent manner. It forms SDS-stable complexes with serine protease 13 (SP13), and prevents SP13 from cleaving prophenoloxidase. Injection of recombinant serpin-3 into larvae results in decreased fungi-induced melanin synthesis and reduced the expression of attacin, cecropin, gloverin, and peptidoglycan recognition protein-1 genes in the fat body. Altogether, serpin-3 plays important roles in the regulation of prophenoloxidase activation and antimicrobial peptide production in O. furnacalis larvae. PMID:25818483

  16. SYK regulates macrophage MHC-II expression via activation of autophagy in response to oxidized LDL

    Science.gov (United States)

    Choi, Soo-Ho; Gonen, Ayelet; Diehl, Cody J; Kim, Jungsu; Almazan, Felicidad; Witztum, Joseph L; Miller, Yury I

    2015-01-01

    Adaptive immunity, which plays an important role in the development of atherosclerosis, is mediated by major histocompatibility complex (MHC)-dependent antigen presentation. In atherosclerotic lesions, macrophages constitute an important class of antigen-presenting cells that activate adaptive immune responses to oxidized low-density lipoprotein (OxLDL). It has been reported that autophagy regulates adaptive immune responses by enhancing antigen presentation to MHC class II (MHC-II). In a previous study, we have demonstrated that SYK (spleen tyrosine kinase) regulates generation of reactive oxygen species (ROS) and activation of MAPK8/JNK1 in macrophages. Because ROS and MAPK8 are known to regulate autophagy, in this study we investigated the role of SYK in autophagy, MHC-II expression and adaptive immune response to OxLDL. We demonstrate that OxLDL induces autophagosome formation, MHC-II expression, and phosphorylation of SYK in macrophages. Gene knockout and pharmacological inhibitors of NOX2 and MAPK8 reduced OxLDL-induced autophagy. Using bone marrow-derived macrophages isolated from wild-type and myeloid-specific SYK knockout mice, we demonstrate that SYK regulates OxLDL-induced ROS generation, MAPK8 activation, BECN1-BCL2 dissociation, autophagosome formation and presentation of OxLDL-derived antigens to CD4+ T cells. ldlr−/− syk−/− mice fed a high-fat diet produced lower levels of IgG to malondialdehyde (MDA)-LDL, malondialdehyde-acetaldehyde (MAA)-LDL, and OxLDL compared to ldlr−/− mice. These results provide new insights into the mechanisms by which SYK regulates MHC-II expression via autophagy in macrophages and may contribute to regulation of adaptive immune responses in atherosclerosis. PMID:25946330

  17. SYK regulates macrophage MHC-II expression via activation of autophagy in response to oxidized LDL.

    Science.gov (United States)

    Choi, Soo-Ho; Gonen, Ayelet; Diehl, Cody J; Kim, Jungsu; Almazan, Felicidad; Witztum, Joseph L; Miller, Yury I

    2015-01-01

    Adaptive immunity, which plays an important role in the development of atherosclerosis, is mediated by major histocompatibility complex (MHC)-dependent antigen presentation. In atherosclerotic lesions, macrophages constitute an important class of antigen-presenting cells that activate adaptive immune responses to oxidized low-density lipoprotein (OxLDL). It has been reported that autophagy regulates adaptive immune responses by enhancing antigen presentation to MHC class II (MHC-II). In a previous study, we have demonstrated that SYK (spleen tyrosine kinase) regulates generation of reactive oxygen species (ROS) and activation of MAPK8/JNK1 in macrophages. Because ROS and MAPK8 are known to regulate autophagy, in this study we investigated the role of SYK in autophagy, MHC-II expression and adaptive immune response to OxLDL. We demonstrate that OxLDL induces autophagosome formation, MHC-II expression, and phosphorylation of SYK in macrophages. Gene knockout and pharmacological inhibitors of NOX2 and MAPK8 reduced OxLDL-induced autophagy. Using bone marrow-derived macrophages isolated from wild-type and myeloid-specific SYK knockout mice, we demonstrate that SYK regulates OxLDL-induced ROS generation, MAPK8 activation, BECN1-BCL2 dissociation, autophagosome formation and presentation of OxLDL-derived antigens to CD4(+) T cells. ldlr(-/-) syk(-/-) mice fed a high-fat diet produced lower levels of IgG to malondialdehyde (MDA)-LDL, malondialdehyde-acetaldehyde (MAA)-LDL, and OxLDL compared to ldlr(-/-) mice. These results provide new insights into the mechanisms by which SYK regulates MHC-II expression via autophagy in macrophages and may contribute to regulation of adaptive immune responses in atherosclerosis.

  18. Hormonal and metabolic regulation of tomato fruit sink activity and yield under salinity

    DEFF Research Database (Denmark)

    Albacete, Alfonso; Cantero-Navarro, Elena; Balibrea, María E.;

    2014-01-01

    structures, thus contributing to the transport of assimilates from the source leaves through changes in sucrolytic enzymes and their regulation by phytohormones. In this study, classical and functional physiological approaches have been integrated to study the influence of metabolic and hormonal factors...... sucrolytic activities (mainly cwInv and sucrose synthase), sink strength, and fruit weight, whereas the ethylene-releasing compound ethephon had a negative effect in equivalent non-stressed fruits. Fruit yield was increased by both the constitutive expression of CIN1 in the fruits (up to 4-fold) or IPT......) and tZ concentration, and (ii) a decrease in the ACC levels and the activity of the invertase inhibitor. This study provides new functional evidences about the role of metabolic and hormonal inter-regulation of local sink processes in controlling tomato fruit sink activity, growth, and yield under...

  19. Chromoselective Photocatalysis: Controlled Bond Activation through Light-Color Regulation of Redox Potentials.

    Science.gov (United States)

    Ghosh, Indrajit; König, Burkhard

    2016-06-27

    Catalysts that can be regulated in terms of activity and selectivity by external stimuli may allow the efficient multistep synthesis of complex molecules and pharmaceuticals. Herein, we report the light-color regulation of the redox potential of a photocatalyst to control the activation of chemical bonds. Light-color control of the redox power of a photocatalyst introduces a new selectivity parameter to photoredox catalysis: Instead of changing the catalyst or ligand, alteration of the color of the visible-light irradiation adjusts the selectivity in catalytic transformations. By using this principle, the selective activation of aryl-halide bonds for C-H arylation and the sequential conversion of functional groups with different reduction potentials is possible by simply applying different colors of light for excitation of the photocatalyst.

  20. Complement System Part I – Molecular Mechanisms of Activation and Regulation

    Science.gov (United States)

    Merle, Nicolas S.; Church, Sarah Elizabeth; Fremeaux-Bacchi, Veronique; Roumenina, Lubka T.

    2015-01-01

    Complement is a complex innate immune surveillance system, playing a key role in defense against pathogens and in host homeostasis. The complement system is initiated by conformational changes in recognition molecular complexes upon sensing danger signals. The subsequent cascade of enzymatic reactions is tightly regulated to assure that complement is activated only at specific locations requiring defense against pathogens, thus avoiding host tissue damage. Here, we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and pathology. This article will review the mechanisms of activation of alternative, classical, and lectin pathways, the formation of C3 and C5 convertases, the action of anaphylatoxins, and the membrane-attack-complex. We will also discuss the importance of structure–function relationships using the example of atypical hemolytic uremic syndrome. Lastly, we will discuss the development and benefits of therapies using complement inhibitors. PMID:26082779

  1. Selective regulation of maize plasma membrane aquaporin trafficking and activity by the SNARE SYP121.

    Science.gov (United States)

    Besserer, Arnaud; Burnotte, Emeline; Bienert, Gerd Patrick; Chevalier, Adrien S; Errachid, Abdelmounaim; Grefen, Christopher; Blatt, Michael R; Chaumont, François

    2012-08-01

    Plasma membrane intrinsic proteins (PIPs) are aquaporins facilitating the diffusion of water through the cell membrane. We previously showed that the traffic of the maize (Zea mays) PIP2;5 to the plasma membrane is dependent on the endoplasmic reticulum diacidic export motif. Here, we report that the post-Golgi traffic and water channel activity of PIP2;5 are regulated by the SNARE (for soluble N-ethylmaleimide-sensitive factor protein attachment protein receptor) SYP121, a plasma membrane resident syntaxin involved in vesicle traffic, signaling, and regulation of K(+) channels. We demonstrate that the expression of the dominant-negative SYP121-Sp2 fragment in maize mesophyll protoplasts or epidermal cells leads to a decrease in the delivery of PIP2;5 to the plasma membrane. Protoplast and oocyte swelling assays showed that PIP2;5 water channel activity is negatively affected by SYP121-Sp2. A combination of in vitro (copurification assays) and in vivo (bimolecular fluorescence complementation, Förster resonance energy transfer, and yeast split-ubiquitin) approaches allowed us to demonstrate that SYP121 and PIP2;5 physically interact. Together with previous data demonstrating the role of SYP121 in regulating K(+) channel trafficking and activity, these results suggest that SYP121 SNARE contributes to the regulation of the cell osmotic homeostasis.

  2. Selective Regulation of Maize Plasma Membrane Aquaporin Trafficking and Activity by the SNARE SYP121[W

    Science.gov (United States)

    Besserer, Arnaud; Burnotte, Emeline; Bienert, Gerd Patrick; Chevalier, Adrien S.; Errachid, Abdelmounaim; Grefen, Christopher; Blatt, Michael R.; Chaumont, François

    2012-01-01

    Plasma membrane intrinsic proteins (PIPs) are aquaporins facilitating the diffusion of water through the cell membrane. We previously showed that the traffic of the maize (Zea mays) PIP2;5 to the plasma membrane is dependent on the endoplasmic reticulum diacidic export motif. Here, we report that the post-Golgi traffic and water channel activity of PIP2;5 are regulated by the SNARE (for soluble N-ethylmaleimide-sensitive factor protein attachment protein receptor) SYP121, a plasma membrane resident syntaxin involved in vesicle traffic, signaling, and regulation of K+ channels. We demonstrate that the expression of the dominant-negative SYP121-Sp2 fragment in maize mesophyll protoplasts or epidermal cells leads to a decrease in the delivery of PIP2;5 to the plasma membrane. Protoplast and oocyte swelling assays showed that PIP2;5 water channel activity is negatively affected by SYP121-Sp2. A combination of in vitro (copurification assays) and in vivo (bimolecular fluorescence complementation, Förster resonance energy transfer, and yeast split-ubiquitin) approaches allowed us to demonstrate that SYP121 and PIP2;5 physically interact. Together with previous data demonstrating the role of SYP121 in regulating K+ channel trafficking and activity, these results suggest that SYP121 SNARE contributes to the regulation of the cell osmotic homeostasis. PMID:22942383

  3. Natural compounds regulate energy metabolism by the modulating the activity of lipid-sensing nuclear receptors.

    Science.gov (United States)

    Goto, Tsuyoshi; Kim, Young-Il; Takahashi, Nobuyuki; Kawada, Teruo

    2013-01-01

    Obesity causes excess fat accumulation in various tissues, most notoriously in the adipose tissue, along with other insulin-responsive organs such as skeletal muscle and the liver, which predisposes an individual to the development of metabolic abnormalities. The molecular mechanisms underlying obesity-induced metabolic abnormalities have not been completely elucidated; however, in recent years, the search for therapies to prevent the development of obesity and obesity-associated metabolic disorders has increased. It is known that several nuclear receptors, when activated by specific ligands, regulate carbohydrate and lipid metabolism at the transcriptional level. The expression of lipid metabolism-related enzymes is directly regulated by the activity of various nuclear receptors via their interaction with specific response elements in promoters of those genes. Many natural compounds act as ligands of nuclear receptors and regulate carbohydrate and lipid metabolism by regulating the activities of these nuclear receptors. In this review, we describe our current knowledge of obesity, the role of lipid-sensing nuclear receptors in energy metabolism, and several examples of food factors that act as agonists or antagonists of nuclear receptors, which may be useful for the management of obesity and the accompanying energy metabolism abnormalities.

  4. Active site loop conformation regulates promiscuous activity in a lactonase from Geobacillus kaustophilus HTA426.

    Science.gov (United States)

    Zhang, Yu; An, Jiao; Yang, Guang-Yu; Bai, Aixi; Zheng, Baisong; Lou, Zhiyong; Wu, Geng; Ye, Wei; Chen, Hai-Feng; Feng, Yan; Manco, Giuseppe

    2015-01-01

    Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL) from Geobacillus kaustophilus HTA426 (GkaP) exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km) toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity.

  5. Active site loop conformation regulates promiscuous activity in a lactonase from Geobacillus kaustophilus HTA426.

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    Full Text Available Enzyme promiscuity is a prerequisite for fast divergent evolution of biocatalysts. A phosphotriesterase-like lactonase (PLL from Geobacillus kaustophilus HTA426 (GkaP exhibits main lactonase and promiscuous phosphotriesterase activities. To understand its catalytic and evolutionary mechanisms, we investigated a "hot spot" in the active site by saturation mutagenesis as well as X-ray crystallographic analyses. We found that position 99 in the active site was involved in substrate discrimination. One mutant, Y99L, exhibited 11-fold improvement over wild-type in reactivity (kcat/Km toward the phosphotriesterase substrate ethyl-paraoxon, but showed 15-fold decrease toward the lactonase substrate δ-decanolactone, resulting in a 157-fold inversion of the substrate specificity. Structural analysis of Y99L revealed that the mutation causes a ∼6.6 Å outward shift of adjacent loop 7, which may cause increased flexibility of the active site and facilitate accommodation and/or catalysis of organophosphate substrate. This study provides for the PLL family an example of how the evolutionary route from promiscuity to specificity can derive from very few mutations, which promotes alteration in the conformational adjustment of the active site loops, in turn draws the capacity of substrate binding and activity.

  6. Sclerostin binds and regulates the activity of cysteine-rich protein 61

    Energy Technology Data Exchange (ETDEWEB)

    Craig, Theodore A. [Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (United States); Bhattacharya, Resham; Mukhopadhyay, Debabrata [Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (United States); Kumar, Rajiv, E-mail: rkumar@mayo.edu [Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (United States); Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905 (United States)

    2010-01-29

    Sclerostin, a secreted glycoprotein, regulates osteoblast function. Using yeast two-hybrid and direct protein interaction analyses, we demonstrate that sclerostin binds the Wnt-modulating and Wnt-modulated, extracellular matrix protein, cysteine-rich protein 61 (Cyr61, CCN1), which regulates mesenchymal stem cell proliferation and differentiation, osteoblast and osteoclast function, and angiogenesis. Sclerostin was shown to inhibit Cyr61-mediated fibroblast attachment, and Cyr61 together with sclerostin increases vascular endothelial cell migration and increases osteoblast cell division. The data show that sclerostin binds to and influences the activity of Cyr61.

  7. Safety research activities for Japanese regulations of spent fuel interim storage facilities

    International Nuclear Information System (INIS)

    Japan Nuclear Energy Safety Organization (JNES) carries out (a) preparation of technical documents, (b) technical evaluations of standards (prepared by academic societies), etc. and (c) other R and D activities, to support Nuclear Regulation Authority (NRA: which controls the regulations for Spent Fuel Interim Storage Facilities). In 2012 fiscal year, JNES carried out dynamic test of spent fuel to examine the integrity of spent fuel under cask drop accidents, and preparation for PWR spent fuel storage test to prove long term integrity of spent fuel and cask itself. Some of these tests will be also carried out in 2013 fiscal year and after. (author)

  8. Considerations on Law no. 78/2014 regarding the Regulation of the Volunteering Activity in Romania

    Directory of Open Access Journals (Sweden)

    Tache BOCĂNIALĂ

    2014-08-01

    Full Text Available In this paper we aim at highlighting the progress in the regulation of volunteering activity in Romania through the recent adoption by the Parliament of the Law no. 78/2014 on the regulation of volunteering in Romania. The new legislative act, which replaced Volunteering Law no. 195 / 2001 (republished tries and we believe that it actually succeeds in providing consistent and harmonized solutions at European level to problems of organizations working with volunteers and thus creating a modern legal framework, appropriately adapted to the national and European context in the field of volunteering.

  9. Secreted proteases. Regulation of their activity and their possible role in metastasis.

    Science.gov (United States)

    Goldberg, G I; Frisch, S M; He, C; Wilhelm, S M; Reich, R; Collier, I E

    1990-01-01

    Extracellular matrix metalloproteases are secreted by the resident cells of the tissue in a proenzyme form, and their extracellular activity is regulated at the level of gene expression, proenzyme activation, and interaction with inhibitors. To understand the molecular mechanisms that control the activity of ECM metalloproteases and their effect on the cellular phenotype, we have established cell lines in which the transcription of the protease genes is repressed. We also have undertaken a detailed study of the pathway of extracellular activation of interstitial procollagenase. Stable transfection of three human tumor cell lines--H-ras-transformed bronchial epithelial cells TBE-1, fibrosarcoma cells HT1080, and melanoma cells A2058--with the adenovirus E1A gene dramatically repressed the expression of the secreted proteases, type IV and interstitial collagenases, and urokinase-type plasminogen activator. Concomitantly, E1A-expressing cells showed reduced metastatic activity in vivo and reduced ability to traverse a reconstituted basement membrane in vitro. Monospecific anti-type IV collagenase antibody inhibited the invasive activity of parental tumor cell lines in the in vitro system, suggesting a possible causal relationship between the effect of E1A on the expression of secreted proteases and the reduced metastatic potential of the E1A-expressing transformants. We have also studied the mechanism of regulation of metalloprotease activity at the level of extracellular activation by investigating the cascade of proteolytic events that results in the activation of interstitial procollagenase. Cocultivation of the major cellular components of skin, dermal fibroblasts, and epidermal keratinocytes induces activation of interstitial procollagenase and prostromelysin in the presence of plasminogen. This activation occurs through a uPA-plasmin-dependent pathway in which plasmin catalyzes the first step in activation of both collagenase and stromelysin by amino

  10. Atrial natriuretic peptide regulates lipid mobilization and oxygen consumption in human adipocytes by activating AMPK

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Sandra C. [Translational Sciences - Translational Medicine, Novartis Institutes for Biomedical Research, Inc., 220 Massachusetts Avenue, Cambridge, MA 02139 (United States); Chau, Mary D.L.; Yang, Qing [Cardiovascular and Metabolism Disease Area, Novartis Institutes for Biomedical Research, Inc., 100 Technology Square, Cambridge, MA 02139 (United States); Gauthier, Marie-Soleil [Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02140 (United States); Clairmont, Kevin B.; Wu, Zhidan; Gromada, Jesper [Cardiovascular and Metabolism Disease Area, Novartis Institutes for Biomedical Research, Inc., 100 Technology Square, Cambridge, MA 02139 (United States); Dole, William P., E-mail: bill.dole@novartis.com [Translational Sciences - Translational Medicine, Novartis Institutes for Biomedical Research, Inc., 220 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2011-07-08

    Highlights: {yields} Treatment of differentiated human adipocytes with atrial natriuretic peptide (ANP) increased lipolysis and oxygen consumption by activating AMP-activated protein kinase (AMPK). {yields} ANP stimulated lipid mobilization by selective activation of the alpha2 subunit of AMPK and increased energy utilization through activation of both the alpha1 and alpha2 subunits of AMPK. {yields} ANP enhanced adipocyte mitochondrial oxidative capacity as evidenced by induction of oxidative mitochondrial genes and increase in oxygen consumption. {yields} Exposure of human adipocytes to fatty acids and (TNF{alpha}) induced insulin resistance and decreased expression of mitochondrial genes which was restored to normal by ANP. -- Abstract: Atrial natriuretic peptide (ANP) has been shown to regulate lipid and carbohydrate metabolism providing a possible link between cardiovascular function and metabolism by mediating the switch from carbohydrate to lipid mobilization and oxidation. ANP exerts a potent lipolytic effect via cGMP-dependent protein kinase (cGK)-I mediated-stimulation of AMP-activated protein kinase (AMPK). Activation of the ANP/cGK signaling cascade also promotes muscle mitochondrial biogenesis and fat oxidation. Here we demonstrate that ANP regulates lipid metabolism and oxygen utilization in differentiated human adipocytes by activating the alpha2 subunit of AMPK. ANP treatment increased lipolysis by seven fold and oxygen consumption by two fold, both of which were attenuated by inhibition of AMPK activity. ANP-induced lipolysis was shown to be mediated by the alpha2 subunit of AMPK as introduction of dominant-negative alpha2 subunit of AMPK attenuated ANP effects on lipolysis. ANP-induced activation of AMPK enhanced mitochondrial oxidative capacity as evidenced by a two fold increase in oxygen consumption and induction of mitochondrial genes, including carnitine palmitoyltransferase 1A (CPT1a) by 1.4-fold, cytochrome C (CytC) by 1.3-fold, and

  11. Danthron activates AMP-activated protein kinase and regulates lipid and glucose metabolism in vitro

    Institute of Scientific and Technical Information of China (English)

    Rong ZHOU; Ling WANG; Xing XU; Jing CHEN; Li-hong HU; Li-li CHEN; Xu SHEN

    2013-01-01

    Aim:To discover the active compound on AMP-activated protein kinase (AMPK) activation and investigate the effects of the active compound 1,8-dihydroxyanthraquinone (danthron) from the traditional Chinese medicine rhubarb on AMPK-mediated lipid and glucose metabolism in vitro.Methods:HepG2 and C2C12 cells were used.Cell viability was determined using MTT assay.Real-time PCR was performed to measure the gene expression.Western blotting assay was applied to investigate the protein phosphorylation level.Enzymatic assay kits were used to detect the total cholesterol (TC),triglyceride (TG) and glucose contents.Results:Danthron (0.1,1,and 10 μmol/L) dose-dependently promoted the phosphorylation of AMPK and acetyl-CoA carboxylase (ACC)in both HepG2 and C2C12 cells.Meanwhile,danthron treatment significantly reduced the lipid synthesis related sterol regulatory element-binding protein 1c (SREBP1c) and fatty acid synthetase (FAS) gene expressions,and the TC and TG levels.In addition,danthron treatment efficiently increased glucose consumption.The actions of danthron on lipid and glucose metabolism were abolished or reversed by co-treatment with the AMPK inhibitor compound C.Conclusion:Danthron effectively reduces intracellular lipid contents and enhanced glucose consumption in vitro via activation of AMPK signaling pathway.

  12. Regulation of the activity of the dual-function DnaA protein in Caulobacter crescentus.

    Directory of Open Access Journals (Sweden)

    Carmen Fernandez-Fernandez

    Full Text Available DnaA is a conserved essential bacterial protein that acts as the initiator of chromosomal replication as well as a master transcriptional regulator in Caulobacter crescentus. Thus, the intracellular levels of active DnaA need to be tightly regulated during the cell cycle. Our previous work suggested that DnaA may be regulated at the level of its activity by the replisome-associated protein HdaA. Here, we describe the construction of a mutant DnaA protein [DnaA(R357A]. The R357 residue in the AAA+ domain of the C. crescentus DnaA protein is equivalent to the R334 residue of the E. coli DnaA protein, which is required for the Regulatory Inactivation of DnaA (RIDA. We found that the expression of the DnaA(R357A mutant protein in C. crescentus, but not the expression of the wild-type DnaA protein at similar levels, causes a severe phenotype of over-initiation of chromosomal replication and that it blocks cell division. Thus, the mutant DnaA(R357A protein is hyper-active to promote the initiation of DNA replication, compared to the wild-type DnaA protein. DnaA(R357A could not replace DnaA in vivo, indicating that the switch in DnaA activity once chromosomal replication has started may be an essential process in C. crescentus. We propose that the inactivation of DnaA is the main mechanism ensuring that chromosomal replication starts only once per cell cycle. We further observed that the R357A substitution in DnaA does not promote the activity of DnaA as a direct transcriptional activator of four important genes, encoding HdaA, the GcrA master cell cycle regulator, the FtsZ cell division protein and the MipZ spatial regulator of cell division. Thus, the AAA+ domain of DnaA may play a role in temporally regulating the bifunctionality of DnaA by reallocating DnaA molecules from initiating DNA replication to transcribing genes within the unique DnaA regulon of C. crescentus.

  13. Regulation of the activity of the dual-function DnaA protein in Caulobacter crescentus.

    Science.gov (United States)

    Fernandez-Fernandez, Carmen; Gonzalez, Diego; Collier, Justine

    2011-01-01

    DnaA is a conserved essential bacterial protein that acts as the initiator of chromosomal replication as well as a master transcriptional regulator in Caulobacter crescentus. Thus, the intracellular levels of active DnaA need to be tightly regulated during the cell cycle. Our previous work suggested that DnaA may be regulated at the level of its activity by the replisome-associated protein HdaA. Here, we describe the construction of a mutant DnaA protein [DnaA(R357A)]. The R357 residue in the AAA+ domain of the C. crescentus DnaA protein is equivalent to the R334 residue of the E. coli DnaA protein, which is required for the Regulatory Inactivation of DnaA (RIDA). We found that the expression of the DnaA(R357A) mutant protein in C. crescentus, but not the expression of the wild-type DnaA protein at similar levels, causes a severe phenotype of over-initiation of chromosomal replication and that it blocks cell division. Thus, the mutant DnaA(R357A) protein is hyper-active to promote the initiation of DNA replication, compared to the wild-type DnaA protein. DnaA(R357A) could not replace DnaA in vivo, indicating that the switch in DnaA activity once chromosomal replication has started may be an essential process in C. crescentus. We propose that the inactivation of DnaA is the main mechanism ensuring that chromosomal replication starts only once per cell cycle. We further observed that the R357A substitution in DnaA does not promote the activity of DnaA as a direct transcriptional activator of four important genes, encoding HdaA, the GcrA master cell cycle regulator, the FtsZ cell division protein and the MipZ spatial regulator of cell division. Thus, the AAA+ domain of DnaA may play a role in temporally regulating the bifunctionality of DnaA by reallocating DnaA molecules from initiating DNA replication to transcribing genes within the unique DnaA regulon of C. crescentus.

  14. Activity-dependent regulation of calcium and ribosomes in the chick cochlear nucleus.

    Science.gov (United States)

    Call, C L; Hyson, R L

    2016-03-01

    Cochlea removal results in the death of 20-30% of neurons in the chick cochlear nucleus, nucleus magnocellularis (NM). Two potentially cytotoxic events, a dramatic rise in intracellular calcium concentration ([Ca(2+)]i) and a decline in the integrity of ribosomes are observed within 1h of deafferentation. Glutamatergic input from the auditory nerve has been shown to preserve NM neuron health by activating metabotropic glutamate receptors (mGluRs), maintaining both normal [Ca(2+)]i and ribosomal integrity. One interpretation of these results is that a common mGluR-activated signaling cascade is required for the maintenance of both [Ca(2+)]i and ribosomal integrity. This could happen if both responses are influenced directly by a common messenger, or if the loss of mGluR activation causes changes in one component that secondarily causes changes in the other. The present studies tested this common-mediator hypothesis in slice preparations by examining activity-dependent regulation of [Ca(2+)]i and ribosomes in the same tissue after selectively blocking group I mGluRs (1-Aminoindan-1,5-dicarboxylic acid (AIDA)) or group II mGluRs (LY 341495) during unilateral auditory nerve stimulation. Changes in [Ca(2+)]i of NM neurons were measured using fura-2 ratiometric calcium imaging and the tissue was subsequently processed for Y10B immunoreactivity (Y10B-ir), an antibody that recognizes a ribosomal epitope. The group I mGluR antagonist blocked the activity-dependent regulation of both [Ca(2+)]i and Y10B-ir, but the group II antagonist blocked only the activity-dependent regulation of Y10B-ir. That is, even when group II receptors were blocked, stimulation continued to maintain low [Ca(2+)]i, but it did not maintain Y10B-ir. These results suggest a dissociation in how calcium and ribosomes are regulated in NM neurons and that ribosomes can be regulated through a mechanism that is independent of calcium regulation. PMID:26739326

  15. Structure based discovery of small molecules to regulate the activity of human insulin degrading enzyme.

    Directory of Open Access Journals (Sweden)

    Bilal Çakir

    Full Text Available BACKGROUND: Insulin-degrading enzyme (IDE is an allosteric Zn(+2 metalloprotease involved in the degradation of many peptides including amyloid-β, and insulin that play key roles in Alzheimer's disease (AD and type 2 diabetes mellitus (T2DM, respectively. Therefore, the use of therapeutic agents that regulate the activity of IDE would be a viable approach towards generating pharmaceutical treatments for these diseases. Crystal structure of IDE revealed that N-terminal has an exosite which is ∼30 Å away from the catalytic region and serves as a regulation site by orientation of the substrates of IDE to the catalytic site. It is possible to find small molecules that bind to the exosite of IDE and enhance its proteolytic activity towards different substrates. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we applied structure based drug design method combined with experimental methods to discover four novel molecules that enhance the activity of human IDE. The novel compounds, designated as D3, D4, D6, and D10 enhanced IDE mediated proteolysis of substrate V, insulin and amyloid-β, while enhanced degradation profiles were obtained towards substrate V and insulin in the presence of D10 only. CONCLUSION/SIGNIFICANCE: This paper describes the first examples of a computer-aided discovery of IDE regulators, showing that in vitro and in vivo activation of this important enzyme with small molecules is possible.

  16. GPS2/KDM4A Pioneering Activity Regulates Promoter-Specific Recruitment of PPARγ

    Directory of Open Access Journals (Sweden)

    M. Dafne Cardamone

    2014-07-01

    Full Text Available Timely and selective recruitment of transcription factors to their appropriate DNA-binding sites represents a critical step in regulating gene activation; however, the regulatory strategies underlying each factor’s effective recruitment to specific promoter and/or enhancer regions are not fully understood. Here, we identify an unexpected regulatory mechanism by which promoter-specific binding, and therefore function, of peroxisome proliferator-activator receptor γ (PPARγ in adipocytes requires G protein suppressor 2 (GPS2 to prime the local chromatin environment via inhibition of the ubiquitin ligase RNF8 and stabilization of the H3K9 histone demethylase KDM4A/JMJD2. Integration of genome-wide profiling data indicates that the pioneering activity of GPS2/KDM4A is required for PPARγ-mediated regulation of a specific transcriptional program, including the lipolytic enzymes adipose triglyceride lipase (ATGL and hormone-sensitive lipase (HSL. Hence, our findings reveal that GPS2 exerts a biologically important function in adipose tissue lipid mobilization by directly regulating ubiquitin signaling and indirectly modulating chromatin remodeling to prime selected genes for activation.

  17. Rabin8 regulates neurite outgrowth in both GEF activity-dependent and -independent manners.

    Science.gov (United States)

    Homma, Yuta; Fukuda, Mitsunori

    2016-07-01

    Many aspects of membrane-trafficking events are regulated by Rab-family small GTPases. Neurite outgrowth requires massive addition of proteins and lipids to the tips of growing neurites by membrane trafficking, and although several Rabs, including Rab8, Rab10, and Rab11, have been implicated in this process, their regulatory mechanisms during neurite outgrowth are poorly understood. Here, we show that Rabin8, a Rab8-guanine nucleotide exchange factor (GEF), regulates nerve growth factor (NGF)-induced neurite outgrowth of PC12 cells. Knockdown of Rabin8 results in inhibition of neurite outgrowth, whereas overexpression promotes it. We also find that Rab10 is a novel substrate of Rabin8 and that both Rab8 and Rab10 function during neurite outgrowth downstream of Rabin8. Surprisingly, however, a GEF activity-deficient isoform of Rabin8 also promotes neurite outgrowth, indicating the existence of a GEF activity-independent role of Rabin8. The Arf6/Rab8-positive recycling endosomes (Arf6/Rab8-REs) and Rab10/Rab11-positive REs (Rab10/Rab11-REs) in NGF-stimulated PC12 cells are differently distributed. Rabin8 localizes on both RE populations and appears to activate Rab8 and Rab10 there. These localizations and functions of Rabin8 are Rab11 dependent. Thus Rabin8 regulates neurite outgrowth both by coordinating with Rab8, Rab10, and Rab11 and by a GEF activity-independent mechanism. PMID:27170183

  18. Structure Based Discovery of Small Molecules to Regulate the Activity of Human Insulin Degrading Enzyme

    Science.gov (United States)

    Çakir, Bilal; Dağliyan, Onur; Dağyildiz, Ezgi; Bariş, İbrahim; Kavakli, Ibrahim Halil; Kizilel, Seda; Türkay, Metin

    2012-01-01

    Background Insulin-degrading enzyme (IDE) is an allosteric Zn+2 metalloprotease involved in the degradation of many peptides including amyloid-β, and insulin that play key roles in Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM), respectively. Therefore, the use of therapeutic agents that regulate the activity of IDE would be a viable approach towards generating pharmaceutical treatments for these diseases. Crystal structure of IDE revealed that N-terminal has an exosite which is ∼30 Å away from the catalytic region and serves as a regulation site by orientation of the substrates of IDE to the catalytic site. It is possible to find small molecules that bind to the exosite of IDE and enhance its proteolytic activity towards different substrates. Methodology/Principal Findings In this study, we applied structure based drug design method combined with experimental methods to discover four novel molecules that enhance the activity of human IDE. The novel compounds, designated as D3, D4, D6, and D10 enhanced IDE mediated proteolysis of substrate V, insulin and amyloid-β, while enhanced degradation profiles were obtained towards substrate V and insulin in the presence of D10 only. Conclusion/Significance This paper describes the first examples of a computer-aided discovery of IDE regulators, showing that in vitro and in vivo activation of this important enzyme with small molecules is possible. PMID:22355395

  19. Otud7b facilitates T cell activation and inflammatory responses by regulating Zap70 ubiquitination.

    Science.gov (United States)

    Hu, Hongbo; Wang, Hui; Xiao, Yichuan; Jin, Jin; Chang, Jae-Hoon; Zou, Qiang; Xie, Xiaoping; Cheng, Xuhong; Sun, Shao-Cong

    2016-03-01

    Signal transduction from the T cell receptor (TCR) is crucial for T cell-mediated immune responses and, when deregulated, also contributes to the development of autoimmunity. How TCR signaling is regulated is incompletely understood. In this study, we demonstrate a ubiquitin-dependent mechanism in which the deubiquitinase Otud7b has a crucial role in facilitating TCR signaling. Upon TCR ligation, Otud7b is rapidly recruited to the tyrosine kinase Zap70, a central mediator of TCR-proximal signaling. Otud7b deficiency attenuates the activation of Zap70 and its downstream pathways and impairs T cell activation and differentiation, rendering mice refractory to T cell-mediated autoimmune and inflammatory responses. Otud7b facilitated Zap70 activation by deubiquitinating Zap70, thus preventing the association of Zap70 with the negative-regulatory phosphatases Sts1 and Sts2. These findings establish Otud7b as a positive regulator of TCR-proximal signaling and T cell activation, highlighting the importance of deubiquitination in regulating Zap70 function. PMID:26903241

  20. Molecular kinetics. Ras activation by SOS: allosteric regulation by altered fluctuation dynamics.

    Science.gov (United States)

    Iversen, Lars; Tu, Hsiung-Lin; Lin, Wan-Chen; Christensen, Sune M; Abel, Steven M; Iwig, Jeff; Wu, Hung-Jen; Gureasko, Jodi; Rhodes, Christopher; Petit, Rebecca S; Hansen, Scott D; Thill, Peter; Yu, Cheng-Han; Stamou, Dimitrios; Chakraborty, Arup K; Kuriyan, John; Groves, Jay T

    2014-07-01

    Activation of the small guanosine triphosphatase H-Ras by the exchange factor Son of Sevenless (SOS) is an important hub for signal transduction. Multiple layers of regulation, through protein and membrane interactions, govern activity of SOS. We characterized the specific activity of individual SOS molecules catalyzing nucleotide exchange in H-Ras. Single-molecule kinetic traces revealed that SOS samples a broad distribution of turnover rates through stochastic fluctuations between distinct, long-lived (more than 100 seconds), functional states. The expected allosteric activation of SOS by Ras-guanosine triphosphate (GTP) was conspicuously absent in the mean rate. However, fluctuations into highly active states were modulated by Ras-GTP. This reveals a mechanism in which functional output may be determined by the dynamical spectrum of rates sampled by a small number of enzymes, rather than the ensemble average.

  1. Nuclear Factor-κB: Activation and Regulation during Toll-like Receptor Signaling

    Institute of Scientific and Technical Information of China (English)

    Ruaidhrí J. Carmody; Youhai H. Chen

    2007-01-01

    Toll-like receptors (TLRs) recognize distinct microbial components to initiate the innate and adaptive immune responses. TLR activation culminates in the expression of appropriate pro-inflammatory and immunomodulatory factors to meet pathogenic challenges. The transcription factor NF-κB is the master regulator of all TLR-induced responses and its activation is the pivotal event in TLR-mediated activation of the innate immune response. Many of the key molecular events required for TLR-induced NF-κB activation have been elucidated. However, much remain to be learned about the ability of TLRs to generate pathogen-specific responses using a limited number of transcription factors. This review will focus on our current understanding of NF-κB activation by TLRs and potential mechanisms for achieving a signal-specific response through NF-κB.

  2. ROCK1 in AgRP neurons regulates energy expenditure and locomotor activity in male mice.

    Science.gov (United States)

    Huang, Hu; Lee, Seung Hwan; Ye, Chianping; Lima, Ines S; Oh, Byung-Chul; Lowell, Bradford B; Zabolotny, Janice M; Kim, Young-Bum

    2013-10-01

    Normal leptin signaling is essential for the maintenance of body weight homeostasis. Proopiomelanocortin- and agouti-related peptide (AgRP)-producing neurons play critical roles in regulating energy metabolism. Our recent work demonstrates that deletion of Rho-kinase 1 (ROCK1) in the AgRP neurons of mice increased body weight and adiposity. Here, we report that selective loss of ROCK1 in AgRP neurons caused a significant decrease in energy expenditure and locomotor activity of mice. These effects were independent of any change in food intake. Furthermore, AgRP neuron-specific ROCK1-deficient mice displayed central leptin resistance, as evidenced by impaired Signal Transducer and Activator of Transcription 3 activation in response to leptin administration. Leptin's ability to hyperpolarize and decrease firing rate of AgRP neurons was also abolished in the absence of ROCK1. Moreover, diet-induced and genetic forms of obesity resulted in reduced ROCK1 activity in murine arcuate nucleus. Of note, high-fat diet also impaired leptin-stimulated ROCK1 activity in arcuate nucleus, suggesting that a defect in hypothalamic ROCK1 activity may contribute to the pathogenesis of central leptin resistance in obesity. Together, these data demonstrate that ROCK1 activation in hypothalamic AgRP neurons is required for the homeostatic regulation of energy expenditure and adiposity. These results further support previous work identifying ROCK1 as a key regulator of energy balance and suggest that targeting ROCK1 in the hypothalamus may lead to development of antiobesity therapeutics. PMID:23885017

  3. Adaptation of the Agrobacterium tumefaciens VirG response regulator to activate transcription in plants.

    Science.gov (United States)

    Czarnecka-Verner, Eva; Salem, Tarek A; Gurley, William B

    2016-02-01

    The Agrobacterium tumefaciens VirG response regulator of the VirA/VirG two-component system was adapted to function in tobacco protoplasts. The subcellular localization of VirG and VirA proteins transiently expressed in onion cells was determined using GFP fusions. Preliminary studies using Gal4DBD-VP16 fusions with VirG and Escherichia coli UhpA, and NarL response regulators indicated compatibility of these bacterial proteins with the eukaryotic transcriptional apparatus. A strong transcriptional activator based on tandem activation domains from the Drosophila fushi tarazu and Herpes simplex VP16 was created. Selected configurations of the two-site Gal4-vir box GUS reporters were activated by chimeric effectors dependent on either the yeast Gal4 DNA-binding domain or that of VirG. Transcriptional induction of the GUS reporter was highest for the VirE19-element promoter with both constitutive and wild-type VirG-tandem activation domain effectors. Multiple VirE19 elements increased the reporter activity proportionately, indicating that the VirG DNA binding domain was functional in plants. The VirG constitutive-Q-VP16 effector was more active than the VirG wild-type. In both the constitutive and wild-type forms of VirG, Q-VP16 activated transcription of the GUS reporter best when located at the C-terminus, i.e. juxtaposed to the VirG DNA binding domain. These results demonstrate the possibility of using DNA binding domains from bacterial response regulators and their cognate binding elements in the engineering of plant gene expression.

  4. Role of GLTSCR2 in the regulation of telomerase activity and chromosome stability.

    Science.gov (United States)

    Kim, Jee-Youn; An, Yong-Min; Park, Jae-Hoon

    2016-08-01

    Telomerase is essential for regulating telomeres, and its activation is a critical step in cellular immortalization and tumorigenesis. The transcriptional activation of human telomerase reverse transcriptase (hTERT) is critical for telomerase expression. Although several transcriptional activators have been identified, factors responsible for enhancing the hTERT promoter remain to be fully elucidated. In the present study, the role of glioma tumor-suppressor candidate region gene 2 (GLTSCR2) in telomerase regulation was analyzed. A doxycyclin-inducible green fluorescent protein (GFP)-tagged GLTSCR2-expressing adenovirus (Ad‑GLT/GFP) was used for the transduction of SK‑Hep‑1 and T98G cancer cells, and normal human umbilical vein endothelial cells. Changes in telomerase activity using telomere repeat amplification protocol assay were assessed, and the gene expression levels of hTERT were then examined. To investigate chromosome instability and senescence, Giemsa and β-galactosidase staining was performed. The results revealed that overexpression of GLTSCR2 significantly increased telomerase activity in the cancer and normal cell lines. This increase was consistent with increases in the protein and mRNA expression levels of hTERT. In luciferase assays, the hTERT promoter was activated by GLTSCR2. Knockdown of GLTSCR2 led to the downregulation of telomerase activity, abnormal nuclear morphology as a marker of chromosome instability, significant suppression of growth rate, alterations in cellular morphology and, eventually, cellular senescence. Taken together, the results of the present study suggested that GLTSCR2 is crucially involved in the positive regulation of telomerase and chromosome stability. PMID:27357325

  5. Nrf2 regulates PU.1 expression and activity in the alveolar macrophage.

    Science.gov (United States)

    Staitieh, Bashar S; Fan, Xian; Neveu, Wendy; Guidot, David M

    2015-05-15

    Alveolar macrophage (AM) immune function depends on the activation of the transcription factor PU.1 by granulocyte macrophage colony-stimulating factor. We have determined that chronic alcohol ingestion dampens PU.1 signaling via an unknown zinc-dependent mechanism; specifically, although PU.1 is not known to be a zinc-dependent transcription factor, zinc treatment reversed alcohol-mediated dampening of PU.1 signaling. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a zinc-dependent basic leucine zipper protein essential for antioxidant defenses, is also impaired by chronic alcohol ingestion and enhanced by zinc treatment. We hypothesized that the response of PU.1 to zinc treatment may result from the action of Nrf2 on PU.1. We first performed Nrf2/PU.1 protein coimmunoprecipitation on a rat AM cell line (NR8383) and found no evidence of protein-protein interactions. We then found evidence of increased Nrf2 binding to the PU.1 promoter region by chromatin immunoprecipitation. We next activated Nrf2 using either sulforaphane or an overexpression vector and inhibited Nrf2 with silencing RNA to determine whether Nrf2 could actively regulate PU.1. Nrf2 activation increased protein expression of both factors as well as gene expression of their respective downstream effectors, NAD(P)H dehydrogenase[quinone] 1 (NQO1) and cluster of differentiation antigen-14 (CD14). In contrast, Nrf2 silencing decreased the expression of both proteins, as well as gene expression of their effectors. Activating and inhibiting Nrf2 in primary rat AMs resulted in similar effects. Taken together, these findings suggest that Nrf2 regulates the expression and activity of PU.1 and that antioxidant response and immune activation are coordinately regulated within the AM.

  6. Prostaglandin E2 regulates melanocyte dendrite formation through activation of PKCζ

    International Nuclear Information System (INIS)

    Prostaglandins are lipid signaling intermediates released by keratinocytes in response to ultraviolet irradiation (UVR) in the skin. The main prostaglandin released following UVR is PGE2, a ligand for 4 related G-protein-coupled receptors (EP1, EP2, EP3 and EP4). Our previous work established that PGE2 stimulates melanocyte dendrite formation through activation of the EP1 and EP3 receptors. The purpose of the present report is to define the signaling intermediates involved in EP1- and EP3-dependent dendrite formation in human melanocytes. We recently showed that activation of the atypical PKCζ isoform stimulates melanocyte dendricity in response to treatment with lysophosphatidylcholine. We therefore examined the potential contribution of PKCζ activation on EP1- and EP3-dependent dendrite formation in melanocytes. Stimulation of the EP1 and EP3 receptors by selective agonists activated PKCζ, and inhibition of PKCζ activation abrogated EP1- and EP3-receptor-mediated melanocyte dendricity. Because of the importance of Rho-GTP binding proteins in the regulation of melanocyte dendricity, we also examined the effect of EP1 and EP3 receptor activation on Rac and Rho activity. Neither Rac nor Rho was activated upon treatment with EP1,3-receptor agonists. We show that melanocytes express only the EP3A1 isoform, but not the EP3B receptor isoform, previously associated with Rho activation, consistent with a lack of Rho stimulation by EP3 agonists. Our data suggest that PKCζ activation plays a predominant role in regulation of PGE2-dependent melanocyte dendricity

  7. Swelling-Activated Anion Channels Are Essential for Volume Regulation of Mouse Thymocytes

    Directory of Open Access Journals (Sweden)

    Ravshan Z. Sabirov

    2011-12-01

    Full Text Available Channel-mediated trans-membrane chloride movement is a key process in the active cell volume regulation under osmotic stress in most cells. However, thymocytes were hypothesized to regulate their volume by activating a coupled K-Cl cotransport mechanism. Under the patch-clamp, we found that osmotic swelling activates two types of macroscopic anion conductance with different voltage-dependence and pharmacology. At the single-channel level, we identified two types of events: one corresponded to the maxi-anion channel, and the other one had characteristics of the volume-sensitive outwardly rectifying (VSOR chloride channel of intermediate conductance. A VSOR inhibitor, phloretin, significantly suppressed both macroscopic VSOR-type conductance and single-channel activity of intermediate amplitude. The maxi-anion channel activity was largely suppressed by Gd3+ ions but not by phloretin. Surprisingly, [(dihydroindenyloxy] alkanoic acid (DIOA, a known antagonist of K-Cl cotransporter, was found to significantly suppress the activity of the VSOR-type single-channel events with no effect on the maxi-anion channels at 10 μM. The regulatory volume decrease (RVD phase of cellular response to hypotonicity was mildly suppressed by Gd3+ ions and was completely abolished by phloretin suggesting a major impact of the VSOR chloride channel and modulatory role of the maxi-anion channel. The inhibitory effect of DIOA was also strong, and, most likely, it occurred via blocking the VSOR Cl− channels.

  8. Protamine sulfate down-regulates thrombin generation by inhibiting factor V activation.

    LENUS (Irish Health Repository)

    Ni Ainle, Fionnuala

    2009-08-20

    Protamine sulfate is a positively charged polypeptide widely used to reverse heparin-induced anticoagulation. Paradoxically, prospective randomized trials have shown that protamine administration for heparin neutralization is associated with increased bleeding, particularly after cardiothoracic surgery with cardiopulmonary bypass. The molecular mechanism(s) through which protamine mediates this anticoagulant effect has not been defined. In vivo administration of pharmacologic doses of protamine to BALB\\/c mice significantly reduced plasma thrombin generation and prolonged tail-bleeding time (from 120 to 199 seconds). Similarly, in pooled normal human plasma, protamine caused significant dose-dependent prolongations of both prothrombin time and activated partial thromboplastin time. Protamine also markedly attenuated tissue factor-initiated thrombin generation in human plasma, causing a significant decrease in endogenous thrombin potential (41% +\\/- 7%). As expected, low-dose protamine effectively reversed the anticoagulant activity of unfractionated heparin in plasma. However, elevated protamine concentrations were associated with progressive dose-dependent reduction in thrombin generation. To assess the mechanism by which protamine mediates down-regulation of thrombin generation, the effect of protamine on factor V activation was assessed. Protamine was found to significantly reduce the rate of factor V activation by both thrombin and factor Xa. Protamine mediates its anticoagulant activity in plasma by down-regulation of thrombin generation via a novel mechanism, specifically inhibition of factor V activation.

  9. Extracellular-regulated kinase 2 is activated by the enhancement of hinge flexibility.

    Science.gov (United States)

    Sours, Kevin M; Xiao, Yao; Ahn, Natalie G

    2014-05-01

    Protein motions underlie conformational and entropic contributions to enzyme catalysis; however, relatively little is known about the ways in which this occurs. Studies of the mitogen-activated protein kinase ERK2 (extracellular-regulated protein kinase 2) by hydrogen-exchange mass spectrometry suggest that activation enhances backbone flexibility at the linker between N- and C-terminal domains while altering nucleotide binding mode. Here, we address the hypothesis that enhanced backbone flexibility within the hinge region facilitates kinase activation. We show that hinge mutations enhancing flexibility promote changes in the nucleotide binding mode consistent with domain movement, without requiring phosphorylation. They also lead to the activation of monophosphorylated ERK2, a form that is normally inactive. The hinge mutations bypass the need for pTyr but not pThr, suggesting that Tyr phosphorylation controls hinge motions. In agreement, monophosphorylation of pTyr enhances both hinge flexibility and nucleotide binding mode, measured by hydrogen-exchange mass spectrometry. Our findings demonstrate that regulated protein motions underlie kinase activation. Our working model is that constraints to domain movement in ERK2 are overcome by phosphorylation at pTyr, which increases hinge dynamics to promote the active conformation of the catalytic site.

  10. Salinomycin activates AMP-activated protein kinase-dependent autophagy in cultured osteoblastoma cells: a negative regulator against cell apoptosis.

    Directory of Open Access Journals (Sweden)

    Lun-qing Zhu

    Full Text Available BACKGROUND: The malignant osteoblastoma has poor prognosis, thus the search for novel and more efficient chemo-agents against this disease is urgent. Salinomycin induces broad anti-cancer effects both in vivo and in vitro, however, its role in osteoblastoma is still not clear. KEY FINDINGS: Salinomycin induced both apoptosis and autophagy in cultured U2OS and MG-63 osteoblastoma cells. Inhibition of autophagy by 3-methyladenine (3-MA, or by RNA interference (RNAi of light chain 3B (LC3B, enhanced salinomycin-induced cytotoxicity and apoptosis. Salinomycin induced a profound AMP-activated protein kinase (AMPK activation, which was required for autophagy induction. AMPK inhibition by compound C, or by AMPKα RNAi prevented salinomycin-induced autophagy activation, while facilitating cancer cell death and apoptosis. On the other hand, the AMPK agonist AICAR promoted autophagy activation in U2OS cells. Salinomycin-induced AMPK activation was dependent on reactive oxygen species (ROS production in osteoblastoma cells. Antioxidant n-acetyl cysteine (NAC significantly inhibited salinomycin-induced AMPK activation and autophagy induction. CONCLUSIONS: Salinomycin activates AMPK-dependent autophagy in osteoblastoma cells, which serves as a negative regulator against cell apoptosis. AMPK-autophagy inhibition might be a novel strategy to sensitize salinomycin's effect in cancer cells.

  11. The non-catalytic domains of Drosophila katanin regulate its abundance and microtubule-disassembly activity.

    Directory of Open Access Journals (Sweden)

    Kyle D Grode

    Full Text Available Microtubule severing is a biochemical reaction that generates an internal break in a microtubule and regulation of microtubule severing is critical for cellular processes such as ciliogenesis, morphogenesis, and meiosis and mitosis. Katanin is a conserved heterodimeric ATPase that severs and disassembles microtubules, but the molecular determinants for regulation of microtubule severing by katanin remain poorly defined. Here we show that the non-catalytic domains of Drosophila katanin regulate its abundance and activity in living cells. Our data indicate that the microtubule-interacting and trafficking (MIT domain and adjacent linker region of the Drosophila katanin catalytic subunit Kat60 cooperate to regulate microtubule severing in two distinct ways. First, the MIT domain and linker region of Kat60 decrease its abundance by enhancing its proteasome-dependent degradation. The Drosophila katanin regulatory subunit Kat80, which is required to stabilize Kat60 in cells, conversely reduces the proteasome-dependent degradation of Kat60. Second, the MIT domain and linker region of Kat60 augment its microtubule-disassembly activity by enhancing its association with microtubules. On the basis of our data, we propose that the non-catalytic domains of Drosophila katanin serve as the principal sites of integration of regulatory inputs, thereby controlling its ability to sever and disassemble microtubules.

  12. Regulation and control of thermally activated building systems; Regelung und Steuerung von thermoaktiven Bauteilsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Toedtli, Juerg [Consulting Juerg Toedtli, Zuerich (Switzerland); Gwerder, Markus; Renggli, Franz; Guentensperger, Werner [Siemens Building Technologies, Zug (Switzerland); Lehmann, Beat; Dorer, Viktor [EMPA, Duebendorf (Switzerland). Abt. Building Technologies; Hildebrand, Kurt [Hochschule Luzern - Technik und Architektur, Horw (Switzerland)

    2009-11-15

    Thermally activated building systems (TABS) are becoming increasingly important in terms of energy efficient cooling and heating of buildings. In practice, however, regulation and control of such systems often causes problems. Started five years ago with the aim of getting to grips with these problems, the TABS Control research project was completed in early 2009. The project yielded the following results: various models and simulation programs for TABS; performance-bound calculations for regulating zones; a range of zone regulation/control strategies for planners to choose from, including good solutions for automatic switching between heating and cooling, for pulsed operation of the zone pump and for room temperature control; the implementation of a subset of these strategies as standard solutions in a Siemens building automation system; laboratory tests on these strategies; a new procedure for the integrated planning of TABS and their regulation/control (referred to as UBB planning procedure - Unknown But Bounded); an Excel planning tool; guidelines on selecting the hydraulic switching topology; a method for operation optimization; the theoretical basis for the new integrated planning procedure and the new regulation/ control strategies; a patent application.

  13. The role of osteoblasts in regulating hematopoietic stem cell activity and tumor metastasis

    Directory of Open Access Journals (Sweden)

    Neiva K.

    2005-01-01

    Full Text Available Bone marrow stromal cells are critical regulators of hematopoiesis. Osteoblasts are part of the stromal cell support system in bone marrow and may be derived from a common precursor. Several studies suggested that osteoblasts regulate hematopoiesis, yet the entire mechanism is not understood. It is clear, however, that both hematopoietic precursors and osteoblasts interact for the production of osteoclasts and the activation of resorption. We observed that hematopoietic stem cells (HSCs regulate osteoblastic secretion of various growth factors, and that osteoblasts express some soluble factors exclusively in the presence of HSCs. Osteoblasts and hematopoietic cells are closely associated with each other in the bone marrow, suggesting a reciprocal relationship between them to develop the HSC niche. One critical component regulating the niche is stromal-derived factor-1 (SDF-1 and its receptor CXCR4 which regulates stem cell homing and, as we have recently demonstrated, plays a crucial role in facilitating those tumors which metastasize to bone. Osteoblasts produce abundant amounts of SDF-1 and therefore osteoblasts play an important role in metastasis. These findings are discussed in the context of the role of osteoblasts in marrow function in health and disease.

  14. Regulation of mitogen-activated protein kinase pathways by the plasma membrane Na+/H+ exchanger, NHE1

    DEFF Research Database (Denmark)

    Pedersen, Stine Helene Falsig; Darborg, Barbara Vasek; Rentsch, Maria Louise;

    2006-01-01

    The mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK, play a major role in the regulation of pivotal cellular processes such as cell death/survival balance, cell cycle progression, and cell migration. MAPK...... activity is regulated by a three-tiered phosphorelay system, which is in turn regulated by a complex network of signaling events and scaffolding proteins. The ubiquitous plasma membrane Na(+)/H(+) exchanger NHE1 is activated by, and implicated in, the physiological/pathophysiological responses to many of...

  15. A Critical SUMO1 Modification of LKB1 Regulates AMPK Activity during Energy Stress

    KAUST Repository

    Ritho, Joan

    2015-07-23

    SUMOylation has been implicated in cellular stress adaptation, but its role in regulating liver kinase B1 (LKB1), a major upstream kinase of the energy sensor AMP-activated protein kinase (AMPK), is unknown. Here, we show that energy stress triggers an increase in SUMO1 modification of LKB1, despite a global reduction in both SUMO1 and SUMO2/3 conjugates. During metabolic stress, SUMO1 modification of LKB1 lysine 178 is essential in promoting its interaction with AMPK via a SUMO-interacting motif (SIM) essential for AMPK activation. The LKB1 K178R SUMO mutant had defective AMPK signaling and mitochondrial function, inducing death in energy-deprived cells. These results provide additional insight into how LKB1-AMPK signaling is regulated during energy stress, and they highlight the critical role of SUMOylation in maintaining the cell’s energy equilibrium.

  16. Regulation of active site coupling in glutamine-dependent NAD[superscript +] synthetase

    Energy Technology Data Exchange (ETDEWEB)

    LaRonde-LeBlanc, Nicole; Resto, Melissa; Gerratana, Barbara; (Maryland)

    2009-05-21

    NAD{sup +} is an essential metabolite both as a cofactor in energy metabolism and redox homeostasis and as a regulator of cellular processes. In contrast to humans, Mycobacterium tuberculosis NAD{sup +} biosynthesis is absolutely dependent on the activity of a multifunctional glutamine-dependent NAD{sup +} synthetase, which catalyzes the ATP-dependent formation of NAD{sup +} at the synthetase domain using ammonia derived from L-glutamine in the glutaminase domain. Here we report the kinetics and structural characterization of M. tuberculosis NAD{sup +} synthetase. The kinetics data strongly suggest tightly coupled regulation of the catalytic activities. The structure, the first of a glutamine-dependent NAD{sup +} synthetase, reveals a homooctameric subunit organization suggesting a tight dependence of catalysis on the quaternary structure, a 40-{angstrom} intersubunit ammonia tunnel and structural elements that may be involved in the transfer of information between catalytic sites.

  17. Private CSR Activities in Oligopolistic Markets: Is there any room for Regulation?

    OpenAIRE

    Evangelos Mitrokostas; Emmanuel Petrakis

    2008-01-01

    The present paper examines the conditions under which the regulator can complement the provision of Corporate Social Responsibility (CSR) activities by private firms in an oligopolistic market. Our main finding is that if there is no credible information disclosure about SR characteristics of the firms' products to consumers, no firm will have incentives to undertake CSR effort in equilibrium. However, if the necessary information about the CSR aspects of each firm's product, otherwise unobse...

  18. Cyclic dermal BMP signalling regulates stem cell activation during hair regeneration.

    Science.gov (United States)

    Plikus, Maksim V; Mayer, Julie Ann; de la Cruz, Damon; Baker, Ruth E; Maini, Philip K; Maxson, Robert; Chuong, Cheng-Ming

    2008-01-17

    In the age of stem cell engineering it is critical to understand how stem cell activity is regulated during regeneration. Hairs are mini-organs that undergo cyclic regeneration throughout adult life, and are an important model for organ regeneration. Hair stem cells located in the follicle bulge are regulated by the surrounding microenvironment, or niche. The activation of such stem cells is cyclic, involving periodic beta-catenin activity. In the adult mouse, regeneration occurs in waves in a follicle population, implying coordination among adjacent follicles and the extrafollicular environment. Here we show that unexpected periodic expression of bone morphogenetic protein 2 (Bmp2) and Bmp4 in the dermis regulates this process. This BMP cycle is out of phase with the WNT/beta-catenin cycle, thus dividing the conventional telogen into new functional phases: one refractory and the other competent for hair regeneration, characterized by high and low BMP signalling, respectively. Overexpression of noggin, a BMP antagonist, in mouse skin resulted in a markedly shortened refractory phase and faster propagation of the regenerative wave. Transplantation of skin from this mutant onto a wild-type host showed that follicles in donor and host can affect their cycling behaviours mutually, with the outcome depending on the equilibrium of BMP activity in the dermis. Administration of BMP4 protein caused the competent region to become refractory. These results show that BMPs may be the long-sought 'chalone' inhibitors of hair growth postulated by classical experiments. Taken together, results presented in this study provide an example of hierarchical regulation of local organ stem cell homeostasis by the inter-organ macroenvironment. The expression of Bmp2 in subcutaneous adipocytes indicates physiological integration between these two thermo-regulatory organs. Our findings have practical importance for studies using mouse skin as a model for carcinogenesis, intra-cutaneous drug

  19. Activation of mammalian retinoid X receptors by the insect growth regulator methoprene.

    OpenAIRE

    Harmon, M A; Boehm, M F; Heyman, R A; Mangelsdorf, D J

    1995-01-01

    We report that methoprene and its derivatives can stimulate gene transcription in vertebrates by acting through the retinoic acid-responsive transcription factors, the retinoid X receptors (RXRs). Methoprene is an insect growth regulator in domestic and agricultural use as a pesticide. At least one metabolite of methoprene, methoprene acid, directly binds to RXR and is a transcriptional activator in both insect and mammalian cells. Unlike the endogenous RXR ligand, 9-cis-retinoic acid, this a...

  20. Na,K-ATPase activity in mouse muscle is regulated by AMPK and PGC-1α.

    Science.gov (United States)

    Ingwersen, Maria S; Kristensen, Michael; Pilegaard, Henriette; Wojtaszewski, Jørgen F P; Richter, Erik A; Juel, Carsten

    2011-07-01

    Na,K-ATPase activity, which is crucial for skeletal muscle function, undergoes acute and long-term regulation in response to muscle activity. The aim of the present study was to test the hypothesis that AMP kinase (AMPK) and the transcriptional coactivator PGC-1α are underlying factors in long-term regulation of Na,K-ATPase isoform (α,β and PLM) abundance and Na(+) affinity. Repeated treatment of mice with the AMPK activator AICAR decreased total PLM protein content but increased PLM phosphorylation, whereas the number of α- and β-subunits remained unchanged. The K(m) for Na(+) stimulation of Na,K-ATPase was reduced (higher affinity) after AICAR treatment. PLM abundance was increased in AMPK kinase-dead mice compared with control mice, but PLM phosphorylation and Na,K-ATPase Na(+) affinity remained unchanged. Na,K-ATPase activity and subunit distribution were also measured in mice with different degrees of PGC-1α expression. Protein abundances of α1 and α2 were reduced in PGC-1α +/- and -/- mice, and the β(1)/β(2) ratio was increased with PGC-1α overexpression (TG mice). PLM protein abundance was decreased in TG mice, but phosphorylation status was unchanged. Na,K-ATPase V (max) was decreased in PCG-1α TG and KO mice. Experimentally in vitro induced phosphorylation of PLM increased Na,K-ATPase Na(+) affinity, confirming that PLM phosphorylation is important for Na,K-ATPase function. In conclusion, both AMPK and PGC-1α regulate PLM abundance, AMPK regulates PLM phosphorylation and PGC-1α expression influences Na,K-ATPase α(1) and α(2) content and β(1)/β(2) isoform ratio. Phosphorylation of the Na,K-ATPase subunit PLM is an important regulatory mechanism.

  1. Natural Melanogenesis Inhibitors Acting Through the Down-Regulation of Tyrosinase Activity

    OpenAIRE

    Te-Sheng Chang

    2012-01-01

    Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme, tyrosinase, catalyzes the first and only rate-limiting steps in melanogenesis, and the down-regulation of enzyme activity is the most reported method for the inhibition of melanogenesis. Because of the cosmetically important issue of hyperpigmentation, there is a big demand for melanogenesis inhibitors. This encourages researchers to seek potent melanogenesis inhibitors for cosmetic u...

  2. Protein Kinase C Regulates the Cell Surface Activity of Endothelin-Converting Enzyme-1

    OpenAIRE

    Smith, A Ian; Lew, Rebecca A.; Thomas, Walter G; Tochon-Danguy, Nathalie

    2006-01-01

    The potent vasoconstrictor endothelin is a 21 amino acid peptide whose principal physiological function is to regulate vascular tone. The generation of endothelin is crucially dependent on the local presence and activity of endothelin converting enzyme-1 (ECE-1) expressed on the surface of vascular endothelial cells. In this study, we have shown in endothelial cells that the enzyme is phosphorylated, and that phosphorylation is increased by phorbol ester stimulation of protein kinase C (PKC)....

  3. Global regulator Anr represses PlcH phospholipase activity in Pseudomonas aeruginosa when oxygen is limiting

    OpenAIRE

    Jackson, Angelyca A.; Daniels, Emily F.; Hammond, John H.; Willger, Sven D.; Hogan, Deborah A.

    2014-01-01

    Haemolytic phospholipase C (PlcH) is a potent virulence and colonization factor that is expressed at high levels by Pseudomonas aeruginosa within the mammalian host. The phosphorylcholine liberated from phosphatidylcholine and sphingomyelin by PlcH is further catabolized into molecules that both support growth and further induce plcH expression. We have shown previously that the catabolism of PlcH-released choline leads to increased activity of Anr, a global transcriptional regulator that pro...

  4. The activity-dependent transcription factor NPAS4 regulates domain-specific inhibition

    OpenAIRE

    Bloodgood, Brenda L.; Sharma, Nikhil; Browne, Heidi Adlman; Trepman, Alissa Z.; Greenberg, Michael E.

    2013-01-01

    A heterogeneous population of inhibitory neurons controls the flow of information through a neural circuit1–3. Inhibitory synapses that form on pyramidal neuron dendrites modulate the summation of excitatory synaptic potentials4–6 and prevent the generation of dendritic calcium spikes7,8. Precisely timed somatic inhibition limits both the number of action potentials and the time window during which firing can occur8,9. The activity-dependent transcription factor NPAS4 regulates inhibitory syn...

  5. Direct Ionic Regulation of the Activity of Myo-Inositol Biosynthesis Enzymes in Mozambique Tilapia.

    Directory of Open Access Journals (Sweden)

    Fernando D Villarreal

    Full Text Available Myo-inositol (Ins is a major compatible osmolyte in many cells, including those of Mozambique tilapia (Oreochromis mossambicus. Ins biosynthesis is highly up-regulated in tilapia and other euryhaline fish exposed to hyperosmotic stress. In this study, enzymatic regulation of two enzymes of Ins biosynthesis, Ins phosphate synthase (MIPS and inositol monophosphatase (IMPase, by direct ionic effects is analyzed. Specific MIPS and IMPase isoforms from Mozambique tilapia (MIPS-160 and IMPase 1 were selected based on experimental, phylogenetic, and structural evidence supporting their role for Ins biosynthesis during hyperosmotic stress. Recombinant tilapia IMPase 1 and MIPS-160 activity was assayed in vitro at ionic conditions that mimic changes in the intracellular milieu during hyperosmotic stress. The in vitro activities of MIPS-160 and IMPase 1 are highest at alkaline pH of 8.8. IMPase 1 catalytic efficiency is strongly increased during hyperosmolality (particularly for the substrate D-Ins-3-phosphate, Ins-3P, mainly as a result of [Na+] elevation. Furthermore, the substrate-specificity of IMPase 1 towards D-Ins-1-phosphate (Ins-1P is lower than towards Ins-3P. Because MIPS catalysis results in Ins-3P this results represents additional evidence for IMPase 1 being the isoform that mediates Ins biosynthesis in tilapia. Our data collectively demonstrate that the Ins biosynthesis enzymes are activated under ionic conditions that cells are exposed to during hypertonicity, resulting in Ins accumulation, which, in turn, results in restoration of intracellular ion homeostasis. We propose that the unique and direct ionic regulation of the activities of Ins biosynthesis enzymes represents an efficient biochemical feedback loop for regulation of intracellular physiological ion homeostasis during hyperosmotic stress.

  6. Peroxisome proliferator-activated receptor delta : regulation of skeletal muscle metabolism

    OpenAIRE

    Krämer, David Kitz

    2006-01-01

    Peroxisome Proliferator-Activated Receptor (PPAR) δ is a nuclear transcription factor which has been implicated in the regulation of lipid metabolism in skeletal muscle. In addition to the postural and locomotive functions of skeletal muscle, this organ has a major impact role on whole body metabolism. Reduced insulin sensitivity is a characteristic feature in subjects with type 2 diabetes mellitus. Physical exercise/muscle contraction alters the metabolic properties of skel...

  7. REGULATION OF PRODUCTION PERFORMANCE OF CHICORY PLANTS BY FOLIAR APPLICATION OF BIOLOGICALLY ACTIVE SUBSTANCES

    OpenAIRE

    MAREK KOVÁR; IVAN ČERNÝ

    2012-01-01

    In this study were evaluated both the growth and yield potentials of three chicory (Cichorium intybus var. sativum) varieties ('Fredonia Nova', 'Oesia' a 'Maurane') growing in natural agro-ecological conditions from 2006 to 2008. Regulation of the crop productivity by foliar application of biologically active substances (Atonik, Polybor 150, and Biafit Gold) was also studied. Evaluation of growth-production performance of chicory was realized as: leaf area index (LAI), photosynthetic potentia...

  8. CREB activity in dopamine D1 receptor expressing neurons regulates cocaine-induced behavioral effects

    Directory of Open Access Journals (Sweden)

    Ainhoa eBilbao

    2014-06-01

    Full Text Available IIt is suggested that striatal cAMP responsive element binding protein (CREB regulates sensitivity to psychostimulants. To test the cell-specificity of this hypothesis we examined the effects of a dominant-negative CREB protein variant expressed in dopamine receptor D1 (D1R neurons on cocaine-induced behaviors. A transgenic mouse strain was generated by pronuclear injection of a BAC-derived transgene harboring the A-CREB sequence under the control of the D1R gene promoter. Compared to wild-type, drug-naïve mutants showed moderate alterations in gene expression, especially a reduction in basal levels of activity-regulated transcripts such as Arc and Egr2. Drug-naïve mutants showed moderate alterations in gene expression, most prominently a reduction in basal levels of activity-regulated transcripts such as Arc and Egr2, when compared to wild-type controls. The behavioral responses to cocaine were elevated in mutant mice. Locomotor activity after acute treatment, psychomotor sensitization after intermittent drug injections and the conditioned locomotion after saline treatment were increased compared to wild-type littermates. Transgenic mice had significantly higher cocaine conditioned place preference, displayed normal extinction of the conditioned preference, but showed an augmented cocaine-seeking response following priming-induced reinstatement. This enhanced cocaine-seeking response was associated with increased levels of activity-regulated transcripts and prodynorphin. The primary reinforcing effects of cocaine were not altered in the mutant mice as they did not differ from wild-type in cocaine self-administration under a fixed ratio schedule at the training dose. Collectively, our data indicate that expression of a dominant-negative CREB variant exclusively in neurons expressing D1R is sufficient to recapitulate the previously reported behavioral phenotypes associated with virally expressed dominant-negative CREB.

  9. DMPD: Nuclear factor-kappaB: activation and regulation during toll-like receptorsignaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17349209 Nuclear factor-kappaB: activation and regulation during toll-like receptor...signaling. Carmody RJ, Chen YH. Cell Mol Immunol. 2007 Feb;4(1):31-41. (.png) (.svg) (.html) (.csml) Show Nuclear... factor-kappaB: activation and regulation during toll-like receptorsignaling. PubmedID 17349209 Title Nuclear

  10. AMP-activated protein kinase in contraction regulation of skeletal muscle metabolism: necessary and/or sufficient?

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Wojtaszewski, Jørgen; Richter, Erik

    2009-01-01

    In skeletal muscle, the contraction-activated heterotrimeric 5'-AMP-activated protein kinase (AMPK) protein is proposed to regulate the balance between anabolic and catabolic processes by increasing substrate uptake and turnover in addition to regulating the transcription of proteins involved...

  11. Extracellular signal-regulated kinases 1 and 2 activation in endothelial cells exposed to cyclic strain

    Science.gov (United States)

    Ikeda, M.; Takei, T.; Mills, I.; Kito, H.; Sumpio, B. E.

    1999-01-01

    The aim of this study was to determine whether extracellular signal-regulated kinases 1/2 (ERK1/ERK2) are activated and might play a role in enhanced proliferation and morphological change induced by strain. Bovine aortic endothelial cells (BAEC) were subjected to an average of 6 or 10% strain at a rate of 60 cycles/min for up to 4 h. Cyclic strain caused strain- and time-dependent phosphorylation and activation of ERK1/ERK2. Peak phosphorylation and activation of ERK1/ERK2 induced by 10% strain were at 10 min. A specific ERK1/ERK2 kinase inhibitor, PD-98059, inhibited phosphorylation and activation of ERK1/ERK2 but did not inhibit the increased cell proliferation and cell alignment induced by strain. Treatment of BAEC with 2,5-di-tert-butyl-1, 4-benzohydroquinone, to deplete inositol trisphosphate-sensitive calcium storage, and gadolinium chloride, a Ca2+ channel blocker, did not inhibit the activation of ERK1/ERK2. Strain-induced ERK1/ERK2 activation was partly inhibited by the protein kinase C inhibitor calphostin C and completely inhibited by the tyrosine kinase inhibitor genistein. These data suggest that 1) ERK1/ERK2 are not critically involved in the strain-induced cell proliferation and orientation, 2) strain-dependent activation of ERK1/ERK2 is independent of intracellular and extracellular calcium mobilization, and 3) protein kinase C activation and tyrosine kinase regulate strain-induced activation of ERK1/ERK2.

  12. The N-terminal domain allosterically regulates cleavage and activation of the epithelial sodium channel.

    Science.gov (United States)

    Kota, Pradeep; Buchner, Ginka; Chakraborty, Hirak; Dang, Yan L; He, Hong; Garcia, Guilherme J M; Kubelka, Jan; Gentzsch, Martina; Stutts, M Jackson; Dokholyan, Nikolay V

    2014-08-15

    The epithelial sodium channel (ENaC) is activated upon endoproteolytic cleavage of specific segments in the extracellular domains of the α- and γ-subunits. Cleavage is accomplished by intracellular proteases prior to membrane insertion and by surface-expressed or extracellular soluble proteases once ENaC resides at the cell surface. These cleavage events are partially regulated by intracellular signaling through an unknown allosteric mechanism. Here, using a combination of computational and experimental techniques, we show that the intracellular N terminus of γ-ENaC undergoes secondary structural transitions upon interaction with phosphoinositides. From ab initio folding simulations of the N termini in the presence and absence of phosphatidylinositol 4,5-bisphosphate (PIP2), we found that PIP2 increases α-helical propensity in the N terminus of γ-ENaC. Electrophysiology and mutation experiments revealed that a highly conserved cluster of lysines in the γ-ENaC N terminus regulates accessibility of extracellular cleavage sites in γ-ENaC. We also show that conditions that decrease PIP2 or enhance ubiquitination sharply limit access of the γ-ENaC extracellular domain to proteases. Further, the efficiency of allosteric control of ENaC proteolysis is dependent on Tyr(370) in γ-ENaC. Our findings provide an allosteric mechanism for ENaC activation regulated by the N termini and sheds light on a potential general mechanism of channel and receptor activation.

  13. The N-terminal Domain Allosterically Regulates Cleavage and Activation of the Epithelial Sodium Channel*

    Science.gov (United States)

    Kota, Pradeep; Buchner, Ginka; Chakraborty, Hirak; Dang, Yan L.; He, Hong; Garcia, Guilherme J. M.; Kubelka, Jan; Gentzsch, Martina; Stutts, M. Jackson; Dokholyan, Nikolay V.

    2014-01-01

    The epithelial sodium channel (ENaC) is activated upon endoproteolytic cleavage of specific segments in the extracellular domains of the α- and γ-subunits. Cleavage is accomplished by intracellular proteases prior to membrane insertion and by surface-expressed or extracellular soluble proteases once ENaC resides at the cell surface. These cleavage events are partially regulated by intracellular signaling through an unknown allosteric mechanism. Here, using a combination of computational and experimental techniques, we show that the intracellular N terminus of γ-ENaC undergoes secondary structural transitions upon interaction with phosphoinositides. From ab initio folding simulations of the N termini in the presence and absence of phosphatidylinositol 4,5-bisphosphate (PIP2), we found that PIP2 increases α-helical propensity in the N terminus of γ-ENaC. Electrophysiology and mutation experiments revealed that a highly conserved cluster of lysines in the γ-ENaC N terminus regulates accessibility of extracellular cleavage sites in γ-ENaC. We also show that conditions that decrease PIP2 or enhance ubiquitination sharply limit access of the γ-ENaC extracellular domain to proteases. Further, the efficiency of allosteric control of ENaC proteolysis is dependent on Tyr370 in γ-ENaC. Our findings provide an allosteric mechanism for ENaC activation regulated by the N termini and sheds light on a potential general mechanism of channel and receptor activation. PMID:24973914

  14. MUC1-C oncoprotein regulates glycolysis and pyruvate kinase M2 activity in cancer cells.

    Directory of Open Access Journals (Sweden)

    Michio Kosugi

    Full Text Available Aerobic glycolysis in cancer cells is regulated by multiple effectors that include Akt and pyruvate kinase M2 (PKM2. Mucin 1 (MUC1 is a heterodimeric glycoprotein that is aberrantly overexpressed by human breast and other carcinomas. Here we show that transformation of rat fibroblasts by the oncogenic MUC1-C subunit is associated with Akt-mediated increases in glucose uptake and lactate production, consistent with the stimulation of glycolysis. The results also demonstrate that the MUC1-C cytoplasmic domain binds directly to PKM2 at the B- and C-domains. Interaction between the MUC1-C cytoplasmic domain Cys-3 and the PKM2 C-domain Cys-474 was found to stimulate PKM2 activity. Conversely, epidermal growth factor receptor (EGFR-mediated phosphorylation of the MUC1-C cytoplasmic domain on Tyr-46 conferred binding to PKM2 Lys-433 and inhibited PKM2 activity. In human breast cancer cells, silencing MUC1-C was associated with decreases in glucose uptake and lactate production, confirming involvement of MUC1-C in the regulation of glycolysis. In addition, EGFR-mediated phosphorylation of MUC1-C in breast cancer cells was associated with decreases in PKM2 activity. These findings indicate that the MUC1-C subunit regulates glycolysis and that this response is conferred in part by PKM2. Thus, the overexpression of MUC1-C oncoprotein in diverse human carcinomas could be of importance to the Warburg effect of aerobic glycolysis.

  15. SUMOylation can regulate the activity of ETS-like transcription factor 4.

    Science.gov (United States)

    Kaikkonen, Sanna; Makkonen, Harri; Rytinki, Miia; Palvimo, Jorma J

    2010-08-01

    ETS-like transcription factor 4 (ELK4) (a.k.a. serum response factor accessory protein 1) belongs to the ternary complex factor (TCF) subfamily of E twenty-six (ETS) domain transcription factors. Compared to the other TCF subfamily members, ELK1 and ELK3 (NET), there is limited information of the mechanisms regulating the ELK4 activity. Here, we show that the ELK4 can be covalently modified (SUMOylated) by small ubiquitin-related modifier (SUMO) 1 protein, an important regulator of signaling and transcription. SUMOylation of ELK4 was reversed by SUMO-specific proteases (SENP) 1 and 2 and stimulated by SUMO E3 ligase PIAS3. Conserved lysine residue 167 that is located in the NET inhibitory domain of ELK4 was identified as the main site of SUMO-1 conjugation. Interestingly, mutation of the K167 disrupting the SUMOylation markedly enhanced the transcriptional activity of the ELK4, but weakened its repressive function on c-fos promoter. In conclusion, our results suggest that covalent modification by SUMO-1 can regulate the activity of ELK4, contributing to the transcriptional repression by the ELK4. PMID:20637912

  16. TDP-43 regulates the microprocessor complex activity during in vitro neuronal differentiation.

    Science.gov (United States)

    Di Carlo, Valerio; Grossi, Elena; Laneve, Pietro; Morlando, Mariangela; Dini Modigliani, Stefano; Ballarino, Monica; Bozzoni, Irene; Caffarelli, Elisa

    2013-12-01

    TDP-43 (TAR DNA-binding protein 43) is an RNA-binding protein implicated in RNA metabolism at several levels. Even if ubiquitously expressed, it is considered as a neuronal activity-responsive factor and a major signature for neurological pathologies, making the comprehension of its activity in the nervous system a very challenging issue. TDP-43 has also been described as an accessory component of the Drosha-DGCR8 (DiGeorge syndrome critical region gene 8) microprocessor complex, which is crucially involved in basal and tissue-specific RNA processing events. In the present study, we exploited in vitro neuronal differentiation systems to investigate the TDP-43 demand for the microprocessor function, focusing on both its canonical microRNA biosynthetic activity and its alternative role as a post-transcriptional regulator of gene expression. Our findings reveal a novel role for TDP-43 as an essential factor that controls the stability of Drosha protein during neuronal differentiation, thus globally affecting the production of microRNAs. We also demonstrate that TDP-43 is required for the Drosha-mediated regulation of Neurogenin 2, a master gene orchestrating neurogenesis, whereas post-transcriptional control of Dgcr8, another Drosha target, resulted to be TDP-43-independent. These results implicate a previously uncovered contribution of TDP-43 in regulating the abundance and the substrate specificity of the microprocessor complex and provide new insights into TDP-43 as a key player in neuronal differentiation.

  17. Active Erk Regulates Microtubule Stability in H-ras-Transformed Cells

    Directory of Open Access Journals (Sweden)

    Rene E. Harrison

    2001-01-01

    Full Text Available Increasing evidence suggests that activated erk regulates cell functions, at least in part, by mechanisms that do not require gene transcription. Here we show that the map kinase, erk, decorates microtubules (MTs and mitotic spindles in both parental and mutant active rastransfected 10T1 /2 fibroblasts and MCF10A breast epithelial cells. Approximately 20% of total cellular erk decorated MTs in both cell lines. A greater proportion of activated erk was associated with MTs in the presence of mutant active H-ras than in parental cells. Activation of erk by the ras pathway coincided with a decrease in the stability of MT, as detected by a stability marker. The MKK1 inhibitor, PD98059 and transfection of a dominant negative MKK1 blocked ras-induced instability of MTs but did not modify the association of erk with MTs or affect MT stability of the parental cells. These results indicate that the subset of active erk kinase that associates with MTs contributes to their instability in the presence of a mutant active ras. The MT-associated subset of active erk likely contributes to the enhanced invasive and proliferative abilities of cells containing mutant active H-ras.

  18. A Molecular Brake in the Kinase Hinge Region Regulates the Activity of Receptor Tyrosine Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Chen,H.; Ma, J.; Li, W.; Eliseenkova, A.; Xu, C.; Neubert, T.; Miller, W.; Mohammadi, M.

    2007-01-01

    Activating mutations in the tyrosine kinase domain of receptor tyrosine kinases (RTKs) cause cancer and skeletal disorders. Comparison of the crystal structures of unphosphorylated and phosphorylated wild-type FGFR2 kinase domains with those of seven unphosphorylated pathogenic mutants reveals an autoinhibitory 'molecular brake' mediated by a triad of residues in the kinase hinge region of all FGFRs. Structural analysis shows that many other RTKs, including PDGFRs, VEGFRs, KIT, CSF1R, FLT3, TEK, and TIE, are also subject to regulation by this brake. Pathogenic mutations activate FGFRs and other RTKs by disengaging the brake either directly or indirectly.

  19. Multilayer Active Control For Structural Damping And Optical-Path Regulation

    Science.gov (United States)

    Rahman, Zahidul H.; Spanos, John T.; Fanson, James L.

    1995-01-01

    Two active-control concepts incorporated into system for suppression of vibrations in truss structure and regulation of length of optical path on structure to nanometer level. Optical-path-length-control subsystem contains two feedback control loops to obtain active damping in wide amplitude-and-frequency range. Concept described in more detail in number of previous articles, including "Stabilizing Optical-Path Length on a Vibrating Structure" (NPO-19040), "Controllable Optical Delay Line for Stellar Interferometry" (NPO-18686), "Test Bed for Control of Optical-Path Lengths" (NPO-18487).

  20. An overview of the AECB's strategy for regulating radioactive waste management activities

    International Nuclear Information System (INIS)

    The goal of the Canadian Atomic Energy Control Board in regulating the management of radioactive wastes is to ensure the protection of people and the environment. A program of cooperation with other agencies, identification and adoption of baselines for describing radioactive wastes, development of explicit criteria and requirements, publication of related regulatory documents, establishment of independent consultative processes with technical experts and the public, and maintenance of awareness and compatibility with international activities is underway. Activities related to high-level radioactive waste, uranium mine and mill tailings, low- and medium-level wastes, radioactive effluents from nuclear facilities, and decommissioning and decontamination are described

  1. Auxin influx inhibitors 1-NOA, 2-NOA, and CHPAA interfere with membrane dynamics in tobacco cells

    OpenAIRE

    Laňková, M. (Martina); Smith, R. S.; Pešek, B. (Bedřich); Kubeš, M. (Martin); Zažímalová, E. (Eva); Petrášek, J. (Jan); Hoyerová, K.

    2010-01-01

    The phytohormone auxin is transported through the plant body either via vascular pathways or from cell to cell by specialized polar transport machinery. This machinery consists of a balanced system of passive diffusion combined with the activities of auxin influx and efflux carriers. Synthetic auxins that differ in the mechanisms of their transport across the plasma membrane together with polar auxin transport inhibitors have been used in many studies on particular auxin carriers and their ro...

  2. Limbic Activity Modulation Guided by Functional Magnetic Resonance Imaging-Inspired Electroencephalography Improves Implicit Emotion Regulation.

    Science.gov (United States)

    Keynan, Jackob N; Meir-Hasson, Yehudit; Gilam, Gadi; Cohen, Avihay; Jackont, Gilan; Kinreich, Sivan; Ikar, Limor; Or-Borichev, Ayelet; Etkin, Amit; Gyurak, Anett; Klovatch, Ilana; Intrator, Nathan; Hendler, Talma

    2016-09-15

    The amygdala has a pivotal role in processing traumatic stress; hence, gaining control over its activity could facilitate adaptive mechanism and recovery. To date, amygdala volitional regulation could be obtained only via real-time functional magnetic resonance imaging (fMRI), a highly inaccessible procedure. The current article presents high-impact neurobehavioral implications of a novel imaging approach that enables bedside monitoring of amygdala activity using fMRI-inspired electroencephalography (EEG), hereafter termed amygdala-electrical fingerprint (amyg-EFP). Simultaneous EEG/fMRI indicated that the amyg-EFP reliably predicts amygdala-blood oxygen level-dependent activity. Implementing the amyg-EFP in neurofeedback demonstrated that learned downregulation of the amyg-EFP facilitated volitional downregulation of amygdala-blood oxygen level-dependent activity via real-time fMRI and manifested as reduced amygdala reactivity to visual stimuli. Behavioral evidence further emphasized the therapeutic potential of this approach by showing improved implicit emotion regulation following amyg-EFP neurofeedback. Additional EFP models denoting different brain regions could provide a library of localized activity for low-cost and highly accessible brain-based diagnosis and treatment. PMID:26996601

  3. Activation of the TOR Signalling Pathway by Glutamine Regulates Insect Fecundity.

    Science.gov (United States)

    Zhai, Yifan; Sun, Zhongxiang; Zhang, Jianqing; Kang, Kui; Chen, Jie; Zhang, Wenqing

    2015-05-29

    The target of rapamycin (TOR) positively controls cell growth in response to nutrients such as amino acids. However, research on the specific nutrients sensed by TOR is limited. Glutamine (Gln), a particularly important amino acid involved in metabolism in organisms, is synthesised and catalysed exclusively by glutamine synthetase (GS), and our previous studies have shown that Gln may regulate fecundity in vivo levels of the brown planthopper (BPH) Nilaparvata lugens. Until now, it has remained unclear whether Gln activates or inhibits the TOR signalling pathway. Here, we performed the combined analyses of iTRAQ (isobaric tags for relative and absolute quantification) and DGE (tag-based digital gene expression) data in N. lugens at the protein and transcript levels after GS RNAi, and we found that 52 pathways overlap, including the TOR pathway. We further experimentally demonstrate that Gln activates the TOR pathway by promoting the serine/threonine protein kinase AKT and inhibiting the 5'AMP-activated protein kinase AMPK phosphorylation activity in the pest. Furthermore, TOR regulates the fecundity of N. lugens probably by mediating vitellogenin (Vg) expression. This work is the first report that Gln activates the TOR pathway in vivo.

  4. Dimer formation and transcription activation in the sporulation response regulator Spo0A.

    Science.gov (United States)

    Lewis, Richard J; Scott, David J; Brannigan, James A; Ladds, Joanne C; Cervin, Marguerite A; Spiegelman, George B; Hoggett, James G; Barák, Imrich; Wilkinson, Anthony J

    2002-02-15

    The response regulator Spo0A is the master control element in the initiation of sporulation in Bacillus subtilis. Like many other multi-domain response regulators, the latent activity of the effector, C-terminal domain is stimulated by phosphorylation on a conserved aspartic acid residue in the regulatory, N-terminal domain. If a threshold concentration of phosphorylated Spo0A is achieved, the transcription of genes required for sporulation is activated, whereas the genes encoding stationary phase sentinels are repressed, and sporulation proceeds. Despite detailed genetic, biochemical and structural characterisation, it is not understood how the phosphorylation signal in the receiver domain is transduced into DNA binding and transcription activation in the distal effector domain. An obstacle to our understanding of Spo0A function is the uncertainty concerning changes in quaternary structure that accompany phosphorylation. Here we have revisited this question and shown unequivocally that Spo0A forms dimers upon phosphorylation and that the subunit interactions in the dimer are mediated principally by the receiver domain. Purified dimers of two mutants of Spo0A, in which the phosphorylatable aspartic acid residue has been substituted, activate transcription from the spoIIG promoter in vitro, whereas monomers do not. This suggests that dimers represent the activated form of Spo0A. PMID:11851334

  5. Structural and functional diversity in the activity and regulation of DAPK-related protein kinases.

    Science.gov (United States)

    Temmerman, Koen; Simon, Bertrand; Wilmanns, Matthias

    2013-11-01

    Within the large group of calcium/calmodulin-dependent protein kinases (CAMKs) of the human kinome, there is a distinct branch of highly related kinases that includes three families: death-associated protein-related kinases, myosin light-chain-related kinases and triple functional domain protein-related kinases. In this review, we refer to these collectively as DMT kinases. There are several functional features that span the three families, such as a broad involvement in apoptotic processes, cytoskeletal association and cellular plasticity. Other CAMKs contain a highly conserved HRD motif, which is a prerequisite for kinase regulation through activation-loop phosphorylation, but in all 16 members of the DMT branch, this is replaced by an HF/LD motif. This DMT kinase signature motif substitutes phosphorylation-dependent active-site interactions with a local hydrophobic core that maintains an active kinase conformation. Only about half of the DMT kinases have an additional autoregulatory domain, C-terminal to the kinase domain that binds calcium/calmodulin in order to regulate kinase activity. Protein substrates have been identified for some of the DMT kinases, but little is known about the mechanism of recognition. Substrate conformation could be an equally important parameter in substrate recognition as specific preferences in sequence position. Taking the data together, this kinase branch encapsulates a treasure trove of features that renders it distinct from many other protein kinases and calls for future research activities in this field. PMID:23745726

  6. Activation of the TOR Signalling Pathway by Glutamine Regulates Insect Fecundity.

    Science.gov (United States)

    Zhai, Yifan; Sun, Zhongxiang; Zhang, Jianqing; Kang, Kui; Chen, Jie; Zhang, Wenqing

    2015-01-01

    The target of rapamycin (TOR) positively controls cell growth in response to nutrients such as amino acids. However, research on the specific nutrients sensed by TOR is limited. Glutamine (Gln), a particularly important amino acid involved in metabolism in organisms, is synthesised and catalysed exclusively by glutamine synthetase (GS), and our previous studies have shown that Gln may regulate fecundity in vivo levels of the brown planthopper (BPH) Nilaparvata lugens. Until now, it has remained unclear whether Gln activates or inhibits the TOR signalling pathway. Here, we performed the combined analyses of iTRAQ (isobaric tags for relative and absolute quantification) and DGE (tag-based digital gene expression) data in N. lugens at the protein and transcript levels after GS RNAi, and we found that 52 pathways overlap, including the TOR pathway. We further experimentally demonstrate that Gln activates the TOR pathway by promoting the serine/threonine protein kinase AKT and inhibiting the 5'AMP-activated protein kinase AMPK phosphorylation activity in the pest. Furthermore, TOR regulates the fecundity of N. lugens probably by mediating vitellogenin (Vg) expression. This work is the first report that Gln activates the TOR pathway in vivo. PMID:26024507

  7. [Regulation of biochar on matrix enzyme activities and microorganisms around cucumber roots under continuous cropping].

    Science.gov (United States)

    Zou, Chun-jiao; Zhang, Yong-yong; Zhang, Yi-ming; Guo, Xiao-ou; Li, Ming-jing; Li, Tian-lai

    2015-06-01

    The effects of addition of biochar on the matrix enzymes activity, microorganisms population and microbial community structure were evaluated under cucumber continuous cropping for 6 years (11 rotations). Cucumbers were grown in pots in greenhouse with 5% or 3% of medium (by mass) substituted with biochar. The control consisted of medium alone without biochar. The results showed that the activity of peroxidase was significantly improved to the level of the first rotation crop form 30 to 120 d after planting in both biochar treatments, with the effect of 5% biochar being more significant than that of 3% biochar. However, the neutral phosphatase activity was markedly reduced after biochar treatment. The addition of 5% biochar had significant regulation effect on the activities of invertase and urease from 30 to 90 d after planting, while the addition of 3% biochar had little effect. The populations of bacteria and actinomycetes were increased and the fungi population was reduced in both biochar treatments from 30 to 90 d after planting, and the effect of 5% biochar was more significant than that of 3% biochar. Meanwhile, the addition of biochar significantly increased the diversity of the bacterial community structure. In summary, biochar had obvious regulation effect on soil enzyme activity, microorganism quantity and microbial community in continuous cropping nutrition medium. PMID:26572031

  8. Transient epileptiform signaling during neuronal network development: regulation by external stimulation and bimodal GABAergic activity.

    Science.gov (United States)

    Zemianek, Jill M; Shultz, Abraham M; Lee, Sangmook; Guaraldi, Mary; Yanco, Holly A; Shea, Thomas B

    2013-04-01

    A predominance of excitatory activity, with protracted appearance of inhibitory activity, accompanies cortical neuronal development. It is unclear whether or not inhibitory neuronal activity is solicited exclusively by excitatory neurons or whether the transient excitatory activity displayed by developing GABAergic neurons contributes to an excitatory threshold that fosters their conversion to inhibitory activity. We addressed this possibility by culturing murine embryonic neurons on multi-electrode arrays. A wave of individual 0.2-0.4 mV signals ("spikes") appeared between approx. 20-30 days in culture, then declined. A transient wave of high amplitude (>0.5 mV) epileptiform activity coincided with the developmental decline in spikes. Bursts (clusters of ≥3 low-amplitude spikes within 0.7s prior to returning to baseline) persisted following this decline. Addition of the GABAergic antagonist bicuculline initially had no effect on signaling, consistent with delayed development of GABAergic synapses. This was followed by a period in which bicuculline inhibited overall signaling, confirming that GABAergic neurons initially display excitatory activity in ex vivo networks. Following the transient developmental wave of epileptiform signaling, bicuculline induced a resurgence of epileptiform signaling, indicating that GABAergic neurons at this point displayed inhibitory activity. The appearance of transition after the developmental and decline of epileptiform activity, rather than immediately after the developmental decline in lower-amplitude spikes, suggests that the initial excitatory activity of GABAergic neurons contributes to their transition into inhibitory neurons, and that inhibitory GABAergic activity is essential for network development. Prior studies indicate that a minority (25%) of neurons in these cultures were GABAergic, suggesting that inhibitory neurons regulate multiple excitatory neurons. A similar robust increase in signaling following cessation of

  9. Regulation of protease-activated receptor 1 signaling by the adaptor protein complex 2 and R4 subfamily of regulator of G protein signaling proteins.

    Science.gov (United States)

    Chen, Buxin; Siderovski, David P; Neubig, Richard R; Lawson, Mark A; Trejo, Joann

    2014-01-17

    The G protein-coupled protease-activated receptor 1 (PAR1) is irreversibly proteolytically activated by thrombin. Hence, the precise regulation of PAR1 signaling is important for proper cellular responses. In addition to desensitization, internalization and lysosomal sorting of activated PAR1 are critical for the termination of signaling. Unlike most G protein-coupled receptors, PAR1 internalization is mediated by the clathrin adaptor protein complex 2 (AP-2) and epsin-1, rather than β-arrestins. However, the function of AP-2 and epsin-1 in the regulation of PAR1 signaling is not known. Here, we report that AP-2, and not epsin-1, regulates activated PAR1-stimulated phosphoinositide hydrolysis via two different mechanisms that involve, in part, a subset of R4 subfamily of "regulator of G protein signaling" (RGS) proteins. A significantly greater increase in activated PAR1 signaling was observed in cells depleted of AP-2 using siRNA or in cells expressing a PAR1 (420)AKKAA(424) mutant with defective AP-2 binding. This effect was attributed to AP-2 modulation of PAR1 surface expression and efficiency of G protein coupling. We further found that ectopic expression of R4 subfamily members RGS2, RGS3, RGS4, and RGS5 reduced activated PAR1 wild-type signaling, whereas signaling by the PAR1 AKKAA mutant was minimally affected. Intriguingly, siRNA-mediated depletion analysis revealed a function for RGS5 in the regulation of signaling by the PAR1 wild type but not the AKKAA mutant. Moreover, activation of the PAR1 wild type, and not the AKKAA mutant, induced Gαq association with RGS3 via an AP-2-dependent mechanism. Thus, AP-2 regulates activated PAR1 signaling by altering receptor surface expression and through recruitment of RGS proteins. PMID:24297163

  10. AMP-activated protein kinase (AMPK) regulates the insulin-induced activation of the nitric oxide synthase in human platelets.

    Science.gov (United States)

    Fleming, Ingrid; Schulz, Christian; Fichtlscherer, Birgit; Kemp, Bruce E; Fisslthaler, Beate; Busse, Rudi

    2003-11-01

    Little is known about the signaling cascades that eventually regulate the activity of the endothelial nitric oxide synthase (eNOS) in platelets. Here, we investigated the effects of insulin on the phosphorylation and activation of eNOS in washed human platelets and in endothelial cells. Insulin activated the protein kinase Akt in cultured endothelial cells and increased the phosphorylation of eNOS on Ser(1177) but failed to increase endothelial cyclic GMP levels or to elicit the relaxation of endothelium-intact porcine coronary arteries. In platelets, insulin also elicited the activation of Akt as well as the phosphorylation of eNOS and initiated NO production which was associated with increased cyclic GMP levels and the inhibition of thrombin-induced aggregation. The insulin-induced inhibition of aggregation was accompanied by a decreased Ca(2+) response to thrombin and was also prevented by N(omega) nitro-L-arginine. In platelets, but not in endothelial cells, insulin induced the activation of the AMP-activated protein kinase (AMPK), a metabolic stress-sensing kinase which was sensitive to the phosphatidylinositol 3-kinase (PI3-K) inhibitor wortmannin and the AMPK inhibitor iodotubercidin. Moreover, the insulin-mediated inhibition of thrombin-induced aggregation was prevented by iodotubercidin. Insulin-independent activation of the AMPK using 5-aminoimidazole-4-carboxamide ribonucleoside, increased platelet eNOS phosphorylation, increased cyclic GMP levels and attenuated platelet aggregation. These results highlight the differences in the signal transduction cascade activated by insulin in endothelial cells and platelets, and demonstrate that insulin stimulates the formation of NO in human platelets, in the absence of an increase in Ca(2+), by acti-vating PI3-K and AMPK which phosphorylates eNOS on Ser(1177).

  11. Mechanisms and metabolic regulation of PPARα activation in Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Ning, Li-Jun; He, An-Yuan; Li, Jia-Min; Lu, Dong-Liang; Jiao, Jian-Gang; Li, Ling-Yu; Li, Dong-Liang; Zhang, Mei-Ling; Chen, Li-Qiao; Du, Zhen-Yu

    2016-09-01

    Although the key metabolic regulatory functions of mammalian peroxisome proliferator-activated receptor α (PPARα) have been thoroughly studied, the molecular mechanisms and metabolic regulation of PPARα activation in fish are less known. In the first part of the present study, Nile tilapia (Nt)PPARα was cloned and identified, and high mRNA expression levels were detected in the brain, liver, and heart. NtPPARα was activated by an agonist (fenofibrate) and by fasting and was verified in primary hepatocytes and living fish by decreased phosphorylation of NtPPARα and/or increased NtPPARα mRNA and protein expression. In the second part of the present work, fenofibrate was fed to fish or fish were fasted for 4weeks to investigate the metabolic regulatory effects of NtPPARα. A transcriptomic study was also performed. The results indicated that fenofibrate decreased hepatic triglyceride and 18C-series fatty acid contents but increased the catabolic rate of intraperitoneally injected [1-(14)C] palmitate in vivo, hepatic mitochondrial β-oxidation efficiency, the quantity of cytochrome b DNA, and carnitine palmitoyltransferase-1a mRNA expression. Fenofibrate also increased serum glucose, insulin, and lactate concentrations. Fasting had stronger hypolipidemic and gene regulatory effects than those of fenofibrate. Taken together, we conclude that: 1) liver is one of the main target tissues of the metabolic regulation of NtPPARα activation; 2) dephosphorylation is the basal NtPPARα activation mechanism rather than enhanced mRNA and protein expression; 3) activated NtPPARα has a hypolipidemic effect by increasing activity and the number of hepatic mitochondria; and 4) PPARα activation affects carbohydrate metabolism by altering energy homeostasis among nutrients. PMID:27320014

  12. Teacher practice in secondary vocational education : Between teacher-regulated activities of student learning and student self-regulation

    NARCIS (Netherlands)

    van Beek, J.A.; de Jong, F.P.C.M.; Minnaert, A.E.M.G.; Wubbels, Th.

    2014-01-01

    The interplay between teacher regulation and student self-regulation of learning is an important topic in contemporary theories of teaching and learning. This study used mixed methods, including a student perception inventory and observations, to investigate whether teachers differ in their regulati

  13. Regulation of tyrosinase expression and activity in cultured human retinal pigment epithelial cells.

    Science.gov (United States)

    Abul-Hassan, K; Walmsley, R; Tombran-Tink, J; Boulton, M

    2000-12-01

    The purpose of this study was to investigate the regulation of tyrosinase gene expression and activity in cultured human retinal pigment epithelial (RPE) cells. The tyrosinase promoter (Ty.prom) region (400 bp) was PCR amplified and cloned into a modified mammalian expression vector (pcDNA3.1) upstream of a firefly luciferase (Luc) cDNA and was designated 'pcDNA3.1-Ty.prom.Luc'. The plasmid was co-transfected into RPE cells with a second mammalian expression plasmid (pRL-TK) containing a herpes simplex virus thymidine kinase promoter region upstream of Renilla Luc in a protocol designated the 'dual luciferase assay' (DLA). After co-transfection, cells were treated with a range of potential melanogenic agents; basic fibroblast growth factor (bFGF), methyl methane sulphonate, alpha-melanocyte stimulating hormone, verapamil, phorbol myristate acetate, cholera toxin (CT), pigment epithelium derived factor (PEDF), and L-tyrosine. The expression of tyrosinase promoter and enzymatic activities were determined 48 hr post-transfection using the DLA and DOPA oxidase assays, respectively. Tyrosinase activity could not be detected in RPE cells with any of the treatments. Tyrosinase promoter activity was significantly up-regulated in RPE cells treated with bFGF, PEDF, verapamil, CT and tyrosine compared with control cells. In conclusion, the tyrosinase gene is not only expressed but can be regulated in response to different chemicals in cultured human RPE cells. However, it appears that RPE cells in culture lack a post-transcriptional and/or translational modification point(s), which are necessary for tyrosinase enzymic activity. PMID:11153695

  14. Proteolytic fragmentation of inositol 1,4,5-trisphosphate receptors: a novel mechanism regulating channel activity?

    Science.gov (United States)

    Wang, Liwei; Alzayady, Kamil J; Yule, David I

    2016-06-01

    Inositol 1,4,5-trisphosphate receptors (IP3 Rs) are a family of ubiquitously expressed intracellular Ca(2+) release channels. Regulation of channel activity by Ca(2+) , nucleotides, phosphorylation, protein binding partners and other cellular factors is thought to play a major role in defining the specific spatiotemporal characteristics of intracellular Ca(2+) signals. These properties are, in turn, believed pivotal for the selective and specific physiological activation of Ca(2+) -dependent effectors. IP3 Rs are also substrates for the intracellular cysteine proteases, calpain and caspase. Cleavage of the IP3 R has been proposed to play a role in apoptotic cell death by uncoupling regions important for IP3 binding from the channel domain, leaving an unregulated leaky Ca(2+) pore. Contrary to this hypothesis, we demonstrate following proteolysis that N- and C-termini of IP3 R1 remain associated, presumably through non-covalent interactions. Further, we show that complementary fragments of IP3 R1 assemble into tetrameric structures and retain their ability to be regulated robustly by IP3 . While peptide continuity is clearly not necessary for IP3 -gating of the channel, we propose that cleavage of the IP3 R peptide chain may alter other important regulatory events to modulate channel activity. In this scenario, stimulation of the cleaved IP3 R may support distinct spatiotemporal Ca(2+) signals and activation of specific effectors. Notably, in many adaptive physiological events, the non-apoptotic activities of caspase and calpain are demonstrated to be important, but the substrates of the proteases are poorly defined. We speculate that proteolytic fragmentation may represent a novel form of IP3 R regulation, which plays a role in varied adaptive physiological processes.

  15. The relationship between plasminogen activation inhibitor-1 and proinflammatory and counterinflammatory mediators in children with meningococcal septic shock

    NARCIS (Netherlands)

    Kornelisse, R.F.; Hazalzet, J.A.; Savelkoul, H.F.J.; Hop, W.C.J.; Suur, M.H.; Borsboom, A.N.J.; Risseeuw-Appel, I.M.; Voort, van der E.; Neijens, H.J.; Groot, de R.

    1996-01-01

    Proinflammatory cytokines (tumor necrosis factor [TNF]-alpha and interleukin [IL]-6 and -8), counterinflammatory compounds (IL-10 and soluble TNF receptors p55 and p75 [sTNFR-55 and -75]), and hemostatic parameters were determined in 38 patients with meningococcal septic shock. Eleven patients (29%)

  16. Plasminogen activator inhibitor-1 in cigarette smoke exposure and influenza A virus infection-induced lung injury.

    Directory of Open Access Journals (Sweden)

    Yashodhar P Bhandary

    Full Text Available Parenchymal lung inflammation and airway and alveolar epithelial cell apoptosis are associated with cigarette smoke exposure (CSE, which contributes to chronic obstructive pulmonary disease (COPD. Epidemiological studies indicate that people exposed to chronic cigarette smoke with or without COPD are more susceptible to influenza A virus (IAV infection. We found increased p53, PAI-1 and apoptosis in AECs, with accumulation of macrophages and neutrophils in the lungs of patients with COPD. In Wild-type (WT mice with passive CSE (PCSE, p53 and PAI-1 expression and apoptosis were increased in AECs as was lung inflammation, while those lacking p53 or PAI-1 resisted AEC apoptosis and lung inflammation. Further, inhibition of p53-mediated induction of PAI-1 by treatment of WT mice with caveolin-1 scaffolding domain peptide (CSP reduced PCSE-induced lung inflammation and reversed PCSE-induced suppression of eosinophil-associated RNase1 (EAR1. Competitive inhibition of the p53-PAI-1 mRNA interaction by expressing p53-binding 3'UTR sequences of PAI-1 mRNA likewise suppressed CS-induced PAI-1 and AEC apoptosis and restored EAR1 expression. Consistent with PCSE-induced lung injury, IAV infection increased p53, PAI-1 and apoptosis in AECs in association with pulmonary inflammation. Lung inflammation induced by PCSE was worsened by subsequent exposure to IAV. Mice lacking PAI-1 that were exposed to IAV showed minimal viral burden based on M2 antigen and hemagglutination analyses, whereas transgenic mice that overexpress PAI-1 without PCSE showed increased M2 antigen and inflammation after IAV infection. These observations indicate that increased PAI-1 expression promotes AEC apoptosis and exacerbates lung inflammation induced by IAV following PCSE.

  17. Elevated plasma levels of vascular endothelial growth factor and plasminogen activator inhibitor-1 decrease during improvement of psoriasis

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen; Christensen, Ib Jarle; Svendsen, M N;

    2002-01-01

    OBJECTIVE AND DESIGN: An evaluation of angiogenesis related molecules during open treatment of psoriasis. MATERIALS AND SUBJECTS: Plasma samples and skin biopsies from 16 patients with psoriasis and plasma samples from 13 healthy controls. TREATMENT: Ranitidine 300 mg orally twice daily for 6 mon...... improvement of the disease suggest that the two molecules may play a role in pathogenesis of psoriasis.......OBJECTIVE AND DESIGN: An evaluation of angiogenesis related molecules during open treatment of psoriasis. MATERIALS AND SUBJECTS: Plasma samples and skin biopsies from 16 patients with psoriasis and plasma samples from 13 healthy controls. TREATMENT: Ranitidine 300 mg orally twice daily for 6...

  18. Interactions of plasminogen activator inhibitor-1 with vitronectin involve an extensive binding surface and induce mutual conformational rearrangements

    DEFF Research Database (Denmark)

    Blouse, Grant E; Dupont, Daniel Miotto; Schar, Christine R;

    2009-01-01

    . In support of this model are recent results that define a PAI-1-binding site on vitronectin that lies outside the somatomedin B domain (Schar, C. R., Blouse, G. E., Minor, K. H., and Peterson, C. B. (2008) J. Biol. Chem. 283, 10297-10309) and the complementary site on PAI-1 (Schar, C. R., Jensen, J. K...

  19. Regulation of the activity of the Bacillus licheniformis A5 glutamine synthetase.

    Science.gov (United States)

    Donohue, T J; Bernlohr, R W

    1981-10-01

    The regulation of glutamine synthetase activity by positive and negative effectors of enzyme activity singularly and in combinations was studied by using a homogeneous enzyme preparation from Bacillus licheniformis A5. Phosphorylribosyl pyrophosphate at concentrations greater than 2mM stimulated glutamine synthetase activity by approximately 70%. The concentration of phosphorylribosyl pyrophosphate required for half-maximal stimulation of enzyme activity was 0.4 mM. Results obtained from studies of fractional inhibition of glutamine synthetase activity were consistent with the presence of one allosteric site for glutamine binding (apparent I0.5, 2.2mM) per active enzyme unit at a glutamate concentration of 50 mM. At a glutamate concentration of 30 mM or less, the data were consistent with the enzyme containing two binding sites for glutamine (one of which was an allosteric site with an apparent I0.5 of 0.4 mM). Bases on an analysis of the response of glutamine synthetase activity to positive and negative effectors in vitro and to the intracellular concentration of these effectors in vivo, the primary modulators of glutamine synthetase activity in B. licheniformis A5 appear to be glutamine and alanine (apparent I0.5, 5.2mM). PMID:6169702

  20. Regulation of sucrose synthase activity and sugar yield by nitrogen in sugar beet

    Institute of Scientific and Technical Information of China (English)

    LI Caifeng; MA Fengming; LI Wenhua; WANG Rui; CHEN Shengyong; LUO Yu

    2007-01-01

    The content of sugar is influenced by sucrose synthase (SS) activity in roots. The effects of nitrogen level in the aminonitrate ratio on SS activity of leaves and roots, roots yield and sugar content in sugar beet were studied in the field experiment by nutrient solution culture. The results showed that SS activity in leaves was lower than that in roots. With nitrogen level increasing,SS decomposition activity enhanced, and synthesis activity reduced. SS activity was regulated by different nitrogen forms and the ratio of NO3- and NH4+. SS synthesis activity was enhanced as NH4+ increasing when NO3-: NH4+≥ 1, and it decreased as increasing NH4+ when NO3-: NH4+≤1, and it was the highest when NO3-: NH4+=1. SS decomposition activity was enhanced as NO3- increasing.Sucrose content in root was lowed as nitrogen level increasing, but it was enhanced as NH4+ increasing in the same nitrogen level.Root and sugar yield were the highest in the medium nitrogen level and NO3-: NH4+=1. The result in field experiment corresponded with that in the nutrient fluid culture. It provides a basis for using reasonably nitrogen fertilizer in sugar beet production.

  1. Inferring yeast cell cycle regulators and interactions using transcription factor activities

    Directory of Open Access Journals (Sweden)

    Galbraith Simon J

    2005-06-01

    Full Text Available Abstract Background Since transcription factors are often regulated at the post-transcriptional level, their activities, rather than expression levels may provide valuable information for investigating functions and their interactions. The recently developed Network Component Analysis (NCA and its generalized form (gNCA provide a robust framework for deducing the transcription factor activities (TFAs from various types of DNA microarray data and transcription factor-gene connectivity. The goal of this work is to demonstrate the utility of TFAs in inferring transcription factor functions and interactions in Saccharomyces cerevisiae cell cycle regulation. Results Using gNCA, we determined 74 TFAs from both wild type and fkh1 fkh2 deletion mutant microarray data encompassing 1529 ORFs. We hypothesized that transcription factors participating in the cell cycle regulation exhibit cyclic activity profiles. This hypothesis was supported by the TFA profiles of known cell cycle factors and was used as a basis to uncover other potential cell cycle factors. By combining the results from both cluster analysis and periodicity analysis, we recovered nearly 90% of the known cell cycle regulators, and identified 5 putative cell cycle-related transcription factors (Dal81, Hap2, Hir2, Mss11, and Rlm1. In addition, by analyzing expression data from transcription factor knockout strains, we determined 3 verified (Ace2, Ndd1, and Swi5 and 4 putative interaction partners (Cha4, Hap2, Fhl1, and Rts2 of the forkhead transcription factors. Sensitivity of TFAs to connectivity errors was determined to provide confidence level of these predictions. Conclusion By subjecting TFA profiles to analyses based upon physiological signatures we were able to identify cell cycle related transcription factors consistent with current literature, transcription factors with potential cell cycle dependent roles, and interactions between transcription factors.

  2. The AU-rich element mRNA decay-promoting activity of BRF1 is regulated by mitogen-activated protein kinase-activated protein kinase 2

    OpenAIRE

    Maitra, Sushmit; Chou, Chu-Fang; Luber, Christian A.; Lee, Kyung-Yeol; Mann, Matthias; Chen, Ching-Yi

    2008-01-01

    Regulated mRNA decay is a highly important process for the tight control of gene expression. Inherently unstable mRNAs contain AU-rich elements (AREs) in the 3′ untranslated regions that direct rapid mRNA decay by interaction with decay-promoting ARE-binding proteins (ARE-BPs). The decay of ARE-containing mRNAs is regulated by signaling pathways that are believed to directly target ARE-BPs. Here, we show that BRF1 involved in ARE-mediated mRNA decay (AMD) is phosphorylated by MAPK-activated p...

  3. Regulation of Hepatic Triacylglycerol Metabolism by CGI-58 Does Not Require ATGL Co-activation

    Directory of Open Access Journals (Sweden)

    Caleb C. Lord

    2016-07-01

    Full Text Available Adipose triglyceride lipase (ATGL and comparative gene identification 58 (CGI-58 are critical regulators of triacylglycerol (TAG turnover. CGI-58 is thought to regulate TAG mobilization by stimulating the enzymatic activity of ATGL. However, it is not known whether this coactivation function of CGI-58 occurs in vivo. Moreover, the phenotype of human CGI-58 mutations suggests ATGL-independent functions. Through direct comparison of mice with single or double deficiency of CGI-58 and ATGL, we show here that CGI-58 knockdown causes hepatic steatosis in both the presence and absence of ATGL. CGI-58 also regulates hepatic diacylglycerol (DAG and inflammation in an ATGL-independent manner. Interestingly, ATGL deficiency, but not CGI-58 deficiency, results in suppression of the hepatic and adipose de novo lipogenic program. Collectively, these findings show that CGI-58 regulates hepatic neutral lipid storage and inflammation in the genetic absence of ATGL, demonstrating that mechanisms driving TAG lipolysis in hepatocytes differ significantly from those in adipocytes.

  4. Regulation of Hepatic Triacylglycerol Metabolism by CGI-58 Does Not Require ATGL Co-activation.

    Science.gov (United States)

    Lord, Caleb C; Ferguson, Daniel; Thomas, Gwynneth; Brown, Amanda L; Schugar, Rebecca C; Burrows, Amy; Gromovsky, Anthony D; Betters, Jenna; Neumann, Chase; Sacks, Jessica; Marshall, Stephanie; Watts, Russell; Schweiger, Martina; Lee, Richard G; Crooke, Rosanne M; Graham, Mark J; Lathia, Justin D; Sakaguchi, Takuya F; Lehner, Richard; Haemmerle, Guenter; Zechner, Rudolf; Brown, J Mark

    2016-07-26

    Adipose triglyceride lipase (ATGL) and comparative gene identification 58 (CGI-58) are critical regulators of triacylglycerol (TAG) turnover. CGI-58 is thought to regulate TAG mobilization by stimulating the enzymatic activity of ATGL. However, it is not known whether this coactivation function of CGI-58 occurs in vivo. Moreover, the phenotype of human CGI-58 mutations suggests ATGL-independent functions. Through direct comparison of mice with single or double deficiency of CGI-58 and ATGL, we show here that CGI-58 knockdown causes hepatic steatosis in both the presence and absence of ATGL. CGI-58 also regulates hepatic diacylglycerol (DAG) and inflammation in an ATGL-independent manner. Interestingly, ATGL deficiency, but not CGI-58 deficiency, results in suppression of the hepatic and adipose de novo lipogenic program. Collectively, these findings show that CGI-58 regulates hepatic neutral lipid storage and inflammation in the genetic absence of ATGL, demonstrating that mechanisms driving TAG lipolysis in hepatocytes differ significantly from those in adipocytes. PMID:27396333

  5. Membrane lipids regulate ganglioside GM2 catabolism and GM2 activator protein activity.

    Science.gov (United States)

    Anheuser, Susi; Breiden, Bernadette; Schwarzmann, Günter; Sandhoff, Konrad

    2015-09-01

    Ganglioside GM2 is the major lysosomal storage compound of Tay-Sachs disease. It also accumulates in Niemann-Pick disease types A and B with primary storage of SM and with cholesterol in type C. Reconstitution of GM2 catabolism with β-hexosaminidase A and GM2 activator protein (GM2AP) at uncharged liposomal surfaces carrying GM2 as substrate generated only a physiologically irrelevant catabolic rate, even at pH 4.2. However, incorporation of anionic phospholipids into the GM2 carrying liposomes stimulated GM2 hydrolysis more than 10-fold, while the incorporation of plasma membrane stabilizing lipids (SM and cholesterol) generated a strong inhibition of GM2 hydrolysis, even in the presence of anionic phospholipids. Mobilization of membrane lipids by GM2AP was also inhibited in the presence of cholesterol or SM, as revealed by surface plasmon resonance studies. These lipids also reduced the interliposomal transfer rate of 2-NBD-GM1 by GM2AP, as observed in assays using Förster resonance energy transfer. Our data raise major concerns about the usage of recombinant His-tagged GM2AP compared with untagged protein. The former binds more strongly to anionic GM2-carrying liposomal surfaces, increases GM2 hydrolysis, and accelerates intermembrane transfer of 2-NBD-GM1, but does not mobilize membrane lipids.

  6. Membrane lipids regulate ganglioside GM2 catabolism and GM2 activator protein activity.

    Science.gov (United States)

    Anheuser, Susi; Breiden, Bernadette; Schwarzmann, Günter; Sandhoff, Konrad

    2015-09-01

    Ganglioside GM2 is the major lysosomal storage compound of Tay-Sachs disease. It also accumulates in Niemann-Pick disease types A and B with primary storage of SM and with cholesterol in type C. Reconstitution of GM2 catabolism with β-hexosaminidase A and GM2 activator protein (GM2AP) at uncharged liposomal surfaces carrying GM2 as substrate generated only a physiologically irrelevant catabolic rate, even at pH 4.2. However, incorporation of anionic phospholipids into the GM2 carrying liposomes stimulated GM2 hydrolysis more than 10-fold, while the incorporation of plasma membrane stabilizing lipids (SM and cholesterol) generated a strong inhibition of GM2 hydrolysis, even in the presence of anionic phospholipids. Mobilization of membrane lipids by GM2AP was also inhibited in the presence of cholesterol or SM, as revealed by surface plasmon resonance studies. These lipids also reduced the interliposomal transfer rate of 2-NBD-GM1 by GM2AP, as observed in assays using Förster resonance energy transfer. Our data raise major concerns about the usage of recombinant His-tagged GM2AP compared with untagged protein. The former binds more strongly to anionic GM2-carrying liposomal surfaces, increases GM2 hydrolysis, and accelerates intermembrane transfer of 2-NBD-GM1, but does not mobilize membrane lipids. PMID:26175473

  7. Telomerase regulates MYC-driven oncogenesis independent of its reverse transcriptase activity.

    Science.gov (United States)

    Koh, Cheryl M; Khattar, Ekta; Leow, Shi Chi; Liu, Chia Yi; Muller, Julius; Ang, Wei Xia; Li, Yinghui; Franzoso, Guido; Li, Shang; Guccione, Ernesto; Tergaonkar, Vinay

    2015-05-01

    Constitutively active MYC and reactivated telomerase often coexist in cancers. While reactivation of telomerase is thought to be essential for replicative immortality, MYC, in conjunction with cofactors, confers several growth advantages to cancer cells. It is known that the reactivation of TERT, the catalytic subunit of telomerase, is limiting for reconstituting telomerase activity in tumors. However, while reactivation of TERT has been functionally linked to the acquisition of several "hallmarks of cancer" in tumors, the molecular mechanisms by which this occurs and whether these mechanisms are distinct from the role of telomerase on telomeres is not clear. Here, we demonstrated that first-generation TERT-null mice, unlike Terc-null mice, show delayed onset of MYC-induced lymphomagenesis. We further determined that TERT is a regulator of MYC stability in cancer. TERT stabilized MYC levels on chromatin, contributing to either activation or repression of its target genes. TERT regulated MYC ubiquitination and proteasomal degradation, and this effect of TERT was independent of its reverse transcriptase activity and role in telomere elongation. Based on these data, we conclude that reactivation of TERT, a direct transcriptional MYC target in tumors, provides a feed-forward mechanism to potentiate MYC-dependent oncogenesis. PMID:25893605

  8. Endosomal SNARE proteins regulate CFTR activity and trafficking in epithelial cells.

    Science.gov (United States)

    Bilan, Frédéric; Nacfer, Magali; Fresquet, Fleur; Norez, Caroline; Melin, Patricia; Martin-Berge, Alice; Costa de Beauregard, Marie-Alyette; Becq, Frédéric; Kitzis, Alain; Thoreau, Vincent

    2008-07-01

    The Cystic Fibrosis Transmembrane conductance Regulator (CFTR) protein is a chloride channel localized at the apical plasma membrane of epithelial cells. We previously described that syntaxin 8, an endosomal SNARE (Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptor) protein, interacts with CFTR and regulates its trafficking to the plasma membrane and hence its channel activity. Syntaxin 8 belongs to the endosomal SNARE complex which also contains syntaxin 7, vti1b and VAMP8. Here, we report that these four endosomal SNARE proteins physically and functionally interact with CFTR. In LLC-PK1 cells transfected with CFTR and in Caco-2 cells endogenously expressing CFTR, we demonstrated that endosomal SNARE protein overexpression inhibits CFTR activity but not swelling- or calcium-activated iodide efflux, indicating a specific effect upon CFTR activity. Moreover, co-immunoprecipitation experiments in LLC-PK1-CFTR cells showed that CFTR and SNARE proteins belong to a same complex and pull-down assays showed that VAMP8 and vti1b preferentially interact with CFTR N-terminus tail. By cell surface biotinylation and immunofluorescence experiments, we evidenced that endosomal SNARE overexpression disturbs CFTR apical targeting. Finally, we found a colocalization of CFTR and endosomal SNARE proteins in Rab11-positive recycling endosomes, suggesting a new role for endosomal SNARE proteins in CFTR trafficking in epithelial cells.

  9. FGFR2c-mediated ERK-MAPK activity regulates coronal suture development.

    Science.gov (United States)

    Pfaff, Miles J; Xue, Ke; Li, Li; Horowitz, Mark C; Steinbacher, Derek M; Eswarakumar, Jacob V P

    2016-07-15

    Fibroblast growth factor receptor 2 (FGFR2) signaling is critical for proper craniofacial development. A gain-of-function mutation in the 2c splice variant of the receptor's gene is associated with Crouzon syndrome, which is characterized by craniosynostosis, the premature fusion of one or more of the cranial vault sutures, leading to craniofacial maldevelopment. Insight into the molecular mechanism of craniosynostosis has identified the ERK-MAPK signaling cascade as a critical regulator of suture patency. The aim of this study is to investigate the role of FGFR2c-induced ERK-MAPK activation in the regulation of coronal suture development. Loss-of-function and gain-of-function Fgfr2c mutant mice have overlapping phenotypes, including coronal synostosis and craniofacial dysmorphia. In vivo analysis of coronal sutures in loss-of-function and gain-of-function models demonstrated fundamentally different pathogenesis underlying coronal suture synostosis. Calvarial osteoblasts from gain-of-function mice demonstrated enhanced osteoblastic function and maturation with concomitant increase in ERK-MAPK activation. In vitro inhibition with the ERK protein inhibitor U0126 mitigated ERK protein activation levels with a concomitant reduction in alkaline phosphatase activity. This study identifies FGFR2c-mediated ERK-MAPK signaling as a key mediator of craniofacial growth and coronal suture development. Furthermore, our results solve the apparent paradox between loss-of-function and gain-of-function FGFR2c mutants with respect to coronal suture synostosis. PMID:27034231

  10. A ubiquitin ligase complex regulates caspase activation during sperm differentiation in Drosophila.

    Directory of Open Access Journals (Sweden)

    Eli Arama

    2007-10-01

    Full Text Available In both insects and mammals, spermatids eliminate their bulk cytoplasm as they undergo terminal differentiation. In Drosophila, this process of dramatic cellular remodeling requires apoptotic proteins, including caspases. To gain further insight into the regulation of caspases, we screened a large collection of sterile male flies for mutants that block effector caspase activation at the onset of spermatid individualization. Here, we describe the identification and characterization of a testis-specific, Cullin-3-dependent ubiquitin ligase complex that is required for caspase activation in spermatids. Mutations in either a testis-specific isoform of Cullin-3 (Cul3(Testis, the small RING protein Roc1b, or a Drosophila orthologue of the mammalian BTB-Kelch protein Klhl10 all reduce or eliminate effector caspase activation in spermatids. Importantly, all three genes encode proteins that can physically interact to form a ubiquitin ligase complex. Roc1b binds to the catalytic core of Cullin-3, and Klhl10 binds specifically to a unique testis-specific N-terminal Cullin-3 (TeNC domain of Cul3(Testis that is required for activation of effector caspase in spermatids. Finally, the BIR domain region of the giant inhibitor of apoptosis-like protein dBruce is sufficient to bind to Klhl10, which is consistent with the idea that dBruce is a substrate for the Cullin-3-based E3-ligase complex. These findings reveal a novel role of Cullin-based ubiquitin ligases in caspase regulation.

  11. Regulation of Drug Disposition Gene Expression in Pregnant Mice with Car Receptor Activation

    Directory of Open Access Journals (Sweden)

    Amanda S. Bright

    2016-07-01

    Full Text Available More than half of pregnant women use prescription medications in order to maintain both maternal and fetal health. The constitutive androstane receptor (Car critically affects the disposition of chemicals by regulating the transcription of genes encoding metabolic enzymes and transporters. However, the effects of Car activation on chemical disposition during pregnancy are unclear. This study aims to determine the degree to which pregnancy alters the expression of drug metabolizing enzymes and transporters in response to the pharmacological activation of Car. To test this, pregnant C57BL/6 mice were administered IP doses of vehicle, or a potent Car agonist, TCPOBOP, on gestation days 14, 15 and 16. Hepatic mRNA and protein expression of Car target genes (phase I, II and transporters were quantified on gestation day 17. Pregnancy-related changes, such as induction of Cyp2b10, Ugt1a1 and Sult1a1 and repression of Ugt1a6, Gsta1, Gsta2 and Mrp6, were observed. Interestingly, the induction of Cyp2b10, Gsta1, Gsta2 and Mrp2–4 mRNAs by TCPOBOP was attenuated in maternal livers suggesting that Car activation is impeded by the biochemical and/or physiological changes that occur during gestation. Taken together, these findings suggest that pregnancy and pharmacological activation of Car can differentially regulate the expression of drug metabolism and transport genes.

  12. Liver X Receptor (LXR) activation negatively regulates visfatin expression in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Mayi, Therese Hervee; Rigamonti, Elena [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Pattou, Francois [Univ Lille Nord de France, F-59000 Lille (France); Department of Endocrine Surgery, University Hospital, Lille (France); U859 Biotherapies for Diabetes, INSERM, Lille (France); Staels, Bart, E-mail: bart.staels@pasteur-lille.fr [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France); Chinetti-Gbaguidi, Giulia [Univ Lille Nord de France, F-59000 Lille (France); INSERM UR1011, F-59000 Lille (France); UDSL, F-59000 Lille (France); Institut Pasteur de Lille, F-59019 Lille (France)

    2011-01-07

    Research highlights: {yields} Synthetic LXR ligands decreased visfatin expression in human macrophages. {yields} LXR activation leads to a modest and transient decrease of NAD{sup +} concentration. {yields} LXR activation decreased PPAR{gamma}-induced visfatin in human macrophages. -- Abstract: Adipose tissue macrophages (ATM) are the major source of visfatin, a visceral fat adipokine upregulated during obesity. Also known to play a role in B cell differentiation (pre-B cell colony-enhancing factor (PBEF)) and NAD biosynthesis (nicotinamide phosphoribosyl transferase (NAMPT)), visfatin has been suggested to play a role in inflammation. Liver X Receptor (LXR) and Peroxisome Proliferator-Activated Receptor (PPAR){gamma} are nuclear receptors expressed in macrophages controlling the inflammatory response. Recently, we reported visfatin as a PPAR{gamma} target gene in human macrophages. In this study, we examined whether LXR regulates macrophage visfatin expression. Synthetic LXR ligands decreased visfatin gene expression in a LXR-dependent manner in human and murine macrophages. The decrease of visfatin mRNA was paralleled by a decrease of protein secretion. Consequently, a modest and transient decrease of NAD{sup +} concentration was observed. Interestingly, LXR activation decreased the PPAR{gamma}-induced visfatin gene and protein secretion in human macrophages. Our results identify visfatin as a gene oppositely regulated by the LXR and PPAR{gamma} pathways in human macrophages.

  13. IscR regulates RNase LS activity by repressing rnlA transcription.

    Science.gov (United States)

    Otsuka, Yuichi; Miki, Kumiko; Koga, Mitsunori; Katayama, Natsu; Morimoto, Wakako; Takahashi, Yasuhiro; Yonesaki, Tetsuro

    2010-07-01

    The Escherichia coli endoribonuclease LS was originally identified as a potential antagonist of bacteriophage T4. When the T4 dmd gene is defective, RNase LS cleaves T4 mRNAs and antagonizes T4 reproduction. This RNase also plays an important role in RNA metabolisms in E. coli. rnlA is an essential gene for RNase LS activity, but the transcriptional regulation of this gene remains to be elucidated. An Fe-S cluster protein, IscR, acts as a transcription factor and controls the expression of genes that are necessary for Fe-S cluster biogenesis. Here, we report that overexpression of IscR suppressed RNase LS activity, causing the loss of antagonist activity against phage T4. This suppressive effect did not require the ligation of Fe-S cluster into IscR. beta-Galactosidase reporter assays showed that transcription from an rnlA promoter increased in iscR-deleted cells compared to wild-type cells, and gel-mobility shift assays revealed specific binding of IscR to the rnlA promoter region. RT-PCR analysis demonstrated that endogenous rnlA mRNA was reduced by overexpression of IscR and increased by deletion of iscR. From these results, we conclude that IscR negatively regulates transcription of rnlA and represses RNase LS activity.

  14. Curcumin down-regulates AR gene expression and activation in prostate cancer cell lines.

    Science.gov (United States)

    Nakamura, Keiichiro; Yasunaga, Yutaka; Segawa, Takehiko; Ko, Daejin; Moul, Judd W; Srivastava, Shiv; Rhim, Johng S

    2002-10-01

    Curcumin, traditionally used as a seasoning spice in Indian cuisine, has been reported to decrease the proliferation potential of prostate cancer cells, by a mechanism that is not fully understood. In the current study, we have evaluated the effects of curcumin in cell growth, activation of signal transduction, and transforming activities of both androgen-dependent and independent cell lines. Prostate cancer cell lines, LNCaP and PC-3, were treated with curcumin and its effects were further analyzed on signal transduction and expression of androgen receptor (AR) and AR-related cofactors using transient transfection assay and Western blotting. Our results show that curcumin down-regulates transactivation and expression of AR, activator protein-1 (AP-1), nuclear factor-kappaB (NF-kappaB), and CREB (cAMP response element-binding protein)-binding protein (CBP). Curcumin also inhibited the transforming activities of both cell lines as evidenced by the reduced colony forming ability in soft agar. The results obtained here demonstrate that curcumin has a potential therapeutic effect on prostate cancer cells through down-regulation of AR and AR-related cofactors (AP-1, NF-kappaB and CBP). PMID:12239622

  15. Drosophila protein kinase N (Pkn) is a negative regulator of actin-myosin activity during oogenesis.

    Science.gov (United States)

    Ferreira, Tânia; Prudêncio, Pedro; Martinho, Rui Gonçalo

    2014-10-15

    Nurse cell dumping is an actin-myosin based process, where 15 nurse cells of a given egg chamber contract and transfer their cytoplasmic content through the ring canals into the growing oocyte. We isolated two mutant alleles of protein kinase N (pkn) and showed that Pkn negatively-regulates activation of the actin-myosin cytoskeleton during the onset of dumping. Using live-cell imaging analysis we observed that nurse cell dumping rates sharply increase during the onset of fast dumping. Such rate increase was severely impaired in pkn mutant nurse cells due to excessive nurse cell actin-myosin activity and/or loss of tissue integrity. Our work demonstrates that the transition between slow and fast dumping is a discrete event, with at least a five to six-fold dumping rate increase. We show that Pkn negatively regulates nurse cell actin-myosin activity. This is likely to be important for directional cytoplasmic flow. We propose Pkn provides a negative feedback loop to help avoid excessive contractility after local activation of Rho GTPase.

  16. Tissue-specific regulation of expression and activity of P-glycoprotein in adjuvant arthritis rats.

    Science.gov (United States)

    Achira, Meguru; Totsuka, Ryuichi; Fujimura, Hisako; Kume, Toshiyuki

    2002-07-01

    Cyclosporine A and steroids are effective against rheumatoid arthritis and also known as substrates of P-glycoprotein (P-gp). We investigated the effect of arthritis on the hepatic and intestinal P-gp activity in rats, and substantiated the expression level of the hepatic P-gp. Doxorubicin was used as a P-gp substrate. Cumulative biliary excretion and intestinal exsorption of doxorubicin following intravenous administration were compared between adjuvant arthritis (AA) and normal rats. Intestinal P-gp activity was also investigated by intestinal everted sac method, and hepatic P-gp was detected by FITC-labeled antibody and visualized using a confocal laser microscope system. Biliary clearance of doxorubicin in AA rats was significantly decreased from that in normal rats. The expression level of the hepatic P-gp in AA rats was very low compared to normal rats, indicating down-regulation. Intestinal exsorption clearance was not different between AA and normal rats. Permeability of doxorubicin across intestinal everted sac was comparable between AA and normal rats, corresponding to in vivo study. In AA rats, hepatic P-gp activity was decreased due to the reduction of expression level, but intestinal P-gp activity was not changed. Different regulation systems may be involved in liver and intestine. PMID:12113888

  17. Regulation of phase I and phase II steroid metabolism enzymes by PPARα activators

    International Nuclear Information System (INIS)

    Peroxisome proliferators (PP) are a large class of structurally diverse chemicals that mediate their effects in the liver mainly through the peroxisome proliferator-activated receptor α (PPARα). Exposure to some PP results in alterations of steroid levels that may be mechanistically linked to adverse effects in reproductive organs. We hypothesized that changes in steroid levels after PP exposure are due to alterations in the levels of P450 enzymes that hydroxylate testosterone and estrogen. In testosterone hydroxylase assays, exposure to the PP, WY-14,643 (WY), gemfibrozil or di-n-butyl phthalate (DBP) led to compound-specific increases in 6β and 16β-testosterone and androstenedione hydroxylase activities and decreases in 16α, 2α-hydroxylase activities by all three PP. The decreases in 16α and 2α-testosterone hydroxylase activity can be attributed to a 2α and 16α- testosterone hydroxylase, CYP2C11, which we previously showed was dramatically down-regulated in these same tissues (Corton et al., 1998; Mol. Pharmacol. 54, 463-473). To explain the increases in 6β- and 16β-testosterone hydroxylase activities, we examined the expression of P450 family members known to carry out these functions. Alterations in the 6β-testosterone hydroxylases CYP3A1, CYP3A2 and the 16β-testosterone hydroxylase, CYP2B1 were observed after exposure to some PP. The male-specific estrogen sulfotransferase was down-regulated in rat liver after exposure to all PP. The mouse 6β-testosterone hydroxylase, Cyp3a11 was down-regulated by WY in wild-type but not PPARα-null mice. In contrast, DEHP increased Cyp3a11 in both wild-type and PPARα-null mice. These studies demonstrate that PP alter the expression and activity of a number of enzymes which regulate levels of sex steroids. The changes in these enzymes may help explain why exposure to some PP leads to adverse effects in endocrine tissues that produce or are the targets of sex hormones

  18. MiR-16 regulates mouse peritoneal macrophage polarization and affects T-cell activation.

    Science.gov (United States)

    Jia, Xiaoqin; Li, Xiaomin; Shen, Yating; Miao, Junjun; Liu, Hao; Li, Guoli; Wang, Zhengbing

    2016-10-01

    MiR-16 is a tumour suppressor that is down-regulated in certain human cancers. However, little is known on its activity in other cell types. In this study, we examined the biological significance and underlying mechanisms of miR-16 on macrophage polarization and subsequent T-cell activation. Mouse peritoneal macrophages were isolated and induced to undergo either M1 polarization with 100 ng/ml of interferon-γ and 20 ng/ml of lipopolysaccharide, or M2 polarization with 20 ng/ml of interleukin (IL)-4. The identity of polarized macrophages was determined by profiling cell-surface markers by flow cytometry and cytokine production by ELISA. Macrophages were infected with lentivirus-expressing miR-16 to assess the effects of miR-16. Effects on macrophage-T cell interactions were analysed by co-culturing purified CD4(+) T cells with miR-16-expressing peritoneal macrophages, and measuring activation marker CD69 by flow cytometry and cytokine secretion by ELISA. Bioinformatics analysis was applied to search for potential miR-16 targets and understand its underlying mechanisms. MiR-16-induced M1 differentiation of mouse peritoneal macrophages from either the basal M0- or M2-polarized state is indicated by the significant up-regulation of M1 marker CD16/32, repression of M2 marker CD206 and Dectin-1, and increased secretion of M1 cytokine IL-12 and nitric oxide. Consistently, miR-16-expressing macrophages stimulate the activation of purified CD4(+) T cells. Mechanistically, miR-16 significantly down-regulates the expression of PD-L1, a critical immune suppressor that controls macrophage-T cell interaction and T-cell activation. MiR-16 plays an important role in shifting macrophage polarization from M2 to M1 status, and functionally activating CD4(+) T cells. This effect is potentially mediated through the down-regulation of immune suppressor PD-L1.

  19. Effect of daptomycin on local interleukin-6, matrix metalloproteinase-9, and metallopeptidase inhibitor 1 in patients with MRSA-infected diabetic foot.

    Science.gov (United States)

    Ambrosch, Andreas; Halevy, Daniel; Fwity, Boushra; Brin, Thomas; Lobmann, Ralf

    2014-03-01

    Infection is a major cause of the diabetic foot syndrome that is promoted by the increased burden of multiresistant germs like methicillin-resistant Staphylococcus aureus (MRSA). Maximizing positive outcome for serious MRSA infections requires an aggressive treatment approach and careful monitoring of the healing process. Therefore, we examined 8 patients with MRSA-infected diabetic foot syndrome of Wagner classification grade 2 or 3 (corresponding to the Texas classification stage 2 or 3) during antibiotic treatment with daptomycin. We documented the wound size and obtained samples of wound secretion for analyses of proinflammatory interleukin-6 (IL-6), protease (matrix metalloproteinase-9 [MMP-9]), and antiprotease (metallopeptidase inhibitor 1 [TIMP-1]) activity. During the course of anti-MRSA therapy, we observed a decrease in the concentration of local IL-6 within the first 3 days followed by a decrease of MMP-9 and an increase of TIMP-1. Finally, a reduction of wound size was documented. The present data show that efficient antimicrobial treatment with daptomycin has a number of beneficial effects on wound healing at the molecular level in MRSA-infected diabetic foot ulcers.

  20. Doxycycline blocks gastric ulcer by regulating matrix metalloproteinase-2 activity and oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Laishram Pradeepkumar Singh; Amartya Mishra; Debjit Saha; Snehasikta Swarnakar

    2011-01-01

    AIM: To examine the effect of doxycycline on the activity of matrix metalloproteinases (MMPs) and oxidative stress in gastric tissues of rats following gastric injury. METHODS: Gastric ulcers were generated in rats by administration of 70% ethanol, and activity of doxycycline was tested by administration 30 min prior to ethanol. Similarly, the effect of doxycycline was tested in an indomethacin-induced gastric ulcer model. The activities and expression of MMPs were examined by zymography and Western blot analysis. RESULTS: Gastric injury in rats as judged by elevated ulcer indices following exposure to ulcerogen, either indomethacin or ethanol, was reversed significantly by doxycycline. Indomethacin-induced ulcerated gastric tissues exhibited about 12-fold higher proMMP-9 activity and about 5-fold higher proMMP-3 activity as compared to control tissues. Similarly, ethanol induced about 22-fold and about 6-fold higher proMMP-9 and proMMP-3 activities, respectively, in rat gastric tissues. Both proMMP-9 and MMP-3 activities were markedly decreased by doxycycline in ulcerogen treated rat gastric tissues. In contrast, the reduced MMP-2 activity in ulcerated tissues was increased by doxycycline during ulcer prevention. On the other hand, doxycycline inhibited significantly proMMP-9, -2 and -3 activities in vitro . In addition, doxycycline reduced oxidative load in gastric tissues and scavenged H2O2 in vitro . Our results suggest a novel regulatory role of doxycycline on MMP-2 activity in addition to inhibitory action on MMP-9 and MMP-3 during prevention of gastric ulcers. CONCLUSION: This is the first demonstration of dual action of doxycycline, that is, regulation of MMP activity and reduction of oxidative stress in arresting gastric injury.

  1. Systematic Analysis of the Functions of Lysine Acetylation in the Regulation of Tat Activity.

    Directory of Open Access Journals (Sweden)

    Minghao He

    Full Text Available The Tat protein of HIV-1 has several well-known properties, such as nucleocytoplasmic trafficking, transactivation of transcription, interaction with tubulin, regulation of mitotic progression, and induction of apoptosis. Previous studies have identified a couple of lysine residues in Tat that are essential for its functions. In order to analyze the functions of all the lysine residues in Tat, we mutated them individually to alanine, glutamine, and arginine. Through systematic analysis of the lysine mutants, we discovered several previously unidentified characteristics of Tat. We found that lysine acetylation could modulate the subcellular localization of Tat, in addition to the regulation of its transactivation activity. Our data also revealed that lysine mutations had distinct effects on microtubule assembly and Tat binding to bromodomain proteins. By correlation analysis, we further found that the effects of Tat on apoptosis and mitotic progression were not entirely attributed to its effect on microtubule assembly. Our findings suggest that Tat may regulate diverse cellular activities through binding to different proteins and that the acetylation of distinct lysine residues in Tat may modulate its interaction with various partners.

  2. Mfge8 regulates enterocyte lipid storage by promoting enterocyte triglyceride hydrolase activity

    Science.gov (United States)

    Khalifeh-Soltani, Amin; Gupta, Deepti; Ha, Arnold; Iqbal, Jahangir; Hussain, Mahmood; Podolsky, Michael J.

    2016-01-01

    The small intestine has an underappreciated role as a lipid storage organ. Under conditions of high dietary fat intake, enterocytes can minimize the extent of postprandial lipemia by storing newly absorbed dietary fat in cytoplasmic lipid droplets. Lipid droplets can be subsequently mobilized for the production of chylomicrons. The mechanisms that regulate this process are poorly understood. We report here that the milk protein Mfge8 regulates hydrolysis of cytoplasmic lipid droplets in enterocytes after interacting with the αvβ3 and αvβ5 integrins. Mice deficient in Mfge8 or the αvβ3 and αvβ5 integrins accumulate excess cytoplasmic lipid droplets after a fat challenge. Mechanistically, interruption of the Mfge8-integrin axis leads to impaired enterocyte intracellular triglyceride hydrolase activity in vitro and in vivo. Furthermore, Mfge8 increases triglyceride hydrolase activity through a PI3 kinase/mTORC2–dependent signaling pathway. These data identify a key role for Mfge8 and the αvβ3 and αvβ5 integrins in regulating enterocyte lipid processing.

  3. Temporal self-regulation Theory: A neurobiologically informed model for physical activity behavior

    Directory of Open Access Journals (Sweden)

    Peter eHall

    2015-03-01

    Full Text Available Dominant explanatory models for physical activity behavior are limited by the exclusion of several important components, including temporal dynamics, ecological forces, and neurobiological factors. The latter may be a critical omission, given the relevance of several aspects of cognitive function for the self-regulatory processes that are likely required for consistent implementation of physical activity behavior in everyday life. This narrative mini-review introduces temporal self-regulation theory (TST; Hall & Fong, 2007; 2013, as a new explanatory model for physical activity behavior. Important features of the model include consideration of the default status of the physical activity behavior, as well as the disproportionate influence of temporally proximal behavioral contingencies. Most importantly, the TST model proposes positive feedback loops linking executive function and the performance of physical activity behavior. Specifically, those with relatively stronger executive control (and optimized brain structures supporting it, such as the dorsolateral prefrontal cortex are able to implement physical activity with more consistency than others, which in turn serves to strengthen the executive control network itself. The TST model has the potential to explain everyday variants of incidental physical activity, sport-related excellence via capacity for deliberate practise, and variability in the propensity to schedule and implement exercise routines.

  4. A systems approach to hemostasis: 3. Thrombus consolidation regulates intrathrombus solute transport and local thrombin activity.

    Science.gov (United States)

    Stalker, Timothy J; Welsh, John D; Tomaiuolo, Maurizio; Wu, Jie; Colace, Thomas V; Diamond, Scott L; Brass, Lawrence F

    2014-09-11

    Hemostatic thrombi formed after a penetrating injury have a distinctive structure in which a core of highly activated, closely packed platelets is covered by a shell of less-activated, loosely packed platelets. We have shown that differences in intrathrombus molecular transport emerge in parallel with regional differences in platelet packing density and predicted that these differences affect thrombus growth and stability. Here we test that prediction in a mouse vascular injury model. The studies use a novel method for measuring thrombus contraction in vivo and a previously characterized mouse line with a defect in integrin αIIbβ3 outside-in signaling that affects clot retraction ex vivo. The results show that the mutant mice have a defect in thrombus consolidation following vascular injury, resulting in an increase in intrathrombus transport rates and, as predicted by computational modeling, a decrease in thrombin activity and platelet activation in the thrombus core. Collectively, these data (1) demonstrate that in addition to the activation state of individual platelets, the physical properties of the accumulated mass of adherent platelets is critical in determining intrathrombus agonist distribution and platelet activation and (2) define a novel role for integrin signaling in the regulation of intrathrombus transport rates and localization of thrombin activity. PMID:24951426

  5. Active dendrites regulate the impact of gliotransmission on rat hippocampal pyramidal neurons.

    Science.gov (United States)

    Ashhad, Sufyan; Narayanan, Rishikesh

    2016-06-01

    An important consequence of gliotransmission, a signaling mechanism that involves glial release of active transmitter molecules, is its manifestation as N-methyl-d-aspartate receptor (NMDAR)-dependent slow inward currents in neurons. However, the intraneuronal spatial dynamics of these events or the role of active dendrites in regulating their amplitude and spatial spread have remained unexplored. Here, we used somatic and/or dendritic recordings from rat hippocampal pyramidal neurons and demonstrate that a majority of NMDAR-dependent spontaneous slow excitatory potentials (SEP) originate at dendritic locations and are significantly attenuated through their propagation across the neuronal arbor. We substantiated the astrocytic origin of SEPs through paired neuron-astrocyte recordings, where we found that specific infusion of inositol trisphosphate (InsP3) into either distal or proximal astrocytes enhanced the amplitude and frequency of neuronal SEPs. Importantly, SEPs recorded after InsP3 infusion into distal astrocytes exhibited significantly slower kinetics compared with those recorded after proximal infusion. Furthermore, using neuron-specific infusion of pharmacological agents and morphologically realistic conductance-based computational models, we demonstrate that dendritically expressed hyperpolarization-activated cyclic-nucleotide-gated (HCN) and transient potassium channels play critical roles in regulating the strength, kinetics, and compartmentalization of neuronal SEPs. Finally, through the application of subtype-specific receptor blockers during paired neuron-astrocyte recordings, we provide evidence that GluN2B- and GluN2D-containing NMDARs predominantly mediate perisomatic and dendritic SEPs, respectively. Our results unveil an important role for active dendrites in regulating the impact of gliotransmission on neurons and suggest astrocytes as a source of dendritic plateau potentials that have been implicated in localized plasticity and place cell

  6. DMPD: Regulation of arachidonic acid release and cytosolic phospholipase A2activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 10080535 Regulation of arachidonic acid release and cytosolic phospholipase A2activ...on of arachidonic acid release and cytosolic phospholipase A2activation. PubmedID 10080535 Title Regulation of arachidonic acid relea...ation. Gijon MA, Leslie CC. J Leukoc Biol. 1999 Mar;65(3):330-6. (.png) (.svg) (.html) (.csml) Show Regulati...se and cytosolic phospholipase A2activation. Authors Gij

  7. Classroom Activities to Engage Students and Promote Critical Thinking about Genetic Regulation of Bacterial Quorum Sensing

    Directory of Open Access Journals (Sweden)

    Kimberly Aebli

    2016-05-01

    Full Text Available We developed an interactive activity to mimic bacterial quorum sensing, and a classroom worksheet to promote critical thinking about genetic regulation of the lux operon. The interactive quorum sensing activity engages students and provides a direct visualization of how population density functions to influence light production in bacteria. The worksheet activity consists of practice problems that require students to apply basic knowledge of the lux operon in order to make predictions about genetic complementation experiments, and students must evaluate how genetic mutations in the lux operon affect gene expression and overall phenotype. The worksheet promotes critical thinking and problem solving skills, and emphasizes the roles of diffusible signaling molecules, regulatory proteins, and structural proteins in quorum sensing.

  8. Regulation of myelin genes implicated in psychiatric disorders by functional activity in axons

    Directory of Open Access Journals (Sweden)

    Philip R Lee

    2009-06-01

    Full Text Available Myelination is a highly dynamic process that continues well into adulthood in humans. Several recent gene expression studies have found abnormal expression of genes involved in myelination in the prefrontal cortex of brains from patients with schizophrenia and other psychiatric illnesses. Defects in myelination could contribute to the pathophysiology of psychiatric illness by impairing information processing as a consequence of altered impulse conduction velocity and synchrony between cortical regions carrying out higher level cognitive functions. Myelination can be altered by impulse activity in axons and by environmental experience. Psychiatric illness is treated by psychotherapy, behavioral modification, and drugs affecting neurotransmission, raising the possibility that myelinating glia may not only contribute to such disorders, but that activity-dependent effects on myelinating glia could provide one of the cellular mechanisms contributing to the therapeutic effects of these treatments. This review examines evidence showing that genes and gene networks important for myelination can be regulated by functional activity in axons.

  9. S-nitrosylation regulates mitochondrial quality control via activation of parkin

    Science.gov (United States)

    Ozawa, Kentaro; Komatsubara, Akira T.; Nishimura, Yuhei; Sawada, Tomoyo; Kawafune, Hiroto; Tsumoto, Hiroki; Tsuji, Yuichi; Zhao, Jing; Kyotani, Yoji; Tanaka, Toshio; Takahashi, Ryosuke; Yoshizumi, Masanori

    2013-01-01

    Parkin, a ubiquitin E3 ligase of the ring between ring fingers family, has been implicated in mitochondrial quality control. A series of recent reports have suggested that the recruitment of parkin is regulated by phosphorylation. However, the molecular mechanism that activates parkin to induce mitochondrial degradation is not well understood. Here, and in contrast to previous reports that S-nitrosylation of parkin is exclusively inhibitory, we identify a previously unrecognized site of S-nitrosylation in parkin (Cys323) that induces mitochondrial degradation. We demonstrate that endogenous S-nitrosylation of parkin is in fact responsible for activation of its E3 ligase activity to induce aggregation and degradation. We further demonstrate that mitochondrial uncoupling agents result in denitrosylation of parkin, and that prevention of denitrosylation restores mitochondrial degradation. Our data indicates that NO both positive effects on mitochondrial quality control, and suggest that targeted S-nitrosylation could provide a novel therapeutic strategy against Parkinson's disease. PMID:23857542

  10. Regulation of protein synthesis and autophagy in activated dendritic cells: implications for antigen processing and presentation.

    Science.gov (United States)

    Argüello, Rafael J; Reverendo, Marisa; Gatti, Evelina; Pierre, Philippe

    2016-07-01

    Antigenic peptides presented in the context of major histocompatibility complex (MHC) molecules originate from the degradation of both self and non-self proteins. T cells can therefore recognize at the surface of surveyed cells, the self-peptidome produced by the cell itself (mostly inducing tolerance) or immunogenic peptides derived from exogenous origins. The initiation of adaptive immune responses by dendritic cells (DCs), through the antigenic priming of naïve T cells, is associated to microbial pattern recognition receptors engagement. Activation of DCs by microbial product or inflammatory cytokines initiates multiple processes that maximize DC capacity to present exogenous antigens and stimulate T cells by affecting major metabolic and membrane traffic pathways. These include the modulation of protein synthesis, the regulation of MHC and co-stimulatory molecules transport, as well as the regulation of autophagy, that, all together promote exogenous antigen presentation while limiting the display of self-antigens by MHC molecules.

  11. Regulation of programmed cell death by plasminogen activator inhibitor type 1 (PAI-1)

    DEFF Research Database (Denmark)

    Lademann, Ulrik Axel; Rømer, Maria Unni Koefoed

    2008-01-01

    PA) observed in tumours; however, several lines of evidence suggest that PAI-1 may contribute directly to the pathology of the disease. PAI-1 has been reported to have an effect on most of the basic cellular processes including cell adhesion, cell migration, cell invasion, and cell proliferation and increasing...... numbers of reports suggest that PAI-1 also can regulate programmed cell death (PCD) in cancer cells and normal cells. A number of reports suggest that PAI-1 can inhibit PCD through its pro-adhesive/anti-proteolytic property whereas other reports suggest that PAI-1 induces PCD through its anti......-adhesive property.Furthermore,it has been suggested that PAI-1 can either induce or inhibit PCD though activation of cell signalling pathways.This review will focus on the regulation of programmed cell death by PAI-1 in both normal cells and cancer cells....

  12. Diacylglycerol Kinases: Regulated Controllers of T Cell Activation, Function, and Development

    Directory of Open Access Journals (Sweden)

    Gary A. Koretzky

    2013-03-01

    Full Text Available Diacylglycerol kinases (DGKs are a diverse family of enzymes that catalyze the conversion of diacylglycerol (DAG, a crucial second messenger of receptor-mediated signaling, to phosphatidic acid (PA. Both DAG and PA are bioactive molecules that regulate a wide set of intracellular signaling proteins involved in innate and adaptive immunity. Clear evidence points to a critical role for DGKs in modulating T cell activation, function, and development. More recently, studies have elucidated factors that control DGK function, suggesting an added complexity to how DGKs act during signaling. This review summarizes the available knowledge of the function and regulation of DGK isoforms in signal transduction with a particular focus on T lymphocytes.

  13. The Influence of Competitiveness and Regulations on Entrepreneurial Activity in Emerging and Advanced Economies

    Directory of Open Access Journals (Sweden)

    Mário Raposo

    2014-10-01

    Full Text Available This paper aims to investigate the link between business regulations, pillars of competitiveness, and new firms at country level using a structural equation model. The research developed to support this paper is based on the idea that entrepreneurship, measured as the process of new firm formation, is a vital link to the economic growth of countries. The data used belongs to a sample of 41 countries with emerging and advanced economies that appear simultaneously in three databases: The Global Entrepreneurship Monitor (GEM, the Global Competitiveness Report (GCR, and the Doing Business Report (DBR. At country level, the process is hindered by the competitiveness conditions of the country’s phase of economic development, and by the regulation and institutional arrangements that shape economic activity.

  14. Transcriptional regulation by Poly(ADP-ribose polymerase-1 during T cell activation

    Directory of Open Access Journals (Sweden)

    Parrilla Pascual

    2008-04-01

    Full Text Available Abstract Background Accumulating evidence suggests an important role for the enzyme poly(ADP-ribose polymerase-1 (PARP-1 as an integral part of the gene expression regulatory machinery during development and in response to specific cellular signals. PARP-1 might modulate gene expression through its catalytic activity leading to poly(ADP-ribosylation of nuclear proteins or by its physical association with relevant proteins. Recently, we have shown that PARP-1 is activated during T cell activation. However, the proposed role of PARP-1 in reprogramming T cell gene expression upon activation remains largely unexplored. Results In the present study we use oligonucleotide microarray analysis to gain more insight into the role played by PARP-1 during the gene expression reprogramming that takes place in T cells upon activation with anti-CD3 stimulation alone, or in combination with anti-CD28 co-stimulation. We have identified several groups of genes with expression modulated by PARP-1. The expression of 129 early-response genes to anti-CD3 seems to be regulated by PARP-1 either in a positive (45 genes or in a negative manner (84 genes. Likewise, in the presence of co-stimulation (anti-CD3 + anti-CD28 stimulation, the expression of 203 genes is also regulated by PARP-1 either up (173 genes or down (30 genes. Interestingly, PARP-1 deficiency significantly alters expression of genes associated with the immune response such as chemokines and genes involved in the Th1/Th2 balance. Conclusion This study provides new insights into changes in gene expression mediated by PARP-1 upon T cell activation. Pathway analysis of PARP-1 as a nuclear signalling molecule in T cells would be of relevance for the future development of new therapeutic approaches targeting PARP-1 in the acquired immune response.

  15. Angiotensin II Stimulation of DPP4 Activity Regulates Megalin in the Proximal Tubules.

    Science.gov (United States)

    Aroor, Annayya; Zuberek, Marcin; Duta, Cornel; Meuth, Alex; Sowers, James R; Whaley-Connell, Adam; Nistala, Ravi

    2016-01-01

    Proteinuria is a marker of incipient kidney injury in many disorders, including obesity. Previously, we demonstrated that megalin, a receptor endocytotic protein in the proximal tubule, is downregulated in obese mice, which was prevented by inhibition of dipeptidyl protease 4 (DPP4). Obesity is thought to be associated with upregulation of intra-renal angiotensin II (Ang II) signaling via the Ang II Type 1 receptor (AT₁R) and Ang II suppresses megalin expression in proximal tubule cells in vitro. Therefore, we tested the hypothesis that Ang II will suppress megalin protein via activation of DPP4. We used Ang II (200 ng/kg/min) infusion in mice and Ang II (10(-8) M) treatment of T35OK-AT₁R proximal tubule cells to test our hypothesis. Ang II-infused mouse kidneys displayed increases in DPP4 activity and decreases in megalin. In proximal tubule cells, Ang II stimulated DPP4 activity concurrent with suppression of megalin. MK0626, a DPP4 inhibitor, partially restored megalin expression similar to U0126, a mitogen activated protein kinase (MAPK)/extracellular regulated kinase (ERK) kinase kinase (MEK) 1/2 inhibitor and AG1478, an epidermal growth factor receptor (EGFR) inhibitor. Similarly, Ang II-induced ERK phosphorylation was suppressed with MK0626 and Ang II-induced DPP4 activity was suppressed by U0126. Therefore, our study reveals a cross talk between AT₁R signaling and DPP4 activation in the regulation of megalin and underscores the significance of targeting DPP4 in the prevention of obesity related kidney injury progression. PMID:27213360

  16. Angiotensin II Stimulation of DPP4 Activity Regulates Megalin in the Proximal Tubules

    Directory of Open Access Journals (Sweden)

    Annayya Aroor

    2016-05-01

    Full Text Available Proteinuria is a marker of incipient kidney injury in many disorders, including obesity. Previously, we demonstrated that megalin, a receptor endocytotic protein in the proximal tubule, is downregulated in obese mice, which was prevented by inhibition of dipeptidyl protease 4 (DPP4. Obesity is thought to be associated with upregulation of intra-renal angiotensin II (Ang II signaling via the Ang II Type 1 receptor (AT1R and Ang II suppresses megalin expression in proximal tubule cells in vitro. Therefore, we tested the hypothesis that Ang II will suppress megalin protein via activation of DPP4. We used Ang II (200 ng/kg/min infusion in mice and Ang II (10−8 M treatment of T35OK-AT1R proximal tubule cells to test our hypothesis. Ang II-infused mouse kidneys displayed increases in DPP4 activity and decreases in megalin. In proximal tubule cells, Ang II stimulated DPP4 activity concurrent with suppression of megalin. MK0626, a DPP4 inhibitor, partially restored megalin expression similar to U0126, a mitogen activated protein kinase (MAPK/extracellular regulated kinase (ERK kinase kinase (MEK 1/2 inhibitor and AG1478, an epidermal growth factor receptor (EGFR inhibitor. Similarly, Ang II-induced ERK phosphorylation was suppressed with MK0626 and Ang II-induced DPP4 activity was suppressed by U0126. Therefore, our study reveals a cross talk between AT1R signaling and DPP4 activation in the regulation of megalin and underscores the significance of targeting DPP4 in the prevention of obesity related kidney injury progression.

  17. Antithrombin up-regulates AMP-activated protein kinase signalling during myocardial ischaemia/reperfusion injury.

    Science.gov (United States)

    Ma, Yina; Wang, Jinli; Gao, Junjie; Yang, Hui; Wang, Yanqing; Manithody, Chandrashekhara; Li, Ji; Rezaie, Alireza R

    2015-02-01

    Antithrombin (AT) is a protein of the serpin superfamily involved in regulation of the proteolytic activity of the serine proteases of the coagulation system. AT is known to exhibit anti-inflammatory and cardioprotective properties when it binds to heparan sulfate proteoglycans (HSPGs) on vascular cells. AMP-activated protein kinase (AMPK) plays an important cardioprotective role during myocardial ischaemia and reperfusion (I/R). To determine whether the cardioprotective signaling function of AT is mediated through the AMPK pathway, we evaluated the cardioprotective activities of wild-type AT and its two derivatives, one having high affinity and the other no affinity for heparin, in an acute I/R injury model in C57BL/6J mice in which the left anterior descending coronary artery was occluded. The serpin derivatives were given 5 minutes before reperfusion. The results showed that AT-WT can activate AMPK in both in vivo and ex vivo conditions. Blocking AMPK activity abolished the cardioprotective function of AT against I/R injury. The AT derivative having high affinity for heparin was more effective in activating AMPK and in limiting infraction, but the derivative lacking affinity for heparin was inactive in eliciting AMPK-dependent cardioprotective activity. Activation of AMPK by AT inhibited the inflammatory c-Jun N-terminal protein kinase (JNK) pathway during I/R. Further studies revealed that the AMPK activity induced by AT also modulates cardiac substrate metabolism by increasing glucose oxidation but inhibiting fatty acid oxidation during I/R. These results suggest that AT binds to HSPGs on heart tissues to invoke a cardioprotective function by triggering cardiac AMPK activation, thereby attenuating JNK inflammatory signalling pathways and modulating substrate metabolism during I/R. PMID:25230600

  18. Heat shock protein 70 regulates platelet integrin activation, granule secretion and aggregation.

    Science.gov (United States)

    Rigg, Rachel A; Healy, Laura D; Nowak, Marie S; Mallet, Jérémy; Thierheimer, Marisa L D; Pang, Jiaqing; McCarty, Owen J T; Aslan, Joseph E

    2016-04-01

    Molecular chaperones that support protein quality control, including heat shock protein 70 (Hsp70), participate in diverse aspects of cellular and physiological function. Recent studies have reported roles for specific chaperone activities in blood platelets in maintaining hemostasis; however, the functions of Hsp70 in platelet physiology remain uninvestigated. Here we characterize roles for Hsp70 activity in platelet activation and function. In vitro biochemical, microscopy, flow cytometry, and aggregometry assays of platelet function, as well as ex vivo analyses of platelet aggregate formation in whole blood under shear, were carried out under Hsp70-inhibited conditions. Inhibition of platelet Hsp70 blocked platelet aggregation and granule secretion in response to collagen-related peptide (CRP), which engages the immunoreceptor tyrosine-based activation motif-bearing collagen receptor glycoprotein VI (GPVI)-Fc receptor-γ chain complex. Hsp70 inhibition also reduced platelet integrin-αIIbβ3 activation downstream of GPVI, as Hsp70-inhibited platelets showed reduced PAC-1 and fibrinogen binding. Ex vivo, pharmacological inhibition of Hsp70 in human whole blood prevented the formation of platelet aggregates on collagen under shear. Biochemical studies supported a role for Hsp70 in maintaining the assembly of the linker for activation of T cells signalosome, which couples GPVI-initiated signaling to integrin activation, secretion, and platelet function. Together, our results suggest that Hsp70 regulates platelet activation and function by supporting linker for activation of T cells-associated signaling events downstream of platelet GPVI engagement, suggesting a role for Hsp70 in the intracellular organization of signaling systems that mediate platelet secretion, "inside-out" activation of platelet integrin-αIIbβ3, platelet-platelet aggregation, and, ultimately, hemostatic plug and thrombus formation.

  19. Aerobic glycolysis during brain activation: adrenergic regulation and influence of norepinephrine on astrocytic metabolism.

    Science.gov (United States)

    Dienel, Gerald A; Cruz, Nancy F

    2016-07-01

    Aerobic glycolysis occurs during brain activation and is characterized by preferential up-regulation of glucose utilization compared with oxygen consumption even though oxygen level and delivery are adequate. Aerobic glycolysis is a widespread phenomenon that underlies energetics of diverse brain activities, such as alerting, sensory processing, cognition, memory, and pathophysiological conditions, but specific cellular functions fulfilled by aerobic glycolysis are poorly understood. Evaluation of evidence derived from different disciplines reveals that aerobic glycolysis is a complex, regulated phenomenon that is prevented by propranolol, a non-specific β-adrenoceptor antagonist. The metabolic pathways that contribute to excess utilization of glucose compared with oxygen include glycolysis, the pentose phosphate shunt pathway, the malate-aspartate shuttle, and astrocytic glycogen turnover. Increased lactate production by unidentified cells, and lactate dispersal from activated cells and lactate release from the brain, both facilitated by astrocytes, are major factors underlying aerobic glycolysis in subjects with low blood lactate levels. Astrocyte-neuron lactate shuttling with local oxidation is minor. Blockade of aerobic glycolysis by propranolol implicates adrenergic regulatory processes including adrenal release of epinephrine, signaling to brain via the vagus nerve, and increased norepinephrine release from the locus coeruleus. Norepinephrine has a powerful influence on astrocytic metabolism and glycogen turnover that can stimulate carbohydrate utilization more than oxygen consumption, whereas β-receptor blockade 're-balances' the stoichiometry of oxygen-glucose or -carbohydrate metabolism by suppressing glucose and glycogen utilization more than oxygen consumption. This conceptual framework may be helpful for design of future studies to elucidate functional roles of preferential non-oxidative glucose utilization and glycogen turnover during brain

  20. Carbonic anhydrase III regulates peroxisome proliferator-activated receptor-{gamma}2

    Energy Technology Data Exchange (ETDEWEB)

    Mitterberger, Maria C. [Cell Metabolism and Differentiation Research Group, Institute for Biomedical Aging Research of the Austrian Academy of Sciences, 6020 Innsbruck (Austria); Kim, Geumsoo [Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8012 (United States); Rostek, Ursula [Cell Metabolism and Differentiation Research Group, Institute for Biomedical Aging Research of the Austrian Academy of Sciences, 6020 Innsbruck (Austria); Levine, Rodney L. [Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8012 (United States); Zwerschke, Werner, E-mail: werner.zwerschke@oeaw.ac.at [Cell Metabolism and Differentiation Research Group, Institute for Biomedical Aging Research of the Austrian Academy of Sciences, 6020 Innsbruck (Austria)

    2012-05-01

    Carbonic anhydrase III (CAIII) is an isoenzyme of the CA family. Because of its low specific anhydrase activity, physiological functions in addition to hydrating CO{sub 2} have been proposed. CAIII expression is highly induced in adipogenesis and CAIII is the most abundant protein in adipose tissues. The function of CAIII in both preadipocytes and adipocytes is however unknown. In the present study we demonstrate that adipogenesis is greatly increased in mouse embryonic fibroblasts (MEFs) from CAIII knockout (KO) mice, as demonstrated by a greater than 10-fold increase in the induction of fatty acid-binding protein-4 (FABP4) and increased triglyceride formation in CAIII{sup -/-} MEFs compared with CAIII{sup +/+} cells. To address the underlying mechanism, we investigated the expression of the two adipogenic key regulators, peroxisome proliferator-activated receptor-{gamma}2 (PPAR{gamma}2) and CCAAT/enhancer binding protein-{alpha}. We found a considerable (approximately 1000-fold) increase in the PPAR{gamma}2 expression in the CAIII{sup -/-} MEFs. Furthermore, RNAi-mediated knockdown of endogenous CAIII in NIH 3T3-L1 preadipocytes resulted in a significant increase in the induction of PPAR{gamma}2 and FABP4. When both CAIII and PPAR{gamma}2 were knocked down, FABP4 was not induced. We conclude that down-regulation of CAIII in preadipocytes enhances adipogenesis and that CAIII is a regulator of adipogenic differentiation which acts at the level of PPAR{gamma}2 gene expression. -- Highlights: Black-Right-Pointing-Pointer We discover a novel function of Carbonic anhydrase III (CAIII). Black-Right-Pointing-Pointer We show that CAIII is a regulator of adipogenesis. Black-Right-Pointing-Pointer We demonstrate that CAIII acts at the level of PPAR{gamma}2 gene expression. Black-Right-Pointing-Pointer Our data contribute to a better understanding of the role of CAIII in fat tissue.

  1. Leptin differentially regulate STAT3 activation in ob/ob mouse adipose mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Zhou Zhou

    2012-12-01

    Full Text Available Abstract Background Leptin-deficient ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute toward increased adipocyte cell numbers, obesity, and inflamm ation. Currently, information is lacking regarding regulation of adipose stem cell numbers as well as leptin-induced inflammation and its signaling pathway in ob/ob mice. Methods Using leptin deficient ob/ob mice, we investigated whether leptin injection into ob/ob mice increases adipose stem cell numbers and adipose tissue inflammatory marker MCP-1 mRNA and secretion levels. We also determined leptin mediated signaling pathways in the adipose stem cells. Results We report here that adipose stem cell number is significantly increased following leptin injection in ob/ob mice and with treatment of isolated stem cells with leptin in vitro. Leptin also up-regulated MCP-1 secretion in a dose- and time-dependent manner. We further showed that increased MCP-1 mRNA levels were due to increased phosphorylation of Signal Transducer and Activator of Transcription 3 (STAT3 Ser727 but not STAT3 Tyr705 phosphorylation, suggesting differential regulation of MCP-1 gene expression under basal and leptin-stimulated conditions in adipose stem cells. Conclusions Taken together, these studies demonstrate that leptin increases adipose stem cell number and differentially activates STAT3 protein resulting in up-regulation of MCP-1 gene expression. Further studies of mechanisms mediating adipose stem cell hyperplasia and leptin signaling in obesity are warranted and may help identify novel anti-obesity target strategies.

  2. COUP-TFII mediates progesterone regulation of uterine implantation by controlling ER activity.

    Directory of Open Access Journals (Sweden)

    Isao Kurihara

    2007-06-01

    Full Text Available Progesterone and estrogen are critical regulators of uterine receptivity. To facilitate uterine remodeling for embryo attachment, estrogen activity in the uterine epithelia is attenuated by progesterone; however, the molecular mechanism by which this occurs is poorly defined. COUP-TFII (chicken ovalbumin upstream promoter transcription factor II; also known as NR2F2, a member of the nuclear receptor superfamily, is highly expressed in the uterine stroma and its expression is regulated by the progesterone-Indian hedgehog-Patched signaling axis that emanates from the epithelium. To further assess COUP-TFII uterine function, a conditional COUP-TFII knockout mouse was generated. This mutant mouse is infertile due to implantation failure, in which both embryo attachment and uterine decidualization are impaired. Using this animal model, we have identified a novel genetic pathway in which BMP2 lies downstream of COUP-TFII. Epithelial progesterone-induced Indian hedgehog regulates stromal COUP-TFII, which in turn controls BMP2 to allow decidualization to manifest in vivo. Interestingly, enhanced epithelial estrogen activity, which impedes maturation of the receptive uterus, was clearly observed in the absence of stromal-derived COUP-TFII. This finding is consistent with the notion that progesterone exerts its control of implantation through uterine epithelial-stromal cross-talk and reveals that stromal-derived COUP-TFII is an essential mediator of this complex cross-communication pathway. This finding also provides a new signaling paradigm for steroid hormone regulation in female reproductive biology, with attendant implications for furthering our understanding of the molecular mechanisms that underlie dysregulation of hormonal signaling in such human reproductive disorders as endometriosis and endometrial cancer.

  3. Antitumor and immune regulation activities of the extracts of some Chinese marine invertebrates

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lixin; FAN Xiao; HAN Lijun

    2005-01-01

    Extracts of 21 marine invertebrates belonging to Coelenterata, Mollusca, Annelida, Bryozoa,Echiura, Arthropoda, Echinodermata and Urochordata were screened for the studies on their antitumor and immune regulation activities. Antitumor activity was determined by MTT method and immune regulation activity was studied using T- and B-lymphocytes in mice spleen in vitro. It was found that the n-butanol part of Asterina pectinifera, the acetic ether part of Tubuaria marina, 95% ethanol extract of Acanthochiton rubrolineatus have a high inhibition rate of 96.7%, 63.9% and 50.5% respectively on tumor cell line HL-60 at the concentration of 0.063 mg/ml. The inhibition rate of the acetic ether part of Tubuaria marina on the tumor cell line A-549 is 65.4 % at concentration of 0.063 mg/mL. The 95% ethanol extract of Meretrix meretrix has so outstanding promoting effect on T-lymphocyfes that their multiplication increases 25% when the sample concentration is only 1 μg/ml. On B-lymphocytes, the 95% extract of Rapana venosa, at concentration of 100μg/ml, has a promotion percentage of 60%. On the other hand, under the condition of no cytotoxic effect, the 95% ethanol extracts of Acanthochiton rubrolineatus and Cellana toreum can reach 92% inhibition rate on T lymphocyte at concentration of 100 μg/ml, while the inhibition rate on B lymphocyte of the 95% extract of Acanthochiton rubrolineatus reaches 92% at the same concentration.

  4. Energy Conservation Analysis and Control of Hybrid Active Semiactive Suspension with Three Regulating Damping Levels

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-01-01

    Full Text Available Active suspension has not been popularized for high energy consumption. To address this issue, this paper introduces the concept of a new kind of suspension. The linear motor is considered to be integrated into an adjustable shock absorber to form the hybrid active semiactive suspension (HASAS. To realize the superiority of HASAS, its energy consumption and regeneration mechanisms are revealed. And the system controller which is composed of linear quadratic regulator (LQR controller, mode decision and switch controller, and the sliding mode control based thrust controller is developed. LQR controller is designed to maintain the suspension control objectives, while mode decision and switch controller decides the optimal damping level to tune motor thrust. The thrust controller ensures motor thrust tracking. An adjustable shock absorber with three regulating levels to be used in HASAS is trial produced and tested to obtain its working characteristics. Finally, simulation analysis is made with the experimental three damping characteristics. The impacts of adjustable damping on the motor force and energy consumption are investigated. Simulation results demonstrate the advantages of HASAS in energy conservation with various suspension control objectives. Even self-powered active control and energy regenerated to the power source can be realized.

  5. Tetraspanin CD151 Is a Negative Regulator of FcεRI-Mediated Mast Cell Activation.

    Science.gov (United States)

    Abdala-Valencia, Hiam; Bryce, Paul J; Schleimer, Robert P; Wechsler, Joshua B; Loffredo, Lucas F; Cook-Mills, Joan M; Hsu, Chia-Lin; Berdnikovs, Sergejs

    2015-08-15

    Mast cells are critical in the pathogenesis of allergic disease due to the release of preformed and newly synthesized mediators, yet the mechanisms controlling mast cell activation are not well understood. Members of the tetraspanin family are recently emerging as modulators of FcεRI-mediated mast cell activation; however, mechanistic understanding of their function is currently lacking. The tetraspanin CD151 is a poorly understood member of this family and is specifically induced on mouse and human mast cells upon FcεRI aggregation but its functional effects are unknown. In this study, we show that CD151 deficiency significantly exacerbates the IgE-mediated late phase inflammation in a murine model of passive cutaneous anaphylaxis. Ex vivo, FcεRI stimulation of bone marrow-derived mast cells from CD151(-/-) mice resulted in significantly enhanced expression of proinflammatory cytokines IL-4, IL-13, and TNF-α compared with wild-type controls. However, FcεRI-induced mast cell degranulation was unaffected. At the molecular signaling level, CD151 selectively regulated IgE-induced activation of ERK1/2 and PI3K, associated with cytokine production, but had no effect on the phospholipase Cγ1 signaling, associated with degranulation. Collectively, our data indicate that CD151 exerts negative regulation over IgE-induced late phase responses and cytokine production in mast cells. PMID:26136426

  6. Regulation of Cop9 signalosome activity by the EF-hand Ca2+-binding protein tescalcin.

    Science.gov (United States)

    Levay, Konstantin; Slepak, Vladlen Z

    2014-06-01

    The Ca(2+)-binding protein tescalcin is known to be involved in hematopoietic cell differentiation; however, this mechanism is poorly understood. Here, we identify CSN4 (subunit 4 of the COP9 signalosome) as a novel binding partner of tescalcin. The COP9 signalosome (CSN) is a multiprotein complex that is essential for development in all eukaryotes. This interaction is selective, Ca(2+)-dependent and involves the PCI domain of CSN4 subunit. We then investigated tescalcin and CSN activity in human erythroleukemia HEL and promyelocytic leukemia K562 cells and find that phorbol 12-myristate 13-acetate (PMA)-induced differentiation, resulting in the upregulation of tescalcin, coincides with reduced deneddylation of cullin-1 (Cul1) and stabilization of p27(Kip1) - molecular events that are associated with CSN activity. The knockdown of tescalcin led to an increase in Cul1 deneddylation, expression of F-box protein Skp2 and the transcription factor c-Jun, whereas the levels of cell cycle regulators p27(Kip1) and p53 decreased. These effects are consistent with the hypothesis that tescalcin might play a role as a negative regulator of CSN activity towards Cul1 in the process of induced cell differentiation.

  7. Substrate Stiffness Regulates Proinflammatory Mediator Production through TLR4 Activity in Macrophages

    Science.gov (United States)

    Previtera, Michelle L.; Sengupta, Amitabha

    2015-01-01

    Clinical data show that disease adversely affects tissue elasticity or stiffness. While macrophage activity plays a critical role in driving disease pathology, there are limited data available on the effects of tissue stiffness on macrophage activity. In this study, the effects of substrate stiffness on inflammatory mediator production by macrophages were investigated. Bone marrow–derived macrophages were grown on polyacrylamide gels that mimicked the stiffness of a variety of soft biological tissues. Overall, macrophages grown on soft substrates produced less proinflammatory mediators than macrophages grown on stiff substrates when the endotoxin LPS was added to media. In addition, the pathways involved in stiffness–regulated proinflammation were investigated. The TLR4 signaling pathway was examined by evaluating TLR4, p–NF–κB p65, MyD88, and p–IκBα expression as well as p–NF–κB p65 translocation. Expression and translocation of the various signaling molecules were higher in macrophages grown on stiff substrates than on soft substrates. Furthermore, TLR4 knockout experiments showed that TLR4 activity enhanced proinflammation on stiff substrates. In conclusion, these results suggest that proinflammatory mediator production initiated by TLR4 is mechanically regulated in macrophages. PMID:26710072

  8. Locked and proteolysis-based transcription activator-like effector (TALE) regulation.

    Science.gov (United States)

    Lonzarić, Jan; Lebar, Tina; Majerle, Andreja; Manček-Keber, Mateja; Jerala, Roman

    2016-02-18

    Development of orthogonal, designable and adjustable transcriptional regulators is an important goal of synthetic biology. Their activity has been typically modulated through stimulus-induced oligomerization or interaction between the DNA-binding and activation/repression domain. We exploited a feature of the designable Transcription activator-like effector (TALE) DNA-binding domain that it winds around the DNA which allows to topologically prevent it from binding by intramolecular cyclization. This new approach was investigated through noncovalent ligand-induced cyclization or through a covalent split intein cyclization strategy, where the topological inhibition of DNA binding by cyclization and its restoration by a proteolytic release of the topologic constraint was expected. We show that locked TALEs indeed have diminished DNA binding and regain full transcriptional activity by stimulation with the rapamycin ligand or site-specific proteolysis of the peptide linker, with much higher level of activation than rapamycin-induced heterodimerization. Additionally, we demonstrated reversibility, activation of genomic targets and implemented logic gates based on combinations of protein cyclization, proteolytic cleavage and ligand-induced dimerization, where the strongest fold induction was achieved by the proteolytic cleavage of a repression domain from a linear TALE. PMID:26748097

  9. Locked and proteolysis-based transcription activator-like effector (TALE) regulation.

    Science.gov (United States)

    Lonzarić, Jan; Lebar, Tina; Majerle, Andreja; Manček-Keber, Mateja; Jerala, Roman

    2016-02-18

    Development of orthogonal, designable and adjustable transcriptional regulators is an important goal of synthetic biology. Their activity has been typically modulated through stimulus-induced oligomerization or interaction between the DNA-binding and activation/repression domain. We exploited a feature of the designable Transcription activator-like effector (TALE) DNA-binding domain that it winds around the DNA which allows to topologically prevent it from binding by intramolecular cyclization. This new approach was investigated through noncovalent ligand-induced cyclization or through a covalent split intein cyclization strategy, where the topological inhibition of DNA binding by cyclization and its restoration by a proteolytic release of the topologic constraint was expected. We show that locked TALEs indeed have diminished DNA binding and regain full transcriptional activity by stimulation with the rapamycin ligand or site-specific proteolysis of the peptide linker, with much higher level of activation than rapamycin-induced heterodimerization. Additionally, we demonstrated reversibility, activation of genomic targets and implemented logic gates based on combinations of protein cyclization, proteolytic cleavage and ligand-induced dimerization, where the strongest fold induction was achieved by the proteolytic cleavage of a repression domain from a linear TALE.

  10. Biologically active substances-enriched diet regulates gonadotrope cell activation pathway in liver of adult and old rats.

    Science.gov (United States)

    Oszkiel, Hanna; Wilczak, Jacek; Jank, Michał

    2014-09-01

    According to the Hippocrates' theorem "Let food be your medicine and medicine be your food", dietary interventions may induce changes in the metabolic and inflammatory state by modulating the expression of important genes involved in the chronic disorders. The aim of the present study was to evaluate the influence of long-term (14 months) use of biologically active substances-enriched diet (BASE-diet) on transcriptomic profile of rats' liver. The experiment was conducted on 36 Sprague-Dawley rats divided into two experimental groups (fed with control or BASE-diet, both n = 18). Control diet was a semi-synthetic diet formulated according to the nutritional requirements for laboratory animals. The BASE-diet was enriched with a mixture of polyphenolic compounds, β-carotene, probiotics, and n-3 and n-6 polyunsaturated fatty acids. In total, n = 3,017 differentially expressed (DE) genes were identified, including n = 218 DE genes between control and BASE groups after 3 months of feeding and n = 1,262 after 14 months. BASE-diet influenced the expression of genes involved particularly in the gonadotrope cell activation pathway and guanylate cyclase pathway, as well as in mast cell activation, gap junction regulation, melanogenesis and apoptosis. Especially genes involved in regulation of GnRH were strongly affected by BASE-diet. This effect was stronger with the age of animals and the length of diet use. It may suggest a link between the diet, reproductive system function and aging. PMID:25156242

  11. Correlation of matrix metalloproteinase-2, -9, tissue inhibitor-1 of matrix metalloproteinase and CD44 variant 6 in head and neck cancer metastasis

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This study aimed to explore the molecular mechanism in tumor invasion and metastasis. The expression of matrix metalloproteinase-2,-9 (MMP-2, MMP-9), tissue inhibitor-1 of matrix metalloproteinase (TIMP-1), cell adhesion molecule 44 variant 6 (CD44v6), HER2/neu and p53 was investigated in 154 patients with head and neck squamous cell carcinoma (SCC) by ABC and ImmunoMax immunohistochemical method. Their clinical relevance and correlation were analysed. The expression of MMP-2, MMP-9, TIMP-1, CD44v6, HER2/neu and p53 was found in cancer cells in 87.01%, 85.71%, 68.18%, 98.05%, 55.19% and 50.65% cases respectively. Linear regression and correlation analysis revealed that there was close positive relationship (P<0.05) between the expression of MMP-2 and MMP-9, TIMP-1 and CD44v6, HER2/neu and MMP-9, MMP-2 and p53. Up-regulation of MMP-2 was accompanied by advanced T stage(P<0.01). There was also a trend of MMP-2 expression being related with tumor metastasis. Increased expression of HER2/neu was found in patients with tumor recurrence(P<0.05). The expression of TIMP-1 was higher in laryngeal cancer than that in pharyngeal cancer, and higher in keratinizing and non-keratinizing SCC than that in basaloid SCC(P<0.05). These findings suggested that MMP-2 and MMP-9, HER2/neu and MMP-9, MMP-2 and p53 had a coordinate function in aggression of tumor; that MMP-2 had a more important function than MMP-9 in tumor invasion and metastasis; and that HER2/neu might serve as a biomarker for poor prognosis in HNSCC.

  12. Hydrogen peroxide down-regulates inositol 1,4,5-trisphosphate receptor content through proteasome activation.

    Science.gov (United States)

    Martín-Garrido, A; Boyano-Adánez, M C; Alique, M; Calleros, L; Serrano, I; Griera, M; Rodríguez-Puyol, D; Griendling, K K; Rodríguez-Puyol, M

    2009-11-15

    Hydrogen peroxide (H(2)O(2)) is implicated in the regulation of signaling pathways leading to changes in vascular smooth muscle function. Contractile effects produced by H(2)O(2) are due to the phosphorylation of myosin light chain kinase triggered by increases in intracellular calcium (Ca(2+)) from intracellular stores or influx of extracellular Ca(2+). One mechanism for mobilizing such stores involves the phosphoinositide pathway. Inositol 1,4,5-trisphosphate (IP(3)) mobilizes intracellular Ca(2+) by binding to a family of receptors (IP(3)Rs) on the endoplasmic-sarcoplasmic reticulum that act as ligand-gated Ca(2+) channels. IP(3)Rs can be rapidly ubiquitinated and degraded by the proteasome, causing a decrease in cellular IP(3)R content. In this study we show that IP(3)R(1) and IP(3)R(3) are down-regulated when vascular smooth muscle cells (VSMC) are stimulated by H(2)O(2), through an increase in proteasome activity. Moreover, we demonstrate that the decrease in IP(3)R by H(2)O(2) is accompanied by a reduction in calcium efflux induced by IP(3) in VSMC. Also, we observed that angiotensin II (ANGII) induces a decrease in IP(3)R by activation of NADPH oxidase and that preincubation with H(2)O(2) decreases ANGII-mediated calcium efflux and planar cell surface area in VSMC. The decreased IP(3) receptor content observed in cells was also found in aortic rings, which exhibited a decreased ANGII-dependent contraction after treatment with H(2)O(2). Altogether, these results suggest that H(2)O(2) mediates IP(3)R down-regulation via proteasome activity.

  13. CREB activity in dopamine D1 receptor expressing neurons regulates cocaine-induced behavioral effects.

    Science.gov (United States)

    Bilbao, Ainhoa; Rieker, Claus; Cannella, Nazzareno; Parlato, Rosanna; Golda, Slawomir; Piechota, Marcin; Korostynski, Michal; Engblom, David; Przewlocki, Ryszard; Schütz, Günther; Spanagel, Rainer; Parkitna, Jan R

    2014-01-01

    It is suggested that striatal cAMP responsive element binding protein (CREB) regulates sensitivity to psychostimulants. To test the cell-specificity of this hypothesis we examined the effects of a dominant-negative CREB protein variant expressed in dopamine receptor D1 (D1R) neurons on cocaine-induced behaviors. A transgenic mouse strain was generated by pronuclear injection of a BAC-derived transgene harboring the A-CREB sequence under the control of the D1R gene promoter. Compared to wild-type, drug-naïve mutants showed moderate alterations in gene expression, especially a reduction in basal levels of activity-regulated transcripts such as Arc and Egr2. The behavioral responses to cocaine were elevated in mutant mice. Locomotor activity after acute treatment, psychomotor sensitization after intermittent drug injections and the conditioned locomotion after saline treatment were increased compared to wild-type littermates. Transgenic mice had significantly higher cocaine conditioned place preference, displayed normal extinction of the conditioned preference, but showed an augmented cocaine-seeking response following priming-induced reinstatement. This enhanced cocaine-seeking response was associated with increased levels of activity-regulated transcripts and prodynorphin. The primary reinforcing effects of cocaine were not altered in the mutant mice as they did not differ from wild-type in cocaine self-administration under a fixed ratio schedule at the training dose. Collectively, our data indicate that expression of a dominant-negative CREB variant exclusively in neurons expressing D1R is sufficient to recapitulate the previously reported behavioral phenotypes associated with virally expressed dominant-negative CREB. PMID:24966820

  14. Potential of Natural Products in the Inhibition of Adipogenesis through Regulation of PPARγ Expression and/or Its Transcriptional Activity

    Directory of Open Access Journals (Sweden)

    Shi Feng

    2016-09-01

    Full Text Available Obesity is a global health problem characterized as an increase in the mass of adipose tissue. Adipogenesis is one of the key pathways that increases the mass of adipose tissue, by which preadipocytes mature into adipocytes through cell differentiation. Peroxisome proliferator-activated receptor γ (PPARγ, the chief regulator of adipogenesis, has been acutely investigated as a molecular target for natural products in the development of anti-obesity treatments. In this review, the regulation of PPARγ expression by natural products through inhibition of CCAAT/enhancer-binding protein β (C/EBPβ and the farnesoid X receptor (FXR, increased expression of GATA-2 and GATA-3 and activation of the Wnt/β-catenin pathway were analyzed. Furthermore, the regulation of PPARγ transcriptional activity associated with natural products through the antagonism of PPARγ and activation of Sirtuin 1 (Sirt1 and AMP-activated protein kinase (AMPK were discussed. Lastly, regulation of mitogen-activated protein kinase (MAPK by natural products, which might regulate both PPARγ expression and PPARγ transcriptional activity, was summarized. Understanding the role natural products play, as well as the mechanisms behind their regulation of PPARγ activity is critical for future research into their therapeutic potential for fighting obesity.

  15. Thalamic involvement in the regulation of alpha EEG activity in psychiatric patients

    International Nuclear Information System (INIS)

    1. This correlation involved: right thalamus and FP2 (r=0.587, p=0.021); F8 (r=0.777, p=0.001) electrode positions (right frontal lobe). No significant correlations were identified in the analysis of Gr 2. Conclusions: The current study provides evidence of a relationship between decreased right thalamic activity as in Gr 1, and right anterior quadrant alpha power activity. Frontal alpha activity is associated with a clinical presentation of depressive symptoms, ADHD, or an amotivational syndrome. This data support a role for thalamic activity in the regulating of frontal lobe electrical activity. It is not clear why such a relationship does not exist in Gr 2

  16. Unfolded protein response and activated degradative pathways regulation in GNE myopathy.

    Directory of Open Access Journals (Sweden)

    Honghao Li

    Full Text Available Although intracellular beta amyloid (Aβ accumulation is known as an early upstream event in the degenerative course of UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE myopathy, the process by which Aβdeposits initiate various degradative pathways, and their relationship have not been fully clarified. We studied the possible secondary responses after amyloid beta precursor protein (AβPP deposition including unfolded protein response (UPR, ubiquitin proteasome system (UPS activation and its correlation with autophagy system. Eight GNE myopathy patients and five individuals with normal muscle morphology were included in this study. We performed immunofluorescence and immunoblotting to investigate the expression of AβPP, phosphorylated tau (p-tau and endoplasmic reticulum molecular chaperones. Proteasome activities were measured by cleavage of fluorogenic substrates. The expression of proteasome subunits and linkers between proteasomal and autophagy systems were also evaluated by immunoblotting and relative quantitative real-time RT-PCR. Four molecular chaperones, glucose-regulated protein 94 (GRP94, glucose-regulated protein 78 (GRP78, calreticulin and calnexin and valosin containing protein (VCP were highly expressed in GNE myopathy. 20S proteasome subunits, three main proteasome proteolytic activities, and the factors linking UPS and autophagy system were also increased. Our study suggests that AβPP deposition results in endoplasmic reticulum stress (ERS and highly expressed VCP deliver unfolded proteins from endoplasmic reticulum to proteosomal system which is activated in endoplasmic reticulum associated degradation (ERAD in GNE myopathy. Excessive ubiquitinated unfolded proteins are exported by proteins that connect UPS and autophagy to autophagy system, which is activated as an alternative pathway for degradation.

  17. The Androgen Receptor Regulates PPARγ Expression and Activity in Human Prostate Cancer Cells.

    Science.gov (United States)

    Olokpa, Emuejevoke; Bolden, Adrienne; Stewart, LaMonica V

    2016-12-01

    The peroxisome proliferator activated receptor gamma (PPARγ) is a ligand-activated transcription factor that regulates growth and differentiation within normal prostate and prostate cancers. However the factors that control PPARγ within the prostate cancers have not been characterized. The goal of this study was to examine whether the androgen receptor (AR) regulates PPARγ expression and function within human prostate cancer cells. qRT-PCR and Western blot analyses revealed nanomolar concentrations of the AR agonist dihydrotestosterone (DHT) decrease PPARγ mRNA and protein within the castration-resistant, AR-positive C4-2 and VCaP human prostate cancer cell lines. The AR antagonists bicalutamide and enzalutamide blocked the ability of DHT to reduce PPARγ levels. In addition, siRNA mediated knockdown of AR increased PPARγ protein levels and ligand-induced PPARγ transcriptional activity within the C4-2 cell line. Furthermore, proteasome inhibitors that interfere with AR function increased the level of basal PPARγ and prevented the DHT-mediated suppression of PPARγ. These data suggest that AR normally functions to suppress PPARγ expression within AR-positive prostate cancer cells. To determine whether increases in AR protein would influence PPARγ expression and activity, we used lipofectamine-based transfections to overexpress AR within the AR-null PC-3 cells. The addition of AR to PC-3 cells did not significantly alter PPARγ protein levels. However, the ability of the PPARγ ligand rosiglitazone to induce activation of a PPARγ-driven luciferase reporter and induce expression of FABP4 was suppressed in AR-positive PC-3 cells. Together, these data indicate AR serves as a key modulator of PPARγ expression and function within prostate tumors. J. Cell. Physiol. 231: 2664-2672, 2016. © 2016 Wiley Periodicals, Inc. PMID:26945682

  18. Arginase reciprocally regulates nitric oxide synthase activity and contributes to endothelial dysfunction in aging blood vessels

    Science.gov (United States)

    Berkowitz, Dan E.; White, Ron; Li, Dechun; Minhas, Khalid M.; Cernetich, Amy; Kim, Soonyul; Burke, Sean; Shoukas, Artin A.; Nyhan, Daniel; Champion, Hunter C.; Hare, Joshua M.

    2003-01-01

    BACKGROUND: Although abnormal L-arginine NO signaling contributes to endothelial dysfunction in the aging cardiovascular system, the biochemical mechanisms remain controversial. L-arginine, the NO synthase (NOS) precursor, is also a substrate for arginase. We tested the hypotheses that arginase reciprocally regulates NOS by modulating L-arginine bioavailability and that arginase is upregulated in aging vasculature, contributing to depressed endothelial function. METHODS AND RESULTS: Inhibition of arginase with (S)-(2-boronoethyl)-L-cysteine, HCl (BEC) produced vasodilation in aortic rings from young (Y) adult rats (maximum effect, 46.4+/-9.4% at 10(-5) mol/L, P<0.01). Similar vasorelaxation was elicited with the additional arginase inhibitors N-hydroxy-nor-L-arginine (nor-NOHA) and difluoromethylornithine (DFMO). This effect required intact endothelium and was prevented by 1H-oxadiazole quinoxalin-1-one (P<0.05 and P<0.001, respectively), a soluble guanylyl cyclase inhibitor. DFMO-elicited vasodilation was greater in old (O) compared with Y rat aortic rings (60+/-6% versus 39+/-6%, P<0.05). In addition, BEC restored depressed L-arginine (10(-4) mol/L)-dependent vasorelaxant responses in O rings to those of Y. Arginase activity and expression were increased in O rings, whereas NOS activity and cyclic GMP levels were decreased. BEC and DFMO suppressed arginase activity and restored NOS activity and cyclic GMP levels in O vessels to those of Y. CONCLUSIONS: These findings demonstrate that arginase modulates NOS activity, likely by regulating intracellular L-arginine availability. Arginase upregulation contributes to endothelial dysfunction of aging and may therefore be a therapeutic target.

  19. TRIM11 negatively regulates IFNβ production and antiviral activity by targeting TBK1.

    Directory of Open Access Journals (Sweden)

    Younglang Lee

    Full Text Available The innate immune response is a host defense mechanism against infection by viruses and bacteria. Type I interferons (IFNα/β play a crucial role in innate immunity. If not tightly regulated under normal conditions and during immune responses, IFN production can become aberrant, leading to inflammatory and autoimmune diseases. In this study, we identified TRIM11 (tripartite motif containing 11 as a novel negative regulator of IFNβ production. Ectopic expression of TRIM11 decreased IFNβ promoter activity induced by poly (I:C stimulation or overexpression of RIG-I (retinoic acid-inducible gene-I signaling cascade components RIG-IN (constitutively active form of RIG-I, MAVS (mitochondrial antiviral signaling protein, or TBK1 (TANK-binding kinase-1. Conversely, TRIM11 knockdown enhanced IFNβ promoter activity induced by these stimuli. Moreover, TRIM11 overexpression inhibited the phosphorylation and dimerization of IRF3 and expression of IFNβ mRNA. By contrast, TRIM11 knockdown increased the IRF3 phosphorylation and IFNβ mRNA expression. We also found that TRIM11 and TBK1, a key kinase that phosphorylates IRF3 in the RIG-I pathway, interacted with each other through CC and CC2 domain, respectively. This interaction was enhanced in the presence of the TBK1 adaptor proteins, NAP1 (NF-κB activating kinase-associated protein-1, SINTBAD (similar to NAP1 TBK1 adaptor or TANK (TRAF family member-associated NF-κB activator. Consistent with its inhibitory role in RIG-I-mediated IFNβ signaling, TRIM11 overexpression enhanced viral infectivity, whereas TRIM11 knockdown produced the opposite effect. Collectively, our results suggest that TRIM11 inhibits RIG-I-mediated IFNβ production by targeting the TBK1 signaling complex.

  20. Structural Basis of Response Regulator Inhibition by a Bacterial Anti-Activator Protein

    OpenAIRE

    Melinda D Baker; Neiditch, Matthew B.

    2011-01-01

    The complex interplay between the response regulator ComA, the anti-activator RapF, and the signaling peptide PhrF controls competence development in Bacillus subtilis. More specifically, ComA drives the expression of genetic competence genes, while RapF inhibits the interaction of ComA with its target promoters. The signaling peptide PhrF accumulates at high cell density and upregulates genetic competence by antagonizing the interaction of RapF and ComA. How RapF functions mechanistically to...

  1. Some proposals on technical system for regulation of industrial activities involving NORMs

    International Nuclear Information System (INIS)

    In accordance with the relevant provisions of 'Law of People's Republic of China on Prevention and Control of Radioactive Pollution' and 'Basic standards for protection against ionizing radiation and for safety of radiant sources' (GB 18871-2002), based on domestic specific situations and the international regulatory practices on NORM facilities, some constructive suggestions of technical system for regulation industrial activities involving NORMs were put forward in the paper. Several aspects such as justification evaluation, dose system, radioactivity classification management system, monitoring, decommissioning, radiation protection system, and management of existing NORM facilities were addressed. (authors)

  2. Structure Based Discovery of Small Molecules to Regulate the Activity of Human Insulin Degrading Enzyme

    OpenAIRE

    Bilal Çakir; Onur Dağliyan; Ezgi Dağyildiz; İbrahim Bariş; Ibrahim Halil Kavakli; Seda Kizilel; Metin Türkay

    2012-01-01

    Structure Based Discovery of Small Molecules to Regulate the Activity of Human Insulin Degrading Enzyme Bilal C¸ akir1, Onur Dag˘ liyan1, Ezgi Dag˘ yildiz1, I˙brahim Baris¸1, Ibrahim Halil Kavakli1,2*, Seda Kizilel1*, Metin Tu¨ rkay3* 1 Department of Chemical and Biological Engineering, Koc¸ University, Sariyer, Istanbul, Turkey, 2 Department of Molecular Biology and Genetics, Koc¸ University, Sariyer, Istanbul, Turkey, 3 Department of Industrial Engineering, Koc¸ University...

  3. Effects of activated fibroblasts on phenotype modulation, EGFR signalling and cell cycle regulation in OSCC cells

    Energy Technology Data Exchange (ETDEWEB)

    Berndt, Alexander, E-mail: alexander.berndt@med.uni-jena.de [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Büttner, Robert, E-mail: Robert-Buettner@gmx.net [Institute of Biochemistry and Biophysics, Friedrich Schiller University Jena, 07740 Jena (Germany); Gühne, Stefanie, E-mail: stefanie_guehne@gmx.net [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Gleinig, Anna, E-mail: annagleinig@yahoo.com [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Richter, Petra, E-mail: P.Richter@med.uni-jena.de [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Chen, Yuan, E-mail: Yuan.Chen@med.uni-jena.de [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Franz, Marcus, E-mail: Marcus.Franz@med.uni-jena.de [Clinic of Internal Medicine I, Jena University Hospital, 07740 Jena (Germany); Liebmann, Claus, E-mail: Claus.Liebmann@uni-jena.de [Institute of Biochemistry and Biophysics, Friedrich Schiller University Jena, 07740 Jena (Germany)

    2014-04-01

    Crosstalk between carcinoma associated fibroblasts (CAFs) and oral squamous cell carcinoma (OSCC) cells is suggested to mediate phenotype transition of cancer cells as a prerequisite for tumour progression, to predict patients’ outcome, and to influence the efficacy of EGFR inhibitor therapies. Here we investigate the influence of activated fibroblasts as a model for CAFs on phenotype and EGFR signalling in OSCC cells in vitro. For this, immortalised hTERT-BJ1 fibroblasts were activated with TGFβ1 and PDGFAB to generate a myofibroblast or proliferative phenotype, respectively. Conditioned media (FCM{sub TGF}, FCM{sub PDGF}) were used to stimulate PE/CA-PJ15 OSCC cells. Results were compared to the effect of conditioned media of non-stimulated fibroblasts (FCM{sub B}). FCM{sub TGF} stimulation leads to an up-regulation of vimentin in the OSCC cells and an enhancement of invasive behaviour, indicating EMT-like effects. Similarly, FCM{sub TGF}≫FCM{sub PDGF} induced up-regulation of EGFR, but not of ErbB2/ErbB3. In addition, we detected an increase in basal activities of ERK, PI3K/Akt and Stat3 (FCM{sub TGF}>FCM{sub PDGF}) accompanied by protein interaction of vimentin with pERK. These effects are correlated with an increased proliferation. In summary, our results suggest that the activated myofibroblast phenotype provides soluble factors which are able to induce EMT-like phenomena and to increase EGFR signalling as well as cell proliferation in OSCC cells. Our results indicate a possible influence of activated myofibroblasts on EGFR-inhibitor therapy. Therefore, CAFs may serve as promising novel targets for combined therapy strategies. - Highlights: • A cell culture model for cancer associated fibroblasts is described. • The mutual interaction with OSCC cells leads to up-regulation of EGFR in tumour cells. • mCAF induces EGFR downstream signalling with increased proliferation in OSCC. • Erk activation is associated with protein interaction with vimentin

  4. Interactive Effects of Dorsomedial Hypothalamic Nucleus and Time-Restricted Feeding on Fractal Motor Activity Regulation.

    Science.gov (United States)

    Lo, Men-Tzung; Chiang, Wei-Yin; Hsieh, Wan-Hsin; Escobar, Carolina; Buijs, Ruud M; Hu, Kun

    2016-01-01

    One evolutionary adaptation in motor activity control of animals is the anticipation of food that drives foraging under natural conditions and is mimicked in laboratory with daily scheduled food availability. Food anticipation is characterized by increased activity a few hours before the feeding period. Here we report that 2-h food availability during the normal inactive phase of rats not only increases activity levels before the feeding period but also alters the temporal organization of motor activity fluctuations over a wide range of time scales from minutes up to 24 h. We demonstrate this multiscale alteration by assessing fractal patterns in motor activity fluctuations-similar fluctuation structure at different time scales-that are robust in intact animals with ad libitum food access but are disrupted under food restriction. In addition, we show that fractal activity patterns in rats with ad libitum food access are also perturbed by lesion of the dorsomedial hypothalamic (DMH)-a neural node that is involved in food anticipatory behavior. Instead of further disrupting fractal regulation, food restriction restores the disrupted fractal patterns in these animals after the DMH lesion despite the persistence of the 24-h rhythms. This compensatory effect of food restriction is more clearly pronounced in the same animals after the additional lesion of the suprachiasmatic nucleus (SCN)-the central master clock in the circadian system that generates and orchestrates circadian rhythms in behavior and physiological functions in synchrony with day-night cycles. Moreover, all observed influences of food restriction persist even when data during the food anticipatory and feeding period are excluded. These results indicate that food restriction impacts dynamics of motor activity at different time scales across the entire circadian/daily cycle, which is likely caused by the competition between the food-induced time cue and the light-entrained circadian rhythm of the SCN. The

  5. Interactive Effects of Dorsomedial Hypothalamic Nucleus and Time-Restricted Feeding on Fractal Motor Activity Regulation

    Science.gov (United States)

    Lo, Men-Tzung; Chiang, Wei-Yin; Hsieh, Wan-Hsin; Escobar, Carolina; Buijs, Ruud M.; Hu, Kun

    2016-01-01

    One evolutionary adaptation in motor activity control of animals is the anticipation of food that drives foraging under natural conditions and is mimicked in laboratory with daily scheduled food availability. Food anticipation is characterized by increased activity a few hours before the feeding period. Here we report that 2-h food availability during the normal inactive phase of rats not only increases activity levels before the feeding period but also alters the temporal organization of motor activity fluctuations over a wide range of time scales from minutes up to 24 h. We demonstrate this multiscale alteration by assessing fractal patterns in motor activity fluctuations—similar fluctuation structure at different time scales—that are robust in intact animals with ad libitum food access but are disrupted under food restriction. In addition, we show that fractal activity patterns in rats with ad libitum food access are also perturbed by lesion of the dorsomedial hypothalamic (DMH)—a neural node that is involved in food anticipatory behavior. Instead of further disrupting fractal regulation, food restriction restores the disrupted fractal patterns in these animals after the DMH lesion despite the persistence of the 24-h rhythms. This compensatory effect of food restriction is more clearly pronounced in the same animals after the additional lesion of the suprachiasmatic nucleus (SCN)—the central master clock in the circadian system that generates and orchestrates circadian rhythms in behavior and physiological functions in synchrony with day-night cycles. Moreover, all observed influences of food restriction persist even when data during the food anticipatory and feeding period are excluded. These results indicate that food restriction impacts dynamics of motor activity at different time scales across the entire circadian/daily cycle, which is likely caused by the competition between the food-induced time cue and the light-entrained circadian rhythm of the

  6. Interactive effects of dorsomedial hypothalamic nucleus and time-restricted feeding on fractal motor activity regulation

    Directory of Open Access Journals (Sweden)

    Men-Tzung eLo

    2016-05-01

    Full Text Available One evolutionary adaptation in motor activity control of animals is the anticipation of food that drives foraging under natural conditions and is mimicked in laboratory with daily scheduled food availability. Food anticipation is characterized by increased activity a few hours before the feeding period. Here we report that 2-hour food availability during the normal inactive phase of rats not only increases activity levels before the feeding period but also alters the temporal organization of motor activity fluctuations over a wide range of time scales from minutes up to 24 hours. We demonstrate this multiscale alteration by assessing fractal patterns in motor activity fluctuations – similar fluctuation structure at different time scales — that are robust in intact animals with ad libitum food access but are disrupted under food restriction. In addition, we show that fractal activity patterns in rats with ad libitum food access are also perturbed by lesion of the dorsomedial hypothalamic (DMH — a neural node that is involved in food anticipatory behavior. Instead of further disrupting fractal regulation, food restriction restores the disrupted fractal patterns in these animals after the DMH lesion despite the persistence of the 24-h rhythms. This compensatory effect of food restriction is more clearly pronounced in the same animals after the additional lesion of the suprachiasmatic nucleus (SCN — the central master clock in the circadian system that generates and orchestrates circadian rhythms in behavior and physiological functions in synchrony with day-night cycles. Moreover, all observed influences of food restriction persist even when data during the food anticipatory and feeding period are excluded. These results indicate that food restriction impacts dynamics of motor activity at different time scales across the entire circadian/daily cycle, which is likely caused by the competition between the food-induced time cue and the light

  7. TAM receptors affect adult brain neurogenesis by negative regulation of microglial cell activation.

    Science.gov (United States)

    Ji, Rui; Tian, Shifu; Lu, Helen J; Lu, Qingjun; Zheng, Yan; Wang, Xiaomin; Ding, Jixiang; Li, Qiutang; Lu, Qingxian

    2013-12-15

    TAM tyrosine kinases play multiple functional roles, including regulation of the target genes important in homeostatic regulation of cytokine receptors or TLR-mediated signal transduction pathways. In this study, we show that TAM receptors affect adult hippocampal neurogenesis and loss of TAM receptors impairs hippocampal neurogenesis, largely attributed to exaggerated inflammatory responses by microglia characterized by increased MAPK and NF-κB activation and elevated production of proinflammatory cytokines that are detrimental to neuron stem cell proliferation and neuronal differentiation. Injection of LPS causes even more severe inhibition of BrdU incorporation in the Tyro3(-/-)Axl(-/-)Mertk(-/-) triple-knockout (TKO) brains, consistent with the LPS-elicited enhanced expression of proinflammatory mediators, for example, IL-1β, IL-6, TNF-α, and inducible NO synthase, and this effect is antagonized by coinjection of the anti-inflammatory drug indomethacin in wild-type but not TKO brains. Conditioned medium from TKO microglia cultures inhibits neuron stem cell proliferation and neuronal differentiation. IL-6 knockout in Axl(-/-)Mertk(-/-) double-knockout mice overcomes the inflammatory inhibition of neurogenesis, suggesting that IL-6 is a major downstream neurotoxic mediator under homeostatic regulation by TAM receptors in microglia. Additionally, autonomous trophic function of the TAM receptors on the proliferating neuronal progenitors may also promote progenitor differentiation into immature neurons.

  8. SUMOylation of DEC1 Protein Regulates Its Transcriptional Activity and Enhances Its Stability

    Science.gov (United States)

    Li, Shujing; Bi, Hailian; Yang, Chunhua; Zhao, Feng; Liu, Ying; Ao, Xiang; Chang, Alan K.; Wu, Huijian

    2011-01-01

    Differentiated embryo-chondrocyte expressed gene 1 (DEC1, also known as sharp2, stra13, or BHLHB2) is a mammalian basic helix-loop-helix protein that is involved in many aspects of gene regulation through acting as a transcription factor. Changes in DEC1 expression levels have been implicated in the development of cancers. Using COS-7 cell, we showed that DEC1 can be modified by the small ubiquitin-like modifiers, SUMO1, 2 and 3. Two major SUMOylation sites (K159 and K279) were identified in the C-terminal domain of DEC1. Substitution of either K159 or K279 with arginine reduced DEC1 SUMOylation, but substitution of both K159 and K279 abolished SUMOylation, and more protein appeared to be retained in the cytoplasm compared to wild-type DEC1. The expression of DEC1 was up-regulated after serum starvation as previously reported, but at the same time, serum starvation also led to more SUMOylation of DEC1. In MCF-7 cells SUMOylation also stabilized DEC1 through inhibiting its ubiquitination. Moreover, SUMOylation of DEC1 promoted its repression of CLOCK/BMAL1-mediated transcriptional activity through recruitment of histone deacetylase1. These findings suggested that posttranslational modification of DEC1 in the form of SUMOylation may serve as a key factor that regulates the function of DEC1 in vivo. PMID:21829689

  9. GADD34 suppresses lipopolysaccharide-induced sepsis and tissue injury through the regulation of macrophage activation.

    Science.gov (United States)

    Ito, S; Tanaka, Y; Oshino, R; Okado, S; Hori, M; Isobe, K-I

    2016-01-01

    Growth arrest and DNA damage inducible protein 34 (GADD34) is induced by various cellular stresses, such as DNA damage, endoplasmic reticulum stress, and amino-acid deprivation. Although the major roles of GADD34 are regulating ER stress responses and apoptosis, a recent study suggested that GADD34 is linked to innate immune responses. In this report, we investigated the roles of GADD34 in inflammatory responses against bacterial infection. To explore the effects of GADD34 on systemic inflammation in vivo, we employed a lipopolysaccharide (LPS)-induced murine sepsis model and assessed the lethality, serum cytokine levels, and tissue injury in the presence or absence of GADD34. We found that GADD34 deficiency increased the lethality and serum cytokine levels in LPS-induced sepsis. Moreover, GADD34 deficiency enhanced tissue destruction, cell death, and pro-inflammatory cytokine expression in LPS-induced acute liver injury. Pro-inflammatory cytokine production after LPS stimulation is regulated by the Toll-like receptor 4 (TLR4)-mediated NF-κB signaling pathway. In vitro experiments revealed that GADD34 suppressed pro-inflammatory cytokine production by macrophages through dephosphorylation of IKKβ. In conclusion, GADD34 attenuates LPS-induced sepsis and acute tissue injury through suppressing macrophage activation. Targeting this anti-inflammatory role of GADD34 may be a promising area for the development of therapeutic agents to regulate inflammatory disorders. PMID:27171261

  10. SUMOylation of DEC1 protein regulates its transcriptional activity and enhances its stability.

    Directory of Open Access Journals (Sweden)

    Yongde Hong

    Full Text Available Differentiated embryo-chondrocyte expressed gene 1 (DEC1, also known as sharp2, stra13, or BHLHB2 is a mammalian basic helix-loop-helix protein that is involved in many aspects of gene regulation through acting as a transcription factor. Changes in DEC1 expression levels have been implicated in the development of cancers. Using COS-7 cell, we showed that DEC1 can be modified by the small ubiquitin-like modifiers, SUMO1, 2 and 3. Two major SUMOylation sites (K(159 and K(279 were identified in the C-terminal domain of DEC1. Substitution of either K(159 or K(279 with arginine reduced DEC1 SUMOylation, but substitution of both K(159 and K(279 abolished SUMOylation, and more protein appeared to be retained in the cytoplasm compared to wild-type DEC1. The expression of DEC1 was up-regulated after serum starvation as previously reported, but at the same time, serum starvation also led to more SUMOylation of DEC1. In MCF-7 cells SUMOylation also stabilized DEC1 through inhibiting its ubiquitination. Moreover, SUMOylation of DEC1 promoted its repression of CLOCK/BMAL1-mediated transcriptional activity through recruitment of histone deacetylase1. These findings suggested that posttranslational modification of DEC1 in the form of SUMOylation may serve as a key factor that regulates the function of DEC1 in vivo.

  11. 40 CFR 260.41 - Procedures for case-by-case regulation of hazardous waste recycling activities.

    Science.gov (United States)

    2010-07-01

    ... of hazardous waste recycling activities. 260.41 Section 260.41 Protection of Environment... Rulemaking Petitions § 260.41 Procedures for case-by-case regulation of hazardous waste recycling activities... hazardous waste recycling activities described in § 261.6(a)(2)(iii) under the provisions of § 261.6 (b)...

  12. Plant growth regulators induced urease activity in Cucurbita pepo L. cotyledons.

    Science.gov (United States)

    El Shora, Hamed M; Ali, Awatif S

    2016-03-01

    This study is aimed to investigate the activity of urease (EC 3.5.1.5, urea amidohydrolase) that catalyzes the hydrolysis of urea in 5-day-old Cucurbita pepo cotyledons subjected to various concentrations of different growth regulators. The treatment of C. pepo cotyledons with different concentrations (100-600 μmol) of different auxins [indole-3-acetic acid (IAA), indole butyric acid (IBA), indole propionic acid (IPA) and naphthalene acetic acid (NAA)]; or with different concentrations (100-300 μmol) of different cytokinins [kinetin, zeatin and benzyladenine (6-BA)] resulted in a significant increase of urease activity, compared to control. The optimal effects were recorded for each of 500 μmol of IAA and 300 μmol of zeatin treatments. A gradual increase in urease activity was detected in cotyledons treated with various concentrations (0.2-1.0 mM) of 28-homobrassinolide (HBL), in relative to control. A substantial increase in urease activity was observed in cotyledons subjected to different concentrations of triazole (10-60 mg L(-1)), containing either triadimefon (TDM) or hexaconazole (HEX), compared to control. The combination of 300 μmol zeatin with any of protein inhibitors, namely 5-fluorouridine (FUrd), cordycepin and α-amanitin, resulted in the alleviation of their inhibitory effect on the urease activity.

  13. Disruption of dopamine neuron activity pattern regulation through selective expression of a human KCNN3 mutation.

    Science.gov (United States)

    Soden, Marta E; Jones, Graham L; Sanford, Christina A; Chung, Amanda S; Güler, Ali D; Chavkin, Charles; Luján, Rafael; Zweifel, Larry S

    2013-11-20

    The calcium-activated small conductance potassium channel SK3 plays an essential role in the regulation of dopamine neuron activity patterns. Here we demonstrate that expression of a human disease-related SK3 mutation (hSK3Δ) in dopamine neurons of mice disrupts the balance between tonic and phasic dopamine neuron activity. Expression of hSK3Δ suppressed endogenous SK currents, reducing coupling between SK channels and NMDA receptors (NMDARs) and increasing permissiveness for burst firing. Consistent with enhanced excitability of dopamine neurons, hSK3Δ increased evoked calcium signals in dopamine neurons in vivo and potentiated evoked dopamine release. Specific expression of hSK3Δ led to deficits in attention and sensory gating and heightened sensitivity to a psychomimetic drug. Sensory-motor alterations and psychomimetic sensitivity were recapitulated in a mouse model of transient, reversible dopamine neuron activation. These results demonstrate the cell-autonomous effects of a human ion channel mutation on dopamine neuron physiology and the impact of activity pattern disruption on behavior.

  14. Changes in self-regulation-related prefrontal activities in eating disorders: a near infrared spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Chihiro Sutoh

    Full Text Available OBJECTIVE: The aim of this study is to clarify the symptomatology of the eating disorders examining the prefrontal function and activity associated with self-regulation among participants with or without eating disorders. METHODS: Ten patients with anorexia nervosa, fourteen with bulimia nervosa, and fourteen healthy control participants performed two cognitive tasks assessing self-regulatory functions, an auditorily distracted word fluency task and a rock-paper-scissors task under the measurements on prefrontal oxyhemoglobin concentration with near infrared spectroscopy. The psychiatric symptoms of patient groups were assessed with several questionnaires. RESULTS: Patients with bulimia nervosa showed decreased performances and prefrontal hyper activation patterns. Prefrontal activities showed a moderate negative correlation with task performances not in the patient groups but only in the healthy participants. The prefrontal activities of the patient groups showed positive correlations with some symptom scale aspects. CONCLUSIONS: The decreased cognitive abilities and characteristic prefrontal activation patterns associated with self-regulatory functions were shown in patients with bulimia nervosa, which correlated with their symptoms. These findings suggest inefficient prefrontal self-regulatory function of bulimia nervosa that associate with its symptoms.

  15. Histone tails regulate DNA methylation by allosterically activating de novo methyltransferase

    Institute of Scientific and Technical Information of China (English)

    Bin-Zhong Li; Guo-Liang Xu; Zheng Huang; Qing-Yan Cui; Xue-Hui Song; Lin Du; Albert Jeltsch; Ping Chen; Guohong Li; En Li

    2011-01-01

    Cytosine methylation of genomic DNA controls gene expression and maintains genome stability. How a specific DNA sequence is targeted for methylation by a methyltransferase is largely unknown. Here, we show that histone H3 tails lacking lysine 4 (K4) methylation function as an allosteric activator for methyltransferase Dnmt3a by binding to its plant homeodomain (PHD). In vitro, histone H3 peptides stimulated the methylation activity of Dnmt3a up to 8-fold, in a manner reversely correlated with the level of K4 methylation. The biological significance of allosteric regulation was manifested by molecular modeling and identification of key residues in both the PHD and the catalytic domain of Dnmt3a whose mutations impaired the stimulation of methylation activity by H3 peptides but not the binding of H3 peptides. Significantly, these mutant Dnmt3a proteins were almost inactive in DNA methylation when expressed in mouse embryonic stem cells while their recruitment to genomic targets was unaltered. We therefore propose a two-step mechanism for de novo DNA methylation - first recruitment of the methyltransferase probably assisted by a chromatin- or DNA-binding factor, and then allosteric activation depending on the interaction between Dnmt3a and the histone tails - the latter might serve as a checkpoint for the methylation activity.

  16. Effect of cadence regulation on muscle activation patterns during robot assisted gait: a dynamic simulation study.

    Science.gov (United States)

    Hussain, Shahid; Xie, Sheng Q; Jamwal, Prashant K

    2013-03-01

    Cadence or stride frequency is an important parameter being controlled in gait training of neurologically impaired subjects. The aim of this study was to examine the effects of cadence variation on muscle activation patterns during robot assisted unimpaired gait using dynamic simulations. A twodimensional (2-D) musculoskeletal model of human gait was developed considering eight major muscle groups along with existing ground contact force (GCF) model. A 2-D model of a robotic orthosis was also developed which provides actuation to the hip, knee and ankle joints in the sagittal plane to guide subjects limbs on reference trajectories. A custom inverse dynamics algorithm was used along with a quadratic minimization algorithm to obtain a feasible set of muscle activation patterns. Predicted patterns of muscle activations during slow, natural and fast cadence were compared and the mean muscle activations were found to be increasing with an increase in cadence. The proposed dynamic simulation provide important insight into the muscle activation variations with change in cadence during robot assisted gait and provide the basis for investigating the influence of cadence regulation on neuromuscular parameters of interest during robot assisted gait.

  17. The regulation of the SARK promoter activity by hormones and environmental signals.

    Science.gov (United States)

    Delatorre, Carla A; Cohen, Yuval; Liu, Li; Peleg, Zvi; Blumwald, Eduardo

    2012-09-01

    The Senescence Associated Receptor Protein Kinase (P(SARK)) promoter, fused to isopentenyltransferase (IPT) gene has been shown to promote drought tolerance in crops. We dissected P(SARK) in order to understand the various elements associated with its activation and suppression. The activity of P(SARK) was higher in mature and early senescing leaves, and abiotic stress induced its activity in mature leaves. Bioinformatics analysis suggests the interactions of multiple cis-acting elements in the control of P(SARK) activity. In vitro gel shift assays and yeast one hybrid system revealed interactions of P(SARK) with transcription factors related to abscisic acid and cytokinin response. Deletion analysis of P(SARK), fused to GUS-reporter gene was used to identify specific regions regulating transcription under senescence or during drought stress. Effects of exogenous hormonal treatments were characterized in entire plants and in leaf disk assays, and regions responsive to various hormones were defined. Our results indicate a complex interaction of plant hormones and additional factors modulating P(SARK) activity under stress resulting in a transient induction of expression.

  18. 41 CFR 101-6.2103 - What programs and activities of GSA are subject to these regulations?

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true What programs and activities of GSA are subject to these regulations? 101-6.2103 Section 101-6.2103 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT...

  19. 41 CFR 101-6.2106 - What procedures apply to the selection of programs and activities under these regulations?

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true What procedures apply to the selection of programs and activities under these regulations? 101-6.2106 Section 101-6.2106 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY...

  20. Cognitive emotion regulation in children: Reappraisal of emotional faces modulates neural source activity in a frontoparietal network

    Directory of Open Access Journals (Sweden)

    Ida Wessing

    2015-06-01

    Full Text Available Emotion regulation has an important role in child development and psychopathology. Reappraisal as cognitive regulation technique can be used effectively by children. Moreover, an ERP component known to reflect emotional processing called late positive potential (LPP can be modulated by children using reappraisal and this modulation is also related to children's emotional adjustment. The present study seeks to elucidate the neural generators of such LPP effects. To this end, children aged 8–14 years reappraised emotional faces, while neural activity in an LPP time window was estimated using magnetoencephalography-based source localization. Additionally, neural activity was correlated with two indexes of emotional adjustment and age. Reappraisal reduced activity in the left dorsolateral prefrontal cortex during down-regulation and enhanced activity in the right parietal cortex during up-regulation. Activity in the visual cortex decreased with increasing age, more adaptive emotion regulation and less anxiety. Results demonstrate that reappraisal changed activity within a frontoparietal network in children. Decreasing activity in the visual cortex with increasing age is suggested to reflect neural maturation. A similar decrease with adaptive emotion regulation and less anxiety implies that better emotional adjustment may be associated with an advance in neural maturation.