Science.gov

Sample records for expressed camp phosphodiesterase

  1. Phosphodiesterases and subcellular compartmentalized cAMP signaling in the cardiovascular system.

    PubMed

    Stangherlin, Alessandra; Zaccolo, Manuela

    2012-01-01

    Phosphodiesterases are key enzymes in the cAMP signaling cascade. They convert cAMP in its inactive form 5'-AMP and critically regulate the intensity and the duration of cAMP-mediated signals. Multiple isoforms exist that possess different intracellular distributions, different affinities for cAMP, and different catalytic and regulatory properties. This complex repertoire of enzymes provides a multiplicity of ways to modulate cAMP levels, to integrate more signaling pathways, and to respond to the specific needs of the cell within distinct subcellular domains. In this review we summarize key findings on phosphodiesterase compartmentalization in the cardiovascular system.

  2. Phosphodiesterases in the rat ovary: effect of cAMP in primordial follicles.

    PubMed

    Petersen, Tonny Studsgaard; Stahlhut, Martin; Andersen, Claus Yding

    2015-07-01

    Phosphodiesterases (PDEs) are important regulators of the intracellular cAMP concentration, which is a central second messenger that affects a multitude of intracellular functions. In the ovaries, cAMP exerts diverse functions, including regulation of ovulation and it has been suggested that augmented cAMP levels stimulate primordial follicle growth. The present study examined the gene expression, enzyme activity and immunolocalization of the different cAMP hydrolysing PDEs families in the rat ovary. Further, the effect of PDE4 inhibition on primordial follicle activation in cultured neonatal rat ovaries was also evaluated. We found varied expression of all eight families in the ovary with Pde7b and Pde8a having the highest expression each accounting for more than 20% of the total PDE mRNA. PDE4 accounted for 15-26% of the total PDE activity. Immunoreactive PDE11A was found in the oocytes and PDE2A in the corpora lutea. Incubating neonatal rat ovaries with PDE4 inhibitors did not increase primordial follicle activation or change the expression of the developing follicle markers Gdf9, Amh, Inha, the proliferation marker Mki67 or the primordial follicle marker Tmeff2. In addition, the cAMP analogue 8-bromo-cAMP did not increase AKT1 or FOXO3A phosphorylation associated with follicle activation or increase the expression of Kitlg known to be associated with follicle differentiation but did increase the Tmeff2, Mki67 and Inha expression in a dose-dependent manner. In conclusion, this study shows that both Pde7b and Pde8a are highly expressed in the rodent ovary and that PDE4 inhibition does not cause an increase in primordial follicle activation.

  3. Phosphodiesterase DosP increases persistence by reducing cAMP which reduces the signal indole.

    PubMed

    Kwan, Brian W; Osbourne, Devon O; Hu, Ying; Benedik, Michael J; Wood, Thomas K

    2015-03-01

    Persisters are bacteria that are highly tolerant to antibiotics due to their dormant state and are of clinical significance owing to their role in infections. Given that the population of persisters increases in biofilms and that cyclic diguanylate (c-di-GMP) is an intracellular signal that increases biofilm formation, we sought to determine whether c-di-GMP has a role in bacterial persistence. By examining the effect of 30 genes from Escherichia coli, including diguanylate cyclases that synthesize c-di-GMP and phosphodiesterases that breakdown c-di-GMP, we determined that DosP (direct oxygen sensing phosphodiesterase) increases persistence by over a thousand fold. Using both transcriptomic and proteomic approaches, we determined that DosP increases persistence by decreasing tryptophanase activity and thus indole. Corroborating this effect, addition of indole reduced persistence. Despite the role of DosP as a c-di-GMP phosphodiesterase, the decrease in tryptophanase activity was found to be a result of cyclic adenosine monophosphate (cAMP) phosphodiesterase activity. Corroborating this result, the reduction of cAMP via CpdA, a cAMP-specific phosphodiesterase, increased persistence and reduced indole levels similarly to DosP. Therefore, phosphodiesterase DosP increases persistence by reducing the interkingdom signal indole via reduction of the global regulator cAMP.

  4. Cyclic nucleotide phosphodiesterase-mediated integration of cGMP and cAMP signaling in cells of the cardiovascular system.

    PubMed

    Maurice, Donald H

    2005-05-01

    Numerous pharmacological and physiological agents acting via either cAMP- or cGMP-mediated impact the activities of cells of the cardiovascular system. While most define cAMP and cGMP signaling systems as separate and independent, recent advances in our understanding of cyclic nucleotide signaling, and more specifically, of the roles which cyclic nucleotide phosphodiesterases (PDEs) play in these events, have altered this view. In this short chapter, I will review the data identifying expression of several PDEs in cells of the cardiovascular system. In addition, I will review the data that identify PDEs as enzymes capable of allowing integration between cAMP and cGMP signaling in cells, and propose that cAMP and cGMP signaling systems can represent parallel and interdependent signaling systems. Moreover, I will propose that cGMP-mediated effects on the activities of variants of the Phosphodiesterase 2 (PDE2), PDE3 and PDE5 families may act to coordinate linkage between cAMP and cGMP signaling in these cells.

  5. [Cyclic nucleotide phosphodiesterase IV expression, activity and targeting in cells of cardiovascular system].

    PubMed

    Yan, Jun; Zhu, Hai-Bo

    2007-06-01

    Cyclic nucleotide second messages (cAMP and cGMP) play a central role in signal transduction and regulation of physiologic responses. The only way to inactivate them is to degrade them through the action of phosphodiesterases (PDEs). Recent advances show that PDE4, a cAMP specific phosphodiesterase, has specific functions in regulating the activities of the cardiovascular system. PDE4 is expressed in the cells of cardiovascular systems including cardiomyocytes, vascular smooth muscle cells, and vascular endothelial cells. The expression level of PDE4 is shown to be downregulated in the failure hearts, while it is upregulated in hypertrophied hearts. And PDE4 deficiency in mice is associated with a cardiac phenotype comprised of a progressive, age-related cardiomyopathy, accelerated heart failure after myocardial infarction and exercise-induced arrhythmias. Local levels of cAMP regulate the precise opening of the ryanodine receptor complex (RyR2) which releases calcium at the start of a heartbeat. Loss or inhibition of PDE4 activity increases calcium flow through RyR2, and causes leakiness and heart failure in mice. These finding may show us a new target for treating cardiovascular diseases.

  6. The Role of Type 4 Phosphodiesterases in Generating Microdomains of cAMP: Large Scale Stochastic Simulations

    PubMed Central

    Oliveira, Rodrigo F.; Terrin, Anna; Di Benedetto, Giulietta; Cannon, Robert C.; Koh, Wonryull; Kim, MyungSook; Zaccolo, Manuela; Blackwell, Kim T.

    2010-01-01

    Cyclic AMP (cAMP) and its main effector Protein Kinase A (PKA) are critical for several aspects of neuronal function including synaptic plasticity. Specificity of synaptic plasticity requires that cAMP activates PKA in a highly localized manner despite the speed with which cAMP diffuses. Two mechanisms have been proposed to produce localized elevations in cAMP, known as microdomains: impeded diffusion, and high phosphodiesterase (PDE) activity. This paper investigates the mechanism of localized cAMP signaling using a computational model of the biochemical network in the HEK293 cell, which is a subset of pathways involved in PKA-dependent synaptic plasticity. This biochemical network includes cAMP production, PKA activation, and cAMP degradation by PDE activity. The model is implemented in NeuroRD: novel, computationally efficient, stochastic reaction-diffusion software, and is constrained by intracellular cAMP dynamics that were determined experimentally by real-time imaging using an Epac-based FRET sensor (H30). The model reproduces the high concentration cAMP microdomain in the submembrane region, distinct from the lower concentration of cAMP in the cytosol. Simulations further demonstrate that generation of the cAMP microdomain requires a pool of PDE4D anchored in the cytosol and also requires PKA-mediated phosphorylation of PDE4D which increases its activity. The microdomain does not require impeded diffusion of cAMP, confirming that barriers are not required for microdomains. The simulations reported here further demonstrate the utility of the new stochastic reaction-diffusion algorithm for exploring signaling pathways in spatially complex structures such as neurons. PMID:20661441

  7. Molecular cloning of rat homologues of the Drosophila melanogaster dunce cAMP phosphodiesterase: evidence for a family of genes.

    PubMed Central

    Swinnen, J V; Joseph, D R; Conti, M

    1989-01-01

    To study the structure and function of cyclic nucleotide phosphodiesterases (PDEs) involved in mammalian gametogenesis, a rat testis cDNA library was screened at low stringency with a cDNA clone coding for the Drosophila melanogaster dunce-encoded PDE as a probe. This screening resulted in the isolation of two groups of cDNA clones, differing in their nucleotide sequences (ratPDE1 and ratPDE2). In the rat testis, RNA transcripts corresponding to both groups of clones were expressed predominantly in germ cells. Additional screenings of a Sertoli cell cDNA library with a ratPDE2 clone as a probe led to the isolation of two more groups of clones (rat-PDE3 and ratPDE4). Unlike ratPDE1 and ratPDE2, these clones hybridized to transcripts present predominantly in the Sertoli cell. In the middle of the coding region, all four groups of clones were homologous to each other. The deduced amino acid sequences of part of this region were also homologous to the D. melanogaster dunce PDE and to PDEs from bovine and yeast. These data indicate that a family of genes homologous to the D. melanogaster dunce-encoded PDE is present in the rat and that these genes are differentially expressed in somatic and germ cells of the seminiferous tubule. These findings provide a molecular basis for the observed heterogeneity of cAMP PDEs. Images PMID:2546153

  8. New fluorescent analogs of cAMP and cGMP available as substrates for cyclic nucleotide phosphodiesterase.

    PubMed

    Hiratsuka, T

    1982-11-25

    The synthesis of fluorescent derivatives of cAMP and cGMP, by reaction with isatoic anhydride in aqueous solution at mild pH and temperature, yielding 2'-O-anthraniloyl derivatives of cyclic nucleotides, is here described. 2'-O-(N-Methylanthraniloyl) derivatives were also synthesized by reaction with N-methylisatoic anhydride. Upon excitation at 330-350 nm, these derivatives exhibited maximum fluorescence emission at 430-445 nm in aqueous solution with quantum yields of 0.11-0.26. Their fluorescence was sensitive to the polarity of solvent; in N,N-dimethylformamide quantum yields of 0.8-0.95. The major differences between the two fluorophores were the longer wavelength of the emission maximum of the N-methylanthraniloyl group and its greater quantum yield. The derivatives were substrates for beef heart cyclic nucleotide phosphodiesterase, 15-24% as effective as the natural substrate cAMP. When combined with thin layer chromatography techniques, two apparent Km values (3-4 microM and 36-76 microM) for the cAMP derivatives and one value (10-18 microM) for the cGMP derivatives were obtained. The results indicate that these 2'-hydroxyl-modified cAMP and cGMP can be useful fluorescent substrate analogs for cyclic nucleotide phosphodiesterase.

  9. Pharmacophore modeling and virtual screening for the discovery of new type 4 cAMP phosphodiesterase (PDE4) inhibitors.

    PubMed

    Niu, Miaomiao; Dong, Fenggong; Tang, Shi; Fida, Guissi; Qin, Jingyi; Qiu, Jiadan; Liu, Kangbo; Gao, Weidong; Gu, Yueqing

    2013-01-01

    Type 4 cAMP phosphodiesterase (PDE4) inhibitors show a broad spectrum of anti-inflammatory effects in almost all kinds of inflamed cells, by an increase in cAMP levels which is a pivotal second messenger responsible for various biological processes. These inhibitors are now considered as the potential drugs for treatment of chronic inflammatory diseases. However, some recently marketed inhibitors e.g., roflumilast, have shown adverse effects such as nausea and emesis, thus restricting its use. In order to identify novel PDE4 inhibitors with improved therapeutic indexes, a highly correlating (r = 0.963930) pharmacophore model (Hypo1) was established on the basis of known PDE4 inhibitors. Validated Hypo1 was used in database screening to identify chemical with required pharmacophoric features. These compounds are further screened by using the rule of five, ADMET and molecular docking. Finally, twelve hits which showed good results with respect to following properties such as estimated activity, calculated drug-like properties and scores were proposed as potential leads to inhibit the PDE4 activity. Therefore, this study will not only assist in the development of new potent hits for PDE4 inhibitors, but also give a better understanding of their interaction with PDE4. On a wider scope, this will be helpful for the rational design of novel potent enzyme inhibitors.

  10. The role of the PDE4D cAMP phosphodiesterase in the regulation of glucagon-like peptide-1 release

    PubMed Central

    Ong, WK; Gribble, FM; Reimann, F; Lynch, MJ; Houslay, MD; Baillie, GS; Furman, BL; Pyne, NJ

    2009-01-01

    Background and purpose: Increases in intracellular cyclic AMP (cAMP) augment the release/secretion of glucagon-like peptide-1 (GLP-1). As cAMP is hydrolysed by cAMP phosphodiesterases (PDEs), we determined the role of PDEs and particularly PDE4 in regulating GLP-1 release. Experimental approach: GLP-1 release, PDE expression and activity were investigated using rats and GLUTag cells, a GLP-1-releasing cell line. The effects of rolipram, a selective PDE4 inhibitor both in vivo and in vitro and stably overexpressed catalytically inactive PDE4D5 (D556A-PDE4D5) mutant in vitro on GLP-1 release were investigated. Key results: Rolipram (1.5 mg·kg−1 i.v.) increased plasma GLP-1 concentrations approximately twofold above controls in anaesthetized rats and enhanced glucose-induced GLP-1 release in GLUTag cells (EC50∼1.2 nmol·L−1). PDE4D mRNA transcript and protein were detected in GLUTag cells using RT-PCR with gene-specific primers and Western blotting with a specific PDE4D antibody respectively. Moreover, significant PDE activity was inhibited by rolipram in GLUTag cells. A GLUTag cell clone (C1) stably overexpressing the D556A-PDE4D5 mutant, exhibited elevated intracellular cAMP levels and increased basal and glucose-induced GLP-1 release compared with vector-transfected control cells. A role for intracellular cAMP/PKA in enhancing GLP-1 release in response to overexpression of D556A-PDE4D5 mutant was demonstrated by the finding that the PKA inhibitor H89 reduced both basal and glucose-induced GLP-1 release by 37% and 39%, respectively, from C1 GLUTag cells. Conclusions and implications: PDE4D may play an important role in regulating intracellular cAMP linked to the regulation of GLP-1 release. British Journal of Pharmacology (2009) 157, 633–644; doi:10.1111/j.1476-5381.2009.00194.x; published online 9 April 2009 PMID:19371330

  11. Cardiac Cyclic Nucleotide Phosphodiesterases: Function, Regulation, and Therapeutic Prospects

    PubMed Central

    Knight, W. E.; Yan, C.

    2014-01-01

    The second messengers cAMP and cGMP exist in multiple discrete compartments and regulate a variety of biological processes in the heart. The cyclic nucleotide phosphodiesterases, by catalyzing the hydrolysis of cAMP and cGMP, play crucial roles in controlling the amplitude, duration, and compartmentalization of cyclic nucleotide signaling. Over 60 phosphodiesterase isoforms, grouped into 11 families, have been discovered to date. In the heart, both cAMP- and cGMP-hydrolyzing phosphodiesterases play important roles in physiology and pathology. At least 7 of the 11 phosphodiesterase family members appear to be expressed in the myocardium, and evidence supports phosphodiesterase involvement in regulation of many processes important for normal cardiac function including pacemaking and contractility, as well as many pathological processes including remodeling and myocyte apoptosis. Pharmacological inhibitors for a number of phosphodiesterase families have also been used clinically or preclinically to treat several types of cardiovascular disease. In addition, phosphodiesterase inhibitors are also being considered for treatment of many forms of disease outside the cardiovascular system, raising the possibility of cardiovascular side effects of such agents. This review will discuss the roles of phosphodiesterases in the heart, in terms of expression patterns, regulation, and involvement in physiological and pathological functions. Additionally, the cardiac effects of various phosphodiesterase inhibitors, both potentially beneficial and detrimental, will be discussed. PMID:22951903

  12. Neurotrophins elevate cAMP to reach a threshold required to overcome inhibition by MAG through extracellular signal-regulated kinase-dependent inhibition of phosphodiesterase.

    PubMed

    Gao, Ying; Nikulina, Elena; Mellado, Wilfredo; Filbin, Marie T

    2003-12-17

    Inhibitors of regeneration in myelin, such as myelin-associated glycoprotein (MAG), play an important role in preventing regeneration after CNS injury. Elevation of cAMP, either with dibutyryl-cAMP (db-cAMP) or by priming with a variety of neurotrophins, overcomes inhibition by MAG and myelin. However, activation of cAMP is not generally regarded as a signaling pathway for neurotrophins. Here we show that the NGF-like neurotrophins overcome inhibition by MAG by activating tyrosine kinase receptors. We also show that activation of extracellular signal-regulated kinase (Erk) by BDNF is required to overcome inhibition by MAG, and that activated Erk transiently inhibits phosphodiesterase 4 (PDE4), the enzyme that hydrolyzes cAMP. Inhibition of PDE4 then allows cAMP to increase and so initiates the pathway to overcome inhibition. Furthermore, we also show that basal levels of Erk activation and basal cAMP levels contribute to the effects of db-cAMP by pushing the combined levels of cAMP above a threshold required to overcome inhibition. Together, these results not only show how NGF-like neurotrophins can elevate cAMP and overcome inhibition but also point to a novel mechanism of cross talk in neurons from the Erk to the cAMP signaling pathways.

  13. [Effect of red light on activity of cAMP phosphodiesterases in photoperiodically different cereals and vernalized winter wheat].

    PubMed

    Fedenko, E P; Koksharova, T A

    2007-01-01

    Red light illumination of seedlings of photoperiodically different cereals had a different effect on the activity of multiple cyclic adenosine monophosphate phosphodiesterases. The response of all phosphodiesterase forms was reversed in fully vernalized winter wheat Triticum aestivum L.

  14. Intracellular membrane association of the Aplysia cAMP phosphodiesterase long and short forms via different targeting mechanisms.

    PubMed

    Kim, Kun-Hyung; Jun, Yong-Woo; Park, Yongsoo; Lee, Jin-A; Suh, Byung-Chang; Lim, Chae-Seok; Lee, Yong-Seok; Kaang, Bong-Kiun; Jang, Deok-Jin

    2014-09-12

    Phosphodiesterases (PDEs) play key roles in cAMP compartmentalization, which is required for intracellular signaling processes, through specific subcellular targeting. Previously, we showed that the long and short forms of Aplysia PDE4 (ApPDE4), which are localized to the membranes of distinct subcellular organelles, play key roles in 5-hydroxytryptamine-induced synaptic facilitation in Aplysia sensory and motor synapses. However, the molecular mechanism of the isoform-specific distinct membrane targeting was not clear. In this study, we further investigated the molecular mechanism of the membrane targeting of the ApPDE4 long and short forms. We found that the membrane targeting of the long form was mediated by hydrophobic interactions, mainly via 16 amino acids at the N-terminal region, whereas the short form was targeted solely to the plasma membrane, mainly by nonspecific electrostatic interactions between their N termini and the negatively charged lipids such as the phosphatidylinositol polyphosphates PI4P and PI(4,5)P2, which are embedded in the inner leaflet of the plasma membrane. Moreover, oligomerization of the long or short form by interaction of their respective upstream conserved region domains, UCR1 and UCR2, enhanced their plasma membrane targeting. These results suggest that the long and short forms of ApPDE4 are distinctly targeted to intracellular membranes through their direct association with the membranes via hydrophobic and electrostatic interactions, respectively.

  15. Expression and Genetic Activation of Cyclic Di-GMP-Specific Phosphodiesterases in Escherichia coli

    PubMed Central

    Reinders, Alberto; Hee, Chee-Seng; Ozaki, Shogo; Mazur, Adam; Boehm, Alex; Schirmer, Tilman

    2015-01-01

    ABSTRACT Intracellular levels of the bacterial second messenger cyclic di-GMP (c-di-GMP) are controlled by antagonistic activities of diguanylate cyclases and phosphodiesterases. The phosphodiesterase PdeH was identified as a key regulator of motility in Escherichia coli, while deletions of any of the other 12 genes encoding potential phosphodiesterases did not interfere with motility. To analyze the roles of E. coli phosphodiesterases, we demonstrated that most of these proteins are expressed under laboratory conditions. We next isolated suppressor mutations in six phosphodiesterase genes, which reinstate motility in the absence of PdeH by reducing cellular levels of c-di-GMP. Expression of all mutant alleles also led to a reduction of biofilm formation. Thus, all of these proteins are bona fide phosphodiesterases that are capable of interfering with different c-di-GMP-responsive output systems by affecting the global c-di-GMP pool. This argues that E. coli possesses several phosphodiesterases that are inactive under laboratory conditions because they lack appropriate input signals. Finally, one of these phosphodiesterases, PdeL, was studied in more detail. We demonstrated that this protein acts as a transcription factor to control its own expression. Motile suppressor alleles led to a strong increase of PdeL activity and elevated pdeL transcription, suggesting that enzymatic activity and transcriptional control are coupled. In agreement with this, we showed that overall cellular levels of c-di-GMP control pdeL transcription and that this control depends on PdeL itself. We thus propose that PdeL acts both as an enzyme and as a c-di-GMP sensor to couple transcriptional activity to the c-di-GMP status of the cell. IMPORTANCE Most bacteria possess multiple diguanylate cyclases and phosphodiesterases. Genetic studies have proposed that these enzymes show signaling specificity by contributing to distinct cellular processes without much cross talk. Thus, spatial

  16. 2',3'-cAMP hydrolysis by metal-dependent phosphodiesterases containing DHH, EAL, and HD domains is non-specific: Implications for PDE screening.

    PubMed

    Rao, Feng; Qi, Yaning; Murugan, Elavazhagan; Pasunooti, Swathi; Ji, Qiang

    2010-07-30

    The recent report of 2',3'-cAMP isolated from rat kidney is the first proof of its biological existence, which revived interest in this mysterious molecule. 2',3'-cAMP serves as an extracellular adenosine source, but how it is degraded remains unclear. Here, we report that 2',3'-cAMP can be hydrolyzed by six phosphodiesterases containing three different families of hydrolytic domains, generating invariably 3'-AMP but not 2'-AMP. The catalytic efficiency (k(cat)/K(m)) of each enzyme against 2',3'-cAMP correlates with that against the widely used non-specific substrate bis(p-nitrophenyl)phosphate (bis-pNPP), indicating that 2',3'-cAMP is a previously unknown non-specific substrate for PDEs. Furthermore, we show that the exclusive formation of 3'-AMP is due to the P-O2' bond having lower activation energy and is not the result of steric exclusion at enzyme active site. Our analysis provides mechanistic basis to dissect protein function when 2',3'-cAMP hydrolysis is observed.

  17. Gene expression and cAMP.

    PubMed Central

    Nagamine, Y; Reich, E

    1985-01-01

    By comparing the 5'-flanking region of the porcine gene for the urokinase form of plasminogen activator with those of other cAMP-regulated genes, we identify a 29-nucleotide sequence that is tentatively proposed as the cAMP-regulatory unit. Homologous sequences are present (i) in the cAMP-regulated rat tyrosine aminotransferase, prolactin, and phosphoenolpyruvate carboxykinase genes and (ii) 5' to the transcription initiation sites of cAMP-regulated Escherichia coli genes. From this we conclude that the expression of cAMP-responsive genes in higher eukaryotes may be controlled, as in E. coli, by proteins that form complexes with cAMP and then show sequence-specific DNA-binding properties. The complex formed by cAMP and the regulatory subunit of the type II mammalian protein kinase might be one candidate for this function. Based on several homologies we suggest that this subunit may have retained both the DNA-binding specificity and transcription-regulating properties in addition to the nucleotide-binding domains of the bacterial cAMP-binding protein. If this were so, dissociation of protein kinase by cAMP would activate two processes: (i) protein phosphorylation by the catalytic subunit and (ii) transcription regulation by the regulatory subunit. PMID:2991882

  18. Challenge of human Jurkat T-cells with the adenylate cyclase activator forskolin elicits major changes in cAMP phosphodiesterase (PDE) expression by up-regulating PDE3 and inducing PDE4D1 and PDE4D2 splice variants as well as down-regulating a novel PDE4A splice variant.

    PubMed Central

    Erdogan, S; Houslay, M D

    1997-01-01

    The cAMP phosphodiesterase (PDE) 3 and PDE4 isoforms provide the major cAMP-hydrolysing PDE activities in Jurkat T-cells, with additional contributions from the PDE1 and PDE2 isoforms. Challenge of cells with the adenylate cyclase activator forskolin led to a rapid, albeit transient, increase in PDE3 activity occurring over the first 45 min, followed by a sustained increase in PDE3 activity which began after approximately 3 h and continued for at least 24 h. Only this second phase of increase in PDE3 activity was blocked by the transcriptional inhibitor actinomycin D. After approximately 3 h of exposure to forskolin, PDE4 activity had increased, via a process that could be inhibited by actinomycin D, and it remained elevated for at least a 24 h period. Such actions of forskolin were mimicked by cholera toxin and 8-bromo-cAMP. Forskolin increased intracellular cAMP concentrations in a time-dependent fashion and its action was enhanced when PDE induction was blocked with actinomycin D. Reverse transcription (RT)-PCR analysis, using generic primers designed to detect transcripts representing enzymically active products of the four PDE4 genes, identified transcripts for PDE4A and PDE4D but not for PDE4B or PDE4C in untreated Jurkat T-cells. Forskolin treatment did not induce transcripts for either PDE4B or PDE4C; however, it reduced the RT-PCR signal for PDE4A transcripts and markedly enhanced that for PDE4D transcripts. Using RT-PCR primers for PDE4 splice variants, a weak signal for PDE4D1 was evident in control cells whereas, in forskolin-treated cells, clear signals for both PDE4D1 and PDE4D2 were detected. RT-PCR analysis of the PDE4A species indicated that it was not the PDE4A isoform PDE-46 (PDE4A4B). Immunoblotting of control cells for PDE4 forms identified a single PDE4A species of approximately 118 kDa, which migrated distinctly from the PDE4A4B isoform PDE-46, with immunoprecipitation analyses showing that it provided all of the PDE4 activity in control

  19. Silymarin Activates c-AMP Phosphodiesterase and Stimulates Insulin Secretion in a Glucose-Dependent Manner in HIT-T15 Cells

    PubMed Central

    Meng, Ran; Mahadevan, Jana; Oseid, Elizabeth; Vallerie, Sara; Robertson, R. Paul

    2016-01-01

    Silymarin (SIL) is a flavonoid extracted from milk thistle seed that has been reported to decrease hyperglycemia in people with type 2 diabetes (T2D). However, it is not known whether SIL has direct secretory effects on β-cells. Using the β-cell line HIT-T15, SIL was shown to decrease intracellular peroxide levels and to augment glucose-stimulated insulin secretion (GSIS). However, the latter was observed using a concentration range of 25–100 µM, which was too low to affect endogenous peroxide levels. The stimulatory effect of SIL dissipated at higher concentrations (100–200 µM), and mild apoptosis was observed. The smaller concentrations of SIL also decreased cAMP phosphodiesterase activity in a Ca2+/calmodulin-dependent manner. The stimulatory effects of SIL on GSIS were inhibited by three different inhibitors of exocytosis, indicating that SIL’s mechanism of stimulating GSIS operated via closing β-cell K-ATP channels, and perhaps more distal sites of action involving calcium influx and G-proteins. We concluded that augmentation of GSIS by SIL can be observed at concentrations that also inhibit cAMP phosphodiesterase without concomitant lowering of intracellular peroxides. PMID:27973458

  20. Hydrogen sulfide-mediated stimulation of mitochondrial electron transport involves inhibition of the mitochondrial phosphodiesterase 2A, elevation of cAMP and activation of protein kinase A.

    PubMed

    Módis, Katalin; Panopoulos, Panagiotis; Coletta, Ciro; Papapetropoulos, Andreas; Szabo, Csaba

    2013-11-01

    Although hydrogen sulfide (H₂S) is generally known as a mitochondrial poison, recent studies show that lower concentrations of H₂S play a physiological role in the stimulation of mitochondrial electron transport and cellular bioenergetics. This effect involves electron donation at Complex II. Other lines of recent studies demonstrated that one of the biological actions of H₂S involves inhibition of cAMP and cGMP phosphodiesterases (PDEs). Given the emerging functional role of the mitochondrial isoform of cAMP PDE (PDE2A) in the regulation of mitochondrial function the current study investigated whether cAMP-dependent mechanisms participate in the stimulatory effect of NaHS on mitochondrial function. In isolated rat liver mitochondria, partial digestion studies localized PDE2A into the mitochondrial matrix. NaHS exerted a concentration-dependent inhibitory effect on recombinant PDE2A enzyme in vitro. Moreover, NaHS induced an elevation of cAMP levels when added to isolated mitochondria and stimulated the mitochondrial electron transport. The latter effect was inhibited by Rp-cAMP, an inhibitor of the cAMP-dependent protein kinase (PKA). The current findings suggest that the direct electron donating effect of NaHS is amplified by an intramitochondrial cAMP system, which may involve the inhibition of PDE2A and subsequent, cAMP-mediated stimulation of PKA.

  1. Phosphodiesterase 10A in the rat pineal gland: localization, daily and seasonal regulation of expression and influence on signal transduction.

    PubMed

    Spiwoks-Becker, Isabella; Wolloscheck, Tanja; Rickes, Oliver; Kelleher, Debra K; Rohleder, Nils; Weyer, Veronika; Spessert, Rainer

    2011-01-01

    The cyclic nucleotide phosphodiesterase 10A (PDE10A) is highly expressed in striatal spiny projection neurons and represents a therapeutic target for the treatment of psychotic symptoms. As reported previously [J Biol Chem 2009; 284:7606-7622], in this study PDE10A was seen to be additionally expressed in the pineal gland where the levels of PDE10A transcript display daily changes. As with the transcript, the amount of PDE10A protein was found to be under daily and seasonal regulation. The observed cyclicity in the amount of PDE10A mRNA persists under constant darkness, is blocked by constant light and is modulated by the lighting regime. It therefore appears to be driven by the master clock in the suprachiasmatic nucleus (SCN). Since adrenergic agonists and dibutyryl-cAMP induce PDE10A mRNA, the in vitro clock-dependent control of Pde10a appears to be mediated via a norepinephrine → β-adrenoceptor → cAMP/protein kinase A signaling pathway. With regard to the physiological role of PDE10A in the pineal gland, the specific PDE10A inhibitor papaverine was seen to enhance the adrenergic stimulation of the second messenger cAMP and cGMP. This indicates that PDE10A downregulates adrenergic cAMP and cGMP signaling by decreasing the half-life of both nucleotides. Consistent with its effect on cAMP, PDE10A inhibition also amplifies adrenergic induction of the cAMP-inducible gene arylalkylamine N-acetyltransferase (Aanat) which codes the rate-limiting enzyme in pineal melatonin formation. The findings of this study suggest that Pde10a expression is under circadian and seasonal regulation and plays a modulatory role in pineal signal transduction and gene expression.

  2. Role of phosphodiesterase 4 expression in the Epac1 signaling-dependent skeletal muscle hypertrophic action of clenbuterol.

    PubMed

    Ohnuki, Yoshiki; Umeki, Daisuke; Mototani, Yasumasa; Shiozawa, Kouichi; Nariyama, Megumi; Ito, Aiko; Kawamura, Naoya; Yagisawa, Yuka; Jin, Huiling; Cai, Wenqian; Suita, Kenji; Saeki, Yasutake; Fujita, Takayuki; Ishikawa, Yoshihiro; Okumura, Satoshi

    2016-05-01

    Clenbuterol (CB), a selective β2-adrenergic receptor (AR) agonist, induces muscle hypertrophy and counteracts muscle atrophy. However, it is paradoxically less effective in slow-twitch muscle than in fast-twitch muscle, though slow-twitch muscle has a greater density of β-AR We recently demonstrated that Epac1 (exchange protein activated by cyclic AMP [cAMP]1) plays a pivotal role in β2-AR-mediated masseter muscle hypertrophy through activation of the Akt and calmodulin kinase II (CaMKII)/histone deacetylase 4 (HDAC4) signaling pathways. Here, we investigated the role of Epac1 in the differential hypertrophic effect of CB using tibialis anterior muscle (TA; typical fast-twitch muscle) and soleus muscle (SOL; typical slow-twitch muscle) of wild-type (WT) and Epac1-null mice (Epac1KO). The TA mass to tibial length (TL) ratio was similar in WT and Epac1KO at baseline and was significantly increased after CB infusion in WT, but not in Epac1KO The SOL mass to TL ratio was also similar in WT and Epac1KO at baseline, but CB-induced hypertrophy was suppressed in both mice. In order to understand the mechanism involved, we measured the protein expression levels of β-AR signaling-related molecules, and found that phosphodiesterase 4 (PDE4) expression was 12-fold greater in SOL than in TA These results are consistent with the idea that increased PDE4-mediated cAMP hydrolysis occurs in SOL compared to TA, resulting in a reduced cAMP concentration that is insufficient to activate Epac1 and its downstream Akt and CaMKII/HDAC4 hypertrophic signaling pathways in SOL of WT This scenario can account for the differential effects of CB on fast- and slow-twitch muscles.

  3. Effects of repeated treatment with phosphodiesterase-4 inhibitors on cAMP signaling, hippocampal cell proliferation, and behavior in the forced-swim test.

    PubMed

    Xiao, Lan; O'Callaghan, James P; O'Donnell, James M

    2011-08-01

    The effects of repeated treatment with the phosphodiesterase-4 (PDE4) inhibitors rolipram, piclamilast, and 4-(2-(3-(cyclopentyloxy)-4-methoxyphenyl)-2-phenylethyl)pyridine (CDP840), which differ in their interactions with high- and low-affinity binding conformers of the enzyme, were contrasted to those of acute treatment on cAMP signaling, hippocampal cell proliferation, and immobility in the forced-swim test in rats. Repeated treatment with rolipram (1 and 3 mg/kg), piclamilast (0.3 and 1 mg/kg), or CDP840 (10 and 30 mg/kg) for 16 days increased cAMP and phosphorylation of cAMP response element binding protein (pCREB) in hippocampus and prefrontal cortex. In addition, repeated treatment with the PDE4 inhibitors increased proliferation and survival of newborn cells in the hippocampus and produced antidepressant-like effects on behavior, as evidenced by decreased immobility in the forced-swim test. Acute treatment with rolipram (3 mg/kg), piclamilast (1 mg/kg), or CDP840 (30 mg/kg) induced transient increases in cAMP and pCREB in hippocampus and prefrontal cortex, but the dose and time dependence of these effects did not parallel the behavioral effects. Compared with rolipram and piclamilast, repeated treatment with CDP840 exerted lesser effects on neural and behavioral measures, probably because of its weak interaction with the high-affinity binding conformer of PDE4. This suggests the relative importance of the high-affinity binding conformer in the mediation of the long-term effects of PDE4 inhibition on cAMP/pCREB signaling, hippocampal cell proliferation, and antidepressant-like effects on behavior.

  4. Loss of phosphodiesterase 10A expression is associated with progression and severity in Parkinson's disease.

    PubMed

    Niccolini, Flavia; Foltynie, Thomas; Reis Marques, Tiago; Muhlert, Nils; Tziortzi, Andri C; Searle, Graham E; Natesan, Sridhar; Kapur, Shitij; Rabiner, Eugenii A; Gunn, Roger N; Piccini, Paola; Politis, Marios

    2015-10-01

    The mechanisms underlying neurodegeneration and loss of dopaminergic signalling in Parkinson's disease are still only partially understood. Phosphodiesterase 10A (PDE10A) is a basal ganglia expressed dual substrate enzyme, which regulates cAMP and cGMP signalling cascades, thus having a key role in the regulation of dopaminergic signalling in striatal pathways, and in promoting neuronal survival. This study aimed to assess in vivo the availability of PDE10A in patients with Parkinson's disease using positron emission tomography molecular imaging with (11)C-IMA107, a highly selective PDE10A radioligand. We studied 24 patients with levodopa-treated, moderate to advanced Parkinson's disease. Their positron emission tomography imaging data were compared to those from a group of 12 healthy controls. Parametric images of (11)C-IMA107 binding potential relative to non-displaceable binding (BPND) were generated from the dynamic (11)C-IMA107 scans using the simplified reference tissue model with the cerebellum as the reference tissue. Corresponding region of interest analysis showed lower mean (11)C-IMA107 BPND in the caudate (P < 0.001), putamen (P < 0.001) and globus pallidus (P = 0.025) in patients with Parkinson's disease compared to healthy controls, which was confirmed with voxel-based analysis. Longer Parkinson's duration correlated with lower (11)C-IMA107 BPND in the caudate (r = -0.65; P = 0.005), putamen (r = -0.51; P = 0.025), and globus pallidus (r = -0.47; P = 0.030). Higher Unified Parkinson's Disease Rating Scale part-III motor scores correlated with lower (11)C-IMA107 BPND in the caudate (r = -0.54; P = 0.011), putamen (r = -0.48; P = 0.022), and globus pallidus (r = -0.70; P < 0.001). Higher Unified Dyskinesia Rating Scale scores in those Parkinson's disease with levodopa-induced dyskinesias (n = 12), correlated with lower (11)C-IMA107 BPND in the caudate (r = -0.73; P = 0.031) and putamen (r = -0.74; P = 0.031). Our findings demonstrate striatal and

  5. HPRT-Deficiency Dysregulates cAMP-PKA Signaling and Phosphodiesterase 10A Expression: Mechanistic Insight and Potential Target for Lesch-Nyhan Disease?

    PubMed Central

    Guibinga, Ghiabe-Henri; Murray, Fiona; Barron, Nikki

    2013-01-01

    Lesch-Nyhan Disease (LND) is the result of mutations in the X-linked gene encoding the purine metabolic enzyme, hypoxanthine guanine phosphoribosyl transferase (HPRT). LND gives rise to severe neurological anomalies including mental retardation, dystonia, chorea, pyramidal signs and a compulsive and aggressive behavior to self injure. The neurological phenotype in LND has been shown to reflect aberrant dopaminergic signaling in the basal ganglia, however there are little data correlating the defect in purine metabolism to the neural-related abnormalities. In the present studies, we find that HPRT-deficient neuronal cell lines have reduced CREB (cAMP response element-binding protein) expression and intracellular cyclic AMP (cAMP), which correlates with attenuated CREB-dependent transcriptional activity and a reduced phosphorylation of protein kinase A (PKA) substrates such as synapsin (p-syn I). Of interest, we found increased expression of phosphodiesterase 10A (PDE10A) in HPRT-deficient cell lines and that the PDE10 inhibitor papaverine and PDE10A siRNA restored cAMP/PKA signaling. Furthermore, reconstitution of HPRT expression in mutant cells partly increased cAMP signaling synapsin phosphorylation. In conclusion, our data show that HPRT-deficiency alters cAMP/PKA signaling pathway, which is in part due to the increased of PDE10A expression and activity. These findings suggest a mechanistic insight into the possible causes of LND and highlight PDE10A as a possible therapeutic target for this intractable neurological disease. PMID:23691025

  6. Important role of phosphodiesterase 3B for the stimulatory action of cAMP on pancreatic beta-cell exocytosis and release of insulin.

    PubMed

    Härndahl, Linda; Jing, Xing-Jun; Ivarsson, Rosita; Degerman, Eva; Ahrén, Bo; Manganiello, Vincent C; Renström, Erik; Holst, Lena Stenson

    2002-10-04

    Cyclic AMP potentiates glucose-stimulated insulin release and mediates the stimulatory effects of hormones such as glucagon-like peptide 1 (GLP-1) on pancreatic beta-cells. By inhibition of cAMP-degrading phosphodiesterase (PDE) and, in particular, selective inhibition of PDE3 activity, stimulatory effects on insulin secretion have been observed. Molecular and functional information on beta-cell PDE3 is, however, scarce. To provide such information, we have studied the specific effects of the PDE3B isoform by adenovirus-mediated overexpression. In rat islets and rat insulinoma cells, approximate 10-fold overexpression of PDE3B was accompanied by a 6-8-fold increase in membrane-associated PDE3B activity. The cAMP concentration was significantly lowered in transduced cells (INS-1(832/13)), and insulin secretion in response to stimulation with high glucose (11.1 mm) was reduced by 40% (islets) and 50% (INS-1). Further, the ability of GLP-1 (100 nm) to augment glucose-stimulated insulin secretion was inhibited by approximately 30% (islets) and 70% (INS-1). Accordingly, when stimulating with cAMP, a substantial decrease (65%) in exocytotic capacity was demonstrated in patch-clamped single beta-cells. In untransduced insulinoma cells, application of the PDE3-selective inhibitor OPC3911 (10 microm) was shown to increase glucose-stimulated insulin release as well as cAMP-enhanced exocytosis. The findings suggest a significant role of PDE3B as an important regulator of insulin secretory processes.

  7. Phosphodiesterase-4 Inhibition Alters Gene Expression and Improves Isoniazid – Mediated Clearance of Mycobacterium tuberculosis in Rabbit Lungs

    PubMed Central

    Subbian, Selvakumar; Tsenova, Liana; O'Brien, Paul; Yang, Guibin; Koo, Mi-Sun; Peixoto, Blas; Fallows, Dorothy; Dartois, Veronique; Muller, George; Kaplan, Gilla

    2011-01-01

    Tuberculosis (TB) treatment is hampered by the long duration of antibiotic therapy required to achieve cure. This indolent response has been partly attributed to the ability of subpopulations of less metabolically active Mycobacterium tuberculosis (Mtb) to withstand killing by current anti-TB drugs. We have used immune modulation with a phosphodiesterase-4 (PDE4) inhibitor, CC-3052, that reduces tumor necrosis factor alpha (TNF-α) production by increasing intracellular cAMP in macrophages, to examine the crosstalk between host and pathogen in rabbits with pulmonary TB during treatment with isoniazid (INH). Based on DNA microarray, changes in host gene expression during CC-3052 treatment of Mtb infected rabbits support a link between PDE4 inhibition and specific down-regulation of the innate immune response. The overall pattern of host gene expression in the lungs of infected rabbits treated with CC-3052, compared to untreated rabbits, was similar to that described in vitro in resting Mtb infected macrophages, suggesting suboptimal macrophage activation. These alterations in host immunity were associated with corresponding down-regulation of a number of Mtb genes that have been associated with a metabolic shift towards dormancy. Moreover, treatment with CC-3052 and INH resulted in reduced expression of those genes associated with the bacterial response to INH. Importantly, CC-3052 treatment of infected rabbits was associated with reduced ability of Mtb to withstand INH killing, shown by improved bacillary clearance, from the lungs of co-treated animals compared to rabbits treated with INH alone. The results of our study suggest that changes in Mtb gene expression, in response to changes in the host immune response, can alter the responsiveness of the bacteria to antimicrobial agents. These findings provide a basis for exploring the potential use of adjunctive immune modulation with PDE4 inhibitors to enhance the efficacy of existing anti-TB treatment. PMID:21949656

  8. Altered phosphodiesterase 3-mediated cAMP hydrolysis contributes to a hypermotile phenotype in obese JCR:LA-cp rat aortic vascular smooth muscle cells: implications for diabetes-associated cardiovascular disease.

    PubMed

    Netherton, Stuart J; Jimmo, Sandra L; Palmer, Daniel; Tilley, Douglas G; Dunkerley, Heather A; Raymond, Daniel R; Russell, James C; Absher, P Marlene; Sage, E Helene; Vernon, Robert B; Maurice, Donald H

    2002-04-01

    Cardiovascular diseases represent a significant cause of morbidity and mortality in diabetes. Of the many animal models used in the study of non-insulin-dependent (type 2) diabetes, the JCR:LA-cp rat is unique in that it develops insulin resistance in the presence of obesity and manifests both peripheral and coronary vasculopathies. In this animal model, arterial vascular smooth muscle cells (VSMCs) from homozygous obese (cp/cp) rats, but not from age-matched healthy (+/+ or + /cp, collectively defined +/?) littermates, display an " activated" phenotype in vitro and in vivo and have an elevated level of cAMP phosphodiesterase (PDE) activity. In this report, we confirm that cp/cp rat aortic VSMCs have an elevated level of PDE3 activity and show that only particulate PDE3 (PDE3B) activity is elevated. In marked contrast to results obtained in + /? VSMCs, simultaneous activation of adenylyl cyclase and inhibition of PDE3 activity in cp/cp VSMCs synergistically increased cAMP. Although PDE3 inhibition did not potentiate the antimigratory effects of forskolin on +/? VSMCs, PDE3 inhibition did markedly potentiate the forskolin-induced inhibition of migration of cp/cp-derived VSMCs. Although PDE3 activity was elevated in cp/cp rat aortic VSMCs, levels of expression of cytosolic PDE3 (PDE3A) and PDE3B in +/? and cp/cp VSMCs, as well as activation of these enzymes following activation of the cAMP-protein kinase A signaling cascade, were not different. Our data are consistent with an increased role for PDE3 in regulating cAMP-dependent signaling in cp/cp VSMCs and identify PDE3 as a cellular activity potentially responsible for the phenotype of cp/cp VSMCs.

  9. The localization and concentration of the PDE2-encoded high-affinity cAMP phosphodiesterase is regulated by cAMP-dependent protein kinase A in the yeast Saccharomyces cerevisiae.

    PubMed

    Hu, Yun; Liu, Enkai; Bai, Xiaojia; Zhang, Aili

    2010-03-01

    The genome of the yeast Saccharomyces cerevisiae encodes two cyclic AMP (cAMP) phosphodiesterases, a low-affinity one, Pde1, and a high-affinity one, Pde2. Pde1 has been ascribed a function for downregulating agonist-induced cAMP accumulation in a protein kinase A (PKA)-governed negative feedback loop, whereas Pde2 controls the basal cAMP level in the cell. Here we show that PKA regulates the localization and protein concentration of Pde2. Pde2 is accumulated in the nucleus in wild-type cells growing on glucose, or in strains with hyperactive PKA. In contrast, in derepressed wild-type cells or cells with attenuated PKA activity, Pde2 is distributed over the nucleus and cytoplasm. We also show evidence indicating that the Pde2 protein level is positively correlated with PKA activity. The increase in the Pde2 protein level in high-PKA strains and in cells growing on glucose was due to its increased half-life. These results suggest that, like its low-affinity counterpart, the high-affinity phosphodiesterase may also play an important role in the PKA-controlled feedback inhibition of intracellular cAMP.

  10. Receptor-mediated stimulation of lipid signalling pathways in CHO cells elicits the rapid transient induction of the PDE1B isoform of Ca2+/calmodulin-stimulated cAMP phosphodiesterase.

    PubMed

    Spence, S; Rena, G; Sullivan, M; Erdogan, S; Houslay, M D

    1997-01-01

    Chinese hamster ovary cells (CHO cells) do not exhibit any Ca2+/calmodulin-stimulated cAMP phosphodiesterase (PDE1) activity. Challenge of CHO cells with agonists for endogenous P2-purinoceptors, lysophosphatidic acid receptors and thrombin receptors caused a similar rapid transient induction of PDE1 activity in each instance. This was also evident on noradrenaline challenge of a cloned CHO cell line transfected so as to overexpress alpha 1B-adrenoceptors. This novel PDE1 activity appeared within about 15 min of exposure to ligands, rose to a maximum value within 30 min to 1 h and then rapidly decreased. In each case, the expression of novel PDE1 activity was blocked by the transcriptional inhibitor actinomycin D. Challenge with insulin of either native CHO cells or a CHO cell line transfected so as to overexpress the human insulin receptor failed to induce PDE1 activity. Reverse transcriptase-PCR analyses, using degenerate primers able to detect the PDE1C isoform, did not amplify any fragment from RNA preparations of CHO cells expressing PDE1 activity, although they did so from the human thyroid carcinoma FTC133 cell line. Reverse transcriptase-PCR analyses, using degenerate primers able to detect the PDE1A and PDE1B isoforms, successfully amplified a fragment of the predicted size from RNA preparations of both CHO cells expressing PDE1 activity and human Jurkat T-cells. Sequencing of the PCR products, generated using the PDE1A/B primers, yielded a novel sequence which, by analogy with sequences reported for bovine and murine PDE1B forms, suggests that the PDE1 species induced in CHO cells through protein kinase C activation and that expressed in Jurkat T-cells are PDE1B forms.

  11. [Effect of vernalization and red light illumination of seedlings of bread wheat (Triticum aestivum L.) on the temperature profile of the cAMP phosphodiesterase activity].

    PubMed

    Fedenko, E P; Koksharova, T A; Agamalova, S R; Beliaeva, E V

    2004-01-01

    Phenotypic manifestations of Vrn (vernalization) and Ppd (photoperiodism) genes responsible for transition of bread wheat Triticum aestivum L. to generative growth (flowering) are mutually related. Since the mechanism of phytochrome-induced photoperiodism involves the enzymes of cyclic adenosine monophosphate metabolism and phosphodiesterase in particular, we tested involvement of phosphodiesterase in the process of winter wheat vernalization and formation of flowering competence in alternate wheat requiring a long day but no vernalization for the transition to flowering. We studied temperature dependence of phosphodiesterase activity in vernalized and unvernalized winter wheat on the one hand and in etiolated and red light illuminated seedlings of alternate wheat on the other hand. Short-term experiments demonstrated that vernalization and red light illumination are similar to long day by the effect on the long-day plants. Both influences induced a pronounced inversion of the temperature profile of phosphodiesterase activity in the 28-45 degrees C range. We propose that phosphodiesterase is involved in vernalization processes and can serve as a sensor of low temperature in winter wheat. Changed temperature profile is a radical control mechanism of phosphodiesterase activity in response to the influences (red light and vernalizing temperatures) responsible for competence of various bread wheat forms for generative growth.

  12. cAMP-Specific phosphodiesterase-4 enzymes in the cardiovascular system: a molecular toolbox for generating compartmentalized cAMP signaling.

    PubMed

    Houslay, Miles D; Baillie, George S; Maurice, Donald H

    2007-04-13

    Cyclic AMP regulates a vast number of distinct events in all cells. Early studies established that its hydrolysis by cyclic nucleotide phosphodiesterases (PDEs) controlled both the magnitude and the duration of its influence. Recent evidence shows that PDEs also act as coincident detectors linking cyclic-nucleotide- and non-cyclic-nucleotide-based cellular signaling processes and are tethered with great selectively to defined intracellular structures, thereby integrating and spatially restricting their cellular effects in time and space. Although 11 distinct families of PDEs have been defined, and cells invariably express numerous individual PDE enzymes, a large measure of our increased appreciation of the roles of these enzymes in regulating cyclic nucleotide signaling has come from studies on the PDE4 family. Four PDE4 genes encode more than 20 isoforms. Alternative mRNA splicing and the use of different promoters allows cells the possibility of expressing numerous PDE4 enzymes, each with unique amino-terminal-targeting and/or regulatory sequences. Dominant negative and small interfering RNA-mediated knockdown strategies have proven that particular isoforms can uniquely control specific cellular functions. Thus the protein kinase A phosphorylation status of the beta(2) adrenoceptor and, thereby, its ability to switch its signaling to extracellular signal-regulated kinase activation, is uniquely regulated by PDE4D5 in cardiomyocytes. We describe how cardiomyocytes and vascular smooth muscle cells selectively vary both the expression and the catalytic activities of PDE4 isoforms to regulate their various functions and how altered regulation of these processes can influence the development, or resolution, of cardiovascular pathologies, such as heart failure, as well as various vasculopathies.

  13. Defining the role of a FYVE domain in the localization and activity of a cAMP phosphodiesterase implicated in osmoregulation in Trypanosoma cruzi

    PubMed Central

    Schoijet, Alejandra C.; Miranda, Kildare; Medeiros, Lia Carolina Soares; de Souza, Wanderley; Flawiá, Mirtha M.; Torres, Héctor N.; Pignataro, Omar P.; Docampo, Roberto; Alonso, Guillermo D.

    2010-01-01

    Summary Intracellular levels of cyclic nucleotide second messengers are regulated predominantly by a large superfamily of phosphodiesterases. Trypanosoma cruzi, the causative agent of Chagas disease, encodes four different phosphodiesterase (PDE) families. One of these PDEs, T. cruzi phosphodiesterase C2 (TcrPDEC2) has been characterized as a FYVE-domain containing protein. Here, we report a novel role for TcrPDEC2 in osmoregulation in T. cruzi and reveal the relevance of its FYVE domain. Our data show that treatment of epimastigotes with TcrPDEC2 inhibitors improves their regulatory volume decrease, whereas cells overexpressing this enzyme are unaffected by the same inhibitors. Consistent with these results, TcrPDEC2 localizes to the contractile vacuole complex, showing strong labeling in the region corresponding to the spongiome. Furthermore, transgenic parasites overexpressing a truncated version of TcrPDEC2 without the FYVE domain show a failure in its targeting to the contractile vacuole complex and a marked decrease in phosphodiesterase activity, supporting the importance of this domain to the localization and activity of TcrPDEC2. Taking together, the results here presented are consistent with the importance of the cyclic AMP signaling pathway in regulatory volume decrease and implicate TcrPDEC2 as a specifically localized phosphodiesterase involved in osmoregulation in T. cruzi. PMID:21166893

  14. Chronic antidepressant administration increases the expression of cAMP response element binding protein (CREB) in rat hippocampus.

    PubMed

    Nibuya, M; Nestler, E J; Duman, R S

    1996-04-01

    The present study demonstrates that chronic, but not acute, adminstration of several different classes of antidepressants, including serotonin- and norepinephrine-selective reuptake inhibitors, increases the expression of cAMP response element binding protein (CREB) mRNA in rat hippocampus. In contrast, chronic administration of several nonantidepressant psychotropic drugs did not influence expression of CREB mRNA, demonstrating the pharmacological specificity of this effect. In situ hybridization analysis demonstrates that antidepressant administration increases expression of CREB mRNA in CA1 and CA3 pyramidal and dentate gyrus granule cell layers of the hippocampus. In addition, levels of CRE immunoreactivity and of CRE binding activity were increased by chronic antidepressant administration, which indicates that expression and function of CREB protein are increased along with its mRNA. Chronic administration of the phosphodiesterase (PDE) inhibitors rolipram or papaverine also increased expression of CREB mRNA in hippocampus, demonstrating a role for the cAMP cascade. Moreover, coadministration of rolipram with imipramine resulted in a more rapid induction of CREB than with either treatment alone. Increased expression and function of CREB suggest that specific target genes may be regulated by these treatments. We have found that levels of brain-derived neurotrophic factor (BDNF) and trkB mRNA are also increased by administration of antidepressants or PDE inhibitors. These findings indicate that upregulation of CREB is a common action of chronic antidepressant treatments that may lead to regulation of specific target genes, such as BDNF and trkB, and to the long-term effects of these treatments on brain function.

  15. Altered gene expression in rat mesenteric tissue following in vivo exposure to a phosphodiesterase 4 inhibitor

    SciTech Connect

    Dagues, Nicolas . E-mail: nicolas.dagues@pfizer.com; Pawlowski, Valerie; Guigon, Ghislaine; Ledieu, David; Sobry, Cecile; Hanton, Gilles; Freslon, Jean-Louis; Chevalier, Stephan

    2007-01-01

    Vascular injury is a relatively common finding during the pre-clinical toxicity testing of drugs. The mechanisms of the injury are poorly understood and in turn, sensitive and specific biomarkers for pre-clinical and clinical monitoring do not exist. The present study was undertaken to investigate the molecular mechanisms of drug-induced vascular injury in mesenteric tissue of rats treated with the selective phosphodiesterase 4 (PDE4) inhibitor CI-1044. In a time-course study, male Sprague Dawley rats were given daily doses of 40 or 80 mg/kg for 1, 2 or 3 successive days and were euthanized the following day. Gene expression profiles in mesenteric tissue were determined using Affymetrix RG{sub U}34A microarrays and fibrinogen and cytokine measurements were performed in blood samples. Hierarchical clustering analysis produced a clear pattern separation of the animals with inflammation, animal with inflammation and necrosis and animals without any lesion. Genes associated with inflammation, procoagulation, extracellular matrix remodeling were up-regulated. An altered expression of genes involved in vascular tone regulation, lipid and glucose metabolism was also observed. Selected genes expression changes were confirmed by TaqMan real-time RT-PCR. The inflammatory process was also detected in the bloodstream at the protein level since fibrinogen, IL6 and IL1{beta} concentrations were increased in treated animals. Overall, the present study reveals several molecular changes supporting the hypothesis by which PDE4 inhibitor-induced vascular lesions in rats are triggered by an inflammatory mechanism and/or a vascular tone dysregulation.

  16. Interaction with receptor for activated C-kinase 1 (RACK1) sensitizes the phosphodiesterase PDE4D5 towards hydrolysis of cAMP and activation by protein kinase C

    PubMed Central

    Bird, Rebecca J.; Baillie, George S.; Yarwood, Stephen J.

    2010-01-01

    We have previously identified the PKC (protein kinase C)-anchoring protein RACK1 (receptor for activated C-kinase 1), as a specific binding partner for the cAMP-specific phosphodiesterase PDE4D5, suggesting a potential site for cross-talk between the PKC and cAMP signalling pathways. In the present study we found that elevation of intracellular cAMP, with the β2-adrenoceptor agonist isoproterenol (isoprenaline), led to activation of PDE4 enzymes in the particulate and soluble fractions of HEK (human embryonic kidney)-293 cells. In contrast activation of PDE4D5, with isoproterenol and the PKC activator PMA, was restricted to the particulate fraction, where it interacts with RACK1; however, RACK1 is dispensable for anchoring PDE4D5 to the particulate fraction. Kinetic studies demonstrated that RACK1 alters the conformation of particulate-associated PDE4D5 so that it more readily interacts with its substrate cAMP and with rolipram, a PDE4 inhibitor that specifically targets the active site of the enzyme. Interaction with RACK1 was also essential for PKC-dependent and ERK (extracellular-signal-regulated kinase)-independent phosphorylation (on Ser126), and activation of PDE4D5 in response to PMA and isoproterenol, both of which trigger the recruitment of PKCα to RACK1. Together these results reveal novel signalling cross-talk, whereby RACK1 mediates PKC-dependent activation of PDE4D5 in the particulate fraction of HEK-293 cells in response to elevations in intracellular cAMP. PMID:20819076

  17. Quercetin promotes neurite growth through enhancing intracellular cAMP level and GAP-43 expression.

    PubMed

    Chen, Ming-Ming; Yin, Zhi-Qi; Zhang, Lu-Yong; Liao, Hong

    2015-09-01

    The present study was designed to investigate the role of quercetin on neurite growth in N1E-115 cells and the underlying mechanisms. Quercetin was evaluated for its effects on cell numbers of neurites, neurite length, intracellular cAMP content, and Gap-43 expression in N1E-115 cells in vitro by use of microscopy, LANCE(tm) cAMP 384 kit, and Western blot analysis, respectively. Our results showed that quercetin could increase the neurite length in a concentration-dependent manner, but had no effect on the numbers of cells. Quercetin significantly increased the expression of cellular cAMP in a time- and concentration-dependent manner. The Gap-43 expression was up-regulated in a time-dependent manner. In conclusion, quercetin could promote neurite growth through increasing the intracellular cAMP level and Gap-43 expression.

  18. Down-regulation by prostaglandins of type-II phospholipase A2 expression in guinea-pig alveolar macrophages: a possible involvement of cAMP.

    PubMed Central

    Vial, D; Arbibe, L; Havet, N; Dumarey, C; Vargaftig, B; Touqui, L

    1998-01-01

    We have demonstrated previously that isolated guinea-pig alveolar macrophages (AM) synthesize type-II phospholipase A2 (PLA2-II) through a tumour necrosis factor-alpha (TNF-alpha)-dependent process. This synthesis is enhanced by lipopolysaccharide (LPS) and accompanied by a release of prostaglandin E2 (PGE2) into the medium. Because agents elevating intracellular cAMP, such as PGE2, have been shown to stimulate PLA2-II expression in various cell types, we investigated the modulation of PLA2-II synthesis by cAMP in AM. Surprisingly, incubation of AM with PGE2, dibutyryl-cAMP, cholera toxin or rolipram (an inhibitor of specific cAMP-phosphodiesterase) inhibited both basal and LPS-stimulated PLA2-II expression. The inhibitory effect of PGE2 was observed at concentrations similar to those released by AM. Moreover, treatment of AM with either aspirin or neutralizing PGE2 monoclonal antibody stimulated PLA2-II synthesis. These effects were closely correlated with the ability of these agents to modulate TNF-alpha release, which was decreased by dibutyryl-cAMP and exogenous PGE2, whereas neutralizing PGE2 antibody markedly increased this release. Hence, in contrast to other cell systems, we report that: (i) agents elevating intracellular cAMP levels down-regulate both basal and LPS-induced PLA2-II synthesis, (ii) prostaglandins exert a negative feedback effect on this synthesis, probably through an elevation of intracellular cAMP levels, and (iii) inhibition of TNF-alpha release may account, at least in part, for the down-regulation of PLA2-II expression by endogenously produced prostaglandins and cAMP-elevating agents. PMID:9461495

  19. Reduced expression of cytochrome oxidases largely explains cAMP inhibition of aerobic growth in Shewanella oneidensis

    PubMed Central

    Yin, Jianhua; Meng, Qiu; Fu, Huihui; Gao, Haichun

    2016-01-01

    Inhibition of bacterial growth under aerobic conditions by elevated levels of cyclic adenosine 3′,5′-monophosphate (cAMP), first revealed more than 50 years ago, was attributed to accumulation of toxic methylglyoxal (MG). Here, we report a Crp-dependent mechanism rather than MG accumulation that accounts for the phenotype in Shewanella oneidensis, an emerging research model for the bacterial physiology. We show that a similar phenotype can be obtained by removing CpdA, a cAMP phosphodiesterase that appears more effective than its Escherichia coli counterpart. Although production of heme c and cytochromes c is correlated well with cAMP levels, neither is sufficient for the retarded growth. Quantities of overall cytochromes c increased substantially in the presence of elevated cAMP, a phenomenon resembling cells respiring on non-oxygen electron acceptors. In contrast, transcription of Crp-dependent genes encoding both cytochromes bd and cbb3 oxidases is substantially repressed under the same condition. Overall, our results suggest that cAMP of elevated levels drives cells into a low-energetic status, under which aerobic respiration is inhibited. PMID:27076065

  20. Effect of phosphodiesterase 4 inhibitors on NFAT-dependent cyclooxygenase-2 expression in human T lymphocytes.

    PubMed

    Jimenez, José L; Iñiguez, Miguel A; Muñoz-Fernández, M Angeles; Fresno, Manuel

    2004-12-01

    Transcriptional induction of cyclooxygenase-2 (COX-2) occurs early after T cell receptor triggering and has functional implications in inflammation. Here, we show that phosphodiesterase (PDE)-4 inhibitors block COX-2 induction and prostaglandin synthesis in activated T cells. COX-2 inhibition by PDE4 inhibitors occurs mainly at the transcriptional level. Two response elements for the nuclear factor of activated T cells (NFAT) in the COX-2 promoter were required for inhibition by these drugs. PDE4 inhibitors did not affect NFAT nuclear translocation upon T cell activation; rather they prevented NFAT binding to DNA and induction of the transactivation function of GAL4-NFAT. These effects seem to be cAMP/PKA independent as they were not mimicked by the permeable analog dBcAMP or by forskolin, neither can be reverted by the PKA inhibitors H89 or KT-5720. These results may explain some of the anti-inflammatory properties of PDE4 inhibitors through the blockade of NFAT-mediated transactivation of pro-inflammatory genes such as COX-2.

  1. Brucella melitensis cyclic di-GMP phosphodiesterase BpdA controls expression of flagellar genes.

    PubMed

    Petersen, Erik; Chaudhuri, Pallab; Gourley, Chris; Harms, Jerome; Splitter, Gary

    2011-10-01

    Brucella melitensis encounters a variety of conditions and stimuli during its life cycle--including environmental growth, intracellular infection, and extracellular dissemination--which necessitates flexibility of bacterial signaling to promote virulence. Cyclic-di-GMP is a bacterial secondary signaling molecule that plays an important role in adaptation to changing environments and altering virulence in a number of bacteria. To investigate the role of cyclic-di-GMP in B. melitensis, all 11 predicted cyclic-di-GMP-metabolizing proteins were separately deleted and the effect on virulence was determined. Three of these cyclic-di-GMP-metabolizing proteins were found to alter virulence. Deletion of the bpdA and bpdB genes resulted in attenuation of virulence of the bacterium, while deletion of the cgsB gene produced a hypervirulent strain. In a Vibrio reporter system to monitor apparent alteration in levels of cyclic-di-GMP, both BpdA and BpdB displayed a phenotype consistent with cyclic-di-GMP-specific phosphodiesterases, while CgsB displayed a cyclic-di-GMP synthase phenotype. Further analysis found that deletion of bpdA resulted in a dramatic decrease in flagellar promoter activities, and a flagellar mutant showed similar phenotypes to the bpdA and bpdB mutant strains in mouse models of infection. These data indicate a potential role for regulation of flagella in Brucella melitensis via cyclic-di-GMP.

  2. Ectonucleotide pyrophosphatase/phosphodiesterase activity in Neuro-2a neuroblastoma cells: changes in expression associated with neuronal differentiation.

    PubMed

    Gómez-Villafuertes, Rosa; Pintor, Jesús; Miras-Portugal, María Teresa; Gualix, Javier

    2014-11-01

    Neuro-2a (N2a) neuroblastoma cells display an ectoenzymatic hydrolytic activity capable of degrading diadenosine polyphosphates. The Apn A-cleaving activity has been analysed with the use of the fluorogenic compound BODIPY FL guanosine 5'-O-(3-thiotriphosphate) thioester. Hydrolysis of this dinucleotide analogue showed a hyperbolic kinetic with a Km value of 4.9 ± 1.3 μM. Diadenosine pentaphosphate, diadenosine tetraphosphate, diadenosine triphosphate, and the nucleoside monophosphate AMP behaved as an inhibitor of BODIPY FL guanosine 5'-O-(3-thiotriphosphate) thioester extracellular degradation. Ectoenzymatic activity shared the typical characteristics of the ectonucleotide pyrophosphatase/phosphodiesterase family, as hydrolysis reached maximal activity at alkaline pH and was dependent on the presence of divalent cations, being strongly inhibited by EDTA and activated by Zn(2+) ions. Both NPP1 and NPP3 isozymes are expressed in N2a cells, their expression levels substantially changing when cells differentiate into a neuronal-like phenotype. In this sense, it is relevant to point the expression pattern of the NPP3 protein, whose levels were drastically reduced in the differentiated cells, being almost completely absent after 24 h of differentiation. Enzymatic activity assays carried out with differentiated N2a cells showed that NPP1 is the main isozyme involved in the extracellular degradation of dinucleotides in these cells, this enzyme reducing its activity and changing its subcellular location following neuronal differentiation. We described the presence of an ectoenzymatic activity able to hydrolyse diadenosine polyphosphates (ApnA) in N2a cells. This activity displays biochemical features that are typical of the ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) family members, as demonstrated by the use of the fluorogenic compound BODIPY-FL-GTPγS. Both NPP1 and NPP3 ectoenzymes are expressed in N2a cells, their levels dramatically changing when cells

  3. Acidosis is a key regulator of osteoblast ecto-nucleotidase pyrophosphatase/phosphodiesterase 1 (NPP1) expression and activity.

    PubMed

    Orriss, Isabel R; Key, Michelle L; Hajjawi, Mark O R; Millán, José L; Arnett, Timothy R

    2015-12-01

    Previous work has shown that acidosis prevents bone nodule formation by osteoblasts in vitro by inhibiting mineralisation of the collagenous matrix. The ratio of phosphate (Pi ) to pyrophosphate (PPi ) in the bone microenvironment is a fundamental regulator of bone mineralisation. Both Pi and PPi , a potent inhibitor of mineralisation, are generated from extracellular nucleotides by the actions of ecto-nucleotidases. This study investigated the expression and activity of ecto-nucleotidases by osteoblasts under normal and acid conditions. We found that osteoblasts express mRNA for a number of ecto-nucleotidases including NTPdase 1-6 (ecto-nucleoside triphosphate diphosphohydrolase) and NPP1-3 (ecto-nucleotide pyrophosphatase/phosphodiesterase). The rank order of mRNA expression in differentiating rat osteoblasts (day 7) was Enpp1 > NTPdase 4 > NTPdase 6 > NTPdase 5 >  alkaline phosphatase > ecto-5-nucleotidase > Enpp3 > NTPdase 1 > NTPdase 3 > Enpp2 > NTPdase 2. Acidosis (pH 6.9) upregulated NPP1 mRNA (2.8-fold) and protein expression at all stages of osteoblast differentiation compared to physiological pH (pH 7.4); expression of other ecto-nucleotidases was unaffected. Furthermore, total NPP activity was increased up to 53% in osteoblasts cultured in acid conditions (P < 0.001). Release of ATP, one of the key substrates for NPP1, from osteoblasts, was unaffected by acidosis. Further studies showed that mineralised bone formation by osteoblasts cultured from NPP1 knockout mice was increased compared with wildtypes (2.5-fold, P < 0.001) and was partially resistant to the inhibitory effect of acidosis. These results indicate that increased NPP1 expression and activity might contribute to the decreased mineralisation observed when osteoblasts are exposed to acid conditions.

  4. Alterations of Phosphodiesterases in Adrenocortical Tumors

    PubMed Central

    Hannah-Shmouni, Fady; Faucz, Fabio R.; Stratakis, Constantine A.

    2016-01-01

    Alterations in the cyclic (c)AMP-dependent signaling pathway have been implicated in the majority of benign adrenocortical tumors (ACTs) causing Cushing syndrome (CS). Phosphodiesterases (PDEs) are enzymes that regulate cyclic nucleotide levels, including cyclic adenosine monophosphate (cAMP). Inactivating mutations and other functional variants in PDE11A and PDE8B, two cAMP-binding PDEs, predispose to ACTs. The involvement of these two genes in ACTs was initially revealed by a genome-wide association study in patients with micronodular bilateral adrenocortical hyperplasia. Thereafter, PDE11A or PDE8B genetic variants have been found in other ACTs, including macronodular adrenocortical hyperplasias and cortisol-producing adenomas. In addition, downregulation of PDE11A expression and inactivating variants of the gene have been found in hereditary and sporadic testicular germ cell tumors, as well as in prostatic cancer. PDEs confer an increased risk of ACT formation probably through, primarily, their action on cAMP levels, but other actions might be possible. In this report, we review what is known to date about PDE11A and PDE8B and their involvement in the predisposition to ACTs. PMID:27625633

  5. 2', 3'-cyclic nucleotide 3'-phosphodiesterase is expressed in dissociated rat cerebellar cells and included in the postsynaptic density fraction.

    PubMed

    Cho, Sun-Jung; Jung, Jae Seob; Jin, IngNyol; Moon, Il Soo

    2003-08-31

    We have shown by protein sequencing that the phosphotyrosine-containing 48 kDa protein band of the rat cerebellar postsynaptic density fraction (CBL-PSD) is 2', 3'-cyclic nucleotide 3'-phosphodiesterase 2 (CNP2). Immunoblot analysis indicated that both CNP1 and CNP2 isoforms are present in the CBL-PSD fraction, whereas there is little CNP2 in the forebrain (FB)-PSD fraction. Both isoforms in the CBL-PSD fraction were tyrosine-phosphorylated to a basal extent. They were efficiently dissociated from the complexes in the PSD fraction by salt, but not by non-ionic detergents such as n-octyl glucoside (OG) and Triton X-100. Immunocytochemistry of dissociated cerebellar cultures revealed patchy CNP staining in oligodendrocytes (OLs), Purkinje cells (PCs), and unidentified PSD95-positive cells, but no staining in granule cells (GCs). Our results indicate that both CNP1 and CNP2 are expressed in cerian populations of cerebellar cells in addition to OL, and that they are associated with complexes that are co-isolated with the PSD.

  6. Expression and Characterization of a Novel Glycerophosphodiester Phosphodiesterase from Pyrococcus furiosus DSM 3638 That Possesses Lysophospholipase D Activity

    PubMed Central

    Wang, Fanghua; Lai, Linhui; Liu, Yanhua; Yang, Bo; Wang, Yonghua

    2016-01-01

    Glycerophosphodiester phosphodiesterases (GDPD) are enzymes which degrade various glycerophosphodiesters to produce glycerol-3-phosphate and the corresponding alcohol moiety. Apart from this, a very interesting finding is that this enzyme could be used in the degradation of toxic organophosphorus esters, which has resulted in much attention on the biochemical and application research of GDPDs. In the present study, a novel GDPD from Pyrococcus furiosus DSM 3638 (pfGDPD) was successfully expressed in Escherichia coli and biochemically characterized. This enzyme hydrolyzed bis(p-nitrophenyl) phosphate, one substrate analogue of organophosphorus diester, with an optimal reaction temperature 55 °C and pH 8.5. The activity of pfGDPD was strongly dependent on existing of bivalent cations. It was strongly stimulated by Mn2+ ions, next was Co2+ and Ni2+ ions. Further investigations were conducted on its substrate selectivity towards different phospholipids. The results indicated that except of glycerophosphorylcholine (GPC), this enzyme also possessed lysophospholipase D activity toward both sn1-lysophosphatidylcholine (1-LPC) and sn2-lysophosphatidylcholine (2-LPC). Higher activity was found for 1-LPC than 2-LPC; however, no hydrolytic activity was found for phosphatidylcholine (PC). Molecular docking based on the 3D-modeled structure of pfGDPD was conducted in order to provide a structural foundation for the substrate selectivity. PMID:27248999

  7. Sarcoplasmic reticulum-associated cyclic adenosine 5'-monophosphate phosphodiesterase activity in normal and failing human hearts.

    PubMed Central

    Movsesian, M A; Smith, C J; Krall, J; Bristow, M R; Manganiello, V C

    1991-01-01

    Sarcoplasmic reticulum-associated cAMP phosphodiesterase activity was examined in microsomes prepared from the left ventricular myocardium of eight heart transplant recipients with end-stage idiopathic dilated cardiomyopathy and six unmatched organ donors with normal cardiac function. At cAMP concentrations less than or equal to 1.0 microM, sarcoplasmic reticulum-associated cAMP phosphodiesterase activity was functionally homogeneous. cAMP phosphodiesterase activity was inhibited competitively by cGMP (Ki = 0.031 +/- 0.008 microM) and the cilostamide derivative OPC 3911 (Ki = 0.018 +/- 0.004 microM), but was essentially insensitive to rolipram. Vmax and Km were 781.7 +/- 109.2 nmol/mg per min and 0.188 +/- 0.031 microM, respectively, in microsomes prepared from nonfailing hearts and 793.9 +/- 68.9 nmol/mg per min and 0.150 +/- 0.027 microM in microsomes prepared from failing hearts. Microsomes prepared from nonfailing and failing hearts did not differ with respect to either the ratio of cAMP phosphodiesterase activity to ATP-dependent Ca2+ accumulation activity or the sensitivity of cAMP phosphodiesterase activity to inhibition by OPC 3911. These data suggest that the diminished inotropic efficacy of phosphodiesterase inhibitors in failing human hearts does not result from changes in the level, kinetic properties, or pharmacologic sensitivity of sarcoplasmic reticulum-associated cAMP phosphodiesterase activity. PMID:1647414

  8. Selective Phosphodiesterase 4B Inhibitors: A Review

    PubMed Central

    Azam, Mohammed Afzal; Tripuraneni, Naga Srinivas

    2014-01-01

    Abstract Phosphodiesterase 4B (PDE4B) is a member of the phosphodiesterase family of proteins that plays a critical role in regulating intracellular levels of cyclic adenosine monophosphate (cAMP) by controlling its rate of degradation. It has been demonstrated that this isoform is involved in the orchestra of events which includes inflammation, schizophrenia, cancers, chronic obstructive pulmonary disease, contractility of the myocardium, and psoriatic arthritis. Phosphodiesterase 4B has constituted an interesting target for drug development. In recent years, a number of PDE4B inhibitors have been developed for their use as therapeutic agents. In this review, an up-to-date status of the inhibitors investigated for the inhibition of PDE4B has been given so that this rich source of structural information of presently known PDE4B inhibitors could be helpful in generating a selective and potent inhibitor of PDE4B. PMID:25853062

  9. Diatom acclimation to elevated CO2 via cAMP signalling and coordinated gene expression

    NASA Astrophysics Data System (ADS)

    Hennon, Gwenn M. M.; Ashworth, Justin; Groussman, Ryan D.; Berthiaume, Chris; Morales, Rhonda L.; Baliga, Nitin S.; Orellana, Mónica V.; Armbrust, E. V.

    2015-08-01

    Diatoms are responsible for ~40% of marine primary productivity, fuelling the oceanic carbon cycle and contributing to natural carbon sequestration in the deep ocean. Diatoms rely on energetically expensive carbon concentrating mechanisms (CCMs) to fix carbon efficiently at modern levels of CO2 (refs , , ). How diatoms may respond over the short and long term to rising atmospheric CO2 remains an open question. Here we use nitrate-limited chemostats to show that the model diatom Thalassiosira pseudonana rapidly responds to increasing CO2 by differentially expressing gene clusters that regulate transcription and chromosome folding, and subsequently reduces transcription of photosynthesis and respiration gene clusters under steady-state elevated CO2. These results suggest that exposure to elevated CO2 first causes a shift in regulation, and then a metabolic rearrangement. Genes in one CO2-responsive cluster included CCM and photorespiration genes that share a putative cAMP-responsive cis-regulatory sequence, implying these genes are co-regulated in response to CO2, with cAMP as an intermediate messenger. We verified cAMP-induced downregulation of CCM gene δ-CA3 in nutrient-replete diatom cultures by inhibiting the hydrolysis of cAMP. These results indicate an important role for cAMP in downregulating CCM and photorespiration genes under elevated CO2 and provide insights into mechanisms of diatom acclimation in response to climate change.

  10. Sequence and expression analysis of the gene encoding inducible cAMP early repressor in tilapia.

    PubMed

    Chen, Ming; Wang, Rui; Gan, Xi; Lei, Aiying; Li, Chao; Yu, Xiaoli; Huang, Jun; Huang, Ting; Liang, Wanwen

    2010-06-01

    Suppression subtractive hybridization library was generated by comparison of cDNA populations isolated from peripheral leukocytes of pre- and post-immunized tilapia. One cDNA sequence encoding complete inducible cAMP early repressor was obtained from the library. The sequence was characterized by the presence of the basic structure of ICER IIgamma. Expression of ICER was in the tissues of four types of tilapia was decreased after infection with Streptococcus. After immunization, expression of ICER was initially decreased and then increased after 7 days. In addition, the order for the overall expression of ICER gene after infection and the increases of ICER expression later after immunization in these four types of tilapia was positively correlated to the disease resistance and productivity of these four species of tilapia. Our results provided molecular mechanisms for the different disease resistance capability in different species of tilapia. In addition, our results also provided reference molecular marker for breeding disease resistant tilapia, cAMP responsive element modulator.

  11. Exchange factors directly activated by cAMP mediate melanocortin 4 receptor-induced gene expression

    PubMed Central

    Glas, Evi; Mückter, Harald; Gudermann, Thomas; Breit, Andreas

    2016-01-01

    Gs protein-coupled receptors regulate many vital body functions by activation of cAMP response elements (CRE) via cAMP-dependent kinase A (PKA)-mediated phosphorylation of the CRE binding protein (CREB). Melanocortin 4 receptors (MC4R) are prototypical Gs-coupled receptors that orchestrate the hypothalamic control of food-intake and metabolism. Remarkably, the significance of PKA for MC4R-induced CRE-dependent transcription in hypothalamic cells has not been rigorously interrogated yet. In two hypothalamic cell lines, we observed that blocking PKA activity had only weak or no effects on reporter gene expression. In contrast, inhibitors of exchange factors directly activated by cAMP-1/2 (EPAC-1/2) mitigated MC4R-induced CRE reporter activation and mRNA induction of the CREB-dependent genes c-fos and thyrotropin-releasing hormone. Furthermore, we provide first evidence that extracellular-regulated kinases-1/2 (ERK-1/2) activated by EPACs and not PKA are the elusive CREB kinases responsible for MC4R-induced CREB/CRE activation in hypothalamic cells. Overall, these data emphasize the pivotal role of EPACs rather than PKA in hypothalamic gene expression elicited by a prototypical Gs-coupled receptor. PMID:27612207

  12. Sensitivity of GBM cells to cAMP agonist-mediated apoptosis correlates with CD44 expression and agonist resistance with MAPK signaling

    PubMed Central

    Daniel, Paul M; Filiz, Gulay; Mantamadiotis, Theo

    2016-01-01

    In some cell types, activation of the second messenger cAMP leads to increased expression of proapoptotic Bim and subsequent cell death. We demonstrate that suppression of the cAMP pathway is a common event across many cancers and that pharmacological activation of cAMP in glioblastoma (GBM) cells leads to enhanced BIM expression and apoptosis in specific GBM cell types. We identified the MAPK signaling axis as the determinant of cAMP agonist sensitivity in GBM cells, with high MAPK activity corresponding to cAMP resistance and low activity corresponding to sensitization to cAMP-induced apoptosis. Sensitive cells were efficiently killed by cAMP agonists alone, while targeting both the cAMP and MAPK pathways in resistant GBM cells resulted in efficient apoptosis. We also show that CD44 is differentially expressed in cAMP agonist-sensitive and -resistant cells. We thus propose that CD44 may be a useful biomarker for distinguishing tumors that may be sensitive to cAMP agonists alone or cAMP agonists in combination with other pathway inhibitors. This suggests that using existing chemotherapeutic compounds in combination with existing FDA-approved cAMP agonists may fast track trials toward improved therapies for difficult-to-treat cancers, such as GBM. PMID:27906173

  13. Ascorbic acid inhibits PMP22 expression by reducing cAMP levels.

    PubMed

    Kaya, Ferdinand; Belin, Sophie; Bourgeois, Patrice; Micaleff, Joelle; Blin, Olivier; Fontés, Michel

    2007-03-01

    Charcot-Marie-Tooth [CMT] syndrome is the most common hereditary peripheral neuropathy. CMT1A, which accounts for 50% of all CMT cases, usually results from triploidy of the PMP22 gene. Preclinical trials using an animal model show that disabled mice force-fed with high doses of ascorbic acid partially recover muscular strength after a few months of treatment, and suggest that high doses of ascorbic acid repress PMP22 expression. In this study, we demonstrated that ascorbic acid represses PMP22 gene expression by acting on intracellular cAMP levels and adenylate cyclase activity. This action is dose dependent and specific to ascorbic acid, since repression is not observed after treatment with other antioxidants. The new properties of ascorbic acid are discussed, along with the implications of these findings for CMT disease treatment.

  14. Inhibin alpha gene expression in human trophoblasts is regulated by interactions between TFAP2 and cAMP signaling pathways.

    PubMed

    Depoix, Christophe L; Debiève, Frédéric; Hubinont, Corinne

    2014-11-01

    Inhibin α (Inha) gene expression is regulated, in rat granulosa cells, via a cyclic 3',5'-adenosine monophosphate (AMP)-response element (CRE) found in a region of the promoter that is homologous to the human INHA promoter. We previously found that during in vitro cytotrophoblast differentiation, human INHA gene expression was regulated by TFAP2A via association with an AP-2 site located upstream of this CRE. The aim of this study was to evaluate if the human INHA gene was also regulated by cAMP in trophoblasts, and to investigate the possible crosstalk between TFAP2 and cAMP signaling pathways in the regulation of INHA gene expression. Treatment with cAMP or forskolin increased INHA mRNA expression by 7- and 2-fold in primary cytotrophoblasts and choriocarcinoma-derived BeWo cells, respectively. Treatment with the protein kinase A inhibitor H-89 reduced forskolin-induced luciferase activity by ∼40% in BeWo cells transfected with an INHA promoter-driven luciferase reporter vector. TFAP2 overexpression increased basal luciferase activity, whereas the dominant repressor KCREB abolished it. Surprisingly, mutation of the CRE also eliminated the TFAP2-induced transcription, although TFAP2 overexpression was still able to increase forskolin-induced luciferase activity when the AP-2 binding site, but not the CRE site, was mutated. Thus, INHA gene expression is upregulated by cAMP via CRE in human trophoblasts, and TFAP2 regulates this expression by interacting with CRE.

  15. Levodopa-induced dyskinesias are associated with transient down-regulation of cAMP and cGMP in the caudate-putamen of hemiparkinsonian rats: reduced synthesis or increased catabolism?

    PubMed

    Sancesario, Giuseppe; Morrone, Luigi Antonio; D'Angelo, Vincenza; Castelli, Valentina; Ferrazzoli, Davide; Sica, Francesco; Martorana, Alessandro; Sorge, Roberto; Cavaliere, Federica; Bernardi, Giorgio; Giorgi, Mauro

    2014-12-01

    Second messenger cAMP and cGMP represent a key step in the action of dopamine that modulates directly or indirectly their synthesis. We aimed to verify whether levodopa-induced dyskinesias are associated with changes of the time course of levodopa/dopamine stimulated cAMP and cGMP levels, and/or with changes of their catabolism by phosphodiesterase activity in rats with experimental hemiparkinsonism. Microdialysis and tissue homogenates of the striatal tissues demonstrated that extracellular and intracellular cAMP/cGMP levels were lower in dyskinetic animals during the increasing phase of dyskinesias compared to eukinetic animals, but cAMP/cGMP levels increased in dyskinetic animals during the phase of decreasing and extinction of dyskinesias. Dyskinesias and the abnormal lowering of striatal cGMP and cAMP after levodopa were prevented by pretreatment with the multipotent drug amantadine, outlining the inverse relationship of cAMP/cGMP to dyskinesias. Moreover, dyskinetic animals showed higher striatal hydrolyzing cGMP-phosphodiesterase but not hydrolyzing cAMP-phosphodiesterase activity, suggesting that low cGMP but not cAMP levels could be due to increased catabolism. However, expressions of isozyme phosphodiesterase-1B and -10A highly and specifically located in the basal ganglia were not changed after levodopa in dyskinetic and eukinetic animals: accordingly, selective inhibitors of phosphodiesterase-1B and -10A were ineffective on levodopa dyskinesias. Therefore, the isozyme(s) expressing higher cGMP-phosphodiesterase activity in the striatum of dyskinetic animal should be determined. These observations suggest that dopamine-mediated processes of synthesis and/or degradation of cAMP/cGMP could be acutely impaired in levodopa dyskinesias, opening new ways to understanding physiopathology and treatment.

  16. In vivo model with targeted cAMP biosensor reveals changes in receptor-microdomain communication in cardiac disease.

    PubMed

    Sprenger, Julia U; Perera, Ruwan K; Steinbrecher, Julia H; Lehnart, Stephan E; Maier, Lars S; Hasenfuss, Gerd; Nikolaev, Viacheslav O

    2015-04-28

    3',5'-cyclic adenosine monophosphate (cAMP) is an ubiquitous second messenger that regulates physiological functions by acting in distinct subcellular microdomains. Although several targeted cAMP biosensors are developed and used in single cells, it is unclear whether such biosensors can be successfully applied in vivo, especially in the context of disease. Here, we describe a transgenic mouse model expressing a targeted cAMP sensor and analyse microdomain-specific second messenger dynamics in the vicinity of the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA). We demonstrate the biocompatibility of this targeted sensor and its potential for real-time monitoring of compartmentalized cAMP signalling in adult cardiomyocytes isolated from a healthy mouse heart and from an in vivo cardiac disease model. In particular, we uncover the existence of a phosphodiesterase-dependent receptor-microdomain communication, which is affected in hypertrophy, resulting in reduced β-adrenergic receptor-cAMP signalling to SERCA.

  17. Aip regulates cAMP signalling and GH secretion in GH3 cells.

    PubMed

    Formosa, R; Xuereb-Anastasi, A; Vassallo, J

    2013-08-01

    Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene have been linked to predisposition to pituitary adenomas. However, the mechanism by which this occurs remains unknown. AIP interacts with a number of interesting proteins, including members of the cAMP signalling pathway that has been shown to be consistently altered in pituitary tumours. The functional role of Aip was investigated using both over-expression and knock down of Aip in GH3 cells. cAMP signalling and its downstream effectors, including GH secretion, were then investigated. cAMP signalling was analysed using cAMP assays, cAMP-response element-promoter luciferase reporter assays, real-time PCR and finally secreted GH quantification. Over-expression of wild-type (WT)-Aip reduced forskolin-induced cAMP signalling at the total cAMP level, luciferase reporter activity and target gene expression, when compared with empty vector and the non-functional R304X mutant. Additionally, GH secretion was reduced in WT-Aip over-expressing GH3 cells treated with forskolin. Knock down of endogenous Aip resulted in increased cAMP signalling but a decrease in GH secretion was also noted. Inhibition of phosphodiesterase activity using general and selective inhibitors did not completely ablate the effect of Aip on forskolin-augmented cAMP signalling. A mechanism by which Aip acts as a tumour suppressor, by maintaining a low cAMP signalling and concentration, is suggested. Mutations of Aip render the protein incapable of such activity. This effect appears not to be mediated by the AIP-PDE interaction, suggesting the involvement of other interacting partners in mediating this outcome.

  18. cAMP analogs and their metabolites enhance TREK-1 mRNA and K+ current expression in adrenocortical cells.

    PubMed

    Enyeart, Judith A; Liu, Haiyan; Enyeart, John J

    2010-03-01

    bTREK-1 K(+) channels set the resting membrane potential of bovine adrenal zona fasciculata (AZF) cells and function pivotally in the physiology of cortisol secretion. Adrenocorticotropic hormone controls the function and expression of bTREK-1 channels through signaling mechanisms that may involve cAMP and downstream effectors including protein kinase A (PKA) and exchange protein 2 directly activated by cAMP (Epac2). Using patch-clamp and Northern blot analysis, we explored the regulation of bTREK-1 mRNA and K(+) current expression by cAMP analogs and several of their putative metabolites in bovine AZF cells. At concentrations sufficient to activate both PKA and Epac2, 8-bromoadenosine-cAMP enhanced the expression of both bTREK-1 mRNA and K(+) current. N(6)-Benzoyladenosine-cAMP, which activates PKA but not Epac, also enhanced the expression of bTREK-1 mRNA and K(+) current measured at times from 24 to 96 h. An Epac-selective cAMP analog, 8-(4-chlorophenylthio)-2'-O-methyl-cAMP (8CPT-2'-OMe-cAMP), potently stimulated bTREK-1 mRNA and K(+) current expression, whereas the nonhydrolyzable Epac activator 8-(4-chlorophenylthio)-2'-O-methyl-cAMP, Sp-isomer was ineffective. Metabolites of 8CPT-2'-OMe-cAMP, including 8-(4-chlorophenylthio)-2'-O-methyladenosine-5'-O-monophosphate and 8CPT-2'-OMe-adenosine, promoted the expression of bTREK-1 transcripts and ion current with a temporal pattern, potency, and effectiveness resembling that of the parent compound. Likewise, at low concentrations, 8-(4-chlorophenylthio)-cAMP (8CPT-cAMP; 30 microM) but not its nonhydrolyzable analog 8-(4-chlorophenylthio)-cAMP, Sp-isomer, enhanced the expression of bTREK-1 mRNA and current. 8CPT-cAMP metabolites, including 8CPT-adenosine and 8CPT-adenine, also increased bTREK-1 expression. These results indicate that cAMP increases the expression of bTREK-1 mRNA and K(+) current through a cAMP-dependent but Epac2-independent mechanism. They further demonstrate that one or more metabolites of 8

  19. Role of phosphodiesterase and adenylate cyclase isozymes in murine colonic glucagon-like peptide 1 secreting cells

    PubMed Central

    Friedlander, Ronn S; Moss, Catherine E; Mace, Jessica; Parker, Helen E; Tolhurst, Gwen; Habib, Abdella M; Wachten, Sebastian; Cooper, Dermot M; Gribble, Fiona M; Reimann, Frank

    2011-01-01

    BACKGROUND AND PURPOSE Glucagon-like peptide-1 (GLP-1) is secreted from enteroendocrine L-cells after food intake. Increasing GLP-1 signalling either through inhibition of the GLP-1 degrading enzyme dipeptidyl-peptidase IV or injection of GLP-1-mimetics has recently been successfully introduced for the treatment of type 2 diabetes. Boosting secretion from the L-cell has so far not been exploited, due to our incomplete understanding of L-cell physiology. Elevation of cyclic adenosine monophosphate (cAMP) has been shown to be a strong stimulus for GLP-1 secretion and here we investigate the activities of adenylate cyclase (AC) and phosphodiesterase (PDE) isozymes likely to shape cAMP responses in L-cells. EXPERIMENTAL APPROACH Expression of AC and PDE isoforms was quantified by RT-PCR. Single cell responses to stimulation or inhibition of AC and PDE isoforms were monitored with real-time cAMP probes. GLP-1 secretion was assessed by elisa. KEY RESULTS Quantitative PCR identified expression of protein kinase C- and Ca2+-activated ACs, corresponding with phorbolester and cytosolic Ca2+-stimulated cAMP elevation. Inhibition of PDE2, 3 and 4 were found to stimulate GLP-1 secretion from murine L-cells in primary culture. This corresponded with cAMP elevations monitored with a plasma membrane targeted cAMP probe. Inhibition of PDE3 but not PDE2 was further shown to prevent GLP-1 secretion in response to guanylin, a peptide secreted into the gut lumen, which had not previously been implicated in L-cell secretion. CONCLUSIONS AND IMPLICATIONS Our results reveal several mechanisms shaping cAMP responses in GLP-1 secreting cells, with some of the molecular components specifically expressed in L-cells when compared with their epithelial neighbours, thus opening new strategies for targeting these cells therapeutically. PMID:21054345

  20. C(2)-ceramide influences the expression and insulin-mediated regulation of cyclic nucleotide phosphodiesterase 3B and lipolysis in 3T3-L1 adipocytes.

    PubMed

    Mei, Jie; Holst, Lena Stenson; Landström, Tova Rahn; Holm, Cecilia; Brindley, David; Manganiello, Vincent; Degerman, Eva

    2002-03-01

    Cyclic nucleotide phosphodiesterase (PDE) 3B plays an important role in the antilipolytic action of insulin and, thereby, the release of fatty acids from adipocytes. Increased concentrations of circulating fatty acids as a result of elevated or unrestrained lipolysis cause insulin resistance. The lipolytic action of tumor necrosis factor (TNF)-alpha is thought to be one of the mechanisms by which TNF-alpha induces insulin resistance. Ceramide is the suggested second messenger of TNF-alpha action, and in this study, we used 3T3-L1 adipocytes to investigate the effects of C(2)-ceramide (a short-chain ceramide analog) on the expression and regulation of PDE3B and lipolysis. Incubation of adipocytes with 100 micromol/l C(2)-ceramide (N-acetyl-sphingosine) resulted in a time-dependent decrease of PDE3B activity, accompanied by decreased PDE3B protein expression. C(2)-ceramide, in a time- and dose-dependent manner, stimulated lipolysis, an effect that was blocked by H-89, an inhibitor of protein kinase A. These ceramide effects were prevented by 20 micromol/l troglitazone, an antidiabetic drug. In addition to downregulation of PDE3B, the antilipolytic action of insulin was decreased by ceramide treatment. These results, together with data from other studies on PDE3B and lipolysis in diabetic humans and animals, suggest a novel pathway by which ceramide induces insulin resistance. Furthermore, PDE3B is demonstrated to be a target for troglitazone action in adipocytes.

  1. Lesbian camp: An unearthing.

    PubMed

    Nielsen, Elly-Jean

    2016-01-01

    Camp-a sensibility, a style, and a form of artistic self-expression-is an elusive concept said to be in the eye of the beholder. To refute Susan Sontag's ( 1966 ) claims that camp is apolitical and not especially homosexual, a number of recent scholarly works have been geared toward revealing camp's fundamental gayness. With the odd footnote aside, lesbian camp has been collapsed into the category of gay male camp, if not eclipsed entirely. Despite the negligible efforts made to legitimize lesbian camp, there are numerous salient cultural examples one might draw on to illustrate, typify, and substantiate a lesbian camp sensibility. I lay the ground work for this scholarly exercise by outlining various definitions and critiques of camp, and by discussing its history and application to queer theory. Then, to unveil lesbian camp, three non-mutually exclusive categories are discussed: classic, erotic, and radical. By gathering various strands of inquiry, and various textual examples (e.g., photography, artistic performances, and literary tropes), this article attempts to reach a more inclusive and nuanced understanding of lesbian camp.

  2. Identification and Characterization of a Novel Phosphodiesterase from the Metagenome of an Indian Coalbed

    PubMed Central

    Singh, Durgesh Narain; Gupta, Ankush; Singh, Vijay Shankar; Mishra, Rajeev; Kateriya, Suneel; Tripathi, Anil Kumar

    2015-01-01

    Phosphoesterases are involved in the degradation of organophosphorus compounds. Although phosphomonoesterases and phosphotriesterases have been studied in detail, studies on phosphodiesterases are rather limited. In our search to find novel phosphodiesterases using metagenomic approach, we cloned a gene encoding a putative phosphodiesterase (PdeM) from the metagenome of the formation water collected from an Indian coal bed. Bioinformatic analysis showed that PdeM sequence possessed the characteristic signature motifs of the class III phosphodiesterases and phylogenetic study of PdeM enabled us to identify three distinct subclasses (A, B, and C) within class III phosphodiesterases, PdeM clustering in new subclass IIIB. Bioinformatic, biochemical and biophysical characterization of PdeM further revealed some of the characteristic features of the phosphodiesterases belonging to newly described subclass IIIB. PdeM is a monomer of 29.3 kDa, which exhibits optimum activity at 25°C and pH 8.5, but low affinity for bis(pNPP) as well as pNPPP. The recombinant PdeM possessed phosphodiesterase, phosphonate-ester hydrolase and nuclease activity. It lacked phosphomonoesterase, phosphotriesterase, and RNAse activities. Overexpression of PdeM in E.coli neither affected catabolite respression nor did the recombinant protein hydrolyzed cAMP in vitro, indicating its inability to hydrolyze cAMP. Although Mn2+ was required for the activity of PdeM, but addition of metals (Mn2+ or Fe3+) did not induce oligomerization. Further increase in concentration of Mn2+ upto 3 mM, increased α-helical content as well as the phosphodiesterase activity. Structural comparison of PdeM with its homologs showed that it lacked critical residues required for dimerization, cAMP hydrolysis, and for the high affinity binding of bis(pNPP). PdeM, thus, is a novel representative of new subclass of class III phosphodiesterases. PMID:25658120

  3. Atrazine acts as an endocrine disrupter by inhibiting cAMP-specific phosphodiesterase-4

    SciTech Connect

    Kucka, Marek; Pogrmic-Majkic, Kristina; Fa, Svetlana; Stojilkovic, Stanko S.; Kovacevic, Radmila

    2012-11-15

    Atrazine, one of the most commonly used herbicides worldwide, acts as an endocrine disruptor, but the mechanism of its action has not been characterized. In this study, we show that atrazine rapidly increases cAMP levels in cultured rat pituitary and testicular Leydig cells in a concentration-dependent manner, but less effectively than 3-isobutyl-1-methylxanthine, a competitive non-specific inhibitor of phosphodiesterases (PDEs). In forskolin (an activator of adenylyl cyclase)- and probenecid (an inhibitor of cyclic nucleotide transporters)-treated cells, but not in 3-isobutyl-1-methylxanthine-treated cells, atrazine further increased cAMP levels, indicating that inhibition of PDEs accounts for accumulation of cAMP. In contrast to cAMP, atrazine did not alter cGMP levels, further indicating that it inhibits cAMP-specific PDEs. Atrazine-induced changes in cAMP levels were sufficient to stimulate prolactin release in pituitary cells and androgen production in Leydig cells, indicating that it acts as an endocrine disrupter both in cells that secrete by exocytosis of prestored hormones and in cells that secrete by de novo hormone synthesis. Rolipram abolished the stimulatory effect of atrazine on cAMP release in both cell types, suggesting that it acts as an inhibitor of PDE4s, isoforms whose mRNA transcripts dominate in pituitary and Leydig cells together with mRNA for PDE8A. In contrast, immortalized lacto-somatotrophs showed low expression of these mRNA transcripts and several fold higher cAMP levels compared to normal pituitary cells, and atrazine was unable to further increase cAMP levels. These results indicate that atrazine acts as a general endocrine disrupter by inhibiting cAMP-specific PDE4s. -- Highlights: ► Atrazine stimulates cAMP accumulation in pituitary and Leydig cells. ► Atrazine also stimulates PRL and androgens secretion. ► Stimulatory effects of atrazine were abolished in cells with IBMX-inhibited PDEs. ► Atrazine specificity toward c

  4. Differential expression of L- and S-MAG upon cAMP stimulated differentiation in oligodendroglial cells.

    PubMed

    Erb, M; Steck, A J; Nave, K A; Schaeren-Wiemers, N

    2003-02-01

    Myelin-associated glycoprotein (MAG), an immunoglobulin-like cell signaling protein involved in axon-glial interactions, displays two intracellular C-termini as a result of alternative mRNA splicing. During brain development, the two MAG mRNAs that encode L-MAG and S-MAG differ in their relative abundance. We have investigated the differential expression of L- and S-MAG upon cAMP treatment in the oligodendroglial cell line Oli-neu, a cell line able to differentiate in vitro. We have engineered GFP and VSVG fusions by small insertions into the alternatively spliced exons of the cloned MAG gene and reintroduced them into Oli-neu cells. The individually tagged MAG isoforms were expressed under the control of the MAG promoter and regulatory region. In this system, L-MAG was the predominant isoform before the stimulation of cells with cAMP, whereas upon cAMP treatment the S-MAG isoform was predominantly expressed in cells with a high degree of morphological differentiation. We suggest that the regulation of the MAG alternative splicing and the morphological differentiation in oligodendrocytes are controlled both by the same cAMP-responsive differentiation step.

  5. Two Phosphodiesterase Genes, PDEL and PDEH, Regulate Development and Pathogenicity by Modulating Intracellular Cyclic AMP Levels in Magnaporthe oryzae

    PubMed Central

    Zhang, Haifeng; Liu, Kaiyue; Zhang, Xing; Tang, Wei; Wang, Jiansheng; Guo, Min; Zhao, Qian; Zheng, Xiaobo; Wang, Ping; Zhang, Zhengguang

    2011-01-01

    Cyclic AMP (cAMP) signaling plays an important role in regulating multiple cellular responses, such as growth, morphogenesis, and/or pathogenicity of eukaryotic organisms such as fungi. As a second messenger, cAMP is important in the activation of downstream effector molecules. The balance of intracellular cAMP levels depends on biosynthesis by adenylyl cyclases (ACs) and hydrolysis by cAMP phosphodiesterases (PDEases). The rice blast fungus Magnaporthe oryzae contains a high-affinity (PdeH/Pde2) and a low-affinity (PdeL/Pde1) PDEases, and a previous study showed that PdeH has a major role in asexual differentiation and pathogenicity. Here, we show that PdeL is required for asexual development and conidial morphology, and it also plays a minor role in regulating cAMP signaling. This is in contrast to PdeH whose mutation resulted in major defects in conidial morphology, cell wall integrity, and surface hydrophobicity, as well as a significant reduction in pathogenicity. Consistent with both PdeH and PdeL functioning in cAMP signaling, disruption of PDEH only partially rescued the mutant phenotype of ΔmagB and Δpka1. Further studies suggest that PdeH might function through a feedback mechanism to regulate the expression of pathogenicity factor Mpg1 during surface hydrophobicity and pathogenic development. Moreover, microarray data revealed new insights into the underlying cAMP regulatory mechanisms that may help to identify potential pathogenicity factors for the development of new disease management strategies. PMID:21386978

  6. Overexpression of phosphodiesterase-4 subtypes involved in surgery-induced neuroinflammation and cognitive dysfunction in mice.

    PubMed

    Wang, Wei; Zhang, Xiao-Ying; Feng, Ze-Guo; Wang, Dong-Xin; Zhang, Hao; Sui, Bo; Zhang, Yong-Yi; Zhao, Wei-Xing; Fu, Qiang; Xu, Zhi-Peng; Mi, Wei-Dong

    2017-02-21

    Postoperative cognitive dysfunction (POCD) is characterized by cognitive impairments in patients after surgery. Hippocampal neuroinflammation induced by surgery is highly associated with POCD. Phosphodiesterase-4 (PDE4) is an enzyme that specifically hydrolyses cyclic adenosine monophosphate (cAMP), which plays an important role during neuroinflammation and the process of learning and memory. However, the role of PDE4 in the development of POCD remains unclear. Male 14-month-old C57BL/6 mice received carotid artery exposure to mimic POCD. First, we evaluated cognitive performance by a Morris water maze (MWM) and fear conditioning system (FCS) test after surgery. The expression of PDE4 subtypes, pro-inflammatory cytokines, p-CREB and PSD95 as well as cAMP levels were investigated. Then, we used rolipram, a PDE4 inhibitor, to block the effects of PDE4. The cognitive performance of the mice and the expression of PDE4 subtypes, pro-inflammatory cytokines, p-CREB and PSD95 as well as cAMP levels were examined again. Mice displayed learning and memory impairment, overexpression of PDE4B and PDE4D, elevation of pro-inflammatory cytokines, and reduction in the expression of p-CREB, PSD95 and cAMP levels after surgery. The expression of PDE4B and PDE4D in the hippocampus decreased following blocking of PDE4 by rolipram. Meanwhile, rolipram attenuated the cognitive impairment and the elevation of pro-inflammatory cytokines induced by surgery. Moreover, rolipram reversed the reduction of p-CREB and PSD95. These results indicate that PDE4 subtype overexpression may be involved in the development of surgery-induced cognitive dysfunction in mice.

  7. Antenatal Maternally-Administered Phosphodiesterase Type 5 Inhibitors Normalize eNOS Expression in the Fetal Lamb Model of Congenital Diaphragmatic Hernia

    PubMed Central

    Shue, Eveline H; Schecter, Samuel C.; Gong, Wenhui; Etemadi, Mozziyar; Johengen, Michael; Iqbal, Corey; Derderian, S. Christopher; Oishi, Peter; Fineman, Jeffrey R.; Miniati, Doug

    2013-01-01

    Purpose Pulmonary hypertension (pHTN), a main determinant of survival in congenital diaphragmatic hernia (CDH), results from in utero vascular remodeling. Phosphodiesterase type 5 (PDE5) inhibitors have never been used antenatally to treat pHTN. The purpose of this study is to determine if antenatal PDE5 inhibitors can prevent pHTN in the fetal lamb model of CDH. Methods CDH were created in pregnant ewes. Postoperatively, pregnant ewes received oral placebo or tadalafil, a PDE5 inhibitor, until delivery. Near term gestation, lambs underwent resuscitations, and lung tissue was snap frozen for protein analysis. Results Mean cGMP levels were 0.53±0.11 in placebo-treated fetal lambs and 1.73±0.21 in tadalafil-treated fetal lambs (p=0.002). Normalized expression of eNOS was 82±12% in Normal-Placebo, 61±5% in CDH-Placebo, 116±6% in Normal-Tadalafil, and 86±8% in CDH-Tadalafil lambs. Normalized expression of β-sGC was 105±15% in Normal-Placebo, 82±3% in CDH-Placebo, 158±16% in Normal-Tadalafil, and 86±8% in CDH-Tadalafil lambs. Endothelial NOS and β-sGC were significantly decreased in CDH (p = 0.0007 and 0.01 for eNOS and β-sGC, respectively), and tadalafil significantly increased eNOS expression (p = 0.0002). Conclusions PDE5 inhibitors can cross the placental barrier. β-sGC and eNOS are downregulated in fetal lambs with CDH. Antenatal PDE5 inhibitors normalize eNOS and may prevent in utero vascular remodeling in CDH. PMID:24439578

  8. cGMP Signaling, Phosphodiesterases and Major Depressive Disorder

    PubMed Central

    Reierson, Gillian W; Guo, Shuyu; Mastronardi, Claudio; Licinio, Julio; Wong, Ma-Li

    2011-01-01

    Deficits in neuroplasticity are hypothesized to underlie the pathophysiology of major depressive disorder (MDD): the effectiveness of antidepressants is thought to be related to the normalization of disrupted synaptic transmission and neurogenesis. The cyclic adenosine monophosphate (cAMP) signaling cascade has received considerable attention for its role in neuroplasticity and MDD. However components of a closely related pathway, the cyclic guanosine monophosphate (cGMP) have been studied with much lower intensity, even though this signaling transduction cascade is also expressed in the brain and the activity of this pathway has been implicated in learning and memory processes. Cyclic GMP acts as a second messenger; it amplifies signals received at postsynaptic receptors and activates downstream effector molecules resulting in gene expression changes and neuronal responses. Phosphodiesterase (PDE) enzymes degrade cGMP into 5’GMP and therefore they are involved in the regulation of intracellular levels of cGMP. Here we review a growing body of evidence suggesting that the cGMP signaling cascade warrants further investigation for its involvement in MDD and antidepressant action. PMID:22654729

  9. Eviprostat activates cAMP signaling pathway and suppresses bladder smooth muscle cell proliferation.

    PubMed

    Li, Kai; Yao, Jian; Chi, Yuan; Sawada, Norifumi; Araki, Isao; Kitamura, Masanori; Takeda, Masayuki

    2013-06-06

    Eviprostat is a popular phytotherapeutic agent for the treatment of lower urinary tract symptoms (LUTS). At present, the signaling mechanisms underlying its therapeutic effects are still poorly understood. Given that cAMP has been reported to suppress cell hyperplasia and hypertrophy in various pathological situations, we asked whether the effect of Eviprostat could be ascribed to the activation of the cAMP signaling pathway. In the study, exposure of cAMP response element (CRE)-secreted alkaline phosphatase (SEAP) (CRE-SEAP)-reporter cells to Eviprostat elevated SEAP secretion, which was associated with an increased phosphorylation of vasodilator-stimulated phosphoprotein (VASP) and cAMP-response element-binding protein (CREB), as well as enhanced expression of CRE-regulated protein connexin43, indicating an activation of the cAMP signaling pathway. Consistent with these observations, Eviprostat-induced expression of Cx43 was abolished in the presence of adenylyl cyclase inhibitor SQ22536 or PKA inhibitor H89, whereas it was mimicked by adenylyl cyclase activator, forskolin. Further analysis demonstrated that Eviprostat significantly potentiated the effect of phosphodiesterase 3 (PDE3) inhibitor, but not that of PDE4 inhibitor, on CRE activation. Moreover, Eviprostat suppressed PDGF-induced activation of ERK and Akt and inhibited cell proliferation and hillock formation in both mesangial cells and bladder smooth muscle cells. Collectively, activation of the cAMP signaling pathway could be an important mechanism by which Eviprostat exerts its therapeutic effects for LUTS.

  10. Archaeology Camp.

    ERIC Educational Resources Information Center

    White, John R.

    1984-01-01

    A summer camp for gifted youth (13-16 years old) featured two field archaeology sessions in which students participated in excavation and field trips to nearby archaeological sites along with traditional camp activities. (CL)

  11. Summer Camp.

    ERIC Educational Resources Information Center

    Pfisterer, Bill

    About 50 participants and 8 supervisors attended the Summer Camp. Visitors were encouraged and parents often came to see what their kids were doing. Before arriving at camp, the students learned how important balancing the supplies was when loading the boats. On the way to camp, students studied the: (1) landmarks so that they could find their way…

  12. Summer Camp.

    ERIC Educational Resources Information Center

    Burns, Maxine; And Others

    Government regulation of children's summer camps, particularly involving health and safety standards, is discussed in a series of brief interviews with camp directors and representatives of camp associations. Transcribed from the National Public Radio weekly broadcast, "Options in Education," the program includes a lengthy montage of…

  13. Preliminary study on the relationship between cAMP level and gsp expression in cultured human pituitary somatotrophinomas.

    PubMed

    Lei, T; Liu, Q; Li, L; Zhang, L; Shu, K; Xue, D

    2000-01-01

    In order to investigate the relationship between abnormal intracellular signal transduction and tumorgenesis of human pituitary somatotrophinomas, the effects of protein kinase A (PKA)-dependent growth hormone (GH) releasing hormone (GHRH) and protein kinase C (PKC)-dependent GH-releasing peptide (GHRP-6) on cAMP production were observed by using cell culture and biochemical methods, and the expression of the gsp oncogene was detected by using PCR and direct sequence assay methods in 11 patients with human pituitary somatotrophinomas. It was found that GHRP-6 exerted significant stimulatory effect on cAMP production by 2 gsp-positive tumors and no effect on the gsp-negative tumors. GHRP-6 could enhance the stimulation of cAMP production induced by GHRH in tumor without gsp oncogenes. It was suggested that both GHRH and GHRP-6 exert identical effects on human pituitary soamtotrophinomas, which was contributed to the cross-talk between the two intracellular signal transduction pathways in pituitary cells.

  14. UCR1C is a novel activator of phosphodiesterase 4 (PDE4) long isoforms and attenuates cardiomyocyte hypertrophy

    PubMed Central

    Wang, Li; Burmeister, Brian T.; Johnson, Keven R.; Baillie, George S.; Karginov, Andrei V.; Skidgel, Randal A.; O’Bryan, John P.; Carnegie, Graeme K.

    2015-01-01

    Hypertrophy increases the risk of heart failure and arrhythmia. Prevention or reversal of the maladaptive hypertrophic phenotype has thus been proposed to treat heart failure. Chronic β-adrenergic receptor (β-AR) stimulation induces cardiomyocyte hypertrophy by elevating 3′, 5′-cyclic adenosine monophosphate (cAMP) levels and activating downstream effectors such protein kinase A (PKA). Conversely, hydrolysis of cAMP by phosphodiesterases (PDEs) spatiotemporally restricts cAMP signaling. Here, we demonstrate that PDE4, but not PDE3, is critical in regulating cardiomyocyte hypertrophy, and may represent a potential target for preventing maladaptive hypertrophy. We identify a sequence within the upstream conserved region 1 of PDE4D, termed UCR1C, as a novel activator of PDE4 long isoforms. UCR1C activates PDE4 in complex with A-Kinase anchoring protein (AKAP)-Lbc resulting in decreased PKA signaling facilitated by AKAP-Lbc. Expression of UCR1C in cardiomyocytes inhibits hypertrophy in response to chronic β-AR stimulation. This effect is partially due to inhibition of nuclear PKA activity, which decreases phosphorylation of the transcription factor cAMP response element-binding protein (CREB). In conclusion, PDE4 activation by UCR1C attenuates cardiomyocyte hypertrophy by specifically inhibiting nuclear PKA activity. PMID:25683917

  15. Cyclic Nucleotide Phosphodiesterases: important signaling modulators and therapeutic targets

    PubMed Central

    Ahmad, Faiyaz; Murata, Taku; Simizu, Kasumi; Degerman, Eva; Maurice, Donald; Manganiello, Vincent

    2014-01-01

    By catalyzing hydrolysis of cAMP and cGMP, cyclic nucleotide phosphodiesterases are critical regulators of their intracellular concentrations and their biological effects. Since these intracellular second messengers control many cellular homeostatic processes, dysregulation of their signals and signaling pathways initiate or modulate pathophysiological pathways related to various disease states, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication, chronic obstructive pulmonary disease, and psoriasis. Alterations in expression of PDEs and PDE-gene mutations (especially mutations in PDE6, PDE8B, PDE11A and PDE4) have been implicated in various diseases and cancer pathologies. PDEs also play important role in formation and function of multi-molecular signaling/regulatory complexes called signalosomes. At specific intracellular locations, individual PDEs, together with pathway-specific signaling molecules, regulators, and effectors, are incorporated into specific signalosomes, where they facilitate and regulate compartmentalization of cyclic nucleotide signaling pathways and specific cellular functions. Currently, only a limited number of PDE inhibitors (PDE3, PDE4, PDE5 inhibitors) are used in clinical practice. Future paths to novel drug discovery include the crystal structure-based design approach, which has resulted in generation of more effective family-selective inhibitors, as well as burgeoning development of strategies to alter compartmentalized cyclic nucleotide signaling pathways by selectively targeting individual PDEs and their signalosome partners. PMID:25056711

  16. Phosphodiesterase sequence variants may predispose to prostate cancer

    PubMed Central

    de Alexandre, Rodrigo Bertollo; Horvath, Anelia; Szarek, Eva; Manning, Allison D.; Leal, Leticia Ferro; Kardauke, Fabio; Epstein, Jonathan A.; Carraro, Dirce Maria; Soares, Fernando Augusto; Apanasovich, Tatiyana; Stratakis, Constantine A.; Faucz, Fabio Rueda

    2015-01-01

    We hypothesized that mutations that inactivate phosphodiesterase (PDE) activity and lead to increased cyclic AMP (cAMP) and cyclic GMP (cGMP) levels may be associated with prostate cancer (PCa). We sequenced the entire PDE coding sequences in the DNA of 16 biopsy samples from PCa patients. Novel mutations were confirmed in the somatic or germline state by Sanger sequencing. Data were then compared to the 1000 Genome Project. PDE, CREB and pCREB protein expression was also studied in all samples, in both normal and abnormal tissue, by immunofluorescence. We identified 3 previously described PDE sequence variants that were significantly higher in PCa. Four novel sequence variations, one each in the PDE4B, PDE6C, PDE7B and PDE10A genes, respectively, were also found in the PCa samples. Interestingly, PDE10A and PDE4B novel variants that were present in 19% and 6% of the patients, respectively, were found in the tumor tissue only. In patients carrying PDE defects, there was pCREB accumulation (p<0.001), and an increase of the pCREB/CREB ratio (patients 0.97± 0.03; controls 0.52± 0.03; p-value < 0.001) by immunohistochemical analysis. We conclude that PDE sequence variants may play a role in the predisposition and/or progression to PCa at the germline and/or somatic state, respectively. Larger such studies are needed to confirm these findings. PMID:25979379

  17. Cyclic 3′,5′-Adenosine Monophosphate Phosphodiesterase of Escherichia coli

    PubMed Central

    Nielsen, L. D.; Monard, D.; Rickenberg, H. V.

    1973-01-01

    The cyclic 3′,5′-adenosine monophosphate (c-AMP) phosphodiesterase from Escherichia coli has been partially purified. The enzyme has an apparent molecular weight of 30,000, a Michaelis constant of 0.5 mM c-AMP, and a pH optimum of 7. The partially purified enzyme requires for activity the presence of a reducing compound and of either iron or a protein which seemingly acts as iron carrier. PMID:4355491

  18. Phosphodiesterase 2 negatively regulates adenosine-induced transcription of the tyrosine hydroxylase gene in PC12 rat pheochromocytoma cells.

    PubMed

    Makuch, Edyta; Kuropatwa, Marianna; Kurowska, Ewa; Ciekot, Jaroslaw; Klopotowska, Dagmara; Matuszyk, Janusz

    2014-07-05

    Adenosine induces expression of the tyrosine hydroxylase (TH) gene in PC12 cells. However, it is suggested that atrial natriuretic peptide (ANP) inhibits expression of this gene. Using real-time PCR and luciferase reporter assays we found that ANP significantly decreases the adenosine-induced transcription of the TH gene. Results of measurements of cyclic nucleotide concentrations indicated that ANP-induced accumulation of cGMP inhibits the adenosine-induced increase in cAMP level. Using selective phosphodiesterase 2 (PDE2) inhibitors and a synthetic cGMP analog activating PDE2, we found that PDE2 is involved in coupling the ANP-triggered signal to the cAMP metabolism. We have established that ANP-induced elevated levels of cGMP as well as cGMP analog stimulate hydrolytic activity of PDE2, leading to inhibition of adenosine-induced transcription of the TH gene. We conclude that ANP mediates negative regulation of TH gene expression via stimulation of PDE2-dependent cAMP breakdown in PC12 cells.

  19. Identification and Localization of the Cyclic Nucleotide Phosphodiesterase 10A in Bovine Testis and Mature Spermatozoa

    PubMed Central

    Goupil, Serge; Maréchal, Loïze; El Hajj, Hassan; Tremblay, Marie-Ève; Richard, François J.

    2016-01-01

    In mammals, adenosine 3’, 5’-cyclic monophosphate (cAMP) is known to play highly important roles in sperm motility and acrosomal exocytosis. It is known to act through protein phosphorylation via PRKA and through the activation of guanine nucleotide exchange factors like EPAC. Sperm intracellular cAMP levels depend on the activity of adenylyl cyclases, mostly SACY, though transmembrane-containing adenylyl cyclases are also present, and on the activity of cyclic nucleotide phosphodiesterases (PDE) whose role is to degrade cAMP into 5’-AMP. The PDE superfamily is subdivided into 11 families (PDE1 to 11), which act on either cAMP or cGMP, or on both cAMP and cGMP although with different enzymatic properties. PDE10, which is more effective on cAMP than cGMP, has been known for almost 15 years and is mostly studied in the brain where it is associated with neurological disorders. Although a high level of PDE10A gene expression is observed in the testis, information on the identity of the isoforms or on the cell type that express the PDE10 protein is lacking. The objective of this study was to identify the PDE10A isoforms expressed in the testis and germ cells, and to determine the presence and localization of PDE10A in mature spermatozoa. As a sub-objective, since PDE10A transcript variants were reported strictly through analyses of bovine genomic sequence, we also wanted to determine the nucleotide and amino acid sequences by experimental evidence. Using RT-PCR, 5’- and 3’-RACE approaches we clearly show that PDE10A transcript variants X3 and X5 are expressed in bovine testis as well as in primary spermatocytes and spermatids. We also reveal using a combination of immunological techniques and proteomics analytical tools that the PDE10A isoform X4 is present in the area of the developing acrosome of spermatids and of the acrosome of mature spermatozoa. PMID:27548062

  20. Chronic Cognitive Dysfunction after Traumatic Brain Injury Is Improved with a Phosphodiesterase 4B Inhibitor

    PubMed Central

    Titus, David J.; Wilson, Nicole M.; Freund, Julie E.; Carballosa, Melissa M.; Sikah, Kevin E.; Furones, Concepcion; Dietrich, W. Dalton; Gurney, Mark E.

    2016-01-01

    Learning and memory impairments are common in traumatic brain injury (TBI) survivors. However, there are no effective treatments to improve TBI-induced learning and memory impairments. TBI results in decreased cAMP signaling and reduced cAMP-response-element binding protein (CREB) activation, a critical pathway involved in learning and memory. TBI also acutely upregulates phosphodiesterase 4B2 (PDE4B2), which terminates cAMP signaling by hydrolyzing cAMP. We hypothesized that a subtype-selective PDE4B inhibitor could reverse the learning deficits induced by TBI. To test this hypothesis, adult male Sprague-Dawley rats received sham surgery or moderate parasagittal fluid-percussion brain injury. At 3 months postsurgery, animals were administered a selective PDE4B inhibitor or vehicle before cue and contextual fear conditioning, water maze training and a spatial working memory task. Treatment with the PDE4B inhibitor significantly reversed the TBI-induced deficits in cue and contextual fear conditioning and water maze retention. To further understand the underlying mechanisms of these memory impairments, we examined hippocampal long-term potentiation (LTP). TBI resulted in a significant reduction in basal synaptic transmission and impaired expression of LTP. Treatment with the PDE4B inhibitor significantly reduced the deficits in basal synaptic transmission and rescued LTP expression. The PDE4B inhibitor reduced tumor necrosis factor-α levels and increased phosphorylated CREB levels after TBI, suggesting that this drug inhibited molecular pathways in the brain known to be regulated by PDE4B. These results suggest that a subtype-selective PDE4B inhibitor is a potential therapeutic to reverse chronic learning and memory dysfunction and deficits in hippocampal synaptic plasticity following TBI. SIGNIFICANCE STATEMENT Currently, there are an estimated 3.2–5.3 million individuals living with disabilities from traumatic brain injury (TBI) in the United States, and 8 of

  1. Phosphodiesterase 7 Inhibition Preserves Dopaminergic Neurons in Cellular and Rodent Models of Parkinson Disease

    PubMed Central

    Morales-Garcia, Jose A.; Redondo, Miriam; Alonso-Gil, Sandra; Gil, Carmen; Perez, Concepción; Martinez, Ana; Santos, Angel; Perez-Castillo, Ana

    2011-01-01

    Background Phosphodiesterase 7 plays a major role in down-regulation of protein kinase A activity by hydrolyzing cAMP in many cell types. This cyclic nucleotide plays a key role in signal transduction in a wide variety of cellular responses. In the brain, cAMP has been implicated in learning, memory processes and other brain functions. Methodology/Principal Findings Here we show a novel function of phosphodiesterase 7 inhibition on nigrostriatal dopaminergic neuronal death. We found that S14, a heterocyclic small molecule inhibitor of phosphodiesterase 7, conferred significant neuronal protection against different insults both in the human dopaminergic cell line SH-SY5Y and in primary rat mesencephalic cultures. S14 treatment also reduced microglial activation, protected dopaminergic neurons and improved motor function in the lipopolysaccharide rat model of Parkinson disease. Finally, S14 neuroprotective effects were reversed by blocking the cAMP signaling pathways that operate through cAMP-dependent protein kinase A. Conclusions/Significance Our findings demonstrate that phosphodiesterase 7 inhibition can protect dopaminergic neurons against different insults, and they provide support for the therapeutic potential of phosphodiesterase 7 inhibitors in the treatment of neurodegenerative disorders, particularly Parkinson disease. PMID:21390306

  2. Mechanically induced c-fos expression is mediated by cAMP in MC3T3-E1 osteoblasts

    NASA Technical Reports Server (NTRS)

    Fitzgerald, J.; Hughes-Fulford, M.

    1999-01-01

    In serum-deprived MC3T3-E1 osteoblasts, mechanical stimulation caused by mild (287 x g) centrifugation induced a 10-fold increase in mRNA levels of the proto-oncogene, c-fos. Induction of c-fos was abolished by the cAMP-dependent protein kinase inhibitor H-89, suggesting that the transient c-fos mRNA increase is mediated by cAMP. Down-regulation of protein kinase C (PKC) activity by chronic TPA treatment failed to significantly reduce c-fos induction, suggesting that TPA-sensitive isoforms of PKC are not responsible for c-fos up-regulation. In addition, 287 x g centrifugation increased intracellular prostaglandin E2 (PGE2) levels 2.8-fold (P<0. 005). Since we have previously shown that prostaglandin E2 (PGE2) can induce c-fos expression via a cAMP-mediated mechanism, we asked whether the increase in c-fos mRNA was due to centrifugation-induced PGE2 release. Pretreatment with the cyclooxygenase inhibitors indomethacin and flurbiprofen did not hinder the early induction of c-fos by mechanical stimulation. We conclude that c-fos expression induced by mild mechanical loading is dependent primarily on cAMP, not PKC, and initial induction of c-fos is not necessarily dependent on the action of newly synthesized PGE2.

  3. Constellation of HCN channels and cAMP regulating proteins in dendritic spines of the primate prefrontal cortex: potential substrate for working memory deficits in schizophrenia.

    PubMed

    Paspalas, Constantinos D; Wang, Min; Arnsten, Amy F T

    2013-07-01

    Schizophrenia associates with impaired prefrontal cortical (PFC) function and alterations in cyclic AMP (cAMP) signaling pathways. These include genetic insults to disrupted-in-schizophrenia (DISC1) and phosphodiesterases (PDE4s) regulating cAMP hydrolysis, and increased dopamine D1 receptor (D1R) expression that elevates cAMP. We used immunoelectron microscopy to localize DISC1, PDE4A, PDE4B, and D1R in monkey PFC and to view spatial interactions with hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that gate network inputs when opened by cAMP. Physiological interactions between PDE4s and HCN channels were tested in recordings of PFC neurons in monkeys performing a spatial working memory task. The study reveals a constellation of cAMP-related proteins (DISC1, PDE4A, and D1R) and HCN channels next to excitatory synapses and the spine neck in thin spines of superficial PFC, where working memory microcircuits interconnect and spine loss is most evident in schizophrenia. In contrast, channels in dendrites were distant from synapses and cAMP-related proteins, and were associated with endosomal trafficking. The data suggest that a cAMP signalplex is selectively positioned in the spines to gate PFC pyramidal cell microcircuits. Single-unit recordings confirmed physiological interactions between cAMP and HCN channels, consistent with gating actions. These data may explain why PFC networks are especially vulnerable to genetic insults that dysregulate cAMP signaling.

  4. Is zucchini a phosphodiesterase or a ribonuclease?

    PubMed

    Nureki, Osamu

    2014-01-01

    Zucchini (Zuc), a member of the phospholipase D (PLD) superfamily, is essential for the primary PIWI-interacting RNA (piRNA) biogenesis and the suppression of transposon expression, which are crucial for the genome integrity of germline cells. However, it has been ambiguous whether Zuc acts as a phosphodiesterase to produce phosphatidic acid (PA), the lipid signaling molecule, or as a nuclease. The recent three papers describing the crystal structures and functional analyses of fly and mouse Zuc proteins have elucidated that Zuc is a PLD family single-strand ribonuclease, not a phosphodiesterase, and functions in the maturation of primary piRNAs. This review will discuss in detail how the crystal structures clearly predict the function of Zuc, which is subsequently demonstrated by biochemical analysis to conclude the previous controversial discussion on the real function of Zuc.

  5. Mechanisms Restricting Diffusion of Intracellular cAMP.

    PubMed

    Agarwal, Shailesh R; Clancy, Colleen E; Harvey, Robert D

    2016-01-22

    Although numerous receptors stimulate cAMP production in a wide array of cells, many elicit distinct, highly localized responses, implying that the subcellular distribution of cAMP is not uniform. One often used explanation is that phosphodiesterases, which breakdown cAMP, act as functional barriers limiting diffusion. However, several studies refute the notion that this is sufficient, suggesting that phosphodiesterase-independent movement of cAMP must occur at rates slower than free diffusion. But, until now this has never been demonstrated. Using Raster Image Correlation Spectroscopy (RICS), we measured the diffusion coefficient of a fluorescently-labeled cAMP derivative (φ450-cAMP) as well as other fluorescent molecules in order to investigate the role that molecular size, cell morphology, and buffering by protein kinase A (PKA) play in restricting cAMP mobility in different cell types. Our results demonstrate that cytosolic movement of cAMP is indeed much slower than the rate of free diffusion and that interactions with PKA, especially type II PKA associated with mitochondria, play a significant role. These findings have important implications with respect to cAMP signaling in all cells.

  6. Loss of cAMP-specific phosphodiesterase rescues spore development in G protein mutant in dictyostelium.

    PubMed

    Schwebs, David J; Nguyen, Hoai-Nghia; Miller, Jamison A; Hadwiger, Jeffrey A

    2014-02-01

    Cyclic AMP (cAMP) is an important intracellular signaling molecule for many G protein-mediated signaling pathways but the specificity of cAMP signaling in cells with multiple signaling pathways is not well-understood. In Dictyostelium, at least two different G protein signaling pathways, mediated by the Gα2 and Gα4 subunits, are involved with cAMP accumulation, spore production, and chemotaxis and the stimulation of these pathways results in the activation of ERK2, a mitogen-activated protein kinase that can down regulate the cAMP-specific phosphodiesterase RegA. The regA gene was disrupted in gα2(−) and gα4(−) cells to determine if the absence of this phosphodiesterase rescues the development of these G protein mutants as it does for erk2(−) mutants. There gA(−) mutation had no major effects on developmental morphology but enriched the distribution of the Gα mutant cells to the prespore/prestalk border in chimeric aggregates. The loss of RegA function had no effect on Gα4- mediated folate chemotaxis. However, the regA gene disruption in gα4(−) cells, but not in gα2(−) cells, resulted in a substantial rescue and acceleration of spore production. This rescue in sporulation required cell autonomous signaling because the precocious sporulation could not be induced through intercellular signaling in chimeric aggregates. However, intercellular signals from regA(−) strains increased the expression of the prestalk gene ecmB and accelerated the vacuolization of stalk cells. Intercellular signaling from the gα4(−)regA(−) strain did not induce ecmA gene expression indicating cell-type specificity in the promotion of prestalk cell development. regA gene disruption in a Gα4(HC) (Gα4 overexpression) strain did not result in precocious sporulation or stalk cell development indicating that elevated Gα4 subunit expression can mask regA(−) associated phenotypes even when provided with wild-type intercellular signaling. These findings indicate that

  7. cAMP stimulation of StAR expression and cholesterol metabolism is modulated by co-expression of labile suppressors of transcription and mRNA turnover.

    PubMed

    Jefcoate, Colin R; Lee, Jinwoo; Cherradi, Nadia; Takemori, Hiroshi; Duan, Haichuan

    2011-04-10

    The steroidogenic acute regulatory (StAR) protein is generated in rodents from 1.6 kb and 3.5 kb mRNA formed by alternative polyadenylation. The zinc finger protein, TIS11B (also Znf36L1), is elevated by cAMP in adrenal cells in parallel with StAR mRNA. TIS11b selectively destabilizes the 3.5 kb mRNA through AU-rich sequences at the end of the 3'UTR. siRNA suppression shows that TIS11b surprisingly increases StAR protein and cholesterol metabolism. StAR transcription is directly activated by PKA phosphorylation. cAMP responsive element binding (CREB) protein 1 phosphorylation is a key step leading to recruitment of the co-activator, CREB binding protein (CBP). A second protein, CREB regulated transcription coactivator (TORC/CRTC), enhances this recruitment, but is inhibited by salt inducible kinase (SIK). Basal StAR transcription is constrained through this phosphorylation of TORC. PKA provides an alternative stimulation by phosphorylating SIK, which prevents TORC inactivation. PKA stimulation of StAR nuclear transcripts substantially precedes TORC recruitment to the StAR promoter, which may, therefore, mediate a later step in mRNA production. Inhibition of SIK by staurosporine elevates StAR transcription and TORC recruitment to maximum levels, but without CREB phosphorylation. TORC suppression by SIK evidently limits basal StAR transcription. Staurosporine and cAMP stimulate synergistically. SIK targets the phosphatase, PP2a (activation), and Type 2 histone de-acetylases (inhibition), which may each contribute to suppression. Staurosporine stimulation through SIK inhibition is repeated in cAMP stimulation of many steroidogenic genes regulated by steroidogenic factor 1 (SF-1) and CREB. TIS11b and SIK may combine to attenuate StAR expression when hormonal stimuli decline.

  8. Up-regulation of M1 muscarinic receptors expressed in CHOm1 cells by panaxynol via cAMP pathway.

    PubMed

    Hao, Wang; Xing-Jun, Wu; Yong-Yao, Cui; Liang, Zhu; Yang, Lu; Hong-Zhuan, Chen

    Loss of cholinergic neurons along with muscarinic acetylcholine receptors (mAChRs) in cerebral cortex and hippocampus is closely associated with Alzheimer's disease (AD). Recent drug development for AD treatment focuses heavily on identifying M(1) receptor agonists. However, mAChRs undergo down-regulation in response to agonist-induced sustained activation. Therefore, therapeutic effectiveness wanes during continuous use. Thus, another potentially effective approach, which overcomes this drawback is to develop compounds, which instead up-regulate M(1) receptor expression. In the present study, we took this alternative approach and contrasted in Chinese hamster ovary cells transfected with human m(1) subtype gene (CHOm(1) cells) changes of M(1) receptor expression levels caused by muscarinic agonists and upregulators of its expression. The muscarinic agonists carbachol and pilocarpine reduced M(1) receptor number in CHOm(1) cells by 29 and 46%, respectively, at 100muM, whereas panaxynol, a polyacetylene compound isolated from the lipophilic fraction of Panax notoginseng, concentration-dependently up-regulated the M(1) receptor number after pre-incubation with CHOm(1) cells for 48 h, reaching a plateau at 1 microM, and was accompanied by enhanced M(1) mRNA levels. Moreover, the protein kinase A (PKA) inhibitor RP-adenosine-3',5'-cyclic mono-phosphoro-thioate triethylamine salt (RP-cAMPs) 5 microM completely prevented panaxynol-induced up-regulation of M(1) receptors. Panaxynol (1muM) caused a significant and consistent stimulation of cAMP accumulation (27% increase above basal at 40 min). These results suggest that in CHOm(1) cells panaxynol up-regulates M(1) receptor number through cAMP pathway-mediated stimulation of gene transcription.

  9. In resting COS1 cells a dominant negative approach shows that specific, anchored PDE4 cAMP phosphodiesterase isoforms gate the activation, by basal cyclic AMP production, of AKAP-tethered protein kinase A type II located in the centrosomal region.

    PubMed

    McCahill, Angela; McSorley, Theresa; Huston, Elaine; Hill, Elaine V; Lynch, Martin J; Gall, Irene; Keryer, Guy; Lygren, Birgitte; Tasken, Kjetil; van Heeke, Gino; Houslay, Miles D

    2005-09-01

    We employ a novel, dominant negative approach to identify a key role for certain tethered cyclic AMP specific phosphodiesterase-4 (PDE4) isoforms in regulating cyclic AMP dependent protein kinase A (PKA) sub-populations in resting COS1 cells. A fraction of PKA is clearly active in resting COS1 cells and this activity increases when cells are treated with the selective PDE4 inhibitor, rolipram. Point mutation of a critical, conserved aspartate residue in the catalytic site of long PDE4A4, PDE4B1, PDE4C2 and PDE4D3 isoforms renders them catalytically inactive. Overexpressed in resting COS1 cells, catalytically inactive forms of PDE4C2 and PDE4D3, but not PDE4A4 and PDE4B1, are constitutively PKA phosphorylated while overexpressed active versions of all these isoforms are not. Inactive and active versions of all these isoforms are PKA phosphorylated in cells where protein kinase A is maximally activated with forskolin and IBMX. By contrast, rolipram challenge of COS1 cells selectively triggers the PKA phosphorylation of recombinant, active PDE4D3 and PDE4C2 but not recombinant, active PDE4A4 and PDE4B1. Purified, recombinant PDE4D3 and PDE4A4 show a similar dose-dependency for in vitro phosphorylation by PKA. Disruption of the tethering of PKA type-II to PKA anchor proteins (AKAPs), achieved using the peptide Ht31, prevents inactive forms of PDE4C2 and PDE4D3 being constitutively PKA phosphorylated in resting cells as does siRNA-mediated knockdown of PKA-RII, but not PKA-RI. PDE4C2 and PDE4D3 co-immunoprecipitate from COS1 cell lysates with 250 kDa and 450 kDa AKAPs that tether PKA type-II and not PKA type-I. PKA type-II co-localises with AKAP450 in the centrosomal region of COS1 cells. The perinuclear distribution of recombinant, inactive PDE4D3, but not inactive PDE4A4, overlaps with AKAP450 and PKA type-II. The distribution of PKA phosphorylated inactive PDE4D3 also overlaps with that of AKAP450 in the centrosomal region of COS1 cells. We propose that a novel role

  10. Exposure to an Extremely-Low-Frequency Magnetic Field Stimulates Adrenal Steroidogenesis via Inhibition of Phosphodiesterase Activity in a Mouse Adrenal Cell Line

    PubMed Central

    Kitaoka, Kazuyoshi; Kawata, Shiyori; Yoshida, Tomohiro; Kadoriku, Fumiya; Kitamura, Mitsuo

    2016-01-01

    Extremely low-frequency magnetic fields (ELF-MFs) are generated by power lines and household electrical devices. In the last several decades, some evidence has shown an association between ELF-MF exposure and depression and/or anxiety in epidemiological and animal studies. The mechanism underlying ELF-MF-induced depression is considered to involve adrenal steroidogenesis, which is triggered by ELF-MF exposure. However, how ELF-MFs stimulate adrenal steroidogenesis is controversial. In the current study, we investigated the effect of ELF-MF exposure on the mouse adrenal cortex-derived Y-1 cell line and the human adrenal cortex-derived H295R cell line to clarify whether the ELF-MF stimulates adrenal steroidogenesis directly. ELF-MF exposure was found to significantly stimulate adrenal steroidogenesis (p < 0.01–0.05) and the expression of adrenal steroid synthetic enzymes (p < 0.05) in Y-1 cells, but the effect was weak in H295R cells. Y-1 cells exposed to an ELF-MF showed significant decreases in phosphodiesterase activity (p < 0.05) and intracellular Ca2+ concentration (p < 0.01) and significant increases in intracellular cyclic adenosine monophosphate (cAMP) concentration (p < 0.001–0.05) and cAMP response element-binding protein phosphorylation (p < 0.05). The increase in cAMP was not inhibited by treatment with NF449, an inhibitor of the Gs alpha subunit of G protein. Our results suggest that ELF-MF exposure stimulates adrenal steroidogenesis via an increase in intracellular cAMP caused by the inhibition of phosphodiesterase activity in Y-1 cells. The same mechanism may trigger the increase in adrenal steroid secretion in mice observed in our previous study. PMID:27100201

  11. Effect of cAMP signaling on expression of glucocorticoid receptor, Bim and Bad in glucocorticoid-sensitive and resistant leukemic and multiple myeloma cells

    PubMed Central

    Dong, Hongli; Carlton, Michael E.; Lerner, Adam; Epstein, Paul M.

    2015-01-01

    Stimulation of cAMP signaling induces apoptosis in glucocorticoid-sensitive and resistant CEM leukemic and MM.1 multiple myeloma cell lines, and this effect is enhanced by dexamethasone in both glucocorticoid-sensitive cell types and in glucocorticoid-resistant CEM cells. Expression of the mRNA for the glucocorticoid receptor alpha (GR) promoters 1A3, 1B and 1C, expression of mRNA and protein for GR, and the BH3-only proapoptotic proteins, Bim and Bad, and the phosphorylation state of Bad were examined following stimulation of the cAMP and glucocorticoid signaling pathways. Expression levels of GR promoters were increased by cAMP and glucocorticoid signaling, but GR protein expression was little changed in CEM and decreased in MM.1 cells. Stimulation of these two signaling pathways induced Bim in CEM cells, induced Bad in MM.1 cells, and activated Bad, as indicated by its dephosphorylation on ser112, in both cell types. This study shows that leukemic and multiple myeloma cells, including those resistant to glucocorticoids, can be induced to undergo apoptosis by stimulating the cAMP signaling pathway, with enhancement by glucocorticoids, and the mechanism by which this occurs may be related to changes in Bim and Bad expression, and in all cases, to activation of Bad. PMID:26528184

  12. Effect of cAMP signaling on expression of glucocorticoid receptor, Bim and Bad in glucocorticoid-sensitive and resistant leukemic and multiple myeloma cells.

    PubMed

    Dong, Hongli; Carlton, Michael E; Lerner, Adam; Epstein, Paul M

    2015-01-01

    Stimulation of cAMP signaling induces apoptosis in glucocorticoid-sensitive and resistant CEM leukemic and MM.1 multiple myeloma cell lines, and this effect is enhanced by dexamethasone in both glucocorticoid-sensitive cell types and in glucocorticoid-resistant CEM cells. Expression of the mRNA for the glucocorticoid receptor alpha (GR) promoters 1A3, 1B and 1C, expression of mRNA and protein for GR, and the BH3-only proapoptotic proteins, Bim and Bad, and the phosphorylation state of Bad were examined following stimulation of the cAMP and glucocorticoid signaling pathways. Expression levels of GR promoters were increased by cAMP and glucocorticoid signaling, but GR protein expression was little changed in CEM and decreased in MM.1 cells. Stimulation of these two signaling pathways induced Bim in CEM cells, induced Bad in MM.1 cells, and activated Bad, as indicated by its dephosphorylation on ser112, in both cell types. This study shows that leukemic and multiple myeloma cells, including those resistant to glucocorticoids, can be induced to undergo apoptosis by stimulating the cAMP signaling pathway, with enhancement by glucocorticoids, and the mechanism by which this occurs may be related to changes in Bim and Bad expression, and in all cases, to activation of Bad.

  13. The roles of phosphodiesterase 2 in the central nervous and peripheral systems.

    PubMed

    Zhang, Chong; Yu, Yingcong; Ruan, Lina; Wang, Chuang; Pan, Jianchun; Klabnik, Jonathan; Lueptow, Lindsay; Zhang, Han-Ting; O'Donnell, James M; Xu, Ying

    2015-01-01

    Phosphodiesterase 2 (PDE2) is a ubiquitous enzyme whose major role is to hydrolyze the important second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). In the central nervous system, pharmacological inhibition of PDE2 results in boosted cAMP and/or cGMP signaling, which is responsible for series of changes in protein expression relevant to psychiatric and learning and memory disorders, such as depression, anxiety, and cognition deficits in Alzheimer's disease. In the periphery, inhibition of PDE2 exhibits beneficial effects in the diseased cardiovascular system, the respiratory system, skeletal muscles and Candida albicans-caused systemic infections. Even though blood-brain barrier penetration properties and selectivity of currently available PDE2 inhibitors have hindered them from entering clinical trials, PDE2 is still of great potential therapeutic values in different categories of diseases, and there is demand for development of new generation drugs targeting PDE2 for treatment of diseases in central nervous and peripheral systems.

  14. Relationship between Platelet PPARs, cAMP Levels, and P-Selectin Expression: Antiplatelet Activity of Natural Products.

    PubMed

    Fuentes, Eduardo; Palomo, Iván

    2013-01-01

    Platelets are no longer considered simply as cells participating in thrombosis. In atherosclerosis, platelets are regulators of multiple processes, with the recruitment of inflammatory cells towards the lesion sites, inflammatory mediators release, and regulation of endothelial function. The antiplatelet therapy has been used for a long time in an effort to prevent and treat cardiovascular diseases. However, limited efficacy in some patients, drug resistance, and side effects are limitations of current antiplatelet therapy. In this context, a large number of natural products (polyphenols, terpenoids, alkaloids, and fatty acids) have been reported with antiplatelet activity. In this sense, the present paper describes mechanisms of antiplatelet action of natural products on platelet P-selectin expression through cAMP levels and its role as peroxisome proliferator-activated receptors agonists.

  15. Relationship between Platelet PPARs, cAMP Levels, and P-Selectin Expression: Antiplatelet Activity of Natural Products

    PubMed Central

    Fuentes, Eduardo; Palomo, Iván

    2013-01-01

    Platelets are no longer considered simply as cells participating in thrombosis. In atherosclerosis, platelets are regulators of multiple processes, with the recruitment of inflammatory cells towards the lesion sites, inflammatory mediators release, and regulation of endothelial function. The antiplatelet therapy has been used for a long time in an effort to prevent and treat cardiovascular diseases. However, limited efficacy in some patients, drug resistance, and side effects are limitations of current antiplatelet therapy. In this context, a large number of natural products (polyphenols, terpenoids, alkaloids, and fatty acids) have been reported with antiplatelet activity. In this sense, the present paper describes mechanisms of antiplatelet action of natural products on platelet P-selectin expression through cAMP levels and its role as peroxisome proliferator-activated receptors agonists. PMID:24324520

  16. cAMP signaling increases histone deacetylase 8 expression via the Epac2–Rap1A–Akt pathway in H1299 lung cancer cells

    PubMed Central

    Park, Ji-Yeon; Juhnn, Yong-Sung

    2017-01-01

    This study was performed to investigate the signaling pathway that mediates cyclic AMP (cAMP)-induced inhibition of histone deacetylase 8 (HDAC8) degradation, and the effect and underlying mechanisms of the resulting increase in HDAC8 expression on cisplatin-induced apoptosis in lung cancer cells. cAMP signaling increased HDAC8 expression via a protein kinase A (PKA)-independent pathway in H1299 non-small cell lung cancer cells. However, treatment with a selective activator of an exchange protein that was activated by cAMP (Epac) increased HDAC8 expression, and Epac2 inhibition abolished the isoproterenol (ISO)-induced increase in HDAC8 expression. ISO and the Epac activator activated Rap1, and Rap1A activation increased HDAC8 expression; moreover, inhibition of Rap1A with a dominant negative Rap1A or by shRNA-mediated knockdown abolished the ISO-induced increase in HDAC8 expression. Activation of cAMP signaling and Rap1A decreased the activating phosphorylation of Akt. Akt inhibition with a pharmacological inhibitor or expression of a dominant negative Akt inhibited the MKK4/JNK pathway and increased HDAC8 expression. The Akt inhibitor-induced increase in HDAC8 expression was abolished by pretreatment with proteasomal or lysosomal inhibitors. The ISO treatment increased cisplatin-induced apoptosis, which was abolished by HDAC8 knockdown. Exogenous HDAC8 expression increased cisplatin-induced apoptosis and decreased TIPRL expression, and the knockdown of TIPRL increased the apoptosis of cisplatin-treated cells. The ISO treatment decreased cisplatin-induced transcription of the TIPRL gene in a HDAC8-dependent manner. In conclusion, the Epac–Rap1–Akt pathway mediates cAMP signaling-induced inhibition of JNK-dependent HDAC8 degradation, and the resulting HDAC8 increase augments cisplatin-induced apoptosis by repressing TIPRL expression in H1299 lung cancer cells. PMID:28232663

  17. cAMP signaling increases histone deacetylase 8 expression via the Epac2-Rap1A-Akt pathway in H1299 lung cancer cells.

    PubMed

    Park, Ji-Yeon; Juhnn, Yong-Sung

    2017-02-24

    This study was performed to investigate the signaling pathway that mediates cyclic AMP (cAMP)-induced inhibition of histone deacetylase 8 (HDAC8) degradation, and the effect and underlying mechanisms of the resulting increase in HDAC8 expression on cisplatin-induced apoptosis in lung cancer cells. cAMP signaling increased HDAC8 expression via a protein kinase A (PKA)-independent pathway in H1299 non-small cell lung cancer cells. However, treatment with a selective activator of an exchange protein that was activated by cAMP (Epac) increased HDAC8 expression, and Epac2 inhibition abolished the isoproterenol (ISO)-induced increase in HDAC8 expression. ISO and the Epac activator activated Rap1, and Rap1A activation increased HDAC8 expression; moreover, inhibition of Rap1A with a dominant negative Rap1A or by shRNA-mediated knockdown abolished the ISO-induced increase in HDAC8 expression. Activation of cAMP signaling and Rap1A decreased the activating phosphorylation of Akt. Akt inhibition with a pharmacological inhibitor or expression of a dominant negative Akt inhibited the MKK4/JNK pathway and increased HDAC8 expression. The Akt inhibitor-induced increase in HDAC8 expression was abolished by pretreatment with proteasomal or lysosomal inhibitors. The ISO treatment increased cisplatin-induced apoptosis, which was abolished by HDAC8 knockdown. Exogenous HDAC8 expression increased cisplatin-induced apoptosis and decreased TIPRL expression, and the knockdown of TIPRL increased the apoptosis of cisplatin-treated cells. The ISO treatment decreased cisplatin-induced transcription of the TIPRL gene in a HDAC8-dependent manner. In conclusion, the Epac-Rap1-Akt pathway mediates cAMP signaling-induced inhibition of JNK-dependent HDAC8 degradation, and the resulting HDAC8 increase augments cisplatin-induced apoptosis by repressing TIPRL expression in H1299 lung cancer cells.

  18. Bacterial subversion of cAMP signalling inhibits cathelicidin expression, which is required for innate resistance to Mycobacterium tuberculosis.

    PubMed

    Gupta, Shashank; Winglee, Kathryn; Gallo, Richard; Bishai, William R

    2017-01-18

    Antimicrobial peptides such as cathelicidins are important components of innate immune defence against inhaled microorganisms, and have shown antimicrobial activity against Mycobacterium tuberculosis in in vitro models. Despite this, little is known about the regulation and expression of cathelicidin during tuberculosis in vivo. We sought to determine whether the cathelicidin-related antimicrobial peptide gene (Cramp), the murine functional homologue of the human cathelicidin gene (CAMP or LL-37), is required for regulation of protective immunity during M. tuberculosis infection in vivo. We used Cramp(-/-) mice in a validated model of pulmonary tuberculosis, and conducted cell-based assays with macrophages from these mice. We evaluated the in vivo susceptibility of Cramp(-/-) mice to infection, and also dissected various pro-inflammatory immune responses against M. tuberculosis. We observed increased susceptibility of Cramp(-/-) mice to M. tuberculosis as compared with wild-type mice. Macrophages from Cramp(-/-) mice were unable to control M. tuberculosis growth in an in vitro infection model, were deficient in intracellular calcium influx, and were defective in stimulating T cells. Additionally, CD4(+) and CD8(+) T cells from Cramp(-/-) mice produced less interferon-β upon stimulation. Furthermore, bacterial-derived cAMP modulated cathelicidin expression in macrophages. Our results demonstrate that cathelicidin is required for innate resistance to M. tuberculosis in a relevant animal model and is a key mediator in regulation of the levels of pro-inflammatory cytokines by calcium and cyclic nucleotides. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  19. Dual specificity and novel structural folding of yeast phosphodiesterase-1 for hydrolysis of second messengers cyclic adenosine and guanosine 3',5'-Monophosphate

    DOE PAGES

    Tian, Yuanyuan; Cui, Wenjun; Huang, Manna; ...

    2014-08-05

    Cyclic nucleotide phosphodiesterases (PDEs) decompose second messengers cAMP and cGMP that play critical roles in many physiological processes. PDE1 of Saccharomyces cerevisiae has been subcloned and expressed in Escherichia coli. Recombinant yPDE1 has a KM of 110 μM and a kcat of 16.9 s⁻¹ for cAMP and a KM of 105 μM and a kcat of 11.8 s₅⁻¹ for cGMP. Thus, the specificity constant (kcat/KMcAMP)/(kcat/KMcGMP) of 1.4 indicates a dual specificity of yPDE1 for hydrolysis of both cAMP and cGMP. The crystal structures of unliganded yPDE1 and its complex with GMP at 1.31 Å resolution reveal a new structural foldingmore » that is different from those of human PDEs but is partially similar to that of some other metalloenzymes such as metallo-β-lactamase. In spite of their different structures and divalent metals, yPDE1 and human PDEs may share a common mechanism for hydrolysis of cAMP and cGMP.« less

  20. Dual Specificity and Novel Structural Folding of Yeast Phosphodiesterase-1 for Hydrolysis of Second Messengers Cyclic Adenosine and Guanosine 3′,5′-Monophosphate

    PubMed Central

    2015-01-01

    Cyclic nucleotide phosphodiesterases (PDEs) decompose second messengers cAMP and cGMP that play critical roles in many physiological processes. PDE1 of Saccharomyces cerevisiae has been subcloned and expressed in Escherichia coli. Recombinant yPDE1 has a KM of 110 μM and a kcat of 16.9 s–1 for cAMP and a KM of 105 μM and a kcat of 11.8 s–1 for cGMP. Thus, the specificity constant (kcat/KMcAMP)/(kcat/KMcGMP) of 1.4 indicates a dual specificity of yPDE1 for hydrolysis of both cAMP and cGMP. The crystal structures of unliganded yPDE1 and its complex with GMP at 1.31 Å resolution reveal a new structural folding that is different from those of human PDEs but is partially similar to that of some other metalloenzymes such as metallo-β-lactamase. In spite of their different structures and divalent metals, yPDE1 and human PDEs may share a common mechanism for hydrolysis of cAMP and cGMP. PMID:25050706

  1. Molecular cloning, expression, and localization of a brain-specific phosphodiesterase I/nucleotide pyrophosphatase (PD-I alpha) from rat brain.

    PubMed

    Narita, M; Goji, J; Nakamura, H; Sano, K

    1994-11-11

    We have isolated cDNA clones encoding the rat brain phosphodiesterase I/nucleotide pyrophosphatase (PD-I alpha), a novel member of the membrane phosphodiesterase I gene family. PD-I alpha cDNA has a 2,655-nucleotide open reading frame encoding a polypeptide of 885 amino acids with a calculated M(r) of 101,302. Northern blot analysis revealed that PD-I alpha transcript was abundantly present in cerebrum and cerebellum while its level was quite low in other tissues. In situ hybridization analysis revealed that PD-I alpha mRNA is localized in secretory epithelial cells in the brain and the eye including choroid plexus epithelial cells, ciliary epithelial cells, iris pigment epithelial cells, and retinal pigment cells. Localization of PD-I alpha mRNA was also observed in glial cells in the molecular layer of the cerebellum. These results indicate that this protein might be involved in the synthesis of adenosine as well as in the regulation of the secretion/transport of epithelial cells and glial cells in the central nervous system.

  2. The NMRA/NMRAL1 homologue PadA modulates the expression of extracellular cAMP relay genes during aggregation in Dictyostelium discoideum.

    PubMed

    Garciandia, Ane; Suarez, Teresa

    2013-09-15

    NMRA-like proteins belong to a class of conserved transcriptional regulators that function as direct sensors of the metabolic state of the cell and link basic metabolism to changes in gene expression. PadA was the first NMRA-like protein described in Dictyostelium discoideum and was shown to be necessary for prestalk cell differentiation and correct development. We describe and characterize padA(-) mutant phenotype during the onset of development, which results in the formation of abnormally small territories and impairment of cAMP responses. Transcriptional analysis shows that cAMP-induced gene expression is downregulated in padA(-), particularly the genes that establish the extracellular cAMP relay. The mutant phenotype can be rescued with the constitutive expression of one of these genes, carA, encoding the cAMP receptor. Transcriptional analysis of padA(-)/A15::carA showed that carA maximum mRNA levels were not reached during aggregation. Our data support a regulatory role for PadA on the regulation of extracellular cAMP relay genes during aggregation and suggest that PadA is required to achieve carA full induction.

  3. The effect of resveratrol on beta amyloid-induced memory impairment involves inhibition of phosphodiesterase-4 related signaling

    PubMed Central

    Wang, Gang; Chen, Ling; Pan, Xiaoyu; Chen, Jiechun; Wang, Liqun; Wang, Weijie; Cheng, Ruochuan; Wu, Fan; Feng, Xiaoqing; Yu, Yingcong; Zhang, Han-Ting; O'Donnell, James M.; Xu, Ying

    2016-01-01

    Resveratrol, a natural polyphenol found in red wine, has wide spectrum of pharmacological properties including antioxidative and antiaging activities. Beta amyloid peptides (Aβ) are known to involve cognitive impairment, neuroinflammatory and apoptotic processes in Alzheimer's disease (AD). Activation of cAMP and/or cGMP activities can improve memory performance and decrease the neuroinflammation and apoptosis. However, it remains unknown whether the memory enhancing effect of resveratrol on AD associated cognitive disorders is related to the inhibition of phosphodiesterase 4 (PDE4) subtypes and subsequent increases in intracellular cAMP and/or cGMP activities. This study investigated the effect of resveratrol on Aβ1-42-induced cognitive impairment and the participation of PDE4 subtypes related cAMP or cGMP signaling. Mice microinfused with Aβ1-42 into bilateral CA1 subregions displayed learning and memory impairment, as evidenced by reduced memory acquisition and retrieval in the water maze and retention in the passive avoidance tasks; it was also significant that neuroinflammatory and pro-apoptotic factors were increased in Aβ1-42-treated mice. Aβ1-42-treated mice also increased in PDE4A, 4B and 4D expression, and decreased in PKA level. However, PKA inhibitor H89, but not PKG inhibitor KT5823, prevented resveratrol's effects on these parameters. Resveratrol also reversed Aβ1-42-induced decreases in phosphorylated cAMP response-element binding protein (pCREB), brain derived neurotrophic factor (BDNF) and anti-apoptotic factor BCl-2 expression, which were reversed by H89. These findings suggest that resveratrol reversing Aβ-induced learning and memory disorder may involve the regulation of neuronal inflammation and apoptosis via PDE4 subtypes related cAMP-CREB-BDNF signaling. PMID:26980711

  4. CREM confers cAMP responsiveness in human steroidogenic acute regulatory protein expression in NCI-H295R cells rather than SF-1/Ad4BP.

    PubMed

    Sugawara, Teruo; Sakuragi, Noriaki; Minakami, Hisanori

    2006-10-01

    Steroidogenic acute regulatory (StAR) protein plays a critical role in steroid hormone synthesis. Tropic hormones induce human StAR gene expression by a cAMP-dependent pathway. Steroidogenic factor-1/adrenal-4-binding protein (SF-1/Ad4BP) plays an important role in the expression of human StAR gene. We investigated the mechanism of cAMP responsiveness in human StAR gene expression in NCI-H295R cells. The StAR promoter activity and protein levels in cells subjected to various treatments were examined. Anti-SF-1/Ad4BP IgG transfection treatment resulted in decreases in the basal StAR promoter activity and StAR protein levels, but did not affect cAMP-stimulated promoter activity and protein levels. The basal and cAMP-stimulated StAR promoter activity levels were reduced in SF-1/Ad4BP mutant (G35E)-transfected cells, but the cAMP induction of StAR promoter activity in response to 1 mM 8-Br-cAMP was not inhibited when G35E SF-1/Ad4BP mutant expression vectors were co-transfected with cAMP-response element-binding (CREB) expression vectors. Although the basal StAR mRNA expression and protein levels were decreased by SF-1/Ad4BP-siRNA treatment, the cAMP-stimulated StAR mRNA expression and protein levels did not change. The basal StAR promoter activity level was not decreased by cAMP-response element modulator (CREM)-siRNA treatment, but the cAMP-stimulated StAR promoter activity level, the magnitude of cAMP induction of StAR promoter, and the cAMP-stimulated StAR protein level were decreased. The cAMP induction of StAR promoter activity in cells was inhibited when S117ACREM mutant expressionvectors were transfected. We conclude that inhibition of the function of SF-1/Ad4BP does not reduce the cAMP induction of StAR promoter activity and protein level. CREM is needed to confer cAMP responsiveness in human StAR protein expression.

  5. cAMP signaling increases histone deacetylase 8 expression by inhibiting JNK-dependent degradation via autophagy and the proteasome system in H1299 lung cancer cells.

    PubMed

    Park, Ji-Yeon; Juhnn, Yong-Sung

    2016-02-05

    This study aimed to investigate the roles of autophagy and the ubiquitin-proteasome system in the degradation of histone deacetylase 8 (HDAC8) and to clarify the mechanism by which cAMP signaling regulates this degradation. cAMP signaling was activated by treating H1299 non-small cell lung cancer cells with isoproterenol or forskolin/3-isobutyl-1-methylxanthine, and HDAC8 expression was assessed by western blot analysis. The inhibition of autophagy and ubiquitin-proteasome-dependent degradation increased HDAC8 expression. cAMP signaling inhibited JNK activation, which decreased the phosphorylation of Bcl-2, thereby reducing autophagy, and the phosphorylation of Itch, thereby reducing ubiquitination. These results suggest that the HDAC8 protein is degraded via autophagy and the ubiquitin-proteasome system and that cAMP signaling increases HDAC8 protein levels by reducing JNK-mediated autophagy and ubiquitin-proteasome-dependent degradation of the HDAC8 protein in H1299 lung cancer cells.

  6. [Hemophilia camps.

    PubMed

    Juárez-Sierra, Julieta; Del Pilar Torres-Arreola, Laura; Marín-Palomares, Teresa; Dueñas-González, María Teresa; Monteros-Rincón, Martha Patricia; Osorio-Guzmán, Maricela

    2013-01-01

    We reported the experience of hemophilia camps which was accomplished with patients from hospitals of the Instituto Mexicano del Seguro Social. The aim was to prepare the families and patients regarding the disease treatment, in order to promote the self sufficiency and to know the impact of the program on the course of the disease. Surveys were applied about treatment items and personal opinions were collected. The results of the national hemophilia camp were: group of 56 patients, average 14 years, 2 % women, 51 % severe hemophilia and 43 % had hemophilic brothers. Benefits: patients increased their knowledge about earlier bleeding identification and the self-infusion method; they became aware on their responsibility in self care, timely treatment and duties at home. Hemophilia camps with patients are an option for attitude change before disease complications. Social network creation and the increase in self-sufficiency are other benefits.

  7. [Interaction of adenosin-3',5'-cyclosulfate with adenosine-3'5'-cyclophosphate dependent protein kinase and phosphodiesterase].

    PubMed

    Severin, E S; Tkachuk, V A; Guliaev, N N

    1976-02-01

    Interaction of adenosine-3',5'-cyclosulphate (cAMS) cAMP analogue, having sulphur atom instead of phosphorus in a six-term cyclic system with pig brain proteinkinase and rabbit skeletal muscle phosphodiesterase is studied. The affinity of proteinkinase to cAMS was found to be in 25000 times lower than the affinity of cAMP, the affinity of cAMS to the active site of phosphodiesterase being high enough. It is suggested that in the regulatory subunit of proteinkinase positive kationic group participates in nucleotide binding by interacting with negative oxygen atom of six-term cyclophosphate system. There is no such a group in the active site of phospodiesterase, because the absence of negative charge in case of cAMS only slightly affects the constant of cAMS binding by phosphodiesterase.

  8. Organized Camping's Honorable Tradition.

    ERIC Educational Resources Information Center

    Miranda, Wilma

    1990-01-01

    Profiles three twentieth-century outdoor camping leaders. Describes early camping programs as "experimental intentional communities" teaching personal and social empowerment. Portia Mansfield's Wyonegonic Camps emphasized cooperation and artistic freedom. Joshua Lieberman's Pioneer Youth Camp taught workers' children social…

  9. Angiotensin II regulates brain (pro)renin receptor expression through activation of cAMP response element-binding protein.

    PubMed

    Li, Wencheng; Liu, Jiao; Hammond, Sean L; Tjalkens, Ronald B; Saifudeen, Zubaida; Feng, Yumei

    2015-07-15

    We reported that brain (pro)renin receptor (PRR) expression levels are elevated in DOCA-salt-induced hypertension; however, the underlying mechanism remained unknown. To address whether ANG II type 1 receptor (AT1R) signaling is involved in this regulation, we implanted a DOCA pellet and supplied 0.9% saline as the drinking solution to C57BL/6J mice. Sham pellet-implanted mice that were provided regular drinking water served as controls. Concurrently, mice were intracerebroventricularly infused with the AT1R blocker losartan, angiotensin-converting-enzyme inhibitor captopril, or artificial cerebrospinal fluid for 3 wk. Intracerebroventricular infusion of losartan or captopril attenuated DOCA-salt-induced PRR mRNA elevation in the paraventricular nucleus of the hypothalamus, suggesting a role for ANG II/AT1R signaling in regulating PRR expression during DOCA-salt hypertension. To test which ANG II/AT1R downstream transcription factors were involved in PRR regulation, we treated Neuro-2A cells with ANG II with or without CREB (cAMP response element-binding protein) or AP-1 (activator protein-1) inhibitors, or CREB siRNA. CREB and AP-1 inhibitors, as well as CREB knockdown abolished ANG II-induced increases in PRR levels. ANG II also induced PRR upregulation in primary cultured neurons. Chromatin immunoprecipitation assays revealed that ANG II treatment increased CREB binding to the endogenous PRR promoter in both cultured neurons and hypothalamic tissues of DOCA-salt hypertensive mice. This increase in CREB activity was reversed by AT1R blockade. Collectively, these findings indicate that ANG II acts via AT1R to upregulate PRR expression both in cultured cells and in DOCA-salt hypertensive mice by increasing CREB binding to the PRR promoter.

  10. Identification, characterization and subcellular localization of TcPDE1, a novel cAMP-specific phosphodiesterase from Trypanosoma cruzi.

    PubMed Central

    D'Angelo, Maximiliano A; Sanguineti, Santiago; Reece, Jeffrey M; Birnbaumer, Lutz; Torres, Héctor N; Flawiá, Mirtha M

    2004-01-01

    Compartmentalization of cAMP phosphodiesterases plays a key role in the regulation of cAMP signalling in mammals. In the present paper, we report the characterization and subcellular localization of TcPDE1, the first cAMP-specific phosphodiesterase to be identified from Trypanosoma cruzi. TcPDE1 is part of a small gene family and encodes a 929-amino-acid protein that can complement a heat-shock-sensitive yeast mutant deficient in phospho-diesterase genes. Recombinant TcPDE1 strongly associates with membranes and cannot be released with NaCl or sodium cholate, suggesting that it is an integral membrane protein. This enzyme is specific for cAMP and its activity is not affected by cGMP, Ca2+, calmodulin or fenotiazinic inhibitors. TcPDE1 is sensitive to the phosphodiesterase inhibitor dipyridamole but is resistant to 3-isobutyl-1-methylxanthine, theophylline, rolipram and zaprinast. Papaverine, erythro-9-(2-hydroxy-3-nonyl)-adenine hydrochloride, and vinpocetine are poor inhibitors of this enzyme. Confocal laser scanning of T. cruzi epimastigotes showed that TcPDE1 is associated with the plasma membrane and concentrated in the flagellum of the parasite. The association of TcPDE1 with this organelle was confirmed by subcellular fractionation and cell-disruption treatments. The localization of this enzyme is a unique feature that distinguishes it from all the trypanosomatid phosphodiesterases described so far and indicates that compartmentalization of cAMP phosphodiesterases could also be important in these parasites. PMID:14556647

  11. Inhibitory effect of luteolin on the odorant-induced cAMP level in HEK293 cells expressing the olfactory receptor.

    PubMed

    Yoon, Yeo Cho; Hwang, Jin-Teak; Sung, Mi-Jeong; Wang, Shuaiyu; Munkhtugs, Davaatseren; Rhyu, Mee-Ra; Park, Jae-Ho

    2012-01-01

    Luteolin is a flavonoid in many fruits and vegetables. Although luteolin has important biological functions, including antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities, little is known about the functions of luteolin in the olfactory system. Various odorants can be detected and distinguished by using several molecular processes, including the binding of odorants to odorant receptors, activation of adenylyl cyclase (AC), changes of cyclic adenosine monophosphate (cAMP) and Ca(2+) levels in olfactory sensory neurons, as well as changes in membrane potentials and the transmission of electric signals to the brain. Because AC-cAMP signal transduction plays a pivotal role in the olfactory system, we evaluated the effects of luteolin on the AC-cAMP pathway that had been stimulated by the odorant eugenol. We demonstrated that eugenol caused an upregulation of the cAMP level and the phosphorylation of phosphokinase A (PKA, a downstream target of cAMP) in human embryonic kidney 293 (HEK293) cells expressing the murine eugenol receptor. This upregulation significantly decreased in the presence of luteolin, suggesting that luteolin inhibited the odorant-induced production of cAMP and affected the downstream phosphorylation of PKA.

  12. Camp Minden

    EPA Pesticide Factsheets

    Camp Minden is a Superfund Site located near the City of Minden, Louisiana. In October 2012, one of the storage bunkers exploded. In October 2014, the EPA signed a Settlement Agreement and selected a method to dispose of the remaining explosives.

  13. Non-raft adenylyl cyclase 2 defines a cAMP signaling compartment that selectively regulates IL-6 expression in airway smooth muscle cells: differential regulation of gene expression by AC isoforms.

    PubMed

    Bogard, Amy S; Birg, Anna V; Ostrom, Rennolds S

    2014-04-01

    Adenylyl cyclase (AC) isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions. Most cell types express multiple AC isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses in human bronchial smooth muscle cells (BSMC). Overexpression of AC2, AC3, or AC6 had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes. These data show that different AC isoforms can differentially regulate gene expression. Most notable, overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production by BSMC was induced by Fsk and select G protein-coupled receptor (GPCR) agonists, though IL-6 levels did not directly correlate with global cAMP levels. Treatment with PKA selective 6-Bnz-cAMP or Epac selective 8-CPT-2Me-cAMP cAMP analogs revealed a predominant role for PKA in cAMP-mediated induction of IL-6. IL-6 promoter mutations demonstrated that AP-1 and CRE transcription sites were required for Fsk to stimulate IL-6 expression. Our present study defines an AC2 cAMP signaling compartment that specifically regulates IL-6 expression in BSMC via Epac and PKA and demonstrates that other AC isoforms are excluded from this pool.

  14. Expression of orphan G-protein coupled receptor GPR174 in CHO cells induced morphological changes and proliferation delay via increasing intracellular cAMP

    SciTech Connect

    Sugita, Kazuya; Yamamura, Chiaki; Tabata, Ken-ichi; Fujita, Norihisa

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer Expression of GPR174 in CHO cells induces morphological changes and proliferation delay. Black-Right-Pointing-Pointer These are due to increase in intracellular cAMP concentration. Black-Right-Pointing-Pointer Lysophosphatidylserine was identified to stimulate GPR174 leading to activate ACase. Black-Right-Pointing-Pointer The potencies of fatty acid moiety on LysoPS were oleoyl Greater-Than-Or-Slanted-Equal-To stearoyl > palmitoyl. Black-Right-Pointing-Pointer We propose that GPR174 is a lysophosphatidylserine receptor. -- Abstract: We established cell lines that stably express orphan GPCR GPR174 using CHO cells, and studied physiological and pharmacological features of the receptor. GPR174-expressing cells showed cell-cell adhesion with localization of actin filaments to cell membrane, and revealed significant delay of cell proliferation. Since the morphological changes of GPR174-cells were very similar to mock CHO cells treated with cholera toxin, we measured the concentration of intracellular cAMP. The results showed the concentration was significantly elevated in GPR174-cells. By measuring intracellular cAMP concentration in GPR174-cells, we screened lipids and nucleotides to identify ligands for GPR174. We found that lysophosphatidylserine (LysoPS) stimulated increase in intracellular cAMP in a dose-dependent manner. Moreover, phosphorylation of Erk was elevated by LysoPS in GPR174 cells. These LysoPS responses were inhibited by NF449, an inhibitor of G{alpha}{sub s} protein. These results suggested that GPR174 was a putative LysoPS receptor conjugating with G{alpha}{sub s}, and its expression induced morphological changes in CHO cells by constitutively activating adenylyl cycles accompanied with cell conjunctions and delay of proliferation.

  15. cGMP-selective phosphodiesterase inhibitors stimulate mitochondrial biogenesis and promote recovery from acute kidney injury.

    PubMed

    Whitaker, Ryan M; Wills, Lauren P; Stallons, L Jay; Schnellmann, Rick G

    2013-12-01

    Recent studies demonstrate that mitochondrial dysfunction is a mediator of acute kidney injury (AKI). Consequently, restoration of mitochondrial function after AKI may be key to the recovery of renal function. Mitochondrial function can be restored through the generation of new, functional mitochondria in a process called mitochondrial biogenesis (MB). Despite its potential therapeutic significance, very few pharmacological agents have been identified to induce MB. To examine the efficacy of phosphodiesterase (PDE) inhibitors (PDE3: cAMP and cGMP activity; and PDE4: cAMP activity) in stimulating MB, primary cultures of renal proximal tubular cells (RPTCs) were treated with a panel of inhibitors for 24 hours. PDE3, but not PDE4, inhibitors increased the FCCP-uncoupled oxygen consumption rate (OCR), a marker of MB. Exposure of RPTCs to the PDE3 inhibitors, cilostamide and trequinsin, for 24 hours increased peroxisome proliferator-activated receptor γ coactivator-1α, and multiple mitochondrial electron transport chain genes. Cilostamide and trequinsin also increased mRNA expression of mitochondrial genes and mitochondrial DNA copy number in mice renal cortex. Consistent with these experiments, 8-Br-cGMP increased FCCP-uncoupled OCR and mitochondrial gene expression, whereas 8-Br-cAMP had no effect. The cGMP-specific PDE5 inhibitor sildenafil also induced MB in RPTCs and in vivo in mouse renal cortex. Treatment of mice with sildenafil after folic acid-induced AKI promoted restoration of MB and renal recovery. These data provide strong evidence that specific PDE inhibitors that increase cGMP are inducers of MB in vitro and in vivo, and suggest their potential efficacy in AKI and other diseases characterized by mitochondrial dysfunction and suppressed MB.

  16. Resveratrol provides neuroprotection by inhibiting phosphodiesterases and regulating the cAMP/AMPK/SIRT1 pathway after stroke in rats.

    PubMed

    Wan, Dan; Zhou, Yehan; Wang, Ke; Hou, Yongying; Hou, Ruihang; Ye, Xiufeng

    2016-03-01

    Dysfunction of energy metabolism can be a significant and fundamental pathophysiological basis for strokes. In studies of both humans and rodents, resveratrol, a natural polyphenol, has been reported to provide protection from cerebral ischemic injury by regulating expression of silent mating type information regulation 2 homolog 1 (SIRT1). However, direct evidence demonstrating that resveratrol exerts neuroprotection from cerebral ischemia injury by decreasing energy consumption is still lacking. Therefore, the aim of this study was to elucidate the mechanisms and signaling pathways through which resveratrol regulates energy metabolism in the ischemic brain, and to identify potential targets of resveratrol. ATP levels in brain tissues were detected by high performance liquid chromatography. SIRT1 and the phosphorylation of adenosine-monophosphate-activated protein kinase (P-AMPK) expressiones were evaluated by western blot. Levels of phosphodiesterase (PDEs) and cAMP were quantitated by real-time PCR and ELISA, respectively. Results showed that resveratrol significantly reduced the harmful effects of cerebral ischemic injury in vivo. Moreover, levels of ATP, p-AMPK, SIRT1, and cAMP were increased by resveratrol and PDE inhibitors. In conclusion, our findings indicate that resveratrol provides neuroprotection by inhibiting PDEs and regulating the cAMP/AMPK/SIRT1 pathway, which reduces ATP energy consumption during ischemia.

  17. Clinical and Molecular Genetics of the Phosphodiesterases (PDEs)

    PubMed Central

    Azevedo, Monalisa F.; Faucz, Fabio R.; Bimpaki, Eirini; Horvath, Anelia; Levy, Isaac; de Alexandre, Rodrigo B.; Ahmad, Faiyaz; Manganiello, Vincent

    2014-01-01

    Cyclic nucleotide phosphodiesterases (PDEs) are enzymes that have the unique function of terminating cyclic nucleotide signaling by catalyzing the hydrolysis of cAMP and GMP. They are critical regulators of the intracellular concentrations of cAMP and cGMP as well as of their signaling pathways and downstream biological effects. PDEs have been exploited pharmacologically for more than half a century, and some of the most successful drugs worldwide today affect PDE function. Recently, mutations in PDE genes have been identified as causative of certain human genetic diseases; even more recently, functional variants of PDE genes have been suggested to play a potential role in predisposition to tumors and/or cancer, especially in cAMP-sensitive tissues. Mouse models have been developed that point to wide developmental effects of PDEs from heart function to reproduction, to tumors, and beyond. This review brings together knowledge from a variety of disciplines (biochemistry and pharmacology, oncology, endocrinology, and reproductive sciences) with emphasis on recent research on PDEs, how PDEs affect cAMP and cGMP signaling in health and disease, and what pharmacological exploitations of PDEs may be useful in modulating cyclic nucleotide signaling in a way that prevents or treats certain human diseases. PMID:24311737

  18. Robustness of self-organizing chemoattractant field arising from precise pulse induction of its breakdown enzyme: a single-cell level analysis of PDE expression in Dictyostelium.

    PubMed

    Masaki, Noritaka; Fujimoto, Koichi; Honda-Kitahara, Mai; Hada, Emi; Sawai, Satoshi

    2013-03-05

    The oscillation of chemoattractant cyclic AMP (cAMP) in Dictyostelium discoideum is a collective phenomenon that occurs when the basal level of extracellular cAMP exceeds a threshold and invokes cooperative mutual excitation of cAMP synthesis and secretion. For pulses to be relayed from cell to cell repetitively, secreted cAMP must be cleared and brought down to the subthreshold level. One of the main determinants of the oscillatory behavior is thus how much extracellular cAMP is degraded by extracellular phosphodiesterase (PDE). To date, the exact nature of PDE gene regulation remains elusive. Here, we performed live imaging analysis of mRNA transcripts for pdsA--the gene encoding extracellular PDE. Our analysis revealed that pdsA is upregulated during the rising phase of cAMP oscillations. Furthermore, by analyzing isolated cells, we show that expression of pdsA is strictly dependent on the presence of extracellular cAMP. pdsA is induced only at ∼1 nM extracellular cAMP, which is almost identical to the threshold concentration for the cAMP relay response. The observed precise regulation of PDE expression together with degradation of extracellular cAMP by PDE form a dual positive and negative feedback circuit, and model analysis shows that this sets the cAMP level near the threshold concentration for the cAMP relay response for a wide range of adenylyl cyclase activity. The overlap of the thresholds could allow oscillations of chemoattractant cAMP to self-organize at various starving conditions, making its development robust to fluctuations in its environment.

  19. Glucagon and cAMP inhibit cholesterol 7alpha-hydroxylase (CYP7A1) gene expression in human hepatocytes: discordant regulation of bile acid synthesis and gluconeogenesis.

    PubMed

    Song, Kwang-Hoon; Chiang, John Y L

    2006-01-01

    The gene encoding cholesterol 7alpha-hydroxylase (CYP7A1) is tightly regulated to control bile acid synthesis and maintain lipid homeostasis. Recent studies in mice suggest that bile acid synthesis is regulated by the fasted-to-fed cycle, and fasting induces CYP7A1 gene expression in parallel to the induction of peroxisome proliferators-activated receptor gamma co-activator 1alpha (PGC-1alpha) and phosphoenolpyruvate carboxykinase (PEPCK). How glucagon regulates CYP7A1 gene expression in the human liver is not clear. Here we show that glucagon and cyclic adenosine monophosphate (cAMP) strongly repressed CYP7A1 mRNA expression in human primary hepatocytes. Reporter assays confirmed that cAMP and protein kinase A (PKA) inhibited human CYP7A1 gene transcription, in contrast to their stimulation of the PEPCK gene. Mutagenesis analysis identified a PKA-responsive region located within the previously identified HNF4alpha binding site in the human CYP7A1 promoter. Glucagon and cAMP increased HNF4alpha phosphorylation and reduced the amount of HNF4alpha present in CYP7A1 chromatin. Our findings suggest that glucagon inhibited CYP7A1 gene expression via PKA phosphorylation of HNF4alpha, which lost its ability to bind the CYP7A1 gene and resulted in inhibition of human CYP7A1 gene transcription. In conclusion, this study unveils a species difference in nutrient regulation of the human and mouse CYP7A1 gene and suggests a discordant regulation of bile acid synthesis and gluconeogenesis by glucagon in human livers during fasting.

  20. cAMP-specific PDE4 phosphodiesterases and AIP in the pathogenesis of pituitary tumors.

    PubMed

    Bolger, Graeme B; Bizzi, Mariana F; Pinheiro, Sergio V; Trivellin, Giampaolo; Smoot, Lisa; Accavitti, Mary-Ann; Korbonits, Márta; Ribeiro-Oliveira, Antonio

    2016-05-01

    PDE4 cyclic nucleotide phosphodiesterases regulate cAMP abundance in cells and therefore regulate numerous processes, including cell growth and differentiation. The rat PDE4A5 isoform (human homolog PDE4A4) interacts with the AIP protein (also called XAP2 or ARA-9). Germline mutations in AIP occur in approximately 20% of patients with Familial Isolated Pituitary Adenoma (FIPA) and 20% of childhood-onset simplex somatotroph adenomas. We therefore examined the protein expression of PDE4A4 and the closely related isoform PDE4A8 in normal human pituitary tissue and in pituitary adenomas. PDE4A4 had low expression in normal pituitary but was significantly overexpressed in somatotroph, lactotroph, corticotroph and clinically nonfunctioning gonadotroph adenomas (P<0.0001 for all subtypes). Likewise, PDE4A8 was expressed in normal pituitary and was also significantly overexpressed in the adenoma subtypes (P<0.0001 for all). Among the different adenoma subtypes, corticotroph and lactotroph adenomas were the highest and lowest expressed for PDE4A4, respectively, whereas the opposite was observed for PDE4A8. Naturally occurring oncogenic variants in AIP were shown by a two-hybrid assay to disrupt the ability of AIP to interact with PDE4A5. A reverse two-hybrid screen identified numerous additional variants in the tetratricopeptide repeat (TPR) region of AIP that also disrupted its ability to interact with PDE4A5. The expression of PDE4A4 and PDE4A8 in normal pituitary, their increased expression in adenomatous pituitary cells where AIP is meant to participate, and the disruption of the PDE4A4-AIP interaction by AIP mutants may play a role in pituitary tumorigenesis.

  1. Regulation of the pro-inflammatory cytokine osteopontin by GIP in adipocytes - A role for the transcription factor NFAT and phosphodiesterase 3B

    SciTech Connect

    Omar, Bilal; Banke, Elin; Guirguis, Emilia; Aakesson, Lina; Manganiello, Vincent; Lyssenko, Valeriya; Groop, Leif; Gomez, Maria F.; Degerman, Eva

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer GIP stimulates lipogenesis and osteopontin expression in primary adipocytes. Black-Right-Pointing-Pointer GIP-induced osteopontin expression is NFAT-dependent. Black-Right-Pointing-Pointer Osteopontin expression is PDE3-dependent. Black-Right-Pointing-Pointer Osteopontin expression is increased in PDE3B KO mice. -- Abstract: The incretin - glucose-dependent insulinotropic polypeptide (GIP) - and the pro-inflammatory cytokine osteopontin are known to have important roles in the regulation of adipose tissue functions. In this work we show that GIP stimulates lipogenesis and osteopontin expression in primary adipocytes. The GIP-induced increase in osteopontin expression was inhibited by the NFAT (the transcription factor nuclear factor of activated T-cells) inhibitor A-285222. Also, the NFAT kinase glycogen synthase kinase (GSK) 3 was upregulated by GIP. To test whether cAMP might be involved in GIP-mediated effects on osteopontin a number of strategies were used. Thus, the {beta}3-adrenergic receptor agonist CL316,243 stimulated osteopontin expression, an effects which was mimicked by OPC3911, a specific inhibitor of phosphodiesterase 3. Furthermore, treatment of phosphodiesterase 3B knock-out mice with CL316,243 resulted in a dramatic upregulation of osteopontin in adipose tissue which was not the case in wild-type mice. In summary, we delineate mechanisms by which GIP stimulates osteopontin in adipocytes. Given the established link between osteopontin and insulin resistance, our data suggest that GIP by stimulating osteopontin expression, also could promote insulin resistance in adipocytes.

  2. A Computational Modeling and Simulation Approach to Investigate Mechanisms of Subcellular cAMP Compartmentation.

    PubMed

    Yang, Pei-Chi; Boras, Britton W; Jeng, Mao-Tsuen; Docken, Steffen S; Lewis, Timothy J; McCulloch, Andrew D; Harvey, Robert D; Clancy, Colleen E

    2016-07-01

    Subcellular compartmentation of the ubiquitous second messenger cAMP has been widely proposed as a mechanism to explain unique receptor-dependent functional responses. How exactly compartmentation is achieved, however, has remained a mystery for more than 40 years. In this study, we developed computational and mathematical models to represent a subcellular sarcomeric space in a cardiac myocyte with varying detail. We then used these models to predict the contributions of various mechanisms that establish subcellular cAMP microdomains. We used the models to test the hypothesis that phosphodiesterases act as functional barriers to diffusion, creating discrete cAMP signaling domains. We also used the models to predict the effect of a range of experimentally measured diffusion rates on cAMP compartmentation. Finally, we modeled the anatomical structures in a cardiac myocyte diad, to predict the effects of anatomical diffusion barriers on cAMP compartmentation. When we incorporated experimentally informed model parameters to reconstruct an in silico subcellular sarcomeric space with spatially distinct cAMP production sites linked to caveloar domains, the models predict that under realistic conditions phosphodiesterases alone were insufficient to generate significant cAMP gradients. This prediction persisted even when combined with slow cAMP diffusion. When we additionally considered the effects of anatomic barriers to diffusion that are expected in the cardiac myocyte dyadic space, cAMP compartmentation did occur, but only when diffusion was slow. Our model simulations suggest that additional mechanisms likely contribute to cAMP gradients occurring in submicroscopic domains. The difference between the physiological and pathological effects resulting from the production of cAMP may be a function of appropriate compartmentation of cAMP signaling. Therefore, understanding the contribution of factors that are responsible for coordinating the spatial and temporal

  3. A Computational Modeling and Simulation Approach to Investigate Mechanisms of Subcellular cAMP Compartmentation

    PubMed Central

    Yang, Pei-Chi; Boras, Britton W.; Jeng, Mao-Tsuen; Lewis, Timothy J.; McCulloch, Andrew D.; Harvey, Robert D.; Clancy, Colleen E.

    2016-01-01

    Subcellular compartmentation of the ubiquitous second messenger cAMP has been widely proposed as a mechanism to explain unique receptor-dependent functional responses. How exactly compartmentation is achieved, however, has remained a mystery for more than 40 years. In this study, we developed computational and mathematical models to represent a subcellular sarcomeric space in a cardiac myocyte with varying detail. We then used these models to predict the contributions of various mechanisms that establish subcellular cAMP microdomains. We used the models to test the hypothesis that phosphodiesterases act as functional barriers to diffusion, creating discrete cAMP signaling domains. We also used the models to predict the effect of a range of experimentally measured diffusion rates on cAMP compartmentation. Finally, we modeled the anatomical structures in a cardiac myocyte diad, to predict the effects of anatomical diffusion barriers on cAMP compartmentation. When we incorporated experimentally informed model parameters to reconstruct an in silico subcellular sarcomeric space with spatially distinct cAMP production sites linked to caveloar domains, the models predict that under realistic conditions phosphodiesterases alone were insufficient to generate significant cAMP gradients. This prediction persisted even when combined with slow cAMP diffusion. When we additionally considered the effects of anatomic barriers to diffusion that are expected in the cardiac myocyte dyadic space, cAMP compartmentation did occur, but only when diffusion was slow. Our model simulations suggest that additional mechanisms likely contribute to cAMP gradients occurring in submicroscopic domains. The difference between the physiological and pathological effects resulting from the production of cAMP may be a function of appropriate compartmentation of cAMP signaling. Therefore, understanding the contribution of factors that are responsible for coordinating the spatial and temporal

  4. Role of phosphodiesterase-4 on ethanol elicited locomotion and narcosis.

    PubMed

    Baliño, Pablo; Ledesma, Juan Carlos; Aragon, Carlos M G

    2016-02-01

    The cAMP signaling pathway has emerged as an important modulator of the pharmacological effects of ethanol. In this respect, the cAMP-dependent protein kinase has been shown to play an important role in the modulation of several ethanol-induced behavioral actions. Cellular levels of cAMP are maintained by the activity of adenylyl cyclases and phosphodiesterases. In the present work we have focused on ascertaining the role of PDE4 in mediating the neurobehavioral effects of ethanol. For this purpose, we have used the selective PDE4 inhibitor Ro 20-1724. This compound has been proven to enhance cellular cAMP response by PDE4 blockade and can be administered systemically. Swiss mice were injected intraperitoneally (i.p.) with Ro 20-1724 (0-5 mg/kg; i.p.) at different time intervals before ethanol (0-4 g/kg; i.p.) administration. Immediately after the ethanol injection, locomotor activity, loss of righting reflex, PKA footprint and enzymatic activity were assessed. Pretreatment with Ro 20-1724 increased ethanol-induced locomotor stimulation in a dose-dependent manner. Doses that increased locomotor stimulation did not modify basal locomotion or the suppression of motor activity produced by high doses of this alcohol. Ro 20-1724 did not alter the locomotor activation produced by amphetamine or cocaine. The time of loss of righting reflex evoked by ethanol was increased after pretreatment with Ro 20-1724. This effect was selective for the narcotic effects of ethanol since Ro 20-1724 did not affect pentobarbital-induced narcotic effects. Moreover, Ro 20-1724 administration increased the PKA footprint and enzymatic activity response elicited by ethanol. These data provide further evidence of the key role of the cAMP signaling pathway in the central effects of ethanol.

  5. Modulation of cAMP levels by high-fat diet and curcumin and regulatory effects on CD36/FAT scavenger receptor/fatty acids transporter gene expression.

    PubMed

    Zingg, Jean-Marc; Hasan, Syeda T; Nakagawa, Kiyotaka; Canepa, Elisa; Ricciarelli, Roberta; Villacorta, Luis; Azzi, Angelo; Meydani, Mohsen

    2017-01-02

    Curcumin, a polyphenol from turmeric (Curcuma longa), reduces inflammation, atherosclerosis, and obesity in several animal studies. In Ldlr(-/-) mice fed a high-fat diet (HFD), curcumin reduces plasma lipid levels, therefore contributing to a lower accumulation of lipids and to reduced expression of fatty acid transport proteins (CD36/FAT, FABP4/aP2) in peritoneal macrophages. In this study, we analyzed the molecular mechanisms by which curcumin (500, 1000, 1500 mg/kg diet, for 4 months) may influence plasma and tissue lipid levels in Ldlr(-/-) mice fed an HFD. In liver, HFD significantly suppressed cAMP levels, and curcumin restored almost normal levels. Similar trends were observed in adipose tissues, but not in brain, skeletal muscle, spleen, and kidney. Treatment with curcumin increased phosphorylation of CREB in liver, what may play a role in regulatory effects of curcumin in lipid homeostasis. In cell lines, curcumin increased the level of cAMP, activated the transcription factor CREB and the human CD36 promoter via a sequence containing a consensus CREB response element. Regulatory effects of HFD and Cur on gene expression were observed in liver, less in skeletal muscle and not in brain. Since the cAMP/protein kinase A (PKA)/CREB pathway plays an important role in lipid homeostasis, energy expenditure, and thermogenesis by increasing lipolysis and fatty acid β-oxidation, an increase in cAMP levels induced by curcumin may contribute to its hypolipidemic and anti-atherosclerotic effects. © 2016 BioFactors, 43(1):42-53, 2017.

  6. Inhibitors of phosphodiesterases PDE2, PDE3, and PDE4 do not increase the sinoatrial tachycardia of noradrenaline and prostaglandin PGE₁ in mice.

    PubMed

    Galindo-Tovar, Alejandro; Vargas, María Luisa; Kaumann, Alberto J

    2016-02-01

    Phosphodiesterases PDE2, PDE3, and PDE4 are expressed in murine sinoatrial cells. PDE3 and/or PDE4 reduce heart rate but apparently do not influence the tachycardia mediated through sinoatrial β1- and β2-adrenoceptors despite the high content of sinoatrial cAMP. The function of PDE2 is, however, uncertain. Prostaglandin PGE1 elicits sinoatrial tachycardia through EP receptors, but the control by phosphodiesterases is unknown. We investigated on spontaneously beating right atria of mice the effects of the PDE2 inhibitors Bay 60-7550 and EHNA on basal beating and the tachycardia produced by noradrenaline (3 nM) and PGE1 (1 μM). Bay 60-7550 (1 μM), but not EHNA (10 μM), increased basal sinoatrial beating. EHNA also failed to produce tachycardia in the presence of the adenosine deaminase inhibitor 2'-deoxycoformycin (10 μM), remaining inconclusive whether PDE2 reduces basal sinoatrial beating. Rolipram (10 μM) and cilostamide (300 nM) caused moderate tachycardia. The tachycardia evoked by Bay 60-7550 was similar in the absence and presence of rolipram. Noradrenaline elicited stable tachycardia that was not increased by Bay 60-7550. A stable tachycardia caused by PGE1 was not increased by the inhibitors of PDE2, PDE3, and PDE4. Unlike PDE3 and PDE4 which reduce murine basal sinoatrial beating, a possible effect of PDE2 needs further research. The stable tachycardia produced by noradrenaline and PGE1, together with the lack potentiation by the inhibitors of PDE2, PDE3, and PDE4, suggests that cAMP generated at the receptor compartments is hardly hydrolyzed by these phophodiesterases. Evidence from human volunteers is consistent with this proposal.

  7. Victory Junction Gang Camp

    ERIC Educational Resources Information Center

    Shell, Ryan

    2007-01-01

    This article describes the Victory Junction Gang Camp, a not-for-profit, NASCAR-themed camp for children with chronic medical conditions that serves 24 different disease groups. The mission of the camp is to give children life-changing camping experiences that are exciting, fun, and empowering in a safe and medically sound environment. While doing…

  8. Astro Camp Plus

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Stennis Space Center's new Astro Camp Plus camp kicked off June 19 for teens ages 13-15. The new camp delves more deeply into the science, math and technology concepts introduced in the center's popular Astro Camp series. Campers including Jasmyne White (left) and Dana Yingst, both of Slidell, La., learn how NASA uses 'podcasting' to broadcast video, and made their own podcasts.

  9. Maternal exposure to secondhand cigarette smoke primes the lung for induction of phosphodiesterase-4D5 isozyme and exacerbated Th2 responses: rolipram attenuates the airway hyperreactivity and muscarinic receptor expression but not lung inflammation and atopy.

    PubMed

    Singh, Shashi P; Mishra, Neerad C; Rir-Sima-Ah, Jules; Campen, Mathew; Kurup, Viswanath; Razani-Boroujerdi, Seddigheh; Sopori, Mohan L

    2009-08-01

    Airway hyperreactivity (AHR), lung inflammation, and atopy are clinical signs of allergic asthma. Gestational exposure to cigarette smoke (CS) markedly increases the risk for childhood allergic asthma. Muscarinic receptors regulate airway smooth muscle tone, and asthmatics exhibit increased AHR to muscarinic agonists. We have previously reported that in a murine model of bronchopulmonary aspergillosis, maternal exposure to mainstream CS increases AHR after acute intratracheal administration of Aspergillus fumigatus extract. However, the mechanism by which gestational CS induces allergic asthma is unclear. We now show for the first time that, compared with controls, mice exposed prenatally to secondhand CS exhibit increased lung inflammation (predominant infiltration by eosinophils and polymorphs), atopy, and airway resistance, and produce proinflammatory cytokines (IL-4, IL-5, IL-6, and IL-13, but not IL-2 or IFN-gamma). These changes, which occur only after an allergen (A. fumigatus extract) treatment, are correlated with marked up-regulated lung expression of M1, M2, and M3 muscarinic receptors and phosphodiesterase (PDE)4D5 isozyme. Interestingly, the PDE4-selective inhibitor rolipram attenuates the increase in AHR, muscarinic receptors, and PDE4D5, but fails to down-regulate lung inflammation, Th2 cytokines, or serum IgE levels. Thus, the fetus is extraordinarily sensitive to CS, inducing allergic asthma after postnatal exposure to allergens. Although the increased AHR might reflect increased PDE4D5 and muscarinic receptor expression, the mechanisms underlying atopy and lung inflammation are unrelated to the PDE4 activity. Thus, PDE4 inhibitors might ease AHR, but are unlikely to attenuate lung inflammation and atopy associated with childhood allergic asthma.

  10. Mitotic activation of the DISC1-inducible cyclic AMP phosphodiesterase-4D9 (PDE4D9), through multi-site phosphorylation, influences cell cycle progression.

    PubMed

    Sheppard, Catherine L; Lee, Louisa C Y; Hill, Elaine V; Henderson, David J P; Anthony, Diana F; Houslay, Daniel M; Yalla, Krishna C; Cairns, Lynne S; Dunlop, Allan J; Baillie, George S; Huston, Elaine; Houslay, Miles D

    2014-09-01

    In Rat-1 cells, the dramatic decrease in the levels of both intracellular cyclic 3'5' adenosine monophosphate (cyclic AMP; cAMP) and in the activity of cAMP-activated protein kinase A (PKA) observed in mitosis was paralleled by a profound increase in cAMP hydrolyzing phosphodiesterase-4 (PDE4) activity. The decrease in PKA activity, which occurs during mitosis, was attributable to PDE4 activation as the PDE4 selective inhibitor, rolipram, but not the phosphodiesterase-3 (PDE3) inhibitor, cilostamide, specifically ablated this cell cycle-dependent effect. PDE4 inhibition caused Rat-1 cells to move from S phase into G2/M more rapidly, to transit through G2/M more quickly and to remain in G1 for a longer period. Inhibition of PDE3 elicited no observable effects on cell cycle dynamics. Selective immunopurification of each of the four PDE4 sub-families identified PDE4D as being selectively activated in mitosis. Subsequent analysis uncovered PDE4D9, an isoform whose expression can be regulated by Disrupted-In-Schizophrenia 1 (DISC1)/activating transcription factor 4 (ATF4) complex, as the sole PDE4 species activated during mitosis in Rat-1 cells. PDE4D9 becomes activated in mitosis through dual phosphorylation at Ser585 and Ser245, involving the combined action of ERK and an unidentified 'switch' kinase that has previously been shown to be activated by H2O2. Additionally, in mitosis, PDE4D9 also becomes phosphorylated at Ser67 and Ser81, through the action of MK2 (MAPKAPK2) and AMP kinase (AMPK), respectively. The multisite phosphorylation of PDE4D9 by all four of these protein kinases leads to decreased mobility (band-shift) of PDE4D9 on SDS-PAGE. PDE4D9 is predominantly concentrated in the perinuclear region of Rat-1 cells but with a fraction distributed asymmetrically at the cell margins. Our investigations demonstrate that the diminished levels of cAMP and PKA activity that characterise mitosis are due to enhanced cAMP degradation by PDE4D9. PDE4D9, was found to

  11. ElaC encodes a novel binuclear zinc phosphodiesterase.

    PubMed

    Vogel, Andreas; Schilling, Oliver; Niecke, Manfred; Bettmer, Jorg; Meyer-Klaucke, Wolfram

    2002-08-09

    ElaC is a widespread gene found in eubacteria, archaebacteria, and mammals with a highly conserved sequence. Two human ElaC variants were recently associated with cancer (Tavtigian, S. V., Simard, J., Teng, D. H., Abtin, V., Baumgard, M., Beck, A., Camp, N. J., Carillo, A. R., Chen, Y., Dayananth, P., Desrochers, M., Dumont, M., Farnham, J. M., Frank, D., Frye, C., Ghaffari, S., Gupte, J. S., Hu, R., Iliev, D., Janecki, T., Kort, E. N., Laity, K. E., Leavitt, A., Leblanc, G., McArthur-Morrison, J., Pederson, A., Penn, B., Peterson, K. T., Reid, J. E., Richards, S., Schroeder, M., Smith, R., Snyder, S. C., Swedlund, B., Swensen, J., Thomas, A., Tranchant, M., Woodland, A. M., Labrie, F., Skolnick, M. H., Neuhausen, S., Rommens, J., and Cannon-Albright, L. A. (2001) Nat. Genet. 27, 172-180; Yanaihara, N., Kohno, T., Takakura, S., Takei, K., Otsuka, A., Sunaga, N., Takahashi, M., Yamazaki, M., Tashiro, H., Fukuzumi, Y., Fujimori, Y., Hagiwara, K., Tanaka, T., and Yokota, J. (2001) Genomics 72, 169-179). Analysis of the primary sequence indicates homology to an arylsulfatase and predicts a metallo-beta-lactamase fold. At present, no ElaC gene product has been investigated. We cloned the Escherichia coli ElaC gene and purified the recombinant gene product. An enzymatic analysis showed that ElaC does not encode an arylsulfatase but rather encodes a phosphodiesterase that hydrolyzes bis(p-nitrophenyl)phosphate with a k(cat) of 59 s(-1) and K' of 4 mm. Kinetic analysis of the dimeric enzyme revealed positive cooperativity for the substrate bis(p-nitrophenyl)phosphate with a Hill coefficient of 1.6, whereas hydrolysis of the substrate thymidine-5'-p-nitrophenyl phosphate followed Michaelis-Menten kinetics. Furthermore, the enzyme is capable of binding two zinc or two iron ions. However, it displays phosphodiesterase activity only in the zinc form. The metal environment characterized by zinc K-edge x-ray absorption spectroscopy was modeled with two histidine residues, one

  12. Intracellular tortuosity underlies slow cAMP diffusion in adult ventricular myocytes

    PubMed Central

    Richards, Mark; Lomas, Oliver; Jalink, Kees; Ford, Kerrie L.; Vaughan-Jones, Richard D.; Lefkimmiatis, Konstantinos; Swietach, Pawel

    2016-01-01

    Aims 3′,5′-Cyclic adenosine monophosphate (cAMP) signals in the heart are often confined to concentration microdomains shaped by cAMP diffusion and enzymatic degradation. While the importance of phosphodiesterases (degradative enzymes) in sculpting cAMP microdomains is well established in cardiomyocytes, less is known about cAMP diffusivity (DcAMP) and factors affecting it. Many earlier studies have reported fast diffusivity, which argues against sharply defined microdomains. Methods and results [cAMP] dynamics in the cytoplasm of adult rat ventricular myocytes were imaged using a fourth generation genetically encoded FRET-based sensor. The [cAMP]-response to the addition and removal of isoproterenol (β-adrenoceptor agonist) quantified the rates of cAMP synthesis and degradation. To obtain a read out of DcAMP, a stable [cAMP] gradient was generated using a microfluidic device which delivered agonist to one half of the myocyte only. After accounting for phosphodiesterase activity, DcAMP was calculated to be 32 µm2/s; an order of magnitude lower than in water. Diffusivity was independent of the amount of cAMP produced. Saturating cAMP-binding sites with the analogue 6-Bnz-cAMP did not accelerate DcAMP, arguing against a role of buffering in restricting cAMP mobility. cAMP diffused at a comparable rate to chemically unrelated but similar sized molecules, arguing for a common physical cause of restricted diffusivity. Lower mitochondrial density and order in neonatal cardiac myocytes allowed for faster diffusion, demonstrating the importance of mitochondria as physical barriers to cAMP mobility. Conclusion In adult cardiac myocytes, tortuosity due to physical barriers, notably mitochondria, restricts cAMP diffusion to levels that are more compatible with microdomain signalling. PMID:27089919

  13. Distinct pools of cAMP centre on different isoforms of adenylyl cyclase in pituitary-derived GH3B6 cells.

    PubMed

    Wachten, Sebastian; Masada, Nanako; Ayling, Laura-Jo; Ciruela, Antonio; Nikolaev, Viacheslav O; Lohse, Martin J; Cooper, Dermot M F

    2010-01-01

    Microdomains have been proposed to explain specificity in the myriad of possible cellular targets of cAMP. Local differences in cAMP levels can be generated by phosphodiesterases, which control the diffusion of cAMP. Here, we address the possibility that adenylyl cyclases, the source of cAMP, can be primary architects of such microdomains. Distinctly regulated adenylyl cyclases often contribute to total cAMP levels in endogenous cellular settings, making it virtually impossible to determine the contribution of a specific isoform. To investigate cAMP dynamics with high precision at the single-isoform level, we developed a targeted version of Epac2-camps, a cAMP sensor, in which the sensor was tagged to a catalytically inactive version of the Ca(2+)-stimulable adenylyl cyclase 8 (AC8). This sensor, and less stringently targeted versions of Epac2-camps, revealed opposite regulation of cAMP synthesis in response to Ca(2+) in GH(3)B(6) pituitary cells. Ca(2+) release triggered by thyrotropin-releasing hormone stimulated the minor endogenous AC8 species. cAMP levels were decreased by inhibition of AC5 and AC6, and simultaneous activation of phosphodiesterases, in different compartments of the same cell. These findings demonstrate the existence of distinct adenylyl-cyclase-centered cAMP microdomains in live cells and open the door to their molecular micro-dissection.

  14. Phosphodiesterase Inhibition to Target the Synaptic Dysfunction in Alzheimer's Disease

    NASA Astrophysics Data System (ADS)

    Bales, Kelly R.; Plath, Niels; Svenstrup, Niels; Menniti, Frank S.

    Alzheimer's Disease (AD) is a disease of synaptic dysfunction that ultimately proceeds to neuronal death. There is a wealth of evidence that indicates the final common mediator of this neurotoxic process is the formation and actions on synaptotoxic b-amyloid (Aβ). The premise in this review is that synaptic dysfunction may also be an initiating factor in for AD and promote synaptotoxic Aβ formation. This latter hypothesis is consistent with the fact that the most common risk factors for AD, apolipoprotein E (ApoE) allele status, age, education, and fitness, encompass suboptimal synaptic function. Thus, the synaptic dysfunction in AD may be both cause and effect, and remediating synaptic dysfunction in AD may have acute effects on the symptoms present at the initiation of therapy and also slow disease progression. The cyclic nucleotide (cAMP and cGMP) signaling systems are intimately involved in the regulation of synaptic homeostasis. The phosphodiesterases (PDEs) are a superfamily of enzymes that critically regulate spatial and temporal aspects of cyclic nucleotide signaling through metabolic inactivation of cAMP and cGMP. Thus, targeting the PDEs to promote improved synaptic function, or 'synaptic resilience', may be an effective and facile approach to new symptomatic and disease modifying therapies for AD. There continues to be a significant drug discovery effort aimed at discovering PDE inhibitors to treat a variety of neuropsychiatric disorders. Here we review the current status of those efforts as they relate to potential new therapies for AD.

  15. Compartmentation of cAMP signalling in cardiomyocytes in health and disease.

    PubMed

    Perera, R K; Nikolaev, V O

    2013-04-01

    3',5'-cyclic adenosine monophosphate (cAMP) is a ubiquitous second messenger critically involved in the regulation of heart function. It has been shown to act in discrete subcellular signalling compartments formed by differentially localized receptors, phosphodiesterases and protein kinases. Cardiac diseases such as hypertrophy or heart failure are associated with structural and functional remodelling of these microdomains which leads to changes in cAMP compartmentation. In this review, we will discuss recent key findings which provided new insights into cAMP compartmentation in cardiomyocytes with a particular focus on its alterations in heart disease.

  16. GS-5759, a Bifunctional β2-Adrenoceptor Agonist and Phosphodiesterase 4 Inhibitor for Chronic Obstructive Pulmonary Disease with a Unique Mode of Action: Effects on Gene Expression in Human Airway Epithelial Cells.

    PubMed

    Joshi, Taruna; Yan, Dong; Hamed, Omar; Tannheimer, Stacey L; Phillips, Gary B; Wright, Clifford D; Kim, Musong; Salmon, Michael; Newton, Robert; Giembycz, Mark A

    2017-02-01

    (R)-6-[(3-{[4-(5-{[2-hydroxy-2-(8-hydroxy-2-oxo-1,2-dihydroquinolin-5-yl)ethyl]amino}pent-1-yn-1-yl)phenyl] carbamoyl}phenyl)sulphonyl]-4-[(3-methoxyphenyl)amino]-8-methylquinoline-3-carboxamide trifluoroacetic acid (GS-5759) is a bifunctional ligand composed of a quinolinone-containing pharmacophore [β2-adrenoceptor agonist orthostere (β2A)] found in several β2-adrenoceptor agonists, including indacaterol, linked covalently to a phosphodiesterase 4 (PDE4) inhibitor related to 6-[3-(dimethylcarbamoyl)benzenesulphonyl]-4-[(3-methoxyphenyl)amino]-8-methylquinoline-3-carboxamide (GSK 256066) by a pent-1-yn-1-ylbenzene spacer. GS-5759 had a similar affinity for PDE4B1 and the native β2-adrenoceptor expressed on BEAS-2B human airway epithelial cells. However, compared with the monofunctional parent compound, β2A, the KA of GS-5759 for the β2-adrenoceptor was 35-fold lower. Schild analysis determined that the affinities of the β-adrenoceptor antagonists, (2R,3R)-1-[(2,3-dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl) amino]-2-butanol (ICI 118551) and propranolol, were agonist-dependent, being significantly lower for GS-5759 than β2A. Collectively, these data can be explained by "forced proximity," bivalent binding where the pharmacophore in GS-5759 responsible for PDE4 inhibition also interacts with a nonallosteric domain within the β2-adrenoceptor that enhances the affinity of β2A for the orthosteric site. Microarray analyses revealed that, after 2-hour exposure, GS-5759 increased the expression of >3500 genes in BEAS-2B cells that were highly rank-order correlated with gene expression changes produced by indacaterol and GSK 256066 in combination (Ind/GSK). Moreover, the line of regression began close to the origin with a slope of 0.88, indicating that the magnitude of most gene expression changes produced by Ind/GSK was quantitatively replicated by GS-5759. Thus, GS-5759 is a novel compound exhibiting dual β2-adrenoceptor agonism and PDE4 inhibition

  17. Histamine H2 receptor antagonism by T-593: studies on cAMP generation in Hepa cells expressing histamine H2 receptor.

    PubMed

    Tashiro, T; Ono, K; Watanabe, T; Inoie, M; Arai, H; Kimura, S; Kurokawa, K

    1999-07-01

    Histamine H2 receptor antagonism by T-593 was investigated in Hepa cells expressing canine histamine H2 receptors. T-593 inhibited generation of cAMP in Hepa cells stimulated by 10(-5) mol/l histamine with an IC50 value of 2.3 x 10(-6) mol/l, (S)-(-)-T-593, one of the enantiomers comprising racemic T-593, inhibited cAMP generation with an IC50 value of 6.1 x 10(-7) mol/l. On the other hand, the other enantiomer (R)-(+)-T-593 exhibited only a negligible effect. Incubation of the cell with (S)-(-)-T-593 for 60 min depressed the maximal response of the concentration-response curve of histamine with a nonparallel rightward shift. The slope of a Schild plot was 1.27. In contrast, (S)-(-)-T-593 caused a parallel rightward shift of the curve, with a Schild plot slope that did not significantly differ from unity, by treating the cells for 15 min. The H2 receptor-blocking action of (S)-(-)-T-593 remained almost unaffected after washing out the drug, whereas the effect of ranitidine was reversible after washing. These results suggest that T-593 possesses a time-dependent insurmountable antagonistic action against histamine H2 receptor. T-593 may interact with the histamine H2 receptor molecule in a slowly associable and dissociable manner.

  18. Engineering of a red-light-activated human cAMP/cGMP-specific phosphodiesterase.

    PubMed

    Gasser, Carlos; Taiber, Sandra; Yeh, Chen-Min; Wittig, Charlotte Helene; Hegemann, Peter; Ryu, Soojin; Wunder, Frank; Möglich, Andreas

    2014-06-17

    Sensory photoreceptors elicit vital physiological adaptations in response to incident light. As light-regulated actuators, photoreceptors underpin optogenetics, which denotes the noninvasive, reversible, and spatiotemporally precise perturbation by light of living cells and organisms. Of particular versatility, naturally occurring photoactivated adenylate cyclases promote the synthesis of the second messenger cAMP under blue light. Here, we have engineered a light-activated phosphodiesterase (LAPD) with complementary light sensitivity and catalytic activity by recombining the photosensor module of Deinococcus radiodurans bacterial phytochrome with the effector module of Homo sapiens phosphodiesterase 2A. Upon red-light absorption, LAPD up-regulates hydrolysis of cAMP and cGMP by up to sixfold, whereas far-red light can be used to down-regulate activity. LAPD also mediates light-activated cAMP and cGMP hydrolysis in eukaryotic cell cultures and in zebrafish embryos; crucially, the biliverdin chromophore of LAPD is available endogenously and does not need to be provided exogenously. LAPD thus establishes a new optogenetic modality that permits light control over diverse cAMP/cGMP-mediated physiological processes. Because red light penetrates tissue more deeply than light of shorter wavelengths, LAPD appears particularly attractive for studies in living organisms.

  19. Isolation and characterization of PDE9A, a novel human cGMP-specific phosphodiesterase.

    PubMed

    Fisher, D A; Smith, J F; Pillar, J S; St Denis, S H; Cheng, J B

    1998-06-19

    We have cloned and characterized the first human isozyme in a new family of cyclic nucleotide phosphodiesterases, PDE9A. By sequence homology in the catalytic domain, PDE9A is almost equidistant from all eight known mammalian PDE families but is most similar to PDE8A (34% amino acid identity) and least like PDE5A (28% amino acid identity). We report the cloning of human cDNA encoding a full-length protein of 593 amino acids, including a 261-amino acid region located near the C terminus that is homologous to the approximately 270-amino acid catalytic domain of other PDEs. PDE9A is expressed in all eight tissues examined as a approximately 2. 0-kilobase mRNA, with highest levels in spleen, small intestine, and brain. The full-length PDE9A was expressed in baculovirus fused to an N-terminal 9-amino acid FLAG tag. Kinetic analysis of the baculovirus-expressed enzyme shows it to be a very high affinity cGMP-specific PDE with a Km of 170 nM for cGMP and 230 microM for cAMP. The Km for cGMP makes PDE9A one of the highest affinity PDEs known. The Vmax for cGMP (4.9 nmol/min/microg recombinant enzyme) is about twice as fast as that of PDE4 for cAMP. The enzyme is about twice as active in vitro in 1-10 mM Mn2+ than in the same concentration of Mg2+ or Ca2+. PDE9A is insensitive (up to 100 microM) to a variety of PDE inhibitors including rolipram, vinpocetine, SKF-94120, dipyridamole, and 3-isobutyl-1-methyl-xanthine but is inhibited (IC50 = 35 microM) by zaprinast, a PDE5 inhibitor. PDE9A lacks a region homologous to the allosteric cGMP-binding regulatory regions found in the cGMP-binding PDEs: PDE2, PDE5, and PDE6.

  20. The Emotional Benefits of Camping.

    ERIC Educational Resources Information Center

    Johnson, Rebecca Cowan

    1991-01-01

    Regardless of participant background, age, or ethnic origin, camp can aid in the following key components of emotional maturity: open, positive and appropriate expression of feelings; self-acceptance; a sense of self; an awareness and acceptance of others and their feelings; the ability to develop relationships; and emotional stability. (LP)

  1. Phosphodiesterase 11A (PDE11A), Enriched in Ventral Hippocampus Neurons, is Required for Consolidation of Social but not Nonsocial Memories in Mice

    PubMed Central

    Hegde, Shweta; Capell, Will R; Ibrahim, Baher A; Klett, Jennifer; Patel, Neema S; Sougiannis, Alexander T; Kelly, Michy P

    2016-01-01

    The capacity to form long-lasting social memories is critical to our health and survival. cAMP signaling in the ventral hippocampal formation (VHIPP) appears to be required for social memory formation, but the phosphodiesterase (PDE) involved remains unknown. Previously, we showed that PDE11A, which degrades cAMP and cGMP, is preferentially expressed in CA1 and subiculum of the VHIPP. Here, we determine whether PDE11A is expressed in neurons where it could directly influence synaptic plasticity and whether expression is required for the consolidation and/or retrieval of social memories. In CA1, and possibly CA2, PDE11A4 is expressed throughout neuronal cell bodies, dendrites (stratum radiatum), and axons (fimbria), but not astrocytes. Unlike PDE2A, PDE9A, or PDE10A, PDE11A4 expression begins very low at postnatal day 7 (P7) and dramatically increases until P28, at which time it stabilizes to young adult levels. This expression pattern is consistent with the fact that PDE11A is required for social long-term memory (LTM) formation during adolescence and adulthood. Male and female PDE11 knockout (KO) mice show normal short-term memory (STM) for social odor recognition (SOR) and social transmission of food preference (STFP), but no LTM 24 h post training. Importantly, PDE11A KO mice show normal LTM for nonsocial odor recognition. Deletion of PDE11A may impair memory consolidation by impairing requisite protein translation in the VHIPP. Relative to WT littermates, PDE11A KO mice show reduced expression of RSK2 and lowered phosphorylation of S6 (pS6–235/236). Together, these data suggest PDE11A is selectively required for the proper consolidation of recognition and associative social memories. PMID:27339393

  2. Short-term or long-term treatments with a phosphodiesterase-4 (PDE4) inhibitor result in opposing agonist-induced Ca2+ responses in endothelial cells

    PubMed Central

    Campos-Toimil, M; Keravis, T; Orallo, F; Takeda, K; Lugnier, C

    2008-01-01

    Background and purpose: We previously reported that agonist-induced rises in cytoplasmic Ca2+ concentration ([Ca2+]i) in human umbilical vein endothelial cells (HUVEC) were inhibited after a short-term (2 min) pre-treatment with cAMP-elevating agents. The aim of this work was to study the effects of longer term (8 h) pre-treatment with dibutyryl-cAMP (db-cAMP) or rolipram, a specific inhibitor of phosphodiesterase-4 (PDE4), on [Ca2+]i, cAMP levels and PDE activity and expression in HUVEC. Experimental approach: [Ca2+]i changes were measured in isolated HUVEC by Fura-2 imaging. Intracellular cAMP levels and PDE4 activity were assessed by enzyme-immunoassay and radio-enzymatic assay, respectively. PDE expression was measured by northern and western blot analysis. Key results: Long-term pre-treatment of HUVEC with rolipram or db-cAMP significantly increased ATP-, histamine- and thrombin-induced [Ca2+]i rises. Short-term pre-treatment with rolipram was associated with an increase in cAMP, whereas long-term pre-treatment was associated with a decrease in cAMP. Long-term pre-treatment with rolipram or db-cAMP induced a significant increase in PDE4 activity and the expression of 74 kDa-PDE4A and 73 kDa-PDE4B was specifically enhanced. All these effects were suppressed by cycloheximide. Conclusions and implications: Our data suggest that sustained inhibition of PDE4 by rolipram induced an increase in PDE4 activity, possibly as a compensatory mechanism to accelerate cAMP degradation and that PDE4A and PDE4B were implicated in the regulation of [Ca2+]i. Thus, isozyme-specific PDE4 inhibitors might be useful as therapeutic agents in diseases where [Ca2+]i handling is altered, such as atherosclerosis, hypertension and tolerance to β-adrenoceptor agonists. PMID:18311187

  3. A Summer Camp Assessment.

    ERIC Educational Resources Information Center

    Pratte, Janice L.; DiNardi, Salvatore R.

    1979-01-01

    Reported are the results of a project assessing the impact of a revised Massachusetts sanitary code on 500 summer camps for children. The study compared camp compliances with the proposed regulations to the level of compliance with existing regulations. (BT)

  4. Michelle: Growing Through Camping

    ERIC Educational Resources Information Center

    Ouellet, Annette M.

    1977-01-01

    A mother, whose physically handicapped 7-year-old daughter has prosthetic feet, describes how her child adjusted well first to a summer day camp and then to a week long camping program run by the Girl Scouts. (GW)

  5. 1,3-Dichloro-2-propanol inhibits progesterone production through the expression of steroidogenic enzymes and cAMP concentration in Leydig cells.

    PubMed

    Sun, Jianxia; Bai, Shun; Bai, Weibin; Zou, Feiyan; Zhang, Lei; Li, Guoqiang; Hu, Yunfeng; Li, Mingwei; Yan, Rian; Su, Zhijian; Huang, Yadong

    2014-07-01

    1,3-Dichloro-2-propanol (1,3-DCP) is a well-known food processing contaminant that has been shown to impede male reproductive function. However, its mechanism of action remains elusive. In this study, the effects of 1,3-DCP on progesterone production were investigated using the R2C Leydig cell model. 1,3-DCP significantly reduced cell viability from 7.48% to 97.4% at doses comprised between 0.5 and 6mM. Single cell gel/comet assays and atomic force microscopy assays showed that 1,3-DCP induced early phase cell apoptosis. In addition, 1,3-DCP significantly reduced progesterone production detected by radioimmunoassay (RIA). The results from quantitative polymerase chain reaction and western blotting demonstrated that the mRNA expression levels of steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage enzyme and 3β-hydroxysteroid dehydrogenase were significantly down-regulated in R2C cells. Particularly, the change rhythm of Star expression was highly consistent with progesterone production. Furthermore, the cyclic adenosine monophosphate (cAMP) and the mitochondrial membrane potential mediated by ROS, which are involved in regulating progesterone synthesis were also decreased in response to the 1,3-DCP treatment. Overall, the data presented here suggested that 1,3-DCP interferes with the male steroidogenic capacity mainly by down-regulating the level of cAMP and the key enzymes involved in the androgen synthesis pathway.

  6. Spilanthol from Acmella Oleracea Lowers the Intracellular Levels of cAMP Impairing NKCC2 Phosphorylation and Water Channel AQP2 Membrane Expression in Mouse Kidney.

    PubMed

    Gerbino, Andrea; Schena, Giorgia; Milano, Serena; Milella, Luigi; Barbosa, Alan Franco; Armentano, Francesca; Procino, Giuseppe; Svelto, Maria; Carmosino, Monica

    2016-01-01

    Acmella oleracea is well recognized in Brazilian traditional medicine as diuretic, although few scientific data have been published to support this effect. Aim of this study was to determine the molecular effect of Acmella oleracea extract and its main alkylamide spilanthol on two major processes involved in the urine concentrating mechanism: Na-K-2Cl symporter (NKCC2) activity in the thick ascending limb and water channel aquaporin 2 accumulation at the apical plasma membrane of collecting duct cells. Phosphorylation of NKCC2 was evaluated as index of its activation by Western blotting. Rate of aquaporin 2 apical expression was analyzed by confocal laser microscopy. Spilanthol-induced intracellular signalling events were dissected by video-imaging experiments. Exposure to spilanthol reduced the basal phosphorylation level of NKCC2 both in freshly isolated mouse kidney slices and in NKCC2-expresing HEK293 cells. In addition, exposure to spilanthol strongly reduced both desmopressin and low Cl--dependent increase in NKCC2 phosphorylation in mouse kidney slices and NKCC2-expressing HEK293 cells, respectively. Similarly, spilanthol reduced both desmopressin- and forskolin-stimulated aquaporin 2 accumulation at the apical plasma membrane of collecting duct in mouse kidney slice and MCD4 cells, respectively. Of note, when orally administered, spilanthol induced a significant increase in both urine output and salt urinary excretion associated with a markedly reduced urine osmolality compared with control mice. Finally, at cellular level, spilanthol rapidly reduced or reversed basal and agonist-increased cAMP levels through a mechanism involving increases in intracellular [Ca2+]. In conclusion, spilanthol-induced inhibition of cAMP production negatively modulates urine-concentrating mechanisms thus holding great promise for its use as diuretic.

  7. Spilanthol from Acmella Oleracea Lowers the Intracellular Levels of cAMP Impairing NKCC2 Phosphorylation and Water Channel AQP2 Membrane Expression in Mouse Kidney

    PubMed Central

    Gerbino, Andrea; Schena, Giorgia; Milano, Serena; Milella, Luigi; Barbosa, Alan Franco; Armentano, Francesca; Procino, Giuseppe; Svelto, Maria; Carmosino, Monica

    2016-01-01

    Acmella oleracea is well recognized in Brazilian traditional medicine as diuretic, although few scientific data have been published to support this effect. Aim of this study was to determine the molecular effect of Acmella oleracea extract and its main alkylamide spilanthol on two major processes involved in the urine concentrating mechanism: Na-K-2Cl symporter (NKCC2) activity in the thick ascending limb and water channel aquaporin 2 accumulation at the apical plasma membrane of collecting duct cells. Phosphorylation of NKCC2 was evaluated as index of its activation by Western blotting. Rate of aquaporin 2 apical expression was analyzed by confocal laser microscopy. Spilanthol-induced intracellular signalling events were dissected by video-imaging experiments. Exposure to spilanthol reduced the basal phosphorylation level of NKCC2 both in freshly isolated mouse kidney slices and in NKCC2-expresing HEK293 cells. In addition, exposure to spilanthol strongly reduced both desmopressin and low Cl−-dependent increase in NKCC2 phosphorylation in mouse kidney slices and NKCC2-expressing HEK293 cells, respectively. Similarly, spilanthol reduced both desmopressin- and forskolin-stimulated aquaporin 2 accumulation at the apical plasma membrane of collecting duct in mouse kidney slice and MCD4 cells, respectively. Of note, when orally administered, spilanthol induced a significant increase in both urine output and salt urinary excretion associated with a markedly reduced urine osmolality compared with control mice. Finally, at cellular level, spilanthol rapidly reduced or reversed basal and agonist-increased cAMP levels through a mechanism involving increases in intracellular [Ca2+]. In conclusion, spilanthol-induced inhibition of cAMP production negatively modulates urine-concentrating mechanisms thus holding great promise for its use as diuretic. PMID:27213818

  8. Camp is a Celebration.

    ERIC Educational Resources Information Center

    North Dakota Farmers Union, Jamestown. Dept. of Youth Activities.

    A camping workbook provides materials for use in discussion of 3 important aspects of farm living: rural power, communication, and conservation. It is intended that this material be used in class sessions held during a junior youth camp. A sample of the youth camp schedule reveals 3 forty-five minute time periods during the day designated as class…

  9. Cyclic nucleotide phosphodiesterase 3A1 protects the heart against ischemia-reperfusion injury.

    PubMed

    Oikawa, Masayoshi; Wu, Meiping; Lim, Soyeon; Knight, Walter E; Miller, Clint L; Cai, Yujun; Lu, Yan; Blaxall, Burns C; Takeishi, Yasuchika; Abe, Jun-ichi; Yan, Chen

    2013-11-01

    Phosphodiesterase 3A (PDE3A) is a major regulator of cAMP in cardiomyocytes. PDE3 inhibitors are used for acute treatment of congestive heart failure, but are associated with increased incidence of arrhythmias and sudden death with long-term use. We previously reported that chronic PDE3A downregulation or inhibition induced myocyte apoptosis in vitro. However, the cardiac protective effect of PDE3A has not been demonstrated in vivo in disease models. In this study, we examined the role of PDE3A in regulating myocardial function and survival in vivo using genetically engineered transgenic mice with myocardial overexpression of the PDE3A1 isozyme (TG). TG mice have reduced cardiac function characterized by reduced heart rate and ejection fraction (52.5±7.8% vs. 83.9±4.7%) as well as compensatory expansion of left ventricular diameter (4.19±0.19mm vs. 3.10±0.18mm). However, there was no maladaptive increase of fibrosis and apoptosis in TG hearts compared to wild type (WT) hearts, and the survival rates also remained the same. The diminution of cardiac contractile function is very likely attributed to a decrease in beta-adrenergic receptor (β-AR) response in TG mice. Importantly, the myocardial infarct size (4.0±1.8% vs. 24.6±3.8%) and apoptotic cell number (1.3±1.0% vs. 5.6±1.5%) induced by ischemia/reperfusion (I/R) injury were significantly attenuated in TG mice. This was associated with decreased expression of inducible cAMP early repressor (ICER) and increased expression of anti-apoptotic protein BCL-2. To further verify the anti-apoptotic effects of PDE3A1, we performed in vitro apoptosis study in isolated adult TG and WT cardiomyocytes. We found that the apoptotic rates stimulated by hypoxia/reoxygenation or H2O2 were indeed significantly reduced in TG myocytes, and the differences between TG and WT myocytes were completely reversed in the presence of the PDE3 inhibitor milrinone. These together indicate that PDE3A1 negatively regulates β-AR signaling

  10. Identification of nucleotide pyrophosphatase/alkaline phosphodiesterase I activity associated with the mouse plasma cell differentiation antigen PC-1.

    PubMed Central

    Rebbe, N F; Tong, B D; Finley, E M; Hickman, S

    1991-01-01

    The protein responsible for both nucleotide pyrophosphatase (EC 3.6.1.9) and alkaline phosphodiesterase I (EC 3.1.4.1) activities was purified from MOPC 315 plasmacytoma cells. A single SDS/PAGE-purified 115-kDa protein band was used to produce a rabbit polyclonal antiserum. This antibody preparation precipitated alkaline phosphodiesterase I activity, indicating that the SDS/PAGE-purified protein was nucleotide pyrophosphatase/alkaline phosphodiesterase I. When used for Western blot analysis, the antiserum detected a 115-kDa protein as well as a 220-kDa protein band. Multiple overlapping cDNA clones were isolated from a cDNA expression library screened with this anti-nucleotide pyrophosphatase/alkaline phosphodiesterase I antiserum. Sequence analysis indicated that the isolated cDNA clones encoded PC-1, a murine plasma cell differentiation antigen. To confirm the suspected enzymatic identity of PC-1, a recombinant PC-1 fusion protein was expressed in bacteria, purified, and used to produce another rabbit polyclonal antiserum. This antiserum likewise immunoprecipitated alkaline phosphodiesterase I activity and recognized the 115-kDa and 220-kDa proteins in Western blot analyses of cell extracts. Furthermore, expression of nucleotide pyrophosphatase/alkaline phosphodiesterase I corresponded directly with mRNA and protein levels of PC-1 in cells known to express different levels of nucleotide pyrophosphatase/alkaline phosphodiesterase I activity. Finally, steroid induction of enzymatic activity was mirrored by levels of PC-1 mRNA and protein expression. Together, these data indicate that the plasma cell differentiation antigen PC-1 is a membrane-bound enzyme, nucleotide pyrophosphatase/alkaline phosphodiesterase I. Images PMID:1647027

  11. Creating healthy camp experiences.

    PubMed

    Walton, Edward A; Tothy, Alison S

    2011-04-01

    The American Academy of Pediatrics has created recommendations for health appraisal and preparation of young people before participation in day or resident camps and to guide health and safety practices for children at camp. These recommendations are intended for parents, primary health care providers, and camp administration and health center staff. Although camps have diverse environments, there are general guidelines that apply to all situations and specific recommendations that are appropriate under special conditions. This policy statement has been reviewed and is supported by the American Camp Association.

  12. Development of a New Radiofluorinated Quinoline Analog for PET Imaging of Phosphodiesterase 5 (PDE5) in Brain

    PubMed Central

    Liu, Jianrong; Wenzel, Barbara; Dukic-Stefanovic, Sladjana; Teodoro, Rodrigo; Ludwig, Friedrich-Alexander; Deuther-Conrad, Winnie; Schröder, Susann; Chezal, Jean-Michel; Moreau, Emmanuel; Brust, Peter; Maisonial-Besset, Aurélie

    2016-01-01

    Phosphodiesterases (PDEs) are enzymes that play a major role in cell signalling by hydrolysing the secondary messengers cyclic adenosine monophosphate (cAMP) and/or cyclic guanosine monophosphate (cGMP) throughout the body and brain. Altered cyclic nucleotide-mediated signalling has been associated with a wide array of disorders, including neurodegenerative disorders. Recently, PDE5 has been shown to be involved in neurodegenerative disorders such as Alzheimer’s disease, but its precise role has not been elucidated yet. To visualize and quantify the expression of this enzyme in brain, we developed a radiotracer for specific PET imaging of PDE5. A quinoline-based lead compound has been structurally modified resulting in the fluoroethoxymethyl derivative ICF24027 with high inhibitory activity towards PDE5 (IC50 = 1.86 nM). Radiolabelling with fluorine-18 was performed by a one-step nucleophilic substitution reaction using a tosylate precursor (RCY(EOB) = 12.9% ± 1.8%; RCP > 99%; SA(EOS) = 70–126 GBq/μmol). In vitro autoradiographic studies of [18F]ICF24027 on different mouse tissue as well as on porcine brain slices demonstrated a moderate specific binding to PDE5. In vivo studies in mice revealed that [18F]ICF24027 was metabolized under formation of brain penetrable radiometabolites making the radiotracer unsuitable for PET imaging of PDE5 in brain. PMID:27110797

  13. Stimulation of StAR expression by cAMP is controlled by inhibition of highly inducible SIK1 via CRTC2, a co-activator of CREB.

    PubMed

    Lee, Jinwoo; Tong, Tiegang; Takemori, Hiroshi; Jefcoate, Colin

    2015-06-15

    In mouse steroidogenic cells the activation of cholesterol metabolism is mediated by steroidogenic acute regulatory protein (StAR). Here, we visualized a coordinated regulation of StAR transcription, splicing and post-transcriptional processing, which are synchronized by salt inducible kinase (SIK1) and CREB-regulated transcription coactivator (CRTC2). To detect primary RNA (pRNA), spliced primary RNA (Sp-RNA) and mRNA in single cells, we generated probe sets by using fluorescence in situ hybridization (FISH). These methods allowed us to address the nature of StAR gene expression and to visualize protein-nucleic acid interactions through direct detection. We show that SIK1 represses StAR expression in Y1 adrenal and MA10 testis cells through inhibition of processing mediated by CRTC2. Digital image analysis matches qPCR analyses of the total cell culture. Evidence is presented for spatially separate accumulation of StAR pRNA and Sp-RNA at the gene loci in the nucleus. These findings establish that cAMP, SIK and CRTC mediate StAR expression through activation of individual StAR gene loci.

  14. Sp1 Upregulates cAMP Response Element-Binding Protein Expression During Retinoic Acid-Induced Mucous Differentiation of Normal Human Bronchial Epithelial Cells

    PubMed Central

    Hong, Jeong Soo; Kim, Seung-Wook; Koo, Ja Seok

    2010-01-01

    Cyclic 3′,5′-adenosine monophosphate (cAMP) response-element (CRE) binding protein (CREB) is an important transcription factor that is differentially regulated in cells of various types. We recently reported that RA rapidly activates CREB without using retinoic acid (RA) receptors RAR and RXR in normal human tracheobronchial epithelial (NHTBE) cells. However, little is known about RA’s role in the physiologic regulation of CREB expression in the early mucous differentiation of NHTBE cells. Here, we report that RA upregulated CREB gene expression and that using 5′-serial deletion promoter analysis and mutagenesis analyses, two Sp1-binding sites located at nucleotides −217 and −150, which flank the transcription initiation site, were essential for RA induction of CREB gene transcription. Furthermore, we found that CREs located at nucleotides −119 and −98 contributed to basal promoter activity. Interestingly, RA also upregulated Sp1 in a time- and dose-dependent manner. Knockdown of endogenous Sp1 using small interfering RNA (siRNA) decreased RA-induced CREB gene expression. However, the converse was not true: knockdown of CREB using CREB siRNA did not affect RA-induced Sp1 gene expression. We conclude that RA upregulates CREB gene expression during the early stage of NHTBE cell differentiation and that RA-inducible Sp1 plays a major role in upregulating human CREB gene expression. This result implies that cooperation of these two transcription factors play a crucial role in mediating early events of normal mucous cell differentiation of bronchial epithelial cells. PMID:17937658

  15. p54nrb/NONO regulates cyclic AMP-dependent glucocorticoid production by modulating phosphodiesterase mRNA splicing and degradation.

    PubMed

    Lu, Jia Yang; Sewer, Marion B

    2015-04-01

    Glucocorticoid production in the adrenal cortex is activated in response to an increase in cyclic AMP (cAMP) signaling. The nuclear protein p54(nrb)/NONO belongs to the Drosophila behavior/human splicing (DBHS) family and has been implicated in several nuclear processes, including transcription, splicing, and RNA export. We previously identified p54(nrb)/NONO as a component of a protein complex that regulates the transcription of CYP17A1, a gene required for glucocorticoid production. Based on the multiple mechanisms by which p54(nrb)/NONO has been shown to control gene expression and the ability of the protein to be recruited to the CYP17A1 promoter, we sought to further define the molecular mechanism by which p54(nrb)/NONO confers optimal cortisol production. We show here that silencing p54(nrb)/NONO expression in H295R human adrenocortical cells decreases the ability of the cells to increase intracellular cAMP production and subsequent cortisol biosynthesis in response to adrenocorticotropin hormone (ACTH) stimulation. Interestingly, the expression of multiple phosphodiesterase (PDE) isoforms, including PDE2A, PDE3A, PDE3B, PDE4A, PDE4D, and PDE11A, was induced in p54(nrb)/NONO knockdown cells. Investigation of the mechanism by which silencing of p54(nrb)/NONO led to increased expression of select PDE isoforms revealed that p54(nrb)/NONO regulates the splicing of a subset of PDE isoforms. Importantly, we also identify a role for p54(nrb)/NONO in regulating the stability of PDE transcripts by facilitating the interaction between the exoribonuclease XRN2 and select PDE transcripts. In summary, we report that p54(nrb)/NONO modulates cAMP-dependent signaling, and ultimately cAMP-stimulated glucocorticoid biosynthesis by regulating the splicing and degradation of PDE transcripts.

  16. p54nrb/NONO Regulates Cyclic AMP-Dependent Glucocorticoid Production by Modulating Phosphodiesterase mRNA Splicing and Degradation

    PubMed Central

    Lu, Jia Yang

    2015-01-01

    Glucocorticoid production in the adrenal cortex is activated in response to an increase in cyclic AMP (cAMP) signaling. The nuclear protein p54nrb/NONO belongs to the Drosophila behavior/human splicing (DBHS) family and has been implicated in several nuclear processes, including transcription, splicing, and RNA export. We previously identified p54nrb/NONO as a component of a protein complex that regulates the transcription of CYP17A1, a gene required for glucocorticoid production. Based on the multiple mechanisms by which p54nrb/NONO has been shown to control gene expression and the ability of the protein to be recruited to the CYP17A1 promoter, we sought to further define the molecular mechanism by which p54nrb/NONO confers optimal cortisol production. We show here that silencing p54nrb/NONO expression in H295R human adrenocortical cells decreases the ability of the cells to increase intracellular cAMP production and subsequent cortisol biosynthesis in response to adrenocorticotropin hormone (ACTH) stimulation. Interestingly, the expression of multiple phosphodiesterase (PDE) isoforms, including PDE2A, PDE3A, PDE3B, PDE4A, PDE4D, and PDE11A, was induced in p54nrb/NONO knockdown cells. Investigation of the mechanism by which silencing of p54nrb/NONO led to increased expression of select PDE isoforms revealed that p54nrb/NONO regulates the splicing of a subset of PDE isoforms. Importantly, we also identify a role for p54nrb/NONO in regulating the stability of PDE transcripts by facilitating the interaction between the exoribonuclease XRN2 and select PDE transcripts. In summary, we report that p54nrb/NONO modulates cAMP-dependent signaling, and ultimately cAMP-stimulated glucocorticoid biosynthesis by regulating the splicing and degradation of PDE transcripts. PMID:25605330

  17. Expression profile of rat hippocampal neurons treated with the neuroprotective compound 2,4-dinitrophenol: up-regulation of cAMP signaling genes.

    PubMed

    Sebollela, Adriano; Freitas-Corrêa, Léo; Oliveira, Fábio F; Mendes, Camila T; Wasilewska-Sampaio, Ana Paula; Camacho-Pereira, Juliana; Galina, Antonio; Brentani, Helena; Passetti, Fabio; De Felice, Fernanda G; Dias-Neto, Emmanuel; Ferreira, Sérgio T

    2010-08-01

    2,4-Dinitrophenol (DNP) is classically known as a mitochondrial uncoupler and, at high concentrations, is toxic to a variety of cells. However, it has recently been shown that, at subtoxic concentrations, DNP protects neurons against a variety of insults and promotes neuronal differentiation and neuritogenesis. The molecular and cellular mechanisms underlying the beneficial neuroactive properties of DNP are still largely unknown. We have now used DNA microarray analysis to investigate changes in gene expression in rat hippocampal neurons in culture treated with low micromolar concentrations of DNP. Under conditions that did not affect neuronal viability, high-energy phosphate levels or mitochondrial oxygen consumption, DNP induced up-regulation of 275 genes and down-regulation of 231 genes. Significantly, several up-regulated genes were linked to intracellular cAMP signaling, known to be involved in neurite outgrowth, synaptic plasticity, and neuronal survival. Differential expression of specific genes was validated by quantitative RT-PCR using independent samples. Results shed light on molecular mechanisms underlying neuroprotection by DNP and point to possible targets for development of novel therapeutics for neurodegenerative disorders.

  18. Pseudomonas aeruginosa Homoserine Lactone Activates Store-operated cAMP and Cystic Fibrosis Transmembrane Regulator-dependent Cl− Secretion by Human Airway Epithelia*

    PubMed Central

    Schwarzer, Christian; Wong, Steven; Shi, James; Matthes, Elizabeth; Illek, Beate; Ianowski, Juan P.; Arant, Ryan J.; Isacoff, Ehud; Vais, Horia; Foskett, J. Kevin; Maiellaro, Isabella; Hofer, Aldebaran M.; Machen, Terry E.

    2010-01-01

    The ubiquitous bacterium Pseudomonas aeruginosa frequently causes hospital-acquired infections. P. aeruginosa also infects the lungs of cystic fibrosis (CF) patients and secretes N-(3-oxo-dodecanoyl)-S-homoserine lactone (3O-C12) to regulate bacterial gene expression critical for P. aeruginosa persistence. In addition to its effects as a quorum-sensing gene regulator in P. aeruginosa, 3O-C12 elicits cross-kingdom effects on host cell signaling leading to both pro- or anti-inflammatory effects. We find that in addition to these slow effects mediated through changes in gene expression, 3O-C12 also rapidly increases Cl− and fluid secretion in the cystic fibrosis transmembrane regulator (CFTR)-expressing airway epithelia. 3O-C12 does not stimulate Cl− secretion in CF cells, suggesting that lactone activates the CFTR. 3O-C12 also appears to directly activate the inositol trisphosphate receptor and release Ca2+ from the endoplasmic reticulum (ER), lowering [Ca2+] in the ER and thereby activating the Ca2+-sensitive ER signaling protein STIM1. 3O-C12 increases cytosolic [Ca2+] and, strikingly, also cytosolic [cAMP], the known activator of CFTR. Activation of Cl− current by 3O-C12 was inhibited by a cAMP antagonist and increased by a phosphodiesterase inhibitor. Finally, a Ca2+ buffer that lowers [Ca2+] in the ER similar to the effect of 3O-C12 also increased cAMP and ICl. The results suggest that 3O-C12 stimulates CFTR-dependent Cl− and fluid secretion in airway epithelial cells by activating the inositol trisphosphate receptor, thus lowering [Ca2+] in the ER and activating STIM1 and store-operated cAMP production. In CF airways, where CFTR is absent, the adaptive ability to rapidly flush the bacteria away is compromised because the lactone cannot affect Cl− and fluid secretion. PMID:20739289

  19. Regulation of cyclooxygenase-2 expression by cAMP response element and mRNA stability in a human airway epithelial cell line exposed to zinc

    SciTech Connect

    Wu Weidong Silbajoris, Robert A.; Cao Dongsun; Bromberg, Philip A.; Zhang Qiao; Peden, David B.; Samet, James M.

    2008-09-01

    Exposure to zinc-laden particulate matter in ambient and occupational settings has been associated with proinflammatory responses in the lung. Cyclooxygenase 2-derived eicosanoids are important modulators of airway inflammation. In this study, we characterized the transcriptional and posttranscriptional events that regulate COX-2 expression in a human bronchial epithelial cell line BEAS-2B exposed to Zn{sup 2+}. Zn{sup 2+} exposure resulted in pronounced increases in COX-2 mRNA and protein expression, which were prevented by pretreatment with the transcription inhibitor actinomycin D, implying the involvement of transcriptional regulation. This was supported by the observation of increased COX-2 promoter activity in Zn{sup 2+}-treated BEAS-2B cells. Mutation of the cAMP response element (CRE), but not the {kappa}B-binding sites in the COX-2 promoter markedly reduced COX-2 promoter activity induced by Zn{sup 2+}. Inhibition of NF{kappa}B activation did not block Zn{sup 2+}-induced COX-2 expression. Measurement of mRNA stability demonstrated that Zn{sup 2+} exposure impaired the degradation of COX-2 mRNA in BEAS-2B cells. This message stabilization effect of Zn{sup 2+} exposure was shown to be dependent on the integrity of the 3'-untranslated region found in the COX-2 transcript. Taken together, these data demonstrate that the CRE and mRNA stability regulates COX-2 expression induced in BEAS-2B cells exposed to extracellular Zn{sup 2+}.

  20. Cyclic AMP, Protein Kinase A, and Phosphodiesterases: Proceedings of an International Workshop

    PubMed Central

    Stratakis, C. A.

    2014-01-01

    Cyclic nucleotides cAMP and cGMP are part of almost all major cellular signaling pathways. Phosphodiesterases (PDEs) are enzymes that regulate the intracellular levels of cAMP and cGMP. Protein kinase A or cAMP-dependent protein kinase mediates most cAMP effects in the cell. Over the last 25 years, various components of this group of molecules have been involved in human diseases, both genetic and acquired. Lately, the PDEs attract more attention. The pharmacological exploitation of the PDE’s ability to regulate cGMP and cAMP, and through them, a variety of signaling pathways, has led to a number of new drugs for diverse applications from the treatment of erectile dysfunction to heart failure, asthma, and chronic obstructive pulmonary disease. We present the abstracts (available online) and selected articles from the proceedings of a meeting that took place at the National Institutes of Health (NIH), Bethesda, MD, June 8–10, 2011. PMID:22951901

  1. Auphen and dibutyryl cAMP suppress growth of hepatocellular carcinoma by regulating expression of aquaporins 3 and 9 in vivo

    PubMed Central

    Peng, Rui; Zhao, Guang-Xi; Li, Jing; Zhang, Yu; Shen, Xi-Zhong; Wang, Ji-Yao; Sun, Jian-Yong

    2016-01-01

    AIM: To investigate whether the regulation of aquaporin 3 (AQP3) and AQP9 induced by Auphen and dibutyryl cAMP (dbcAMP) inhibits hepatic tumorigenesis. METHODS: Expression of AQP3 and AQP9 was detected by Western blot, immunohistochemistry (IHC), and RT-PCR in HCC samples and paired non-cancerous liver tissue samples from 30 hepatocellular carcinoma (HCC) patients. A xenograft tumor model was used in vivo. Nine nude mice were divided into control, Auphen-treated, and dbcAMP-treated groups (n = 3 for each group). AQP3 and AQP9 protein expression after induction of xenograft tumors was detected by IHC and mRNA by RT-PCR analysis. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay and histological evaluation were used to detect apoptosis of tumor cells, and the concentration of serum α-fetoprotein (AFP) was measured using RT-PCR and an ELISA kit. RESULTS: The volumes and weights of tumors decreased significantly in the Auphen- and dbcAMP-treated mice compared with the control mice (P < 0.01). The levels of AQP3 were significantly lower in the Auphen treatment group, and levels of AQP9 were significantly higher in thedbcAMP treatment mice than in the control mice (P < 0.01). The reduction of AQP3 by Auphen and increase of AQP9 by dbcAMP in nude mice suppressed tumor growth of HCC, which resulted in reduced AFP levels in serum and tissues, and apoptosis of tumor cells in the Auphen- and dbcAMP-treated mice, when compared with control mice (P < 0.01). Compared with para-carcinoma tissues, AQP3 expression increased in tumor tissues whereas the expression of AQP9 decreased. By correlating clinicopathological and expression levels, we demonstrated that the expression of AQP3 and AQP9 was correlated with clinical progression of HCC and disease outcomes. CONCLUSION: AQP3 increases in HCC while AQP9 decreases. Regulation of AQP3 and AQP9 expression by Auphen and dbcAMP inhibits the development and growth of HCC. PMID:27022216

  2. Forskolin, an Inducer of Camp, Up-Regulates Acetylcholinesterase Expression and Protects Against Organophosphate Exposure in Neuro 2A Cells

    DTIC Science & Technology

    2004-11-16

    of dbcAMP for 7 days. B. Extracellular AChE expression determined by microassay of 20 µl culture supernatant. C. Cells were lysed with 1% nonidet - P40 ...determined by microassay using 20 µl culture supernatant. C. Intracellular AChE expression. Cells were lysed with 1% nonidet - P40 and the...phosphate buffer containing 1% Nonidet P-40 or with a lysis buffer, T- PER, purchased from Sigma. The homogenate was centrifuged for 10 minutes at 3,000 x g

  3. Altering cAMP levels within a central pattern generator modifies or disrupts rhythmic motor output.

    PubMed

    Clemens, Stefan; Calin-Jageman, Robert; Sakurai, Akira; Katz, Paul S

    2007-12-01

    Cyclic AMP is a second messenger that has been implicated in the neuromodulation of rhythmically active motor patterns. Here, we tested whether manipulating cAMP affects swim motor pattern generation in the mollusc, Tritonia diomedea. Inhibiting adenylyl cyclase (AC) with 9-cyclopentyladenine (9-CPA) slowed or stopped the swim motor pattern. Inhibiting phosphodiesterase with 3-isobutyl-1-methylxanthine (IBMX) or applying dibutyryl-cAMP (dB-cAMP) disrupted the swim motor pattern, as did iontophoresing cAMP into the central pattern generator neuron C2. Additionally, during wash-in, IBMX sometimes temporarily produced extended or spontaneous swim motor patterns. Photolysis of caged cAMP in C2 after initiation of the swim motor pattern inhibited subsequent bursting. These results suggest that cAMP levels can dynamically modulate swim motor pattern generation, possibly shaping the output of the central pattern generator on a cycle-by-cycle basis.

  4. A role for phosphodiesterase 3B in acquisition of brown fat characteristics by white adipose tissue in male mice.

    PubMed

    Guirguis, Emilia; Hockman, Steven; Chung, Youn Wook; Ahmad, Faiyaz; Gavrilova, Oksana; Raghavachari, Nalini; Yang, Yanqin; Niu, Gang; Chen, Xiaoyuan; Yu, Zu Xi; Liu, Shiwei; Degerman, Eva; Manganiello, Vincent

    2013-09-01

    Obesity is linked to various diseases, including insulin resistance, diabetes, and cardiovascular disorders. The idea of inducing white adipose tissue (WAT) to assume characteristics of brown adipose tissue (BAT), and thus gearing it to fat burning instead of storage, is receiving serious consideration as potential treatment for obesity and related disorders. Phosphodiesterase 3B (PDE3B) links insulin- and cAMP-signaling networks in tissues associated with energy metabolism, including WAT. We used C57BL/6 PDE3B knockout (KO) mice to elucidate mechanisms involved in the formation of BAT in epididymal WAT (EWAT) depots. Examination of gene expression profiles in PDE3B KO EWAT revealed increased expression of several genes that block white and promote brown adipogenesis, such as C-terminal binding protein, bone morphogenetic protein 7, and PR domain containing 16, but a clear BAT-like phenotype was not completely induced. However, acute treatment of PDE3B KO mice with the β3-adrenergic agonist, CL316243, markedly increased the expression of cyclooxygenase-2, which catalyzes prostaglandin synthesis and is thought to be important in the formation of BAT in WAT and the elongation of very long-chain fatty acids 3, which is linked to BAT recruitment upon cold exposure, causing a clear shift toward fat burning and the induction of BAT in KO EWAT. These data provide insight into the mechanisms of BAT formation in mouse EWAT, suggesting that, in a C57BL/6 background, an increase in cAMP, caused by ablation of PDE3B and administration of CL316243, may promote differentiation of prostaglandin-responsive progenitor cells in the EWAT stromal vascular fraction into functional brown adipocytes.

  5. Camp Joy: Embracing Diversity.

    ERIC Educational Resources Information Center

    Krehbiel, Amy

    2001-01-01

    Camp Joy (Ohio) offers a racially integrated program to disadvantaged inner-city foster children. To attract quality minority staff, the camp recruits through former campers, word of mouth, a leader-in-training program, job and internship fairs, and networking with nearby colleges and social agencies. Staff training and the intrinsic rewards of…

  6. Orienteering in Camping.

    ERIC Educational Resources Information Center

    Larson, Elston F.

    One of the recent developments in camping is "orienteering", a program using a map and compass. Orienteering can be dovetailed into an overall camping program and used to "point up" the entire program, or it can be confined to a single simple game. The arrangement depends on the situation. The minimum age of the participants should be about 9 or…

  7. Friends' Discovery Camp

    ERIC Educational Resources Information Center

    Seymour, Seth

    2008-01-01

    This article features Friends' Discovery Camp, a program that allows children with and without autism spectrum disorder to learn and play together. In Friends' Discovery Camp, campers take part in sensory-rich experiences, ranging from hands-on activities and performing arts to science experiments and stories teaching social skills. Now in its 7th…

  8. Physical Fitness at Camp.

    ERIC Educational Resources Information Center

    Steen, Thomas B.; And Others

    1990-01-01

    Describes decline in youth fitness, emphasizing role of camping programs in youth fitness education. Describes Michigan camp's fitness program, consisting of daily workouts, fitness education, and record keeping. Describes fitness consultants' role in program. Discusses program's highlights and problems, suggesting changes for future use. Shows…

  9. Camp Nursing: Student Internships.

    ERIC Educational Resources Information Center

    Harwood, Catherine Hoe; Van Hofwegen, Lynn

    2002-01-01

    Camps can meet or supplement their health care delivery needs by using student nurses. Three models for student nurse internships, basic information about nursing education, and tips for negotiating student nurse internships are described. Sidebars present resources for camp health centers, nursing student competence characteristics, types of…

  10. Today's Child - Tomorrow's Camp.

    ERIC Educational Resources Information Center

    Ditter, Robert B.

    1988-01-01

    Are camps solely in the business of providing fun, or are they facilitators of crucial life skills? A social worker explores the fun versus character-building debate, concluding that though camp is not group therapy, it contributes to overall personal growth and to the social and emotional development of all children. (JMM)

  11. Marketing for Camp Trends.

    ERIC Educational Resources Information Center

    Biddle, Alicia

    1998-01-01

    To effectively market a camp, current trends and issues must be considered: specialty programming, the Americans With Disabilities Act, competing recreational programs, changes in the school year, programming for seniors, and accountability. Camps should have a marketing strategy that includes public relations, a marketing plan, a pricing…

  12. Building Communities through Camping.

    ERIC Educational Resources Information Center

    Rubendall, Robert L.

    Summer camp is a type of laboratory for community living. Society's needs have changed from providing a positive summer challenge for idle youth to experimenting with the demands and rewards of working in community groups. Decentralized camping emphasizes the team decision-making approach to teach self-reliance and awareness of democratic…

  13. Camp's "Disneyland" Effect.

    ERIC Educational Resources Information Center

    Renville, Gary

    1999-01-01

    Describes the positive mental, physical, and social growth impacts that the camping experience had on the author, and urges camp program evaluation to plan and implement such changes. Sidebar lists steps of effective evaluation: program goals and objectives, goals of evaluation, implementation of evaluation, data analysis, and findings and…

  14. Maximizing Camp Property.

    ERIC Educational Resources Information Center

    Knapp, Clifford

    1987-01-01

    Provides selected 14-item outdoor-environmental education bibliography and 20-item checklist of factors weekend/summer camp directors should consider when pondering entry into the outdoor education market. Covers issues of camp philosophy, staff, facilities additions/alterations, equipment, food service, competition, environmental impact,…

  15. Impact of Therapeutic Camping

    ERIC Educational Resources Information Center

    Shniderman, Craig M.

    1974-01-01

    There has been little interest in, and only slight illumination of, the impact of therapeutic camping for emotionally disturbed children. This study seeks to validate the belief that camping is therapeutic. Subjects were 52 boys, 5 to 11 1/2 years of age. Results support the hypothesis. (Author/HMV)

  16. cAMP enhances BMP2-signaling through PKA and MKP1-dependent mechanisms

    SciTech Connect

    Ghayor, Chafik; Ehrbar, Martin; Miguel, Blanca San; Graetz, Klaus W.; Weber, Franz E.

    2009-04-03

    Recent studies suggest that the elevation of intracellular cyclic adenosine monophosphate (cAMP) and the activation of the protein kinase A regulate BMP-induced osteogenesis. However, the precise mechanisms underlying the enhancing effect of cAMP on BMP2 signaling were not completely revealed. In this study we investigated the effect of elevated cAMP level and PKA activation on the BMP2-induced osteoblastic differentiation in pluripotent C2C12 cells. Alkaline phosphatase activity and its mRNA were consistently induced by BMP2 treatment. The pretreatment of C2C12 cells with Forskolin, a cAMP generating agent, dbcAMP, an analogue of cAMP, or IBMX (3-isobutyl 1-methyl xanthine), and a nonspecific inhibitor of phosphodiesterases elicited further activation of alkaline phosphatase. Furthermore, elevated intracellular cAMP level increased BMP2-induced MKP1. On the other hand, BMP2-induced Erk phosphorylation (p44/p42) and cell proliferation were suppressed in the presence of cAMP. Thus, cAMP might enhance BMP2-induced osteoblastic differentiation by a MKP1-Erk-dependent mechanism.

  17. Altered responsiveness to cocaine and increased immobility in the forced swim test associated with elevated cAMP response element-binding protein expression in nucleus accumbens.

    PubMed

    Pliakas, A M; Carlson, R R; Neve, R L; Konradi, C; Nestler, E J; Carlezon, W A

    2001-09-15

    Drugs of abuse regulate the transcription factor cAMP response element-binding protein (CREB) in striatal regions, including the nucleus accumbens (NAc). To explore how regulation of CREB in the NAc affects behavior, we used herpes simplex virus (HSV) vectors to elevate CREB expression in this region or to overexpress a dominant-negative mutant CREB (mCREB) that blocks CREB function. Rats treated with HSV-mCREB in place conditioning studies spent more time in environments associated with cocaine, indicating increased cocaine reward. Conversely, rats treated with HSV-CREB spent less time in cocaine-associated environments, indicating increased cocaine aversion. Studies in which drug-environment pairings were varied to coincide with either the early or late effects of cocaine suggest that CREB-associated place aversions reflect increased cocaine withdrawal. Because cocaine withdrawal can be accompanied by symptoms of depression, we examined how altered CREB function in the NAc affects behavior in the forced swim test (FST). Elevated CREB expression increased immobility in the FST, an effect that is opposite to that caused by standard antidepressants and is consistent with a link between CREB and dysphoria. Conversely, overexpression of mCREB decreased immobility, an effect similar to that caused by antidepressants. Moreover, the kappa opioid receptor antagonist nor-Binaltorphimine decreased immobility in HSV-CREB- and HSV-mCREB-treated rats, suggesting that CREB-mediated induction of dynorphin (an endogenous kappa receptor ligand) contributes to immobility behavior in the FST. Exposure to the FST itself dramatically increased CREB function in the NAc. These findings raise the possibility that CREB-mediated transcription within the NAc regulates dysphoric states.

  18. The phosphodiesterase type 2 inhibitor BAY 60-7550 reverses functional impairments induced by brain ischemia by decreasing hippocampal neurodegeneration and enhancing hippocampal neuronal plasticity.

    PubMed

    Soares, Ligia Mendes; Meyer, Erika; Milani, Humberto; Steinbusch, Harry W M; Prickaerts, Jos; de Oliveira, Rúbia M Weffort

    2017-02-01

    Cognitive and affective impairments are the most characterized consequences following cerebral ischemia. BAY 60-7550, a selective phosphodiesterase type 2 inhibitor (PDE2-I), presents memory-enhancing and anxiolytic-like properties. The behavioral effects of BAY 60-7550 have been associated with its ability to prevent hydrolysis of both cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) thereby interfering with neuronal plasticity. Here, we hypothesize that PDE2-I treatment could promote functional recovery after brain ischemia. Mice C57Bl/6 were submitted to bilateral common carotid artery occlusion (BCCAO), an experimental model of transient brain ischemia, for 20 min. During 21 days after reperfusion, the animals were tested in a battery of behavioral tests including the elevated zero maze (EZM), object location task (OLT) and forced swim test (FST). The effects of BAY 60-7550 were evaluated on neuronal nuclei (NeuN), caspase-9, cAMP response element-binding protein (CREB), phosphorylated CREB (pCREB) and brain-derived neurotrophic factor (BDNF) expression in the hippocampus. BCCAO increased anxiety levels, impaired hippocampus-dependent cognitive function and induced despair-like behavior in mice. Hippocampal neurodegeneration was evidenced by a decrease in NeuN and increase incaspase-9 protein levels in BCCAO mice. Ischemic mice also showed low BDNF protein levels in the hippocampus. Repeated treatment with BAY 60-7550 attenuated the behavioral impairments induced by BCCAO in mice. Concomitantly, BAY 60-7550 enhanced expression of pCREB and BDNF protein levels in the hippocampus of ischemic mice. The present findings suggest that chronic inhibition of PDE2 provides functional recovery in BCCAO mice possibly by augmenting hippocampal neuronal plasticity.

  19. Inactivation of oncogenic cAMP-specific phosphodiesterase 4D by miR-139-5p in response to p53 activation

    PubMed Central

    Cao, Bo; Wang, Kebing; Liao, Jun-Ming; Zhou, Xiang; Liao, Peng; Zeng, Shelya X; He, Meifang; Chen, Lianzhou; He, Yulong; Li, Wen; Lu, Hua

    2016-01-01

    Increasing evidence highlights the important roles of microRNAs in mediating p53’s tumor suppression functions. Here, we report miR-139-5p as another new p53 microRNA target. p53 induced the transcription of miR-139-5p, which in turn suppressed the protein levels of phosphodiesterase 4D (PDE4D), an oncogenic protein involved in multiple tumor promoting processes. Knockdown of p53 reversed these effects. Also, overexpression of miR-139-5p decreased PDE4D levels and increased cellular cAMP levels, leading to BIM-mediated cell growth arrest. Furthermore, our analysis of human colorectal tumor specimens revealed significant inverse correlation between the expression of miR-139-5p and that of PDE4D. Finally, overexpression of miR-139-5p suppressed the growth of xenograft tumors, accompanied by decrease in PDE4D and increase in BIM. These results demonstrate that p53 inactivates oncogenic PDE4D by inducing the expression of miR-139-5p. DOI: http://dx.doi.org/10.7554/eLife.15978.001 PMID:27383270

  20. The phosphodiesterase-4 inhibitor rolipram protects from ischemic stroke in mice by reducing blood-brain-barrier damage, inflammation and thrombosis.

    PubMed

    Kraft, Peter; Schwarz, Tobias; Göb, Eva; Heydenreich, Nadine; Brede, Marc; Meuth, Sven G; Kleinschnitz, Christoph

    2013-09-01

    Blood-brain-barrier (BBB) disruption, inflammation and thrombosis are important steps in the pathophysiology of acute ischemic stroke but are still inaccessible to therapeutic interventions. Rolipram specifically inhibits the enzyme phosphodiesterase (PDE) 4 thereby preventing the inactivation of the intracellular second messenger cyclic adenosine monophosphate (cAMP). Rolipram has been shown to relief inflammation and BBB damage in a variety of neurological disorders. We investigated the therapeutic potential of rolipram in a model of brain ischemia/reperfusion injury in mice. Treatment with 10mg/kg rolipram, but not 2 mg/kg rolipram, 2 h after 60 min of transient middle cerebral artery occlusion (tMCAO) reduced infarct volumes by 50% and significantly improved clinical scores on day 1 compared with vehicle-treated controls. Rolipram maintained BBB function upon stroke as indicated by preserved expression of the tight junction proteins occludin and claudin-5. Accordingly, the formation of vascular brain edema was strongly attenuated in mice receiving rolipram. Moreover, rolipram reduced the invasion of neutrophils as well as the expression of the proinflammatory cytokines IL-1β and TNFα but increased the levels of TGFβ-1. Finally, rolipram exerted antithrombotic effects upon stroke and fewer neurons in the rolipram group underwent apoptosis. Rolipram is a multifaceted antiinflammatory and antithrombotic compound that protects from ischemic neurodegeneration in clinically meaningful settings.

  1. Foreign Language Camps: Camp Waskowitz. Teacher's Guide and Planning Book.

    ERIC Educational Resources Information Center

    Baudin, Phil; And Others

    This guide to running a foreign language camp is intended to cover all aspects of camp administration and program planning. The philosophy of language camps is set forth. The chairperson's responsibilities regarding staff recruitment, staff assignments, and handling finances are outlined. Sample schedules for French, Spanish, and German camps are…

  2. Sphingomyelin Phosphodiesterase Acid-like 3A (SMPDL3A) Is a Novel Nucleotide Phosphodiesterase Regulated by Cholesterol in Human Macrophages*

    PubMed Central

    Traini, Mathew; Quinn, Carmel M.; Sandoval, Cecilia; Johansson, Erik; Schroder, Kate; Kockx, Maaike; Meikle, Peter J.; Jessup, Wendy; Kritharides, Leonard

    2014-01-01

    Cholesterol-loaded foam cell macrophages are prominent in atherosclerotic lesions and play complex roles in both inflammatory signaling and lipid metabolism, which are underpinned by large scale reprogramming of gene expression. We performed a microarray study of primary human macrophages that showed that transcription of the sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) gene is up-regulated after cholesterol loading. SMPDL3A protein expression in and secretion from primary macrophages are stimulated by cholesterol loading, liver X receptor ligands, and cyclic AMP, and N-glycosylated SMPDL3A protein is detectable in circulating blood. We demonstrate for the first time that SMPDL3A is a functional phosphodiesterase with an acidic pH optimum. We provide evidence that SMPDL3A is not an acid sphingomyelinase but unexpectedly is active against nucleotide diphosphate and triphosphate substrates at acidic and neutral pH. SMPDL3A is a major source of nucleotide phosphodiesterase activity secreted by liver X receptor-stimulated human macrophages. Extracellular nucleotides such as ATP may activate pro-inflammatory responses in immune cells. Increased expression and secretion of SMPDL3A by cholesterol-loaded macrophage foam cells in lesions may decrease local concentrations of pro-inflammatory nucleotides and potentially represent a novel anti-inflammatory axis linking lipid metabolism with purinergic signaling in atherosclerosis. PMID:25288789

  3. Camp Invention Connects to Classrooms.

    ERIC Educational Resources Information Center

    Krebs, Danute V.; Clark, Barbara D.

    2000-01-01

    This article describes Camp Invention, a national creativity day camp that integrates science, math, social studies, and the arts. The one week camp for children entering grades 2-6 attracts many academically gifted children because of its hands-on curriculum. The camp's curriculum and activities are discussed. (Contains two references.) (CR)

  4. Camping Skills. Environmental Education Curriculum.

    ERIC Educational Resources Information Center

    Topeka Public Schools, KS.

    This unit on camping skills is designed for special education students at the high school level. The objective of the unit is to provide students with an adequate camping knowledge and skill development to allow them to participate in camping activities. There is an emphasis on maintaining environmental quality as a part of good camping practices.…

  5. Transcription of the gene for the gap junctional protein connexin43 and expression of functional cell-to-cell channels are regulated by cAMP.

    PubMed Central

    Mehta, P P; Yamamoto, M; Rose, B

    1992-01-01

    We investigated the mechanism by which cyclic AMP (cAMP) induces gap junctional communication via cell-to-cell channels in a communication-deficient rat Morris hepatoma cell line. We found that under basal conditions, the cells transcribe cx43 at a low level but do not transcribe cx26 or cx32. Elevation of intracellular cAMP, which induced communication, increased cx43 mRNA 15- to 40-fold and the rate of cx43 transcription 6-fold. Cx43 protein was detected by immunostaining in junctions of only those cells in which communication had been induced. We found the regulation by cAMP also in other cell lines; namely, in those with a low basal level of cx43 mRNA. Images PMID:1327297

  6. Camping in the Snow.

    ERIC Educational Resources Information Center

    Brown, Constance

    1979-01-01

    Describes the experience of winter snow camping. Provides suggestions for shelter, snow kitchens, fires and stoves, cooking, latrines, sleeping warm, dehydration prevention, and clothing. Illustrated with full color photographs. (MA)

  7. Pre-Camp Checklists.

    ERIC Educational Resources Information Center

    Camping Magazine, 1995

    1995-01-01

    Provides checklists to prepare for camp opening. Covers such areas as health histories of all campers and staff, staff credentials, condition of facilities and equipment, staff training, horse stables and equipment, and safety of swimming areas. (LP)

  8. Hitler's Death Camps.

    ERIC Educational Resources Information Center

    Wieser, Paul

    1995-01-01

    Presents a high school lesson on Hitler's death camps and the widespread policy of brutality and oppression against European Jews. Includes student objectives, instructional procedures, and a chart listing the value of used clothing taken from the Jews. (CFR)

  9. Phosphodiesterase-10A Inverse Changes in Striatopallidal and Striatoentopeduncular Pathways of a Transgenic Mouse Model of DYT1 Dystonia.

    PubMed

    D'Angelo, Vincenza; Castelli, Valentina; Giorgi, Mauro; Cardarelli, Silvia; Saverioni, Ilaria; Palumbo, Francesca; Bonsi, Paola; Pisani, Antonio; Giampà, Carmela; Sorge, Roberto; Biagioni, Stefano; Fusco, Francesca R; Sancesario, Giuseppe

    2017-02-22

    We report that changes of phosphodiesterase-10A (PDE10A) can map widespread functional imbalance of basal ganglia circuits in a mouse model of DYT1 dystonia overexpressing mutant torsinA. PDE10A is a key enzyme in the catabolism of second messenger cAMP and cGMP, whose synthesis is stimulated by D1 receptors and inhibited by D2 receptors preferentially expressed in striatoentopeducuncular/substantia nigra or striatopallidal pathways, respectively. PDE10A was studied in control mice (NT) and in mice carrying human wild-type torsinA (hWT) or mutant torsinA (hMT). Quantitative analysis of PDE10A expression was assessed in different brain areas by rabbit anti-PDE10A antibody immunohistochemistry and Western blotting. PDE10A-dependent cAMP hydrolyzing activity and PDE10A mRNA were also assessed. Striatopallidal neurons were identified by rabbit anti-enkephalin antibody.In NT mice, PDE10A is equally expressed in medium spiny striatal neurons and in their projections to entopeduncular nucleus/substantia nigra and to external globus pallidus. In hMT mice, PDE10A content selectively increases in enkephalin-positive striatal neuronal bodies; moreover, PDE10A expression and activity in hMT mice, compared with NT mice, significantly increase in globus pallidus but decrease in entopeduncular nucleus/substantia nigra. Similar changes of PDE10A occur in hWT mice, but such changes are not always significant. However, PDE10A mRNA expression appears comparable among NT, hWT, and hMT mice.In DYT1 transgenic mice, the inverse changes of PDE10A in striatoentopeduncular and striatopallidal projections might result over time in an imbalance between direct and indirect pathways for properly focusing movement. The decrease of PDE10A in the striatoentopeduncular/nigral projections might lead to increased intensity and duration of D1-stimulated cAMP/cGMP signaling; conversely, the increase of PDE10A in the striatopallidal projections might lead to increased intensity and duration of D2

  10. Guidebook: InCamp Education for Migrant Farmworkers.

    ERIC Educational Resources Information Center

    Lynch, Robert; Smith, Mona

    An In-Camp Learning Program focuses on the specific needs of the out-of-school youth and adult migrant farmworker. Although its primary intent is that of education, other areas such as health and social services are addressed. In 1975, New York's In-Camp Learning Program focused on the assessed and expressed educational needs of approximately 400…

  11. Cytokine-induced iNOS and ERK1/2 inhibit adenylyl cyclase type 5/6 activity and stimulate phosphodiesterase 4D5 activity in intestinal longitudinal smooth muscle.

    PubMed

    Mahavadi, Sunila; Nalli, Ancy D; Kumar, Divya P; Hu, Wenhui; Kuemmerle, John F; Grider, John R; Murthy, Karnam S

    2014-08-15

    This study identified a distinctive pattern of expression and activity of adenylyl cyclase (AC) and phosphodiesterase (PDE) isoforms in mouse colonic longitudinal smooth muscle cells and determined the changes in their expression and/or activity in response to proinflammatory cytokines (IL-1β and TNF-α) in vitro and 2,4,6 trinitrobenzene sulphonic acid (TNBS)-induced colonic inflammation in vivo. AC5/6 and PDE4D5, expressed in circular muscle cells, were also expressed in longitudinal smooth muscle. cAMP formation was tightly regulated via feedback phosphorylation of AC5/6 and PDE4D5 by PKA. Inhibition of PKA activity by myristoylated PKI blocked phosphorylation of AC5/6 and PDE4D5 and enhanced cAMP formation. TNBS treatment in vivo and IL-1β and TNF-α in vitro induced inducible nitric oxide synthase (iNOS) expression, stimulated ERK1/2 activity, caused iNOS-mediated S-nitrosylation and inhibition of AC5/6, and induced phosphorylation of PDE4D5 and stimulated its activity. The resultant decrease in AC5/6 activity and increase in PDE4D5 activity decreased cAMP formation and smooth muscle relaxation. S-nitrosylation and inhibition of AC5/6 activity were reversed by the iNOS inhibitor 1400W, whereas phosphorylation and activation of PDE4D5 were reversed by the phosphatidylinositol 3-kinase inhibitor LY294002 and the ERK1/2 inhibitor PD98059. The effects of IL-1β or TNF-α on forskolin-stimulated cAMP formation and smooth muscle relaxation reflected inhibition of AC5/6 activity and activation of PDE4D5 and were partly reversed by 1400W or PD98059 and completely reversed by a combination of the two inhibitors. The changes in the cAMP/PKA signaling and smooth muscle relaxation contribute to colonic dysmotility during inflammation.

  12. Therapeutic utility of phosphodiesterase type I inhibitors in neurological conditions.

    PubMed

    Medina, Alexandre E

    2011-01-01

    Neuronal plasticity is an essential property of the brain that is impaired in different neurological conditions. Phosphodiesterase type 1 (PDE1) inhibitors can enhance levels of the second messengers cAMP/cGMP leading to the expression of neuronal plasticity-related genes, neurotrophic factors, and neuroprotective molecules. These neuronal plasticity enhancement properties make PDE1 inhibitors good candidates as therapeutic agents in many neurological conditions. However, the lack of specificity of the drugs currently available poses a challenge to the systematic evaluation of the beneficial effect of these agents. The development of more specific drugs may pave the way for the use of PDE1 inhibitors as therapeutic agents in cases of neurodevelopmental conditions such as fetal alcohol spectrum disorders and in degenerative disorders such as Alzheimer's and Parkinson's.

  13. Methoxychlor and Its Metabolite HPTE Inhibit cAMP Production and Expression of Estrogen Receptors α and β in the Rat Granulosa Cell In Vitro

    PubMed Central

    Harvey, Craig N.; Chen, Joseph C.; Bagnell, Carol A.; Uzumcu, Mehmet

    2015-01-01

    The major metabolite of the estrogenic pesticide methoxychlor (MXC) HPTE is a stronger ESR1 agonist than MXC and acts also as an ESR2 antagonist. In granulosa cells (GCs), FSH stimulates estradiol via the second messenger cAMP. HPTE inhibits estradiol biosynthesis, and this effect is greater in FSH-treated GCs than in cAMP-treated GCs. Therefore; we examined the effect of MXC/HPTE on FSH-stimulated cAMP production in cultured GCs. To test involvement of ESR-signaling, we used the ESR1 and ESR2 antagonist ICI 182,780, ESR2 selective antagonist PHTPP, and ESR2 selective agonist DPN. ESR1 and ESR2 mRNA and protein levels were quantified. Both HPTE and MXC inhibited the FSH-induced cAMP production. ICI 182,780 and PHTPP mimicked the inhibitory action of HPTE. MXC/HPTE reduced FSH-stimulated Esr2 mRNA and protein to basal levels. MXC/HPTE also inhibited FSH-stimulated Esr1. The greater inhibition on FSH-stimulated GCs is likely due to reduced cAMP level that involves ESR-signaling, through ESR2. PMID:25549949

  14. Changes in the expression of LIMP-2 during cerulein-induced pancreatitis in rats: Effect of inhibition of leukocyte infiltration, cAMP and MAPKs early on in its development.

    PubMed

    García-Hernández, Violeta; Sarmiento, Nancy; Sánchez-Bernal, Carmen; Coveñas, Rafael; Hernández-Hernández, Angel; Calvo, José J; Sánchez-Yagüe, Jesús

    2016-03-01

    Lysosomal integral membrane protein-2 (LIMP-2) is an important protein in lysosomal biogenesis and function and also plays a role in the tissue inflammatory response. It is known that lysosomes play a central role in acute pancreatitis, with inflammatory cell infiltration triggering the disease early on. In this study we report increases in pancreatic LIMP-2 protein and mRNA levels as early events that occur during the development of cerulein (Cer)-induced acute pancreatitis (AP) in rats. GdCl3, a macrophage inhibitor, but not FK506, a T lymphocyte inhibitor, was able to reverse the increase in LIMP-2 expression after Cer treatment, although such reversion was abolished if the animals were depleted of neutrophils due to a vinblastine sulfate pre-treatment. Immunostaining revealed that the cellular source of LIMP-2 was mainly acinar cells. Additionally, pre-treatments with the MAPKs inhibitors SP600125 and PD98059, inhibitors of JNK and ERK½ activation, respectively, but not of rolipram, a type IV phosphodiesterase inhibitor, suppressed the increase in the expression of LIMP-2 after Cer administration. Together, these results indicate that neutrophils are able to drive a macrophage activation that would regulate the increase in LIMP-2 expression during the early phase of Cer-induced AP, with the stress kinases JNK and ERK½ also playing a coordinated role in the increase of LIMP-2 expression due to Cer.

  15. Cyclic nucleotide phosphodiesterases (PDEs): coincidence detectors acting to spatially and temporally integrate cyclic nucleotide and non-cyclic nucleotide signals.

    PubMed

    Maurice, Donald H; Wilson, Lindsay S; Rampersad, Sarah N; Hubert, Fabien; Truong, Tammy; Kaczmarek, Milosz; Brzezinska, Paulina; Freitag, Silja I; Umana, M Bibiana; Wudwud, Alie

    2014-04-01

    The cyclic nucleotide second messengers cAMP and cGMP each affect virtually all cellular processes. Although these hydrophilic small molecules readily diffuse throughout cells, it is remarkable that their ability to activate their multiple intracellular effectors is spatially and temporally selective. Studies have identified a critical role for compartmentation of the enzymes which hydrolyse and metabolically inactivate these second messengers, the PDEs (cyclic nucleotide phosphodiesterases), in this specificity. In the present article, we describe several examples from our work in which compartmentation of selected cAMP- or cGMP-hydrolysing PDEs co-ordinate selective activation of cyclic nucleotide effectors, and, as a result, selectively affect cellular functions. It is our belief that therapeutic strategies aimed at targeting PDEs within these compartments will allow greater selectivity than those directed at inhibiting these enzymes throughout the cells.

  16. The phosphodiesterase-4 inhibitor rolipram attenuates heroin-seeking behavior induced by cues or heroin priming in rats.

    PubMed

    Lai, Miaojun; Zhu, Huaqiang; Sun, Anna; Zhuang, Dingding; Fu, Dan; Chen, Weisheng; Zhang, Han-Ting; Zhou, Wenhua

    2014-09-01

    Inhibition of phosphodiesterase-4 (PDE4), an enzyme that specifically hydrolyzes cyclic adenosine monophosphate (cAMP) increases intracellular cAMP/cAMP-response element binding protein (CREB) signaling. Activation of this signaling is considered as an important compensatory response that decreases motivational properties of drugs of abuse. However, it is not known whether PDE4 is involved in heroin seeking. Self-administration of heroin (50 μg/kg/infusion) was performed under the fixed ratio 1 (FR1) schedule for 14 d and then drug seeking was extinguished for 10 d. The progressive ratio schedule was used to evaluate the relative motivational value of heroin reinforcement. After training, the conditioned cue or heroin priming (250 μg/kg) was introduced for the reinstatement of heroin-seeking behavior. Pretreatment (i.p.) with rolipram (0.03-0.3 mg/kg), a prototypical, selective PDE4 inhibitor, failed to inhibit heroin self-administration under the FR1 schedule, but decreased the reward values under the progressive ratio schedule in a dose-dependent manner. In addition, rolipram decreased the reinstatement of heroin seeking induced by cues or heroin priming even at the lowest dose (0.03 mg/kg); in contrast, the highest dose (0.3 mg/kg) of rolipram was required to decrease sucrose reinforcement. Finally, the effects of rolipram on heroin-seeking behavior were correlated with the increases in expression of phosphorylated CREB in the nucleus accumbens. The study demonstrated that rolipram inhibited heroin reward and heroin-seeking behavior. The results suggest that PDE4 plays an essential role in mediating heroin seeking and that PDE4 inhibitors may be used as a potential pharmacotherapeutic approach for heroin addiction.

  17. Regulation of Adrenal Steroidogenesis by the High-affinity Phosphodiesterase 8 Family

    PubMed Central

    Tsai, L-C. L.; Beavo, J. A.

    2014-01-01

    The main function of cyclic AMP phosphodiesterases (PDEs) is to degrade cAMP, a ubiquitous second messenger. Therefore, PDEs can function as prime regulators of cAMP/PKA-dependent processes such as steroidogenesis. Until recently, the roles of the PDE8 family have been largely unexplored, presumably due to the lack of a selective inhibitor. This review focuses on recent reports about the regulatory roles of the PDE8 family in adrenal steroidogenesis, as well as the inhibitory properties and specificity of a new PDE8-selective inhibitor, PF-04957325. We also describe a method of measuring urinary corticosterone levels in vivo as a minimally invasive way of monitoring the stress level in a mouse. PMID:22903278

  18. ABCD of the phosphodiesterase family: interaction and differential activity in COPD

    PubMed Central

    Halpin, David MG

    2008-01-01

    Phosphodiesterases (PDEs) are important enzymes that hydrolyze the cyclic nucleotides adenosine 3′5′-cyclic monophosphate (cAMP) and guanosine 3′5′-cyclic mono-phosphate (cGMP) to their inactive 5′ monophosphates. They are highly conserved across species and as well as their role in signal termination, they also have a vital role in intracellular localization of cyclic nucleotide signaling and integration of the cyclic nucleotide pathways with other signaling pathways. Because of their pivotal role in intracellular signaling, they are now of considerable interest as therapeutic targets in a wide variety diseases, including COPD where PDE inhibitors may have bronchodilator, anti-inflammatory and pulmonary vasodilator actions. This review examines the diversity and cellular localization of the isoforms of PDE, the known and speculative relevance of this to the treatment of COPD, and the range of PDE inhibitors in development together with a discussion of their possible role in treating COPD. PMID:19281073

  19. Active site similarity between human and Plasmodium falciparum phosphodiesterases: considerations for antimalarial drug design

    NASA Astrophysics Data System (ADS)

    Howard, Brittany L.; Thompson, Philip E.; Manallack, David T.

    2011-08-01

    The similarity between Plasmodium falciparum phosphodiesterase enzymes ( PfPDEs) and their human counterparts have been examined and human PDE9A was found to be a suitable template for the construction of homology models for each of the four PfPDE isoforms. In contrast, the architecture of the active sites of each model was most similar to human PDE1. Molecular docking was able to model cyclic guanosine monophosphate (cGMP) substrate binding in each case but a docking mode supporting cyclic adenosine monophosphate (cAMP) binding could not be found. Anticipating the potential of PfPDE inhibitors as anti-malarial drugs, a range of reported PDE inhibitors including zaprinast and sildenafil were docked into the model of PfPDEα. The results were consistent with their reported biological activities, and the potential of PDE1/9 inhibitor analogues was also supported by docking.

  20. Toward the identification of the cardiac cGMP inhibited-phosphodiesterase catalytic site

    NASA Astrophysics Data System (ADS)

    Fossa, Paola; Boggia, Raffaella; Mosti, Luisa

    1998-07-01

    Cyclic nucleotide phosphodiesterases (PDEs) comprise a complex group of enzymes; five major PDE families or classes with distinctive properties have been identified. Among these a great deal of interest has recently been focused on the so called cGMP-inhibited low Km cAMP phosphodiesterase (cGI PDE) or PDE III. A number of positive inotropic agents, including the well-known milrinone, display a specific inhibition of PDE III as primary mechanism of action. Recent studies have been carried out to develop a pharmacophore model of the PDE III active site. We therefore performed molecular modelling and 3D-SAR studies so as to better define structural requirements for potent and selective enzymatic inhibition. The DISCO (DIStance COmparison) strategy has been applied on a set of compounds taken from literature and a milrinone analogue previously synthesized by us, all of which are characterized by a marked inotropic effect but with varying degrees of enzyme selectivity. A common pharmacophoric model was derived, validated and considered as starting point to perform a 3D-SAR study using the GRID force field and PCA (Principal Component Analysis) with the aim of rationally designing more selective inhibitors. This paper presents the results of this theoretical approach.

  1. ERK regulation of phosphodiesterase 4 enhances dopamine-stimulated AMPA receptor membrane insertion.

    PubMed

    Song, Roy S; Massenburg, Ben; Wenderski, Wendy; Jayaraman, Vino; Thompson, Lauren; Neves, Susana R

    2013-09-17

    AMPA-type glutamate receptor (AMPAR) trafficking is essential for modulating synaptic transmission strength. Prior studies that have characterized signaling pathways underlying AMPAR trafficking have identified the cAMP/PKA-mediated phosphorylation of GluA1, an AMPAR subunit, as a key step in the membrane insertion of AMPAR. Inhibition of ERK impairs AMPAR membrane insertion, but the mechanism by which ERK exerts its effect is unknown. Dopamine, an activator of both PKA and ERK, induces AMPAR insertion, but the relationship between the two protein kinases in the process is not understood. We used a combination of computational modeling and live cell imaging to determine the relationship between ERK and PKA in AMPAR insertion. We developed a dynamical model to study the effects of phosphodiesterase 4 (PDE4), a cAMP phosphodiesterase that is phosphorylated and inhibited by ERK, on the membrane insertion of AMPAR. The model predicted that PKA could be a downstream effector of ERK in regulating AMPAR insertion. We experimentally tested the model predictions and found that dopamine-induced ERK phosphorylates and inhibits PDE4. This regulation results in increased cAMP levels and PKA-mediated phosphorylation of DARPP-32 and GluA1, leading to increased GluA1 trafficking to the membrane. These findings provide unique insight into an unanticipated network topology in which ERK uses PDE4 to regulate PKA output during dopamine signaling. The combination of dynamical models and experiments has helped us unravel the complex interactions between two protein kinase pathways in regulating a fundamental molecular process underlying synaptic plasticity.

  2. Effects of estrogen treatment on expression of brain-derived neurotrophic factor and cAMP response element-binding protein expression and phosphorylation in rat amygdaloid and hippocampal structures.

    PubMed

    Zhou, Jin; Zhang, Huaibo; Cohen, Rochelle S; Pandey, Subhash C

    2005-01-01

    Clinical studies indicate an effect of estrogen (E2) on affect and cognition, which may be mediated by the cAMP response element-binding protein (CREB) pathway and CREB-related gene target brain-derived neurotrophic factor (BDNF). We investigated the effect of E2 on CREB expression and phosphorylation and BDNF expression in the amygdala and hippocampus, areas involved in emotional processing. Ovariectomized rats were given 10 microg 17beta-estradiol or vehicle for 14 days and expression of components of the CREB signaling pathway, i.e., CREB, phosphorylated CREB (pCREB), and BDNF in amygdala and hippocampus were investigated using immunogold labeling. Levels of BDNF mRNA were determined by in situ reverse-transcriptase polymerase chain reaction. We also examined the effect of E2 on calcium/calmodulin kinase (CaMK IV) immunolabeling in the hippocampus. E2 increased immunolabeling and mRNA levels of BDNF in the medial and basomedial amygdala and CA1 and CA3 regions of the hippocampus, but not in any other amygdaloid or hippocampal regions examined. E2 increased immunolabeling of CREB and pCREB in the medial and basomedial, but not central or basolateral amygdala. E2 also increased CaMK IV and pCREB immunolabeling in the CA1 and CA3 regions, but not CA2 region or dentate gyrus, of the hippocampus. There was no change in immunolabeling of CREB in any hippocampal region. These data identify a signaling pathway through which E2 increases BDNF expression that may underlie some actions of E2 on affective behavior and indicate neuroanatomical heterogeneity in the E2 effect within the amygdala and hippocampus.

  3. Phosphodiesterases reduce spontaneous sinoatrial beating but not the 'fight or flight' tachycardia elicited by agonists through Gs-protein-coupled receptors.

    PubMed

    Kaumann, Alberto J

    2011-07-01

    Cyclic AMP (cAMP) steers the generation of basal heart beat in the sinoatrial node. It also induces sinoatrial tachycardia and increased cardiac force, elicited through activation of Gs-protein-coupled receptors (GsPCRs). Phosphodiesterases (PDEs) hydrolyse cAMP. In the heart mainly PDE3 and PDE4 would be expected to limit those functions, and the PDE isoenzymes do indeed reduce basal sinoatrial beating rate and blunt the positive inotropic effects of agonists, mediated by GsPCRs. By contrast, recent evidence shows that GsPCR-mediated sinoatrial tachycardia is not controlled by PDE1-5. A PDE-resistant cAMP pool in sinoatrial cells, generated through activation of GsPCRs, including β(1)- and β(2)-adrenoceptors, appears to guarantee unrestrained tachycardia during fight or flight stress.

  4. Regulatory mechanisms of cAMP levels as a multiple target for antiplatelet activity and less bleeding risk.

    PubMed

    Fuentes, Eduardo; Palomo, Iván

    2014-08-01

    Platelet activation is a critical component of atherothrombosis. The multiple pathways of platelet activation limit the effect of specific receptor/pathway inhibitors, resulting in limited clinical efficacy. Recent research has confirmed that combination therapy results in enhanced antithrombotic efficacy without increasing bleeding risk. In this way, the best-known inhibitor and turn off signaling in platelet activation is cAMP. In this article we discuss the mechanisms of regulation of intraplatelet cAMP levels, a) platelet-dependent pathway: Gi/Gs protein-coupled receptors, phosphodiesterase inhibition and activation of PPARs and b) platelet-independent pathway: inhibition of adenosine uptake by erythrocytes. With respect to the association between intraplatelet cAMP levels and bleeding risk it is possible to establish that compounds/drugs with pleitropic effect for increased intraplatelet cAMP level could have an antithrombotic activity with less risk of bleeding.

  5. Basic Camp Management: An Introduction to Camp Administration. Second Edition.

    ERIC Educational Resources Information Center

    Ball, Armand; Ball, Beverly

    From its perspective of experience in the field, this book offers practical and specific guidance for successfully managing an organized summer camp. It may also serve as a beginning orientation for potential camp directors, a quick reference for experienced directors, or a text for entry level courses in practical camp administration. This second…

  6. How Green Is Camping? Environmental Stewardship in North Carolina Camps.

    ERIC Educational Resources Information Center

    Warren, Roger; Bingham, Cindy

    1994-01-01

    A survey of 47 residential camps in North Carolina revealed that most camps had written environmental objectives, practiced recycling, attempted to reduce water use and energy consumption, practiced low-impact camping, included environmental issues in staff training, and provided environmental education to campers. Includes survey questions. (LP)

  7. 36 CFR 13.1222 - Camping.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Camp Campground and other designated areas. (b) Camping in Brooks Camp Campground for more than a total... site in the Brooks Camp Campground while in operation as a designated fee area is prohibited....

  8. 36 CFR 13.1222 - Camping.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Camp Campground and other designated areas. (b) Camping in Brooks Camp Campground for more than a total... site in the Brooks Camp Campground while in operation as a designated fee area is prohibited....

  9. 36 CFR 13.1222 - Camping.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Camp Campground and other designated areas. (b) Camping in Brooks Camp Campground for more than a total... site in the Brooks Camp Campground while in operation as a designated fee area is prohibited....

  10. 36 CFR 13.1222 - Camping.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Camp Campground and other designated areas. (b) Camping in Brooks Camp Campground for more than a total... site in the Brooks Camp Campground while in operation as a designated fee area is prohibited....

  11. 36 CFR 13.1222 - Camping.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Camp Campground and other designated areas. (b) Camping in Brooks Camp Campground for more than a total... site in the Brooks Camp Campground while in operation as a designated fee area is prohibited....

  12. [Phosphodiesterase 3 mediates cross-talk between the protein kinase- and cGMP- dependent pathways and cyclic AMP metabolism].

    PubMed

    Makuch, Edyta; Matuszyk, Janusz

    2012-07-20

    PDE3 is a dual-substrate phosphodiesterase responsible for hydrolyzing both cAMP and cGMP whilst being simultaneously inhibited by cGMP. This feature is related to presence of the 44 amino acid insert in the catalytic domain, which determines the mechanism of introduction of the cyclic nucleotide into the catalytic pocket of the enzyme. Once bound in the catalytic site cGMP results in steric hindrance for cAMP to enter the site. The regulatory domain of PDE3 consists of two hydrophobic regions: NHR1 and NHR2. Their presence defines the enzyme's intracellular localization, thus determining its participation in particular signaling cascades. Due to the properties of PDE3 this enzyme has exceptional importance for the cross-talk between cAMP-dependent signaling and other cascades. There are two different mechanisms of action of PDE3 enzymes in cell signaling pathways. In many signaling cascades assembly of a signalosome is necessary for phosphorylation and activation of the PDE3 proteins. In response to certain hormones and growth factors, PDE3 merges the metabolism of cAMP with protein kinase-dependent signaling pathways. PDE3 also controls the level of cAMP with regard to the alternating concentration of cGMP. This effect occurs in signaling cascades activated by natriuretic peptide.

  13. Regulation of cAMP Intracellular Levels in Human Platelets Stimulated by 2-Arachidonoylglycerol.

    PubMed

    Signorello, Maria Grazia; Leoncini, Giuliana

    2016-05-01

    We demonstrated that in human platelets the endocannabinoid 2-arachidonoylglycerol (2-AG) decreased dose- and time-dependently cAMP intracellular levels. No effect on cAMP decrease induced by 2-AG was observed in the presence of the adenylate cyclase inhibitor SQ22536 as well in platelets pretreated with the thromboxane A2 receptor antagonist, SQ29548 or with aspirin, inhibitor of arachidonic acid metabolism through the cyclooxygenase pathway. An almost complete recovering of cAMP level was measured in platelets pretreated with the specific inhibitor of phosphodiesterase (PDE) 3A, milrinone. In platelets pretreated with LY294002 or MK2206, inhibitors of PI3K/AKT pathway, and with U73122, inhibitor of phospholipase C pathway, only a partial prevention was shown. cAMP intracellular level depends on synthesis by adenylate cyclase and hydrolysis by PDEs. In 2-AG-stimulated platelets adenylate cyclase activity seems to be unchanged. In contrast PDEs appear to be involved. In particular PDE3A was specifically activated, as milrinone reversed cAMP reduction by 2-AG. 2-AG enhanced PDE3A activity through its phosphorylation. The PI3K/AKT pathway and PKC participate to this PDE3A phosphorylation/activation mechanism as it was greatly inhibited by platelet pretreatment with LY294002, MK2206, U73122, or the PKC specific inhibitor GF109203X. Taken together these data suggest that 2-AG potentiates its power of platelet agonist reducing cAMP intracellular level.

  14. Spatiotemporal regulation of cAMP signaling controls the human trophoblast fusion

    PubMed Central

    Gerbaud, Pascale; Taskén, Kjetil; Pidoux, Guillaume

    2015-01-01

    During human placentation, mononuclear cytotrophoblasts fuse to form multinucleated syncytia ensuring hormonal production and nutrient exchanges between the maternal and fetal circulation. Syncytial formation is essential for the maintenance of pregnancy and for fetal growth. The cAMP signaling pathway is the major route to trigger trophoblast fusion and its activation results in phosphorylation of specific intracellular target proteins, in transcription of fusogenic genes and assembly of macromolecular protein complexes constituting the fusogenic machinery at the plasma membrane. Specificity in cAMP signaling is ensured by generation of localized pools of cAMP controlled by cAMP phosphodiesterases (PDEs) and by discrete spatial and temporal activation of protein kinase A (PKA) in supramolecular signaling clusters inside the cell organized by A-kinase-anchoring proteins (AKAPs) and by organization of signal termination by protein phosphatases (PPs). Here we present original observations on the available components of the cAMP signaling pathway in the human placenta including PKA, PDE, and PP isoforms as well as AKAPs. We continue to discuss the current knowledge of the spatiotemporal regulation of cAMP signaling triggering trophoblast fusion. PMID:26441659

  15. Cyclic adenosine 3',5'-monophosphate levels and activities of adenylate cyclase and cyclic adenosine 3',5'-monophosphate phosphodiesterase in Pseudomonas and Bacteroides.

    PubMed Central

    Siegel, L S; Hylemon, P B; Phibbs, P V

    1977-01-01

    A modified Gilman assay was used to determine the concentrations of cyclic adenosine 3',5'-monophosphate (cAMP) in rapidly filtered cells and in the culture filtrates of Pseudomonas aeruginosa, Escherichia coli K-12, and Bacteroides fragilis. In P. aeruginosa cultures, levels of cAMP in the filtrate increased with the culture absorbance (3.5 to 19.8 X 10(-9) M) but did not vary significantly with the carbon source used to support growth. Intracellular concentrations (0.8 to 3.2 X 10(-5) M) were substantially higher and did not vary appreciably during growth or with carbon source. Sodium cAMP (5 mM) failed to reverse the catabolite repression of inducible glucose-6-phosphate dehydrogenase (EC 1.1.1.49) synthesis caused by the addition of 10 mM succinate. Exogenous cAMP also had no discernible effect on the catabolite repression control of inducible mannitol dehydrogenase (EC 1.1.1.67). P. aeruginosa was found to contain both soluble cAMP phosphodiesterase (EC 3.1.4.17) and membrane-associated adenylate cyclase (EC 4.6.1.1) activity, and these were compared to the activities detected in crude extracts of E. coli. B. fragilis crude cell extracts contain neither of these enzyme activities, and little or no cAMP was detected in cells or culture filtrates of this anaerobic bacterium. PMID:187575

  16. Cyclic AMP effectors in African trypanosomes revealed by genome-scale RNA interference library screening for resistance to the phosphodiesterase inhibitor CpdA.

    PubMed

    Gould, Matthew K; Bachmaier, Sabine; Ali, Juma A M; Alsford, Sam; Tagoe, Daniel N A; Munday, Jane C; Schnaufer, Achim C; Horn, David; Boshart, Michael; de Koning, Harry P

    2013-10-01

    One of the most promising new targets for trypanocidal drugs to emerge in recent years is the cyclic AMP (cAMP) phosphodiesterase (PDE) activity encoded by TbrPDEB1 and TbrPDEB2. These genes were genetically confirmed as essential, and a high-affinity inhibitor, CpdA, displays potent antitrypanosomal activity. To identify effectors of the elevated cAMP levels resulting from CpdA action and, consequently, potential sites for adaptations giving resistance to PDE inhibitors, resistance to the drug was induced. Selection of mutagenized trypanosomes resulted in resistance to CpdA as well as cross-resistance to membrane-permeable cAMP analogues but not to currently used trypanocidal drugs. Resistance was not due to changes in cAMP levels or in PDEB genes. A second approach, a genome-wide RNA interference (RNAi) library screen, returned four genes giving resistance to CpdA upon knockdown. Validation by independent RNAi strategies confirmed resistance to CpdA and suggested a role for the identified cAMP Response Proteins (CARPs) in cAMP action. CARP1 is unique to kinetoplastid parasites and has predicted cyclic nucleotide binding-like domains, and RNAi repression resulted in >100-fold resistance. CARP2 and CARP4 are hypothetical conserved proteins associated with the eukaryotic flagellar proteome or with flagellar function, with an orthologue of CARP4 implicated in human disease. CARP3 is a hypothetical protein, unique to Trypanosoma. CARP1 to CARP4 likely represent components of a novel cAMP signaling pathway in the parasite. As cAMP metabolism is validated as a drug target in Trypanosoma brucei, cAMP effectors highly divergent from the mammalian host, such as CARP1, lend themselves to further pharmacological development.

  17. A Flying Summer Camp

    ERIC Educational Resources Information Center

    Mercurio, Frank X.

    1975-01-01

    Describes a five-day summer camp which provided 12 children, ages 9-14, with a complete flying experience. The training consisted of ground school and one hour actual flying time, including the basics of aircraft control and a flight prepared and executed by the students. (MLH)

  18. Recycling at Camp.

    ERIC Educational Resources Information Center

    Cummins, William M.

    1988-01-01

    Outlines a Michigan summer camp's efforts to reduce solid waste disposal by recycling cardboard, tin, glass, aluminum, and plastic milk containers. Points out variables affecting the success of such efforts. Discusses Michigan state funding for the development of recycling programs. (SV)

  19. Saving the Camping Experience.

    ERIC Educational Resources Information Center

    Davies, Jean S.

    1989-01-01

    Discusses developmental encroachment on isolated caves near Pittsford, Vermont. Describes cooperative effort by recreational camps and other agencies to acquire land surrounding cave entrances for conservation. Details successes and hurdles of land acquisition. Describes ongoing work by local campers to maintain and enjoy caves and property. (TES)

  20. Alaska's Logging Camp School.

    ERIC Educational Resources Information Center

    Millward, Robert E.

    1999-01-01

    A visit to Ketchikan, Alaska, reveals a floating, one-teacher logging-camp school that uses multiage grouping and interdisciplinary teaching. There are 10 students. The school gym and playground, bunkhouse, fuel tanks, mess hall, and students' homes bob up and down and are often moved to other sites. (MLH)

  1. Roles of phosphodiesterases in the regulation of the cardiac cyclic nucleotide cross-talk signaling network.

    PubMed

    Zhao, Claire Y; Greenstein, Joseph L; Winslow, Raimond L

    2016-02-01

    The balanced signaling between the two cyclic nucleotides (cNs) cAMP and cGMP plays a critical role in regulating cardiac contractility. Their degradation is controlled by distinctly regulated phosphodiesterase isoenzymes (PDEs), which in turn are also regulated by these cNs. As a result, PDEs facilitate communication between the β-adrenergic and Nitric Oxide (NO)/cGMP/Protein Kinase G (PKG) signaling pathways, which regulate the synthesis of cAMP and cGMP respectively. The phenomena in which the cAMP and cGMP pathways influence the dynamics of each other are collectively referred to as cN cross-talk. However, the cross-talk response and the individual roles of each PDE isoenzyme in shaping this response remain to be fully characterized. We have developed a computational model of the cN cross-talk network that mechanistically integrates the β-adrenergic and NO/cGMP/PKG pathways via regulation of PDEs by both cNs. The individual model components and the integrated network model replicate experimentally observed activation-response relationships and temporal dynamics. The model predicts that, due to compensatory interactions between PDEs, NO stimulation in the presence of sub-maximal β-adrenergic stimulation results in an increase in cytosolic cAMP accumulation and corresponding increases in PKA-I and PKA-II activation; however, the potentiation is small in magnitude compared to that of NO activation of the NO/cGMP/PKG pathway. In a reciprocal manner, β-adrenergic stimulation in the presence of sub-maximal NO stimulation results in modest cGMP elevation and corresponding increase in PKG activation. In addition, we demonstrate that PDE2 hydrolyzes increasing amounts of cAMP with increasing levels of β-adrenergic stimulation, and hydrolyzes increasing amounts of cGMP with decreasing levels of NO stimulation. Finally, we show that PDE2 compensates for inhibition of PDE5 both in terms of cGMP and cAMP dynamics, leading to cGMP elevation and increased PKG activation

  2. Modulation of Compartmentalised Cyclic Nucleotide Signalling via Local Inhibition of Phosphodiesterase Activity

    PubMed Central

    Brescia, Marcella; Zaccolo, Manuela

    2016-01-01

    Cyclic nucleotide phosphodiesterases (PDEs) are the only enzymes that degrade the cyclic nucleotides cAMP and cGMP, and play a key role in modulating the amplitude and duration of the signal delivered by these two key intracellular second messengers. Defects in cyclic nucleotide signalling are known to be involved in several pathologies. As a consequence, PDEs have long been recognized as potential drug targets, and they have been the focus of intense research for the development of therapeutic agents. A number of PDE inhibitors are currently available for the treatment of disease, including obstructive pulmonary disease, erectile dysfunction, and heart failure. However, the performance of these drugs is not always satisfactory, due to a lack of PDE-isoform specificity and their consequent adverse side effects. Recent advances in our understanding of compartmentalised cyclic nucleotide signalling and the role of PDEs in local regulation of cAMP and cGMP signals offers the opportunity for the development of novel strategies for therapeutic intervention that may overcome the current limitation of conventional PDE inhibitors. PMID:27706091

  3. An adenylyl cyclase with a phosphodiesterase domain in basal plants with a motile sperm system

    PubMed Central

    Kasahara, Masahiro; Suetsugu, Noriyuki; Urano, Yuki; Yamamoto, Chiaki; Ohmori, Mikiya; Takada, Yuki; Okuda, Shujiro; Nishiyama, Tomoaki; Sakayama, Hidetoshi; Kohchi, Takayuki; Takahashi, Fumio

    2016-01-01

    Adenylyl cyclase (AC), which produces the signalling molecule cAMP, has numerous important cellular functions in diverse organisms from prokaryotes to eukaryotes. Here we report the identification and characterization of an AC gene from the liverwort Marchantia polymorpha. The encoded protein has both a C-terminal AC catalytic domain similar to those of class III ACs and an N-terminal cyclic nucleotide phosphodiesterase (PDE) domain that degrades cyclic nucleotides, thus we designated the gene MpCAPE (COMBINED AC with PDE). Biochemical analyses of recombinant proteins showed that MpCAPE has both AC and PDE activities. In MpCAPE-promoter-GUS lines, GUS activity was specifically detected in the male sexual organ, the antheridium, suggesting MpCAPE and thus cAMP signalling may be involved in the male reproductive process. CAPE orthologues are distributed only in basal land plants and charophytes that use motile sperm as the male gamete. CAPE is a subclass of class III AC and may be important in male organ and cell development in basal plants. PMID:27982074

  4. Immunomodulatory Effects of Lippia sidoides Extract: Induction of IL-10 Through cAMP and p38 MAPK-Dependent Mechanisms

    PubMed Central

    Rajgopal, Arun; Rebhun, John F.; Burns, Charlie R.; Scholten, Jeffrey D.; Balles, John A.

    2015-01-01

    Abstract Lippia sidoides is an aromatic shrub that grows wild in the northeastern region of Brazil. In local traditional medicine, the aerial portions of this species are used as anti-infectives, antiseptics, spasmolytics, sedatives, hypotensives, and anti-inflammatory agents. In this research, we evaluate the potential immunological properties of Lippia extract through in vitro analysis of its ability to modulate intracellular cyclic adenosine monophosphate (cAMP) levels and interleukin-10 (IL-10) production. These results show that Lippia extract increases intracellular cAMP through the inhibition of phosphodiesterase activity. They also demonstrate that Lippia extract increases IL-10 production in THP-1 monocytes through both an increase in intracellular cAMP and the activation of p38 MAPK. These results suggest that the Lippia-mediated inhibition of phosphodiesterase activity and the subsequent increase in intracellular cAMP may explain some of the biological activities associated with L. sidoides. In addition, the anti-inflammatory activity of L. sidoides may also be due, in part, to its ability to induce IL-10 production through the inhibition of cyclic nucleotide-dependent phosphodiesterase activity and by its activation of the p38 MAPK pathway. PMID:25599252

  5. Advances in targeting cyclic nucleotide phosphodiesterases

    PubMed Central

    Maurice, Donald H.; Ke, Hengming; Ahmad, Faiyaz; Wang, Yousheng; Chung, Jay; Manganiello, Vincent C.

    2014-01-01

    Cyclic nucleotide phosphodiesterases (PDEs) catalyse the hydrolysis of cyclic AMP and cyclic GMP, thereby regulating the intracellular concentrations of these cyclic nucleotides, their signalling pathways and, consequently, myriad biological responses in health and disease. Currently, a small number of PDE inhibitors are used clinically for treating the pathophysiological dysregulation of cyclic nucleotide signalling in several disorders, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication and chronic obstructive pulmonary disease. However, pharmaceutical interest in PDEs has been reignited by the increasing understanding of the roles of individual PDEs in regulating the subcellular compartmentalization of specific cyclic nucleotide signalling pathways, by the structure-based design of novel specific inhibitors and by the development of more sophisticated strategies to target individual PDE variants. PMID:24687066

  6. PET measurements of cAMP-mediated phosphodiesterase-4 with (R)-[11C]rolipram.

    PubMed

    Kenk, Miran; Thomas, Adam; Lortie, Mireille; Dekemp, Rob; Beanlands, Rob S; Dasilva, Jean N

    2011-01-01

    Cyclic adenosine monophosphate (cAMP) is the common second messenger in signal-transduction cascades originating at a number of monoamine receptors involved in neurotransmission, cardiac function and smooth muscle contraction. Altered regulation of cAMP synthesis (at receptors, G-protein subunits or adenylyl cyclase) and breakdown by phosphodiesterase (PDE) enzymes have been implicated in a number of pathologies. The PDE4 inhibitor (R)-rolipram, and the less active (S)- enantiomer, have been labeled with carbon-11 and characterized by in vivo and in vitro experiments for use in the evaluation of altered PDE4 levels in the brain and cardiac tissues. (R)-[11C]Rolipram has been shown to bind selectively to PDE4 over other PDE isozymes, with specific binding reflecting approximately 80 and 40% of the total detected radioactivity in the rat brain and the heart, respectively. Tracer retention in PDE4-rich tissues is increased by cAMP-elevating treatments, as detected by in vivo PET studies and ex vivo biodistribution experiments. In vivo PET imaging studies display strong region-specific signal in the brain and heart, as evaluated in rats, pigs, monkeys and humans. Impaired cAMP-mediated signaling was observed in animal models of aging, obesity, anthracycline-induced cardiotoxicity and myocardial infarction using (R)-[11C]rolipram. Given the critical role of cAMP in multiple hormonal pathways, the good safety profile and well-characterized pharmacokinetics, (R)-[11C]rolipram PET imaging provides a novel tool for serial monitoring of cAMP-mediated signaling at the PDE4 level, yielding insight into pathological progression with potential for directing therapy.

  7. Cell-cell contact mediates cAMP secretion in Dictyostelium discoideum.

    PubMed

    Fontana, D R; Price, P L; Phillips, J C

    1991-01-01

    Cyclic adenosine 3':5' monophosphate (cAMP) and cell-cell contact regulate developmental gene expression in Dictyostelium discoideum. Developing D. discoideum amoebae synthesize and secrete cAMP following the binding of cAMP to their surface cAMP receptor, a response called cAMP signaling. We have demonstrated two responses of developing D. discoideum amoebae to cell-cell contact. Cell-cell contact elicits cAMP secretion and alters the amount of cAMP secreted in a subsequent cAMP signaling response. Depending upon experimental conditions, bacterial-amoebal contact and amoebal-amoebal contact can enhance or diminish the amount of cAMP secreted during a subsequent cAMP signaling response. We have hypothesized that cell-cell contact regulates D. discoideum development by altering cellular and extracellular levels of cAMP. To begin testing this hypothesis, these responses were further characterized. The two responses to cell-cell contact are independent, i.e., they can each occur in the absence of the other. The responses to cell-cell contact also have unique temperature dependences when compared to each other, cAMP signaling, and phagocytosis. This suggests that these four responses have unique steps in their transduction mechanisms. The secretion of cAMP in response to cell-cell contact appears to be a non-specific response; contact between D. discoideum amoebae and Enterobacter aerogenes, latex beads, or other amoebae elicits cAMP secretion. Despite the apparent similarities of the effects of bacterial-amoebal and amoebal-amoebal contact on the cAMP signaling response, this contact-induced response appears to be specific. Latex beads addition does not alter the magnitude of a subsequent cAMP signaling response.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Day Camp Manual: A Study of Mandatory Standards and Desirable Camping Practices for Children's Day Camps. Book V. Revised 1974.

    ERIC Educational Resources Information Center

    Babcock, William

    The final book in a 5-book day camp manual is a questionnaire developed by the Ontario Camping Association to help directors of children's summer day camps check camp operations, principles, and procedures, and to help them determine how and where a camp can be improved. The questionnaire, to be completed by the director with the aid of another…

  9. cAMP and in vivo hypoxia induce tob, ifr1, and fos expression in erythroid cells of the chick embryo.

    PubMed

    Dragon, Stefanie; Offenhäuser, Nina; Baumann, Rosemarie

    2002-04-01

    During avian embryonic development, terminal erythroid differentiation occurs in the circulation. Some of the key events, such as the induction of erythroid 2,3-bisphosphoglycerate (2,3-BPG), carbonic anhydrase (CAII), and pyrimidine 5'-nucleotidase (P5N) synthesis are oxygen dependent (Baumann R, Haller EA, Schöning U, and Weber M, Dev Biol 116: 548-551, 1986; Dragon S and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 280: R870-R878, 2001; Dragon S, Carey C, Martin K, and Baumann R, J Exp Biol 202: 2787-2795, 1999; Dragon S, Glombitza S, Götz R, and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 271: R982-R989, 1996; Dragon S, Hille R, Götz R, and Baumann R, Blood 91: 3052-3058, 1998; Million D, Zillner P, and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 261: R1188-R1196, 1991) in an indirect way: hypoxia stimulates the release of norepinephrine (NE)/adenosine into the circulation (Dragon et al., J Exp Biol 202: 2787-2795, 1999; Dragon et al., Am J Physiol Regulatory Integrative Comp Physiol 271: R982-R989, 1996). This leads via erythroid beta-adrenergic/adenosine A(2) receptor activation to a cAMP signal inducing several proteins in a transcription-dependent manner (Dragon et al., Am J Physiol Regulatory Integrative Comp Physiol 271: R982-R989, 1996; Dragon et al., Blood 91: 3052-3058, 1998; Glombitza S, Dragon S, Berghammer M, Pannermayr M, and Baumann R, Am J Physiol Regulatory Integrative Comp Physiol 271: R973-R981, 1996). To understand how the cAMP-dependent processes are initiated, we screened an erythroid cDNA library for cAMP-regulated genes. We detected three genes that were strongly upregulated (>5-fold) by cAMP in definitive and primitive red blood cells. They are homologous to the mammalian Tob, Ifr1, and Fos proteins. In addition, the genes are induced in the intact embryo during short-term hypoxia. Because the genes are regulators of proliferation and differentiation in other cell types, we suggest that cAMP

  10. Renal Epithelial Cyst Formation and Enlargement in vitro: Dependence on cAMP

    NASA Astrophysics Data System (ADS)

    Mangoo-Karim, Roberto; Uchic, Marie; Lechene, Claude; Grantham, Jared J.

    1989-08-01

    Cysts, a common abnormality of kidneys, are collections of urine-like fluid enclosed by a continuous layer of epithelial cells. Renal cysts derive from nephrons and collecting ducts and progressively enlarge as a consequence of epithelial proliferation and transepithelial fluid secretion. The initiation of cyst formation and the factors that control cyst enlargement are unknown. We used an in vitro model of renal cysts to explore the role of the cAMP signal transduction system in the formation and expansion of cysts. MDCK cells, cultured in hydrated-collagen gel, produced polarized monolayered epithelial cysts when intracellular cAMP was increased by prostaglandin E1, arginine vasopressin, cholera toxin, forskolin, or 8-bromoadenosine 3',5'-cyclic monophosphate. All agonists were potentiated by 3-isobutyl-1-methylxanthine, a nucleotide phosphodiesterase inhibitor. The cell proliferation component of cyst enlargement was accelerated by cAMP agonists, as shown by the increased growth of MDCK cells in subconfluent monolayers. The fluid secretion component, reflected by the transepithelial movement of fluid across polarized monolayers of MDCK cells grown on permeable supports, was stimulated by cAMP agonists in the basolateral medium. Chloride levels were higher in the cyst fluid and the secreted fluid than in the bathing medium. We conclude that the development of MDCK cysts is dependent on cAMP. This signal transduction system may be an important modulator of epithelial cell proliferation and transepithelial fluid secretion in the kidney.

  11. Base Camp Design Simulation Training

    DTIC Science & Technology

    2011-07-01

    It is a treasure-trove of engineering blueprints, bill of materials ( BOMs ), and plans. This 600- man base camp, Figure 6, inputted into VBS2TM...the technical proficiencies required in the construction of base camps. There are no blue prints or bill of materials included in the training. Yet...that “base camps need DOTMLPF (doctrine, organization, training, material , leadership and education, personnel, and facilities) solutions to address

  12. cAMP and Mitochondria

    PubMed Central

    Valsecchi, Federica; Ramos-Espiritu, Lavoisier S.; Buck, Jochen; Levin, Lonny R.

    2013-01-01

    Phosphorylation of mitochondrial proteins has emerged as a major regulatory mechanism for metabolic adaptation. cAMP signaling and PKA phosphorylation of mitochondrial proteins have just started to be investigated, and the presence of cAMP-generating enzymes and PKA inside mitochondria is still controversial. Here, we discuss the role of cAMP in regulating mitochondrial bioenergetics through protein phosphorylation and the evidence for soluble adenylyl cyclase as the source of cAMP inside mitochondria. PMID:23636265

  13. Newly synthesized cAMP is integrated at a membrane protein complex signalosome to ensure receptor response specificity.

    PubMed

    Guinzberg, Raquel; Díaz-Cruz, Antonio; Acosta-Trujillo, Carlos; Vilchis-Landeros, María Magdalena; Vázquez-Meza, Héctor; Lozano-Flores, Carlos; Chiquete-Felix, Natalia; Varela-Echavarría, Alfredo; Uribe-Carvajal, Salvador; Riveros-Rosas, Héctor; Piña, Enrique

    2017-01-01

    Spatiotemporal regulation of cAMP within the cell is required to achieve receptor-specific responses. The mechanism through which the cell selects a specific response to newly synthesized cAMP is not fully understood. In hepatocyte plasma membranes, we identified two functional and independent cAMP-responsive signaling protein macrocomplexes that produce, use, degrade, and regulate their own nondiffusible (sequestered) cAMP pool to achieve their specific responses. Each complex responds to the stimulation of an adenosine G protein-coupled receptor (Ado-GPCR), bound to either A2A or A2B , but not simultaneously to both. Each isoprotein involved in each signaling cascade was identified by measuring changes in cAMP levels after receptor activation, and its participation was confirmed by antibody-mediated inactivation. A2A -Ado-GPCR selective stimulation activates adenylyl cyclase 6 (AC6), which is bound to AKAP79/150, to synthesize cAMP which is used by two other AKAP79/150-tethered proteins: protein kinase A (PKA) and phosphodiesterase 3A (PDE3A). In contrast, A2B -Ado-GPCR stimulation activates D-AKAP2-attached AC5 to generate cAMP, which is channeled to two other D-AKAP2-tethered proteins: guanine-nucleotide exchange factor 2 (Epac2) and PDE3B. In both cases, prior activation of PKA or Epac2 with selective cAMP analogs prevents de novo cAMP synthesis. In addition, we show that cAMP does not diffuse between these protein macrocomplexes or 'signalosomes'. Evidence of coimmunoprecipitation and colocalization of some proteins belonging to each signalosome is presented. Each signalosome constitutes a minimal functional signaling unit with its own machinery to synthesize and regulate a sequestered cAMP pool. Thus, each signalosome is devoted to ensure the transmission of a unique and unequivocal message through the cell.

  14. The effect of phosphodiesterase inhibitors on the extinction of cocaine-induced conditioned place preference in mice.

    PubMed

    Liddie, Shervin; Anderson, Karen L; Paz, Andres; Itzhak, Yossef

    2012-10-01

    Several phosphodiesterase inhibitors (PDEis) improve cognition, suggesting that an increase in brain cAMP and cGMP facilitates learning and memory. Since extinction of drug-seeking behavior requires associative learning, consolidation and formation of new memory, the present study investigated the efficacy of three different PDEis in the extinction of cocaine-induced conditioned place preference (CPP) in B6129S mice. Mice were conditioned by escalating doses of cocaine which was resistant to extinction by free exploration. Immediately following each extinction session mice received (a) saline/vehicle, (b) rolipram (PDE4 inhibitor), (c) BAY-73-6691 (PDE9 inhibitor) or (d) papaverine (PDE10A inhibitor). Mice that received saline/vehicle during extinction training showed no reduction in CPP for >10 days. BAY-73-6691 (a) dose-dependently increased cGMP in hippocampus and amygdala, (b) significantly facilitated extinction and (c) diminished the reinstatement of cocaine CPP. Rolipram, which selectively increased brain cAMP levels, and papaverine which caused increases in both cAMP and cGMP levels, had no significant effect on the extinction of cocaine CPP. The results suggest that increase in hippocampal and amygdalar cGMP levels via blockade of PDE9 has a prominent role in the consolidation of extinction learning.

  15. AMPK antagonizes hepatic glucagon-stimulated cyclic AMP signalling via phosphorylation-induced activation of cyclic nucleotide phosphodiesterase 4B

    PubMed Central

    Johanns, M.; Lai, Y.-C.; Hsu, M.-F.; Jacobs, R.; Vertommen, D.; Van Sande, J.; Dumont, J. E.; Woods, A.; Carling, D.; Hue, L.; Viollet, B.; Foretz, M; Rider, M H

    2016-01-01

    Biguanides such as metformin have previously been shown to antagonize hepatic glucagon-stimulated cyclic AMP (cAMP) signalling independently of AMP-activated protein kinase (AMPK) via direct inhibition of adenylate cyclase by AMP. Here we show that incubation of hepatocytes with the small-molecule AMPK activator 991 decreases glucagon-stimulated cAMP accumulation, cAMP-dependent protein kinase (PKA) activity and downstream PKA target phosphorylation. Moreover, incubation of hepatocytes with 991 increases the Vmax of cyclic nucleotide phosphodiesterase 4B (PDE4B) without affecting intracellular adenine nucleotide concentrations. The effects of 991 to decrease glucagon-stimulated cAMP concentrations and activate PDE4B are lost in hepatocytes deleted for both catalytic subunits of AMPK. PDE4B is phosphorylated by AMPK at three sites, and by site-directed mutagenesis, Ser304 phosphorylation is important for activation. In conclusion, we provide a new mechanism by which AMPK antagonizes hepatic glucagon signalling via phosphorylation-induced PDE4B activation. PMID:26952277

  16. No ordinary boot camp.

    PubMed

    Tichy, N M

    2001-04-01

    Many companies now run boot camps--comprehensive orientation programs designed to help new hires hit the ground running. They're intense and intimidating, and new employees emerge from them with strong bonds to other recruits and to the organization. But at Trilogy, organizational consultant Noel Tichy discovered one program that's a breed apart. In this article, Tichy gives us a detailed tour of Trilogy's boot camp, Trilogy University, to demonstrate why it's so different--and so effective. Like the best boot camps, it serves as an immersion in both the technical skills new recruits will need for their jobs and Trilogy's corporate culture, which emphasizes risk-taking, teamwork, humility, and a strong customer focus. But this is a new-employee orientation session that's so fundamental to the company as a whole that it's presided over by the CEO and top corporate executives for fully six months of the year. Why? In two three-month sessions, these top executives hone their own strategic thinking about the company as they decide what to teach the new recruits each session. They also find the company's next generation of new products as they judge the innovative ideas the recruits are tasked with developing--making the program Trilogy's main R&D engine. And they pull the company's rising technical stars into mentoring roles for the new recruits, helping to build the next generation of top leadership. After spending months on-site studying Trilogy University, Tichy came away highly impressed by the power of the virtuous teaching cycle the program has set in motion. Leaders of the organization are learning from recruits at the same time that the recruits are learning from the leaders. It's a model, he argues, that other companies would do well to emulate.

  17. The Camp Health Manual. An Excellent Reference Written Especially for Organized Camps. Revised.

    ERIC Educational Resources Information Center

    Goldring, David; Middelkamp, J. Neal

    This book is a guide to the diagnosis and care of sick children in organized camping situations. This book presents health care information for the management of medical and surgical problems by the camp counselor, camp director, camp nurse, and camp physician. The chapters are: (1) Camp Standards; (2) The Infirmary; (3) Infirmary Supplies; (4)…

  18. Blending Technology with Camp Tradition: Technology Can Simplify Camp Operations.

    ERIC Educational Resources Information Center

    Salzman, Jeff

    2000-01-01

    Discusses uses of technology appropriate for camps, which are service organizations based on building relationships. Describes relationship marketing and how it can be enhanced through use of Web sites, interactive brochures, and client databases. Outlines other technology uses at camp: automated dispensing of medications, satellite tracking of…

  19. A JUNIOR HIGH SCHOOL ORIENTATION CAMP, A COORDINATED CAMPING EXPERIENCE.

    ERIC Educational Resources Information Center

    NEALE, DANIEL; AND OTHERS

    A 2-WEEK SUMMER CAMPING PROGRAM WAS OFFERED TO 61 DISADVANTAGED STUDENTS ABOUT TO ENTER LINCOLN JUNIOR HIGH IN MINNEAPOLIS, MINNESOTA. THE PROGRAM'S PRIMARY PURPOSE WAS TO EASE THE STUDENT'S TRANSITION INTO JUNIOR HIGH SCHOOL. THROUGH CAMPING ACTIVITIES AND SCHOOL ORIENTATION CLASSES CONDUCTED BY THE LINCOLN STAFF, CAMPERS WOULD BECOME ACQUAINTED…

  20. Camp Director Education Curriculum Guide. Camp Administration Series.

    ERIC Educational Resources Information Center

    Stein, Sue, Ed.

    Part of Project STRETCH, a special personnel preparation grant, this guide contains 13 units on the practical and philosophical areas practitioners, educators, and consumers believed should be included in a basic course for administration of an organized camp: growth and development special populations, camp director's role, philosophy and…

  1. Summer Camp as Therapeutic Context: The Camp Logan Program.

    ERIC Educational Resources Information Center

    McCammon, Susan; And Others

    These symposium papers describe various aspects of the Camp Logan, South Carolina, program, a therapeutic summer residential program for children, ages 8-14, who have significant behavior problems. The philosophy and advantages of the therapeutic camping model are discussed, e.g., structure during the summer, controlled though informal…

  2. Camp Greentop's Adventure Camp: We Ain't No Rudypoo's.

    ERIC Educational Resources Information Center

    Groff, Diane; Albright, Brian; Purvis, Katie; Creamer, Justin; Pease, Alicia

    2002-01-01

    A day-by-day account describes Camp Greentop's first 5-day adventure camping trip, which was attended by five individuals with disabilities and their counselors. The first day was spent in games and initiatives designed to develop communication, teamwork, and dependability. Other days were devoted to hiking, rock climbing, and whitewater rafting.…

  3. Living with Cancer at Camp Rainbow.

    ERIC Educational Resources Information Center

    Williams, Wayne; Breitenstein, Donna

    1988-01-01

    Describes the camping experience at Camp Rainbow (Arkansas), specifically designed for children with cancer and their siblings. Discusses the emotional impact of childhood cancer on patients, parents, and siblings, and suggests positive outcomes of camp participation. Includes eight references. (SV)

  4. Current use of phosphodiesterase inhibitors in urology

    PubMed Central

    Hakky, Tariq Said; Jain, Lakshay

    2015-01-01

    The causes of male erectile dysfunction (ED) are quite variable and are now commonly divided into etiologies such as ischemia, smooth muscle damage, or altered blood flow. Although varying rates of ED have been reported in literature, the number of men with ED is projected to increase worldwide by 2025 to approximately 322 million. Since the introduction of phosphodiesterase 5 (PDE5) inhibitors, there has been a paradigm shift in the treatment of ED because PDE5 inhibitors address a broad spectrum of etiologies for ED. Today, the American Urological Association recommends the use of three PDE5 inhibitors (sildenafil, tadalafil, and vardenafil) as a first-line therapy for the treatment of ED. This review evaluates the pharmacological mechanism of PDE5 inhibitors along with the impact and use of sildenafil, vardenafil, tadalafil, and avanafil. By increasing intracellular cGMP levels, PDE5 inhibitors have been shown to be effective in the treatment of ED. Through their effects on other cellular signaling pathways, PDE5 inhibitors have the potential for treating other urologic conditions as well. The use of PDE5 inhibitors can also be combined to produce a synergistic effect in conditions such as male hypogonadism and benign prostatic hyperplasia in addition to ED. PMID:26328208

  5. Inhibition of phosphodiesterase-1 attenuates cold-induced pulmonary hypertension.

    PubMed

    Crosswhite, Patrick; Sun, Zhongjie

    2013-03-01

    Chronic exposure to cold caused pulmonary arterial hypertension (cold-induced pulmonary hypertension [CIPH]) and increased phosphodiesterase-1C (PDE-1C) expression in pulmonary arteries (PAs) in rats. The purpose of this study is to investigate a hypothesis that inhibition of PDE-1 would decrease inflammatory infiltrates and superoxide production leading to attenuation of CIPH. Three groups of male rats were exposed to moderate cold (5±1°C) continuously, whereas 3 groups were maintained at room temperature (23.5±1°C, warm; 6 rats/group). After 8-week exposure to cold, 3 groups in each temperature condition received continuous intravenous infusion of 8-isobutyl-methylxanthine (8-IBMX) (PDE-1 inhibitor), apocynin (NADPH oxidase inhibitor) or vehicle, respectively, for 1 week. Cold exposure significantly increased right-ventricular systolic pressure compared with warm groups (33.8±3.2 versus 18.6±0.3 mm Hg), indicating that animals developed CIPH. Notably, treatment with 8-IBMX significantly attenuated the cold-induced increase in right ventricular pressure (23.5±1.8 mm Hg). Cold exposure also caused right-ventricular hypertrophy, whereas 8-IBMX reversed cold-induced right ventricular hypertrophy. Cold exposure increased PDE-1C protein expression, macrophage infiltration, NADPH oxidase activity, and superoxide production in PAs and resulted in PA remodeling. 8-IBMX abolished cold-induced upregulation of PDE-1C in PAs. Interestingly, inhibition of PDE-1 eliminated cold-induced macrophage infiltration, NADPH oxidase activation, and superoxide production in PAs and reversed PA remodeling. Inhibition of NADPH oxidase by apocynin abolished cold-induced superoxide production and attenuated CIPH and PA remodeling. In conclusion, inhibition of PDE-1 attenuated CIPH and reversed cold-induced PA remodeling by suppressing macrophage infiltration and superoxide production, suggesting that upregulation of PDE-1C expression may be involved in the pathogenesis of CIPH.

  6. Ultraviolet light induction of skin carcinoma in the mouse; influence of cAMP modifying agents.

    PubMed

    Zajdela, F; Latarjet, R

    1978-01-01

    A short review of pathogenic factors in U.V. light skin carcinogenesis in the mouse is presented. Caffeine and theophylline applied locally during U.V. irradiation caused a 50 percent reduction of skin tumour induction in Swiss mice. These two chemicals are inhibitors of DNA postreplication repair, but they also raise the intracellular level of cyclic AMP by inhibiting cAMP phosphodiesterase with, as a consequence, a possible slowing down of cellular growth. Control experiments using three different chemicals capable of raising the cAMP level in epidermal cells gave negative results. These experimental data are compatible with our original hypothesis according to which production of skin cancers by U.V. radiation is in same way related to DNA repair which helps the cell to survive but allows or favours the occurrence of errors in cellular DNA.

  7. Encountering Child Abuse at Camp.

    ERIC Educational Resources Information Center

    Durall, John K.

    1997-01-01

    Defines child abuse, including the three categories: physical, sexual, and psychological. Presents characteristics and behaviors of each type of abuse, and long-term effects. Discusses how to handle abuse that occurs at camp, and the effects on the camp. Sidebars present abuse statistics, 15 activities that promote psychological wellness, and 8…

  8. Kids Camping Takes the Challenge.

    ERIC Educational Resources Information Center

    James, Vickie L.; Hohnbaum, Claudia

    2002-01-01

    A Wisconsin Girl Scout camp integrated The Healthy Kids Challenge into its program. The camp evaluated policies related to meals, snacks, physical activities, team building, and self-esteem. Staff inservice training resulted in healthier meals on the same budget and developed ownership of the program. Campers and families had opportunities to…

  9. Cloning, chromosomal assignment, and regulation of the rat thyrotropin receptor: Expression of the gene is regulated by thyrotropin, agents that increase cAMP levels, and thyroid autoantibodies

    SciTech Connect

    Akamizu, Takashi; Ikuyama, Shoichiro; Saji, Motoyasu; Kosugi, Shinji; Kozak, C.; McBride, O.W.; Kohn, L.D. )

    1990-08-01

    A rat thyrotropin (thyroid-stimulating hormone, TSH) receptor cDNA was isolated that encoded a protein of 764 amino acids, M{sub r} 86,528. Transfection of the cDNA caused COS-7 cells to develop a TSH-sensitive adenylate cyclase response and the ability to bind {sup 125}I-labeled TSH; both activities were similar to those of rat FRTL-5 thyroid cells and not duplicated by lutropin. The gene represented by the cDNA was assigned to mouse chromosome 12 and human chromosome 14. Northern analyses identified two species of mRNA, 5.6 and 3.3 kilobases, in FRTL-5 thyroid cells; the transcripts appeared to differ only in the extent of their 3{prime} noncoding sequences. There were minimal amounts of the two mRNAs in rat ovary, and neither was detected in RNA preparations from rat testis, liver, lung, brain, spleen, and FRT thyroid cells, which do not have a functional TSH receptor. TSH decreased both mRNA species 3- to 4-fold within 8 hr in FRTL-5 thyroid cells; down-regulation was dependent on TSH concentration and duplicated by forskolin, cholera toxin, or 8-bromo-cAMP but not by a phorbol ester. Down-regulation was also duplicated by throid-stimulating autoantibodies, which increased cAMP levels, but not by thyrotropin binding-inhibiting autoantibodies, which actually increased TSH receptor mRNA levels.

  10. 36 CFR 13.25 - Camping.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... impacting park resources. (c) Designated campgrounds. Except at designated campgrounds, camping is... camping in designated campgrounds. Violating restrictions, terms, and conditions is prohibited....

  11. 36 CFR 13.25 - Camping.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... impacting park resources. (c) Designated campgrounds. Except at designated campgrounds, camping is... camping in designated campgrounds. Violating restrictions, terms, and conditions is prohibited....

  12. 36 CFR 13.25 - Camping.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... impacting park resources. (c) Designated campgrounds. Except at designated campgrounds, camping is... camping in designated campgrounds. Violating restrictions, terms, and conditions is prohibited....

  13. 36 CFR 13.25 - Camping.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... impacting park resources. (c) Designated campgrounds. Except at designated campgrounds, camping is... camping in designated campgrounds. Violating restrictions, terms, and conditions is prohibited....

  14. 36 CFR 13.25 - Camping.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... impacting park resources. (c) Designated campgrounds. Except at designated campgrounds, camping is... camping in designated campgrounds. Violating restrictions, terms, and conditions is prohibited....

  15. Pharmacological profile of T-1032, a novel specific phosphodiesterase type 5 inhibitor, in isolated rat aorta and rabbit corpus cavernosum.

    PubMed

    Takagi, M; Mochida, H; Noto, T; Yano, K; Inoue, H; Ikeo, T; Kikkawa, K

    2001-01-05

    This study was designed to examine the pharmacological properties of T-1032 (methyl-2-(4-aminophenyl)-1,2-dihydro-1-oxo-7-(2-pyridinylmethoxy)-4-(3,4,5-trimethoxyphenyl)-3-isoquinoline carboxylate sulfate), a novel phosphodiesterase type 5 inhibitor, in isolated rat aorta and rabbit corpus cavernosum. T-1032 (3x10(-11) to 3x10(-7) M) caused an endothelium-dependent relaxation in the isolated rat aorta precontracted with phenylephrine, and the relaxation was accompanied by an increase in cGMP but not cAMP levels. The T-1032-induced relaxation was attenuated by N(G)-nitro-L-arginine methyl ester (L-NAME) (10(-3) M), a nitric oxide (NO) synthase inhibitor, or 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (ODQ) (10(-5) M), a guanylyl cyclase inhibitor. T-1032 (10(-9), 10(-8) M) produced a potentiation of the relaxation induced by sodium nitroprusside, but not of the relaxation induced by isoproterenol. In the isolated rabbit corpus cavernosum precontracted with phenylephrine, the electrical field stimulation-induced relaxation was attenuated by treatment with tetrodotoxin (10(-6) M) as well as L-NAME (10(-4) M). The L-NAME-inhibited relaxation was restored by treatment with L-arginine (5x10(-4) M). T-1032 (10(-9) to 10(-6) M) and sildenafil (10(-9) to 10(-6) M) produced a potentiation of the electrical field stimulation-induced relaxation as well as a decrease in basal tension in a concentration-dependent manner. It was concluded that T-1032 had potentiating effects on the NO/cGMP signaling pathway in isolated tissues, probably through specific blockade of phosphodiesterase type 5. T-1032 would be a useful compound to examine the physiologic functions of phosphodiesterase type 5 in mammalian tissues.

  16. Localization and activity of tissue bound cyclic nucleotide phosphodiesterase in normal and lack of changes in psoriatic human skin.

    PubMed

    Mahrle, G; Organos, C E

    1976-12-01

    This study has been undertaken to elucidate the localization and the activity of cyclic nucleotide phosphodiesterase (PDE) in psoriatic epidermis compared to normal. The results showed that the evaluation of cytochemical methods may be difficult because of the various factors which interfere with the reaction and the considerable amount of background staining. Additionally, only the tissue bound particulate enzyme fraction may be demonstrated by cytochemical means. Nevertheless, the method did reveal that the activity of PDE, if any, is localized on the cytoplasmic membranes of the cells, independent of their origin, and not on the cell surface. Moreover, no differences were found between normal and psoriatic skin. It seems, therefore, that the intracellular degradation of cAMP remains unaltered in psoriasis.

  17. Identification in Silico and Experimental Validation of Novel Phosphodiesterase 7 Inhibitors with Efficacy in Experimental Autoimmune Encephalomyelitis Mice

    PubMed Central

    2012-01-01

    A neural network model has been developed to predict the inhibitory capacity of any chemical structure to be a phosphodiesterase 7 (PDE7) inhibitor, a new promising kind of drugs for the treatment of neurological disorders. The numerical definition of the structures was achieved using CODES program. Through the validation of this neural network model, a novel family of 5-imino-1,2,4-thiadiazoles (ITDZs) has been identified as inhibitors of PDE7. Experimental extensive biological studies have demonstrated the ability of ITDZs to inhibit PDE7 and to increase intracellular levels of cAMP. Among them, the derivative 15 showed a high in vitro potency with desirable pharmacokinetic profile (safe genotoxicity and blood brain barrier penetration). Administration of ITDZ 15 in an experimental autoimmune encephalomyelitis (EAE) mouse model results in a significant attenuation of clinical symptoms, showing the potential of ITDZs, especially compound 15, for the effective treatment of multiple sclerosis. PMID:23077723

  18. Phosphodiesterase-5 Inhibitors: Action on the Signaling Pathways of Neuroinflammation, Neurodegeneration, and Cognition

    PubMed Central

    Peixoto, Christina Alves; Nunes, Ana Karolina Santana; Garcia-Osta, Ana

    2015-01-01

    Phosphodiesterase type 5 inhibitors (PDE5-Is) have recently emerged as a potential therapeutic strategy for neuroinflammatory, neurodegenerative, and memory loss diseases. Mechanistically, PDE5-Is produce an anti-inflammatory and neuroprotection effect by increasing expression of nitric oxide synthases and accumulation of cGMP and activating protein kinase G (PKG), the signaling pathway of which is thought to play an important role in the development of several neurodiseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). The aim of this paper was to review present knowledge of the signaling pathways that underlie the use of PDE5-Is in neuroinflammation, neurogenesis, learning, and memory. PMID:26770022

  19. Desynchronization of Cells on the Developmental Path Triggers the Formation of Spiral Waves of cAMP during Dictyostelium Aggregation

    NASA Astrophysics Data System (ADS)

    Lauzeral, Jacques; Halloy, Jose; Goldbeter, Albert

    1997-08-01

    Whereas it is relatively easy to account for the formation of concentric (target) waves of cAMP in the course of Dictyostelium discoideum aggregation after starvation, the origin of spiral waves remains obscure. We investigate a physiologically plausible mechanism for the spontaneous formation of spiral waves of cAMP in D. discoideum. The scenario relies on the developmental path associated with the continuous changes in the activity of enzymes such as adenylate cyclase and phosphodiesterase observed during the hours that follow starvation. These changes bring the cells successively from a nonexcitable state to an excitable state in which they relay suprathreshold cAMP pulses, and then to autonomous oscillations of cAMP, before the system returns to an excitable state. By analyzing a model for cAMP signaling based on receptor desensitization, we show that the desynchronization of cells on this developmental path triggers the formation of fully developed spirals of cAMP. Developmental paths that do not correspond to the sequence of dynamic transitions no relay-relay-oscillations-relay are less able or fail to give rise to the formation of spirals.

  20. Modulation in the expression of SHP-1, SHP-2 and PTP1B due to the inhibition of MAPKs, cAMP and neutrophils early on in the development of cerulein-induced acute pancreatitis in rats.

    PubMed

    García-Hernández, Violeta; Sarmiento, Nancy; Sánchez-Bernal, Carmen; Matellán, Laura; Calvo, José J; Sánchez-Yagüe, Jesús

    2014-02-01

    The protein tyrosine phosphatases (PTPs) SHP-1, SHP-2 and PTP1B are overexpressed early on during the development of cerulein -induced acute pancreatitis (AP) in rats, and their levels can be modulated by some species of mitogen-activated protein kinases (MAPKs), the intracellular levels of cAMP and by general leukocyte infiltration, the latter at least for SHP-2 and PTP1B. In this study we show that cerulein treatment activates extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) but not p38 MAPK during the early phase of cerulein-induced AP (2h after the first injection of cerulein). Therefore, by using the MAPK inhibitors SP600125 (a specific JNK inhibitor) and PD98059 (a specific ERK inhibitor), we have unmasked the particular MAPK that underlies the modulation of the expression levels of these PTPs. JNK would act by preventing SHP-1 protein expression from increasing beyond a certain level. ERK 1/2 was the main MAPK involved in the increase in SHP-2 protein expression due to cerulein. JNK negatively modulated the SH2-domain containing PTPs. Both MAPKs played a role in the increase in PTP1B protein expression due to cerulein. Finally, by using the white blood cell inhibitors vinblastine sulfate, gadolinium chloride and FK506 (tacrolimus), we show that the macrophage activity or T-lymphocytes does not modulate the expression of any of the PTPs, although neutrophil infiltration was found to be a regulator of SHP-2 and PTP1B protein expression due to cerulein.

  1. [Blockade of NMDA receptor enhances corticosterone-induced downregulation of brain-derived neurotrophic factor gene expression in the rat hippocampus through cAMP response element binding protein pathway].

    PubMed

    Feng, Hao; Lu, Li-Min; Huang, Ying; Zhu, Yi-Chun; Yao, Tai

    2005-10-25

    High concentration of corticosterone leads to morphological and functional impairments in hippocampus, ranging from a reversible atrophy of pyramidal CA3 apical dendrites to the impairment of long-term potentiation (LTP) and hippocampus-dependent learning and memory. Glutamate and N-methyl-D-aspartate (NMDA) receptor play an important role in this effect. Because of the importance of brain-derived neurotrophic factor (BDNF) in the functions of the hippocampal neurons, alteration of the expression of BDNF is thought to be involved in the corticosterone effect on the hippocampus. To determine whether change in BDNF in the hippocampus is involved in the corticosterone effect, we injected corticosterone (2 mg/kg, s.c.) to Sprague-Dawley rats and measured the mRNA, proBDNF and mature BDNF protein levels in the hippocampus. We also measured the phosphorylation level of the transcription factor cAMP response element binding protein (CREB). Furthermore, we intraperitoneally injected NMDA receptor antagonist MK801 (0.1 mg/kg) 30 min before corticosterone administration to investigate whether and how MK801 affected the regulation of BDNF gene expression by corticosterone. Our results showed that 3 h after single s.c. injection of corticsterone, the expression of BDNF mRNA, proBDNF and mature BDNF protein decreased significantly (P<0.01). MK801 promoted the downregulation of BDNF gene expression in the rat hippocampus by corticosterone. We also found that either applying corticosterone or co-applying corticosterone with MK801 downregulated the phosphoration level of CREB, the latter (corticosterone plus MK801) being more effective (P<0.05). Taken together, our results indicate that corticosterone downregulates BDNF gene expression in the rat hippocampus through CREB pathway and that blockade of NMDA receptor enhances this effect of corticosterone in reducing BDNF expression.

  2. Berberine attenuates cAMP-induced lipolysis via reducing the inhibition of phosphodiesterase in 3T3-L1 adipocytes.

    PubMed

    Zhou, Libin; Wang, Xiao; Yang, Ying; Wu, Ling; Li, Fengying; Zhang, Rong; Yuan, Guoyue; Wang, Ning; Chen, Mingdao; Ning, Guang

    2011-04-01

    Berberine, a hypoglycemic agent, has been shown to decrease plasma free fatty acids (FFAs) level in insulin-resistant rats. In the present study, we explored the mechanism responsible for the antilipolytic effect of berberine in 3T3-L1 adipocytes. It was shown that berberine attenuated lipolysis induced by catecholamines, cAMP-raising agents, and a hydrolyzable cAMP analog, but not by tumor necrosis factor α and a nonhydrolyzable cAMP analog. Unlike insulin, the inhibitory effect of berberine on lipolysis in response to isoproterenol was not abrogated by wortmannin, an inhibitor of phosphatidylinositol 3-kinase, but additive to that of PD98059, an extracellular signal-regulated kinase kinase inhibitor. Prior exposure of adipocytes to berberine decreased the intracellular cAMP production induced by isoproterenol, forskolin, and 3-isobutyl-1-methylxanthine (IBMX), along with hormone-sensitive lipase (HSL) Ser-563 and Ser-660 dephosphorylation, but had no effect on perilipin phosphorylation. Berberine stimulated HSL Ser-565 as well as adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. However, compound C, an AMPK inhibitor, did not reverse the regulatory effect of berberine on HSL Ser-563, Ser-660, and Ser-565 phosphorylation, nor the antilipolytic effect of berberine. Knockdown of AMPK using RNA interference also failed to restore berberine-suppressed lipolysis. cAMP-raising agents increased AMPK activity, which was not additive to that of berberine. Stimulation of adipocytes with berberine increased phosphodiesterase (PDE) 3B and PDE4 activity measured by hydrolysis of (3)[H]cAMP. These results suggest that berberine exerts an antilipolytic effect mainly by reducing the inhibition of PDE, leading to a decrease in cAMP and HSL phosphorylation independent of AMPK pathway.

  3. Phosphodiesterase-5 inhibition suppresses colonic inflammation-induced tumorigenesis via blocking the recruitment of MDSC

    PubMed Central

    Lin, Shiyong; Wang, Jing; Wang, Lihui; Wen, Jing; Guo, Yandong; Qiao, Weiguang; Zhou, Jieqiong; Xu, Guoliang; Zhi, Fachao

    2017-01-01

    Phosphodiesterase 5 (PDE-5) is a major isoform of cGMP phosphodiesterase in diverse tissues and plays a critical role in regulating intracellular cGMP concentrations. However, the distribution and expression of PDE-5 in colitis-related colon cancer was still unclear, not even the function and mechanism. Western blotting and ELISA were performed to detect colonic PDE-5 expression in AOM/DSS-induced tumorigenesis model. Sildenafil, a specific PDE-5 inhibitor, was used to treat AOM/DSS-induced and AOM-induced colonic tumorigenesis model and DSS-induced colitis model. The leukocyte infiltration in colonic tissue was examined by flow cytometry and immunofluorescence staining. Further matrigel-based invasion assay was employed to determine the effects of Sildenafil on myeloid-derived suppressor cell (MDSC) in vitro. We first demonstrated the upregulation of colonic PDE-5 expression and the prevention role of PDE-5 inhibition in AOM/DSS-induced tumorigenesis model. More importantly, PDE-5 inhibitor Sildenafil inhibited colonic tumorigenesis dependent on inflammation and suppressed DSS-induced colitis. Molecular mechanism investigation indicated that Sildenafil regulated inflammation microenvironment via directly inhibiting MDSC infiltration in colonic tissue. The study provides solid evidence for the use of PDE-5 inhibitor in preventing and treating colonic inflammation-related tumorigenesis. PMID:28123846

  4. Inhibition of Uterine Contractility by Thalidomide Analogs via Phosphodiesterase-4 Inhibition and Calcium Entry Blockade.

    PubMed

    Fernández-Martínez, Eduardo; Ponce-Monter, Héctor; Soria-Jasso, Luis E; Ortiz, Mario I; Arias-Montaño, José-Antonio; Barragán-Ramírez, Guillermo; Mayén-García, Cynthia

    2016-10-07

    Uterine relaxation is crucial during preterm labor. Phosphodiesterase-4 (PDE-4) inhibitors have been proposed as tocolytics. Some thalidomide analogs are PDE-4 inhibitors. The aim of this study was to assess the uterus-relaxant properties of two thalidomide analogs, methyl 3-(4-nitrophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4NO2PDPMe) and methyl 3-(4-aminophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4APDPMe) and were compared to rolipram in functional studies of spontaneous phasic, K⁺-induced tonic, and Ca(2+)-induced contractions in isolated pregnant human myometrial tissues. The accumulation of cAMP was quantified in HeLa cells. The presence of PDE-4B2 and phosphorylated myosin light-chain (pMLC), in addition to the effect of thalidomide analogs on oxytocin-induced pMLC, were assessed in human uterine myometrial cells (UtSMCs). Thalidomide analogs had concentration-dependent inhibitory effects on spontaneous and tonic contractions and inhibited Ca(2+)-induced responses. Tonic contraction was equipotently inhibited by 4APDPMe and rolipram (IC50 = 125 ± 13.72 and 98.45 ± 8.86 µM, respectively). Rolipram and the thalidomide analogs inhibited spontaneous and tonic contractions equieffectively. Both analogs increased cAMP accumulation in a concentration-dependent manner (p < 0.05) and induced changes in the subcellular localization of oxytocin-induced pMLC in UtSMCs. The inhibitory effects of thalidomide analogs on the contractions of pregnant human myometrium tissue may be due to their PDE-4 inhibitory effect and novel mechanism as calcium-channel blockers.

  5. Insight into the Phosphodiesterase Mechanism from Combined QM/MM Free Energy Simulations

    PubMed Central

    Wong, Kin-Yiu; Gao, Jiali

    2011-01-01

    Summary Molecular dynamics simulations employing a combined quantum mechanical and molecular mechanical potential have been carried out to elucidate the reaction mechanism of the hydrolysis of a cyclic nucleotide cAMP substrate by phosphodiesterase 4B (PDE4B). PDE4B is a member of the PDE superfamily of enzymes that play crucial roles in cellular signal transduction. We have determined a two-dimensional potential of mean force for the coupled phosphoryl bond cleavage and proton transfer through a general acid catalysis mechanism in PDE4B. The results indicate that the ring-opening process takes place through an SN2 reaction mechanism, followed by a proton transfer to stabilize the leaving group. The computed free energy of activation for the PDE4B-catalyzed cAMP hydrolysis is about 13 kcal/mol and an overall reaction free energy is about −17 kcal/mol, both in accord with experimental results. In comparison with the uncatalyzed reaction in water, the enzyme PDE4B provides a strong stabilization of the transition state, lowering the free energy barrier by 14 kcal/mol. We found that the proton transfer from the general acid residue His234 to the O3' oxyanion of the ribosyl leaving group lags behind the nucleophilic attack, resulting in a shallow minimum on the free energy surface. A key contributing factor to transition state stabilization is the elongation of the distance between the divalent metal ions Zn2+ and Mg2+ in the active site as the reaction proceeds from the Michaelis complex to the transition state. PMID:21595828

  6. The Influences of Presentation Modes and Conducting Gestures on the Perceptions of Expressive Choral Performance of High School Musicians Attending a Summer Choral Camp

    ERIC Educational Resources Information Center

    Napoles, Jessica

    2013-01-01

    The purpose of this study was to examine the influences of presentation modes (audio and visual) on perceptions of expressive choral performance. The stimulus recording included four choral selections, each conducted by a different conductor in two ways: using expressive conducting gestures and using strict conducting gestures. Three groups of…

  7. Self-Concept Change in Camp Staff.

    ERIC Educational Resources Information Center

    Henderson, Karla A.; Bialeschki, M. Deborah

    The 1981 study ascertained whether the self-concept of 66 camp staff from 2 Wisconsin camps changed more than a control group of 18 college students attending summer school; if differences in self-concept were based on a particular characteristic (age, gender, staff position, years at camp); and in what ways, if any, self-concept of camp staff…

  8. DAY CAMPING FOR THE MENTALLY RETARDED.

    ERIC Educational Resources Information Center

    GINGLEND, DAVID; GOULD, KAY

    EMPHASIS IS PLACED ON MENTAL HEALTH, PHYSICAL DEVELOPMENT AND COORDINATION (BOTH MOTOR AND MUSCULAR), SOCIAL ADJUSTMENT, AND LANGUAGE AND INTELLECTUAL DEVELOPMENT. SECTIONS ARE DEVOTED TO ORGANIZATION OF A DAY CAMPING PROGRAM, SELECTING THE STAFF AND THE CAMPERS, THE DAY CAMP IN OPERATION, DAY CAMPING AS A TRAINING PERIOD, CAMP RELATIONS WITH THE…

  9. Easter Seal Guide to Special Camping Programs.

    ERIC Educational Resources Information Center

    Crane, Helen B., Ed.

    Intended for organizations having or planning to establish resident resident camping programs for people with special needs, this guide supplements the American Camping Association's Standards. The philosophy, aims, and objectives of specialized camping programs are considered, and the following are discussed: administration, camp site selection,…

  10. Camp Barnabas! No Limits! No Boundaries!

    ERIC Educational Resources Information Center

    Teas, Cyndy; Robertson, Donna

    2007-01-01

    This article profiles Camp Barnabas, a non-denominational Christian camp for people with special needs located in southwest Missouri. For one week, campers have every opportunity possible to be a participant in the world around them, not just an observer. The camp's goal is to provide a typical camp experience--bugs, chants, cheers and incredible…

  11. Camp Courageous of Iowa Staff Manual.

    ERIC Educational Resources Information Center

    Camp Courageous of Iowa, Monticello.

    Designed as a useful and practical tool for the staff at Camp Courageous of Iowa, a year-round residential camp serving all handicapped individuals, the manual outlines safety rules for camp activities, characteristics of the mentally and physically handicapped, and a general description of the camp and its objectives. Contents of the manual…

  12. Slave Labor Camps of the Third Reich.

    ERIC Educational Resources Information Center

    Stone, Adolf

    1983-01-01

    Describes the ground rules used by Nazi architects in choosing the sites for slave labor camps. While some, like Auschwitz, became extermination camps, others also produced armaments. One camp, Theresienstadt, became a "model" camp to show to reporters and Red Cross representatives. (CS)

  13. American Camping Association Annual Report, 1999.

    ERIC Educational Resources Information Center

    American Camping Association, Martinsville, IN.

    Founded in 1910 as the Camp Directors' Association of America, the American Camping Association (ACA) is the largest organization serving the organized camping industry. Over 5,500 members come from all segments of the camp profession. This annual report for 1999 describes ACA activities in support of organizational commitments. These commitments…

  14. Standards for Day and Resident Camps: The Accreditation Programs of the American Camping Association. 1990 Edition.

    ERIC Educational Resources Information Center

    American Camping Association, Martinsville, IN.

    The purpose of this manual is to educate camp directors and camp personnel regarding government-recognized standard practices and procedures followed within the camp industry. These standards also provide a basis for voluntary accreditation of camps by the American Camping Association (ACA) beyond the minimum requirements of licensing. The manual…

  15. Guide to Camp Nursing: Qualifications, Responsibilities Outlined for the Professional Camp Nurse. Revised.

    ERIC Educational Resources Information Center

    Auld, Margaret E.; Ehlke, Graceann

    This guide was developed to help the nurse in any outdoor setting or organized camp program serving children and youth to: (1) understand the responsibilities of camp nursing; (2) be aware of the nurse's relationships with the camp director and other workers; (3) relate the camp health program to the overall objectives of the camping program; (4)…

  16. Basic Camp Management: An Introduction to Camp Administration. Revised 3rd Edition.

    ERIC Educational Resources Information Center

    Ball, Armand; Ball, Beverly

    This book is the primary text for the Certified Camp Director Program and the Basic Camp Directors Course sponsored by the American Camping Association (Indiana). It provides an orientation for new and prospective camp directors and a quick reference for experienced camp directors. The book covers the following topics: (1) an historical overview…

  17. Von Braun's Dream: Space Camp.

    ERIC Educational Resources Information Center

    Coleman, C. C.

    1982-01-01

    Describes the "Space Camp" program for boys and girls at the Alabama Space and Rocket Center (Huntsville, Alabama), including typical activities. Includes address for obtaining information on participation in the program. (JN)

  18. Camping Out On An Asteroid

    NASA Video Gallery

    An astronaut and a geologist recently spent three days camping out as though they were on an asteroid. They were inside NASA's Space Exploration Vehicle prototype, flying it virtually in a digital ...

  19. Structural Basis for the Design of Selective Phosphodiesterase 4B Inhibitors

    PubMed Central

    Fox, David; Burgin, Alex B.; Gurney, Mark E.

    2014-01-01

    Phosphodiesterase-4B (PDE4B) regulates the pro-inflammatory Toll Receptor –Tumor Necrosis Factor α (TNFα) pathway in monocytes, macrophages and microglial cells. As such, it is an important, although under-exploited molecular target for anti-inflammatory drugs. This is due in part to the difficulty of developing selective PDE4B inhibitors as the amino acid sequence of the PDE4 active site is identical in all PDE4 subtypes (PDE4A-D). We show that highly selective PDE4B inhibitors can be designed by exploiting sequence differences outside the active site. Specifically, PDE4B selectivity can be achieved by capture of a C-terminal regulatory helix, now termed CR3 (Control Region 3), across the active site in a conformation that closes access by cAMP. PDE4B selectivity is driven by a single amino acid polymorphism in CR3 (Leu674 in PDE4B1 versus Gln594 in PDE4D). The reciprocal mutations in PDE4B and PDE4D cause a 70-80 fold shift in selectivity. Our structural studies show that CR3 is flexible and can adopt multiple orientations and multiple registries in the closed conformation. The new co-crystal structure with bound ligand provides a guide map for the design of PDE4B selective anti-inflammatory drugs. PMID:24361374

  20. Phosphodiesterase Inhibition Rescues Chronic Cognitive Deficits Induced by Traumatic Brain Injury

    PubMed Central

    Titus, David J.; Sakurai, Atsushi; Kang, Yuan; Furones, Concepcion; Jergova, Stanislava; Santos, Rosmery; Sick, Thomas J.; Atkins, Coleen M.

    2013-01-01

    Traumatic brain injury (TBI) modulates several cell signaling pathways in the hippocampus critical for memory formation. Previous studies have found that the cAMP-protein kinase A signaling pathway is downregulated after TBI and that treatment with a phosphodiesterase (PDE) 4 inhibitor rolipram rescues the decrease in cAMP. In the present study, we examined the effect of rolipram on TBI-induced cognitive impairments. At 2 weeks after moderate fluid-percussion brain injury or sham surgery, adult male Sprague Dawley rats received vehicle or rolipram (0.03 mg/kg) 30 min before water maze acquisition or cue and contextual fear conditioning. TBI animals treated with rolipram showed a significant improvement in water maze acquisition and retention of both cue and contextual fear conditioning compared with vehicle-treated TBI animals. Cue and contextual fear conditioning significantly increased phosphorylated CREB levels in the hippocampus of sham animals, but not in TBI animals. This deficit in CREB activation during learning was rescued in TBI animals treated with rolipram. Hippocampal long-term potentiation was reduced in TBI animals, and this was also rescued with rolipram treatment. These results indicate that the PDE4 inhibitor rolipram rescues cognitive impairments after TBI, and this may be mediated through increased CREB activation during learning. PMID:23516287

  1. Structures of the four subfamilies of phosphodiesterase-4 provide insight into the selectivity of their inhibitors.

    PubMed

    Wang, Huanchen; Peng, Ming-Sheng; Chen, Yi; Geng, Jie; Robinson, Howard; Houslay, Miles D; Cai, Jiwen; Ke, Hengming

    2007-12-01

    PDE4 (phosphodiesterase-4)-selective inhibitors have attracted much attention as potential therapeutics for the treatment of both depression and major inflammatory diseases, but their practical application has been compromised by side effects. A possible cause for the side effects is that current PDE4-selective inhibitors similarly inhibit isoforms from all four PDE4 subfamilies. The development of PDE4 subfamily-selective inhibitors has been hampered by a lack of structural information. In the present study, we rectify this by providing the crystal structures of the catalytic domains of PDE4A, PDE4B and PDE4D in complex with the PDE4 inhibitor NVP {4-[8-(3-nitrophenyl)-[1,7]naphthyridin-6-yl]benzoic acid} as well as the unliganded PDE4C structure. NVP binds in the same conformation to the deep cAMP substrate pocket and interacts with the same residues in each instance. However, detailed structural comparison reveals significant conformational differences. Although the active sites of PDE4B and PDE4D are mostly comparable, PDE4A shows significant displacements of the residues next to the invariant glutamine residue that is critical for substrate and inhibitor binding. PDE4C appears to be more distal from other PDE4 subfamilies, with certain key residues being disordered. Our analyses provide the first structural basis for the development of PDE4 subfamily-selective inhibitors.

  2. Bovine cone photoreceptor cGMP phosphodiesterase structure deduced from a cDNA clone.

    PubMed Central

    Li, T S; Volpp, K; Applebury, M L

    1990-01-01

    A full-length cDNA clone encoding the alpha' subunit of cGMP phosphodiesterase (PDE) from bovine cone photoreceptors was selected by probing a retinal library with a DNA fragment encoding the catalytic core of the rod cGMP PDE alpha subunit. Identity of the clone was confirmed by comparing its deduced sequence with cone PDE peptide sequences determined by Charbonneau et al. [Charbonneau, H., Prusti, R. K., LeTrong, H., Sonnenburg, W. K., Mullaney, P. J., Walsh, K. A. & Beavo, J. A. (1990) Proc. Natl. Acad. Sci. USA, pp. 288-292]. The cone PDE alpha' and the rod PDE alpha and beta subunits are encoded by distinct genes. cGMP PDE subunits share a common ancestry with cAMP PDEs and cyclic nucleotide-binding proteins. Sequence comparisons predict the presence of a catalytic core and possible secondary sites for noncatalytic cGMP binding. The presence of a C-terminal CAAX (Cys-aliphatic-aliphatic-Xaa) motif suggests the cone enzyme may be posttranslationally modified by proteolysis, methylation, and isoprenylation. Images PMID:2153291

  3. Structures of the Four Subfamilies of Phosphodiesterase-4 Provide Insight into the Selectivity of Their Inhibitors

    SciTech Connect

    Wang, H.; Peng, M; Chen , Y; Geng, J; Robinson, H; Houslay , M; Cai, J; Ke, H

    2007-01-01

    PDE4 (phosphodiesterase-4)-selective inhibitors have attracted much attention as potential therapeutics for the treatment of both depression and major inflammatory diseases, but their practical application has been compromised by side effects. A possible cause for the side effects is that current PDE4-selective inhibitors similarly inhibit isoforms from all four PDE4 subfamilies. The development of PDE4 subfamily-selective inhibitors has been hampered by a lack of structural information. In the present study, we rectify this by providing the crystal structures of the catalytic domains of PDE4A, PDE4B and PDE4D in complex with the PDE4 inhibitor NVP 4-[8-(3-nitrophenyl)-[1,7]naphthyridin-6-yl]benzoic acid as well as the unliganded PDE4C structure. NVP binds in the same conformation to the deep cAMP substrate pocket and interacts with the same residues in each instance. However, detailed structural comparison reveals significant conformational differences. Although the active sites of PDE4B and PDE4D are mostly comparable, PDE4A shows significant displacements of the residues next to the invariant glutamine residue that is critical for substrate and inhibitor binding. PDE4C appears to be more distal from other PDE4 subfamilies, with certain key residues being disordered. Our analyses provide the first structural basis for the development of PDE4 subfamily-selective inhibitors.

  4. Phosphodiesterase inhibition rescues chronic cognitive deficits induced by traumatic brain injury.

    PubMed

    Titus, David J; Sakurai, Atsushi; Kang, Yuan; Furones, Concepcion; Jergova, Stanislava; Santos, Rosmery; Sick, Thomas J; Atkins, Coleen M

    2013-03-20

    Traumatic brain injury (TBI) modulates several cell signaling pathways in the hippocampus critical for memory formation. Previous studies have found that the cAMP-protein kinase A signaling pathway is downregulated after TBI and that treatment with a phosphodiesterase (PDE) 4 inhibitor rolipram rescues the decrease in cAMP. In the present study, we examined the effect of rolipram on TBI-induced cognitive impairments. At 2 weeks after moderate fluid-percussion brain injury or sham surgery, adult male Sprague Dawley rats received vehicle or rolipram (0.03 mg/kg) 30 min before water maze acquisition or cue and contextual fear conditioning. TBI animals treated with rolipram showed a significant improvement in water maze acquisition and retention of both cue and contextual fear conditioning compared with vehicle-treated TBI animals. Cue and contextual fear conditioning significantly increased phosphorylated CREB levels in the hippocampus of sham animals, but not in TBI animals. This deficit in CREB activation during learning was rescued in TBI animals treated with rolipram. Hippocampal long-term potentiation was reduced in TBI animals, and this was also rescued with rolipram treatment. These results indicate that the PDE4 inhibitor rolipram rescues cognitive impairments after TBI, and this may be mediated through increased CREB activation during learning.

  5. Daily rhythm in pineal phosphodiesterase (PDE) activity reflects adrenergic/3',5'-cyclic adenosine 5'-monophosphate induction of the PDE4B2 variant.

    PubMed

    Kim, Jong-So; Bailey, Michael J; Ho, Anthony K; Møller, Morten; Gaildrat, Pascaline; Klein, David C

    2007-04-01

    The pineal gland is a photoneuroendocrine transducer that influences circadian and circannual dynamics of many physiological functions via the daily rhythm in melatonin production and release. Melatonin synthesis is stimulated at night by a photoneural system through which pineal adenylate cyclase is adrenergically activated, resulting in an elevation of cAMP. cAMP enhances melatonin synthesis through actions on several elements of the biosynthetic pathway. cAMP degradation also appears to increase at night due to an increase in phosphodiesterase (PDE) activity, which peaks in the middle of the night. Here, it was found that this nocturnal increase in PDE activity results from an increase in the abundance of PDE4B2 mRNA (approximately 5-fold; doubling time, approximately 2 h). The resulting level is notably higher (>6-fold) than in all other tissues examined, none of which exhibit a robust daily rhythm. The increase in PDE4B2 mRNA is followed by increases in PDE4B2 protein and PDE4 enzyme activity. Results from in vivo and in vitro studies indicate that these changes are due to activation of adrenergic receptors and a cAMP-dependent protein kinase A mechanism. Inhibition of PDE4 activity during the late phase of adrenergic stimulation enhances cAMP and melatonin levels. The evidence that PDE4B2 plays a negative feedback role in adrenergic/cAMP signaling in the pineal gland provides the first proof that cAMP control of PDE4B2 is a physiologically relevant control mechanism in cAMP signaling.

  6. Expression profiling of cumulus cells reveals functional changes during ovulation and central roles of prostaglandin EP2 receptor in cAMP signaling.

    PubMed

    Tamba, Shigero; Yodoi, Rieko; Morimoto, Kazushi; Inazumi, Tomoaki; Sukeno, Mamiko; Segi-Nishida, Eri; Okuno, Yasushi; Tsujimoto, Gozoh; Narumiya, Shuh; Sugimoto, Yukihiko

    2010-06-01

    To understand the role of prostaglandin (PG) receptor EP2 (Ptger2) signaling in ovulation and fertilization, we investigated time-dependent expression profiles in wild-type (WT) and Ptger2(-/-) cumuli before and after ovulation by using microarrays. We prepared cumulus cells from mice just before and 3, 9 and 14 h after human chorionic gonadotropin injection. Key genes including cAMP-related and epidermal growth factor (EGF) genes, as well as extracellular matrix- (ECM-) related and chemokine genes were up-regulated in WT cumuli at 3 h and 14 h, respectively. Ptger2 deficiency differently affected the expression of many of the key genes at 3 h and 14 h. These results indicate that the gene expression profile of cumulus cells greatly differs before and after ovulation, and in each situation, PGE(2)-EP2 signaling plays a critical role in cAMP-regulated gene expression in the cumulus cells under physiological conditions.

  7. cAMP response element-binding protein-mediated gene expression increases the intrinsic excitability of CA1 pyramidal neurons.

    PubMed

    Lopez de Armentia, Mikel; Jancic, Dragana; Olivares, Roman; Alarcon, Juan M; Kandel, Eric R; Barco, Angel

    2007-12-12

    To investigate the role of CREB-mediated gene expression on the excitability of CA1 pyramidal neurons, we obtained intracellular recordings from pyramidal neurons of transgenic mice expressing a constitutively active form of CREB, VP16-CREB, in a regulated and restricted manner. We found that transgene expression increased the neuronal excitability and inhibited the slow and medium afterhyperpolarization currents. These changes may contribute to the reduced threshold for LTP observed in these mice. When strong transgene expression was turned on for prolonged period of time, these mice also showed a significant loss of hippocampal neurons and sporadic epileptic seizures. These deleterious effects were dose dependent and could be halted, but not reversed by turning off transgene expression. Our experiments reveal a new role for hippocampal CREB-mediated gene expression, identify the slow afterhyperpolarization as a primary target of CREB action, provide a new mouse model to investigate temporal lobe epilepsy and associated neurodegeneration, and illustrate the risks of cell death associated to a sustained manipulation of this pathway. As a result, our study has important implications for both the understanding of the cellular bases of learning and memory and the consideration of therapies targeted to the CREB pathway.

  8. Development of a high throughput screen for allosteric modulators of melanocortin-4 receptor signaling using a real time cAMP assay

    PubMed Central

    Pantel, Jacques; Williams, Savannah Y.; Mi, Dehui; Sebag, Julien; Corbin, Jackie D.; Weaver, C. David; Cone, Roger D.

    2011-01-01

    The melanocortin MC4 receptor is a potential target for the development of drugs for both obesity and cachexia. Melanocortin MC4 receptor ligands known thus far are orthosteric agonists or antagonists, however the agonists, in particular, have generally exhibited unwanted side effects. For some receptors, allosteric modulators are expected to reduce side-effect profiles. To identify allosteric modulators of the melanocortin MC4 receptor, we created HEK293 cell lines coexpressing the human melanocortin MC4 receptor and a modified luciferase-based cAMP sensor. Monitoring luminescence as a readout of real-time intracellular cAMP concentration, we demonstrate this cell line is able to report melanocortin agonist responses, as well as inverse agonist response to the physiological AgRP peptide. Based on the MC4R-GLO cell line, we developed an assay that was shown to meet HTS standards (Z’=0.50). A pilot screen run on the Microsource Spectrum compound library (n= 2,000) successfully identified 62 positive modulators. This screen identified predicted families of compounds: β2AR agonists –the β2AR being endogenously expressed in HEK293 cells-, an adenylyl cyclase activator and finally a distribution of phosphodiesterase (PDE) inhibitors well characterized or recently identified. In this last category, we identified a structural family of coumarin-derived compounds (imperatorin, osthol and prenyletin), along with deracoxib, a drug in veterinary use for its COX2 inhibitory properties. This latter finding unveiled a new off-target mechanism of action for deracoxib as a PDE inhibitor. Overall, these data are the first report of an HTS for allosteric modulators for a Gs protein coupled receptor. PMID:21296065

  9. Outward currents in Drosophila larval neurons: dunce lacks a maintained outward current component downregulated by cAMP.

    PubMed

    Delgado, R; Davis, R; Bono, M R; Latorre, R; Labarca, P

    1998-02-15

    Outward current modulation by cAMP was investigated in wild type (wt) and dunce (dnc) Drosophila larval neurons. dnc is deficient in a cAMP phosphodiesterase and has altered memory. Outward current modulation by cAMP was investigated by acute or chronic exposure to cAMP analogs. The analysis included a scrutiny of outward current modulation by cAMP in neurons from the mushroom bodies (mrb). In Drosophila, the mrb are the centers of olfactory acquisition and retention. Based on outward current patterns, neurons were classified into four types. Downmodulation of outward currents induced by acute application of cAMP analogs was reversible and found only in type I and type IV neurons. In the general wt neuron population, approximately half of neurons exhibited cAMP-modulated, 4-aminopyridine (4-AP)-sensitive currents. On the other hand, a significantly larger fraction of mrb neurons in wt (70%) was endowed with cAMP-modulated, 4-AP-sensitive currents. Only 30% of the dnc neurons displayed outward currents modulated by cAMP. The deficit of cAMP-modulated outward currents was most severe in neurons derived from the mrb of dnc individuals. Only 4% of the mrb neurons of dnc were cAMP-modulated. The dnc defect can be induced by chronic exposure of wt neurons to cAMP analogs. These results document for the first time a well defined electrophysiological neuron phenotype in correlation with the dnc defect. Moreover, this study demonstrates that in dnc mutants such a deficiency affects most severely neurons in brain centers of acquisition and retention.

  10. cAMP modulation during sheep in vitro oocyte maturation delays progression of meiosis without affecting oocyte parthenogenetic developmental competence.

    PubMed

    Buell, Margaret; Chitwood, James L; Ross, Pablo J

    2015-03-01

    Removal of oocytes from their natural inhibitory follicular environment results in spontaneous resumption of meiosis independent of normal signaling events that occur in vivo. Controlling the onset of meiotic resumption via maintenance of elevated oocyte cAMP levels with adenylyl cyclase (AC) activation and phosphodiesterase (PDE) inhibition, and subsequent hormone stimulation with follicle FSH has been shown to dramatically improve developmental competence of bovine and murine IVM oocytes. This study evaluated the effect of cAMP modulation during IVM of sheep oocytes on meiotic progression and development to blastocyst after parthenogenetic activation. Changes in oocyte cAMP levels were quantified during the first 2h of in vitro maturation in control or cAMP-modulating medium. No significant changes in intra-oocyte cAMP were observed under control conditions, though a slight and transient drop was noticed at 15 min of maturation. Addition of the AC stimulator Forskolin and the PDE inhibitors IBMX altered the cAMP profile, resulting in 10-fold elevation of cAMP by 15 min and sustained >3-fold elevated levels from 30 to 120 min. The effect of cAMP elevation on meiotic resumption was measured by completion of germinal vesicle breakdown. Modulated oocytes were significantly delayed when compared to control media oocytes. Also, progression to MII was significantly delayed in modulated versus control oocytes at 20 and 24h, though no differences persisted to 28 h. Lastly, when control and modulated oocytes were parthenogenetically activated, no differences in blastocyst formation were observed. Thus, while cAMP modulation delayed meiotic progression, it did not improve developmental competence of sheep IVM oocytes.

  11. Selective enhancement of wnt4 expression by cyclic AMP-associated cooperation between rat central astrocytes and microglia.

    PubMed

    Ohnishi, Masatoshi; Urasaki, Tomoka; Ochiai, Hiroyuki; Matsuoka, Kohei; Takeo, Shin; Harada, Tomoki; Ohsugi, Yoshihito; Inoue, Atsuko

    2015-11-13

    The wnt protein family has important members involved in cell differentiation, proliferation and plasticity expression; however, little is known about its biosynthesis processes. On the other hand, an increase in the intracerebral cyclic adenosine 3', 5'-monophosphate (cAMP) level leads to synaptic plasticity via the de novo synthesis of any protein. Here, the effect of dibutyryl cAMP (dbcAMP), a membrane permeability cAMP analog, on the wnt family was investigated in rat primary-cultured glial cells containing astrocytes and microglia. Among wnt3a, 4, 5a, 7a and 11 mRNA, only wnt4 expression was increased by longer treatment (24 h), compared with short treatment (2 h), with dbcAMP in a concentration-dependent manner, and its effect reached statistical significance at 1 mM. In cultures of isolated astrocytes or microglia, wnt4 expression was not affected by 1 mM dbcAMP for 24 h, and microglial wnt4 protein was undetectable even when cells were treated with the drug. Mixed glial cells treated for 24 h with 1 mM dbcAMP showed significantly increased wnt4 protein, as well as mRNA. Immunofluorescence manifested that cells that expressed wnt4 protein were astrocytes, but not microglia. Intraperitoneal injection of 1.25 mg/kg rolipram, a phosphodiesterase (PDE) IV inhibitor that can pass through the blood brain barrier and inhibits cAMP degradation specifically, showed a tendency to increase wnt4 expression in the adult rat brain after 24 h, and the increases in wnt4 mRNA and protein levels reached statistical significance in the hippocampus and striatum, respectively. This is the first finding to help elucidate the selective biosynthesis of central wnt4 through cAMP-stimulated microglia and astrocytes interaction.

  12. Activated cAMP receptors switch encystation into sporulation.

    PubMed

    Kawabe, Yoshinori; Morio, Takahiro; James, John L; Prescott, Alan R; Tanaka, Yoshimasa; Schaap, Pauline

    2009-04-28

    Metazoan embryogenesis is controlled by a limited number of signaling modules that are used repetitively at successive developmental stages. The development of social amoebas shows similar reiterated use of cAMP-mediated signaling. In the model Dictyostelium discoideum, secreted cAMP acting on 4 cAMP receptors (cARs1-4) coordinates cell movement during aggregation and fruiting body formation, and induces the expression of aggregation and sporulation genes at consecutive developmental stages. To identify hierarchy in the multiple roles of cAMP, we investigated cAR heterogeneity and function across the social amoeba phylogeny. The gene duplications that yielded cARs 2-4 occurred late in evolution. Many species have only a cAR1 ortholog that duplicated independently in the Polysphondylids and Acytostelids. Disruption of both cAR genes of Polysphondylium pallidum (Ppal) did not affect aggregation, but caused complete collapse of fruiting body morphogenesis. The stunted structures contained disorganized stalk cells, which supported a mass of cysts instead of spores; cAMP triggered spore gene expression in Ppal, but not in the cAR null mutant, explaining its sporulation defect. Encystation is the survival strategy of solitary amoebas, and lower taxa, like Ppal, can still encyst as single cells. Recent findings showed that intracellular cAMP accumulation suffices to trigger encystation, whereas it is a complementary requirement for sporulation. Combined, the data suggest that cAMP signaling in social amoebas evolved from cAMP-mediated encystation in solitary amoebas; cAMP secretion in aggregates prompted the starving cells to form spores and not cysts, and additionally organized fruiting body morphogenesis. cAMP-mediated aggregation was the most recent innovation.

  13. The cAMP Response Element Binding protein (CREB) is activated by Insulin-like Growth Factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast

    SciTech Connect

    Zuloaga, R.; Fuentes, E.N.; Molina, A.; Valdés, J.A.

    2013-10-18

    Highlights: •IGF-1 induces the activation of CREB via IGF-1R/PI3K/PLC signaling pathway. •Calcium dependent signaling pathways regulate myostatin gene expression. •IGF-1 regulates myostatin gene expression via CREB transcription in skeletal myoblast. -- Abstract: Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP{sub 3}/calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA–CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation.

  14. The matching of electrostatic extrema: A useful method in drug design? A study of phosphodiesterase III inhibitors

    NASA Astrophysics Data System (ADS)

    Apaya, Robert P.; Lucchese, Baldo; Price, Sarah L.; Vinter, J. G.

    1995-02-01

    Ligands which bind to a specific protein binding site are often expected to have a similar electrostatic environment which complements that of the binding site. One method of assessing molecular electrostatic similarity is to examine the possible overlay of the maxima and minima in the electrostatic potential outside the molecules and thereby match the regions where strong electrostatic interactions, including hydrogen bonds, with the residues of the binding site may be possible. This approach is validated with accurate calculations of the electrostatic potential, derived from a distributed multipole analysis of an ab initio charge density of the molecule, so that the effects of lone pair and π-electron density are correctly included. We have applied this method to the phosphodiesterase (PDE) III substrate adenosine-3',5'-cyclic monophosphate (cAMP) and a range of nonspecific and specific PDE III inhibitors. Despite the structural variation between cAMP and the inhibitors, it is possible to match three or four extrema to produce relative orientations in which the inhibitors are sufficiently sterically and electrostatically similar to the natural substrate to account for their affinity for PDE III. This matching of extrema is more apparent using the accurate electrostatic models than it was when this approach was first applied, using semiempirical point charge models. These results reinforce the hypothesis of electrostatic similarity and give weight to the technique of extrema matching as a useful tool in drug design.

  15. Alkaline ribonuclease and phosphodiesterase activity in rat liver plasma membranes

    PubMed Central

    Prospero, Terence D.; Burge, Malcolm L. E.; Norris, Kenneth A.; Hinton, Richard H.; Reid, Eric

    1973-01-01

    The ribonuclease and phosphodiesterase activities of rat liver plasma membranes, purified from the crude nuclear fraction by centrifugation in an A-XII zonal rotor and flotation, were examined and compared. The plasma membrane is responsible for between 65 and 90% of the phosphodiesterase activity of the cell and between 25 and 30% of the particulate ribonuclease activity measured at pH8.7 in the presence of 7.5mm-MgCl2. Both enzymes were most active between pH8.5 and 8.9. Close to the pH optimum, both enzymes were more active in Tris buffer than in Bicine or glycine buffer. Both plasma-membrane phosphodiesterase and ribonuclease were strongly activated by Mg2+, there being at least a 12-fold difference between the activity in the presence of Mg2+ and of EDTA. There is, however, a difference in the response of the enzymes to Mg2+ and EDTA in that the phosphodiesterase is fully activated by 1.0mm-MgCl2 and fully inhibited by 1.0mm-EDTA, whereas the ribonuclease requires 7.5mm-MgCl2 for full activation and 5mm-EDTA for full inhibition. Density-gradient centrifugation has indicated that on solubilization in Triton X-100 most of the ribonuclease activity is released into a small fragment of the same size as that containing the phosphodiesterase activity. The relationship between the two activities is discussed in view of these results. PMID:4353377

  16. Camp Standards with Interpretations for the Accreditation of Organized Camps. Revised Edition. Basic Standards Course Participant Workbook.

    ERIC Educational Resources Information Center

    American Camping Association, Martinsville, IN.

    The American Camping Association's (ACA) Camp Standards Program assists camp administrators in providing a quality camp experience and assists the public in selecting camps that meet standards accepted by the industry and recognized by the government. ACA Camp Standards represent desirable practices basic to quality programs. Accredited camps and…

  17. Visfatin is present in bovine mammary epithelial cells, lactating mammary gland and milk, and its expression is regulated by cAMP pathway.

    PubMed

    Yonezawa, Tomo; Haga, Satoshi; Kobayashi, Yosuke; Takahashi, Tatsuyuki; Obara, Yoshiaki

    2006-12-11

    Visfatin was originally identified as a growth factor for immature B cells, and recently demonstrated to bind insulin receptor. Visfatin mRNA and protein were detected by RT-PCR and Western blot analysis in cloned bovine mammary epithelial cells, lactating bovine mammary gland and human breast cancer cell line, MCF-7. Immunocytochemical staining localized the visfatin protein in the cytosol and nucleus of both cells. Quantitative-RT-PCR analysis revealed that the expression of the visfatin mRNA was significantly elevated when treated with forskolin (500 microM), isopreterenol (1-10 microM) and dibutyric cyclic AMP (1 mM) for 24 h, and significantly reduced when treated with insulin (5-50 ng/ml) and dexsamethasone (0.5-250 nM) for 24 h. These results indicate that mammary epithelial cells express the visfatin protein and secrete them into the milk.

  18. Prayer Camps and Biomedical Care in Ghana: Is Collaboration in Mental Health Care Possible?

    PubMed Central

    Arias, Daniel; Taylor, Lauren; Ofori-Atta, Angela; Bradley, Elizabeth H.

    2016-01-01

    Background Experts have suggested that intersectoral partnerships between prayer camps and biomedical care providers may be an effective strategy to address the overwhelming shortage of mental health care workers in Africa and other low-income settings. Nevertheless, previous studies have not explored whether the prayer camp and biomedical staff beliefs and practices provide sufficient common ground to enable cooperative relationships. Therefore, we sought to examine the beliefs and practices of prayer camp staff and the perspective of biomedical care providers, with the goal of characterizing interest in—and potential for—intersectoral partnership between prayer camp staff and biomedical care providers. Methods We conducted 50 open-ended, semi-structured interviews with prophets and staff at nine Christian prayer camps in Ghana, and with staff within Ghana’s three public psychiatric hospitals. We used the purposive sampling method to recruit participants and the constant comparative method for qualitative data analysis. Results Prayer camp staff expressed interest in collaboration with biomedical mental health care providers, particularly if partnerships could provide technical support introducing medications in the prayer camp and address key shortcomings in their infrastructure and hygienic conditions. Nevertheless, challenges for collaboration were apparent as prayer camp staff expressed strong beliefs in a spiritual rather than biomedical explanatory model for mental illness, frequently used fasting and chained restraints in the course of treatment, and endorsed only short-term use of medication to treat mental illness—expressing concerns that long-term medication regimens masked underlying spiritual causes of illness. Biomedical providers were skeptical about the spiritual interpretations of mental illness held by faith healers, and were concerned by the use of chains, fasting, and the lack of adequate living facilities for patients in prayer camps

  19. Repressible extracellular phosphodiesterases showing cyclic 2',3'- and cyclic 3',5'-nucleotide phosphodiesterase activities in Neurospora crassa.

    PubMed Central

    Hasunuma, K

    1983-01-01

    Two molecular species of repressible extracellular phosphodiesterases showing cyclic 2',3'- and cyclic 3',5'-nucleotide phosphodiesterase activities were detected in mycelial culture media of wild-type Neurospora crassa and purified. The two molecular species were found to be monomeric and polymeric forms of an enzyme constituted of identical subunits having molecular weights of 50,000. This enzyme had the same electrophoretic mobility as repressible acid phosphatase. The enzyme designated repressible cyclic phosphodiesterase showed pH optima of 3.2 to 4.0 with a cyclic 3',5'-AMP substrate and 5.0 to 5.6 with a cyclic 2',3'-AMP substrate. Repressible cyclic phosphodiesterase was activated by MnCl2 and CoCl2 with cyclic 2',3'-AMP as substrate and was slightly activated by MnCl2 with cyclic 3',5'-AMP. The enzyme hydrolyzed cyclic 3',5'- and cyclic 2',3'-nucleotides, in addition to bis-rho-nitrophenyl phosphate, but not certain 5' -and 3'-nucleotides. 3'-GMP and 3'-CMP were hydrolyzed less efficiently. Mutant strains A1 (nuc-1) and B1 (nuc-2), which cannot utilize RNA or DNA as a sole source of phosphorus, were unable to produce repressible cyclic phosphodiesterase. The wild type (74A) and a heterocaryon between strains A1 and B1 produced the enzyme and showed growth on orthophosphate-free media containing cyclic 2',3'-AMP or cyclic 3',5'-AMP, whereas both mutants showed little or no growth on these media. Images PMID:6311798

  20. Hydromania: Summer Science Camp Curriculum.

    SciTech Connect

    Moura, Joan

    1995-07-01

    In 1992, Bonneville Power Administration (BPA) and the US Department of Energy (DOE) began a collaborative pilot project with the Portland Parks and Recreation Community Schools Program and others to provide summer science camps to children in Grades 4--6. Camps run two weeks in duration between late June and mid-August. Sessions are five days per week, from 9 a.m. to 3 p.m. In addition to hands-on science and math curriculum, at least three field trips are incorporated into the educational learning experience. The purpose of the BPA/DOE summer camps is to make available opportunities for fun, motivating experiences in science to students who otherwise would have difficulty accessing them. This includes inner city, minority, rural and low income students. Public law 101-510, which Congress passed in 1990, authorizes DOE facilities to establish collaborative inner-city and rural partnership programs in science and math. A primary goal of the BPA summer hands on science camps is to bring affordable science camp experiences to students where they live. It uses everyday materials to engage students` minds and to give them a sense that they have succeeded through a fun hands-on learning environment.

  1. Inhibition of Phosphodiesterase-4 during Pneumococcal Pneumonia Reduces Inflammation and Lung Injury in Mice.

    PubMed

    Tavares, Luciana P; Garcia, Cristiana C; Vago, Juliana P; Queiroz-Junior, Celso M; Galvão, Izabela; David, Bruna A; Rachid, Milene A; Silva, Patrícia M R; Russo, Remo C; Teixeira, Mauro M; Sousa, Lirlândia P

    2016-07-01

    Pneumococcal pneumonia is a leading cause of mortality worldwide. The inflammatory response to bacteria is necessary to control infection, but it may also contribute to tissue damage. Phosphodiesterase-4 inhibitors, such as rolipram (ROL), effectively reduce inflammation. Here, we examined the impact of ROL in a pneumococcal pneumonia murine model. Mice were infected intranasally with 10(5)-10(6) CFU of Streptococcus pneumoniae, treated with ROL in a prophylactic or therapeutic schedule in combination, or not, with the antibiotic ceftriaxone. Inflammation and bacteria counts were assessed, and ex vivo phagocytosis assays were performed. ROL treatment during S. pneumoniae infection decreased neutrophil recruitment into lungs and airways and reduced lung injury. Prophylactic ROL treatment also decreased cytokine levels in the airways. Although modulation of inflammation by ROL ameliorated pneumonia, bacteria burden was not reduced. On the other hand, antibiotic therapy reduced bacteria without reducing neutrophil infiltration, cytokine level, or lung injury. Combined ROL and ceftriaxone treatment decreased lethality rates and was more efficient in reducing inflammation, by increasing proresolving protein annexin A1 (AnxA1) expression, and bacterial burden by enhancing phagocytosis. Lack of AnxA1 increased inflammation and lethality induced by pneumococcal infection. These data show that immunomodulatory effects of phosphodiesterase-4 inhibitors are useful during severe pneumococcal pneumonia and suggest their potential benefit as adjunctive therapy during infectious diseases.

  2. Management of diabetes at summer camps.

    PubMed

    Ciambra, Roberta; Locatelli, Chiara; Suprani, Tosca; Pocecco, Mauro

    2005-01-01

    We report our experience in the organization of diabetic children summer-camps since 1973. Guidelines for organization have been recently reported by the SIEDP (Società Italiana di Endocrinologia e Diabetologia Pediatrica). Our attention is focused on diabetes management at camp, organization and planning, medical staff composition and staff training, treatment of diabetes-related emergencies, written camp management plan, diabetes education and psychological issues at camp, prevention of possible risks, assessment of effectiveness of education in summer camps and research at camp.

  3. Cultural behaviour and the invention of traditions: music and musical practices in the early concentration camps, 1933-6/7.

    PubMed

    Fackler, Guido

    2010-01-01

    This article investigates music in the concentration camps before the second world war. For the camp authorities, ordering prisoners to sing songs or play in orchestras was an instrument of domination. But for the prisoners, music could also be an expression of solidarity and survival: inmates could retain a degree of their own agency in the pre-war camps, despite the often unbearable living conditions and harsh treatment by guards. The present article emphasizes this ambiguity of music in the early camps. It illustrates the emergence of musical traditions in the pre-war camps which came to have a significant impact on everyday life in the camps. It helps to overcome the view that concentration camp prisoners were simply passive victims.

  4. A novel pineal-specific product of the oligopeptide transporter PepT1 gene: circadian expression mediated by cAMP activation of an intronic promoter.

    PubMed

    Gaildrat, Pascaline; Møller, Morten; Mukda, Sujira; Humphries, Ann; Carter, David A; Ganapathy, Vadivel; Klein, David C

    2005-04-29

    The oligopeptide transporter 1, PepT1, is a member of the Slc15 family of 12 membrane-spanning domain transporters; PepT1 has proton/peptide cotransport activity and is selectively expressed in intestinal epithelial cells, where it is responsible for the nutritional absorption of di- and tri-peptides. Here, a novel PepT1 gene product has been identified in the rat pineal gland, termed pgPepT1. It encodes a 150-amino acid protein encompassing the C-terminal 3 membrane-spanning domains of intestinal PepT1 protein, with 3 additional N-terminal residues. Expression of pgPepT1 appears to be restricted to the pineal gland and follows a marked circadian pattern with >100-fold higher levels of mRNA occurring at night; this is accompanied by an accumulation of membrane-associated pgPepT1 protein ( approximately 16 kDa). The daily rhythm in pgPepT1 mRNA is regulated by the well described neural pathway that controls pineal melatonin production. This includes the retina, the circadian clock in the suprachiasmatic nucleus, central structures, and projections from the superior cervical ganglia; activation of this pathway results in the release of norepinephrine. Here it was found that pgPepT1 expression is mediated by a norepinephrine-->cyclic AMP mechanism that activates an alternative promoter located in intron 20 of the gene. pgPepT1 protein was found to have transporter-modulator activity; it could contribute to circadian changes in pineal function through this mechanism.

  5. He Sapa Bloketu Waecun: 2008 Summer Science and Cultural Camps

    NASA Astrophysics Data System (ADS)

    Kliche, D. V.; Sanovia, J.; Decker, R.; Bolman, J.

    2008-12-01

    The South Dakota School of Mines, Humboldt State University and Sinte Gleska University with support from the National Science Foundation, sponsored four camps for South Dakota Lakota youth to nurture a geosciences learning community linked to culturally significant sites in the Black Hills. These camps utilized outdoor, experiential learning to integrate indigenous knowledge with contemporary western science. The project resulted in increased awareness among Native and non-Native Americans, young and adult, about the importance of geosciences in their connection and interpretation of nature. The project also motivated participants in learning and becoming active in land and resources protection and the importance of becoming knowledgeable and active in regulatory policies (both Tribal and State). The four camps were scheduled during the month of June, 2008, which is the month of the summer solstice, a sacred time for the Lakota people which signal the Lakota Sundance Ceremony. The timing of the camps was chosen to give the Native American participants the framework to express their connection to Native lands through the understanding of their oral history. For the first time in such camps, middle and high school students were encouraged to have a parent or relative attending with them. The camps proved to be a great success among students and their families. The curriculum and activities helped participants immerse themselves mentally, physically and spiritually into an experience of a life time. We plan to show our results from these camps and emphasize the usefulness of this new approach in teaching science and encouraging the new generation to pursue careers in geosciences.

  6. Phosphodiesterase 5 inhibitors augment UT-15C-stimulated ATP release from erythrocytes of humans with pulmonary arterial hypertension.

    PubMed

    Bowles, Elizabeth A; Moody, Gina N; Yeragunta, Yashaswini; Stephenson, Alan H; Ellsworth, Mary L; Sprague, Randy S

    2015-01-01

    Both prostacyclin analogs and phosphodiesterase 5 (PDE5) inhibitors are effective treatments for pulmonary arterial hypertension (PAH). In addition to direct effects on vascular smooth muscle, prostacyclin analogs increase cAMP levels and ATP release from healthy human erythrocytes. We hypothesized that UT-15C, an orally available form of the prostacyclin analog, treprostinil, would stimulate ATP release from erythrocytes of humans with PAH and that this release would be augmented by PDE5 inhibitors. Erythrocytes were isolated and the effect of UT-15C on cAMP levels and ATP release were measured in the presence and absence of the PDE5 inhibitors, zaprinast or tadalafil. In addition, the ability of a soluble guanylyl cyclase inhibitor to prevent the effects of tadalafil was determined. Erythrocytes of healthy humans and humans with PAH respond to UT-15C with increases in cAMP levels and ATP release. In both groups, UT-15C-induced ATP release was potentiated by zaprinast and tadalafil. The effect of tadalafil was prevented by pre-treatment with an inhibitor of soluble guanylyl cyclase in healthy human erythrocytes. Importantly, UT-15C-induced ATP release was greater in PAH erythrocytes than in healthy human erythrocytes in both the presence and the absence of PDE5 inhibitors. The finding that prostacyclin analogs and PDE5 inhibitors work synergistically to enhance release of the potent vasodilator ATP from PAH erythrocytes provides a new rationale for the co-administration of these drugs in this disease. Moreover, these results suggest that the erythrocyte is a novel target for future drug development for the treatment of PAH.

  7. Touching the Spirit: The Spiritual Benefits of Camp.

    ERIC Educational Resources Information Center

    Drovdahl, Robert

    1991-01-01

    Discusses the nature of spirituality and the resources people use in responding to spirituality based on Robert Coles' book, "The Spiritual Life of Children." Answers questions as to how to use the camp experience to afford campers opportunities for spiritual growth while respecting the many expressions of spirituality in society. (LP)

  8. Academic Boot Camp for the Writing of Psychology Research Reports

    ERIC Educational Resources Information Center

    Skues, Jason L.; Wise, Lisa

    2014-01-01

    Herein, we describe the implementation of, and responses to, a structured writing workshop in the form of an academic boot camp. Participants were 42 undergraduate psychology students from a medium-sized Australian university who were completing their major assignment for the semester. A majority of the students expressed satisfaction with the…

  9. Astro Camp is a blast!

    NASA Technical Reports Server (NTRS)

    2006-01-01

    An Astro Camp counselor and her campers perform a science experiment to learn what types of `fuel' will best propel their 'rockets.' Stennis Space Center's popular series of day camps have campers design, build and test model rockets based on the principles that would be used to build different types of rockets suitable for a mission to the moon or Mars. They learn details like how far they would travel, how long it would take, what supplies they would need and how to survive in that environment.

  10. Protein kinase C activation inhibits eosinophil degranulation through stimulation of intracellular cAMP production.

    PubMed

    Ezeamuzie, Charles I; Taslim, Najla

    2004-11-01

    The mechanism of inhibition of eosinophil degranulation by protein kinase C (PKC) was investigated in complement C5a (C5a)-stimulated degranulation of highly purified human eosinophils using the specific PKC activator - phorbol 12-myristate 13-acetate (PMA). C5a-induced release of eosinophil peroxidase and eosinophil cationic protein was potently inhibited in a concentration-dependent manner by PMA (IC(50): 3 and 5 nM, respectively). The inhibition by PMA, but not histamine, was significantly reversed by the specific, but isoform nonselective, PKC inhibitor Ro 31-8220 (1 microM). In the presence of phosphodiesterase inhibitor rolipram (5 microM), PMA stimulated a pronounced concentration-dependent increase in intracellular cAMP, with a potency 400 times that of histamine (EC(50): 55 nM vs 22.5 microM). The inactive PMA analogue, 4alpha-PMA, had no such effect. The cAMP production by PMA, but not histamine, was significantly reversed by Ro 31-8220 (1 microM) and the selective inhibitor of the novel PKCdelta, rottlerin (1-3 microM), but not the selective inhibitor of the classical PKC isoforms, Gö 6976 (0.01-0.1 microM). Western blot analysis revealed the presence of six PKC isoforms (alpha, betaI, betaII, delta, iota and zeta) in isolated eosinophils. Chelation of internal or external calcium had no effect on PMA-induced cAMP response, but abolished that induced by histamine. There was a good correlation between increase in intracellular cAMP and inhibition of degranulation. These results show, for the first time, that in human eosinophils, PMA, via activation of PKCdelta isoform, can stimulate cAMP production, and that this may be the basis for its potent anti-degranulatory effect.

  11. Protein kinase C activation inhibits eosinophil degranulation through stimulation of intracellular cAMP production

    PubMed Central

    Ezeamuzie, Charles I; Taslim, Najla

    2004-01-01

    The mechanism of inhibition of eosinophil degranulation by protein kinase C (PKC) was investigated in complement C5a (C5a)-stimulated degranulation of highly purified human eosinophils using the specific PKC activator – phorbol 12-myristate 13-acetate (PMA). C5a-induced release of eosinophil peroxidase and eosinophil cationic protein was potently inhibited in a concentration-dependent manner by PMA (IC50: 3 and 5 nM, respectively). The inhibition by PMA, but not histamine, was significantly reversed by the specific, but isoform nonselective, PKC inhibitor Ro 31-8220 (1 μM). In the presence of phosphodiesterase inhibitor rolipram (5 μM), PMA stimulated a pronounced concentration-dependent increase in intracellular cAMP, with a potency 400 times that of histamine (EC50: 55 nM vs 22.5 μM). The inactive PMA analogue, 4α-PMA, had no such effect. The cAMP production by PMA, but not histamine, was significantly reversed by Ro 31-8220 (1 μM) and the selective inhibitor of the novel PKCδ, rottlerin (1–3 μM), but not the selective inhibitor of the classical PKC isoforms, Gö 6976 (0.01–0.1 μM). Western blot analysis revealed the presence of six PKC isoforms (α, βI, βII, δ, ι and ζ) in isolated eosinophils. Chelation of internal or external calcium had no effect on PMA-induced cAMP response, but abolished that induced by histamine. There was a good correlation between increase in intracellular cAMP and inhibition of degranulation. These results show, for the first time, that in human eosinophils, PMA, via activation of PKCδ isoform, can stimulate cAMP production, and that this may be the basis for its potent anti-degranulatory effect. PMID:15504748

  12. cAMP induction by ouabain promotes endothelin-1 secretion via MAPK/ERK signaling in beating rabbit atria.

    PubMed

    Peng, Li-Qun; Li, Ping; Zhang, Qiu-Li; Hong, Lan; Liu, Li-Ping; Cui, Xun; Cui, Bai-Ri

    2016-01-01

    Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the Na(+)-K(+)-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain (3.0 µmol/L) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 (3.0 µmol/L), an inhibitor for reverse mode of Na(+)-Ca(2+) exchangers (NCX), but did not by L-type Ca(2+) channel blocker nifedipine (1.0 µmol/L) or protein kinase A (PKA) selective inhibitor H-89 (3.0 µmol/L). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline (100.0 µmol/L), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP (0.5 µmol/L) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 (30 µmol/L), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

  13. cAMP/PKA/CREB/GLT1 signaling involved in the antidepressant-like effects of phosphodiesterase 4D inhibitor (GEBR-7b) in rats

    PubMed Central

    Liu, Xu; Guo, Haibiao; Sayed, Mohammad Daud SOM; Lu, Yang; Yang, Ting; Zhou, Dongsheng; Chen, Zhongming; Wang, Haitao; Wang, Chuang; Xu, Jiangping

    2016-01-01

    Objectives GEBR-7b, a potential phosphodiesterase 4D inhibitor, has been shown to have memory-enhancing effects in rodents. However, it is still unknown whether GEBR-7b also has the antidepressant-like effects in rats. Herein, we examined the potential of GEBR-7b to attenuate depression-like behaviors in the rat model of depression induced by chronic unpredictable stress (CUS). Next, we also investigated the alterations of cyclic adenosine monophosphate (cAMP), protein kinase A (PKA) catalytic subunit (PKAca), cAMP response element-binding (CREB), and glutamate transporter 1 (GLT1) levels produced by GEBR-7b in the rats model of depression. Methods Effects of GEBR-7b on CUS (35 days)-induced depression-like behaviors were examined by measuring immobility time in the forced swimming test (FST). Hippocampal cAMP levels were examined by enzyme-linked immunosorbent assay, whereas PKAca, phosphorylation of CREB (pCREB), CREB, and GLT1 in the hippocampus of rats were subjected to Western blot analysis. Results CUS exposure caused a depression-like behavior evidenced by the increased immobility time in FST. Depression-like behavior induced by CUS was accompanied by a significant increased GLT, decreased cAMP, PKAca, pCREB activities in hippocampus. However, repeated GEBR-7b administration significantly reversed CUS-induced depression-like behavior and changes of cAMP/PKA/CREB/GLT1 signaling. No alteration was observed in locomotor activity in open field test. Conclusion These findings indicate that GEBR-7b reversed the depression-like behaviors induced by CUS in rats, which is at least in part mediated by modulating cAMP, PKAca, pCREB, and GLT1 levels in the hippocampus of rats, supporting its neuroprotective potential against behavioral and biochemical dysfunctions induced by CUS. PMID:26855578

  14. Going Camping? A Basic Guide to Camping with Students.

    ERIC Educational Resources Information Center

    1977

    Beginning with the "often overlooked areas", this guide to camping trips for secondary students presents initial planning procedures such as: site selection; number of leaders per number of students (2 leaders for each group of 10-12); parental permission forms; transportation arrangements; public school announcements; medical aid expertise and…

  15. Making Camp Environmentally Friendly: How Two Camps Did It.

    ERIC Educational Resources Information Center

    Westerman, Martin; Griner-Johnson, Russ

    1991-01-01

    Describes the efforts of two camps administered by the Brandeis-Bardin Institute (Brandeis, California) in implementing water and energy conservation programs, involving recycling, composting, and landfill savings. Programs were successful in eliminating excess waste and teaching campers to care more about their environments at home and at work.…

  16. Camp Counseling: A Great Resume Builder.

    ERIC Educational Resources Information Center

    Fass, Jack R.

    1993-01-01

    Advocates camp counseling as an excellent preparation for human services careers. Camp counseling offers (1) leisure services preparation; (2) leadership training; (3) collaborative skills; and (4) life experience. (KS)

  17. Including People with Disabilities in Camp Programs: A Resource for Camp Directors.

    ERIC Educational Resources Information Center

    Roswal, Glenn M., Ed.; Dowd, Karen J., Ed.; Bynum, Jerry W., Ed.

    Written primarily by camp administrators affiliated with the National Easter Seal Society, this publication is designed to help camp directors meet the challenges of including campers of all abilities in their camp programs. The first section provides an overview of the inclusion concept in general and at camp, and discusses legal and medical…

  18. The role of ventral striatal cAMP signaling in stress-induced behaviors

    PubMed Central

    Plattner, Florian; Hayashi, Kanehiro; Hernandez, Adan; Benavides, David R.; Tassin, Tara C.; Tan, Chunfeng; Day, Jonathan; Fina, Maggy W.; Yuen, Eunice Y.; Yan, Zhen; Goldberg, Matthew S.; Nairn, Angus C.; Greengard, Paul; Nestler, Eric J.; Taussig, Ronald; Nishi, Akinori; Houslay, Miles D.; Bibb, James A.

    2015-01-01

    The cAMP/PKA signaling cascade is a ubiquitous pathway acting downstream of multiple neuromodulators. We found that the phosphorylation of phosphodiesterase-4 (PDE4) by cyclin-dependent protein kinase 5 (Cdk5) facilitates cAMP degradation and homeostasis of cAMP/PKA signaling. In mice, loss of Cdk5 throughout the forebrain elevated cAMP levels and increased PKA activity in striatal neurons, and altered behavioral responses to acute or chronic stressors. Ventral striatum- or D1 dopamine receptor-specific conditional knockout of Cdk5, or ventral striatum infusion of a small interfering peptide that selectively targets the regulation of PDE4 by Cdk5, all produced analogical effects on stress-induced behavioral responses. Together, our results demonstrate that altering cAMP signaling in medium spiny neurons of the ventral striatum can effectively modulate stress-induced behavioral states. We propose that targeting the Cdk5 regulation of PDE4 could be a new therapeutic approach for clinical conditions associated with stress, such as depression. PMID:26192746

  19. Extension Sustainability Camp: Design, Implementation, and Evaluation

    ERIC Educational Resources Information Center

    Brain, Roslynn; Upton, Sally; Tingey, Brett

    2015-01-01

    Sustainability Camps provide an opportunity for Extension educators to be in the forefront of sustainability outreach and to meet the growing demand for sustainability education. This article shares development, implementation, and evaluation of an Extension Sustainability Camp for youth, grades 4-6. Camp impact was measured via daily pre-and…

  20. The Elementary Camp Experience: An ARC Partnership

    ERIC Educational Resources Information Center

    Krzemien, Marta; Krotzer, Kate

    2012-01-01

    Foreign Language Elementary Summer Camp is a fantastic way to spend part of the summer. For the past ten years in Glastonbury, Connecticut, the authors have offered a variety of foreign language elementary camps that meet daily for three hours for three to four weeks during July. Currently, they offer camps for Chinese, English Language Learners…

  1. Camping for Youth with Chronic Illnesses.

    ERIC Educational Resources Information Center

    Burns, Joanna L.; Keller, M. Jean

    1994-01-01

    Camp Fortnight brought 25 British children with cystic fibrosis to experience a 2-week camping program in Texas. Campers (ages 11-15) participated in wilderness experiences, a challenge course, fishing, horseback riding, creative arts, cooking, hiking, outdoor camping, and field trips. Profiles campers and their experiences. (LP)

  2. Day Camp Manual: Program. Book IV.

    ERIC Educational Resources Information Center

    Babcock, William

    Book IV in a 5-book day camp manual discusses the camp program. Section I describes the organization, definition, and elements essential to successful day camp programs. Section II, which addresses the benefits and special considerations of mass programs, includes rainy day contingencies, materials to have on hand, and activity suggestions.…

  3. Evaluation of Florida's Eckerd Wilderness Camp Program.

    ERIC Educational Resources Information Center

    Florida State Dept. of Health and Rehabilitative Services, Tallahassee.

    This report evaluates year-long wilderness camping rehabilitation program for juvenile delinquents believed "emotionally problemed." The remote camps teach through an experience curriculum encompassing daily camping style tasks, with integration of experience via three-day home visits every six weeks followed by written reports by…

  4. Language Camps: Thirteen Years of Minor Miracles.

    ERIC Educational Resources Information Center

    Peterson, Jean

    A language camp program that began with a small group of 10- to 12-year-olds whose faculty parents wanted them to retain the German learned on sabbaticals abroad has developed into a program of annual week-long day and resident camps for 150 children, aged 9 to 14 years, learning German, French, Spanish, and Norwegian. The camp was originally…

  5. Camping & the Whirl of Insurance Cycles.

    ERIC Educational Resources Information Center

    Milgrim, Darrow

    1988-01-01

    Suggests possible responses for summer camp operators facing insurance rate increases and other insurance industry changes. Examines areas of risk in summer camping and suggests general ways that camps can become more desirable to the insurance industry as "insurable groups." (TES)

  6. American Camping Association Annual Report, 2000.

    ERIC Educational Resources Information Center

    American Camping Association, Martinsville, IN.

    The American Camping Association (ACA) is a community of camp professionals dedicated to enriching the lives of children and adults through the camp experience. This annual report describes ACA activities during 2000, grouped in five areas: (1) expansion of services and other development of ACA's 24 regional sections and partnerships with other…

  7. IDENTIFICATION OF CHOLINERGIC AND NONCHOLINERGIC NEURONS IN THE PONS EXPRESSING PHOSPHORYLATED cAMP RESPONSE ELEMENT-BINDING PROTEIN (pCREB) AS A FUNCTION OF RAPID EYE MOVEMENT (REM) SLEEP

    PubMed Central

    DATTA, S.; SIWEK, D. F.; STACK, E. C.

    2009-01-01

    Recent studies have shown that in the pedunculopontine tegmental nucleus (PPT), increased neuronal activity and kainate receptor-mediated activation of intracellular protein kinase A (PKA) are important physiological and molecular steps for the generation of REM sleep. In the present study performed on rats, phosphorylated cAMP response element-binding protein (pCREB) immunostaining was used as a marker for increased intracellular PKA activation and as a reflection of increased neuronal activity. To identify whether activated cells were either cholinergic or noncholinergic, the PPT and laterodorsal tegmental nucleus (LDT) cells were immunostained for choline acetyltransferase (ChAT) in combination with pCREB or c-Fos. The results demonstrated that during high REM sleep (HR, ~27%), significantly higher numbers of cells expressed pCREB and c-Fos in the PPT, of which 95% of pCREB-expressing cells were ChAT-positive. With high REM sleep, the numbers of pCREB-positive cells were also significantly higher in the medial pontine reticular formation (mPRF), pontine reticular nucleus oral (PnO), and dorsal subcoeruleus nucleus (SubCD) but very few in the locus coeruleus (LC) and dorsal raphe nucleus (DRN). Conversely, with low REM sleep (LR, ~2%), the numbers of pCREB expressing cells were very few in the PPT, mPRF, PnO, and SubCD but significantly higher in the LC and DRN. The results of regression analyses revealed significant positive relationships between the total percentages of REM sleep and numbers of ChAT+/pCREB+ (Rsqr = 0.98) cells in the PPT and pCREB+ cells in the mPRF (Rsqr = 0.88), PnO (Rsqr = 0.87), and SubCD (Rsqr = 0.84); whereas significantly negative relationships were associated with the pCREB+ cells in the LC (Rsqr = 0.70) and DRN (Rsqr = 0.60). These results provide evidence supporting the hypothesis that during REM sleep, the PPT cholinergic neurons are active, whereas the LC and DRN neurons are inactive. More importantly, the regression analysis

  8. Summer Science Camps Program (SSC).

    ERIC Educational Resources Information Center

    National Science Foundation, Washington, DC. Directorate for Education and Human Resources.

    The Summer Science Camps (SSC) Program supports residential and commuter enrichment projects for seventh through ninth grade minority students who are underrepresented in science, engineering, and mathematics. Eligible organizations include school districts, museums, colleges, universities, and nonprofit youth-centered and/or community-based…

  9. AVTC Hosts TechnoCamp

    ERIC Educational Resources Information Center

    Miner, Brenda

    2006-01-01

    The Area Vo-Tech Center (AVTC) in Russellville, Arkansas, recently hosted its first TechnoCamp to encourage enrollment based on the aptitude and interest level of the students enrolling in the various programs. The center currently offers student enrollment in auto technology, computer engineering, cosmetology, construction technology, drafting…

  10. Sleep At Camp: A Survey.

    ERIC Educational Resources Information Center

    Pravda, Myra

    1997-01-01

    Among 40 camp directors surveyed, the majority believed that campers get enough sleep, but that staff members and directors do not get enough sleep. Addresses how sleep deprivation can affect job performance and offers strategies for helping staff understand the importance of sleep to keep them alert and functioning in their job. Includes…

  11. Winter Wilderness Travel and Camping.

    ERIC Educational Resources Information Center

    Gilchrest, Norman

    Knowledge and skill are needed for safe and enjoyable travel and camping in the wilderness in winter. The beauty of snow and ice, reduced human use, and higher tolerance of animals toward humans make the wilderness attractive during winter. The uniqueness of winter travel presents several challenges that are not present in other seasons. Safety is…

  12. Lyme Disease Comes to Camp.

    ERIC Educational Resources Information Center

    Peterson, Michael

    1989-01-01

    Describes one summer camp's plan for dealing with Lyme disease. Describes the disease and the deer tick. Recommends avoiding tick exposure through clothing, frequent examination, showers, and avoiding high grass and brushy areas, and using chemical insect repellents and chemicals to kill ticks in deer mouse nests. (DHP)

  13. Boot Camp Prisons in 1993.

    ERIC Educational Resources Information Center

    MacKenzie, Doris Layton

    1993-01-01

    Describes the boot-camp prison program, its goals, and its drug-treatment and drug-education activities, and its development and change. The article presents the results of a multisite study from eight states that examined the variations in the shock-incarceration concept and its effect. (GLR)

  14. Interplay of palmitoylation and phosphorylation in the trafficking and localization of phosphodiesterase 10A: implications for the treatment of schizophrenia.

    PubMed

    Charych, Erik I; Jiang, Li-Xin; Lo, Frederick; Sullivan, Kelly; Brandon, Nicholas J

    2010-07-07

    Phosphodiesterase 10A (PDE10A) is a striatum-enriched, dual-specific cyclic nucleotide phosphodiesterase that has gained considerable attention as a potential therapeutic target for psychiatric disorders such as schizophrenia. As such, a PDE10A-selective inhibitor compound, MP-10, has recently entered clinical testing. Since little is known about the cellular regulation of PDE10A, we sought to elucidate the mechanisms that govern its subcellular localization in striatal medium spiny neurons. Previous reports suggest that PDE10A is primarily membrane bound and is transported throughout medium spiny neuron axons and dendrites. Moreover, it has been shown in PC12 cells that the localization of the major splice form, PDE10A2, may be regulated by protein kinase A phosphorylation at threonine 16 (Thr-16). Using an antibody that specifically recognizes phosphorylated Thr-16 (pThr-16) of PDE10A2, we provide evidence that phosphorylation at Thr-16 is critical for the regulation of PDE10A subcellular localization in vivo. Furthermore, we demonstrate in primary mouse striatal neuron cultures that PDE10A membrane association and transport throughout dendritic processes requires palmitoylation of cysteine 11 (Cys-11) of PDE10A2, likely by the palmitoyl acyltransferases DHHC-7 and -19. Finally, we show that Thr-16 phosphorylation regulates PDE10A trafficking and localization by preventing palmitoylation of Cys-11 rather than by interfering with palmitate-lipid interactions. These data support a model whereby PDE10A trafficking and localization can be regulated in response to local fluctuations in cAMP levels. Given this, we propose that excessive striatal dopamine release, as occurs in schizophrenia, might exert differential effects on the regulation of PDE10A localization in the two striatal output pathways.

  15. Potentiation of penile tumescence by T-1032, a new potent and specific phosphodiesterase type V inhibitor, in dogs.

    PubMed

    Noto, T; Inoue, H; Ikeo, T; Kikkawa, K

    2000-09-01

    We examined the mechanism underlying the potentiation of penile tumescence by methyl 2-(4-aminophenyl)-1, 2dihydro-1-oxo-7-(2-pyridinylmethoxy)-4-(3,4, 5-trimethoxyphenyl)3-isoquinoline carboxylate sulfate (T-1032), a new potent and selective phosphodiesterase type V inhibitor. In vivo, pelvic nerve stimulation induced a penile tumescence together with increase of total nitric oxide metabolite levels within the corpus cavernosa of anesthetized dogs. Intravenous (1-100 microg/kg) and intraduodenal (3, 30, 300 microg/kg) treatment with T-1032 dose dependently potentiated the tumescence. The potency of T-1032 was equivalent to that of sildenafil. T-1032 did not influence the intracavernous pressure when the pelvic nerve stimulation was absent. The potentiation of tumescence was more pronounced by intracavernous than i.v. injection. Intracavernous N(G)-nitro-L-arginine, a nitric-oxide synthase inhibitor, but not N(G)-nitro-D-arginine diminished the effects of T-1032 on the tumescence. Furthermore, i.v. T-1032 augmented the tumescence induced by sodium nitroprusside (SNP) but not by vasoactive intestinal polypeptide (VIP). In vitro, in isolated preparations of canine corpus cavernosum precontracted with phenylephrine, SNP (0. 01-100 microM) and VIP (0.01-1 microM) produced a dose-dependent relaxation accompanied by an increase in cGMP and cAMP levels, respectively. T-1032 augmented the relaxation induced by SNP but not by VIP. These data suggest that oral treatment with T-1032 has potential to improve erectile dysfunction through the inhibition of phosphodiesterase type V in the smooth muscles of corpus cavernosa.

  16. Rod outer segment structure influences the apparent kinetic parameters of cyclic GMP phosphodiesterase

    PubMed Central

    1994-01-01

    Cyclic GMP hydrolysis by the phosphodiesterase (PDE) of retinal rod outer segments (ROS) is a key amplification step in phototransduction. Definitive estimates of the turnover number, kcat, and of the Km are crucial to quantifying the amplification contributed by the PDE. Published estimates for these kinetic parameters vary widely; moreover, light-dependent changes in the Km of PDE have been reported. The experiments and analyses reported here account for most observed variations in apparent Km, and they lead to definitive estimates of the intrinsic kinetic parameters in amphibian rods. We first obtained a new and highly accurate estimate of the ratio of holo-PDE to rhodopsin in the amphibian ROS, 1:270. We then estimated the apparent kinetic parameters of light-activated PDE of suspensions of disrupted frog ROS whose structural integrity was systematically varied. In the most severely disrupted ROS preparation, we found Km = 95 microM and kcat = 4,400 cGMP.s-1. In suspensions of disc-stack fragments of greater integrity, the apparent Km increased to approximately 600 microM, though kcat remained unchanged. In contrast, the Km for cAMP was not shifted in the disc stack preparations. A theoretical analysis shows that the elevated apparent Km of suspensions of disc stacks can be explained as a consequence of diffusion with hydrolysis in the disc stack, which causes active PDEs nearer the center of the stack to be exposed to a lower concentration of cyclic GMP than PDEs at the disc stack rim. The analysis predicts our observation that the apparent Km for cGMP is elevated with no accompanying decrease in kcat. The analysis also predicts the lack of a Km shift for cAMP and the previously reported light dependence of the apparent Km for cGMP. We conclude that the intrinsic kinetic parameters of the PDE do not vary with light or structural integrity, and are those of the most severely disrupted disc stacks. PMID:7931138

  17. Kinetic and Structural Studies of Phosphodiesterase-8A and Implication on the Inhibitor Selectivity

    SciTech Connect

    Wang, H.; Yan, Z; Yang, S; Cai, J; Robinson, H; Ke, H

    2008-01-01

    Cyclic nucleotide phosphodiesterase-8 (PDE8) is a family of cAMP-specific enzymes and plays important roles in many biological processes, including T-cell activation, testosterone production, adrenocortical hyperplasia, and thyroid function. However, no PDE8 selective inhibitors are available for trial treatment of human diseases. Here we report kinetic properties of the highly active PDE8A1 catalytic domain prepared from refolding and its crystal structures in the unliganded and 3-isobutyl-1-methylxanthine (IBMX) bound forms at 1.9 and 2.1 Angstroms resolutions, respectively. The PDE8A1 catalytic domain has a KM of 1.8 eM, Vmax of 6.1 emol/min/mg, a kcat of 4.0 s-1 for cAMP, and a KM of 1.6 mM, Vmax of 2.5 emol/min/mg, a kcat of 1.6 s-1 for cGMP, thus indicating that the substrate specificity of PDE8 is dominated by KM. The structure of the PDE8A1 catalytic domain has similar topology as those of other PDE families but contains two extra helices around Asn685-Thr710. Since this fragment is distant from the active site of the enzyme, its impact on the catalysis is unclear. The PDE8A1 catalytic domain is insensitive to the IBMX inhibition (IC50 = 700 eM). The unfavorable interaction of IBMX in the PDE8A1-IBMX structure suggests an important role of Tyr748 in the inhibitor binding. Indeed, the mutation of Tyr748 to phenylalanine increases the PDE8A1 sensitivity to several nonselective or family selective PDE inhibitors. Thus, the structural and mutagenesis studies provide not only insight into the enzymatic properties but also guidelines for design of PDE8 selective inhibitors.

  18. Phosphodiesterase7 Inhibition Activates Adult Neurogenesis in Hippocampus and Subventricular Zone In Vitro and In Vivo.

    PubMed

    Morales-Garcia, Jose A; Echeverry-Alzate, Victor; Alonso-Gil, Sandra; Sanz-SanCristobal, Marina; Lopez-Moreno, Jose A; Gil, Carmen; Martinez, Ana; Santos, Angel; Perez-Castillo, Ana

    2017-02-01

    The phosphodiesterase 7 (PDE7) enzyme is one of the enzymes responsible for controlling intracellular levels of cyclic adenosine 3',5'-monophosphate in the immune and central nervous system. We have previously shown that inhibitors of this enzyme are potent neuroprotective and anti-inflammatory agents. In addition, we also demonstrated that PDE7 inhibition induces endogenous neuroregenerative processes toward a dopaminergic phenotype. Here, we show that PDE7 inhibition controls stem cell expansion in the subgranular zone of the dentate gyrus of the hippocampus (SGZ) and the subventricular zone (SVZ) in the adult rat brain. Neurospheres cultures obtained from SGZ and SVZ of adult rats treated with PDE7 inhibitors presented an increased proliferation and neuronal differentiation compared to control cultures. PDE7 inhibitors treatment of neurospheres cultures also resulted in an increase of the levels of phosphorylated cAMP response element binding protein, suggesting that their effects were indeed mediated through the activation of the cAMP/PKA signaling pathway. In addition, adult rats orally treated with S14, a specific inhibitor of PDE7, presented elevated numbers of proliferating progenitor cells, and migrating precursors in the SGZ and the SVZ. Moreover, long-term treatment with this PDE7 inhibitor shows a significant increase in newly generated neurons in the olfactory bulb and the hippocampus. Also a better performance in memory tests was observed in S14 treated rats, suggesting a functional relevance for the S14-induced increase in SGZ neurogenesis. Taken together, our results indicate for the first time that inhibition of PDE7 directly regulates proliferation, migration and differentiation of neural stem cells, improving spatial learning and memory tasks. Stem Cells 2017;35:458-472.

  19. Phosphodiesterases Regulate BAY 41-2272-Induced VASP Phosphorylation in Vascular Smooth Muscle Cells

    PubMed Central

    Adderley, Shaquria P.; Joshi, Chintamani N.; Martin, Danielle N.; Tulis, David Anthony

    2012-01-01

    BAY 41-2272 (BAY), a stimulator of soluble guanylyl cyclase, increases cyclic nucleotides and inhibits proliferation of vascular smooth muscle cells (VSMCs). In this study, we elucidated mechanisms of action of BAY in its regulation of vasodilator-stimulated phosphoprotein (VASP) with an emphasis on VSMC phosphodiesterases (PDEs). BAY alone increased phosphorylation of VASPSer239 and VASPSer157, respective indicators of PKG and PKA signaling. IBMX, a non-selective inhibitor of PDEs, had no effect on BAY-induced phosphorylation at VASPSer239 but inhibited phosphorylation at VASPSer157. Selective inhibitors of PDE3 or PDE4 attenuated BAY-mediated increases at VASPSer239 and VASPSer157, whereas PDE5 inhibition potentiated BAY-mediated increases only at VASPSer157. In comparison, 8Br-cGMP increased phosphorylation at VASPSer239 and VASPSer157 which were not affected by selective PDE inhibitors. In the presence of 8Br-cAMP, inhibition of either PDE4 or PDE5 decreased VASPSer239 phosphorylation and inhibition of PDE3 increased phosphorylation at VASPSer239, while inhibition of PDE3 or PDE4 increased and PDE5 inhibition had no effect on VASPSer157 phosphorylation. These findings demonstrate that BAY operates via cAMP and cGMP along with regulation by PDEs to phosphorylate VASP in VSMCs and that the mechanism of action of BAY in VSMCs is different from that of direct cyclic nucleotide analogs with respect to VASP phosphorylation and the involvement of PDEs. Given a role for VASP as a critical cytoskeletal protein, these findings provide evidence for BAY as a regulator of VSMC growth and a potential therapeutic agent against vasculoproliferative disorders. PMID:22347188

  20. The ACA Standards Organizer. A Tool for the Preparation of Camps for Visitation for American Camping Association Camp Accreditation and Site Approval.

    ERIC Educational Resources Information Center

    Chenery, Mary Faeth

    This comprehensive guide helps camp administrators prepare for camp accreditation and site approval visits by the American Camping Association (ACA). The introductory sections outline the purpose and administration of the standards program and provide definitions of camping terms. Standards are organized under one section for camp accreditation…

  1. beta2-adrenergic receptor signaling and desensitization elucidated by quantitative modeling of real time cAMP dynamics.

    PubMed

    Violin, Jonathan D; DiPilato, Lisa M; Yildirim, Necmettin; Elston, Timothy C; Zhang, Jin; Lefkowitz, Robert J

    2008-02-01

    G protein-coupled receptor signaling is dynamically regulated by multiple feedback mechanisms, which rapidly attenuate signals elicited by ligand stimulation, causing desensitization. The individual contributions of these mechanisms, however, are poorly understood. Here, we use an improved fluorescent biosensor for cAMP to measure second messenger dynamics stimulated by endogenous beta(2)-adrenergic receptor (beta(2)AR) in living cells. beta(2)AR stimulation with isoproterenol results in a transient pulse of cAMP, reaching a maximal concentration of approximately 10 microm and persisting for less than 5 min. We investigated the contributions of cAMP-dependent kinase, G protein-coupled receptor kinases, and beta-arrestin to the regulation of beta(2)AR signal kinetics by using small molecule inhibitors, small interfering RNAs, and mouse embryonic fibroblasts. We found that the cAMP response is restricted in duration by two distinct mechanisms in HEK-293 cells: G protein-coupled receptor kinase (GRK6)-mediated receptor phosphorylation leading to beta-arrestin mediated receptor inactivation and cAMP-dependent kinase-mediated induction of cAMP metabolism by phosphodiesterases. A mathematical model of beta(2)AR signal kinetics, fit to these data, revealed that direct receptor inactivation by cAMP-dependent kinase is insignificant but that GRK6/beta-arrestin-mediated inactivation is rapid and profound, occurring with a half-time of 70 s. This quantitative system analysis represents an important advance toward quantifying mechanisms contributing to the physiological regulation of receptor signaling.

  2. cAMP and forskolin decrease. gamma. -aminobutyric acid-gated chloride flux in rat brain synaptoneurosomes

    SciTech Connect

    Heuschneider, G.; Schwartz, R.D. )

    1989-04-01

    The effects of the cyclic nucleotide cAMP on {gamma}-aminobutyric acid-gated chloride channel function were investigated. The membrane-permeant cAMP analog N{sup 6}, O{sup 2{prime}}-dibutyryladenosine 3{prime},5{prime}-cyclic monophosphate inhibited muscimol-induced {sup 36}Cl{sup {minus}} uptake into rat cerebral cortical synaptoneurosomes in a concentration-dependent manner. The inhibition was due to a decrease in the maximal effect of muscimol, with no change in potency. Similar effects were observed with 8-(4-chlorophenylthio)adenosine 3{prime},5{prime}-cyclic monophosphate, 8-bromoadenosine 3{prime},5{prime}-cyclic monophosphate, and the phosphodiesterase inhibitor isobutylmethylxanthine. The effect of endogenous cAMP accumulation on the {gamma}-aminobutyric acid-gated Cl{sup {minus}} channel was studied with forskolin, an activator of adenylate cyclase. Under identical conditions, in the intact synaptoneurosomes, forskolin inhibited muscimol-induced {sup 36}Cl{sup {minus}} uptake and generated cAMP with similar potencies. Surprisingly, 1,9-dideoxyforskolin, which does not activate adenylate cyclase, also inhibited the muscimol response, suggesting that forskolin and its lipophilic derivatives may interact with the Cl{sup {minus}} channel directly. The data suggest that {gamma}-aminobutyric acid (GABA{sub A}) receptor function in brain can be regulated by cAMP-dependent phosphorylation.

  3. Engineering of Bacillus subtilis Strains To Allow Rapid Characterization of Heterologous Diguanylate Cyclases and Phosphodiesterases

    PubMed Central

    Gao, Xiaohui; Dong, Xiao; Subramanian, Sundharraman; Matthews, Paige M.; Cooper, Caleb A.; Kearns, Daniel B.

    2014-01-01

    Microbial processes, including biofilm formation, motility, and virulence, are often regulated by changes in the available concentration of cyclic dimeric guanosine monophosphate (c-di-GMP). Generally, high c-di-GMP concentrations are correlated with decreased motility and increased biofilm formation and low c-di-GMP concentrations are correlated with an increase in motility and activation of virulence pathways. The study of c-di-GMP is complicated, however, by the fact that organisms often encode dozens of redundant enzymes that synthesize and hydrolyze c-di-GMP, diguanylate cyclases (DGCs), and c-di-GMP phosphodiesterases (PDEs); thus, determining the contribution of any one particular enzyme is challenging. In an effort to develop a facile system to study c-di-GMP metabolic enzymes, we have engineered a suite of Bacillus subtilis strains to assess the effect of individual heterologously expressed proteins on c-di-GMP levels. As a proof of principle, we characterized all 37 known genes encoding predicted DGCs and PDEs in Clostridium difficile using parallel readouts of swarming motility and fluorescence from green fluorescent protein (GFP) expressed under the control of a c-di-GMP-controlled riboswitch. We found that 27 of the 37 putative C. difficile 630 c-di-GMP metabolic enzymes had either active cyclase or phosphodiesterase activity, with agreement between our motility phenotypes and fluorescence-based c-di-GMP reporter. Finally, we show that there appears to be a threshold level of c-di-GMP needed to inhibit motility in Bacillus subtilis. PMID:25085482

  4. "Store-operated" cAMP signaling contributes to Ca2+-activated Cl- secretion in T84 colonic cells.

    PubMed

    Nichols, Jonathan M; Maiellaro, Isabella; Abi-Jaoude, Joanne; Curci, Silvana; Hofer, Aldebaran M

    2015-10-15

    Apical cAMP-dependent CFTR Cl(-) channels are essential for efficient vectorial movement of ions and fluid into the lumen of the colon. It is well known that Ca(2+)-mobilizing agonists also stimulate colonic anion secretion. However, CFTR is apparently not activated directly by Ca(2+), and the existence of apical Ca(2+)-dependent Cl(-) channels in the native colonic epithelium is controversial, leaving the identity of the Ca(2+)-activated component unresolved. We recently showed that decreasing free Ca(2+) concentration ([Ca(2+)]) within the endoplasmic reticulum (ER) lumen elicits a rise in intracellular cAMP. This process, which we termed "store-operated cAMP signaling" (SOcAMPS), requires the luminal ER Ca(2+) sensor STIM1 and does not depend on changes in cytosolic Ca(2+). Here we assessed the degree to which SOcAMPS participates in Ca(2+)-activated Cl(-) transport as measured by transepithelial short-circuit current (Isc) in polarized T84 monolayers in parallel with imaging of cAMP and PKA activity using fluorescence resonance energy transfer (FRET)-based reporters in single cells. In Ca(2+)-free conditions, the Ca(2+)-releasing agonist carbachol and Ca(2+) ionophore increased Isc, cAMP, and PKA activity. These responses persisted in cells loaded with the Ca(2+) chelator BAPTA-AM. The effect on Isc was enhanced in the presence of the phosphodiesterase (PDE) inhibitor 3-isobutyl-1-methylxanthine (IBMX), inhibited by the CFTR inhibitor CFTRinh-172 and the PKA inhibitor H-89, and unaffected by Ba(2+) or flufenamic acid. We propose that a discrete component of the "Ca(2+)-dependent" secretory activity in the colon derives from cAMP generated through SOcAMPS. This alternative mode of cAMP production could contribute to the actions of diverse xenobiotic agents that disrupt ER Ca(2+) homeostasis, leading to diarrhea.

  5. Both protein kinase A and exchange protein activated by cAMP coordinate adhesion of human vascular endothelial cells.

    PubMed

    Netherton, Stuart J; Sutton, Jayda A; Wilson, Lindsay S; Carter, Rhonda L; Maurice, Donald H

    2007-10-12

    cAMP regulates integrin-dependent adhesions of vascular endothelial cells (VECs) to extracellular matrix proteins, their vascular endothelial cadherin-dependent intercellular adhesions, and their proliferation and migration in response to growth and chemotactic factors. Previously, we reported that cAMP-elevating agents differentially inhibited migration of human VECs isolated from large vascular structures (macro-VECs, human aortic endothelial cells [HAECs]) or small vascular structures (micro-VECs, human microvascular endothelial cells [HMVECs]) and that cAMP hydrolysis by phosphodiesterase (PDE)3 and PDE4 enzymes was important in coordinating this difference. Here we report that 2 cAMP-effector enzymes, namely protein kinase (PK)A and exchange protein activated by cAMP (EPAC), each regulate extracellular matrix protein-based adhesions of both macro- and micro-VECs. Of interest and potential therapeutic importance, we report that although specific pharmacological activation of EPAC markedly stimulated adhesion of micro-VECs to extracellular matrix proteins when PKA was inhibited, this treatment only modestly promoted adhesion of macro-VECs. Consistent with an important role for cAMP PDEs in this difference, PDE3 or PDE4 inhibitors promoted EPAC-dependent adhesions in micro-VECs when PKA was inhibited but not in macro-VECs. At a molecular level, we identify multiple, nonoverlapping, PKA- or EPAC-based signaling protein complexes in both macro- and micro-VECs and demonstrate that each of these complexes contains either PDE3B or PDE4D but not both of these PDEs. Taken together, our data support the concept that adhesion of macro- and micro-VECs is differentially regulated by cAMP and that these differences are coordinated through selective actions of cAMP at multiple nonoverlapping signaling complexes that contain PKA or EPAC and distinct PDE variants.

  6. Prostaglandin E2 inhibits NLRP3 inflammasome activation through EP4 receptor and intracellular cAMP in human macrophages

    PubMed Central

    Liu, Yueqin; Martinez-Anton, Asuncion; Qi, Hai-Yan; Logun, Carolea; Alsaaty, Sara; Park, Yong Hwan; Kastner, Daniel L.; Chae, Jae Jin; Shelhamer, James H.

    2015-01-01

    Prostaglandin E2 (PGE2) is a potent lipid mediator involved in maintaining homeostasis but also promotion of acute inflammation or immune suppression in chronic inflammation and cancer. NLRP3 inflammasome plays an important role in host defense. Uncontrolled activation of NLRP3 inflammasome, due to mutations in the NLRP3 gene causes cryopyrin-associated periodic syndromes (CAPS). Here, we showed that NLRP3 inflammasome activation is inhibited by PGE2 in human primary monocyte-derived macrophages. This effect was mediated through prostaglandin E receptor 4 (EP4) and an increase in intracellular cAMP, independently of protein kinase A (PKA) or exchange protein directly activated by cAMP (Epac). A specific agonist of EP4 mimicked, while its antagonist or EP4 knockdown reversed PGE2-mediated NLRP3 inhibition. PGE2 caused an increase in intracellular cAMP. Blockade of adenylate cyclase by its inhibitor reversed PGE2-mediated NLRP3 inhibition. Increase of intracellular cAMP by an activator of adenylate cyclase or an analog of cAMP, or a blockade of cAMP degradation by phosphodiesterase inhibitor decreased NLRP3 activation. PKA or Epac agonists did not mimic and their antagonists did not reverse PGE2-mediated NLRP3 inhibition. In addition, constitutive IL-1β secretion from LPS-primed PBMCs of CAPS patients was substantially reduced by high doses of PGE2. Moreover, blocking cytosolic phospholipase A2α by its inhibitor or siRNA or inhibiting cyclooxygenase 2, resulting in inhibition of endogenous PGE2 production, caused an increase in NLRP3 inflammasome activation. Our results suggest that PGE2 might play a role in maintaining homeostasis during the resolution phase of inflammation and might serve as an autocrine and paracrine regulator. PMID:25917098

  7. “Store-operated” cAMP signaling contributes to Ca2+-activated Cl− secretion in T84 colonic cells

    PubMed Central

    Nichols, Jonathan M.; Maiellaro, Isabella; Abi-Jaoude, Joanne; Curci, Silvana

    2015-01-01

    Apical cAMP-dependent CFTR Cl− channels are essential for efficient vectorial movement of ions and fluid into the lumen of the colon. It is well known that Ca2+-mobilizing agonists also stimulate colonic anion secretion. However, CFTR is apparently not activated directly by Ca2+, and the existence of apical Ca2+-dependent Cl− channels in the native colonic epithelium is controversial, leaving the identity of the Ca2+-activated component unresolved. We recently showed that decreasing free Ca2+ concentration ([Ca2+]) within the endoplasmic reticulum (ER) lumen elicits a rise in intracellular cAMP. This process, which we termed “store-operated cAMP signaling” (SOcAMPS), requires the luminal ER Ca2+ sensor STIM1 and does not depend on changes in cytosolic Ca2+. Here we assessed the degree to which SOcAMPS participates in Ca2+-activated Cl− transport as measured by transepithelial short-circuit current (Isc) in polarized T84 monolayers in parallel with imaging of cAMP and PKA activity using fluorescence resonance energy transfer (FRET)-based reporters in single cells. In Ca2+-free conditions, the Ca2+-releasing agonist carbachol and Ca2+ ionophore increased Isc, cAMP, and PKA activity. These responses persisted in cells loaded with the Ca2+ chelator BAPTA-AM. The effect on Isc was enhanced in the presence of the phosphodiesterase (PDE) inhibitor 3-isobutyl-1-methylxanthine (IBMX), inhibited by the CFTR inhibitor CFTRinh-172 and the PKA inhibitor H-89, and unaffected by Ba2+ or flufenamic acid. We propose that a discrete component of the “Ca2+-dependent” secretory activity in the colon derives from cAMP generated through SOcAMPS. This alternative mode of cAMP production could contribute to the actions of diverse xenobiotic agents that disrupt ER Ca2+ homeostasis, leading to diarrhea. PMID:26316590

  8. Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog.

    PubMed Central

    Shang, E S; Skare, J T; Erdjument-Bromage, H; Blanco, D R; Tempst, P; Miller, J N; Lovett, M A

    1997-01-01

    We report the purification, molecular cloning, and characterization of a 40-kDa glycerophosphodiester phosphodiesterase homolog from Borrelia hermsii. The 40-kDa protein was solubilized from whole organisms with 0.1% Triton X-100, phase partitioned into the Triton X-114 detergent phase, and purified by fast-performance liquid chromatography (FPLC). The gene encoding the 40-kDa protein was cloned from a B. hermsii chromosomal DNA lambda EXlox expression library and identified by using affinity antibodies generated against the purified native protein. The deduced amino acid sequence included a 20-amino-acid signal peptide encoding a putative leader peptidase II cleavage site, indicating that the 40-kDa protein was a lipoprotein. Based on significant homology (31 to 52% identity) of the 40-kDa protein to glycerophosphodiester phosphodiesterases of Escherichia coli (GlpQ), Bacillus subtilis (GlpQ), and Haemophilus influenzae (Hpd; protein D), we have designated this B. hermsii 40-kDa lipoprotein a glycerophosphodiester phosphodiesterase (Gpd) homolog, the first B. hermsii lipoprotein to have a putative functional assignment. A nonlipidated form of the Gpd homolog was overproduced as a fusion protein in E. coli BL21(DE3)(pLysE) and was used to immunize rabbits to generate specific antiserum. Immunoblot analysis with anti-Gpd serum recognized recombinant H. influenzae protein D, and conversely, antiserum to H. influenzae protein D recognized recombinant B. hermsii Gpd (rGpd), indicating antigenic conservation between these proteins. Antiserum to rGpd also identified native Gpd as a constituent of purified outer membrane vesicles prepared from B. hermsii. Screening of other pathogenic spirochetes with anti-rGpd serum revealed the presence of antigenically related proteins in Borrelia burgdorferi, Treponema pallidum, and Leptospira kirschneri. Further sequence analysis both upstream and downstream of the Gpd homolog showed additional homologs of glycerol metabolism

  9. Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog.

    PubMed

    Shang, E S; Skare, J T; Erdjument-Bromage, H; Blanco, D R; Tempst, P; Miller, J N; Lovett, M A

    1997-04-01

    We report the purification, molecular cloning, and characterization of a 40-kDa glycerophosphodiester phosphodiesterase homolog from Borrelia hermsii. The 40-kDa protein was solubilized from whole organisms with 0.1% Triton X-100, phase partitioned into the Triton X-114 detergent phase, and purified by fast-performance liquid chromatography (FPLC). The gene encoding the 40-kDa protein was cloned from a B. hermsii chromosomal DNA lambda EXlox expression library and identified by using affinity antibodies generated against the purified native protein. The deduced amino acid sequence included a 20-amino-acid signal peptide encoding a putative leader peptidase II cleavage site, indicating that the 40-kDa protein was a lipoprotein. Based on significant homology (31 to 52% identity) of the 40-kDa protein to glycerophosphodiester phosphodiesterases of Escherichia coli (GlpQ), Bacillus subtilis (GlpQ), and Haemophilus influenzae (Hpd; protein D), we have designated this B. hermsii 40-kDa lipoprotein a glycerophosphodiester phosphodiesterase (Gpd) homolog, the first B. hermsii lipoprotein to have a putative functional assignment. A nonlipidated form of the Gpd homolog was overproduced as a fusion protein in E. coli BL21(DE3)(pLysE) and was used to immunize rabbits to generate specific antiserum. Immunoblot analysis with anti-Gpd serum recognized recombinant H. influenzae protein D, and conversely, antiserum to H. influenzae protein D recognized recombinant B. hermsii Gpd (rGpd), indicating antigenic conservation between these proteins. Antiserum to rGpd also identified native Gpd as a constituent of purified outer membrane vesicles prepared from B. hermsii. Screening of other pathogenic spirochetes with anti-rGpd serum revealed the presence of antigenically related proteins in Borrelia burgdorferi, Treponema pallidum, and Leptospira kirschneri. Further sequence analysis both upstream and downstream of the Gpd homolog showed additional homologs of glycerol metabolism

  10. Adenosine 3',5-cyclic monophosphate phosphodiesterase activity in granulosa cells from Booroola x Romney ewes with and without the F gene.

    PubMed

    McNatty, K P; Heath, D A; Lun, S; Hudson, N L

    1989-02-01

    Granulosa cells from ovarian follicles (greater than or equal to 1 mm diameter) in Booroola ewes which are homozygous (FF) or heterozygous (F+) for the F gene have previously been shown to produce significantly more cAMP in response to FSH or LH than those from similar sized follicles in ewes without the F gene (++). The aim of these studies was to test whether these F gene-specific differences arose because of differences in cAMP-phosphodiesterase (cAMP-PDE) activity. In the first study using 1 mumol cAMP/l as substrate, no F gene-specific effects were noted in cAMP-PDE activity in granulosa cells from small (1-2.5 mm diameter, n = 4 per genotype) or large (greater than or equal to 3 mm diameter, n = 4 per genotype) follicles from FF, F+ or ++ ewes, despite F gene-specific effects in FSH (1 microgram/ml)- and LH (0.1 microgram/ml)-induced cAMP accumulation in these same cell preparations. The overall mean levels of cAMP-PDE across all genotypes in cells from small and large follicles were 0.47 +/- 0.04 (S.E.M., n = 12) and 0.28 +/- 0.03 pmol cAMP/10(6) cells per min respectively; the mean PDE activity in cells from small follicles was significantly (P less than 0.05) higher compared with that in cells from large follicles. In a second study, granulosa cells from each genotype were pooled over all follicle sizes (greater than or equal to 1 mm diameter, one pool per genotype) and the rates of cAMP hydrolysis tested over a range of substrate concentrations (0-16 mumol/l) but no gene-specific differences with respect to the Michaelis constant and maximum velocity were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Strategic approaches to drug design. II. Modelling studies on phosphodiesterase substrates and inhibitors

    NASA Astrophysics Data System (ADS)

    Davis, A.; Warrington, B. H.; Vinter, J. G.

    1987-07-01

    Modelling studies have been carried out on the phosphodiesterase (PDE) substrates, adenosine- and guanosine-3'5'-cyclic monophosphates, and on a number of non-specific and type III-specific phosphodiesterase inhibitors. These studies have assisted the understanding of PDE substrate differentiation and the design of potent, selective PDE type III inhibitors.

  12. Between life and death: experiences of concentration camp mussulmen during the holocaust.

    PubMed

    Ryn, Z

    1990-02-01

    During the years of 1981 and 1982, 89 former prisoners of the Auschwitz-Birkenau concentration camp responded to questionnaires on mussulmen-prisoners in the extreme phase of starvation disease. In this article, I describe the origin of the term "mussulman," mussulmens' somatic and mental state, their behavior and camp customs. Prisoners characterized as mussulmen remain between life and death, without expressing emotional reactions and defense mechanisms apart from a hypersensibility to food-related stimuli. A mussulman was a product of the camp factory of death. A deep somatic and emotional stigma remains in those who survived the mussulmen state.

  13. Sildenafil and Phosphodiesterase-5 Inhibitors to Reduce Cardiotoxicity and Enhance the Response of Breast Tumors to Doxorubicin

    DTIC Science & Technology

    2007-03-01

    AD_________________ Award Number: W81XWH-06-1-0360 TITLE: Sildenafil and phosphodiesterase-5...Feb 2007 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Sildenafil and phosphodiesterase-5 inhibitors to reduce cardiotoxicity and enhance the...the differential effects of phosphodiesterase inhibitors, such as sildenafil , in terms of protecting cardiac cells and the heart from the toxicity

  14. Effect of 3,3',5-triiodothyronine and 3,5-diiodothyronine on progesterone production, cAMP synthesis, and mRNA expression of STAR, CYP11A1, and HSD3B genes in granulosa layer of chicken preovulatory follicles.

    PubMed

    Sechman, A; Pawlowska, K; Hrabia, A

    2011-10-01

    In vitro studies were performed to assess whether stimulatory effects of triiodothyronine (T3) on progesterone (P4) production in a granulosa layer (GL) of chicken preovulatory follicles are associated with 3',5'-cyclic adenosine monophosphate (cAMP) synthesis and mRNA expression of STAR protein, CYP11A1, and HSD3B. Effects of 3,5-diiodothyronine (3,5-T2) on steroidogenic function in these follicles were also investigated. The GL of F3 to F1 follicles was incubated in medium supplemented with T3 or 3,5-T2, LH, or forskolin (F), and a combination of each iodothyronine with LH or F. Levels of P4 and cAMP in culture media were determined by RIA. Expression of genes involved in P4 synthesis (ie, STAR protein, CYP11A1, and HSD3B) in the GL of F3 to F1 follicles incubated in medium with T3 or 3,5-T2 and their combination with LH was performed by real-time PCR. Triiodothyronine increased basal and LH- and F-stimulated P4 secretion by preovulatory follicles. The 3,5-T2 elevated P4 synthesis by F3, had no effect on F2 follicles, and diminished P4 production by the GL of F1 follicles. It had no effect on LH-stimulated P4 production; however, it augmented F-stimulated P4 production by F2 and F1 follicles. Although T3 did not affect basal and F-stimulated cAMP synthesis by the GL of preovulatory follicles, it increased LH-stimulated synthesis of this nucleotide. However, 3,5-T2 elevated F-stimulated cAMP synthesis in F3 and F2 follicles; it did not change basal and LH-stimulated cAMP production. Triiodothyronine decreased basal STAR and CYP11A1 mRNAs in F3 follicles, increased them in F1 follicles, and elevated HSD3B mRNA levels in F1 follicles. Triiodothyronine augmented LH-stimulated STAR, CYP11A1, and HSD3B mRNA levels in F2 and CYP11A1 in F1 follicles. However, T3 decreased LH-stimulated STAR and HSD3B mRNA levels in F1 follicles. The 3,5-T2 did not affect basal STAR and CYP11A1 mRNA expression in all investigated follicles; however, it decreased LH-stimulated STAR

  15. Chemical Validation of Phosphodiesterase C as a Chemotherapeutic Target in Trypanosoma cruzi, the Etiological Agent of Chagas' Disease▿ †

    PubMed Central

    King-Keller, Sharon; Li, Minyong; Smith, Alyssa; Zheng, Shilong; Kaur, Gurpreet; Yang, Xiaochuan; Wang, Binghe; Docampo, Roberto

    2010-01-01

    Trypanosoma cruzi phosphodiesterase (PDE) C (TcrPDEC), a novel and rather unusual PDE in which, unlike all other class I PDEs, the catalytic domain is localized in the middle of the polypeptide chain, is able to hydrolyze cyclic GMP (cGMP), although it prefers cyclic AMP (cAMP), and has a FYVE-type domain in its N-terminal region (S. Kunz et al., FEBS J. 272:6412-6422, 2005). TcrPDEC shows homology to the mammalian PDE4 family members. PDE4 inhibitors are currently under development for the treatment of inflammatory diseases, such as asthma, chronic pulmonary diseases, and psoriasis, and for treating depression and serving as cognitive enhancers. We therefore tested a number of compounds originally synthesized as potential PDE4 inhibitors on T. cruzi amastigote growth, and we obtained several useful hits. We then conducted homology modeling of T. cruzi PDEC and identified other compounds as potential inhibitors through virtual screening. Testing of these compounds against amastigote growth and recombinant TcrPDEC activity resulted in several potent inhibitors. The most-potent inhibitors were found to increase the cellular concentration of cAMP. Preincubation of cells in the presence of one of these compounds stimulated volume recovery after hyposmotic stress, in agreement with their TcrPDEC inhibitory activity in vitro, providing chemical validation of this target. The compounds found could be useful tools in the study of osmoregulation in T. cruzi. In addition, their further optimization could result in the development of new drugs against Chagas' disease and other trypanosomiases. PMID:20625148

  16. cGMP-PDE3-cAMP signal pathway involved in the inhibitory effect of CNP on gastric motility in rat.

    PubMed

    Cai, Ying-Lan; Sun, Qian; Huang, Xu; Jiang, Jing-Zhi; Zhang, Mo-Han; Piao, Li-Hua; Jin, Zheng; Xu, Wen-Xie

    2013-01-10

    In the present study, we investigated the mechanism of C-type natriuretic peptide (CNP)-induced inhibitory effect on spontaneous contraction of gastric antral smooth muscle to clarify CNP-NPR-B/pGC-cGMP downstream signal transduction pathway using organ bath and ELISA methods in rat. CNP significantly reduced the amplitude of the spontaneous contraction and increased the contents of cGMP and cAMP in the gastric antral smooth muscle tissue. In the presence of IBMX, a non-selective phosphodiesterase (PDE) inhibitor, the inhibitory effect of CNP on spontaneous contraction was significantly suppressed; however, the production of cGMP but not cAMP was still increased by CNP. EHNA, a PDE2 inhibitor, did not affect both CNP-induced inhibition of the contraction and CNP-induced increase of cGMP and cAMP generations in gastric smooth muscle tissue, while milrinone, a PDE3 inhibitor, similar to IBMX, attenuated the CNP-induced inhibitory effect on spontaneous contraction and increased the content of cGMP but not cAMP. The results suggest that cGMP-PDE3-cAMP signal pathway is also involved in the CNP-induced inhibition of gastric motility in rat.

  17. Central Atlantic Magmatic Province (CAMP): The Palisade Sill Connection

    NASA Astrophysics Data System (ADS)

    Ghatak, A.; Basu, A. R.

    2012-12-01

    The extensively studied 200Ma Central Atlantic Magmatic Province (CAMP) is considered to be the world's largest continental Large Igneous Province (LIP) covering up to 7 X 106 km2. This igneous province has been linked to the ~200Ma Mesozoic opening of the Central Atlantic Ocean. This opening fragmented the CAMP into several segments that occur on four different tectonic plates today. The CAMP related LIP is different from others in that it constitutes almost entirely of dikes and sills with sparse volcanic outflows. The 200 Ma Palisade Sill, exposed along the Hudson River in northeastern North America is an expression of the CAMP magmatism. On the basis of similar ages of eruption, Palisade Sill tholeiites have been correlated to other CAMP exposures in four continents. We provide an isotopic tracer study of the Palisade Sill basalts and relate them to low-Ti (<2 wt %) CAMP related tholeiites from North and South America, western Europe, and West Africa. We report Nd-Sr-Pb isotopic and multiple trace element data of 19 basalts and gabbros, 3 chilled margin basalts, and 4 sandstones spanning the entire length and thickness of the Palisade Sill in New York and New Jersey. These geochemical data are essential to understand the relationship between mantle geodynamic processes involved in the generation of the CAMP tholeiites prior to the formation of the of the Atlantic Ocean crust. The Palisade Sill basalts of this study yield the typical composition of low-Ti CAMP tholeiites with small LREE enrichments (LaN/SmN = 1.7 to 2.3), radiogenic Sr and negative ɛNd(I) values (87Sr/87Sr(I) = 0.70668 to 0.71037; ɛNd(I) = -0.64 to -3.8), and Pb-isotopic ratios (e.g. 206Pb/204Pb = 18.11 to 18.69) above the NHRL and subparallel to it. These geochemical data indicate the Palisade Sill basalts were derived from a slightly enriched OIB-like mantle source. Further, these rocks were derived by ~15% melting of a slightly depleted spinel peridotite with up to 20% contamination by the

  18. [Intracellular cAMP involvement in the synchronized activity of noradrenaline in response to evoked release of the transmitter quanta in the frog synapses].

    PubMed

    Bukharaeva, E A; Samigullin, D V; Nikol'skiĭ, E E; Vyskocil, F

    2000-04-01

    An analogue of cyclic AMP (db-cAMP) penetrating into the frog neuromuscular junction's cell, as well as the adenylyl cyclase activator forskolin, and inhibitor of nucleotide-depending phosphodiesterase isobutilmethylxantine alter the kinetics of the quanta secretion resulting in synchronizing of the process of the transmitter release. Following a db-cAMP preliminary action, no such synchronizing of the transmitter release occurred. Action of noradrenaline on the time course of the secretion seems to be realised through activation of presynaptic beta-adrenoreceptors, augmentation of the adenylyl cyclase activity, and the rise of the intracellular cAMP.

  19. Group Experience: The Essence of Camping. An Occasional Paper.

    ERIC Educational Resources Information Center

    Brower, Robert; Brower, Mary

    1980-01-01

    Five propositions related to the values of the group experience in camping are argued: (1) the group experience is the essence of camping; (2) groups influence behavior and enhance mental health; (3) camps serve a variety of purposes; (4) knowledge of group dynamics can influence camp outcomes; and (5) good camps benefit society. An elaboration on…

  20. A Day in the Life of Three Special Needs Camps

    ERIC Educational Resources Information Center

    Winbaum, Stephen

    2006-01-01

    In this article, the author talks about three special needs camps--Camp Kirk, Camp Talisman and Camp Caglewood. Camp Kirk's philosophy is to encourage their children to take risks in a structured setting, like high ropes courses, rock climbing wall, martial arts, and traditional activities like swimming, arts and craft, drama, and others. Once…

  1. The Characterization of Escherichia coli CpdB as a Recombinant Protein Reveals that, besides Having the Expected 3´-Nucleotidase and 2´,3´-Cyclic Mononucleotide Phosphodiesterase Activities, It Is Also Active as Cyclic Dinucleotide Phosphodiesterase

    PubMed Central

    López-Villamizar, Iralis; Cabezas, Alicia; Pinto, Rosa María; Canales, José; Ribeiro, João Meireles; Cameselle, José Carlos; Costas, María Jesús

    2016-01-01

    Endogenous cyclic diadenylate phosphodiesterase activity was accidentally detected in lysates of Escherichia coli BL21. Since this kind of activity is uncommon in Gram-negative bacteria, its identification was undertaken. After partial purification and analysis by denaturing gel electrophoresis, renatured activity correlated with a protein identified by fingerprinting as CpdB (cpdB gene product), which is annotated as 3´-nucleotidase / 2´,3´-cyclic-mononucleotide phosphodiesterase, and it is synthesized as a precursor protein with a signal sequence removable upon export to the periplasm. It has never been studied as a recombinant protein. The coding sequence of mature CpdB was cloned and expressed as a GST fusion protein. The study of the purified recombinant protein, separated from GST, confirmed CpdB annotation. The assay of catalytic efficiencies (kcat/Km) for a large substrate set revealed novel CpdB features, including very high efficiencies for 3´-AMP and 2´,3´-cyclic mononucleotides, and previously unknown activities on cyclic and linear dinucleotides. The catalytic efficiencies of the latter activities, though low in relative terms when compared to the major ones, are far from negligible. Actually, they are perfectly comparable to those of the ‘average’ enzyme and the known, bona fide cyclic dinucleotide phosphodiesterases. On the other hand, CpdB differs from these enzymes in its extracytoplasmic location and in the absence of EAL, HD and DHH domains. Instead, it contains the domains of the 5´-nucleotidase family pertaining to the metallophosphoesterase superfamily, although CpdB lacks 5´-nucleotidase activity. The possibility that the extracytoplasmic activity of CpdB on cyclic dinucleotides could have physiological meaning is discussed. PMID:27294396

  2. [Phosphodiesterase-5 inhibitors for the treatment of pulmonary arterial hypertension].

    PubMed

    Beltrán-Gámez, Miguel E; Sandoval-Zárate, Julio; Pulido, Tomás

    2015-01-01

    In experimental and clinical cardiology, phosphodiesterase type 5 (PDE-5) inhibitors have brought scientific interest as a therapeutic tool in pulmonary arterial hypertension (PAH) management in recent years. Phosphodiesterases are a superfamily of enzymes that inactivate cyclic adenosine monophosphate and cyclic guanosine monophosphate, the second messengers of prostacyclin and nitric oxide. The rationale for the use of PDE-5 inhibitors in PAH is based on their capacity to overexpresss the nitric oxide pathway pursued inhibition of cyclic guanosine monophosphate hydrolysis. By increasing cyclic guanosine monophosphate levels it promotes vasodilation, antiproliferative and pro-apoptotic effects that may reverse pulmonary vascular remodeling. There is also evidence that these drugs may directly enhance right ventricular contractility through an increase in cyclic adenosine monophosphate mediated by the inhibition of the cyclic guanosine monophosphate -sensitive PDE-3. Sildenafil, tadalafil and vardenafil are 3 specific PDE-5 inhibitors in current clinical use, which share similar mechanisms of action but present some significant differences regarding potency, selectivity for PDE-5 and pharmacokinetic properties. Sildenafil received approval in 2005 by the Food and Drug Administration and the European Medicines Agency and tadalafil in 2009 by the Food and Drug Administration and the European Medicines Agency for the treatment of PAH in patients classified as NYHA/WHO functional class II and III. In Mexico, sildenafil and tadalafil were approved by Comisión Federal de Protección contra Riesgos Sanitarios for this indication in 2010 and 2011, respectively.

  3. Phosphodiesterases and Adrenal Cushing in Mice and Humans

    PubMed Central

    Szarek, E.; Stratakis, C. A.

    2016-01-01

    The majority of benign adrenal cortex lesions leading to Cushing syndrome are associated to one or another abnormality of the cAMP/cGMP-phosphodiesterase signaling pathway. Phosphodiesterases (PDEs) are key regulatory enzymes of intracellular cAMP/cGMP levels. These second messengers play important regulatory roles in controlling steroidogenesis in the adrenal. Disruption of PDEs has been associated with a number of adrenal diseases. Specifically, genetic mutations have been associated with benign adrenal lesions, leading to Cushing syndrome and/or related adrenal hyperplasias. A Genome Wide Association study, in 2006, led to the identification of mutations in 2 PDE genes: PDE8B and PDE11A; mutations in these 2 genes modulate steroidogenesis. Further human studies have identified PDE2 as also directly regulating steroidogenesis. PDE2 decreases aldosterone production. This review focuses on the most recent knowledge we have gained on PDEs and their association with adrenal steroidogenesis and altered function, through analysis of patient cohorts and what we have learned from mouse studies. PMID:25232906

  4. Purification and characterization of phosphodiesterase from Crotalus venom.

    PubMed

    Philipps, G R

    1975-07-01

    A procedure for the purification of phosphodiesterase from Crotalus venom on DEAE-cellulose at alkaline pH is described. The enzyme gives a single band in polyacrylamide gels and is free of contaminating nucleolytic enzymes. The molecular weight is about 115000. Concentration in an Amicon ultrafiltrator gave a highly concentrated active enzyme. Phosphodiesterase is relatively stable and can be stored at 4 degrees C in the presence of Mg2 and serum albumin for years. For the detection of contaminating endonuclease, an assay was used in which tRNA was the substrate and possible internal breaks were detected in polyacrylamide gel after denaturation. With bis(p-nitrophenyl) phosphate as substrate, 15mM Mg2 was necessary for optimal activity. The reaction remained linear for at least 15 min at 22 degrees C. At 45 degrees C, the liberation of p-nitrophenol was highest within 25 min of incubation. At 75 degrees C, inactivation of the enzyme occurred after 4 min.

  5. Studies on the soluble phosphodiesterases of chicken gizzard smooth muscle.

    PubMed Central

    Birnbaum, R J; Head, J F

    1983-01-01

    In this study we describe the identification of four soluble forms of cyclic nucleotide phosphodiesterase from chicken gizzard smooth muscle. These isoenzymes were separated from one another by ion-exchange chromatography on DEAE-cellulose and by calmodulin-Sepharose affinity chromatography. Each form migrates as a single discrete band when it is electrophoresed on non-denaturing polyacrylamide gels and stained for phosphodiesterase activity. Each form is also eluted as a single peak on gel-permeation chromatography, giving apparent Mr values of 114 000, 116 000, 122 000 and 59 000. All four enzymes have apparent Km values in the 0-20 microM range, although their relative specificities for cyclic AMP and cyclic GMP differ. Two of the forms bind to calmodulin in a Ca2+-dependent manner; however, only one is activated by calmodulin. The interaction of the second calmodulin-binding form with calmodulin is disrupted by the papaverine derivative verapamil without significantly altering the hydrolytic activity of the enzyme. Images Fig. 2. Fig. 4. Fig. 5. PMID:6318728

  6. Determination of phosphodiesterase I activity in human blood serum.

    PubMed

    Hynie, I; Meuffels, M; Poznanski, W J

    1975-09-01

    Phosphodiesterase I (EC 3.1.4.1) activity was detected in normal human blood serum. The enzyme is stable at laboratory temperature for three days, but is inactivated at pH less than 7. The pH for optimum activity increases with the substrate concentration (under the conditions used, from pH 9.0 to 10.2) and, conversely, the Km increases with pH and buffer concentration. The enzyme is inhibited by ethylenediaminetetraacetate but not by phosphate (0.1 mol/liter). We developed a simple quantitative method for its determination, based on hydrolysis of the p-nitrophenyl ester of thymidine 5'-monophosphate and subsequent measurement of the liberated p-nitrophenol at 400 nm in NaOH (0.1 mol/liter). Normal values (mean +/- 2 SD) were determined to be 33 +/- 6.4 U/liter. Preliminary studies indicate that phosphodiesterase I activity is greater than normal in serum of patients with necrotic changes in the liver or kidney or in cases of breast cancer, but not in that of patients with myocardial infarction, bone cancer, lung cancer, or chronic liver cirrhosis.

  7. Phosphodiesterase 4D acts downstream of Neuropilin to control Hedgehog signal transduction and the growth of medulloblastoma.

    PubMed

    Ge, Xuecai; Milenkovic, Ljiljana; Suyama, Kaye; Hartl, Tom; Purzner, Teresa; Winans, Amy; Meyer, Tobias; Scott, Matthew P

    2015-09-15

    Alterations in Hedgehog (Hh) signaling lead to birth defects and cancers including medulloblastoma, the most common pediatric brain tumor. Although inhibitors targeting the membrane protein Smoothened suppress Hh signaling, acquired drug resistance and tumor relapse call for additional therapeutic targets. Here we show that phosphodiesterase 4D (PDE4D) acts downstream of Neuropilins to control Hh transduction and medulloblastoma growth. PDE4D interacts directly with Neuropilins, positive regulators of Hh pathway. The Neuropilin ligand Semaphorin3 enhances this interaction, promoting PDE4D translocation to the plasma membrane and cAMP degradation. The consequent inhibition of protein kinase A (PKA) enhances Hh transduction. In the developing cerebellum, genetic removal of Neuropilins reduces Hh signaling activity and suppresses proliferation of granule neuron precursors. In mouse medulloblastoma allografts, PDE4D inhibitors suppress Hh transduction and inhibit tumor growth. Our findings reveal a new regulatory mechanism of Hh transduction, and highlight PDE4D as a promising target to treat Hh-related tumors.

  8. Themes from a Camp Maintenance Network: Camp Maintenance and Property Personnel Share Their Insights and Challenges.

    ERIC Educational Resources Information Center

    Whyman, Wynne

    2003-01-01

    A camp maintenance survey was completed by maintenance personnel from 99 camps. Results highlighted several important considerations: ensuring sufficient maintenance funds for aging infrastructure, including camp/property personnel in decision making, publicizing completed maintenance projects, examining long-term needs of the land, and adopting…

  9. Forskolin's effect on transient K current in nudibranch neurons is not reproduced by cAMP.

    PubMed

    Coombs, J; Thompson, S

    1987-02-01

    Forskolin, a diterpene extracted from Coleus forskolii, stimulates the production of cAMP in a variety of cells and is potentially an important tool for studying the role of cAMP in the modulation of neuronal excitability. We studied the effects of forskolin on neurons of nudibranch molluscs and found that it caused characteristic, reversible changes in the amplitude and waveform of the transient K current, IA, and also activated an inward current similar to the cAMP-dependent inward current previously described in molluscan neurons. Forskolin altered the time course of IA activation and inactivation but did not affect the voltage dependence or the reversal potential of the current. IA normally inactivates exponentially, but in forskolin the time course of inactivation can be fit by the sum of 2 exponentials with an initial rate that is faster than the control and a final rate that is much slower. On depolarization in forskolin, IA begins to activate at the normal rate, but a slower component of activation is also seen. The changes in IA in the nudibranch cells were qualitatively different than the changes caused by forskolin in Aplysia bag cell neurons (Strong, 1984). Experiments were performed to determine whether these effects of forskolin require cAMP. Intracellular injection of cAMP, application of membrane-permeable analogs of cAMP, application of phosphodiesterase inhibitors, and intracellular injection of the active catalytic subunit of cAMP-dependent protein kinase did not affect the amplitude or waveform of IA. Also, the changes in IA that are caused by forskolin were not prevented or reversed by intracellular injection of an inhibitor of cAMP-dependent protein kinase. Cyclic AMP did, however, activate inward current at voltages near the resting potential. We conclude that the changes in IA and the activation of inward current represent separate affects of forskolin. The inward current appears to depend on an increase in intracellular cAMP, while the

  10. Program evaluation of Protovation Camp

    NASA Astrophysics Data System (ADS)

    Healy, Laurel Lynell Martin

    The purpose of this program evaluation was to determine the extent to which Protovation Camp utilized the combined resources of multiple institutions to impact student learning in science, technology, engineering, and math. The partnership consisted of multiple institutions: the university, providing graduate students to facilitate inquiry-based lessons; the science center, allowing the use of their facilities and resources; and the elementary school, contributing rising third through fifth grade campers. All of these components were examined. The mixed-methods approach used post hoc quantitative data for campers, which consisted of pre-test and post-test scores on the Test of Science-Related Attitudes (TOSRA), the Draw-A-Scientist Test, and content tests based on the camp activities. Additionally, TOSRA scores and current survey results for the graduate students were used along with qualitative data collected from plusdelta charts to determine the impact of participation in Protovation Camp on teachers and students. Results of the program evaluation indicated that when students were taught inquiry-based lessons that ignite wonder, both their attitudes toward science and their knowledge about science improved. An implication for teacher preparation programs was that practicing inquiry-based lessons on actual students (campers) was an important component for teachers (graduate students) as they prepare to positively impact student learning in their own classrooms. Immediate feedback from the campers in the form of pre-test and post-test scores and from peers on plusdelta charts allowed the graduate students the opportunity to make needed adjustments to improve effectiveness before using the lesson with a new set of campers or later in their own classrooms. Keywords. Teacher preparation, Inquiry-based instruction, STEM instructions, University and museum partnerships

  11. 32 CFR 552.170 - Camp Bonneville Area Access Office.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Land Use Policy for Fort Lewis, Yakima Training Center, and Camp Bonneville § 552.170 Camp Bonneville Area Access Office. Camp...

  12. 32 CFR 552.170 - Camp Bonneville Area Access Office.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Land Use Policy for Fort Lewis, Yakima Training Center, and Camp Bonneville § 552.170 Camp Bonneville Area Access Office. Camp...

  13. Cis-Lunar Base Camp

    NASA Technical Reports Server (NTRS)

    Merrill, Raymond G.; Goodliff, Kandyce E.; Mazanek, Daniel D.; Reeves, John D., Jr.

    2012-01-01

    Historically, when mounting expeditions into uncharted territories, explorers have established strategically positioned base camps to pre-position required equipment and consumables. These base camps are secure, safe positions from which expeditions can depart when conditions are favorable, at which technology and operations can be tested and validated, and facilitate timely access to more robust facilities in the event of an emergency. For human exploration missions into deep space, cis-lunar space is well suited to serve as such a base camp. The outer regions of cis-lunar space, such as the Earth-Moon Lagrange points, lie near the edge of Earth s gravity well, allowing equipment and consumables to be aggregated with easy access to deep space and to the lunar surface, as well as more distant destinations, such as near-Earth Asteroids (NEAs) and Mars and its moons. Several approaches to utilizing a cis-lunar base camp for sustainable human exploration, as well as some possible future applications are identified. The primary objective of the analysis presented in this paper is to identify options, show the macro trends, and provide information that can be used as a basis for more detailed mission development. Compared within are the high-level performance and cost of 15 preliminary cis-lunar exploration campaigns that establish the capability to conduct crewed missions of up to one year in duration, and then aggregate mass in cis-lunar space to facilitate an expedition from Cis-Lunar Base Camp. Launch vehicles, chemical propulsion stages, and electric propulsion stages are discussed and parametric sizing values are used to create architectures of in-space transportation elements that extend the existing in-space supply chain to cis-lunar space. The transportation options to cis-lunar space assessed vary in efficiency by almost 50%; from 0.16 to 0.68 kg of cargo in cis-lunar space for every kilogram of mass in Low Earth Orbit (LEO). For the 15 cases, 5-year campaign

  14. Contribution of the cyclic nucleotide phosphodiesterases PdeA and PdeB to adaptation of Myxococcus xanthus cells to osmotic or high-temperature stress.

    PubMed

    Kimura, Yoshio; Nakatuma, Hiromi; Sato, Naoko; Ohtani, Mika

    2006-01-01

    A tBLASTn search of the Myxococcus xanthus genome database at The Institute for Genomic Research (TIGR) identified three genes (pdeA, pdeB, and pdeC) that encode proteins homologous to 3',5'-cyclic nucleotide phosphodiesterase. pdeA, pdeB, and pdeC mutants, constructed by replacing a part of the gene with the kanamycin or tetracycline resistance gene, showed normal growth, development, and germination under nonstress conditions. However, the spores of mutants, especially the pdeA and pdeB mutants, placed under osmotic stress germinated earlier than the wild-type spores. The phenotype was the opposite of that of the receptor-type adenylyl cyclase (cyaA or cyaB) mutant. Also, pdeA and pdeB mutants were found to have impaired growth under the condition of high-temperature stress. Intracellular cyclic AMP (cAMP) levels of pdeA or pdeB mutant cells under these stressful conditions were about 1.3-fold to 2.0-fold higher than those of wild-type cells. These results suggest that PdeA and PdeB may be involved in osmotic adaptation during spore germination and temperature adaptation during vegetative growth through the regulation of cAMP levels.

  15. Vasoactive intestinal peptide synergistically stimulates DNA synthesis in mouse 3T3 cells: Role of cAMP, Ca sup 2+ , and protein kinase C

    SciTech Connect

    Zurier, B.B.; Kozma, M.; Sinnett-Smith, J.; Rozengurt, E. )

    1988-05-01

    Vasoactive intestinal peptide synergistically stimulated initiation of DNA synthesis in Swiss 3T3 cells. The peptide stimulated ({sup 3}H)thymidine incorporation in the presence of insulin and either forskolin or an inhibitor of cAMP phosphodiesterase in a concentration-dependent manner. Half-maximal effect was obtained at 1 nM. At mitogenic concentrations, VIP stimulated a marked accumulation (eightfold) of cAMP. In contrast to other growth-promoting neuropeptides, VIP did not induce an increase in cytosolic free Ca{sup 2+} or the activation of protein kinase C. The authors conclude that neuropeptides can modulate long-term cell proliferation through multiple signaling pathways.

  16. Tim Horton Camps: Spotlight on Onondaga Farms.

    ERIC Educational Resources Information Center

    Evanson, Jason

    2003-01-01

    Tim Horton Children's Foundation operates camps for disadvantaged children that build their self-confidence. The newest camp, Onondaga Farms in Ontario, is also a year-round outdoor education center. Its five program streams--environmental education, creative arts, agriculture, adventure, and recreation--all have direct links to Ontario's…

  17. Forest Fire: A Crisis Reality for Camp.

    ERIC Educational Resources Information Center

    Brown, Don; Mickelson, Rhonda

    2002-01-01

    Two camp directors were interviewed about evacuations from their camps due to forest fires. Topics covered include descriptions of the events; actions taken; aspects of advance planning that proved helpful; unexpected portions of the experience and resultant changes made in plans; relations with outside agencies, the media, and parents; working…

  18. Why It's Good to Go to Camp

    ERIC Educational Resources Information Center

    Howell, Matthew

    2008-01-01

    In the author's fourth year of undergraduate studies at the University of Waterloo he had the opportunity to explore the benefits attained by children attending a summer camp by way of an academic literature review. The author worked with Dr. Troy Glover who has been commissioned by a group of camping associations to perform a study on the…

  19. Accounting Boot Camp for College Juniors

    ERIC Educational Resources Information Center

    Myring, Mark; Wrege, William; Van Alst, Lucinda

    2008-01-01

    We describe a day-long introduction to new accounting majors, which we call a boot camp. Boot camp it is an effort to make juniors more aware of their identity, career purposes and learning resources that are now parts of their world, much of which is not covered explicitly in the accounting curriculum. This paper provides an overview of the…

  20. Summer Camp of Mathematical Modeling in China

    ERIC Educational Resources Information Center

    Tian, Xiaoxi; Xie, Jinxing

    2013-01-01

    The Summer Camp of Mathematical Modeling in China is a recently created experience designed to further Chinese students' academic pursuits in mathematical modeling. Students are given more than three months to research on a mathematical modeling project. Researchers and teams with outstanding projects are invited to the Summer Camp to present…

  1. Smart Kids at CAMP-US

    ERIC Educational Resources Information Center

    Sinatra, Richard

    2004-01-01

    This article describes the summer literacy, athletic, and computer program know as CAMP-US. Each year, CAMP-US serves approximately 500 children in 10-day sessions. The first half of each day is devoted to literacy and computer instruction, while the second half is spent engaging in recreational activities such as swimming, soccer, softball,…

  2. Children with Cancer: Positive Benefits of Camp.

    ERIC Educational Resources Information Center

    Winfree, Christy; Williams, Richard; Powell, Gwynn M.

    2002-01-01

    A relatively new method of helping pediatric cancer patients cope with their illness is specially designed summer camps. Camp helps children with cancer address psychological effects of the disease, bodily changes, and self-concept, and helps parents and siblings cope. Sidebars present resources and tips on incorporating children with cancer into…

  3. Suicides in the Nazi Concentration Camps.

    ERIC Educational Resources Information Center

    Ryn, Zdzislaw

    1986-01-01

    On the basis of psychiatric interviews with 69 former prisoners of the Auschwitz-Birkenau concentration camp, this paper describes the circumstances, motives, and ways of committing suicide in the camp. The interviews made it clear that thousands of prisoners perished by suicide. The number of committed suicides was larger than that of attempted…

  4. Camping Safety--Bring 'Em Back Alive.

    ERIC Educational Resources Information Center

    Schmidt, Ernest F.

    1980-01-01

    A "prioritized" list of dangers of the woods is discussed and suggestions for safety in organized camping are listed. Available from: Center for Environmental, Camping and Outdoor Education; University of North Carolina at Greensboro; Pine Lake Field Campus; 4016 Blumenthal Road; Greensboro, NC, 27406. (AN)

  5. A Kid's Guide to Family Camping.

    ERIC Educational Resources Information Center

    Regimbal, Celia; Kasakow, Nancy

    Fifth and sixth grade students of the University School at the University of Wyoming participated in a successful week's overnight outdoor experience in September 1983. Because results of a pre-camp questionnaire indicated that most students had minimal knowledge of the planning necessary for camping, activities and classes were organized to…

  6. Tech Camp Unleashes Creativity and Collaboration

    ERIC Educational Resources Information Center

    Bardin, Joe

    2008-01-01

    Each August, teachers from around the state gather for the Arizona K-12 Center's Tech Camp, a week-long immersion in technology for the classroom. The Arizona K-12 Center's mission is to improve teaching and learning in Arizona's schools through high-quality professional development and teacher leadership. The formula Tech Camp follows is a simple…

  7. Outdoor Education Project Report, Camp Alpine.

    ERIC Educational Resources Information Center

    Palmer, N. J.

    A report is given of Project Alpine, two summer pilot programs in outdoor education sponsored by the Mesa Public Schools of Arizona. The report outlines the duties of camp personnel and includes an instruction sheet used by camp counselors. Various activities held for the campers (boys and girls from both upper elementary and secondary grades) are…

  8. American Camping Association. Annual Report, 1985.

    ERIC Educational Resources Information Center

    American Camping Association, Martinsville, IN.

    The 1985 American Camping Association (ACA) annual report reviews trends and successes of the year. The document is in the format of a calendar covering the period October 1985 through September 1986. Calendar pages, on which relevant camping events are noted, alternate with pages of text. An introductory message from ACA President Jean McMullan…

  9. Teen Moms and Babies Benefit from Camping.

    ERIC Educational Resources Information Center

    Goode, Marsha; Broesamle, Barbara

    1987-01-01

    Describes nine-day residential camp for Michigan teenage mothers/babies to enhance personal growth and develop responsible social skills. Outlines goals, pre-camp planning, staff, activities, evaluation. Reports 31 teen moms (ages 13-21) and 35 babies attended in 1986. Indicates participants were in therapy, experienced abuse, had low self-esteem,…

  10. High-Level Wellness at Camp.

    ERIC Educational Resources Information Center

    Ardell, Donald B.

    1979-01-01

    Describes features of the Frost Valley YMCA Wellness Camp for Young People. Self-responsibility, nutritional awareness, physical fitness, stress management, and environmental sensitivity are stressed. Settings such as school camps and nature trips provide opportunities for the counselor to interrupt, intervene, and influence, essential in…

  11. Science Camp: Just for the Girls

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2007-01-01

    Research shows that girls tend to lose interest in science and math as they move through the education pipeline--a retreat that often begins during middle school. Summer science camps can be part of reversing that trend, some say. Academic camps are on the rise across the country, including ones to get adolescent girls excited about the…

  12. Is ROEE Good for Your Camp?

    ERIC Educational Resources Information Center

    Parry, Jim

    1998-01-01

    Resident outdoor environmental education (ROEE) is a camp-based extension of the classroom for two to five days, promoting student independence, interpersonal skills, and ecological awareness. Advantages and disadvantages of the "camp as innkeeper" and full program-provider models are given. Program development guidelines cover expenses,…

  13. Foreign Language Camps: A Success Story.

    ERIC Educational Resources Information Center

    Shrum, Judith

    The foreign language camps, operated by Virginia Tech since 1981, offer high school students a one-week foreign language experience in French, German, or Spanish. The camps bring together native speakers, high school students and teachers, and university students and faculty to experience learning situations similar to those encountered in a…

  14. Cedar Ridge Camp: Using the Local Environment

    ERIC Educational Resources Information Center

    Burke, Grayson

    2007-01-01

    In 2007 Cedar Ridge Camp opened for its first season as a traditional co-ed summer camp and year-round outdoor education and recreation centre. The mission would centre on creating a program that would encourage personal development and growth through a shared outdoor experience. Cedar Ridge's main goals were to promote the formation of close…

  15. A cardiac mitochondrial cAMP signaling pathway regulates calcium accumulation, permeability transition and cell death

    PubMed Central

    Wang, Z; Liu, D; Varin, A; Nicolas, V; Courilleau, D; Mateo, P; Caubere, C; Rouet, P; Gomez, A-M; Vandecasteele, G; Fischmeister, R; Brenner, C

    2016-01-01

    Although cardiac cytosolic cyclic 3′,5′-adenosine monophosphate (cAMP) regulates multiple processes, such as beating, contractility, metabolism and apoptosis, little is known yet on the role of this second messenger within cardiac mitochondria. Using cellular and subcellular approaches, we demonstrate here the local expression of several actors of cAMP signaling within cardiac mitochondria, namely a truncated form of soluble AC (sACt) and the exchange protein directly activated by cAMP 1 (Epac1), and show a protective role for sACt against cell death, apoptosis as well as necrosis in primary cardiomyocytes. Upon stimulation with bicarbonate (HCO3−) and Ca2+, sACt produces cAMP, which in turn stimulates oxygen consumption, increases the mitochondrial membrane potential (ΔΨm) and ATP production. cAMP is rate limiting for matrix Ca2+ entry via Epac1 and the mitochondrial calcium uniporter and, as a consequence, prevents mitochondrial permeability transition (MPT). The mitochondrial cAMP effects involve neither protein kinase A, Epac2 nor the mitochondrial Na+/Ca2+ exchanger. In addition, in mitochondria isolated from failing rat hearts, stimulation of the mitochondrial cAMP pathway by HCO3− rescued the sensitization of mitochondria to Ca2+-induced MPT. Thus, our study identifies a link between mitochondrial cAMP, mitochondrial metabolism and cell death in the heart, which is independent of cytosolic cAMP signaling. Our results might have implications for therapeutic prevention of cell death in cardiac pathologies. PMID:27100892

  16. Interactions of Calcium Fluctuations during Cardiomyocyte Contraction with Real-Time cAMP Dynamics Detected by FRET

    PubMed Central

    Sprenger, Julia U.; Bork, Nadja I.; Herting, Jonas; Fischer, Thomas H.; Nikolaev, Viacheslav O.

    2016-01-01

    Calcium (Ca2+) and 3’,5’-cyclic adenosine monophosphate (cAMP) play a critical role for cardiac excitation-contraction-coupling. Both second messengers are known to interact with each other, for example via Ca2+-dependent modulation of phosphodiesterase 1 (PDE1) and adenylyl cyclase 5/6 (AC 5/6) activities, which is supposed to occur especially at the local level in distinct subcellular microdomains. Currently, many studies analyze global and local cAMP signaling and its regulation in resting cardiomyocytes devoid of electrical stimulation. For example, Förster resonance energy transfer (FRET) microscopy is a popular approach for visualization of real time cAMP dynamics performed in resting cardiomyocytes to avoid potential contractility-related movement artifacts. However, it is unknown whether such data are comparable with the cell behavior under more physiologically relevant conditions during contraction. Here, we directly compare the cAMP-FRET responses to AC stimulation and PDE inhibition in resting vs. paced adult mouse ventricular cardiomyocytes for both cytosolic and subsarcolemmal microdomains. Interestingly, no significant differences in cAMP dynamics could be detected after β-adrenergic (isoproterenol) stimulation, suggesting low impact of rapidly changing contractile Ca2+ concentrations on cytosolic cAMP levels associated with AC activation. However, the contribution of the calcium-dependent PDE1, but not of the Ca2+-insensitive PDE4, to the regulation of cAMP levels after forskolin stimulation was significantly increased. This increase could be mimicked by pretreatment of resting cells with Ca2+ elevating agents. Ca2+ imaging demonstrated significantly higher amplitudes of Ca2+ transients in forskolin than in isoproterenol stimulated cells, suggesting that forskolin stimulation might lead to stronger activation of PDE1. In conclusion, changes in intracellular Ca2+ during cardiomyocyte contraction dynamically interact with cAMP levels, especially

  17. Synergistic induction of insulin resistance by endothelin-1 and cAMP in 3T3-L1 adipocytes.

    PubMed

    Chai, Shin-Pei; Fong, Jim C

    2015-10-01

    Both endothelin-1 (ET-1) and cAMP are implicated for inducing insulin resistance. Since we have shown previously that there is a crosstalk between ET-1 and cAMP signaling pathways in regulating glucose uptake in 3T3-L1 adipocytes, we extended our investigation in this study on whether they may have a synergistic effect on inducing insulin resistance. Our results showed that it was indeed the case. Insulin-stimulated glucose uptake, phosphorylation of PKB, IRS-1-associated PI3K, and IRS-1 tyrosine phosphorylation were all inhibited by ET-1 and 8-bromo cAMP in a synergistic manner. IRS-1 protein levels were similarly decreased by ET-1 and 8-bromo cAMP, attributable to suppressed mRNA expression. In addition, after correction for the loss in IRS-1 protein, the inhibition of insulin-stimulated IRS-1 tyrosine phosphorylation or IRS-1-associated PI3K was mainly caused by cAMP. Moreover, whereas IRS-2 protein levels were increased by cAMP or ET-1 plus cAMP, insulin-stimulated IRS-2-associated PI3K activities were abolished by both treatments. Furthermore, ET-1 and β-adrenergic agonists had similar synergistic inhibition on insulin-stimulated glucose uptake. In conclusion, we have shown that ET-1 and cAMP may synergistically induce insulin resistance in adipocytes via inhibiting IRS-1 expression as well as insulin-stimulated IRS-1/IRS-2 activities.

  18. [Medicine in the Soviet labor camps].

    PubMed

    Supady, J

    1998-01-01

    The existence of medical attention in Soviet labour camps was dictated not by humane reasons but by economical motives. It was just a wish to regenerate physical strength of some labour camp's slaves in order to exploit them to work out definite production as well as ideological plans. However, despite the lack of medicines, equipment, proper housing conditions and qualified staff, employed in labour camp's medical service people--doctors, hospital attendants, nurses, etc.--that were mostly recruited from amongst prisoners, showed a great deal of kindness and did their best to come to unwell and ill patients' assistance. Prisoners' lives were not uncommonly saved through exemption from work by a doctor's decision sending to hospital or transfer to another health category. In comparison with gehenna of labour camp's slave everyday life a sojourn in camp hospital seemed a paradise and a rescue from death to prisoners.

  19. Diabetic nephropathy: Treatment with phosphodiesterase type 5 inhibitors.

    PubMed

    Thompson, Cecil Stanley

    2013-08-15

    The importance of nitric oxide (NO) in vascular physiology is irrefutable; it stimulates the intracellular production of cyclic guanosine monophosphate (cGMP), initiating vascular smooth muscle relaxation. This biochemical process increases the diameter of small arteries, regulating blood flow distribution between arterioles and the microvasculature. The kidney is no exception, since NO predominantly dilates the glomerular afferent arterioles. It is now evident that the vascular production of cGMP can be augmented by inhibitors of phosphodiesterase type 5 (PDE 5), the enzyme which breakdowns this cyclic nucleotide. This has clinical relevance, since diabetic nephropathy (DN) a major microvascular complication of diabetes mellitus and the most common cause of end-stage renal disease, increases intraglomerular capillary pressure, leading to glomerular hypertension. PDE 5 inhibitors may have, therefore, the potential to reduce glomerular hypertension. This review describes the use of PDE 5 inhibitors to improve the metabolic, haemodynamic and inflammatory pathways/responses, all of which are dysfunctional in DN.

  20. cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

    SciTech Connect

    Bhattacharjee, Rajesh; Xiang, Wenpei; Wang, Yinna; Zhang, Xiaoying

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. Black-Right-Pointing-Pointer cAMP blocks NF-{kappa}B activation induced by TNF and actinomycin D. Black-Right-Pointing-Pointer cAMP blocks DISC formation following TNF and actinomycin D exposure. Black-Right-Pointing-Pointer cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor {alpha} (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found

  1. Therapeutic camping for children with end-stage renal disease.

    PubMed

    Warady, B A

    1994-06-01

    Therapeutic camping experiences for children with end-stage renal disease (ESRD) have proliferated in the United States and abroad. This report is based on the results of a survey designed to accumulate data on the development and implementation of 20 such camps. Children attending camp ranged in age from 1 year to 19 years. Single disease-specific camps were most common, while camps for children with a variety of chronic illnesses, including ESRD, and mainstream camps were also conducted. Facilities were available for hemodialysis and continuous ambulatory peritoneal dialysis, but not automated peritoneal dialysis, in the majority of surveyed camps. Dialysis nurses, pediatric nephrologists, dietitians and social workers were the medical personnel that most frequently participated in the camps. On average, 32 dialysis/transplant patient campers (range 6-100) attended camp for a 1-week session. Therapeutic camping experiences for children with ESRD are extremely successful and attempts to increase the availability of similar camps should be encouraged.

  2. Camp Blanding Lightning Mapping Array

    NASA Technical Reports Server (NTRS)

    Blakeslee,Richard; Christian, Hugh; Bailey, Jeffrey; Hall, John; Uman, Martin; Jordan, Doug; Krehbiel, Paul; Rison, William; Edens, Harald

    2011-01-01

    A seven station, short base-line Lightning Mapping Array was installed at the Camp Blanding International Center for Lightning Research and Testing (ICLRT) during April 2011. This network will support science investigations of Terrestrial Gamma-Ray Flashes (TGFs) and lightning initiation using rocket triggered lightning at the ICLRT. The network operations and data processing will be carried out through a close collaboration between several organizations, including the NASA Marshall Space Flight Center, University of Alabama in Huntsville, University of Florida, and New Mexico Tech. The deployment was sponsored by the Defense Advanced Research Projects Agency (DARPA). The network does not have real-time data dissemination. Description, status and plans will be discussed.

  3. Characterization of Binding and Inhibitory Properties of TAK-063, a Novel Phosphodiesterase 10A Inhibitor

    PubMed Central

    Harada, Akina; Suzuki, Kazunori; Kamiguchi, Naomi; Miyamoto, Maki; Tohyama, Kimio; Nakashima, Kosuke; Taniguchi, Takahiko; Kimura, Haruhide

    2015-01-01

    Phosphodiesterase 10A (PDE10A) inhibition is a novel and promising approach for the treatment of central nervous system disorders such as schizophrenia and Huntington’s disease. A novel PDE10A inhibitor, TAK-063 [1-[2-fluoro-4-(1H-pyrazol-1-yl)phenyl]-5-methoxy-3-(1-phenyl-1H-pyrazol-5-yl)-pyridazin-4(1H)-one] has shown high inhibitory activity and selectivity for human recombinant PDE10A2 in vitro; the half-maximal inhibitory concentration was 0.30 nM, and selectivity over other phosphodiesterases (PDEs) was more than 15000-fold. TAK-063 at 10 µM did not show more than 50% inhibition or stimulation of 91 enzymes or receptors except for PDEs. In vitro autoradiography (ARG) studies using rat brain sections revealed that [3H]TAK-063 selectively accumulated in the caudate putamen (CPu), nucleus accumbens (NAc), globus pallidus, substantia nigra, and striatonigral projection, where PDE10A is highly expressed. This [3H]TAK-063 accumulation was almost entirely blocked by an excess amount of MP-10, a PDE10A selective inhibitor, and the accumulation was not observed in brain slices of Pde10a-knockout mice. In rat brain sections, [3H]TAK-063 bound to a single high-affinity site with mean ± SEM dissociation constants of 7.2 ± 1.2 and 2.6 ± 0.5 nM for the CPu and NAc shell, respectively. Orally administered [14C]TAK-063 selectively accumulated in PDE10A expressing brain regions in an in vivo ARG study in rats. Striatal PDE10A occupancy by TAK-063 in vivo was measured using T-773 as a tracer and a dose of 0.88 mg/kg (p.o.) was calculated to produce 50% occupancy in rats. Translational studies with TAK-063 and other PDE10A inhibitors such as those presented here will help us better understand the pharmacological profile of this class of potential central nervous system drugs. PMID:25815469

  4. Functional interrelationships in the alkaline phosphatase superfamily: phosphodiesterase activity of Escherichia coli alkaline phosphatase.

    PubMed

    O'Brien, P J; Herschlag, D

    2001-05-15

    Escherichia coli alkaline phosphatase (AP) is a proficient phosphomonoesterase with two Zn(2+) ions in its active site. Sequence homology suggests a distant evolutionary relationship between AP and alkaline phosphodiesterase/nucleotide pyrophosphatase, with conservation of the catalytic metal ions. Furthermore, many other phosphodiesterases, although not evolutionarily related, have a similar active site configuration of divalent metal ions in their active sites. These observations led us to test whether AP could also catalyze the hydrolysis of phosphate diesters. The results described herein demonstrate that AP does have phosphodiesterase activity: the phosphatase and phosphodiesterase activities copurify over several steps; inorganic phosphate, a strong competitive inhibitor of AP, inhibits the phosphodiesterase and phosphatase activities with the same inhibition constant; a point mutation that weakens phosphate binding to AP correspondingly weakens phosphate inhibition of the phosphodiesterase activity; and mutation of active site residues substantially reduces both the mono- and diesterase activities. AP accelerates the rate of phosphate diester hydrolysis by 10(11)-fold relative to the rate of the uncatalyzed reaction [(k(cat)/K(m))/k(w)]. Although this rate enhancement is substantial, it is at least 10(6)-fold less than the rate enhancement for AP-catalyzed phosphate monoester hydrolysis. Mutational analysis suggests that common active site features contribute to hydrolysis of both phosphate monoesters and phosphate diesters. However, mutation of the active site arginine to serine, R166S, decreases the monoesterase activity but not the diesterase activity, suggesting that the interaction of this arginine with the nonbridging oxygen(s) of the phosphate monoester substrate provides a substantial amount of the preferential hydrolysis of phosphate monoesters. The observation of phosphodiesterase activity extends the previous observation that AP has a low level of

  5. cAMP initiates early phase neuron-like morphology changes and late phase neural differentiation in mesenchymal stem cells.

    PubMed

    Zhang, Linxia; Seitz, Linsey C; Abramczyk, Amy M; Liu, Li; Chan, Christina

    2011-03-01

    The intracellular second messenger cAMP is frequently used in induction media to induce mesenchymal stem cells (MSCs) into neural lineage cells. To date, an understanding of the role cAMP exerts on MSCs and whether cAMP can induce MSCs into functional neurons is still lacking. We found cAMP initiated neuron-like morphology changes early and neural differentiation much later. The early phase changes in morphology were due to cell shrinkage, which subsequently rendered some cells apoptotic. While the morphology changes occurred prior to the expression of neural markers, it is not required for neural marker expression and the two processes are differentially regulated downstream of cAMP-activated protein kinase A. cAMP enabled MSCs to gain neural marker expressions with neuronal function, such as, calcium rise in response to neuronal activators, dopamine, glutamate, and potassium chloride. However, only some of the cells induced by cAMP responded to the three neuronal activators and further lack the neuronal morphology, suggesting that although cAMP is able to direct MSCs towards neural differentiation, they do not achieve terminal differentiation.

  6. cAMP initiates early phase neuron-like morphology changes and late phase neural differentiation in mesenchymal stem cells

    PubMed Central

    Zhang, Linxia; Seitz, Linsey C.; Abramczyk, Amy M.; Liu, Li

    2010-01-01

    The intracellular second messenger cAMP is frequently used in induction media to induce mesenchymal stem cells (MSCs) into neural lineage cells. To date, an understanding of the role cAMP exerts on MSCs and whether cAMP can induce MSCs into functional neurons is still lacking. We found cAMP initiated neuron-like morphology changes early and neural differentiation much later. The early phase changes in morphology were due to cell shrinkage, which subsequently rendered some cells apoptotic. While the morphology changes occurred prior to the expression of neural markers, it is not required for neural marker expression and the two processes are differentially regulated downstream of cAMP-activated protein kinase A. cAMP enabled MSCs to gain neural marker expressions with neuronal function, such as, calcium rise in response to neuronal activators, dopamine, glutamate, and potassium chloride. However, only some of the cells induced by cAMP responded to the three neuronal activators and further lack the neuronal morphology, suggesting that although cAMP is able to direct MSCs towards neural differentiation, they do not achieve terminal differentiation. PMID:20725762

  7. Creating a Successful Summer Physics Camp

    NASA Astrophysics Data System (ADS)

    Gregory, Amanda

    2009-10-01

    The summer physics camp hosted by the Texas State University San Marcos Society of Physics Students chapter is geared toward middle school children aged 9 to 12 years. Camp administrators aim to create an environment that is both conducive to learning and fun. Our overarching goal is to provide local youth a basic knowledge of physical concepts as well as encourage their continued interest in physics. Physical concepts are taught through a combination of short lectures, group activities, and entertaining demonstrations. This presentation will discuss the basic curriculum, activities and demonstrations that have been performed in past camps, as well as plans for future curricula and expansions.

  8. Phosphodiesterase Inhibition and Regulation of Dopaminergic Frontal and Striatal Functioning: Clinical Implications

    PubMed Central

    Heckman, Pim R. A.; van Duinen, Marlies A.; Bollen, Eva P. P.; Nishi, Akinori; Wennogle, Lawrence P.; Blokland, Arjan

    2016-01-01

    Background: The fronto-striatal circuits are the common neurobiological basis for neuropsychiatric disorders, including schizophrenia, Parkinson’s disease, Huntington’s disease, attention deficit hyperactivity disorder, obsessive-compulsive disorder, and Tourette’s syndrome. Fronto-striatal circuits consist of motor circuits, associative circuits, and limbic circuits. All circuits share 2 common features. First, all fronto-striatal circuits consist of hyper direct, direct, and indirect pathways. Second, all fronto-striatal circuits are modulated by dopamine. Intracellularly, the effect of dopamine is largely mediated through the cyclic adenosine monophosphate/protein kinase A signaling cascade with an additional role for the cyclic guanosine monophosphate/protein kinase G pathway, both of which can be regulated by phosphodiesterases. Phosphodiesterases are thus a potential target for pharmacological intervention in neuropsychiatric disorders related to dopaminergic regulation of fronto-striatal circuits. Methods: Clinical studies of the effects of different phosphodiesterase inhibitors on cognition, affect, and motor function in relation to the fronto-striatal circuits are reviewed. Results: Several selective phosphodiesterase inhibitors have positive effects on cognition, affect, and motor function in relation to the fronto-striatal circuits. Conclusion: Increased understanding of the subcellular localization and unraveling of the signalosome concept of phosphodiesterases including its function and dysfunction in the fronto-striatal circuits will contribute to the design of new specific inhibitors and enhance the potential of phosphodiesterase inhibitors as therapeutics in fronto-striatal circuits. PMID:27037577

  9. Termination of cAMP signals by Ca2+ and Gαi via extracellular Ca2+ sensors

    PubMed Central

    Gerbino, Andrea; Ruder, Warren C.; Curci, Silvana; Pozzan, Tullio; Zaccolo, Manuela; Hofer, Aldebaran M.

    2005-01-01

    Termination of cyclic adenosine monophosphate (cAMP) signaling via the extracellular Ca2+-sensing receptor (CaR) was visualized in single CaR-expressing human embryonic kidney (HEK) 293 cells using ratiometric fluorescence resonance energy transfer–dependent cAMP sensors based on protein kinase A and Epac. Stimulation of CaR rapidly reversed or prevented agonist-stimulated elevation of cAMP through a dual mechanism involving pertussis toxin–sensitive Gαi and the CaR-stimulated increase in intracellular [Ca2+]. In parallel measurements with fura-2, CaR activation elicited robust Ca2+ oscillations that increased in frequency in the presence of cAMP, eventually fusing into a sustained plateau. Considering the Ca2+ sensitivity of cAMP accumulation in these cells, lack of oscillations in [cAMP] during the initial phases of CaR stimulation was puzzling. Additional experiments showed that low-frequency, long-duration Ca2+ oscillations generated a dynamic staircase pattern in [cAMP], whereas higher frequency spiking had no effect. Our data suggest that the cAMP machinery in HEK cells acts as a low-pass filter disregarding the relatively rapid Ca2+ spiking stimulated by Ca2+-mobilizing agonists under physiological conditions. PMID:16247029

  10. "It's not Just Camp!": Understanding the Meaning of Children's Cancer Camps for Children and Families.

    PubMed

    Laing, Catherine M; Moules, Nancy J

    2016-01-01

    The purpose of this philosophical hermeneutic inquiry was to understand the meaning of children's cancer camps for the child with cancer and the family. Six childhood cancer families and 5 cancer camp counselors were interviewed, in order to bring understanding to this topic. Findings from this research revealed that camp means different things for different families, and that much is at play in the cancer camp experience: the healing and developmental power of play, finding acceptance and fit, grief as something to live with versus "get over," storytelling as a means of reshaping and understanding traumatic experiences, and the solidarity of the community as one that creates intense, healing bonds. Children's cancer camps, we conclude, should be considered a necessity, versus a luxury, and could even be thought of as a psychosocial intervention for some children and families. Barriers such as structure of funding and access to resources are present and likely due to the separateness of camps from hospital programs.

  11. Prostaglandin E1 inhibits collagenase gene expression in rabbit synoviocytes and human fibroblasts.

    PubMed

    Salvatori, R; Guidon, P T; Rapuano, B E; Bockman, R S

    1992-07-01

    Cartilage breakdown, as seen in inflammatory and degenerative joint diseases, can be mediated by proteolytic enzymes, such as the metalloproteinase collagenase, the only enzyme able to digest collagen at neutral pH. In vitro collagenase gene expression can be stimulated by the phorbol ester tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate. We have investigated the effect of prostaglandin E1 (PGE1) on 12-O-tetradecanoyl-phorbol-13-acetate-stimulated collagenase mRNA levels in the rabbit synoviocyte cell line HIG-82. PGE1, but not PGE2 or PGF2 alpha, was able to selectively reduce collagenase mRNA levels in a dose-dependent fashion. PGE1 markedly increased intracellular levels of cAMP, while PGE2 and PGF2 alpha had little or no effect on cAMP production in the HIG-82 synoviocytes. Agents known to increase intracellular cAMP levels, such as the adenyl cyclase activator forskolin and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), mimicked the effect of PGE1, on collagenase mRNA levels. PGE1, forskolin, and IBMX also decreased collagenase mRNA levels in human skin fibroblasts, demonstrating that this observation was not unique to the HIG-82 cell line. Transient transfection experiments carried out in HIG-82 cells using a 1.2-kilobase portion of the 5'-flanking region of the human collagenase gene linked to the reporter gene luciferase demonstrated that PGE1, forskolin, and IBMX exert their inhibitory effect on the promoter region of the collagenase gene.

  12. Design and Development Issues for Educational Robotics Training Camps

    ERIC Educational Resources Information Center

    Ucgul, Memet; Cagiltay, Kursat

    2014-01-01

    The aim of this study is to explore critical design issues for educational robotics training camps and to describe how these factors should be implemented in the development of such camps. For this purpose, two robotics training camps were organized for elementary school students. The first camp had 30 children attendees, and the second had 22. As…

  13. Site and Facilities: A Resource Book for Camps.

    ERIC Educational Resources Information Center

    Ball, Armand, Ed.; Ball, Beverly, Ed.

    This resource book draws together articles on the development and maintenance of camp sites and facilities. The articles, previously published by "Camping Magazine" and "Journal of Christian Camping," cover (1) site planning and long-range development, including redesigning multiple camp facilities for year-round programs, remodeling and…

  14. 32 CFR 552.170 - Camp Bonneville Area Access Office.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 3 2014-07-01 2014-07-01 false Camp Bonneville Area Access Office. 552.170 Section 552.170 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY..., Yakima Training Center, and Camp Bonneville § 552.170 Camp Bonneville Area Access Office. Camp...

  15. 32 CFR 552.170 - Camp Bonneville Area Access Office.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 3 2012-07-01 2009-07-01 true Camp Bonneville Area Access Office. 552.170 Section 552.170 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY..., Yakima Training Center, and Camp Bonneville § 552.170 Camp Bonneville Area Access Office. Camp...

  16. 32 CFR 552.170 - Camp Bonneville Area Access Office.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Camp Bonneville Area Access Office. 552.170 Section 552.170 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY..., Yakima Training Center, and Camp Bonneville § 552.170 Camp Bonneville Area Access Office. Camp...

  17. (Compendium of State Laws and Regulations for Youth Camps).

    ERIC Educational Resources Information Center

    Brookhiser, Judy, Comp.; van der Smissen, Betty, Comp.

    State laws and regulations applicable to youth camp operations provided by state agencies are organized in this Compendium under ten major headings; personnel; program safety; personal health, first aid, and medical services; site and facilities; sanitation; food service; transportation; primitive camping and out-of-camp trips; day camping; and…

  18. Accreditation Standards for Camp Programs and Services. Revised 1998 Edition.

    ERIC Educational Resources Information Center

    American Camping Association, Martinsville, IN.

    The American Camping Association (ACA) accreditation program aims to educate camp owners and directors in the administration of key aspects of camp operation, particularly those related to program quality and the health and safety of campers and staff, and to assist the public in selecting camps that meet industry-accepted and…

  19. Day Camping for the 80's--An Administrative Perspective.

    ERIC Educational Resources Information Center

    Umstead, Elizabeth C.

    1980-01-01

    Previews the 1980 National Day Camp Symposium and discusses influences of the 1980s on day camps. Also discusses precamp planning, the camp season, and postcamp activities. Available from: Center for Environmental, Camping and Outdoor Education; University of North Carolina at Greensboro; Pine Lake Field Campus; 4016 Blumenthal Road; Greensboro,…

  20. Why Do Counselors Return to Work at Camp?

    ERIC Educational Resources Information Center

    Becker, William A.

    The reasons that counselors in resident summer camps return to work are explored, taking into account the differences between private and agency camps, and differing attitudes of male and female camp counselors. A random sample of returning counselors at 15 private and 15 agency camps in the Northeast were selected for the study. Six attitudinal…

  1. cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes.

    PubMed

    Bhattacharjee, Rajesh; Xiang, Wenpei; Wang, Yinna; Zhang, Xiaoying; Billiar, Timothy R

    2012-06-22

    Tumor necrosis factor α (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF+ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found that cAMP exerts its affect at the proximal level of TNF signaling by inhibiting the formation of the DISC complex upon the binding of TNF to TNFR1. In conclusion, our study shows that cAMP prevents TNF+ActD-induced apoptosis in rat hepatocytes by inhibiting DISC complex formation.

  2. Estradiol increases cAMP in the oviductal secretory cells through a nongenomic mechanism.

    PubMed

    Oróstica, María L; Lopez, John; Rojas, Israel; Rocco, Jocelyn; Díaz, Patricia; Reuquén, Patricia; Cardenas, Hugo; Parada-Bustamante, Alexis; Orihuela, Pedro A

    2014-09-01

    In the rat oviduct, estradiol (E2) accelerates egg transport by a nongenomic action that requires previous conversion of E2 to methoxyestrogens via catechol-O-methyltranferase (COMT) and activation of estrogen receptor (ER) with subsequent production of cAMP and inositol triphosphate (IP3). However, the role of the different oviductal cellular phenotypes on this E2 nongenomic pathway remains undetermined. The aim of this study was to investigate the effect of E2 on the levels of cAMP and IP3 in primary cultures of secretory and smooth muscle cells from rat oviducts and determine the mechanism by which E2 increases cAMP in the secretory cells. In the secretory cells, E2 increased cAMP but not IP3, while in the smooth muscle cells E2 decreased cAMP and increased IP3. Suppression of protein synthesis by actinomycin D did not prevent the E2-induced cAMP increase, but this was blocked by the ER antagonist ICI 182 780 and the inhibitors of COMT OR 486, G protein-α inhibitory (Gαi) protein pertussis toxin and adenylyl cyclase (AC) SQ 22536. Expression of the mRNA for the enzymes that metabolizes estrogens, Comt, Cyp1a1, and Cyp1b1 was found in the secretory cells, but this was not affected by E2. Finally, confocal immunofluorescence analysis showed that E2 induced colocalization between ESR1 (ERα) and Gαi in extranuclear regions of the secretory cells. We conclude that E2 differentially regulates cAMP and IP3 in the secretory and smooth muscle cells of the rat oviduct. In the secretory cells, E2 increases cAMP via a nongenomic action that requires activation of COMT and ER, coupling between ESR1 and Gαi, and stimulation of AC.

  3. New insights into the mechanism of light modulated signaling by heterotrimeric G-proteins: ENVOY acts on gna1 and gna3 and adjusts cAMP levels in Trichoderma reesei (Hypocrea jecorina)

    PubMed Central

    Tisch, Doris; Kubicek, Christian P.; Schmoll, Monika

    2011-01-01

    Sensing of environmental signals is often mediated by G-protein coupled receptors and their cognate heterotrimeric G-proteins. In Trichoderma reesei (Hypocrea jecorina) the signals transmitted via the G-protein alpha subunits GNA1 and GNA3 cause considerable modulation of cellulase transcript levels and the extent of this adjustment is dependent on the light status. We therefore intended to elucidate the underlying mechanism connecting light response and heterotrimeric G-protein signaling. Analysis of double mutant strains showed that constitutive activation of GNA1 or GNA3 in the absence of the PAS/LOV domain protein ENVOY (ENV1) leads to the phenotype of constitutive G-alpha activation in darkness. In light, however the deletion-phenotype of Δenv1 was observed with respect to growth, conidiation and cellulase gene transcription. Additionally deletion of env1 causes decreased intracellular cAMP accumulation, even upon constitutive activation of GNA1 or GNA3. While supplementation of cAMP caused an even more severe growth phenotype of all strains lacking env1 in light, addition of the phosphodiesterase inhibitor caffeine rescued the growth phenotype of these strains. ENV1 is consequently suggested to connect the light response pathway with nutrient signaling by the heterotrimeric G-protein cascade by adjusting transcript levels of gna1 and gna3 and action on cAMP levels – presumably through inhibition of a phosphodiesterase. PMID:21220037

  4. cGMP phosphodiesterase inhibition improves the vascular and metabolic actions of insulin in skeletal muscle.

    PubMed

    Genders, A J; Bradley, E A; Rattigan, S; Richards, S M

    2011-08-01

    There is considerable support for the concept that insulin-mediated increases in microvascular blood flow to muscle impact significantly on muscle glucose uptake. Since the microvascular blood flow increases with insulin have been shown to be nitric oxide-dependent inhibition of cGMP-degrading phosphodiesterases (cGMP PDEs) is predicted to enhance insulin-mediated increases in microvascular perfusion and muscle glucose uptake. Therefore, we studied the effects of the pan-cGMP PDE inhibitor zaprinast on the metabolic and vascular actions of insulin in muscle. Hyperinsulinemic euglycemic clamps (3 mU·min(-1)·kg(-1)) were performed in anesthetized rats and changes in microvascular blood flow assessed from rates of 1-methylxanthine metabolism across the muscle bed by capillary xanthine oxidase in response to insulin and zaprinast. We also characterized cGMP PDE isoform expression in muscle by real-time PCR and immunostaining of frozen muscle sections. Zaprinast enhanced insulin-mediated microvascular perfusion by 29% and muscle glucose uptake by 89%, while whole body glucose infusion rate during insulin infusion was increased by 33% at 2 h. PDE2, -9, and -10 were the major isoforms expressed at the mRNA level in muscle, while PDE1B, -9A, -10A, and -11A proteins were expressed in blood vessels. Acute administration of the cGMP PDE inhibitor zaprinast enhances muscle microvascular blood flow and glucose uptake response to insulin. The expression of a number of cGMP PDE isoforms in skeletal muscle suggests that targeting specific cGMP PDE isoforms may provide a promising avenue for development of a novel class of therapeutics for enhancing muscle insulin sensitivity.

  5. A Lightning Safety Primer for Camps.

    ERIC Educational Resources Information Center

    Attarian, Aram

    1992-01-01

    Provides the following information about lightning, which is necessary for camp administrators and staff: (1) warning signs of lightning; (2) dangers of lightning; (3) types of lightning injuries; (4) prevention of lightning injury; and (5) helpful training tips. (KS)

  6. Camp Minden Fact Sheet November 2014

    EPA Pesticide Factsheets

    On October 28, 2014, the Environmental Protection Agency (EPA) signed a Settlement Agreement for the destruction of more than 15 million pounds of military propellants at the Explo Systems, Inc., Camp Minden, Louisiana site.

  7. The ω-3 fatty acid eicosapentaenoic acid elicits cAMP generation in colonic epithelial cells via a “store-operated” mechanism

    PubMed Central

    Roy, Jessica; Lefkimmiatis, Konstantinos; Moyer, Mary Pat; Curci, Silvana

    2010-01-01

    Eicosapentaenoic acid (EPA) is an ω-3 polyunsaturated fatty acid abundant in fish oil that exerts a wide spectrum of documented beneficial health effects in humans. Because dietary interventions are relatively inexpensive and are widely assumed to be safe, they have broad public appeal. Their endorsement can potentially have a major impact on human health, but hard mechanistic evidence that specifies how these derivatives work at the cellular level is limited. EPA (50 μM) caused a small elevation of cytoplasmic Ca2+ concentration ([Ca2+]) in intact NCM460 human colonic epithelial cells as measured by fura 2 and a profound drop of [Ca2+] within the endoplasmic reticulum (ER) of permeabilized cells as monitored by compartmentalized mag-fura 2. Total internal reflection fluorescence microscopy showed that this loss of ER store [Ca2+] led to translocation of the ER-resident transmembrane Ca2+ sensor STIM1. Using sensitive FRET-based sensors for cAMP in single cells, we further found that EPA caused a substantial increase in cellular cAMP concentration, a large fraction of which was dependent on the drop in ER [Ca2+], but independent of cytosolic Ca2+. An additional component of the EPA-induced cAMP signal was sensitive to the phosphodiesterase inhibitor isobutyl methylxanthine. We conclude that EPA slowly releases ER Ca2+ stores, resulting in the generation of cAMP. The elevated cAMP is apparently independent of classical G protein-coupled receptor activation and is likely the consequence of a newly described “store-operated” cAMP signaling pathway that is mediated by STIM1. PMID:20576916

  8. Standards for Day and Resident Camps: The Accreditation Programs of the American Camping Association. 1990 Edition, Revised 1993.

    ERIC Educational Resources Information Center

    American Camping Association, Martinsville, IN.

    This book outlines standards that provide a basis for camp accreditation and site approval by the American Camping Association (ACA), Inc. The purpose of the ACA accreditation programs is to educate camp owners and directors in the administration of key aspects of camp operation, particularly those related to program quality and the health and…

  9. An offsite activity policy for asthma camp.

    PubMed

    Clack, Gail

    2010-03-01

    This article outlines the activities undertaken during asthma camps and highlights the benefits for children and young people. These include: improved understanding of asthma, increased concordance with medication, greater participation in physical activity and enhanced self-confidence. In the absence of a nationally agreed offsite activity policy, the author demonstrates the use of a clinical governance framework to develop a local offsite activity policy for asthma camps to ensure the safety of children and young people as well as staff.

  10. Aggregation of scaffolding protein DISC1 dysregulates phosphodiesterase 4 in Huntington's disease.

    PubMed

    Tanaka, Motomasa; Ishizuka, Koko; Nekooki-Machida, Yoko; Endo, Ryo; Takashima, Noriko; Sasaki, Hideyuki; Komi, Yusuke; Gathercole, Amy; Huston, Elaine; Ishii, Kazuhiro; Hui, Kelvin Kai-Wan; Kurosawa, Masaru; Kim, Sun-Hong; Nukina, Nobuyuki; Takimoto, Eiki; Houslay, Miles D; Sawa, Akira

    2017-04-03

    Huntington's disease (HD) is a polyglutamine (polyQ) disease caused by aberrant expansion of the polyQ tract in Huntingtin (HTT). While motor impairment mediated by polyQ-expanded HTT has been intensively studied, molecular mechanisms for nonmotor symptoms in HD, such as psychiatric manifestations, remain elusive. Here we have demonstrated that HTT forms a ternary protein complex with the scaffolding protein DISC1 and cAMP-degrading phosphodiesterase 4 (PDE4) to regulate PDE4 activity. We observed pathological cross-seeding between DISC1 and mutant HTT aggregates in the brains of HD patients as well as in a murine model that recapitulates the polyQ pathology of HD (R6/2 mice). In R6/2 mice, consequent reductions in soluble DISC1 led to dysregulation of DISC1-PDE4 complexes, aberrantly increasing the activity of PDE4. Importantly, exogenous expression of a modified DISC1, which binds to PDE4 but not mutant HTT, normalized PDE4 activity and ameliorated anhedonia in the R6/2 mice. We propose that cross-seeding of mutant HTT and DISC1 and the resultant changes in PDE4 activity may underlie the pathology of a specific subset of mental manifestations of HD, which may provide an insight into molecular signaling in mental illness in general.

  11. Discovery of a Phosphodiesterase 9A Inhibitor as a Potential Hypoglycemic Agent

    PubMed Central

    2015-01-01

    Phosphodiesterase 9 (PDE9) inhibitors have been studied as potential therapeutics for treatment of diabetes and Alzheimer’s disease. Here we report a potent PDE9 inhibitor 3r that has an IC50 of 0.6 nM and >150-fold selectivity over other PDEs. The HepG2 cell-based assay shows that 3r inhibits the mRNA expression of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase. These activities of 3r, together with the reasonable pharmacokinetic properties and no acute toxicity at 1200 mg/kg dosage, suggest its potential as a hypoglycemic agent. The crystal structure of PDE9-3r reveals significantly different conformation and hydrogen bonding pattern of 3r from those of previously published 28s. Both 3r and 28s form a hydrogen bond with Tyr424, a unique PDE9 residue (except for PDE8), but 3r shows an additional hydrogen bond with Ala452. This structure information might be useful for design of PDE9 inhibitors. PMID:25432025

  12. Design and synthesis of fluorescent substrates for human tyrosyl-DNA phosphodiesterase I

    PubMed Central

    Rideout, Marc C.; Raymond, Amy C.; Burgin, Alex B.

    2004-01-01

    Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a DNA repair enzyme that acts upon protein–DNA covalent complexes. Tdp1 hydrolyzes 3′-phosphotyrosyl bonds to generate 3′-phosphate DNA and free tyrosine in vitro. Mutations in Tdp1 have been linked to patients with spinocerebellar ataxia, and over-expression of Tdp1 results in resistance to known anti-cancer compounds. Tdp1 has been shown to be involved in double-strand break repair in yeast, and Tdp1 has also been implicated in single-strand break repair in mammalian cells. Despite the biological importance of this enzyme and the possibility that Tdp1 may be a molecular target for new anti-cancer drugs, there are very few assays available for screening inhibitor libraries or for characterizing Tdp1 function, especially under pre-steady-state conditions. Here, we report the design and synthesis of a fluorescence-based assay using oligonucleotide and nucleotide substrates containing 3′-(4-methylumbelliferone)-phosphate. These substrates are efficiently cleaved by Tdp1, generating the fluorescent 4-methylumbelliferone reporter molecule. The kinetic characteristics determined for Tdp1 using this assay are in agreement with the previously published values, and this fluorescence-based assay is validated using the standard gel-based methods. This sensitive assay is ideal for kinetic analysis of Tdp1 function and for high-throughput screening of Tdp1 inhibitory molecules. PMID:15333697

  13. Efficacy and tolerability of tadalafil, a novel phosphodiesterase 5 inhibitor, in treatment of erectile dysfunction.

    PubMed

    Padma-Nathan, Harin

    2003-11-06

    Advances in molecular biology and protein chemistry, along with increasing understanding of the mechanisms of penile erection, have spurred development of pharmacologic approaches to the treatment of erectile dysfunction (ED). The next generation of oral agents includes tadalafil, a potent, highly selective phosphodiesterase 5 inhibitor. In vitro studies have shown that tadalafil enhances relaxation of trabecular smooth muscle, and clinical trials have supported its efficacy and tolerability in a broad population of men with ED. The effect of tadalafil in enhancing the erectile response to sexual stimulation is relatively rapid in onset and lasts for >or=24 hours. The ability of patients with ED treated with tadalafil to achieve improved erectile function is demonstrated by significantly increased subjective measures of penetration ability, successful intercourse, and sexual satisfaction. Partners have expressed similar or higher levels of satisfaction with the results of treatment. Men with ED of psychogenic, organic, or mixed etiology and in a range from mild to severe have experienced significant improvment with tadalafil treatment. Response to treatment in men with diabetes has been robust and not affected by disease severity. Tadalafil has been well tolerated. Adverse events have generally been mild or moderate and have abated with continued treatment. Headache and dyspepsia have been most frequently reported. Changes in color vision have been rare (<0.1%) with tadalafil across all clinical trials. Tadalafil appears to be a safe and effective treatment for men with ED.

  14. Dysregulated human Tyrosyl-DNA phosphodiesterase I acts as cellular toxin

    PubMed Central

    Cuya, Selma M.; Comeaux, Evan Q.; Wanzeck, Keith; Yoon, Karina J.; van Waardenburg, Robert C.A.M.

    2016-01-01

    Tyrosyl-DNA phosphodiesterase I (TDP1) hydrolyzes the drug-stabilized 3’phospho-tyrosyl bond formed between DNA topoisomerase I (TOPO1) and DNA. TDP1-mediated hydrolysis uses a nucleophilic histidine (Hisnuc) and a general acid/base histidine (Hisgab). A Tdp1Hisgab to Arg mutant identified in patients with the autosomal recessive neurodegenerative disease SCAN1 causes stabilization of the TDP1-DNA intermediate. Based on our previously reported Hisgab-substitutions inducing yeast toxicity (Gajewski et al. J. Mol. Biol. 415, 741-758, 2012), we propose that converting TDP1 into a cellular poison by stabilizing the covalent enzyme-DNA intermediate is a novel therapeutic strategy for cancer treatment. Here, we analyzed the toxic effects of two TDP1 catalytic mutants in HEK293 cells. Expression of human Tdp1HisnucAla and Tdp1HisgabAsn mutants results in stabilization of the covalent TDP1-DNA intermediate and induces cytotoxicity. Moreover, these mutants display reduced in vitro catalytic activity compared to wild type. Co-treatment of Tdp1mutant with topotecan shows more than additive cytotoxicity. Overall, these results support the hypothesis that stabilization of the TDP1-DNA covalent intermediate is a potential anti-cancer therapeutic strategy. PMID:27893431

  15. Estimating the rate constant of cyclic GMP hydrolysis by activated phosphodiesterase in photoreceptors

    NASA Astrophysics Data System (ADS)

    Reingruber, Jürgen; Holcman, David

    2008-10-01

    The early steps of light response occur in the outer segment of rod and cone photoreceptor. They involve the hydrolysis of cGMP, a soluble cyclic nucleotide, that gates ionic channels located in the outer segment membrane. We shall study here the rate by which cGMP is hydrolyzed by activated phosphodiesterase (PDE). This process has been characterized experimentally by two different rate constants βd and βsub: βd accounts for the effect of all spontaneously active PDE in the outer segment, and βsub characterizes cGMP hydrolysis induced by a single light-activated PDE. So far, no attempt has been made to derive the experimental values of βd and βsub from a theoretical model, which is the goal of this work. Using a model of diffusion in the confined rod geometry, we derive analytical expressions for βd and βsub by calculating the flux of cGMP molecules to an activated PDE site. We obtain the dependency of these rate constants as a function of the outer segment geometry, the PDE activation and deactivation rates and the aqueous cGMP diffusion constant. Our formulas show good agreement with experimental measurements. Finally, we use our derivation to model the time course of the cGMP concentration in a transversally well-stirred outer segment.

  16. Structural snapshots of the catalytic cycle of the phosphodiesterase Autotaxin.

    PubMed

    Hausmann, Jens; Keune, Willem-Jan; Hipgrave Ederveen, Agnes L; van Zeijl, Leonie; Joosten, Robbie P; Perrakis, Anastassis

    2016-08-01

    Autotaxin (ATX) is a secreted phosphodiesterase that produces the signalling lipid lysophosphatidic acid (LPA). The bimetallic active site of ATX is structurally related to the alkaline phosphatase superfamily. Here, we present a new crystal structure of ATX in complex with orthovanadate (ATX-VO5), which binds the Oγ nucleophile of Thr209 and adopts a trigonal bipyramidal conformation, following the nucleophile attack onto the substrate. We have now a portfolio of ATX structures we discuss as intermediates of the catalytic mechanism: the new ATX-VO5 structure; a unique structure where the nucleophile Thr209 is phosphorylated (ATX-pThr). Comparing these to a complex with the LPA product (ATX-LPA) and with a complex with a phosphate ion (ATX-PO4), that represent the Michaelis complex of the reaction, we observe movements of Thr209, changes in the relative displacement of the zinc ions, and a water molecule that likely fulfils the second nucleophilic attack. We propose that ATX follows the associative two-step in-line displacement mechanism.

  17. Effects of alkyl substituents of xanthine on phosphodiesterase isoenzymes.

    PubMed

    Miyamoto, K; Sakai, R; Kurita, M; Ohmae, S; Sanae, F; Sawanishi, H; Hasegawa, T; Takagi, K

    1995-03-01

    The structure-activity relationships of a series of alkylxanthine derivatives were investigated. The partition coefficient of alkylxanthines enlarged with an elongation of the alkyl chain at the 1-, 3-, or 7-position of xanthine. There was a mild correlation between the apparent partition coefficient and the tracheal relaxant activity or the inhibitory activity on phosphodiesterase (PDE) IV isoenzyme, while the tracheal relaxant activity closely correlated with the PDE IV inhibitory activity. Regarding substituents at different positions, the alkylation at the 3-position increased the inhibitory activity on every PDE isoenzyme. The alkylation at the 1-position potentiated the inhibitory activity on PDE IV with the alkyl chain length, but decreased the activities on other PDE isoenzymes. The alkylation at the 7-position was characteristic in its decrease in inhibitory activity on PDE III. These results suggested that the potency of the inhibitory activity of xanthine derivatives on PDE isoenzymes is not dependent simply upon their hydrophobicity but upon change in the affinity for the active sites on PDE isoenzymes by the introduction of the alkyl group at particular positions of the xanthine skeleton.

  18. Practical enantioselective process for a chiral phosphodiesterase-4 inhibitor.

    PubMed

    Chen, Cheng-Yi

    2005-11-01

    L-869298 is a potent and selective phosphodiesterase-4 (PDE4) inhibitor, which is potentially useful in the treatment of asthma and chronic obstructive pulmonary disorder. A catalytic asymmetric synthesis that is suitable for the preparation of kilogram quantities of L-869298, and which does not require the use of chromatography, has been developed to support the on-going drug development program of L-869298 at Merck Research Laboratories. The catalytic asymmetric hydrogenation of an aromatic heteroaromatic ketone afforded the corresponding alcohol in almost perfect enantioselectivity. Activation of the alcohol via formation of the 4-toluenesulfonate, followed by an unprecedented displacement of the tosylate via the lithium enolate of ethyl-3-pyridyl acetate N-oxide, generated the chiral tetra-substituted ethane. The displacement reaction proceeded with inversion of configuration and without loss of optical purity. Deprotection of the displacement adduct followed by decarboxylation, afforded L-869298 in excellent overall yield. The methodology developed could be readily extended to the synthesis of several other chiral PDE4 inhibitors.

  19. Overview of phosphodiesterase 5 inhibition in erectile dysfunction.

    PubMed

    Rosen, Raymond C; Kostis, John B

    2003-11-06

    Since the early 1980s, research on the mechanisms of penile erection has done much to clarify erectile physiology and pathophysiology. More recent studies have identified the importance of neurochemical mediators in erection. These include the nitric oxide-cyclic guanosine monophosphate (cGMP) cell-signaling system-a complex molecular pathway that mediates smooth muscle relaxation in the corpus cavernosum. Phosphodiesterase 5 (PDE5) inactivates cGMP, which terminates nitric oxide-cGMP-mediated smooth muscle relaxation. Inhibition of PDE5 is expected to enhance penile erection by preventing cGMP degradation. Development of pharmacologic agents with this effect has closely paralleled the emerging science. The prototype of this new therapeutic class of PDE5 inhibitors is sildenafil, which was approved for treatment of erectile dysfunction in 1998. Tadalafil and vardenafil are new agents in this class. These agents have demonstrated improvement in erectile function and have been shown to be well tolerated in diverse populations comprising thousands of men worldwide. Profiles of these 3 PDE5 inhibitors are reviewed herein.

  20. Phosphodiesterase 4B negatively regulates endotoxin-activated interleukin-1 receptor antagonist responses in macrophages

    PubMed Central

    Yang, Jing-Xing; Hsieh, Kou-Chou; Chen, Yi-Ling; Lee, Chien-Kuo; Conti, Marco; Chuang, Tsung-Hsien; Wu, Chin-Pyng; Jin, S.-L. Catherine

    2017-01-01

    Activation of TLR4 by lipopolysaccharide (LPS) induces both pro-inflammatory and anti-inflammatory cytokine production in macrophages. Type 4 phosphodiesterases (PDE4) are key cAMP-hydrolyzing enzymes, and PDE4 inhibitors are considered as immunosuppressors to various inflammatory responses. We demonstrate here that PDE4 inhibitors enhance the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1Ra) secretion in LPS-activated mouse peritoneal macrophages, and this response was regulated at the transcriptional level rather than an increased IL-1Ra mRNA stability. Studies with PDE4-deficient macrophages revealed that the IL-1Ra upregulation elicited by LPS alone is PKA-independent, whereas the rolipram-enhanced response was mediated by inhibition of only PDE4B, one of the three PDE4 isoforms expressed in macrophages, and it requires PKA but not Epac activity. However, both pathways activate CREB to induce IL-1Ra expression. PDE4B ablation also promoted STAT3 phosphorylation (Tyr705) to LPS stimulation, but this STAT3 activation is not entirely responsible for the IL-1Ra upregulation in PDE4B-deficient macrophages. In a model of LPS-induced sepsis, only PDE4B-deficient mice displayed an increased circulating IL-1Ra, suggesting a protective role of PDE4B inactivation in vivo. These findings demonstrate that PDE4B negatively modulates anti-inflammatory cytokine expression in innate immune cells, and selectively targeting PDE4B should retain the therapeutic benefits of nonselective PDE4 inhibitors. PMID:28383060

  1. Phosphodiesterase-5 is a therapeutic target for peripheral neuropathy in diabetic mice.

    PubMed

    Wang, L; Chopp, M; Szalad, A; Liu, Z; Bolz, M; Alvarez, F M; Lu, M; Zhang, L; Cui, Y; Zhang, R L; Zhang, Z G

    2011-10-13

    Peripheral neuropathy is a common and major complication of diabetes, the underlying mechanisms of which are not fully understood. Using a mouse model of type II diabetes, the present study investigated the role of phosphodiesterase-5 (PDE5) in peripheral neuropathy. BKS.Cg-m+/+Leprdb/J (db/db) mice were treated with sildenafil, a specific inhibitor of PDE5, at doses of 2 and 10 mg/kg or saline. Levels of PDE5 and morphometric parameters in sciatic nerve tissue as well as the motor and sensory function were measured in these mice. In diabetic mice, PDE5 expression in sciatic nerve tissue was significantly upregulated, whereas the myelin sheath thickness, myelin basic protein (MBP), and subcutaneous nerve fibers were significantly reduced. Treatment with sildenafil significantly improved neurological function, assayed by motor and sensory conducting velocities and thermal and mechanical noxious stimuli, concomitantly with increases in myelin sheath thickness, MBP levels, and subcutaneous nerve fibers. In vitro, hyperglycemia upregulated PDE5 in Schwann cells and reduced Schwann cell proliferation, migration, and expression of brain-derived neurotrophic factor (BDNF). Blockage of PDE5 with sildenafil increased cyclic guanosine monophosphate (cGMP) and completely abolished the effect of hyperglycemia on Schwann cells. Sildenafil upregulated cGMP-dependent protein kinase G I (PKGI), whereas inhibition of PKGI with a PKG inhibitor, KT5823, suppressed the inhibitory effect of sildenafil on Schwann cells. These data indicate that hyperglycemia substantially upregulates PDE5 expression and that the cGMP/PKG signaling pathway activated by sildenafil mediates the beneficial effects of sildenafil on diabetic peripheral neuropathy.

  2. Summary of the American Camping Association Camp Ecological Training Project, 1972.

    ERIC Educational Resources Information Center

    Fluchel, Robert W.; Gregory, Charles A.

    Briefly summarized is the American Camping Association's Camp Ecological Training Project, its goals, accomplishments, problems, and future potential as seen by the first two Itinerant Ecologists who participated in the project. Creation of an ecological awareness and conservation consciousness were the major goals of the project. To accomplish…

  3. A Summer Like No Other: Israeli Teens Experience American Camping at Tamarack Camps.

    ERIC Educational Resources Information Center

    Bice, Wendy Rose

    2003-01-01

    A Jewish camp in Michigan hosted more than 300 Israeli teens during its 2002 camping season. American and Israeli campers lived in the same cabins so they could learn about each other's culture and develop friendships. To make the visitors welcome, informational brochures sent to Israeli families were translated into Hebrew, and area families…

  4. Allegheny National Forest, CCC Camp ANF1 , The camp’s main ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Allegheny National Forest, CCC Camp ANF-1 , The camp’s main entrance is located at the intersection of Duhring Road (ANF 131) and ANF 124, Pennsylvania, with the interior site road known as Trail Ride Drive., Marienville, Forest County, PA

  5. Catch the Dream of Camping: Albuquerque Keynoters Share Insight into the Future of Camping.

    ERIC Educational Resources Information Center

    Coleman, Marla

    2000-01-01

    Highlights the views of three keynote speakers who will share their insights into the future of the camp experience at the next American Camping Association National Conference. Environmentalist Bill McKibben, educator Cynthia Tobias, and futurist Ira Blumenthal focus, respectively, on connecting children to the natural world, understanding…

  6. Camping in the Disciplines: Assessing the Effect of Writing Camps on Graduate Student Writers

    ERIC Educational Resources Information Center

    Busl, Gretchen; Donnelly, Kara Lee; Capdevielle, Matthew

    2015-01-01

    In the past ten years, an increasing number of universities have begun organizing writing "camps," or full-week immersion experiences, in an effort to address the increased need to support graduate student writing. Outside of anecdotes and testimonials, we have previously had very little data about these camps' success. This study,…

  7. Business and Finance: A Resource Book for Camps. Camp Administration Series.

    ERIC Educational Resources Information Center

    Ball, Armand, Ed.; Ball, Beverly, Ed.

    this resource book contains 35 articles designed to present general information concerning camp business and financial management to directors or administrators. Typically a specialist is employed to supervise camp business and finance, but the administrator needs to have a broad understanding of five specific business topics: (1) liability and…

  8. Camp Teaches Life Lessons: A Director's Commentary on Camp's Lasting Educational Value.

    ERIC Educational Resources Information Center

    Gucker, Peter L.

    2001-01-01

    At camp, children learn values and skills that are seldom included in school curricula. The community-based environment of camps is conducive to learning self-assurance, community respect, and healthy competition, and to understanding diversity. Exposure to Nature promotes an infectious enthusiasm for the wilderness and for learning outdoor…

  9. Different Roles of GNAS and cAMP Signaling During Early and Late Stages of Osteogenic Differentiation

    PubMed Central

    Zhang, S.; Kaplan, F. S.; Shore, E. M.

    2013-01-01

    Progressive osseous heteroplasia (POH) and fibrous dysplasia (FD) are genetic diseases of bone formation at opposite ends of the osteogenic spectrum: imperfect osteogenesis of the skeleton occurs in FD, while heterotopic ossification in skin, subcutaneous fat, and skeletal muscle forms in POH. POH is caused by heterozygous inactivating germline mutations in GNAS, which encodes G-protein subunits regulating the cAMP pathway, while FD is caused by GNAS somatic activating mutations. We used pluripotent mouse ES cells to examine the effects of Gnas dysregulation on osteoblast differentiation. At the earliest stages of osteogenesis, Gnas transcripts Gs α, XLαs and 1A are expressed at low levels and cAMP levels are also low. Inhibition of cAMP signaling (as in POH) by 2′,5′-dideoxyadenosine enhanced osteoblast differentiation while conversely, increased cAMP signaling (as in FD), induced by forskolin, inhibited osteoblast differentiation. Notably, increased cAMP was inhibitory for osteogenesis only at early stages after osteogenic induction. Expression of osteogenic and adipogenic markers showed that increased cAMP enhanced adipogenesis and impaired osteoblast differentiation even in the presence of osteogenic factors, supporting cAMP as a critical regulator of osteoblast and adipocyte lineage commitment. Furthermore, increased cAMP signaling decreased BMP pathway signaling, indicating that G protein-cAMP pathway activation (as in FD) inhibits osteoblast differentiation, at least in part by blocking the BMP-Smad pathway, and suggesting that GNAS inactivation as occurs in POH enhances osteoblast differentiation, at least in part by stimulating BMP signaling. These data support that differences in cAMP levels during early stages of cell differentiation regulate cell fate decisions. PMID:22903279

  10. cAMP Promotes Cell Migration Through Cell Junctional Complex Dynamics and Actin Cytoskeleton Remodeling: Implications in Skin Wound Healing.

    PubMed

    Kim, Mi Ok; Ryu, Jung Min; Suh, Han Na; Park, Soo Hyun; Oh, Yeon-Mok; Lee, Sang Hun; Han, Ho Jae

    2015-11-01

    Stem cells have attracted great interest for their therapeutic capacity in tissue regeneration. Cyclic adenosine 3',5'-monophosphate (cAMP), existing in high concentration at wound sites, mediated various signaling pathways such as cytoskeleton dynamics, cell adhesion, and cell migration in stem cells, which suggest the critical roles of cAMP in the wound healing process through functional regulation of stem cells. However, the mechanisms behind the effect of cAMP on mouse embryonic stem cell (mESC) motility and its roles on skin wound healing remain to be fully elucidated. In the present study, 8-Bromo cAMP-treated mESCs showed significant wound closure and improved neovascularization. Moreover, 8-Bromo cAMP stimulated mESC migration into the wound bed. 8-Bromo cAMP also increased ESC motility in in vitro migration assay. 8-Bromo cAMP induced myosin light chain phosphorylation through Rac1 and Cdc42 signaling, which were involved in 8-Bromo cAMP-induced decrease in expression of junction proteins (connexin 43, E-cadherin, and occludin) at the plasma membrane. Subsequently, 8-Bromo cAMP induced the disruption of cell junctions (including gap junctions, adherens junctions, and tight junctions), which reduced the function of the gap junctions and cell adhesion. In addition, 8-Bromo cAMP-induced Rac1 and Cdc42 activation increased Arp3, TOCA, PAK, and N-WASP expression, but decreased cofilin phosphorylation level, which elicited actin cytoskeleton remodeling. In contrast to the control, 8-Bromo cAMP evoked a substantial migration of cells into the denuded area, which was blocked by the small interfering RNAs of the signaling pathway-related molecules or by inhibitors. In conclusion, cAMP enhanced the migration of mESCs through effective coordination of junctional disruption and actin cytoskeleton remodeling, which increased the wound healing capacity of ESCs.

  11. Selective tracheal relaxation and phosphodiesterase-IV inhibition by xanthine derivatives.

    PubMed

    Miyamoto, K; Kurita, M; Ohmae, S; Sakai, R; Sanae, F; Takagi, K

    1994-05-17

    The effects of substitutions in the xanthine nucleus on tracheal relaxant activity, atrium chronotropic activity, adenosine A1 affinity, and inhibitory activities on cyclic AMP-phosphodiesterase isoenzymes in guinea pigs were studied. Substitution with a long alkyl chain at the N1-position of xanthine nucleus increased the tracheal relaxant activity without leading to positive chronotropic action, and long alkyl chains at the N3-position increased both activities. N7-substitutions with n-propyl and 2'-oxopropyl groups, such as in denbufylline, increased bronchoselectivity. N7-substitution decreased the adenosine A1 affinity, but substitution at either the N1- or N3-position increased it. The bronchorelaxant activity of xanthine derivatives was closely correlated with their inhibition of phosphodiesterase-IV, but not with their adenosine A1 affinity; the positive chronotropic effects were related to their inhibition of phosphodiesterase-III. This study confirms that the bronchorelaxation of xanthine derivatives is mediated by inhibition of the isoenzyme phosphodiesterase-IV. The results of structure-activity analysis suggest that substitutions at the N1- and N7-positions should be tried in the development of xanthine derivatives that are selective bronchodilators and phosphodiesterase-IV inhibitors.

  12. Anxiogenic-Like Behavioral Phenotype of Mice Deficient in Phosphodiesterase 4B (PDE4B)

    PubMed Central

    Zhang, Han-Ting; Huang, Ying; Masood, Anbrin; Stolinski, Lisa R; Li, Yunfeng; Zhang, Lei; Dlaboga, Daniel; Jin, S-L Catherine; Conti, Marco; O’Donnell, James M

    2009-01-01

    Phosphodiesterase-4 (PDE4), an enzyme that catalyzes the hydrolysis of cyclic AMP and plays a critical role in controlling its intracellular concentration, has been implicated in depression- and anxiety-like behaviors. However, the functions of the four PDE4 subfamilies (PDE4A, PDE4B, PDE4C, and PDE4D) remain largely unknown. In animal tests sensitive to anxiolytics, antidepressants, memory enhancers, or analgesics, we examined the behavioral phenotype of mice deficient in PDE4B (PDE4B−/−). Immunoblot analysis revealed loss of PDE4B expression in the cerebral cortex and amygdala of PDE4B−/− mice. The reduction of PDE4B expression was accompanied by decreases in PDE4 activity in the brain regions of PDE4B−/− mice. Compared to PDE4B + / + littermates, PDE4B−/− mice displayed anxiogenic-like behavior, as evidenced by decreased head-dips and time spent in head-dipping in the holeboard test, reduced transitions and time on the light side in the light–dark transition test, and decreased initial exploration and rears in the open-field test. Consistent with anxiogenic-like behavior, PDE4B−/− mice displayed increased levels of plasma corticosterone. In addition, these mice also showed a modest increase in the proliferation of neuronal cells in the hippocampal dentate gyrus. In the forced-swim test, PDE4B−/− mice exhibited decreased immobility; however, this was not supported by the results from the tail-suspension test. PDE4B−/− mice did not display changes in memory, locomotor activity, or nociceptive responses. Taken together, these results suggest that the PDE4B subfamily is involved in signaling pathways that contribute to anxiogenic-like effects on behavior PMID:17700644

  13. Let's go to camp! An innovative pediatric practice placement.

    PubMed

    Schick Makaroff, Kara; Scobie, Robin; Williams, Cheryl; Kidd, Janeen

    2013-01-01

    Each year, children living with disabilities escape from their families for 1 week at camp armed with their sun block, sleeping bags and talent-show costumes. In British Columbia, Canada, Easter Seals Camps offer such adventures to over 800 children/teens with physical/mental disabilities, providing free, overnight camping with on-site nurses. Easter Seals Camps offer pediatric placements to nursing students to work with nurses in a multidisciplinary team. In this paper, we describe this partnership, explain the role of camp nurse, portray student learning opportunities and offer recommendations to pediatric nurses who may consider participating in similar innovative placements in pediatric camps.

  14. The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History.

    PubMed

    Elhwuegi, A S

    2016-01-01

    The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review.

  15. Phosphodiesterase type 5 inhibitor abuse: a critical review.

    PubMed

    Lowe, Gregory; Costabile, Raymond

    2011-06-01

    Abuse of sildenafil has been reported since its introduction in 1999 and commonly documented in combination with illicit drugs among men and women of all ages. Increased risks of sexually transmissible diseases including HIV have been associated with sildenafil use in men who have sex with men. Recognizing the abuse potential of phosphodiesterase type 5 inhibitors (PDE5), we aim to summarize the current knowledge of this abuse. An investigation of EMBASE, PubMed, the Food and Drug Administration (FDA) website, MedWatch, and search engines was performed to evaluate information regarding sildenafil, tadalafil, and vardenafil abuse. The EMBASE search provided 46 articles fitting the search criteria and evaluation led to 21 separate publications with specific information regarding PDE5 abuse. A PubMed search found 10 additional publications. MedWatch reported 44 separate warnings since 2000, most of which reported contamination of herbal products with active drug components. Few reports of abuse were among the 14,818 reports in the FDA AERS for sildenafil. A search for "internet drug store" revealed 6.4 million hits and of 7000 internet pharmacies identified by the Verified Internet Pharmacy Practice Sites Program (VIPPS) only 4% were in proper compliance. The role internet pharmacies play in counterfeit PDE5 or abuse is not well documented; however based on easy access, direct patient marketing, and low advertised cost it is likely this role is underreported. Currently the best recommendation for providers is to recognize the possibility of abuse and to educate patients on risks of this behavior.

  16. Phosphodiesterase 4D gene polymorphisms in sudden sensorineural hearing loss.

    PubMed

    Chien, Chen-Yu; Tai, Shu-Yu; Wang, Ling-Feng; Hsi, Edward; Chang, Ning-Chia; Wang, Hsun-Mo; Wu, Ming-Tsang; Ho, Kuen-Yao

    2016-09-01

    The phosphodiesterase 4D (PDE4D) gene has been reported as a risk gene for ischemic stroke. The vascular factors are between the hypothesized etiologies of sudden sensorineural hearing loss (SSNHL), and this genetic effect might be attributed for its role in SSNHL. We hypothesized that genetic variants of the PDE4D gene are associated with susceptibility to SSNHL. We conducted a case-control study with 362 SSNHL cases and 209 controls. Three single nucleotide polymorphisms (SNPs) were selected. The genotypes were determined using TaqMan technology. Hardy-Weinberg equilibrium (HWE) was tested for each SNP, and genetic effects were evaluated according to three inheritance modes. We carried out sex-specific analysis to analyze the overall data. All three SNPs were in HWE. When subjects were stratified by sex, the genetic effect was only evident in females but not in males. The TT genotype of rs702553 exhibited an adjusted odds ratio (OR) of 3.83 (95 % confidence interval = 1.46-11.18) (p = 0.006) in female SSNHL. The TT genotype of SNP rs702553 was associated with female SSNHL under the recessive model (p = 0.004, OR 3.70). In multivariate logistic regression analysis, TT genotype of rs702553 was significantly associated with female SSNHL (p = 0.0043, OR 3.70). These results suggest that PDE4D gene polymorphisms influence the susceptibility for the development of SSNHL in the southern Taiwanese female population.

  17. The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History

    PubMed Central

    Elhwuegi, AS

    2016-01-01

    The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review. PMID:27398244

  18. Action of methyl-, propyl- and butylparaben on GPR30 gene and protein expression, cAMP levels and activation of ERK1/2 and PI3K/Akt signaling pathways in MCF-7 breast cancer cells and MCF-10A non-transformed breast epithelial cells.

    PubMed

    Wróbel, Anna Maria; Gregoraszczuk, Ewa Łucja

    2015-10-14

    In the present study, we examined cAMP levels and activation of the MAPK/ERK1/2 and PI3K/Akt signaling pathways in response to the actions of parabens on GPR30 in MCF-7 and MCF-10A cells. Cells were exposed to methyl-, propyl- or butylparaben at a concentration of 20nM; 17-β-estradiol (10nM) was used as a positive control. 17β-estradiol and all tested parabens increased GPR30 gene and protein expression in MCF-7 and MCF-10A cells. No parabens affected cAMP levels in either cell line, with the exception of propylparaben in MCF-10A cells. 17β-estradiol, propylparaben, and butylparaben increased phosphorylation of ERK1/2 in MCF-7 cells, whereas 17β-estradiol, methyl- and butylparaben, but not propylparaben, increased phosphorylation of ERK1/2 in MCF-10A cells. Akt activation was noted only in MCF-7 cells and only with propylparaben treatment. Collectively, the data presented here point to a nongenomic mechanism of action of parabens in activation GPR30 in both cancer and non-cancer breast cell lines through βγ dimer-mediated activation of the ERK1/2 pathway, but not the cAMP/PKA pathway. Moreover, among investigated parabens, propylparaben appears to inhibit apoptosis in cancer cells through activation of Akt kinases, confirming conclusions suggested by our previously published data. Nevertheless, continuing research on the carcinogenic action of parabens is warranted.

  19. Sildenafil and Phosphodiesterase-5 Inhibitors to Reduce Cardiotoxicity and Enhance the Response of Breast Tumor Cells to Doxorubicin

    DTIC Science & Technology

    2009-03-01

    AD_________________ AWARD NUMBER: W81XWH-06-1-0360 TITLE: Sildenafil and Phosphodiesterase-5...2009 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Sildenafil and Phosphodiesterase-5 Inhibitors to Teduce Cardiotoxicity and Enhance the Response...for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT In the current work, we report that sildenafil does not

  20. Hydroxycarbamide decreases sickle reticulocyte adhesion to resting endothelium by inhibiting endothelial lutheran/basal cell adhesion molecule (Lu/BCAM) through phosphodiesterase 4A activation.

    PubMed

    Chaar, Vicky; Laurance, Sandrine; Lapoumeroulie, Claudine; Cochet, Sylvie; De Grandis, Maria; Colin, Yves; Elion, Jacques; Le Van Kim, Caroline; El Nemer, Wassim

    2014-04-18

    Vaso-occlusive crises are the main acute complication in sickle cell disease. They are initiated by abnormal adhesion of circulating blood cells to vascular endothelium of the microcirculation. Several interactions involving an intricate network of adhesion molecules have been described between sickle red blood cells and the endothelial vascular wall. We have shown previously that young sickle reticulocytes adhere to resting endothelial cells through the interaction of α4β1 integrin with endothelial Lutheran/basal cell adhesion molecule (Lu/BCAM). In the present work, we investigated the functional impact of endothelial exposure to hydroxycarbamide (HC) on this interaction using transformed human bone marrow endothelial cells and primary human pulmonary microvascular endothelial cells. Adhesion of sickle reticulocytes to HC-treated endothelial cells was decreased despite the HC-derived increase of Lu/BCAM expression. This was associated with decreased phosphorylation of Lu/BCAM and up-regulation of the cAMP-specific phosphodiesterase 4A expression. Our study reveals a novel mechanism for HC in endothelial cells where it could modulate the function of membrane proteins through the regulation of phosphodiesterase expression and cAMP-dependent signaling pathways.

  1. Cyclic nucleotide phosphodiesterase activity in 10-nm filaments and microtubule preparations from bovine brain

    PubMed Central

    Runge, Marschall S.; Hewgley, Paula B.; Puett, David; Williams, Robley C.

    1979-01-01

    Cyclic nucleotide phosphodiesterase activity (3′:5′-cyclic-AMP 5′-nucleotidohydrolase, EC 3.1.4.17), which is activatable by Ca2+-dependent regulator protein (CDR), has been identified in cycled microtubule preparations from bovine brain. By using various methods to fractionate the microtubule preparation into subfractions (e.g., phosphocellulose chromatography to obtain purified 6S tubulin and soluble microtubule-associated proteins, and gel exclusion chromatography on Bio-Gel A-150m to obtain 10-nm filaments), we found that all the fractions exhibited some enzymic activity, but that most of the phosphodiesterase activity was localized in the 10-nm filament fraction. By using cyclic GMP as substrate, a specific activity of 921 ± 168 pmol/mg of filament protein·min was determined. Also, 10-nm filaments were prepared directly from brain homogenates by differential centrifugation and gel exclusion chromatography. This fraction also contained phosphodiesterase activity but of slightly lower specific activity (752 ± 9 pmol/mg of protein·min). The filament-associated enzymic activity was stable during storage (-70°C) and to several salt extractions at moderate ionic strength (0.5 M); the latter finding indicates that the phosphodiesterase is not adsorbed to the filaments via nonspecific electrostatic interactions. Although a chelating agent was present in the initial homogenization buffer and generally in all buffers used in preparing fractions, an activator of a smooth muscle phosphodiesterase was released upon boiling the 10-nm filaments. This activator obtained in the boiled supernatant was Ca2+-sensitive, trifluoperazine-sensitive, and stimulated smooth muscle phosphodiesterase to nearly the same extent as purified (exogenous) CDR; thus, it probably represents filament-associated CDR. Images PMID:223149

  2. Ab Initio QM/MM Study Shows a Highly Dissociated SN2 Hydrolysis Mechanism for the cGMP-Specific Phosphodiesterase-5.

    PubMed

    Li, Zhe; Wu, Yinuo; Feng, Ling-Jun; Wu, Ruibo; Luo, Hai-Bin

    2014-12-09

    Phosphodiesterases (PDEs) are the sole enzymes hydrolyzing the important second messengers cGMP and cAMP and have been identified as therapeutic targets for several diseases. The most successful examples are PDE5 inhibitors (i.e., sildenafil and tadalafil), which have been approved for the treatment of male erectile dysfunction and pulmonary hypertension. However, the side effects mostly due to nonselective inhibition toward other PDE isoforms, set back the clinical usage of PDE5 inhibitors. Until now, the exact catalytic mechanism of the substrate cGMP by PDE5 is still unclear. Herein, the first computational study on the catalytic hydrolysis mechanism of cGMP for PDE5 (catalytic domain) is performed by employing the state-of-the-art ab initio quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulations. Our simulations show a SN2 type reaction procedure via a highly dissociated transition state with a reaction barrier of 8.88 kcal/mol, which is quite different from the previously suggested hydrolysis mechanism of cAMP for PDE4. Furthermore, the subsequent ligand exchange and the release of the product GMP have also been investigated by binding energy analysis and MD simulations. It is deduced that ligand exchange would be the rate-determining step of the whole reaction, which is consistent with many previous experimental results. The obtained mechanistic insights should be valuable for not only the rational design of more specific inhibitors toward PDE5 but also understanding the general hydrolysis mechanism of cGMP-specific PDEs.

  3. Phospholipid turnover and ultrastructural correlates during spontaneous germinal vesicle breakdown of the bovine oocyte: Effects of a cyclic AMP phosphodiesterase inhibitor

    SciTech Connect

    Homa, S.T.; Webster, S.D.; Russell, R.K. )

    1991-08-01

    The turnover of (32P)orthophosphate in bovine oocyte phospholipids was studied during the early stages of spontaneous meiotic maturation, and during inhibition of this process by the cAMP phosphodiesterase inhibitor 3-isobutyl-1-methyl-xanthine (IBMX). Radioactive lipids were separated by TLC and the meiotic stage was determined cytogenetically. Ultrastructure of the nuclear membrane was examined using transmission EM. During the commitment period to meiotic resumption, which precedes germinal vesicle breakdown (GVBD), small localized convolutions appeared in the intact nuclear membrane. This was accompanied by a decrease in (32P)phosphatidic acid (PA) and an increase in (32P)-phosphatidylcholine (PC). This was followed by extensive convolutions, and subsequent dissociation, of the nuclear membrane, concomitant with a tremendous surge in (32P)PC and (32P)phosphatidylethanolamine (PE). The cAMP-mediated maintenance of meiotic arrest involved retention of entire nuclear envelope integrity and total inhibition of the surge in (32P)PC and (32P)PE which accompanied GVBD. The increase in (32P)phosphatidylinositol (PI) associated with all stages of early meiotic resumption was unaffected by IBMX. Microinjection of heparin inhibited GVBD, and injection of inositol 1,4,5-trisphosphate (IP3) overrode IBMX-maintained meiotic arrest in almost 40% of the oocytes. The results suggest that there may be several functions for phospholipid turnover in the regulation of spontaneous meiotic resumption in the bovine oocyte. The first precedes the commitment period, and involves IP3 generation to serve as the primary signal for meiotic resumption. The second occurs concomitant with the commitment period, is unaffected by the level of intracellular cAMP, and is associated with the general turnover of phospholipid.

  4. Proof-of-Concept Randomized Controlled Study of Cognition Effects of the Proprietary Extract Sceletium tortuosum (Zembrin) Targeting Phosphodiesterase-4 in Cognitively Healthy Subjects: Implications for Alzheimer's Dementia

    PubMed Central

    Chiu, Simon; Farina-Woodbury, Michel; Terpstra, Kristen; Antongiorgi, Joalex; Bureau, Yves; Cernovsky, Zack; Hou, Jirui; Sanchez, Veronica; Williams, Marissa; Copen, John; Husni, Mariwan; Goble, Liz

    2014-01-01

    Introduction. Converging evidence suggests that PDE-4 (phosphodiesterase subtype 4) plays a crucial role in regulating cognition via the PDE-4-cAMP cascade signaling involving phosphorylated cAMP response element binding protein (CREB). Objective. The primary endpoint was to examine the neurocognitive effects of extract Sceletium tortuosum (Zembrin) and to assess the safety and tolerability of Zembrin in cognitively healthy control subjects. Method. We chose the randomized double-blind placebo-controlled cross-over design in our study. We randomized normal healthy subjects (total n = 21) to receive either 25 mg capsule Zembrin or placebo capsule once daily for 3 weeks, in a randomized placebo-controlled 3-week cross-over design. We administered battery of neuropsychological tests: CNS Vital Signs and Hamilton depression rating scale (HAM-D) at baseline and regular intervals and monitored side effects with treatment emergent adverse events scale. Results. 21 subjects (mean age: 54.6 years ± 6.0 yrs; male/female ratio: 9/12) entered the study. Zembrin at 25 mg daily dosage significantly improved cognitive set flexibility (P < 0.032) and executive function (P < 0.022), compared with the placebo group. Positive changes in mood and sleep were found. Zembrin was well tolerated. Conclusion. The promising cognitive enhancing effects of Zembrin likely implicate the PDE-4-cAMP-CREB cascade, a novel drug target in the potential treatment of early Alzheimer's dementia. This trial is registered with ClinicalTrials.gov NCT01805518. PMID:25389443

  5. Proof-of-Concept Randomized Controlled Study of Cognition Effects of the Proprietary Extract Sceletium tortuosum (Zembrin) Targeting Phosphodiesterase-4 in Cognitively Healthy Subjects: Implications for Alzheimer's Dementia.

    PubMed

    Chiu, Simon; Gericke, Nigel; Farina-Woodbury, Michel; Badmaev, Vladimir; Raheb, Hana; Terpstra, Kristen; Antongiorgi, Joalex; Bureau, Yves; Cernovsky, Zack; Hou, Jirui; Sanchez, Veronica; Williams, Marissa; Copen, John; Husni, Mariwan; Goble, Liz

    2014-01-01

    Introduction. Converging evidence suggests that PDE-4 (phosphodiesterase subtype 4) plays a crucial role in regulating cognition via the PDE-4-cAMP cascade signaling involving phosphorylated cAMP response element binding protein (CREB). Objective. The primary endpoint was to examine the neurocognitive effects of extract Sceletium tortuosum (Zembrin) and to assess the safety and tolerability of Zembrin in cognitively healthy control subjects. Method. We chose the randomized double-blind placebo-controlled cross-over design in our study. We randomized normal healthy subjects (total n = 21) to receive either 25 mg capsule Zembrin or placebo capsule once daily for 3 weeks, in a randomized placebo-controlled 3-week cross-over design. We administered battery of neuropsychological tests: CNS Vital Signs and Hamilton depression rating scale (HAM-D) at baseline and regular intervals and monitored side effects with treatment emergent adverse events scale. Results. 21 subjects (mean age: 54.6 years ± 6.0 yrs; male/female ratio: 9/12) entered the study. Zembrin at 25 mg daily dosage significantly improved cognitive set flexibility (P < 0.032) and executive function (P < 0.022), compared with the placebo group. Positive changes in mood and sleep were found. Zembrin was well tolerated. Conclusion. The promising cognitive enhancing effects of Zembrin likely implicate the PDE-4-cAMP-CREB cascade, a novel drug target in the potential treatment of early Alzheimer's dementia. This trial is registered with ClinicalTrials.gov NCT01805518.

  6. Improvement of spatial memory function in APPswe/PS1dE9 mice after chronic inhibition of phosphodiesterase type 4D.

    PubMed

    Sierksma, A S R; van den Hove, D L A; Pfau, F; Philippens, M; Bruno, O; Fedele, E; Ricciarelli, R; Steinbusch, H W M; Vanmierlo, T; Prickaerts, J

    2014-02-01

    Phosphodiesterase type 4 inhibitors (PDE4-Is) have received increasing attention as cognition-enhancers and putative treatment strategies for Alzheimer's disease (AD). By preventing cAMP breakdown, PDE4-Is can enhance intracellular signal transduction and increase the phosphorylation of cAMP response element-binding protein (CREB) and transcription of proteins related to synaptic plasticity and associated memory formation. Unfortunately, clinical development of PDE4-Is has been seriously hampered by emetic side effects. The new isoform-specific PDE4D-I, GEBR-7b, has shown to have beneficial effects on memory at non-emetic doses. The aim of the current study was to investigate chronic cognition-enhancing effects of GEBR-7b in a mouse model of AD. To this extent, 5-month-old (5M) APPswe/PS1dE9 mice received daily subcutaneous injections with GEBR-7b (0.001 mg/kg) or vehicle for a period of 3 weeks, and were tested on affective and cognitive behavior at 7M. We demonstrated a cognition-enhancing potential in APPswe/PS1dE9 mice as their spatial memory function at 7M in the object location test was improved by prior GEBR-7b treatment. APPswe/PS1dE9 mice displayed lower levels of CREB phosphorylation, which remained unaltered after chronic GEBR-7b treatment, and higher levels of tau in the hippocampus. Hippocampal brain-derived neurotrophic factor levels and synaptic densities were not different between experimental groups and no effects were observed on hippocampal GSK3β and tau phosphorylation or Aβ levels. In conclusion, GEBR-7b can enhance spatial memory function in the APPswe/PS1dE9 mouse model of AD. Although the underlying mechanisms of its cognition-enhancing potential remain to be elucidated, PDE4D inhibition appears an interesting novel therapeutic option for cognitive deficits in AD.

  7. Synthesis of Novel Tadalafil Analogues and their Evaluation as Phosphodiesterase Inhibitors and Anticancer Agents

    PubMed Central

    Abadi, Ashraf H.; Abouel-Ella, Dalal A.; Ahmed, Nermin S.; Gary, Bernard D.; Thaiparambil, Jose T.; Tinsley, Heather N.; Keeton, Adam B.; Piazza, Gary A.

    2016-01-01

    Two closely related series of novel β-carboline derivatives, electronically similar to tadalafil (CAS 171596-29-5), were synthesized and evaluated for their inhibitory effects upon phosphodiesterase 5 (PDE5) and phosphodiesterase 11 (PDE11) and their in vitro tumor cell growth inhibitory activity versus HT29 colorectal carcinoma cell line. Interestingly, some of the synthesized compounds showed growth inhibitory properties that appear to be associated with their ability to inhibit PDE5. Moreover, the PDE5 inhibition seems relevant to the stereochemical aspects of the compounds. PMID:19813465

  8. Camp Hope: Integrating Tai Chi and Humanbecoming in a Camp for Children.

    PubMed

    Delis, Pamela Coombs; Leger, Robin R; Longton, Fran; Chandler, David Lynn

    2015-10-01

    This article is about Camp Hope, a two-week summer day program for children age 6-12 from low income families and violent neighborhoods and for children who are struggling academically or identified as having behavioral health issues. The camp is operated by House of Peace and Education (HOPE) a 501(c)(3) nonprofit company that began in 1996. The program is designed to offer enrichment activities in a caring community for young children. The theoretical framework behind the vision and policies is Parse's humanbecoming paradigm. In particular, the camp administrators and staff try to see all persons as co-creating of their everchanging humanuniverse process.

  9. 8. VIEW EAST, CIVILIAN CONSERVATION CORPS CAMP PARSONS GARAGE, MODERN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW EAST, CIVILIAN CONSERVATION CORPS CAMP PARSONS GARAGE, MODERN SHED, CIVILIAN CONSERVATION CORPS CAMP PARSONS BLACKSMITH SHOP, AND MODERN SHED. - Parsons Nursery, South side of U.S. Route 219, Parsons, Tucker County, WV

  10. Woods and Camping Safety for the Whole Family

    MedlinePlus

    ... What's in this article? Planning Ahead Common Camping Dangers Proper Clothing Setting Up a Campsite Drinking the Water Food Supplies and Foraging Plants and Insects Protecting Against Animals What to Pack First-Aid Kits Camping Emergency ...

  11. CPSC Warns of Carbon Monoxide Poisoning with Camping Equipment

    MedlinePlus

    ... Warns of Carbon Monoxide Poisoning Hazard with Camping Equipment The U.S. Consumer Product Safety Commission (CPSC) warns ... about the carbon monoxide (CO) hazard with camping equipment. CO can kill you! From 2002–2006, CPSC ...

  12. 25 CFR 248.9 - Camping and use restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-LIEU FISHING SITES § 248.9 Camping and use restrictions. All camping, picnicking, use of alcoholic beverages, setting or use of fires, use of the sites for cleaning of fish, the deposit of any garbage,...

  13. 25 CFR 248.9 - Camping and use restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-LIEU FISHING SITES § 248.9 Camping and use restrictions. All camping, picnicking, use of alcoholic beverages, setting or use of fires, use of the sites for cleaning of fish, the deposit of any garbage,...

  14. 25 CFR 248.9 - Camping and use restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...-LIEU FISHING SITES § 248.9 Camping and use restrictions. All camping, picnicking, use of alcoholic beverages, setting or use of fires, use of the sites for cleaning of fish, the deposit of any garbage,...

  15. 25 CFR 248.9 - Camping and use restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...-LIEU FISHING SITES § 248.9 Camping and use restrictions. All camping, picnicking, use of alcoholic beverages, setting or use of fires, use of the sites for cleaning of fish, the deposit of any garbage,...

  16. 25 CFR 248.9 - Camping and use restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...-LIEU FISHING SITES § 248.9 Camping and use restrictions. All camping, picnicking, use of alcoholic beverages, setting or use of fires, use of the sites for cleaning of fish, the deposit of any garbage,...

  17. Contingency Base Camp Operations and Management: Staffing and Organization

    DTIC Science & Technology

    2013-09-17

    in a low-intensity conflict such as peacekeeping. The military devel- oped a number of enduring base camps such as Camp Bondsteel in Kosovo and Camp...works and engineering support All base camps require provision of potable water, waste water collection and treatment, solid waste collection and...IBCT (TF Red Bulls). Because the BCT also had responsibility for their International Security Assistance Force (ISAF) mission outside the wire

  18. Phosphodiesterase 9A Controls Nitric-oxide Independent cGMP and Hypertrophic Heart Disease

    PubMed Central

    Lee, Dong I.; Zhu, Guangshuo; Sasaki, Takashi; Cho, Gun-Sik; Hamdani, Nazha; Holewinski, Ronald; Jo, Su-Hyun; Danner, Thomas; Zhang, Manling; Rainer, Peter P.; Bedja, Djahida; Kirk, Jonathan A.; Ranek, Mark J.; Dostmann, Wolfgang R.; Kwon, Chulan; Margulies, Kenneth B.; Van Eyk, Jennifer E.; Paulus, Walter J.; Takimoto, Eiki; Kass, David A.

    2015-01-01

    Cyclic guanosine monophosphate (cGMP) is a second messenger molecule that transduces nitric oxide (NO) and natriuretic peptide (NP) coupled signaling, stimulating phosphorylation changes by protein kinase G (PKG). Enhancing cGMP synthesis or blocking its degradation by phosphodiesterase type 5A (PDE5A) protects against cardiovascular disease1,2. However, cGMP stimulation alone is limited by counter-adaptions including PDE upregulation3. Furthermore, though PDE5A regulates NO-generated cGMP4,5, NO-signaling is often depressed by heart disease6. PDEs controlling NP-coupled cGMP remain uncertain. Here we show that cGMP-selective PDE9A7,8 is expressed in mammalian heart including humans, and is upregulated by hypertrophy and cardiac failure. PDE9A regulates NP rather than NO-stimulated cGMP in heart myocytes and muscle, and its genetic or selective pharmacological inhibition protects against pathological responses to neuro-hormones, and sustained pressure-overload stress. PDE9A inhibition reverses pre-established heart disease independent of NO-synthase (NOS) activity, whereas PDE5A inhibition requires active NOS. Transcription factor activation and phospho-proteome analyses of myocytes with each PDE selectively inhibited reveals substantial differential targeting, with phosphorylation changes from PDE5A inhibition being more sensitive to NOS activation. Thus, unlike PDE5A, PDE9A can regulate cGMP signaling independent of the NO-pathway, and its role in stress-induced heart disease suggests potential as a therapeutic target. PMID:25799991

  19. Adjunctive Phosphodiesterase-4 Inhibitor Therapy Improves Antibiotic Response to Pulmonary Tuberculosis in a Rabbit Model

    PubMed Central

    Subbian, Selvakumar; Tsenova, Liana; Holloway, Jennifer; Peixoto, Blas; O'Brien, Paul; Dartois, Véronique; Khetani, Vikram; Zeldis, Jerome B.; Kaplan, Gilla

    2016-01-01

    Objectives Adjunctive host-directed therapy is emerging as a new potential approach to improve the outcome of conventional antimicrobial treatment for tuberculosis (TB). We tested the ability of a phosphodiesterase-4 inhibitor (PDE4i) CC-11050, co-administered with the first-line anti-TB drug isoniazid (INH), to accelerate bacillary killing and reduce chronic inflammation in the lungs of rabbits with experimental Mycobacterium tuberculosis (Mtb) infection. Methods A rabbit model of pulmonary TB that recapitulates the pathologic manifestations seen in humans was used. Rabbits were infected with virulent Mtb by aerosol exposure and treated for eight weeks with INH with or without CC-11050, starting at four weeks post infection. The effect of CC-11050 treatment on disease severity, pathology, bacillary load, T cell proliferation and global lung transcriptome profiles were analyzed. Results Significant improvement in bacillary clearance and reduced lung pathology and fibrosis were noted in the rabbits treated for eight weeks with INH + CC-11050, compared to those treated with INH or CC-11050 only. In addition, expression of host genes associated with tissue remodeling, tumor necrosis factor alpha (TNF-α) regulation, macrophage activation and lung inflammation networks was dampened in CC-11050-treated, compared to the untreated rabbits. Conclusions Adjunctive CC-11050 therapy significantly improves the response of rabbits with experimental pulmonary TB to INH treatment. We propose that CC-11050 may be a promising candidate for host directed therapy of patients with pulmonary TB, reducing the duration and improving clinical outcome of antibiotic treatment. PMID:26981575

  20. Phosphodiesterase 10A inhibitor MP-10 effects in primates: Comparison with risperidone and mechanistic implications

    PubMed Central

    Uthayathas, Subramaniam; Masilamoni, Gunasingh J.; Shaffer, Christopher L.; Schmidt, Christopher J.; Menniti, Frank S.; Papa, Stella M.

    2013-01-01

    Phosphodiesterase 10A (PDE10A) is highly expressed in striatal medium spiny neurons of both the direct and indirect output pathways. Similar to dopamine D2 receptor antagonists acting on indirect pathway neurons, PDE10A inhibitors have shown behavioral effects in rodent models that predict antipsychotic efficacy. These findings have supported the clinical investigation of PDE10A inhibitors as a new treatment for schizophrenia. However, PDE10A inhibitors and D2 antagonists differ in effects on direct pathway and other neurons of the basal ganglia, indicating that these two drug classes may have divergent antipsychotic efficacy and side effect profile. In the present study, we compare the behavioral effects of the selective PDE10A inhibitor MP-10 to those of the clinical standard D2 antagonist risperidone in rhesus monkeys using a standardized motor disability scale for parkinsonian primates and a newly designed “Drug Effects on Nervous System” scale to assess non-motor effects. Behavioral effects of MP-10 correlated with its plasma levels and its regulation of metabolic activity in striatal and cortical regions as measured by FDG-PET imaging. While MP-10 and risperidone broadly impacted similar behavioral domains in the primate, their effects had a different underlying basis. MP-10-treated animals retained the ability to respond but did not engage tasks, whereas risperidone-treated animals retained the motivation to respond but were unable to perform the intended actions. These findings are discussed in light of what is currently known about the modulation of striatal circuitry by these two classes of compounds, and provide insight into interpreting emerging clinical data with PDE10A inhibitors for the treatment of psychotic symptoms. PMID:24490227

  1. Regulation of nicotinic acetylcholine receptor phosphorylation in rat myotubes by forskolin and cAMP

    SciTech Connect

    Miles, K.; Anthony, D.T.; Rubin, L.L.; Greengard, P.; Huganir, R.L.

    1987-09-01

    The nicotinic acetylcholine receptor (Ac-ChoR) from rat myotubes prelabeled in culture with (/sup 32/P)orthophosphate was isolated by acetylcholine affinity chromatography followed by immunoaffinity chromatography. Under basal conditions, the nicotinic AcChoR was shown to be phosphorylated in situ on the ..beta.. and delta subunits. Regulation of AcChoR phosphorylation by cAMP-dependent protein kinase was explored by the addition of forskolin or cAMP analogues to prelabeled cell cultures. Forskolin, an activator of adenylate cyclase, stimulated the phosphorylation of the delta subunit 20-fold over basal phosphorylation and induced phosphorylation of the ..cap alpha.. subunit. The effect of forskolin was dose dependent with a half-maximal response at 8 ..mu..M in the presence of 35 ..mu..M Ro 20-1724, a phosphodiesterase inhibitor. Stimulation of delta subunit phosphorylation was almost maximal within 5 min, whereas stimulation of ..cap alpha.. subunit phosphorylation was not maximal until 45 min after forskolin treatment. Stimulation of AcChoR phosphorylation by 8-benzylthioadenosine 3',5'-cyclic monophosphate was identical to that obtained by forskolin. Two-dimensional thermolytic phosphopeptide maps of the delta subunit revealed a single major phosphopeptide. These results correlate closely with the observed effects of forskolin on AcChoR desensitization in muscle and suggest that cAMP-dependent phosphorylation of the delta subunit increases the rate of AcChoR desensitization in rat myotubes.

  2. Camp Health Aide Manual = Manual para trabajadores de salud.

    ERIC Educational Resources Information Center

    Robinson, June Grube; And Others

    This bilingual manual serves as a textbook for migrant Camp Health Aides. Camp Health Aides are members of migrant labor camps enlisted to provide information about health and social services to migrant workers and their families. The manual is divided into 12 tabbed sections representing lessons. Teaching notes printed on contrasting paper…

  3. Transitioning Traditions: Rectifying an Ontario Camp's Indian Council Ring

    ERIC Educational Resources Information Center

    Wilkes, Taylor

    2011-01-01

    Council Ring has always been a very special event, remembered fondly by generations of campers. Taylor Statten Camps (TSC) are not the only camps to cherish such an activity. Across Canada there are dozens of camps that have supported "Indian" assemblies in the past, but a select few still do. Most organizations abandoned them during the…

  4. Illegal Drug Abuse and the Community Camp Strategy in China.

    ERIC Educational Resources Information Center

    Wang, Wen

    1999-01-01

    Provides an initial evaluation of the community camp approach to drug detoxification and rehabilitation utilized in China. Open-ended interviewing schedules were given to two samples from two government sponsored rehabilitation community camps in 1994. Results show that in the two community camps, an average of twelve months' training yielded a…

  5. Summer Camp and Positive Youth Development: Program with Romanian Youth

    ERIC Educational Resources Information Center

    Feenstra, Jennifer S.

    2015-01-01

    A variety of activities are used in camps to help promote positive youth development, improving social skills and self-esteem in campers. I expanded on previous camp research in this study to address the influence camps have on trust, belief in the honesty of others, empowerment, and care for others in youth in Eastern Europe. Since 1999, New…

  6. Camping with a Purpose...A 4-H Handbook.

    ERIC Educational Resources Information Center

    Heller, John H.; And Others

    The 4-H handbook focuses on factors to consider and things to be done when developing a camping program. Since the emphasis, structure, and administration of 4-H camping varies, the booklet is flexible enough to be adapted to different state, district, and county situations. Major topics are camping's importance to extension education,…

  7. Camp selection and the role of health care providers.

    PubMed

    Thurber, Christopher A

    2007-10-01

    The selection of a summer camp that best matches a child's interests, abilities, and developmental level is essential. This article provides information to assist families in their consideration of camp type, location, length of stay, gender composition, and structure. It also outlines the way that health care providers can assist families in selecting the most appropriate camp for their child.

  8. The Traditional Camp: Out of Touch, Out of Time.

    ERIC Educational Resources Information Center

    Hilliard, David A.

    1994-01-01

    Discusses how camps can survive by changing their marketing approach, organizational structure, and programming to meet the needs of the community. Profiles Wyman Center, a residential camp near Saint Louis, Missouri, that has prospered as a result of breaking with tradition and redefining the terms "camp" and "customer." (LP)

  9. Minimum-Impact Camping in the Front Woods.

    ERIC Educational Resources Information Center

    Schatz, Curt

    1994-01-01

    Minimum-impact camping techniques that can be applied to resident camp programs include controlling group size and behavior, designing camp sites, moving groups frequently, proper use of fires, proper disposal of food and human wastes, use of biodegradable soaps, and encouraging staff and camper awareness of impacts on the environment. (LP)

  10. Guidebook: In-Camp Education for Migrant Farmworkers.

    ERIC Educational Resources Information Center

    Lynch, Robert; Smith, Mona

    An In-Camp Learning Program focuses on the specific needs of the out-of-school youth and adult migrant farmworker. Although its primary intent is that of education, the program addresses other areas such as health and social services. In 1976, New York's In-Camp Learning Program served 400 migrant farmworkers in 15 camps in the counties of…

  11. Whatever Happened to School Camping? An Occasional Paper.

    ERIC Educational Resources Information Center

    Donaldson, George W.; Donaldson, Louise E.

    1982-01-01

    School camping began with three movements in American society: children's camping, which has been traced back as far as 1823; the Nature Study Movement, which is thought to have begun as early as 1839; and the holistic "new education." In 1940, L. B. Sharp opened National Camp in New Jersey and Julian W. Smith initiated the Clear Lake…

  12. Leadership Skills in Three Chords: Guitars at Camp.

    ERIC Educational Resources Information Center

    Ticknor, Susie

    1992-01-01

    Describes how the guitar can be used to enrich a camp experience. The guitar has an attention-drawing quality, a group-bonding potential, and a mood-setting ability that make it effective in a variety of camp situations. Discusses some common problems with guitar use at camp, and offers recommendations for effective use. (KS)

  13. 28 CFR 523.15 - Camp or farm good time.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Camp or farm good time. 523.15 Section..., CLASSIFICATION, AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.15 Camp or farm good time. An inmate assigned to a farm or camp is automatically awarded extra good time, beginning on the date of commitment...

  14. 28 CFR 523.15 - Camp or farm good time.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Camp or farm good time. 523.15 Section..., CLASSIFICATION, AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.15 Camp or farm good time. An inmate assigned to a farm or camp is automatically awarded extra good time, beginning on the date of commitment...

  15. 28 CFR 523.15 - Camp or farm good time.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Camp or farm good time. 523.15 Section..., CLASSIFICATION, AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.15 Camp or farm good time. An inmate assigned to a farm or camp is automatically awarded extra good time, beginning on the date of commitment...

  16. 28 CFR 523.15 - Camp or farm good time.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Camp or farm good time. 523.15 Section..., CLASSIFICATION, AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.15 Camp or farm good time. An inmate assigned to a farm or camp is automatically awarded extra good time, beginning on the date of commitment...

  17. 28 CFR 523.15 - Camp or farm good time.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Camp or farm good time. 523.15 Section..., CLASSIFICATION, AND TRANSFER COMPUTATION OF SENTENCE Extra Good Time § 523.15 Camp or farm good time. An inmate assigned to a farm or camp is automatically awarded extra good time, beginning on the date of commitment...

  18. Foreign Language Camps: Jefferson County Public Schools R-1.

    ERIC Educational Resources Information Center

    Trujillo, Lorenzo A.; And Others

    The planning and operation of Jefferson County (Colorado) Public Schools' foreign language camps are described. The weekend-long camps attempt to duplicate an authentic cultural experience in a foreign village through cultural activities and language immersion. French, Spanish, Russian, and German camps are conducted for county high school foreign…

  19. 49 CFR 218.80 - Movement of occupied camp cars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Movement of occupied camp cars. 218.80 Section 218... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Protection of Occupied Camp Cars § 218.80 Movement of occupied camp cars. Occupied cars may not be humped or flat switched unless coupled...

  20. 49 CFR 218.80 - Movement of occupied camp cars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movement of occupied camp cars. 218.80 Section 218... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD OPERATING PRACTICES Protection of Occupied Camp Cars § 218.80 Movement of occupied camp cars. Occupied cars may not be humped or flat switched unless coupled...