Sample records for 2,3-cyclic-nucleotide phosphodiesterases

  1. Myelin 2',3'-cyclic nucleotide 3'-phosphodiesterase: active-site ligand binding and molecular conformation.

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    Matti Myllykoski

    Full Text Available The 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase is a highly abundant membrane-associated enzyme in the myelin sheath of the vertebrate nervous system. CNPase is a member of the 2H phosphoesterase family and catalyzes the formation of 2'-nucleotide products from 2',3'-cyclic substrates; however, its physiological substrate and function remain unknown. It is likely that CNPase participates in RNA metabolism in the myelinating cell. We solved crystal structures of the phosphodiesterase domain of mouse CNPase, showing the binding mode of nucleotide ligands in the active site. The binding mode of the product 2'-AMP provides a detailed view of the reaction mechanism. Comparisons of CNPase crystal structures highlight flexible loops, which could play roles in substrate recognition; large differences in the active-site vicinity are observed when comparing more distant members of the 2H family. We also studied the full-length CNPase, showing its N-terminal domain is involved in RNA binding and dimerization. Our results provide a detailed picture of the CNPase active site during its catalytic cycle, and suggest a specific function for the previously uncharacterized N-terminal domain.

  2. The myelin membrane-associated enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase: on a highway to structure and function. (United States)

    Raasakka, Arne; Kursula, Petri


    The membrane-anchored myelin enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) was discovered in the early 1960s and has since then troubled scientists with its peculiar catalytic activity and high expression levels in the central nervous system. Despite decades of research, the actual physiological relevance of CNPase has only recently begun to unravel. In addition to a role in myelination, CNPase is also involved in local adenosine production in traumatic brain injury and possibly has a regulatory function in mitochondrial membrane permeabilization. Although research focusing on the CNPase phosphodiesterase activity has been helpful, several open questions concerning the protein function in vivo remain unanswered. This review is focused on past research on CNPase, especially in the fields of structural biology and enzymology, and outlines the current understanding regarding the biochemical and physiological significance of CNPase, providing ideas and directions for future research.

  3. In aging, the vulnerability of rat brain mitochondria is enhanced due to reduced level of 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNP) and subsequently increased permeability transition in brain mitochondria in old animals. (United States)

    Krestinina, Olga; Azarashvili, Tamara; Baburina, Yulia; Galvita, Anastasia; Grachev, Dmitry; Stricker, Rolf; Reiser, Georg


    Aging is accompanied by progressive dysfunction of mitochondria associated with a continuous decrease of their capacity to produce ATP. Mitochondria isolated from brain of aged animals show an increased mitochondrial permeability transition pore (mPTP) opening. We recently detected new regulators of mPTP function in brain mitochondria, the enzyme 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNP) and its substrates 2', 3'-cAMP and 2', 3'-cNADP, and the neuronal protein p42(IP4). Here, we compared parameters of mPTP opening in non-synaptic brain mitochondria isolated from young and old rats. In mitochondria from old rats (>18 months), mPTP opening occurred at a lower threshold of Ca(2+) concentration than in mitochondria from young rats (aging was accompanied by decreased levels of voltage-dependent anion channel (VDAC; by 69%) and of p42(IP4) (by 59%). Thus, reduced levels of CNP in mitochondria could lead to a rise in the concentration of the mPTP promoter 2', 3'-cAMP. The level of CNP and p42(IP4) and, probably VDAC, might be essential for myelination and electrical activity of axons. We propose that in aging the reduction in the level of these proteins leads to mitochondrial dysfunction, in particular, to a decreased threshold Ca(2+) concentration to induce mPTP opening. This might represent initial steps of age-related mitochondrial dysfunction, resulting in myelin and axonal pathology.

  4. The effect of levamisole on phosphodiesterase activity. (United States)

    Constantopoulos, A; Kafasi, V; Doulas, N; Liakakos, D; Matsaniotis, N


    Phosphodiesterase activity of mouse liver homogenates was estimated in presence and absence of levamisole. The enzyme activity was 1394 and 1399 nmoles/mg protein/30 min respectively. Our data show that levamisole does not affect the phosphodiesterase activity.

  5. Two phosphodiesterases from Ustilago maydis share structural and biochemical properties with non-fungal phosphodiesterases

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    Charu eAgarwal


    Full Text Available The dependence of Protein Kinase A (PKA activity on cAMP levels is an important facet of the dimorphic switch between budding and filamentous growth as well as for pathogenicity in some fungi. To better understand these processes in the pathogenic fungus Ustilago maydis, we characterized the structure and biochemical functions of two phosphodiesterase (PDE genes. Phosphodiesterases are enzymes involved in cAMP turnover and thus, contribute to the regulation of the cAMP-PKA signaling pathway. Two predicted homologues of PDEs were identified in the genome of U. maydis and hypothesized to be involved in cAMP turnover, thus regulating activity of the PKA catalytic subunit. Both umpde1 and umpde2 genes contain domains associated with phosphodiesterase activity predicted by InterPro analysis. Biochemical characterization of recombinantly produced UmPde1 (U. maydis Phosphodiesterase I and UmPde2 demonstrated that both enzymes have phosphodiesterase activity in vitro, yet neither was inhibited by the phosphodiesterase inhibitor IBMX. Moreover, UmPde1 is specific for cAMP, while UmPde2 has broader substrate specificity, utilizing cAMP and cGMP as substrates. In addition, UmPde2 was also found to have nucleotide phosphatase activity that was higher with GMP compared to AMP. These results demonstrate that UmPde1 is a bona fide phosphodiesterase, while UmPde2 has more general activity as a cyclic nucleotide phosphodiesterase and/or GMP/AMP phosphatase. Thus, UmPde1 and UmPde2 likely have important roles in cell morphology and development and share some characteristics with a variety of non-fungal phosphodiesterases.

  6. Subclasses of oligodendrocytes populate the mouse hippocampus

    NARCIS (Netherlands)

    Vinet, Jonathan; Lemieux, Philippe; Tamburri, Albert; Tiesinga, Paul; Scafidi, Joseph; Gallo, Vittorio; Sik, Attila


    Oligodendrocytes are the myelin-forming cells of the central nervous system that facilitate transmission of axonal electrical impulses. Using transgenic mice expressing 2',3' cyclic nucleotide 3' phosphodiesterase (CNPase)-enhanced green fluorescent protein, a three-dimensional reconstruction tool a

  7. Analysis of the effects of phosphodiesterase type 3 and 4 inhibitors in cerebral arteries

    DEFF Research Database (Denmark)

    Birk, Steffen; Edvinsson, Lars; Olesen, Jes;


    Inhibitors of phosphodiesterases 3 and 4, the main cyclic AMP (cAMP) degrading enzymes in arteries, may have therapeutic potential in cerebrovascular disorders. We analysed the effects of such phosphodiesterases in guinea pig cerebral arteries with organ bath technique and cyclic nucleotide assays...... the major contributors to total cAMP hydrolysis in the arteries examined. The phosphodiesterase 3 inhibitors additionally attenuated cyclic GMP (cGMP) hydrolysis, but relaxant responses were not dependent on an intact endothelium or on the nitric oxide-cGMP pathway. Conversely, the phosphodiesterase 4....... Guinea pig and human cerebral arteries were used for phosphodiesterase assays. Cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy]-3,4-dihydro-2(1H)-quinolinone), a phosphodiesterase 3 inhibitor, was compared to conventional phosphodiesterase 3 and 4 inhibitors. Phosphodiesterases 3 and 4 were...

  8. Cyclic nucleotide specific phosphodiesterases of Leishmania major

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    Linder Markus


    Full Text Available Abstract Background Leishmania represent a complex of important human pathogens that belong to the systematic order of the kinetoplastida. They are transmitted between their human and mammalian hosts by different bloodsucking sandfly vectors. In their hosts, the Leishmania undergo several differentiation steps, and their coordination and optimization crucially depend on numerous interactions between the parasites and the physiological environment presented by the fly and human hosts. Little is still known about the signalling networks involved in these functions. In an attempt to better understand the role of cyclic nucleotide signalling in Leishmania differentiation and host-parasite interaction, we here present an initial study on the cyclic nucleotide-specific phosphodiesterases of Leishmania major. Results This paper presents the identification of three class I cyclic-nucleotide-specific phosphodiesterases (PDEs from L. major, PDEs whose catalytic domains exhibit considerable sequence conservation with, among other, all eleven human PDE families. In contrast to other protozoa such as Dictyostelium, or fungi such as Saccharomyces cerevisiae, Candida ssp or Neurospora, no genes for class II PDEs were found in the Leishmania genomes. LmjPDEA contains a class I catalytic domain at the C-terminus of the polypeptide, with no other discernible functional domains elsewhere. LmjPDEB1 and LmjPDEB2 are coded for by closely related, tandemly linked genes on chromosome 15. Both PDEs contain two GAF domains in their N-terminal region, and their almost identical catalytic domains are located at the C-terminus of the polypeptide. LmjPDEA, LmjPDEB1 and LmjPDEB2 were further characterized by functional complementation in a PDE-deficient S. cerevisiae strain. All three enzymes conferred complementation, demonstrating that all three can hydrolyze cAMP. Recombinant LmjPDEB1 and LmjPDEB2 were shown to be cAMP-specific, with Km values in the low micromolar range

  9. Extraction and DNA Digestion of 5'-Phosphodiesterase from Malt Root

    Institute of Scientific and Technical Information of China (English)

    ZOU Hechang; CAI Guangqi; CAI Wen; LI Hailong; GU Yi; PARK Yongdoo; MENG Fanguo


    This study investigated the extraction of 5'-phosphodiesterase from malt root and the degradation of nucleic acids by this enzyme.The extraction used grade precipitation with ammonium sulfate and enzy-matic hydrolysis.Samples were assayed using the modified Bradford method and high performance liquid chromatography.The results show that 5'-phosphodiesterase is isolated by grade precipitation with 30% and 80% saturation of ammonium sulfate and can be utilized to degrade deoxydbonucleic acid.The hydrolysate has four kinds of deoxynucleotides: 5'-dCMP,5'-dTMP,5'-dAMP,and 5'-dGMP.The optimum reaction tem-perature is 70℃,and the optimum pH is 5.5-6.0 for the reaction.The percentage of deoxynucleotides indi-ceted by the China Pharmacopoeia (2000 edition) in the product is over 70%.The extraction of 5'-phosphodiesterase from malt root is shown to be possible and economical.Products from the enzymatic hydrolysate of DNA meet the pharmacopoeia.

  10. The role of cGMP hydrolysing phosphodiesterases 1 and 5 in cerebral artery dilatation

    DEFF Research Database (Denmark)

    Kruuse, C; Rybalkin, S D; Khurana, T S;


    The aim was to investigate the presence and activity of cGMP hydrolysing phosphodiesterases in guinea pig basilar arteries and the effect of selective and non-selective phosphodiesterase inhibitors on cerebral artery dilatation involving the nitric oxide (NO)-guanosine cyclic 3'5-monophosphate (c...... by cGMP-independent mechanisms. Targeting the phosphodiesterases present in cerebral arteries, with selective inhibitors or activators of phosphodiesterase, may be a possible new way of treating cerebrovascular disease.......The aim was to investigate the presence and activity of cGMP hydrolysing phosphodiesterases in guinea pig basilar arteries and the effect of selective and non-selective phosphodiesterase inhibitors on cerebral artery dilatation involving the nitric oxide (NO)-guanosine cyclic 3'5-monophosphate (c......GMP) pathway. Immunoreactivity to phosphodiesterases 1A, 1B and 5, but not phosphodiesterase 1C was found in fractions of homogenised cerebral arteries eluted by high-pressure liquid chromatography (HPLC). Both the phosphodiesterase 1 inhibitor 8-methoxymethyl-1-methyl-3-(2methylpropyl)-xanthine (8-MM...

  11. Identification and Characterization of a Novel Phosphodiesterase from the Metagenome of an Indian Coalbed (United States)

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


    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

  12. Phosphodiesterase 1 regulation is a key mechanism in vascular aging

    DEFF Research Database (Denmark)

    Niño, Paula K Bautista; Durik, Matej; Danser, A H Jan


    Reduced nitric oxide (NO)/cGMP signalling is observed in age-related vascular disease. We hypothesize that this disturbed signalling involves effects of genomic instability, a primary causal factor in aging, on vascular smooth muscle cells (VSMCs) and that the underlying mechanism plays a role...... in human age-related vascular disease. To test our hypothesis, we combined experiments in mice with genomic instability resulting from the defective nucleotide excision repair gene ERCC1 (Ercc1(d/-) mice), human VSMC cultures and population genome-wide association studies (GWAS). Aortic rings of Ercc1(d....../-) mice showed 43% reduced responses to the soluble guanylate cyclase (sGC) stimulator sodium nitroprusside (SNP). Inhibition of phosphodiesterase (PDE) 1 and 5 normalized SNP-relaxing effects in Ercc1(d/-) to wild-type (WT) levels. PDE1C levels were increased in lung and aorta. cGMP hydrolysis by PDE...

  13. Diabetic nephropathy: Treatment with phosphodiesterase type 5 inhibitors. (United States)

    Thompson, Cecil Stanley


    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.

  14. Evidence for a Messenger Function of Cyclic GMP During Phosphodiesterase Induction in Dictyostelium discoideum

    NARCIS (Netherlands)

    Haastert, Peter J.M. van; Pasveer, Frank J.; Meer, Rob C. van der; Heijden, Paul R. van der; Walsum, Hans van; Konijn, Theo M.


    Chemotactic stimulation of vegetative or aggregative Dictyostelium discoideum cells induced a transient elevation of cyclic GMP levels. The addition of chemoattractants to postvegetative cells by pulsing induced phosphodiesterase activity. The following lines of evidence suggest a messenger function

  15. Phosphodiesterase Inhibition and Regulation of Dopaminergic Frontal and Striatal Functioning: Clinical Implications (United States)

    Heckman, Pim R. A.; van Duinen, Marlies A.; Bollen, Eva P. P.; Nishi, Akinori; Wennogle, Lawrence P.; Blokland, Arjan


    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

  16. Effects of alkyl substituents of xanthine on phosphodiesterase isoenzymes. (United States)

    Miyamoto, K; Sakai, R; Kurita, M; Ohmae, S; Sanae, F; Sawanishi, H; Hasegawa, T; Takagi, K


    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.

  17. Selective tracheal relaxation and phosphodiesterase-IV inhibition by xanthine derivatives. (United States)

    Miyamoto, K; Kurita, M; Ohmae, S; Sakai, R; Sanae, F; Takagi, K


    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.

  18. Role of phosphodiesterase-4 on ethanol elicited locomotion and narcosis. (United States)

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


    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.

  19. Traumatic brain injury upregulates phosphodiesterase expression in the hippocampus

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    Nicole M Wilson


    Full Text Available Traumatic brain injury (TBI results in significant impairments in hippocampal synaptic plasticity. A molecule critically involved in hippocampal synaptic plasticity, 3',5'-cyclic adenosine monophosphate (cAMP, is downregulated in the hippocampus after TBI, but the mechanism that underlies this decrease is unknown. To address this question, we determined whether phosphodiesterase (PDE expression in the hippocampus is altered by TBI. Young adult male Sprague Dawley rats received sham surgery or moderate parasagittal fluid-percussion brain injury. Animals were analyzed by western blotting for changes in PDE expression levels in the hippocampus. We found that PDE1A levels were significantly increased at 30 min, 1 hr and 6 hr after TBI. PDE4B2 and 4D2 were also significantly increased at 1, 6 and 24 hr after TBI. Additionally, phosphorylation of PDE4A was significantly increased at 6 and 24 hr after TBI. No significant changes were observed in levels of PDE1B, 1C, 3A, 8A or 8B between 30 min to 7 days after TBI. To determine the spatial profile of these increases, we used immunohistochemistry and flow cytometry at 24 hr after TBI. PDE1A and phospho-PDE4A localized to neuronal cell bodies. PDE4B2 was expressed in neuronal dendrites, microglia and infiltrating CD11b+ immune cells. PDE4D was predominantly found in microglia and infiltrating CD11b+ immune cells. To determine if inhibition of PDE4 would improve hippocampal synaptic plasticity deficits after TBI, we treated hippocampal slices with rolipram, a pan-PDE4 inhibitor. Rolipram partially rescued the depression in basal synaptic transmission and converted a decaying form of LTP into long-lasting LTP. Overall, these results identify several possible PDE targets for reducing hippocampal synaptic plasticity deficits and improving cognitive dysfunction acutely after TBI.

  20. Phosphodiesterase 4D gene polymorphisms in sudden sensorineural hearing loss. (United States)

    Chien, Chen-Yu; Tai, Shu-Yu; Wang, Ling-Feng; Hsi, Edward; Chang, Ning-Chia; Wang, Hsun-Mo; Wu, Ming-Tsang; Ho, Kuen-Yao


    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.

  1. Coronary vasodilatory, spasmolytic and cAMP-phosphodiesterase inhibitory properties of dihydropyranocoumarins and dihydrofuranocoumarins

    DEFF Research Database (Denmark)

    Thastrup, Ole; Fjalland, B; Lemmich, J


    Twenty-three dihydropyrano- and dihydrofuranocoumarins, most of plant origin, were examined for their effects on the coronary flow of isolated perfused guinea-pig heart, on the Ba2+-induced spasms in isolated guinea-pig ileum, on the cAMP level in guinea-pig heart homogenate and on the cAMP metab...... between the coronary vasodilatory and the cAMP-phosphodiesterase inhibitory activity. The results indicate involvement of cAMP-phosphodiesterase inhibition in coronary vasodilatory effects of acyloxydihydropyrano- and acyloxydihydrofurano-coumarins....

  2. Structure and Mechanism of PhnP, a Phosphodiesterase of the Carbon-Phosphorus Lyase Pathway

    DEFF Research Database (Denmark)

    He, Shu-Mei; Wathier, Matthew; Podzelinska, Kateryna;


    PhnP is a phosphodiesterase that plays an important role within the bacterial carbon-phosphorus lyase (CP-lyase) pathway by recycling a "dead-end" intermediate, 5-phospho-α-d-ribosyl 1,2-cyclic phosphate, that is formed during organophosphonate catabolism. As a member of the metallo-β-lactamase s...

  3. Identification and characterization of DdPDE3, a cGMP-selective phosphodiesterase from Dictyostelium

    NARCIS (Netherlands)

    Kuwayama, H; Snippe, H; Derks, M; Roelofs, J; van Haastert, PJM


    In Dictyostelium cAMP and cGMP have important functions as first and second messengers in chemotaxis and development. Two cyclic-nucleotide phosphodiesterases (DdPDE 1 and 2) have been identified previously, an extracellular dual-specificity enzyme and an intracellular cAMP-specific enzyme (encoded

  4. The role of cGMP hydrolysing phosphodiesterases 1 and 5 in cerebral artery dilatation

    DEFF Research Database (Denmark)

    Kruuse, Christina; Rybalkin, S D; Khurana, T S;


    -IBMX) and the phosphodiesterase 5 inhibitors zaprinast and dipyridamole induced dilatation of cerebral arteries. The dilatory response to 8-MM-IBMX was reduced by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) (10 microM) and endothelial removal and restored by sodium nitroprusside (0.1 microM) pretreatment, indicating...

  5. Neuronal nitric oxide synthase supports Renin release during sodium restriction through inhibition of phosphodiesterase 3

    DEFF Research Database (Denmark)

    Sällström, Johan; Jensen, Boye L; Skøtt, Ole


    NOS supports renin release by cyclic guanosine monophosphate (cGMP)-mediated inhibition of cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase 3 (PDE3) in juxtaglomerular (JG) cells. METHODS: The experiments were performed in conscious nNOS⁻(/)⁻ and wild types after 10 days on a low-sodium diet...

  6. 2'-phosphodiesterase and 2',5'-oligoadenylate synthetase activities in the lowest metazoans, sponge [porifera

    DEFF Research Database (Denmark)

    Saby, Emilie; Poulsen, Jesper Buchhave; Justesen, Just;


    Sponges [porifera], the most ancient metazoans, contain modules related to the vertebrate immune system, including the 2′,5′-oligoadenylate synthetase (OAS). The components of the antiviral 2′,5′-oligoadenylate (2–5A) system (OAS, 2′-Phosphodiesterase (2′-PDE) and RNAse L) of vertebrates have...

  7. Clinical effects of phosphodiesterase 3A mutations in inherited hypertension with brachydactyly. (United States)

    Toka, Okan; Tank, Jens; Schächterle, Carolin; Aydin, Atakan; Maass, Philipp G; Elitok, Saban; Bartels-Klein, Eireen; Hollfinger, Irene; Lindschau, Carsten; Mai, Knut; Boschmann, Michael; Rahn, Gabriele; Movsesian, Matthew A; Müller, Thomas; Doescher, Andrea; Gnoth, Simone; Mühl, Astrid; Toka, Hakan R; Wefeld-Neuenfeld, Yvette; Utz, Wolfgang; Töpper, Agnieszka; Jordan, Jens; Schulz-Menger, Jeanette; Klussmann, Enno; Bähring, Sylvia; Luft, Friedrich C


    Autosomal-dominant hypertension with brachydactyly is a salt-independent Mendelian syndrome caused by activating mutations in the gene encoding phosphodiesterase 3A. These mutations increase the protein kinase A-mediated phosphorylation of phosphodiesterase 3A resulting in enhanced cAMP-hydrolytic affinity and accelerated cell proliferation. The phosphorylated vasodilator-stimulated phosphoprotein is diminished, and parathyroid hormone-related peptide is dysregulated, potentially accounting for all phenotypic features. Untreated patients die prematurely of stroke; however, hypertension-induced target-organ damage is otherwise hardly apparent. We conducted clinical studies of vascular function, cardiac functional imaging, platelet function in affected and nonaffected persons, and cell-based assays. Large-vessel and cardiac functions indeed seem to be preserved. The platelet studies showed normal platelet function. Cell-based studies demonstrated that available phosphodiesterase 3A inhibitors suppress the mutant isoforms. However, increasing cGMP to indirectly inhibit the enzyme seemed to have particular use. Our results shed more light on phosphodiesterase 3A activation and could be relevant to the treatment of severe hypertension in the general population.

  8. Inhibition of human platelet aggregation by dihydropyrano- and dihydrofuranocoumarins, a new class of cAMP-phosphodiesterase inhibitors

    DEFF Research Database (Denmark)

    Thastrup, Ole; Knudsen, J B; Lemmich, J;


    Certain esters of dihydropyranocoumarin and dihydrofuranocoumarin alcohols have previously been shown to inhibit the cAMP-phosphodiesterase from bovine heart. We now report that these naturally occurring coumarins inhibit the high affinity (Km = 1.1 microM) cAMP-phosphodiesterase from human...... platelets with activities that closely correlate with those obtained using phosphodiesterase from bovine heart tissue. Additionally the coumarins inhibit the aggregation of human platelets induced with ADP, adrenaline and collagen with activities comparable to those of dipyridamole. A lack of significant...

  9. Synthesis of triazole Schiff bases: novel inhibitors of nucleotide pyrophosphatase/phosphodiesterase-1. (United States)

    Khan, Khalid Mohammed; Siddiqui, Salman; Saleem, Muhammad; Taha, Muhammad; Saad, Syed Muhammad; Perveen, Shahnaz; Choudhary, M Iqbal


    A series of Schiff base triazoles 1–25 was synthesized and evaluated for their nucleotide pyrophosphatase/phosphodiesterase-1 inhibitory activities. Among twenty-five compounds, three compounds 10 (IC50 = 132.20 ± 2.89 lM), 13 (IC50 = 152.83 ± 2.39 lM), and 22 (IC50 = 251.0 ± 6.64 lM) were identified as potent inhibitors with superior activities than the standard EDTA (IC50 = 277.69 ± 2.52 lM). The newly identified inhibitors may open a new avenue for the development of treatment of phosphodiesterase-I related disorders. These compounds were also evaluated for carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase inhibitory potential and were found to be inactive. The compounds showed non-toxic effect towards PC3 cell lines.

  10. Structure and biological function of ENPP6, a choline-specific glycerophosphodiester-phosphodiesterase


    Junko Morita; Kuniyuki Kano; Kazuki Kato; Hiroyuki Takita; Hideki Sakagami; Yasuo Yamamoto; Emiko Mihara; Hirofumi Ueda; Takanao Sato; Hidetoshi Tokuyama; Hiroyuki Arai; Hiroaki Asou; Junichi Takagi; Ryuichiro Ishitani; Hiroshi Nishimasu


    Choline is an essential nutrient for all living cells and is produced extracellularly by sequential degradation of phosphatidylcholine (PC). However, little is known about how choline is produced extracellularly. Here, we report that ENPP6, a choline-specific phosphodiesterase, hydrolyzes glycerophosphocholine (GPC), a degradation product of PC, as a physiological substrate and participates in choline metabolism. ENPP6 is highly expressed in liver sinusoidal endothelial cells and developing o...

  11. Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog.


    Shang, E S; Skare, J T; Erdjument-Bromage, H.; Blanco, D R; Tempst, P.; Miller, J N; Lovett, M A


    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...

  12. Erectile dysfunction: on the efficacy of a phosphodiesterase inhibitor in patients with multiple risk factors

    Institute of Scientific and Technical Information of China (English)

    HarveyA.Rosenstock; SamuelD.Axelrad


    With the 1998 introduction of sildenafil(Viagra),the first available oral phosphodiesterase inhibitor, therehas been an increased interest in the treatment of erectiledysfunction (ED), the most common sexual dysfunctionof males. Most experts estimate that 25 to 30 millionmen in the United States experience erectile dysfunc-tion. The incidence of erectile dysfunction increaseswith age such that 52 % of all men at some time can

  13. Ustilago maydis phosphodiesterases play a role in the dimorphic switch and in pathogenicity. (United States)

    Agarwal, Charu; Aulakh, Kavita B; Edelen, Kaly; Cooper, Michael; Wallen, R Margaret; Adams, Seth; Schultz, David J; Perlin, Michael H


    Components of the cAMP (cyclic AMP) signalling cascades are conserved from fungi to humans, and are particularly important for fungal dimorphism and pathogenicity. Previous work has described two phosphodiesterases, UmPde1 and UmPde2, in Ustilago maydis which show strong phosphodiesterase activity. We further characterized the biological function(s) of these phosphodiesterases in U. maydis. Specifically, we examined their possible role(s) in regulation of the cAMP-dependent protein kinase A (PKA) pathway and their roles in filamentous growth and pathogenicity. We found that UmPde1, which shares 35 % similarity with Cryptococcus neoformans Pde1, also displays functional homology with this enzyme. UmPde1 complements the capsule-formation defect of C. neoformans strains deleted for Pde1. In U. maydis, the cell morphology of the umpde1 deletion mutant resembled the multiple budding phenotypes seen with the ubc1 mutant, which lacks the regulatory subunit of PKA. Interestingly, on low-ammonium medium, umpde2 deletion strains showed a reduction in filamentation that was comparable to that of ubc1 deletion strains; however, umpde1 deletion strains showed normal filamentation on low-ammonium medium. Furthermore, both the ubc1 deletion strain in which the PKA pathway was constitutively active and the umpde1 deletion strains were significantly reduced in pathogenicity, while the umpde2 deletion strains showed a trend for reduced pathogenicity compared with wild-type strains. These data support a role for the phosphodiesterases UmPde1 and UmPde2 in regulating the U. maydis cAMP-dependent PKA pathway through modulation of cAMP levels, thus affecting dimorphic growth and pathogenicity.

  14. Modification of a bi-functional diguanylate cyclase-phosphodiesterase to efficiently produce cyclic diguanylate monophosphate

    Directory of Open Access Journals (Sweden)

    Natasha M. Nesbitt


    Full Text Available Cyclic-diGMP is a bacterial messenger that regulates many physiological processes, including many attributed to pathogenicity. Bacteria synthesize cyclic-diGMP from GTP using diguanylate cyclases; its hydrolysis is catalyzed by phosphodiesterases. Here we report the over-expression and purification of a bi-functional diguanylate cyclase-phosphodiesterase from Agrobacterium vitis S4. Using homology modeling and primary structure alignment, we identify several amino acids predicted to participate in the phosphodiesterase reaction. Upon altering selected residues, we obtain variants of the enzyme that efficiently and quantitatively catalyze the synthesis of cyclic-diGMP from GTP without hydrolysis to pGpG. Additionally, we identify a variant that produces cyclic-diGMP while immobilized to NiNTA beads and can catalyze the conversion of [α-32P]-GTP to [32P]-cyclic-diGMP. In short, we characterize a novel cyclic-diGMP processing enzyme and demonstrate its utility for efficient and cost-effective production of cyclic-diGMP, as well as modified cyclic-diGMP molecules, for use as probes in studying the many important biological processes mediated by cyclic-diGMP.

  15. Effects of phosphodiesterase 4 inhibition on alveolarization and hyperoxia toxicity in newborn rats.

    Directory of Open Access Journals (Sweden)

    Céline Méhats

    Full Text Available BACKGROUND: Prolonged neonatal exposure to hyperoxia is associated with high mortality, leukocyte influx in airspaces, and impaired alveolarization. Inhibitors of type 4 phosphodiesterases are potent anti-inflammatory drugs now proposed for lung disorders. The current study was undertaken to determine the effects of the prototypal phosphodiesterase-4 inhibitor rolipram on alveolar development and on hyperoxia-induced lung injury. METHODOLOGY/FINDINGS: Rat pups were placed under hyperoxia (FiO2>95% or room air from birth, and received rolipram or its diluent daily until sacrifice. Mortality rate, weight gain and parameters of lung morphometry were recorded on day 10. Differential cell count and cytokine levels in bronchoalveolar lavage and cytokine mRNA levels in whole lung were recorded on day 6. Rolipram diminished weight gain either under air or hyperoxia. Hyperoxia induced huge mortality rate reaching 70% at day 10, which was prevented by rolipram. Leukocyte influx in bronchoalveolar lavage under hyperoxia was significantly diminished by rolipram. Hyperoxia increased transcript and protein levels of IL-6, MCP1, and osteopontin; rolipram inhibited the increase of these proteins. Alveolarization was impaired by hyperoxia and was not restored by rolipram. Under room air, rolipram-treated pups had significant decrease of Radial Alveolar Count. CONCLUSIONS: Although inhibition of phosphodiesterases 4 prevented mortality and lung inflammation induced by hyperoxia, it had no effect on alveolarization impairment, which might be accounted for by the aggressiveness of the model. The less complex structure of immature lungs of rolipram-treated pups as compared with diluent-treated pups under room air may be explained by the profound effect of PDE4 inhibition on weight gain that interfered with normal alveolarization.

  16. Future options for disease intervention: important advances in phosphodiesterase 4 inhibitors

    Directory of Open Access Journals (Sweden)

    R. A. McIvor


    Full Text Available Current drug treatments for chronic obstructive pulmonary disease (COPD focus on managing symptoms of the disease and include short- and long-acting beta2-agonists, anticholinergic agents (ipratroprium, tiotropium, methylxanthines (theophylline and inhaled corticosteroids (ICS. Cyclic nucleotide phosphodiesterases (PDEs play a key role in cell signalling by degrading cyclic adenosine monophosphate (cAMP and cyclic guanosine monophosphate. PDE4 is expressed in inflammatory cells and inhibition of this enzyme enhances the anti-inflammatory effects of cAMP in all key cells involved in COPD. Two PDE4 inhibitors, roflumilast and cilomilast, have been extensively evaluated in patients with COPD. Results from patients with moderate-to-severe and severe-to-very severe COPD have shown that roflumilast significantly improves forced expiratory volume in one second (FEV1 and significantly decreases exacerbations, particularly in patients with severe disease. Roflumilast is well tolerated with a low incidence of gastrointestinal adverse events that declines with continued treatment. Clinical trials with cilomilast have produced more varied results. Significant improvements in FEV1 and reductions in exacerbation rates versus placebo were observed in two of four trials. Cilomilast also has a high risk for gastrointestinal adverse events that does not appear to dissipate over 24 weeks of treatment. While further research is needed to fully determine the place in chronic obstructive pulmonary disease therapy for phosphodiesterase 4 inhibitors, they have several important potential benefits in the treatment of this disease, including convenient once-daily oral administration and freedom from adverse effects associated with corticosteroids. The fact that phosphodiesterase 4 inhibitors have potent anti-inflammatory effects and are administered orally, thereby reaching the systemic circulation, may decrease the severity of systemic comorbidities in chronic

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


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


    Sensory photoreceptors not only enable organisms to derive spatial and temporal cues from incident light but also provide the basis for optogenetics, which denotes the manipulation by light of living systems with supreme spatial and temporal resolution. To expand the scope of optogenetics, we have engineered the light-activated phosphodiesterase LAPD, which degrades the ubiquitous second messengers cAMP and cGMP in a red-light–stimulated manner. Both cAMP and cGMP are key to the regulation of...

  18. Synthesis of sildenafil analogues from anacardic acid and their phosphodiesterase-5 inhibition. (United States)

    Paramashivappa, R; Phani Kumar, P; Subba Rao, P V; Srinivasa Rao, A


    Anacardic acid (6-pentadecylsalicylic acid), a major component of cashew nut shell liquid, consists of a heterogeneous mixture of monoenes, dienes, and trienes. The enes mixture of anacardic acid was hydrogenated to a saturated compound. Using saturated anacardic acid as a starting material, analogues of sildenafil [a potent phosphodiesterase-5 (PDE(5)) inhibitor and an orally active drug for the treatment of erectile dysfunction] were synthesized, to observe the effect of the pentadecyl side chain on PDE(5) inhibition. The synthesized compounds were characterized by spectral studies and tested for PDE(5) inhibition, and the results were compared with those obtained with sildenafil.

  19. Porcine ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1/CD203a)

    DEFF Research Database (Denmark)

    Petersen, Cathrine Bie; Hillig, Ann-Britt Nygaard; Viuff, Birgitte;


    /phosphodiesterase 1 (NPP1/CD203a). The porcine NPP1/CD203a encoding gene was mapped to chromosome 1 using a radiation hybrid panel, and transcription was investigated by RT-PCR analysis of several tissues. The cDNA was cloned and introduced into COS7 cells resulting in expression of functionally active enzyme...... and verification of the specificity of an SWC9 reacting monoclonal antibody. The antibody was used for immunohistochemical examination of various porcine tissues. Most prominent expression of NPP1/CD203a was found in lung macrophages and liver sinusoids....

  20. Engineering of a red-light-activated human cAMP/cGMP-specific phosphodiesterase. (United States)

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


    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.

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

    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


    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. The c-di-GMP phosphodiesterase BifA regulates biofilm development in Pseudomonas putida. (United States)

    Jiménez-Fernández, Alicia; López-Sánchez, Aroa; Calero, Patricia; Govantes, Fernando


    We previously showed the isolation of biofilmpersistent Pseudomonas putida mutants that fail to undergo biofilm dispersal upon entry in stationary phase. Two such mutants were found to bear insertions in PP0914, encoding a GGDEF/EAL domain protein with high similarity to Pseudomon asaeruginosa BifA. Here we show the phenotypic characterization of a ΔbifA mutant in P. putida KT2442.This mutant displayed increased biofilm and pellicle formation, cell aggregation in liquid medium and decreased starvation-induced biofilm dispersal relative to the wild type. Unlike its P. aeruginosa counterpart, P. putida BifA did not affect swarming motility. The hyperadherent phenotype of the ΔbifA mutant correlates with a general increase in cyclic diguanylate (c-di-GMP) levels, Congo Red-binding exopolyaccharide production and transcription of the adhesin-encoding lapA gene. Integrity of the EAL motif and a modified GGDEF motif (altered to GGDQF)were crucial for BifA activity, and c-di-GMP depletion by overexpression of a heterologous c-di-GMP phosphodiesterase in the ΔbifA mutant restored wild-type biofilm dispersal and lapA expression.Our results indicate that BifA is a phosphodiesterase involved in the regulation of the c-di-GMP pool and required for the generation of the low c-di-GMP signal that triggers starvation-induced biofilm dispersal.

  3. Pathophysiology of visual disorders induced by phosphodiesterase inhibitors in the treatment of erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Moschos MM


    Full Text Available Marilita M Moschos, Eirini Nitoda 1st Department of Ophthalmology, Medical School, National & Kapodistrian University of Athens, Athens, Greece Aim: The aim of this review was to summarize the ocular action of the most common phosphodiesterase (PDE inhibitors used for the treatment of erectile dysfunction and the subsequent visual disorders.Method: This is a literature review of several important articles focusing on the pathophysiology of visual disorders induced by PDE inhibitors.Results: PDE inhibitors have been associated with ocular side effects, including changes in color vision and light perception, blurred vision, transient alterations in electroretinogram (ERG, conjunctival hyperemia, ocular pain, and photophobia. Sildenafil and tadalafil may induce reversible increase in intraocular pressure and be involved in the development of nonarteritic ischemic optic neuropathy. Reversible idiopathic serous macular detachment, central serous chorioretinopathy, and ERG disturbances have been related to the significant impact of sildenafil and tadalafil on retinal perfusion.Discussion: So far, PDE inhibitors do not seem to cause permanent toxic effects on chorioretinal tissue and photoreceptors. However, physicians should write down any visual symptom observed during PDE treatment and refer the patients to ophthalmologists. Keywords: erectile dysfunction, pathophysiological mechanisms, phosphodiesterase inhibitors, PDE5, visual disorders

  4. The new base excision repair pathway in mammals mediated by tyrosyl-DNA-phosphodiesterase 1

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    Lavrik O. I.


    Full Text Available Human tyrosyl-DNA phosphodiesterase 1 (Tdp1 hydrolyzes the phosphodiester bond at a DNA 3' end linked to a tyrosyl moiety and has been implicated in the repair of Topoisomerase I (TopI-DNA covalent complexes. Tdp1 can also hydrolyze other 3' end DNA alterations including 3' phosphoglycolate and 3' abasic (AP sites, and exhibits the 3' nucleosidase activity indicating that it may function as a general 3' end-processing DNA repair enzyme. Recently we have shown a new Tdp1 activity generating DNA strand break with the 3' phosphate termini from the AP site. AP sites are formed spontaneously and are inevitable intermediates during base excision repair of DNA base damages. AP sites are both mutagenic and cytotoxic, and key enzymes for their removal are AP endonucleases. However, AP endonuclease independent repair, initiated by DNA glycosylases performing beta, delta-elimination cleavage of the AP sites, has been described in mammalian cells. Here, we describe another AP endonuclease independent repair pathway for removal of AP sites that is initiated by tyrosyl phosphodiesterase Tdp1. We propose that repair is completed by the action of a polynucleotide kinase, a DNA polymerase and finally a DNA ligase to seal the gap.

  5. Significance of salivary phosphodiesterase level in oral squamous cell carcinoma patients

    Directory of Open Access Journals (Sweden)

    Yousef Rezaei Chianeh


    Full Text Available Oral cancer, more specifically oral squamous cell carcinoma (OSCC consider as common cancer that 300,000 people diagnosed per year worldwide. The only effective treatment for OSCC is surgical intervention. Over the past two decades, overall disease condition has not improved although advancement of treatment has considerably increased. The phosphodiesterase (PDEs are responsible for the hydrolysis of the second messengers with a fundamental role in the transduction of the intracellular signals. In numerous pathological conditions such as cellular differentiation, apoptosis, and tumor invasivity the different PDF activity has been observed that shown role in pathophysiological mechanism. The role of PDEs as an intervention factor for activation of angiogenesis by influencing a tumor growth has been shown. The objective of this study was to estimate and compare salivary PDEs levels in healthy controls and biopsy-proven oral cancer patients before definitive therapy. Study was done in patients age between 25-65 years biopsy proven oral cancer patients and control group. After obtaining prior consent from biopsy-proven oral cancer patients (n=26 (before onset of any definitive treatment and age- and sex-matched healthy controls (n=29, salivary sample was collected for estimation of the activity of phosphodiesterases (PDEs. [Int J Res Med Sci 2013; 1(4.000: 417-420

  6. Dissociable effects of acetylcholinesterase inhibitors and phosphodiesterase type 5 inhibitors on object recognition memory: acquisition versus consolidation

    NARCIS (Netherlands)

    Prickaerts, L.; Sik, A.; Staay, van der F.J.; Vente, de J.; Blokland, A.


    Rationale Phosphodiesterase enzyme type 5 (PDE5) inhibitors and acetylcholinesterase (AChE) inhibitors have cognition-enhancing properties. However, it is not known whether these drug classes affect the same memory processes. Objective We investigated the memory-enhancing effects of the PDE5 inhibit

  7. Correlation between topoisomerase I and tyrosyl-DNA phosphodiesterase 1 activities in non-small cell lung cancer tissue

    DEFF Research Database (Denmark)

    Jakobsen, Ann-Katrine; Lauridsen, Kristina Lystlund; Samuel, Evelyn Benuja


    Topoisomerase I (TOP1) regulates DNA topology during replication and transcription whereas tyrosyl-DNA phosphodiesterase 1 (TDP1) is involved in the repair of several types of DNA damages, including damages from defective TOP1 catalysis. TOP1 is the target of chemotherapeutic drugs of the camptot...

  8. Sildenafil and Phosphodiesterase-5 Inhibitors to Reduce Cardiotoxicity and Enhance the Response of Breast Tumor Cells to Doxorubicin (United States)


    promotes nor ame- liorates Adriamycin-induced cytotoxicity against either bone marrow cells or macrophages. Serafini et al. found that sildenafil reversed...Immunol 108(5):671–680 29. Serafini P et al (2006) Phosphodiesterase-5 inhibition augments endogenous antitumor immunity by reducing myeloid-derived

  9. Isolation and Partial Characterization of a Cyclic GMP-Dependent Cyclic GMP-Specific Phosphodiesterase from Dictyostelium discoideum

    NARCIS (Netherlands)

    Bulgakov, Roman; Haastert, Peter J.M. van


    The cellular slime mold, Dictyostelium discoideum, contains at least two classes of phosphodiesterase activity. One class of enzymes hydrolyses cyclic AMP (cAMP) and cyclic GMP (cGMP) with approximately equal rates. Another enzyme, which is less than 5% of the total activity, specifically hydrolyses

  10. Enhanced tumor necrosis factor suppression and cyclic adenosine monophosphate accumulation by combination of phosphodiesterase inhibitors and prostanoids

    NARCIS (Netherlands)

    Sinha, B; Semmler, J; Eisenhut, T; Eigler, A; Endres, S


    We investigated cooperative effects of phosphodiesterase (PDE) inhibitors and prostanoids on cyclic adenosine monophosphate (cAMP) accumulation and tumor necrosis factor (TNF)-alpha synthesis in human peripheral blood mononuclear cells (PBMC). PDE inhibitors alone induced only a small increase in cA

  11. Phosphodiesterases Inhibition by Bacilli Calmette-Guérin Contributes to Decrease Asthma in Allergic Rats

    Directory of Open Access Journals (Sweden)

    Yajuan Wang


    Full Text Available Phosphodiesterases  (PDE  hydrolyse intracellular cAMP  and  cGMP  to  inactive  5’ monophosphates. Decreased level of cAMP is involved in the pathogenesis of asthma. We and others have shown that phosphodiesterases were upregulated in the lung of allergic rats, and Bacilli Calmette-Guérin (BCG induced the production of cAMP in vitro. However, it is unclear how BCG’s effect asthma and whether it is related to PDEs.In  this  study,  BCG  was  intraperitoneally  injected  into  male  Sprague-Dawley rats sensitized and later the rats were challenged with ovabumin/pertusis. The inflammation in lungs was measured. Airway hyperresponsiveness was determined using MedLab software after intravenous methacholine challenge. Furthermore,  cAMP level and adenylate cyclase activity in lungs were analyzed by ELISA, phosphodiesterases activities were analyzed by HPLC, while PDEs mRNA levels in lungs was analyzed by reverse transcription-polymerase chain  reaction.  Administration  of  BCG  significantly attenuated  allergen-induced  lung inflammatory response  and  hyper  responsiveness  as  compared  with  vehicle treatment. Furthermore,  the  levels of  cAMP in lungs were significantly increased in  BCG-treated allergic rats. Interestingly, administration of BCG decreased the activity of cAMP-PDE, but not adenylyl cyclase (AC, activity in lungs of animals. Furthermore, pretreatment with BCG significantly decreased the mRNA levels of PDE4A, 4C, 5 and 8, which were induced in lungs of allergic rats.BCG  administration  attenuated  airway inflammatory  response  and  bronchial  hyper responsiveness in rats, which are the most important symptoms in asthma. The decreased PDEs  mRNA  and  inhibited cAMP-PDE  activities by BCG  contribute,  at least in part, prevention of allergen-induced airway inflammation and asthma in rats.

  12. Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog. (United States)

    Shang, E S; Skare, J T; Erdjument-Bromage, H; Blanco, D R; Tempst, P; Miller, J N; Lovett, M A


    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

  13. Effects of phosphodiesterase 4 inhibitor on cough response in guinea pigs sensitized and challenged with ovalbumin

    Institute of Scientific and Technical Information of China (English)

    吕寒静; 邱忠民; 魏为利; 余莉; 刘瑞麟; 张敏


    Background There is currently considerable interest in the potential value of selective inhibitors of cyclic nucleotide phosphodiesterase 4 in the treatment of asthma. However, whether they influence eosinophilic airway inflammation-associated cough remains unclear. The objective of this study was to investigate the effects of selective phosphodiesterase 4 inhibitor SB207499 on cough response and airway inflammation in guinea pigs sensitized and challenged with ovalbumin. Methods Forty sensitized guinea pigs were randomly divided into four groups: control (n=10), challenge (n=10), SB207499 (n=10) and aminophylline (n=10), then challenged with aerosol of 1% ovalbumin or saline. Two hours later, animals were intraperitoneally injected with either saline, 25 mg/kg of SB207499 or aminophylline. At the 24th hour, the injection was repeated with 2.5 mg/kg and 25 mg/kg SB207499 or aminophylline, then cough response to inhaled capsaicin and airway responsiveness to methacholine inducing a 150% of the peak airway pressure to the baseline (PC150) was measured. Finally, total cell number and differentials in bronchoalveolar lavage fluid were analysed. Results The cough frequency per 3 minutes and PC150 in the challenge group were (22±4) times/3 minutes and (198±54) μg/ml, which were significantly different from (6±2) times/3 minutes and (691±81) μg/ml in the control group (P<0.05, respectively). The injection of 25 mg/kg SB207499 significantly inhibited the increased cough response and airway hyperresponsiveness, the cough frequency and PC150 in guinea pigs were (13±2) times/3 minutes and (680±81) μg/ml (P<0.05), which differed significantly from (18±2) times/3 minutes and (400±86) μg/ml after the administration of the same dose of aminophylline (P<0.05). The inhibition of SB207499 on cough response was dose-dependent. Similarly, SB207499 decreased the total cell number and percentage of eosinophils in bronchoalveolar lavage fluid to (2.1±0.5)×106/ml and (20±5

  14. Phosphodiesterases: Regulators of cyclic nucleotide signals and novel molecular target for movement disorders. (United States)

    Sharma, Sorabh; Kumar, Kushal; Deshmukh, Rahul; Sharma, Pyare Lal


    Movement disorders rank among the most common neurological disorders. During the last two decades substantial progress has been made in understanding of the pathological basis of these disorders. Although, several mechanisms have been proposed, downregulation of cyclic nucleotide mediated signaling cascade has consistently been shown to contribute to the striatal dysfunctioning as seen in movement disorders. Thus, counteracting dysregulated cyclic nucleotide signaling has been considered to be beneficial in movement disorders. Cyclic nucleotide phosphodiesterases (PDEs) are the enzymes responsible for the breakdown of cyclic nucleotides and upregulation in PDE activity has been reported in various movement disorders. Thus, PDE inhibition is considered to be a novel strategy to restore cerebral cyclic nucleotide levels and their downstream signalling cascade. Indeed, various PDE inhibitors have been tested pre-clinically and were reported to be neuroprotective in various neurodegenerative disorders associated with movement disabilities. In this review, we have discussed a putative role of PDE inhibitors in movement disorders and associated abnormalities.


    Directory of Open Access Journals (Sweden)

    M. N. Mamedov


    Full Text Available About 150 million men worldwide and about 50% of men aged 40-88 y.o. in outpatient practice suffer from erectile dysfunction (ED. There is a linear relation between the age and ED rate. The main reason of ED in the majority of men (about 80% of patients is cardiovascular diseases (atherosclerosis, hypertension, diabetes mellitus, as well as certain risk factors (smoking, alcohol abuse, physical inactivity etc.. The problem of ED in cardiac outpatients and modern pharmacotherapy is discussed. The phosphodiesterase-5 (PDE5 inhibitors increase the relaxing effect of nitric oxide and increase cyclic GMP levels during sexual arousal. It results in increase of cavernosum blood flow, contributing to the physiological erection. Three PDE5 inhibitors (sildenafil, tadalafil, vardenafil are used in clinical practice nowadays.

  16. Active site similarity between human and Plasmodium falciparum phosphodiesterases: considerations for antimalarial drug design (United States)

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


    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.

  17. Phosphodiesterase 4B genetic variants are not associated with antipsychotic-induced tardive dyskinesia. (United States)

    Souza, Renan P; Remington, Gary; Meltzer, Herbert Y; Lieberman, Jeffrey A; Kennedy, James L; Wong, Albert H C


    Phosphodiesterase 4B (PDE4B) has been evaluated as a genetic risk factor for schizophrenia. Selective PDE4 inhibitor drugs have antipsychotic-like effects and reduce tardive dyskinesia-like movements in animal models. We investigated whether PDE4B genetic variants are associated with antipsychotic-induced tardive dyskinesia incidence and severity in schizophrenia patients. Our sample consisted of 169 Caucasian patients taking typical antipsychotic medication for at least 1 year. We found two PDE4B gene variants to be nominally associated with tardive dyskinesia (rs1338719 and rs7528545) in the overall population and two other variants nominally associated with the presence of tardive dyskinesia and severity in female patients (rs1890196 and rs783036). None of these results survived correction for multiple testing. Overall, our results do not support a genetic association between tardive dyskinesia and PDE4B.

  18. Nitric oxide-induced changes in endothelial expression of phosphodiesterases 2, 3, and 5

    DEFF Research Database (Denmark)

    Schankin, Christoph J; Kruse, Lars S; Reinisch, Veronika M;


    line containing such PDEs. METHODS: Real time polymerase chain reaction and Western blots were used to show expression of PDE2A, PDE3B, and PDE5A in a stable cell line of human brain microvascular endothelial cells. Effects of NO on PDE expression were analyzed at specific time intervals after......OBJECTIVE: To investigate nitric oxide (NO)-mediated changes in expression of cyclic nucleotide degrading phosphodiesterases 2A (PDE2A), PDE3B, and PDE5A in human endothelial cells. BACKGROUND: Nitric oxide induces production of cyclic guanosine monophosphate (cGMP), which along with cyclic...... adenosine monophosphate (cAMP) is degraded by PDEs. NO donors and selective inhibitors of PDE3 and PDE5 induce migraine-like headache and play a role in endothelial dysfunction during stroke. The current study investigates possible NO modulation of cGMP-related PDEs relevant to headache induction in a cell...

  19. The inhibition of phosphodiesterase type 5 as a novel target for antidepressant action

    DEFF Research Database (Denmark)

    Liebenberg, Nico


    therapy of depression. A recent study from our laboratory reported an antidepressant-like response in the rat forced swim test (FST) following chronic (11 day) co-administration of the phosphodiesterase type 5 (PDE5) inhibitor sildenafil and the muscarinic acetylcholine (mACh) receptor antagonist atropine......-related, suggesting that it may differentially affect the regulation of neurotransmission associated with antidepressant and depressogenic responses at different doses. Unlike the mood-regulating responses, however, the anxiolytic-like responses following chronic PDE5 inhibition does not appear to involve...... not involve up-regulation of frontal cortical and hippocampal mACh receptors. In summary, this project emphasises the potential of PDE5 inhibition as a novel antidepressant and anxiolytic strategy, and provides important insight into the specific neuronal mechanism(s) that may be involved...

  20. 2'-phosphodiesterase and 2',5'-oligoadenylate synthetase activities in the lowest metazoans, sponge [porifera]. (United States)

    Saby, Emilie; Poulsen, Jesper Buchhave; Justesen, Just; Kelve, Merike; Uriz, Maria Jesus


    Sponges [porifera], the most ancient metazoans, contain modules related to the vertebrate immune system, including the 2',5'-oligoadenylate synthetase (OAS). The components of the antiviral 2',5'-oligoadenylate (2-5A) system (OAS, 2'-Phosphodiesterase (2'-PDE) and RNAse L) of vertebrates have not all been identified in sponges. Here, we demonstrate for the first time that in addition to the OAS activity, sponges possess a 2'-PDE activity, which highlights the probable existence of a premature 2-5A system. Indeed, Suberites domuncula and Crella elegans exhibited this 2-5A degrading activity. Upon this finding, two out of three elements forming the 2-5A system have been found in sponges, only a endoribonuclease, RNAse L or similar, has to be found. We suspect the existence of a complex immune system in sponges, besides the self/non-self recognition system and the use of phagocytosis and secondary metabolites against pathogens.

  1. An alpha-glucose-1-phosphate phosphodiesterase is present in rat liver cytosol

    Energy Technology Data Exchange (ETDEWEB)

    Srisomsap, C.; Richardson, K.L.; Jay, J.C.; Marchase, R.B. (Univ. of Alabama, Birmingham (USA))


    UDP-glucose:glycoprotein glucose-1-phosphotransferase (Glc-phosphotransferase) catalyzes the transfer of alpha-Glc-1-P from UDP-Glc to mannose residues on acceptor glycoproteins. The predominant acceptor for this transfer in both mammalian cells and Paramecium is a cytoplasmic glycoprotein of 62-63 kDa. When cytoplasmic proteins from rat liver were fractionated by preparative isoelectric focusing following incubation of a liver homogenate with the 35S-labeled phosphorothioate analogue of UDP-Glc ((beta-35S)UDP-Glc), the acceptor was found to have a pI of about 6.0. This fraction, when not labeled prior to the focusing, became very heavily labeled when mixed with (beta-35S). UDP-Glc and intact liver microsomes, a rich source of the Glc-phosphotransferase. In addition, it was observed that the isoelectric fractions of the cytosol having pI values of 2-3.2 contained a degradative activity, alpha-Glc-1-P phosphodiesterase, that was capable of removing alpha-Glc-1-P, monitored through radioactive labeling both in the sugar and the phosphate, as an intact unit from the 62-kDa acceptor. Identification of the product of this cleavage was substantiated by its partial transformation to UDP-Glc in the presence of UTP and UDP-Glc pyrophosphorylase. The alpha-Glc-1-P phosphodiesterase had a pH optimum of 7.5 and was not effectively inhibited by any of the potential biochemical inhibitors that were tested. Specificity for the Glc-alpha-1-P-6-Man diester was suggested by the diesterase's inability to degrade UDP-Glc or glucosylphosphoryldolichol. This enzyme may be important in the regulation of secretion since the alpha-Glc-1-P present on the 62-kDa phosphoglycoprotein appears to be removed and then rapidly replaced in response to secretagogue.

  2. Cyclic AMP control measured in two compartments in HEK293 cells: phosphodiesterase K(M is more important than phosphodiesterase localization.

    Directory of Open Access Journals (Sweden)

    Karina Matthiesen

    Full Text Available The intracellular second messenger cyclic AMP (cAMP is degraded by phosphodiesterases (PDE. The knowledge of individual families and subtypes of PDEs is considerable, but how the different PDEs collaborate in the cell to control a cAMP signal is still not fully understood. In order to investigate compartmentalized cAMP signaling, we have generated a membrane-targeted variant of the cAMP Bioluminiscence Resonance Energy Transfer (BRET sensor CAMYEL and have compared intracellular cAMP measurements with it to measurements with the cytosolic BRET sensor CAMYEL in HEK293 cells. With these sensors we observed a slightly higher cAMP response to adenylyl cyclase activation at the plasma membrane compared to the cytosol, which is in accordance with earlier results from Fluorescence Resonance Energy Transfer (FRET sensors. We have analyzed PDE activity in fractionated lysates from HEK293 cells using selective PDE inhibitors and have identified PDE3 and PDE10A as the major membrane-bound PDEs and PDE4 as the major cytosolic PDE. Inhibition of membrane-bound or cytosolic PDEs can potentiate the cAMP response to adenylyl cyclase activation, but we see no significant difference between the potentiation of the cAMP response at the plasma membrane and in cytosol when membrane-bound and cytosolic PDEs are inhibited. When different levels of stimulation were tested, we found that PDEs 3 and 10 are mainly responsible for cAMP degradation at low intracellular cAMP concentrations, whereas PDE4 is more important for control of cAMP at higher concentrations.

  3. A deletion in the gene encoding sphingomyelin phosphodiesterase 3 (Smpd3) results in osteogenesis and dentinogenesis imperfecta in the mouse. (United States)

    Aubin, Isabelle; Adams, Carolyn P; Opsahl, Sibylle; Septier, Dominique; Bishop, Colin E; Auge, Nathalie; Salvayre, Robert; Negre-Salvayre, Anne; Goldberg, Michel; Guénet, Jean-Louis; Poirier, Christophe


    The mouse mutation fragilitas ossium (fro) leads to a syndrome of severe osteogenesis and dentinogenesis imperfecta with no detectable collagen defect. Positional cloning of the locus identified a deletion in the gene encoding neutral sphingomyelin phosphodiesterase 3 (Smpd3) that led to complete loss of enzymatic activity. Our knowledge of SMPD3 function is consistent with the pathology observed in mutant mice and provides new insight into human pathologies.

  4. Characterization of phosphodiesterase 2A in human malignant melanoma PMP cells. (United States)

    Morita, Hiroshi; Murata, Taku; Shimizu, Kasumi; Okumura, Kenya; Inui, Madoka; Tagawa, Toshiro


    The prognosis for malignant melanoma is poor; therefore, new diagnostic methods and treatment strategies are urgently needed. Phosphodiesterase 2 (PDE2) is one of 21 phosphodiesterases, which are divided into 11 families (PDE1-PDE11). PDE2 hydrolyzes cyclic AMP (cAMP) and cyclic GMP (cGMP), and its binding to cGMP enhances the hydrolysis of cAMP. We previously reported the expression of PDE1, PDE3 and PDE5 in human malignant melanoma cells. However, the expression of PDE2 in these cells has not been investigated. Herein, we examined the expression of PDE2A and its role in human oral malignant melanoma PMP cells. Sequencing of RT-PCR products revealed that PDE2A2 was the only variant expressed in PMP cells. Four point mutations were detected; one missense mutation at nucleotide position 734 (from C to T) resulted in the substitution of threonine with isoleucine at amino acid position 214. The other three were silent mutations. An in vitro migration assay and a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay revealed that suppressing PDE2 activity with its specific inhibitor, erythro-9-(2-hydroxy-3-nonyl)-adenine (EHNA), had no impact on cell motility or apoptosis. Furthermore, the cytotoxicity of EHNA, assessed using a trypan blue exclusion assay, was negligible. On the other hand, assessment of cell proliferation by BrdU incorporation and cell cycle analysis by flow cytometry revealed that EHNA treatment inhibited DNA synthesis and increased the percentage of G2/M-arrested cells. Furthermore, cyclin A mRNA expression was downregulated, while cyclin E mRNA expression was upregulated in EHNA-treated cells. Our results demonstrated that the PDE2A2 variant carrying point mutations is expressed in PMP cells and may affect cell cycle progression by modulating cyclin A expression. Thus, PDE2A2 is a possible new molecular target for the treatment of malignant melanoma.

  5. Characterization of binding and inhibitory properties of TAK-063, a novel phosphodiesterase 10A inhibitor.

    Directory of Open Access Journals (Sweden)

    Akina Harada

    Full Text Available 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-ylphenyl]-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.

  6. Absorption, distribution, metabolism and excretion of novel phosphodiesterase type 4 inhibitor ASP3258 in rats. (United States)

    Ohtsu, Yoshiaki; Sonoda, Takuya; Susaki, Yoko; Tohda, Toshifumi; Fukunaga, Yasuhisa; Iwatsubo, Takafumi; Noguchi, Kiyoshi


    The potent and selective phosphodiesterase 4 inhibitor ASP3258 is a novel therapeutic agent for asthma and chronic obstructive pulmonary disease (COPD). After a single oral administration to rats, ASP3258 is rapidly absorbed with a bioavailability of 106%. In situ absorption data indicated that ASP3258 is mainly absorbed in the small intestine. Tissue distribution data after oral administration of (14)C-ASP3258 showed rapid and extensive distribution to various tissues. Excluding the gastrointestinal tract, the tissues with the highest concentrations were liver, heart and plasma. Liquid chromatography-nuclear magnetic resonance spectroscopy data revealed that O-glucuronidation of the carboxylic acid moiety of ASP3258 (formation of an acyl glucuronide) plays a key role in metabolism. No indication was found that the acyl glucuronide reacted with proteins in plasma or tissues. When (14)C-ASP3258 was orally administered to intact rats, urinary and fecal excretion accounted for 1.3% and 100.6% of the administered radioactivity, respectively. After a single oral administration of (14)C-ASP3258 to bile-cannulated rats, urinary and biliary excretion accounted for 0.7% and 93.8% of the administered radioactivity, respectively. These findings suggest that fecal excretion via bile plays an important role in the elimination of ASP3258-derived radioactivity. In vitro metabolic profiles were relatively similar among the species examined, suggesting that our findings in rats may help us to understand pharmacokinetics, efficacy and safety profiles in humans and other species.

  7. Phosphodiesterase: an interface connecting cognitive deficits to neuropsychiatric and neurodegenerative diseases. (United States)

    Wang, Zhen-Zhen; Zhang, Yi; Zhang, Han-Ting; Li, Yun-Feng


    Phosphodiesterases (PDEs) are the only known enzymes to degrade intracellular cyclic AMP and/or cyclic GMP. The PDE superfamily consists of 11 families (PDE1- PDE11), each of which has 1 to 4 subtypes. Some of the subtypes may have multiple splice variants (e.g. PDE4D1-PDE4D11), leading to a total of more than 100 known proteins to date. Growing attention has been paid to the potential of PDEs as therapeutic targets for mood disorders and/or diseases affecting cognitive activity by controlling the rate of hydrolysis of the two aforementioned second messengers in recent years. The loss of cognitive functions is one of the major complaints most patients with CNS diseases face; it has an even more prominent negative impact on the quality of daily life. Cognitive dysfunction is usually a prognosis in patients suffering from neuropsychiatric and neurodegenerative diseases, including depression, schizophrenia, and Alzheimer's disease. This review will focus on the contributions of PDEs to the interface between cognitive deficits and neuropsychiatric and neurodegenerative disorders. It is expected to make for the understanding and discovery that selective PDE inhibitors have the therapeutic potential for cognitive dysfunctions associated with neuropsychiatric and neurodegenerative disorders.

  8. Pathophysiology of visual disorders induced by phosphodiesterase inhibitors in the treatment of erectile dysfunction (United States)

    Moschos, Marilita M; Nitoda, Eirini


    Aim The aim of this review was to summarize the ocular action of the most common phosphodiesterase (PDE) inhibitors used for the treatment of erectile dysfunction and the subsequent visual disorders. Method This is a literature review of several important articles focusing on the pathophysiology of visual disorders induced by PDE inhibitors. Results PDE inhibitors have been associated with ocular side effects, including changes in color vision and light perception, blurred vision, transient alterations in electroretinogram (ERG), conjunctival hyperemia, ocular pain, and photophobia. Sildenafil and tadalafil may induce reversible increase in intraocular pressure and be involved in the development of non-arteritic ischemic optic neuropathy. Reversible idiopathic serous macular detachment, central serous chorioretinopathy, and ERG disturbances have been related to the significant impact of sildenafil and tadalafil on retinal perfusion. Discussion So far, PDE inhibitors do not seem to cause permanent toxic effects on chorioretinal tissue and photoreceptors. However, physicians should write down any visual symptom observed during PDE treatment and refer the patients to ophthalmologists. PMID:27799745

  9. Trigger phosphodiesterases as a novel class of c-di-GMP effector proteins (United States)


    The bacterial second messenger c-di-GMP controls bacterial biofilm formation, motility, cell cycle progression, development and virulence. It is synthesized by diguanylate cyclases (with GGDEF domains), degraded by specific phosphodiesterases (PDEs, with EAL of HD-GYP domains) and sensed by a wide variety of c-di-GMP-binding effectors that control diverse targets. c-di-GMP-binding effectors can be riboswitches as well as proteins with highly diverse structures and functions. The latter include ‘degenerate’ GGDEF/EAL domain proteins that are enzymatically inactive but still able to bind c-di-GMP. Surprisingly, two enzymatically active ‘trigger PDEs’, the Escherichia coli proteins PdeR and PdeL, have recently been added to this list of c-di-GMP-sensing effectors. Mechanistically, trigger PDEs are multifunctional. They directly and specifically interact with a macromolecular target (e.g. with a transcription factor or directly with a promoter region), whose activity they control by their binding and degradation of c-di-GMP—their PDE activity thus represents the c-di-GMP sensor or effector function. In this process, c-di-GMP serves as a regulatory ligand, but in contrast to classical allosteric control, this ligand is also degraded. The resulting kinetics and circuitry of control are ideally suited for trigger PDEs to serve as key components in regulatory switches. This article is part of the themed issue ‘The new bacteriology’. PMID:27672149

  10. Effect of selective phosphodiesterase inhibitors on the rat eosinophil chemotactic response in vitro

    Directory of Open Access Journals (Sweden)

    Alessandra C Alves


    Full Text Available In the present study, we have performed a comparative analysis of the effect of selective inhibitors of phosphodiesterase (PDE type III, IV and V on eosinophil chemotaxis triggered by platelet activating factor (PAF and leukotriene B4 (LTB4 in vitro. The effect of the analogues N6-2'-O-dibutyryladenosine 3':5' cyclic monophosphate (Bt2 cyclic AMP and N2-2'-O- dibutyrylguanosine 3':5' cyclic monophosphate (Bt2 cyclic GMP has also been determined. The eosinophils were obtained from the peritoneal cavity of naive Wistar rats and purified in discontinuous Percoll gradients to 85-95% purity. We observed that pre-incubation of eosinophils with the PDE type IV inhibitor rolipram suppressed the chemotactic response triggered by PAF and LTB4, in association with an increase in the intracellular levels of cyclic AMP. In contrast, neither zaprinast (type V inhibitor nor type III inhibitors milrinone and SK&F 94836 affected the eosinophil migration. Only at the highest concentration tested did the analogue Bt2 cyclic AMP suppress the eosinophil chemotaxis, under conditions where Bt2 cyclic GMP was ineffective. We have concluded that inhibition of PDE IV, but not PDE III or V, was able to block the eosinophil chemotaxis in vitro, suggesting that the suppressive activity of selective PDE IV inhibitors on tissue eosinophil accumulation may, at least, be partially dependent on their ability to directly inhibit the eosinophil migration.

  11. Evaluation of antidepressant and anxiolytic activity of phosphodiesterase 3 inhibitor - Cilostazol

    Directory of Open Access Journals (Sweden)

    Dipesh S Patel


    Full Text Available Background: Cyclic nucleotide Phosphodiesterases (PDEs are ubiquitously distributed in mammalian tissues and play a major role in cell signaling by hydrolyzing cyclic Adenosine Monophosphate (cAMP and cyclic Guanosine Monophosphate (cGMP. Impairments in signal transduction have been implicated as possible mechanism of reduced plasticity and neuronal survival in major depressive disorders. PDE inhibitors possess a potentially powerful means to manipulate secondary messengers involved in learning, memory and mood. Cilostazol is an antiplatelet agent indicated for the treatment of intermittent claudication with peripheral artery occlusion and for the prevention of ischemic stroke worldwide. Various animal studies have reported neuroprotective, anti apoptotic, cognition and cerebral blood flow improvement properties of cilostazol. Materials and Methods: In this study, the antidepressant and anxiolytic effects of cilostazol were evaluated in mice using behavioral tests sensitive to clinically effective antidepressant compound. Results: Cilostazol, administered intraperitoneally (20 mg/kg, decreased immobility time of mice when subjected to forced swim test and tail suspension test as compared to standard fluoxetine (20 mg/kg. Cilostazol also produced significant decrease in the number of marbles buried as compared to fluoxetine in marble burying model. Conclusion: The present study suggests that cilostazol possesses potential antidepressant and anxiolytic activity, which could be of therapeutic interest for use in patients with depressive disorders.

  12. Homocysteine and copper interact to promote type 5 phosphodiesterase expression in rabbit cavernosal smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Matthew Hotston; Jamie Y.Jeremy; Jonathon Bloor; Nick S.Greaves; Raj Persad; Giarmi Angelini; Nilima Shukla


    Aim: To study the effects of homocysteine and copper on type 5 phosphodiesterase (PDE5) expression in cavernosal vascular smooth muscle cells (CVSMCs) and to investigate superoxide (O2) derived from nicotinamide adenine dinucleotide phosphate oxidase as homocysteine and copper generate O2, and O2- upregulates PDE5 expression.Methods: CVSMCs derived from rabbit penis were incubated with homocysteine or copper chloride with or without superoxide dismutase (SOD), catalase, sildenafil citrate, or apocynin (nicotinamide adenine dinucleotide phosphate inhibitor) for 16 h. The expression of PDE5 and of glyceraldehyde-3-phosphate dehydrogenase (internal standard) was assessed using Western blot analysis. In parallel, O2 was measured spectrophotometrically. Results: CuCl2alone (up to 10 μmol/L) and homocysteine alone (up to 100 μmol/L) had no effect on O2 formation in CVSMCs compared to controls. In combination, however, homocysteine and CuCl2 arkedly increased O2 formation, an effect blocked by SOD, catalase, apocynin, and sildenafil (1 μmol/L) when co-incubated over the same time course.PDE5 expression was also significantly increased in CVSMCs incubated with homocysteine and CuCl2, compared to controls. This effect was also negated by 16-h co-incubation with SOD, catalase, apocynin and sildenafil. Conclusion:This represents a novel pathogenic mechanism underlying ED, and indicates that the therapeutic actions of prolonged sildenafil use are mediated in part through inhibition of this pathway.

  13. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants (United States)

    Olivares-González, Lorena; Martínez-Fernández de la Cámara, Cristina; Hervás, David; Marín, María Pilar; Lahoz, Agustin; Millán, José María


    Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP) has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE) with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2) for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation) mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities) and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions. PMID:27861632

  14. Erectile dysfunction and heart failure: the role of phosphodiesterase type 5 inhibitors (United States)

    Al-Ameri, H; Kloner, R A


    The phosphodiesterase type 5 (PDE-5) inhibitors are effective in treating erectile dysfunction (ED). ED and heart failure (HF) share similar risk factors, and commonly present together. This association has led to questions ranging from the safety and efficacy of PDE-5 inhibitors in HF patients to a possible role for this class of medication to treat HF patients with or without ED. In addition to endothelial dysfunction, there are causes of ED specific to patients with HF including low exercise tolerance, depression and HF medications. Before treating HF patients with PDE-5 inhibitors, patients should be assessed for their risk of a cardiac event during sexual activity. PDE-5 inhibitors are safe and effective in treating ED in HF patients. An improvement in erectile function by PDE-5 inhibitors was associated with an improvement in quality of life and reduction in depression. Several studies demonstrated the effect of PDE-5 inhibitors on HF per se. PDE-5 inhibitors improved endothelial dysfunction, increased exercise tolerance, decreased pulmonary vascular resistance and pulmonary artery pressure, and increased cardiac index. Several mechanisms whereby PDE-5 inhibitors improve HF have been proposed. PDE-5 inhibitors already have a role in treating primary pulmonary hypertension; however additional studies are needed to determine if they will become a standard therapy for HF patients. PMID:19387454

  15. Properties of a cyclic 3'5'-nucleotide phosphodiesterase from Vigna mungo. (United States)

    Lee, C H; Abidin, U Z


    Cyclic AMP phosphodiesterase (PDE) partially purified from roots of Vigna mungo exhibited optimum activity at pH 5.5 to 6.0 and maximum enzyme activity at 50 degrees C. Levels of PDE activity in roots remained relatively constant from the first to the eleventh day after germination; on the twelfth day there was a 400% increase in PDE activity. The enzyme was stable for at least 48 hours at 28 degrees C, retaining 92% of its original activity. Plant growth hormones including gibberellic acid, indoleacetic acid and kinetin at 1.0 and 10.0 microM concentrations did not have any significant effect on enzyme activity. Nucleotides tested including cyclic 2'3' AMP, cyclic 2'3' GMP completely abolished enzyme activity at 1.0mM while cyclic 3'5' GMP, cyclic 3'5' GMP, 2'deoxy 5' ATP, 2'deoxy 5'GTP and 5'ADP were also inhibitory to the enzyme. The enzyme was stimulated by Mg2+, Fe2+ and NH4+ while Cu2+ and Fe3+ were inhibitory. Theophylline, caffeine, phosphate, pyrophosphate and EDTA were inhibitory to the enzyme.

  16. Reduced Airway Hyperresponsiveness by Phosphodiesterase 3 and 4 Inhibitors in Guinea-Pigs

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    Nöella Germain


    Full Text Available The aim of the present study was to compare the effects of selective phosphodiesterase (PDE 3, 4 and 5 inhibitors on antigen-induced airway hyperresponsiveness in sensitized guinea-pigs. When the sensitized guinea-pigs were orally pre-treated with the selective PDE4 inhibitor, Ro 20-1724 (30 mg/kg, and studied 48 h after OA, a significant reduction (p<0.01 of the leftward shift of the dose-response curve to ACh was noted, whereas it was ineffective at the lower dose (10 mg/kg. Administration of the selective PDE3 inhibitor, milrinone (30 mg/kg also elicited a significant reduction (p<0.01 of the airway hyperresponsiveness, whereas the PDE5 inhibitor zaprinast (30 mg/kg was ineffective. These results show that both PDE3 and PDE4 inhibitors are able to inhibit the antigen-induced airway hyperresponsiveness in sensitized guinea-pigs and support the potential utility of selective PDE inhibitors in the treatment of asthma.

  17. Cyclic nucleotide phosphodiesterase isoenzymes in guinea-pig tracheal muscle and bronchorelaxation by alkylxanthines. (United States)

    Miyamoto, K; Kurita, M; Sakai, R; Sanae, F; Wakusawa, S; Takagi, K


    In this study the phosphodiesterase (PDE) isoenzymes in guinea-pig trachealis smooth muscle were separated by DEAE-Sepharose anion exchange chromatography, identified, and characterized. Furthermore the effect of theophylline and 1-n-butyl-3-n-propylxanthine (BPX) on the isolated PDE isoenzymes and on their tracheal relaxant effect were investigated and compared with the nonxanthine PDE inhibitors amrinone and Ro 20-1724. We identified five distinct isoenzymes in guinea-pig tracheal muscle; calcium/calmodulin-stimulated cyclic AMP PDE (PDE I), cyclic GMP-stimulated cyclic AMP PDE (PDE II), cyclic GMP-inhibited and amrinone-sensitive cyclic AMP PDE (PDE III), cyclic AMP-specific and Ro 20-1724-sensitive PDE (PDE IV), and cyclic GMP-specific PDE (PDE V). BPX strongly inhibited the PDE IV isoenzyme with high selectivity, while the inhibitory effect of theophylline was weak. The PDE IV inhibitors BPX and Ro 20-1724 synergistically increased the relaxant effect of the beta 2-adrenoceptor agonist salbutamol in carbachol-contracted trachea much more strongly than theophylline. In contrast, amrinone, a PDE III inhibitor, hardly influenced the relaxant effect of salbutamol, suggesting that the PDE IV isoenzyme is functionally associated with beta 2-adrenoceptors in guinea-pig trachea and that inhibition of this enzyme potentiates the ability of salbutamol to increase the intracellular cyclic AMP content. These results indicate that the PDE IV isoenzyme plays a significant role in alkylxanthine-mediated relaxation of guinea-pig trachea.

  18. Phosphatidylinositol phosphodiesterase (phospholipase C) activity in the pineal gland: characterization and photoneural regulation

    Energy Technology Data Exchange (ETDEWEB)

    Ho, A.K.; Klein, D.C.


    Phosphatidylinositol phosphodiesterase (PL-C) appears to be a key element in the adrenergic regulation of pineal cyclic AMP levels. In the present study, the rat pineal enzyme was characterized using exogenous (/sup 3/H)phosphatidylinositol (0.5 mM) as substrate. Half the enzyme activity was found in the cytosolic fraction, but the highest specific concentration was associated with the membrane fraction. Two pH optima (5.5 and 7.5) of enzyme activity were observed for the membrane fraction but only one in the cytosol fraction (pH 5.5). Enzyme activity in both fractions was Ca2+ dependent. In the case of the membrane protein in pH 7.5, the enzyme activity was sensitive to changes in Ca2+ in the 10-100 nM range. Addition of an equimolar concentration of phosphatidylinositol 4-phosphate nearly completely inhibited the hydrolysis of (/sup 3/H)phosphatidylinositol; other phospholipids (1.0 mM) were less potent. This may reflect our present finding that (/sup 3/H)phosphatidylinositol 4-phosphate is a better substrate than (/sup 3/H)phosphatidylinositol for the enzyme. Stimulus deprivation (2 weeks of constant light or superior cervical ganglionectomy) reduced the cytosolic activity by 30% and had no effect on the membrane-associated enzyme.

  19. Topical therapy for psoriasis: a promising future. Focus on JAK and phosphodiesterase-4 inhibitors. (United States)

    Rafael, Adilia; Torres, Tiago


    Psoriasis is a common, chronic and disabling skin disorder affecting approximately 2% of the population, associated with significant negative impact on the patient's quality of life. Approximately 80% of those affected with psoriasis have mild-to-moderate forms and are usually treated with topical therapy, whereas phototherapy and systemic therapies are used for those with severe disease. In the past three decades, the major advances in psoriasis therapy have been in systemic agents for the treatment of moderate-to-severe psoriasis, particularly new immunomodulatory and biological molecules, while topical therapies have remained relatively unchanged over the past decades. Indeed, topical corticosteroids and vitamin D3 analogs are still the gold standard of therapy for mild-to-moderate psoriasis. Thus, there is a need to develop new and more effective topical agents in the short and long term, with a better efficacy and safety profile than corticosteroids and vitamin D3 analogs. Over the past five years, investigation into topical therapy has expanded, with exciting new drugs being developed. Preliminary results of these emerging agents that selectively target disease-defining pathogenic pathways seem to be promising, although long-term and large-scale studies assessing safety and efficacy are still lacking. The aim of this article was to review the clinical and research data of some emerging topical agents, focusing on Janus kinase-signal transducer and activator of transcription and phosphodiesterase type 4 inhibitors, which are currently being investigated.

  20. Phosphodiesterase-3 inhibitor (cilostazol) attenuates oxidative stress-induced mitochondrial dysfunction in the heart

    Institute of Scientific and Technical Information of China (English)

    Siriporn C.Chattipakorn; Savitree Thummasorn; Jantira Sanit; Nipon Chattipakorn


    Background Cilostazol is a type 3 phosphodiesterase inhibitor which has been previously demonstrated to prevent the occurrence of tachyarrhythmia and improve defibrillation efficacy. However, the mechanism for this beneficial effect is still unclear. Since cardiac mito-chondria have been shown to play a crucial role in fatal cardiac arrhythmias and that oxidative stress is one of the main contributors to arr-hythmia generation, we tested the effects of cilostazol on cardiac mitochondria under severe oxidative stress. Methods Mitochondria were isolated from rat hearts and treated with H2O2 to induce oxidative stress. Cilostazol, at various concentrations, was used to study its protective effects. Pharmacological interventions, including a mitochondrial permeability transition pore (mPTP) blocker, cyclosporine A (CsA), and an inner membrane anion channel (IMAC) blocker, 4’-chlorodiazepam (CDP), were used to investigate the mechanistic role of cilostazol on cardiac mitochondria. Cardiac mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential change and mi-tochondrial swelling were determined as indicators of cardiac mitochondrial function. Results Cilostazol preserved cardiac mitochondrial function when exposed to oxidative stress by preventing mitochondrial depolarization, mitochondrial swelling, and decreasing ROS produc-tion. Conclusions Our findings suggest that cardioprotective effects of cilostazol reported previously could be due to its prevention of car-diac mitochondrial dysfunction caused by severe oxidative stress.

  1. Trigger phosphodiesterases as a novel class of c-di-GMP effector proteins. (United States)

    Hengge, Regine


    The bacterial second messenger c-di-GMP controls bacterial biofilm formation, motility, cell cycle progression, development and virulence. It is synthesized by diguanylate cyclases (with GGDEF domains), degraded by specific phosphodiesterases (PDEs, with EAL of HD-GYP domains) and sensed by a wide variety of c-di-GMP-binding effectors that control diverse targets. c-di-GMP-binding effectors can be riboswitches as well as proteins with highly diverse structures and functions. The latter include 'degenerate' GGDEF/EAL domain proteins that are enzymatically inactive but still able to bind c-di-GMP. Surprisingly, two enzymatically active 'trigger PDEs', the Escherichia coli proteins PdeR and PdeL, have recently been added to this list of c-di-GMP-sensing effectors. Mechanistically, trigger PDEs are multifunctional. They directly and specifically interact with a macromolecular target (e.g. with a transcription factor or directly with a promoter region), whose activity they control by their binding and degradation of c-di-GMP-their PDE activity thus represents the c-di-GMP sensor or effector function. In this process, c-di-GMP serves as a regulatory ligand, but in contrast to classical allosteric control, this ligand is also degraded. The resulting kinetics and circuitry of control are ideally suited for trigger PDEs to serve as key components in regulatory switches.This article is part of the themed issue 'The new bacteriology'.

  2. Effects of the phosphodiesterase 4 inhibitor RPR 73401 in a model of immunological inflammation. (United States)

    Ehinger, A M; Gorr, G; Hoppmann, J; Telser, E; Ehinger, B; Kietzmann, M


    The study was performed to investigate effects of the phosphodiesterase 4 inhibitor RPR 73401 [N-(3, 5-dichloropyrid-4-yl)-3-cyclopentyl-oxy-4-methoxybenzamid] on an allergic skin reaction. To simulate an immunological inflammation, BALB/c mice were sensitized to dinitrochlorobenzene or toluenediisocyanate. At first, the abdominal skin was shaved and 50 microliter Freund's adjuvant were injected intracutaneously once. Then, the horny layer was removed by adhesive tape stripping and 100 microliter 0.5% dinitrochlorobenzene or 5% toluenediisocyanate were administered on the epidermis for 4 days. After repeated local treatment of the ear skin with 20 microliter 3% RPR 73401 or intraperitoneal administration of 1 and 5 mg/kg RPR 73401, 20 microliter 1% dinitrochlorobenzene or 0.5% toluenediisocyanate were given topically as a challenge. The vehicle controls showed a high increase in ear thickness over 48 h after challenge, whereas RPR 73401 administered on either route reduced this increase significantly. Nevertheless after topical administration, RPR 73401 had a longer lasting effect. These and other results may point to an indication for RPR 73401 in immunological dermatitis.

  3. Erektile Dysfunktion, Phosphodiesterase-5-Hemmer und KHK - die Sicht des Kardiologen

    Directory of Open Access Journals (Sweden)

    Schmid P


    Full Text Available Die erektile Dysfunktion (ED kommt vermehrt bei Patienten mit koronarer Herzkrankheit (KHK vor und wird üblicherweise mit Phosphodiesterase- 5-Hemmern (PDE-5-Hemmer wie Sildenafil, Vardenafil und Tadalafil behandelt. Dies geht mit einem systemischen Blutdruckabfall von bis zu 10 mmHg systolisch und bis 6 mmHg diastolisch einher. Die Herzfrequenz bleibt gleich oder steigt minimal an, das Doppelprodukt (RR sys x HF als Maß des myokardialen Sauerstoffverbrauches bleibt unverändert oder sinkt ab. Koronarangiographische Untersuchungen bei KHK-Patienten unter Sildenafil ergaben gegenüber Placebo keine Unterschiede in der Hämodynamik. Auch die Koronarreserve, die Blutflußgeschwindigkeit, der Durchmesser der Koronararterien, das Blutflußvolumen und der Koronargefäßwiderstand blieben unbeeinflußt. Die körperliche Leistungsfähigkeit wurde durch Sildenafil und Vardenafil nicht verändert. Eine kardiovaskuläre Exzeßmortalität liegt durch Einnahme von PDE-5-Hemmern nicht vor. Absolute Kontraindikation für eine Therapie mit PDE-5-Hemmern ist die gleichzeitige Gabe von NO-Donatoren (Nitrate, Molsidomin, Nitroprussid-Natrium, relative Kontraindikationen sind eine akute Koronarinsuffizienz, Herzinsuffizienz mit niedrigem Blutdruck, vorbestehende antihypertensive 3- bis 4-fach-Kombinationstherapie, Pharmaka, die den Abbau bzw. die Elimination von PDE-5-Hemmern reduzieren, sowie Antiarrhythmika der Klasse III.

  4. Novel role of phosphodiesterase inhibitors in the management of end-stage heart failure

    Institute of Scientific and Technical Information of China (English)

    Abhishek Jaiswal; Vinh Q Nguyen; Thierry H Le Jemtel; Keith C Ferdinand


    In advanced heart failure(HF), chronic inotropic therapy with intravenous milrinone, a phosphodiesterase Ⅲ inhibitor, is used as a bridge to advanced management that includes transplantation, ventricular assist device implantation, or palliation. This is especially true when repeated attempts to wean off inotropic support result in symptomatic hypotension, worsened symptoms, and/or progressive organ dysfunction. Unfortunately, patients in this clinical predicament are considered hemodynamically labile and may escape the benefits of guidelinedirected HF therapy. In this scenario, chronic milrinone infusion may be beneficial as a bridge to introduction of evidence based HF therapy. However, this strategy is not well studied, and in general, chronic inotropic infusion is discouraged due to potential cardiotoxicity that accelerates disease progression and proarrhythmic effects that increase sudden death. Alternatively, chronic inotropic support with milrinone infusion is a unique opportunity in advanced HF. This review discusses evidence that long-term intravenous milrinone support may allow introduction of beta blocker(BB) therapy. When used together, milrinone does not attenuate the clinical benefits of BB therapy while BB mitigates cardiotoxic effects of milrinone. In addition, BB therapy decreases the risk of adverse arrhythmias associated with milrinone. We propose that advanced HF patients who are intolerant to BB therapy may benefit from a trial of intravenous milrinone as a bridge to BB initiation. The discussed clinical scenarios demonstrate that concomitant treatment with milrinone infusion and BB therapy does not adversely impact standard HF therapy and may improve left ventricular function and morbidity associated with advanced HF.

  5. The cyclic AMP phosphodiesterase RegA critically regulates encystation in social and pathogenic amoebas. (United States)

    Du, Qingyou; Schilde, Christina; Birgersson, Elin; Chen, Zhi-hui; McElroy, Stuart; Schaap, Pauline


    Amoebas survive environmental stress by differentiating into encapsulated cysts. As cysts, pathogenic amoebas resist antibiotics, which particularly counteracts treatment of vision-destroying Acanthamoeba keratitis. Limited genetic tractability of amoeba pathogens has left their encystation mechanisms unexplored. The social amoeba Dictyostelium discoideum forms spores in multicellular fruiting bodies to survive starvation, while other dictyostelids, such as Polysphondylium pallidum can additionally encyst as single cells. Sporulation is induced by cAMP acting on PKA, with the cAMP phosphodiesterase RegA critically regulating cAMP levels. We show here that RegA is deeply conserved in social and pathogenic amoebas and that deletion of the RegA gene in P. pallidum causes precocious encystation and prevents cyst germination. We heterologously expressed and characterized Acanthamoeba RegA and performed a compound screen to identify RegA inhibitors. Two effective inhibitors increased cAMP levels and triggered Acanthamoeba encystation. Our results show that RegA critically regulates Amoebozoan encystation and that components of the cAMP signalling pathway could be effective targets for therapeutic intervention with encystation.

  6. Phosphodiesterase inhibitors for persistent pulmonary hypertension of the newborn: a review. (United States)

    Travadi, J N; Patole, S K


    Persistent pulmonary hypertension of the newborn (PPHN) is a complex syndrome with multiple causes, with an incidence of 0.43-6.8/1,000 live births and a mortality of 10-20%. Survivors have high morbidity in the forms of neurodevelopmental and audiological impairment, cognitive delays, hearing loss, and a high rate of rehospitalization. The optimal approach to the management of PPHN remains controversial. Inhaled nitric oxide (iNO) is currently regarded as the gold standard therapy, but with as many as 30% of cases failing to respond, has not proven to be the single magic bullet. Given the complex pathophysiology of the disease, any such magic bullet is unlikely. A number of recent studies have suggested a role for specific phosphodiesterase (PDE) inhibitors in the management of PPHN. Sildenafil, a specific PDE5 inhibitor, appears the most promising of such agents. We aim to review the current status and limitations of iNO and the potential of PDE inhibitors in the management of PPHN. The reasons why caution is warranted before specific PDE5 inhibitors like sildenafil are labelled as potential magic bullets for PPHN will be discussed. The need for randomized-controlled trials to determine the safety, efficacy, and long-term outcome following treatment with sildenafil in PPHN is emphasized.

  7. Lung vasodilatory response to inhaled iloprost in experimental pulmonary hypertension: amplification by different type phosphodiesterase inhibitors

    Directory of Open Access Journals (Sweden)

    Weissmann Norbert


    Full Text Available Abstract Inhaled prostanoids and phosphodiesterase (PDE inhibitors have been suggested for treatment of severe pulmonary hypertension. In catheterized rabbits with acute pulmonary hypertension induced by continuous infusion of the stable thromboxane analogue U46619, we asked whether sildenafil (PDE1/5/6 inhibitor, motapizone (PDE3 inhibitor or 8-Methoxymethyl-IBMX (PDE1 inhibitor synergize with inhaled iloprost. Inhalation of iloprost caused a transient pulmonary artery pressure decline, levelling off within per se ineffective dose of each PDE inhibitor (200 μg/kg × min 8-Methoxymethyl-IBMX, 1 μg/kg × min sildenafil, 5 μg/kg × min motapizone with subsequent iloprost nebulization, marked amplification of the prostanoid induced pulmonary vasodilatory response was noted and the area under the curve of PPA reduction was nearly threefold increased with all approaches, as compared to sole iloprost administration. Further amplification was achieved with the combination of inhaled iloprost with sildenafil plus motapizone, but not with sildenafil plus 8MM-IBMX. Systemic hemodynamics and gas exchange were not altered for all combinations. We conclude that co-administration of minute systemic doses of selective PDE inhibitors with inhaled iloprost markedly enhances and prolongs the pulmonary vasodilatory response to inhaled iloprost, with maintenance of pulmonary selectivity and ventilation perfusion matching. The prominent effect of sildenafil may be operative via both PDE1 and PDE5, and is further enhanced by co-application of a PDE3 inhibitor.

  8. Aggregation of scaffolding protein DISC1 dysregulates phosphodiesterase 4 in Huntington's disease. (United States)

    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


    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.

  9. Synthesis, Pharmacological Profile and Docking Studies of New Sulfonamides Designed as Phosphodiesterase-4 Inhibitors (United States)

    Cardozo, Suzana Vanessa S.; Carvalho, Vinicius de Frias; Romeiro, Nelilma Correia; Silva, Patrícia Machado Rodrigues e; Martins, Marco Aurélio; Barreiro, Eliezer J.; Lima, Lídia Moreira


    Prior investigations showed that increased levels of cyclic AMP down-regulate lung inflammatory changes, stimulating the interest in phosphodiesterase (PDE)4 as therapeutic target. Here, we described the synthesis, pharmacological profile and docking properties of a novel sulfonamide series (5 and 6a-k) designed as PDE4 inhibitors. Compounds were screened for their selectivity against the four isoforms of human PDE4 using an IMAP fluorescence polarized protocol. The effect on allergen- or LPS-induced lung inflammation and airway hyper-reactivity (AHR) was studied in A/J mice, while the xylazine/ketamine-induced anesthesia test was employed as a behavioral correlate of emesis in rodents. As compared to rolipram, the most promising screened compound, 6a (LASSBio-448) presented a better inhibitory index concerning PDE4D/PDE4A or PDE4D/PDE4B. Accordingly, docking analyses of the putative interactions of LASSBio-448 revealed similar poses in the active site of PDE4A and PDE4C, but slight unlike orientations in PDE4B and PDE4D. LASSBio-448 (100 mg/kg, oral), 1 h before provocation, inhibited allergen-induced eosinophil accumulation in BAL fluid and lung tissue samples. Under an interventional approach, LASSBio-448 reversed ongoing lung eosinophilic infiltration, mucus exacerbation, peribronchiolar fibrosis and AHR by allergen provocation, in a mechanism clearly associated with blockade of pro-inflammatory mediators such as IL-4, IL-5, IL-13 and eotaxin-2. LASSBio-448 (2.5 and 10 mg/kg) also prevented inflammation and AHR induced by LPS. Finally, the sulfonamide derivative was shown to be less pro-emetic than rolipram and cilomilast in the assay employed. These findings suggest that LASSBio-448 is a new PDE4 inhibitor with marked potential to prevent and reverse pivotal pathological features of diseases characterized by lung inflammation, such as asthma. PMID:27695125

  10. Seminal vesicles and diabetic neuropathy: ultrasound evaluation after prolonged treatment with a selective phosphodiesterase-5 inhibitor. (United States)

    La Vignera, S; Condorelli, R A; Vicari, E; Lotti, F; Favilla, V; Morgia, G; Maggi, M; Calogero, A E


    We have previously reported that infertile patients with diabetes mellitus (DM) have a particular ultrasound features of the seminal vesicles (SV) characterized by higher fundus-to-body ratio and lower pre- and post-ejaculatory difference in body antero-posterior diameter (APD). Based on these premises the aim of the present study was to investigate possible ultrasound SV changes in infertile patients with DM and diabetic neuropathy (DN), after prolonged administration of tadalafil (TAD) (a specific phosphodiesterase-5 inhibitor). To accomplish this, 20 infertile patients with symptomatic DN and erectile dysfunction were selected and arbitrarily divided into two groups which were assigned to: daily administration of 5 mg TAD for 3 months (Group A) (n = 10) and administration of placebo (Group B) (n = 10). All patients underwent to scrotal and prostate-vesicular transrectal ultrasound evaluation and semen analysis (Laboratory Manual for the Examination and Processing of Human Semen, WHO, 2010) before and after treatment. The following SV US parameters were recorded: (i) body APD; (ii) fundus APD; (iii) parietal thickness of the right and left SVs; and (iv) number of polycyclic areas within both SVs. We then calculated the following parameters: (i) fundus/body (F/B) ratio; (ii) difference of the parietal thickness between the right and the left SV and (iii) pre- and post-ejaculatory APD difference. In addition, we also evaluated the SV ejection fraction. Group A patients showed a significant reduction in F/B ratio and higher pre- and post-ejaculatory body SV APD difference compared with baseline or Group B after 3 months. These patients showed also a significant increase in SV ejection fraction and a significant improvement of the total sperm count, progressive motility, seminal levels of fructose, leucocytes and ejaculate volume. In conclusion, these results suggest that infertile DM patients with DN and erectile dysfunction had an improvement of ultrasound features

  11. Pivotal effects of phosphodiesterase inhibitors on myocyte contractility and viability in normal and ischemic hearts

    Institute of Scientific and Technical Information of China (English)

    Yuan James RAO; Lei XI


    Phosphodiesterases (PDEs) are enzymes that degrade cellular cAMP and cGMP and are thus essential for regulating the cyclic nucleotides. At least 11 families of PDEs have been identified, each with a distinctive structure, activity, expression, and tissue distribution. The PDE type-3, -4, and -5 (PDE3, PDE4, PDE5) are localized to specific regions of the cardiomyo-cyte, such as the sarcoplasmic reticulum and Z-disc, where they are likely to influence cAMP/cGMP signaling to the end effectors of contractility. Several PDE inhibitors exhibit remarkable hemodynamic and inotropic properties that may be valuable to clinical practice. In particular, PDE3 inhibitors have potent cardiotonic effects that can be used for short-term inotropic support, especially in situations where adrenergic stimulation is insufficient. Most relevant to this review, PDE in-hibitors have also been found to have cytoprotective effects in the heart. For example, PDE3 inhibitors have been shown to be cardioprotective when given before ischemic attack, whereas PDE5 inhibitors, which include three widely used erectile dysfunction drugs (sildenafil, vardenafil and tadalafil), can induce remarkable cardioprotection when administered either prior to ischemia or upon reperfusion. This article provides an overview of the current laboratory and clinical evidence, as well as the cellular mechanisms by which the inhibitors of PDE3, PDE4 and PDE5 exert their beneficial effects on normal and ischemic hearts. It seems that PDE inhibitors hold great promise as clinically applicable agents that can improve car-diac performance and cell survival under critical situations, such as ischemic heart attack, cardiopulmonary bypass surgery, and heart failure.

  12. Hemorheological efficiency of drugs, targeting on intracellular phosphodiesterase activity: in vitro study. (United States)

    Muravyov, Alexei V; Yakusevich, Vladimir V; Chuchkanov, Fedor A; Maimistova, Alla A; Bulaeva, Svetlana V; Zaitsev, Lev G


    This in vitro study was designed to examine changes of red cell microrheological parameters (red cell aggregation and their suspension viscosity) after cell incubation with some drugs having phosphodiesterase (PDE) inhibitory activity (pentoxifylline - 25.0 microg/ml; drotaverine - 10.0 microg/ml; vinpocetine - 5.0 microg/ml; papaverine - 10.0 microg/ml; caffeine - 25.0 microg/ml; 3-isobutyl-1-methylxanthine [IBMX] - 10.0 microg/ml). Concentrations of used drugs for in vitro red cell microrheology study were the similar with those which it could be possible in blood of patient after intravenous therapeutic infusion. Red blood cells were separated from the blood by centrifugation at 1400 g for 15 min and washed 3 times with phosphate buffered saline (PBS). The washed RBCs were then resuspended in PBS at a hematocrit of approximately 40%. In each of the research sessions these RBC suspensions were divided into two aliquots and exposed to: one of the drug at 37 degrees C for 15 min; remaining aliquot (red cell suspension with PBS) was kept at 37 degrees C for 15 min and served as the control. It was found that all of used drugs decreased red cell aggregation and their suspension viscosity significantly. Since IBMX and vinpocetine are the specific inhibitor PDE activity it might be suppose that cellular PDE is molecular target in RBCs for this class of drugs. The obtained data reveals evidence that drugs, acting as PDE inhibitors, might be considered as microrheologically positive remedies.

  13. Does Tyrosyl DNA Phosphodiesterase-2 Play a Role in Hepatitis B Virus Genome Repair? (United States)

    Boregowda, Rajeev; Sohn, Ji A.; Ledesma, Felipe Cortes; Caldecott, Keith W.; Seeger, Christoph; Hu, Jianming


    Hepatitis B virus (HBV) replication and persistence are sustained by a nuclear episome, the covalently closed circular (CCC) DNA, which serves as the transcriptional template for all viral RNAs. CCC DNA is converted from a relaxed circular (RC) DNA in the virion early during infection as well as from RC DNA in intracellular progeny nucleocapsids via an intracellular amplification pathway. Current antiviral therapies suppress viral replication but cannot eliminate CCC DNA. Thus, persistence of CCC DNA remains an obstacle toward curing chronic HBV infection. Unfortunately, very little is known about how CCC DNA is formed. CCC DNA formation requires removal of the virally encoded reverse transcriptase (RT) protein from the 5’ end of the minus strand of RC DNA. Tyrosyl DNA phosphodiesterase-2 (Tdp2) was recently identified as the enzyme responsible for cleavage of tyrosyl-5’ DNA linkages formed between topoisomerase II and cellular DNA. Because the RT-DNA linkage is also a 5’ DNA-phosphotyrosyl bond, it has been hypothesized that Tdp2 might be one of several elusive host factors required for CCC DNA formation. Therefore, we examined the role of Tdp2 in RC DNA deproteination and CCC DNA formation. We demonstrated Tdp2 can cleave the tyrosyl-minus strand DNA linkage using authentic HBV RC DNA isolated from nucleocapsids and using RT covalently linked to short minus strand DNA produced in vitro. On the other hand, our results showed that Tdp2 gene knockout did not block CCC DNA formation during HBV infection of permissive human hepatoma cells and did not prevent intracellular amplification of duck hepatitis B virus CCC DNA. These results indicate that although Tdp2 can remove the RT covalently linked to the 5’ end of the HBV minus strand DNA in vitro, this protein might not be required for CCC DNA formation in vivo. PMID:26079492

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

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

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


    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.

  16. Phosphodiesterase type 5 inhibitors increase Herceptin transport and treatment efficacy in mouse metastatic brain tumor models.

    Directory of Open Access Journals (Sweden)

    Jinwei Hu

    Full Text Available BACKGROUND: Chemotherapeutic drugs and newly developed therapeutic monoclonal antibodies are adequately delivered to most solid and systemic tumors. However, drug delivery into primary brain tumors and metastases is impeded by the blood-brain tumor barrier (BTB, significantly limiting drug use in brain cancer treatment. METHODOLOGY/PRINCIPAL FINDINGS: We examined the effect of phosphodiesterase 5 (PDE5 inhibitors in nude mice on drug delivery to intracranially implanted human lung and breast tumors as the most common primary tumors forming brain metastases, and studied underlying mechanisms of drug transport. In vitro assays demonstrated that PDE5 inhibitors enhanced the uptake of [(14C]dextran and trastuzumab (Herceptin, a humanized monoclonal antibody against HER2/neu by cultured mouse brain endothelial cells (MBEC. The mechanism of drug delivery was examined using inhibitors for caveolae-mediated endocytosis, macropinocytosis and coated pit/clathrin endocytosis. Inhibitor analysis strongly implicated caveolae and macropinocytosis endocytic pathways involvement in the PDE5 inhibitor-enhanced Herceptin uptake by MBEC. Oral administration of PDE5 inhibitor, vardenafil, to mice with HER2-positive intracranial lung tumors led to an increased tumor permeability to high molecular weight [(14C]dextran (2.6-fold increase and to Herceptin (2-fold increase. Survival time of intracranial lung cancer-bearing mice treated with Herceptin in combination with vardenafil was significantly increased as compared to the untreated, vardenafil- or Herceptin-treated mice (p0.05. CONCLUSIONS/SIGNIFICANCE: These findings suggest that PDE5 inhibitors may effectively modulate BTB permeability, and enhance delivery and therapeutic efficacy of monoclonal antibodies in hard-to-treat brain metastases from different primary tumors that had metastasized to the brain.

  17. Mechanistic and Evolutionary Insights from Comparative Enzymology of Phosphomonoesterases and Phosphodiesterases across the Alkaline Phosphatase Superfamily. (United States)

    Sunden, Fanny; AlSadhan, Ishraq; Lyubimov, Artem Y; Ressl, Susanne; Wiersma-Koch, Helen; Borland, Jamar; Brown, Clayton L; Johnson, Tory A; Singh, Zorawar; Herschlag, Daniel


    Naively one might have expected an early division between phosphate monoesterases and diesterases of the alkaline phosphatase (AP) superfamily. On the contrary, prior results and our structural and biochemical analyses of phosphate monoesterase PafA, from Chryseobacterium meningosepticum, indicate similarities to a superfamily phosphate diesterase [Xanthomonas citri nucleotide pyrophosphatase/phosphodiesterase (NPP)] and distinct differences from the three metal ion AP superfamily monoesterase, from Escherichia coli AP (EcAP). We carried out a series of experiments to map out and learn from the differences and similarities between these enzymes. First, we asked why there would be independent instances of monoesterases in the AP superfamily? PafA has a much weaker product inhibition and slightly higher activity relative to EcAP, suggesting that different metabolic evolutionary pressures favored distinct active-site architectures. Next, we addressed the preferential phosphate monoester and diester catalysis of PafA and NPP, respectively. We asked whether the >80% sequence differences throughout these scaffolds provide functional specialization for each enzyme's cognate reaction. In contrast to expectations from this model, PafA and NPP mutants with the common subset of active-site groups embedded in each native scaffold had the same monoesterase:diesterase specificities; thus, the >10(7)-fold difference in native specificities appears to arise from distinct interactions at a single phosphoryl substituent. We also uncovered striking mechanistic similarities between the PafA and EcAP monoesterases, including evidence for ground-state destabilization and functional active-site networks that involve different active-site groups but may play analogous catalytic roles. Discovering common network functions may reveal active-site architectural connections that are critical for function, and identifying regions of functional modularity may facilitate the design of new enzymes

  18. Anxiolytic-like effect of etazolate, a type 4 phosphodiesterase inhibitor in experimental models of anxiety. (United States)

    Ankur, Jindal; Mahesh, Radhakrishan; Bhatt, Shvetank


    Etazolate is a selective inhibitor of type 4 phosphodiesterase (PDE4) class enzyme. Antidepressant-like effect of etazolate has been previously demonstrated in the rodent models of depression. The present study was designed to investigate the anxiolytic-like activity of etazolate in experimental mouse models of anxiety. The putative anxiolytic effect of etazolate (0.25-1 mg/kg, ip) was studied in mice by using a battery of behavioural tests of anxiety such as elevated plus maze (EPM), light/dark (L/D) aversion, hole board (HB) and open field (OFT) with diazepam (2 mg/kg, ip) as reference anxiolytic. Like diazepam (2 mg/kg, ip), etazolate (0.5 and 1 mg/kg, ip) significantly increased the percentage of both time spent and entries into open arms in the EPM test. In the L/D test etazolate (0.5 and 1 mg/kg, ip) increased the both total time spent in and latency time to leave the light compartment. Etazolate (0.5 and 1 mg/kg, ip) also significantly increased head dipping scores and time spent in head dipping, whereas significantly decreased the head dipping latency in HB test. In addition, etazolate (0.5 and 1 mg/kg, ip) significantly increased the ambulation scores (square crossed) and number of rearing in OFT. In conclusion, these findings indicated that etazolate exhibited an anxiolytic-like effect in experimental models of anxiety and may be considered an alternative approach for the management of anxiety disorder.

  19. Phosphodiesterase 4D polymorphisms associate with the short-term outcome in ischemic stroke (United States)

    Song, Yan-li; Wang, Chun-juan; Wu, Yi-ping; Lin, Jie; Wang, Peng-lian; Du, Wan-liang; Liu, Li; Lin, Jin-xi; Wang, Yi-long; Wang, Yong-jun; Liu, Gai-fen


    It has been demonstrated that phosphodiesterase 4D (PDE4D) genetic polymorphism is associated with ischemic stroke. However, the association between PDE4D gene and prognosis after ischemic stroke remains unknown. We consecutively enrolled ischemic stroke patients admitted to Beijing Tiantan Hospital from October 2009 to December 2013. Clinical, laboratory and imaging data upon admission were collected. All patients were followed up 3 months after stroke onset. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the associations of genetic polymorphisms with 3-month outcome after ischemic stroke and different subtypes, under various genetic models. A total of 1447 patients were enrolled, and 3-month follow-up data were obtained from 1388 (95.92%). Multivariate regression analysis showed that SNP87 of PDE4D gene was associated with increased risk of unfavorable outcome after total ischemic stroke (OR = 1.47, 95%CI 1.12–1.93), as well as stroke due to large-artery atherosclerosis (OR = 1.49, 95%CI 1.04–2.11) and small-artery occlusion (OR = 1.76, 95%CI 1.05–2.96) under a recessive model. No association between SNP83 genotype and poor outcome was found. Overall, this study demonstrated that the TT genotype of SNP87 in PDE4D was associated with increased risk of poor outcome after total ischemic stroke, large-artery atherosclerosis and small-artery occlusion, in a Chinese population. PMID:28225001

  20. Effect of phosphodiesterase inhibitors on nitric oxide production by glial cells. (United States)

    Yoshikawa, Minka; Suzumura, Akio; Ito, Atsushi; Tamaru, Tsukasa; Takayanagi, Tetsuya


    Nitric oxide (NO) is considered to play a crucial role in the development of various pathological processes in the CNS, such as neuronal degeneration, inflammation and demyelination. In order to search for the agents which suppress NO production in the CNS, we examined the effects of one of the agents which elevate cyclic AMP production, phosphodiesterase inhibitors (PDEIs), on NO production by glial cells in vitro. All the types of PDEIs, from type I- to V-specific and non-specific, suppressed the production of NO by mouse microglia and astrocytes stimulated with lipopolysaccharide, in a dose-dependent manner. Suppression of inducible NO synthase by PDEIs was confirmed by the expression of mRNA by RT-PCR. Although it required 10 microM or higher concentration to effectively suppress NO production in vitro, certain combinations of three different PDEIs synergistically suppressed NO production by astrocytes at 1 microM which could be obtained in vivo at usual therapeutic doses. Similary, combinations of three PDEIs at 1 microM synergistically increased intracellular cAMP in astrocytes. The suppressive effects of PDEIs on NO production were abolished by addition of tumor necrosis factor alpha (TNFalpha). Thus, the main suppression mechanism of NO might be indirect through suppression of TNFalpha. Since some PDEIs are reported to pass through the blood-brain-barrier, the combination of three PDEIs may be worth trying in neurological diseases, such as multiple sclerosis, human immunodeficiency virus-related neurological diseases and other neurodegenerative disorders in which NO may play a crucial role.

  1. Overexpression of phosphodiesterase-4 subtypes involved in surgery-induced neuroinflammation and cognitive dysfunction in mice. (United States)

    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


    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.

  2. Phosphodiesterase7 Inhibition Activates Adult Neurogenesis in Hippocampus and Subventricular Zone In Vitro and In Vivo. (United States)

    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


    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.

  3. Loss of extra-striatal phosphodiesterase 10A expression in early premanifest Huntington's disease gene carriers. (United States)

    Wilson, Heather; Niccolini, Flavia; Haider, Salman; Marques, Tiago Reis; Pagano, Gennaro; Coello, Christopher; Natesan, Sridhar; Kapur, Shitij; Rabiner, Eugenii A; Gunn, Roger N; Tabrizi, Sarah J; Politis, Marios


    Huntington's disease (HD) is a monogenic neurodegenerative disorder with an underlying pathology involving the toxic effect of mutant huntingtin protein primarily in striatal and cortical neurons. Phosphodiesterase 10A (PDE10A) regulates intracellular signalling cascades, thus having a key role in promoting neuronal survival. Using positron emission tomography (PET) with [(11)C]IMA107, we investigated the in vivo extra-striatal expression of PDE10A in 12 early premanifest HD gene carriers. Image processing and kinetic modelling was performed using MIAKAT™. Parametric images of [(11)C]IMA107 non-displaceable binding potential (BPND) were generated from the dynamic [(11)C]IMA107 scans using the simplified reference tissue model with the cerebellum as the reference tissue for nonspecific binding. We set a threshold criterion for meaningful quantification of [(11)C]IMA107 BPND at 0.30 in healthy control data; regions meeting this criterion were designated as regions of interest (ROIs). MRI-based volumetric analysis showed no atrophy in ROIs. We found significant differences in mean ROIs [(11)C]IMA107 BPND between HD gene carriers and healthy controls. HD gene carriers had significant loss of PDE10A within the insular cortex and occipital fusiform gyrus compared to healthy controls. Insula and occipital fusiform gyrus are important brain areas for the regulation of cognitive and limbic function that is impaired in HD. Our findings suggest that dysregulation of PDE10A-mediated intracellular signalling could be an early phenomenon in the course of HD with relevance also for extra-striatal brain areas.

  4. Tyrosyl-DNA phosphodiesterase I catalytic mutants reveal an alternative nucleophile that can catalyze substrate cleavage. (United States)

    Comeaux, Evan Q; Cuya, Selma M; Kojima, Kyoko; Jafari, Nauzanene; Wanzeck, Keith C; Mobley, James A; Bjornsti, Mary-Ann; van Waardenburg, Robert C A M


    Tyrosyl-DNA phosphodiesterase I (Tdp1) catalyzes the repair of 3'-DNA adducts, such as the 3'-phosphotyrosyl linkage of DNA topoisomerase I to DNA. Tdp1 contains two conserved catalytic histidines: a nucleophilic His (His(nuc)) that attacks DNA adducts to form a covalent 3'-phosphohistidyl intermediate and a general acid/base His (His(gab)), which resolves the Tdp1-DNA linkage. A His(nuc) to Ala mutant protein is reportedly inactive, whereas the autosomal recessive neurodegenerative disease SCAN1 has been attributed to the enhanced stability of the Tdp1-DNA intermediate induced by mutation of His(gab) to Arg. However, here we report that expression of the yeast His(nuc)Ala (H182A) mutant actually induced topoisomerase I-dependent cytotoxicity and further enhanced the cytotoxicity of Tdp1 His(gab) mutants, including H432N and the SCAN1-related H432R. Moreover, the His(nuc)Ala mutant was catalytically active in vitro, albeit at levels 85-fold less than that observed with wild type Tdp1. In contrast, the His(nuc)Phe mutant was catalytically inactive and suppressed His(gab) mutant-induced toxicity. These data suggest that the activity of another nucleophile when His(nuc) is replaced with residues containing a small side chain (Ala, Asn, and Gln), but not with a bulky side chain. Indeed, genetic, biochemical, and mass spectrometry analyses show that a highly conserved His, immediately N-terminal to His(nuc), can act as a nucleophile to catalyze the formation of a covalent Tdp1-DNA intermediate. These findings suggest that the flexibility of Tdp1 active site residues may impair the resolution of mutant Tdp1 covalent phosphohistidyl intermediates and provide the rationale for developing chemotherapeutics that stabilize the covalent Tdp1-DNA intermediate.

  5. Inhibitory effect of acetamide-45 on airway inflammation and phosphodiesterase 4 in allergic rats

    Institute of Scientific and Technical Information of China (English)

    Kai WANG; Hua-hao SHEN; Jun-chun CHEN; Zhong CHEN


    Aim: To determine the effects of acetamide-45 on respiratory function, airway inflammation, and the activity of phosphodiesterase 4 (PDE4) in allergic rats.Methods: Rats were sensitized by a single intramuscular injection with ovalbumin (OVA) and were challenged with ovalbumin applied by using an aerosol repeatedly for 7 d after 2 weeks. Acetamide-45 at concentrations of 5, 10, or 30 mg/kg was then administered by intraperitoneal injection. Changes in dynamic lung compliance and lung resistance, the accumulation of inflammatory cells in bronchoalveolar lavage, PDE4 activity, and the concentration of interleukin-4 in rat lung tissue were determined. Results: Seven days of treatment with acetamide-45 prevented eosinophil accumulation in allergic rats. At doses of 5, 10, and 30 mg/kg, acetamide-45 decreased lung resistance to 0.20±0.04, 0.25±0.07, and 0.22±0.05compliance to 0.41±0.07, 0.39±0.06, and 0.42±0.09 mL/cmH2O (P<0.05 vs OVA).After being treated with different doses of acetamide-45, the PDE4 activities in the concentrations of interleukin-4 in lung tissue were 6.22± 1.13, 5.95± 1.20,and 5.68±2.20 μg/g protein (P<0.05 vs OVA). Conclusions: Acetamide-45 was found to improve respiratory function and inhibit airway inflammation in this animal model, and the PDE4 activity of lung tissue was obviously inhibited.Acetamide-45 was an effective anti-inflammatory agent in respiratory inflammation,and the mechanism of its action might depend on inhibition of PDE4.

  6. Phosphodiesterases in the rat ovary: effect of cAMP in primordial follicles. (United States)

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


    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.

  7. Treatment of Cognitive Impairment in Schizophrenia: Potential Value of Phosphodiesterase Inhibitors in Prefrontal Dysfunction. (United States)

    Duinen, Marlies Van; Reneerkens, Olga A H; Lambrecht, Lena; Sambeth, Anke; Rutten, Bart P F; Os, Jim Van; Blokland, Arjan; Prickaerts, Jos


    No pharmacological treatment is available to date that shows satisfactory effects on cognitive symptoms in patients diagnosed with schizophrenia. Phosphodiesterase inhibitors (PDE-Is) improve neurotransmitter signaling by interfering in intracellular second messenger cascades. By preventing the breakdown of cAMP and/or cGMP, central neurotransmitter activity is maintained. Different PDE families exist with distinct characteristics among which substrate specificity and regional distribution. Preclinical data is promising especially with regard to inhibition of PDE2, PDE4, PDE5 and PDE10. In addition, cognitive improvement has been reported in both elderly and/or non-impaired young human subjects after PDE1 or PDE4 inhibition. Moreover, some of these studies show effects on cognitive domains relevant to schizophrenia, in particular memory. The current review incorporates an overview of the distinct molecular characteristics of the different PDE families and their relationship to the neurobiological mechanisms related to cognitive dysfunction in schizophrenia. So far, procognitive effects of only three types of PDE-Is have been assessed in patients diagnosed with schizophrenia inhibiting PDE3, PDE5 and PDE10. However, the limited data available do not allow to draw firm conclusions on the value of PDE-Is as cognitive enhancers in schizophrenia yet. The field is still in its infancy, but nevertheless different PDE-Is seem promising as candidate to optimise neural communication in the prefrontal cortex favouring cognitive functioning in patients diagnosed with schizophrenia, in particular dual inhibitors including PDE1-Is, PDE3-Is and PDE10A-Is.

  8. Clinical and preclinical treatment of urologic diseases with phosphodiesterase isoenzymes 5 inhibitors: an update

    Directory of Open Access Journals (Sweden)

    Wen-Hao Zhang


    Full Text Available Phosphodiesterase isoenzymes 5 inhibitors (PDE5-Is are the first-line therapy for erectile dysfunction (ED. The constant discoveries of nitric oxide (NO/cyclic guanosine monophosphate (cGMP cell-signaling pathway for smooth muscle (SM control in other urogenital tracts (UGTs make PDE5-Is promising pharmacologic agents against other benign urological diseases. This article reviews the literature and contains some previously unpublished data about characterizations and activities of PDE5 and its inhibitors in treating urological disorders. Scientific discoveries have improved our understanding of cell-signaling pathway in NO/cGMP-mediated SM relaxation in UGTs. Moreover, the clinical applications of PDE5-Is have been widely recognized. On-demand PDE5-Is are efficacious for most cases of ED, while daily-dosing and combination with testosterone are recommended for refractory cases. Soluble guanylate cyclase (sGC stimulators also have promising role in the management of severe ED conditions. PDE5-Is are also the first rehabilitation strategy for postoperation or postradiotherapy ED for prostate cancer patients. PDE5-Is, especially combined with α-adrenoceptor antagonists, are very effective for benign prostatic hyperplasia (BPH except on maximum urinary flow rate (Q max with tadalafil recently proved for BPH with/without ED. Furthermore, PDE5-Is are currently under various phases of clinical or preclinical researches with promising potential for other urinary and genital illnesses, such as priapism, premature ejaculation, urinary tract calculi, overactive bladder, Peyronie′s disease, and female sexual dysfunction. Inhibition of PDE5 is expected to be an effective strategy in treating benign urological diseases. However, further clinical studies and basic researches investigating mechanisms of PDE5-Is in disorders of UGTs are required.

  9. An HD-domain phosphodiesterase mediates cooperative hydrolysis of c-di-AMP to affect bacterial growth and virulence (United States)

    Huynh, TuAnh Ngoc; Luo, Shukun; Pensinger, Daniel; Sauer, John-Demian; Tong, Liang; Woodward, Joshua J.


    The nucleotide cyclic di-3′,5′- adenosine monophosphate (c-di-AMP) was recently identified as an essential and widespread second messenger in bacterial signaling. Among c-di-AMP–producing bacteria, altered nucleotide levels result in several physiological defects and attenuated virulence. Thus, a detailed molecular understanding of c-di-AMP metabolism is of both fundamental and practical interest. Currently, c-di-AMP degradation is recognized solely among DHH-DHHA1 domain-containing phosphodiesterases. Using chemical proteomics, we identified the Listeria monocytogenes protein PgpH as a molecular target of c-di-AMP. Biochemical and structural studies revealed that the PgpH His-Asp (HD) domain bound c-di-AMP with high affinity and specifically hydrolyzed this nucleotide to 5′-pApA. PgpH hydrolysis activity was inhibited by ppGpp, indicating a cross-talk between c-di-AMP signaling and the stringent response. Genetic analyses supported coordinated regulation of c-di-AMP levels in and out of the host. Intriguingly, a L. monocytogenes mutant that lacks c-di-AMP phosphodiesterases exhibited elevated c-di-AMP levels, hyperinduced a host type-I IFN response, and was significantly attenuated for infection. Furthermore, PgpH homologs, which belong to the 7TMR-HD family, are widespread among hundreds of c-di-AMP synthesizing microorganisms. Thus, PgpH represents a broadly conserved class of c-di-AMP phosphodiesterase with possibly other physiological functions in this crucial signaling network. PMID:25583510

  10. Selective inhibition of purified human phosphodiesterase 4A expressed in yeast cell GL62 by ciclamilast, piclamilast, and rolipram

    Institute of Scientific and Technical Information of China (English)

    Jun-chun CHEN; Ji-qiang CHEN; Qiang-min Xie; Yi-liang ZHU


    AIM: To improve the specific activity of human phosphodiesterase 4A (PDE4A) expressed in yeast cell GL62 and investigate the effects of selective phosphodiesterase 4 (PDE4) inhibitors (ciclamilast, piclamilast, and rolipram),selective phosphodiesterase 5 (PDES) inhibitor zaprinast, and cyclooxygenase (COX) inhibitors (aspirin, indomethacin)on human PDE4A activity expressed in yeast cell GL62. METHODS: Human PDE4A was expressed in yeast cell GL62 after CuSO4 induction and the specific activity of human PDE4A was improved by ammonium sulfate fractionation, DEAE Sephadex A-50 chromatography, and Sephadex G-100 chromatography. The activity of PDE4A was measured by high performance liquid chromatography (HPLC). RESULTS: Induced PDE4A activity expressed in crude yeast cell GL62 supernatant and pellet was (340±21) nmol.g-1.min-1 and (250±25) nmol.g-1.min-lrespectively. The specific activity of recombinant PDE4A in supernatant was improved 6.4 fold. Ciclamilast,piclamilast, and rolipram could inhibit PDE4A activity. The ICs0 values (95 % confidence limits) of ciclamilast,piclamilast, and rolipram were 1.27 (0.84-1.91), 66.4 (33.3-132.2), and 3.73 (2.51-5.53) μmol/L respectively.Zaprinast, aspirin, and indomethacin had no obvious inhibitory effect on PDE4A activity. CONCLUSION: The specific activity of PDE4A expressed in yeast cell GL62 can be improved by ammonium sulfate fractionation,DEAE Sephadex A-50 chromatography, and Sephadex G-100 chromatography. Ciclamilast, piclamilast, and rolipram can inhibit PDE4A activity while zaprinast, aspirin, and indomethacin have no obvious inhibitory effect on PDE4A activity. Human PDE4A expressed in GL62 might be useful in the research and screening of new selective PDE4 inhibitors.

  11. Active Site Metal Occupancy and Cyclic Di-GMP Phosphodiesterase Activity of Thermotoga maritima HD-GYP. (United States)

    Miner, Kyle D; Kurtz, Donald M


    HD-GYPs make up a subclass of the metal-dependent HD phosphohydrolase superfamily and catalyze conversion of cyclic di(3',5')-guanosine monophosphate (c-di-GMP) to 5'-phosphoguanylyl-(3'→5')-guanosine (pGpG) and GMP. Until now, the only reported crystal structure of an HD-GYP that also exhibits c-di-GMP phosphodiesterase activity contains a His/carboxylate ligated triiron active site. However, other structural and phylogenetic correlations indicate that some HD-GYPs contain dimetal active sites. Here we provide evidence that an HD-GYP c-di-GMP phosphodiesterase, TM0186, from Thermotoga maritima can accommodate both di- and trimetal active sites. We show that an as-isolated iron-containing TM0186 has an oxo/carboxylato-bridged diferric site, and that the reduced (diferrous) form is necessary and sufficient to catalyze conversion of c-di-GMP to pGpG, but that conversion of pGpG to GMP requires more than two metals per active site. Similar c-di-GMP phosphodiesterase activities were obtained with divalent iron or manganese. On the basis of activity correlations with several putative metal ligand residue variants and molecular dynamics simulations, we propose that TM0186 can accommodate both di- and trimetal active sites. Our results also suggest that a Glu residue conserved in a subset of HD-GYPs is required for formation of the trimetal site and can also serve as a labile ligand to the dimetal site. Given the anaerobic growth requirement of T. maritima, we suggest that this HD-GYP can function in vivo with either divalent iron or manganese occupying di- and trimetal sites.

  12. Interaction between leucine and phosphodiesterase 5 inhibition in modulating insulin sensitivity and lipid metabolism

    Directory of Open Access Journals (Sweden)

    Fu L


    Full Text Available Lizhi Fu,1 Fenfen Li,1 Antje Bruckbauer,2 Qiang Cao,1 Xin Cui,1 Rui Wu,1 Hang Shi,1 Bingzhong Xue,1 Michael B Zemel21Department of Biology, Center for Obesity Reversal, Georgia State University, Atlanta, GA, 2NuSirt Biopharma Inc., Nashville, TN, USA Purpose: Leucine activates SIRT1/AMP-activated protein kinase (AMPK signaling and markedly potentiates the effects of other sirtuin and AMPK activators on insulin signaling and lipid metabolism. Phosphodiesterase 5 inhibition increases nitric oxide–cGMP signaling, which in turn exhibits a positive feedback loop with both SIRT1 and AMPK, thus amplifying peroxisome proliferator-activated receptor γ co-activator α (PGC1α-mediated effects. Methods: We evaluated potential synergy between leucine and PDE5i on insulin sensitivity and lipid metabolism in vitro and in diet-induced obese (DIO mice. Results: Leucine (0.5 mM exhibited significant synergy with subtherapeutic doses (0.1–10 nM of PDE5-inhibitors (sildenafil and icariin on fat oxidation, nitric oxide production, and mitochondrial biogenesis in hepatocytes, adipocytes, and myotubes. Effects on insulin sensitivity, glycemic control, and lipid metabolism were then assessed in DIO-mice. DIO-mice exhibited fasting and postprandial hyperglycemia, insulin resistance, and hepatic steatosis, which were not affected by the addition of leucine (24 g/kg diet. However, the combination of leucine and a subtherapeutic dose of icariin (25 mg/kg diet for 6 weeks reduced fasting glucose (38%, P<0.002, insulin (37%, P<0.05, area under the glucose tolerance curve (20%, P<0.01, and fully restored glucose response to exogenous insulin challenge. The combination also inhibited hepatic lipogenesis, stimulated hepatic and muscle fatty acid oxidation, suppressed hepatic inflammation, and reversed high-fat diet-induced steatosis. Conclusion: These robust improvements in insulin sensitivity, glycemic control, and lipid metabolism indicate therapeutic potential for

  13. Distinct patterns of constitutive phosphodiesterase activity in mouse sinoatrial node and atrial myocardium.

    Directory of Open Access Journals (Sweden)

    Rui Hua

    Full Text Available Phosphodiesterases (PDEs are critical regulators of cyclic nucleotides in the heart. In ventricular myocytes, the L-type Ca(2+ current (I(Ca,L is a major target of regulation by PDEs, particularly members of the PDE2, PDE3 and PDE4 families. Conversely, much less is known about the roles of PDE2, PDE3 and PDE4 in the regulation of action potential (AP properties and I(Ca,L in the sinoatrial node (SAN and the atrial myocardium, especially in mice. Thus, the purpose of our study was to measure the effects of global PDE inhibition with Isobutyl-1-methylxanthine (IBMX and selective inhibitors of PDE2, PDE3 and PDE4 on AP properties in isolated mouse SAN and right atrial myocytes. We also measured the effects of these inhibitors on I(Ca,L in SAN and atrial myocytes in comparison to ventricular myocytes. Our data demonstrate that IBMX markedly increases spontaneous AP frequency in SAN myocytes and AP duration in atrial myocytes. Spontaneous AP firing in SAN myocytes was also increased by the PDE2 inhibitor erythro-9-[2-hydroxy-3-nonyl] adenine (EHNA, the PDE3 inhibitor milrinone (Mil and the PDE4 inhibitor rolipram (Rol. In contrast, atrial AP duration was increased by EHNA and Rol, but not by Mil. IBMX also potently, and similarly, increased I(Ca,L in SAN, atrial and ventricular myocytes; however, important differences emerged in terms of which inhibitors could modulate I(Ca,L in each myocyte type. Consistent with our AP measurements, EHNA, Mil and Rol each increased I(Ca,L in SAN myocytes. Also, EHNA and Rol, but not Mil, increased atrial I(Ca,L. In complete contrast, no selective PDE inhibitors increased I(Ca,L in ventricular myocytes when given alone. Thus, our data show that the effects of selective PDE2, PDE3 and PDE4 inhibitors are distinct in the different regions of the myocardium indicating important differences in how each PDE family constitutively regulates ion channel function in the SAN, atrial and ventricular myocardium.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kucka, Marek [Section on Cellular Signaling, Program in Developmental Neuroscience, NICHD, NIH, Bethesda, MD (United States); Pogrmic-Majkic, Kristina; Fa, Svetlana [Laboratory for Ecotoxicology, Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, 21000 Novi Sad (Serbia); Stojilkovic, Stanko S. [Section on Cellular Signaling, Program in Developmental Neuroscience, NICHD, NIH, Bethesda, MD (United States); Kovacevic, Radmila, E-mail: [Laboratory for Ecotoxicology, Department of Biology and Ecology, University of Novi Sad, Faculty of Sciences, 21000 Novi Sad (Serbia)


    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

  15. Loss of phosphodiesterase 10A expression is associated with progression and severity in Parkinson's disease. (United States)

    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


    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 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 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 pallidal loss of PDE10A expression, which is associated with Parkinson's duration and severity of motor symptoms and complications. PDE10A is an

  16. Phosphodiesterase 5 inhibitors prevent 3,4-methylenedioxymethamphetamine-induced 5-HT deficits in the rat. (United States)

    Puerta, Elena; Hervias, Isabel; Goñi-Allo, Beatriz; Lasheras, Berta; Jordan, Joaquin; Aguirre, Norberto


    Phosphodiesterase 5 (PDE5) inhibitors are often used in combination with club drugs such as 3,4-methylenedioxymethamphetamine (MDMA or ecstasy). We investigated the consequences of such combination in the serotonergic system of the rat. Oral administration of sildenafil citrate (1.5 or 8 mg/kg) increased brain cGMP levels and protected in a dose-dependent manner against 5-hydroxytryptamine depletions caused by MDMA (3 x 5 mg/kg, i.p., every 2 h) in the striatum, frontal cortex and hippocampus without altering the acute hyperthermic response to MDMA. Intrastriatal administration of the protein kinase G (PKG) inhibitor, KT5823 [(9S, 10R, 12R)-2,3,9,10,11,12-Hexahydro-10-methoxy-2,9-dimethyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid, methyl ester)], suppressed sildenafil-mediated protection. By contrast, the cell permeable cGMP analogue, 8-bromoguanosine cyclic 3',5'-monophosphate, mimicked sildenafil effects further suggesting the involvement of the PKG pathway in mediating sildenafil protection. Because mitochondrial ATP-sensitive K(+) channels are a target for PKG, we next administered the specific mitochondrial ATP-sensitive K(+) channel blocker, 5-hydroxydecanoic acid, 30 min before sildenafil. 5-hydroxydecanoic acid completely reversed the protection afforded by sildenafil, thereby implicating the involvement of mitochondrial ATP-sensitive K(+) channels. Sildenafil also increased Akt phosphorylation, and so the possible involvement of the Akt/endothelial nitric oxide synthase (eNOS)/sGC signalling pathway was analysed. Neither the phosphatidylinositol 3-kinase inhibitor, wortmannin, nor the selective eNOS inhibitor, L-N5-(1-iminoethyl)-L-ornithine dihydrochloride, reversed the protection afforded by sildenafil, suggesting that Akt/eNOS/sGC cascade does not participate in the protective mechanisms. Our data also show that the protective effect of sildenafil can be extended to vardenafil, another PDE5

  17. Identification and Localization of the Cyclic Nucleotide Phosphodiesterase 10A in Bovine Testis and Mature Spermatozoa (United States)

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


    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

  18. Effects of phosphodiesterase 5 inhibitors on sperm parameters and fertilizing capacity

    Institute of Scientific and Technical Information of China (English)

    F. Dimitriadis; I. Georgiou; M. Saito; T. Watanabe; I. Miyagawa; N. Sofikitis; D. Giannakis; N. Pardalidis; K. Zikopoulos; E. Paraskevaidis; N. Giotitsas; V. Kalaboki; P. Tsounapi; D. Baltogiannis


    The aim of this review study is to elucidate the effects that phosphodiesterase 5 (PDE5) inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase (AC) system and the cGMP/guanylate cyclase (GC) system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability.The stimulation of GC by low doses of nitric oxide (NO) leads to an improvement or maintenance of sperm motility,whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil's actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the

  19. Association between a variation in the phosphodiesterase 4D gene and bone mineral density

    Directory of Open Access Journals (Sweden)

    Sambrook Philip N


    Full Text Available Abstract Background Fragility fractures caused by osteoporosis are a major cause of morbidity and mortality in aging populations. Bone mineral density (BMD is a useful surrogate marker for risk of fracture and is a highly heritable trait. The genetic variants underlying this genetic contribution are largely unknown. Methods We performed a large-scale association study investigating more than 25,000 single nucleotide polymorphisms (SNPs located within 16,000 genes. Allele frequencies were estimated in contrasting DNA pools from white females selected for low (2, n = 319 and high (> 1.11 g/cm2, n = 321 BMD at the lumbar spine. Significant findings were verified in two additional sample collections. Results Based on allele frequency differences between DNA pools and subsequent individual genotyping, one of the candidate loci indicated was the phosphodiesterase 4D (PDE4D gene region on chromosome 5q12. We subsequently tested the marker SNP, rs1498608, in a second sample of 138 white females with low (2 and 138 females with high (>1.04 g/cm2 lumbar spine BMD. Odds ratios were 1.5 (P = 0.035 in the original sample and 2.1 (P = 0.018 in the replication sample. Association fine mapping with 80 SNPs located within 50 kilobases of the marker SNP identified a 20 kilobase region of association containing exon 6 of PDE4D. In a second, family-based replication sample with a preponderance of females with low BMD, rs1498608 showed an opposite relationship with BMD at different sites (p = 0.00044-0.09. We also replicated the previously reported association of the Ser37Ala polymorphism in BMP2, known to interact biologically with PDE4D, with BMD. Conclusion This study indicates that variants in the gene encoding PDE4D account for some of the genetic contribution to bone mineral density variation in humans. The contrasting results from different samples indicate that the effect may be context-dependent. PDE4 inhibitors have been shown to increase bone mass in

  20. Physiological Role of phnP-specified Phosphoribosyl Cyclic Phosphodiesterase in Catabolism of Organophosphonic Acids by the Carbon−Phosphorus Lyase Pathway

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; McSorley, Fern R.; Zechel, David L.


    In Escherichia coli , internalization and catabolism of organophosphonicacids are governed by the 14-cistron phnCDEFGHIJKLMNOP operon. The phnP gene product was previously shown to encode a phosphodiesterase with unusual specificity toward ribonucleoside 2',3'-cyclic phosphates. Furthermore, phnP...

  1. COVER FIGURE in Nucleic Acids Research (Volume 39, Issue 9) entitled "The involvement of the nuclear-encoded human 2'-phosphodiesterase in mitochondrial RNA turnover"

    DEFF Research Database (Denmark)

    Poulsen, Jesper Buchhave


    (English) Cover: The involvement of the nuclear-encoded human 2'-phosphodiesterase (2'-PDE) in mitochondrial RNA turnover. The 2'-PDE precursor (upper left corner) gets directed into the mitochondrial matrix by an N-terminal mitochondrial signaling peptide (blue). Inside the matrix, this signalin...

  2. Phosphodiesterase-5 activity exerts a coronary vasoconstrictor influence in awake swine that is mediated in part via an increase in endothelin production

    NARCIS (Netherlands)

    Z. Zhou (Zhichao); V.J. de Beer (Vincent Jacob); S.B. Bender (Shawn ); A.H.J. Danser (Jan); D. Merkus (Daphne); H. Laughlin (Harold); D.J.G.M. Duncker (Dirk)


    textabstractNitric oxide (NO)-induced coronary vasodilation is mediated through production of cyclic guanosine monophosphate (cGMP) and through inhibition of the endothelin-1 (ET) system. We previously demonstrated that phosphodiesterase-5 (PDE5)-mediated cGMP breakdown and ET each exert a vasoconst

  3. 1-(2-Ethoxyethyl)-1H-pyrazolo[4,3-d]pyrimidines as potent phosphodiesterase 5 (PDE5) inhibitors. (United States)

    Tollefson, Michael B; Acker, Brad A; Jacobsen, E J; Hughes, Robert O; Walker, John K; Fox, David N A; Palmer, Michael J; Freeman, Sandra K; Yu, Ying; Bond, Brian R


    1H-Pyrazolo[4,3-d]pyrimidines are a class of potent and selective second generation phosphodiesterase 5 (PDE5) inhibitors. This work explores the potency, selectivity and efficacy of 1-(2-ethoxyethyl)-1H-pyrazolo[4,5-d]pyrimidines as PDE5 inhibitors resulting in the advancement of a clinical candidate.

  4. 1-(2-(2,2,2-trifluoroethoxy)ethyl-1H-pyrazolo[4,3-d]pyrimidines as potent phosphodiesterase 5 (PDE5) inhibitors. (United States)

    Tollefson, Michael B; Acker, Brad A; Jacobsen, E J; Hughes, Robert O; Walker, John K; Fox, David N A; Palmer, Michael J; Freeman, Sandra K; Yu, Ying; Bond, Brian R


    1H-Pyrazolo[4,3-d]pyrimidines were previously disclosed as a potent second generation class of phosphodiesterase 5 (PDE5) inhibitors. This work explores the advancement of more selective and potent PDE5 inhibitors resulting from the substitution of 2-(2,2,2-trifluoroethoxy)ethyl at the 1 position in the so-called alkoxy pocket.

  5. Cyclic nucleotide specificity of the activator and catalytic sites of a cGMP-stimulated cGMP phosphodiesterase from Dictyostelium discoideum

    NARCIS (Netherlands)

    Kesbeke, Fanja; Baraniak, Janina; Bulgakov, Roman; Jastorff, Bernd; Morr, Michael; Petridis, Georg; Stec, Wojciech J.; Seela, Frank; Haastert, Peter J.M. van


    The cellular slime mold Dictyostelium discoideum has an intracellular phosphodiesterase which specifically hydrolyzes cGMP. The enzyme is activated by low cGMP concentrations, and is involved in the reduction of chemoattractant-mediated elevations of cGMP levels. The interaction of 20 cGMP derivativ

  6. Uncovering the function of Disrupted in Schizophrenia 1 through interactions with the cAMP phosphodiesterase PDE4: Contributions of the Houslay lab to molecular psychiatry. (United States)

    Brandon, Nicholas J


    Nearly 10years ago the laboratory of Miles Houslay was part of a collaboration which identified and characterized the interaction between Disrupted in Schizophrenia 1 and phosphodiesterase type 4. This work has had significant impact on our thinking of psychiatric illness causation and the potential for therapeutics.

  7. Serum and CNTF stimulate oligodendroglia and reduce fiber outgrowth from striatal cultures. (United States)

    Dahl-Jørgensen, A; Ostergaard, K; Pedersen, E B; Zimmer, J


    Organotypic slice cultures of newborn rat striatal tissue displayed an exceptionally dense and fasciculated outgrowth of GABAergic fibers when grown in a chemically defined medium, compared to serum-containing medium. The enhanced fiber growth was not the result of an increased density of GABAergic neurons in the cultures, but coincided with a marked reduction of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase)-immunoreactive cells within and around the cultures. An inverse, causal relationship between the number of CNPase-positive cells, presumably of oligodendroglial lineage, and GABAergic fiber outgrowth was further evidenced by the observation that addition of ciliary neurotrophic factor (CNTF) to the chemically defined medium resulted in both an increase in CNPase-positive cells and a decrease in GABAergic fiber outgrowth. The observations suggest that CNTF and serum indirectly inhibit axonal growth by stimulating oligodendroglial cells.

  8. The multiple roles of myelin protein genes during the development of the oligodendrocyte. (United States)

    Fulton, Daniel; Paez, Pablo M; Campagnoni, Anthony T


    It has become clear that the products of several of the earliest identified myelin protein genes perform functions that extend beyond the myelin sheath. Interestingly, these myelin proteins, which comprise proteolipid protein, 2',3'-cyclic nucleotide 3'-phosphodiesterase and the classic and golli MBPs (myelin basic proteins), play important roles during different stages of oligodendroglial development. These non-myelin-related functions are varied and include roles in the regulation of process outgrowth, migration, RNA transport, oligodendrocyte survival and ion channel modulation. However, despite the wide variety of cellular functions performed by the different myelin genes, the route by which they achieve these many functions seems to converge upon a common mechanism involving Ca(2+) regulation, cytoskeletal rearrangements and signal transduction. In the present review, the newly emerging functions of these myelin proteins will be described, and these will then be discussed in the context of their contribution to oligodendroglial development.

  9. Myelin-specific proteins: a structurally diverse group of membrane-interacting molecules. (United States)

    Han, Huijong; Myllykoski, Matti; Ruskamo, Salla; Wang, Chaozhan; Kursula, Petri


    The myelin sheath is a multilayered membrane in the nervous system, which has unique biochemical properties. Myelin carries a set of specific high-abundance proteins, the structure and function of which are still poorly understood. The proteins of the myelin sheath are involved in a number of neurological diseases, including autoimmune diseases and inherited neuropathies. In this review, we briefly discuss the structural properties and functions of selected myelin-specific proteins (P0, myelin oligodendrocyte glycoprotein, myelin-associated glycoprotein, myelin basic protein, myelin-associated oligodendrocytic basic protein, P2, proteolipid protein, peripheral myelin protein of 22 kDa, 2',3'-cyclic nucleotide 3'-phosphodiesterase, and periaxin); such properties include, for example, interactions with lipid bilayers and the presence of large intrinsically disordered regions in some myelin proteins. A detailed understanding of myelin protein structure and function at the molecular level will be required to fully grasp their physiological roles in the myelin sheath.

  10. The current status of structural studies on proteins of the myelin sheath (Review). (United States)

    Kursula, P


    Myelin, the multilayered membrane structure surrounding axons, provides a unique environment to its proteins, which are either transmembrane proteins or interacting intimately with the membrane surface. Although myelin-specific proteins have been studied for decades, remarkably little is known of their three-dimensional structures. In addition, the exact functions of myelin proteins are to a large extent unknown. In this report, our current knowledge of peripheral nervous system myelin protein structures is reviewed, and the current status of attempts to solve the structures of full-length myelin proteins is evaluated. Furthermore, molecular models for the extracellular domain of the myelin-associated glycoprotein and the putative kinase-like domain of 2',3'-cyclic nucleotide 3'-phosphodiesterase are presented and discussed.

  11. Novel Radioligands for Cyclic Nucleotide Phosphodiesterase Imaging with Positron Emission Tomography: An Update on Developments Since 2012

    Directory of Open Access Journals (Sweden)

    Susann Schröder


    Full Text Available Cyclic nucleotide phosphodiesterases (PDEs are a class of intracellular enzymes that inactivate the secondary messenger molecules, cyclic adenosine monophosphate (cAMP and cyclic guanosine monophosphate (cGMP. Thus, PDEs regulate the signaling cascades mediated by these cyclic nucleotides and affect fundamental intracellular processes. Pharmacological inhibition of PDE activity is a promising strategy for treatment of several diseases. However, the role of the different PDEs in related pathologies is not completely clarified yet. PDE-specific radioligands enable non-invasive visualization and quantification of these enzymes by positron emission tomography (PET in vivo and provide an important translational tool for elucidation of the relationship between altered expression of PDEs and pathophysiological effects as well as (pre-clinical evaluation of novel PDE inhibitors developed as therapeutics. Herein we present an overview of novel PDE radioligands for PET published since 2012.

  12. Chemosensitizing acridones: in vitro calmodulin dependent cAMP phosphodiesterase inhibition, docking, pharmacophore modeling and 3D QSAR studies. (United States)

    Rajendra Prasad, V V S; Deepak Reddy, G; Appaji, D; Peters, G J; Mayur, Y C


    Calmodulin inhibitors have proved to play a significant role in sensitizing MDR cancer cells by interfering with cellular drug accumulation. The present investigation focuses on the evaluation of in vitro inhibitory efficacy of chloro acridones against calmodulin dependent cAMP phosphodiesterase (PDE1c). Moreover, molecular docking of acridones was performed with PDE1c in order to identify the possible protein ligand interactions and results thus obtained were compared with in vitro data. In addition an efficient pharmacophore model was developed from a set of 38 chemosensitizing acridones effective against doxorubicin resistant (HL-60/DX) cancer cell lines. Pharmacophoric features such as one hydrogen bond acceptor, one hydrophobic region, a positive ion group and three aromatic rings i.e., AHPRRR have been identified. Ligand based 3D-QSAR was also performed by employing partial least square regression analysis.

  13. Localization and activity of tissue bound cyclic nucleotide phosphodiesterase in normal and lack of changes in psoriatic human skin. (United States)

    Mahrle, G; Organos, C E


    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.

  14. Discovery of selective inhibitors of tyrosyl-DNA phosphodiesterase 2 by targeting the enzyme DNA-binding cleft. (United States)

    Kossmann, Bradley R; Abdelmalak, Monica; Lopez, Sophia; Tender, Gabrielle; Yan, Chunli; Pommier, Yves; Marchand, Christophe; Ivanov, Ivaylo


    Tyrosyl-DNA phosphodiesterase 2 (TDP2) processes protein/DNA adducts resulting from abortive DNA topoisomerase II (Top2) activity. TDP2 inhibition could provide synergism with the Top2 poison class of chemotherapeutics. By virtual screening of the NCI diversity small molecule database, we identified selective TDP2 inhibitors and experimentally verified their selective inhibitory activity. Three inhibitors exhibited low-micromolar IC50 values. Molecular dynamics simulations revealed a common binding mode for these inhibitors, involving association to the TDP2 DNA-binding cleft. MM-PBSA per-residue energy decomposition identified important interactions of the compounds with specific TDP2 residues. These interactions could provide new avenues for synthetic optimization of these scaffolds.

  15. Interplay of palmitoylation and phosphorylation in the trafficking and localization of phosphodiesterase 10A: implications for the treatment of schizophrenia. (United States)

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


    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.

  16. Formation and dimerization of the phosphodiesterase active site of the Pseudomonas aeruginosa MorA, a bi-functional c-di-GMP regulator. (United States)

    Phippen, Curtis William; Mikolajek, Halina; Schlaefli, Henry George; Keevil, Charles William; Webb, Jeremy Stephen; Tews, Ivo


    Diguanylate cyclases (DGC) and phosphodiesterases (PDE), respectively synthesise and hydrolyse the secondary messenger cyclic dimeric GMP (c-di-GMP), and both activities are often found in a single protein. Intracellular c-di-GMP levels in turn regulate bacterial motility, virulence and biofilm formation. We report the first structure of a tandem DGC-PDE fragment, in which the catalytic domains are shown to be active. Two phosphodiesterase states are distinguished by active site formation. The structures, in the presence or absence of c-di-GMP, suggest that dimerisation and binding pocket formation are linked, with dimerisation being required for catalytic activity. An understanding of PDE activation is important, as biofilm dispersal via c-di-GMP hydrolysis has therapeutic effects on chronic infections.

  17. Local and systemic alterations in cyclic 3',5' AMP phosphodiesterase activity in relation to tail regeneration under hypothyroidism and T4 replacement in the lizard, Mabuya carinata. (United States)

    Ramachandran, A V; Swamy, M S; Kurup, A K


    To establish the relationship between thyroid hormone and cyclic Adenosine monophosphate (cAMP) during lacertilian tail regeneration, cAMP phosphodiesterase, the hydrolytic enzyme of cAMP, was assayed in the tail regenerate, liver, and skeletal muscle of control (group A), chemically thyroidectomized (group B), and thyroidectomized and T4-replaced (group C) animals during various periods of tail regeneration. Enzyme activity was elevated in all three tissues of group B animals. Animals of group C showed an intermediate level of enzyme activity between controls (group A) and experimental animals (group B). These observations suggest a possible regulatory role of thyroxine in maintaining optimum levels of phosphodiesterase. The retardation in regeneration observable in the hypothyroid group of animals may be correlated with low levels of tissue cAMP. However, the operation of other influencing factors on phosphodiesterase during regeneration can be surmised from the observed tendency to exhibit similar patterns of phase-specific modulations in enzyme activity. Our observations are discussed in terms of phase-specific involvement of cAMP in regeneration, as well as its role in other metabolic aspects and the possible mode of indirect control exerted by thyroxine on lacertilian tail regeneration.

  18. Phosphodiesterase 10A (PDE10A) localization in the R6/2 mouse model of Huntington's disease. (United States)

    Leuti, Alessandro; Laurenti, Daunia; Giampà, Carmela; Montagna, Elena; Dato, Clemente; Anzilotti, Serenella; Melone, Mariarosa A B; Bernardi, Giorgio; Fusco, Francesca R


    In Huntington's disease (HD) mutant huntingtin protein impairs the function of several transcription factors, in particular the cAMP response element-binding protein (CREB). CREB activation can be increased by targeting phosphodiesterases such as phospohodiesterase 4 (PDE4) and phosphodiesterase 10A (PDE10A). Indeed, both PDE4 inhibition (DeMarch et al., 2008) and PDE10A inhibition (Giampà et al., 2010) proved beneficial in the R6/2 mouse model of HD. However, Hebb et al. (2004) reported PDE10A decline in R6/2 mice. These findings raise the issue of how PDE10A inhibition is beneficial in HD if such enzyme is lost. R6/2 mice and their wild type littermates were treated with the PDE10A inhibitor TP10 (a gift from Pfizer) or saline, sacrificed at 5, 9, and 13 weeks of age, and single and double label immunohistochemistry and western blotting were performed. PDE10A increased dramatically in the spiny neurons of R6/2 compared to the wild type mice. Conversely, in the striatal cholinergic interneurons, PDE10A was lower and it did not change significantly with disease progression. In the other subsets of striatal interneurons (namely, parvalbuminergic, somatostatinergic, and calretininergic interneurons) PDE10A immunoreactivity was higher in the R6/2 compared to the wild-type mice. In the TP10 treated R6/2, PDE10A levels were lower than in the saline treated mice in the medium spiny neurons, whereas they were higher in all subsets of striatal interneurons except for the cholinergic ones. However, in the whole striatum densitometry studies, PDE10A immunoreactivity was lower in the R6/2 compared to the wild-type mice. Our study demonstrates that PDE10A is increased in the spiny neurons of R6/2 mice striatum. Thus, the accumulation of PDE10A in the striatal projection neurons, by hydrolyzing greater amounts of cyclic nucleotides, is likely to contribute to cell damage in HD. Consequently, the beneficial effect of TP10 in HD models (Giampà et al., 2009, 2010) is explained

  19. The upstream conserved regions (UCRs) mediate homo- and hetero-oligomerization of type 4 cyclic nucleotide phosphodiesterases (PDE4s). (United States)

    Xie, Moses; Blackman, Brigitte; Scheitrum, Colleen; Mika, Delphine; Blanchard, Elise; Lei, Tao; Conti, Marco; Richter, Wito


    PDE4s (type 4 cyclic nucleotide phosphodiesterases) are divided into long and short forms by the presence or absence of conserved N-terminal domains termed UCRs (upstream conserved regions). We have shown previously that PDE4D2, a short variant, is a monomer, whereas PDE4D3, a long variant, is a dimer. In the present study, we have determined the apparent molecular masses of various long and short PDE4 variants by size-exclusion chromatography and sucrose density-gradient centrifugation. Our results indicate that dimerization is a conserved property of all long PDE4 forms, whereas short forms are monomers. Dimerization is mediated by the UCR domains. Given their high sequence conservation, the UCR domains mediate not only homo-oligomerization, but also hetero-oligomerization of distinct PDE4 long forms as detected by co-immunoprecipitation assays and FRET microscopy. Endogenous PDE4 hetero-oligomers are, however, low in abundance compared with homo-dimers, revealing the presence of mechanisms that predispose PDE4s towards homo-oligomerization. Oligomerization is a prerequisite for the regulatory properties of the PDE4 long forms, such as their PKA (protein kinase A)-dependent activation, but is not necessary for PDE4 protein-protein interactions. As a result, individual PDE4 protomers may independently mediate protein-protein interactions, providing a mechanism whereby PDE4s contribute to the assembly of macromolecular signalling complexes.

  20. A new structure-based QSAR method affords both descriptive and predictive models for phosphodiesterase-4 inhibitors. (United States)

    Dong, Xialan; Zheng, Weifan


    We describe the application of a new QSAR (quantitative structure-activity relationship) formalism to the analysis and modeling of PDE-4 inhibitors. This new method takes advantage of the X-ray structural information of the PDE-4 enzyme to characterize the small molecule inhibitors. It calculates molecular descriptors based on the matching of their pharmacophore feature pairs with those (the reference) of the target binding pocket. Since the reference is derived from the X-ray crystal structures of the target under study, these descriptors are target-specific and easy to interpret. We have analyzed 35 indole derivative-based PDE-4 inhibitors where Partial Least Square (PLS) analysis has been employed to obtain the predictive models. Compared to traditional QSAR methods such as CoMFA and CoMSIA, our models are more robust and predictive measured by statistics for both the training and test sets of molecules. Our method can also identify critical pharmacophore features that are responsible for the inhibitory potency of the small molecules. Thus, this structure-based QSAR method affords both descriptive and predictive models for phosphodiesterase-4 inhibitors. The success of this study has also laid a solid foundation for systematic QSAR modeling of the PDE family of enzymes, which will ultimately contribute to chemical genomics research and drug discovery targeting the PDE enzymes.

  1. Antidepressant-like properties of phosphodiesterase type 5 inhibitors and cholinergic dependency in a genetic rat model of depression. (United States)

    Liebenberg, Nico; Harvey, Brian H; Brand, Linda; Brink, Christiaan B


    We explored the antidepressant-like properties of two phosphodiesterase type 5 (PDE5) inhibitors in a genetic animal model of depression, namely Flinders sensitive line rats. We investigated the dose-dependency of the antidepressant-like action of sildenafil, and its interaction with the cholinergic system and behavioural correlates of monoaminergic neurotransmission, in the forced swim test. Antidepressant-like properties of tadalafil (a structurally distinct PDE5 inhibitor) were also evaluated. Flinders sensitive line rats were treated for 14 days with vehicle, fluoxetine, atropine or PDE5 inhibitors+/-atropine. Immobility, swimming and climbing behaviours were assessed in the forced swim test. In combination with atropine (1 mg/kg), both sildenafil (10, 20 mg/kg) and tadalafil (10 mg/kg) decreased immobility while increasing swimming (serotonergic) and climbing (noradrenergic) behaviours. Interestingly, sildenafil (3 mg/kg) decreased immobility while selectively increasing climbing behaviour in the absence of atropine. These results suggest that the antidepressant-like activity of PDE5 inhibitors involve alterations in monoaminergic neurotransmission, but involve a dependence on inherent cholinergic tone so that the final response is determined by the relative extent of activation of these systems. Furthermore, the behavioural profile of sildenafil alone, and its observed antidepressant-like properties, shows strict dose-dependency, with only higher doses showing an interaction with the cholinergic system.

  2. Human biodistribution and dosimetry of {sup 18}F-JNJ42259152, a radioligand for phosphodiesterase 10A imaging

    Energy Technology Data Exchange (ETDEWEB)

    Laere, Koen van [University Hospital Leuven and KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); University Hospital Leuven - Gasthuisberg, Division of Nuclear Medicine, Leuven (Belgium); Ahmad, Rawaha U.; Hudyana, Hendra; Koole, Michel [University Hospital Leuven and KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); Celen, Sofie; Bormans, Guy [KU Leuven, Laboratory for Radiopharmacy, Leuven (Belgium); Dubois, Kristof; Schmidt, Mark E. [Division of Janssen Pharmaceuticals NV, Janssen Research and Development, Beerse (Belgium)


    Phosphodiesterase 10A (PDE10A) is a cAMP/cGMP-hydrolysing enzyme with a central role in striatal signalling and implicated in neuropsychiatric disorders such as Huntington's disease, Parkinson's disease, schizophrenia and addiction. We have developed a novel PDE10A PET ligand, {sup 18}F-JNJ42259152, and describe here its human dynamic biodistribution, safety and dosimetry. Six male subjects (age range 23-67 years) underwent ten dynamic whole-body PET/CT scans over 6 h after bolus injection of 175.5 {+-} 9.4 MBq {sup 18}F-JNJ42259152. Source organs were delineated on PET/CT and individual organ doses and effective dose were determined using the OLINDA software. F-JNJ42259152 was readily taken up by the brain and showed exclusive retention in the brain, especially in the striatum with good washout starting after 20 min. The tracer was cleared through both the hepatobiliary and the urinary routes. No defluorination was observed. Organ absorbed doses were largest for the gallbladder (239 {mu}Sv/MBq) and upper large intestine (138 {mu}Sv/MBq). The mean effective dose was 24.9 {+-} 4.1 {mu}Sv/MBq. No adverse events were encountered. In humans, {sup 18}F-JNJ42259152 has an appropriate distribution, brain kinetics and safety. The estimated effective dose was within WHO class IIb with low interindividual variability. Therefore, the tracer is suitable for further kinetic evaluation in humans. (orig.)

  3. Genetic deletion and pharmacological inhibition of phosphodiesterase 10A protects mice from diet-induced obesity and insulin resistance. (United States)

    Nawrocki, Andrea R; Rodriguez, Carlos G; Toolan, Dawn M; Price, Olga; Henry, Melanie; Forrest, Gail; Szeto, Daphne; Keohane, Carol Ann; Pan, Yie; Smith, Karen M; Raheem, Izzat T; Cox, Christopher D; Hwa, Joyce; Renger, John J; Smith, Sean M


    Phosphodiesterase 10A (PDE10A) is a novel therapeutic target for the treatment of schizophrenia. Here we report a novel role of PDE10A in the regulation of caloric intake and energy homeostasis. PDE10A-deficient mice are resistant to diet-induced obesity (DIO) and associated metabolic disturbances. Inhibition of weight gain is due to hypophagia after mice are fed a highly palatable diet rich in fats and sugar but not a standard diet. PDE10A deficiency produces a decrease in caloric intake without affecting meal frequency, daytime versus nighttime feeding behavior, or locomotor activity. We tested THPP-6, a small molecule PDE10A inhibitor, in DIO mice. THPP-6 treatment resulted in decreased food intake, body weight loss, and reduced adiposity at doses that produced antipsychotic efficacy in behavioral models. We show that PDE10A inhibition increased whole-body energy expenditure in DIO mice fed a Western-style diet, achieving weight loss and reducing adiposity beyond the extent seen with food restriction alone. Therefore, chronic THPP-6 treatment conferred improved insulin sensitivity and reversed hyperinsulinemia. These data demonstrate that PDE10A inhibition represents a novel antipsychotic target that may have additional metabolic benefits over current medications for schizophrenia by suppressing food intake, alleviating weight gain, and reducing the risk for the development of diabetes.

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

    Directory of Open Access Journals (Sweden)

    Fanghua Wang


    Full Text Available 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.

  5. Novel Therapeutic Targets for Phosphodiesterase 5 Inhibitors: current state-of-the-art on systemic arterial hypertension and atherosclerosis. (United States)

    Vasquez, Elisardo C; Gava, Agata L; Graceli, Jones B; Balarini, Camille M; Campagnaro, Bianca P; Pereira, Thiago Melo C; Meyrelles, Silvana S


    The usefulness of selective inhibitors of phosphodiesterase 5 (PDE5) is well known, first for the treatment of male erectile dysfunction and more recently for pulmonary hypertension. The discovery that PDE5 is present in the systemic artery endothelium and smooth muscle cells led investigators to test the extra sexual effects of sildenafil, the first and most investigated PDE5 inhibitor, in diseases affecting the systemic arteries. Cumulative data from experimental and clinical studies have revealed beneficial effects of sildenafil on systemic arterial hypertension and its target organs, such as the heart, kidneys and vasculature. An important effect of sildenafil is reduction of hypertension and improvement of endothelial function in experimental models of hypertension and hypertensive subjects. Interestingly, in angiotensin-dependent hypertension, its beneficial effects on endothelial and kidney dysfunctions seem to at least in part be caused by its ability to decrease the levels of angiotensin II and increase angiotensin 1-7, in addition to improving nitric oxide bioavailability and diminishing reactive oxygen species. Another remarkable finding on the effects of sildenafil comes from studies in apolipoprotein E knockout mice, a model of atherosclerosis that closely resembles human atherosclerotic disease. In this review, we focus on the promising beneficial effects of sildenafil for treating systemic high blood pressure, especially resistant hypertension, and the endothelial dysfunction that is present in hypertension and atherosclerosis.

  6. Synthesis, radiolabeling and in vivo evaluation of [{sup 11}C]RAL-01, a potential phosphodiesterase 5 radioligand

    Energy Technology Data Exchange (ETDEWEB)

    Jakobsen, Steen [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark)]. E-mail:; Kodahl, Gitte Munkebo [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark); Olsen, Aage Kristian [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark); Cumming, Paul [PET Centre, Aarhus University Hospitals, 8000 Aarhus (Denmark); Centre for Functionally Integrative Neuroscience, Aarhus University, Aarhus (Denmark)


    Very few tracers are available for imaging studies of second messenger systems. We developed a radiosynthesis for the phosphodiesterase (PDE) 5 inhibitor [{sup 11}C]RAL-01. Whole body distribution studies using positron emission tomography (PET) revealed a time-dependant passage through the liver and accumulation of radioactivity in the bile of the Landrace pig. Displaceable binding was readily discerned in the myocardium, and traces of binding were seen in pulmonary tissue, consistent with the use of this class of drug in the treatment of pulmonary hypertension and heart failure. [{sup 11}C]RAL-01 readily entered the brain and obtained an equilibrium distribution volume of 4-5 ml g{sup -1}. Mean parametric images suggested the presence of a small displaceable binding component, but this binding was not significant in the present group of three pigs. Thus, [{sup 11}C]RAL-01 shows considerable promise for PET studies of biliary elimination and of PDE5 binding in the cardiovascular system. However, analogues of higher affinity may be required for investigations of central nervous system binding sites.

  7. Sildenafil and analogous phosphodiesterase type 5 (PDE-5) inhibitors in herbal food supplements sampled on the Dutch market. (United States)

    Reeuwijk, N M; Venhuis, B J; de Kaste, D; Hoogenboom, L A P; Rietjens, I M C M; Martena, M J


    Herbal food supplements, claiming to enhance sexual potency, may contain deliberately added active pharmacological ingredients (APIs) that can be used for the treatment of erectile dysfunction (ED). The aim of this study was to determine whether herbal food supplements on the Dutch market indeed contain APIs that inhibit phosphodiesterase type 5 (PDE-5) inhibitors, such as sildenafil and analogous PDE-5 inhibitors. Herbal food supplements intended to enhance sexual potency (n = 71), and two soft drinks, were sampled from 2003 up to and including 2012. In 23 herbal supplements, nine different PDE-5 inhibitors were identified; in a few cases (n = 3), more than one inhibitor was indentified. The presence of these APIs was however not stated on the label. The concentrations of PDE-5 inhibitors per dose unit were analysed. Furthermore, the potential pharmacologically active properties of the detected PDE-5 inhibitors were estimated by using data from the scientific and patent literature regarding (1) in vitro PDE-5 activity, (2) reported effective doses of registered drugs with PDE-5 inhibitor activity and (3) similarity to other structural analogues. It was concluded that 18 of the 23 herbal food supplements, when used as recommended, would have significant pharmacological effects due to added APIs. Adequate use of existing regulation and control measures seems necessary to protect consumers against the adverse effects of these products.

  8. Photodynamics of blue-light-regulated phosphodiesterase BlrP1 protein from Klebsiella pneumoniae and its photoreceptor BLUF domain

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, A. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany); Penzkofer, A. [Institut II - Experimentelle und Angewandte Physik, Universitaet Regensburg, Universitaetstrasse 31, D-93053 Regensburg (Germany)], E-mail:; Griese, J.; Schlichting, I. [Max-Planck-Institut fuer medizinische Forschung, Abteilung Biomolekulare Mechanismen, Jahnstrasse 29, D-69120 Heidelberg (Germany); Kirienko, Natalia V.; Gomelsky, Mark [Department of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071 (United States)


    The BlrP1 protein from the enteric bacterium Klebsiella pneumoniae consists of a BLUF and an EAL domain and may activate c-di-GMP phosphodiesterase by blue-light. The full-length protein, BlrP1, and its BLUF domain, BlrP1{sub B}LUF, are characterized by optical absorption and emission spectroscopy. The cofactor FAD in its oxidized redox state (FAD{sub ox}) is brought from the dark-adapted receptor state to the 10-nm red-shifted putative signalling state by violet light exposure. The recovery to the receptor state occurs with a time constant of about 1 min. The quantum yield of signalling state formation is about 0.17 for BlrP1{sub B}LUF and about 0.08 for BlrP1. The fluorescence efficiency of the FAD{sub ox} cofactor is small due to photo-induced reductive electron transfer. Prolonged light exposure converts FAD{sub ox} in the signalling state to the fully reduced hydroquinone form FAD{sub red}H{sup -} and causes low-efficient chromophore release with subsequent photo-degradation. The photo-cycle and photo-reduction dynamics in the receptor state and in the signalling state are discussed.

  9. Photodynamics of blue-light-regulated phosphodiesterase BlrP1 protein from Klebsiella pneumoniae and its photoreceptor BLUF domain (United States)

    Tyagi, A.; Penzkofer, A.; Griese, J.; Schlichting, I.; Kirienko, Natalia V.; Gomelsky, Mark


    The BlrP1 protein from the enteric bacterium Klebsiella pneumoniae consists of a BLUF and an EAL domain and may activate c-di-GMP phosphodiesterase by blue-light. The full-length protein, BlrP1, and its BLUF domain, BlrP1_BLUF, are characterized by optical absorption and emission spectroscopy. The cofactor FAD in its oxidized redox state (FAD ox) is brought from the dark-adapted receptor state to the 10-nm red-shifted putative signalling state by violet light exposure. The recovery to the receptor state occurs with a time constant of about 1 min. The quantum yield of signalling state formation is about 0.17 for BlrP1_BLUF and about 0.08 for BlrP1. The fluorescence efficiency of the FAD ox cofactor is small due to photo-induced reductive electron transfer. Prolonged light exposure converts FAD ox in the signalling state to the fully reduced hydroquinone form FAD redH - and causes low-efficient chromophore release with subsequent photo-degradation. The photo-cycle and photo-reduction dynamics in the receptor state and in the signalling state are discussed.

  10. Conformation Changes N-terminal Involvement and cGMP Signal Relay in the Phosphodiesterase-5 GAF Domain

    Energy Technology Data Exchange (ETDEWEB)

    H Wang; H Robinson; H Ke


    The activity of phosphodiesterase-5 (PDE5) is specific for cGMP and is regulated by cGMP binding to GAF-A in its regulatory domain. To better understand the regulatory mechanism, x-ray crystallographic and biochemical studies were performed on constructs of human PDE5A1 containing the N-terminal phosphorylation segment, GAF-A, and GAF-B. Superposition of this unliganded GAF-A with the previously reported NMR structure of cGMP-bound PDE5 revealed dramatic conformational differences and suggested that helix H4 and strand B3 probably serve as two lids to gate the cGMP-binding pocket in GAF-A. The structure also identified an interfacial region among GAF-A, GAF-B, and the N-terminal loop, which may serve as a relay of the cGMP signal from GAF-A to GAF-B. N-terminal loop 98-147 was physically associated with GAF-B domains of the dimer. Biochemical analyses showed an inhibitory effect of this loop on cGMP binding and its involvement in the cGMP-induced conformation changes.

  11. Patient preference and satisfaction in erectile dysfunction therapy: a comparison of the three phosphodiesterase-5 inhibitors sildenafil, vardenafil and tadalafil

    Directory of Open Access Journals (Sweden)

    Amr Abdel Raheem


    Full Text Available Amr Abdel Raheem1, Philip Kell21St. Peter’s Andrology Department, The Institute of Urology, London, and Cairo University, Egypt; 2St. Peter’s Andrology Department, The Institute of Urology, London, UKAbstract: Erectile dysfunction (ED is a problem that may affect up to 52% of men between the ages of 40 and 70. It can be distressing because of its negative effect on self-esteem, quality of life, and interpersonal relationships. Oral phosphodiesterase-5 inhibitors (PDE5 inhibitors are now the first choice of treatment in ED. The availability of three (sildenafil citrate, tadalafil, and vardenafil well tolerated and effective oral PDE5 inhibitors gives treatment options for men with ED. Although the mechanism of action is the same for the three drugs, they differ in their pharmacokinetics. Several preference studies were conducted between the three PDE5 inhibitors but they were not free from bias. Because of the lack of overwhelming reliable data showing that one PDE5 inhibitor is superior to another, current opinion is that the individual patient should have the opportunity to test all three drugs and then select the one that best suits him and his partner.Keywords: erectile dysfunction, PDE5 inhibitors, patient preference

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

    Directory of Open Access Journals (Sweden)

    Jianrong Liu


    Full Text Available 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.

  13. Mechanism of repair of 5'-topoisomerase II-DNA adducts by mammalian tyrosyl-DNA phosphodiesterase 2

    Energy Technology Data Exchange (ETDEWEB)

    Schellenberg, Matthew J; Appel, C Denise; Adhikari, Sanjay; Robertson, Patrick D; Ramsden, Dale A; Williams, R Scott [NIH; (Georgetown); (UNC)


    The topoisomerase II (topo II) DNA incision-and-ligation cycle can be poisoned (for example following treatment with cancer chemotherapeutics) to generate cytotoxic DNA double-strand breaks (DSBs) with topo II covalently conjugated to DNA. Tyrosyl-DNA phosphodiesterase 2 (Tdp2) protects genomic integrity by reversing 5'-phosphotyrosyl–linked topo II–DNA adducts. Here, X-ray structures of mouse Tdp2–DNA complexes reveal that Tdp2 β–2-helix–β DNA damage–binding 'grasp', helical 'cap' and DNA lesion–binding elements fuse to form an elongated protein-DNA conjugate substrate-interaction groove. The Tdp2 DNA-binding surface is highly tailored for engagement of 5'-adducted single-stranded DNA ends and restricts nonspecific endonucleolytic or exonucleolytic processing. Structural, mutational and functional analyses support a single–metal ion catalytic mechanism for the exonuclease-endonuclease-phosphatase (EEP) nuclease superfamily and establish a molecular framework for targeted small-molecule blockade of Tdp2-mediated resistance to anticancer topoisomerase drugs.

  14. [Phosphodiesterase 3 mediates cross-talk between the protein kinase- and cGMP- dependent pathways and cyclic AMP metabolism]. (United States)

    Makuch, Edyta; Matuszyk, Janusz


    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.

  15. Phosphodiesterase 2 negatively regulates adenosine-induced transcription of the tyrosine hydroxylase gene in PC12 rat pheochromocytoma cells. (United States)

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


    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.

  16. Correlation between selective inhibition of the cyclic nucleotide phosphodiesterases and the contractile activity in human pregnant myometrium near term. (United States)

    Leroy, M J; Cedrin, I; Breuiller, M; Giovagrandi, Y; Ferre, F


    The present study was carried out to determine the ability of various pharmacological agents to selectively inhibit each cytosolic form of phosphodiesterase isolated from the longitudinal layer of human myometria near term. Among the drugs tested, zaprinast specifically inhibits the first form of PDE which hydrolyses both substrates (cAMP and cGMP) and is stimulated by the Ca2+-calmodulin complex. A second form of PDE specific for cAMP hydrolysis and Ca2+-calmodulin insensitive is only present during pregnancy. Rolipram is the most potent and selective inhibitor of this second form. It is also the most efficient compound to inhibit in vitro the spontaneous contractions of near term myometria. The double effect of rolipram suggests an important role of the second form of PDE in the mechanisms of contractility during the pregnancy. In addition rolipram or other derivatives might be of a therapeutic interest in the prevention of prematurity in so far as they are devoid of undesirable maternal and fetal side effects.

  17. Sex-dependent association of phosphodiesterase 4D gene polymorphisms with ischemic stroke in Henan Han population

    Institute of Scientific and Technical Information of China (English)

    HE Ying; QI Hua; SONG Guo-ying; ZHENG Hong; XU Yu-ming; BAI Jun-yu; SONG Bo; TAN Song; CHANG Yin-shu; LI Tao; SHI Cong-cong; ZHANG Hua; FENG Qing-chuan


    Background Recent evidence has implicated the gene for phosphodiesterase 4D (PDE4D) as susceptibility gene for ischemic stroke (IS) in lcelandic population.However,there are few reports on the associations between PDE4D gene polymorphisms and IS in Chinese individuals.The present study aimed to investigate the possible association of genetic polymorphisms in PDE4D gene with IS in Henan Han population.Methods A total of 400 patients with IS and 400 matched controls were examined using a case-control design.Two single nucleotide polymorphism (SNPs) (rs918592 and rs2910829) in PDE4D gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.Odds ratios (OR) and 95% confidence intervals (95% Cl) were calculated to test the association between the genetic factors and IS.Genetic parameter and association studies were carried out with SPSS 16.0.Results Among the two SNPs tested,the rs918592 was significantly associated with IS (OR:1.351,95% Cl:1.110-1.645),especially in male patients (OR:1.427,95% Cl:1.105-1.844).Haplotype analysis showed that A-T was associated with an increased risk of the IS (OR:2.114,95% Cl:2.005-2.230) while G-T was associated with decreased risk of IS (OR:0.419,95% Cl:0.302-0.583).Protecting effect of haplotype G-T was also significant in males (OR:0.264,95% Cl:0.162-0.431).Conclusions The present study demonstrated a strong association of rs918592 with IS.Haplotype A-T increased the risk of IS while haplotype G-T had a protective effect in Henan Hen population.The association was sex-dependent with male patients showing stronger effect.

  18. Analysis of the Active-Site Mechanism of Tyrosyl-DNA Phosphodiesterase I: A Member of the Phospholipase D Superfamily

    Energy Technology Data Exchange (ETDEWEB)

    Gajewski, Stefan; Comeaux, Evan Q.; Jafari, Nauzanene; Bharatham, Nagakumar; Bashford, Donald; White, Stephen W.; van Waardenburg, Robert C.A.M. (UAB); (SJCH)


    Tyrosyl-DNA phosphodiesterase I (Tdp1) is a member of the phospholipase D superfamily that hydrolyzes 3'-phospho-DNA adducts via two conserved catalytic histidines - one acting as the lead nucleophile and the second acting as a general acid/base. Substitution of the second histidine specifically to arginine contributes to the neurodegenerative disease spinocerebellar ataxia with axonal neuropathy (SCAN1). We investigated the catalytic role of this histidine in the yeast protein (His432) using a combination of X-ray crystallography, biochemistry, yeast genetics, and theoretical chemistry. The structures of wild-type Tdp1 and His432Arg both show a phosphorylated form of the nucleophilic histidine that is not observed in the structure of His432Asn. The phosphohistidine is stabilized in the His432Arg structure by the guanidinium group that also restricts the access of nucleophilic water molecule to the Tdp1-DNA intermediate. Biochemical analyses confirm that His432Arg forms an observable and unique Tdp1-DNA adduct during catalysis. Substitution of His432 by Lys does not affect catalytic activity or yeast phenotype, but substitutions with Asn, Gln, Leu, Ala, Ser, and Thr all result in severely compromised enzymes and DNA topoisomerase I-camptothecin dependent lethality. Surprisingly, His432Asn did not show a stable covalent Tdp1-DNA intermediate that suggests another catalytic defect. Theoretical calculations revealed that the defect resides in the nucleophilic histidine and that the pK{sub a} of this histidine is crucially dependent on the second histidine and on the incoming phosphate of the substrate. This represents a unique example of substrate-activated catalysis that applies to the entire phospholipase D superfamily.

  19. Meiotic arrest in vitro by phosphodiesterase 3-inhibitor enhances maturation capacity of human oocytes and allows subsequent embryonic development. (United States)

    Nogueira, D; Ron-El, R; Friedler, S; Schachter, M; Raziel, A; Cortvrindt, R; Smitz, J


    Controlling nuclear maturation during oocyte culture might improve nuclear-cytoplasmic maturation synchrony. We aimed to evaluate the quality of in vitro-matured, germinal vesicle (GV)-stage human oocytes following a prematuration culture (PMC) with a meiotic arrester, phosphodiesterase 3-inhibitor (PDE3-I). Follicles (diameter, 6-12 mm) were retrieved 34-36 h post-hCG administration from informed, consenting patients who had undergone controlled ovarian stimulation. Cumulus-enclosed oocytes (CEOs) presenting moderate expansion or full compaction were placed in PMC with the PDE3-I, Org9935, for 24 or 48 h. Subsequently, oocytes were removed from PMC, denuded of cumulus cells, matured in vitro, and fertilized, and the resulting embryos were cultured. In the presence of PDE3-I, approximately 98% of the oocytes were arrested at the GV stage. Following PDE3-I removal, oocytes acquired a higher maturation rate than oocytes that were immediately denuded of cumulus cells after retrieval and in vitro matured (67% vs. 46%, P = 0.01). In controls, immature CEOs retrieved with moderate expansion reached higher maturation rates compared to fully compacted CEOs, but in PMC groups, high values of maturation were achieved for both morphological classes of CEOs. No effect of PMC on fertilization was observed. A 24-h PMC period proved to be the most effective in preserving embryonic integrity. Similar proportions of nuclear abnormalities were observed in embryos of all in vitro groups. In summary, PMC with the specific PDE3-I had a beneficial effect on human CEOs by enhancing maturation, benefiting mainly the fully compacted CEOs. This resulted in an increased yield of mature oocytes available for insemination without compromising embryonic development. These results suggest that applying an inhibitor to control the rate of nuclear maturity by regulating intraoocyte PDE3 activity may allow the synchronization of nuclear and ooplasmic maturation.

  20. A role for phosphodiesterase 3B in acquisition of brown fat characteristics by white adipose tissue in male mice. (United States)

    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


    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.

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

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


    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. Incidence rate of prostate cancer in men treated for erectile dysfunction with phosphodiesterase type 5 inhibitors: retrospective analysis

    Institute of Scientific and Technical Information of China (English)

    Anthony H Chavez; K Scott Coffield; M Hasan Rajab; Chanhee Jo


    The purpose of this study was to determine the incidence rate of prostate cancer among men with erectile dysfunction (ED) treated with phosphodiesterase type 5 inhibitors (PDE-5i) over a 7-year period with ED of the same age and with similar risk factors who were not treated with PDE-5i.In a retrospective review of electronic medical records and billing databases between the years 2000 and 2006,men with ED between the ages of 50 and 69 years and no history of prostate cancer prior to 2000 were identified.These individuals were divided into two groups:2362 men who had treatment with PDE-5i,and 2612 men who did not have treatment.Demographic data in each group were compared.During the study period,97 (4.1%) men with ED treated with PDE-5i were diagnosed with prostate cancer compared with 258 (9.9%) men with ED in the non-treated group (P<00001).A higher percentage of African Americans were treated with PDE-5i vs.those who were not (10.5% vs.7.1%; P<0.0001).The PDE-5i group had lower documented diagnosis of elevated prostate-specific antigen (10.0% vs.13.1%; P=0.0008) and higher percentage of benign prostatic hyperplasia (38.4% vs.35.1%; P=0.0149).Men with ED treated with PDE-5i tended to have less chance (adjusted odds ratio:0.4; 95% confidence intervals:0.3-0.5; P<0.0001) of having prostate cancer.Our data suggest that men with ED treated with PDE-5i tended to have less of a chance of being diagnosed with prostate cancer.Further research is warranted.

  3. Characterization of sensory neuron subpopulations selectively expressing green fluorescent protein in phosphodiesterase 1C BAC transgenic mice

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    Anderson Rebecca L


    Full Text Available Abstract Background The complex neuronal circuitry of the dorsal horn of the spinal cord is as yet poorly understood. However, defining the circuits underlying the transmission of information from primary afferents to higher levels is critical to our understanding of sensory processing. In this study, we have examined phosphodiesterase 1C (Pde1c BAC transgenic mice in which a green fluorescent protein (GFP reporter gene reflects Pde1c expression in sensory neuron subpopulations in the dorsal root ganglia and spinal cord. Results Using double labeling immunofluorescence, we demonstrate GFP expression in specific subpopulations of primary sensory neurons and a distinct neuronal expression pattern within the spinal cord dorsal horn. In the dorsal root ganglia, their distribution is restricted to those subpopulations of primary sensory neurons that give rise to unmyelinated C fibers (neurofilament 200 negative. A small proportion of both non-peptidergic (IB4-binding and peptidergic (CGRP immunoreactive subclasses expressed GFP. However, GFP expression was more common in the non-peptidergic than the peptidergic subclass. GFP was also expressed in a subpopulation of the primary sensory neurons immunoreactive for the vanilloid receptor TRPV1 and the ATP-gated ion channel P2X3. In the spinal cord dorsal horn, GFP positive neurons were largely restricted to lamina I and to a lesser extent lamina II, but surprisingly did not coexpress markers for key neuronal populations present in the superficial dorsal horn. Conclusion The expression of GFP in subclasses of nociceptors and also in dorsal horn regions densely innervated by nociceptors suggests that Pde1c marks a unique subpopulation of nociceptive sensory neurons.

  4. Protective effects of phosphodiesterase inhibitors on lung function and remodeling in a murine model of chronic asthma

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    Campos H.S.


    Full Text Available The aim of the present study was to compare the efficacy of a novel phosphodiesterase 4 and 5 inhibitor, LASSBio596, with that of dexamethasone in a murine model of chronic asthma. Lung mechanics (airway resistance, viscoelastic pressure, and static elastance, histology, and airway and lung parenchyma remodeling (quantitative analysis of collagen and elastic fiber were analyzed. Thirty-three BALB/c mice were randomly assigned to four groups. In the asthma group (N = 9, mice were immunized with 10 µg ovalbumin (OVA, ip on 7 alternate days, and after day 40 they were challenged with three intratracheal instillations of 20 µg OVA at 3-day intervals. Control mice (N = 8 received saline under the same protocol. In the dexamethasone (N = 8 and LASSBio596 (N = 8 groups, the animals of the asthma group were treated with 1 mg/kg dexamethasone disodium phosphate (0.1 mL, ip or 10 mg/kg LASSBio596 dissolved in dimethyl sulfoxide (0.2 mL, ip 24 h before the first intratracheal instillation of OVA, for 8 days. Airway resistance, viscoelastic pressure and static elastance increased significantly in the asthma group (77, 56, and 76%, respectively compared to the control group. The asthma group presented more intense alveolar collapse, bronchoconstriction, and eosinophil and neutrophil infiltration than the control group. Both LASSBio596 and dexamethasone inhibited the changes in lung mechanics, tissue cellularity, bronchoconstriction, as well as airway and lung parenchyma remodeling. In conclusion, LASSBio596 at a dose of 10 mg/kg effectively prevented lung mechanical and morphometrical changes and had the potential to block fibroproliferation in a BALB/c mouse model of asthma.

  5. cGMP-phosphodiesterase inhibition enhances photic responses and synchronization of the biological circadian clock in rodents.

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    Santiago A Plano

    Full Text Available The master circadian clock in mammals is located in the hypothalamic suprachiasmatic nuclei (SCN and is synchronized by several environmental stimuli, mainly the light-dark (LD cycle. Light pulses in the late subjective night induce phase advances in locomotor circadian rhythms and the expression of clock genes (such as Per1-2. The mechanism responsible for light-induced phase advances involves the activation of guanylyl cyclase (GC, cGMP and its related protein kinase (PKG. Pharmacological manipulation of cGMP by phosphodiesterase (PDE inhibition (e.g., sildenafil increases low-intensity light-induced circadian responses, which could reflect the ability of the cGMP-dependent pathway to directly affect the photic sensitivity of the master circadian clock within the SCN. Indeed, sildenafil is also able to increase the phase-shifting effect of saturating (1200 lux light pulses leading to phase advances of about 9 hours, as well as in C57 a mouse strain that shows reduced phase advances. In addition, sildenafil was effective in both male and female hamsters, as well as after oral administration. Other PDE inhibitors (such as vardenafil and tadalafil also increased light-induced phase advances of locomotor activity rhythms and accelerated reentrainment after a phase advance in the LD cycle. Pharmacological inhibition of the main downstream target of cGMP, PKG, blocked light-induced expression of Per1. Our results indicate that the cGMP-dependent pathway can directly modulate the light-induced expression of clock-genes within the SCN and the magnitude of light-induced phase advances of overt rhythms, and provide promising tools to design treatments for human circadian disruptions.

  6. Chronic lymphocytic leukemia and B and T cells differ in their response to cyclic nucleotide phosphodiesterase inhibitors. (United States)

    Meyers, John A; Su, Derrick W; Lerner, Adam


    Phosphodiesterase (PDE)4 inhibitors, which activate cAMP signaling by reducing cAMP catabolism, are known to induce apoptosis in B lineage chronic lymphocytic leukemia (CLL) cells but not normal human T cells. The explanation for such differential sensitivity remains unknown. In this study, we report studies contrasting the response to PDE4 inhibitor treatment in CLL cells and normal human T and B cells. Affymetrix gene chip analysis in the three cell populations following treatment with the PDE4 inhibitor rolipram identified a set of up-regulated transcripts with unusually high fold changes in the CLL samples, several of which are likely part of compensatory negative feedback loops. The high fold changes were due to low basal transcript levels in CLL cells, suggesting that cAMP-mediated signaling may be unusually tightly regulated in this cell type. Rolipram treatment augmented cAMP levels and induced ATF-1/CREB serine 63/133 phosphorylation in both B lineage cell types but not T cells. As treatment with the broad-spectrum PDE inhibitor 3-isobutyl-1-methylxanthine induced T cell CREB phosphorylation, we tested a series of family-specific PDE inhibitors for their ability to mimic 3-isobutyl-1-methylxanthine-induced ATF-1/CREB phosphorylation. Whereas PDE3 inhibitors alone had no effect, the combination of PDE3 and PDE4 inhibitors induced ATF-1/CREB serine 63/133 phosphorylation in T cells. Consistent with this observation, PDE3B transcript and protein levels were low in CLL cells but easily detectable in T cells. Combined PDE3/4 inhibition did not induce T cell apoptosis, suggesting that cAMP-mediated signal transduction that leads to robust ATF-1/CREB serine 63/133 phosphorylation is not sufficient to induce apoptosis in this lymphoid lineage.

  7. Chemical Validation of Phosphodiesterase C as a Chemotherapeutic Target in Trypanosoma cruzi, the Etiological Agent of Chagas' Disease▿ † (United States)

    King-Keller, Sharon; Li, Minyong; Smith, Alyssa; Zheng, Shilong; Kaur, Gurpreet; Yang, Xiaochuan; Wang, Binghe; Docampo, Roberto


    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

  8. Effect of the phosphodiesterase type 5 inhibitor tadalafil on pulmonary hemodynamics in a canine model of pulmonary hypertension. (United States)

    Hori, Yasutomo; Kondo, Chigusa; Matsui, Maho; Yamagishi, Maki; Okano, Shozo; Chikazawa, Seishiro; Kanai, Kazutaka; Hoshi, Fumio; Itoh, Naoyuki


    Phosphodiesterase type 5 (PDE5) inhibitors are used for treating pulmonary arterial hypertension (PAH) in dogs. The long-acting PDE5 inhibitor tadalafil was recently approved for treatment of PAH in humans. Basic information related to the pharmacological and hemodynamic effects of tadalafil in dogs is scarce. In this study, the hemodynamic effects of tadalafil after intravenous (IV) and oral administration were investigated in a healthy vasoconstrictive PAH Beagle dog model induced by U46619, a thromboxane A2 mimetic. Six healthy Beagle dogs were anesthetized with propofol and maintained with isoflurane. Fluid-filled catheters were placed into the descending aorta to measure systemic arterial pressure and in the pulmonary artery to measure pulmonary arterial pressure (PAP). U46619 was infused via the cephalic vein to induce PAH. IV infusion of U46619 significantly elevated PAP from baseline in a dose-dependent manner. U46619-elevated PAP and pulmonary vascular resistance was significantly attenuated by the simultaneous infusion of tadalafil at 100 and 200 µg/kg/h. Likewise, oral administration of tadalafil at 1.0, 2.0, and 4.0 mg/kg significantly attenuated U46619-elevated PAP in a dose-dependent manner. U46619-elevated systolic and mean PAP decreased significantly 1 h after oral tadalafil administration at 4.0 mg/kg, and this effect was maintained for 6 h. In conclusion, tadalafil had a pharmacological effect in dogs and IV infusion of tadalafil induced pulmonary arterial relaxation, while oral administration of tadalafil decreased PAP. These results suggest that tadalafil may offer a new therapeutic option for treating dogs with PAH.

  9. Phosphodiesterase-4 inhibition alters gene expression and improves isoniazid-mediated clearance of Mycobacterium tuberculosis in rabbit lungs.

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    Selvakumar Subbian


    Full Text Available 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.

  10. Phosphodiesterase 4B is essential for TH2-cell function and development of airway hyperresponsiveness in allergic asthma (United States)

    Catherine Jin, S.-L.; Goya, Sho; Nakae, Susumu; Wang, Dan; Bruss, Matthew; Hou, Chiaoyin; Umetsu, Dale; Conti, Marco


    Background Cyclic AMP (cAMP) signaling modulates functions of inflammatory cells involved in the pathogenesis of asthma, and type 4 cAMP-specific phosphodiesterases (PDE4s) are essential components of this pathway. Induction of the PDE4 isoform PDE4B is necessary for Toll-like receptor signaling in monocytes and macrophages and is associated with T cell receptor/CD3 in T cells; however, its exact physiological function in the development of allergic asthma remains undefined. Objectives We investigated the role of PDE4B in the development of allergen-induced airway hyperresponsiveness (AHR) and TH2-driven inflammatory responses. Methods Wild-type and PDE4B−/− mice were sensitized and challenged with ovalbumin and AHR measured in response to inhaled methacholine. Airway inflammation was characterized by analyzing leukocyte infiltration and cytokine accumulation in the airways. Ovalbumin-stimulated cell proliferation and TH2 cytokine production were determined in cultured bronchial lymph node cells. Results Mice deficient in PDE4B do not develop AHR. This protective effect was associated with a significant decrease in eosinophils recruitment to the lungs and decreased TH2 cytokine levels in the bronchoalveolar lavage fluid. Defects in T-cell replication, TH2 cytokine production, and dendritic cell migration were evident in cells from the airway-draining lymph nodes. Conversely, accumulation of the TH1 cytokine IFN-γ was not affected in PDE4B−/− mice. Ablation of the orthologous PDE4 gene PDE4A has no impact on airway inflammation. Conclusion By relieving a cAMP-negative constraint, PDE4B plays an essential role in TH2-cell activation and dendritic cell recruitment during airway inflammation. These findings provide proof of concept that PDE4 inhibitors with PDE4B selectivity may have efficacy in asthma treatment. PMID:21047676

  11. Treatment of psoriatic arthritis in a phase 3 randomised, placebo-controlled trial with apremilast, an oral phosphodiesterase 4 inhibitor (United States)

    Kavanaugh, Arthur; Mease, Philip J; Gomez-Reino, Juan J; Adebajo, Adewale O; Wollenhaupt, Jürgen; Gladman, Dafna D; Lespessailles, Eric; Hall, Stephen; Hochfeld, Marla; Hu, ChiaChi; Hough, Douglas; Stevens, Randall M; Schett, Georg


    Objectives Apremilast, an oral phosphodiesterase 4 inhibitor, regulates inflammatory mediators. Psoriatic Arthritis Long-term Assessment of Clinical Efficacy 1 (PALACE 1) compared apremilast with placebo in patients with active psoriatic arthritis despite prior traditional disease-modifying antirheumatic drug (DMARD) and/or biologic therapy. Methods In the 24-week, placebo-controlled phase of PALACE 1, patients (N=504) were randomised (1:1:1) to placebo, apremilast 20 mg twice a day (BID) or apremilast 30 mg BID. At week 16, patients without ≥20% reduction in swollen and tender joint counts were required to be re-randomised equally to either apremilast dose if initially randomised to placebo or remained on their initial apremilast dose. Patients on background concurrent DMARDs continued stable doses (methotrexate, leflunomide and/or sulfasalazine). Primary outcome was the proportion of patients achieving 20% improvement in modified American College of Rheumatology response criteria (ACR20) at week 16. Results At week 16, significantly more apremilast 20 mg BID (31%) and 30 mg BID (40%) patients achieved ACR20 versus placebo (19%) (p<0.001). Significant improvements in key secondary measures (physical function, psoriasis) were evident with both apremilast doses versus placebo. Across outcome measures, the 30-mg group generally had higher and more consistent response rates, although statistical comparison was not conducted. The most common adverse events were gastrointestinal and generally occurred early, were self-limiting and infrequently led to discontinuation. No imbalance in major adverse cardiac events, serious or opportunistic infections, malignancies or laboratory abnormalities was observed. Conclusions Apremilast was effective in the treatment of psoriatic arthritis, improving signs and symptoms and physical function. Apremilast demonstrated an acceptable safety profile and was generally well tolerated. Clinical trial registration number NCT

  12. Eukaryotic-type Ser/Thr protein kinase mediated phosphorylation of mycobacterial phosphodiesterase affects its localization to the cell wall

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    Neha eMalhotra


    Full Text Available Phosphodiesterase enzymes, involved in cAMP hydrolysis reaction, are present throughout phylogeny and their phosphorylation mediated regulation remains elusive in prokaryotes. In this context, we focused on this enzyme from Mycobacterium tuberculosis. The gene encoded by Rv0805 was PCR amplified and expressed as a histidine-tagged protein (mPDE utilizing Escherichia coli based expression system. In kinase assays, upon incubation with mycobacterial Clade I eukaryotic-type Ser/Thr kinases (PknA, PknB and PknL, Ni-NTA purified mPDE protein exhibited transphosphorylation ability albeit with varying degree. When mPDE was co-expressed one at a time with these kinases in E. coli, it was also recognized by an anti-phosphothreonine antibody, which further indicates its phosphorylating ability. Mass spectrometric analysis identified Thr-309 of mPDE as a phosphosite. In concordance with this observation, anti-phosphothreonine antibody marginally recognized mPDE-T309A mutant protein; however, such alteration did not affect the enzymatic activity. Interestingly, mPDE expressed in Mycobacterium smegmatis yielded a phosphorylated protein that preferentially localized to cell wall. In contrast, mPDE-T309A, the phosphoablative variant of mPDE, did not show such behaviour. On the other hand, phosphomimics of mPDE (T309D or T309E, exhibited similar cell wall anchorage as was observed with the wild-type. Thus, our results provide credence to the fact that eukaryotic-type Ser/Thr kinase mediated phosphorylation of mPDE renders negative charge to the protein, promoting its localization on cell wall. Furthermore, multiple sequence alignment revealed that Thr-309 is conserved among mPDE orthologs of M. tuberculosis complex, which presumably emphasizes evolutionary significance of phosphorylation at this residue.

  13. Berberine attenuates cAMP-induced lipolysis via reducing the inhibition of phosphodiesterase in 3T3-L1 adipocytes. (United States)

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


    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.

  14. Effect of multifunctional protein YB-1 on the AP site cleavage by AP endonuclease 1 and tyrosyl phosphodiesterase 1

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    Ovchinnikov L. P.


    Full Text Available Apurinic/apyrimidinic sites (AP sites which represent one of the most abundantly generated DNA lesions in the cell are generally repaired by base excision repair (BER pathway. Multifunctional protein YB-1 is known to participate in cellular response to genotoxic stress and was shown to interact with several components of BER – DNA glycosylases NTH1, NEIL2, DNA polymerase and DNA ligase III. Therefore, it is of great interest to investigate the influence of YB-1 on one of the major BER enzymes, responsible for AP site cleavage, AP endonuclease APE1, and on tyrosyl phosphodiesterase Tdp1, participating in APE1 independent pathway of AP site repair. Aim. Effect of multifunctional protein YB-1 on the AP site cleavage by the activities of APE1 and Tdp1 was studied. Methods. Gel-mobility shift assays and enzyme activity tests. Results. YB-1 was shown to inhibit the cleavage of AP site located in single-stranded DNA by both APE1 and Tdp1. Stimulation of APE1 activity on protruding double-stranded DNA in the presence of YB-1 was observed, whereas no effect on Tdp1-mediated cleavage of AP site in double-stranded DNA was found. Conclusions. YB-1 can modulate the repair of AP sites in DNA by both positively stimulating APE1 during the classic BER of AP sites and avoiding a possible generation of doublestrand breaks, arising from the cleavage of single-stranded portion of DNA substrate already used by different DNA-processing pathway

  15. Striatal phosphodiesterase 10A and medial prefrontal cortical thickness in patients with schizophrenia: a PET and MRI study. (United States)

    Bodén, R; Persson, J; Wall, A; Lubberink, M; Ekselius, L; Larsson, E-M; Antoni, G


    The enzyme phosphodiesterase 10A (PDE10A) is abundant in striatal medium spiny neurons and has been implicated in the pathophysiology of schizophrenia in animal models and is investigated as a possible new pharmacological treatment target. A reduction of prefrontal cortical thickness is common in schizophrenia, but how this relates to PDE10A expression is unknown. Our study aim was to compare, we believe for the first time, the striatal non-displaceable binding potential (BPND) of the new validated PDE10A ligand [(11)C]Lu AE92686 between patients with schizophrenia and healthy controls. Furthermore, we aimed to assess the correlation of PDE10A BPND to cortical thickness. Sixteen healthy male controls and 10 male patients with schizophrenia treated with clozapine, olanzapine or quetiapine were investigated with positron emission tomography (PET) and magnetic resonance imaging (MRI). Striatal binding potential (BPND) of [(11)C]Lu AE92686 was acquired through dynamic PET scans and cortical thickness by structural MRI. Clinical assessments of symptoms and cognitive function were performed and the antipsychotic dosage was recorded. Patients with schizophrenia had a significantly lower BPND of [(11)C]Lu AE92686 in striatum (P=0.003) than healthy controls. The striatal BPND significantly correlated to cortical thickness in the medial prefrontal cortex and superior frontal gyrus across patients with schizophrenia and healthy controls. No significant correlation was observed between the BPND for [(11)C]Lu AE92686 in striatum and age, schizophrenia symptoms, antipsychotic dosage, coffee consumption, smoking, duration of illness or cognitive function in the patients. In conclusion, PDE10A may be important for functioning in the striato-cortical interaction and in the pathophysiology of schizophrenia.

  16. Phosphodiesterase 5 inhibitors augment UT-15C-stimulated ATP release from erythrocytes of humans with pulmonary arterial hypertension. (United States)

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


    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.


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    J Nandhakumar


    Full Text Available The role of PDE-4 inhibitor etazolate, was evaluated in the presence of PDE-7 inhibitor, BRL-50481, in animal models of epilepsy. Seizures were induced in the animals by subjecting them to injection of chemical convulsants, Pilocarpine, Kainic acid (KA and maximal electroshock (MES. The combination of etazolate and BRL50481 treated mice showed a significant (P<0.001 quick onset of action, jerky movements and convulsion when compared to gabapentin. The combination of etazolate and sGC inhibitor, methylene blue (MB treated mice showed a significant (P<0.001 delay in onset of action, jerky movements and convulsion when compare to gabapentin as well as against the combination of etazolate with BRL 50481.The present study mainly highlights the individual effects of etazolate and combination with BRL-50481 potentiates (P<0.001 the onset of seizure activity against all models of convulsion. The study mainly comprises the onset of seizures, mortality/recovery, percentage of prevention of seizures (anticonvulsant and total duration of convulsive time. The total convulsive time was prolonged significantly (P<0.05 and P<0.01 in combination of methylene blue with etazolate treated (28.59% and 35.15 % groups, compared to DMSO received group (100% in the MES model. In the same way, the combination of calcium channel modulator (CCM and calcium channel blocker (CCB amiodarone and nifedipine respectively, with etazolate showed a significant (P<0.001 delay in onset of seizures, compared to DMSO and etazolate treated groups in all models of epilepsy. This confirms that both CCM and CCB possess anticonvulsant activity. Finally, the study reveals that identification of new cAMP mediated phosphodiesterases family members offers a potential new therapy for epilepsy management in future.

  18. Angiotensin-(1-7) Downregulates Diabetes-Induced cGMP Phosphodiesterase Activation in Rat Corpus Cavernosum (United States)

    Benter, Ibrahim F.


    Molecular mechanisms of the beneficial effects of angiotensin-(1-7), Ang-(1-7), in diabetes-related complications, including erectile dysfunction, remain unclear. We examined the effect of diabetes and/or Ang-(1-7) treatment on vascular reactivity and cyclic guanosine monophosphate (cGMP) phosphodiesterase (PDE) in corpus cavernosum. Male Wistar rats were grouped as (1) control, (2) diabetic (streptozotocin, STZ, treated), (3) control + Ang-(1-7), and (4) diabetic + Ang-(1-7). Following 3 weeks of Ang-(1-7) treatment subsequent to induction of diabetes, rats were sacrificed. Penile cavernosal tissue was isolated to measure vascular reactivity, PDE gene expression and activity, and levels of p38MAP kinase, nitrites, and cGMP. Carbachol-induced vasorelaxant response after preincubation of corpus cavernosum with PE was significantly attenuated in diabetic rats, and Ang-(1-7) markedly corrected the diabetes-induced impairment. Gene expression and activity of PDE and p38MAP kinase were significantly increased in cavernosal tissue of diabetic rats, and Ang-(1-7) markedly attenuated STZ-induced effects. Ang-(1-7) significantly increased the levels of nitrite and cGMP in cavernosal tissue of control and diabetic rats. Cavernosal tissue of diabetic rats had significantly reduced cGMP levels and Ang-(1-7) markedly prevented the STZ-induced cGMP depletion. This study demonstrates that attenuation of diabetes-induced PDE activity might be one of the key mechanisms in the beneficial effects of Ang-(1-7).

  19. Host cell contact induces expression of virulence factors and VieA, a cyclic di-GMP phosphodiesterase, in Vibrio cholerae. (United States)

    Dey, Amit K; Bhagat, Abha; Chowdhury, Rukhsana


    Vibrio cholerae, a noninvasive bacterium, colonizes the intestinal epithelium and secretes cholera toxin (CT), a potent enterotoxin that causes the severe fluid loss characteristic of the disease cholera. In this study, we demonstrate that adherence of V. cholerae to the intestinal epithelial cell line INT 407 strongly induces the expression of the major virulence genes ctxAB and tcpA and the virulence regulatory gene toxT. No induction of toxR and tcpP, which encode transcriptional activators of toxT, was observed in adhered bacteria, and the adherence-dependent upregulation of toxT expression was independent of ToxR and TcpP. A sharp increase in the expression of the vieA gene, which encodes a cyclic di-GMP (c-di-GMP) phosphodiesterase, was observed in INT 407-adhered V. cholerae immediately after infection. Induction of toxT, ctxAB, and tcpA in INT 407-adhered vieA mutant strain O395 ΔvieA was consistently lower than in the parent strain, although no effect was observed in unadhered bacteria, suggesting that VieA has a role in the upregulation of toxT expression specifically in host cell-adhered V. cholerae. Furthermore, though VieA has both a DNA binding helix-turn-helix domain and an EAL domain conferring c-di-GMP phosphodiesterase activity, the c-di-GMP phosphodiesterase activity of VieA is necessary and sufficient for the upregulation of toxT expression.

  20. Targeted disruption of the heat shock protein 20–phosphodiesterase 4D (PDE4D interaction protects against pathological cardiac remodelling in a mouse model of hypertrophy

    Directory of Open Access Journals (Sweden)

    Tamara P. Martin


    Full Text Available Phosphorylated heat shock protein 20 (HSP20 is cardioprotective. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs and a mouse model of pressure overload mediated hypertrophy, we show that peptide disruption of the HSP20–phosphodiesterase 4D (PDE4D complex results in attenuation of action potential prolongation and protection against adverse cardiac remodelling. The later was evidenced by improved contractility, decreased heart weight to body weight ratio, and reduced interstitial and perivascular fibrosis. This study demonstrates that disruption of the specific HSP20–PDE4D interaction leads to attenuation of pathological cardiac remodelling.

  1. The phosphodiesterase 5 inhibitor sildenafil has no effect on cerebral blood flow or blood velocity, but nevertheless induces headache in healthy subjects

    DEFF Research Database (Denmark)

    Kruuse, Christina; Thomsen, Lars Lykke; Jacobsen, Torsten Bjørn


    , and regional cerebral blood flow in the perfusion area of the middle cerebral artery (rCBFmca) was measured using single photon emission computed tomography and xenon inhalation. Radial and temporal artery diameters were studied using high-frequency ultrasound. Blood pressure and heart rate were recorded......Cyclic nucleotides are important hemodynamic regulators in many tissues. Glyceryl trinitrate markedly dilates large cerebral arteries and increases cGMP. Here, the authors study the effect of sildenafil, a selective inhibitor of cGMP-hydrolyzing phosphodiesterase 5 on cerebral hemodynamics...

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


    Edyta Makuch; Janusz Matuszyk


     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 regio...

  3. Targeted disruption of the heat shock protein 20–phosphodiesterase 4D (PDE4D) interaction protects against pathological cardiac remodelling in a mouse model of hypertrophy (United States)

    Martin, Tamara P.; Hortigon-Vinagre, Maria P.; Findlay, Jane E.; Elliott, Christina; Currie, Susan; Baillie, George S.


    Phosphorylated heat shock protein 20 (HSP20) is cardioprotective. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and a mouse model of pressure overload mediated hypertrophy, we show that peptide disruption of the HSP20–phosphodiesterase 4D (PDE4D) complex results in attenuation of action potential prolongation and protection against adverse cardiac remodelling. The later was evidenced by improved contractility, decreased heart weight to body weight ratio, and reduced interstitial and perivascular fibrosis. This study demonstrates that disruption of the specific HSP20–PDE4D interaction leads to attenuation of pathological cardiac remodelling. PMID:25426411

  4. Targeted disruption of the heat shock protein 20-phosphodiesterase 4D (PDE4D) interaction protects against pathological cardiac remodelling in a mouse model of hypertrophy. (United States)

    Martin, Tamara P; Hortigon-Vinagre, Maria P; Findlay, Jane E; Elliott, Christina; Currie, Susan; Baillie, George S


    Phosphorylated heat shock protein 20 (HSP20) is cardioprotective. Using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and a mouse model of pressure overload mediated hypertrophy, we show that peptide disruption of the HSP20-phosphodiesterase 4D (PDE4D) complex results in attenuation of action potential prolongation and protection against adverse cardiac remodelling. The later was evidenced by improved contractility, decreased heart weight to body weight ratio, and reduced interstitial and perivascular fibrosis. This study demonstrates that disruption of the specific HSP20-PDE4D interaction leads to attenuation of pathological cardiac remodelling.

  5. Synthesis and biological activity of pyrido[3',2':4,5]furo[3,2-d]pyrimidine derivatives as novel and potent phosphodiesterase type 4 inhibitors. (United States)

    Taltavull, Joan; Serrat, Jordi; Gràcia, Jordi; Gavaldà, Amadeu; Córdoba, Mònica; Calama, Elena; Montero, José Luis; Andrés, Míriam; Miralpeix, Montserrat; Vilella, Dolors; Hernández, Begoña; Beleta, Jorge; Ryder, Hamish; Pagès, Lluís


    A series of pyrido[3',2':4,5]furo[3,2-d]pyrimidines (PFP) were synthesized and tested for phosphodiesterase type 4 (PDE4) inhibitory activity, with the potential to treat asthma and chronic obstructive pulmonary disease (COPD). Structure-activity relationships within this series, leading to an increase of potency on the enzyme, is presented. Both gem-dimethylcyclohexyl moieties fused to the pyridine ring and the substitution at the 5 position of the PFP scaffold, proved to be key elements in order to get a high affinity in the enzyme.

  6. Adherence to Phosphodiesterase Type 5 Inhibitors in the Treatment of Erectile Dysfunction in Long-Term Users: How Do Men Use the Inhibitors?

    Directory of Open Access Journals (Sweden)

    Ana Carvalheira, PhD


    Conclusion: The analysis of men's narratives revealed a combination of factors that influence the adherence to PDE5-i. The psychological and medication-related factors were the most prevalent. This study highlighted the importance of taking these factors into account, both at the time of prescription and during the follow-up in order to improve adherence. Carvalheira A, Forjaz V, and Pereira NM. Adherence to phosphodiesterase type 5 inhibitors in the treatment of erectile dysfunction in long-term users: How do men use the inhibitors? Sex Med 2014;2:96–102.

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

    Directory of Open Access Journals (Sweden)

    Ran Meng


    Full Text Available 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.

  8. Phosphodiesterase activity is regulated by CC2D1A that is implicated in non-syndromic intellectual disability

    KAUST Repository

    Altawashi, Azza


    Background: Cyclic adenosine 3?5?-monophosphate (cAMP) is a key regulator of many cellular processes, including in the neuronal system, and its activity is tuned by Phosphodiesterase (PDE) activation. Further, the CC2D1A protein, consisting of N-Terminal containing four DM14 domains and C-terminal containing C2 domain, was shown to regulate the cAMP-PKA pathway. A human deletion mutation lacking the fourth DM14 and the adjacent C2 domain results in Non Syndromic Intellectual Disability (NSID) also referred to as Non Syndromic Mental Retardation (NSMR). Findings. Here we demonstrate that in Mouse Embryonic Fibroblasts (MEF) CC2D1A co-localizes with PDE4D in the cytosol before cAMP stimulation and on the periphery after stimulation, and that the movement to the periphery requires the full-length CC2D1A. In CC2D1A mouse mutant cells, the absence of three of the four DM14 domains abolishes migration of the complex to the periphery and causes constitutive phosphorylation of PDE4D Serine 126 (Sssup126esup) via the cAMP-dependent protein kinase A (PKA) resulting in PDE4D hyperactivity. Suppressing PDE4D activity with Rolipram in turn restores the down-stream phosphorylation of the "cAMP response element-binding protein" (CREB) that is defective in mouse mutant cells. Conclusion: Our findings suggest that CC2D1A is a novel regulator of PDE4D. CC2D1A interacts directly with PDE4D regulating its activity and thereby fine-tuning cAMP-dependent downstream signaling. Based on our in vitro evidence we propose a model which links CC2D1A structure and function to cAMP homeostasis thereby affecting CREB phosphorylation. We speculate that CC2D1A and/or PDE4D may be promising targets for therapeutic interventions in many disorders with impaired PDE4D function such as NSID. 2013 Al-Tawashi and Gehring; licensee BioMed Central Ltd.

  9. Chronic administration of phosphodiesterase type 5 inhibitor suppresses renal production of endothelin-1 in dogs with congestive heart failure. (United States)

    Yamamoto, Takashi; Wada, Atsuyuki; Ohnishi, Masato; Tsutamoto, Takayoshi; Fujii, Masanori; Matsumoto, Takehiro; Takayama, Tomoyuki; Wang, Xinwen; Kurokawa, Kiyoshi; Kinoshita, Masahiko


    Endothelin-1 (ET-1) and atrial natriuretic peptide (ANP) play important roles in the regulation of body fluid balance in congestive heart failure (CHF). Renal production of ET-1 increases in CHF and it is a significant independent predictor of sodium excretion. ANP inhibits the ET system through cGMP, a second messenger of ANP. However, in severe CHF, plasma cGMP levels reached a plateau despite the activation of ANP secretion. Thus, ANP does not seem to sufficiently oppose exaggerated ET-1 actions in severe CHF, partially due to the accelerated degradation of cGMP, through phosphodiesterase type 5 (PDE5). We examined the chronic effects of a PDE5 inhibitor, T-1032 (1 mg/kg per day, n=5), on renal function and renal production of ET-1 in dogs with CHF induced by rapid ventricular pacing (270 beats/min). Vehicle dogs were given a placebo (n=5) and normal dogs (n=5) served as normal controls without pacing. In this experimentally produced CHF, plasma levels of ET-1, ANP and cGMP were elevated and renal production of cGMP was increased compared with the normal group, associated with increases in renal expression of preproET-1 mRNA and the number of ET-1-positive cells in glomeruli. In the T-1032 group, systemic and renal production of cGMP were further increased compared with the vehicle group despite no significant difference in plasma ANP levels between the two groups. Subsequently, the agent significantly improved urine flow rate, sodium excretion rate and glomerular filtration rate (GFR) associated with reductions in renal expression of preproET-1 mRNA and the number of ET-1-positive cells compared with the vehicle group. Moreover, there was a significant negative correlation between the number of ET-1-positive cells and GFR (r=-0.802 and Prenal ANP and ET-1 through the cGMP pathway, subsequently preventing renal dysfunction during the progression of CHF.

  10. Influence of erectile dysfunction course on its progress and efficacy of treatment with phosphodiesterase type 5 inhibitors

    Institute of Scientific and Technical Information of China (English)

    LIU De-feng; JIANG Hui; HONG Kai; ZHAO Lian-ming; TANG Wen-hao; MA Lu-lin


    Background Erectile dysfunction (ED) is a common impairment among older men, and the prevalence rates increase sharply after age of 60 years. Most studies have focused on the prevalence rate or dangerouse factors. The aim of this study was to investigate the basic epidemiologic data about ED patients with different ED courses. The purpose of this researth was to understand the therapeutic effect of phosphodiesterase type 5 inhibitor (PDE5-1) and see how and why the ED course impact the progress of ED and the therapeutic effect of PDE5-1 treatment.Methods From June 2008 to June 2009, 4252 questionnaires (Quality of Erection Questionnaire, QEQ) were gathered from 46 centers by urology or andrology doctors all around China. Patients with ED (age > 20 years) filled in first half of the questionnaires when they came for the first time, and then completed the second half 4 weeks after PDE5-1 therapy.Results ED courses of most patients were less than 5 years (<5 years, 74.0%; 5-10 years 20.8%; >10 years, 5.2%). As ED course increasing, the incidence of the risk factors of ED, such as smoking, drinking, hypertension, diabetes, heart disease and hyperlipidemia also increase (P ≤0.01). PDE5-1 was effective in improving the quality of sexual activities (P ≤0.01). Administration of PDE5-1 improves satisfaction, enjoyment and frequency of sexual activities. The longer the ED course, the worse the therapeutic effect (<5 years, 96.1%; 5-10 years, 94.9%; >10 years, 89.0%) (P<0.01).Conclusions The ED course greatly affected the therapeutic effect of PDE5-1, the patients with ED should consult doctor at early stage of the disease. Admistration of PDE5-1 effectively improves the penile erection and the quality of sexual life of the patients hence should be considered as first-line medicine in the treatment of ED.

  11. Cardiac effects of r-79595 and its isomers (r-80122 and r-80123) in an acute heart-failure model - a new class of cardiotonic agents with highly selective phosphodiesterase-iii inhibitory properties

    NARCIS (Netherlands)



    R 79595 (N-cyclohexyl-N-methyl-2-[[[phenyl (1,2,3,5-tetrahydro-2 oxoimidazo [2,1-b]-quinazolin-7-yl) methylene] amin] oxy] acetamide) and its isomers represent a novel class of compounds with phosphodiesterase (PDE) inhibitory and cardiotonic (positive inotropic) actions. The cardiac effects of this

  12. Discovery and Early Clinical Development of 2-{6-[2-(3,5-Dichloro-4-pyridyl)acetyl]-2,3-dimethoxyphenoxy}-N-propylacetamide (LEO 29102), a Soft-Drug Inhibitor of Phosphodiesterase 4 for Topical Treatment of Atopic Dermatitis

    DEFF Research Database (Denmark)

    Felding, Jakob; D. Sørensen, Morten; Poulsen, Tina D.;


    Development of orally available phosphodiesterase 4 (PDE4) inhibitors as anti-inflammatory drugs has been going on for decades. However, only roflumilast has received FDA approval. One key challenge has been the low therapeutic window observed in the dinic for PDE4 inhibitors, primarily due to PDE4...

  13. Phosphodiesterase-10A Inverse Changes in Striatopallidal and Striatoentopeduncular Pathways of a Transgenic Mouse Model of DYT1 Dystonia. (United States)

    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


    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

  14. Phosphodiesterases inhibitors and airway disease%磷酸二酯酶抑制剂与呼吸道疾病

    Institute of Scientific and Technical Information of China (English)

    李庆玲; 解卫平


    磷酸二酯酶(PDE)存在于许多炎症细胞及结构细胞中,目前已发现11种.PDE抑制剂主要抑制体内环磷酸腺苷(cAMP)及环磷酸鸟苷(cGMP)水解,使细胞内cAMP及cGMP浓度增加,引起一系列生理功能,如平滑肌舒张、减轻细胞炎症及免疫反应等.PDE4特异性水解cAMP,选择性PDE4抑制剂具有广泛抗炎作用,如抑制细胞趋化,抑制中性粒细胞、嗜酸粒细胞、巨噬细胞及T细胞细胞因子及化学趋化物质释放.第二代PDE4抑制剂Cilomilast和Roflumilast已进入临床实验阶段,并已证实对支气管哮喘(简称哮喘)及慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)有效.由于胃肠道副作用,这类药物临床应用受到一定限制.PDE5可特异性水解cGMP,对缺氧性肺动脉高压和血管重塑有效.PDE3和PDE7特异性水解cAMP,PDE7参与T细胞激活.目前其他PDE抑制剂与PDE4抑制剂混合制剂正在研发中.PDE4-PDE7双重抑制剂可能对哮喘及COPD更有效.PDE3-PDE4双重抑制剂具有更强的支气管舒张作用及气道保护作用.%Phosphodiesterases exist as 11 families in a variety of inflammatory and structural cells.They hydrolyse intracellular cyclic adenosine monophosphate(cAMP)and cyclic guanosine monophosphate (cGMP)into inactive state.So PDE inhibitors allow the elevation of cAMP and cGMP which lead to a variety of cellular effects including airway smooth muscle relaxation and inhibition of cellular inflanlmation or of immune responses.PDE4 inhibitors specifically prevent the hydrolysis of cAMP.Selective PDE4 inhibitors have broad spectrum anti-inflammatory effects such as inhibition of cell trafficking,cytokine and chemokine release from inflammatory cells.The new type PDE4 inhibitors,Cilomilast and Roflumilast,have reached clinical trial stage and were demonstrated to have beneficial effects in asthma and chronic obstructive pulmonary disease(COPD).The side effects of these PDE4 inhibitors may limit their

  15. Successful shortening of tuberculosis treatment using adjuvant host-directed therapy with FDA-approved phosphodiesterase inhibitors in the mouse model.

    Directory of Open Access Journals (Sweden)

    Mamoudou Maiga

    Full Text Available Global control of tuberculosis (TB, an infectious disease that claims nearly 2 million lives annually, is hindered by the long duration of chemotherapy required for curative treatment. Lack of adherence to this intense treatment regimen leads to poor patient outcomes, development of new or additional drug resistance, and continued spread of M.tb. within communities. Hence, shortening the duration of TB therapy could increase drug adherence and cure in TB patients. Here, we report that addition of the United Stated Food and Drug Administration-approved phosphodiesterase inhibitors (PDE-Is cilostazol and sildenafil to the standard TB treatment regimen reduces tissue pathology, leads to faster bacterial clearance and shortens the time to lung sterilization by one month, compared to standard treatment alone, in a murine model of TB. Our data suggest that these PDE-Is could be repurposed for use as adjunctive drugs to shorten TB treatment in humans.

  16. Successful Shortening of Tuberculosis Treatment Using Adjuvant Host-Directed Therapy with FDA-Approved Phosphodiesterase Inhibitors in the Mouse Model (United States)

    Ammerman, Nicole C.; Gupta, Radhika; Guo, Haidan; Maiga, Marama C.; Lun, Shichun; Bishai, William R.


    Global control of tuberculosis (TB), an infectious disease that claims nearly 2 million lives annually, is hindered by the long duration of chemotherapy required for curative treatment. Lack of adherence to this intense treatment regimen leads to poor patient outcomes, development of new or additional drug resistance, and continued spread of M.tb. within communities. Hence, shortening the duration of TB therapy could increase drug adherence and cure in TB patients. Here, we report that addition of the United Stated Food and Drug Administration-approved phosphodiesterase inhibitors (PDE-Is) cilostazol and sildenafil to the standard TB treatment regimen reduces tissue pathology, leads to faster bacterial clearance and shortens the time to lung sterilization by one month, compared to standard treatment alone, in a murine model of TB. Our data suggest that these PDE-Is could be repurposed for use as adjunctive drugs to shorten TB treatment in humans. PMID:22319585

  17. [The action of émoksipin on the basal activity of cyclic nucleotide phosphodiesterase and on the late receptor potential of the isolated retina]. (United States)

    Shvedova, A A; Polianskiĭ, N B; Akopian, G Kh; Dzhafarov, A I


    The influence of emoxypin (derivate of 3-hydroxypyridine) upon the late receptor potential (LRP) and activity of the cyclic 3',5'-nucleotide phosphodiesterase (PDE) have been investigated. The inhibition of PDE and increase of the amplitude of LPR have been shown. The curve (RP as a function of the stimulus light intensity) was moved towards the lesser lighting and the time of the achievement of the maximum was increased. Thus, emoxypin produces an effect on the LRP like classical inhibitors of PDE. It is suggested that increase of the functional activity of the retinae upon the influence of emoxypin in caused by the influence of the one towards the system of the cyclic nucleotides.


    Institute of Scientific and Technical Information of China (English)

    QI Hong(祁红); ZHANG Yong(张勇); CHEN Hong-zhuan(陈红专); Marie Jo LEROY; Charles ADVENIER


    Objective To investigate the effects of novel selective phosphodiesterase4 ( PDE4) inhibitors,Ariflo and SB242126A, on the endothelin-1 ( ET-1 ) - induced contractility occurring in nonpregnant human myometrium specimens. Methods Contractile responses to Ariflo and SB242126A were recorded cumulatively on isolated human longitudinal myometrium specimens obtained through surgical operations. Results Ariflo and SB242126A could inhibit both the frequency and amplitude of spontaneous contractions of myometrium (pD2 =8.6and 7. 6,n =4) and ET-1-induced contractions in a concentration-dependent manner (pD2 =7. 7 and 8. 1 ,n =5),with a potency similar to that of Rolipram. Conclusion Ariflo and SB242126A have an obvious inhibitory effect on endothelin-1-induced contractility of isolated human myometrium. The finding suggested that PDE4 inhibitors might have clinical potential in treating preterm labour and dysmenorrhoea.

  19. Synthesis, Molecular Modeling, and Biological Evaluation of Novel Tetrahydro-β-Carboline Hydantoin and Tetrahydro-β-Carboline Thiohydantoin Derivatives as Phosphodiesterase 5 Inhibitors

    Directory of Open Access Journals (Sweden)

    Ashraf H. Abadi


    Full Text Available Two series of fused tetrahydro-β-carboline hydantoin and tetrahydro-β-carboline thiohydantoin derivatives with a pendant 2,4-dimethoxyphenyl at position 5 were synthesized, and chiral carbons at positions 5 and 11a swing from R,R to R,S, S,R, and S,S. The prepared analogues were evaluated for their capacity to inhibit phosphodiesterase 5 (PDE5 isozyme. The R absolute configuration of C-5 in the β-carboline hydantoin derivatives was found to be essential for the PDE5 inhibition. Chiral carbon derived from amino acid even if of the S configuration (L-tryptophan may lead to equiactive or more active isomers than those derived from amino acid with the R configuration (D-tryptophan. This expands the horizon from which efficient PDE5 inhibitors can be derived and may offer an economic advantage. The thiohydantoin derivatives were less active than their hydantoin congeners.

  20. A xanthine derivative denbufylline inhibits negative inotropic response to verapamil in guinea pig ventricular papillary muscles, independent of its phosphodiesterase inhibitory activity. (United States)

    Sanae, F; Ohmae, S; Takagi, K; Miyamoto, K


    A phosphodiesterase (PDE) III inhibitor, amrinone, inhibited both the negative inotropic actions of verapamil and nicardipine in guinea pig ventricular papillary muscle; this effect was canceled by the protein kinase A inhibitor H-89. The PDE IV inhibitor 1,3-di-n-butyl-7-(2'-oxopropyl)xanthine (denbufylline), which elicited a negative inotropic action by itself, attenuated the action of verapamil up to 10 microM, without any interaction with nicardipine. The attenuation by denbufylline was not influenced by H-89. This suggests that in the ventricular papillary muscle, denbufylline acts on some verapamil-sensitive site(s) in the membrane and interferes with the calcium channel function without involvement of its PDE inhibitory activity.

  1. Discovery of [¹¹C]MK-8193 as a PET tracer to measure target engagement of phosphodiesterase 10A (PDE10A) inhibitors. (United States)

    Cox, Christopher D; Hostetler, Eric D; Flores, Broc A; Evelhoch, Jeffrey L; Fan, Hong; Gantert, Liza; Holahan, Marie; Eng, Waisi; Joshi, Aniket; McGaughey, Georgia; Meng, Xiangjun; Purcell, Mona; Raheem, Izzat T; Riffel, Kerry; Yan, Youwei; Renger, John J; Smith, Sean M; Coleman, Paul J


    Phosphodiesterase 10A (PDE10A) inhibition has recently been identified as a potential mechanism to treat multiple symptoms that manifest in schizophrenia. In order to facilitate preclinical development and support key proof-of-concept clinical trials of novel PDE10A inhibitors, it is critical to discover positron emission tomography (PET) tracers that enable plasma concentration/PDE10A occupancy relationships to be established across species with structurally diverse PDE10A inhibitors. In this Letter, we describe how a high-throughput screening hit was optimized to provide [(11)C]MK-8193 (8j), a PET tracer that supports the determination of plasma concentration/PDE10A occupancy relationships for structurally diverse series of PDE10A inhibitors in both rat and rhesus monkey.

  2. Cyclic AMP-phosphodiesterase IIIA1 inhibitors decrease cytosolic Ca2+ concentration and increase the Ca2+ content of intracellular storage sites in human platelets. (United States)

    Roevens, P; de Chaffoy de Courcelles, D


    The effect of cyclic AMP-phosphodiesterase (cAMP-PDE) inhibitors on Ca2+ homeostasis in human platelets was studied using both quin-2 (2-(bis-(acetylamino)-5-methyl-phenoxy)methyl-6-methoxy-8-bis-(acetylami no) quinoline) and chlorotetracycline (CTC) to measure changes in cytosolic Ca2+ as well as changes in the amount of Ca2+ accumulated in intracellular storage sites. At therapeutic concentrations (1 microM) milrinone and R 80 122 but not enoximone decreased the cytosolic Ca2+ concentration in the resting platelet while the Ca2+ content in intracellular stores was increased. These observations are in accord with the proposed mechanism of action of cAMP-PDE inhibitors on cardiomyocites and highlight the particular role of cAMP in regulation of Ca2+ homeostasis.

  3. Design, synthesis, and pharmacological evaluation of N-acylhydrazones and novel conformationally constrained compounds as selective and potent orally active phosphodiesterase-4 inhibitors. (United States)

    Kümmerle, Arthur E; Schmitt, Martine; Cardozo, Suzana V S; Lugnier, Claire; Villa, Pascal; Lopes, Alexandra B; Romeiro, Nelilma C; Justiniano, Hélène; Martins, Marco A; Fraga, Carlos A M; Bourguignon, Jean-Jacques; Barreiro, Eliezer J


    Among a small series of tested N-acylhydrazones (NAHs), the compound 8a was selected as a selective submicromolar phosphodiesterase-4 (PDE4) inhibitor associated with anti-TNF-α properties measured both in vitro and in vivo. The recognition pattern of compound 8a was elucidated through molecular modeling studies based on the knowledge of the 3D-structure of zardaverine, a PDE4 inhibitor resembling the structure of 8a, cocrystallized with the PDE4. Based on further conformational analysis dealing with N-methyl-NAHs, a quinazoline derivative (19) was designed as a conformationally constrained NAH analogue and showed similar in vitro pharmacological profile, compared with 8a. In addition 19 was found active when tested orally in LPS-evoked airway hyperreactivity and fully confirmed the working hypothesis supporting this work.

  4. The Cyclic Di-GMP Phosphodiesterase Gene Rv1357c/BCG1419c Affects BCG Pellicle Production and In Vivo Maintenance. (United States)

    Flores-Valdez, Mario Alberto; Aceves-Sánchez, Michel de Jesús; Pedroza-Roldán, César; Vega-Domínguez, Perla Jazmín; Prado-Montes de Oca, Ernesto; Bravo-Madrigal, Jorge; Laval, Françoise; Daffé, Mamadou; Koestler, Ben; Waters, Christopher M


    Bacteria living in a surface-attached community that contains a heterogeneous population, coated with an extracellular matrix, and showing drug tolerance (biofilms) are often linked to chronic infections. In mycobacteria, the pellicle mode of growth has been equated to an in vitro biofilm and meets several of the criteria mentioned above, while tuberculosis infection presents a chronic (latent) phase of infection. As mycobacteria lack most genes required to control biofilm production by other microorganisms, we deleted or expressed from the hsp60 strong promoter the only known c-di-GMP phosphodiesterase (PDE) gene in Mycobacterium bovis BCG. We found changes in pellicle production, cellular protein profiles, lipid production, resistance to nitrosative stress and maintenance in lungs and spleens of immunocompetent BALB/mice. Our results show that pellicle production and capacity to remain within the host are linked in BCG.

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

    Energy Technology Data Exchange (ETDEWEB)

    Omar, Bilal [Department of Experimental Medical Sciences, Diabetes, Metabolism and Endocrinology, Biomedical Center, Lund University, Lund (Sweden); Banke, Elin, E-mail: [Department of Experimental Medical Sciences, Diabetes, Metabolism and Endocrinology, Biomedical Center, Lund University, Lund (Sweden); Guirguis, Emilia [Cardiovascular Pulmonary Branch, NHLBI, NIH, Bethesda, MD (United States); Aakesson, Lina [Department of Clinical Sciences, Diabetes and Celiac Disease Unit, Clinical Research Centre, Lund University, Malmoe (Sweden); Manganiello, Vincent [Cardiovascular Pulmonary Branch, NHLBI, NIH, Bethesda, MD (United States); Lyssenko, Valeriya; Groop, Leif [Department of Clinical Sciences, Diabetes and Endocrinology, Clinical Research Centre, Lund University, Malmoe (Sweden); Gomez, Maria F. [Department of Clinical Sciences, Vascular ET Coupling, Clinical Research Centre, Lund University, Malmoe (Sweden); Degerman, Eva [Department of Experimental Medical Sciences, Diabetes, Metabolism and Endocrinology, Biomedical Center, Lund University, Lund (Sweden)


    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.

  6. Phosphodiesterase 5a Inhibition with Adenoviral Short Hairpin RNA Benefits Infarcted Heart Partially through Activation of Akt Signaling Pathway and Reduction of Inflammatory Cytokines.

    Directory of Open Access Journals (Sweden)

    Longhu Li

    Full Text Available Treatment with short hairpin RNA (shRNA interference therapy targeting phosphodiesterase 5a after myocardial infarction (MI has been shown to mitigate post-MI heart failure. We investigated the mechanisms that underpin the beneficial effects of PDE5a inhibition through shRNA on post-MI heart failure.An adenoviral vector with an shRNA sequence inserted was adopted for the inhibition of phosphodiesterase 5a (Ad-shPDE5a in vivo and in vitro. Myocardial infarction (MI was induced in male C57BL/6J mice by left coronary artery ligation, and immediately after that, the Ad-shPDE5a was injected intramyocardially around the MI region and border areas.Four weeks post-MI, the Ad-shPDE5a-treated mice showed significant mitigation of the left ventricular (LV dilatation and dysfunction compared to control mice. Infarction size and fibrosis were also significantly reduced in Ad-shPDE5a-treated mice. Additionally, Ad-shPDE5a treatment decreased the MI-induced inflammatory cytokines interleukin (IL-1β, IL-6, tumor necrosis factor-α, and transforming growth factor-β1, which was confirmed in vitro in Ad-shPDE5a transfected myofibroblasts cultured under oxygen glucose deprivation. Finally, Ad-shPDE5a treatment was found to activate the myocardial Akt signaling pathway in both in vivo and in vitro experiments.These findings indicate that PDE5a inhibition by Ad-shPDE5a via the Akt signal pathway could be of significant value in the design of future therapeutics for post-MI heart failure.

  7. Myelin deposition in the optic tectum of trout as monitored by enzymatic and morphometric analyses. (United States)

    Jeserich, G; Breer, H


    The activity of arylsulfatase A and 2'3'-cyclic nucleotide 3'-phosphohydrolase was studied in the brain of trout in parallel to the structural differentiation of tissue from early larval stages into adulthood. Whereas in the optic tectum, phosphodiesterase activity could not be detected before the second month after hatching in brainstem, the enzyme had already reached 80% of adult level. In tectum it was from the fourth to the seventh month that this enzyme dramatically increased, thereby reaching about the adult level. The developmental profile of arylsulfatase A was profoundly different, since 1) considerable activity was found in tectum at early larval stages and 2) the activity showed a peak between two and six months and then dropped markedly. Morphometric analysis of the two myelinated layers of trout tectum support and extend the biochemical results leading to the conclusion that the phosphodiesterase activity reflects the prevailing degree of myelination, whereas the developmental profile of the sulfolipid-metabolizing enzyme indicates the rate of myelin accumulation.

  8. 磷酸二酯酶5抑制剂治疗先天性心脏病合并肺动脉高压%Phosphodiesterase 5 inhibitors treatment of congenital heart disease with pulmonary arterial hypertension

    Institute of Scientific and Technical Information of China (English)

    龚霄雷; 徐卓明; 刘锦纷


    肺动脉高压在先天性心脏病中很常见,有效地降低患儿肺血管阻力,能够改善其远期生存率.对肺动脉高压病理生理的研究发现,使用磷酸二酯酶5抑制剂可使肺血管舒张,降低肺血管阻力.目前磷酸二酯酶5抑制剂西地那非在国外已用于治疗肺动脉高压.多个临床试验已经证明磷酸二酯酶5抑制剂能够显著降低肺血管阻力,改善患者远期生存率和生活质量,且能较好地被患者耐受.%Pulmonary arterial hypertension is common in patients with congenital heart disease.An effective reduction in pulmonary vascular resistance could improve the survival rate in the future.Research in the pathophysiology of pulmonary arterial hypertension shows that phosphodiesterase 5 inhibitors result in pulmonary vasodilation,decrease vascular resistance.Sildenafil,a inhibitor of phosphodiesterase 5 has been permitted to treat pulmonary arterial hypertension oversea now.Phosphodiesterase 5 inhibitors are proved to reduce pulmonary vascular resistance significantly,improve the survival rate in the future and be well tolerated.This review contains the changes of hemodynamics,exercise tolerance,side effect and pharmacokinetics of phosphodiesterase 5 inhibitors.

  9. Effect of selective phosphodiesterase 4 inhibitor,rolipram, on cytokine and gelatinase B (MMP-9) release in the whole blood from adult patients with cystic fibrosis.

    Institute of Scientific and Technical Information of China (English)



    AIM: Inflammation plays a critical role in lung disease progression in cystic fibrosis being able to be associated with the development of tissue remodeling. These processes are mainly due to pro-inflammatory cytokines release and to an imbalance between proteases and antiproteases involving matrix metalloproteinases (MMP). Phosphodiesterase 4 (PDE4) inhibitors, by elevating intracellular cAMP, are known to be potent inhibitors of

  10. Effect of Phosphodiesterase-5 Inhibition on Exercise Capacity and Clinical Status in Heart Failure with Preserved Ejection Fraction: A Randomized Clinical Trial (United States)

    Redfield, Margaret M; Chen, Horng H; Borlaug, Barry A; Semigran, Marc J.; Lee, Kerry L.; Lewis, Gregory; LeWinter, Martin M.; Rouleau, Jean L.; Bull, David A.; Mann, Douglas L.; Deswal, Anita; Stevenson, Lynne W.; Givertz, Michael M.; Ofili, Elizabeth O.; O’Connor, Christopher M.; Felker, G. Michael; Goldsmith, Steven R.; Bart, Bradley A.; McNulty, Steven E; Ibarra, Jenny C.; Lin, Grace; Oh, Jae K.; Patel, Manesh R.; Kim, Raymond J.; Tracy, Russell P.; Velazquez, Eric J.; Anstrom, Kevin J.; Hernandez, Adrian F.; Mascette, Alice M.; Braunwald, Eugene


    Importance Studies in experimental and human heart failure suggest that phosphodiesterase type-5 inhibitors may enhance cardiovascular function, and thus, exercise capacity in heart failure with preserved ejection fraction. Objective To determine the effect of the phosphodiesterase type-5 inhibitor, sildenafil, in comparison to placebo on exercise capacity and clinical status in heart failure with preserved ejection fraction. Design, setting, and patients Multicenter, double-blind, placebo-controlled, parallel design, randomized clinical trial of 216 stable outpatients with heart failure, ejection fraction ≥ 50%, elevated N-terminal pro-brain natriuretic peptide or elevated invasively-measured filling pressures, and reduced exercise capacity. Participants were randomized from October 2008 through February 2012 at 26 centers in the United States and Canada. Intervention Sildenafil (n=113) or placebo (n=103) administered orally at 20 mg three times daily for 12 weeks followed by 60 mg three times daily for 12 weeks. Main outcome measures Primary endpoint was change in peak oxygen consumption after 24 weeks of therapy. Secondary endpoints included change in six-minute walk distance and a three tier hierarchical composite clinical status score where patients were ranked (range 1-N) based on time to death, time to cardiovascular or cardiorenal hospitalization and change in quality of life for participants alive without cardiovascular or cardiorenal hospitalization at 24 weeks. Results Median age was 69 years and 48% of patients were female. At baseline, median peak oxygen consumption (11.7 ml/kg/min) and six-minute walk distance (308 meters) were reduced and median E/e′ (16), left atrial volume index (44 ml/m2) and pulmonary artery systolic pressure (41 mmHg) were consistent with chronically-elevated left ventricular filling pressures. At 24 weeks, median (interquartile range) changes in peak oxygen consumption (ml/kg/min) in patients who received placebo [−0

  11. Benefits and risks of testosterone treatment for hypoactive sexual desire disorder in women: a critical review of studies published in the decades preceding and succeeding the advent of phosphodiesterase type 5 inhibitors

    Directory of Open Access Journals (Sweden)

    Sandra Léa Bonfim Reis


    Full Text Available With advancing age, there is an increase in the complaints of a lack of a libido in women and erectile dysfunction in men. The efficacy of phosphodiesterase type 5 inhibitors, together with their minimal side effects and ease of administration, revolutionized the treatment of erectile dysfunction. For women, testosterone administration is the principal treatment for hypoactive sexual desire disorder. We sought to evaluate the use of androgens in the treatment of a lack of libido in women, comparing two periods, i.e., before and after the advent of the phosphodiesterase type 5 inhibitors. We also analyzed the risks and benefits of androgen administration. We searched the Latin-American and Caribbean Health Sciences Literature, Cochrane Library, Excerpta Medica, Scientific Electronic Library Online, and Medline (PubMed databases using the search terms disfunção sexual feminina/female sexual dysfunction, desejo sexual hipoativo/female hypoactive sexual desire disorder, testosterona/testosterone, terapia androgênica em mulheres/androgen therapy in women, and sexualidade/sexuality as well as combinations thereof. We selected articles written in English, Portuguese, or Spanish. After the advent of phosphodiesterase type 5 inhibitors, there was a significant increase in the number of studies aimed at evaluating the use of testosterone in women with hypoactive sexual desire disorder. However, the risks and benefits of testosterone administration have yet to be clarified.

  12. Postulated vasoactive neuropeptide immunopathology affecting the blood–brain/blood–spinal barrier in certain neuropsychiatric fatigue-related conditions: A role for phosphodiesterase inhibitors in treatment?

    Directory of Open Access Journals (Sweden)

    Sonya Marshall-Gradisnik


    contribute to the BBB and BSB integrity and contain PACAP and VIP receptors. Autoimmunity of these receptors would likely affect BBB and VRS function and therefore may contribute to the etiology of these conditions by affecting CNS and immunological homeostasis, including promoting neuropsychological symptomatology. PACAP and VIP, as potent activators of adenylate cyclase (AC, have a key role in cyclic adenosine monophosphate (cAMP production affecting regulatory T cell (Treg and other immune functions. Phosphodiesterase enzymes (PDEs catalyze cAMP and PDE inhibitors (PDEIs maintain cAMP levels and have proven and well known therapeutic benefit in animal models such as experimental allergic encephalomyelitis (EAE. Therefore PDEIs may have a role in therapy for certain neuropsychiatric fatigue-related conditions.Keywords: vasoactive neuropeptides, multiple sclerosis, Parkinson’s disease, chronic fatigue syndrome, phosphodiesterase inhibitors, cyclic AMP, adenylate cyclase, Virchow–Robin spaces

  13. Seminal vesicles of infertile patients with male accessory gland infection: ultrasound evaluation after prolonged treatment with tadalafil, a selective phosphodiesterase-5 inhibitor. (United States)

    La Vignera, S


    The aim of this study was to investigate possible ultrasound seminal vesicle (SV) changes in infertile patients with 'hypertrophic-congestive' (HCUF) or 'fibro-sclerotic' (FSUF) ultrasound form of male accessory gland infection (MAGI) after prolonged administration of tadalafil (TAD), a selective phosphodiesterase-5 inhibitor. Forty infertile patients with HCUF and 40 patients with FSUF and erectile dysfunction were selected and arbitrarily divided into two groups, who were prescribed TAD 5 mg daily for 3 months, the first 20 consecutive patients with HCUF (group A1) or FSUF (group A2) or placebo, the second 20 consecutive patients with HCUF (group B1) or FSUF (group B2). All patients underwent scrotal and prostate-vesicular transrectal ultrasound evaluation and semen analysis (WHO, 2010) before and after treatment. Group A1 patients showed a significant reduction in fundus/body ratio and higher pre- and post-ejaculatory body SV antero-posterior diameter difference compared with the other three groups. These patients showed also a significant increase in SV ejection fraction and a significant improvement in the total sperm count, progressive motility, seminal levels of fructose and ejaculate volume. These results suggest that infertile patients with HCUF had an improvement in SV ultrasound features suggestive of chronic inflammation after daily treatment with low doses of TAD.

  14. The high-affinity phosphodiesterase BcPde2 has impact on growth, differentiation and virulence of the phytopathogenic ascomycete Botrytis cinerea.

    Directory of Open Access Journals (Sweden)

    Karin Harren

    Full Text Available Components of the cAMP signaling pathway, such as the adenylate cyclase Bac and the protein kinase A (PKA were shown to affect growth, morphogenesis and differentiation as well as virulence of the phytopathogenic fungus Botrytis cinerea. While loss of Bac caused drastically reduced intracellular cAMP levels, deletion of the PKA resulted in extremely increased cAMP concentrations. To regulate the intracellular level of the second messenger cAMP, a balance between its biosynthesis through adenylate cyclase activity and its hydrolysis by phosphodiesterases (PDEs is crucial. Here, we report the functional characterization of the two PDEs in the ascomycete B. cinerea, BcPde1 and BcPde2. While deletion of bcpde2 resulted in severely affected vegetative growth, conidiation, germination and virulence, the bcpde1 deletion strain displayed a wild-type-like phenotype. However, the double bcpde1/2 deletion mutant exhibited an even stronger phenotype. Localization studies revealed that BcPde2 accumulates at the plasma membrane, but is also localized in the cytoplasm. BcPde1 was shown to be distributed in the cytoplasm as well, but also accumulates in so far unknown mobile vesicles. Overexpression of bcpde1 in the Δbcpde2 background rescued the deletion phenotype, and in addition an increased transcript level of bcpde1 in the Δbcpde2 strain was observed, indicating redundant functions of both PDEs and an interdependent gene expression.

  15. Early and rapid development of insulin resistance, islet dysfunction and glucose intolerance after high-fat feeding in mice overexpressing phosphodiesterase 3B

    DEFF Research Database (Denmark)

    Walz, Helena A; Härndahl, Linda; Wierup, Nils


    did not reveal reduced insulin sensitivity in these tissues. Significant steatosis was noted in livers from high-fat-fed wild-type and RIP-PDE3B/2 mice and liver triacyl-glycerol content was 3-fold higher than in wild-type mice fed a control diet. Histochemical analysis revealed severe islet......AMP-degrading enzyme phosphodiesterase 3B (RIP-PDE3B/2 mice) were metabolically challenged with a high-fat diet. We found that RIP-PDE3B/2 mice early and rapidly develop glucose intolerance and insulin resistance, as compared with wild-type littermates, after 2 months of high-fat feeding. This was evident from......Inadequate islet adaptation to insulin resistance leads to glucose intolerance and type 2 diabetes. Here we investigate whether beta-cell cAMP is crucial for islet adaptation and prevention of glucose intolerance in mice. Mice with a beta-cell-specific, 2-fold overexpression of the c...

  16. 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. (United States)

    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


    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 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 NCT01805518.

  17. Efficacy and safety of phosphodiesterase type 5 inhibitors on primary premature ejaculation in men receiving selective serotonin reuptake inhibitors therapy: a systematic review and meta-analysis. (United States)

    Men, C; Yu, L; Yuan, H; Cui, Y


    We performed a systematic review and meta-analysis to assess whether selective serotonin reuptake inhibitors (SSRIs) and phosphodiesterase type 5 inhibitors (PDE5-Is) may have an additive therapeutic effect. A literature review was performed to identify all published randomised controlled trials (RCT) that used SSRIs combined with PDE5-Is therapy for the treatment of primary PE. The search included the following databases: EMBASE, MEDLINE and the Cochrane Controlled Trials Register. The reference lists of the retrieved studies were also investigated. Five publications involving a total of 419 patients were used in the analysis, including 5 RCTs that compared PDE5-Is plus SSRIs with SSRIs treating primary PE. Primary efficacy endpoints: IELT (the standardised mean difference (SMD) = 1.07, 95% confidence interval (CI) = 1.00 to 1.14, P < 0.00001) indicated that utilisation of PDE5-Is and SSRIs was more effective than the SSRIs alone for a long time in patients with primary PE. Safety assessments included headache (odds ratio (OR) = 3.16, 95% CI = 1.63 to 6.11, P = 0.0006), and flushing indicated that PDE5-Is plus SSRIs were well tolerated. This meta-analysis indicates that PDE5-Is combined with SSRIs seem to provide significantly better ejaculatory latency time as compared with SSRIs alone in patients with primary PE.

  18. Exposure to an Extremely-Low-Frequency Magnetic Field Stimulates Adrenal Steroidogenesis via Inhibition of Phosphodiesterase Activity in a Mouse Adrenal Cell Line. (United States)

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


    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 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.

  19. 磷酸二酯酶与疾病相关的药理学研究进展%Review on Pharmcology of Phosphodiesterases Related Diseases

    Institute of Scientific and Technical Information of China (English)



    Cyclic nucleotide phosphodiesterases( PDEs ), which are distributed in mammalian tissues,play an important role in cell signaling by hydrolyzing cAMP and cGMP. PDEs can selectively regulate various cellular functions such as myocardial contraction , neurodegeneration , apoptosis , lipogenesis , glycogenolysis and gluconeogenesis. Thus PDE has the potential to become target of the treatment for various diseases , including depression,asthma,inflammation and erectile dysfunction etc. . Here is to make a brief review on the pharmacology of PDE related diseases.%磷酸二酯酶超家族(PDEs)是细胞内重要的第二信使cAMP和cGMP的催化水解酶.该家族参与大量的生理学过程,包括心肌收缩、神经退行性病变、细胞凋亡、脂肪生成、糖原分解和糖异生作用等.因此,PDE具有成为多种疾病治疗靶点的潜力,包括抑郁、哮喘、炎症与勃起功能障碍等.现就磷酸二酯酶相关疾病的药理学进展作简单的综述.

  20. Development of highly potent phosphodiesterase 4 inhibitors with anti-neuroinflammation potential: Design, synthesis, and structure-activity relationship study of catecholamides bearing aromatic rings. (United States)

    Zhou, Zhong-Zhen; Ge, Bing-Chen; Zhong, Qiu-Ping; Huang, Chang; Cheng, Yu-Fang; Yang, Xue-Mei; Wang, Hai-Tao; Xu, Jiang-Ping


    In this study, catecholamides (7a-l) bearing different aromatic rings (such as pyridine-2-yl, pyridine-3-yl, phenyl, and 2-chlorophenyl groups) were synthesized as potent phosphodiesterase (PDE) 4 inhibitors. The inhibitory activities of these compounds were evaluated against the core catalytic domains of human PDE4 (PDE4CAT), full-length PDE4A4, PDE4B1, PDE4C1, and PDE4D7 enzymes, and other PDE family members. Eight of the synthesized compounds were identified as having submicromolar IC50 values in the mid-to low-nanomolar range. Careful analysis on the structure-activity relationship of compounds 7a-l revealed that the replacement of the 4-methoxy group with the difluoromethoxy group improved inhibitory activities. More interesting, 4-difluoromethoxybenzamides 7i and 7j exhibited preference for PDE4 with higher selectivities of about 3333 and 1111-fold over other PDEs, respectively. In addition, compound 7j with wonderful PDE4D7 inhibitory activities inhibited LPS-induced TNF-α production in microglia.

  1. Radiosynthesis and Radiotracer Properties of a 7-(2-[18F]Fluoroethoxy-6-methoxypyrrolidinylquinazoline for Imaging of Phosphodiesterase 10A with PET

    Directory of Open Access Journals (Sweden)

    Detlef Briel


    Full Text Available Phosphodiesterase 10A (PDE10A is a key enzyme of intracellular signal transduction which is involved in the regulation of neurotransmission. The molecular imaging of PDE10A by PET is expected to allow a better understanding of physiological and pathological processes related to PDE10A expression and function in the brain. The aim of this study was to develop a new 18F-labeled PDE10A ligand based on a 6,7-dimethoxy-4-pyrrolidinylquinazoline and to evaluate its properties in biodistribution studies. Nucleophilic substitution of the 7-tosyloxy-analogue led to the 7-[18F]fluoroethoxy-derivative [18F]IV with radiochemical yields of 25% ± 9% (n = 9, high radiochemical purity of ≥99% and specific activities of 110–1,100 GBq/μmol. [18F]IV showed moderate PDE10A affinity (KD,PDE10A = 14 nM and high metabolic stability in the brain of female CD-1 mice, wherein the radioligand entered rapidly with a peak uptake of 2.3% ID/g in striatum at 5 min p.i. However, ex vivo autoradiographic and in vivo blocking studies revealed no target specific accumulation and demonstrated [18F]IV to be inapplicable for imaging PDE10A with PET.

  2. Cows are not mice: the role of cyclic AMP, phosphodiesterases, and adenosine monophosphate-activated protein kinase in the maintenance of meiotic arrest in bovine oocytes. (United States)

    Bilodeau-Goeseels, Sylvie


    Meiotic maturation in mammalian oocytes is initiated during fetal development, and is then arrested at the dictyate stage - possibly for several years. Oocyte meiosis resumes in preovulatory follicles in response to the lutenizing hormone (LH) surge or spontaneously when competent oocytes are removed from follicles and cultured. The mechanisms involved in meiotic arrest and resumption in bovine oocytes are not fully understood, and several studies point to important differences between oocytes from rodent and livestock species. This paper reviews earlier and contemporary studies on the effects of cAMP-elevating agents and phosphodiesterase (PDE) enzyme inhibitors on the maintenance of meiotic arrest in bovine oocytes in vitro. Contrary to results obtained with mouse oocytes, bovine oocyte meiosis is inhibited by activators of the energy sensor adenosine monophosphate-activated protein kinase (AMPK, mammalian gene PRKA), which is activated by AMP, the degradation product of cAMP. It is not clear whether or not the effects were due to AMPK activation, and they may depend on culture conditions. Evidence suggests that other signaling pathways (for example, the cGMP/nitric oxide pathway) are involved in bovine oocyte meiotic arrest, but further studies are needed to understand the interactions between the signaling pathways that lead to maturation promoting factor (MPF) being inactive or active. An improved understanding of the mechanisms involved in the control of bovine oocyte meiosis will facilitate better control of the process in vitro, resulting in increased developmental competence and increased efficiency of in vitro embryo production procedures.

  3. The phosphodiesterase-4 inhibitor rolipram protects from ischemic stroke in mice by reducing blood-brain-barrier damage, inflammation and thrombosis. (United States)

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


    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.

  4. Design, Synthesis, and Structure–Activity Relationship, Molecular Modeling, and NMR Studies of a Series of Phenyl Alkyl Ketones as Highly Potent and Selective Phosphodiesterase-4 Inhibitors (United States)

    Zheng, Shilong; Kaur, Gurpreet; Wang, Huanchen; Li, Minyong; Macnaughtan, Megan; Yang, Xiaochuan; Reid, Suazette; Prestegard, James; Wang, Binghe; Ke, Hengming


    Phosphodiesterase 4 catalyzes the hydrolysis of cyclic AMP and is a target for the development of anti-inflammatory agents. We have designed and synthesized a series of phenyl alkyl ketones as PDE4 inhibitors. Among them, 13 compounds were identified as having submicromolar IC50 values. The most potent compounds have IC50 values of in the mid- to low-nanomolar range. Compound 5v also showed preference for PDE4 with selectivity of >2000-fold over PDE7, PDE9, PDE2, and PDE5. Docking of 5v, 5zf, and 5za into the binding pocket of the PDE4 catalytic domain revealed a similar binding profile to PDE4 with rolipram except that the fluorine atoms of the difluoromethyl groups of 5v, 5za, and 5zf are within a reasonable range for hydrogen bond formation with the amide hydrogen of Thr 333 and the long alkyl chain bears additional van der Waals interactions with His 160, Asp 318, and Tyr 159. PMID:19049349

  5. Crystal Structure of the Leishmania Major Phosphodiesterase LmjPDEB1 and Insight into the Design of hte Parasite-Selective Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Wang,H.; Yan, Z.; Geng, J.; Kunz, S.; Seebeck, T.; Ke, H.


    Human leishmaniasis is a major public health problem in many countries, but chemotherapy is in an unsatisfactory state. Leishmania major phosphodiesterases (LmjPDEs) have been shown to play important roles in cell proliferation and apoptosis of the parasite. Thus LmjPDE inhibitors may potentially represent a novel class of drugs for the treatment of leishmaniasis. Reported here are the kinetic characterization of the LmjPDEB1 catalytic domain and its crystal structure as a complex with 3-isobutyl-1-methylxanthine (IBMX) at 1.55 Angstroms resolution. The structure of LmjPDEB1 is similar to that of human PDEs. IBMX stacks against the conserved phenylalanine and forms a hydrogen bond with the invariant glutamine, in a pattern common to most inhibitors bound to human PDEs. However, an extensive structural comparison reveals subtle, but significant differences between the active sites of LmjPDEB1 and human PDEs. In addition, a pocket next to the inhibitor binding site is found to be unique to LmjPDEB1. This pocket is isolated by two gating residues in human PDE families, but constitutes a natural expansion of the inhibitor binding pocket in LmjPDEB1. The structure particularity might be useful for the development of parasite-selective inhibitors for the treatment of leishmaniasis.

  6. Hydrogen sulfide-mediated stimulation of mitochondrial electron transport involves inhibition of the mitochondrial phosphodiesterase 2A, elevation of cAMP and activation of protein kinase A. (United States)

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


    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.

  7. Determination of ASP3258, a novel phosphodiesterase type 4 inhibitor, in rat plasma by high-performance liquid chromatography with fluorescence detection and its application to pharmacokinetic study. (United States)

    Ohtsu, Yoshiaki; Takanuki, Fumiyo; Fukunaga, Yasuhisa; Noguchi, Kiyoshi


    The potent phosphodiesterase 4 inhibitor ASP3258 contains a carboxylic acid moiety and a naphthyridine ring and is a novel therapeutic agent for asthma and chronic obstructive pulmonary disease. To support the drug development of ASP3258, we developed and validated a simple method for its determination in rat plasma. Following the addition of the analog AS1406604-00 as an internal standard, plasma samples were processed using C18 -bonded solid-phase extraction cartridges under acidic conditions and injected into a high-performance liquid chromatography system with fluorescence detection. Chromatographic separation was achieved on a Shiseido Capcell Pak C18 UG120 column (3.0 × 150 mm, 5 µm) with a mobile phase consisting of acetonitrile-0.5% acetic acid (50:50, v/v). HPLC eluent was monitored with a fluorescence detector set at a wavelength of 315 nm for excitation and 365 nm for emission. The calibration curve was linear over a range of 2.5-250 ng/mL. Validation data demonstrated that the method is selective, sensitive and accurate. In addition, the present method was successfully applied to rat plasma samples from a pharmacokinetic study.

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

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    Edyta Makuch


    Full Text Available  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.

  9. Lineage A Betacoronavirus NS2 Proteins and the Homologous Torovirus Berne pp1a Carboxy-Terminal Domain Are Phosphodiesterases That Antagonize Activation of RNase L. (United States)

    Goldstein, Stephen A; Thornbrough, Joshua M; Zhang, Rong; Jha, Babal K; Li, Yize; Elliott, Ruth; Quiroz-Figueroa, Katherine; Chen, Annie I; Silverman, Robert H; Weiss, Susan R


    Viruses in the family Coronaviridae, within the order Nidovirales, are etiologic agents of a range of human and animal diseases, including both mild and severe respiratory diseases in humans. These viruses encode conserved replicase and structural proteins as well as more diverse accessory proteins, encoded in the 3' ends of their genomes, that often act as host cell antagonists. We previously showed that 2',5'-phosphodiesterases (2',5'-PDEs) encoded by the prototypical Betacoronavirus, mouse hepatitis virus (MHV), and by Middle East respiratory syndrome-associated coronavirus antagonize the oligoadenylate-RNase L (OAS-RNase L) pathway. Here we report that additional coronavirus superfamily members, including lineage A betacoronaviruses and toroviruses infecting both humans and animals, encode 2',5'-PDEs capable of antagonizing RNase L. We used a chimeric MHV system (MHV(Mut)) in which exogenous PDEs were expressed from an MHV backbone lacking the gene for a functional NS2 protein, the endogenous RNase L antagonist. With this system, we found that 2',5'-PDEs encoded by the human coronavirus HCoV-OC43 (OC43; an agent of the common cold), human enteric coronavirus (HECoV), equine coronavirus (ECoV), and equine torovirus Berne (BEV) are enzymatically active, rescue replication of MHV(Mut) in bone marrow-derived macrophages, and inhibit RNase L-mediated rRNA degradation in these cells. Additionally, PDEs encoded by OC43 and BEV rescue MHV(Mut) replication and restore pathogenesis in wild-type (WT) B6 mice. This finding expands the range of viruses known to encode antagonists of the potent OAS-RNase L antiviral pathway, highlighting its importance in a range of species as well as the selective pressures exerted on viruses to antagonize it.IMPORTANCE Viruses in the family Coronaviridae include important human and animal pathogens, including the recently emerged viruses severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and Middle East respiratory

  10. Constitutively active signaling by the G protein βγ-subunit mediates intrinsically increased phosphodiesterase-4 activity in human asthmatic airway smooth muscle cells.

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    Aihua Hu

    Full Text Available Signaling by the Gβγ subunit of Gi protein, leading to downstream c-Src-induced activation of the Ras/c-Raf1/MEK-ERK1/2 signaling pathway and its upregulation of phosphodiesterase-4 (PDE4 activity, was recently shown to mediate the heightened contractility in proasthmatic sensitized isolated airway smooth muscle (ASM, as well as allergen-induced airway hyperresponsiveness and inflammation in an in vivo animal model of allergic asthma. This study investigated whether cultured human ASM (HASM cells derived from asthmatic donor lungs exhibit constitutively increased PDE activity that is attributed to intrinsically upregulated Gβγ signaling coupled to c-Src activation of the Ras/MEK/ERK1/2 cascade. We show that, relative to normal cells, asthmatic HASM cells constitutively exhibit markedly increased intrinsic PDE4 activity coupled to heightened Gβγ-regulated phosphorylation of c-Src and ERK1/2, and direct co-localization of the latter with the PDE4D isoform. These signaling events and their induction of heightened PDE activity are acutely suppressed by treating asthmatic HASM cells with a Gβγ inhibitor. Importantly, along with increased Gβγ activation, asthmatic HASM cells also exhibit constitutively increased direct binding of the small Rap1 GTPase-activating protein, Rap1GAP, to the α-subunit of Gi protein, which serves to cooperatively facilitate Ras activation and, thereby, enable enhanced Gβγ-regulated ERK1/2-stimulated PDE activity. Collectively, these data are the first to identify that intrinsically increased signaling via the Gβγ subunit, facilitated by Rap1GAP recruitment to the α-subunit, mediates the constitutively increased PDE4 activity detected in asthmatic HASM cells. These new findings support the notion that interventions targeted at suppressing Gβγ signaling may lead to novel approaches to treat asthma.

  11. A meta-regression evaluating the effectiveness and prognostic factors of oral phosphodiesterase type 5 inhibitors for the treatment of erectile dysfunction

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    Jin-Qiu Yuan


    Full Text Available The effectiveness of phosphodiesterase type 5 inhibitors (PDE5-Is for erectile dysfunction (ED varies considerably among trials, but available studies investigating the factors that affect the effectiveness are few and findings are not consistent. A systematic search was performed in PubMed, Cochrane Library, and EMBASE to identify randomized controlled trials comparing PDE5-Is with placebo for the treatment of ED. The methodological quality of included studies was assessed by the Cochrane Collaboration′s tool for assessing risk of bias. The associations between prespecified study-level factors and effectiveness were tested by a random effects meta-regression model. This study included 93 trials with 26 139 patients. When all PDE5-Is were grouped together, Caucasian ethnicity was associated with 15.636% (95% confidence interval [CI]: 0.858% to 32.579% increase in risk ratio (RR for Global Assessment Questionnaire question-1 (GAQ-1, and 1.473 (95% CI: 0.406 to 2.338 score increase in mean difference (MD for posttreatment International Index of Erectile Function-Erectile Function domain score (IIEF-EF, compared to Asian ethnicity. A one-score increase in baseline IIEF-EF was associated with −5.635% (95% CI: −9.120% to −2.017% reduction in RR for GAQ-1, and −0.229 (95% CI: −0.425 to −0.042 score decrease in MD for posttreatment IIEF-EF. In conclusion, PDE5-Is are more effective in Caucasians than Asians, and in patients with more severe ED.

  12. Sildenafil, a phosphodiesterase type 5 inhibitor, enhances the antidepressant activity of amitriptyline but not desipramine, in the forced swim test in mice. (United States)

    Socała, Katarzyna; Nieoczym, Dorota; Wyska, Elżbieta; Poleszak, Ewa; Wlaź, Piotr


    The cholinergic theory of depression highlights the involvement of muscarinic acetylcholine receptors in the neurobiology of mood disorders. The present study was designed to investigate the effect of sildenafil, a phosphodiesterase type 5 inhibitor which exhibits cholinomimetic properties, alone and in combination with scopolamine in the forced swim test in mice. Moreover, we assessed the ability of sildenafil to modify the antidepressant activity of two tricyclic antidepressants with distinct cholinolytic activity, amitriptyline and desipramine. Swim sessions were conducted by placing mice in glass cylinders filled with water for 6 min and the duration of behavioral immobility during the last 4 min of the test was evaluated. Locomotor activity was measured with photoresistor actimeters. To evaluate the potential pharmacokinetic interaction between amitriptyline and sildenafil, brain and serum concentrations of amitriptyline were determined by HPLC. Sildenafil (1.25-20 mg/kg) as well as scopolamine (0.5 mg/kg) and its combination with sildenafil (1.25 mg/kg) did not affect the total immobility time duration. However, joint administration of scopolamine with sildenafil at doses of 2.5 and 5 mg/kg significantly reduced immobility time as compared to control group. Moreover, co-administration of scopolamine with sildenafil at the highest dose (5 mg/kg) significantly decreased immobility time as compared to scopolamine-treated group. Sildenafil (1.25, 2.5 and 5 mg/kg) significantly enhanced the antidepressant activity of amitriptyline (5 mg/kg). No changes in anti-immobility action of desipramine (20 mg/kg) in combination with sildenafil (5, 10 and 20 mg/kg) were observed. Sildenafil did not affect amitriptyline level in both brain and serum. In conclusion, the present study suggests that sildenafil may enhance the activity of antidepressant drugs which exhibit cholinolytic activity.

  13. Sildenafil, a phosphodiesterase type 5 inhibitor, enhances the activity of two atypical antidepressant drugs, mianserin and tianeptine, in the forced swim test in mice. (United States)

    Socała, Katarzyna; Nieoczym, Dorota; Wyska, Elżbieta; Poleszak, Ewa; Wlaź, Piotr


    Sildenafil, a selective phosphodiesterase type 5 inhibitor, has recently been reported to abolish anti-immobility action of antidepressant drugs, i.e., bupropion, venlafaxine and S-citalopram, in the forced swim test in mice. The present study was designed to investigate the influence of sildenafil on the potential of two atypical antidepressants, namely mianserin and tianeptine. Swim sessions were conducted by placing mice in glass cylinders filled with water for 6 min and the duration of the behavioral immobility during the last 4 min of the test was evaluated. Locomotor activity was measured with photoresistor actimeters. To evaluate the potential pharmocokinetic interaction, total brain concentrations of the studied antidepressants were determined by HPLC method. Sildenafil at a dose of 2.5 mg/kg did not affect the activity of mianserin (20 mg/kg) in the forced swim test. Interestingly, at higher doses (5 and 10 mg/kg), sildenafil significantly enhanced the anti-immobility action of mianserin. Likewise, sildenafil (5, 10 and 20 mg/kg) robustly augmented the antidepressant activity of tianeptine (30 mg/kg). Mianserin alone, as well as in a combination with sildenafil at the highest dose, caused a potent reduction in locomotor activity. However, the changes in motor activity did not interfere with the data obtained in the forced swim test. Sildenafil significantly increased the total brain tianeptine concentration. No alteration in mianserin level in the brain after sildenafil co-administration was observed. The present study suggests that sildenafil enhances the activity of mianserin and tianeptine in the forced swim test in mice. The changes in the antidepressant activity of mianserin evoked by sildenafil co-administration were related to pharmacodynamic interaction while the interaction between tianeptine and sildenafil was, at least in part, pharmacokinetic in nature.

  14. Phosphodiesterase inhibition mediates matrix metalloproteinase activity and the level of collagen degradation fragments in a liver fibrosis ex vivo rat model

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    Veidal Sanne Skovgård


    Full Text Available Abstract Background Accumulation of extracellular matrix (ECM and increased matrix metalloproteinase (MMP activity are hallmarks of liver fibrosis. The aim of the present study was to develop a model of liver fibrosis combining ex vivo tissue culture of livers from CCl4 treated animals with an ELISA detecting a fragment of type III collagen generated in vitro by MMP-9 (C3M, known to be associated with liver fibrosis and to investigate cAMP modulation of MMP activity and liver tissue turnover in this model. Findings In vivo: Rats were treated for 8 weeks with CCl4/Intralipid. Liver slices were cultured for 48 hours. Levels of C3M were determined in the supernatants of slices cultured without treatment, treated with GM6001 (positive control or treated with IBMX (phosphodiesterase inhibitor. Enzymatic activity of MMP-2 and MMP-9 were studied by gelatin zymography. Ex vivo: The levels of serum C3M increased 77% in the CCl4-treated rats at week 8 (p 4-treated animals had highly increased MMP-9, but not MMP-2 activity, compared to slices derived from control animals. Conclusions We have combined an ex vivo model of liver fibrosis with measurement of a biochemical marker of collagen degradation in the condition medium. This technology may be used to evaluate the molecular process leading to structural fibrotic changes, as collagen species are the predominant structural part of fibrosis. These data suggest that modulation of cAMP may play a role in regulation of collagen degradation associated with liver fibrosis.

  15. Recreational Use of Phosphodiesterase 5 Inhibitors and Its Associated Factors among Undergraduate Male Students in an Ethiopian University: A Cross-Sectional Study (United States)

    Bhagavathula, Akshaya Srikanth; Gebresillassie, Begashaw Melaku; Tefera, Yonas Getaye; Belachew, Sewunet Admasu; Erku, Daniel Asfaw


    Purpose To assess the prevalence of phosphodiesterase 5 (PDE5) inhibitor use and associated factors among University of Gondar undergraduate students. Materials and Methods An institution-based, cross-sectional study, using a survey questionnaire, was conducted from October to December 2015 to assess PDE5 inhibitor use and associated factors among male students at the University of Gondar. A Self-Esteem and Relationship questionnaire (14 items), an International Index of Erectile Function questionnaire (15 items) and a questionnaire on PDE5 inhibitor use (14 items) were included in the survey. Results Across all respondents (age, 21.9±1.88 years), more than half (55.7%, n=233) had heard about PDE5 inhibitors, but only 23 men (5.5%) reported trying a PDE5 inhibitor drug at least once. Older students were more likely to use PDE5 inhibitors compared to younger students (adjusted odds ratio [AOR], 1.40; 95% confidence interval [CI], 1.109~1.768). Those students who were smokers were 5.15 times more likely to use PDE5 inhibitors as compared to their non-smoking counterparts (AOR, 5.15; 95% CI, 2.096~12.687). In addition, multivariate logistic regression showed that being in a relationship, alcohol use, greater number of cigarettes smoked per day, and more sexual partners were significantly associated with PDE5 inhibitor use. Conclusions The prevalence of PDE5 inhibitor use among undergraduate students was 5.5%. Cigarette smoking and other substance use, older age, and greater number of sexual partners were significantly associated factors for PDE5 inhibitor use. These findings suggest that restricting access to PDE5 inhibitor drugs is essential to curtailing misuse among university students. PMID:28053948

  16. Simulating biochemical physics with computers: 1. Enzyme catalysis by phosphotriesterase and phosphodiesterase; 2. Integration-free path-integral method for quantum-statistical calculations (United States)

    Wong, Kin-Yiu

    We have simulated two enzymatic reactions with molecular dynamics (MD) and combined quantum mechanical/molecular mechanical (QM/MM) techniques. One reaction is the hydrolysis of the insecticide paraoxon catalyzed by phosphotriesterase (PTE). PTE is a bioremediation candidate for environments contaminated by toxic nerve gases (e.g., sarin) or pesticides. Based on the potential of mean force (PMF) and the structural changes of the active site during the catalysis, we propose a revised reaction mechanism for PTE. Another reaction is the hydrolysis of the second-messenger cyclic adenosine 3'-5'-monophosphate (cAMP) catalyzed by phosphodiesterase (PDE). Cyclicnucleotide PDE is a vital protein in signal-transduction pathways and thus a popular target for inhibition by drugs (e.g., ViagraRTM). A two-dimensional (2-D) free-energy profile has been generated showing that the catalysis by PDE proceeds in a two-step SN2-type mechanism. Furthermore, to characterize a chemical reaction mechanism in experiment, a direct probe is measuring kinetic isotope effects (KIEs). KIEs primarily arise from internuclear quantum-statistical effects, e.g., quantum tunneling and quantization of vibration. To systematically incorporate the quantum-statistical effects during MD simulations, we have developed an automated integration-free path-integral (AIF-PI) method based on Kleinert's variational perturbation theory for the centroid density of Feynman's path integral. Using this analytic method, we have performed ab initio pathintegral calculations to study the origin of KIEs on several series of proton-transfer reactions from carboxylic acids to aryl substituted alpha-methoxystyrenes in water. In addition, we also demonstrate that the AIF-PI method can be used to systematically compute the exact value of zero-point energy (beyond the harmonic approximation) by simply minimizing the centroid effective potential.

  17. Ab Initio QM/MM Study Shows a Highly Dissociated SN2 Hydrolysis Mechanism for the cGMP-Specific Phosphodiesterase-5. (United States)

    Li, Zhe; Wu, Yinuo; Feng, Ling-Jun; Wu, Ruibo; Luo, Hai-Bin


    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.

  18. Cyclic AMP effectors in African trypanosomes revealed by genome-scale RNA interference library screening for resistance to the phosphodiesterase inhibitor CpdA. (United States)

    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


    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.

  19. Ontogeny of catecholamine and adenosine receptor-mediated cAMP signaling of embryonic red blood cells: role of cGMP-inhibited phosphodiesterase 3 and hemoglobin. (United States)

    Baumann, R; Blass, C; Götz, R; Dragon, S


    We have previously shown that the cAMP signaling pathway controls major aspects of embryonic red blood cell (RBC) function in avian embryos (Glombitza et al, Am J Physiol 271:R973, 1996; and Dragon et al, Am J Physiol 271:R982, 1996) that are important for adaptation of the RBC gas transport properties to the progressive hypercapnia and hypoxia of later stages of avian embryonic development. Data about the ontogeny of receptor-mediated cAMP signaling are lacking. We have analyzed the response of primitive and definitive chick embryo RBC harvested from day 3 to 18 of development towards forskolin, beta-adrenergic, and A2 receptor agonists. The results show a strong response of immature definitive and primitive RBC to adenosine A2 and beta-adrenergic receptor agonists, which is drastically reduced in the last stage of development, coincident with the appearance of mature, transcriptionally inactive RBC. Modulation of cGMP-inhibited phosphodiesterase 3 (PDE3) has a controlling influence on cAMP accumulation in definitive RBC. Under physiological conditions, PDE3 is inhibited due to activation of soluble guanylyl cyclase (sGC). Inhibition of sGC with the specific inhibitor ODQ decreases receptor-mediated stimulation of cAMP production; this effect is reversed by the PDE3 inhibitor milrinone. sGC is acitivated by nitric oxide (NO), but we found no evidence for production of NO by erythrocyte NO-synthase. However, embryonic hemoglobin releases NO in an oxygen-linked manner that may activate guanylyl cyclase.

  20. Changes in the expression of extracellular regulated kinase (ERK 1/2) in the R6/2 mouse model of Huntington's disease after phosphodiesterase IV inhibition. (United States)

    Fusco, Francesca R; Anzilotti, Serenella; Giampà, Carmela; Dato, Clemente; Laurenti, Daunia; Leuti, Alessandro; Colucci D'Amato, Luca; Perrone, Lorena; Bernardi, Giorgio; Melone, Mariarosa A B


    The mitogen-activated protein kinases (MAPKs) superfamily comprises three major signaling pathways: the extracellular signal-regulated protein kinases (ERKs), the c-Jun N-terminal kinases or stress-activated protein kinases (JNKs/SAPKs) and the p38 family of kinases. ERK 1/2 signaling has been implicated in a number of neurodegenerative disorders, including Huntington's disease (HD). Phosphorylation patterns of ERK 1/2 and JNK are altered in cell models of HD. In this study, we aimed at studying the correlations between ERK 1/2 and the neuronal vulnerability to HD degeneration in the R6/2 transgenic mouse model of HD. Single and double-label immunofluorescence for phospho-ERK (pERK, the activated form of ERK) and for each of the striatal neuronal markers were employed on perfusion-fixed brain sections from R6/2 and wild-type mice. Moreover, Phosphodiesterase 4 inhibition through rolipram was used to study the effects on pERK expression in the different types of striatal neurons. We completed our study with western blot analysis. Our study shows that pERK levels increase with age in the medium spiny striatal neurons and in the parvalbumin interneurons, and that rolipram counteracts such increase in pERK. Conversely, cholinergic and somatostatinergic interneurons of the striatum contain higher levels of pERK in the R6/2 mice compared to the controls. Rolipram induces an increase in pERK expression in these interneurons. Thus, our study confirms and extends the concept that the expression of phosphorylated ERK 1/2 is related to neuronal vulnerability and is implicated in the pathophysiology of cell death in HD.

  1. Angiotensin-converting enzyme inhibition prevents myocardial infarction-induced increase in renal cortical cGMP and cAMP phosphodiesterase activities. (United States)

    Clauss, François; Charloux, Anne; Piquard, François; Doutreleau, Stéphane; Talha, Samy; Zoll, Joffrey; Lugnier, Claire; Geny, Bernard


    We investigated whether myocardial infarction (MI) enhances renal phosphodiesterases (PDE) activities, investigating particularly the relative contribution of PDE1-5 isozymes in total PDE activity involved in both cGMP and cAMP pathways, and whether angiotensin-converting enzyme inhibition (ACEi) decreases such renal PDE hyperactivities. We also investigated whether ACEi might thereby improve atrial natriuretic peptide (ANP) efficiency. We studied renal cortical PDE1-5 isozyme activities in sham (SH)-operated, MI rats and in MI rats treated with perindopril (ACEi) 1 month after coronary artery ligation. Circulating atrial natriuretic peptide (ANP), its second intracellular messenger cyclic guanosine monophosphate (cGMP) and cGMP/ANP ratio were also determined. Cortical cGMP-PDE2 (80.3 vs. 65.1 pmol/min/mg) and cGMP-PDE1 (50.7 vs. 30.1 pmol/min/mg), and cAMP-PDE2 (161 vs. 104.1 pmol/min/mg) and cAMP-PDE4 (307.5 vs. 197.2 pmol/min/mg) activities were higher in MI than in SH rats. Despite increased ANP plasma level, ANP efficiency tended to be decreased in MI compared to SH rats. Perindopril restored PDE activities and tended to improve ANP efficiency in MI rats. One month after coronary ligation, perindopril treatment of MI rats prevents the increase in renal cortical PDE activities. This may contribute to increase renal ANP efficiency in MI rats.

  2. Analysis of substrate specificity and kinetics of cyclic nucleotide phosphodiesterases with N'-methylanthraniloyl-substituted purine and pyrimidine 3',5'-cyclic nucleotides by fluorescence spectrometry.

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    Daniel Reinecke

    Full Text Available As second messengers, the cyclic purine nucleotides adenosine 3',5'-cyclic monophosphate (cAMP and guanosine 3',5'-cyclic monophosphate (cGMP play an essential role in intracellular signaling. Recent data suggest that the cyclic pyrimidine nucleotides cytidine 3',5'-cyclic monophosphate (cCMP and uridine 3',5'-cyclic monophosphate (cUMP also act as second messengers. Hydrolysis by phosphodiesterases (PDEs is the most important degradation mechanism for cAMP and cGMP. Elimination of cUMP and cCMP is not completely understood, though. We have shown that human PDEs hydrolyze not only cAMP and cGMP but also cyclic pyrimidine nucleotides, indicating that these enzymes may be important for termination of cCMP- and cUMP effects as well. However, these findings were acquired using a rather expensive HPLC/mass spectrometry assay, the technical requirements of which are available only to few laboratories. N'-Methylanthraniloyl-(MANT-labeled nucleotides are endogenously fluorescent and suitable tools to study diverse protein/nucleotide interactions. In the present study, we report the synthesis of new MANT-substituted cyclic purine- and pyrimidine nucleotides that are appropriate to analyze substrate specificity and kinetics of PDEs with more moderate technical requirements. MANT-labeled nucleoside 3',5'-cyclic monophosphates (MANT-cNMPs are shown to be substrates of various human PDEs and to undergo a significant change in fluorescence upon cleavage, thus allowing direct, quantitative and continuous determination of hydrolysis via fluorescence detection. As substrates of several PDEs, MANT-cNMPs show similar kinetics to native nucleotides, with some exceptions. Finally, they are shown to be also appropriate tools for PDE inhibitor studies.

  3. Synthesis, 18F-Radiolabelling and Biological Characterization of Novel Fluoroalkylated Triazine Derivatives for in Vivo Imaging of Phosphodiesterase 2A in Brain via Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    Susann Schröder


    Full Text Available Phosphodiesterase 2A (PDE2A is highly and specifically expressed in particular brain regions that are affected by neurological disorders and in certain tumors. Development of a specific PDE2A radioligand would enable molecular imaging of the PDE2A protein via positron emission tomography (PET. Herein we report on the syntheses of three novel fluoroalkylated triazine derivatives (TA2–4 and on the evaluation of their effect on the enzymatic activity of human PDE2A. The most potent PDE2A inhibitors were 18F-radiolabelled ([18F]TA3 and [18F]TA4 and investigated regarding their potential as PET radioligands for imaging of PDE2A in mouse brain. In vitro autoradiography on rat brain displayed region-specific distribution of [18F]TA3 and [18F]TA4, which is consistent with the expression pattern of PDE2A protein. Metabolism studies of both [18F]TA3 and [18F]TA4 in mice showed a significant accumulation of two major radiometabolites of each radioligand in brain as investigated by micellar radio-chromatography. Small-animal PET/MR studies in mice using [18F]TA3 revealed a constantly increasing uptake of activity in the non-target region cerebellum, which may be caused by the accumulation of brain penetrating radiometabolites. Hence, [18F]TA3 and [18F]TA4 are exclusively suitable for in vitro investigation of PDE2A. Nevertheless, further structural modification of these promising radioligands might result in metabolically stable derivatives.

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

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


    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.

  5. Identification of PDE9 as a cGMP-specific phosphodiesterase in germinal vesicle oocytes: A proposed role in the resumption of meiosis (United States)

    Hanna, Carol B.; Yao, Shan; Wu, Xuemei; Jensen, Jeffrey T.


    Objective To identify a cGMP-specific phosphodiesterase (PDE) in non-human primate germinal vesicle (GV) oocytes and establish a proposed effect on oocyte maturation through preliminary experiments in mouse GV oocytes. Design Controlled non-human primate and rodent experiments. Setting Academic research institution. Animals Rhesus macaques and B6/129F1 mice. Interventions Rhesus macaques were stimulated with FSH to collect GV oocytes and cumulus for gene expression analysis. Female mice were stimulated with PMSG to collect GV oocytes. Main Outcome Measures PDE transcript expression in primate GV oocytes and cumulus cells. Fluorescence polarization (FP) measurements of PDE3A activity. Spontaneous resumption of meiosis in mouse GV oocytes. Results Five PDE transcripts were detected in Rhesus GV oocytes, only PDE9A was cGMP-specific. FP assays indicated cGMP has an inhibitory effect on PDE3A while the PDE9 inhibitor, BAY73-6691, did not. Similarly, BAY73-6691, had little effect on preventing spontaneous maturation in oocytes, but did augment the inhibitory effects of cGMP. Inclusion of 0µM (control), 10µM, 100µM, and 1 mM BAY73-6691 significantly increased the proportion of mouse oocytes maintaining GV arrest in the presence of the cGMP analog 8-Br-cGMP at: 100µM (8.8%, 11.4%, 18.8%, and 28%), 500µM (21.1%, 38.1%, 74.5%,and 66.5%), and 1 mM (57.8%, 74.5%, 93.9%, and 94.0%) respectively, when P<0.05. Conclusions PDE9 is a cGMP-specific hydrolyzing enzyme present in primate oocytes, and PDE9 antagonists augment the inhibitory effect of cGMP during spontaneous in vitro maturation of GV mouse oocytes. PMID:22704629

  6. Design and synthesis of 4,5,6,7-tetrahydro-1H-1,2-diazepin-7-one derivatives as a new series of Phosphodiesterase 4 (PDE4) inhibitors. (United States)

    Guariento, Sara; Karawajczyk, Anna; Bull, James A; Marchini, Gessica; Bielska, Martyna; Iwanowa, Xenia; Bruno, Olga; Fossa, Paola; Giordanetto, Fabrizio


    Phosphodiesterase 4 (PDE4) inhibitors have attractive therapeutic potential in respiratory, inflammatory, metabolic and CNS disorders. The present work details the design, chemical exploration and biological profile of a novel PDE4 inhibitor chemotype. A diazepinone ring was identified as an under-represented heterocyclic system fulfilling a set of PDE4 structure-based design hypotheses. Rapid exploration of the structure activity relationships for the series was enabled by robust and scalable two/three-steps parallel chemistry protocols. The resulting compounds demonstrated PDE4 inhibitory activity in cell free and cell-based assays comparable to the Zardaverine control used, suggesting potential avenues for their further development.

  7. Myocilin is involved in NgR1/Lingo-1-mediated oligodendrocyte differentiation and myelination of the optic nerve. (United States)

    Kwon, Heung Sun; Nakaya, Naoki; Abu-Asab, Mones; Kim, Hong Sug; Tomarev, Stanislav I


    Myocilin is a secreted glycoprotein that belongs to a family of olfactomedin domain-containing proteins. Although myocilin is detected in several ocular and nonocular tissues, the only reported human pathology related to mutations in the MYOCILIN gene is primary open-angle glaucoma. Functions of myocilin are poorly understood. Here we demonstrate that myocilin is a mediator of oligodendrocyte differentiation and is involved in the myelination of the optic nerve in mice. Myocilin is expressed and secreted by optic nerve astrocytes. Differentiation of optic nerve oligodendrocytes is delayed in Myocilin-null mice. Optic nerves of Myocilin-null mice contain reduced levels of several myelin-associated proteins including myelin basic protein, myelin proteolipid protein, and 2'3'-cyclic nucleotide 3'-phosphodiesterase compared with those of wild-type littermates. This leads to reduced myelin sheath thickness of optic nerve axons in Myocilin-null mice compared with wild-type littermates, and this difference is more pronounced at early postnatal stages compared with adult mice. Myocilin also affects differentiation of oligodendrocyte precursors in vitro. Its addition to primary cultures of differentiating oligodendrocyte precursors increases levels of tested markers of oligodendrocyte differentiation and stimulates elongation of oligodendrocyte processes. Myocilin stimulation of oligodendrocyte differentiation occurs through the NgR1/Lingo-1 receptor complex. Myocilin physically interacts with Lingo-1 and may be considered as a Lingo-1 ligand. Myocilin-induced elongation of oligodendrocyte processes may be mediated by activation of FYN and suppression of RhoA GTPase.

  8. Nogo-A and myelin-associated glycoprotein differently regulate oligodendrocyte maturation and myelin formation. (United States)

    Pernet, Vincent; Joly, Sandrine; Christ, Franziska; Dimou, Leda; Schwab, Martin E


    Nogo-A is one of the most potent oligodendrocyte-derived inhibitors for axonal regrowth in the injured adult CNS. However, the physiological function of Nogo-A in development and in healthy oligodendrocytes is still unknown. In the present study, we investigated the role of Nogo-A for myelin formation in the developing optic nerve. By quantitative real-time PCR, we found that the expression of Nogo-A increased faster in differentiating oligodendrocytes than that of the major myelin proteins MBP (myelin basic protein), PLP (proteolipid protein)/DM20, and CNP (2',3'-cyclic nucleotide 3'-phosphodiesterase). The analysis of optic nerves and cerebella of mice deficient for Nogo-A (Nogo-A(-/-)) revealed a marked delay of oligodendrocyte differentiation, myelin sheath formation, and axonal caliber growth within the first postnatal month. The combined deletion of Nogo-A and MAG caused a more severe transient hypomyelination. In contrast to MAG(-/-) mice, Nogo-A(-/-) mutants did not present abnormalities in the structure of myelin sheaths and Ranvier nodes. The common binding protein for Nogo-A and MAG, NgR1, was exclusively upregulated in MAG(-/-) animals, whereas the level of Lingo-1, a coreceptor, remained unchanged. Together, our results demonstrate that Nogo-A and MAG are differently involved in oligodendrocyte maturation in vivo, and suggest that Nogo-A may influence also remyelination in pathological conditions such as multiple sclerosis.

  9. A functional role for EGFR signaling in myelination and remyelination. (United States)

    Aguirre, Adan; Dupree, Jeff L; Mangin, J M; Gallo, Vittorio


    Cellular strategies for oligodendrocyte regeneration and remyelination involve characterizing endogenous neural progenitors that are capable of generating oligodendrocytes during normal development and after demyelination, and identifying the molecular signals that enhance oligodendrogenesis from these progenitors. Using both gain- and loss-of-function approaches, we explored the role of epidermal growth factor receptor (EGFR) signaling in adult myelin repair and in oligodendrogenesis. We show that 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) promoter-driven overexpression of human EGFR (hEGFR) accelerated remyelination and functional recovery following focal demyelination of mouse corpus callosum. Lesion repopulation by Cspg4+ (also known as NG2) Ascl1+ (also known as Mash1) Olig2+ progenitors and functional remyelination were accelerated in CNP-hEGFR mice compared with wild-type mice. EGFR overexpression in subventricular zone (SVZ) and corpus callosum during early postnatal development also expanded this NG2+Mash1+Olig2+ progenitor population and promoted SVZ-to-lesion migration, enhancing oligodendrocyte generation and axonal myelination. Analysis of hypomorphic EGFR-mutant mice confirmed that EGFR signaling regulates oligodendrogenesis and remyelination by NG2+Mash1+Olig2+ progenitors. EGFR targeting holds promise for enhancing oligodendrocyte regeneration and myelin repair.

  10. Severe Hypomyelination and Developmental Defects Are Caused in Mice Lacking Protein Arginine Methyltransferase 1 (PRMT1) in the Central Nervous System. (United States)

    Hashimoto, Misuzu; Murata, Kazuya; Ishida, Junji; Kanou, Akihiko; Kasuya, Yoshitoshi; Fukamizu, Akiyoshi


    Protein arginine methyltransferase 1 (PRMT1) is involved in cell proliferation, DNA damage response, and transcriptional regulation. Although PRMT1 is extensively expressed in the CNS at embryonic and perinatal stages, the physiological role of PRMT1 has been poorly understood. Here, to investigate the primary function of PRMT1 in the CNS, we generated CNS-specific PRMT1 knock-out mice by the Cre-loxP system. These mice exhibited postnatal growth retardation with tremors, and most of them died within 2 weeks after birth. Brain histological analyses revealed prominent cell reduction in the white matter tracts of the mutant mice. Furthermore, ultrastructural analysis demonstrated that myelin sheath was almost completely ablated in the CNS of these animals. In agreement with hypomyelination, we also observed that most major myelin proteins including myelin basic protein (MBP), 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase), and myelin-associated glycoprotein (MAG) were dramatically decreased, although neuronal and astrocytic markers were preserved in the brain of CNS-specific PRMT1 knock-out mice. These animals had a reduced number of OLIG2(+) oligodendrocyte lineage cells in the white matter. We found that expressions of transcription factors essential for oligodendrocyte specification and further maturation were significantly suppressed in the brain of the mutant mice. Our findings provide evidence that PRMT1 is required for CNS development, especially for oligodendrocyte maturation processes.

  11. Protective Effect of Electroacupuncture on Neural Myelin Sheaths is Mediated via Promotion of Oligodendrocyte Proliferation and Inhibition of Oligodendrocyte Death After Compressed Spinal Cord Injury. (United States)

    Huang, Siqin; Tang, Chenglin; Sun, Shanquan; Cao, Wenfu; Qi, Wei; Xu, Jin; Huang, Juan; Lu, Weitian; Liu, Qian; Gong, Biao; Zhang, Yi; Jiang, Jin


    Electroacupuncture (EA) has been used worldwide to treat demyelinating diseases, but its therapeutic mechanism is poorly understood. In this study, a custom-designed model of compressed spinal cord injury (CSCI) was used to induce demyelination. Zusanli (ST36) and Taixi (KI3) acupoints of adult rats were stimulated by EA to demonstrate its protective effect. At 14 days after EA, both locomotor skills and ultrastructural features of myelin sheath were significantly improved. Phenotypes of proliferating cells were identified by double immunolabeling of 5-ethynyl-2'-deoxyuridine with antibodies to cell markers: NG2 [oligodendrocyte precursor cell (OPC) marker], 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) (oligodendrocyte marker), and glial fibrillary acidic protein (GFAP) (astrocyte marker). EA enhanced the proliferation of OPCs and CNPase, as well as the differentiation of OPCs by promoting Olig2 (the basic helix-loop-helix protein) and attenuating Id2 (the inhibitor of DNA binding 2). EA could also improve myelin basic protein (MBP) and protect existing oligodendrocytes from apoptosis by inhibiting caspase-12 (a representative of endoplasmic reticulum stress) and cytochrome c (an apoptotic factor and hallmark of mitochondria). Therefore, our results indicate that the protective effect of EA on neural myelin sheaths is mediated via promotion of oligodendrocyte proliferation and inhibition of oligodendrocyte death after CSCI.

  12. White matter apoptosis is increased by delayed hypothermia and rewarming in a neonatal piglet model of hypoxic ischemic encephalopathy. (United States)

    Wang, B; Armstrong, J S; Reyes, M; Kulikowicz, E; Lee, J-H; Spicer, D; Bhalala, U; Yang, Z-J; Koehler, R C; Martin, L J; Lee, J K


    Therapeutic hypothermia is widely used to treat neonatal hypoxic ischemic (HI) brain injuries. However, potentially deleterious effects of delaying the induction of hypothermia and of rewarming on white matter injury remain unclear. We used a piglet model of HI to assess the effects of delayed hypothermia and rewarming on white matter apoptosis. Piglets underwent HI injury or sham surgery followed by normothermic or hypothermic recovery at 2h. Hypothermic groups were divided into those with no rewarming, slow rewarming at 0.5°C/h, or rapid rewarming at 4°C/h. Apoptotic cells in the subcortical white matter of the motor gyrus, corpus callosum, lateral olfactory tract, and internal capsule at 29h were identified morphologically and counted by hematoxylin & eosin staining. Cell death was verified by terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL) assay. White matter neurons were also counted, and apoptotic cells were immunophenotyped with the oligodendrocyte marker 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase). Hypothermia, slow rewarming, and rapid rewarming increased apoptosis in the subcortical white matter relative to normothermia (ppiglets had more apoptosis in the lateral olfactory tract than those that were rewarmed (ppiglets had more apoptosis than shams after normothermia, slow rewarming, and rapid rewarming (ppiglet model of HI; in some regions these temperature effects are independent of HI. Vulnerable cells include myelinating oligodendrocytes. This study identifies a deleterious effect of therapeutic hypothermia in the developing brain.

  13. Cytolysis of oligodendrocytes is mediated by killer (K) cells but not by natural killer (NK) cells. (United States)

    Satoh, J; Kim, S U; Kastrukoff, L F


    The cytotoxic activity of killer (K) cells against enriched cultures of bovine oligodendrocytes (BOL) was investigated in multiple sclerosis (MS) and controls. Human K cells mediated cytotoxicity to primary cultures of BOL in the presence of anti-BOL antiserum in all study groups, while BOL were resistant to human natural killer (NK) cells. Cytotoxic activity was significantly reduced in MS when compared to age-matched normal controls but not when compared to other neurologic disease (OND) patients. K cell-mediated lysis of BOL could also be induced with anti-galactocerebroside antibody but not with other antibodies including those specific for OL antigens (myelin basic protein, proteolipid apoprotein, and 2',3'-cyclic nucleotide 3'-phosphodiesterase). Enrichment of the effector population indicated that antibody-dependent cell-mediated cytotoxicity (ADCC) to BOL was mediated by large granular lymphocytes, and the effector population was further characterized by flow cytometry. The effector cells mediating ADCC could be inhibited by protein A of Staphylococcus aureus, and by K562 cells in cold competition assay. These observations indicate that oligodendrocytes are resistant to NK cells but are susceptible to cytolysis mediated by K cells. This may represent a potentially important immune mechanism in the pathogenesis of MS.

  14. Increased density of DISC1-immunoreactive oligodendroglial cells in fronto-parietal white matter of patients with paranoid schizophrenia. (United States)

    Bernstein, Hans-Gert; Jauch, Esther; Dobrowolny, Henrik; Mawrin, Christian; Steiner, Johann; Bogerts, Bernhard


    Profound white matter abnormalities have repeatedly been described in schizophrenia, which involve the altered expression of numerous oligodendrocyte-associated genes. Transcripts of the disrupted-in-schizophrenia 1 (DISC1) gene, a key susceptibility factor in schizophrenia, have recently been shown to be expressed by oligodendroglial cells and to negatively regulate oligodendrocyte differentiation and maturation. To learn more about the putative role(s) of oligodendroglia-associated DISC1 in schizophrenia, we analyzed the density of DISC1-immunoreactive oligodendrocytes in the fronto-parietal white matter in postmortem brains of patients with schizophrenia. Compared with controls (N = 12) and cases with undifferentiated/residual schizophrenia (N = 6), there was a significantly increased density of DISC1-expressing glial cells in paranoid schizophrenia (N = 12), which unlikely resulted from neuroleptic treatment. Pathophysiologically, over-expression of DISC1 protein(s) in white matter oligodendrocytes might add to the reduced levels of two myelin markers, 2',3'-cyclic-nucleotide 3'-phosphodiesterase and myelin basic protein in schizophrenia. Moreover, it might significantly contribute to cell cycle abnormalities as well as to deficits in oligodendroglial cell differentiation and maturation found in schizophrenia.

  15. Postnatal development of neurons, interneurons and glial cells in the substantia nigra of mice. (United States)

    Abe, Manami; Kimoto, Hiroki; Eto, Risa; Sasaki, Taeko; Kato, Hiroyuki; Kasahara, Jiro; Araki, Tsutomu


    We investigated postnatal alterations of neurons, interneurons and glial cells in the mouse substantia nigra using immunohistochemistry. Tyrosine hydroxylase (TH), neuronal nuclei (NeuN), parvalbumin (PV), neuronal nitric oxide synthase (nNOS), glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule 1 (Iba 1), CNPase (2',3'-cyclic nucleotide 3'-phosphodiesterase), brain-derived neurotrophic factor (BDNF) and glial cell-line-derived neurotrophic factor (GDNF) immunoreactivity were measured in 1-, 2-, 4- and 8-week-old mice. In the present study, the maturation of NeuN-immunopositive neurons preceded the production of TH in the substantia nigra during postnatal development in mice. Furthermore, the maturation of nNOS-immunopositive interneurons preceded the maturation of PV-immunopositive interneurons in the substantia nigra during postnatal development. Among astrocytes, microglia and oligodendrocytes, in contrast, the development process of oligodendrocytes is delayed in the substantia nigra. Our double-labeled immunohistochemical study suggests that the neurotrophic factors such as BDNF and GDNF secreted by GFAP-positive astrocytes may play some role in maturation of neurons, interneurons and glial cells of the substantia nigra during postnatal development in mice. Thus, our findings provide valuable information on the development processes of the substantia nigra.

  16. White matter injuries induced by MK-801 in a mouse model of schizophrenia based on NMDA antagonism. (United States)

    Xiu, Yun; Kong, Xiang-Ru; Zhang, Lei; Qiu, Xuan; Chao, Feng-Lei; Peng, Chao; Gao, Yuan; Huang, Chun-Xia; Wang, San-Rong; Tang, Yong


    The etiology of schizophrenia (SZ) is complex and largely unknown. Neuroimaging and postmortem studies have suggested white matter disturbances in SZ. In the present study, we tested the white matter deficits hypothesis of SZ using a mouse model of SZ induced by NMDA receptor antagonist MK-801. We found that mice with repeated chronic MK-801 administration showed increased locomotor activity in the open field test, less exploration of a novel environment in the hole-board test, and increased anxiety in the elevated plus maze but no impairments were observed in coordination or motor function on accelerating rota-rod. The total white matter volume and corpus callosum volume in mice treated with MK-801 were significantly decreased compared to control mice treated with saline. Myelin basic protein and 2', 3'-cyclic nucleotide 3'-phosphodiesterase were also significantly decreased in the mouse model of SZ. Furthermore, we observed degenerative changes of myelin sheaths in the mouse model of SZ. These results provide further evidence of white matter deficits in SZ and indicate that the animal model of SZ induced by MK-801 is a useful model to investigate mechanisms underlying white matter abnormalities in SZ.

  17. Enriched environment induces higher CNPase positive cells in aged rat hippocampus. (United States)

    Zhao, Yuan-Yu; Shi, Xiao-Yan; Zhang, Lei; Wu, Hong; Chao, Feng-Lei; Huang, Chun-Xia; Gao, Yuan; Qiu, Xuan; Chen, Lin; Lu, Wei; Tang, Yong


    It had been reported that enriched environment was beneficial for the brain cognition and for the neurons and synapses in hippocampus. Previous study reported that the oligodendrocyte density in hippocampus was increased when the rats were reared in the enriched environment from weaning to adulthood. However, biological conclusions based on density were difficult to interpret because the changes in density could be due to an alteration of total quantity and/or an alteration in the reference volume. In the present study, we used unbiased stereological methods to investigate the effect of enriched environment on the total number of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) positive cells in CA1 and dentate gyrus (DG) of the hippocampus in aged rats. Our results indicated that there was significant difference in the total numbers of CNPase positive cells in both CA1 and DG between enriched environment group and standard environment group. The present study provided the first evidence for the protective effects of enriched environment on the CNPase positive cells in aged hippocampus.

  18. CNPase Expression in Olfactory Ensheathing Cells

    Directory of Open Access Journals (Sweden)

    Christine Radtke


    Full Text Available A large body of work supports the proposal that transplantation of olfactory ensheathing cells (OECs into nerve or spinal cord injuries can promote axonal regeneration and remyelination. Yet, some investigators have questioned whether the transplanted OECs associate with axons and form peripheral myelin, or if they recruit endogenous Schwann cells that form myelin. Olfactory bulbs from transgenic mice expressing the enhanced green fluorescent protein (eGFP under the control of the 2-3-cyclic nucleotide 3-phosphodiesterase (CNPase promoter were studied. CNPase is expressed in myelin-forming cells throughout their lineage. We examined CNPase expression in both in situ in the olfactory bulb and in vitro to determine if OECs express CNPase commensurate with their myelination potential. eGFP was observed in the outer nerve layer of the olfactory bulb. Dissociated OECs maintained in culture had both intense eGFP expression and CNPase immunostaining. Transplantation of OECs into transected peripheral nerve longitudinally associated with the regenerated axons. These data indicate that OECs in the outer nerve layer of the olfactory bulb of CNPase transgenic mice express CNPase. Thus, while OECs do not normally form myelin on olfactory nerve axons, their expression of CNPase is commensurate with their potential to form myelin when transplanted into injured peripheral nerve.

  19. Growth and differentiation of neural stem cells in a three-dimensional collagen gel scaffold

    Institute of Scientific and Technical Information of China (English)

    Fei Huang; Qiang Shen; Jitong Zhao


    Collagen protein is an ideal scaffold material for the transplantation of neural stem cells. In this study, rat neural stem cells were seeded into a three-dimensional collagen gel scaffold, with suspension cultured neural stem cells being used as a control group. Neural stem cells, which were cultured in medium containing epidermal growth factor and basic fibroblast growth factor, actively expanded and formed neurospheres in both culture groups. In serum-free medium conditions, the processes extended from neurospheres in the collagen gel group were much longer than those in the suspension culture group. Immunofluorescence staining showed that neurospheres cultured in collagen gels were stained positive for nestin and differentiated cells were stained positive for the neuronal marker βIII-tubulin, the astrocytic marker glial fibrillary acidic protein and the oligodendrocytic marker 2',3'-cyclic nucleotide 3'-phosphodiesterase. Compared with neurospheres cultured in suspension, the differentiation potential of neural stem cells cultured in collagen gels increased, with the formation of neurons at an early stage. Our results show that the three-dimensional collagen gel culture system is superior to suspension culture in the proliferation, differentiation and process outgrowth of neural stem cells.

  20. Lipolytic effect of a polyphenolic citrus dry extract of red orange, grapefruit, orange (SINETROL) in human body fat adipocytes. Mechanism of action by inhibition of cAMP-phosphodiesterase (PDE). (United States)

    Dallas, Constantin; Gerbi, Alain; Tenca, Guillaume; Juchaux, Franck; Bernard, François-Xavier


    The present study investigated the lipolytic (break of fat stored) effect of a citrus-based polyphenolic dietary supplement (SINETROL) at human adipocytes (ex vivo), body fat (clinical) and biochemical levels (inhibition of phosphodiesterase). Free fatty acids (FFA) release was used as indicator of human adipocyte lipolysis and SINETROL activity has been compared with known lipolytic products (isoproterenol, theopylline and caffeine). SINETROL stimulated significantly the lipolytic activity in a range of 6 fold greater than the control. Moreover, SINETROL has 2.1 greater activity than guarana 12% caffeine while its content in caffeine is 3 times lower. Clinically, two groups of 10 volunteers with BMI relevant of overweight were compared during 4 and 12 weeks with 1.4 g/day SINETROL and placebo supplementation. In the SINETROL Group the body fat (%) decreased with a significant difference of 5.53% and 15.6% after 4 and 12 weeks, respectively, while the body weight (kg) decreased with a significant difference of 2.2 and 5.2 kg after 4 and 12 weeks, respectively. These observed effects are linked to SINETROL polyphenolic composition and its resulting synergistic activity. SINETROL is a potent inhibitor of cAMP-phosphodiesterase (PDE) (97%) compared to other purified compounds (cyanidin-3 glycoside, narangin, caffeine). These results suggest that SINETROL has a strong lipolytic effect mediated by cAMP-PDE inhibition. SINETROL may serve to prevent obesity by decreasing BMI.

  1. Unfractionated and low-molecular-weight heparin and the phosphodiesterase inhibitors, IBMX and cilostazol, block ex vivo Equid Herpesvirus type-1-induced platelet activation

    Directory of Open Access Journals (Sweden)

    Tracy Stokol


    Full Text Available Equid herpes virus type-1 (EHV-1 is a major pathogen of horses, causing abortion storms and outbreaks of herpes virus myeloencephalopathy. These clinical syndromes are partly attributed to ischemic injury from thrombosis in placental and spinal vessels. The mechanism of thrombosis in affected horses is unknown. We have previously shown that EHV-1 activates platelets through virus-associated tissue factor-initiated thrombin generation. Activated platelets participate in thrombus formation by providing a surface to localize coagulation factor complexes that amplify and propagate thrombin generation. We hypothesized that coagulation inhibitors that suppress thrombin generation (heparins or platelet inhibitors that impede post-receptor thrombin signaling (phosphodiesterase [PDE] antagonists would inhibit EHV-1-induced platelet activation ex vivo. We exposed platelet-rich plasma collected from healthy horses to the RacL11 abortigenic and Ab4 neuropathogenic strains of EHV-1 at 1 plaque forming unit/cell in the presence or absence of unfractionated heparin (UFH, low-molecular-weight (LMWH heparin or the PDE inhibitors, 3-isobutyl-1methylxanthine (IBMX and cilostazol. We assessed platelet activation status in flow cytometric assays by measuring P-selectin expression. We found that all of the inhibitors blocked EHV-1- and thrombin-induced platelet activation in a dose-dependent manner. Platelet activation in PRP was maximally inhibited at concentrations of 0.05 U/mL UFH and 2.5 μg/mL LMWH. These concentrations represented 0.1 to 0.2 U/mL anti-Factor Xa activity measured in chromogenic assays. Both IBMX and cilostazol showed maximal inhibition of platelet activation at the highest tested concentration of 50 μM but inhibition was lower than that seen with UFH and LMWH. Our results indicate that heparin anticoagulants and strong non-selective (IBMX or isoenzyme-3 selective (cilostazol PDE antagonists inhibit ex vivo EHV-1-induced platelet activation

  2. Evidence suggesting phosphodiesterase-3B regulation of NPY/AgRP gene expression in mHypoE-46 hypothalamic neurons. (United States)

    Anamthathmakula, Prashanth; Sahu, Maitrayee; Sahu, Abhiram


    Hypothalamic neurons expressing neuropeptide Y (NPY) and agouti related-protein (AgRP) are critical regulators of feeding behavior and body weight, and transduce the action of many peripheral signals including leptin and insulin. However, intracellular signaling molecules involved in regulating NPY/AgRP neuronal activity are incompletely understood. Since phosphodiesterase-3B (PDE3B) mediates the hypothalamic action of leptin and insulin on feeding, and is expressed in NPY/AgRP neurons, PDE3B could play a significant role in regulating NPY/AgRP neuronal activity. To investigate the direct regulation of NPY/AgRP neuronal activity by PDE3B, we examined the effects of gain-of-function or reduced function of PDE3B on NPY/AgRP gene expression in a clonal hypothalamic neuronal cell line, mHypoE-46, which endogenously express NPY, AgRP and PDE3B. Overexpression of PDE3B in mHypoE-46 cells with transfection of pcDNA-3.1-PDE3B expression plasmid significantly decreased NPY and AgRP mRNA levels and p-CREB levels as compared to the control plasmid. For the PDE3B knockdown study, mHypoE-46 cells transfected with lentiviral PDE3BshRNAmir plasmid or non-silencing lentiviral shRNAmir control plasmid were selected with puromycin, and stably transfected cells were grown in culture for 48h. Results showed that PDE3BshRNAmir mediated knockdown of PDE3B mRNA and protein levels (∼60-70%) caused an increase in both NPY and AgRP gene expression and in p-CREB levels. Together, these results demonstrate a reciprocal change in NPY and AgRP gene expression following overexpression and knockdown of PDE3B, and suggest a significant role for PDE3B in the regulation of NPY/AgRP gene expression in mHypoE-46 hypothalamic neurons.

  3. Long-term phosphodiesterase 5 inhibitor administration reduces inflammatory markers and heat-shock proteins in cavernous tissue of Zucker diabetic fatty rat (ZDF/fa/fa). (United States)

    Toblli, J E; Cao, G; Angerosa, M; Rivero, M


    Oxidative stress and nitrosative stress present in type 2 diabetes mellitus (T2DM) and metabolic syndrome (MS) induce inflammatory response in diverse tissues including cavernous tissue (CT). Heat-shock proteins (HSPs) have an important role in modulating and repairing tissue injury, although their participation in CT in T2DM is unclear. Beyond the specific action of phosphodiesterase type 5 inhibitors (PDE5i) on erectile function, it has been proposed that chronic administration of these agents improves endothelial function and ameliorates fibrotic changes. The aim of this study was to determine in CT of Zucker Diabetic Fatty (ZDF) rat, an experimental model of T2DM and MS: (1) the degree of oxidative stress and nitrosative stress; (2) the magnitude of inflammatory markers such as tumor necrosis factor-α (TNFα) and interleukin 6 (IL6); (3) immunoexpression of HSP70 and HSP27; (4) how a long-term PDE5i administration may modify these variables. For 6 months, (1) untreated ZDF; (2) ZDF+Sildenafil (Sil) and (3) control Lean Zucker Rat (LZR) received no treatment, were studied. Penises were processed for functional 'in vitro' studies, oxidative and nitrosative stress evaluation and immunohistochemistry in CT using TNFα; IL6; nitrotyrosine, HSP70 and HSP27 antibodies. ZDF+Sil presented better relaxation in corporal strips versus untreated ZDF. Furthermore, ZDF+Sil presented less lipoperoxidation in CT versus untreated ZDF. The activity of antioxidant enzymes CuZn superoxide dismutase (CuZnSOD) and glutathione peroxidase (GPx) was also reduced in untreated ZDF in CT along with a decrease in glutathione versus untreated ZDF. Nitrotyrosine expression was increased in untreated-ZDF rats versus ZDF+Sil and LZR. TNFα and IL6 were decreased in CT in ZDF+Sil versus untreated ZDF. Additionally, the expression of HSP70 and HSP27 was reduced in CT in ZDF+Sil versus untreated ZDF. In conclusion, this study provides substantial evidence supporting a protective role of a long

  4. Domain mapping of the retinal cyclic GMP phosphodiesterase gamma-subunit. Function of the domains encoded by the three exons of the gamma-subunit gene. (United States)

    Takemoto, D J; Hurt, D; Oppert, B; Cunnick, J


    Retinal rod-outer-segment phosphodiesterase (PDE) is a heterotetramer consisting of two similar, but not identical, catalytic subunits (alpha and beta) and two identical inhibitory subunits (gamma 2). Previously, we have reported that the site of PDE alpha/beta interaction with PDE gamma is located within residues 54-87 [Cunnick, Hurt, Oppert, Sakamoto & Takemoto (1990) Biochem. J. 271, 721-727]. The site for PDE gamma interaction with transducin alpha (T alpha) was found to encompass residues 24-45 of PDE gamma [Morrison, Cunnick, Oppert & Takemoto (1989) J. Biol. Chem. 264, 11671-11681]. In order to identify binding sites and other functional domains of PDE gamma, the three peptides which are encoded by the three exons of the PDE gamma gene were synthesized chemically. These exons encode for residues 1-49, 50-62 and 63-87 of bovine PDE gamma [Piriev, Purishko, Khramtsov & Lipkin (1990) Dokl. Akad. Nauk. SSSR 315, 229-230]. The peptide encompassing residues 63-87 was inhibitory in a PDE assay, whereas peptides 1-49 and 50-62 had no effect. However, both peptides 1-49 and 63-87 bound to PDE alpha/beta in a solid-phase binding assay. Only peptide 1-49 bound to T alpha.GTP[S] (GTP[S] is guanosine 5'-[gamma-thio]triphosphate). These data confirm that the inhibitory region of PDE gamma is encoded by exon 3 (residues 63-87), whereas a separate binding site for PDE alpha/beta and for T alpha.GTP[S] is encoded by exon 1 (residues 1-49). To study further the structure-function relationship of PDE gamma, this entire protein and two mutants were chemically synthesized. One mutant (-CT) lacked residues 78-87, whereas another replaced tyrosine-84 with glycine (TYR-84). Whereas the synthetic PDE gamma inhibited PDE alpha/beta catalytic activity, the -CT and TVR-84 mutants did not. All three synthetic proteins bound to both PDE alpha/beta and and T alpha.GTP[S]. These data confirm the presence of an alternative binding site on PDE gamma and demonstrate the importance of tyrosine

  5. Inhibition of the striatal specific phosphodiesterase PDE10A ameliorates striatal and cortical pathology in R6/2 mouse model of Huntington's disease.

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    Carmela Giampà

    Full Text Available BACKGROUND: Huntington's disease is a devastating neurodegenerative condition for which there is no therapy to slow disease progression. The particular vulnerability of striatal medium spiny neurons to Huntington's pathology is hypothesized to result from transcriptional dysregulation within the cAMP and CREB signaling cascades in these neurons. To test this hypothesis, and a potential therapeutic approach, we investigated whether inhibition of the striatal-specific cyclic nucleotide phosphodiesterase PDE10A would alleviate neurological deficits and brain pathology in a highly utilized model system, the R6/2 mouse. METHODOLOGY/PRINCIPAL FINDINGS: R6/2 mice were treated with the highly selective PDE10A inhibitor TP-10 from 4 weeks of age until euthanasia. TP-10 treatment significantly reduced and delayed the development of the hind paw clasping response during tail suspension, deficits in rotarod performance, and decrease in locomotor activity in an open field. Treatment prolonged time to loss of righting reflex. These effects of PDE10A inhibition on neurological function were reflected in a significant amelioration in brain pathology, including reduction in striatal and cortical cell loss, the formation of striatal neuronal intranuclear inclusions, and the degree of microglial activation that occurs in response to the mutant huntingtin-induced brain damage. Striatal and cortical levels of phosphorylated CREB and BDNF were significantly elevated. CONCLUSIONS/SIGNIFICANCE: Our findings provide experimental support for targeting the cAMP and CREB signaling pathways and more broadly transcriptional dysregulation as a therapeutic approach to Huntington's disease. It is noteworthy that PDE10A inhibition in the R6/2 mice reduces striatal pathology, consistent with the localization of the enzyme in medium spiny neurons, and also cortical pathology and the formation of neuronal nuclear inclusions. These latter findings suggest that striatal pathology may

  6. A review of analytical methods for the determination of four new phosphodiesterase type 5 inhibitors in biological samples and pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Cristiane Franco Codevilla


    Full Text Available The introduction of oral phosphodiesterase type 5 inhibitor therapy in 1998 revolutionized the treatment of erectile dysfunction. Erectile dysfunction is the most common sexual problem in men. It often has a profound effect on intimate relationships and quality of life. The analysis of pharmaceuticals is an important part of the drug development process as well as for routine analysis and quality control of commercial formulations. Whereas the determination of sildenafil citrate, vardenafil and tadalafil are well documented by a variety of methods, there are few publications about the determination of udenafil, lodenafil carbonate, mirodenafil and avanafil. The paper presents a brief review of the action mechanism, adverse effects, pharmacokinetics and the most recent analytical methods that can determine drug concentration in biological matrices and pharmaceutical formulations of these four drugs.A introdução da terapia oral com inibidores da fosfodiesterase tipo 5, em 1998, revolucionou o tratamento da disfunção erétil. A disfunção erétil é o problema sexual mais comum em homens. Muitas vezes tem um efeito profundo nas relações íntimas e na qualidade de vida. A análise de produtos farmacêuticos é uma parte importante do processo de desenvolvimento de fármacos, bem como para a análise de rotina e controle de qualidade das formulações comerciais. Enquanto a determinação do citrato de sildenafila, vardenafila e tadalafila está bem documentada por uma variedade de métodos, existem poucas publicações sobre a determinação de udenafila, carbonato de lodenafila, mirodenafila e avanafila. O artigo apresenta uma breve revisão do mecanismo de ação, efeitos adversos, farmacocinética e os mais recentes métodos analíticos, que podem determinar a concentração do fármaco em matrizes biológicas e formulações farmacêuticas destes quatro fármacos.

  7. Peripheral phosphodiesterase 4 inhibition produced by 4-[2-(3,4-Bis-difluoromethoxyphenyl)-2-[4-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-phenyl]-ethyl]-3-methylpyridine-1-oxide (L-826,141) prevents experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Moore, Craig S.; Earl, Nathalie; Frenette, Richard;


    Administration of phosphodiesterase 4 (PDE4) inhibitors suppresses the pathogenesis associated with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). In the present study, we compared the effects of rolipram and 4-[2-(3,4-bis-difluoromethoxyphenyl)-2-[4-...

  8. Inibidores de fosfodiesterases: novas perspectivas de uma antiga terapia na asma? Phosphodiesterase inhibitors: new perspectives on an old therapy for asthma?

    Directory of Open Access Journals (Sweden)

    Hisbello Campos


    shifted the treatment toward either prevention or the inhibition of inflammatory markers. In light of this, new drug formulations have been considered. In addition to the beta2 agonists, theophylline, and corticosteroids currently being used, the second generation of selective phosphodiesterase inhibitors has shown promising results. Recent studies suggest that these drugs may soon offer a novel alternative in the treatment of asthma.

  9. Necrose digital em paciente com lúpus eritematoso sistêmico e esclerose sistêmica tratada com inibidores da fosfodiesterase Digital necrosis treated with phosphodiesterase inhibitors in a patient with connective tissue disease

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    Lílian Scussel Lonzetti


    Full Text Available Os inibidores da fosfodiesterase têm sido introduzidos, nos últimos anos, como novos agentes farmacológicos no tratamento dos pacientes com fenômeno de Raynaud e isquemia digital. Será descrito o caso de uma paciente com lúpus eritematoso sistêmico e esclerose sistêmica limitada apresentando fenômeno de Raynaud grave e necrose digital refratária à terapia. A paciente obteve excelente resposta à associação de imunossupressão e sildenafil.The phosphodiesterase inhibitors have been used recently for the treatment of Raynaud's phenomenon and digital ischaemia. We report the case of a patient affected by systemic lupus erythematosus and limited systemic sclerosis who presented severe Raynaud's phenomenon with digital necrosis despite treatment. The patient presented an excellent response to the association of immunosuppressant therapy and sildenafil.

  10. Association study of schizophrenia and phosphodiesterase 4B gene polymorphism%磷酸二酯酶4B基因多态性与精神分裂症的关联研究

    Institute of Scientific and Technical Information of China (English)

    张丽; 陈元堂; 何长江; 敖磊; 行养玲


    Objective To detect the genetic association between schizophrenia and polymorphism of phosphodiesterase 4B (PDE4B) gene. Methods Observed in a sample of 98 parent/offspring trios where the proband net the Amerecan Classification and diagnostic Criteria for Mental Disorders The Forth Revised Edition,criteria for schizophrenia using correlation analysis and haplotype relative risk analysis. The polymorphism of phosphodiesterase 4B gene was detected with PCR methods and SNP typing in all nucleus families. Results The rs2180335 al-lele was connected with schizophrenia (P = 0.02131). Allele A was protective factor (Z = -2. 184) and allele G was the hazard factor (Z = 2.184). The frequency of rs2180335 allele A was 0.452 and the allele G was 0.548. The rs1040716, rs 3767311 and rs472952 allele was independence with schizophrenia. Five kinds haplotypes of A/A in the rs2180335-rs3767311, A/A in the rs 3767311-rs472952, A/A/A in the rs2180335-rs3767311-rs472952,A/G/G/A and T/A/A/A in the rs1040716-rs2180335-rs3767311-rs472952 associated with schizophrenia (P values were 0. 028715,0. 034845,0. 024177,0. 023967,0. 010839,genotype frequencies were 0. 223, 0.223,0.127,0.081,0.073). Conclusion It shows an association between schizophrenia and the rs2180335 polymorphism at nucleotide of phosphodiesterase 4B gene in Chinese.%目的 探讨磷酸二酯酶4B基因多态性与精神分裂症的相关性.方法 运用聚合酶链反应扩增及单核苷酸多态性的分子生物学技术,收集符合精神分裂症诊断标准的98个先证者及其父母组成的核心家系,对其磷酸二酯酶4B基因rs1040716,rs2180335,rs3767311,rs472952多态性分型,进行精神分裂症的磷酸二酯酶4B基因多态性的关联分析和单体型相对风险率分析.结果 rs2180335等位基因与精神分裂症相关联(P=0.02131),其中等位基因A是保护因素(Z=-2.184),G为危险因素(Z=2.184),A等位基因频率为0.452.G为0.548;rs1040716,rs3767311,rs472952与精神分裂

  11. The Pharmacodynamic Impact of Apremilast, an Oral Phosphodiesterase 4 Inhibitor, on Circulating Levels of Inflammatory Biomarkers in Patients with Psoriatic Arthritis: Substudy Results from a Phase III, Randomized, Placebo-Controlled Trial (PALACE 1

    Directory of Open Access Journals (Sweden)

    Peter H. Schafer


    Full Text Available Apremilast, an oral phosphodiesterase 4 inhibitor, demonstrated effectiveness (versus placebo for treatment of active psoriatic arthritis in the psoriatic arthritis long-term assessment of clinical efficacy (PALACE phase III clinical trial program. Pharmacodynamic effects of apremilast on plasma biomarkers associated with inflammation were evaluated in a PALACE 1 substudy. Of 504 patients randomized in PALACE 1, 150 (placebo: n=51; apremilast 20 mg BID: n=51; apremilast 30 mg BID: n=48 provided peripheral blood plasma samples for analysis in a multiplexed cytometric bead array assay measuring 47 proteins associated with systemic inflammatory immune responses. Association between biomarker levels and achievement of 20% improvement from baseline in modified American College of Rheumatology (ACR20 response criteria was assessed by logistic regression. At Week 24, IL-8, TNF-α, IL-6, MIP-1β, MCP-1, and ferritin were significantly reduced from baseline with apremilast 20 mg BID or 30 mg BID versus placebo. ACR20 response correlated with change in TNF-α level with both apremilast doses. At Week 40, IL-17, IL-23, IL-6, and ferritin were significantly decreased and IL-10 and IL-1 receptor antagonists significantly increased with apremilast 30 mg BID versus placebo. In patients with active psoriatic arthritis, apremilast reduced circulating levels of Th1 and Th17 proinflammatory mediators and increased anti-inflammatory mediators.

  12. 低温法制备马铃薯淀粉磷酸双酯的工艺研究%Study on Process in Fabricating Phosphodiesterase of Potato Starch at Low Temperature

    Institute of Scientific and Technical Information of China (English)

    刘高梅; 王常青; 王菲


    为了提高马铃薯淀粉磷酸双酯的特性以及降低生产的能耗,研究采用在40℃的低温条件下,以三氯氧磷为交联剂,聚乙二醇(PEG)为催化剂制备马铃薯淀粉磷酸双酯.结果表明,当稳定剂用量为0.1%、三氯氧磷用量为0.05%、pH 10时所制备的马铃薯淀粉磷酸双酯的粘度为3400 cp,酯化度为0.42.%In roder to enhance the quality of Phosphodiesterase (PDE) of potato starch and slow dowm the energy consumption of production, the low temperature -40℃, POCL3 and PEG were used to fabrica PDE of potato starch. The results showed that the viscosity and degree of esterification on PDE of potato starch was 3400 cp and 0.42 respectively under the conditions which adding stabilizer 0.1%, POCL3 0.05% and pH 10.

  13. Theobromine, the primary methylxanthine found in Theobroma cacao, prevents malignant glioblastoma proliferation by negatively regulating phosphodiesterase-4, extracellular signal-regulated kinase, Akt/mammalian target of rapamycin kinase, and nuclear factor-kappa B. (United States)

    Sugimoto, Naotoshi; Miwa, Shinji; Hitomi, Yoshiaki; Nakamura, Hiroyuki; Tsuchiya, Hiroyuki; Yachie, Akihiro


    Theobromine, a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. We previously showed that methylxanthines, including caffeine and theophylline, have antitumor and antiinflammatory effects, which are in part mediated by their inhibition of phosphodiesterase (PDE). A member of the PDE family, PDE4, is widely expressed in and promotes the growth of glioblastoma, the most common type of brain tumor. The purpose of this study was to determine whether theobromine could exert growth inhibitory effects on U87-MG, a cell line derived from human malignant glioma. We show that theobromine treatment elevates intracellular cAMP levels and increases the activity of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase, whereas it attenuates p44/42 extracellular signal-regulated kinase activity and the Akt/mammalian target of rapamycin kinase and nuclear factor-kappa B signal pathways. It also inhibits cell proliferation. These results suggest that foods and beverages containing cocoa bean extracts, including theobromine, might be extremely effective in preventing human glioblastoma.

  14. Homology modeling, docking studies and molecular dynamic simulations using graphical processing unit architecture to probe the type-11 phosphodiesterase catalytic site: a computational approach for the rational design of selective inhibitors. (United States)

    Cichero, Elena; D'Ursi, Pasqualina; Moscatelli, Marco; Bruno, Olga; Orro, Alessandro; Rotolo, Chiara; Milanesi, Luciano; Fossa, Paola


    Phosphodiesterase 11 (PDE11) is the latest isoform of the PDEs family to be identified, acting on both cyclic adenosine monophosphate and cyclic guanosine monophosphate. The initial reports of PDE11 found evidence for PDE11 expression in skeletal muscle, prostate, testis, and salivary glands; however, the tissue distribution of PDE11 still remains a topic of active study and some controversy. Given the sequence similarity between PDE11 and PDE5, several PDE5 inhibitors have been shown to cross-react with PDE11. Accordingly, many non-selective inhibitors, such as IBMX, zaprinast, sildenafil, and dipyridamole, have been documented to inhibit PDE11. Only recently, a series of dihydrothieno[3,2-d]pyrimidin-4(3H)-one derivatives proved to be selective toward the PDE11 isoform. In the absence of experimental data about PDE11 X-ray structures, we found interesting to gain a better understanding of the enzyme-inhibitor interactions using in silico simulations. In this work, we describe a computational approach based on homology modeling, docking, and molecular dynamics simulation to derive a predictive 3D model of PDE11. Using a Graphical Processing Unit architecture, it is possible to perform long simulations, find stable interactions involved in the complex, and finally to suggest guideline for the identification and synthesis of potent and selective inhibitors.

  15. Particle swarm optimization and genetic algorithm as feature selection techniques for the QSAR modeling of imidazo[1,5-a]pyrido[3,2-e]pyrazines, inhibitors of phosphodiesterase 10A. (United States)

    Goodarzi, Mohammad; Saeys, Wouter; Deeb, Omar; Pieters, Sigrid; Vander Heyden, Yvan


    Quantitative structure-activity relationship (QSAR) modeling was performed for imidazo[1,5-a]pyrido[3,2-e]pyrazines, which constitute a class of phosphodiesterase 10A inhibitors. Particle swarm optimization (PSO) and genetic algorithm (GA) were used as feature selection techniques to find the most reliable molecular descriptors from a large pool. Modeling of the relationship between the selected descriptors and the pIC50 activity data was achieved by linear [multiple linear regression (MLR)] and non-linear [locally weighted regression (LWR) based on both Euclidean (E) and Mahalanobis (M) distances] methods. In addition, a stepwise MLR model was built using only a limited number of quantum chemical descriptors, selected because of their correlation with the pIC50 . The model was not found interesting. It was concluded that the LWR model, based on the Euclidean distance, applied on the descriptors selected by PSO has the best prediction ability. However, some other models behaved similarly. The root-mean-squared errors of prediction (RMSEP) for the test sets obtained by PSO/MLR, GA/MLR, PSO/LWRE, PSO/LWRM, GA/LWRE, and GA/LWRM models were 0.333, 0.394, 0.313, 0.333, 0.421, and 0.424, respectively. The PSO-selected descriptors resulted in the best prediction models, both linear and non-linear.

  16. The influence of phosphodiesterases 4 inhibitor on the phagocytosis of bacteria by human macrophages%磷酸二酯酶4抑制剂对人巨噬细胞噬菌能力的影响

    Institute of Scientific and Technical Information of China (English)

    梁志科; 赵子文; 刘朝晖; 李裕军; 钟维农


    Objective To investigate the influence of phosphodiesterases 4 inhibitor on the phagocytosis of non-biologi-cal particles and gram-positive bacteria,gram-negative bacteria by human alveolar macrophages. Methods Peripheral blood mononuclear cells (PBMCs)were isolated from venous blood from 12 healthy volunteers using Ficoll-Hypaque density gradients.Monocytes were incubated with media containing 2 ng/ml GM-CSF for 12d to allow full differentiation into macrophage (MDM), a functionally equivalent model of human AM.MDMwere pretreated with Rolipram overnight (16-18h),phagocytosis of fluores-cent labeled beads and H.influenzae,S.aureus by MDMwas measured using a fluostar optima fluorimeter.Cell viability was as-say with MTT. Results MDMphagocytosis of beads and bacteria was a time-dependant process.Rolipram in the concentration of 10-8-10-5Mdidn't inhibit or promote phagocytosis of beads and bacteria by MDM,and didn't affect the cell viability. Conclu-sion Phosphodiesterases 4 inhibitor would not affect the human macrophage phagocytic capacity of non-biological particles and bacteria associated with enhanced intracellular cAMP level.%目的:探讨磷酸二酯酶4抑制剂对人肺泡巨噬细胞(AM)吞噬非生物性颗粒及革兰阳性菌、阴性菌能力的影响。方法使用 Ficolll-Hypaque 密度梯度法将外周血单核细胞分离的静脉血,在含有2 ng/m GM-CSF 的培养液中经12天诱导培养成 AM替代细胞模型—单核细胞源性巨噬细胞(MDM)。用酶标仪检测 MDM经磷酸二酯酶4抑制剂 Rolipram 预处理过夜(16~18 h)后吞噬荧光标记的非生物颗粒 Beads 和热灭活的流感嗜血杆菌(H.influenzae)、金黄色葡萄球菌(S.aureus)量的改变,另使用 MTT 法检测细胞活性。结果成功建立的 MDM细胞模型对 Beads 和细菌的吞噬呈时效关。Rolipram 在实验浓度(10~8~10-5 M)下对 MDM吞噬 Beads、H.influenzae 和S.aureus 能力无明显促进

  17. 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. (United States)

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


    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.

  18. Phosphodiesterase 4 inhibitors augment the ability of formoterol to enhance glucocorticoid-dependent gene transcription in human airway epithelial cells: a novel mechanism for the clinical efficacy of roflumilast in severe chronic obstructive pulmonary disease. (United States)

    Moodley, Thunicia; Wilson, Sylvia M; Joshi, Taruna; Rider, Christopher F; Sharma, Pawan; Yan, Dong; Newton, Robert; Giembycz, Mark A


    Post-hoc analysis of two phase III clinical studies found that the phosphodiesterase 4 (PDE4) inhibitor, roflumilast, reduced exacerbation frequency in patients with severe chronic obstructive pulmonary disease (COPD) who were taking inhaled corticosteroids (ICS) concomitantly, whereas patients not taking ICS derived no such benefit. In contrast, in two different trials also performed in patients with severe COPD, roflumilast reduced exacerbation rates in the absence of ICS, indicating that PDE4 inhibition alone is sufficient for therapeutic activity to be realized. Given that roflumilast is recommended as an "add-on" medication to patients with severe disease who will inevitably be taking a long-acting β2-adrenoceptor agonist (LABA)/ICS combination therapy, we tested the hypothesis that roflumilast augments the ability of glucocorticoids to induce genes with anti-inflammatory activity. Using a glucocorticoid response element (GRE) luciferase reporter transfected into human airway epithelial cells [both bronchial epithelium + adenovirus 12 - SV40 hybrid (BEAS-2B) cells and primary cultures], roflumilast enhanced fluticasone propionate-induced GRE-dependent transcription. Roflumilast also produced a sinistral displacement of the concentration-response curves that described the augmentation of GRE-dependent transcription by the LABA formoterol. In BEAS-2B cells and primary airway epithelia, roflumilast interacted with formoterol in a positive cooperative manner to enhance the expression of several glucocorticoid-inducible genes that have anti-inflammatory potential. We suggest that the ability of roflumilast and formoterol to interact in this way supports the concept that these drugs together may impart clinical benefit beyond that achievable by an ICS alone, a PDE4 inhibitor alone, or an ICS/LABA combination therapy. Roflumilast may, therefore, be especially effective in patients with severe COPD.

  19. Phosphodiesterase 4B in the cardiac L-type Ca²⁺ channel complex regulates Ca²⁺ current and protects against ventricular arrhythmias in mice. (United States)

    Leroy, Jérôme; Richter, Wito; Mika, Delphine; Castro, Liliana R V; Abi-Gerges, Aniella; Xie, Moses; Scheitrum, Colleen; Lefebvre, Florence; Schittl, Julia; Mateo, Philippe; Westenbroek, Ruth; Catterall, William A; Charpentier, Flavien; Conti, Marco; Fischmeister, Rodolphe; Vandecasteele, Grégoire


    β-Adrenergic receptors (β-ARs) enhance cardiac contractility by increasing cAMP levels and activating PKA. PKA increases Ca²⁺-induced Ca²⁺ release via phosphorylation of L-type Ca²⁺ channels (LTCCs) and ryanodine receptor 2. Multiple cyclic nucleotide phosphodiesterases (PDEs) regulate local cAMP concentration in cardiomyocytes, with PDE4 being predominant for the control of β-AR-dependent cAMP signals. Three genes encoding PDE4 are expressed in mouse heart: Pde4a, Pde4b, and Pde4d. Here we show that both PDE4B and PDE4D are tethered to the LTCC in the mouse heart but that β-AR stimulation of the L-type Ca²⁺ current (ICa,L) is increased only in Pde4b-/- mice. A fraction of PDE4B colocalized with the LTCC along T-tubules in the mouse heart. Under β-AR stimulation, Ca²⁺ transients, cell contraction, and spontaneous Ca²⁺ release events were increased in Pde4b-/- and Pde4d-/- myocytes compared with those in WT myocytes. In vivo, after intraperitoneal injection of isoprenaline, catheter-mediated burst pacing triggered ventricular tachycardia in Pde4b-/- mice but not in WT mice. These results identify PDE4B in the CaV1.2 complex as a critical regulator of ICa,L during β-AR stimulation and suggest that distinct PDE4 subtypes are important for normal regulation of Ca²⁺-induced Ca²⁺ release in cardiomyocytes.

  20. Application of phosphodiesterase inhibitor-roflumilast in chronic obstructivepulmonary disease%磷酸二酯酶抑制药——罗氟司特在慢性阻塞性肺疾病治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    祝巍; 陈萍


    炎症是慢性阻塞性肺疾病(COPD)发病机制的核心,抗炎治疗在COPD管理中具有重要地位.磷酸二酯酶4 (PDE4)表达于炎症细胞和平滑肌细胞,是抗炎治疗的靶目标.PDE4抑制药能有效拮抗气道炎症,但早期的PDE4抑制药效能低、不良反应多,致使应用受限.新上市的选择性PDE4抑制药——罗氟司特与PDE4有更强的亲和力,能够改善肺功能,减少COPD急性加重,且不良反应轻微,已被2010年COPD防治全球创议推荐用于重度COPD患者的治疗.%Inflammation is the central mechanism of chronic obstructive pulmonary disease (COPD).Anti-inflammaory treatment plays an important role in COPD management. Phosphodiesterase 4 (PDE4) was identified as a therapeutic target for anti-inflammatory agents many years ago, since it is expressed in many inflammatory cells and smooth muscle cells. The application of early PDE4 inhibitors were limited by low potency and hampered by its serious adverse reactions. Current PDE4 inhibitors such as roflumilast have fewer adverse reactions and greater affinity for PDE4, and can improve the lung function, reduce exacerbation rates, make a wide application prospect. GOLD 2010 guideline had recommended its use in the treatment of severe COPD patients.

  1. 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

    Directory of Open Access Journals (Sweden)

    Simon Chiu


    Full Text Available 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 NCT01805518.

  2. QM/MM analysis suggests that Alkaline Phosphatase (AP) and Nucleotide pyrophosphatase/phosphodiesterase slightly tighten the transition state for phosphate diester hydrolysis relative to solution: implication for catalytic promiscuity in the AP superfamily (United States)

    Hou, Guanhua


    Several members of the Alkaline Phosphatase (AP) superfamily exhibit a high level of catalytic proficiency and promiscuity in structurally similar active sites. A thorough characterization of the nature of transition state for different substrates in these enzymes is crucial for understanding the molecular mechanisms that govern those remarkable catalytic properties. In this work, we study the hydrolysis of a phosphate diester, MpNPP−, in solution, two experimentally well-characterized variants of AP (R166S AP, R166S/E322Y AP) and wild type Nucleotide pyrophosphatase/phosphodiesterase (NPP) by QM/MM calculations in which the QM method is an approximate density functional theory previously parameterized for phosphate hydrolysis (SCC-DFTBPR). The general agreements found between these calculations and available experimental data for both solution and enzymes support the use of SCC-DFTBPR/MM for a semi-quantitative analysis of the catalytic mechanism and nature of transition state in AP and NPP. Although phosphate diesters are cognate substrates for NPP but promiscuous substrates for AP, the calculations suggest that their hydrolysis reactions catalyzed by AP and NPP feature similar synchronous transition states that are slightly tighter in nature compared to that in solution, due in part to the geometry of the bimetallic zinc motif. Therefore, this study provides the first direct computational support to the hypothesis that enzymes in the AP superfamily catalyze cognate and promiscuous substrates via similar transition states to those in solution. Our calculations do not support the finding of recent QM/MM studies by López-Canut and coworkers, who suggested that the same diester substrate goes through a much looser transition state in NPP/AP than in solution, a result likely biased by the large structural distortion of the bimetallic zinc site in their simulations. Finally, our calculations for different phosphate diester orientations and phosphorothioate diesters

  3. 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. (United States)

    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


    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.

  4. Chronic intermittent ethanol induced axon and myelin degeneration is attenuated by calpain inhibition. (United States)

    Samantaray, Supriti; Knaryan, Varduhi H; Patel, Kaushal S; Mulholland, Patrick J; Becker, Howard C; Banik, Naren L


    Chronic alcohol consumption causes multifaceted damage to the central nervous system (CNS), underlying mechanisms of which are gradually being unraveled. In our previous studies, activation of calpain, a calcium-activated neutral protease has been found to cause detrimental alterations in spinal motor neurons following ethanol (EtOH) exposure in vitro. However, it is not known whether calpain plays a pivotal role in chronic EtOH exposure-induced structural damage to CNS in vivo. To test the possible involvement of calpain in EtOH-associated neurodegenerative mechanisms the present investigation was conducted in a well-established mouse model of alcohol dependence - chronic intermittent EtOH (CIE) exposure and withdrawal. Our studies indicated significant loss of axonal proteins (neurofilament light and heavy, 50-60%), myelin proteins (myelin basic protein, 20-40% proteolipid protein, 25%) and enzyme (2', 3'-cyclic-nucleotide 3'-phosphodiesterase, 21-55%) following CIE in multiple regions of brain including hippocampus, corpus callosum, cerebellum, and importantly in spinal cord. These CIE-induced deleterious effects escalated after withdrawal in each CNS region tested. Increased expression and activity of calpain along with enhanced ratio of active calpain to calpastatin (sole endogenous inhibitor) was observed after withdrawal compared to EtOH exposure. Pharmacological inhibition of calpain with calpeptin (25 μg/kg) prior to each EtOH vapor inhalation significantly attenuated damage to axons and myelin as demonstrated by immuno-profiles of axonal and myelin proteins, and Luxol Fast Blue staining. Calpain inhibition significantly protected the ultrastructural integrity of axons and myelin compared to control as confirmed by electron microscopy. Together, these findings confirm CIE exposure and withdrawal induced structural alterations in axons and myelin, predominantly after withdrawal and corroborate calpain inhibition as a potential protective strategy against

  5. Exposure to As, Cd and Pb-mixture impairs myelin and axon development in rat brain, optic nerve and retina. (United States)

    Rai, Nagendra Kumar; Ashok, Anushruti; Rai, Asit; Tripathi, Sachin; Nagar, Geet Kumar; Mitra, Kalyan; Bandyopadhyay, Sanghamitra


    Arsenic (As), lead (Pb) and cadmium (Cd) are the major metal contaminants of ground water in India. We have reported the toxic effect of their mixture (metal mixture, MM), at human relevant doses, on developing rat astrocytes. Astrocyte damage has been shown to be associated with myelin disintegration in CNS. We, therefore, hypothesized that the MM would perturb myelinating white matter in cerebral cortex, optic nerve (O.N.) and retina. We observed modulation in the levels of myelin and axon proteins, such as myelin basic protein (MBP), proteolipid protein, 2'-, 3'-cyclic-nucleotide-3'-phosphodiesterase, myelin-associated glycoprotein and neurofilament (NF) in the brain of developing rats. Dose and time-dependent synergistic toxic effect was noted. The MBP- and NF-immunolabeling, as well as luxol-fast blue (LFB) staining demonstrated a reduction in the area of intact myelin-fiber, and an increase in vacuolated axons, especially in the corpus-callosum. Transmission electron microscopy (TEM) of O.N. revealed a reduction in myelin thickness and axon-density. The immunolabeling with MBP, NF, and LFB staining in O.N. supported the TEM data. The hematoxylin and eosin staining of retina displayed a decrease in the thickness of nerve-fiber, plexiform-layer, and retinal ganglion cell (RGC) count. Investigating the mechanism revealed a loss in glutamine synthetase activity in the cerebral cortex and O.N., and a fall in the brain derived neurotrophic factor in retina. An enhanced apoptosis in MBP, NF and Brn3b-containing cells justified the diminution in myelinating axons in CNS. Our findings for the first time indicate white matter damage by MM, which may have significance in neurodevelopmental-pediatrics, neurotoxicology and retinal-cell biology.

  6. Maternal chewing during prenatal stress ameliorates stress-induced hypomyelination, synaptic alterations, and learning impairment in mouse offspring. (United States)

    Suzuki, Ayumi; Iinuma, Mitsuo; Hayashi, Sakurako; Sato, Yuichi; Azuma, Kagaku; Kubo, Kin-Ya


    Maternal chewing during prenatal stress attenuates both the development of stress-induced learning deficits and decreased cell proliferation in mouse hippocampal dentate gyrus. Hippocampal myelination affects spatial memory and the synaptic structure is a key mediator of neuronal communication. We investigated whether maternal chewing during prenatal stress ameliorates stress-induced alterations of hippocampal myelin and synapses, and impaired development of spatial memory in adult offspring. Pregnant mice were divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube, and was initiated on day 12 of pregnancy and continued until delivery. Mice in the stress/chewing group were given a wooden stick to chew during restraint. In 1-month-old pups, spatial memory was assessed in the Morris water maze, and hippocampal oligodendrocytes and synapses in CA1 were assayed by immunohistochemistry and electron microscopy. Prenatal stress led to impaired learning ability, and decreased immunoreactivity of myelin basic protein (MBP) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in the hippocampal CA1 in adult offspring. Numerous myelin sheath abnormalities were observed. The G-ratio [axonal diameter to axonal fiber diameter (axon plus myelin sheath)] was increased and postsynaptic density length was decreased in the hippocampal CA1 region. Maternal chewing during stress attenuated the prenatal stress-induced impairment of spatial memory, and the decreased MBP and CNPase immunoreactivity, increased G-ratios, and decreased postsynaptic-density length in the hippocampal CA1 region. These findings suggest that chewing during prenatal stress in dams could be an effective coping strategy to prevent hippocampal behavioral and morphologic impairments in their offspring.

  7. Differential synaptic integration of interneurons in the outer and inner molecular layers of the developing dentate gyrus. (United States)

    Chittajallu, Ramesh; Kunze, Albrecht; Mangin, Jean-Marie; Gallo, Vittorio


    The dentate gyrus (DG) undergoes continued reorganization and lamination during early postnatal development. Interneurons with anatomically identified synaptic contacts migrate from the outer to the inner regions of the molecular layer (ML) of the DG. By using the 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP)-enhanced green fluorescent protein transgenic mouse, we were able to target and physiologically characterize Dlx2(+) developing ML interneurons. We investigated whether synapses on migrating ML interneurons were functional and defined properties of synaptic inputs onto interneurons that were located in the outer ML (OML) or inner ML (IML). Consistent with ongoing maturation, IML interneurons displayed lower input resistances and more hyperpolarized resting membrane potentials than OML interneurons. Both OML and IML interneurons received a direct excitatory monosynaptic input from the entorhinal cortex via the perforant paths, but this input was differentially sensitive to activation of presynaptic group II and III metabotropic glutamate receptors. Furthermore, only IML interneurons also received significant synaptic input from the CA3/hilar region, especially under conditions of experimentally induced disinhibition. These changes are attributed to a significant reorganization of dendritic fields. GABA(A) receptor-mediated innervation of OML and IML interneurons also displayed significant differences in miniature IPSC amplitude, frequency, and decay kinetics. Finally, cell-attached recordings indicated that GABA(A) receptor activation was depolarizing in OML interneurons but predominantly shunting in IML interneurons. Our data provide evidence that developing ML interneurons receive functional glutamatergic and GABAergic inputs and undergo significant changes in synaptic integration during migration from the OML to the IML.

  8. IL-1β induces hypomyelination in the periventricular white matter through inhibition of oligodendrocyte progenitor cell maturation via FYN/MEK/ERK signaling pathway in septic neonatal rats. (United States)

    Xie, Di; Shen, Fengcai; He, Shaoru; Chen, Mengmeng; Han, Qianpeng; Fang, Ming; Zeng, Hongke; Chen, Chunbo; Deng, Yiyu


    Neuroinflammation elicited by microglia plays a key role in periventricular white matter (PWM) damage (PWMD) induced by infectious exposure. This study aimed to determine if microglia-derived interleukin-1β (IL-1β) would induce hypomyelination through suppression of maturation of oligodendrocyte progenitor cells (OPCs) in the developing PWM. Sprague-Dawley rats (1-day old) were injected with lipopolysaccharide (LPS) (1 mg/kg) intraperitoneally, following which upregulated expression of IL-1β and IL-1 receptor 1 (IL-1R1 ) was observed. This was coupled with enhanced apoptosis and suppressed proliferation of OPCs in the PWM. The number of PDGFR-α and NG2-positive OPCs was significantly decreased in the PWM at 24 h and 3 days after injection of LPS, whereas it was increased at 14 days and 28 days. The protein expression of Olig1, Olig2, and Nkx2.2 was significantly reduced, and mRNA expression of Tcf4 and Axin2 was upregulated in the developing PWM after LPS injection. The expression of myelin basic protein (MBP) and 2',3'-cyclic-nucleotide 3"-phosphodiesterase (CNPase) was downregulated in the PWM at 14 days and 28 days after LPS injection; this was linked to reduction of the proportion of myelinated axons and thinner myelin sheath as revealed by electron microscopy. Primary cultured OPCs treated with IL-1β showed the failure of maturation and proliferation. Furthermore, FYN/MEK/ERK signaling pathway was involved in suppression of maturation of primary OPCs induced by IL-1β administration. Our results suggest that following LPS injection, microglia are activated and produce IL-1β in the PWM in the neonatal rats. Excess IL-1β inhibits the maturation of OPCs via suppression of FYN/MEK/ERK phosphorylation thereby leading to axonal hypomyelination.

  9. Nerve root degeneration and regeneration by intrathecal phenol in rats: a morphologic approach. (United States)

    Romero-Figueroa, Socorro; Aldrete, J Antonio; Martínez-Cruz, Angelina; Orozco, Sandra; Castillo, Sebastian; Castillo-Henkel, Carlos; Guízar-Sahagún, Gabriel


    Intrathecal injection of phenol (ITP) has been used to control intractable pain and spasticity. Direct caustic nerve damage has been postulated as the mechanism of analgesia. Sensation is commonly recovered, suggesting that a spontaneous regeneration process takes place. There is, however, a lack of mechanistic information on ITP therapy. To define morphologically the neurolysis and regeneration phenomena produced by ITP, anesthetized rats were subjected to laminectomy at L5; 5 microl of 22% phenol in saline solution or vehicle (control) was injected. Light and electron microscopy studies of nerve roots were performed at 2, 14, and 60 days after injection. Rats given ITP showed at the early stage a variable amount of roots with signs of infarction characterized by loss of axon-myelin units and thrombosis of intra-root vessels. At 14 days, abundance of macrophages removing debris, open vessels, and nerve sprouts was identified in damaged roots. At this time, non-myelinating glial fibrillary acidic protein-positive Schwann cells were observed in both damaged and apparently undamaged roots. At 60 days, abundance of 2',3'-cyclic nucleotide 3'-phosphodiesterase-positive Schwann cells myelinating newly formed axons was observed in damaged roots. Control rats did not show signs of neural or vascular pathology. Attempting to prevent thrombosis, another group of rats received heparin before ITP; these anti-coagulated rats developed radicular thrombosis, neurolysis, and hemorrhage. In conclusion, neurolysis produced by ITP is associated with acute ischemia (not prevented by heparin) and is followed by vascular, nerve, and myelin regeneration. Our results help understand the lack of efficacy of and some complications by ITP clinical therapy.

  10. Selective myelin defects in the anterior medullary velum of the taiep mutant rat. (United States)

    Song, J; Goetz, B D; Kirvell, S L; Butt, A M; Duncan, I D


    The taiep rat is a myelin mutant in which initial hypomyelination is followed by progressive demyelination of the CNS. An in vitro study suggests that accumulation of microtubules within oligodendrocytes is the cause of the taiep myelin defects (Song et al., 1999). In this article, we analyze microtubule accumulation in relation to taiep myelin defects in vivo in the anterior medullary velum (AMV), a CNS tissue that enables entire oligodendrocyte units to be resolved. Immunohistochemical analysis demonstrated notably high levels of beta-tubulin and the microtubule associated protein tau in the somata and processes of taiep oligodendrocytes. This was correlated with markedly reduced expression of the myelin proteins, proteolipid protein (PLP), myelin basic protein (MBP), 2',3 -cyclic nucleotide 3'-phosphodiesterase, and both large (L) and small (S) isoforms of myelin-associated glycoprotein (MAG). Moreover, PLP and L-MAG, which are dependent on the microtubule system for intracellular transport, accumulated in the perinuclear cytoplasm of the taiep oligodendrocyte. The myelin deficit was most marked in the area of the AMV populated by the small somata oligodendrocytes that have fine long processes that support numerous myelin sheaths of small diameter axons. Type III/IV oligodendrocytes, which have large somata and short processes that support a small number of myelin sheaths of large diameter axons, were also affected to a certain degree in compact myelin sheath formation. These results support the hypothesis that myelin loss and oligodendrocyte disruption in the taiep mutant result from a defect in the microtubule system that transports myelin components from the somata to the myelin sheath.

  11. Effect of Icariin on Cyclic GMP Levels and on the mRNA Expression of cGMP-binding cGMP-specific Phosphodiesterase (PDE5) in Penile Cavernosum

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhaojian; HU Benrong; WANG Jialing; TANG Qiang; TAN Yan; XIANG Jizhou; LIU Juyan


    To further investigate the mechanisms of action of icariin (ICA), we assessed the effects of ICA on the in vitro formation of cGMP and cAMP in isolated rabbit corpus cavernosum. Isolated segments of rabbit corpus cavernosum were exposed to increasing concentrations of ICA and the dose-dependent accumulation of cGMP and cAMP was determined in the tissues samples by means of 125I radioimmunoassay. Responses of the isolated tissues preparations to ICA were compared with those obtained with the reference compounds sildenafil (Sild). Furthermore, the effects of ICA on the mRNA expression of specific cGMP-binding phosphodiesterase type V (PDE5) in rat penis were also observed. After incubation with ICA for 6 h or 14 h respectively, the levels of PDE5 mRNA were examined by reverse transcriptase polymerase chain reaction (RT-PCR). The results showed that ICA increased cGMP concentrations directly (P<0.05), but there was no significant effect on cAMP concentrations (P>0.05). In the presence of sodium nitroprusside (SNP), a stimulatory agent of cGMP,both ICA and Sild increased cGMP concentrations with increasing dose (P<0.01). Their EC50 was 4.62 (ICA) and 0.42 (Sild) μmol/L respectively. Under the same condition, ICA and Sild unaltered cAMP level significantly (P>0.05). There were PDE5A1 and PDE5A2 mRNA expressions in rat corpus cavernosum with PDE5A2 being the dominant isoform. ICA could obviously inhibit these two isoforms mRNA expression in rat penis, and decrease PDE5A1 more pronouncedly (P< 0.01). The present study indicated that the aphrodisiac mechanisms of icariin involved the NO-cGMP signal transduction pathway, with increasing cGMP levels in the corpus cavernosum smooth muscle. The inhibitory effect of icariin on PDE5 mRNA expression, especially on PDE5A1, might account for its molecular mechanisms for its long-term activity.

  12. 磷酸二酯酶参与认知与情绪调节的研究进展%Progress in the role of phosphodiesterases in memory regulation

    Institute of Scientific and Technical Information of China (English)

    陈玲; 徐英; 潘建春


    磷酸二酯酶(PDE)催化水解cAMP和cGMP,是细胞内降解cAMP和cGMP的唯一途径.PDE是一个多基因大家族酶,包含11型不同家族,它们的结构,分布以及调节方式对抑制剂的敏感性都不同.PDE选择性抑制剂可通过抑制cAMP或cGMP水解来调节学习记忆障碍等中枢神经系统疾病.因此,PDE被认为在中枢神经系统疾病的治疗上具有重要地位.本综述介绍目前PDE参与学习记忆障碍这一中枢神经系统疾病调节的研究进展,而且PDE作为中枢神经系统疾病的治疗靶点,研究其选择性抑制剂具有重要的意义.%Phosphodiesterases (PDEs) are a super-family of enzymes that are involved in the regulation of the intracellular second messengers cAMP and cGMP by controlling their rates of hydrolysis. There are 11 different PDE families, and each family has typically multiple isof'orms and splice variants. The PDEs differ in their structures , distribution, modes of regulation, and sensitivity to inhibitors. Since PDEs have been demonstrated to play distinct roles in the process of emotion, and related learning and memory, selective PDE inhibitors, by preventing the breakdown of cAMP and/or cGMP, could modulate mood and related cognitive activity. This review discusses the current status and future development in the burgeoning field of PDEs in the central nervous system. It is becoming increasingly clear that PDE inhibitors have therapeutic potential for the treatment of neuropsychiatric disorders involving disturbances of mood, emotion, and cognition.

  13. Biflavones of Decussocarpus rospigliosii as phosphodiesterases inhibitors. (United States)

    Chaabi, Mehdi; Antheaume, Cyril; Weniger, Bernard; Justiniano, Hélène; Lugnier, Claire; Lobstein, Annelise


    A phytochemical study of an ethyl acetate extract of Decussocarpus rospigliosii leaves led to the isolation of six 3'-8''-biapigenin derivatives identified as amentoflavone (1), podocarpusflavone A (2), sequoiaflavone (3), podocarpusflavone B (4), 7,7''-di-O-methylamentoflavone (5) and heveaflavone (6). Biflavones 1-4 showed strong inhibitory activity on several PDE isoforms. Biflavone (5) showed selective and potent inhibition of the PDE4 isoform (IC50=1.48+/-0.21 microM) and was almost as active as the reference drug Rolipram (IC50=1.1+/-0.2 microM).

  14. AcEST: BP913221 [AcEST

    Lifescience Database Archive (English)

    Full Text Available CNPD_CLOK5 2',3'-cyclic-nucleotide 2'-phosphodiesteras... 35 0.12 sp|A5DI86|SHE9_PICGU Sensitive to high exp...RDRR 82 >sp|A5DI86|SHE9_PICGU Sensitive to high expression protein 9 homolog, mit

  15. Effects of a novel phosphodiesterase IV inhibitor Ariflo on endothelin-1-induced contractility of isolated human uterine myometrium%新型磷酸二酯酶Ⅳ抑制剂Ariflo对内皮素-1诱发离体人子宫平滑肌收缩的影响

    Institute of Scientific and Technical Information of China (English)

    祁红; Leroy MJ; Advenier C; 张勇; Emmanuel N; 陈红专


    目的:研究选择性磷酸二酯酶 (phosphodiesterase,PDE) Ⅳ抑制剂Ariflo对内皮素-1 (endothelin-1,ET-1) 诱发的非妊娠人子宫平滑肌收缩的影响.方法:累积给药法观察药物对离体平滑肌收缩的作用.结果:Ariflo可降低子宫平滑肌自主收缩的收缩频率及收缩幅度 (pD2=7.90),且对ET-1 (3×10-8 mol*L-1)诱发的子宫平滑肌收缩具有浓度依赖性抑制作用(pD2=7.40),作用强度与Rolipram相似.结论:Ariflo对ET-1诱发的离体人子宫平滑肌的收缩具有显著抑制作用,提示在临床上有缓解痛经的作用.

  16. Effects of olfactory ensheathing cells on the proliferation and differentiation of neural stem cells

    Institute of Scientific and Technical Information of China (English)

    Xuewei Xie; Zhouping Tang; Feng Xu; Na Liu; Zaiwang Li; Suiqiang Zhu; Wei Wang


    BACKGROUND: Olfactory ensheathing cells can promote oriented differentiation and proliferation of neural stem cells by cell-secreted neural factors.OBJECTIVE: To observe the effect of olfactory ensheathing cells on the differentiation and proliferation of neural stem cells.DESIGN, TIME AND SETrlNG: Cytology was performed at the Department of Neurology, Tongji Medical College, Huazhong University of Science and Technology, China, from September 2007 to October 2008.MATERIALS: Mouse anti-nestin polyclonal antibody (Chemicon, USA), mouse anti-glial fibrillary acidic protein (GFAP) IgG1, mouse anti-2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) IgG1, mouse anti-Tubulin Class-Ill IgG1 (Neo Markers, USA), Avidin-labeled Cy3 (KPL, USA), and goat anti-mouse IgG1: fluorescein isothiocyanate (FITC) (Serotec, UK) were used in this study.METHODS: Tissues were isolated from the embryonic olfactory bulb and subependymal region of Wistar rats. Serum-free DMEM/F12 culture media was used for co-culture experiments. Neural stem cells were incubated in serum-free or 5% fetal bovine serum-containing DMEM/F12 as controls.MAIN OUTCOME MEASURES: After 7 days of co-culture, neural stem cells and olfactory ensheathing cells underwent immunofluorescent staining for nestin, tubulin, glial fibrillary acidic protein, and CNPase.RESULTS: Olfactory ensheathing cells promoted proliferation and differentiation of neural stem cells into neuron-like cells, astrocytes and oligodendrocytes. The proportion of neuron-like cells was 78.2%, but the proportion of neurons in 5% fetal bovine serum DMEM/F12 was 48.3%. In the serum-free DMEM/F12, neural stem cells contracted, unevenly adhered to the glassware wall, or underwent apoptosis at 7 days.CONCLUSION: Olfactory ensheathing cells promote differentiation of neural stem cells mainly into neuron-like cells, and accelerate proliferation of neural stem cells. The outcome is better compared with serum-free medium or medium containing 5% fetal bovine

  17. Alterations of myelin-specific proteins and sphingolipids characterize the brains of acid sphingomyelinase-deficient mice, an animal model of Niemann-Pick disease type A. (United States)

    Buccinnà, Barbara; Piccinini, Marco; Prinetti, Alessandro; Scandroglio, Federica; Prioni, Simona; Valsecchi, Manuela; Votta, Barbara; Grifoni, Silvia; Lupino, Elisa; Ramondetti, Cristina; Schuchman, Edward H; Giordana, Maria Teresa; Sonnino, Sandro; Rinaudo, Maria Teresa


    Niemann-Pick disease (NPD) type A is a neurodegenerative disorder caused by sphingomyelin (SM) accumulation in lysosomes relying on reduced or absent acid sphingomyelinase (ASM) activity. NPD-A patients develop progressive neurodegeneration including cerebral and cerebellar atrophy, relevant Purkinje cell and myelin deficiency with death within 3 years. ASM'knock-out' (ASMKO) mice, an animal model of NPD-A, develop a phenotype largely mimicking that of NPD-A. The mechanisms underlying myelin formation are poorly documented in ASMKO mice. In this study we determined the content of four myelin-specific proteins, myelin basic protein (MBP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP), myelin associated glycoprotein (MAG) and proteolipid protein (PLP), and that of myelin-enriched sphingolipids in the brains of ASMKO and wild-type mice in early stages of post-natal (pn) life. Protein and mRNA analysis revealed that in ASMKO mice beginning from 4 post-natal weeks (wk-pn), the expression levels of MAG, CNP, and MBP were below those observed in wild-type mice and the same applied to PLP at 10 wk-pn. Moreover, at 4 wk-pn the expression of SOX10, one of the transcription factors involved in oligodendrocyte development and maintenance was lower in ASMKO mice. Lipid analysis showed that SM and the gangliosides GM3 and GM2 accumulated in the brains of ASMKO mice, as opposed to galactocerebroside and galactosulfocerebroside that, in parallel with the mRNAs of UDP-galactose ceramide galactosyltransferase and galactose-3-O-sulfotransferase 1, the two transferases involved in their synthesis, decreased. Myelin lipid analysis showed a progressive sphingomyelin accumulation in ASMKO mice; noteworthy, of the two sphingomyelin species known to be resolved by TLC, only that with the lower Rf accumulated. The immunohistochemical analysis showed that the reduced expression of myelin specific proteins in ASMKO mice at 10 wk-pn was not restricted to the Purkinje layer of the

  18. Chronic exposure to light reverses the effect of maternal separation on proteins in the prefrontal cortex. (United States)

    Dimatelis, J J; Stein, D J; Russell, V A


    Animals subjected to maternal separation display behavioural and endocrine disturbances, as well as structural and functional changes in the prefrontal cortex and limbic areas. The aim of the present study was to determine the effect of maternal separation and treatment with either chronic constant light exposure or anti-depressant (escitalopram) on proteins in the prefrontal cortex. Four experimental groups of male Sprague-Dawley rats were subjected to (1) normal rearing, (2) maternal separation (3 h per day from postnatal day 2 (P2) to P14), (3) maternal separation followed by chronic light exposure (P42-P63) or (4) maternal separation followed by treatment with the anti-depressant drug, escitalopram (P68-P100). Groups 1-3 were treated with saline as vehicle control for the escitalopram-treated group. At P101, all rats were decapitated, and the prefrontal cortex was collected and stored at -80 °C. Tissue from three rats per group was pooled and proteins determined by isobaric tagging for relative and absolute quantification using matrix-assisted laser desorption/ionisation tandem mass spectrometry. Maternal separation led to disruptions in the prefrontal cortex that included hypometabolism by decreasing energy-related proteins (creatine kinase B, aconitate hydratase), decreased cell signalling (synapsin I, calmodulin, 14-3-3 protein epsilon) and impaired plasticity (spectrin, microtubule-associated protein). Maternal separation also increased dihydropyrimidinase-related protein/collapsin response mediator protein (CRMP) and myelin proteolipid protein. Exposure of maternally separated animals to constant light during adolescence reversed the hypometabolic state by increasing energy-related proteins in the prefrontal cortex and increasing cell signalling and cytoskeletal proteins and decreasing the expression of CRMP. Escitalopram had similar effects to light by increasing ATP synthase in maternally separated rats and dissimilar effects by increasing 2',3'-cyclic-nucleotide

  19. Use of a column-switching high-performance liquid chromatography method to assess the presence of specific binding of (R)- and (S)-[{sup 11}C]rolipram and their labeled metabolites to the phosphodiesterase-4 enzyme in rat plasma and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Kenk, Miran; Greene, Michael [Cardiovascular PET Molecular Imaging Program, Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, K1Y 4W7 (Canada); Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, K1H 8M5 (Canada); Lortie, Mireille; Kemp, Robert A. de [Cardiovascular PET Molecular Imaging Program, Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, K1Y 4W7 (Canada); Beanlands, Rob S. [Cardiovascular PET Molecular Imaging Program, Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, K1Y 4W7 (Canada); Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, K1H 8M5 (Canada); DaSilva, Jean N. [Cardiovascular PET Molecular Imaging Program, Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, K1Y 4W7 (Canada); Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, K1H 8M5 (Canada)], E-mail:


    Introduction: To complement recent studies using the high-affinity {sup 11}C-labeled phosphodiesterase-4 (PDE4) inhibitor (R)-rolipram and the less active enantiomer (S)-[{sup 11}C]rolipram for in vivo quantification of PDE4 levels, we evaluated the presence of radiolabeled metabolites and their potential binding to PDE4 in the rat plasma, brain, heart, pancreas, skeletal muscle and brown adipose tissue. Methods: A reverse-phase capture and analytical HPLC column-switch method was used to detect (R)-[{sup 11}C]rolipram, (S)-[{sup 11}C]rolipram and their radiolabeled metabolites in rat plasma and tissue extracts. The relative proportion of PDE4-specific binding of the radiotracers and their labeled metabolites was analyzed following co-injections with a saturating dose of unlabeled (R)-rolipram at 45 min post-tracer injection in tissue extracts. Results: Radiolabeled metabolites were found in the plasma (72-75% of total radioactive signal), and in the heart, skeletal muscle, pancreas and brown adipose tissue (44-52%), but not in the brain. In comparison to polar labeled metabolites, the proportion of unchanged (R)-[{sup 11}C]rolipram was reduced in PDE4-rich organs by co-injection of unlabeled (R)-rolipram. Conversely, no changes were obtained in brown adipose tissue, or with (S)-[{sup 11}C]rolipram, suggesting that radiolabeled metabolites of (R)-[{sup 11}C]rolipram display no specific binding to PDE4. Conclusions: Radiolabeled hydrophilic metabolites are unlikely to compete with (R)-[{sup 11}C]rolipram for PDE4-specific retention. However, due to the high proportion of the radioactive metabolites in the total radioactive signal, any kinetic modeling calculations in the peripheral tissues will need to take into account the presence of labeled metabolites.

  20. Four Novel p.N385K, p.V36A, c.1033–1034insT and c.1417–1418delCT Mutations in the Sphingomyelin Phosphodiesterase 1 (SMPD1 Gene in Patients with Types A and B Niemann-Pick Disease (NPD

    Directory of Open Access Journals (Sweden)

    Masoumeh Dehghan Manshadi


    Full Text Available Background: Types A and B Niemann-Pick disease (NPD are autosomal-recessive lysosomal storage disorders caused by the deficient activity of acid sphingomyelinase due to mutations in the sphingomyelin phosphodiesterase 1 (SMPD1 gene. Methods: In order to determine the prevalence and distribution of SMPD1 gene mutations, the genomic DNA of 15 unrelated Iranian patients with types A and B NPD was examined using PCR, DNA sequencing and bioinformatics analysis. Results: Of 8 patients with the p.G508R mutation, 5 patients were homozygous, while the other 3 were heterozygous. One patient was heterozygous for both the p.N385K and p.G508R mutations. Another patient was heterozygous for both the p.A487V and p.G508R mutations. Two patients (one homozygous and one heterozygous showed the p.V36A mutation. One patient was homozygous for the c.1033–1034insT mutation. One patient was homozygous for the c.573delT mutation, and 1 patient was homozygous for the c.1417–1418delCT mutation. Additionally, bioinformatics analysis indicated that two new p.V36A and p.N385K mutations decreased the acid sphingomyelinase (ASM protein stability, which might be evidence to suggest the pathogenicity of these mutations. Conclusion: with detection of these new mutations, the genotypic spectrum of types A and B NPD is extended, facilitating the definition of disease-related mutations. However, more research is essential to confirm the pathogenic effect of these mutations.

  1. The identification of a novel phosphodiesterase 4 inhibitor, 1-ethyl-5-{5-[(4-methyl-1-piperazinyl)methyl]-1,3,4-oxadiazol-2-yl}-N-(tetrahydro-2H-pyran-4-yl)-1H-pyrazolo[3,4-b]pyridin-4-amine (EPPA-1), with improved therapeutic index using pica feeding in rats as a measure of emetogenicity. (United States)

    Davis, T Gregg; Peterson, John J; Kou, Jen-Pyng; Capper-Spudich, Elizabeth A; Ball, Doug; Nials, Anthony T; Wiseman, Joanne; Solanke, Yemisi E; Lucas, Fiona S; Williamson, Richard A; Ferrari, Livia; Wren, Paul; Knowles, Richard G; Barnette, Mary S; Podolin, Patricia L


    Clinical utility of phosphodiesterase 4 (PDE4) inhibitors as anti-inflammatory agents has, to date, been limited by adverse effects including nausea and emesis, making accurate assessment of emetic versus anti-inflammatory potencies critical to the development of inhibitors with improved therapeutic indices. In the present study we determined the in vitro and in vivo anti-inflammatory potencies of the first-generation PDE4 inhibitor, rolipram, the second-generation inhibitors, roflumilast and cilomilast, and a novel third generation inhibitor, 1-ethyl-5-{5-[(4-methyl-1-piperazinyl)methyl]-1,3,4-oxadiazol-2-yl}-N-(tetrahydro-2H-pyran-4-yl)-1H-pyrazolo[3,4-b]pyridin-4-amine (EPPA-1). The rank-order potency against lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha production by human peripheral blood mononuclear cells was roflumilast (IC(50) = 5 nM) > EPPA-1 (38) > rolipram (269) > cilomilast (389), and against LPS-induced pulmonary neutrophilia in the rat was EPPA-1 (D(50) = 0.042 mg/kg) > roflumilast (0.24) > rolipram (3.34) > cilomilast (4.54). Pica, the consumption of non-nutritive substances in response to gastrointestinal stress, was used as a surrogate measure for emesis, giving a rank-order potency of rolipram (D(50) = 0.495 mg/kg) > roflumilast (1.6) > cilomilast (6.4) > EPPA-1 (24.3). The low and high emetogenic activities of EPPA-1 and rolipram, respectively, detected in the pica model were confirmed in a second surrogate model of emesis, reversal of alpha(2)-adrenoceptor-mediated anesthesia in the mouse. The rank order of therapeutic indices derived in the rat [(pica D(50))/(neutrophilia D(50))] was EPPA-1 (578) > roflumilast (6.4) > cilomilast (1.4) > rolipram (0.15), consistent with the rank order derived in the ferret [(emesis D(50))/(neutrophilia D(50))]. These data validate rat pica feeding as a surrogate for PDE4 inhibitor-induced emesis in higher species, and identify EPPA-1 as a novel PDE4 inhibitor with an improved therapeutic index.

  2. Small-molecule inhibitors of protein kinase C, the Janus kinases (JAK) pathway and phosphodiesterases in the treatment of psoriasis%蛋白激酶C、JAK、磷酸二脂酶的小分子抑制剂在银屑病治疗中的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨建强; 满孝勇; 郑敏


    Psoriasis is a chronic recurrent inflammatory skin disorder clinically characterized by scaly erythema with occasional involvement of joints.Although biological therapies targeting specific inflammatory pathways have proved to be highly effective in recent years,there are no economical drugs for psoriasis with long-term effectiveness.Small-molecule inhibitors (SMIs),a group of compounds with relative molecular weights less than 1 000,mainly target intracellular signaling pathways or molecules,such as protein kinase C,the Janus kinases (JAK) pathway and phosphodiesterases.They were previously developed to treat some autoimmune disorders and inflammatory diseases,and have shown favorable efficacy for the treatment of psoriasis vulgaris and psoriatic arthritis in phase Ⅱ and Ⅲ clinical trials.Hence,SMIs are expected to become a novel option for the management of psoriasis in the future.%银屑病是一种慢性复发性炎症性疾病,临床表现为皮肤的鳞屑性红斑,部分患者可累及关节.尽管目前针对特异性炎症性细胞因子和免疫细胞的生物制剂在银屑病治疗中取得了较为满意的疗效,但仍缺乏长期安全有效而经济的治疗药物.小分子抑制剂是一些相对分子质量<1000的化合物,主要针对一些细胞内信号通路或分子靶点,如蛋白激酶C、JAK通路、磷酸二酯酶等.小分子抑制剂最初在一些自身免疫性疾病和炎症性疾病中应用,现已进入寻常性银屑病和关节病性银屑病的Ⅱ期和Ⅲ期临床试验并取得了较为满意的疗效.因此,小分子抑制剂有望成为治疗银屑病的选择之一.

  3. Characterization of the "Escherichia Coli" Acyl Carrier Protein Phosphodiesterase (United States)

    Thomas, Jacob


    Acyl carrier protein (ACP) is a small essential protein that functions as a carrier of the acyl intermediates of fatty acid synthesis. ACP requires the posttranslational attachment of a 4'phosphopantetheine functional group, derived from CoA, in order to perform its metabolic function. A Mn[superscript 2+] dependent enzymatic activity that removes…

  4. Phosphodiesterase 4 and compartmentalization of cyclic AMP signaling

    Institute of Scientific and Technical Information of China (English)

    WANG ZhengChao; SHI FangXiong


    Cyclic AMP (cAMP), as a second messenger, plays a critical role in cellular signaling transduction. However, it is not clear how this apparently identical cAMP signal induces divergent physiological responses. The potential explanation that cAMP signaling is compartmentalized was proposed by Buxton and Brunton twenty years ago. Compartmentalization of cAMP signaling allows spatially distinct pools of protein kinase A (PKA) to be differently activated. Research on cAMP signaling has regained impetus in many fields of life sciences due to the progress in understanding cAMP signaling complexity and functional diversity. The cAMP/PKA signaling compartments are maintained by A-kinase anchoring proteins (AKAPs) which bind PKA and other signaling proteins, and by PDEs which hydrolyse cAMP and thus terminate PKA activity. PDE4 enzymes belong to PDE superfamily and stand at a crossroad that allows them to integrate various signaling pathways with that of cAMP in spatially distinct compartments. In the current review, the nomenclature, taxonomy and gene expression of PDE4, and the system and region of its effect are described. In addition, the idiographic molecules, mechanisms, and regulation models of PDE4 are summarized. Furthermore, the important roles PDE4 plays in the maturation of rat granulosa cells and cAMP signaling compartmentalization are discussed.

  5. Phosphodiesterase 5 inhibitors (PDE5i) and pulmonary embolism

    NARCIS (Netherlands)

    Gerritsen, R.F.; Bijl, A.; Van Puijenbroek, E.P.


    Introduction: PDE5i-related arterial thromboembolism is described in literature. Published venous thrombotic events are limited to one case of pulmonary embolism (tadalafil) and of recurrent deep venous thrombosis (DVT) related to sildenafil. Aim of the study: Presentation of two cases of vardenafil

  6. Atividade das fosfodiesterases em tecido de granulação submetido a irradiação de elétrons - estudo experimental em ratos Activity of phosphodiesterases in granulation tissue submitted to electron irradiation - experimental study in rats

    Directory of Open Access Journals (Sweden)

    Frab Norberto BÓSCOLO


    Full Text Available Os autores estudaram o efeito de baixas doses de radiação de elétrons na atividade de fosfodiesterases presentes no tecido de granulação, induzido por esponja de PVC, subcutaneamente, na região dorsal de 84 ratos Wistar, divididos em dois grupos, controle e irradiado. A atividade enzimática foi avaliada segundo a evolução do tecido de granulação aos 5, 7, 10, 14, 17, 20 e 24 dias. Os animais foram irradiados com um feixe de elétrons de 6 MeV, dose de 1 Gy, 3 dias após a implantação da esponja, sendo que no momento da irradiação, foram protegidos por uma lâmina de 4 mm de chumbo, tendo sido irradiada somente a área correspondente ao local onde encontrava-se a esponja. Considerando-se a dose e o tipo de radiação empregada, pode-se concluir que houve influência direta da radiação na atividade da enzima 5’-nucleotidase e da ATPase no início do processo de reparação tecidual, aos 5 e 7 dias. Já a enzima fosfatase alcalina não sofreu a ação direta da radiação. É possível que o principal fator tenha sido danos nos constituintes celulares que são responsáveis pela formação do tecido de granulação, determinando a produção enzimática conforme a necessidade.The present study evaluated the effect of low doses of electron radiation on the activity of phosphodiesterases in granulation tissue. In order to induce growth of granulation tissue, a PVC sponge disk was introduced under the dorsal skin of 84 Wistar rats. The rats were divided in two groups, control and irradiated. The enzymatic activity was evaluated according to the evolution of the granulation tissue after 5, 7, 10, 14, 17, 20 and 24 days. Irradiation was carried out 3 days after the implantation of the sponge, by means of a linear accelerator, with energy of 6 MeV, and dose of 1.0 Gy. The results of this study showed that 5’-nucleotidase and ATPase had their activity directly affected by irradiation only in the beginning of the tissue repairing

  7. Establishment of A Pulmonary Arterial Hypertension Model in Rats and Expression of Phosphodiesterase 1C%大鼠肺动脉高压动物模型的建立及磷酸二酯酶1C的表达

    Institute of Scientific and Technical Information of China (English)

    郑晓宇; 覃家锦; 李波; 何巍; 冯旭


    Objective To establish a neointima model of pulmonary arterial hypertension (PAH) in rats by pneumonectomy(PE) and monoerotatine(MCT),and to investigate the expression and function of phosphodiesterase 1C (PDE1C) protein in this PAH model.Methods Three approaches were used to establish PAH model in rats:left lung PE group(PE group),MCT injection group,and MCT injection after PE group (P+M group).Mean pulmonary arterial pressure(mPAP),percentage of media thickness(MT%) and the ratio of right ventricular hypertrophy index (RV/LV+S) of model rats were recorded.Morphological parameters relevant to neointima formation and the muscularization of nonmuscle pulmonary arterioles were observed,and the difference of pulmonary vascular remodeling pattern of the three PAH models was analyzed.The expression of PDE1C was detected in each group by immunohistochemitry.Results The P+M group showed serious lesions in the neointim and right ventricular,and serious right ventricular hypertrophy,and the increasing MT of pulmonary arterials could be seen in the animals.Compared with other groups,P+M group had a significantly higher mPAP and muscularization of nonmuscle arterioles developed significantly.Expression of PDE1C protein increased significantly in the neointima PAH model(P<0.05).Conclusion P+M model is a good model for simulation of severe PAH in human , which is the best animal model for a study on the obstructive PAH.Up-regulation of PDE1C in pulmonary artery smooth muscle cells of PAH animal model might offer a new target for therapy of PAH in human .%  目的以左肺切除(PE)+野百合碱(MCT)建立大鼠肺动脉高压(PAH)新生内膜模型,探讨磷酸二酯酶1C(PDE1C)在该模型肺组织中的表达水平及作用。方法采用单纯PE、MCT、PE+MCT(P+M)3种方法建立大鼠PAH模型;检测模型大鼠平均肺动脉压力(mPAP)、中膜厚度百分比、右心肥厚指数(RV/LV+S)比值,观察新生内膜形成和

  8. 雄激素联合5型磷酸二酯酶抑制剂治疗大鼠糖尿病性勃起功能障碍的研究%Androgen combined with phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction in diabetic rats

    Institute of Scientific and Technical Information of China (English)

    夏磊磊; 沈周俊; 王先进; 许天源; 秦亮; 张祥; 朱照伟; 张小华; 钟山; 张敏光


    ABSTRACT:Objective To establish the rat model of diabetes mellitus erectile dysfunction (DMED) and evaluate the ther‐apeutic effect of androgen combined with phosphodiesterase type 5 (PDE5) inhibitor .Methods DMED models were estab‐lished by peritoneal injection of streptozotocin (STZ) .Four weeks later the DMED rats were randomly divided into 4 groups:DM group ,testosterone group ,sildenafil group ,and testosterone plus sildenafil group .Healthy rats served as controls .Six weeks after the initiation of treatments ,the erectile function of each group was evaluated using electrostimulation of the cav‐ernous nerve .The serum testosterone levels were determined with enzyme‐linked immunosorbent assay (ELISA) .The morpho‐logical changes of corpus cavernosum of penis were evaluated with hematoxylin‐eosin staining and masson staining .The endo‐thelial nitric oxide synthase (eNOS) level were determined with Western blot and immunohistochemistry .Results Compared with healthy rats ,the erectile function ,testosterone level and eNOS level of diabetic rats were significantly decreased .The smooth muscle cells of diabetic rats'corpus cavernosum were reduced while extracellular matrix fibrosis was increased .Testos‐terone replacement and chronic sildenafil treatment could ameliorate erectile function and extracellular matrix fibrosis ,and combined treatment with testosterone and sildenafil had the most significant effect .Conclusions The erectile function of DM rats is significantly impaired .The pathogenesis of DMED may be partly attributed to the low androgen level .Combined treatment of testosterone and sildenafil can significantly improve erectile function and extracellular matrix fibrosis of DMED rats .%目的:建立糖尿病性勃起功能障碍(DMED)大鼠模型,评价雄激素联合5型磷酸二酯酶抑制剂对DMED的治疗作用。方法通过链脲佐菌素(STZ)腹腔注射的方法建立DMED大鼠模型,造模成功4周后随机分

  9. 5型磷酸二酯酶抑制剂对勃起功能障碍大鼠阴茎白膜病变的治疗作用%Therapeutic effect of phosphodiesterase-5 inhibitor on pathological changes of tunica albuginea in erectile dysfunction: experiment with rats

    Institute of Scientific and Technical Information of China (English)

    马逸; 陈斌; 胡剑麟; 王鸿祥; 韩银发; 王益鑫; 黄翼然


    Objective To investigate the pathological changes of tunica albuginea in erectile dysfunction (ED), the role of tunics albuginea in penis erection, and the therapeutic effect of phosphodiesterase-5 inhibitor (PDESI) on ED. Methods Thirty 8-week-old male Sprague-Dawley rats were randomly divided into 3 equal groups:(1) control group fed with normal diet for 16 weeks, (2) high-fat group fed with the diet containing 2% cholesterol and 10% pork fat, and(3) Tadalafil group fed with high-fat diet for 16 weeks and undergoing gastric perfusion of Tadalafil 2 mg/kg daily since the 13th week for 4 weeks. Sixteen weeks later, intracavernous pressure and mean arterial pressure were measured, and the ratio of maximal intracavernous pressure to mean arterial pressure (ICP/MAP) was calculated blood samples were collected. Blood samples were collected from the abdominal aorta to undergo lipid profile test. Then penis was cut. Victoria blue/ponceau red staining and color image analysis were used to observe the content of elastic fibers in the tunics albuginea. Results The ICP/MAP of the high-fat group was 0. 49 ± 0. 05, significantly lower than that of the control group (0. 82±0. 06, P <0. 01 ). The ICP/MAP of the Tadalafil group was 0. 60 ± 0. 02, significantly higher than that of the high-fat group ( P < 0. 05 ). The content of elastic fibers in tunica albuginea of the high-fat group was 468 ± 152, significantly lower than that of the the control group (3292 ± 1123, P < 0. 01 ). The content of elastic fibers in tunica albuginea of the Tedalafil group was 2062 ± 560, significantly higher than that of the high-fat group (P < 0.05 ). Conclusion High fat diet may lead to ED and reduction of elastic fibers in tunica albuginea, and PDE-5Ⅰ reverses such pathological changes.%目的 观察高脂、高胆固醇饮食诱导勃起功能障碍(ED)大鼠阴茎白膜的变化,明确长期小剂量给予5型磷酸二酯酶抑制剂(PDE-5Ⅰ)他达拉非后的治疗作用,研究白膜

  10. 一种新型磷酸二酯酶5抑制剂DA-8159对食源性肥胖大鼠的勃起促进作用%Erectile potentials of a new phosphodiesterase type 5 inhibitor,DA-8159, in diet-induced obese rats

    Institute of Scientific and Technical Information of China (English)

    Jae-Young Yu; Kyung-Koo Kang; Moohi Yoo


    Aim: To examine the changes in the erectile function in diet-induced obese rats and investigate the oral efficacy of DA-8159, a new phosphodiesterase type 5 (PDE5) inhibitor, on penile erection in obese rats. Methods: The rats were fed a high-energy diet for 12 weeks and divided into three groups: an obesity-resistant (OR) control group, an obesityprone (OP) control group, and an OP-DA-8159 treatment (DA-8159) group. The electrostimulation-induced erectile responses were measured in all groups. The body weight, plasma cholesterol, triglyceride and glucose levels were also measured. Results: In the OP control group, the maximum intracavernous pressure (ICP) and ICP/blood pressure (ICP/BP) ratio after electric stimulation were significantly lower than those in OR control group. The corresponding area under the curve (AUC) of the ICP/BP ratio, the detumescence time and the baseline cavernous pressure were also lower than those in the OR control group, but this difference was not significant. The body weight gain, plasma cholesterol and triglyceride level in the OP group were significantly higher than those in the OR group.After administering the DA-8159, a significant increase in the maximum ICP and the ICP/BP ratio were observed. The corresponding AUCs in the DA-8159 group were also higher than those in the two control groups. Furthermore, the detumescence time was significantly prolonged after treatment with DA-8159. Conclusion: These results demonstrate that diet-induced obesity affects the erectile function in rats and these erectile dysfunction (ED) can be improved by the treatment with DA-8159, indicating DA-8159 might be a treatment option for ED associated with obesity.%目的:调查食源性肥胖大鼠的勃起功能的变化,评价口服新型磷酸二酯酶5(PDE5)抑制剂DA-8159对其阴茎勃起的作用.方法:实验大鼠用高热量食物喂养12周后分为三组:不易肥胖对照组(OR),易肥胖对照组(OP)和接受DA-8159处理的OP组(DA-8159

  11. Phosphodiesterase 4 inhibitor rolipram prevents depression- and anxiety-like behaviors in rats exposed to chronic restraint stress%磷酸二酯酶4抑制剂咯利普兰逆转慢性束缚应激诱导的大鼠抑郁和焦虑样行为

    Institute of Scientific and Technical Information of China (English)

    张俊芳; 张忠敏; 赵鑫; 刘爱明; 郭洁洁; 沈璐艳; 王钦文; 王闯


    诱导了大鼠海马内PDE4D表达的上调,PKA、p-CREB及p-Ser9-GSK3β的下调.Rolipram显著逆转了上述效应,且H89显著阻断了Rolipram的药物效应.结论:Rolipram抗抑郁及抗焦虑作用不仅通过CREB/BDNF信号通路,而且还有GSK3 抑制性丝氨酸残基磷酸化信号通路的参与,且CREB介导的信号转导通路对GSK3 抑制性丝氨酸残基磷酸化信号通路发挥重要调节作用.%AIM: To discuss the impact of phosphodiesterase 4 (PDE4) inhibitor rolipram on chronic restraint stress - induced depression - and anxiety - like behaviors in rats. METHODS: (1) Forty SD rats were randomly divided into 4 weight -matched groups: unstressed animals injected with vehicle of lithium chloride (LiCl) and rolipram, restraint - stressed animals injected daily with vehicle prior to stress, restraint stress plus 100 mg/kg LiCl group and restraint stress plus 1 mg/kg rolipram group. The open field test was conducted 24 h before the first stress and drug administration, and then the rats received drugs daily 1 h prior to restraint stress (6 h/d) for 25 d. Daily body weight recording, forced swim-ming test, elevated plus - maze and open field test were conducted to determine the changes of depression - and anxiety -like behaviors. The expression of phosphorylated cAMP response element - binding protein (p - CREB) , brain - derived Reurotrophic factor ( BDNF) , p - Ser21 - glycogen synthase kinase ( GSK) 3α, p - Ser9 - GSK3β, p - Tyr279 - GSK3α, p -Tyr216 - GSK3β, total GSK3α and total GSK3β was measured by Western blotting. (2) Thirty SD rats were randomly divided into 6 groups and the cannula was surgically placed above the CA1 region in the hippocampus. Seven days after the surgery, the restraint stress was conducted for 21 d after microinjection of protein kinase A (PKA) antagonist H89 and in-traperitoneal injection of LiCl and rolipram everyday. The expression of PDE4D, PKA, p - CREB and p - Ser9 - GSK3β was measured by Western blotting. RESULTS: ( 1) No

  12. Histopathologic characterization of the BTBR mouse model of autistic-like behavior reveals selective changes in neurodevelopmental proteins and adult hippocampal neurogenesis

    Directory of Open Access Journals (Sweden)

    Stephenson Diane T


    Full Text Available Abstract Background The inbred mouse strain BTBR T+ tf/J (BTBR exhibits behavioral deficits that mimic the core deficits of autism. Neuroanatomically, the BTBR strain is also characterized by a complete absence of the corpus callosum. The goal of this study was to identify novel molecular and cellular changes in the BTBR mouse, focusing on neuronal, synaptic, glial and plasticity markers in the limbic system as a model for identifying putative molecular and cellular substrates associated with autistic behaviors. Methods Forebrains of 8 to 10-week-old male BTBR and age-matched C57Bl/6J control mice were evaluated by immunohistochemistry using free-floating and paraffin embedded sections. Twenty antibodies directed against antigens specific to neurons, synapses and glia were used. Nissl, Timm and acetylcholinesterase (AchE stains were performed to assess cytoarchitecture, mossy fibers and cholinergic fiber density, respectively. In the hippocampus, quantitative stereological estimates for the mitotic marker bromodeoxyuridine (BrdU were performed to determine hippocampal progenitor proliferation, survival and differentiation, and brain-derived neurotrophic factor (BDNF mRNA was quantified by in situ hybridization. Quantitative image analysis was performed for NG2, doublecortin (DCX, NeuroD, GAD67 and Poly-Sialic Acid Neural Cell Adhesion Molecule (PSA-NCAM. Results In midline structures including the region of the absent corpus callosum of BTBR mice, the myelin markers 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase and myelin basic protein (MBP were reduced, and the oligodendrocyte precursor NG2 was increased. MBP and CNPase were expressed in small ectopic white matter bundles within the cingulate cortex. Microglia and astrocytes showed no evidence of gliosis, yet orientations of glial fibers were altered in specific white-matter areas. In the hippocampus, evidence of reduced neurogenesis included significant reductions in the number of

  13. AcEST: BP916640 [AcEST

    Lifescience Database Archive (English)

    Full Text Available RWRLDQRIIASREAPVE 624 >sp|P10550|NCAP_SYNV Nucleoprotein OS=Sonchus yellow net virus GN=N PE=2 SV=1 Length =...subun... 30 6.5 sp|Q589B9|RPOC1_SILLA DNA-directed RNA polymerase subunit beta' ... 30 8.6 sp|P10550|NCAP_SYNV Nucleoprotein yellow net virus GN... 30 8.6 sp|A4VTE9|CNPD_STRSY 2',3'-cyclic-nucleotide 2'-ph

  14. Role of phosphodiesterase inhibitor Ibudilast in morphine-induced hippocampal injury

    Directory of Open Access Journals (Sweden)

    Mohsen Zhaleh


    Full Text Available Abstract: Background: Opioid drugs are used in the treatment of acute post-surgical pain and chronic pain, such as those associated with cancer. Opioid used is associated with complications such as analgesic tolerance, dependence and opioid abuse. The molecular mechanisms of unwanted opioid responses are varied but recent advances have highlighted elevations in pro-inflammatory cytokines and pro-inflammatory glial following chronic administration of morphine. In this study we investigated the neurodegenerative effects of morphine through its effects on Toll-Like Receptor 4 (TLR4 in the male rat hippocampus and evaluated the level of Interleukin-1 beta (IL-1β. Then we compared the difference between inhibitory effects on mu opioid receptors (by β-Funaltrexamine, β-FNA and TLR4 (by Ibudilast. Subsequently, we assessed the amount of IL-1β and the number of granular cells in male rat hippocampus. Methods: Adult male rats (n=24 were treated with sucrose, morphine, Ibudilast (7.5 mg/kg and β-FNA (20 mg/kg for 30 days. Their brains were isolated and hemisected with one hippocampus for granular cell and the other used for IL-1 β immunoblotting. Results: Data showed that Ibudilast suppresses IL-1 β expression significantly more than β-FNA. The granular cell count displayed significant differences. Conclusions: Our results suggested that Ibudilast can be used for controlling and treatment of morphine-induced CNS inflammations or traumatic conditions.

  15. Phosphodiesterase 3 inhibitor cilostazol induces migraine-like attacks via cyclic AMP increase

    DEFF Research Database (Denmark)

    Guo, Song; Olesen, Jes; Ashina, Messoud


    and that cilostazol-induced attacks responded to their usual migraine treatment. Median time of medication intake was 6 h (range 4-11 h). The present study suggests that intracellular cyclic AMP accumulation plays a crucial role in migraine induction. This knowledge is a further step in our understanding...

  16. Phosphodiesterase 3 and 5 and cyclic nucleotide-gated ion channel expression in rat trigeminovascular system

    DEFF Research Database (Denmark)

    Kruse, Lars S; Sandholdt, Nicolai T H; Gammeltoft, Steen;


    Activation of the trigeminovascular pain signalling system appears involved in migraine pathophysiology. However, the molecular mechanisms are only partially known. Stimulation of cAMP and cGMP production as well as inhibition of their breakdown induce migraine-like headache. Additionally, migraine...... of cAMP and cGMP levels by PDE and activation of CNG may play a role in trigeminovascular pain signalling leading to migraine headache....

  17. Dinuclear metallo-phosphodiesterase models: application of calix[4]arenes as molecular scaffolds

    NARCIS (Netherlands)

    Molenveld, Peter; Engbersen, Johan F.J.; Reinhoudt, David N.


    An important goal in supramolecular chemistry is the synthesis of molecules that exhibit catalytic activity analogous to the activity of enzymes. In this respect, studies toward the biomimetic catalysis of phosphate diester cleavage have received particular attention. In nature this process is catal

  18. Human 2'-phosphodiesterase localizes to the mitochondrial matrix with a putative function in mitochondrial RNA turnover

    DEFF Research Database (Denmark)

    Poulsen, Jesper Buchhave; Andersen, Kasper Røjkjær; Kjær, Karina Hansen


    . Interestingly, 2′-PDE shares both functionally and structurally characteristics with the CCR4-type exonuclease–endonuclease–phosphatase family of deadenylases. Here we show that 2′-PDE locates to the mitochondrial matrix of human cells, and comprise an active 3′–5′ exoribonuclease exhibiting a preference...... a role in the cellular immune system, may also function in mitochondrial RNA turnover....

  19. Phosphodiesterase 5 and effects of sildenafil on cerebral arteries of man and guinea pig

    DEFF Research Database (Denmark)

    Kruuse, Christina; Khurana, Tejvir S; Rybalkin, Sergei D


    and UK-114,542, and a PDE1 inhibitor UK-90,234 on cGMP hydrolysis were investigated in human and guinea pig cerebral arteries. The vasoactive responses of the compounds were evaluated in guinea pig basilar arteries in vitro, with concomitant measurements of cAMP and cGMP. PDE5 was found in human middle...... cerebral arteries. Sildenafil and UK-114,542 inhibited cGMP hydrolysis concentration-dependently in both species. In guinea pig arteries, sildenafil induced an endothelium-dependent vasodilatation only at concentrations above 10 nM, which was augmented by sodium nitroprusside and attenuated by reduction...... of cGMP, but was cGMP independent at high concentrations. UK-114,542 was more and UK-90,234 was less potent than sildenafil. In conclusion, PDE5 is present in human and guinea pig cerebral arteries, and is inhibited by sildenafil at micromolar levels. Sildenafil in vitro is a poor dilator of guinea pig...

  20. Adjunctive Phosphodiesterase-4 Inhibitor Therapy Improves Antibiotic Response to Pulmonary Tuberculosis in a Rabbit Model

    Directory of Open Access Journals (Sweden)

    Selvakumar Subbian


    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.

  1. Resveratrol Ameliorates Aging-Related Metabolic Phenotypes by Inhibiting cAMP Phosphodiesterases

    NARCIS (Netherlands)

    Park, Sung-Jun; Ahmad, Faiyaz; Philp, Andrew; Baar, Keith; Williams, Tishan; Luo, Haibin; Ke, Hengming; Rehmann, Holger; Taussig, Ronald; Brown, Alexandra L.; Kim, Myung K.; Beaven, Michael A.; Burgin, Alex B.; Manganiello, Vincent; Chung, Jay H.


    Resveratrol, a polyphenol in red wine, has been reported as a calorie restriction mimetic with potential antiaging and antidiabetogenic properties. It is widely consumed as a nutritional supplement, but its mechanism of action remains a mystery. Here, we report that the metabolic effects of resverat

  2. Mind the gap: delayed manifestation of long-term object memory improvement by phosphodiesterase inhibitors. (United States)

    Akkerman, S; Blokland, A; Prickaerts, J


    We examined the temporal profile of pharmacologically enhanced episodic memory, using the object recognition task. Male Wistar rats were tested at different retention intervals ranging from 1 h to 24 h. The object discrimination performance of all groups (untreated, placebo, drug treatment) gradually decreased up to an interval (8 h). Interestingly, only after this 8 h interval the memory improving effects of vardenafil and rolipram started to emerge. This time-dependent memory performance shows similarities with the Kamin effect. The delayed manifestation of drug-enhanced memory suggests that two separate memory mechanisms are at play, a quick transient form of memory and a more stable memory form that requires several hours to develop. It is important to take this into account when testing treatments intended for long-term memory enhancement.

  3. Phosphodiesterases in non-neoplastic appearing colonic mucosa from patients with colorectal neoplasia

    DEFF Research Database (Denmark)

    Mahmood, Badar; Damm, Morten Matthiesen Bach; Jensen, Thorbjørn Søren Rønn


    showed overexpression of subtype PDE4B (p = 0.002) and subtype PDE5A (p = 0.02) in colorectal neoplasia patients. Finally, immunohistochemistry for 7 PDE isozymes demonstrated the presence of all 7 isozymes, albeit with weak reactions, and with no differences in localization between colorectal neoplasia...

  4. Comparative analysis of diguanylate cyclase and phosphodiesterase genes in Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    Cruz Diana P


    Full Text Available Abstract Background Klebsiella pneumoniae can be found in environmental habitats as well as in hospital settings where it is commonly associated with nosocomial infections. One of the factors that contribute to virulence is its capacity to form biofilms on diverse biotic and abiotic surfaces. The second messenger Bis-(3’-5’-cyclic dimeric GMP (c-di-GMP is a ubiquitous signal in bacteria that controls biofilm formation as well as several other cellular processes. The cellular levels of this messenger are controlled by c-di-GMP synthesis and degradation catalyzed by diguanylate cyclase (DGC and phophodiesterase (PDE enzymes, respectively. Many bacteria contain multiple copies of these proteins with diverse organizational structure that highlight the complex regulatory mechanisms of this signaling network. This work was undertaken to identify DGCs and PDEs and analyze the domain structure of these proteins in K. pneumoniae. Results A search for conserved GGDEF and EAL domains in three sequenced K. pneumoniae genomes showed that there were multiple copies of GGDEF and EAL containing proteins. Both single domain and hybrid GGDEF proteins were identified: 21 in K. pneumoniae Kp342, 18 in K. pneumoniae MGH 78578 and 17 in K. pneumoniae NTUH-K2044. The majority had only the GGDEF domain, most with the GGEEF motif, and hybrid proteins containing both GGDEF and EAL domains were also found. The I site for allosteric control was identified only in single GGDEF domain proteins and not in hybrid proteins. EAL-only proteins, containing either intact or degenerate domains, were also identified: 15 in Kp342, 15 in MGH 78578 and 10 in NTUH-K2044. Several input sensory domains and transmembrane segments were identified, which together indicate complex regulatory circuits that in many cases can be membrane associated. Conclusions The comparative analysis of proteins containing GGDEF/EAL domains in K. pneumoniae showed that most copies were shared among the three strains and that some were unique to a particular strain. The multiplicity of these proteins and the diversity of structural characteristics suggest that the c-di-GMP network in this enteric bacterium is highly complex and reflects the importance of having diverse mechanisms to control cellular processes in environments as diverse as soils or plants and clinical settings.

  5. Structure of PhnP: a phosphodiesterase of the carbon-phosphorous lyase pathway for phosphonate degradation

    DEFF Research Database (Denmark)

    Podzelinska, Kateryna; He, Shu-Mei; Wathier, Matthew;


    similar to that of the tRNase Z endonucleases but lacks the long exosite module used by these enzymes to bind their tRNA substrates. The active site of PhnP contains what are probably two Mn2+ ions surrounded by an array of active site residues that are identical to those observed in the tRNase Z enzymes......Carbon-phosphorus lyase is a multienzyme system encoded by the phn operon that enables bacteria to metabolize organophosphonates when the preferred nutrient, inorganic phosphate, is scarce. One of the enzymes encoded by this operon, PhnP, is predicted by sequence homology to be a metal...

  6. Long-term cognitive dysfunction in the rat following docetaxel treatment is ameliorated by the phosphodiesterase-4 inhibitor, rolipram. (United States)

    Callaghan, Charlotte K; O'Mara, Shane M


    Clinical studies report evidence of long-term cognitive and other deficits following adjunctive chemotherapy treatment, which is often termed "chemobrain" or "chemo-fog". The neurological bases of these impairments are poorly understood. Here, we hypothesize that systemic chemotherapy treatment causes long-term neurobehavioral deficits, and that these deficits are reversed by manipulation of cAMP by the PDE4 inhibitor, rolipram. Male han Wistar rats were treated with docetaxel (an adjunctive chemotherapeutic agent (1mg/kg i.v.)) or control solution (ethanol/Tween 20/0.9% Saline - 5/5/90) once per week for 4 weeks. They were allowed to recover for 4 weeks, administration of rolipram (0.5mg/kg po) or vehicle (maple syrup) then began and continued daily for 4 weeks. At the end of the treatment regime animals were tested for spatial and recognition memory deficits with the object exploration task and for depressive- and anxiety-like behavior in the forced swim test (FST) and open field exploration. We report docetaxel treatment impaired spatial memory but not object recognition memory, compared to control rats. Docetaxel-treated rats also spent significantly more time immobile than controls in the FST. Chronic rolipram treatment attenuated all of these docetaxel-associated changes, recovering spatial memory and reducing immobility. In conclusion, docetaxel-treated rats exhibit alterations in spatial memory and depressive-like behavior, which are reversed following chronic rolipram administration. These results detect long-term cognitive and mood changes following docetaxel treatment and identify PDE4 inhibition as a target treatment of neuropsychological changes associated with "chemobrain".

  7. Structural, kinetic, and theoretical studies on models of the zinc-containing phosphodiesterase active center: medium-dependent reaction mechanisms. (United States)

    Selmeczi, Katalin; Michel, Carine; Milet, Anne; Gautier-Luneau, Isabelle; Philouze, Christian; Pierre, Jean-Louis; Schnieders, David; Rompel, Annette; Belle, Catherine


    Dinuclear zinc(II) complexes [Zn(2)(bpmp)(mu-OH)](ClO(4))(2) (1) and [Zn(2)(bpmp)(H(2)O)(2)](ClO(4))(3) (2) (H-BPMP=2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol) have been synthesized, structurally characterized, and pH-driven changes in metal coordination observed. The transesterification reaction of 2-hydroxypropyl p-nitrophenyl phosphate (HPNP) in the presence of the two complexes was studied both in a water/DMSO (70:30) mixture and in DMSO. Complex 2 was not reactive whereas for 1 considerable rate enhancement of the spontaneous hydrolysis reaction was observed. A detailed mechanistic investigation by kinetic studies, spectroscopic measurements ((1)H, (31)P NMR spectroscopy), and ESI-MS analysis in conjunction with ab initio calculations was performed on 1. Based on these results, two medium-dependent mechanisms are presented and an unusual bridging phosphate intermediate is proposed for the process in DMSO.

  8. Adenoviral short hairpin RNA targeting phosphodiesterase 5 attenuates cardiac remodeling and cardiac dysfunction following myocardial infarction in mice

    Institute of Scientific and Technical Information of China (English)



    Objective To observe the impact of PDE5shRNA on cardiac remodeling and heart function following myocardial infarction in mice.Methods Myocardial infarction(MI)was induced in mice by left coronary artery ligation.Mice were randomly assigned to sham operation group(n=6),PDE5shRNA group(n=12),common adenovirus group(n=15)and DMEM group(n=8).Four weeks post-MI,the survival rate was evaluated.

  9. The phosphodiesterase 3 inhibitor cilostazol dilates large cerebral arteries in humans without affecting regional cerebral blood flow

    DEFF Research Database (Denmark)

    Birk, Steffen; Kruuse, Christina Rostrup; Petersen, Kenneth A;


    in the middle cerebral arteries (VMCA) was measured with transcranial Doppler, and the superficial temporal and radial arteries diameters were measured with ultrasonography. During the 4-hour observation period, there was no effect on systolic blood pressure (P = 0.28), but diastolic blood pressure decreased...

  10. Characterization of a phosphodiesterase capable of hydrolyzing EA 2192, the most toxic degradation product of the nerve agent VX. (United States)

    Ghanem, Eman; Li, Yingchun; Xu, Chengfu; Raushel, Frank M


    Glycerophosphodiesterase (GpdQ) from Enterobacter aerogenes is a nonspecific diesterase that enables Escherichia coli to utilize alkyl phosphodiesters, such as diethyl phosphate, as the sole phosphorus source. The catalytic properties of GpdQ were determined, and the best substrate found was bis(p-nitrophenyl) phosphate with a kcat/Km value of 6.7 x 10(3) M-1 s-1. In addition, the E. aerogenes diesterase was tested as a catalyst for the hydrolysis of a series of phosphonate monoesters which are the hydrolysis products of the highly toxic organophosphonate nerve agents sarin, soman, GF, VX, and rVX. Among the phosphonate monoesters tested, the hydrolysis product of rVX, isobutyl methyl phosphonate, was the best substrate with a kcat/Km value of 33 M-1 s-1. The ability of GpdQ to hydrolyze the phosphonate monoesters provides an alternative selection strategy in the search of enhanced variants of the bacterial phosphotriesterase (PTE) for the hydrolysis of organophosphonate nerve agents. This investigation demonstrated that the previously reported activity of GpdQ toward the hydrolysis of methyl demeton-S is due to the presence of a diester contaminant in the commercial material. Furthermore, it was shown that GpdQ is capable of hydrolyzing a close analogue of EA 2192, the most toxic and persistent degradation product of the nerve agent VX.

  11. The search for mutations in the gene for the beta subunit of the cGMP phosphodiesterase (PDEB) in patients with autosomal recessive retinitis pigmentosa

    DEFF Research Database (Denmark)

    Riess, O; Noerremoelle, A; Weber, B


    including 196 bp of the 5' region of the PDEB gene have been assessed for mutations by using single-strand conformational polymorphism analysis in 14 patients from 13 unrelated families with autosomal recessive retinitis pigmentosa (ARRP). No disease-causing mutations were found in this group of affected...... individuals of seven different ancestries. However, a frequent intronic and two exonic polymorphisms (Leu489----Gln and Gly842----Gly) were identified. Segregation analysis using these polymorphic sites excludes linkage of ARRP to the PDEB gene in a family with two affected children....

  12. Phosphodiesterase-5 inhibition preserves renal hemodynamics and function in mice with diabetic kidney disease by modulating miR-22 and BMP7 (United States)

    Pofi, Riccardo; Fiore, Daniela; De Gaetano, Rita; Panio, Giuseppe; Gianfrilli, Daniele; Pozza, Carlotta; Barbagallo, Federica; Xiang, Yang Kevin; Giannakakis, Konstantinos; Morano, Susanna; Lenzi, Andrea; Naro, Fabio; Isidori, Andrea M.; Venneri, Mary Anna


    Diabetic Nephropathy (DN) is the leading cause of end-stage renal disease. Preclinical and experimental studies show that PDE5 inhibitors (PDE5is) exert protective effects in DN improving perivascular inflammation. Using a mouse model of diabetic kidney injury we investigated the protective proprieties of PDE5is on renal hemodynamics and the molecular mechanisms involved. PDE5i treatment prevented the development of DN-related hypertension (P < 0.001), the increase of urine albumin creatinine ratio (P < 0.01), the fall in glomerular filtration rate (P < 0.001), and improved renal resistive index (P < 0.001) and kidney microcirculation. Moreover PDE5i attenuated the rise of nephropathy biomarkers, soluble urokinase-type plasminogen activator receptor, suPAR and neutrophil gelatinase-associated lipocalin, NGAL. In treated animals, blood vessel perfusion was improved and vascular leakage reduced, suggesting preserved renal endothelium integrity, as confirmed by higher capillary density, number of CD31+ cells and pericyte coverage. Analysis of the mechanisms involved revealed the induction of bone morphogenetic protein-7 (BMP7) expression, a critical regulator of angiogenesis and kidney homeostasis, through a PDE5i-dependent downregulation of miR-22. In conclusion PDE5i slows the progression of DN in mice, improving hemodynamic parameters and vessel integrity. Regulation of miR-22/BMP7, an unknown mechanism of PDE5is in nephrovascular protection, might represent a novel therapeutic option for treatment of diabetic complications. PMID:28294194

  13. Successful Shortening of Tuberculosis Treatment Using Adjuvant Host-Directed Therapy with FDA-Approved Phosphodiesterase Inhibitors in the Mouse Model


    Mamoudou Maiga; Nisheeth Agarwal; Ammerman, Nicole C.; Radhika Gupta; Haidan Guo; Maiga, Marama C.; Shichun Lun; Bishai, William R.


    Global control of tuberculosis (TB), an infectious disease that claims nearly 2 million lives annually, is hindered by the long duration of chemotherapy required for curative treatment. Lack of adherence to this intense treatment regimen leads to poor patient outcomes, development of new or additional drug resistance, and continued spread of M.tb. within communities. Hence, shortening the duration of TB therapy could increase drug adherence and cure in TB patients. Here, we report that additi...

  14. cGMP inhibition of type 3 phosphodiesterase is the major mechanism by which C-type natriuretic peptide activates CFTR in the shark rectal gland

    NARCIS (Netherlands)

    H.R. de Jonge (Hugo); B.C. Tilly (Bernard); B.M. Hogema (Boris); D.J. Pfau (Daniel); C.A. Kelley (Catherine); M.H. Kelley (Megan); A.M. Melita (August); M.T. Morris (Montana); M.S. Viola (Maria); J.N. Forrest Jr. (John)


    textabstractThe in vitro perfused rectal gland of the dogfish shark (Squalus acanthias) and filter-grown monolayers of primary cultures of shark rectal gland (SRG) epithelial cells were used to analyze the signal transduction pathway by which C-type natriuretic peptide (CNP) stimulates chloride secr

  15. Design, optimization, and biological evaluation of novel keto-benzimidazoles as potent and selective inhibitors of phosphodiesterase 10A (PDE10A). (United States)

    Hu, Essa; Kunz, Roxanne K; Chen, Ning; Rumfelt, Shannon; Siegmund, Aaron; Andrews, Kristin; Chmait, Samer; Zhao, Sharon; Davis, Carl; Chen, Hang; Lester-Zeiner, Dianna; Ma, Ji; Biorn, Christopher; Shi, Jianxia; Porter, Amy; Treanor, James; Allen, Jennifer R


    Our development of PDE10A inhibitors began with an HTS screening hit (1) that exhibited both high p-glycoprotein (P-gp) efflux ratios in rat and human and poor metabolic stability. On the basis of cocrystal structure of 1 in human PDE10A enzyme, we designed a novel keto-benzimidazole 26 with comparable PDE10A potency devoid of efflux liabilities. On target in vivo coverage of PDE10A in rat brain was assessed using our previously reported LC-MS/MS receptor occupancy (RO) technology. Compound 26 achieved 55% RO of PDE10A at 30 mg/kg po and covered PDE10A receptors in rat brain in a dose-dependent manner. Cocrystal structure of 26 in PDE10A confirmed the binding mode of the novel scaffold. Further optimization resulted in the identification of keto-benzimidazole 34, which showed an increased in vivo efficacy of 57% RO in rats at 10 mg/kg po and an improved in vivo rat clearance and oral bioavailability.

  16. Phosphodiesterase-4 inhibition with rolipram attenuates hepatocellular injury in hyperinflammation in vivo and in vitro without influencing inflammation and HO-1 expression

    Directory of Open Access Journals (Sweden)

    Jakob Wollborn


    Full Text Available Objective: To investigate the impact of the phophodiesterase-4 inhibition (PD-4-I with rolipram on hepatic integrity in lipopolysaccharide (LPS induced hyperinflammation. Materials and Methods: Liver microcirculation in rats was obtained using intravital microscopy. Macrohemodynamic parameters, blood assays, and organs were harvested to determine organ function and injury. Hyperinflammation was induced by LPS and PD-4-I rolipram was administered intravenously one hour after LPS application. Cell viability of HepG2 cells was measured by EZ4U-kit based on the dye XTT. Experiments were carried out assessing the influence of different concentrations of tumor necrosis factor alpha (TNF-α and LPS with or without PD-4-I. Results: Untreated LPS-induced rats showed significantly decreased liver microcirculation and increased hepatic cell death, whereas LPS + PD-4-I treatment could improve hepatic volumetric flow and cell death to control level whithout influencing the inflammatory impact. In HepG2 cells TNF-α and LPS significantly reduced cell viability. Coincubation with PD-4-I increased HepG2 viability to control levels. The heme oxygenase 1 (HO-1 pathway did not induce the protective effect of PD-4-I. Conclusion: Intravenous PD-4-I treatment was effective in improving hepatic microcirculation and hepatic integrity, while it had a direct protective effect on HepG2 viability during inflammation.

  17. Investigation of a Putative Estrogen-Imprinting Gene, Phosphodiesterase Type IV Variant (PDE4D4), in Determining Prostate Cancer Risk (United States)


    Rapid amplification of cDNA ends (5’RACE) to characterize...June 1, 2006 5¶- Rapid amplification of cDNA ends . The first-strand cDNA of PDE4D4 was amplified using a reverse specific primer (5¶-AAAGACGA...PDE4D4 was first identified by 5¶- rapid amplification of cDNA ends and a 700-bp CpG island with 60 CpG sites was found to encompass its transcrip- tion

  18. Is phosphodiesterase inhibition arrhythmogenic? Electrophysiologic effects in pithed rats and in normoxic and hypoxic rabbit atria of enoximone, a new cardiotonic agent. (United States)

    Vaughan Williams, E M


    The positive inotropic and chronotropic actions of enoximone were confirmed. At concentrations within the clinical range, enoximone prolonged the chronotropic and hypotensive action of isoproterenol in pithed rats. Very high doses of both enoximone and isoproterenol caused ventricular fibrillation in only one of six rats. In isolated rabbit atria, the maximum frequency at which pacing stimuli were followed 1:1 was increased by enoximone, and atrial flutter was consistently induced, then terminated by greatly suprathreshold stimulation. Enoximone significantly shortened action potential duration (APD), but did not exacerbate the APD-shortening induced by hypoxia. Since such hypoxia-induced shortening occurred in the presence of glucose 11 mmol/L and oxygen 20%, it was concluded that it was unlikely to have been caused by the opening of ATP-regulated potassium channels. These animal experiments suggest that enoximone, at concentrations encountered clinically in humans, does not have any electrophysiologic actions that would be likely to increase the probability of arrhythmias.

  19. Specificity of the Cyclic GMP-Binding Activity and of a Cyclic GMP-Dependent Cyclic GMP Phosphodiesterase in Dictyostelium discoideum

    NARCIS (Netherlands)

    Haastert, Peter J.M. van; Walsum, Hans van; Meer, Rob C. van der; Bulgakov, Roman; Konijn, Theo M.


    The nucleotide specificity of the cyclic GMP-binding activity in a homogenate of Dictyostelium discoideum was determined by competition of cyclic GMP derivatives with [8-3H] cyclic GMP for the binding sites. The results indicate that cyclic GMP is bound to the binding proteins by hydrogen bonds at N

  20. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) determination of stimulants, anorectic drugs and phosphodiesterase 5 inhibitors (PDE5I) in food supplements. (United States)

    Strano-Rossi, Sabina; Odoardi, Sara; Castrignanò, Erika; Serpelloni, Giovanni; Chiarotti, Marcello


    The paper describes a liquid chromatography/high resolution mass spectrometry LC/HRMS method for the simultaneous identification and quantification of stimulants (ephedrines, caffeine, anorectic drugs such as phentermine, phendimetrazine, phenmetrazine, fenfluramine, benfluorex, mephentermine, fencanfamine, sibutramine) and PDE5I (sildenafil, vardenafil and tadalafil) in food supplements using a benchtop Orbitrap mass spectrometer. The mass detector, with a nominal resolving power of 100,000 (FWHM at m/z 200), operated in full scan mode in ESI positive ionization mode. Analytes were identified by retention times, accurate masses and correspondence of experimental and calculated isotopic patterns. The limits of detection (LOD) obtained varied from 1 to 25 ng g(-1) and limits of quantification (LOQ) were 50 ng g(-1) for all compounds. The method was linear for all the analytes in the ranges from 50 to 2000 ng g(-1), giving correlation coefficients>0.99. Accuracy (intended as %E) and repeatability (% CV) were always lower than 15%. The method was applied to the analysis of 36 dietary supplements, revealing the presence of ephedrine and/or pseudoephedrine in four of them, caffeine in eight of them and sildenafil in four of them. In one case, ephedrine was not reported on the label of the dietary supplement, as well as for caffeine in other two cases. A further confirmation of the analytes identity in positive samples was obtained through in-source fragmentation and comparison of the obtained fragments and their relative abundances with those from certified standards. As the acquisition mode is full scan, it would be also possible to re-process a previously acquired datafile for the investigation of untargeted analytes.

  1. Drug Repositioning for Preeclampsia Therapeutics by In Vitro Screening: Phosphodiesterase-5 Inhibitor Vardenafil Restores Endothelial Dysfunction via Induction of Placental Growth Factor. (United States)

    Kakigano, Aiko; Tomimatsu, Takuji; Mimura, Kazuya; Kanayama, Tomoko; Fujita, Satoko; Minato, Kenji; Kumasawa, Keiichi; Taniguchi, Yukiko; Kanagawa, Takeshi; Endo, Masayuki; Ishihara, Tomoaki; Namba, Takushi; Mizushima, Tohru; Kimura, Tadashi


    We screened a library of 528 approved drugs to identify candidate compounds with therapeutic potential as preeclampsia treatments via their proangiogenic properties. Using human umbilical vein endothelial cells (HUVECs), we assessed whether the screened drugs induced placental growth factor (PIGF) and restored damaged endothelial cell function. Enzyme-linked immunosorbent assays (ELISAs) were carried out to measure levels of PlGF in conditioned media treated with each drug (100 µmol/L) in the drug library. Tube formation assays were performed using HUVECs to evaluate the angiogenic effects of drugs that induced PlGF. We also performed ELISA, quantitative reverse transcription polymerase chain reaction, and tube formation assays after treatment with a range of concentrations of the candidate drug. Of the drugs that induced PlGF, vardenafil was the only compound that significantly facilitated tube formation in comparison with the control cells (P preeclampsia was significantly elevated by administration of vardenafil (250 µmol/L). By assessing drug repositioning through screening a library of approved drugs, we identified vardenafil as a potential protective agent against preeclampsia. The therapeutic mechanism of vardenafil may involve inhibition of the systemic maternal antiangiogenic state that leads to preeclampsia, in addition to its vasodilating effect. As concentrations used are high and unlikely to be useful clinically, further work is needed before testing it in humans.

  2. Cyclic adenosine monophosphate metabolism in synaptic growth, strength, and precision: neural and behavioral phenotype-specific counterbalancing effects between dnc phosphodiesterase and rut adenylyl cyclase mutations. (United States)

    Ueda, Atsushi; Wu, Chun-Fang


    Two classic learning mutants in Drosophila, rutabaga (rut) and dunce (dnc), are defective in cyclic adenosine monophosphate (cAMP) synthesis and degradation, respectively, exhibiting a variety of neuronal and behavioral defects. We ask how the opposing effects of these mutations on cAMP levels modify subsets of phenotypes, and whether any specific phenotypes could be ameliorated by biochemical counter balancing effects in dnc rut double mutants. Our study at larval neuromuscular junctions (NMJs) demonstrates that dnc mutations caused severe defects in nerve terminal morphology, characterized by unusually large synaptic boutons and aberrant innervation patterns. Interestingly, a counterbalancing effect led to rescue of the aberrant innervation patterns but the enlarged boutons in dnc rut double mutant remained as extreme as those in dnc. In contrast to dnc, rut mutations strongly affect synaptic transmission. Focal loose-patch recording data accumulated over 4 years suggest that synaptic currents in rut boutons were characterized by unusually large temporal dispersion and a seasonal variation in the amount of transmitter release, with diminished synaptic currents in summer months. Experiments with different rearing temperatures revealed that high temperature (29-30°C) decreased synaptic transmission in rut, but did not alter dnc and wild-type (WT). Importantly, the large temporal dispersion and abnormal temperature dependence of synaptic transmission, characteristic of rut, still persisted in dnc rut double mutants. To interpret these results in a proper perspective, we reviewed previously documented differential effects of dnc and rut mutations and their genetic interactions in double mutants on a variety of physiological and behavioral phenotypes. The cases of rescue in double mutants are associated with gradual developmental and maintenance processes whereas many behavioral and physiological manifestations on faster time scales could not be rescued. We discuss factors that could contribute to the effectiveness of counterbalancing interactions between dnc and rut mutations for phenotypic rescue.

  3. Investigation of a Putative Estrogen-Imprinting Gene, Phosphodiesterase Type IV Variant (Pde4d4), in Determining Prostate Cancer Risk (United States)


    solid bar, plasmid construct containing full-length transcript (2.4kb) of PDE4D4. Panel B, cAMP level assayed by cAMP HTS Immunoassay (Upstate...Kang S, Kim J, Kim HB , et al. Methylation of p16INK4a is a non-rare event in cervical intraepithelial neoplasia. Diagn Mol Pathol 2006;15:74–82. [118

  4. 3D QSAR, pharmacophore indentification studies on series of 1-(2-ethoxyethyl-1H-pyrazolo [4,3-d]pyrimidines as phosphodiesterase V inhibitors

    Directory of Open Access Journals (Sweden)

    Prafulla Choudhari


    Conclusion: The two different QSAR models are generated by using two different principles, both the models are showing similar results which indicate that this kNN-MFA technique can be utilized for cross validation of the results of multiple linear regression studies.

  5. A cAMP Biosensor-Based High-Throughput Screening Assay for Identification of Gs-Coupled GPCR Ligands and Phosphodiesterase Inhibitors

    DEFF Research Database (Denmark)

    Vedel, Line; Bräuner-Osborne, Hans; Mathiesen, Jesper Mosolff


    resulted in prolonged signaling and enabled detection of weak partial agonists and/or ligands with low potency, which is highly advantageous in large HTS settings and hit identification. In addition, the assay enabled detection of β2AR inverse agonists and PDE inhibitors. High signal-to-noise ratios were...... in living cells. We used the β2-adrenergic receptor (β2AR) as a representative Gs-coupled receptor and characterized two cell lines with different expression levels. Low receptor expression allowed detection of desensitization kinetics and delineation of partial agonism, whereas high receptor expression...

  6. Combining a nanosensor and ELISA for measurement of tyrosyl-dna phosphodiesterase 1 (tdp1) activity and protein amount in cell and tissue extract

    DEFF Research Database (Denmark)

    Jakobsen, Ann-Katrine; Stougaard, Magnus


    performed in the exact same aliquot of cell or tissue extract, the combined assay allows the use of minimal amount of cells or tissue and without additional incubation steps compared to the normal ELISA procedure. Measuring protein amount and activity within the same portion of extract also minimizes...

  7. Protein Expression Change of Phosphodiesterase 2 and Phosphodiesterase 3 in Gastric Smooth Muscle of Diabetic Gastroparesis Rats%糖尿病胃动力障碍大鼠胃窦平滑肌中PDE2和PDE3蛋白表达变化

    Institute of Scientific and Technical Information of China (English)

    金政; 张默函; 姜京植; 朴丽花; 蔡英兰


    为了观察糖尿病胃动力障碍大鼠胃窦平滑肌组织中PDE2和PDE3的蛋白含量变化,由腹腔注射STZ制备糖尿病动物模型,利用多道生理信号记录系统记录糖尿病大鼠胃窦平滑肌收缩活动,将发生胃窦平滑肌收缩活动紊乱的大鼠列入糖尿病胃动力障碍模型,再采用免疫组织化学方法观察糖尿病胃动力障碍组大鼠胃窦平滑肌中PDE2和PDE3的分布。结果发现,糖尿病发病胃动力障碍大鼠与正常对照组相比,胃窦平滑肌组织PDE2表达无明显差异,但PDE3表达明显减少( P<0.05)。因此,糖尿病大鼠发生胃动力障碍可能与胃窦平滑肌中PDE3下调有关,糖尿病大鼠胃cGMP-PDE3的改变可能参与胃动力障碍的发生。%In order to observe the changes of PDE2 and PDE3 in gastric smooth muscle of diabetic gastropare-sis rats, rat model of diabetes mellitus was induced by injected streptozotocin ( STZ ) . To record gastric smooth muscle contraction of diabetes rat with multichannel physiology signal recording system. Diabetes rats with gastric smooth muscle contraction indiscriminate were identified as diabetic gastroparesis model. Then to observe content of PDE2 and PDE3 in diabetic gastroparesis rats gastric smooth muscle by immunohistochemistry. Compared with con-trol group rats, PDE2 content in gastroparesis rat gastric smooth muscle was not significantly different, but PDE3 content increased significantly (P<0. 05). Thus, Gastroparesis of diabetes rats may be correlated with PDE3 down-regulation in gastric smooth muscle, and cGMP-PDE3 signal system may be involved in the pathogenesis and development of diabetic gastropathy of gastroparesis.

  8. Protein: MPB3 [TP Atlas

    Lifescience Database Archive (English)

    Full Text Available MPB3 ENPP7 ENPP7 Ectonucleotide pyrophosphatase/phosphodiesterase family member 7 Alkaline sphingomyelin... phosphodiesterase, Intestinal alkaline sphingomyelinase 9606 Homo sapiens Q6UWV6 339221 Q6UWV6 ...

  9. NCBI nr-aa BLAST: CBRC-GACU-01-0024 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-GACU-01-0024 ref|NP_000912.3| phosphodiesterase 3A, cGMP-inhibited [Homo sapie...ns] sp|Q14432|PDE3A_HUMAN cGMP-inhibited 3',5'-cyclic phosphodiesterase A (Cyclic GMP-inhibited phosphodiest...erase A) (CGI-PDE A) gb|AAA35912.2| cGMP-inhibited cAMP phosphodiesterase [Homo sapiens] gb|AAI17370.1| Phosphodiesterase 3A, cGMP...-inhibited [Homo sapiens] gb|AAI17372.1| Phosphodiesterase 3A, cGMP...-inhibited [Homo sapiens] gb|EAW96406.1| phosphodiesterase 3A, cGMP-inhibited [Homo sapiens] NP_000912.3 2e-48 40% ...

  10. Main: 1JH6 [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available Orderedlocusnames=At4g18930; Orfnames=F13c5.100, F13c5_100; Arabidopsis Thaliana Molecule: Cyclic Phosphodiesterase; Chain: A, B; Eng...ineered: Yes Hydrolase 3.1.4.- (Cyclic Phosphodiesterase) A.Hofmann, M.Grella, I.Bo

  11. NCBI nr-aa BLAST: CBRC-OANA-01-2190 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-OANA-01-2190 ref|YP_484804.1| diguanylate phosphodiesterase [Rhodopseudomonas ...palustris HaA2] gb|ABD05893.1| diguanylate phosphodiesterase [Rhodopseudomonas palustris HaA2] YP_484804.1 3.2 32% ...

  12. NCBI nr-aa BLAST: CBRC-BTAU-01-2762 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-BTAU-01-2762 ref|YP_660210.1| diguanylate cyclase/phosphodiesterase [Pseudoalt...eromonas atlantica T6c] gb|ABG39156.1| diguanylate cyclase/phosphodiesterase [Pseudoalteromonas atlantica T6c] YP_660210.1 1.5 23% ...

  13. NCBI nr-aa BLAST: CBRC-DDIS-04-0058 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DDIS-04-0058 ref|ZP_01907090.1| putative phosphodiesterase [Plesiocystis pacif...ica SIR-1] gb|EDM80089.1| putative phosphodiesterase [Plesiocystis pacifica SIR-1] ZP_01907090.1 2e-47 33% ...

  14. NCBI nr-aa BLAST: CBRC-ACAR-01-0293 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-ACAR-01-0293 sp|Q6ZPR5|NSMA3_MOUSE Sphingomyelin phosphodiesterase 4 (Neutral sphingomyelin...ase 3) (Neutral sphingomyelinase III) (nSMase3) (nSMase-3) gb|EDK97470.1| sphingomyelin phosphodiesterase 4, isoform CRA_a [Mus musculus] Q6ZPR5 5e-33 38% ...

  15. NCBI nr-aa BLAST: CBRC-DMEL-03-0067 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DMEL-03-0067 ref|ZP_01586913.1| glycerophosphoryl diester phosphodiesterase [Dinoroseo...bacter shibae DFL 12] gb|ABV95919.1| glycerophosphoryl diester phosphodiesterase [Dinoroseobacter shibae DFL 12] ZP_01586913.1 0.038 29% ...

  16. Effect of phosphodiesterase inhibitor Ro 20-1724 on social interaction ability of developing rats after repeating ketamine anesthesia%磷酸二酯酶-4抑制剂Ro 20-1724对幼年大鼠反复氯胺酮麻醉后社会交往能力的影响

    Institute of Scientific and Technical Information of China (English)

    蒋平; 彭生; 杨夏; 孙海燕


    目的 观察磷酸二酯酶-4抑制剂Ro 20-1724对幼年大鼠反复氯胺酮麻醉后社会交往能力的影响.方法 32只21日龄大鼠,采用随机数字表法分为(C组)、氯胺酮组(K组)、氯胺酮+ R020-1724组(K+R组)、氯胺酮+无水乙醇组(K+E组).无水乙醇为R020-1724助溶剂.腹腔注射70 mg·kg-1氯胺酮,30 min后不给予或给予0.5 mg·kg-1 Ro20-1724或等量无水乙醇溶剂,每天1次,连续7d,给药结束后正常饲养3d.末次给药第4天后进行社会交往能力测试,测试结束后断头取脑剥离海马,ELISA法检测CA1区脑源性神经营养因子(BDNF)的表达.结果 与对照组相比较,K组.大鼠在无生命体的笼子[(60±29) min,(109±33) min,P<0.01]、陌生鼠[(103±35) min,(151±42)min,P<0.01];[(123±34)min,(184±46) min,P<0.05]及熟悉鼠[(89±25) min,(140±38) min,P<0.01]周围停留的时间均显著少于正常对照组;K+R组大鼠停留的时间较K组均显著延长[空笼子(94±34) min,(60±29) min,P<0.01];陌生鼠1[(140 ±41)min,(103 ±35 min),P<0.05];陌生鼠2[(171±45) min,(123±34) min,P<0.01];熟悉鼠[(133±35)min,(89±25) min,P<0.01];K组及K+E组之间差异无统计学意义(P>0.05).海马CA1区BDNF在K组显著低于C组[(8.6±2.7)ng/ml,(11.8±2.4) ng/ml,P<0.01];K+R组较K组显著增加[(10.1±3.6)ng/ml,(8.6±2.7) ng/ml,P<0.05].结论 Ro 20-1724可显著逆转氯胺酮麻醉导致的社会交往损害,海马CA1区BDNF参与了逆转过程.%Objective To observe the effect of Ro 20-1724 on social interaction ability of developing rats after repeated ketamine anesthesia.Methods 32 rats with 21 days old were randomly divided into four groups,control group (C group),ketamine group (K group),ketamine + Ro 20-1724 group (K + R group),ketamine + ethanol group (K + E group).Ethanol was used as a solvent of Ro 20-1724.Ketamine 70 mg· kg-1 was intraperitoneal injected,30 min later,to give or not give Ro 20-1724 0.5 mg · kg-1 or equivalent ethanol solvent for once each day for seven consecutive days.Then the rats were fed for three days.On the fourth day after the last administration,the social interaction ability were assessed in all rats.The expression of brain-derived neurotropic factor (BDNF) in hippocampal CA1 region was detected using conventional ELISA.Results Comparing with rats in C group,the time spent on the cage of lifeless body ((60 ± 29) min vs (109 ± 33) min,P < 0.01),unfamiliar rats (103 ±35)min vs (151 ±42)min,P<0.01;((123 ±34)min vs (184 ±46) min,P<0.05) and familiar rats (89 ± 25) min vs (140 ± 38) min,P < 0.01) in the social interaction test was significantly less in K group.The time spent significantly prolonged in group K + R,comparing with K group (lifeless body:(94 ± 34) min vs (60 ±29) min,P<0.01) ;unfamiliar rat 1:(140 ±41) min vs (103 ±35)min,P<0.05) ;unfamiliar rat 2:(171 ±45)min vs (123 ±34)min,P<0.01) ; familiar rat:(133 ±35)min vs (89 ±25) min,P<0.01).And there was no difference between K group and K + N group (P > 0.05).The expression of BDNF in hippocampal CA1 region was significantly lower in K group,comparing with C group ((8.6 ± 2.7) ng/ml vs (11.8 ± 2.4) ng/ml,P <0.01) ; and there was a significant increase in K + R group,comparing with K group ((10.1 ± 3.6) ng/ml vs (8.6 ± 2.7) ng/ml,P < 0.05).Conclusion Ro 20-1724 significant rescued social interaction impairment induced by ketamine anesthesia in developing rats.And BDNF in hippocampal CA1 region contribute to the reversal process.

  17. Tetomilast.

    LENUS (Irish Health Repository)

    O'Mahony, Seamus


    Otsuka is developing a once-daily oral formulation of the phosphodiesterase-4 inhibitor tetomilast for the potential treatment of ulcerative colitis (phase III) and chronic obstructive pulmonary disease (phase II).

  18. Effects of preemptive enoximone on left ventricular diastolic function after valve replacement for aortic stenosis

    NARCIS (Netherlands)

    van der Maaten, Joost M. A. A.; de Vries, Adrianus J.; Rietman, Gerrit W.; Gallandat Huet, Rolf C. G.; De Hert, Stefan G.


    Objective: Left ventricular (LV) hypertrophy is associated with increased diastolic chamber stiffness early after aortic valve replacement for valve stenosis. Enoximone, a phosphodiesterase III inhibitor, has been shown to improve myocardial contractility and relaxation when administered as a single

  19. The TRAPIST Study. A multicentre randomized placebo controlled clinical trial of trapidil for prevention of restenosis after coronary stenting, measured by 3-D intravascular ultrasound.

    NARCIS (Netherlands)

    P.W.J.C. Serruys (Patrick); D.P. Foley (David); M. Pieper (Michael); J.A. Kleijne; P.J. de Feyter (Pim)


    textabstractBACKGROUND: Studies have reported benefit of oral therapy with the phosphodiesterase inhibitor, trapidil, in reducing restenosis after coronary angioplasty. Coronary stenting is associated with improved late outcome compared with balloon angioplasty, but significant neointimal hyperplasi

  20. Cyclic AMP affects the haemocyte responses of larval Galleria mellonella to selected antigens. (United States)

    Marin, David; Dunphy, Gary B; Mandato, Craig A


    Signal transduction of the innate immediate responses of insect haemocytes to foreign matter is rarely considered. Herein using a combination of adenylate cyclase inhibitors and activators and phosphodiesterase inhibitors we determined that cyclic adenosine monophosphate (cAMP) at high levels normally impairs non-self response. Haemocyte contact with glass and bacteria lowered cAMP in vitro. Inactive phosphodiesterases, including type 4, impaired haemocyte reactions in vitro. Using the drugs in vivo to modulate adenylate cyclase and phosphodiesterases altered the total and types of haemocytes. Adenylate cyclase inhibitors and etazolate (a type 4 phosphodiesterase inhibitor) alone produced changes in the haemograms similar to those caused by Bacillus subtilis. Sequential injections of an enzyme modulator followed by B. subtilis impaired bacterial removal due (1) in the case of enzyme inhibitors, to the removal of haemocytes prior to bacterial challenge and (2) in the case of forskolin and IBMX to the shut-down of the haemocytes. Activating adenylate cyclase or inhibiting phosphodiesterase impaired bacterial removal when co-injecting the compounds and bacteria.

  1. Phosphatase activities in rice-planting meadow brown soil and their responses to fertilization%草甸棕壤水稻田磷酸酶活性及对施肥措施的响应

    Institute of Scientific and Technical Information of China (English)

    沈菊培; 陈振华; 陈利军


    This study is aimed to investigate the activities of phosphomonoesterase (acid-, neutral-, and alkaline-), phosphodiesterase and phosphotriesterase in a rice-planting meadow brown soil at the lower reach of Liao River, and their responses to different fertilization treatments. The results showed that there was no significant difference in soil total P and organic P contents among all treatments, but soil available P content was significantly higher in treatment OM than in other treatments. Soil acid-and neutral phosphomonoesterase had a higher activity than alkaline phosphomonoesterase and phosphodiesterase, while phosphotriesterase had the lowest activity. No significant difference was found in phosphatase activities between different fertilization treatments. Soil acid phosphomonoesterase activity had a significant correlation with soil total P and available P contents, while soil phosphodiesterase activity significantly correlated with soil organic P content.

  2. Women taking the “blue pill” (sildenafil citrate: such a big deal?

    Directory of Open Access Journals (Sweden)

    Lo Monte G


    Full Text Available Giuseppe Lo Monte, Angela Graziano, Isabella Piva, Roberto Marci Department of Morphology, Surgery, and Experimental Medicine, University of Ferrara, Ferrara, Italy Abstract: For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra® in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate should be kept as the last option. Keywords: phosphodiesterase type 5 inhibitors, female sexual arousal disorder (FSAD, sildenafil citrate

  3. 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? (United States)

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


    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.

  4. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries.

    LENUS (Irish Health Repository)

    Maharaj, Chrisen H


    OBJECTIVES: Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. STUDY DESIGN: Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. RESULTS: Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. CONCLUSION: Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  5. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

    Directory of Open Access Journals (Sweden)

    Lynch Tadhg


    Full Text Available Abstract Objectives Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. Study Design Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. Results Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. Conclusion Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  6. Hemorrhagic Cholecystitis in an Elderly Patient Taking Aspirin and Cilostazol

    Directory of Open Access Journals (Sweden)

    David S. Morris


    Full Text Available Hemorrhage is a rare complication of acute cholecystitis. Patients who develop this complication often are receiving anticoagulation therapy or have a pathologic coagulopathy. We present a case of an elderly patient who developed hemorrhagic cholecystitis while taking aspirin and cilostazol, a phosphodiesterase inhibitor. The patient underwent an emergent abdominal exploration. A large, blood-filled gallbladder was found along with a large hematoma between the liver and gallbladder. We also briefly review the literature regarding hemorrhagic cholecystitis, hemorrhage into the biliary tree, and hemorrhage as a complication of aspirin and phosphodiesterase inhibitor therapy.

  7. Alkylxanthines as research tools. (United States)

    Daly, J W


    (1) The methylxanthine caffeine has many pharmacological effects, most of which can be linked to blockade of adenosine receptors, inhibition of phosphodiesterases, and augmentation of calcium-dependent release of calcium from intracellular stores. (2) A variety of xanthines have been developed as potent and/or selective antagonists for adenosine receptors. (3) Several xanthines have been developed that are more potent and more selective inhibitors of cyclic nucleotide phosphodiesterase than caffeine or theophylline. (4) Caffeine remains the xanthine of choice for activation of intracellular calcium-sensitive calcium release channels although millimolar concentrations are required, which can have effects on other aspects of calcium regulation.

  8. Dicty_cDB: SHF745 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available culus BAC clone RP23-292J21 from chromosome 6, complete sequence. 38 2.1 2 AW871630 |AW871630.1 ra80c01.y1 Bird...E PHOSPHODIESTERASE ;, mRNA sequence. 44 4.7 1 AW871214 |AW871214.1 ra56d01.y1 Bird-Rao Meloidogyne incognit... PHOSPHODIESTERASE ;, mRNA sequence. 44 4.7 1 AW829376 |AW829376.1 ra39d01.y1 Bird-Rao Meloidogyne incognita

  9. Some enzymic activities of two Australian ant venoms: a jumper ant Myrmecia pilosula and a bulldog ant Myrmecia pyriformis. (United States)

    Matuszek, M A; Hodgson, W C; King, R G; Sutherland, S K


    Venoms from two related Australian ants, a jumper ant (Myrmecia pilosula) and a bulldog ant (Myrmecia pyriformis), were quantitatively analysed for the following enzymic activities: phospholipase A2, phospholipase B, phospholipase C, hyaluronidase, esterase, acid phosphatase, alkaline phosphatase and phosphodiesterase. Both venoms contained phospholipase A2, phospholipase B, hyaluronidase, acid phosphatase and alkaline phosphatase activities. Myrmecia pyriformis venom had significantly greater phospholipase B, acid phosphatase and alkaline phosphatase activities than Myrmecia pilosula venom. No detectable quantities of phospholipase C, esterase or phosphodiesterase activities were found in either venom.

  10. Structural basis for c-di-GMP-mediated inside-out signaling controlling periplasmic proteolysis.

    Directory of Open Access Journals (Sweden)

    Marcos V A S Navarro

    Full Text Available The bacterial second messenger bis-(3'-5' cyclic dimeric guanosine monophosphate (c-di-GMP has emerged as a central regulator for biofilm formation. Increased cellular c-di-GMP levels lead to stable cell attachment, which in Pseudomonas fluorescens requires the transmembrane receptor LapD. LapD exhibits a conserved and widely used modular architecture containing a HAMP domain and degenerate diguanylate cyclase and phosphodiesterase domains. c-di-GMP binding to the LapD degenerate phosphodiesterase domain is communicated via the HAMP relay to the periplasmic domain, triggering sequestration of the protease LapG, thus preventing cleavage of the surface adhesin LapA. Here, we elucidate the molecular mechanism of autoinhibition and activation of LapD based on structure-function analyses and crystal structures of the entire periplasmic domain and the intracellular signaling unit in two different states. In the absence of c-di-GMP, the intracellular module assumes an inactive conformation. Binding of c-di-GMP to the phosphodiesterase domain disrupts the inactive state, permitting the formation of a trans-subunit dimer interface between adjacent phosphodiesterase domains via interactions conserved in c-di-GMP-degrading enzymes. Efficient mechanical coupling of the conformational changes across the membrane is realized through an extensively domain-swapped, unique periplasmic fold. Our structural and functional analyses identified a conserved system for the regulation of periplasmic proteases in a wide variety of bacteria, including many free-living and pathogenic species.

  11. Hsp70 stabilizes lysosomes and reverts Niemann-Pick disease-associated lysosomal pathology

    DEFF Research Database (Denmark)

    Kirkegaard, Thomas; Roth, Anke G; Petersen, Nikolaj H T


    inhibition of ASM, effectively revert the Hsp70-mediated stabilization of lysosomes. Notably, the reduced ASM activity in cells from patients with Niemann-Pick disease (NPD) A and B-severe lysosomal storage disorders caused by mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1) encoding for ASM...

  12. Critical finger ischemia and myocardial fibrosis development after sudden interruption of sildenafil treatment in a systemic sclerosis patient. (United States)

    Bruni, C; Bellando-Randone, S; Gargani, L; Picano, E; Pingitore, A; Matucci-Cerinic, M; Guiducci, S


    Systemic sclerosis (SSc) is a connective tissue disease frequently associated with Raynaud's Phenomenon (RP). Among possible pharmacological treatments, phosphodiesterase 5 inhibitors are considered in cases of severe non -responsive RP. We present the case of a male SSc patient wh presented with critical finger ischemia and concomitant appearance of myocardial fibrosis after sudden interruption of sildenafil treatment.

  13. Outcome of Pediatric Patients With Pulmonary Arterial Hypertension in the Era of New Medical Therapies

    NARCIS (Netherlands)

    van Loon, Rosa Laura E.; Roofthooft, Marcus T. R.; Delhaas, Tammo; van Osch-Gevers, Magdalena; ten Harkel, Arend D. J.; Strengers, Jan L. M.; Backx, Ad; Hillege, Hans L.; Berger, Rolf M. F.


    Little is known about the effects of "second-generation drugs" (prostanoids, endothelin receptor antagonists, 5-phosphodiesterase inhibitors) in children with pulmonary arterial hypertension (PAH). This study describes the outcome of a national cohort of children with PAH in an era when these drugs

  14. Regulation of Adhesion and Migration by the Rsu1- and PINCH1-mediated Inhibition of Focal Adhesion Formation and Actin Polymerization (United States)


    signaling: new phosphodiesterases and new functions. Current opinion in cell biology. 12:174- 179. Sonoda, Y., T. Ozawa , K.D. Aldape, D.F. Deen, M.S...Cancer research. 61:6674- 6678. 72 Sonoda, Y., T. Ozawa , Y. Hirose, K.D. Aldape, M. McMahon, M.S. Berger, and R.O. Pieper. 2001b. Formation

  15. Comparison Between Tadalafil Plus Paroxetine and Paroxetine Alone in the Treatment of Premature Ejaculation


    Moudi; Kasaeeyan


    Background Several recent studies have investigated the therapeutic role of phosphodiesterase type 5 (PDE5) inhibitors in premature ejaculation (PE) used in the treatment of erectile dysfunction. Objectives In the present research, the efficacy of paroxetine alone and paroxetine plus tadalafil was compared in patients referred because of premature ejaculation. Patients and Methods ...

  16. Identification of cancer-cytotoxic modulators of PDE3A by predictive chemogenomics | Office of Cancer Genomics (United States)

    High cancer death rates indicate the need for new anticancer therapeutic agents. Approaches to discovering new cancer drugs include target-based drug discovery and phenotypic screening. Here, we identified phosphodiesterase 3A modulators as cell-selective cancer cytotoxic compounds through phenotypic compound library screening and target deconvolution by predictive chemogenomics.

  17. Biofilm formation and antibiotic production in Ruegeria mobilis are influenced by intracellular concentrations of cyclic dimeric guanosinmonophosphate

    DEFF Research Database (Denmark)

    D'Alvise, Paul; Magdenoska, Olivera; Melchiorsen, Jette


    formation and production of the potent antibiotic tropodithietic acid (TDA). An introduced phosphodiesterase gene decreased c-di-GMP and reduced biofilm formation and TDA production. tdaC, a key gene for TDA biosynthesis, was expressed only in attached or biofilm-forming cells, and expression was induced...

  18. CC-1088 Celgene. (United States)

    Dredge, Keith


    CC-1088, a thalidomide analog inhibitor of phosphodiesterase 4, was being developed by Celgene for the potential treatment of inflammatory diseases and myelodysplastic syndromes, and had undergone clinical trials. By April 2005, however, the company was no longer developing CC-1088, with CC-10004 presumed to be the preferred compound.

  19. Association study of PDE4B gene variants in Scandinavian schizophrenia and bipolar disorder multicenter case-control samples

    DEFF Research Database (Denmark)

    Kähler, Anna K; Otnaess, Mona K; Wirgenes, Katrine V;


    The phosphodiesterase 4B (PDE4B), which is involved in cognitive function in animal models, is a candidate susceptibility gene for schizophrenia (SZ) and bipolar disorder (BP). Variations in PDE4B have previously been associated with SZ, with a suggested gender-specific effect. We have genotyped...

  20. Cyclic nucleotides differentially regulate the synthesis of tumour necrosis factor-alpha and interleukin-1 beta by human mononuclear cells

    NARCIS (Netherlands)

    Endres, S; Fülle, H J; Sinha, B; Stoll, D; Dinarello, C A; Gerzer, R; Weber, P C


    Recent reports have shown that phosphodiesterase (PDE) inhibitors suppress production of tumour necrosis factor-alpha (TNF-alpha) in mouse macrophages. In the present study we show that theophylline, pentoxifylline and 3-isobutyl-1-methylxanthine markedly suppress the lipopolysaccharide (LPS)-induce

  1. Lipopolysaccharide induces expression of tumour necrosis factor alpha in rat brain : inhibition by methylprednisolone and by rolipram

    NARCIS (Netherlands)

    Buttini, M; Mir, A; Appel, K; Wiederhold, KH; Limonta, S; GebickeHaerter, PJ; Boddeke, HWGM


    1 We have investigated the effects of the phosphodiesterase (PDE) type TV inhibitor rolipram and of the glucocorticoid methylprednisolone on the induction of tumour necrosis factor alpha (TNF-alpha) mRNA and protein in brains of rats after peripheral administration of lipopolysaccharide (LPS). 2 Aft

  2. Domain Modeling: NP_002594.1 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_002594.1 chr8 Multiple Determinants for Inhibitor Selectivity of Cyclic Phosphodiesterases p1zkla_ chr8/NP_002594.1/NP_002594.1_holo_113-429.pdb blast 185Y,186H,190H,194V,226H,2

  3. Cyclic AMP enhancing drugs modulate eicosanoid release from human alveolar macrophages

    NARCIS (Netherlands)

    F.D. Beusenberg; H.C. Hoogsteden (Henk); I.L. Bonta; J.G.C. van Amsterdam (Jan)


    textabstractThe effect of the phosphodiesterase inhibitor isobutyl-methylxanthine (IBMX), salbutamol and sodium nitroprusside was evaluated regarding PGE2 and LTB4 release and cAMP and cGMP level in human alveolar macrophages obtained from controls and COPD patients. Basal levels per five million co

  4. Domain Modeling: NP_878253.1 [SAHG[Archive

    Lifescience Database Archive (English)

    Full Text Available NP_878253.1 chr11 Crystal structure of periplasmic glycerophosphodiester phosphodie...sterase from Escherichia coli c1ydyb_ chr11/NP_878253.1/NP_878253.1_holo_189-457.pdb psi-blast 203H,204R,230E,232D,245H,331D,386R _CA 0 ...

  5. New PDE4 inhibitors based on pharmacophoric similarity between papaverine and tofisopam. (United States)

    Bihel, Frédéric J J; Justiniano, Hélène; Schmitt, Martine; Hellal, Malik; Ibrahim, Mohamed A; Lugnier, Claire; Bourguignon, Jean-Jacques


    Pharmacophoric comparison between papaverine and tofisopam led to identify three new series of micro- to sub-micromolar inhibitors of phosphodiesterase-4, including 7,8-dialkoxy-2,3-benzodiazepin-4-one derivatives, 7,8-dialkoxy-1,4-benzodiazepin-2-one derivatives, and dialkoxybenzophenone derivatives.

  6. Preparation and properties of diuridine 3’,5’-boranophosphate

    Institute of Scientific and Technical Information of China (English)

    陈耀全; 屈付成; 张一兵


    Diuridine 3’, 5’-boianophosphate has been synthesized. Its diastereomers were separated and their configurations were tentatively assigned based on the selective snake venom phosphodiesterase (SVPDE) hydrolysis. It is found that, compared to the unmodified parent compound diuridine phosphate, the nucleophilicity and the stability of the modified compounds to SVPDE are significantly enhanced.

  7. NCBI nr-aa BLAST: CBRC-SARA-01-1177 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-SARA-01-1177 ref|XP_592012.3| PREDICTED: similar to Sphingomyelin phosphodiest...erase 3 (Neutral sphingomyelinase 2) (Neutral sphingomyelinase II) (nSMase2) (nSMase-2) (Confluent 3Y1 cell-associated protein 1) isoform 1 [Bos taurus] XP_592012.3 7.4 33% ...

  8. A Method for Studying cAMP-relay in Dictyostelium discoideum : the Effect of Temperature on cAMP-relay

    NARCIS (Netherlands)

    Haastert, Peter J.M. van


    A simple assay has been developed to quantify the cAMP-relay in Dictyostelium discoideum. The assay is based on the stimulation of cells, in the presence of a phosphodiesterase inhibitor, with 2'-deoxyadenosine 3',5'-monophosphate (dcAMP) at a concentration which saturates cell surface cAMP receptor

  9. Drug: D09989 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 89.gif Treatment of erectile dysfunction (PDE 5 inhibitor) ATC code: G04BE09 phosphodiesterase (PDE) V inhib...BE Drugs used in erectile dysfunction G04BE09 Vardenafil D09989 Vardenafil hydrochloride (USAN) Target-based

  10. The cardiovascular effects of methylxanthines

    NARCIS (Netherlands)

    Riksen, N.P.; Smits, P.; Rongen, G.A.P.J.M.


    In the concentration range that is normally achieved in humans, e.g., after the drinking of coffee or in patients treated with theophylline, the cardiovascular effects of methylxanthines are primarily due to antagonism of adenosine A(1) and A(2) receptors. Inhibition of phosphodiesterases or mobiliz

  11. Decreased catalytic activity and altered activation properties of PDE6C mutants associated with autosomal recessive achromatopsia

    DEFF Research Database (Denmark)

    Grau, Tanja; Artemyev, Nikolai O; Rosenberg, Thomas


    characterization of six missense mutations applying the baculovirus system to express recombinant mutant and wildtype chimeric PDE6C/PDE5 proteins in Sf9 insect cells. Purified proteins were analyzed using Western blotting, phosphodiesterase (PDE) activity measurements as well as inhibition assays by zaprinast...

  12. Pharmacotherapy of erectile dysfunction: Current standards

    Directory of Open Access Journals (Sweden)

    Kew-Kim Chew


    Full Text Available Pharmacotherapy is currently the therapeutic option of choice for erectile dysfunction. Comprising mainly intracavernosal injection therapy using alprostadil or alprostadil combined with phentolamine and/or papaverine and oral phosphodiesterase-5 inhibitors, it is safe and effective if appropriately prescribed and administered. The medications in current use produce satisfactory erectile responses by enhancing cavernosal vasodilatation mainly through their ability to promote relaxation of the smooth muscle cells in the corpora cavernosa involving the synthesis and activity of nitric oxide via the cyclic guanosine monophosphate and cyclic adenosine monophosphate biochemical pathways. The main side-effects and complications of intracavernosal injections are postinjection pain, prolonged erections, priapism and penile fibrosis. There may be a variety of side-effects with phosphodiesterase-5 inhibition but these are usually inconsequential. Recent serious ill health and the need for ongoing long-acting nitrate therapy or frequent use of short-acting nitrates for angina are absolute contraindications to the use of phosphodiesterase-5 inhibitors. Caution has to be exercised in prescribing phosphodiesterase-5 inhibitors for patients with impaired renal or hepatic functions or receiving multi-drug therapy for any systemic disease. All patients presenting with erectile dysfunction should be investigated and treated for cardiovascular risk factors. They should also be counseled regarding lifestyle factors particularly healthy balanced diet, regular physical exercise and inappropriate social habits.

  13. Differential vasoactive effects of sildenafil and tadalafil on cerebral arteries

    DEFF Research Database (Denmark)

    Kruuse, Christina Rostrup; Gupta, Saurabh; Nilsson, Elisabeth


    Phosphodiesterase 5 (PDE5) is associated with migraine pathophysiology, stroke recovery and vasospasm treatment. The potential vascular interplay of PDE5 inhibitors sildenafil, tadalafil and UK-114,542 was studied by intra- versus extra-luminal administration in rat middle cerebral arteries in vi...

  14. Pulmonary Arterial Hypertension in Adults: Novel Drugs and Catheter Ablation Techniques Show Promise? Systematic Review on Pharmacotherapy and Interventional Strategies


    Salvatore Rosanio; Francesco Pelliccia; Carlo Gaudio; Cesare Greco; Abdul M. Keylani; D’Agostino, Darrin C.


    This systematic review aims to provide an update on pharmacological and interventional strategies for the treatment of pulmonary arterial hypertension in adults. Currently US Food and Drug Administration approved drugs including prostanoids, endothelin-receptor antagonists, phosphodiesterase type-5 inhibitors, and soluble guanylate-cyclase stimulators. These agents have transformed the prognosis for pulmonary arterial hypertension patients from symptomatic improvements in exercise tolerance t...

  15. Pharmacotherapy of pulmonary hypertension (according to the 2015 ESC/EAS Guidelines for the diagnosis and treatment of pulmonary hypertension)


    E. L. Trisvetova; S. V. Gubkin


    Indications and efficacy of drugs used for the treatment of pulmonary hypertension are considered. Stages of the treatment of pulmonary arterial hypertension are discussed, including maintenance therapy, specific therapy with calcium channel blockers, prostacyclin analogues, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, prostacyclin agonists, guanylate cyclase stimulators, combination treatment.

  16. Effect of dark rearing on development of visual sense and proteomics of visual cortex in growing rat%避光对生长发育期大鼠视觉及视皮层蛋白质组学的影响

    Institute of Scientific and Technical Information of China (English)

    曲露; 张晔; 衡斌; 刘燕强


    .22] times vs.[6.11±0.59]times),but this change was not statistically significant (t =2.09,P>0.05).Two-dimensional electrophoresis and mass spectrometry assay revealed that 36 different proteins in visual cortex were found in the dark-feed rats compared with the natural environment rats,including 26 loss proteins and 10 extra proteins.Among the different proteins,Eps 15 homology domain-containing protein-3 (EHD3),tubulin alpha-1A chain and 2 ',3 '-cyclic-nucleotide 3 ' phosphordiesterase were the known proteins.Conclusions Dark rearing cause reversible visual loss in critical period plasticity newborn rat,and the change of proteomics in visual cortex is probably an affecting factor.%背景 以往对视皮层发育关键期的研究仅根据已有的神经信号表达系统,就某一种可能是视皮层发育的关键蛋白质进行实验验证,进行视皮层全蛋白质分析对于了解动物进而研究人类视觉发育的可塑性具有重要意义. 目的 了解避光环境对生长发育期大鼠视觉及视皮层蛋白质组学的影响. 方法 将2只同日分娩12只仔鼠的SD母鼠分别饲养在2个鼠笼中,分娩日将2个母鼠的仔鼠一半进行对换,对换的仔鼠剪耳进行区分,即时起一个鼠笼的大鼠在避光处饲养,一个鼠笼的大鼠在自然光照下饲养作为对照.避光饲养的大鼠在完全避光环境下更换食物、水和垫料,至仔鼠40日龄时测定两组仔鼠对近眼物体瞬目的次数.各组分别处死3只大鼠,分离双侧初级视皮层(枕叶),利用二维电泳和质谱分析的方法,检测仔鼠避光环境与自然光照环境下发育和生长的初级视皮层蛋白质组学的差异,经Swissprot与NCBI数据库比对,鉴定差异蛋白.然后将避光饲养的剩余9只大鼠恢复自然光照l0d至大鼠50日龄,作为避光40 d恢复光照10d组比较与同日龄自然光照组9只大鼠对近眼物体瞬目次数的差异. 结果 大鼠40日龄时,避光饲养组大鼠对近

  17. The isolation of plasma membrane from protoplasts of soybean suspension cultures. (United States)

    Galbraith, D W; Northcote, D H


    A procedure for the isolation of plasma membranes from protoplasts of suspension-cultured soybean is described. Protoplasts were prepared by enzymic digestion of the cell wall and the plasma membrane was labelled with radioactive diazotized sulphanilic acid. The membrane systems from broken protoplasts were separated by continuous isopycnic sucrose gradient centrifugation. Radioactivity was localized in a band possessing a buoyant density of 1-14 g ml-1. The activities of NADPH- and NADH-cytochrome c reductase, fumarase, Mg2+-ATPase, IDPase and acid phosphodiesterase in the various regions of the density gradient were determined. A plasma membrane fraction was selected which was relatively uncontaminated with membranes derived from endoplasmic reticulum, tonoplasts and mitochondria. The results indicated that Mg2+-ATPase and possibly acid phosphodiesterase were associated with the plasma membrane.

  18. A comparative study of the biological properties of venoms from snakes of the genus Vipera (true adders) (United States)

    Tan, N H; Ponnudurai, G


    1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, hyaluronidase, alkaline phosphomonoesterase, 5'-nucleotidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 26 samples of venoms of 13 taxa of Vipera were determined and the Sephadex G-75 gel filtration patterns for some of the venoms were also examined. 2. The results indicate the presence of certain common characteristics among the venoms, particularly if V. russelli is excluded from the comparison. The results also support the recently proposed reassignment of V. russelli to a separate genus. 3. The data show that information on venom biological properties can be used for differentiation of venoms of many species of Vipera. Particularly useful for this purpose are the protease, phosphodiesterase, phospholipase A and the procoagulant activities and the Sephadex G-75 gel filtration patterns of the venoms.

  19. Cyclic AMP system in muscle tissue during prolonged hypokinesia (United States)

    Antipenko, Y. A.; Bubeyev, Y. A.; Korovkin, B. F.; Mikhaleva, N. P.


    Components of the cyclic Adenosine-cyclic-35-monophosphate (AMP) system in the muscle tissue of white rats were studied during 70-75 days of hypokinesia, created by placing the animals in small booths which restricted their movements, and during the readaptation period. In the initial period, cyclic AMP levels and the activities of phosphodiesterase and adenylate cyclase in muscle tissue were increased. The values for these indices were roughly equal for controls and experimental animals during the adaptation period, but on the 70th day of the experiment cAMP levels dropped, phosphodiesterase activity increased, and the stimulative effect of epinephrine on the activity of adenylate cyclase decreased. The indices under study normalized during the readaptation period.

  20. Safety and tolerability considerations in the use of sildenafil for children with pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Dodgen AL


    Full Text Available Andrew L Dodgen,1 Kevin D Hill1,2 1Department of Pediatrics, Duke University Medical Center, 2Duke Clinical Research Institute, Durham, NC, USA Abstract: Sildenafil is a phosphodiesterase type-5 inhibitor approved for treatment of pulmonary arterial hypertension (PAH in adults. Data from pediatric trials demonstrate a similar acute safety profile to the adult population but have raised concerns regarding the safety of long-term use in children. Interpretation of these trials remains controversial with major regulatory agencies differing in their recommendations – the US Food and Drug Administration recommends against the use of sildenafil for treatment of PAH in children, while the European Medicines Agency supports its use at “low doses”. Here, we review the available pediatric data regarding dosing, acute, and long-term safety and efficacy of sildenafil for the treatment of PAH in children. Keywords: phosphodiesterase inhibitor, pulmonary vasodilator, STARTS trials

  1. Long-term therapy of interferon-alpha induced pulmonary arterial hypertension with different PDE-5 inhibitors: a case report

    Directory of Open Access Journals (Sweden)

    Baumann Gert


    Full Text Available Abstract background Interferon alpha2 is widely used in hepatitis and high-risk melanoma. Interferon-induced pulmonary arterial hypertension as a side effect is rare. Case presentation We describe a melanoma patient who developed severe pulmonary arterial hypertension 30 months after initiation of adjuvant interferon alpha2b therapy. Discontinuation of interferon did not improve pulmonary arterial hypertension. This patient could be treated successfully with phosphodiesterase-5 inhibitor therapy. Conclusion This is only the 5th case of interferon-induced pulmonary arterial hypertension and the first documented case where pulmonary arterial hypertension was not reversible after termination of interferon alpha2 therapy. If interferon alpha2 treated patients develop respiratory symptoms, pulmonary arterial hypertension should be considered in the differential diagnosis. For these patients phosphodiesterase-5 inhibitors, e.g. sildenafil or vardenafil, could be an effective therapeutic approach.

  2. Pulmonary vasodilation in acute and chronic heart failure: empiricism and evidence. (United States)

    Guglin, Maya


    Pulmonary hypertension in heart failure is associated with exercise intolerance and adverse outcomes. With the availability of multiple drugs that cause pulmonary vasodilation and decrease pulmonary arterial pressure, pulmonary hypertension becomes an attractive therapeutic target. Out of several classes of medications, oral phosphodiesterase inhibitors emerge as the most promising in terms of symptomatic improvement, hemodynamic benefits, reverse cardiac remodeling, and functional capacity. Future trials will show whether the use of these drugs translates to decreased morbidity and mortality in heart failure.

  3. Pleiotropic functions of EAPII/TTRAP/TDP2: Cancer development, chemoresistance and beyond


    Li, Chunyang; Sun, Shi-Yong; Khuri, Fadlo R.; Li, Runzhao


    EAPII (also called TTRAP, TDP2), a protein identified a decade ago, has recently been shown to function as an oncogenic factor. This protein was also proven to be the first 5′-tyrosyl-DNA phosphodiesterase. EAPII has been demonstrated to have promiscuous protein associations, broad responsiveness to various extracellular signals and pleiotropic functions in the development of human diseases including cancer and neurodegenerative disease. Emerging data suggest that EAPII is a multi-functional ...

  4. Structural basis for substrate discrimination and integrin binding by autotaxin


    Hausmann, Jens; Kamtekar, Satwik; Christodoulou, Evangelos; Day, Jacqueline E.; Wu, Tao; Fulkerson, Zachary; Albers, Harald M. H. G.; van Meeteren, Laurens A.; Houben, Anna; Zeijl, Leonie van; Jansen, Silvia; Andries, Maria; Hall, Troii; Pegg, Lyle E.; Benson, Timothy E.


    Autotaxin (ATX) or ecto-nucleotide pyrophosphatase/phosphodiesterase-2 (ENPP2) is a secreted lysophospholipase D that generates the lipid mediator lysophosphatidic acid (LPA), a mitogen and chemo-attractant for many cell types. ATX-LPA signaling has roles in various pathologies including tumour progression and inflammation. However, the molecular basis of substrate recognition and catalysis, and the mechanism of interaction with target cells, has been elusive. Here we present the crystal stru...

  5. Hydrogen Sulfide in the Adipose Tissue—Physiology, Pathology and a Target for Pharmacotherapy


    Jerzy Bełtowski; Anna Jamroz-Wiśniewska


    Hydrogen sulfide (H2S) is synthesized in the adipose tissue mainly by cystathionine γ-lyase (CSE). Several studies have demonstrated that H2S is involved in adipogenesis, that is the differentiation of preadipocytes to adipocytes, most likely by inhibiting phosphodiesterases and increasing cyclic AMP concentration. The effect of H2S on adipose tissue insulin sensitivity and glucose uptake is controversial. Some studies suggest that H2S inhibits insulin-induced glucose uptake and that excess o...

  6. Microgravity changes in heart structure and cyclic-AMP metabolism (United States)

    Philpott, D. E.; Fine, A.; Kato, K.; Egnor, R.; Cheng, L.


    The effects of microgravity on cardiac ultrastructure and cyclic AMP metabolism in tissues of rats flown on Spacelab 3 are reported. Light and electron microscope studies of cell structure, measurements of low and high Km phosphodiesterase activity, cyclic AMP-dependent protein kinase activity, and regulatory subunit compartmentation show significant deviations in flight animals when compared to ground controls. The results indicate that some changes have occurred in cellular responses associated with catecholamine receptor interactions and intracellular signal processing.

  7. Effect of PDE5 inhibition on the modulation of sympathetic α-adrenergic vasoconstriction in contracting skeletal muscle of young and older recreationally active humans

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Piil, Peter Bergmann; Egelund, Jon;


    Aging is associated with an altered regulation of blood flow to contracting skeletal muscle; however, the precise mechanisms remain unclear. We recently demonstrated that inhibition of cGMP-binding phosphodiesterase 5 (PDE5) increased blood flow to contracting skeletal muscle of older but not young......- and α2-adrenergic receptors. The level of the sympatholytic compound ATP was measured in venous plasma by use of the microdialysis technique. Sildenafil increased (P

  8. Modulation of the Cholinergic Mechanisms in the Bronchial Smooth Muscle. (United States)


    Ginsborg and Hirst, 1q72; Sawynok and Jhamandas, 1976), although theopylline has not shown to be a specific adenosine receptor antagonist in all the tissues... theopylline and other cyclic nucletide phosphodiesterase inhibitors. Acta Pharmacol. Toxicol. 45, 336-344. Fredholm, B.B. and P. Hedqvist, 1980...51 mM) evoked release of [3H]-Ach from cholinergic nerves in the bronchial smooth muscle. The effect of theopylline (I mM) on the response to

  9. Draft Genome Sequence of Marine Actinomycete Streptomyces sp. Strain NTK 937, Producer of the Benzoxazole Antibiotic Caboxamycin. (United States)

    Olano, Carlos; Cano-Prieto, Carolina; Losada, Armando A; Bull, Alan T; Goodfellow, Michael; Fiedler, Hans-Peter; Méndez, Carmen; Salas, José A


    Streptomyces sp. strain NTK 937 is the producer of the benzoxazole antibiotic caboxamycin, which has been shown to exert inhibitory activity against Gram-positive bacteria, cytotoxic activity against several human tumor cell lines, and inhibition of the enzyme phosphodiesterase. In this genome announcement, we present a draft genome sequence of Streptomyces sp. NTK 937 in which we identified at least 35 putative secondary metabolite biosynthetic gene clusters.

  10. Treatment of infertility in men with spinal cord injury

    DEFF Research Database (Denmark)

    Brackett, N.L.; Lynne, C.M.; El Dib, Hussein Ibrahim El Desouki Hussein


    Most men with spinal cord injury (SCI) are infertile. Erectile dysfunction, ejaculatory dysfunction and semen abnormalities contribute to the problem. Treatments for erectile dysfunction include phosphodiesterase type 5 inhibitors, intracavernous injections of alprostadil, penile prostheses...... of intrauterine insemination increases as the total motile sperm count inseminated increases. In vitro fertilization and intracytoplasmic sperm injection are options in cases of extremely low total motile sperm count. Reproductive outcomes for SCI male factor infertility are similar to outcomes for general male...... factor infertility...

  11. The multiple roles of myelin protein genes during the development of the oligodendrocyte



    It has become clear that the products of several of the earliest identified myelin protein genes perform functions that extend beyond the myelin sheath. Interestingly, these myelin proteins, which comprise proteolipid protein, 2′,3′-cyclic nucleotide 3′-phosphodiesterase and the classic and golli MBPs (myelin basic proteins), play important roles during different stages of oligodendroglial development. These non-myelin-related functions are varied and include roles in the...

  12. Safety and tolerability considerations in the use of sildenafil for children with pulmonary arterial hypertension


    Dodgen AL; Hill KD


    Andrew L Dodgen,1 Kevin D Hill1,2 1Department of Pediatrics, Duke University Medical Center, 2Duke Clinical Research Institute, Durham, NC, USA Abstract: Sildenafil is a phosphodiesterase type-5 inhibitor approved for treatment of pulmonary arterial hypertension (PAH) in adults. Data from pediatric trials demonstrate a similar acute safety profile to the adult population but have raised concerns regarding the safety of long-term use in children. Interpretation of these trials remains controve...

  13. Three cdg Operons Control Cellular Turnover of Cyclic Di-GMP in Acetobacter xylinum: Genetic Organization and Occurrence of Conserved Domains in Isoenzymes


    Tal, Rony; Wong, Hing C; Calhoon, Roger; Gelfand, David; Fear, Anna Lisa; Volman, Gail; Mayer, Raphael; Ross, Peter; Amikam, Dorit; Weinhouse, Haim; Cohen, Avital; Sapir, Shai; Ohana, Patricia; Benziman, Moshe


    Cyclic di-GMP (c-di-GMP) is the specific nucleotide regulator of β-1,4-glucan (cellulose) synthase in Acetobacter xylinum. The enzymes controlling turnover of c-di-GMP are diguanylate cyclase (DGC), which catalyzes its formation, and phosphodiesterase A (PDEA), which catalyzes its degradation. Following biochemical purification of DGC and PDEA, genes encoding isoforms of these enzymes have been isolated and found to be located on three distinct yet highly homologous operons for cyclic diguany...

  14. Clinical use of alprostadil topical cream in patients with erectile dysfunction: a review


    Anaissie J; Hellstrom WJG


    James Anaissie, Wayne JG Hellstrom Department of Urology, Tulane University School of Medicine, New Orleans, LA, USA Abstract: Erectile dysfunction (ED) is a common and debilitating disorder seen in over 50% of men older than 70 years. Oral phosphodiesterase type 5 (PDE5) inhibitors are the mainstay of treatment for ED, but cannot be used by a significant subset of patients due to systemic side effects and drug–drug interactions. Second-line therapy may include intracaverno...

  15. A multi-targeted liquid chromatography-mass spectrometry screening procedure for the detection in human urine of drugs non-prohibited in sport commonly used by the athletes. (United States)

    Mazzarino, Monica; Cesarei, Lorenzo; de la Torre, Xavier; Fiacco, Ilaria; Robach, Paul; Botrè, Francesco


    This work presents an analytical method for the simultaneous analysis in human urine of 38 pharmacologically active compounds (19 benzodiazepine-like substances, 7 selective serotonin reuptake inhibitors, 4 azole antifungal drugs, 5 inhibitors of the phosphodiesterases type 4 and 3 inhibitors of the phosphodiesterase type 5) by liquid-chromatography coupled with tandem mass spectrometry. The above substances classes include both the most common "non banned" drugs used by the athletes (based on the information reported on the "doping control form") and those drugs who are suspected to be performance enhancing and/or act as masking agents in particular conditions. The chromatographic separation was performed by a reverse-phase octadecyl column using as mobile phases acetonitrile and ultra-purified water, both with 0.1% formic acid. The detection was carried out using a triple quadrupole mass spectrometric analyser, positive electro-spray as ionization source and selected reaction monitoring as acquisition mode. Sample pre-treatment consisted in an enzymatic hydrolysis followed by a liquid-liquid extraction in neutral field using tert-butyl methyl-ether. The analytical procedure, once developed, was validated in terms of sensitivity (lower limits of detection in the range of 1-50 ng mL(-1)), specificity (no interferences were detected at the retention time of all the analytes under investigation), recovery (≥60% with a satisfactory repeatability, CV % lower than 10), matrix effect (lower than 30%) and reproducibility of retention times (CV% lower than 0.1) and of relative abundances (CV% lower than 15). The performance and the applicability of the method was evaluated by analyzing real samples containing benzodiazepines (alprazolam, diazepam, zolpidem or zoplicone) or inhibitors of the phosphodiesterases type 5 (sildenafil or vardenafil) and samples obtained incubating two of the phosphodiesterases type 4 studied (cilomilast or roflumilast) with pooled human liver

  16. Sildenafil citrate-restored eNOS and PDE5 regulation in sickle cell mouse penis prevents priapism via control of oxidative/nitrosative stress. (United States)

    Bivalacqua, Trinity J; Musicki, Biljana; Hsu, Lewis L; Berkowitz, Dan E; Champion, Hunter C; Burnett, Arthur L


    Sildenafil citrate revolutionized the practice of sexual medicine upon its federal regulatory agency approval approximately 15 years ago as the prototypical phosphodiesterase type 5 inhibitor indicated for the treatment of male erectile dysfunction. We now provide scientific support for its alternative use in the management of priapism, a clinical disorder of prolonged and uncontrolled penile erection. Sildenafil administered continuously to sickle cell mice, which show a priapism phenotype, reverses oxidative/nitrosative stress effects in the penis, mainly via reversion of uncoupled endothelial nitric oxide synthase to the functional coupled state of the enzyme, which in turn corrects aberrant signaling and function of the nitric oxide/cyclic GMP/protein kinase G/phosphodiesterase type 5 cascade. Priapism tendencies in these mice are reverted partially toward normal neurostimulated erection frequencies and durations after sildenafil treatment in association with normalized cyclic GMP concentration, protein kinase G activity and phosphodiesterase type 5 activity in the penis. Thus, sildenafil exerts pleiotropic effects in the penis that extend to diverse erection disorders.

  17. Identification of flgZ as a flagellar gene encoding a PilZ domain protein that regulates swimming motility and biofilm formation in Pseudomonas. (United States)

    Martínez-Granero, Francisco; Navazo, Ana; Barahona, Emma; Redondo-Nieto, Miguel; González de Heredia, Elena; Baena, Irene; Martín-Martín, Irene; Rivilla, Rafael; Martín, Marta


    Diguanylate cyclase and phosphodiesterase enzymatic activities control c-di-GMP levels modulating planktonic versus sessile lifestyle behavior in bacteria. The PilZ domain is described as a sensor of c-di-GMP intracellular levels and the proteins containing a PilZ domain represent the best studied class of c-di-GMP receptors forming part of the c-di-GMP signaling cascade. In P. fluorescens F113 we have found two diguanylate cyclases (WspR, SadC) and one phosphodiesterase (BifA) implicated in regulation of swimming motility and biofilm formation. Here we identify a flgZ gene located in a flagellar operon encoding a protein that contains a PilZ domain. Moreover, we show that FlgZ subcellular localization depends on the c-di-GMP intracellular levels. The overexpression analysis of flgZ in P. fluorescens F113 and P. putida KT2440 backgrounds reveal a participation of FlgZ in Pseudomonas swimming motility regulation. Besides, the epistasis of flgZ over wspR and bifA clearly shows that c-di-GMP intracellular levels produced by the enzymatic activity of the diguanylate cyclase WspR and the phosphodiesterase BifA regulates biofilm formation through FlgZ.

  18. Roflumilast enhances the renal protective effects of retinoids in an HIV-1 transgenic mouse model of rapidly progressive renal failure. (United States)

    Zhong, Yifei; Wu, Yingwei; Liu, Ruijie; Deng, Yueyi; Mallipattu, Sandeep K; Klotman, Paul E; Chuang, Peter Y; He, John C


    Retinoic acid decreases proteinuria and glomerulosclerosis in several animal models of kidney disease by protecting podocytes from injury. Our recent in vitro studies suggest that all-trans retinoic acid induces podocyte differentiation by activating the retinoic acid receptor-α (RARα)/cAMP/PKA/CREB pathway. When used in combination with all-trans retinoic acid, an inhibitor of phosphodiesterase 4 further enhanced podocyte differentiation by increasing intracellular cAMP. Additionally, we found that Am580, a specific RARα agonist, has similar renal protective effects as all-trans retinoic acid in a rederived colony of HIV-1 transgenic mice with rapidly progressive renal failure (HIV-Tg) that mimics human HIV-associated nephropathy. Treatment with either the inhibitor of phosphodiesterase 4, roflumilast, or Am580 significantly reduced proteinuria, attenuated kidney injury, and improved podocyte differentiation in these HIV-Tg mice. Additional renal protective effects were found when roflumilast was combined with Am580. Consistent with the in vitro data, glomeruli from HIV-Tg mice treated with both Am580 and roflumilast had more active phosphorylated CREB than with either agent alone. Thus, phosphodiesterase 4 inhibitors could be used in combination with RARα agonists to provide additional renal protection.

  19. Identification of flgZ as a flagellar gene encoding a PilZ domain protein that regulates swimming motility and biofilm formation in Pseudomonas.

    Directory of Open Access Journals (Sweden)

    Francisco Martínez-Granero

    Full Text Available Diguanylate cyclase and phosphodiesterase enzymatic activities control c-di-GMP levels modulating planktonic versus sessile lifestyle behavior in bacteria. The PilZ domain is described as a sensor of c-di-GMP intracellular levels and the proteins containing a PilZ domain represent the best studied class of c-di-GMP receptors forming part of the c-di-GMP signaling cascade. In P. fluorescens F113 we have found two diguanylate cyclases (WspR, SadC and one phosphodiesterase (BifA implicated in regulation of swimming motility and biofilm formation. Here we identify a flgZ gene located in a flagellar operon encoding a protein that contains a PilZ domain. Moreover, we show that FlgZ subcellular localization depends on the c-di-GMP intracellular levels. The overexpression analysis of flgZ in P. fluorescens F113 and P. putida KT2440 backgrounds reveal a participation of FlgZ in Pseudomonas swimming motility regulation. Besides, the epistasis of flgZ over wspR and bifA clearly shows that c-di-GMP intracellular levels produced by the enzymatic activity of the diguanylate cyclase WspR and the phosphodiesterase BifA regulates biofilm formation through FlgZ.

  20. Innate hemocyte responses of Malacosoma disstria larvae (C. Insecta) to antigens are modulated by intracellular cyclic AMP. (United States)

    Gulii, Vladislav; Dunphy, Gary B; Mandato, Craig A


    Invertebrate intracellular hemocyte signaling pathways affecting cellular-antigen responses, although defined for molluscs and some arthropods including dipteran insects, is less known for lepidopterans. Hemocytic-antigen responses of the arboreal pest lepidopteran Malacosoma disstria are linked to cAMP-dependent protein kinase A implicating cAMP in cellular hemocyte immune responses. The purpose in the present study was to determine intracellular cAMP effects on larval M. disstria hemocytes adhering to slides and bacteria. Altering adenylate cyclase and phosphodiesterase activities as well as cAMP levels in vitro and in vivo changed hemocyte responses to antigens. Quiescent hemocytes had high cAMP levels due to adenylate cyclase activity and possibly low phosphodiesterase (type 4) activity. Antigen contact diminished hemocytic cAMP levels. Inhibiting adenylate cyclase increased hemocyte-antigen and hemocyte-hemocyte adhesion, the latter producing nodules in vivo without bacterial antigens. Inhibiting phosphodiesterase type 4 produced the reverse effects. Pharmacologically increasing intracellular cAMP in attached hemocytes caused many of the cells to detach. Diminished intracellular cAMP changed hemograms in vivo in bacteria-free larvae comparable to changes induced by the bacterium, Bacillus subtilis, by producing nodules. Lowering cAMP enhanced also the removal of Xenorhabdus nematophila and B. subtilisin vivo.

  1. Sexual function in hypertensive patients receiving treatment

    Directory of Open Access Journals (Sweden)

    Thorsten Reffelmann


    Full Text Available Thorsten Reffelmann, Robert A KlonerUniversity of Southern California, The Heart Institute, Good Samaritan Hospital, Division of Cardiovascular Medicine, Keck School of Medicine, Los Angeles, CA, USAAbstract: In many forms of erectile dysfunction (ED, cardiovascular risk factors, in particular arterial hypertension, seem to be extremely common. While causes for ED are related to a broad spectrum of diseases, a generalized vascular process seems to be the underlying mechanism in many patients, which in a large portion of clinical cases involves endothelial dysfunction, ie, inadequate vasodilation in response to endothelium-dependent stimuli, both in the systemic vasculature and the penile arteries. Due to this close association of cardiovascular disease and ED, patients with ED should be evaluated as to whether they may suffer from cardiovascular risk factors including hypertension, cardiovascular disease or silent myocardial ischemia. On the other hand, cardiovascular patients, seeking treatment of ED, must be evaluated in order to decide whether treatment of ED or sexual activity can be recommended without significantly increased cardiac risk. The guideline from the first and second Princeton Consensus Conference may be applied in this context. While consequent treatment of cardiovascular risk factors should be accomplished in these patients, many antihypertensive drugs may worsen sexual function as a drug specific side-effect. Importantly, effective treatment for arterial hypertension should not be discontinued as hypertension itself may contribute to altered sexual functioning; to the contrary, alternative antihypertensive regimes should be administered with individually tailored drug regimes with minimal side-effects on sexual function. When phosphodiesterase-5 inhibitors, such as sildenafil, tadalafil and vardenafil, are prescribed to hypertensive patients on antihypertensive drugs, these combinations of antihypertensive drugs and

  2. Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Jens Otto Clemmesen; Annamaria Giraldi; Peter Ott; Kim Dalhoff; Bent Adel Hansen; Fin Stolze Larsen


    AIM: To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with cirrhosis. Phosphodiesterase type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liver disease. However, the effect of phosphodiesterase type-5 inhibitors on splanchnic blood flow and portal hypertension remains essentially unknown. METHODS: Ten patients with biopsy proven cirrhosis (five females/five males, mean age 54±8 years) and an HVPG above 12 mmHg were studied after informed consent. Measurement of splanchnic blood flow and the HVPG during liver vein catheterization were done before and 80 min after oral administration of 50 mg sildenafil. Blood flow was estimated by use of indocyanine green clearance technique and Fick's principle, with correction for non-steady state. RESULTS: The plasma concentration of sildenafil was 222±136 ng/mL 80 min after administration. Mean arterial blood pressure decreased from 77±7 mmHg to 66±12 mmHg, P=0.003, while the splanchnic blood flow and oxygen consumption remained unchanged at 1.14±0.71 L/min and 2.3±0.6 mmol/ min, respectively. Also the HVPG remained unchanged (18±2 mmHg vs 16±2 mmHg) with individual changes ranging from-8 mmHg to+2 mmHg. In seven patients, HVPG decreased and in three it increased. CONCLUSION: In spite of arterial blood pressure decreases 80 min after administration of the phosphodiesterase type-5 inhibitor sildenafil, the present study could not demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG.

  3. Cyclic AMP functions as a primary sexual signal in gametes of Chlamydomonas reinhardtii. (United States)

    Pasquale, S M; Goodenough, U W


    When Chlamydomonas reinhardtii gametes of opposite mating type are mixed together, they adhere by a flagella-mediated agglutination that triggers three rapid mating responses: flagellar tip activation, cell wall loss, and mating structure activation accompanied by actin polymerization. Here we show that a transient 10-fold elevation of intracellular cAMP levels is also triggered by sexual agglutination. We further show that gametes of a single mating type can be induced to undergo all three mating responses when presented with exogenous dibutyryl-cAMP (db-cAMP). These events are also induced by cyclic nucleotide phosphodiesterase inhibitors, which elevate endogenous cAMP levels and act synergistically with db-cAMP. Non-agglutinating mutants of opposite mating type will fuse efficiently in the presence of db-cAMP. No activation of mating events is induced by calcium plus ionophores, 8-bromo-cGMP, dibutyryl-cGMP, nigericin at alkaline pH, phorbol esters, or forskolin. H-8, an inhibitor of cyclic nucleotide-dependent protein kinase, inhibits mating events in agglutinating cells and antagonizes the effects of cAMP on non-agglutinating cells. Adenylate cyclase activity was detected in both the gamete cell body and flagella, with the highest specific activity displayed in flagellar membrane fractions. The flagellar membrane adenylate cyclase is preferentially stimulated by Mn++, unresponsive to NaF, GTP, GTP gamma S, AlF4-, and forskolin, and is inhibited by trifluoperazine. Cyclic nucleotide phosphodiesterase activity is also present in flagella. Our observations indicate that cAMP is a sufficient initial signal for all of the known mating reaction events in C. reinhardtii, and suggest that the flagellar cyclase and/or phosphodiesterase may be important loci of control for the agglutination-stimulated production of this signal.

  4. Novel anti-inflammatory agents in COPD

    DEFF Research Database (Denmark)

    Loukides, Stelios; Bartziokas, Konstantinos; Vestbo, Jørgen


    Inflammation plays a central role in chronic obstructive pulmonary disease (COPD). COPD related inflammation is less responsive to inhaled steroids compared to asthma. There are three major novel anti-inflammatory approaches to the management of COPD. The first approach is phosphodiesterase...... on these strategies exist at the moment. A third potential approach involves novel agents whose mechanism of action is closely related to COPD mechanisms and pathophysiology. Such novel treatments are of great interest since they may treat both COPD and co-morbidities. Several novel agents are currently under...

  5. PDE9A, PDE10A, and PDE11A expression in rat trigeminovascular pain signalling system

    DEFF Research Database (Denmark)

    Kruse, Lars S; Møller, Morten; Tibaek, Maiken


    Activation of the trigeminovascular pain signalling system, including cerebral arteries, meninges, trigeminal ganglion, and brain stem, is involved in migraine. Furthermore, stimulation of cyclic nucleotide (cAMP and cGMP) production as well as inhibition of phosphodiesterases (PDEs) induces head......, the expression of PDE9A, PDE10A, and PDE11A in the trigeminovascular system. The functional implications are yet unknown, but their localisation indicates that they may have a role in the pain pathway of migraine as well as trigeminal neuralgia and trigeminal autonomic cephalalgias....

  6. Small-molecule control of cytokine function: new opportunities for treating immune disorders (United States)

    Sundberg, Thomas B.; Xavier, Ramnik J.; Schreiber, Stuart L.; Shamji, Alykhan F.


    Manipulating cytokine function with protein-based drugs has proven effective for treating a wide variety of autoimmune and auto-inflammatory disorders. However, the limited ability of protein-based drugs to modulate intracellular targets, including many implicated by studies of the genetics and physiology of these diseases, and to coordinately neutralize redundant inflammatory cytokines, suggest an important and complementary role for small molecules in immunomodulatory drug development. The recent clinical approval of Janus kinase and phosphodiesterase inhibitors, along with emerging evidence from other compound classes, firmly establish small molecules as effective tools for modulating therapeutically relevant proteins that give rise to aberrant cytokine signaling or mediate its downstream consequences. PMID:25222143

  7. Current therapies for premature ejaculation. (United States)

    Gur, Serap; Kadowitz, Philip J; Sikka, Suresh C


    Premature ejaculation (PE) subjectively affects 20-30% of men globally. Until recently, understanding of PE was hampered by the absence of a widely accepted definition, paucity of evidence-based clinical studies, and the absence of an appropriate animal model. Here, we elaborate on the current definition of PE, its pathogenesis, currently available therapies, and future treatment prospects. Most treatments for PE are 'off-label' and include selective serotonin reuptake inhibitors (SSRIs), topical anesthetics, tramadol, and phosphodiesterase type 5 (PDE5) inhibitors. Such knowledge of the benefit and limitations of each treatment will help to direct future drug design and formulations.

  8. TSH-induced cyclic AMP production in an ovine thyroid cell line: OVNIS 5H. (United States)

    Fayet, G; Aouani, A; Hovsépian, S


    The TSH-induced cyclic AMP response was studied using a 3-year-old ovine thyroid cell line TSH-independent for growth: OVNIS 5H. The kinetics of cyclic AMP production was followed both in cell layers and in cell culture media, with or without phosphodiesterase inhibitor. It is noteworthy that following the first wave in cyclic AMP obtained within minutes, we observed later a sustained exponential increase in cyclic AMP during the 5 days following TSH stimulation. A bioassay of TSH was derived allowing measurement of 1 microU/ml TSH from a crude bTSH preparation.

  9. Association study between SMPD1 p.L302P and sporadic Parkinson’s disease in ethnic Chinese population



    Purpose: The protein encoded by sphingomyelin phosphodiesterase 1, acid lysosomal (SMPD1) is a lysosomal acid sphingomyelinase. While there are increasing evidences to suggest that lysosomal enzyme defects and Parkinson’s disease (PD) have strong associations, and recently, SMPD1 p.L302P (c.T911C, NM_000543) was found to be a risk factor for PD in Ashkenazi Jewish ancestry population, we try to investigate the possible association between SMPD1 p.L302P and sporadic PD in ethnic Chinese popula...

  10. Sildenafil: Can Cause Acute Ischaemic Stroke? A Case Report

    Directory of Open Access Journals (Sweden)

    Zeynep Özözen Ayas


    Full Text Available Sildenafil is an inhibitor of phosphodiesterase type-5 (PDE-5, is used for erectile dysfunction. There is not enough information about its effects on the central nervous system Headache, nasal congestion, facial flushing, nausea are the most common side effects. However, neurological complications such as third cranial nerve palsy, transient global amnesia, seizures, cerebral hemorrhage, and infarction are less commonly observed. We present a case of a 60-year-old man with acute ischaemic stroke, which we considered to be interrelated to sildenafil intake. Clinicians must be aware of the possibility of neurological side effects when the patient use sildenafil.

  11. Effects of PDE4 inhibitors on lipopolysaccharide-induced priming of superoxide anion production from human mononuclear cells

    Directory of Open Access Journals (Sweden)

    Noëlla Germain


    Full Text Available Aims: Phosphodiesterase 4 (PDE4 inhibitors have been described as potent anti-inflammatory compounds, involving an increase in intracellular levels of cyclic 3',5'-adenosine monophosphate (AMP. The aim of this study was to compare the effects of selective PDE4 inhibitors, rolipram and RP 73-401 with the cell permeable analogue of cyclic AMP, dibutyryl-cyclic AMP (db-cAMP and the anti-inflammatory cytokine interleukin-10 (IL-10 on superoxide anion production from peripheral blood mononuclear cells preincubated with lipopolysaccharide (LPS.

  12. Enzyme assays for synthesis and degradation of 2-5As and other 2'-5' oligonucleotides

    DEFF Research Database (Denmark)

    Poulsen, Jesper Buchhave; Kjær, Karina Hansen; Justesen, Just


    isolation of A(pA)3. A synthetase assay using either of the dNTPs individually together with NAD(+) as substrates is also presented. The nuclease reactions make use of the isolated 2'-5' oligoadenylates in producing a mixture of shorter reaction products, which are resolved by ion-exchange chromatography...... to determine the enzyme activities. A purified human 2'-5' oligoadenylate synthetase and a purified human phosphodiesterase 12 along with crude extracts expressing those proteins, are used to demonstrate the assays. CONCLUSIONS: This paper comprises an assay toolbox for identification and characterization...

  13. Drug Guru: a computer software program for drug design using medicinal chemistry rules. (United States)

    Stewart, Kent D; Shiroda, Melisa; James, Craig A


    Drug Guru (drug generation using rules) is a new web-based computer software program for medicinal chemists that applies a set of transformations, that is, rules, to an input structure. The transformations correspond to medicinal chemistry design rules-of-thumb taken from the historical lore of drug discovery programs. The output of the program is a list of target analogs that can be evaluated for possible future synthesis. A discussion of the features of the program is followed by an example of the software applied to sildenafil (Viagra) in generating ideas for target analogs for phosphodiesterase inhibition. Comparison with other computer-assisted drug design software is given.

  14. Six New Tetraprenylated Alkaloids from the South China Sea Gorgonian Echinogorgia pseudossapo

    Directory of Open Access Journals (Sweden)

    Zhang-Hua Sun


    Full Text Available Six new tetraprenylated alkaloids, designated as malonganenones L–Q (1–6, were isolated from the gorgonian Echinogorgia pseudossapo, collected in Daya Bay of Guangdong Province, China. The structures of 1–6 featuring a methyl group at N-3 and a tetraprenyl chain at N-7 in the hypoxanthine core were established by extensive spectroscopic analyses. Compounds 1–6 were tested for their inhibitory activity against the phosphodiesterases (PDEs-4D, 5A, and 9A, and compounds 1 and 6 exhibited moderate inhibitory activity against PDE4D with IC50 values of 8.5 and 20.3 µM, respectively.

  15. Low-Intensity Extracorporeal Shock Wave as a Novel Treatment for Erectile Dysfunction. (United States)

    Pan, Michael M; Raees, Ayman; Kovac, Jason R


    The paradigm of erectile dysfunction (ED) treatment was fundamentally altered following the introduction of oral phosphodiesterase type 5 inhibitors. Unfortunately, a significant number of men exhibit a suboptimal response and require additional management strategies. One of the novel, minimally invasive strategies being developed is low-intensity extracorporeal shock wave therapy. Used in the hope of delaying placement of an inflatable penile prosthesis, the final phase of ED treatment, low-intensity extracorporeal shock wave therapy is a unique application of an established technology that may hopefully one day expand the medical options for patients with ED. This commentary will highlight the physiology underlying this technique and summarize the most recent studies.

  16. Influence of L-dopa and of thymus fraction on the survival rate of whole-body irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Busse, E.; Helmholz, M. (Humboldt-Universitaet, Berlin (German Democratic Republic). Bereich Medizin (Charite))


    The survival rate of mice with exposure of the whole body (7 Gy) was hardly changed by one dose as well as several doses of the phosphodiesterase inhibitor amantadine and the interferon inductor measles vaccine. However, the survival rates were increased by one administration of L-dopa or by the long-term therapy using L-dopa at 7 and 9 Gy, resp. The survival rates were also increased at 7 and 9 Gy, resp. if the thymus factor was three times applied to the animals after irradiation. The increased survival rates gained by using L-dopa and thymus factor are correlated with the leukocyte values determined.

  17. A 1-year study of the activities of seven hydrolases in a communal wastewater treatment plant: trends and correlations. (United States)

    Kreutz, Jennifer Anna; Böckenhüser, Ina; Wacht, Marion; Fischer, Klaus


    The activities of seven hydrolytic enzymes (L-alanine aminopeptidase, esterase, α-and β-glucosidase, phosphomonoesterase, phosphodiesterase, sulfatase) were monitored during 1 year in parallel and serial treatment units of the biological stage of a communal wastewater treatment plant. The spatial homogeneity of enzyme activities was high (coefficients of variation  0.8) and highly significant (p plant effluent, dry matter content of activated sludge, and sludge volume, were found. The esterase activity was least correlated with other enzymes and often showed deviating dependencies on process parameters, raising questions concerning its appropriateness as a sum parameter for enzymatic and heterotrophic activity.

  18. Pyrazolopyridines as potent PDE4B inhibitors: 5-Heterocycle SAR

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Charlotte J.; Ballantine, Stuart P.; Coe, Diane M.; Cook, Caroline M.; Delves, Christopher J.; Dowle, Mike D.; Edlin, Chris D.; Hamblin, J. Nicole; Holman, Stuart; Johnson, Martin R.; Jones, Paul S.; Keeling, Sue E.; Kranz, Michael; Lindvall, Mika; Lucas, Fiona S.; Neu, Margarete; Solanke, Yemisi E.; Somers, Don O.; Trivedi, Naimisha A.; Wiseman, Joanne O. (GSK)


    Following the discovery of 4-(substituted amino)-1-alkyl-pyrazolo[3,4-b]pyridine-5-carboxamides as potent and selective phosphodiesterase 4B inhibitors, [Hamblin, J. N.; Angell, T.; Ballentine, S., et al. Bioorg. Med. Chem. Lett.2008, 18, 4237] the SAR of the 5-position was investigated further. A range of substituted heterocycles showed good potencies against PDE4. Optimisation using X-ray crystallography and computational modelling led to the discovery of 16, with sub-nM inhibition of LPS-induced TNF-{alpha} production from isolated human peripheral blood mononuclear cells.

  19. Genetic Analysis of Chromomere 3d4 in DROSOPHILA MELANOGASTER . II. Regulatory Sites for the Dunce Gene


    Salz, Helen K.; Kiger, John A.


    Chromomere 3D4 of the X chromosome of D. melanogaster contains two genes, dunce (dnc) and sperm amotile (sam ). Mutations in dnc cause defects in memory formation and female fertility and reduce or eliminate the activity of a cAMP-specific phosphodiesterase designated form II. A fine structure map of this region has been constructed showing the locations of two sam mutations, five dnc mutations and a newly identified locus designated control of fertility (cf) that acts in cis to regulate the...

  20. Dicty_cDB: SHG578 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 292J21 from chromosome 6, complete sequence. 38 1.8 2 AW871630 |AW871630.1 ra80c01.y1 Bird...LEOTIDE PHOSPHODIESTERASE ;, mRNA sequence. 44 4.4 1 AW871214 |AW871214.1 ra56d01.y1 Bird-Rao Meloidogyne in... mRNA sequence. 44 4.4 1 AW829376 |AW829376.1 ra39d01.y1 Bird-Rao Meloidogyne inc

  1. Dicty_cDB: SHG483 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 2J21 from chromosome 6, complete sequence. 38 1.2 2 AW871630 |AW871630.1 ra80c01.y1 Bird-Rao Meloidogyne inc...OTIDE PHOSPHODIESTERASE ;, mRNA sequence. 44 3.5 1 AW871214 |AW871214.1 ra56d01.y1 Bird-Rao Meloidogyne inco...RNA sequence. 44 3.5 1 AW829376 |AW829376.1 ra39d01.y1 Bird-Rao Meloidogyne incog

  2. Modulation of Dopaminergic Pathways to Treat Erectile Dysfunction

    DEFF Research Database (Denmark)

    Simonsen, Ulf; Comerma-Steffensen, Simon; Andersson, Karl-Erik


    The currently recommended first-line treatments of erectile dysfunction, phosphodiesterase type 5 inhibitors (PDE5i), e.g. sildenafil, are efficacious in many patients with erectile dysfunction of vascular origin, but this therapy is insufficient in approximately 30-40% of men with erectile...... preoptic area, the spinal cord, and in the erectile tissue are involved in erection, and several agonists developed for treatment of Parkinson's disease are associated with increased libido. A therapeutic window for treatment of erectile dysfunction was found by sublingual administration of the general...

  3. Does erectile dysfunction drug use contribute to risky sexual behavior?

    Institute of Scientific and Technical Information of China (English)

    Wayne J. G. Hellstrom


    @@ Erectile dysfunction (ED) is a common sexual problem affecting up to one-third of men through-out their lives. According to the Massachusetts Male Aging Study (MMAS), ED affects an estimated 52% of men between the ages of 40 and 70. With the approval of silde-nafil (USA in March 1998), the first phosphodiesterase type 5 (PDE-5) inhibitor to be made available for treatment of ED, and the subse-quent approval of vardenafil (USA in August 2003) and tadalafil (USA in November 2003), the PDE-5 inhibitor class of drugs has rapidly become the first-line therapy for ED of varying etiologies and se-verities.

  4. Drug repurposing and the prior art patents of competitors. (United States)

    Sternitzke, Christian


    Drug repurposing (i.e., finding novel indications for established substances) has received increasing attention in industry recently. One challenge of repositioned drugs is obtaining effective patent protection, especially if the 'novel' indications have already been claimed by competitors within the same drug class. Here, I report the case of patents relating to phosphodiesterase type 5 (PDE5) inhibitors. Patentees of later-filed patents on novel indications (even when they could not observe prior patenting of their direct competitors) filed patents for which patent examiners did not see the prior-filed patents of the competitors as relevant prior art, whereas these follower patent applications often failed because of other reasons.

  5. Response to a single dose of sildenafil in single-ventricle patients: an echocardiographic evaluation. (United States)

    Jackson, Kimberly W; Butts, Ryan J; Svenson, Amy J; McQuinn, Tim C; Atz, Andrew M


    New evidence of increased phosphodiesterase-5 (PDE-5) in hypertrophied human myocardium suggests that sildenafil, a selective PDE-5 inhibitor, may improve muscle contraction and therefore improve ventricular function. The purpose of this study was to compare ventricular function as assessed by echocardiography in 10 surgically palliated single-ventricle patients at baseline and again after a single dose of sildenafil. The velocity time integral of the ventricular outflow tract was increased 2 h after sildenafil administration (p = 0.01), thus suggesting an improvement in cardiac output.

  6. William Harvey Research Conference on PDE inhibitors: drugs with an expanding range of therapeutic uses. (United States)



    Presentations at the William Harvey Research Conference on PDE Inhibitors described the molecular biology, biochemical regulation. pharmacology, and therapeutic utility of inhibitors of cyclic nucleotide phosphodiesterases (PDEs). Most of the talks focused on PDE4 and PDE5. two members of the 11-member PDE family that have attracted much interest over the last several years. These enzymes have been shown to be targets for drugs with wide-ranging clinical utility, including treatment of inflammation, depression, and male erectile dysfunction. The continued investigation of PDEs and the development of potent and selective inhibitors should provide even more therapeutic agents in years to come.

  7. Main: 1FSI [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1FSI シロイヌナズナ Arabidopsis Arabidopsis thaliana (L.) Heynh. Cyclic Phosphodiesterase ...Orderedlocusnames=At4g18930; Orfnames=F13c5.100, F13c5_100; Arabidopsis Thaliana Molecule: Cyclic Phosphodie...R; T05030; T05030.|PDB; 1FSI; X-ray; A/B/C=1-181.|PDB; 1JH6; X-ray; A/B=1-181.|PDB; 1JH7; X-ray; A=1-181.|In...EFTGPRFVPHVTVAVSAYLTADEAKKMFESACDGLKAYTATVDRVSTGTFFFQCVFLLLQTTPEVMEAGEHCKNHFNCSTTTPYMPHLSLLYAELTEEEKKNAQEKAYTLDSSLDGLSFRLNRLALCKTDTEDKTLETWETVAVCNLNP arabi_1FSI.jpg ...

  8. Drug: D04720 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D04720 Drug Levosimendan (USAN/INN); Simdax (TN) C14H12N6O 280.1073 280.2847 D04720...M C01 CARDIAC THERAPY C01C CARDIAC STIMULANTS EXCL. CARDIAC GLYCOSIDES C01CX Other cardiac stimulants C01CX08 Levosime...ndan D04720 Levosimendan (USAN/INN) Target-based classification of drug...s [BR:br08310] Enzymes Hydrolases phosphodiesterase (PDE) III [HSA:5139 5140] [KO:K13296] Levosimendan [ATC:C01CX08] D04720 Levosime

  9. Truncated FAD synthetase for direct biocatalytic conversion of riboflavin and analogs to their corresponding flavin mononucleotides. (United States)

    Iamurri, Samantha M; Daugherty, Ashley B; Edmondson, Dale E; Lutz, Stefan


    The preparation of flavin mononucleotide (FMN) and FMN analogs from their corresponding riboflavin precursors is traditionally performed in a two-step procedure. After initial enzymatic conversion of riboflavin to flavin adenine dinucleotide (FAD) by a bifunctional FAD synthetase, the adenyl moiety of FAD is hydrolyzed with snake venom phosphodiesterase to yield FMN. To simplify the protocol, we have engineered the FAD synthetase from Corynebacterium ammoniagenes by deleting its N-terminal adenylation domain. The newly created biocatalyst is stable and efficient for direct and quantitative phosphorylation of riboflavin and riboflavin analogs to their corresponding FMN cofactors at preparative-scale.

  10. Glutamine enhances glucose-induced mesangial cell proliferation. (United States)

    Lagranha, Claudia J; Doi, Sonia Q; Pithon-Curi, Tania C; Curi, Rui; Sellitti, Donald F


    The proliferation of mesangial cells (MC) in the presence of glutamine (0-20 mM) was determined in both low (5 mM) and high (25 mM) glucose-containing medium. Glutamine in a high glucose (HG) environment increased cell proliferation in a dose-dependent manner. Inhibition of glutamine:fructose 6-phosphate amidotransferase (GFAT) and of phosphodiesterase significantly reduced glutamine-induced proliferation. Supraphysiologic levels of glutamine increase MC proliferation in a HG milieu via GFAT and cAMP-dependent pathways, suggesting that glutamine could pose a risk for diabetic nephropathy.

  11. A novel SMPD1 mutation in two Chinese sibling patients with type B Niemann-Pick disease

    Institute of Scientific and Technical Information of China (English)

    HUA Rong; WU Hui; CUI Zhe; CHEN Jin-xian; WANG Zheng


    Type B Niemann-Pick disease is an autosomal recessive sphingolipidosis due to mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1).Here we present molecular findings for two sibling patients.One mutation V36A due to c.107T>C in exon 1 is a single nucleotide polymorphism and the other N522S due to c.1565 A>G in exon 6 is a novel missense mutation.This non-fatal missense mutation leads to -20% residual lysosomal acid sphingomyelinase activity in vitro and only results in hepatosplenomegaly without neurologic involvement.

  12. Phosphorylation-independent regulation of the diguanylate cyclase WspR.

    Directory of Open Access Journals (Sweden)

    Nabanita De


    Full Text Available Environmental signals that trigger bacterial pathogenesis and biofilm formation are mediated by changes in the level of cyclic dimeric guanosine monophosphate (c-di-GMP, a unique eubacterial second messenger. Tight regulation of cellular c-di-GMP concentration is governed by diguanylate cyclases and phosphodiesterases, which are responsible for its production and degradation, respectively. Here, we present the crystal structure of the diguanylate cyclase WspR, a conserved GGDEF domain-containing response regulator in Gram-negative bacteria, bound to c-di-GMP at an inhibitory site. Biochemical analyses revealed that feedback regulation involves the formation of at least three distinct oligomeric states. By switching from an active to a product-inhibited dimer via a tetrameric assembly, WspR utilizes a novel mechanism for modulation of its activity through oligomerization. Moreover, our data suggest that these enzymes can be activated by phosphodiesterases. Thus, in addition to the canonical pathways via phosphorylation of the regulatory domains, both product and enzyme concentration contribute to the coordination of c-di-GMP signaling. A structural comparison reveals resemblance of the oligomeric states to assemblies of GAF domains, widely used regulatory domains in signaling molecules conserved from archaea to mammals, suggesting a similar mechanism of regulation.

  13. Vasoactive neuropeptides in clinical ophthalmology: An association with autoimmune retinopathy?

    Directory of Open Access Journals (Sweden)

    Donald R Staines


    Full Text Available Donald R Staines1,2, Ekua W Brenu2, Sonya Marshall-Gradisnik21Queensland Health, Gold Coast Population Health Unit, Southport, Gold Coast, Queensland, Australia; 2Faculty of Health Science and Medicine, Population Health and Neuroimmunology Unit, Bond University, Robina, Queensland, AustraliaAbstract: The mammalian eye is protected against pathogens and inflammation in a relatively immune-privileged environment. Stringent mechanisms are activated that regulate external injury, infection, and autoimmunity. The eye contains a variety of cells expressing vasoactive neuropeptides (VNs, and their receptors, located in the sclera, cornea, iris, ciliary body, ciliary process, and the retina. VNs are important activators of adenylate cyclase, deriving cyclic adenosine monophosphate (cAMP from adenosine triphosphate (ATP. Impairment of VN function would arguably impede cAMP production and impede utilization of ATP. Thus VN autoimmunity may be an etiological factor in retinopathy involving perturbations of purinergic signaling. A sound blood supply is necessary for the existence and functional properties of the retina. This paper postulates that impairments in the endothelial barriers and the blood–retinal barrier, as well as certain inflammatory responses, may arise from disruption to VN function. Phosphodiesterase inhibitors and purinergic modulators may have a role in the treatment of postulated VN autoimmune retinopathy.Keywords: retinopathy, autoimmune, vasoactive neuropeptides, phosphodiesterase inhibitors

  14. Linalool from rosewood (Aniba rosaeodora Ducke) oil inhibits adenylate cyclase in the retina, contributing to understanding its biological activity. (United States)

    Sampaio, Lucia de Fatima S; Maia, José Guilherme S; de Parijós, Amanda M; de Souza, Rita Z; Barata, Lauro Euclides S


    Rosewood oil (RO) (Aniba rosaeodora Ducke) is rich in linalool, a monoterpene alcohol, which has well studied anxiolytic, sedative and anticonvulsant effects. The inhibition of the increases in cAMP protects against seizures in a diversity of models of epilepsy. In this paper, the principal aim was to investigate the effects of RO, (±)-linalool and (-)-linalool) on adenylate cyclase. They were tested in chick retinas and forskolin was used to stimulate the enzyme target. The phosphodiesterase inhibitor, 4-(3-butoxy-4-methoxybenzyl)-imidazolidin-2-one, and the non-selective adenosine receptor antagonist 3-isobutyl-methyl-xanthine (IBMX), were used to control the participation of phosphodiesterase and adenosine receptors in the resulting effects, respectively. The cAMP accumulation was measured by enzyme immune assay (EIA). Rosewood oil, (-)-linalool and (±)-linalool inhibited exclusively the cAMP accumulation stimulated by forskolin, even when adenosine receptors were blocked with IBMX. The IC(50) values (in μ m concentration range) calculated from their concentration response-curves were not statistically different, however, the compounds presented a different relative efficacy. These results extend the range of subcellular mechanisms underlying the relaxant action of linalool on the central nervous system.

  15. Treatment of hypertension and renal injury induced by the angiogenesis inhibitor sunitinib: preclinical study. (United States)

    Lankhorst, Stephanie; Kappers, Mariëtte H W; van Esch, Joep H M; Smedts, Frank M M; Sleijfer, Stefan; Mathijssen, Ron H J; Baelde, Hans J; Danser, A H Jan; van den Meiracker, Anton H


    Common adverse effects of angiogenesis inhibition are hypertension and renal injury. To determine the most optimal way to prevent these adverse effects and to explore their interdependency, the following drugs were investigated in unrestrained Wistar Kyoto rats exposed to the angiogenesis inhibitor sunitinib: the dual endothelin receptor antagonist macitentan; the calcium channel blocker amlodipine; the angiotensin-converting enzyme inhibitor captopril; and the phosphodiesterase type 5 inhibitor sildenafil. Mean arterial pressure was monitored telemetrically. After 8 days, rats were euthanized and blood samples and kidneys were collected. In addition, 24-hour urine samples were collected. After sunitinib start, mean arterial pressure increased rapidly by ≈30 mm Hg. Coadministration of macitentan or amlodipine largely prevented this rise, whereas captopril or sildenafil did not. Macitentan, captopril, and sildenafil diminished the sunitinib-induced proteinuria and endothelinuria and glomerular intraepithelial protein deposition, whereas amlodipine did not. Changes in proteinuria and endothelinuria were unrelated. We conclude that in our experimental model, dual endothelin receptor antagonism and calcium channel blockade are suitable to prevent angiogenesis inhibition-induced hypertension, whereas dual endothelin receptor antagonism, angiotensin-converting enzyme inhibitor, and phosphodiesterase type 5 inhibition can prevent angiogenesis inhibition-induced proteinuria. Moreover, the variable response of hypertension and renal injury to different antihypertensive agents suggests that these side effects are, at least in part, unrelated.

  16. From cellulite to smooth skin: is Viagra the new dream cream? (United States)

    Altabas, Karmela; Altabas, Velimir; Berković, Maja Cigrovski; Rotkvić, Vanja Zjacić


    In this article, we provide a hypothesis considering the potential effect of phosphodiesterase 5a inhibitors on cellulite. Cellulite is a significant cosmetic problem for many post-adolescent women. Its pathophysiology is complex and involves the presence of excess subcutaneous fat, the microcirculatory system, lymphatics and the extracellular matrix. Many diverse treatments have been tested to treat cellulite like iontophoresis, ultrasound, thermotherapy, pressotherapy, lymphatic drainage and electrolipophoresis which all enhance skin microcirculation. There have been several attempts to treat cellulite with drugs, but results were insufficient. Phosphodiesterases (PDE) are a superfamily of enzymes degrading adenosine monophosphate (cAMP) and cyclic guanosine monophoshpate (cGMP). Human fat cell lipolysis is mediated by both cAMP- and cGMP-dependent protein kinases. Indeed, high dose sildenafil pretreatment led to increased lipolysis in adipocyte cultures. That effect could not be attributed exclusively to either PDE3b or PDE5a inhibition, since sildenafil inhibited about 50% of the PDE3b activity in pretreated adipocytes. Sildenafil has a potential beneficial effect on skin microcirculation, as well as on tissue hypoxia. Transdermal or local route of administration should be considered.

  17. Pharmacological elevation of cyclic AMP and transmitter release at the mouse neuromuscular junction. (United States)

    Dryden, W F; Singh, Y N; Gordon, T; Lazarenko, G


    Intracellular recordings of spontaneous and evoked end-plate potentials have been made at the neuromuscular junction of mouse hemidiaphragms to determine a possible role of cyclic AMP (cAMP) in the release of acetylcholine from presynaptic terminals. Spontaneous release, as determined from the frequency of miniature end-plate potentials, was increased by drugs that inhibit phosphodiesterase: isobutylmethylxanthine (IBMX), SQ 20,009, theophylline, and caffeine; drugs that stimulate adenylate cyclase: forskolin, fluoride, and cholera toxin, and the stable analogue of cAMP: 8-bromo-cAMP but not dibutyryl cAMP. Release increased with time during maintained exposure to the drugs and generally followed a simple exponential time course with time constants ranging from 8 to 17 min at 20 degrees C, except for SQ 20,009 and cholera toxin which required longer exposure times for effect. The order of potency of the phosphodiesterase inhibitors was IBMX = SQ 20,009 greater than theophylline = caffeine. This is consistent with an effect mediated by an increase in cAMP concentrations within the nerve terminal. Evoked release, determined from the quantal content of the end-plate potential, was increased to a lesser extent than spontaneous release. The results are discussed with reference to the possible involvement of second messengers in the release of vesicles from nerve terminals in vertebrate synapses.

  18. Enzymatic activity of granulations tissues under low doses of radiation. Biochemical analysis in rats; Estudo da atividade enzimatica em tecidos de granulacao de ratos submetidos a baixas doses de radiacao

    Energy Technology Data Exchange (ETDEWEB)

    Tosoni, Guilherme Monteiro [UNESP, Araraquara, SP (Brazil). Faculdade de Odontologia. Dept. de Diagnostico e Cirurgia; Boscolo, Frab Norberto; Cury, Jaime Aparecido [Universidade Estadual de Campinas, Piracicaba, SP (Brazil). Faculdade de Odontologia; Watanabe, Plauto Christopher Aranha [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Odontologia. Dept. de Estomatologia


    This paper was designed to investigate in the rat subcutaneous sponge-induced granulation tissue under low doses of X-ray, the activity of alkaline phosphatase, 5`nucleotide phosphodiesterase and adenosine triphosphatase (ATPase) enzymes. One hundred and fourteen Wistar rats were divided into three groups, as follows: Group I as control, Group II that received single 7,14 R in split-dosis immediately after sponge-implantation at the third and fifth days postoperatively. Biopsies were taken after 7, 11, 14, 21 and 28 days and the activity of the three enzymes was determined. The results have shown that in Group II alkaline phosphatase had higher activity in the 14th day of tissue evolution when compared to Groups I and III . The 5`nucleotide phosphodiesterase activity in Group I was similar in all days checked, although in Group II the enzyme showed higher activity in 7th day and lower in 21st. In Group III the activity was higher after 14 and 7 days and lower after 28 and 21 days. There was no observation of changing in adenosine triphosphatase (ATPase) activity when the three groups were compared. (author) 28 refs., 3 tabs.

  19. The effects of high metal concentrations in soil-compost mixtures on soil enzymes. (United States)

    Warman, P R; Munroe, M D


    The study was undertaken to determine the impact of high-metal composts on the activities of four soil enzymes. High concentrations of metal salts (Cr, Cu, Ni or a Co-Mo-Pb combination) were added to feedstocks during the thermophilic stage of composting. These four metal-enriched composts and an unamended control compost were then mixed with soil collected from long-term agriculture plots under organic management or conventional management. The compost-soil mixtures were prepared at two rates (1:1 or 1:3 compost:soil, v/v) and incubated at 20 degrees C for three weeks. These 20 combinations plus the five composts and the two soils were added to pots and incubated for three weeks. Following incubation, soil enzyme activities (acid phosphatase, arysulfatase, dehydrogenase, phosphodiesterase) were measured using traditional assay procedures. Compared to the control, none of the high-metal composts inhibited soil enzyme activity. Notably, the Cu compost treatment produced significantly higher activity of all four enzymes in the soil compared to the control. Previous soil management influenced the activity of three enzymes, arysulfatase and dehydrogenase had greater activity in the organic soil while phosphatase activity was greater in the conventional soil. Increasing the proportion of compost in the pot had a positive effect on phosphodiesterase activity only. In conclusion, the high-metal compost treatments either enhanced or caused no adverse effects on soil enzyme activity.

  20. Comparative effect of glucagon and isoproterenol on hepatic glycogenolysis and glycolysis in isolated perfused liver

    Directory of Open Access Journals (Sweden)

    Vardanega-Peicher Márcia


    Full Text Available The effect of glucagon and isoproterenol (beta-adrenergic agonist on hepatic glycogenolysis and glycolysis in isolated perfused liver was compared. The levels of isoproterenol and glucagon which promoted the maximal activation of glycogenolysis were 20 muM and 1nM respectively. However, glucagon (1 nM not only increased glycogenolysis but also inhibited glycolysis. Because adenosine-3'-5'-cyclic monophosphate (cAMP is a common second messenger to glucagon and isoproterenol, the level of cAMP that simulates the effect of these substances were investigated. The concentration of cAMP that inhibited glycolysis was five times higher (15 muM than that which stimulated glycogenolysis (3 muM. Similar inhibition of glycolysis was obtained with cAMP agonists resistant to phosphodiesterases, i.e., 8-Br-cAMP and N6-monobutyryl-cAMP (6-MB-cAMP at the concentration of 3 muM. Thus, apparently glucagon could produce higher cellular levels of cAMP than that obtained with the activation of beta-adrenergic receptors. The higher amount of cAMP could be enough to overcome the action of phosphodiesterases and penetrate in the cytosol creating a favourable gradient to inhibit the enzymes of glycolysis.

  1. Autotaxin, Pruritus and Primary Biliary Cholangitis (PBC). (United States)

    Sun, Ying; Zhang, Weici; Evans, Jilly F; Floreani, Annarosa; Zou, Zhengsheng; Nishio, Yukiko; Qi, Ruizhao; Leung, Patrick S C; Bowlus, Christopher L; Gershwin, M Eric


    Autotaxin (ATX) is a 125-kD type II ectonucleotide pyrophosphatase/phosphodiesterase (ENPP2 or NPP2) originally discovered as an unknown "autocrine motility factor" in human melanoma cells. In addition to its pyrophosphatase/phosphodiesterase activities ATX has lysophospholipase D (lysoPLD) activity, catalyzing the conversion of lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA). ATX is the only ENPP family member with lysoPLD activity and it produces most of the LPA in circulation. In support of this, ATX heterozygous mice have 50% of normal LPA plasma levels. The ATX-LPA signaling axis plays an important role in both normal physiology and disease pathogenesis and recently has been linked to pruritus in chronic cholestatic liver diseases, including primary biliary cholangitis (PBC). Several lines of evidence have suggested that a circulating puritogen is responsible, but the identification of the molecule has yet to be definitively identified. In contrast, plasma ATX activity is strongly associated with pruritus in PBC, suggesting a targetable molecule for treatment. We review herein the biochemistry of ATX and the rationale for its role in pruritus.

  2. Influence of neurotropic compounds on the calmodulin- and troponin C-dependent processes

    Energy Technology Data Exchange (ETDEWEB)

    Baldenkov, G.N.; Men' shikov, M.Yu.; Feoktistov, I.A.; Tkachuk, V.A.


    An analysis was made of the effects of neurotropic compounds on the Ca-binding proteins - calmodulin and troponin C. It was shown that most of the neuroleptics of the phenothiazine group interact effectively both with calmodulin and with troponin C and also inhibit the calmodulin-dependent phosphodiesterase of cyclic nucleotides and calcium-activated actomyosin ATPase. Neuroleptics of the butyrophenone group, as well as imipramine and diphenhydramine, are capable of a low-efficiency interaction only with calmodulin. It was found that one of the phenothiazines - methophenazine, which is an effective inhibitor of calmodulin and calmodulin-dependent phosphodiesterase - does not affect troponin C and Ca-dependent actomyosin ATPase. As a result of this, methophenazine can serve as a convenient tool for studying processes regulated by these Ca-binding proteins. It was concluded that troponin C possesses Ca-dependent binding sites for drugs structurally similar to those of calmodulin but binding the drugs less effectively and exhibiting selectivity with respect to certain preparations. It was shown that despite the homology of the two Ca-binding proteins, calmodulin and troponin C, a selective action on the processes regulated by them is possible.

  3. The effects of caffeine on sleep in Drosophila require PKA activity, but not the adenosine receptor. (United States)

    Wu, Mark N; Ho, Karen; Crocker, Amanda; Yue, Zhifeng; Koh, Kyunghee; Sehgal, Amita


    Caffeine is one of the most widely consumed stimulants in the world and has been proposed to promote wakefulness by antagonizing function of the adenosine A2A receptor. Here, we show that chronic administration of caffeine reduces and fragments sleep in Drosophila and also lengthens circadian period. To identify the mechanisms underlying these effects of caffeine, we first generated mutants of the only known adenosine receptor in flies (dAdoR), which by sequence is most similar to the mammalian A2A receptor. Mutants lacking dAdoR have normal amounts of baseline sleep, as well as normal homeostatic responses to sleep deprivation. Surprisingly, these mutants respond normally to caffeine. On the other hand, the effects of caffeine on sleep and circadian rhythms are mimicked by a potent phosphodiesterase inhibitor, IBMX (3-isobutyl-1-methylxanthine). Using in vivo fluorescence resonance energy transfer imaging, we find that caffeine induces widespread increase in cAMP levels throughout the brain. Finally, the effects of caffeine on sleep are blocked in flies that have reduced neuronal PKA activity. We suggest that chronic administration of caffeine promotes wakefulness in Drosophila, at least in part, by inhibiting cAMP phosphodiesterase activity.

  4. Sexual function in patients with chronic angina pectoris. (United States)

    Kloner, Robert A; Henderson, Luana


    Drugs for erectile dysfunction (ED) may be contraindicated with nitrates commonly used to treat patients with angina pectoris, and certain antianginal therapies may worsen ED. The American Heart Association and the Princeton Consensus Conference panel of experts recommend that patients with coronary artery disease and ED who experience angina pectoris undergo full medical evaluations to assess the cardiovascular risks associated with resuming sexual activity before being prescribed therapy for ED. Current antianginal therapies include β blockers, calcium channel blockers, short- and long-acting nitrates, and ranolazine, a late sodium current inhibitor. Short- and long-acting nitrates remain a contraindication with phosphodiesterase-5 inhibitors commonly used to treat patients with ED, and the benefits of the other antianginal therapies must be weighed against their effects on cardiovascular health and erectile function. In conclusion, patients with coronary artery disease and ED who wish to initiate phosphodiesterase-5 inhibitor therapy and need to discontinue nitrate therapy need treatment options that manage their angina pectoris effectively, maintain their cardiovascular health, and provide the freedom to maintain their sexual function.

  5. Capture compound mass spectrometry--a powerful tool to identify novel c-di-GMP effector proteins. (United States)

    Laventie, Benoît-Joseph; Nesper, Jutta; Ahrné, Erik; Glatter, Timo; Schmidt, Alexander; Jenal, Urs


    Considerable progress has been made during the last decade towards the identification and characterization of enzymes involved in the synthesis (diguanylate cyclases) and degradation (phosphodiesterases) of the second messenger c-di-GMP. In contrast, little information is available regarding the molecular mechanisms and cellular components through which this signaling molecule regulates a diverse range of cellular processes. Most of the known effector proteins belong to the PilZ family or are degenerated diguanylate cyclases or phosphodiesterases that have given up on catalysis and have adopted effector function. Thus, to better define the cellular c-di-GMP network in a wide range of bacteria experimental methods are required to identify and validate novel effectors for which reliable in silico predictions fail. We have recently developed a novel Capture Compound Mass Spectrometry (CCMS) based technology as a powerful tool to biochemically identify and characterize c-di-GMP binding proteins. This technique has previously been reported to be applicable to a wide range of organisms(1). Here we give a detailed description of the protocol that we utilize to probe such signaling components. As an example, we use Pseudomonas aeruginosa, an opportunistic pathogen in which c-di-GMP plays a critical role in virulence and biofilm control. CCMS identified 74% (38/51) of the known or predicted components of the c-di-GMP network. This study explains the CCMS procedure in detail, and establishes it as a powerful and versatile tool to identify novel components involved in small molecule signaling.

  6. Non‑Hormonal treatment of BPH/BOO

    Directory of Open Access Journals (Sweden)

    Nadir I Osman


    Full Text Available Objectives: To review the use of non-hormonal pharmacotherapies in the treatment of lower urinary tract symptoms (LUTS due to presumed benign prostatic hyperplasia (BPH. Materials and Methods: A search of the PUBMED database was conducted for the terms BPH, LUTS, bladder outlet obstruction, alpha-adrenoceptor blockers, anti-muscarinics, and phosphodiesterase-5-inhibitors. Results: Medical therapy has long been established as the accepted standard of care in the treatment of male LUTS. The aim of treatment is improvement in symptoms and quality of life whilst minimizing adverse effects. The agents most widely used as 1 st line therapy are alpha-blockers (AB, as a standalone or in combination with 2 other classes of drug; 5-α reductase inhibitors and anti-muscarinics. AB have rapid efficacy, improving symptoms and flow rate in a matter of days, these effects are then maintained over time. AB do not impact on prostate size and do not prevent acute urinary retention or the need for surgery. Anti-mucarinics, alone or in combination with an AB are safe and efficacious in the treatment of bothersome storage symptoms associated with LUTS/BPH. Phosphodiesterase-5 inhibitors are an emerging treatment option that improve LUTS without improving flow rates. Conclusions: AB are the most well-established pharmacotherapy in the management of men with LUTS/BPH. The emergence of different classes of agent offers the opportunity to target underlying pathophysiologies driving symptoms and better individualize treatment.

  7. Specificity and structural analysis of a guinea pig transfer factor-like activity. (United States)

    Dunnick, W A; Bach, F H


    A transfer factor-like activity was prepared by Sephadex G-25 chromatography of immune guinea pig leukocyte lysates. This isolated material leads to antigen-dependent migration inhibition and thymidine uptake by nonimmune lymphoid cells. Tests of the "transfer factor" from guinea pigs immunized to either ovalbumin or bovine gamma-globulin demonstrated the donor specificity of the in vitro activity. The activity is susceptible to heat (56 degrees C), alkali (0.5 M sodium hydroxide), pronase, and phosphodiesterase. The pronase susceptibility is blocked by traysylol, a protease inhibitor; the phosphodiesterase susceptibility is not bocked by traysylol. The guinea pig factor was purified further by alkaline phosphatase treatment. Sephadex G-25 chromatography, and DEAE-cellulose chromatography. The final product, active in vitro, represents about 0.03% of the cellular material absorbing 260 nm light, and contains polymerized amines and phosphate. Gel electrophoresis of the fluram-reactive components suggests a limited heterogeneity of the DEAE-cellulose-purified material. These data are consistent with the active "transfer factor" molecule including both peptide and phosphate-containing components.

  8. cAMP-Signalling Regulates Gametocyte-Infected Erythrocyte Deformability Required for Malaria Parasite Transmission.

    Directory of Open Access Journals (Sweden)

    Ghania Ramdani


    Full Text Available Blocking Plasmodium falciparum transmission to mosquitoes has been designated a strategic objective in the global agenda of malaria elimination. Transmission is ensured by gametocyte-infected erythrocytes (GIE that sequester in the bone marrow and at maturation are released into peripheral blood from where they are taken up during a mosquito blood meal. Release into the blood circulation is accompanied by an increase in GIE deformability that allows them to pass through the spleen. Here, we used a microsphere matrix to mimic splenic filtration and investigated the role of cAMP-signalling in regulating GIE deformability. We demonstrated that mature GIE deformability is dependent on reduced cAMP-signalling and on increased phosphodiesterase expression in stage V gametocytes, and that parasite cAMP-dependent kinase activity contributes to the stiffness of immature gametocytes. Importantly, pharmacological agents that raise cAMP levels in transmissible stage V gametocytes render them less deformable and hence less likely to circulate through the spleen. Therefore, phosphodiesterase inhibitors that raise cAMP levels in P. falciparum infected erythrocytes, such as sildenafil, represent new candidate drugs to block transmission of malaria parasites.

  9. cAMP对缺血神经元保护作用的机制研究%Mechanism of cAMP in Ischemic Neuron Protection

    Institute of Scientific and Technical Information of China (English)

    乌日罕; 赵延欣; 刘学源


    Current researches and trials witness the lack of effective treatment in neuron protection after stroke. Yet phosphodiesterase inhibitors present protective effect in ischemic neuron in an intracellular cAMP enhancing pattern. The protective mechanism of cAMP in ischemic neuron after stroke was discussed. And the evidences for therapeutic utilization of phosphodiesterase inhibitors were offered.%目前对于缺血性脑卒中后神经元的保护仍缺乏明确有效的药物治疗.磷酸二酯酶抑制剂可通过增加细胞内cAMP的含量对缺血性神经元发挥保护作用.本文从cAMP对缺血性神经元胞内和胞外的作用,阐述cAMP对缺血神经元发挥保护作用的机制,并试图为磷酸二酯酶抑制剂等cAMP增效药物的临床应用提供理论基础.

  10. Gender-related differences in pulmonary arterial hypertension targeted drugs administration. (United States)

    Marra, Alberto M; Benjamin, Nicola; Eichstaedt, Christina; Salzano, Andrea; Arcopinto, Michele; Gargani, Luna; D Alto, Michele; Argiento, Paola; Falsetti, Lorenzo; Di Giosia, Paolo; Isidori, Andrea M; Ferrara, Francesco; Bossone, Eduardo; Cittadini, Antonio; Grünig, Ekkehard


    During the last 15 years, a real "paradigm-shift" occurred, due to the development of PAH-targeted drugs, leading to crucial improvements in symptoms, exercise capacity, hemodynamics and outcome of PAH patients. In order to describe differences regarding epidemiology and therapy in PAH according to gender, we performed a review of the available literature in "PubMed" and "Web of Science" databases. In order to find relevant articles, we combined each of the following the keywords "pulmonary arterial hypertension", "gender", "sex", "men", "woman", "male", "female", "phosphodiesterase inhibitors", "endothelin receptor antagonists", "prostanoids". While there is a substantial agreement among epidemiological studies in reporting an increased prevalence of pulmonary arterial hypertension (PAH) among women, male PAH patients are affected by a higher impairment of the right ventricular function and consequently experience poorer outcomes. With regards to PAH-targeted drug administration, endothelin receptor antagonists (ERAs) and prostacyclin analogues (PC) show better treatment results in female PAH patients, while phosphodiesterase-5 inhibitors (PD5-I) seem to exert a more beneficial effect on male patients. However, to date no clear consensus could be formed by the available literature, which is constituted mainly by retrospective studies. Females with PAH are more prone to develop PAH, while males experience poorer outcomes. Females PAH might benefit more from ERAs and PC, while males seem to have more beneficial effects from PD5-I administration. However, more research is warranted in order to assess the most effective treatment for PAH patients according to gender.

  11. Clinical utility of tadalafil in the treatment of pulmonary arterial hypertension: an evidence-based review

    Directory of Open Access Journals (Sweden)

    Henrie AM


    Full Text Available Adam M Henrie, James J Nawarskas, Joe R Anderson College of Pharmacy, University of New Mexico, Albuquerque, NM, USA Abstract: Pulmonary arterial hypertension (PAH is a chronic and disabling condition characterized by an elevated pulmonary vascular resistance and an elevated mean pulmonary arterial pressure. Despite recent improvements in treatment availability, PAH remains challenging to treat, burdensome for patients, and ultimately incurable. Tadalafil is a phosphodiesterase-5 inhibitor that is administered once daily by mouth for the treatment of PAH. Current treatment guidelines recommend tadalafil as an option for patients with World Health Organization functional class II or III PAH. In a placebo-controlled clinical trial, patients taking tadalafil demonstrated significantly improved exercise capacity as measured by the 6-minute walk distance. Patients also experienced decreased incidence of clinical worsening, increased quality of life, and improved cardiopulmonary hemodynamics. Uncontrolled studies and smaller trials have indicated a possible role for tadalafil as a suitable alternative to sildenafil and as a beneficial add-on option when used in combination with other treatments for PAH. Tadalafil is generally safe and well tolerated. Adverse events are typically mild-to-moderate in intensity, and discontinuation rates are usually low. The purpose of this review is to provide an evidence-based evaluation of the clinical utility of tadalafil in the treatment of PAH. Keywords: tadalafil, phosphodiesterase-5 inhibitor, pulmonary arterial hypertension

  12. Update on the clinical utility of sildenafil in the treatment of pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Gautam V Ramani


    Full Text Available Gautam V Ramani, Myung H ParkUniversity of Maryland, Baltimore, MD, USAAbstract: Sildenafil is an orally administered phosphodiesterase type 5 inhibitor that is approved for the treatment of pulmonary arterial hypertension (PAH. The hemodynamic effects of sildenafil are mitigated primarily via potentiating the effects of endogenous nitric oxide, leading to smooth muscle cell relaxation and reductions in pulmonary arterial pressures and pulmonary vascular resistance. When added to standard background therapy in patients with idiopathic or associated PAH from congenital heart disease, anorexigen use, or connective tissue disease, sildenafil treatment results in improved exercise capacity as measured by 6 minute walk distance, improved hemodynamics, and favorable changes in quality of life. Sildenafil use is contraindicated with concomitant nitrate administration, and caution should be exercised when used in combination with antihypertensive agents due to risks of precipitating hypotension. Side effects are generally mild, and include flushing, headaches, and epistaxis. The combination of sildenafil with intravenous epoprostenol is safe and well tolerated, and further improves exercise capacity. Sildenafil is approved only for treatment of PAH, and although emerging data suggest a potential role in treating other types of pulmonary hypertension, larger trials are required to confirm these findings. Keywords: sildenafil, pulmonary arterial hypertension, phosphodiesterase type 5 inhibitor

  13. Novel pyrimidopyrimidine derivatives for inhibition of cellular proliferation and motility induced by h-prune in breast cancer. (United States)

    Virgilio, Antonella; Spano, Daniela; Esposito, Veronica; Di Dato, Valeria; Citarella, Giuseppe; Marino, Natascia; Maffia, Veronica; De Martino, Daniela; De Antonellis, Pasqualino; Galeone, Aldo; Zollo, Massimo


    The human (h)-prune protein is a member of the DHH protein superfamily and it has a cAMP phosphodiesterase activity. Its overexpression in breast, colorectal and gastric cancers correlates with depth of invasion and a high degree of lymph-node metastasis. One mechanism by which h-prune stimulates cell motility and metastasis processes is through its phosphodiesterase activity, which can be suppressed by dipyridamole, a pyrimido[5,4-d]pyrimidine analogue. To obtain new and more potent agents that have high specificity towards inhibition of this h-prune activity, we followed structure-activity-relationship methodologies starting from dipyridamole and synthesised eight new pyrimido-pyrimidine derivatives. We analysed these newly generated compounds for specificity towards h-prune activities in vitro in cellular models using scintillation proximity assay for cAMP-PDE activity, cell index in cell proliferation assays and transwell methodology for two-dimensional cell migration in a top-down strategy of selection. Our findings show that two pyrimido[5,4-d]pyrimidine compounds are more effective than dipyridamole in two highly metastatic cellular models of breast cancer in vitro. Future studies will assess their therapeutic effectiveness against breast and other cancers where there is over-expression of h-prune, and in ad-hoc, proof of concept, animal models.

  14. Cyclic AMP enhances calcium-dependent potassium current in Aplysia neurons. (United States)

    Ewald, D; Eckert, R


    The effect on the Ca-dependent potassium current, IK(Ca), of procedures that increase intracellular cAMP levels was studied in Aplysia neurons using three different pharmacological approaches. Exposure to cAMP analogues which were either resistant to or protected from phosphodiesterase hydrolysis caused an increase in IK(Ca) from 30 to 50% in 10 min. The degree of reversibility of this effect varied from complete with db cAMP to very little with pcpt cAMP. Exposure to cholera toxin, which stimulates the synthesis of endogenous cAMP, increased IK(Ca) 25% in 10 min and the effect was not reversible. Both approaches were effective in all seven neuron types studied. Application of serotonin plus phosphodiesterase inhibitor caused an increase in IK(Ca) in neuron R15 but not in the other neuron types. Application of pentylene tetrazole (PTZ) led to a decrease in IK(Ca). It is proposed that elevation of cyclic AMP mediates an increased sensitivity of the IK(Ca) channel to Ca ions.

  15. Rolipram attenuates MK-801-induced deficits in latent inhibition. (United States)

    Davis, Jennifer A; Gould, Thomas J


    Latent inhibition is used to examine attention and study cognitive deficits associated with schizophrenia. Research using MK-801, an N-methyl-D-aspartate (NMDA) open channel blocker, implicates glutamate receptors in acquisition of latent inhibition of cued fear conditioning. Evidence suggests an important relationship between NMDA-induced increases in cyclic adenosine monophosphate (cAMP) and learning and memory. The authors examine whether amplification of the cAMP signaling pathway by rolipram, a selective Type 4 cAMP phosphodiesterase inhibitor, reverses MK-801-induced impairments in latent inhibition. One day before training, mice were injected with MK-801, rolipram, MK-801 and rolipram, or vehicle and received 20 preexposures or no preexposures to an auditory conditioned stimulus (CS). Training consisted of 2 CS-footshock unconditioned stimulus pairings. Rolipram attenuated the disruptive effect of MK-801 on latent inhibition, which suggests a role for the cAMP signaling pathway in the task and implicates phosphodiesterase inhibition as a target for treating cognitive impairments associated with schizophrenia.

  16. Management of erectile dysfunction post-radical prostatectomy

    Directory of Open Access Journals (Sweden)

    Saleh A


    Full Text Available Alan Saleh, Hamid Abboudi, MB Ghazal-Aswad, Erik K Mayer, Justin A Vale Division of Surgery and Cancer, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK Abstract: Radical prostatectomy is a commonly performed procedure for the treatment of localized prostate cancer. One of the long-term complications is erectile dysfunction. There is little consensus on the optimal management; however, it is agreed that treatment must be prompt to prevent fibrosis and increase oxygenation of penile tissue. It is vital that patient expectations are discussed, a realistic time frame of treatment provided, and treatment started as close to the prostatectomy as possible. Current treatment regimens rely on phosphodiesterase 5 inhibitors as a first-line therapy, with vacuum erection devices and intraurethral suppositories of alprostadil as possible treatment combination options. With nonresponders to these therapies, intracavernosal injections are resorted to. As a final measure, patients undergo the highly invasive penile prosthesis implantation. There is no uniform, objective treatment program for erectile dysfunction post-radical prostatectomy. Management plans are based on poorly conducted and often underpowered studies in combination with physician and patient preferences. They involve the aforementioned drugs and treatment methods in different sequences and doses. Prospective treatments include dietary supplements and gene therapy, which have shown promise with there proposed mechanisms of improving erectile function but are yet to be applied successfully in human patients. Keywords: erectile dysfunction, phosphodiesterase 5 inhibitors, vacuum erection devices, intraurethral suppositories, intracavernosal injections

  17. Inhibition of transducin activation and guanosine triphosphatase activity by aluminum ion. (United States)

    Miller, J L; Hubbard, C M; Litman, B J; Macdonald, T L


    Aluminum ion perturbs the activity of a number of physiologically important enzymes, including members of a family of guanine nucleotide-binding proteins (G-proteins). G-proteins couple cellular receptor proteins to a variety of effector enzymes (including adenylate cyclase, phospholipase C, and the rod photoreceptor phosphodiesterase). We show herein that subnanomolar concentrations of free aluminum ion, produced in a carefully defined and kinetically stable manner through the buffering of total aluminum at 0.1-1.0 mM with calculated ratios of chelating agents, inhibit both the receptor-mediated activation and the self-inactivating GTPase activity of the rod photoreceptor G-protein, Gv. In the presence of 4 X 10(-10) M free aluminum ion, GTPase activity is inhibited from about 25-60% as the magnesium ion concentration is reduced from 10(-3) to about 5 X 10(-5) M. The principal effect of aluminum ion upon Gv is to inhibit receptor catalyzed nucleotide exchange. Binding of the GTP analog 5'-guanylyl imidodiphosphate can be reduced by as much as 90% by aluminum ion following subsaturating rhodopsin stimulation. Aluminum ion can produce either competitive or mixed noncompetitive inhibition of rhodopsin-catalyzed Gv activation and GTPase activity, as a function of whether Gv undergoes single (competitive), or multiple (mixed noncompetitive) nucleotide exchanges. The rod photoreceptor phosphodiesterase is only slightly inhibited by similar aluminum ion activities. Light- and Gv-coupled phosphodiesterase activation exhibits both a lower maximum rate of cyclic guanosine monophosphate hydrolysis and a slower inactivation in the presence of aluminum ion activities from about 10(-12) - 10(-10) M. These data suggest that intracellular free aluminum ion concentrations in the subnanomolar range could markedly affect the ability of cells to transduce extracellular signals. Interestingly, the combination of Al3+ and F- to produce the fluoro-aluminate species (AlFx) also inhibits

  18. Actividades Enzimáticas en Consorcios Bacterianos de Suelos Bajo Cultivo de Papa con Manejo Convencional y Bajo Pastizal Enzyme Activities in Bacterial Consortium Isolated from Soils with Potato Crop under Conventional Management and under Grassland

    Directory of Open Access Journals (Sweden)

    Lizeth Manuela Avellaneda-Torres


    Full Text Available Resumen. Se evaluaron las actividades enzimáticas (ureasa, proteasa, fosfatasa ácida y alcalina, fosfodiesterasa, b-glucosidasa y arilsulfatasa en consorcios bacterianos (Bacillus subtilis, Brevundimonas diminuta, Flavimonas oryzihabitants de suelos bajo cultivo de papa variedad Parda Pastusa, con manejo convencional de aplicación de agroinsumos (PCA y en suelos bajo pastizal sin aplicación de agroinsumos (PSA, en fincas de tres localidades del departamento de Cundinamarca (Tausa, Villapinzón y Zipaquirá, Colombia. Se encontraron efectos por la aplicación de insumos de síntesis química y el tipo de uso del suelo, sobre las actividades enzimáticas; sin embargo, estos fueron diferentes para cada una de las enzimas y localidades. Para el municipio de Villapinzón la actividad de ureasa, fosfatasa ácida, fosfodiesterasa y b-glucosidasa, fue mayor en las muestras PCA con respecto a las PSA en un 89, 71, 67 y 75% respectivamente; para el municipio de Zipaquirá se presentó la misma tendencia en la actividad ureasa, b-glucosidasa y arilsulfatasa con un 50, 71 y 68% respectivamente; finalmente en el municipio de Tausa se mantuvo el mismo comportamiento para la actividad de proteasa, fosfatasa ácida, fosfatasa alcalina, fosfodiesterasa, b-glucosidasa, con un 55, 20, 75, 82 y 87% de mayor actividad en las muestras PCA en relación con las de PSA.Abstract. Enzyme activities were evaluated (urease, protease, acid phosphatase and alkaline phosphodiesterase, b-glucosidase and arylsulfatase in bacterial consortia (Bacillus subtilis, Brevundimonas diminuta, Flavimonas oryzihabitants from either soil with potato cropping under conventional management with the application of agrochemicals (PWA or grassland soils without the use of agrochemicals (GNA on farms of three municipalities (Tausa, Villapinzón and Zipaquirá in the department of Cundinamarca, Colombia. The type of land use and the location affected the tested enzymatic activities. In the

  19. Role of yessotoxin in calcium and cAMP-crosstalks in primary and K-562 human lymphocytes: the effect is mediated by anchor kinase A mitochondrial proteins. (United States)

    Tobío, Araceli; Fernández-Araujo, Andrea; Alfonso, Amparo; Botana, Luis M


    Yessotoxin (YTX) is a marine polyether toxin previously described as a phosphodiesterase (PDE) activator in fresh human lymphocytes. This toxin induces a decrease of adenosine 3',5'-cyclic monophosphate (cAMP) levels in fresh human lymphocytes in a medium with calcium (Ca(2+) ), whereas the contrary effect has been observed in a Ca(2+) -free medium. In the present article, the effect of YTX in K-562 lymphocytes cell line has been analysed. Surprisingly, results obtained in K-562 cell line are completely opposite than in fresh human lymphocytes, since in K-562 cells YTX induces an increase of cAMP levels. YTX cytotoxicity was also studied in both K-562 cell line and fresh human lymphocytes. Results demonstrate that YTX does not modify fresh human lymphocytes viability, whereas in K-562 cells, YTX has a highly cytotoxic effect. It has been described in a previous study that YTX induces a small cytosolic Ca(2+) increase in fresh human lymphocytes but no effect was observed on Ca(2+) pools depletion in these cells. However, our results show that, in K-562 cells, YTX has no effect on cytosolic Ca(2+) levels in a medium with Ca(2+) and induces an increase on Ca(2+) pools depletion followed by a Ca(2+) influx. As far as Ca(2+) modulation is concerned these results demonstrate that YTX has a clear opposite effect in tumoural and fresh human lymphocytes. In addition, intracellular Ca(2+) reservoirs affected by YTX are different than thapsigargin-sensible pools. Furthermore, YTX-dependent Ca(2+) pools depletion was abolished by cAMP analogue (dibutyryl cAMP), phosphodiesterase-4 (PDE4) inhibitor (rolipram), protein kinase A inhibitor (H89) and oxidative phosphorylation uncoupler carbonyl cyanide p-(trifluoromethoxy) (FCCP) treatments. This evidences the crosstalks between Ca(2+) , YTX and cAMP pathways. Also, results obtain demonstrate that YTX-dependent Ca(2+) influx was only abolished by FCCP pre-treatment, which indicates a link between YTX and mitochondria in K-562 cell

  20. Post-prostatectomy erectile dysfunction: contemporary approaches from a US perspective

    Directory of Open Access Journals (Sweden)

    Hamilton Z


    Full Text Available Zachary Hamilton,1 Moben Mirza,2 1Department of Urology, 2Division of Urologic Oncology, Department of Urology, University of Kansas, Kansas City, KS, USA Abstract: Success of cancer surgery often leads to life-changing side effects, and surgical treatment for malignant urologic disease often results in erectile dysfunction (ED. Patients that undergo surgical prostatectomy or cystoprostatectomy will often experience impairment of erections due to disruption of blood and nerve supply. Surgical technique, nerve sparing status, patient age, comorbid conditions, and pretreatment potency status all have an effect on post-surgical ED. Regardless of surgical technique, prostatectomy results in disruption of normal anatomy and nerve supply to the penis, which governs the functional aspects of erection. A variety of different treatment options are available for men who develop ED after prostatectomy, including vacuum erection device, oral phosphodiesterase 5 inhibitors (PDE5I, intracorporal injections, and penile prosthesis. The vacuum erection device creates an artificial erection by forming a vacuum via suction of air to draw blood into the penis. The majority of men using the vacuum erection device daily after prostatectomy, regardless of nerve-sparing status, have erections sufficient for intercourse. Phosphodiesterase 5 inhibitors remain a common treatment option for post-surgical ED and are the mainstay of therapy. They work through cyclic adenosine monophosphate and cyclic guanine monophosphate pathways and are recommended in all forms of ED. Intracorporal injections or intraurethral use of vasoactive substances may be a good second-line therapy in men who do not experience improvement with oral medications. Surgical placement of a penile prosthesis is typically the treatment strategy of choice after other options have failed. Semi-rigid and inflatable devices are available with high satisfaction rates. With careful patient counseling and proper

  1. Carboranyl oligonucleotides. 3. Biochemical properties of oligonucleotides containing 5-(o-carboranyl-l-yl)-2{prime}-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Lesnikowski, Z.J.; Fulcrand, G.; Lloyd, R.M. Jr. [Veterans Affairs Medical Center and Georgia Research Center for AIDS and HIV Infections, Decatur, GA (United States)]|[Emory Univ. School of Medicine, Atlanta, GA (United States)


    Boronated oligonucleotides are potential candidates for boron neutron capture therapy, antisense technology, and as tools in molecular biology. The biological properties of dodecathymidylic acids containing one or more 5-(o-carboran-l-yl)-2{prime}-deoxyuridine residues at different locations within the oligonucleotide chain were studied. 5-(o-carboran-l-yl)-2{prime}-deoxyuridine containing oligonucleotides manifested marked increased lipophilicity and resistance to 3{prime}- or 5{prime}-phosphodiesterases compared to the corresponding unmodified oligomer. They were substrates for T4 polynucleotide kinase and primers for Escherichia coli polymerase I and human immunodeficiency virus type 1 reverse transcriptase but not for human DNA polymerase {alpha} and {beta}. They also formed heteroduplexes that were substrates for E. coli RNase H, an essential property for antisense technology. These studies indicate that the carboranyl-containing oligonucleotides have desirable properties that need to be exploited further in the design of novel biopharmaceuticals. 33 refs., 2 figs., 1 tab.

  2. Pulmonary Arterial Hypertension in Adults: Novel Drugs and Catheter Ablation Techniques Show Promise? Systematic Review on Pharmacotherapy and Interventional Strategies

    Directory of Open Access Journals (Sweden)

    Salvatore Rosanio


    Full Text Available This systematic review aims to provide an update on pharmacological and interventional strategies for the treatment of pulmonary arterial hypertension in adults. Currently US Food and Drug Administration approved drugs including prostanoids, endothelin-receptor antagonists, phosphodiesterase type-5 inhibitors, and soluble guanylate-cyclase stimulators. These agents have transformed the prognosis for pulmonary arterial hypertension patients from symptomatic improvements in exercise tolerance ten years ago to delayed disease progression today. On the other hand, percutaneous balloon atrioseptostomy by using radiofrequency perforation, cutting balloon dilatation, or insertion of butterfly stents and pulmonary artery catheter-based denervation, both associated with very low rate of major complications and death, should be considered in combination with specific drugs at an earlier stage rather than late in the progression of pulmonary arterial hypertension and before the occurrence of overt right-sided heart failure.

  3. Control of the renal renin system by local factors

    DEFF Research Database (Denmark)

    Wagner, C; Jensen, B L; Krämer, B K


    prostanoid, both stimulate renin secretion and renin gene expression by activating cAMP formation in JG cells. Although the direct effect of NO on JG cells is less clear, its overall effect in vivo seems to be to stimulate the renin system. Evidence is emerging that stimulation by NO is related to the c......AMP pathway, and cGMP-induced inhibition of cAMP-phosphodiesterase III (PDE-III) may mediate this effect. ETs, on the other hand, appear to inhibit the renin system, in particular in those pathways activated by cAMP, acting via Ca2+- and protein kinase C-related mechanisms. There is increasing evidence...... that both NO and PGs could be involved in the physiological regulatory mechanisms by which salt intake affects the renin system....

  4. Effects of drugs on platelet function. (United States)

    Morse, E E


    Numerous drugs and chemicals affect the function of human blood platelets. The mechanism of action of some medications is partly understood. Aspirin is the most frequently involved drug. It appears to interfere with the platelet release reaction by acetylation of a platelet membrane protein which may be involved in the synthesis of prostaglandins. Other anti-inflammatory drugs, including indomethacin, phenylbutazone, ibuprophen (Motrin) and clonixin, also interfere with the release reaction but have a shorter acting course than aspirin. Some drugs stimulate adenylcyclase (gliclazide) or block phosphodiesterase, (dipyridamole, caffeine) both of which actions lead to an increase in adenosine cyclic 3':5' monophosphate (cAMP) and decrease aggregation by adenosine diphosphate (ADP). These interactions should be known to clinical scientists since patients using these medicaments may manifest abnormal platelet function tests in the laboratory and mild hemorrhagic syndromes in the clinic.

  5. Mirodenafil for the treatment of erectile dysfunction: a systematic review of the literature. (United States)

    Park, Hyun Jun; Moon, Kyung Hyun; Lee, Seung Wook; Lee, Won Ki; Kam, Sung Chul; Lee, Jun Ho; Park, Nam Cheol


    Phosphodiesterase type 5 (PDE5) inhibitors are the most commonly used treatment for erectile dysfunction (ED). Since the launch of sildenafil, several drugs-including mirodenafil, sildenafil citrate (sildenafil), tadalafil, vardenafil HCL (vardenafil), udenafil, and avanafil-have become available. Mirodenafil is a newly developed pyrrolopyrimidinone compound, which is a potent, reversible, and selective oral PDE5 inhibitor. Mirodenafil was launched in Korea in 2007, and an orally disintegrating film of mirodenafil was developed in 2011 for benefitting patients having difficulty in swallowing tablets. This study aimed to review the pharmacokinetic characteristic profile of mirodenafil and report evidence on its efficacy in the case of ED. In addition, we reviewed randomized controlled studies of mirodenafil's daily administration and efficacy for lower urinary tract symptoms.

  6. Chronic thromboembolic pulmonary arterial hypertension: a review of the literature and novel therapeutic approaches. (United States)

    Androulakis, Emmanuel; Lioudaki, Eirini; Christophides, Theodoros; Ahmad, Mahmood; Fayed, Hossam; Laskar, Nabila; Schreiber, Benjamin


    Chronic thromboembolic pulmonary hypertension is defined as pulmonary hypertension (PH) caused by single or recurrent pulmonary emboli and is characterized by chronic obstruction of the pulmonary arteries leading to increased vascular resistance and PH. Also, progressive remodeling may occur in occluded and nonoccluded territories. Better understanding of the underlying mechanisms and risk factors could improve diagnosis and allow appropriate interventions. Pulmonary endarterectomy is an established approach and is considered the definitive treatment for chronic PH, resulting from thromboembolic disease. Furthermore, percutaneous transluminal pulmonary angioplasty is technically feasible, especially for those with peripheral-type of the disease. In addition, several agents, including prostanoids, endothelin receptor antagonists and phosphodiesterase type-5 inhibitors, have been tested in selected patients yielding promising results. Several novel agents are under investigation, and extensive research is currently in progress aiming to resolve uncertainties in the understanding and treatment of the disease.

  7. Acute effects of sildenafil and dobutamine in the hypertrophic and failing right heart in vivo

    DEFF Research Database (Denmark)

    Andersen, Asger; Nielsen, Jan M; Rasalingam, Sivagowry;


    administration of the PDE-5 inhibitor sildenafil in a single clinically relevant dose did not modulate the in vivo function of the hypertrophic failing right heart of the rat measured by echocardiography and invasive hemodynamics. In the same model, dobutamine acutely improved RV function.......Abstract The purpose of this study was to investigate whether acute intravenous administration of the phosphodiesterase type 5 (PDE-5) inhibitor sildenafil in a single clinically relevant dose improves the in vivo function of the hypertrophic and failing right ventricle (RV). Wistar rats ([Formula......]). Invasive RV pressures were recorded continuously, and transthoracic echocardiography was performed 1, 5, 15, 25, 35, 50, 70, and 90 minutes after injecting the bolus. Cardiac function was compared to baseline measurements to evaluate the in vivo effects of each specific treatment. The PTB procedure caused...

  8. Effect of the caffeine on treated and non-treated plasmid DNA with stannic chloride; Efeito da cafeina em DNA plasmidial tratado e nao tratado com cloreto estanoso

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Silvana Ramos F. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Biofisica e Biometria]|[Universidade Federal Fluminense, Niteroi, RJ (Brazil). Faculdade de Ciencias Medicas. Curso de Pos-graduacao em Patologia Experimental; Mattos, Jose C.P. de; Dantas, Flavio; Araujo, Adriano Caldeira de; Bernardo-Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Biofisica e Biometria]. E-mail:


    Caffeine, a methilxantine drug is a component of coffee, tea, stimulants and other drinks. Caffeine inhibits phosphodiesterase leading to intracellular accumulation of cyclic AMP, blocks adenosine receptors, and increases the release of Ca{sup 2+}. We have studied the possible effect of caffeine in DNA plasmid treated or not with stannous chloride (SnCl{sub 2}). Previous evaluations of the effect of caffeine on the labeling of red blood cells and plasma proteins with technetium-99m have showed a decrease of % ATI in the insoluble fraction of plasma proteins. Samples of DNA were treated with SnCl{sub 2} (0 and 200{mu}g/ml) in 0.8% agarose. SnCl{sub 2} has induced break on DNA and caffeine has not showed effect on the DNA. This indicates that caffeine does not eliminate the oxidant action of SnCl{sub 2} and does not promote break in isolated DNA plasmid. (author)

  9. Milrinone in Enterovirus 71 Brain Stem Encephalitis (United States)

    Wang, Shih-Min


    Enterovirus 71 (EV71) was implicated in a widespread outbreak of hand-foot-and-mouth disease (HFMD) across the Asia Pacific area since 1997 and has also been reported sporadically in patients with brain stem encephalitis. Neurogenic shock with pulmonary edema (PE) is a fatal complication of EV71 infection. Among inotropic agents, milrinone is selected as a therapeutic agent for EV71- induced PE due to its immunopathogenesis. Milrinone is a type III phosphodiesterase inhibitor that has both inotropic and vasodilator effects. Its clinical efficacy has been shown by modulating inflammation, reducing sympathetic over-activity, and improving survival in patients with EV71-associated PE. Milrinone exhibits immunoregulatory and anti-inflammatory effects in the management of systemic inflammatory responses in severe EV71 infection. PMID:27065870

  10. Sildenafil attenuates the fibrotic phenotype of skin fibroblasts in patients with systemic sclerosis. (United States)

    Higuchi, Tomoaki; Kawaguchi, Yasushi; Takagi, Kae; Tochimoto, Akiko; Ota, Yuko; Katsumata, Yasuhiro; Ichida, Hisae; Hanaoka, Masanori; Kawasumi, Hidenaga; Tochihara, Mari; Yamanaka, Hisashi


    Systemic sclerosis (SSc) is a multi-organ fibrotic disease that affects the skin and various internal organs. Therapeutic strategies for tissue fibrosis have not been established; however, aberrantly activated fibroblasts in affected lesions are key targets for modulating fibrosis. Recently, increased intracellular cyclic GMP (cGMP) levels were demonstrated to improve fibrosis levels in various diseases. The purpose of this study was to assess the anti-fibrotic properties of cGMP in cultured fibroblasts from patients with SSc. The phosphodiesterase (PDE) 5 inhibitor sildenafil increased the intracellular cGMP levels in skin fibroblasts in a dose-dependent manner. Sildenafil treatment also significantly decreased the expression of several pro-fibrotic factors that were upregulated by TGF-β1 treatment in SSc skin fibroblasts. These inhibitory effects occurred via non-canonical TGF-β signaling. Our findings revealed that sildenafil might be a novel strategy to treat tissue fibrosis and vasculopathy in SSc.

  11. Anaesthesia for patients undergoing ventricular assist-device implantation. (United States)

    Feussner, Markus; Mukherjee, Chirojit; Garbade, Jens; Ender, Joerg


    In the last 10 years, implantation of ventricular-assist devices has become an interesting option as either bridge-to-transplantation or destination procedure for patients with end-stage congestive heart failure. In the future, the number of ventricular assist device implantations is expected to increase furthermore. In general, this patient cohort is associated with significant co-morbidities, for example, pulmonary hypertension, peripheral vascular disease and renal insufficiency. Anaesthetic management for implantation of ventricular assist devices can be challenging for cardiac anaesthesiologists. Even minor changes in their haemodynamics and physiological parameters can cause significant morbidity and mortality. Experience in haemodynamic monitoring including echocardiography and pharmacological management (use of inotropes, phosphodiesterase inhibitors and vasopressors) is a requirement. Particularly, the diagnosis and therapy of right-sided heart failure after implantation of left-ventricular assist devices should be addressed.

  12. Coadjuvants in the Diabetic Complications: Nutraceuticals and Drugs with Pleiotropic Effects

    Directory of Open Access Journals (Sweden)

    Thiago Melo Costa Pereira


    Full Text Available Because diabetes mellitus (DM is a multifactorial metabolic disease, its prevention and treatment has been a constant challenge for basic and clinical investigators focused on translating their discoveries into clinical treatment of this complex disorder. In this review, we highlight recent experimental and clinical evidences of potential coadjuvants in the management of DM, such as polyphenols (quercetin, resveratrol and silymarin, cultured probiotic microorganisms and drugs acting through direct/indirect or pleiotropic effects on glycemic control in DM. Among several options, we highlight new promising therapeutic coadjuvants, including chemical scavengers, the probiotic kefir and the phosphodiesterase 5 inhibitors, which besides the reduction of hyperglycemia and ameliorate insulin resistance, they reduce oxidative stress and improve endothelial dysfunction in the systemic vascular circulation. In the near future, experimental studies are expected to clear the intracellular pathways involving coadjuvants. The design of clinical trials may also contribute to new strategies with coadjuvants against the harmful effects of diabetic complications.

  13. Peptide and non-peptide opioid-induced hyperthermia in rabbits (United States)

    Kandasamy, S. B.; Williams, B. A.


    The intracerebroventricular administration of prototype nonpeptide opioid receptor (mu, kappa, and sigma) agonists, morphine, ketocyclazocine, and N-allyl-normetazocine was found to induce hyperthermia in rabbits. The similar administration of peptide opioids like beta-endorphin (BE), methionine-enkephalin (ME), and its synthetic analogue D-ala2-methionine-enkephalinamide (DAME) was also found to cause hyperthermia. Results indicate that only the liver-like transport system is important to the ventricular inactivation of BE and DAME. Prostaglandins and norepinephrine were determined not to be involved in peptide and nonpeptide opioid-induced hyperthermia. In addition, cAMP was not required since a phosphodiesterase inhibitor, theophylline, did not accentuate the hyperthermia due to peptide and nonpeptide opioids. Naloxone-sensitive receptors were found to be involved in the induction of hyperthermia by morphine, BE, ME, and DAME since naloxone attenuated them. However, the hyperthermic response to ketocyclazocine and N-allyl-normetazocine was not antagonized by naloxone.

  14. cAMP Signals in Drosophila Motor Neurons Are Confined to Single Synaptic Boutons

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    Isabella Maiellaro


    Full Text Available The second messenger cyclic AMP (cAMP plays an important role in synaptic plasticity. Although there is evidence for local control of synaptic transmission and plasticity, it is less clear whether a similar spatial confinement of cAMP signaling exists. Here, we suggest a possible biophysical basis for the site-specific regulation of synaptic plasticity by cAMP, a highly diffusible small molecule that transforms the physiology of synapses in a local and specific manner. By exploiting the octopaminergic system of Drosophila, which mediates structural synaptic plasticity via a cAMP-dependent pathway, we demonstrate the existence of local cAMP signaling compartments of micrometer dimensions within single motor neurons. In addition, we provide evidence that heterogeneous octopamine receptor localization, coupled with local differences in phosphodiesterase activity, underlies the observed differences in cAMP signaling in the axon, cell body, and boutons.

  15. Current medical and surgical management of Raynaud's syndrome. (United States)

    Landry, Gregory J


    Raynaud's syndrome (RS) is characterized by episodic digital ischemia induced by cold or emotional stress. Pathophysiologic mechanisms include temporary vasospasm and fixed digital artery obstruction. A number of pharmacologic and invasive therapies have been studied to treat RS symptoms; however, there are no specific treatments that are currently approved by the U.S. Food and Drug Administration specifically for RS. Of the available pharmacologic agents, calcium-channel blockers remain the preferred initial treatment for vasospastic RS, although many vasodilators have been studied and found to be efficacious. Vasodilators are less effective in treating digital artery obstruction, and no treatments have been found to be universally beneficial, although the phosphodiesterase V inhibitors have been gaining in popularity. Invasive therapies may have a role in selective cases. In this review, the current evidence of treatment for RS is summarized.

  16. Understanding the Pathophysiology of Premature Ejaculation: Bridging the Link between Pharmacological and Psychological Interventions. (United States)

    Sidi, Hatta; Yusof, Farid; Das, Srijit; Midin, Marhani; Kumar, Jaya; Hatta, Muhammd Hizri


    Premature ejaculation (PE) is one of the commonest male sexual dysfunctions. It is characterized by ejaculation which occurs before or soon after vaginal penetration, which causes significant psychological distress to the individual, and his partner. The exact cause of PE is still unknown but several mechanisms are proposed, and these involve complex interactions of neurophysiological, psychosocial, and cognitive factors. We discuss the role of serotonin, nitric oxide, phosphodiesterase enzymes and other neurotransmitters. Treatment of PE tends to co-occur with other sexual difficulties, especially erectile dysfunction (ED). Treatment with selective serotonin reuptake inhibitors (SSRIs) and Dapoxitene are also discussed in detail. The treatment strategy requires a comprehensive holistic approach incorporating both combination of psychopharmacological agent and cognitive-behavioral therapy (CBT). The present review highlights the integration of the hypothalamic-neural and reverberating emotional circuit and discusses the etiology and treatment for patients with PE.

  17. A new therapeutic approach for erectile dysfunction: Low intensity shockwaves

    Directory of Open Access Journals (Sweden)

    García-Perdomo, Herney Andrés


    Full Text Available Erectile dysfunction is the inability to achieve or sustain a penile erection for vaginal penetration and satisfactory sexual performance. It is the second most frequent problem of sexual dysfunction in men, after premature ejaculation, with an approximate prevalence rate of 30%. Most cases of erectile dysfunction have an organic origin, mostly vascular diseases, but it is also associated with psychological, neurological, and hormonal factors, or with structural alterations of the penis. Therapy with 5-phosphodiesterase inhibitors has been clinically effective, but some patients do not respond to it. Lowintensity shock waves may improve penile vascularity and blood flow, leading to better erections, and improvement of the quality of sexual performance. In this review several studies are included that show the effectiveness of this treatment for erectile dysfunction.

  18. Distribution of PDE8A in the nervous system of the Sprague-Dawley rat

    DEFF Research Database (Denmark)

    Kruse, Lars Schack; Møller, Morten; Kruuse, Christina


    Phosphodiesterases (PDEs) are essential regulators of cyclic nucleotide signaling. Little is known of the distribution and function of the cyclic adenosine monophosphate (cAMP) hydrolyzing PDE8A family. Employing immunohistochemistry and Western blots this study maps the distribution of PDE8A...... in the brain of adult male Sprague-Dawley rats and in the trigeminal ganglion. PDE8A was confined to neuronal perikaryal cytoplasm and to processes extending from those perikarya. The neurons exhibiting PDE8A-immunoreactivity were widely distributed in the forebrain, brain stem, and cerebellum. Strongly....... The localization of the cAMP degrading PDE8A may indicate a role for PDE8A in cAMP signaling related to pain transmission, motor function, cognition and olfaction....

  19. [New treatments for chronic obstructive pulmonary disease]. (United States)

    Miravitlles, Marc


    Treatment of chronic obstructive pulmonary disease (COPD) has underwent a very important advance in the last five years. It has been developed a new long-lasting anticholynergic drug, tiotrope bromure, which has been found to improve lung function and exercise capacity and to decrease relapses. Also the combined treatment of long lasting beta 2 adrenergics with inhaled steroids (salmeterol/fluticasone and formoterol/budesonide) has proven similar results. However, the response to these new drugs is not the same in all patients. Individual characteristics such as gravity, degree of bronchial hyperresponsiveness, frequency of relapses, comorbidity, etc will determine the response to several agents. Thus, it is necessary to perform a detailed diagnostic study in COPD patients in order to select the best treatment in an individualized form. In the future, new specific antiinflammatories such as phosphodiesterase 4 inhibitors or agents with a potential action in tissue regeneration could lead to new perspectives, as well as to new questions, in COPD treatment.

  20. Aspirin: Pharmacology and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Enma V. Paez Espinosa


    Full Text Available Antiplatelet therapy has been documented to reduce risks of cardiovascular disease after acute myocardial infarction, coronary artery bypass graft, and in chronic atrial fibrillation patients, amongst other risk factors. Conventional management of thrombosis-based disorders includes the use of heparin, oral anticoagulants, and the preferred antiplatelet agent aspirin. Interestingly, aspirin was not intended to be used as an antiplatelet agent; rather, after being repurposed, it has become one of the most widely prescribed antithrombotic drugs. To this end, there have been several milestones in the development of antiplatelet agents in the last few decades, such as adenosine diphosphate receptor inhibitors, phosphodiesterase inhibitors, and GPIIb/IIIa inhibitors. However, given some of the limitations of these therapies, aspirin continues to play a major role in the management of thrombotic and cardiovascular disorders and is expected to do so for years to come.