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Sample records for phosphodiesterase iii inhibitor

  1. CHARACTERIZATION OF ORG-20241, A COMBINED PHOSPHODIESTERASE IV/III CYCLIC-NUCLEOTIDE PHOSPHODIESTERASE INHIBITOR FOR ASTHMA

    NARCIS (Netherlands)

    NICHOLSON, CD; BRUIN, J; BARRON, E; SPIERS, [No Value; DEBOER, J; VANAMSTERDAM, RGM; ZAAGSMA, J; KELLY, JJ; DENT, G; GIEMBYCZ, MA; BARNES, PJ

    The pharmacological profile of a novel cyclic nucleotide phosphodiesterase (PDE) inhibitor, Org 20241, has been characterized. The compound selectively inhibits PDE IV (plC(50), 5.2-6.1) and PDE III (plC(50), 4.4-4.6) from animal and human tissues. Org 20241 relaxed preparations of bovine trachea

  2. Minimally invasive monitoring of skeletal muscle hypermetabolism induced by the phosphodiesterase-III-inhibitor milrinone and sodium fluoride.

    Science.gov (United States)

    Schuster, Frank; Johannsen, Stephan; Roewer, Norbert; Anetseder, Martin

    2013-04-01

    We hypothesized that the phosphodiesterase-III-inhibitor milrinone and the non-specific G-protein activator sodium fluoride increase the skeletal muscular lactate levels as a sign of a hypermetabolic response. With approval of the local animal care committee Sprague-Dawley rats were killed and artificially perfused either with Ringer's solution or sodium fluoride 110 mM, while milrinone 1.32 mM or Ringer's solution at 1 μl/min was applied via microdialysis probes in both hind limbs. Lactate was measured spectrophotometrically in the dialysate. Baseline lactate levels before drug application did not differ between hind limbs. Local infusion of milrinone via microdialysis did not significantly increase intramuscular lactate concentrations compared with the Ringer control group. Muscular perfusion with sodium fluoride resulted in a significant increase of lactate and was potentiated by combination with local milrinone. Phosphodiesterase-III-inhibition alone does not significantly influence the lactate levels in skeletal muscle of sacrificed rats. Sodium fluoride infusion leads to an intramuscular lactate increase, which was further potentiated by local inhibition of phosphodiesterase-III. The fluoride-mediated hypermetabolic response following sodium fluoride could be a possible explanation for the observed myotoxic adverse effects in individuals treated by fluoride-containing agents. © 2012 The Authors. JPP © 2012. Royal Pharmaceutical Society.

  3. Effect of phosphodiesterase inhibitors on human arteries in vitro

    NARCIS (Netherlands)

    Vroom, M. B.; Pfaffendorf, M.; van Wezel, H. B.; van Zwieten, P. A.

    1996-01-01

    In the present study, we investigated if the relaxant effects of phosphodiesterase (PDE) III inhibitors on human vessels could be inhibited by a nitric oxide synthase blocker, L-NAME, or by a blocker of ATP-sensitive potassium channels (KATP), glibenclamide. The experiments were performed using an

  4. [Comparison of the effects of phosphodiesterase III inhibitors, milrinone and olprinone, in infant corrective cardiac surgery].

    Science.gov (United States)

    Sakimura, Shotaro; Yoshino, Jun; Izumi, Kaoru; Jimi, Nobuo; Sumiyoshi, Rieko; Mizuno, Keiichiro

    2013-05-01

    Clinical characteristics of phosphodiesterase (PDE) III inhibitors, milrinone and olprinone, is not fully understood in infants. We therefore retrospectively examined the hemodynamics, metabolism, and oxygenation of two different PDE III inhibitors in infants undergoing radical correction of ventricular septal defect with pulmonary hypertension. Twenty-six infants with pulmonary hypertension undergoing ventricular septum defect repair were retrospectively allocated to milrinone group (n= 13)and olprinone group(n=13). Hemodynamic parameters, acid-base balance, oxygenation and postoperative mechanical ventilation period were compared between the two groups at induction of anesthesia, weaning from cardiopulmonary bypass and the end of the surgery. The patients' mean age was 4.4 +/- 2.5 months. Demographic data were almost similar between the two groups. Milrinone and olprinone were administered at the rates of 0.5 and 0.3 microg x kg-1 x min-1 at the end of surgery, respectively. Hemodynamic variables, acid-base balance, Pao2 /FIo2 ratio and mechanical ventilation period were not significantly different between the two groups. No adverse side effects were observed during the study period. The effects of the PDE III inhibitors, milrinone and olprinone, on hemodynamic parameters, acid-base balance and oxygenation were similar in these infants. Both milrinone and olprinone could be used safely in infant cardiac surgery.

  5. Effects of phosphodiesterase III inhibition on length-dependent regulation of myocardial function in coronary surgery patients

    NARCIS (Netherlands)

    de Hert, S. G.; ten Broecke, P. W.; Mertens, E.; Rodrigus, I. E.; Stockman, B. A.

    2002-01-01

    BACKGROUND: Phosphodiesterase III inhibitors increase myocardial contractility and decrease left ventricular (LV) afterload. We studied whether these effects altered LV response to an increase in cardiac load and affected length-dependent regulation of myocardial function. METHODS: Before the start

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

    DEFF Research Database (Denmark)

    Birk, Steffen; Edvinsson, Lars; Olesen, Jes

    2004-01-01

    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...

  7. Phosphodiesterase 4 inhibitor and phosphodiesterase 5 inhibitor combination therapy has antifibrotic and anti-inflammatory effects in mdx mice with Duchenne muscular dystrophy.

    Science.gov (United States)

    Nio, Yasunori; Tanaka, Masayuki; Hirozane, Yoshihiko; Muraki, Yo; Okawara, Mitsugi; Hazama, Masatoshi; Matsuo, Takanori

    2017-12-01

    Duchenne muscular dystrophy (DMD) is the most common inherited muscular dystrophy. Patients experience DMD in their 20s from cardiac or respiratory failure related to progressive muscle wasting. Currently, the only treatments for the symptoms of DMD are available. Muscle fibrosis, a DMD feature, leads to reduced muscle function and muscle mass, and hampers pharmaceutical therapeutic efficacy. Although antifibrotic agents may be useful, none is currently approved. Phosphodiesterase 4 (PDE4) inhibitors have exhibited antifibrotic effects in human and animal models. In this study, we showed beneficial effects of the PDE4 inhibitor piclamilast in the DMD mdx mouse. Piclamilast reduced the mRNA level of profibrotic genes, including collagen 1A1, in the gastrocnemius and diaphragm, in the mdx mouse, and significantly reduced the Sirius red staining area. The PDE5 inhibitors sildenafil and tadalafil ameliorated functional muscle ischemia in boys with DMD, and sildenafil reversed cardiac dysfunction in the mdx mouse. Single-treatment piclamilast or sildenafil showed similar antifibrotic effects on the gastrocnemius; combination therapy showed a potent antifibrotic effect, and piclamilast and combination therapy increased peroxisome proliferator-activated receptor γ coactivator-1α mRNA in mouse gastrocnemius. In summary, we confirmed that piclamilast has significant antifibrotic effects in mdx mouse muscle and is a potential treatment for muscle fibrosis in DMD.-Nio, Y., Tanaka, M., Hirozane, Y., Muraki, Y., Okawara, M., Hazama, M., Matsuo, T. Phosphodiesterase 4 inhibitor and phosphodiesterase 5 inhibitor combination therapy has antifibrotic and anti-inflammatory effects in mdx mice with Duchenne muscular dystrophy. © FASEB.

  8. Effectiveness of Phosphodiesterase-5 Inhibitor Therapy for Portopulmonary Hypertension

    Directory of Open Access Journals (Sweden)

    Jolene H Fisher

    2015-01-01

    Full Text Available BACKGROUND: Portopulmonary hypertension is associated with significant morbidity and mortality. Phosphodiesterase-5 inhibitor therapy is efficacious in other causes of WHO group I pulmonary arterial hypertension.

  9. The effect of phosphodiesterase-5 inhibitors on cerebral blood flow in humans

    DEFF Research Database (Denmark)

    Pauls, Mathilde Mh; Moynihan, Barry; Barrick, Thomas R

    2018-01-01

    , ED, type 2 diabetes, stroke, pulmonary hypertension, Becker muscular dystrophy and subarachnoid haemorrhage. Most studies used middle cerebral artery flow velocity to estimate CBF. Few studies employed direct measurements of tissue perfusion. Resting CBF velocity was unaffected by phosphodiesterase-5...... inhibitors, but cerebrovascular regulation was improved in ED, pulmonary hypertension, diabetes, Becker's and a group of healthy volunteers. This evidence suggests that phosphodiesterase-5 inhibitors improve responsiveness of the cerebral vasculature, particularly in disease states associated...

  10. Phosphodiesterase inhibitors in clinical urology.

    Science.gov (United States)

    Ückert, Stefan; Kuczyk, Markus A; Oelke, Matthias

    2013-05-01

    To date, benign diseases of the male and female lower urinary and genital tract, such as erectile dysfunction, bladder overactivity, lower urinary tract symptomatology secondary to benign prostatic hyperplasia and symptoms of female sexual dysfunction (including arousal and orgasmic disorders), can be therapeutically approached by influencing the function of the smooth musculature of the respective tissues. The use of isoenzyme-selective phosphodiesterase (PDE) inhibitors is considered a great opportunity to treat various diseases of the human urogenital tract. PDE inhibitors, in particular the PDE5 (cyclic GMP PDE) inhibitors avanafil, lodenafil, sildenafil, tadalafil, udenafil and vardenafil, are regarded as efficacious, having a fast onset of drug action and an improved effect-to-adverse event ratio, combining a high response rate with the advantage of an on-demand intake. The purpose of this review is to summarize recent as well as potential future indications, namely, erectile dysfunction, Peyronie's disease, overactive bladder, urinary stone disease, lower urinary tract symptomatology secondary to benign prostatic hyperplasia and premature ejaculation, for the use of PDE inhibitors in clinical urology.

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

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    Alves Alessandra C

    1997-01-01

    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.

  12. Milrinone, a phosphodiesterase III inhibitor, prevents reduction of jugular bulb saturation during rewarming from hypothermic cardiopulmonary bypass.

    Science.gov (United States)

    Iritakenishi, T; Hayashi, Y; Yamanaka, H; Kamibayashi, T; Ueda, K; Mashimo, T

    2012-01-01

    Inadequate cerebral oxygen balance during cardiopulmonary bypass may cause neuropsychological dysfunction. Milrinone, a phosphodiesterase III inhibitor, augments cerebral blood flow by direct vasodilatation. We conducted a prospective, randomized study in patients undergoing cardiac surgery with cardiopulmonary bypass to clarify the clinical efficacy of milrinone in the imbalance of cerebral oxygen supply and demand during the rewarming period of cardiopulmonary bypass. This is a prospective, randomized and placebo-controlled study. After anesthesia, a 5.5 F fiberoptic oximeter catheter was inserted into the right jugular bulb retrogradely for monitoring the jugular venous oxyhemoglobin saturation (SjO(2)). Patients were randomly assigned to two groups, one receiving a continuous infusion of milrinone, 0.5 µg/kg/min during hypothermic cardiopulmonary bypass, and the other receiving saline as control. Milrinone significantly prevented the reduction of the jugular venous oxyhemoglobin saturation at 10 minutes from the start of rewarming compared with the control group, but did not do so from 10 to 20 minutes after rewarming. Milrinone suppresses the reduction of SjO(2) and improves the balance of cerebral oxygen supply and demand during the early rewarming period of hypothermic cardiopulmonary bypass.

  13. Invitro pharmacology of r-80122, a novel phosphodiesterase inhibitor

    NARCIS (Netherlands)

    WILHELM, D; WILFFERT, B; JANSSENS, WJ; LEIDIG, A; MEUTER, C; EBBERT, M; Peters, Thies

    1992-01-01

    The cardiac in vitro effects of R 80122, a novel phosphodiesterase (PDE) inhibitor, were investigated and compared with those of the reference compound milrinone and of the calcium-sensitizer adibendan. In guinea pig left atria, both milrinone and R 80122 increased contractile force; 10 muM

  14. In vitro pharmacology of R 80122, a novel phosphodiesterase inhibitor

    NARCIS (Netherlands)

    Wilhelm, D.; Wilffert, B.; Janssens, W.J.; Leidig, A.; Meuter, C.; Ebbert, M.; Peters, Thies

    1992-01-01

    The cardiac in vitro effects of R 80122, a novel phosphodiesterase (PDE) inhibitor, were investigated and compared with those of the reference compound milrinone and of the calcium-sensitizer adibendan. In guinea pig left atria, both milrinone and R 80122 increased contractile force; 10 μM milrinone

  15. A selective phosphodiesterase 10A inhibitor reduces l-dopa-induced dyskinesias in parkinsonian monkeys.

    Science.gov (United States)

    Beck, Goichi; Maehara, Shunsuke; Chang, Phat Ly; Papa, Stella M

    2018-03-06

    Phosphodiesterase 10A is a member of the phosphodiesterase family whose brain expression is restricted to the striatum. Phosphodiesterase 10A regulates cyclic adenosine monophosphate and cyclic guanosine monophosphate, which mediate responses to dopamine receptor activation, and the levels of these cyclic nucleotides are decreased in experimental models of l-dopa-induced dyskinesia. The elevation of cyclic adenosine monophosphate/cyclic guanosine monophosphate levels by phosphodiesterase 10A inhibition may thus be targeted to reduce l-dopa-induced dyskinesia. The present study was aimed at determining the potential antidyskinetic effects of phosphodiesterase 10A inhibitors in a primate model of Parkinson's disease (PD). The experiments performed in this model were also intended to provide translational data for the design of future clinical trials. Five MPTP-treated macaques with advanced parkinsonism and reproducible l-dopa-induced dyskinesia were used. MR1916, a selective phosphodiesterase 10A inhibitor, at doses 0.0015 to 0.05 mg/kg, subcutaneously, or its vehicle (control test) was coadministered with l-dopa methyl ester acutely (predetermined optimal and suboptimal subcutaneous doses) and oral l-dopa chronically as daily treatment for 5 weeks. Standardized scales were used to assess motor disability and l-dopa-induced dyskinesia by blinded examiners. Pharmacokinetics was also examined. MR1916 consistently reduced l-dopa-induced dyskinesia in acute tests of l-dopa optimal and suboptimal doses. Significant effects were present with every MR1916 dose tested, but the most effective was 0.015 mg/kg. None of the MR1916 doses tested affected the antiparkinsonian action of l-dopa at the optimal dose. The anti-l-dopa-induced dyskinesia effect of MR1916 (0.015 mg/kg, subcutaneously) was sustained with chronic administration, indicating that tolerance did not develop over the 5-week treatment. No adverse effects were observed after MR1916 administration acutely or

  16. Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

    International Nuclear Information System (INIS)

    Lawrie, K.W.M.; Novelli, C.E.A.; Saunders, David

    1995-01-01

    The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano- 14 C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author)

  17. Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lawrie, K.W.M.; Novelli, C.E.A.; Saunders, David [SmithKline Beecham Pharmaceuticals Research and Development, Harlow (United Kingdom). Synthetic Isotope Chemistry Dept.; Coates, W.J. [SmithKline Beecham Pharmaceuticals Research and Development, Welwyn (United Kingdom)

    1995-09-01

    The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano-{sup 14}C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author).

  18. Radioimmunoassays for cyclic AMP cross-react with phosphodiesterase inhibitors and buffer components

    NARCIS (Netherlands)

    Sinha, B; Semmler, J; Haen, E; Moeller, J; Endres, S

    We addressed the issue of cross-reactivity of several commonly used phosphodiesterase inhibitors with radioimmunoassays for cyclic AMP, after we had observed a considerably high cross-reactivity with a noncommercial antibody. Theophylline, pentoxifylline, penthydroxifylline (BL 194), albifylline

  19. 6-Nitrobenzimidazole derivatives: potential phosphodiesterase inhibitors: synthesis and structure-activity relationship.

    Science.gov (United States)

    Khan, K M; Shah, Zarbad; Ahmad, V U; Ambreen, N; Khan, M; Taha, M; Rahim, F; Noreen, S; Perveen, S; Choudhary, M I; Voelter, W

    2012-02-15

    6-Nitrobenzimidazole derivatives (1-30) synthesized and their phosphodiesterase inhibitory activities determined. Out of thirty tested compounds, ten showed a varying degrees of phosphodiesterase inhibition with IC(50) values between 1.5±0.043 and 294.0±16.7 μM. Compounds 30 (IC(50)=1.5±0.043 μM), 1 (IC(50)=2.4±0.049 μM), 11 (IC(50)=5.7±0.113 μM), 13 (IC(50)=6.4±0.148 μM), 14 (IC(50)=10.5±0.51 μM), 9 (IC(50)=11.49±0.08 μM), 3 (IC(50)=63.1±1.48 μM), 10 (IC(50)=120.0±4.47 μM), and 6 (IC(50)=153.2±5.6 μM) showed excellent phosphodiesterase inhibitory activity, much superior to the standard EDTA (IC(50)=274±0.007 μM), and thus are potential molecules for the development of a new class of phosphodiesterase inhibitors. A structure-activity relationship is evaluated. All compounds are characterized by spectroscopic parameters. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Tetomilast: new promise for phosphodiesterase-4 inhibitors?

    Science.gov (United States)

    Bickston, Stephen J; Snider, Kenneth R; Kappus, Matthew R

    2012-12-01

    Tetomilast is a novel thiazole phosphodiesterase-4 (PDE-4) inhibitor, which may prove useful in both the treatment of inflammatory bowel disease (IBD) and chronic obstructive pulmonary disease (COPD). Here, the authors review the pharmacology of the drug, and offer critical review of the available data for use of tetomilast in the treatment of IBD. Peer-reviewed publications, including Phase I and II clinical trials, all other formats included. Tetomilast may be beneficial in IBD. Small differences in molecules and in recombinant proteins can translate into substantial differences in clinical effects and toxicity in IBD. This is a reasonable approach when exploring new options like tetomilast.

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

    Directory of Open Access Journals (Sweden)

    Moschos MM

    2016-10-01

    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

  2. Phosphodiesterase III inhibition affects platelet-monocyte aggregate formation depending on the axis of stimulation.

    NARCIS (Netherlands)

    Horn, N.A.; Anastase, D.M.; Hecker, K.E.; Baumert, J.H.; Scheffer, G.J.; Rossaint, R.

    2006-01-01

    OBJECTIVE: The purpose of this study was to investigate the effect of the phosphodiesterase (PDE) type 3 inhibitor milrinone on the adhesion of platelets to monocytes in vitro. DESIGN: Prospective study. SETTING: University experimental laboratory. PARTICIPANTS: Ten healthy volunteers.

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

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    Nöella Germain

    1999-01-01

    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.

  4. Phosphodiesterase Type 5 Inhibitors, Sport and Doping.

    Science.gov (United States)

    Di Luigi, Luigi; Sansone, Massimiliano; Sansone, Andrea; Ceci, Roberta; Duranti, Guglielmo; Borrione, Paolo; Crescioli, Clara; Sgrò, Paolo; Sabatini, Stefania

    Phosphodiesterase type 5 inhibitors (PDE5i) (e.g., sildenafil, tadalafil, vardenafil, and avanafil) are drugs commonly used to treat erectile dysfunction, pulmonary arterial hypertension, and benign prostatic hyperplasia. PDE5i are not prohibited by the World Anti-Doping Agency (WADA) but are alleged to be frequently misused by healthy athletes to improve sporting performance. In vitro and in vivo studies have reported various effects of PDE5i on cardiovascular, muscular, metabolic, and neuroendocrine systems and the potential, therefore, to enhance performance of healthy athletes during training and competition. This suggests well-controlled research studies to examine the ergogenic effects of PDE5i on performance during activities that simulate real sporting situations are warranted to determine if PDE5i should be included on the prohibited WADA list. In the meantime, there is concern that some otherwise healthy athletes will continue to misuse PDE5i to gain an unfair competitive advantage over their competitors.

  5. Assay of cyclic nucleotide phosphodiesterase using radiolabeled and fluorescent substrates

    International Nuclear Information System (INIS)

    Kincaid, R.L.; Manganiello, V.C.

    1988-01-01

    There are four major classes of phosphodiesterase with different specificities for cAMP and cGMP and different allosteric regulators. Type I phosphodiesterase is activated by calmodulin plus Ca/sup 2+/ and has a higher affinity for cGMP than cAMP. Type II phosphodiesterase likewise has a higher affinity for cGMP than cAMP, but the activity toward one substrate is markedly stimulated by low (micromolar) concentrations of the other nucleotide. Type III phosphodiesterase has a higher affinity for cAMP than cGMP; its activity is increased in responsive cells by certain hormones, e.g., insulin, isoproterenol. Type IV phosphodiesterase is the cGMP-specific enzyme, which also has an allosteric binding site for cGMP. An example of this class of enzyme is the one from retinal rod outer segments, which is activated by light via rhodopsin and the guanine nucleotide-binding protein transducin. There appears to be little structural relatedness among these enzymes based on immunologic analysis, consistent with the possibility that divergent forms evolved from an ancestral enzyme. Determination of the amount of a specific form of phosphodiesterase in crude material is often difficult. Modification of assay conditions by judicious choice of substrate and/or inhibitor concentrations may selectively favor (or reduce) the activity of a particular form; in many instances, however, some fractionation of enzymes may be necessary. This is discussed more fully in the final section of this chapter

  6. The devil is in the details: an analysis of the subtleties between phosphodiesterase inhibitors for erectile dysfunction.

    Science.gov (United States)

    Smith-Harrison, L I; Patel, Abhishek; Smith, Ryan P

    2016-04-01

    Erectile dysfunction (ED) is a common sexual disorder with numerous etiologies involving multiple organ systems that leads to significant distress and decreased quality of life for the affected men. Fortunately, there are several modalities and interventions for treating ED. Oral medications, intra-urethral compounds, intracorporeal injections, vacuum-assist devices and surgically implanted prostheses are all part of the treatment algorithm. One of the first-lines and certainly the most widely used options for treating ED is the family of oral phosphodiesterase type 5 inhibitors (PDE5I). The introduction of these medications in the late 1990s revolutionized the field of sexual medicine. Currently there are no guidelines and minimal literature to help providers choose among drugs in this class. This review will address differences in efficacy and side effects between various members of the oral selective phosphodiesterase-5 inhibitor class of drugs.

  7. A rhodium(III)-based inhibitor of autotaxin with antiproliferative activity.

    Science.gov (United States)

    Kang, Tian-Shu; Wang, Wanhe; Zhong, Hai-Jing; Liang, Jia-Xin; Ko, Chung-Nga; Lu, Jin-Jian; Chen, Xiu-Ping; Ma, Dik-Lung; Leung, Chung-Hang

    2017-02-01

    Cancer of the skin is by far the most common of all cancers. Melanoma accounts for only about 1% of skin cancers but causes a large majority of skin cancer deaths. Autotaxin (ATX), also known as ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2), regulates physiological and pathological functions of lysophosphatidic acid (LPA), and is thus an important therapeutic target. We synthesized ten metal-based complexes and a novel cyclometalated rhodium(III) complex 1 was identified as an ATX enzymatic inhibitor using multiple methods, including ATX enzymatic assay, thermal shift assay, western immunoblotting and so on. Protein thermal shift assays showed that 1 increased the melting temperature (T m ) of ATX by 3.5°C. 1 also reduced ATX-LPA mediated downstream survival signal pathway proteins such as ERK and AKT, and inhibited the activation of the transcription factor nuclear factor κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3). 1 also exhibited strong anti-proliferative activity against A2058 melanoma cells (IC 50 =0.58μM). Structure-activity relationship indicated that both the rhodium(III) center and the auxiliary ligands of complex 1 are important for bioactivity. 1 represents a promising scaffold for the development of small-molecule ATX inhibitors for anti-tumor applications. To our knowledge, complex 1 is the first metal-based ATX inhibitor reported to date. Rhodium complexes will have the increased attention in therapeutic and bioanalytical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Synthesis of[11C]LY186126, an inhibitor of phosphodiesterase

    International Nuclear Information System (INIS)

    Prenant, C.; Crouzel, C.; Comar, D.; Robertson, D.W.

    1992-01-01

    LY186126 [1,3-dihydro-1,3,3-trimethyl-5-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyriddazinyl)-2H-indol-2-one ], an analogue of the cardiotonic agent indolidan, is a potent, selective and competitive inhibitor of an isozymic form of cyclic AMP phosphodiesterase. LY186126 was labelled with carbon-11 to permit pharmacological studies in the dog myocardium by positron emission tomography. Alkylation with [ 11 C]methyl iodide of N-norLY186126 (LY-197055) allowed the production of 1.7 GBq (50mCi) of [ 11 C]LY-186126 in 40 min. The product, was purified by HPLC. (author)

  9. THE PRESENCE OF 5 CYCLIC-NUCLEOTIDE PHOSPHODIESTERASE ISOENZYME ACTIVITIES IN BOVINE TRACHEAL SMOOTH-MUSCLE AND THE FUNCTIONAL-EFFECTS OF SELECTIVE INHIBITORS

    NARCIS (Netherlands)

    VANAMSTERDAM, RGM; DEBOER, J; TENBERGE, RE; NICHOLSON, CD; ZAAGSMA, J

    1991-01-01

    1 The profile of cyclic nucleotide phosphodiesterase (PDE) isoenzymes and the relaxant effects of isoenzyme selective inhibitors were examined in bovine tracheal smooth muscle. The compounds examined were the non-selective inhibitor 3-isobutyl-1-methylxanthine (IBMX), zaprinast (PDE V selective),

  10. Effects of selective phosphodiesterases-4 inhibitors on learning and memory: a review of recent research.

    Science.gov (United States)

    Peng, Sheng; Sun, Haiyan; Zhang, Xiaoqing; Liu, Gongjian; Wang, Guanglei

    2014-09-01

    Phosphodiesterase-4 (PDE-4) regulates the intracellular level of cyclic adenosine monophosphate. Recent studies demonstrated that PDE-4 inhibitors can counteract deficits in long-term memory caused by aging or increased expression of mutant forms of human amyloid precursor proteins, and can influence the process of memory function and cognitive enhancement. Therapeutics, such as ketamine, a drug used in clinical anesthesia, can also cause memory deficits as adverse effects. Targeting PDE-4 with selective inhibitors may offer a novel therapeutic strategy to prevent, slow the progress, and, eventually, treat memory deficits.

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

    Directory of Open Access Journals (Sweden)

    Charu eAgarwal

    2010-11-01

    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.

  12. 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

    2001-01-01

    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 (cGMP...... a close relation to the nitric oxide-cGMP pathway. The responses to zaprinast and dipyridamole, however, were not only moderately affected, but also restored by sodium nitroprusside (0.1 microM) pretreatment. At high concentrations, the dilatory effects of zaprinast and dipyridamole were partly caused...... 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....

  13. Imidazopyridine- and purine-thioacetamide derivatives: potent inhibitors of nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1).

    Science.gov (United States)

    Chang, Lei; Lee, Sang-Yong; Leonczak, Piotr; Rozenski, Jef; De Jonghe, Steven; Hanck, Theodor; Müller, Christa E; Herdewijn, Piet

    2014-12-11

    Nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1) belongs to the family of ecto-nucleotidases, which control extracellular nucleotide, nucleoside, and (di)phosphate levels. To study the (patho)physiological roles of NPP1 potent and selective inhibitors with drug-like properties are required. Therefore, a compound library was screened for NPP1 inhibitors using a colorimetric assay with p-nitrophenyl 5'-thymidine monophosphate (p-Nph-5'-TMP) as an artificial substrate. This led to the discovery of 2-(3H-imidazo[4,5-b]pyridin-2-ylthio)-N-(3,4-dimethoxyphenyl)acetamide (5a) as a hit compound with a Ki value of 217 nM. Subsequent structure-activity relationship studies led to the development of purine and imidazo[4,5-b]pyridine analogues with high inhibitory potency (Ki values of 5.00 nM and 29.6 nM, respectively) when assayed with p-Nph-5'-TMP as a substrate. Surprisingly, the compounds were significantly less potent when tested versus ATP as a substrate, with Ki values in the low micromolar range. A prototypic inhibitor was investigated for its mechanism of inhibition and found to be competitive versus both substrates.

  14. The safety of phosphodiesterase type 5 inhibitors for erectile dysfunction.

    Science.gov (United States)

    Ventimiglia, Eugenio; Capogrosso, Paolo; Montorsi, Francesco; Salonia, Andrea

    2016-01-01

    Phosphodiesterase type 5 inhibitors (PDE5Is) are the leading drugs for the treatment of erectile dysfunction (ED), being recommended as a first line treatment by both the European and US urological guidelines. PDE5Is are highly effective as compared to placebo, well tolerated and have a very low, though not negligible, rate of severe treatment-related adverse events. This paper reviews the safety profile of currently available PDE5Is, comparing them in a broad spectrum ED population and outlining a number of real-life aspects of importance in the real-life everyday clinical setting. Guidelines unanimously agree in considering PDE5Is as first line treatments for ED when well-tolerated and not contraindicated. Despite the fact that no high-grade evidence comparing the efficacy and the safety for PDE5Is is currently available, published data seem to suggest that there are no major differences in their safety profiles. Moreover, although oral PDE5Is were shown to cause more AEs than placebo, they were generally mild and well tolerated.

  15. An Insight into the Pharmacophores of Phosphodiesterase-5 Inhibitors from Synthetic and Crystal Structural Studies

    Energy Technology Data Exchange (ETDEWEB)

    Chen,G.; Wang, H.; Robinson, H.; Cai, J.; Wan, Y.; Ke, H.

    2008-01-01

    Selective inhibitors of cyclic nucleotide phosphodiesterase-5 (PDE5) have been used as drugs for treatment of male erectile dysfunction and pulmonary hypertension. An insight into the pharmacophores of PDE5 inhibitors is essential for development of second generation of PDE5 inhibitors, but has not been completely illustrated. Here we report the synthesis of a new class of the sildenafil derivatives and a crystal structure of the PDE5 catalytic domain in complex with 5-(2-ethoxy-5-(sulfamoyl)-3-thienyl)-1-methyl-3-propyl-1, 6-dihydro-7H-pyrazolo[4, 3-d]pyrimidin-7-one (12). Inhibitor 12 induces conformational change of the H-loop (residues 660-683), which is different from any of the known PDE5 structures. The pyrazolopyrimidinone groups of 12 and sildenafil are well superimposed, but their sulfonamide groups show a positional difference of as much as 1.5 Angstroms . The structure-activity analysis suggests that a small hydrophobic pocket and the H-loop of PDE5 are important for the inhibitor affinity, in addition to two common elements for binding of almost all the PDE inhibitors: the stack against the phenylalanine and the hydrogen bond with the invariant glutamine. However, the PDE5-12 structure does not provide a full explanation to affinity changes of the inhibitors. Thus alternatives such as conformational change of the M-loop are open and further structural study is required.

  16. [Application of precursor ion scanning method in rapid screening of illegally added phosphodiesterase-5 inhibitors and their unknown derivatives in Chinese traditional patent medicines and health foods].

    Science.gov (United States)

    Sun, Jing; Cao, Ling; Feng, Youlong; Tan, Li

    2014-11-01

    The compounds with similar structure often have similar pharmacological activities. So it is a trend for illegal addition that new derivatives of effective drugs are synthesized to avoid the statutory test. This bring challenges to crack down on illegal addition behavior, however, modified derivatives usually have similar product ions, which allow for precursor ion scanning. In this work, precursor ion scanning mode of a triple quadrupole mass spectrometer was first applied to screen illegally added drugs in complex matrix such as Chinese traditional patent medicines and healthy foods. Phosphodiesterase-5 inhibitors were used as experimental examples. Through the analysis of the structure and mass spectrum characteristics of the compounds, phosphodiesterase-5 inhibitors were classified, and their common product ions were screened by full scan of product ions of typical compounds. Then high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with precursor ion scanning mode was established based on the optimization of MS parameters. The effect of mass parameters and the choice of fragment ions were also studied. The method was applied to determine actual samples and further refined. The results demonstrated that this method can meet the need of rapid screening of unknown derivatives of phosphodiesterase-5 inhibitors in complex matrix, and prevent unknown derivatives undetected. This method shows advantages in sensitivity, specificity and efficiency, and is worth to be further investigated.

  17. Effects of rolipram, a phosphodiesterase 4 inhibitor, in combination with imipramine on depressive behavior, CRE-binding activity and BDNF level in learned helplessness rats.

    Science.gov (United States)

    Itoh, Tetsuji; Tokumura, Miwa; Abe, Kohji

    2004-09-13

    The brain cAMP regulating system and its downstream elements play a pivotal role in the therapeutic effects of antidepressants. We previously reported the increase in activities of phosphodiesterase 4, a major phosphodiesterase isozyme hydrolyzing cAMP, in the frontal cortex and hippocampus of learned helplessness rats, an animal model for depression. The present study was undertaken to examine the combination of effects of rolipram, a phosphodiesterase 4 inhibitor, with imipramine, a typical tricyclic antidepressant, on depressive behavior in learned helplessness rats. Concurrently, cAMP-response element (CRE)-binding activity and brain-derived neurotrophic factor (BDNF) levels related to the therapeutic effects of antidepressants were determined. Repeated administration of imipramine (1.25-10 mg/kg, i.p.) or rolipram (1.25 mg/kg, i.p.) reduced the number of escape failures in learned helplessness rats. Imipramine could not completely ameliorate the escape behavior to a level similar to that of non-stressed rats even at 10 mg/kg. However, repeated coadministration of rolipram with imipramine (1.25 and 2.5 mg/kg, respectively) almost completely eliminated the escape failures in learned helplessness rats. The reduction of CRE-binding activities and BDNF levels in the frontal cortex or hippocampus in learned helplessness rats were ameliorated by treatment with imipramine or rolipram alone. CRE-binding activities and/or BDNF levels of the frontal cortex and hippocampus were significantly increased by treatment with a combination of rolipram and imipramine compared to those in imipramine-treated rats. These results indicated that coadministration of phosphodiesterase type 4 inhibitors with antidepressants may be more effective for depression therapy and suggest that elevation of the cAMP signal transduction pathway is involved in the antidepressive effects.

  18. Phosphodiesterase 5 inhibitors in the treatment of premature ejaculation.

    Science.gov (United States)

    Wang, W F; Minhas, S; Ralph, D J

    2006-10-01

    To date, there is no FDA-approved therapy for premature ejaculation (PE). Recently, phosphodiesterase 5 inhibitors (PDE5-Is) have been demonstrated to have encouraging results in the treatment of PE by a few studies. The aim of this review was to assess the updated manuscripts and thereafter present the practical recommendations and possible mechanisms concerning PDE5-Is for treating PE. Using MEDLINE, we searched and assessed the peer manuscripts published from 1 January 1996 to 1 September 2005 about PDE5-Is for treating PE. The results show that the number of patients in all the reports is very few and most of the studies do not employ double-blinded and placebo-controlled tests, though they are prospective and randomized. Therefore, the results and conclusions might be biased. PDE5-Is are suggested to be used in PE with old age or associated with erectile dysfunction (ED), or to be employed alone or in combination with selective-serotonin reuptake inhibitors (SSRIs) when SSRIs fail to treat PE; behavioural therapy is proposed to be used for preventing the recurrence of PE following withdrawal of PDE5-Is. In addition, for the PE patient with a definite aetiological cause, the aetiology should be cured first, if PE still exists, followed by PDE-Is prescription. Possible mechanisms that are involved include relaxing the smooth muscles of vas deferens, seminal vesicle, prostate and urethra; decreasing the central sympathetic output; inducing peripheral analgesia; prolonging the duration of erection; and increasing confidence, the perception of ejaculatory control, overall sexual satisfaction, and decreasing the post-orgasmic refractory time to achieve a second erection after ejaculation. Well-designed multicentre studies are urgently warranted to further elucidate the efficacies and safety as well as mechanisms of PDE5-Is in the treatment of PE.

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

    Directory of Open Access Journals (Sweden)

    Weissmann Norbert

    2005-07-01

    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.

  20. Effects of Intrarenal and Intravenous Infusion of the Phosphodiesterase 3 Inhibitor Milrinone on Renin Secretion

    Science.gov (United States)

    Kumagai, Kazuhiro; Reid, Ian A.

    1994-01-01

    We have reported that administration of the phosphodiesterase III inhibitor milrinone increases renin secretion in conscious rabbits. The aim of the present study was to determine if the increase in renin secretion results from a direct renal action of milrinone, or from an indirect extrarenal effect of the drug. This was accomplished by comparing the effects of intrarenal and intravenous infusion of graded doses of milrinone on plasma renin activity in unilaterally nephrectomized conscious rabbits. Milrinone was infused into the renal artery in doses of 0.01, 0.1 and 1.0 micro-g/kg/min, and intravenously in the same rabbits in doses of 0.01, 0.1, 1.0 and 10 micro-g/kg/min. Each dose was infused for 15 min. No intrarenal dose of milrinone altered plasma renin activity or arterial pressure, although at the highest dose, there was a small increase in heart rate. Intravenous infusion of milrinone at 1.0 micro-g/kg/min increased plasma renin activity to 176 +/- 55% of the control value (P less than 0.05). Heart rate increased but arterial pressure did not change. Intravenous infusion of milrinone at 1O micro-g/kg/min increased plasma renin activity to 386 +/- 193% of control in association with a decrease in arterial pressure and an increase in heart rate. These results confirm that milrinone increases renin secretion, and indicate that the stimulation is due to an extrarenal effect of the drug.

  1. The effect of selective phosphodiesterase inhibitors, alone and in combination, on a murine model of allergic asthma

    Directory of Open Access Journals (Sweden)

    Galbraith Deirdre

    2004-05-01

    Full Text Available Abstract Background The anti-inflammatory effects of the selective phosphodiesterase (PDE inhibitors cilostazol (PDE 3, RO 20-1724 (PDE 4 and sildenafil (PDE 5 were examined in a murine model of allergic asthma. These compounds were used alone and in combination to determine any potential synergism, with dexamethasone included as a positive control. Methods Control and ovalbumin sensitised Balb/C mice were administered orally with each of the possible combinations of drugs at a dose of 3 mg/Kg for 10 days. Results When used alone, RO 20-1724 significantly reduced eosinophil influx into lungs and lowered tumour necrosis factor-α, interleukin-4 and interleukin-5 levels in the bronchoalveolar lavage fluid when compared to untreated mice. Treatment with cilostazol or sildenafil did not significantly inhibit any markers of inflammation measured. Combining any of these PDE inhibitors produced no additive or synergistic effects. Indeed, the anti-inflammatory effects of RO 20-1724 were attenuated by co-administration of either cilostazol or sildenafil. Conclusions These results suggest that concurrent treatment with a PDE 3 and/or PDE 5 inhibitor will reduce the anti-inflammatory effectiveness of a PDE 4 inhibitor.

  2. Effects of fenspiride on human bronchial cyclic nucleotide phosphodiesterase isoenzymes: functional and biochemical study.

    Science.gov (United States)

    Cortijo, J; Naline, E; Ortiz, J L; Berto, L; Girard, V; Malbezin, M; Advenier, C; Morcillo, E J

    1998-01-02

    We have investigated the role of human bronchial cyclic nucleotide phosphodiesterases in the effects of fenspiride, a drug endowed with bronchodilator and anti-inflammatory properties. Functional studies on human isolated bronchi showed that fenspiride (10(-6)-3 x 10(-3) M, 30 min) induced a shift to the left of the concentration-response curves for isoprenaline and sodium nitroprusside with -logEC50 values of 4.1+/-0.1 (n = 7) and 3.5+/-0.2 (n = 8), respectively. Biochemical studies were carried out on three human bronchi in which separation of cyclic nucleotide phosphodiesterase isoenzymes was performed by ion exchange chromatography followed by determination of phosphodiesterase activity with a radioisotopic method. Phosphodiesterase 4 (cyclic AMP-specific) and phosphodiesterase 5 (cyclic GMP-specific) were the major phosphodiesterase isoforms present in the human bronchial tissue. The presence of phosphodiesterase 1 (Ca2+/calmodulin-stimulated), phosphodiesterase 2 (cyclic GMP-stimulated) and, in two cases, phosphodiesterase 3 (cyclic GMP-inhibited) was also identified. Fenspiride inhibited phosphodiesterase 4 and phosphodiesterase 3 activities with -logIC50 values of 4.16+/-0.09 and 3.44+/-0.12, respectively. Phosphodiesterase 5 activity was also inhibited with a -logIC50 value of approximately 3.8. Fenspiride (fenspiride is an effective inhibitor of both cyclic AMP and cyclic GMP hydrolytic activity in human bronchial tissues and this action may contribute to its airway effects.

  3. Beneficial long term effect of a phosphodiesterase-5-inhibitor in cirrhotic portal hypertension: A case report with 8 years follow-up.

    Science.gov (United States)

    Deibert, Peter; Lazaro, Adhara; Stankovic, Zoran; Schaffner, Denise; Rössle, Martin; Kreisel, Wolfgang

    2018-01-21

    Non-selective beta-blockers are the mainstay of medical therapy for portal hypertension in liver cirrhosis. Inhibitors of phosphodiesterase-5 (PDE-5-inhibitors) reduce portal pressure in the acute setting by > 10% which may suggest a long-term beneficial effect. Currently, there is no available data on long-term treatment of portal hypertension with PDE-5-inhibitors. This case of a patient with liver cirrhosis secondary to autoimmune liver disease with episodes of bleeding from esophageal varices is the first documented case in which a treatment with a PDE-5-inhibitor for eight years was monitored. In the acute setting, the PDE-5-inhibitor Vardenafil lowered portal pressure by 13%. The portal blood flow increased by 28% based on Doppler sonography and by 16% using MRI technique. As maintenance medication the PDE-5-inhibitor Tadalafil was used for eight consecutive years with comparable effects on portal pressure and portal blood flow. There were no recurrence of bleeding and no formation of new varices. Influencing the NO-pathway by the use of PDE-5 inhibitors may have long-term beneficial effects in compensated cirrhosis.

  4. Phosphodiesterase type 5 inhibitor abuse: a critical review.

    Science.gov (United States)

    Lowe, Gregory; Costabile, Raymond

    2011-06-01

    Abuse of sildenafil has been reported since its introduction in 1999 and commonly documented in combination with illicit drugs among men and women of all ages. Increased risks of sexually transmissible diseases including HIV have been associated with sildenafil use in men who have sex with men. Recognizing the abuse potential of phosphodiesterase type 5 inhibitors (PDE5), we aim to summarize the current knowledge of this abuse. An investigation of EMBASE, PubMed, the Food and Drug Administration (FDA) website, MedWatch, and search engines was performed to evaluate information regarding sildenafil, tadalafil, and vardenafil abuse. The EMBASE search provided 46 articles fitting the search criteria and evaluation led to 21 separate publications with specific information regarding PDE5 abuse. A PubMed search found 10 additional publications. MedWatch reported 44 separate warnings since 2000, most of which reported contamination of herbal products with active drug components. Few reports of abuse were among the 14,818 reports in the FDA AERS for sildenafil. A search for "internet drug store" revealed 6.4 million hits and of 7000 internet pharmacies identified by the Verified Internet Pharmacy Practice Sites Program (VIPPS) only 4% were in proper compliance. The role internet pharmacies play in counterfeit PDE5 or abuse is not well documented; however based on easy access, direct patient marketing, and low advertised cost it is likely this role is underreported. Currently the best recommendation for providers is to recognize the possibility of abuse and to educate patients on risks of this behavior.

  5. Phosphodiesterase 4 inhibitors for chronic obstructive pulmonary disease.

    Science.gov (United States)

    Chong, Jimmy; Leung, Bonnie; Poole, Phillippa

    2017-09-19

    Chronic obstructive pulmonary disease (COPD) is associated with cough, sputum production or dyspnoea and a reduction in lung function, quality of life and life expectancy. Apart from smoking cessation, there are no other treatments that slow lung function decline. Roflumilast and cilomilast are oral phosphodiesterase 4 (PDE 4 ) inhibitors proposed to reduce the airway inflammation and bronchoconstriction seen in COPD. This is an update of a Cochrane review first published in 2011 and updated in 2013. To evaluate the efficacy and safety of oral PDE 4 inhibitors in the management of stable COPD. We identified randomised controlled trials (RCTs) from the Cochrane Airways Trials Register (date of last search October 2016). We found other trials from web-based clinical trials registers. We included RCTs if they compared oral PDE 4 inhibitors with placebo in people with COPD. We allowed co-administration of standard COPD therapy. One review author extracted data and a second review author checked the data. We reported pooled data in Review Manager as mean differences (MD), standardised mean differences (SMD) or odds ratios (OR). We converted the odds ratios into absolute treatment effects in a 'Summary of findings' table. Thirty-four separate RCTs studying roflumilast (20 trials with 17,627 participants) or cilomilast (14 trials with 6457 participants) met the inclusion criteria, with a duration of between six weeks and one year. These included people across international study centres with moderate to very severe COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades II-IV), with a mean age of 64 years.We considered that the methodological quality of the 34 published and unpublished trials was acceptable overall. Treatment with a PDE 4 inhibitor was associated with a significant improvement in forced expiratory volume in one second (FEV 1 ) over the trial period compared with placebo (MD 51.53 mL, 95% confidence interval (CI) 43.17 to 59.90, 27

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

    Directory of Open Access Journals (Sweden)

    Jinwei Hu

    2010-04-01

    Full Text Available 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.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.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.

  7. Upregulation of Phosphodiesterase type 5 in the Hyperplastic Prostate

    NARCIS (Netherlands)

    W. Zhang (Wenhao); N. Zang (Ning); Y. Jiang (Yaoming); P. Chen (Ping); X. Wang (Xinghuan); X. Zhang (Xinhua)

    2015-01-01

    textabstractBoth erectile dysfunction (ED) and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) are common in the aging male. Numerous clinical trials have demonstrated the efficacy and safety of phosphodiesterase type 5 inhibitors (PDE5-Is) for treating LUTS/BPH with/without

  8. The phosphodiesterase 3 inhibitor ORG 9935 inhibits oocyte maturation in the naturally selected dominant follicle in rhesus macaques.

    Science.gov (United States)

    Jensen, Jeffrey T; Zelinski, Mary B; Stanley, Jessica E; Fanton, John W; Stouffer, Richard L

    2008-04-01

    The study was conducted to determine whether the phosphodiesterase (PDE) 3 inhibitor ORG 9935 prevents the resumption of meiosis in primate oocytes during natural menstrual cycles. Regularly cycling adult female macaques (n=8) were followed during the follicular phase and then started on a 2-day treatment regimen of human recombinant gonadotropins to control the timing of ovulation. Monkeys received no further treatment (controls) or ORG 9935. Oocytes were recovered by laparoscopic follicle aspiration 27 h after an ovulatory stimulus, cultured in vitro in the absence of inhibitor and inseminated. The primary outcome was the meiotic stage of the oocyte. In six ORG 9935 cycles, five of the recovered oocytes were germinal vesicle (GV)-intact, and one exhibited GV breakdown (GVBD). In contrast, all three oocytes that recovered during control cycles were GVBD (pORG 9935-treated oocytes underwent fertilization compared with 2/3 (67%) from controls. These results demonstrate that ORG 9935 blocks resumption of meiosis in the naturally selected dominant follicle in primates and suggest that PDE3 inhibitors have potential clinical use as contraceptives in women.

  9. New Therapeutic Applications of Phosphodiesterase 5 Inhibitors (PDE5-Is).

    Science.gov (United States)

    Ribaudo, Giovanni; Pagano, Mario Angelo; Bova, Sergio; Zagotto, Giuseppe

    2016-01-01

    Phosphodiesterase 5 inhibitors (PDE5-Is) sildenafil, vardenafil, tadalafil and the recently approved avanafil represent the first-line choice for both on-demand and chronic treatment of erectile dysfunction (ED). In addition to this, sildenafil and tadalafil, have also been approved for the treatment of pulmonary arterial hypertension. Due to its expression and localization in many tissues, PDE5 and its regulation has been reported to be involved in several other diseases. We aim to provide an updated overview of the emerging therapeutic applications of PDE5-Is besides ED, taking into account the latest ongoing research reports. We searched online databases (Pubmed, Reaxys, Scopus) to lay the bases for an accurate, quality criteria-based literature update. We focused our attention on most recent research reports, in particular when supported by pre-clinical and clinical data. The regulation of PDE5 may influence pathological conditions such as, among the others, heart failure, cystic fibrosis, cancer, CNS-related diseases, diabetes and dysfunctions affecting male urinary/reproductive system. Sildenafil, vardenafil, tadalafil and the other chemical entities considered PDE5-Is showed overall positive results and significant improvements in the studied disease, thus some discordant results, in particular when comparing pre-clinical and clinical data, have to be pointed out, suggesting that further insights are needed especially to assess the exact molecular pathway underlying.

  10. 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

    2014-04-01

    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.

  11. Selective phosphodiesterase inhibitors: a promising target for cognition enhancement

    OpenAIRE

    Reneerkens, Olga A. H.; Rutten, Kris; Steinbusch, Harry W. M.; Blokland, Arjan; Prickaerts, Jos

    2008-01-01

    Rationale One of the major complaints most people face during aging is an impairment in cognitive functioning. This has a negative impact on the quality of daily life and is even more prominent in patients suffering from neurodegenerative and psychiatric disorders including Alzheimer?s disease, schizophrenia, and depression. So far, the majority of cognition enhancers are generally targeting one particular neurotransmitter system. However, recently phosphodiesterases (PDEs) have gained increa...

  12. 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

    2002-01-01

    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...... of cerebral arterial dilatation, sildenafil caused significantly more headache than placebo. The present results show that sildenafil 100 mg does not dilate cerebral or extracerebral arteries but nevertheless causes headache, which may be attributed to nonvascular mechanisms....

  13. 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

    2009-04-01

    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

  14. Platelet GP II b/III a inhibitors in neurointervention therapeutics

    International Nuclear Information System (INIS)

    Wang Kuizhong; Huang Qinghai; Liu Jianmin

    2007-01-01

    The platelet glucoprotein (GP) II b/III a inhibitors prossess inhibiting platelet aggregation effectly. As new drugs of antiplatelet, they are different in mechanism with action, application and dosage between the II b/III a inhibitors and other tradional antiplatelet drugs such as aspirin or clopidogrel. In familiar with the pharmacologic action and clinical application of II b/III a inhibitors is important for endovascular interventional radiology, especially with important significance for obtaining high quality neuro-endovascular stenting in the perioperative period. (authors)

  15. Phosphodiesterase 5 inhibition as a therapeutic target for ischemic stroke

    DEFF Research Database (Denmark)

    Ölmestig, Joakim N E; Marlet, Ida R; Hainsworth, Atticus H

    2017-01-01

    Phosphodiesterase 5 inhibitors (PDE5i), such as sildenafil (Viagra®) are widely used for erectile dysfunction and pulmonary hypertension. Preclinical studies suggest that PDE5i may improve functional outcome following ischemic stroke. In this systematic review we aimed to evaluate the effects...

  16. LC-ESI-MS/MS analysis of phosphodiesterase-5 inhibitors and their analogues in foods and dietary supplements in Korea.

    Science.gov (United States)

    Jeong, Ji Hye; Lee, Ji Hyun; Kim, Hyung Joo; Park, Hyoung Joon; Hwang, In Sun; Han, Kyoung Moon; Yoon, Chang-Yong; Cho, Sooyeul; Kim, Woo Seong

    2016-01-01

    A number of 188 food and dietary supplement samples were collected from 2009 to the first half of 2013 in Korean online and offline stores. A method to identify phosphodiesterase-5 (PDE-5) inhibitors and their analogues using liquid chromatography-electrospray ionisation-mass spectrometry/mass spectrometry (LC-ESI-MS/MS) was validated. Limit of detection and limit of quantitation of liquid-type and solid-type negative samples ranged from 0.05 to 3.33 ng/mL or ng/g and from 0.15 to 10.00 ng/mL or ng/g, respectively. Recoveries ranged from 83% to 112%. Nineteen PDE-5 inhibitors and their analogues were detected, with tadalafil group compounds being the most frequently observed (53.0%), followed by the sildenafil group (42.5%). Tadalafil concentrations ranged from 0.08 to 138.69 mg/g. Compounds were most frequently detected in capsules (in 40 of 80 adulterated samples). To protect public health and food safety, appropriate monitoring of PDE-5 inhibitors and their analogues in foods and dietary supplements is recommended.

  17. Differential regulation of TNF-α and IL-1β production from endotoxin stimulated human monocytes by phosphodiesterase inhibitors

    Directory of Open Access Journals (Sweden)

    K. L. Molnar-Kimber

    1992-01-01

    Full Text Available The effect of selective PDE-I (vinpocetine, PDE-III (milrinone, CI-930, PDE-IV (rolipram, nitroquazone, and PDE-V (zaprinast isozyme inhibitors on TNF-α and IL-1β production from LPS stimulated human monocytes was investigated. The PDE-IV inhibitors caused a concentration dependent inhibition of TNF-α production, but only partially inhibited IL-1β at high concentrations. High concentrations of the PDE-III inhibitors weakly inhibited TNF-α, but had no effect on IL-1β production. PDE-V inhibition was associated with an augmentation of cytokine secretion. Studies with combinations of PDE isozyme inhibitors indicated that PDE-III and PDE-V inhibitors modulate rolipram's suppression of TNF production in an additive manner. These data confirm that TNF-α and IL-1β production from LPS stimulated human monocytes are differentially regulated, and suggest that PDE-IV inhibitors have the potential to suppress TNF levels in man.

  18. Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

    International Nuclear Information System (INIS)

    Lee, Jiyoun

    2012-01-01

    We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry

  19. Cobalt (III) complexes as novel matrix metalloproteinase-9 inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jiyoun [Sungshin Women' s Univ., Seoul (Korea, Republic of)

    2012-04-15

    We have synthesized a series of novel MMP-9 inhibitors containing cobalt(III) complexes. The synthesized cobalt(III) complexes are effective as enzyme inhibitors and the attachment of a biphenyl group enhanced the efficiency of enzyme inhibition up to 6-fold. When compared to the reported non-hydroxamate MMP inhibitors, the synthesized complexes showed comparable in vitro potency. The enzyme assay showed that the cobalt(III) complex can disrupt the zinc binding active site of MMP-9 and is proposed to work via a ligand exchange mechanism. Since histidine residues are essential for the catalytic activity of a large percentage of enzymes and zinc finger proteins, these cobalt(III) complexes can serve as a prototype inhibitor towards various zinc containing enzymes and proteins. Matrix metalloproteinases (MMPs) are a family of zinc binding endopeptidases that play crucial roles in various physiological processes and diseases such as embryogenic growth, angiogenesis, arthritis, skin ulceration, liver fibrosis and tumor metastasis. Because of their implications in a wide range of diseases, MMPs are considered as intriguing drug targets. The majority of MMP inhibitors are organic small molecules containing a hydroxamate functionality for the zinc binding group. This hydroxamate group binds to a zinc(II) center in a bidentate fashion and creates a distorted trigonal bipyramidal geometry.

  20. Radioprotection of mouse intestine by inhibitors of cyclic amp phosphodiesterase

    International Nuclear Information System (INIS)

    Lehnert, S.

    1979-01-01

    The survival of colony-forming units of the jejunal crypt was used to assay the radioprotective capacity of various inhibitors of cyclic AMP phosphodiesterase. DL-152, RO-20-1724 and the methyl xanthines, caffeine, theophylline, and methyl isbutyl xanthine (MIX) were all found to have some radioprotective effect. The degree of radioprotecton depended on the route of administration of the drug and on the timing of administration with respect to irradiation. Optimum survival of crypt stem cells was found following intraperitoneal administration of DL-152 (60 min before irradiation) or MIX (30 min before irradiaton), and following intravenous administration of caffeine (60 to 120 min before irradiaton) or theophylline (60 min before irradiation). When these protocols were used, crypt stem cell survival could be enhanced by a factor of from 6 to 7. All the compounds investigated produced some elevation of cyclic AMP content of the whole jejunum; this was found to be simultaneous with or to precede the period of maximum radioprotection. Cyclic AMP was localized with immunofluorescent staining; following injection of DL-152 it was found to be elevated in all parts of the jejunum but to the greatest extent in the lower part of the crypt. Survival curves for crypt stem cells from MIX and DL-152 treated mice were found to have almost the same exponential slope as the saline-injected control, suggesting that the mechanism of protection does not depend on induction of hypoxia

  1. Phosphodiesterase inhibitors enhance object memory independent of cerebral blood flow and glucose utilization in rats.

    Science.gov (United States)

    Rutten, Kris; Van Donkelaar, Eva L; Ferrington, Linda; Blokland, Arjan; Bollen, Eva; Steinbusch, Harry Wm; Kelly, Paul At; Prickaerts, Jos Hhj

    2009-07-01

    Phosphodiesterase (PDE) inhibitors prevent the breakdown of the second messengers, cyclic AMP (cAMP) and cyclic GMP (cGMP), and are currently studied as possible targets for cognitive enhancement. Earlier studies indicated beneficial effects of PDE inhibitors in object recognition. In this study we tested the effects of three PDE inhibitors on spatial memory as assessed in a place and object recognition task. Furthermore, as both cAMP and cGMP are known vasodilators, the effects of PDE inhibition on cognitive functions could be explained by enhancement of cerebrovascular function. We examined this possibility by measuring the effects of PDE5 and PDE4 inhibitor treatment on local cerebral blood flow and glucose utilization in rats using [14C]-iodoantipyrine and [14C]-2-deoxyglucose quantitative autoradiography, respectively. In the spatial location task, PDE5 inhibition (cGMP) with vardenafil enhanced only early phase consolidation, PDE4 inhibition (cAMP) with rolipram enhanced only late phase consolidation, and PDE2 inhibition (cAMP and cGMP) with Bay 60-7550 enhanced both consolidation processes. Furthermore, PDE5 inhibition had no cerebrovascular effects in hippocampal or rhinal areas. PDE4 inhibition increased rhinal, but not hippocampal blood flow, whereas it decreased glucose utilization in both areas. In general, PDE5 inhibition decreased the ratio between blood flow and glucose utilization, indicative of general oligaemia; whereas PDE4 inhibition increased this ratio, indicative of general hyperemia. Both oligaemic and hyperemic conditions are detrimental for brain function and do not explain memory enhancement. These results underscore the specific effects of cAMP and cGMP on memory consolidation (object and spatial memory) and provide evidence that the underlying mechanisms of PDE inhibition on cognition are independent of cerebrovascular effects.

  2. Cyclic GMP-mediated memory enhancement in the object recognition test by inhibitors of phosphodiesterase-2 in mice.

    Science.gov (United States)

    Lueptow, Lindsay M; Zhan, Chang-Guo; O'Donnell, James M

    2016-02-01

    Cyclic nucleotide phosphodiesterase-2 (PDE2) is a potential therapeutic target for the treatment of cognitive dysfunction. Using the object recognition test (ORT), this study assessed the effects of two PDE2 inhibitors, Bay 60-7550 and ND7001, on learning and memory, and examined underlying mechanisms. To assess the role of PDE2 inhibition on phases of memory, Bay 60-7550 (3 mg/kg) was administered: 30 min prior to training; 0, 1, or 3 h after training; or 30 min prior to recall testing. To assess cyclic nucleotide involvement in PDE2 inhibitor-enhanced memory consolidation, either the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 20 mg/kg; intraperitoneal (IP)), soluble guanylyl cyclase inhibitor 1H-[-1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ; 20 mg/kg; IP), protein kinase G inhibitor KT5823 (2.5 μg; intracerebroventricular (ICV)), or protein kinase A inhibitor H89 (1 μg; ICV) was administered 30 min prior to the PDE2 inhibitor Bay 60-7550 (3 mg/kg) or ND7001 (3 mg/kg). Changes in the phosphorylation of 3'5'-cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) at Ser-133 and vasodilator-stimulated phosphoprotein (VASP) at Ser-239 were determined to confirm activation of cAMP and 3'5'-cyclic guanosine monophosphate (cGMP) signaling. Bay 60-7550 (3 mg/kg) enhanced memory of mice in the ORT when given 30 min prior to training, immediately after training, or 30 min prior to recall. Inhibitors of the cGMP pathway blocked the memory-enhancing effects of both Bay 60-7550 (3 mg/kg) and ND7001 (3 mg/kg) on early consolidation processes. Bay 60-7550 (3 mg/kg) enhanced phosphorylation of CREB and VASP, both targets of cGMP-dependent protein kinase (PKG). These results confirm a potential of PDE2, or components of its signaling pathway, as a therapeutic target for drug discovery focused on restoring memory function.

  3. Catecholic amides as potential selective phosphodiesterase 4D inhibitors: Design, synthesis, pharmacological evaluation and structure-activity relationships.

    Science.gov (United States)

    Zhou, Zhong-Zhen; Ge, Bing-Chen; Chen, Yu-Fang; Shi, Xiu-Dong; Yang, Xue-Mei; Xu, Jiang-Ping

    2015-11-15

    In this study, a series of catechol-based amides (8a-n) with different amide linkers linking the catecholic moiety to the terminal phenyl ring was designed and synthesized as potent phosphodiesterase (PDE) 4D inhibitors. The inhibitory activities of these compounds were evaluated against the core catalytic domains of human PDE4 (PDE4CAT), full-length PDE4B1 and PDE4D7 enzymes, and other PDE family members. The results indicated the majority of compounds 8a-n displayed moderate to good inhibitory activities against PDE4CAT. Among these compounds, compound 8 j with a short amide linker (-CONHCH2-) displayed comparable PDE4CAT inhibitory activity (IC50=410 nM) with rolipram. More interestingly, compound 8 g, a potent and selective PDE4D inhibitor (IC50=94 nM), exhibited a 10-fold selectivity over the PDE4B subtypes and an over 1000-fold selectivity against other PDE family members. Docking simulations suggested that 8 g forms three extra H-bonds with the N-H of residue Asn487 and two water molecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Evaluation of the phosphodiesterase 3 inhibitor ORG 9935 as a contraceptive in female macaques: initial trials.

    Science.gov (United States)

    Jensen, Jeffrey T; Stouffer, Richard L; Stanley, Jessica E; Zelinski, Mary B

    2010-02-01

    The study was conducted to determine whether a phosphodiesterase (PDE) 3 inhibitor has potential as a novel contraceptive in primates. Regularly cycling adult female cynomolgus macaques of proven fertility (n=16) were treated for 7 months with placebo (controls) or the PDE3 inhibitor ORG 9935 as a daily food treat (150 mg/kg) or as a weekly depot injection (150 mg/kg, sc). After 1 month, a male of proven fertility was introduced into each group. Females underwent weekly monitoring of progesterone (P) and ultrasound evaluation for pregnancy if P remained elevated (1.0 ng/mL) >3 weeks. ORG 9935 values were evaluated using high-performance liquid chromatography. Overall, the pregnancy rate in ORG 9935-treated monkeys (4/8, 50%) did not differ from controls (7/8, 88%; p=.5). However, no animal became pregnant in a cycle when the serum level of ORG 9935 exceeded 300 nmol/L. Moreover, two treated monkeys who mated throughout the treatment phase and did not conceive became pregnant within four cycles after stopping ORG 9935. The other two animals were discontinued prematurely from the protocol. These results demonstrate that ORG 9935 may prevent pregnancy in primates at serum concentrations above 300 nmol/L and that the effect is reversible.

  5. Phosphodiesterase isoenzyme families in human osteoarthritis chondrocytes – functional importance of phosphodiesterase 4

    Science.gov (United States)

    Tenor, Hermann; Hedbom, Erik; Häuselmann, Hans-Jörg; Schudt, Christian; Hatzelmann, Armin

    2002-01-01

    We studied whether selective inhibitors of cyclic nucleotide hydrolysing phosphodiesterase (PDE) isoenzymes influence IL-1β-induced nitric oxide (NO) release from human articular chondrocytes. In addition, the pattern of PDE isoenzymes contributing to cyclic nucleotide hydrolysis in human chondrocytes was characterized.Chondrocytes were isolated from human osteoarthritic cartilage and cultured in alginate beads. IL-1β-induced chondrocyte products (nitric oxide and prostaglandin E2) were measured in culture supernatants after 48 h incubation time. PDE activities were assessed in chondrocyte lysates. Inducible nitric oxide synthase (iNOS) and PDE4A-D proteins were detected by immunoblotting.The selective PDE4 inhibitors Piclamilast and Roflumilast partially attenuated IL-1β-induced NO production whereas selective inhibitors of PDE2 (EHNA), PDE3 (Motapizone) or PDE5 (Sildenafil) were inactive. Indomethacin reversed the reduction of IL-1β-induced NO by PDE4 inhibitors. It was shown that autocrine prostaglandin E2 (PGE2) enabled PDE4 inhibitors to reduce IL-1β-induced NO in this experimental setting.Major PDE4 and PDE1 activities were identified in chondrocyte lysates whereas only minor activities of PDE2, 3 and 5 were found. IL-1β and cyclic AMP-mimetics upregulated PDE4 activity and this was associated with an augmentation of PDE4B2 protein.Based on the view that nitric oxide contributes to cartilage degradation in osteoarthritis our study suggests that PDE4 inhibitors may have chondroprotective effects. PMID:11834608

  6. Skin cancer associated with commonly prescribed drugs: tumor necrosis factor alpha inhibitors (TNF-αIs), angiotensin-receptor blockers (ARBs), phosphodiesterase type 5 inhibitors (PDE5Is) and statins -weighing the evidence.

    Science.gov (United States)

    Nardone, Beatrice; Orrell, Kelsey A; Vakharia, Paras P; West, Dennis P

    2018-02-01

    Skin cancers, including both malignant melanoma (MM) and nonmelanoma skin cancer (NMSC), are the most commonly diagnosed cancers in the US. The incidence of both MM and NMSC continues to rise. Areas covered: Current evidence for an association between four of the most commonly prescribed classes of drugs in the U.S. and risk for MM and NMSC is reported. Medline was searched (January 2000 to May 2017) for each drug in the classes and for 'basal cell carcinoma', 'squamous cell carcinoma', 'non-melanoma skin cancer', 'skin cancer' and 'melanoma'. Skin cancer risk information was reported for: tumor necrosis factor alpha inhibitors (TNF-αIs), angiotensin-receptor blockers (ARBs), phosphodiesterase type 5 inhibitors (PDE5Is) and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)-reductase inhibitors (statins). Expert opinion: Since skin cancer risk is associated with all four classes of these commonly prescribed drugs that represent nearly 20% of the Top 100 drugs in the U.S., these important findings warrant enhanced education, especially for prescribers and those patients at high risk for skin cancer.

  7. Effects of phosphodiesterase inhibitors on atrial dynamics induced by C-type natriuretic peptide in isolated beating rabbit atria

    International Nuclear Information System (INIS)

    Ding Dazhi; Cui Xun; Jin Xiunan; Lan Ying; Liu Liping; Hong Lan

    2010-01-01

    Objective: To investigate the effects of phosphodiesterase inhibitors (PDEI) on atrial dynamics induced by C-type natriuretic peptide (CNP) and the contents of cyclic nucleotide (cAMP, cGMP) in isolated beating rabbit atria. Methods: After the rabbits had been anesthetized, the hearts were removed rapidly. The left auricles were isolated and fixed on the atrial perfusion system. The atrial stroke volume and the pulse pressure were observed by CNP with or without PDEIs pretreatment. The contents of cAMP and cGMP were measured by radioimmunoassay. Results: (1)Compared with control cycle group, CNP (30.0 nmol · L -1 ) obviously decreased the atrial stroke volume and pulse pressure (P 0.05). (2)Compared with control cycle group, IBMX(1000.0 nmol · L -1 ), a non-selective inhibitor of PDE, significantly increased the atrial stroke volume, pulse pressure, cAMP and cGMP contents (P -1 ) plus CNP (30.0 nmol · L -1 )group and IBMX group (P>0.05). (3)Compared with control cycle group, EHNA(30.0 nmol · L -1 ), an inhibitor of PDE2, obviously decreased the atrial stroke volume and pulse pressure (P 0.05). EHNA(30.0 nmol · L -1 ) plus CNP (30.0 nmol · L -1 ) showed similar roles with EHNA only. (4)Compared with control cycle group, milrinone (1.0 nmol · L -1 ), an inhibitor of PDE3, significantly increased the content of cAMP (P 0.05). CNP (30.0 nmol · L -1 ) obviously decreased the atrial stroke volume and pulse pressure (P 0.05). Conclusion: CNP can inhibit atrial dynamics by increasing the content of cGMP, the different inhibitors of PDEs play different roles in the CNP-induced inhibition of atrial dynamics in isolated beating rabbit atria. (authors)

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

    Science.gov (United States)

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

    2016-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Eyob Alemayehu Gebreyohannes

    2016-12-01

    Full Text Available 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.

  10. The phosphodiesterase inhibitor, ibudilast, attenuates neuroinflammation in the MPTP model of Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Joanna Schwenkgrub

    Full Text Available Since the degeneration of the nigrostriatal dopaminergic pathway in Parkinson's disease (PD is associated with the inflammation process and decreased levels of cyclic nucleotides, inhibition of up-regulated cyclic nucleotide phosphodiesterases (PDEs appears to be a promising therapeutic strategy. We used ibudilast (IBD, a non-selective PDE3,4,10,11 inhibitor, due to the abundant PDE 4 and 10 expression in the striatum. The present study for the first time examined the efficacy of IBD in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP mouse model of PD.IBD [0, 20, 30, 40, or 50 mg/kg] was injected b.i.d. subcutaneously for nine days to three-month-old male C57Bl/10Tar mice, beginning two days prior to MPTP (60 mg/kg intoxication. High-pressure liquid chromatography, Western blot analysis, and real time RT-PCR methods were applied.Our study demonstrated that chronic administration of IBD attenuated astroglial reactivity and increased glial cell-derived neurotrophic factor (GDNF production in the striatum. Moreover, IBD reduced TNF-α, IL-6, and IL-1β expression.IBD had a well-defined effect on astroglial activation in the mouse model of PD; however, there was no protective effect in the acute phase of injury. Diminished inflammation and an increased level of GDNF may provide a better outcome in the later stages of neurodegeneration.

  11. Oral phosphodiesterase type 5 inhibitors alleviate recurrent priapism complicating thalassemia intermedia: a case report

    NARCIS (Netherlands)

    Tzortzis, Vassilios; Mitrakas, Lampros; Gravas, Stavros; Mamoulakis, Charalampos; Meissner, Andreas; Kyriakou, Despina; Melekos, Michael D.

    2009-01-01

    Recurrent ischemic priapism still remains a serious and difficult to treat complication of certain hematological disorders. Elucidation of the underlying pathophysiologic mechanisms and application of new effective prophylactic treatments are needed. To present the efficacy of phosphodiesterase type

  12. Prenylated flavonoids as potent phosphodiesterase-4 inhibitors from Morus alba: Isolation, modification, and structure-activity relationship study.

    Science.gov (United States)

    Guo, Yan-Qiong; Tang, Gui-Hua; Lou, Lan-Lan; Li, Wei; Zhang, Bei; Liu, Bo; Yin, Sheng

    2018-01-20

    The bioassay-guided phytochemical study of a traditional Chinese medicine Morus alba led to the isolation of 18 prenylated flavonoids (1-18), of which (±)-cyclomorusin (1/2), a pair of enantiomers, and 14-methoxy-dihydromorusin (3) are the new ones. Subsequent structural modification of the selected components by methylation, esterification, hydrogenation, and oxidative cyclization led to 14 more derivatives (19-32). The small library was screened for its inhibition against phosphodiesterase-4 (PDE4), which is a drug target for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Among them, nine compounds (1-5, 8, 10, 16, and 17) exhibited remarkable activities with IC 50 values ranging from 0.0054 to 0.40 μM, being more active than the positive control rolipram (IC 50  = 0.62 μM). (+)-Cyclomorusin (1), the most active natural PDE4 inhibitor reported so far, also showed a high selectivity across other PDE members with the selective fold greater than 55. The SAR study revealed that the presence of prenyls at C-3 and/or C-8, 2H-pyran ring D, and the phenolic hydroxyl groups were important to the activity, which was further supported by the recognition mechanism study of the inhibitors with PDE4 by using molecular modeling. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Sildenafil, a selective phosphodiesterase type 5 inhibitor, enhances memory reconsolidation of an inhibitory avoidance task in mice.

    Science.gov (United States)

    Boccia, M M; Blake, M G; Krawczyk, M C; Baratti, C M

    2011-07-07

    Intracellular levels of the second messengers cAMP and cGMP are maintained through a balance between production, carried out by adenyl cyclase (AC) and guanylyl cyclase (GC), and degradation, carried out by phosphodiesterases (PDEs). Recently, PDEs have gained increased attention as potential new targets for cognition enhancement, with particular reference to phosphodiesterase type 5 (PDE5A). It is accepted that once consolidation is completed memory becomes permanent, but it has also been suggested that reactivation (memory retrieval) of the original memory makes it sensitive to the same treatments that affect memory consolidation when given after training. This new period of sensitivity coined the term reconsolidation. Sildenafil (1, 3, and 10mg/kg, ip), a cGMP-PDE5 inhibitor, facilitated retention performance of a one-trial step-through inhibitory avoidance task, when administered to CF-1 male mice immediately after retrieval. The effects of sildenafil (1mg/kg, ip) were time-dependent, long-lasting and inversely correlated with memory age. The administration of sildenafil (1mg/kg, ip) 30 min prior to the 2nd retention test did not affect retention of mice given post-retrieval injections of either vehicle or sildenafil (1mg/kg, ip). Finally, an enhancement of retention was also observed in CF-1 female mice receiving sildenafil (1mg/kg, ip) immediately, but not 180 min after retrieval. In the present paper we reported for the first time that systemic administration of sildenafil after memory reactivation enhances retention performance of the original learning. Our results indirectly point out cGMP, a component of the NO/cGMP/PKG pathway, as a necessary factor for memory reconsolidation. Copyright © 2011 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Wen-Hao Zhang

    2016-01-01

    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.

  15. Synthesis, Pharmacological Profile and Docking Studies of New Sulfonamides Designed as Phosphodiesterase-4 Inhibitors.

    Directory of Open Access Journals (Sweden)

    Isabelle Karine da Costa Nunes

    Full Text Available Prior investigations showed that increased levels of cyclic AMP down-regulate lung inflammatory changes, stimulating the interest in phosphodiesterase (PDE4 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.

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

    Science.gov (United States)

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

    2016-01-01

    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.

  17. Exercise training improves erectile dysfunction (ED) in patients with metabolic syndrome on phosphodiesterase-5 (PDE-5) inhibitors.

    Science.gov (United States)

    Maresca, Luigi; D'Agostino, Mariantonietta; Castaldo, Luigi; Vitelli, Alessandra; Mancini, Maria; Torella, Giorgio; Lucci, Rosa; Albano, Giovanna; Del Forno, Domenico; Ferro, Matteo; Altieri, Vincenzo; Giallauria, Francesco; Vigorito, Carlo

    2013-12-01

    Erectile dysfunction (ED) affects about 50% of males aged 40-70 years old. ED shares with atherosclerotic disease several common risk factors; therefore, it may be considered a surrogate marker of atherosclerosis. Since phosphodiesterase-5 inhibitors are well known pharmacologic agents capable of significant improvement in ED, we designed this study to evaluate whether exercise training is of added value in patients with ED who are already on PDE-5 inhibitors. We recruited 20 male patients affected by ED with metabolic syndrome. At baseline, all patients underwent Cardio-Pulmonary Exercise Testing (CPET) and the International Index of Erectile Function (IIEF) test. After the initial evaluation, patients were subdivided into two groups: tadalafil group (group T, n = 10), who were maintained only on tadalafil therapy, and a tadalafil/exercise training group (T/E group, n = 10) who continued tadalafil but in addition underwent a2-month structured exercise training program. Basal anthropometric characteristics of study population showed no significant differences. Although both-groups showed at 2 months an improvement of the IIEF score, this was more evident in the T/E group (T group: 11.2 vs 14.2, P = 0.02; T/E group: 10.8 vs 20.1, P exercise (VO(2peak)) only in the T/E group patients (T group: 13.63 +/- 2.03 vs 14.24 +/- 2.98 mL/kg/min; P = 0.521; T/E group: 13.41 +/- 2.97 vs 16.58 +/- 3.17 mL/kg/min; P = 0.006). A significant correlation was found between the changes in VO(2peak) and the modifications in IIEF score (r = 0.575; P = 0.001). Exercise training in ED patients treated with PDE-5 inhibitors is of added value since further improves ED, as evaluated by IIEF score, and increases functional capacity.

  18. Phosphodiesterase-5 inhibitors and their analogues as adulterants of herbal and food products: analysis of the Malaysian market, 2014-16.

    Science.gov (United States)

    Bujang, Nur Baizura; Chee, Chin Fei; Heh, Choon Han; Rahman, Noorsaadah Abd; Buckle, Michael J C

    2017-07-01

    Adulteration of herbal health supplements with phosphodiesterase-5 (PDE-5) inhibitors and their analogues is becoming a worldwide problem. The aim of this study was to investigate herbal and food products sold in the Malaysian market for the presence of these adulterants. Sixty-two products that claim to enhance men's sexual health were sampled between April 2014 and April 2016. These products included unregistered products seized by the Pharmacy Enforcement Division of the Ministry of Health (n = 39), products sent to the National Pharmaceutical Regulatory Agency for pre-registration testing (n = 9) and products investigated under the post-registration market surveillance programme (n = 14). The products were tested against an in-house spectral library consisting of 61 PDE-5 inhibitors and analogues using a validated liquid chromatography-mass spectrometry ion-trap-time-of-flight (LC-MS IT-TOF) method. Thirty-two (82%) of the unregistered products and two (14%) of the registered products were found to be adulterated with at least one PDE-5 inhibitor or analogue, while none of the pre-registration products contained adulterants. A total of 16 different adulterants were detected and 36% of the adulterated products contained a mixture of two or more adulterants. This study has demonstrated that the adulteration of unregistered herbal products in the Malaysian market is an alarming issue that needs to be urgently addressed by the relevant authorities.

  19. New analogues of Cucurbita maxima trypsin inhibitor III (CMTI III) with simplified structure.

    Science.gov (United States)

    Rolka, K; Kupryszewski, G; Rózycki, J; Ragnarsson, U; Zbyryt, T; Otlewski, J

    1992-10-01

    Seven new analogues of trypsin inhibitor CMTI III were obtained by solid-phase peptide synthesis. Three analogues contained only two, instead of three, disulfide bridges, whereas the molecules of the next four analogues were shortened at the N- and/or C-terminus. The elimination of one disulfide bridge in CMTI III induces a decrease in the association equilibrium constants by 6-7 orders of magnitude, whereas the removal of one, two or three amino-acid residues at the N- and/or C-terminus does not significantly affect the activity.

  20. Tissue turnover of collagen type I, III and elastin is elevated in the PCLS model of IPF and can be restored back to vehicle levels using a phosphodiesterase inhibitor

    DEFF Research Database (Denmark)

    Hansen, Niels Ulrik Brandt; Karsdal, Morten Asser; Brockbank, Sarah

    2016-01-01

    .T., two days apart. The rats were euthanized fourteen days after the last dose. PCLS were made and cultured for 48 h in: medium, medium + 100 μM IBMX (PDE inhibitor), or medium + 10 μM GM6001 (MMP inhibitor). Turnover of type I collagen (P1NP, C1M), type III collagen (iP3NP, C3M) and elastin degradation...... to the culture medium (P ≤ 0.05 - P ≤ 0.0001). Sirius Red and Orcein staining confirmed the presence of collagen and elastin deposition in the lungs of the animals receiving BLM. Conclusions: The protein fingerprint technology allows the assessment of ECM remodeling markers in the BLM PCLS model. By combining...

  1. Hesperetin, a Selective Phosphodiesterase 4 Inhibitor, Effectively Suppresses Ovalbumin-Induced Airway Hyperresponsiveness without Influencing Xylazine/Ketamine-Induced Anesthesia

    Directory of Open Access Journals (Sweden)

    Chung-Hung Shih

    2012-01-01

    Full Text Available Hesperetin, a selective phosphodiesterase (PDE4 inhibitor, is present in the traditional Chinese medicine, “Chen Pi.” Therefore, we were interested in investigating its effects on ovalbumin- (OVA- induced airway hyperresponsiveness, and clarifying its rationale for ameliorating asthma and chronic obstructive pulmonary disease (COPD. Hesperetin was revealed to have a therapeutic (PDE4H/PDE4L ratio of >11. Hesperetin (10 ~ 30 μmol/kg, intraperitoneally (i.p. dose-dependently and significantly attenuated the airway hyperresponsiveness induced by methacholine. It also significantly suppressed the increases in total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils, and levels of cytokines, including interleukin (IL-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF. It dose-dependently and significantly suppressed total and OVA-specific immunoglobulin E levels in the BALF and serum. However, hesperetin did not influence xylazine/ketamine-induced anesthesia, suggesting that hesperetin has few or no emetic effects. In conclusion, the rationales for ameliorating allergic asthma and COPD by hesperetin are anti-inflammation, immunoregulation, and bronchodilation.

  2. Pharmacological characterization of a novel phosphodiesterase type 5 (PDE5) inhibitor lodenafil carbonate on human and rabbit corpus cavernosum.

    Science.gov (United States)

    Toque, Haroldo A; Teixeira, Cleber E; Lorenzetti, Raquel; Okuyama, Cristina E; Antunes, Edson; De Nucci, Gilberto

    2008-09-04

    Nitrergic nerves and endothelial cells release nitric oxide (NO) in the corpus cavernosum, a key mediator that stimulates soluble guanylyl cyclase to increase cGMP levels causing penile erection. Phosphodiesterase 5 (PDE5) inhibitors, such as sildenafil, prolong the NO effects by inhibiting cGMP breakdown. Here, we report a novel PDE5 inhibitor, lodenafil carbonate, (Bis-(2-{4-[4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-benzenesulfonyl]piperazin-1-yl}-ethyl)carbonate) that is a dimer of lodenafil. We therefore aimed to compare the effects of sildenafil, lodenafil and lodenafil carbonate on in vitro human and rabbit cavernosal relaxations, activity of crude PDE extracts from human platelets, as well as stability and metabolic studies in rat, dog and human plasma. Pharmacokinetic evaluations after intravenous and oral administration were performed in male beagles. Functional experiments were conducted using organ bath techniques. Pharmacokinetics was studied in beagles by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), following oral or intravascular administration. All PDE5 inhibitors tested concentration-dependently relaxed (0.001-100 microM) phenylephrine-precontracted rabbit and human corpus cavernosum. The cavernosal relaxations evoked by either acetylcholine (0.01-100 microM) or electrical field stimulation (EFS, 1-20 Hz) were markedly potentiated by sildenafil, lodenafil and lodenafil carbonate. Lodenafil carbonate was more potent to inhibit the cGMP hydrolysis in PDE extracts compared with lodenafil and sildenafil. Following intravascular and single oral administration of lodenafil carbonate, only lodenafil and norlodenafil were detected in vivo. These results indicate that lodenafil carbonate works as a prodrug, being lodenafil the active moiety of lodenafil carbonate.

  3. The role of cilostazol, a phosphodiesterase 3 inhibitor, on oocyte maturation and subsequent pregnancy in mice.

    Directory of Open Access Journals (Sweden)

    Min Li

    Full Text Available It is important to identify effective contraceptive drugs that cause minimal disruption to physiological processes. Phosphodiesterase 3 (PDE3 inhibitors suppress meiosis in oocytes by decreasing the level of cAMP and blocking the extrusion of the first polar body. In this study, we tested the PDE3 inhibitor, cilostazol, as a potential contraceptive agent. The effects of cilostazol treatment in vitro and in vivo on the suppression of oocyte maturation in a mouse model were investigated. The results indicated that treatment with increasing concentrations of cilostazol led to a dose-dependent arrest in meiosis progression. The effective in vitro concentration was 1 µM and was 300 mg/kg in vivo. The effect of cilostazol was reversible. After removal of the drug, meiosis resumed and mouse oocytes matured in vitro, and showed normal chromosome alignment and spindle organization. After fertilization using an ICSI method, the oocytes showed normal morphology, fertilization rate, embryo cleavage, blastocyst formation, and number of viable pups when compared with controls. The offspring showed similar body weight and fertility. In vivo, the mice became infertile if the drug was injected sequentially, and became pregnant following discontinuation of cilostazol. More importantly, no side effects of cilostazol were observed in treated female mice as demonstrated by blood pressure and heart rate monitoring. It is concluded that cilostazol, a drug routinely used for intermittent claudication, can effectively inhibit oocyte maturation in vitro and in vivo, does not affect the developmental potential of oocytes following drug removal and has few side effects in female mice treated with this drug. These findings suggest that cilostazol may be a potential new contraceptive agent that may facilitate an efficacy and safety study of this drug.

  4. First-generation phosphodiesterase type 5 inhibitors dropout: a comprehensive review and meta-analysis.

    Science.gov (United States)

    Corona, G; Rastrelli, G; Burri, A; Serra, E; Gianfrilli, D; Mannucci, E; Jannini, E A; Maggi, M

    2016-11-01

    The discontinuation rate with phosphodiesterase type 5 inhibitors (PDE5i) remains very high. The aim of this study was to review and meta-analyze currently available data regarding dropout of the first-generation of PDE5i including sildenafil, vardenafil, and tadalafil. An extensive Medline Embase and Cochrane search was performed including the following words: 'PDE5i', 'discontinuation'. All observational studies reporting the dropout rate of PDE5i and its specific causes without any arbitrary restrictions were included. Out of 103 retrieved articles, 22 were included in the study. Retrieved trials included a total of 162,936 patients with a mean age of 58.8 ± 7.9 years. Prevalence of reported comorbid diabetes and hypertension were 27.7% and 36.9%, respectively. PDE5i were associated with a mean discontinuation rate of 4% per month (almost 50% after one year). This rate was higher in younger subjects and in those reporting a higher prevalence of associated morbidities. Six main reasons of PDE5i dropout were identified in the evaluated trials. Partner-related problems and lack of efficacy represented the most important reasons for PDE5i discontinuation, although no significant difference among factors was detected. In conclusion, despite their high efficacy and easy administration, the discontinuation rate and dissatisfaction with PDE5i are still very high. Our data showed that no single factor plays a major role in PDE5i dropout, suggesting that the discontinuation rate is usually because of a combination of both medical problems and psychosocial and relational factors. © 2016 American Society of Andrology and European Academy of Andrology.

  5. Inhibition of chlorine-induced lung injury by the type 4 phosphodiesterase inhibitor rolipram

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Weiyuan; Chen, Jing; Schlueter, Connie F. [Department of Environmental and Occupational Health Sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, KY (United States); Rando, Roy J. [Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University Health Sciences Center, New Orleans, LA (United States); Pathak, Yashwant V. [College of Pharmacy, University of South Florida, Tampa, FL (United States); Hoyle, Gary W., E-mail: Gary.Hoyle@louisville.edu [Department of Environmental and Occupational Health Sciences, School of Public Health and Information Sciences, University of Louisville, Louisville, KY (United States)

    2012-09-01

    Chlorine is a highly toxic respiratory irritant that when inhaled causes epithelial cell injury, alveolar-capillary barrier disruption, airway hyperreactivity, inflammation, and pulmonary edema. Chlorine is considered a chemical threat agent, and its release through accidental or intentional means has the potential to result in mass casualties from acute lung injury. The type 4 phosphodiesterase inhibitor rolipram was investigated as a rescue treatment for chlorine-induced lung injury. Rolipram inhibits degradation of the intracellular signaling molecule cyclic AMP. Potential beneficial effects of increased cyclic AMP levels include inhibition of pulmonary edema, inflammation, and airway hyperreactivity. Mice were exposed to chlorine (whole body exposure, 228–270 ppm for 1 h) and were treated with rolipram by intraperitoneal, intranasal, or intramuscular (either aqueous or nanoemulsion formulation) delivery starting 1 h after exposure. Rolipram administered intraperitoneally or intranasally inhibited chlorine-induced pulmonary edema. Minor or no effects were observed on lavage fluid IgM (indicative of plasma protein leakage), KC (Cxcl1, neutrophil chemoattractant), and neutrophils. All routes of administration inhibited chlorine-induced airway hyperreactivity assessed 1 day after exposure. The results of the study suggest that rolipram may be an effective rescue treatment for chlorine-induced lung injury and that both systemic and targeted administration to the respiratory tract were effective routes of delivery. -- Highlights: ► Chlorine causes lung injury when inhaled and is considered a chemical threat agent. ► Rolipram inhibited chlorine-induced pulmonary edema and airway hyperreactivity. ► Post-exposure rolipram treatments by both systemic and local delivery were effective. ► Rolipram shows promise as a rescue treatment for chlorine-induced lung injury.

  6. New active analogues of Cucurbita maxima trypsin inhibitor III (CMTI-III) modified in the non-contact region.

    Science.gov (United States)

    Rózycki, J; Kupryszewski, G; Rolka, K; Ragnarsson, U; Zbyryt, T; Krokoszyńska, I; Wilusz, T

    1994-01-01

    Four new analogues of trypsin inhibitor CMTI-III(3-28) = [desArg1,desVal2,desGly29]CMTI-III which was recently shown to be fully active, were synthesized by the solid-phase method. The introduction of glycine in position 9 (peptide 1) and Gly-Pro-Gly (peptide 2) and Gly-Pro-Asn (peptide 3) in the regions 17-19 and 23-25, respectively, did not change the antitrypsin activity of all modified peptides. All of these substitutions are presumed to be outside the trypsin-binding loop as judged from the X-ray structure of the complex between beta-trypsin and the related inhibitor CMTI-I. Also the fourth analogue which was substituted in all the positions mentioned, exhibited the full activity.

  7. Two-dimensional NMR studies of squash family inhibitors. Sequence-specific proton assignments and secondary structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III

    Energy Technology Data Exchange (ETDEWEB)

    Krisnamoorthi, R.; Yuxi Gong; Chanlan Sun Lin (Kansas State Univ., Manhattan (United States)); VanderVelde, D. (Univ. of Kansas, Lawrence (United States))

    1992-01-28

    The solution structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III (CMTI-III*) was investigated by two-dimensional proton nuclear magnetic resonance (2D NMR) spectroscopy. CMTI-III*, prepared by reacting CMTI-III with trypsin which cleaved the Arg5-Ile6 peptide bond, had the two fragments held together by a disulfide linkage. Sequence-specific {sup 1}H NMR resonance assignments were made for all the 29 amino acid residues of the protein. The secondary structure of CMTI-III*, as deduced from NOESY cross peaks and identification of slowly exchanging hydrogens, contains two turns, a 3{sub 10}-helix, and a triple-stranded {beta}-sheet. Sequential proton assignments were also made for the virgin inhibitor, CMTI-III, at pH 4.71, 30C. Comparison of backbone hydrogen chemical shifts of CMTI-III and CMTI-III* revealed significant changes for residues located far away from the reactive-site region as well as for those located near it, indicating tertiary structural changes that are transmitted through most of the 29 residues of the inhibitor protein. These chemical shift changes were relatively small compared to changes that occurred upon hydrolysis of the reactive-site peptide bond between Arg 5 and Ile6 in CMTI-III.

  8. Two-dimensional NMR studies of squash family inhibitors. Sequence-specific proton assignments and secondary structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III.

    Science.gov (United States)

    Krishnamoorthi, R; Gong, Y X; Lin, C L; VanderVelde, D

    1992-01-28

    The solution structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III (CMTI-III*) was investigated by two-dimensional proton nuclear magnetic resonance (2D NMR) spectroscopy. CMTI-III*, prepared by reacting CMTI-III with trypsin which cleaved the Arg5-Ile6 peptide bond, had the two fragments held together by a disulfide linkage. Sequence-specific 1H NMR resonance assignments were made for all the 29 amino acid residues of the protein. The secondary structure of CMTI-III*, as deduced from NOESY cross peaks and identification of slowly exchanging hydrogens, contains two turns (residues 8-12 and 24-27), a 3(10)-helix (residues 13-16), and a triple-stranded beta-sheet (residues 8-10, 29-27, and 21-25). This secondary structure is similar to that of CMTI-I [Holak, T. A., Gondol, D., Otlewski, J., & Wilusz, T. (1989) J. Mol. Biol. 210, 635-648], which has a Glu instead of a Lys at position 9. Sequential proton assignments were also made for the virgin inhibitor, CMTI-III, at pH 4.71, 30 degrees C. Comparison of backbone hydrogen chemical shifts of CMTI-III and CMTI-III* revealed significant changes for residues located far away from the reactive-site region as well as for those located near it, indicating tertiary structural changes that are transmitted through most of the 29 residues of the inhibitor protein. Many of these residues are functionally important in that they make contact with atoms of the enzyme in the trypsin-inhibitor complex, as revealed by X-ray crystallography [Bode, W., Greyling, H. J., Huber, R., Otlewski, J., & Wilusz, T. (1989) FEBS Lett. 242, 285-292].(ABSTRACT TRUNCATED AT 250 WORDS)

  9. The Human Tyrosyl-DNA Phosphodiesterase 1 (hTdp1) Inhibitor NSC120686 as an Exploratory Tool to Investigate Plant Tdp1 Genes.

    Science.gov (United States)

    Macovei, Anca; Pagano, Andrea; Sabatini, Maria Elisa; Grandi, Sofia; Balestrazzi, Alma

    2018-03-28

    The hTdp1 (human tyrosyl-DNA phosphodiesterase 1) inhibitor NSC120686 has been used, along with topoisomerase inhibitors, as a pharmacophoric model to restrain the Tdp1 activity as part of a synergistic treatment for cancer. While this compound has an end-point application in medical research, in plants, its application has not been considered so far. The originality of our study consists in the use of hTdp1 inhibitor in Medicago truncatula cells, which, unlike human cells, contain two Tdp1 genes. Hence, the purpose of this study was to test the hTdp1 inhibitor NSC120686 as an exploratory tool to investigate the plant Tdp1 genes, since their characterization is still in incipient phases. To do so, M. truncatula calli were exposed to increasing (75, 150, 300 μM) concentrations of NSC120686. The levels of cell mortality and DNA damage, measured via diffusion assay and comet assay, respectively, were significantly increased when the highest doses were used, indicative of a cytotoxic and genotoxic threshold. In addition, the NSC120686-treated calli and untreated MtTdp1α -depleted calli shared a similar response in terms of programmed cell death (PCD)/necrosis and DNA damage. Interestingly, the expression profiles of MtTdp1α and MtTdp1β genes were differently affected by the NSC120686 treatment, as MtTdp1α was upregulated while MtTdp1β was downregulated. The NSC120686 treatment affected not only the MtTdp1 genes but also other genes with roles in alternative DNA repair pathways. Since the expression patterns of these genes were different than what was observed in the MtTdp1α -depleted plants, it could be hypothesized that the NSC120686 treatment exerts a different influence compared to that resulting from the lack of the MtTdp1α gene function.

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

    Science.gov (United States)

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

    2011-08-01

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

  11. Selective inhibition of phosphodiesterases 4, 5 and 9 induces HSP20 phosphorylation and attenuates amyloid beta 1-42 mediated cytotoxicity

    OpenAIRE

    Cameron, Ryan T.; Whiteley, Ellanor; Day, Jon P.; Parachikova, Anna I.; Baillie, George S.

    2017-01-01

    Phosphodiesterase (PDE) inhibitors are currently under evaluation as agents that may facilitate the improvement of cognitive impairment associated with Alzheimer's disease. Our aim was to determine whether inhibitors of PDEs 4, 5 and 9 could alleviate the cytotoxic effects of amyloid beta 1?42 (A?1?42) via a mechanism involving the small heatshock protein HSP20. We show that inhibition of PDEs 4, 5 and 9 but not 3 induces the phosphorylation of HSP20 which, in turn, increases the colocalisati...

  12. Distribution and function of 3',5'-Cyclic-AMP phosphodiesterases in the human ovary

    DEFF Research Database (Denmark)

    Petersen, T S; Kristensen, S G; Jeppesen, J V

    2015-01-01

    The concentration of the important second messenger cAMP is regulated by phosphodiesterases (PDEs) and hence an attractive drug target. However, limited human data are available about the PDEs in the ovary. The aim of the present study was to describe and characterise the PDEs in the human ovary....... Results were obtained by analysis of mRNA microarray data from follicles and granulosa cells (GCs), combined RT-PCR and enzymatic activity analysis in GCs, immunohistochemical analysis of ovarian sections and by studying the effect of PDE inhibitors on progesterone production from cultured GCs. We found...

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

    DEFF Research Database (Denmark)

    Liebenberg, Nico

    2010-01-01

    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...... rats were treated with vehicle/drug(s) for 14 days, whereafter immobility, swimming and climbing behaviours were measured in the FST, or time spent in social interaction in the social interaction test. Following decapitation, saturation binding studies were performed for the measurement of m...

  14. Synthesis, QSAR, and Molecular Dynamics Simulation of Amidino-substituted Benzimidazoles as Dipeptidyl Peptidase III Inhibitors.

    Science.gov (United States)

    Rastija, Vesna; Agić, Dejan; Tomiš, Sanja; Nikolič, Sonja; Hranjec, Marijana; Grace, Karminski-Zamola; Abramić, Marija

    2015-01-01

    A molecular modeling study is performed on series of benzimidazol-based inhibitors of human dipeptidyl peptidase III (DPP III). An eight novel compounds were synthesized in excellent yields using green chemistry approach. This study is aimed to elucidate the structural features of benzimidazole derivatives required for antagonism of human DPP III activity using Quantitative Structure-Activity Relationship (QSAR) analysis, and to understand the mechanism of one of the most potent inhibitor binding into the active site of this enzyme, by molecular dynamics (MD) simulations. The best model obtained includes S3K and RDF045m descriptors which have explained 89.4 % of inhibitory activity. Depicted moiety for strong inhibition activity matches to the structure of most potent compound. MD simulation has revealed importance of imidazolinyl and phenyl groups in the mechanism of binding into the active site of human DPP III.

  15. Co-possession of phosphodiesterase type-5 inhibitors (PDE5-I) with nitrates.

    Science.gov (United States)

    Chang, Li-Ling; Ma, Mark; Allmen, Heather von; Henderson, Scott C; Harper, Kristine; Hornbuckle, Kenneth

    2010-06-01

    Estimate the proportion of phosphodiesterase type-5 inhibitor (PDE5-I) patients who co-possess nitrates and compare the proportion of tadalafil patients dispensed nitrates to a matched control group. Secondarily, examine the percentage of co-possession of PDE5-Is and nitrates where the products were dispensed on the same day or written by the same prescriber. Male patients aged 18+ years filling PDE5-I prescriptions between December 2003 and March 2006 were identified using a U.S. longitudinal prescription database (IMS Health LRx). Similar patients not dispensed a PDE5-I during this period were matched to the tadalafil-dispensed cohort using a propensity score approach. Co-possession, as a proxy for concurrent use, was defined as an overlap in time on therapy for a PDE5-I and nitrate and was compared for the three PDE5-Is and for tadalafil to the matched control group. Among 601,063 tadalafil patients, 3.31% were dispensed a nitrate during the study period, compared to 6.18% in control patients (n = 601,063). When co-possessed prescriptions were defined by overlapping exposure periods, the proportion of PDE5-I patients with co-possessed nitrates ranged from 1.44% (tadalafil) to 1.72% (vardenafil) and 2.13% (sildenafil). Co-possession percentages of PDE5-I prescriptions were 0.83% for tadalafil and 1.07% for sildenafil and vardenafil. The majority (54.29%) of co-possessed PDE5-I and nitrate prescriptions had the nitrate dispensed prior to the PDE5-I prescription identified in the study cohort. Keeping in mind the limitations of observational studies, these results suggest that co-dispensing of nitrates and PDE5-Is is low. Compared to control patients, the proportion of nitrate co-possession was lowest for patients filling tadalafil. Tadalafil patients also had the lowest co-possessed proportion among the three PDE5-I cohorts. While the majority of co-possessed drug pairs were prescribed by different providers, the highest percentage of co-prescribing from the same

  16. Tetomilast.

    LENUS (Irish Health Repository)

    O'Mahony, Seamus

    2012-02-03

    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).

  17. Cyclic nucleotide specific phosphodiesterases of Leishmania major

    Directory of Open Access Journals (Sweden)

    Linder Markus

    2006-03-01

    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

  18. Protective effects of phosphodiesterase-4-specific inhibitor rolipram on acute ischemia-reperfusion injury in rat kidney.

    Science.gov (United States)

    Mammadov, Emin; Aridogan, Ibrahim Atilla; Izol, Volkan; Acikalin, Arbil; Abat, Deniz; Tuli, Abdullah; Bayazit, Yildirim

    2012-12-01

    To investigate the effect of Rolipram, a phosphodiesterase-4-inhibitor, on renal ischemia-reperfusion injury (IRI) in rats. Thirty rats were divided into 5 different groups of 6 rats. Nothing was done to the control group. In the second group, the renal pedicle was clamped for 30 minutes. In the third group, 1 mg/kg of Rolipram was given by intraperitoneal injection 30 minutes before clamping. The fourth group received the same injection when the clamp was placed, as did the fifth group 30 minutes after the clamp was opened. Clamping time was set at 30 minutes. Twenty-four hours later, nephrectomy was performed in all the groups. Half of each kidney was examined histopathologically. Levels of biochemical agents, such as malondialdehyde, superoxide dismutase, and catalase, were measured in the other half. The malondialdehyde (MDA) levels significantly decreased and reached control levels in the group in which Rolipram was administered 30 minutes after reperfusion (P = .07). The catalase and superoxide dismutase activities obtained from renal homogentisates of the ischemia groups were evaluated; there were striking increases in tissue levels of these 2 enzymes in the groups in which Rolipram was administered during ischemia and 30 minutes after ischemia (P < .001). Histopathologically, there was no significant difference in inflammation between the Rolipram-administrated groups compared with group 1 (control) and group 2 (IRI). Tubular necrosis and apoptosis was significantly lower in group 5 than the other groups, except group 1 (P < .001). We suggest that in surgical procedures that can lead to renal IRI, the administration of Rolipram can decrease oxidative renal tissue damage and the severe deterioration of renal function. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Small-Molecule Inhibitors of the Type III Secretion System

    Directory of Open Access Journals (Sweden)

    Lingling Gu

    2015-09-01

    Full Text Available Drug-resistant pathogens have presented increasing challenges to the discovery and development of new antibacterial agents. The type III secretion system (T3SS, existing in bacterial chromosomes or plasmids, is one of the most complicated protein secretion systems. T3SSs of animal and plant pathogens possess many highly conserved main structural components comprised of about 20 proteins. Many Gram-negative bacteria carry T3SS as a major virulence determinant, and using the T3SS, the bacteria secrete and inject effector proteins into target host cells, triggering disease symptoms. Therefore, T3SS has emerged as an attractive target for antimicrobial therapeutics. In recent years, many T3SS-targeting small-molecule inhibitors have been discovered; these inhibitors prevent the bacteria from injecting effector proteins and from causing pathophysiology in host cells. Targeting the virulence of Gram-negative pathogens, rather than their survival, is an innovative and promising approach that may greatly reduce selection pressures on pathogens to develop drug-resistant mutations. This article summarizes recent progress in the search for promising small-molecule T3SS inhibitors that target the secretion and translocation of bacterial effector proteins.

  20. 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.

    Science.gov (United States)

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

    2013-12-01

    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. © 2013 John Wiley & Sons A/S.

  1. The Phosphodiesterase 4 Inhibitor Roflumilast Protects against Cigarette Smoke Extract-Induced Mitophagy-Dependent Cell Death in Epithelial Cells.

    Science.gov (United States)

    Kyung, Sun Young; Kim, Yu Jin; Son, Eun Suk; Jeong, Sung Hwan; Park, Jeong Woong

    2018-04-01

    Recent studies show that mitophagy, the autophagy-dependent turnover of mitochondria, mediates pulmonary epithelial cell death in response to cigarette smoke extract (CSE) exposure and contributes to the development of emphysema in vivo during chronic cigarette smoke (CS) exposure, although the underlying mechanisms remain unclear. In this study, we investigated the role of mitophagy in the regulation of CSE-exposed lung bronchial epithelial cell (Beas-2B) death. We also investigated the role of a phosphodiesterase 4 inhibitor, roflumilast, in CSE-induced mitophagy-dependent cell death. Our results demonstrated that CSE induces mitophagy in Beas-2B cells through mitochondrial dysfunction and increased the expression levels of the mitophagy regulator protein, PTEN-induced putative kinase-1 (PINK1), and the mitochondrial fission protein, dynamin-1-like protein (DRP1). CSE-induced epithelial cell death was significantly increased in Beas-2B cells exposed to CSE but was decreased by small interfering RNA-dependent knockdown of DRP1. Treatment with roflumilast in Beas-2B cells inhibited CSE-induced mitochondrial dysfunction and mitophagy by inhibiting the expression of phospho-DRP1 and -PINK1. Roflumilast protected against cell death and increased cell viability, as determined by the lactate dehydrogenase release test and the MTT assay, respectively, in Beas-2B cells exposed to CSE. These findings suggest that roflumilast plays a protective role in CS-induced mitophagy-dependent cell death. Copyright©2018. The Korean Academy of Tuberculosis and Respiratory Diseases.

  2. Cigarette Smoke-Induced Emphysema and Pulmonary Hypertension Can Be Prevented by Phosphodiesterase 4 and 5 Inhibition in Mice

    Science.gov (United States)

    Pichl, Alexandra; Bednorz, Mariola; Ghofrani, Hossein Ardeschir; Schermuly, Ralph Theo; Seeger, Werner; Grimminger, Friedrich; Weissmann, Norbert

    2015-01-01

    Rationale Chronic obstructive pulmonary disease (COPD) is a widespread disease, with no curative therapies available. Recent findings suggest a key role of NO and sGC-cGMP signaling for the pathogenesis of the disease. Previous data suggest a downregulation/inactivation of the cGMP producing soluble guanylate cyclase, and sGC stimulation prevented cigarette smoke-induced emphysema and pulmonary hypertension (PH) in mice. We thus aimed to investigate if the inhibition of the cGMP degrading phosphodiesterase (PDE)5 has similar effects. Results were compared to the effects of a PDE 4 inhibitor (cAMP elevating) and a combination of both. Methods C57BL6/J mice were chronically exposed to cigarette smoke and in parallel either treated with Tadalafil (PDE5 inhibitor), Piclamilast (PDE4 inhibitor) or both. Functional measurements (lung compliance, hemodynamics) and structural investigations (alveolar and vascular morphometry) as well as the heart ratio were determined after 6 months of tobacco smoke exposure. In addition, the number of alveolar macrophages in the respective lungs was counted. Results Preventive treatment with Tadalafil, Piclamilast or a combination of both almost completely prevented the development of emphysema, the increase in lung compliance, tidal volume, structural remodeling of the lung vasculature, right ventricular systolic pressure, and right ventricular hypertrophy induced by cigarette smoke exposure. Single, but not combination treatment prevented or reduced smoke-induced increase in alveolar macrophages. Conclusion Cigarette smoke-induced emphysema and PH could be prevented by inhibition of the phosphodiesterases 4 and 5 in mice. PMID:26058042

  3. Characterization of the insulin-sensitive low Km cAMP phosphodiesterase from rat adipose tissue

    International Nuclear Information System (INIS)

    Degerman, E.; Belfrage, P.; Manganiello, V.C.

    1986-01-01

    Particulate, but not soluble, low K/sub m/ cAMP phosphodiesterase (PDE) activity of rat adipocytes was increased 50-100% during incubation (10 min) of intact cells with 1-3 nM insulin; activation was less with higher or lower insulin concentrations. Activation was maintained during solubilization with an alkyl polyoxyethylene non-ionic detergent C 13 , E 12 and NaBr and chromatography on DEAE. Enzyme from DEAE was further purified by chromatography on Sepahadex G-200 and Blue-Sepharose. Activity (with 0.5 μM [ 3 H]cAMP) was rather sensitive to inhibition by p-chloromercuribenzoate (IC 50 , 1 μM) and less so by 2,2'-dithiobis-(5-nitropyridine) (160 μM), N-ethylmaleimide (525 μM) and iodoacetamide (750 μM). PDE activity was also rather sensitive to inhibition by cilostamide (IC 50 , ∼40 nM) and the cardiotonic drugs CI 930 (450 nM) and milrinone (630 nM) but rather insensitive to RO 20-1724 (190 μM). Based on effects of these inhibitors, the hormone-sensitive low K/sub m/ particulate cAMP PDE from rat adipocytes seems to be analogous to the insulin-activated particulate PDE from 3T3-L1 adipocytes and the cilostamide-sensitive soluble low K/sub m/ cAMP PDE from bovine liver (designated as III-C), platelets, heart, and other tissues

  4. Interactions of chlorphenesin and divalent metal ions with phosphodiesterase.

    Science.gov (United States)

    Edelson, J; McMullen, J P

    1976-09-01

    Chlorphenesin inhibition of the hydrolysis of cyclic AMP by guinea-pig lung phosphodiesterase was reversed by the addition of exogenous magnesium ions. Chlorphenesin and theophylline inhibition of this enzyme was shown to be noncompetitive when the substrate concentration was low. Kinetic studies of the inhibition of beef heart phosphodiesterase by chlorphenesin and theophylline indicated that the substrate concentration was a factor in determining whether inhibition was competitive or noncompetitive. Calcium, cobalt and copper ions were inhibitory to guinea-pig lung phosphodiesterase. The inhibition due to chlorphenesin was partially reversed by low (40 mM or less) concentrations of barium ions; high concentrations of barium ions, or manganese ions, were inhibitory. The concentration of the divalent cation did not affect the type of inhibition that was observed.

  5. 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

    2008-10-01

    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

  6. Attenuation of ethanol abstinence-induced anxiety- and depressive-like behavior by the phosphodiesterase-4 inhibitor rolipram in rodents.

    Science.gov (United States)

    Gong, Mei-Fang; Wen, Rui-Ting; Xu, Ying; Pan, Jian-Chun; Fei, Ning; Zhou, Yan-Meng; Xu, Jiang-Ping; Liang, Jian-Hui; Zhang, Han-Ting

    2017-10-01

    Withdrawal symptoms stand as a core feature of alcohol dependence. Our previous results have shown that inhibition of phosphodiesterase-4 (PDE4) decreased ethanol seeking and drinking in alcohol-preferring rodents. However, little is known about whether PDE4 is involved in ethanol abstinence-related behavior. The objective of this study was to characterize the role of PDE4 in the development of anxiety- and depressive-like behavior induced by abstinence from ethanol exposure in different animal models. Using three rodent models of ethanol abstinence, we examined the effects of rolipram, a prototypical, selective PDE4 inhibitor, on (1) anxiety-like behavior induced by repeated ethanol abstinence in the elevated plus maze test in fawn-hooded (FH/Wjd) rats, (2) anxiety-like behavior in the open-field test and light-dark transition test following acute ethanol abstinence in C57BL/6J mice, and (3) anxiety- and depressive-like behavior induced by protracted ethanol abstinence in the elevated plus maze, forced-swim, and tail-suspension tests in C57BL/6J mice. Pretreatment with rolipram (0.1 or 0.2 mg/kg) significantly increased entries and time spent in the open arms of the elevated plus maze test in rats with repeated ethanol abstinence. Similarly, in mice with acute ethanol abstinence, administration of rolipram (0.25 or 0.5 mg/kg) dose-dependently increased the crossings in the central zone of the open-field test and duration and transitions on the light side of the light-dark transition test, suggesting anxiolytic-like effects of rolipram. Consistent with these, chronic treatment with rolipram (0.1, 0.3, or 1.0 mg/kg) increased entries in the open arms of the elevated plus maze test; it also reduced the increased duration of immobility in both the forced-swim and tail-suspension tests in mice after protracted ethanol abstinence, suggesting antidepressant-like effects of rolipram. These results provide the first demonstration for that PDE4 plays a role in modulating

  7. Phosphodiesterase-4 inhibition combined with isoniazid treatment of rabbits with pulmonary tuberculosis reduces macrophage activation and lung pathology.

    Science.gov (United States)

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

    2011-07-01

    Tuberculosis (TB) is responsible for significant morbidity and mortality worldwide. Even after successful microbiological cure of TB, many patients are left with residual pulmonary damage that can lead to chronic respiratory impairment and greater risk of additional TB episodes due to reinfection with Mycobacterium tuberculosis. Elevated levels of the proinflammatory cytokine tumor necrosis factor-α and several other markers of inflammation, together with expression of matrix metalloproteinases, have been associated with increased risk of pulmonary fibrosis, tissue damage, and poor treatment outcomes in TB patients. In this study, we used a rabbit model of pulmonary TB to evaluate the impact of adjunctive immune modulation, using a phosphodiesterase-4 inhibitor that dampens the innate immune response, on the outcome of treatment with the antibiotic isoniazid. Our data show that cotreatment of M. tuberculosis infected rabbits with the phosphodiesterase-4 inhibitor CC-3052 plus isoniazid significantly reduced the extent of immune pathogenesis, compared with antibiotic alone, as determined by histologic analysis of infected tissues and the expression of genes involved in inflammation, fibrosis, and wound healing in the lungs. Combined treatment with an antibiotic and CC-3052 not only lessened disease but also improved bacterial clearance from the lungs. These findings support the potential for adjunctive immune modulation to improve the treatment of pulmonary TB and reduce the risk of chronic respiratory impairment. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  8. Exploring pyrazolo[3,4-d]pyrimidine phosphodiesterase 1 (PDE1) inhibitors: a predictive approach combining comparative validated multiple molecular modelling techniques.

    Science.gov (United States)

    Amin, Sk Abdul; Bhargava, Sonam; Adhikari, Nilanjan; Gayen, Shovanlal; Jha, Tarun

    2018-02-01

    Phosphodiesterase 1 (PDE1) is a potential target for a number of neurodegenerative disorders such as Schizophrenia, Parkinson's and Alzheimer's diseases. A number of pyrazolo[3,4-d]pyrimidine PDE1 inhibitors were subjected to different molecular modelling techniques [such as regression-based quantitative structure-activity relationship (QSAR): multiple linear regression, support vector machine and artificial neural network; classification-based QSAR: Bayesian modelling and Recursive partitioning; Monte Carlo based QSAR; Open3DQSAR; pharmacophore mapping and molecular docking analyses] to get a detailed knowledge about the physicochemical and structural requirements for higher inhibitory activity. The planarity of the pyrimidinone ring plays an important role for PDE1 inhibition. The N-methylated function at the 5th position of the pyrazolo[3,4-d]pyrimidine core is required for interacting with the PDE1 enzyme. The cyclopentyl ring fused with the parent scaffold is necessary for PDE1 binding potency. The phenylamino substitution at 3rd position is crucial for PDE1 inhibition. The N2-substitution at the pyrazole moiety is important for PDE1 inhibition compared to the N1-substituted analogues. Moreover, the p-substituted benzyl side chain at N2-position helps to enhance the PDE1 inhibitory profile. Depending on these observations, some new molecules are predicted that may possess better PDE1 inhibition.

  9. Characterization of the insulin-sensitive low Km cAMP phosphodiesterase from rat adipose tissue

    Energy Technology Data Exchange (ETDEWEB)

    Degerman, E.; Belfrage, P.; Manganiello, V.C.

    1986-05-01

    Particulate, but not soluble, low K/sub m/ cAMP phosphodiesterase (PDE) activity of rat adipocytes was increased 50-100% during incubation (10 min) of intact cells with 1-3 nM insulin; activation was less with higher or lower insulin concentrations. Activation was maintained during solubilization with an alkyl polyoxyethylene non-ionic detergent C/sub 13/, E/sub 12/ and NaBr and chromatography on DEAE. Enzyme from DEAE was further purified by chromatography on Sepahadex G-200 and Blue-Sepharose. Activity (with 0.5 ..mu..M (/sup 3/H)cAMP) was rather sensitive to inhibition by p-chloromercuribenzoate (IC/sub 50/, 1 ..mu..M) and less so by 2,2'-dithiobis-(5-nitropyridine) (160 ..mu..M), N-ethylmaleimide (525 ..mu..M) and iodoacetamide (750 ..mu..M). PDE activity was also rather sensitive to inhibition by cilostamide (IC/sub 50/, approx.40 nM) and the cardiotonic drugs CI 930 (450 nM) and milrinone (630 nM) but rather insensitive to RO 20-1724 (190 ..mu..M). Based on effects of these inhibitors, the hormone-sensitive low K/sub m/ particulate cAMP PDE from rat adipocytes seems to be analogous to the insulin-activated particulate PDE from 3T3-L1 adipocytes and the cilostamide-sensitive soluble low K/sub m/ cAMP PDE from bovine liver (designated as III-C), platelets, heart, and other tissues.

  10. Glycine-rich analogues of Cucurbita maxima trypsin inhibitor (CMTI-III) substituted by valine in position 27 display relatively low antitrypsin activity.

    Science.gov (United States)

    Rózycki, J; Kupryszewski, G; Rolka, K; Ragnarsson, U; Zbytryt, T; Krokoszyńska, I; Otlewski, J

    1993-09-01

    Five new analogues of the trypsin inhibitor CMTI-III were synthesized by the solid-phase method. All analogues containing a valine residue in position 27 and glycine residues in some or all of the positions 9, 11, 14, 17, 19, 29 as well as in two cases a norleucine residue in position 8 displayed association equilibrium constants by 6-7 orders of magnitude lower than the native CMTI-III inhibitor.

  11. Psychotherapy and phosphodiesterase-5 inhibitor in early rehabilitation after radical prostatectomy: a prospective randomised controlled trial.

    Science.gov (United States)

    Naccarato, A M E P; Reis, L O; Ferreira, U; Denardi, F

    2016-12-01

    The aim of this study was to evaluate the impact of group psychotherapy and the use of a phosphodiesterase-5 inhibitor (PDE-5i) in the early rehabilitation stage of patients with prostate cancer undergoing radical prostatectomy (RP). Fifty-six patients undergoing RP for prostate cancer were randomised into four groups, and 53 completed the protocol: Group 1 - control (n = 11), Group 2 - group psychotherapy (n = 16), Group 3 - lodenafil 80 mg/one tablet per week (n = 12) and Group 4 - group psychotherapy + lodenafil 80 mg/one tablet per week (n = 14). The groups were individually evaluated for erectile function (IIEF-5) and quality of life - QoL (SF-36) weekly, with two meetings held a week apart before the RP and 12 weekly meetings after surgery. The ages ranged from 39 to 76 years, average 61.84. There were no significant medication side effects. Only Group 4 showed improvement in intimacy with a partner and satisfaction with their sex life (P = 0.045 and P = 0.013 respectively), and with no significant worsening of the IIEF-5 (P = 0.250) reported. All groups showed worsening in the final result of the role limitations caused by physical problems (P = 0.009) and role limitations caused by emotional problems (P = 0.002) of the SF-36, but Group 4 had a significantly higher score for the role limitations caused by physical problems (P = 0.009) than the other groups. In conclusion, precocious integral treatment involving group psychotherapy and PDE-5i before and after RP led to less deterioration of erectile function and other domains related to physical aspects (SF-36), with improvement in intimacy with their partner and satisfaction in their sex life, being superior to single treatments. © 2016 Blackwell Verlag GmbH.

  12. Discovery of Selective Phosphodiesterase 1 Inhibitors with Memory Enhancing Properties.

    Science.gov (United States)

    Dyck, Brian; Branstetter, Bryan; Gharbaoui, Tawfik; Hudson, Andrew R; Breitenbucher, J Guy; Gomez, Laurent; Botrous, Iriny; Marrone, Tami; Barido, Richard; Allerston, Charles K; Cedervall, E Peder; Xu, Rui; Sridhar, Vandana; Barker, Ryan; Aertgeerts, Kathleen; Schmelzer, Kara; Neul, David; Lee, Dong; Massari, Mark Eben; Andersen, Carsten B; Sebring, Kristen; Zhou, Xianbo; Petroski, Robert; Limberis, James; Augustin, Martin; Chun, Lawrence E; Edwards, Thomas E; Peters, Marco; Tabatabaei, Ali

    2017-04-27

    A series of potent thienotriazolopyrimidinone-based PDE1 inhibitors was discovered. X-ray crystal structures of example compounds from this series in complex with the catalytic domain of PDE1B and PDE10A were determined, allowing optimization of PDE1B potency and PDE selectivity. Reduction of hERG affinity led to greater than a 3000-fold selectivity for PDE1B over hERG. 6-(4-Methoxybenzyl)-9-((tetrahydro-2H-pyran-4-yl)methyl)-8,9,10,11-tetrahydropyrido[4',3':4,5]thieno[3,2-e][1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-one was identified as an orally bioavailable and brain penetrating PDE1B enzyme inhibitor with potent memory-enhancing effects in a rat model of object recognition memory.

  13. Modifications outside the proteinase binding loop in Cucurbita maxima trypsin inhibitor III (CMTI-III) analogues change the binding energy with bovine beta-trypsin.

    Science.gov (United States)

    Jaśkiewicz, A; Lis, K; Rózycki, J; Kupryszewski, G; Rolka, K; Ragnarsson, U; Zbyryt, T; Wilusz, T

    1998-10-02

    Five 26-peptide analogues of the trypsin inhibitor [Pro18]CMTI-III containing Leu or Tyr in position 7 and Val or Tyr in position 27: 1 (Leu7, Tyr27), 2 (Tyr7, Val27), 3 (Tyr7, Tyr27), 4 (Leu7, Val27) and 5 (Leu7, Ala18, Tyr27) were synthesized by the solid-phase method. Analogues 1-4 displayed Ka with bovine beta-trypsin of the same order of magnitude as the wild CMTI-III inhibitor, whereas for analogue 5, this value was lower by about 3 orders of magnitude. This indicated that for the analogues with Pro (but not with Ala) in position 18, the side-chain interactions between positions 7 and 27 did not play a critical role for the stabilization of the active structure. In addition, these results also suggest that Tyr7 is involved in an additional aromatic interaction with position 41 of the enzyme.

  14. Phosphodiesterases regulate airway smooth muscle function in health and disease.

    Science.gov (United States)

    Krymskaya, Vera P; Panettieri, Reynold A

    2007-01-01

    On the basis of structure, regulation, and kinetic properties, phosphodiesterases (PDEs) represent a superfamily of enzymes divided into 11 subfamilies that catalyze cytosolic levels of 3',5'-cyclic adenosine monophosphate (cAMP) or 3',5'-cyclic guanosine monophosphate (cGMP) to 5'-AMP or 5'-GMP, respectively. PDE4 represents the major PDE expressed in inflammatory cells as well as airway smooth muscle (ASM), and selective PDE4 inhibitors provide a broad spectrum of anti-inflammatory effects such as abrogating cytokine and chemokine release from inflammatory cells and inhibiting inflammatory cell trafficking. Due to cell- and tissue-specific gene expression and regulation, PDEs modulate unique organ-based functions. New tools or compounds that selectively inhibit PDE subfamilies and genetically engineered mice deficient in selective isoforms have greatly enhanced our understanding of PDE function in airway inflammation and resident cell function. This chapter will focus on recent advances in our understanding of the role of PDE in regulating ASM function.

  15. Phosphodiesterase type 5 inhibitor administered immediately after radical prostatectomy temporarily increases the need for incontinence pads, but improves final continence status

    Directory of Open Access Journals (Sweden)

    Yasuhiro Kaiho

    2016-09-01

    Full Text Available Purpose: To evaluate the effects of phosphodiesterase type 5 inhibitor (PDE5i on urinary continence recovery after bilateral nerve-sparing radical prostatectomy (BNSRP. Materials and Methods: Between 2002 and 2012, 137 of 154 consecutive patients who underwent BNSRP in our institution retrospectively divided into 3 groups that included patients taking PDE5i immediately after surgery (immediate PDE5i group, n=41, patients starting PDE5i at an outpatient clinic after discharge (PDE5i group, n=56, and patients taking no medication (non-PDE5i group, n=40. Using self-administered questionnaires, the proportion of patients who did not require incontinence pads (pad-free patients was calculated preoperatively and at 1, 3, 6, 12, 18, and 24 months after BNSRP. Severity of incontinence was determined based on the pad numbers and then compared among the 3 groups. Results: Proportions of pad-free patients and severity of incontinence initially deteriorated in all of the groups to the lowest values soon after undergoing BNSRP, with gradual improvement noted thereafter. The deterioration was most prominent in the immediate PDE5i group. As compared to the non-PDE5i group, both the PDE5i and immediate PDE5i groups exhibited a better final continence status. Conclusions: PDE5i improves final continence status. However, administration of PDE5i immediately after surgery causes a distinct temporary deterioration in urinary incontinence.

  16. Efficacy of phosphodiesterase type 5 inhibitors for the treatment of distal ureteral calculi: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Montes Cardona

    2017-03-01

    Full Text Available Purpose: To determine the efficacy of phosphodiesterase type 5 inhibitors (PDE5i as medical expulsive therapy (MET for the treatment of distal ureteral calculi. Materials and Methods: A search strategy was conducted in the MEDLINE, CENTRAL, and Embase databases. Searches were also conducted in other databases and unpublished literature. Clinical trials were included without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration’s tool. An analysis of random effects due to statistical heterogeneity was conducted. The primary outcome was the expulsion rate of the distal ureteral calculus in 28 days. The secondary outcomes were the time to expulsion, side effects of treatment, and amount (mg of nonopioid analgesia. The measure of the effect was the risk difference (RD with a 95% confidence interval (CI. The planned interventions were PDE5i vs. placebo, tadalafil vs. placebo, and tadalafil vs. tamsulosin. Results: Four articles were included in the qualitative and quantitative analysis. Records of 580 patients were found among the four studies. A low risk of bias was shown for the majority of the study items. The calculi expulsion rate had an RD of 0.26 (95% CI, 0.15–0.37 and a less prolonged expulsion as a secondary outcome with a mean difference of -4.39 days (95% CI, -6.69 to -2.09 in favor of PDE5i compared with the placebo. No significant difference was found for these outcomes when comparing tadalafil with tamsulosin. Conclusions: Compared with a placebo, PDE5i could be effective as MET for the treatment of distal ureter calculi.

  17. Phosphodiesterase inhibitors suppress Lactobacillus casei cell-wall-induced NF-κB and MAPK activations and cell proliferation through protein kinase A--or exchange protein activated by cAMP-dependent signal pathway.

    Science.gov (United States)

    Saito, Takekatsu; Sugimoto, Naotoshi; Ohta, Kunio; Shimizu, Tohru; Ohtani, Kaori; Nakayama, Yuko; Nakamura, Taichi; Hitomi, Yashiaki; Nakamura, Hiroyuki; Koizumi, Shoichi; Yachie, Akihiro

    2012-01-01

    Specific strains of Lactobacillus have been found to be beneficial in treating some types of diarrhea and vaginosis. However, a high mortality rate results from underlying immunosuppressive conditions in patients with Lactobacillus casei bacteremia. Cyclic AMP (cAMP) is a small second messenger molecule that mediates signal transduction. The onset and progression of inflammatory responses are sensitive to changes in steady-state cAMP levels. L. casei cell wall extract (LCWE) develops arteritis in mice through Toll-like receptor-2 signaling. The purpose of this study was to investigate whether intracellular cAMP affects LCWE-induced pathological signaling. LCWE was shown to induce phosphorylation of the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and cell proliferation in mice fibroblast cells. Theophylline and phosphodiesterase inhibitor increased intracellular cAMP and inhibited LCWE-induced cell proliferation as well as phosphorylation of NF-κB and MAPK. Protein kinase A inhibitor H89 prevented cAMP-induced MAPK inhibition, but not cAMP-induced NF-κB inhibition. An exchange protein activated by cAMP (Epac) agonist inhibited NF-κB activation but not MAPK activation. These results indicate that an increase in intracellular cAMP prevents LCWE induction of pathological signaling pathways dependent on PKA and Epac signaling.

  18. Cyclic AMP-specific phosphodiesterase-4 as a target for the development of antidepressant drugs.

    Science.gov (United States)

    Zhang, Han-Ting

    2009-01-01

    Phosphodiesterase-4 (PDE4), one of eleven PDE enzyme families, specifically catalyzes hydrolysis of cyclic AMP (cAMP); it has four subtypes (PDE4A-D) with at least 25 splice variants. PDE4 plays a critical role in the control of intracellular cAMP concentrations. PDE4 inhibitors produce antidepressant actions in both animals and humans via enhancement of cAMP signaling in the brain. However, their clinical utility has been hampered by side effects, in particular nausea and emesis. While there is still a long way to go before PDE4 inhibitors with high therapeutic indices are available for treatment of depressive disorders, important advances have been made in the development of PDE4 inhibitors as antidepressants. First, limited, but significant studies point to PDE4D as the major PDE4 subtype responsible for antidepressant-like effects of PDE4 inhibitors, although the role of PDE4A cannot be excluded. Second, PDE4D may contribute to emesis, the major side effect of PDE4 inhibitors. For this reason, identification of roles of PDE4D splice variants in mediating antidepressant activity is particularly important. Recent studies using small interfering RNAs (siRNAs) have demonstrated the feasibility to identify cellular functions of individual PDE4 variants. Third, mixed inhibitors of PDE4 and PDE7 or PDE4 and serotonin reuptake have been developed and may be potential antidepressants with minimized side effects. Finally, relatively selective inhibitors of one or two PDE4 subtypes have been synthesized using structure- and scaffold-based design. This review also discusses the relationship between PDE4 and antidepressant activity based on structures, brain distributions, and pharmacological properties of PDE4 and its isoforms.

  19. Is zucchini a phosphodiesterase or a ribonuclease?

    Directory of Open Access Journals (Sweden)

    Osamu Nureki

    2014-12-01

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

  20. Analysis of Prescriptions of Alpha-Blockers and Phosphodiesterase 5 Inhibitors from the Urology Department and Other Departments

    Directory of Open Access Journals (Sweden)

    Dong Hyuk Kang

    2011-12-01

    Full Text Available PurposeWe analyzed the prescriptions of alpha-blockers and phosphodiesterase 5 inhibitors (PDE5Is in the urology department as well as in other departments of the general hospital.MethodsWe investigated the frequency of prescription of alpha-blockers and PDE5Is from 3 general hospitals from January 1, 2007 to December 31, 2009. For alpha-blockers, data were collected from patients to whom alpha-blockers were prescribed from among patients recorded as having benign prostatic hyperplasia according to the 5th Korean Standard Classification of Diseases. For PDE5Is, data were collected from patients to whom PDE5Is were prescribed by the urology department and by other departments. Alpha-blockers were classified into tamsulosin, alfuzosin, doxazosin, and terazosin, whereas PDE5Is were classified into sildenafil, tadalafil, vardenafil, udenafil, and mirodenafil.ResultsAlpha-blockers were prescribed to 11,436 patients in total over 3 years, and the total frequency of prescriptions was 68,565. Among other departments, the nephrology department had the highest frequency of prescription of 3,225 (4.7%, followed by the cardiology (3,101, 4.5%, neurology (2,576, 3.8%, endocrinology (2,400, 3.5%, pulmonology (1,102, 1.6%, and family medicine (915, 1.3% departments in order. PDE5Is were prescribed to 2,854 patients in total over 3 years, and the total frequency of prescriptions was 10,558. The prescription frequency from the urology department was 4,900 (46.4%. Among other departments, the endocrinology department showed the highest prescription frequency of 3,488 (33.0%, followed by the neurology (542, 5.1%, cardiology (467, 4.4%, and family medicine (407, 3.9% departments in order.ConclusionsA high percentage of prescriptions of alpha-blockers and PDE5Is were from other departments. For more specialized medical care by urologists is required in the treatment of lower urinary tract symptoms and erectile dysfunction.

  1. Psiguajadials A-K: Unusual Psidium Meroterpenoids as Phosphodiesterase-4 Inhibitors from the Leaves of Psidium guajava.

    Science.gov (United States)

    Tang, Gui-Hua; Dong, Zhen; Guo, Yan-Qiong; Cheng, Zhong-Bin; Zhou, Chu-Jun; Yin, Sheng

    2017-04-21

    Bioassay-guided fractionation of the ethanolic extract of the leaves of Psidium guajava led to the isolation of 11 new Psidium meroterpenoids, psiguajadials A-K (1-11), along with 17 known ones (12-28). Their structures and absolute configurations were elucidated by spectroscopic methods and comparison of experimental and calculated ECD. Compounds 1 and 2 represent two unprecedented skeletons of 3,5-diformyl-benzyl phloroglucinol-coupled sesquiterpenoid, while 3 is the first example of Psidium meroterpenoids coupling via an oxepane ring. Putative biosynthetic pathways towards 1 and 2 are proposed. Compounds 1-13 and 16-26 exhibited moderate inhibitory activities against phosphodiesterase-4 (PDE4), a drug target for asthma and chronic obstructive pulmonary disease, with IC 50 values in the range of 1.34-7.26 μM.

  2. Resveratrol ameliorates aging-related metabolic phenotypes by inhibiting cAMP phosphodiesterases.

    Science.gov (United States)

    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

    2012-02-03

    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 resveratrol result from competitive inhibition of cAMP-degrading phosphodiesterases, leading to elevated cAMP levels. The resulting activation of Epac1, a cAMP effector protein, increases intracellular Ca(2+) levels and activates the CamKKβ-AMPK pathway via phospholipase C and the ryanodine receptor Ca(2+)-release channel. As a consequence, resveratrol increases NAD(+) and the activity of Sirt1. Inhibiting PDE4 with rolipram reproduces all of the metabolic benefits of resveratrol, including prevention of diet-induced obesity and an increase in mitochondrial function, physical stamina, and glucose tolerance in mice. Therefore, administration of PDE4 inhibitors may also protect against and ameliorate the symptoms of metabolic diseases associated with aging. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Multiple Conformations of Phosphodiesterase-5: Implications for Enzyme Function and Drug Developement

    Energy Technology Data Exchange (ETDEWEB)

    Wang,H.; Liu, Y.; Huai, Q.; Cai, J.; Zoraghi, R.; Francis, S.; Corbin, J.; Robinson, H.; Xin, Z.; et al.

    2006-01-01

    Phosphodiesterase-5 (PDE5) is the target for sildenafil, vardenafil, and tadalafil, which are drugs for treatment of erectile dysfunction and pulmonary hypertension. We report here the crystal structures of a fully active catalytic domain of unliganded PDE5A1 and its complexes with sildenafil or icarisid II. These structures together with the PDE5A1-isobutyl-1-methylxanthine complex show that the H-loop (residues 660-683) at the active site of PDE5A1 has four different conformations and migrates 7 to 35 Angstroms upon inhibitor binding. In addition, the conformation of sildenafil reported herein differs significantly from those in the previous structures of chimerically hybridized or almost inactive PDE5. Mutagenesis and kinetic analyses confirm that the H-loop is particularly important for substrate recognition and that invariant Gly659 which immediately precedes the H-loop is critical for optimal substrate affinity and catalytic activity.

  4. Protective effects of phosphodiesterase 2 inhibitor on depression- and anxiety-like behaviors: involvement of antioxidant and anti-apoptotic mechanisms.

    Science.gov (United States)

    Ding, Lianshu; Zhang, Chong; Masood, Anbrin; Li, Jianxin; Sun, Jiao; Nadeem, Ahmed; Zhang, Han-Ting; O' Donnell, James M; Xu, Ying

    2014-07-15

    Stress occurs in everyday life, but the relationship between stress and the onset or development of depression/anxiety remains unknown. Increasing evidence suggests that the impairment of antioxidant defense and the neuronal cell death are important in the process of emotional disorders. Chronic stress impairs the homeostasis of antioxidants/oxidation, which results in the aberrant stimulation of the cell cycle proteins where cGMP-PKG signaling is thought to have an inhibitory role. Phosphodiesterase 2 (PDE2) is linked to cGMP-PKG signaling and highly expressed in the limbic brain regions including hippocampus and amygdala, which may play important roles in the treatment of depression and anxiety. To address the possible effects of PDE2 inhibitors on depression-/anxiety-like behaviors and the underlying mechanisms, Bay 60-7550 (0.75, 1.5 and 3 mg/kg, i.p.) was administered 30 min before chronic stress. The results suggested that Bay 60-7550 not only restored the behavioral changes but also regulated Cu/Zn superoxide dismutase (SOD) levels differentially in hippocampus and amygdala, which were increased in the hippocampus while decreased in the amygdala. It was also significant that Bay 60-7550 regulated the abnormalities of pro- and anti-apoptotic components, such as Bax, Caspase 3 and Bcl-2, and the indicator of PKG signaling characterized by pVASP(ser239), in these two brain regions. The results suggested that Bay 60-7550 is able to alleviate oxidative stress and mediate part of the apoptotic machinery in neuronal cells possibly through SOD-cGMP/PKG-anti-apoptosis signaling and that inhibition of PDE2 may represent a novel therapeutic target for psychiatric disorders, such as depression and anxiety. Copyright © 2014 Elsevier B.V. All rights reserved.

  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: elin.banke@med.lu.se [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)

    2012-09-07

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

  6. Differential inhibition of calmodulin-sensitive phosphodiesterase and Ca++-adenosine triphosphatase by chlorpromazine-linked calmodulin

    International Nuclear Information System (INIS)

    Prozialeck, W.C.; Wallace, T.L.; Weiss, B.

    1987-01-01

    Upon irradiation with UV light, chlorpromazine binds irreversibly to calmodulin and inactivates it. To determine whether this chlorpromazine-calmodulin (CPZ-CaM) complex can inhibit the actions of native calmodulin, we examined its effects on the activity of calmodulin-sensitive cyclic nucleotide phosphodiesterase from rat brain and on the Ca++-adenosine triphosphatase (ATPase) of human erythrocyte membranes. The CPZ-CaM complex was prepared by irradiating purified bovine brain calmodulin in the presence of chlorpromazine and Ca++. The sample was then dialyzed extensively to remove reversibly bound chlorpromazine and then assayed for its ability to activate calmodulin-sensitive phosphodiesterase and Ca++-ATPase, and for its ability to block the stimulatory effects of native calmodulin on these enzymes. The CPZ-CaM complex had no effect on the basal activity of either enzyme; it neither activated nor inhibited the enzymes when assayed in the absence of calmodulin. However, it affected differentially the activation of the two enzymes by native calmodulin. The CPZ-CaM complex totally inhibited calmodulin-stimulated phosphodiesterase but had no effect on the activation of the ATPase by calmodulin. Other studies showed that CPZ-CaM increased the activation constant (Ka) for the interaction of calmodulin with phosphodiesterase but did not affect the maximal activation (Vmax) of the enzyme by calmodulin. Neither calmodulin nor CPZ-CaM altered the Km for the interaction between phosphodiesterase and cyclic AMP. These results suggest that CPZ-CaM inhibits the calmodulin-induced activation of phosphodiesterase by competing with calmodulin for regulatory sites on the enzyme and not by interacting with calmodulin itself or by blocking the interaction of cyclic AMP with the enzyme

  7. MEK Inhibitors Reverse cAMP-Mediated Anxiety in Zebrafish

    DEFF Research Database (Denmark)

    Lundegaard, Pia R.; Anastasaki, Corina; Grant, Nicola J.

    2015-01-01

    Altered phosphodiesterase (PDE)-cyclic AMP (cAMP) activity is frequently associated with anxiety disorders, but current therapies act by reducing neuronal excitability rather than targeting PDE-cAMP-mediated signaling pathways. Here, we report the novel repositioning of anti-cancer MEK inhibitors...... as anxiolytics in a zebrafish model of anxiety-like behaviors. PDE inhibitors or activators of adenylate cyclase cause behaviors consistent with anxiety in larvae and adult zebrafish. Small-molecule screening identifies MEK inhibitors as potent suppressors of cAMP anxiety behaviors in both larvae and adult...... zebrafish, while causing no anxiolytic behavioral effects on their own. The mechanism underlying cAMP-induced anxiety is via crosstalk to activation of the RAS-MAPK signaling pathway. We propose that targeting crosstalk signaling pathways can be an effective strategy for mental health disorders, and advance...

  8. Phosphodiesterase-5 inhibitor sildenafil preconditions adult cardiac myocytes against necrosis and apoptosis. Essential role of nitric oxide signaling.

    Science.gov (United States)

    Das, Anindita; Xi, Lei; Kukreja, Rakesh C

    2005-04-01

    We investigated the effect of sildenafil in protection against necrosis or apoptosis in cardiomyocytes. Adult mouse ventricular myocytes were treated with sildenafil (1 or 10 microM) for 1 h before 40 min of simulated ischemia (SI). Necrosis was determined by trypan blue exclusion and lactate dehydrogenase release following SI alone or plus 1 or 18 h of reoxygenation (RO). Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated nick end labeling assay and mitochondrial membrane potential measured using a fluorescent probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1). Sildenafil reduced necrosis as indicated by decrease in trypan blue-positive myocytes and leakage of lactate dehydrogenase compared with untreated cells after either SI or SI-RO. The number of terminal deoxynucleotidyl transferase-mediated nick end labeling-positive myocytes or loss of JC-1 fluorescence following SI and 18 h of RO was attenuated in the sildenafil-treated group with concomitant inhibition of caspase 3 activity. An early increase in Bcl-2 to Bax ratio with sildenafil treatment was also observed in myocytes after SI-RO. The increase of Bcl-2 expression by sildenafil was inhibited by nitric-oxide synthase (NOS) inhibitor, L-nitro-amino-methyl-ester. The drug also enhanced mRNA and protein content of inducible NOS (iNOS) and endothelial NOS (eNOS) in the myocytes. Sildenafil-induced protection against necrosis and apoptosis was absent in the myocytes derived from iNOS knock-out mice and was attenuated in eNOS knock-out myocytes. The up-regulation of Bcl-2 expression by sildenafil was also absent in iNOS-deficient myocytes. Reverse transcription-PCR, Western blots, and immunohistochemical assay confirmed the expression of phosphodiesterase-5 in mouse cardiomyocytes. These data provide strong evidence for a direct protective effect of sildenafil against necrosis and apoptosis through NO signaling pathway. The results may have possible

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    Highlights: ► GIP stimulates lipogenesis and osteopontin expression in primary adipocytes. ► GIP-induced osteopontin expression is NFAT-dependent. ► Osteopontin expression is PDE3-dependent. ► 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 β3-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.

  10. 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.

  11. A Phase I clinical trial of lodenafil carbonate, a new phosphodiesterase Type 5 (PDE5) inhibitor, in healthy male volunteers.

    Science.gov (United States)

    Mendes, Gustavo D; dos Santos Filho, Hilton Oliveira; dos Santos Pereira, Alberto; Mendes, Fabiana D; Ilha, Jaime O; Alkharfy, Khalid M; De Nucci, Gilberto

    2012-12-01

    Lodenafil carbonate is a new phosphodiesterase Type 5 (PDE5) inhibitor used in treatment of erectile dysfunction. The present study was conducted to evaluate the safety, tolerability, and pharmacokinetics of lodenafil carbonate after administering ascending (1 - 100 mg) single oral doses to healthy male volunteers (n = 33). The study was an open label, dose-escalation, Phase I clinical trial involving the administration of single oral doses of lodenafil carbonate. Lodenafil carbonate was administered sequentially, escalating in single doses of 1 mg - 100 mg with a washout period of at least 1 week between each dose. The progression to the next dose was allowed after clinical and laboratory exams, Ambulatory Monitoring of Arterial Pressure (AMAP) without relevant clinical modifications and adverse events without clinical relevancy. Blood samples were collected at pre-dose, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 10, 12, 14, 16, 20 and 24 h post-dosing. Plasma samples for measurement of lodenafil carbonate and lodenafil were analyzed by liquid chromatography coupled to tandem mass spectrometry. No serious adverse events were observed, and none of the subjects discontinued the study due to intolerance. The AMAP measurements, clinical and laboratory exams and ECG revealed no significant changes even at higher doses. Lodenafil carbonate was not detected in any samples, indicating that it acts as a prodrug. The mean lodenafil pharmacokinetic parameters for tmax and t1/2 were 1.6 ( ± 0.4) h and 3.3 ( ± 1.1) h, respectively. This study demonstrated that lodenafil carbonate was well tolerated and showed a good safety profile in healthy male volunteers.

  12. Natural abundance 15N NMR assignments delineate structural differences between intact and reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III.

    Science.gov (United States)

    Krishnamoorthi, R; Nemmers, S; Tobias, B

    1992-06-15

    15N NMR assignments were made to the backbone amide nitrogen atoms at natural isotopic abundance of intact and reactive-site (Arg5-Ile6) hydrolyzed Cucurbita maxima trypsin inhibitor III (CMTI-III and CMTI-III*, respectively) by means of 2D proton-detected heteronuclear single bond chemical shift correlation (HSBC) spectroscopy, utilizing the previously made sequence-specific 1H NMR assignments (Krishnamoorthi et al. (1992) Biochemistry 31, 898-904). Comparison of the 15N chemical shifts of the two forms of the inhibitor molecule revealed significant changes not only for residues located near the reactive-site region, but also for those distantly located. Residues Cys3, Arg5, Leu7, Met8, Cys10, Cys16, Glu19, His25, Tyr27, Cys28 and Gly29 showed significant chemical shift changes ranging from 0.3 to 6.1 ppm, thus indicating structural perturbations that were transmitted throughout the molecule. These findings confirm the earlier conclusions based on 1H NMR investigations.

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

    International Nuclear Information System (INIS)

    Srisomsap, C.; Richardson, K.L.; Jay, J.C.; Marchase, R.B.

    1989-01-01

    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

  14. NMR studies of internal dynamics of serine proteinase protein inhibitors: Binding region mobilities of intact and reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor (CMTI)-III of the squash family and comparison with those of counterparts of CMTI-V of the potato I family.

    Science.gov (United States)

    Liu, J; Gong, Y; Prakash, O; Wen, L; Lee, I; Huang, J K; Krishnamoorthi, R

    1998-01-01

    Serine proteinase protein inhibitors follow the standard mechanism of inhibition (Laskowski M Jr, Kato I, 1980, Annu Rev Biochem 49:593-626), whereby an enzyme-catalyzed equilibrium between intact (I) and reactive-site hydrolyzed inhibitor (I*) is reached. The hydrolysis constant, Khyd, is defined as [I*]/[I]. Here, we explore the role of internal dynamics in the resynthesis of the scissile bond by comparing the internal mobility data of intact and cleaved inhibitors belonging to two different families. The inhibitors studied are recombinant Cucurbita maxima trypsin inhibitor III (rCMTI-III; Mr 3 kDa) of the squash family and rCMTI-V (Mr approximately 7 kDa) of the potato I family. These two inhibitors have different binding loop-scaffold interactions and different Khyd values--2.4 (CMTI-III) and 9 (CMTI-V)--at 25 degrees C. The reactive-site peptide bond (P1-P1') is that between Arg5 and Ile6 in CMTI-III, and that between Lys44 and Asp45 in CMTI-V. The order parameters (S2) of backbone NHs of uniformly 15N-labeled rCMTI-III and rCMTI-III* were determined from measurements of 15N spin-lattice and spin-spin relaxation rates, and [1H]-15N steady-state heteronuclear Overhauser effects, using the model-free formalism, and compared with the data reported previously for rCMTI-V and rCMTI-V*. The backbones of rCMTI-III [(S2) = 0.71] and rCMTI-III* [(S2) = 0.63] are more flexible than those of rCMTI-V [(S2) = 0.83] and rCMTI-V* [(S2) = 0.85]. The binding loop residues, P4-P1, in the two proteins show the following average order parameters: 0.57 (rCMTI-III) and 0.44 (rCMTI-III*); 0.70 (rCMTI-V) and 0.40 (rCMTI-V*). The P1'-P4' residues, on the other hand, are associated with (S2) values of 0.56 (rCMTI-III) and 0.47 (rCMTI-III*); and 0.73 (rCMTI-V) and 0.83 (rCMTI-V*). The newly formed C-terminal (Pn residues) gains a smaller magnitude of flexibility in rCMTI-III* due to the Cys3-Cys20 crosslink. In contrast, the newly formed N-terminal (Pn' residues) becomes more flexible

  15. Efficacy of B-Type Natriuretic Peptide Is Coupled to Phosphodiesterase 2A in Cardiac Sympathetic Neurons.

    Science.gov (United States)

    Li, Dan; Lu, Chieh-Ju; Hao, Guoliang; Wright, Hannah; Woodward, Lavinia; Liu, Kun; Vergari, Elisa; Surdo, Nicoletta C; Herring, Neil; Zaccolo, Manuela; Paterson, David J

    2015-07-01

    Elevated B-type natriuretic peptide (BNP) regulates cGMP-phosphodiesterase activity. Its elevation is regarded as an early compensatory response to cardiac failure where it can facilitate sympathovagal balance and cardiorenal homeostasis. However, recent reports suggest a paradoxical proadrenergic action of BNP. Because phosphodiesterase activity is altered in cardiovascular disease, we tested the hypothesis that BNP might lose its efficacy by minimizing the action of cGMP on downstream pathways coupled to neurotransmission. BNP decreased norepinephrine release from atrial preparations in response to field stimulation and also significantly reduced the heart rate responses to sympathetic nerve stimulation in vitro. Using electrophysiological recording and fluorescence imaging, BNP also reduced the depolarization evoked calcium current and intracellular calcium transient in isolated cardiac sympathetic neurons. Pharmacological manipulations suggested that the reduction in the calcium transient was regulated by a cGMP/protein kinase G pathway. Fluorescence resonance energy transfer measurements for cAMP, and an immunoassay for cGMP, showed that BNP increased cGMP, but not cAMP. In addition, overexpression of phosphodiesterase 2A after adenoviral gene transfer markedly decreased BNP stimulation of cGMP and abrogated the BNP responses to the calcium current, intracellular calcium transient, and neurotransmitter release. These effects were reversed on inhibition of phosphodiesterase 2A. Moreover, phosphodiesterase 2A activity was significantly elevated in stellate neurons from the prohypertensive rat compared with the normotensive control. Our data suggest that abnormally high levels of phosphodiesterase 2A may provide a brake against the inhibitory action of BNP on sympathetic transmission. © 2015 American Heart Association, Inc.

  16. Selective inhibition of phosphodiesterase 5 enhances glutamatergic synaptic plasticity and memory in mice.

    Science.gov (United States)

    Uthayathas, Subramaniam; Parameshwaran, Kodeeswaran; Karuppagounder, Senthilkumar S; Ahuja, Manuj; Dhanasekaran, Muralikrishnan; Suppiramaniam, Vishnu

    2013-11-01

    Phosphodiesterases (PDEs) belong to a family of proteins that control metabolism of cyclic nucleotides. Targeting PDE5, for enhancing cellular function, is one of the therapeutic strategies for male erectile dysfunction. We have investigated whether in vivo inhibition of PDE5, which is expressed in several brain regions, will enhance memory and synaptic transmission in the hippocampus of healthy mice. We have found that acute administration of sildenafil, a specific PDE5 inhibitor, enhanced hippocampus-dependent memory tasks. To elucidate the underlying mechanism in the memory enhancement, effects of sildenafil on long-term potentiation (LTP) were measured. The level of LTP was significantly elevated, with concomitant increases in basal synaptic transmission, in mice treated with sildenafil (1 mg/kg/day) for 15 days compared to control mice. These results suggest that moderate PDE5 inhibition enhances memory by increasing synaptic plasticity and transmission in the hippocampus. Copyright © 2013 Wiley Periodicals, Inc.

  17. The xylanase inhibitor TAXI-III counteracts the necrotic activity of a Fusarium graminearum xylanase in vitro and in durum wheat transgenic plants.

    Science.gov (United States)

    Moscetti, Ilaria; Faoro, Franco; Moro, Stefano; Sabbadin, Davide; Sella, Luca; Favaron, Francesco; D'Ovidio, Renato

    2015-08-01

    The xylanase inhibitor TAXI-III has been proven to delay Fusarium head blight (FHB) symptoms caused by Fusarium graminearum in transgenic durum wheat plants. To elucidate the molecular mechanism underlying the capacity of the TAXI-III transgenic plants to limit FHB symptoms, we treated wheat tissues with the xylanase FGSG_03624, hitherto shown to induce cell death and hydrogen peroxide accumulation. Experiments performed on lemmas of flowering wheat spikes and wheat cell suspension cultures demonstrated that pre-incubation of xylanase FGSG_03624 with TAXI-III significantly decreased cell death. Most interestingly, a reduced cell death relative to control non-transgenic plants was also obtained by treating, with the same xylanase, lemmas of TAXI-III transgenic plants. Molecular modelling studies predicted an interaction between the TAXI-III residue H395 and residues E122 and E214 belonging to the active site of xylanase FGSG_03624. These results provide, for the first time, clear indications in vitro and in planta that a xylanase inhibitor can prevent the necrotic activity of a xylanase, and suggest that the reduced FHB symptoms on transgenic TAXI-III plants may be a result not only of the direct inhibition of xylanase activity secreted by the pathogen, but also of the capacity of TAXI-III to avoid host cell death. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  18. Purification and characterization of cGMP binding protein-phosphodiesterase from rat lung

    International Nuclear Information System (INIS)

    Francis, S.H.; Walseth, T.F.; Corbin, J.D.

    1986-01-01

    The cGMP binding protein-phosphodiesterase (cG-BPP) with a phosphodiesterase specific activity of 7 μM/min/mg has been purified from rat lung by sequential chromatography on DEAE-cellulose, Blue-Sepharose, zinc chelate affinity adsorbent and HPLC-DEAE. Migration of the major band on SDS-PAGE corresponds to a MW of ∼93,000. Both cGMP phosphodiesterase activity and cGMP binding from the HPLC-DEAE profile correlate with this band. Since the authors previous work has determined the native MW to be ∼177,000, this suggests a dimeric structure comprised of two 93,000 MW subunits for the rat lung cG-BPP. At low cGMP concentrations, cGMP binding is stimulated ∼20-fold by histone and ∼5-fold by 3-isobutyl-1-methylxanthine(IBMX). The purified protein has one component of cGMP dissociation with a rate constant of 0.045/min. Photolysis of the purified protein in the presence of 32 P-cGMP labels the 93,000 MW band and this labeling is increased by IBMX, indicating that the 93,000 MW band is a subunit of the cGMP-BPP. This implies that the enzyme preparation is nearly homogeneous, a conclusion also supported by a minimum [ 3 H]-cGMP binding stoichiometry of 0.5 mol per 93,000 subunit. An additional protein band with a MW of ∼90,000 also occurs in these preparations which exhibits behavior similar to the 93,000 MW protein. N 2 -Hexyl-cGMP inhibits phosphodiesterase activity by competing with cGMP for hydrolysis at the catalytic site but not at the binding site. N 2 -Hexyl cGMP actually increases cGMP binding. This provides the first evidence that cGMP binding is increased by compounds hydrolyzed at the catalytic site. This interaction between the binding and phosphodiesterase sites could be important in the regulation of the functions of these sites in vivo

  19. Effect of the phosphodiesterase 4 inhibitor roflumilast on glucose metabolism in patients with treatment-naive, newly diagnosed type 2 diabetes mellitus.

    Science.gov (United States)

    Wouters, E F M; Bredenbröker, D; Teichmann, P; Brose, M; Rabe, K F; Fabbri, L M; Göke, B

    2012-09-01

    The phosphodiesterase 4 inhibitor roflumilast is a first-in-class antiinflammatory treatment for severe chronic obstructive pulmonary disease (COPD) associated with chronic bronchitis and a history of frequent exacerbations. In previous clinical studies, a transient and reversible weight decrease was reported with roflumilast, suggesting the systemic actions of this drug may impact metabolism. Our objective was to investigate the effects of roflumilast on glucose homeostasis and body weight. We conducted a 12-wk, randomized, double-blind, placebo-controlled multicenter study with outpatients. Patients (n = 205) with newly diagnosed type 2 diabetes mellitus (DM2) but without COPD were included in the study. Roflumilast 500 μg or placebo was administered once daily. We evaluated mean change in blood glycated hemoglobin levels. We also evaluated mean change from baseline in the postmeal area under the curve (AUC) for a range of metabolic parameters. Roflumilast was associated with a significantly greater reduction in glycated hemoglobin levels than placebo (least square mean = -0.45%; P AUC decreased significantly from baseline to last visit for free fatty acids, glycerol, glucose, and glucagon, whereas they slightly increased for C-peptide and insulin. In contrast to roflumilast, the glucagon AUC increased with placebo, and the insulin AUC decreased. Between-treatment analysis revealed statistically significant differences in favor of roflumilast for glucose (P = 0.0082), glycerol (P = 0.0104), and C-peptide levels (P = 0.0033). Patients in both treatment groups lost weight, although the between-treatment difference of the changes from baseline to last visit [-0.7 (0.4) kg] was not statistically significant (P = 0.0584). Roflumilast lowered glucose levels in patients with newly diagnosed DM2 without COPD, suggesting positive effects on glucose homoeostasis.

  20. Simultaneous Detection of Three Phosphodiesterase Type 5 Inhibitors and Eight of Their Analogs in Lifestyle Products and Screening for Adulterants by High-Performance Thin-Layer Chromatography.

    Science.gov (United States)

    Do, Tiên T K; Theocharis, Grigorios; Reich, Eike

    2015-01-01

    An HPTLC method is proposed to permit effective screening for the presence of three phosphodiesterase type 5 inhibitors (PDE5-Is; sildenafil, vardenafil, and tadalafil) and eight of their analogs (hydroxyacetildenafil, homosildenafil, thiohomosildenafil, acetildenafil, acetaminotadalafil, propoxyphenyl hydroxyhomosildenafil, hydroxyhomosildenafil, and hydroxythiohomosildenafil) in finished products, including tablets, capsules, chocolate, instant coffee, syrup, and chewing gum. For all the finished products, the same simple sample preparation may be applied: ultrasound-assisted extraction in 10 mL methanol for 30 min followed by centrifugation. The Rf values of individual HPTLC bands afford preliminary identification of potential PDE5-Is. Scanning densitometry capabilities enable comparison of the unknown UV spectra with those of known standard compounds and allow further structural insight. Mass spectrometric analysis of the material derived from individual zones supplies an additional degree of confidence. Significantly, the proposed screening technique allows focus on the already known PDE5 Is and provides a platform for isolation and chemical categorization of the newly-synthesized analogs. Furthermore, the scope could be expanded to other therapeutic categories (e.g., analgesics, antidiabetics, and anorexiants) that are occasionally coadulterated along with the PDE5-Is. The method was successfully applied to screening of 45 commercial lifestyle products. Of those, 31 products tested positive for at least one illegal component (sildenafil, tadalafil, propoxyphenyl hydroxyhomosildenafil, or dimethylsildenafil).

  1. Inhibition of PAF-induced expression of CD11b and shedding of L-selectin on human neutrophils and eosinophils by the type IV selective PDE inhibitor, rolipram

    NARCIS (Netherlands)

    Dijkhuizen, B; deMonchy, JGR; Dubois, AEJ; Gerritsen, J; Kauffman, HF

    We quantitatively determined whether the selective phosphodiesterase (PDE) inhibitor, rolipram, inhibits changes in the adhesion molecules CD11b and L-selectin on platelet-activating factor (PAF)-stimulated human neutrophils and eosinophils in vitro. Incubations were performed in human whole blood

  2. Benzoquinones and terphenyl compounds as phosphodiesterase-4B inhibitors from a fungus of the order Chaetothyriales (MSX 47445).

    Science.gov (United States)

    El-Elimat, Tamam; Figueroa, Mario; Raja, Huzefa A; Graf, Tyler N; Adcock, Audrey F; Kroll, David J; Day, Cynthia S; Wani, Mansukh C; Pearce, Cedric J; Oberlies, Nicholas H

    2013-03-22

    Three bioactive compounds were isolated from an organic extract of an ascomycete fungus of the order Chaetothyriales (MSX 47445) using bioactivity-directed fractionation as part of a search for anticancer leads from filamentous fungi. Of these, two were benzoquinones [betulinan A (1) and betulinan C (3)], and the third was a terphenyl compound, BTH-II0204-207:A (2). The structures were elucidated using a set of spectroscopic and spectrometric techniques; the structure of the new compound (3) was confirmed via single-crystal X-ray diffraction. Compounds 1-3 were evaluated for cytotoxicity against a human cancer cell panel, for antimicrobial activity against Staphylococcus aureus and Candida albicans, and for phosphodiesterase (PDE4B2) inhibitory activities. The putative binding mode of 1-3 with PDE4B2 was examined using a validated docking protocol, and the binding and enzyme inhibitory activities were correlated.

  3. 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

    2016-05-01

    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.

  4. Influence of GDP on interaction of transducin with cyclic nucleotide phosphodiesterase and rhodopsin from bovine retinal rods

    International Nuclear Information System (INIS)

    Rybin, V.O.

    1986-01-01

    In the presence of guanine nucleotides and rhodopsin-containing membranes from bovine retinal rod outer segments transducin stimulates light-sensitive cyclic nucleotide phosphodiesterase 5.5- to 7-fold. The activation constant (K/sub act/) for GTP and Gpp(NH)p is equal to 0.25 μM, while that for GDP and GDPβS is 14 and 110 μM, respectively. GDP free of admixtures of other nucleotides does not activate phosphodiesterase at concentrations up to 1 mM, but is bound to transducin and inhibits the Gpp(NH)p-dependent activation of phosphodiesterase. The nature of the interaction of transducin with depolarized rhodopsin also depends on the type of guanine nucleotide bound: in the presence of GDP rhodopsin-containing membranes bind 70-100% of the transducin, whereas in the presence of Gpp(NH)p only 13% of the protein is bound. The data obtained indicate that GDP and GTP convert transducin to two different functional states: the transducin-GTP complex is bound to phosphodiesterase and activates it, while the transducin-GDP complex is bound primarily to rhodopsin

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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......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...

  6. Phosphodiesterase type 4 inhibitor rolipram improves survival of spiral ganglion neurons in vitro.

    Directory of Open Access Journals (Sweden)

    Katharina Kranz

    Full Text Available Sensorineural deafness is caused by damage of hair cells followed by degeneration of the spiral ganglion neurons and can be moderated by cochlear implants. However, the benefit of the cochlear implant depends on the excitability of the spiral ganglion neurons. Therefore, current research focuses on the identification of agents that will preserve their degeneration. In this project we investigated the neuroprotective effect of Rolipram as a promising agent to improve the viability of the auditory neurons. It is a pharmaceutical agent that acts by selective inhibition of the phosphodiesterase 4 leading to an increase in cyclic AMP. Different studies reported a neuroprotective effect of Rolipram. However, its significance for the survival of SGN has not been reported so far. Thus, we isolated spiral ganglion cells of neonatal rats for cultivation with different Rolipram concentrations and determined the neuronal survival rate. Furthermore, we examined immunocytologically distinct proteins that might be involved in the neuroprotective signalling pathway of Rolipram and determined endogenous BDNF by ELISA. When applied at a concentration of 0.1 nM, Rolipram improved the survival of SGN in vitro. According to previous studies, our immunocytological data showed that Rolipram application induces the phosphorylation and thereby activation of the transcription factor CREB. This activation can be mediated by the cAMP-PKA-signalling pathway as well as via ERK as a part of the MAP-kinase pathway. However, only in cultures pre-treated with BDNF, an endogenous increase of BDNF was detected. We conclude that Rolipram has the potential to improve the vitality of neonatal auditory nerve cells in vitro. Further investigations are necessary to prove the effect of Rolipram in vivo in the adult organism after lesion of the hair cells and insertion of cochlear implants.

  7. Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

    Science.gov (United States)

    Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

    2013-12-01

    Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.

  8. A comparison of the inhibitory activity of selective PDE4 inhibitors on eosinophil recruitment in guinea pig skin

    Directory of Open Access Journals (Sweden)

    Mauro M Teixeira

    1997-12-01

    Full Text Available The elevation of intracellular cyclic AMP by phosphodiesterase (PDE4 inhibitors in eosinophils is associated with inhibition of the activation and recruitment of these cells. We have previously shown that systemic treatment with the PDE4 inhibitor rolipram effectively inhibt eosinophil migration in guinea pig skin. In the present study we compare the oral potency and efficacy of the PDE4 inhibitors rolipram, RP 73401 and CDP 840 on allergic and PAF-induced eosinophil recruitment. Rolipram and RP 73401 were equally effective and potent when given by the oral route and much more active than the PDE4 inhibitor CDP 840. We suggest that this guinea pig model of allergic and mediator-induced eosinophil recruitment is both a sensitive and simple tool to test the efficacy and potency of PDE4 inhibitors in vivo.

  9. 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

    2013-03-01

    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.

  10. The Global Online Sexuality Survey (GOSS): the United States of America in 2011 chapter II: phosphodiesterase inhibitors utilization among English speakers.

    Science.gov (United States)

    Shaeer, Osama

    2013-02-01

    Utility of phosphodiesterase inhibitors (PDEi's) for the treatment of erectile dysfunction (ED) has been the focus of experimental and clinical studies. However, public preferences, attitudes, and experiences with PDEi's are rarely addressed from a population/epidemiology viewpoint. The Global Online Sexuality Survey (GOSS) is a worldwide epidemiologic study of sexuality and sexual disorders, first launched in the Middle East in 2010, followed by the United States in 2011. To describe the utilization rates, trends, and attitudes toward PDEi's in the United States in the year 2011. GOSS was randomly deployed to English-speaking male Web surfers in the United States via paid advertising on Facebook®, comprising 146 questions. Utilization rates and preferences for PDEi's by brand. Six hundred three subjects participated; mean age 53.43 years ± 13.9. Twenty-three point seven percent used PDEi's on more consistent basis, 37.5% of those with ED vs. 15.6% of those without ED (recreational users). Unrealistic safety concerns including habituation were pronounced. Seventy-nine point six percent of utilization was on prescription basis. PDEi's were purchased through pharmacies (5.3% without prescription) and in 16.5% over the Internet (68% without prescription). Nine point six percent nonprescription users suffered coronary heart disease. Prescription use was inclined toward sildenafil, generally, and particularly in severe cases, and shifted toward tadalafil in moderate ED and for recreational use, followed by vardenafil. Nonprescription utilization trends were similar, except in recreational use where sildenafil came first. In the United States unrealistic safety concerns over PDEi's utility exist and should be addressed. Preference for particular PDEi's over the others is primarily dictated by health-care providers, despite lack of guidelines that govern physician choice. Online and over-the-counter sales of PDEi's are common, and can expose a subset of users to health

  11. PDE5 Inhibitors-Loaded Nanovesicles: Physico-Chemical Properties and In Vitro Antiproliferative Activity

    Directory of Open Access Journals (Sweden)

    Roberta F. De Rose

    2016-05-01

    Full Text Available Novel therapeutic approaches are required for the less differentiated thyroid cancers which are non-responsive to the current treatment. In this study we tested an innovative formulation of nanoliposomes containing sildenafil citrate or tadalafil, phosphodiesterase-5 inhibitors, on two human thyroid cancer cell lines (TPC-1 and BCPAP. Nanoliposomes were prepared by the thin layer evaporation and extrusion methods, solubilizing the hydrophilic compound sildenafil citrate in the aqueous phase during the hydration step and dissolving the lipophilic tadalafil in the organic phase. Nanoliposomes, made up of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine monohydrate (DPPC, cholesterol, and N-(carbonyl-methoxypolyethylene glycol-2000-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-mPEG2000 (6:3:1 molar ratio, were characterized by a mean diameter of ~100 nm, a very low polydispersity index (~0.1 and a negative surface charge. The drugs did not influence the physico-chemical properties of the systems and were efficiently retained in the colloidal structure. By using cell count and MTT assay, we found a significant reduction of the viability in both cell lines following 24 h treatment with both nanoliposomal-encapsulated drugs, notably greater than the effect of the free drugs. Our findings demonstrate that nanoliposomes increase the antiproliferative activity of phosphodiesterase-5 inhibitors, providing a useful novel formulation for the treatment of thyroid carcinoma.

  12. Inhibition of phosphodiesterase 4 reduces ethanol intake and preference in C57BL/6J mice

    Directory of Open Access Journals (Sweden)

    Yuri A. Blednov

    2014-05-01

    Full Text Available Some anti-inflammatory medications reduce alcohol consumption in rodent models. Inhibition of phosphodiesterases (PDE increases cAMP and reduces inflammatory signaling. Rolipram, an inhibitor of PDE4, markedly reduced ethanol intake and preference in mice and reduced ethanol seeking and consumption in alcohol-preferring fawn-hooded rats (Hu et al., 2011;Wen et al., 2012. To determine if these effects were specific for PDE4, we compared nine PDE inhibitors with different subtype selectivity: propentofylline (nonspecific, vinpocetine (PDE1, olprinone, milrinone (PDE3, zaprinast (PDE5, rolipram, mesopram, piclamilast, and CDP840 (PDE4. Alcohol intake was measured in C57BL/6J male mice using 24-hour two-bottle choice and two-bottle choice with limited (three-hour access to alcohol. Only the selective PDE4 inhibitors reduced ethanol intake and preference in the 24-hour two-bottle choice test. For rolipram, piclamilast, and CDP840, this effect was observed after the first 6 hours but not after the next 18 hours. Mesopram, however, produced a long-lasting reduction of ethanol intake and preference. In the limited access test, rolipram, piclamilast, and mesopram reduced ethanol consumption and total fluid intake and did not change preference for ethanol, whereas CDP840 reduced both consumption and preference without altering total fluid intake. Our results provide novel evidence for a selective role of PDE4 in regulating ethanol drinking in mice. We suggest that inhibition of PDE4 may be an unexplored target for medication development to reduce excessive alcohol consumption.

  13. Antenatal phosphodiesterase 4 inhibition restores postnatal growth and pulmonary development in a model of chorioamnionitis in rabbits.

    Science.gov (United States)

    Homer, L; Launay, E; Joram, N; Jacqueline, C; Jarreau, P-H; Caillon, J; Moyon, T; Branger, B; Potel, G; Roze, J C; Méhats, C; Gras-Leguen, C

    2012-03-01

    Chorioamnionitis is implicated in the pathophysiology of bronchopulmonary disease, and the associated inflammatory response is responsible for adverse effects on alveolar development. The aim of this work was to analyze the effects of a phosphodiesterase 4 (PDE4)-selective inhibitor, rolipram (a modulator of the inflammatory response), in an experimental model of chorioamnionitis on pulmonary development and on the processes of infection and inflammation. Rabbit mothers were assigned to four groups: 1) saline serum inoculation (controls); 2) Escherichia coli intrauterine inoculation (C+); 3) rolipram infusion (R+); and 4) E. coli inoculation + rolipram infusion (C+R+). High rates of morbility and mortality were noticed in mothers and pups (5 of 13 pregnant rabbits in groups with rolipram). Alveolar development, inflammation, and infection were analyzed in pups at day 0 and day 5. At day 0, in the context of chorioamnionitis, rolipram significantly decreased birth weight (p demise and growth retardation.

  14. 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.

    Science.gov (United States)

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

    2013-12-01

    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. © 2013 John Wiley & Sons A/S.

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

    Directory of Open Access Journals (Sweden)

    Veidal Sanne Skovgård

    2012-12-01

    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.

  16. The Efficacy of Medical Treatment of Peyronie’s Disease: Potassium Para-Aminobenzoate Monotherapy vs. Combination Therapy with Tamoxifen, L-Carnitine, and Phosphodiesterase Type 5 Inhibitor

    Directory of Open Access Journals (Sweden)

    Tae Yong Park

    2016-04-01

    Full Text Available Purpose: This study was designed to evaluate the efficacy of medical treatment of Peyronie’s disease. Materials and Methods: A total of 109 patients with Peyronie’s disease who had been treated from January 2011 to December 2014 were retrospectively reviewed in this study. Forty-four patients (Group 1 were treated with 12 mg of potassium para-aminobenzoate daily. Sixty-five patients (Group 2 were treated with combination therapy: tamoxifen (20 mg and acetyl-L-carnitine (300 mg twice daily in addition to a phosphodiesterase type 5 inhibitor. Ability to perform sexual intercourse, pain during erection, size of plaque, and penile curvature angle were assessed. Results: In Group 1, 30 of 44 patients (68.2% discontinued treatment within 12 weeks, while 5 patients (7.7% in Group 2 discontinued treatment. Pain during erection and plaque size were improved in both groups but showed no statistical difference due to the high dropout rate in Group 1. In both groups, penile curvature was improved, but demonstrated no statistical difference between the treatment groups. However, combination therapy demonstrated a better response rate in patients whose penile curvature angle was less than 30o (44.4% vs. 79.1%, p=0.048. The rate of successful sexual intercourse was significantly higher in Group 2 (42.8% vs. 78.3%, p=0.034. The number of patients who underwent surgical correction despite medical treatment was significantly higher in Group 1 (35.7% vs. 13.3%, p=0.048. Conclusions: Early medical combination therapy in Peyronie’s disease may present better results in patients whose curvature angle is less than 30o.

  17. Identification of a rhodium(iii) complex as a Wee1 inhibitor against TP53-mutated triple-negative breast cancer cells.

    Science.gov (United States)

    Yang, Guan-Jun; Zhong, Hai-Jing; Ko, Chung-Nga; Wong, Suk-Yu; Vellaisamy, Kasipandi; Ye, Min; Ma, Dik-Lung; Leung, Chung-Hang

    2018-03-06

    The rhodium(iii) complex 1 was identified as a potent Wee1 inhibitor in vitro and in cellulo. It decreased Wee1 activity and unscheduled mitotic entry, and induced cell damage and death in TP53-mutated triple-negative breast cancer cells. 1 represents a promising scaffold for further development of more potent metal-based Wee1 antagonists.

  18. Phosphodiesterase 2A Inhibitor TAK-915 Ameliorates Cognitive Impairments and Social Withdrawal in N-Methyl-d-Aspartate Receptor Antagonist-Induced Rat Models of Schizophrenia.

    Science.gov (United States)

    Nakashima, Masato; Imada, Haruka; Shiraishi, Eri; Ito, Yuki; Suzuki, Noriko; Miyamoto, Maki; Taniguchi, Takahiko; Iwashita, Hiroki

    2018-04-01

    The pathophysiology of schizophrenia has been associated with glutamatergic dysfunction. Modulation of the glutamatergic signaling pathway, including N -methyl-d-aspartate (NMDA) receptors, can provide a new therapeutic target for schizophrenia. Phosphodiesterase 2A (PDE2A) is highly expressed in the forebrain, and is a dual substrate enzyme that hydrolyzes both cAMP and cGMP, which play pivotal roles as intracellular second messengers downstream of NMDA receptors. Here we characterize the in vivo pharmacological profile of a selective and brain-penetrant PDE2A inhibitor, ( N -{(1 S )-1-[3-fluoro-4-(trifluoromethoxy)phenyl]-2-methoxyethyl}-7-methoxy-2-oxo-2,3-dihydropyrido[2,3- b ]pyrazine-4(1 H )-carboxamide) (TAK-915) as a novel treatment of schizophrenia. Oral administration of TAK-915 at 3 and 10 mg/kg significantly increased cGMP levels in the frontal cortex, hippocampus, and striatum of rats. TAK-915 at 10 mg/kg significantly upregulated the phosphorylation of α -amino-3-hydroxy-5-methylisoxazole-4-proprionic acid receptor subunit GluR1 in the rat hippocampus. TAK-915 at 3 and 10 mg/kg significantly attenuated episodic memory deficits induced by the NMDA receptor antagonist (+)-MK-801 hydrogen maleate (MK-801) in the rat passive avoidance test. TAK-915 at 10 mg/kg significantly attenuated working memory deficits induced by MK-801 in the rat radial arm maze test. Additionally, TAK-915 at 10 mg/kg prevented subchronic phencyclidine-induced social withdrawal in social interaction in rats. In contrast, TAK-915 did not produce antipsychotic-like activity; TAK-915 had little effect on MK-801- or methamphetamine-induced hyperlocomotion in rats. These results suggest that TAK-915 has a potential to ameliorate cognitive impairments and social withdrawal in schizophrenia. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  19. The Phosphodiesterase 4 Inhibitor Prevents Antigen-induced Biphasic Nasal Obstruction in Brown Norway Rats

    Directory of Open Access Journals (Sweden)

    Hirokazu Kawasaki

    2005-01-01

    Conclusions: The present study provides a simple model of allergic biphasic nasal obstruction in BN rats, and also suggests that the PDE4 inhibitor may alleviate nasal obstruction in patients with allergic rhinitis.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    Schmid P

    2004-01-01

    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.

  2. Emerging drugs for the treatment of erectile dysfunction.

    Science.gov (United States)

    Peak, Taylor C; Yafi, Faysal A; Sangkum, Premsant; Hellstrom, Wayne J G

    2015-06-01

    Erectile dysfunction adversely affects the lives of millions of men, and is the most commonly treated sexual disorder today. The erectile process has been extensively investigated, with major advances made in elucidating many of the complex molecular pathways involved. These advances have allowed researchers to design and study drug formulations that target various aspects of this complex process. The initial culmination of this research was the introduction of phosphodiesterase 5-inhibitors. While effective in many patients, they are not satisfactory for all afflicted men. As a result, researchers are developing novel drugs that target different molecular pathways. The paper will review these pathways, and the potential agents that target them. More specifically, first dopaminergic and melanocortin receptor agonists that act centrally will be covered. Then, the paper will examine the "second-generation" phosphodiesterase 5-inhibitors, soluble guanylate cyclases, rho-kinase inhibitors, and maxi-k channel activators that act peripherally. Most of these novel drugs have yet to reach Phase III studies. However, it is likely that in years to come, patients will be selectively treated with these novel agents as a monotherapy or in combination with others acting in a synergistic manner.

  3. Phosphodiesterase (PDE5) inhibition assay for rapid detection of erectile dysfunction drugs and analogs in sexual enhancement products.

    Science.gov (United States)

    Santillo, Michael F; Mapa, Mapa S T

    2018-02-28

    Products marketed as dietary supplements for sexual enhancement are frequently adulterated with phosphodiesterase-5 (PDE5) inhibitors, which are erectile dysfunction drugs or their analogs that can cause adverse health effects. Due to widespread adulteration, a rapid screening assay was developed to detect PDE5 inhibitors in adulterated products. The assay employs fluorescence detection and is based on measuring inhibition of PDE5 activity, the pharmacological mechanism shared among the adulterants. Initially, the assay reaction scheme was established and characterized, followed by analysis of 9 representative PDE5 inhibitors (IC 50 , 0.4-4.0 ng mL -1 ), demonstrating sensitive detection in matrix-free solutions. Next, dietary supplements serving as matrix blanks (n = 25) were analyzed to determine matrix interference and establish a threshold value; there were no false positives. Finally, matrix blanks were spiked with 9 individual PDE5 inhibitors, along with several mixtures. All 9 adulterants were successfully detected (≤ 5 % false negative rate; n = 20) at a concentration of 1.00 mg g -1 , which is over 5 times lower than concentrations commonly encountered in adulterated products. A major distinction of the PDE5 inhibition assay is the ability to detect adulterants without prior knowledge of their chemical structures, demonstrating a broad-based detection capability that can address a continuously evolving threat of new adulterants. The PDE5 inhibition assay can analyze over 40 samples simultaneously within 15 minutes and involves a single incubation step and simple data analysis, all of which are advantageous for combating the widespread adulteration of sex-enhancement products. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

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

    Science.gov (United States)

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

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

  5. Sildenafil preserves diastolic relaxation after reduction by L-NAME and increases phosphodiesterase-5 in the intercalated discs of cardiac myocytes and arterioles

    Directory of Open Access Journals (Sweden)

    Silvia Elaine Ferreira-Melo

    2011-01-01

    Full Text Available OBJECTIVES: We investigated the influence of sildenafil on cardiac contractility and diastolic relaxation and examined the distribution of phosphodiesterase-5 in the hearts of hypertensive rats that were treated with by NG-nitro-L-arginine methyl ester (L-NAME. METHODS: Male Wistar rats were treated with L-NAME and/or sildenafil for eight weeks. The Langendorff method was used to examine the effects of sildenafil on cardiac contractility and diastolic relaxation. The presence and location of phosphodiesterase-5 and phosphodiesterase-3 were assessed by immunohistochemistry, and cGMP plasma levels were measured by ELISA. RESULTS: In isolated hearts, sildenafil prevented the reduction of diastolic relaxation (dP/dt that was induced by L-NAME. In addition, phosphodiesterase-5 immunoreactivity was localized in the intercalated discs between the myocardial cells. The staining intensity was reduced by L-NAME, and sildenafil treatment abolished this reduction. Consistent with these results, the plasma levels of cGMP were decreased in the L-NAME-treated rats but not in rats that were treated with L-NAME + sildenafil. CONCLUSION: The sildenafil-induced attenuation of the deleterious hemodynamic and cardiac morphological effects of L-NAME in cardiac myocytes is mediated (at least in part by the inhibition of phosphodiesterase-5.

  6. Imaging cAMP-specific phosphodiesterase-4 in human brain with R-[11C]rolipram and positron emission tomography

    International Nuclear Information System (INIS)

    DaSilva, Jean N.; Lourenco, Celia M.; Meyer, Jeffrey H.; Houle, Sylvain; Hussey, Douglas; Potter, William Z.

    2002-01-01

    Evidence of disruptions in cAMP-mediated signaling in several neuropsychiatric disorders has led to the development of R-[ 11 C]rolipram for imaging phosphodiesterase-4 (PDE4) enzymes with positron emission tomography (PET). The high-affinity PDE4 inhibitor rolipram was previously reported to have an antidepressant effect in humans. PDE4 is abundant in the brain, and it hydrolyzes cAMP produced following stimulation of various neurotransmitter systems. PDE4 is regulated by intracellular cAMP levels. This paper presents the first PET study of R-[ 11 C]rolipram in living human brain. Consistent with the wide distribution of PDE4, high radioactivity retention was observed in all regions representing the gray matter. Rapid metabolism was observed, and kinetic analysis demonstrated that the data fit in a two-tissue compartment model. R-[ 11 C]Rolipram is thus suitable for imaging PDE4 and possibly cAMP signal transduction in the living human brain with PET. (orig.)

  7. 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)

    SCHNEIDER, J; BECK, E; HEERS, C; CONRAD, C; DECOURCELLES, DD; WILFFERT, B; Peters, Thies

    1992-01-01

    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

  8. Economic analysis of use of counterfeit drugs: health impairment risk of counterfeit phosphodiesterase type 5 inhibitor taken as an example.

    Science.gov (United States)

    Sugita, Minoru; Miyakawa, Michiko

    2010-07-01

    The size of the market for counterfeit drugs throughout the world is considerable. Many cases of health impairment due to counterfeits have been reported. The market share of counterfeits in drug markets in developed countries is smaller than that in developing countries. However, the size of the market for counterfeits of phosphodiesterase type 5 inhibitors (PDE5Is) used as anti-erectile-dysfunction drugs is not small. The purpose of the present study was to analyze the health impairment risk of taking the counterfeit PDE5Is and the convenience of obtaining the counterfeits in Japan, using an economic methodology in order to work out countermeasures for reducing the health impairment risk. Information was obtained by interviewing employees of pharmaceutical and chemical corporations in Japan. The size of the market for counterfeit PDE5Is in Japan was recently estimated to be about 2.5 times larger than that of genuine PDE5Is. The price of the counterfeits in their market is reported to be nearly equal to that of the genuine PDE5Is. An outbreak of severe hypoglycemia among users of counterfeit PDE5Is containing an antidiabetic drug in Singapore was reported in 2008, and seven patients remained comatose as a result of prolonged neuroglycopenia. Four of them subsequently died, so the health impairment risk due to counterfeit PDE5Is should not be ignored. In order to obtain a genuine PDE5I in Japan, a patient must be examined and have a prescription written at a medical institution, and buy it at a dispensing pharmacy. Focusing on the health impairment risk due to counterfeit PDE5Is and the convenience of obtaining the counterfeits in Japan, we analyzed the effects on the prices and quantities of PDE5Is in the market from demand and supply curves, using an economic methodology. From the analysis, it was shown that the health impairment risk due to the counterfeits is underestimated in the market in Japan. Physicians should warn their patients not to buy counterfeit

  9. Heart Protection by Combination Therapy with Esmolol and Milrinone at Late-Ischemia and Early Reperfusion

    OpenAIRE

    Huang, Ming-He; Wu, Yewen; Nguyen, Vincent; Rastogi, Saurabh; McConnell, Bradley K.; Wijaya, Cori; Uretsky, Barry F.; Poh, Kian-Keong; Tan, Huay-Cheem; Fujise, Kenichi

    2011-01-01

    Introduction The present study determined whether late-ischemia/early reperfusion therapy with the β1-adrenergic receptor (AR) blocker esmolol and phosphodiesterase III inhibitor milrinone reduced left ventricular (LV) myocardial infarct size (IS). Methods and Results In an ischemia/reperfusion rat model (30-min ischemia/4-hr reperfusion), esmolol, milrinone or esmolol + milrinone were intravenous (IV) infused over 10 min (from the last 5min of ischemia to the first 5min of reperfusion). LV-I...

  10. Fabrication and evaluation of magnetic phosphodiesterase-5 linked nanoparticles as adsorbent for magnetic dispersive solid-phase extraction of inhibitors from Chinese herbal medicine prior to ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry analysis.

    Science.gov (United States)

    Tao, Yi; Gu, Xianghui; Li, Weidong; Cai, Baochang

    2018-01-12

    In the present study, the preparation of the magnetic phosphodiesterase-5 linked Fe 3 O 4 @ SiO 2 nanoparticles was successfully achieved by amide reaction and the magnetic phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles were evaluated as a new adsorbent for magnetic dispersive solid-phase extraction of ligands from medicinal plant samples before the analysis by UHPLC-Q-TOF/MS. The prepared phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, vibration sample magnetometer and potential laser particle size analyzer. The effects of EDC concentration, incubation time and bead-protein ratio on the amount of immobilized protein were studied. The main experimental parameters affect extraction efficiency of ligands, such as wash times, wash solvents, incubation pH, ion strength and incubation temperature, were investigated and optimized by using echinacoside as a model compound. The absolute recovery of echinacoside was ranged from 98.36%-102.16% in Cistanche tubulosa sample under the optimal extraction conditions. Good linearity was observed in the investigated concentration range of 0.006 mgmL -1 -0.97 mgmL -1 (R 2  = 0.9999). The limit of detection was 0.002 mgmL -1 . The RSDs of within-day and between-day precision were less than 2.3%. Due to the excellent magnetic behavior of Fe 3 O 4 @SiO 2 nanoparticles, the proposed method was shown to be simple and rapid. Remarkably, the magnetic phosphodiesterase-5 linked Fe 3 O 4 @SiO 2 nanoparticles could be recycled for ten times with loss of 10% activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Phosphodiesterases in the rat ovary

    DEFF Research Database (Denmark)

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

    2015-01-01

    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......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...... 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...

  12. Anti-inflammatory effects of the selective phosphodiesterase 3 inhibitor, cilostazol, and antioxidants, enzymatically-modified isoquercitrin and α-lipoic acid, reduce dextran sulphate sodium-induced colorectal mucosal injury in mice.

    Science.gov (United States)

    Kangawa, Yumi; Yoshida, Toshinori; Abe, Hajime; Seto, Yoshiki; Miyashita, Taishi; Nakamura, Michi; Kihara, Tohru; Hayashi, Shim-Mo; Shibutani, Makoto

    2017-04-04

    Developing effective treatments and preventing inflammatory bowel disease (IBD) are urgent challenges in improving patients' health. It has been suggested that platelet activation and reactive oxidative species generation are involved in the pathogenesis of IBD. We examined the inhibitory effects of a selective phosphodiesterase-3 inhibitor, cilostazol (CZ), and two antioxidants, enzymatically modified isoquercitrin (EMIQ) and α-lipoic acid (ALA), against dextran sulphate sodium (DSS)-induced colitis. BALB/c mice were treated with 0.3% CZ, 1.5% EMIQ, and 0.2% ALA in their feed. Colitis was induced by administering 5% DSS in drinking water for 8days. The inhibitory effects of these substances were evaluated by measuring relevant clinical symptoms (faecal blood, diarrhoea, and body weight loss), colon length, plasma cytokine and chemokine levels, whole genome gene expression, and histopathology. Diarrhoea was suppressed by each treatment, while CZ prevented shortening of the colon length. All treatment groups exhibited decreased plasma levels of interleukin (IL)-6 and tumour necrosis factor (TNF)-α compared with the DSS group. Microarray analysis showed that cell adhesion, cytoskeleton regulation, cell proliferation, and apoptosis, which might be related to inflammatory cell infiltration and mucosal healing, were affected in all the groups. DSS-induced mucosal injuries such as mucosal loss, submucosal oedema, and inflammatory cell infiltration in the distal colon were prevented by CZ or antioxidant treatment. These results suggest that anti-inflammatory effects of these agents reduced DSS-induced mucosal injuries in mice and, therefore, may provide therapeutic benefits in IBD. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. 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: steen@pet.auh.dk; 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)

    2006-07-15

    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.

  14. Phosphodiesterases in endocrine physiology and disease.

    Science.gov (United States)

    Vezzosi, Delphine; Bertherat, Jérôme

    2011-08-01

    The cAMP-protein kinase A pathway plays a central role in the development and physiology of endocrine tissues. cAMP mediates the intracellular effects of numerous peptide hormones. Various cellular and molecular alterations of the cAMP-signaling pathway have been observed in endocrine diseases. Phosphodiesterases (PDEs) are key regulatory enzymes of intracellular cAMP levels. Indeed, PDEs are the only known mechanism for inactivation of cAMP by catalysis to 5'-AMP. It has been suggested that disruption of PDEs could also have a role in the pathogenesis of many endocrine diseases. This review summarizes the most recent advances concerning the role of the PDEs in the physiopathology of endocrine diseases. The potential significance of this knowledge can be easily envisaged by the development of drugs targeting specific PDEs.

  15. Changes in calmodulin concentration and cyclic 3',5'-nucleotide phosphodiesterase activity in skeletal muscle of hyper- and hypothyroid rats.

    Science.gov (United States)

    Mano, T; Iwase, K; Yoshimochi, I; Sawai, Y; Oda, N; Nishida, Y; Mokuno, T; Kotake, M; Nakai, A; Hayakawa, N

    1995-08-01

    Hyper- and hypothyroid states occasionally induce skeletal muscle dysfunction i.e. periodic paralysis and thyroid myopathy. The etiology of these diseases remains unclear, but several findings suggest that the catecholamine-beta-receptor-cAMP system or other messenger systems are disturbed in these diseases. In this context, we evaluated changes in the cyclic 3',5'-nucleotide metabolic enzyme, cyclic 3',5'-nucleotide phosphodiesterase (PDE) and calmodulin concentrations in skeletal muscles of hyper- and hypothyroid rats. Activities of cyclic AMP-PDE were low in skeletal muscle both from hyper- and hypothyroid rats, and calmodulin concentration was high in hyperthyroid and low in hypothyroid rats, as compared with normal rats. DE-52 column chromatographic analysis showed that the cGMP hydrolytic activity in peak I and the cAMP hydrolytic activity in peak II were decreased in hypothyroid rats, whereas cAMP hydrolytic activity in peak III was unchanged. The cAMP hydrolytic activity in peak III was decreased in hyperthyroid rats, but the activities in peaks I and II were unchanged. These findings indicate that cAMP and calmodulin may have some role in skeletal muscle function in the hyperthyroid state, and that cAMP and calmodulin-dependent metabolism may be suppressed in the hypothyroid state.

  16. cGMP inhibition of type 3 phosphodiesterase is the major mechanism by which C-type natriuretic peptide activates CFTR in the shark rectal gland

    Science.gov (United States)

    De Jonge, Hugo R.; Tilly, Ben C.; Hogema, Boris M.; Pfau, Daniel J.; Kelley, Catherine A.; Kelley, Megan H.; Melita, August M.; Morris, Montana T.; Viola, Ryan M.

    2013-01-01

    The 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 secretion. CNP binds to natriuretic receptors in the basolateral membrane, elevates cellular cGMP, and opens cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels in the apical membrane. CNP-provoked chloride secretion was completely inhibitable by the nonspecific protein kinase inhibitor staurosporine and the PKA inhibitor H89 but insensitive to H8, an inhibitor of type I and II isoforms of cGMP-dependent protein kinase (cGKI and cGKII). CNP-induced secretion could not be mimicked by nonhydrolyzable cGMP analogs added alone or in combination with the protein kinase C activator phorbolester, arguing against a role for cGK or for cGMP-induced PKC signaling. We failed to detect a dogfish ortholog of cGKII by molecular cloning and affinity chromatography. However, inhibitors of the cGMP-inhibitable isoform of phosphodiesterase (PDE3) including milrinone, amrinone, and cilostamide but not inhibitors of other PDE isoenzymes mimicked the effect of CNP on chloride secretion in perfused glands and monolayers. CNP raised cGMP and cAMP levels in the SRG epithelial cells. This rise in cAMP as well as the CNP and amrinone-provoked chloride secretion, but not the rise in cGMP, was almost completely blocked by the Gαi-coupled adenylyl cyclase inhibitor somatostatin, arguing against a role for cGMP cross-activation of PKA in CNP action. These data provide molecular, functional, and pharmacological evidence for a CNP/cGMP/PDE3/cAMP/PKA signaling cascade coupled to CFTR in the SRG. PMID:24259420

  17. 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.

    1982-01-01

    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

  18. 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

    1992-01-01

    The finding of a mutation in the beta subunit of the cyclic GMP (cGMP) phosphodiesterase gene causing retinal degeneration in mice (the Pdeb gene) prompted a search for disease-causing mutations in the human phosphodiesterase gene (PDEB gene) in patients with retinitis pigmentosa. All 22 exons...

  19. Phosphodiesterase 10A inhibition attenuates sleep deprivation-induced deficits in long-term fear memory.

    Science.gov (United States)

    Guo, Lengqiu; Guo, Zhuangli; Luo, Xiaoqing; Liang, Rui; Yang, Shui; Ren, Haigang; Wang, Guanghui; Zhen, Xuechu

    2016-12-02

    Sleep, particularly rapid eye movement (REM) sleep, is implicated in the consolidation of emotional memories. In the present study, we investigated the protective effects of a phosphodiesterase 10A (PDE10A) inhibitor MP-10 on deficits in long-term fear memory induced by REM sleep deprivation (REM-SD). REM-SD caused deficits in long-term fear memory, however, MP-10 administration ameliorated the deleterious effects of REM-SD on long term fear memory. Brain-derived neurotropic factor (BDNF) and phosphorylated cAMP response element-binding protein (pCREB) were altered in specific brain regions associated with learning and memory in REM-SD rats. Accordingly, REM-SD caused a significant decrease of pCREB in hippocampus and striatum and a significant decrease of BDNF in the hippocampus, striatum and amygdala, however, MP-10 reversed the effects of REM-SD in a dose-dependent manner. Our findings suggest that REM-SD disrupts the consolidation of long-term fear memory and that administration of MP-10 protects the REM-SD-induced deficits in fear memory, which may be due to the MP-10-induced expression of BDNF in the hippocampus, striatum and amygdala, and phosphorylation of CREB in the hippocampus and striatum. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants.

    Directory of Open Access Journals (Sweden)

    Lorena Olivares-González

    Full Text Available 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.

  1. Antagonizing STAT3 dimerization with a rhodium(III) complex.

    Science.gov (United States)

    Ma, Dik-Lung; Liu, Li-Juan; Leung, Ka-Ho; Chen, Yen-Ting; Zhong, Hai-Jing; Chan, Daniel Shiu-Hin; Wang, Hui-Min David; Leung, Chung-Hang

    2014-08-25

    Kinetically inert metal complexes have arisen as promising alternatives to existing platinum and ruthenium chemotherapeutics. Reported herein, to our knowledge, is the first example of a substitutionally inert, Group 9 organometallic compound as a direct inhibitor of signal transducer and activator of transcription 3 (STAT3) dimerization. From a series of cyclometalated rhodium(III) and iridium(III) complexes, a rhodium(III) complex emerged as a potent inhibitor of STAT3 that targeted the SH2 domain and inhibited STAT3 phosphorylation and dimerization. Significantly, the complex exhibited potent anti-tumor activities in an in vivo mouse xenograft model of melanoma. This study demonstrates that rhodium complexes may be developed as effective STAT3 inhibitors with potent anti-tumor activity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. 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

    2006-01-01

    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...... observed. Only L-826,141 at a dose of 30 mg/kg p.o. significantly decreased the clinical severity of EAE compared with vehicle controls. Immunohistochemical detection of the neuronal activity marker Fos confirmed that L-826,141 did not reach concentrations in the central nervous system sufficient...

  3. Calmodulin-activated cyclic nucleotide phosphodiesterase from brain. Relationship of subunit structure to activity assessed by radiation inactivation

    International Nuclear Information System (INIS)

    Kincaid, R.L.; Kemdner, E.; Manganiello, V.C.; Osborne, J.C.; Vaughan, M.

    1981-01-01

    The apparent target sizes of the basal and calmodulin-dependent activities of calmodulin-activated phosphodiesterase from bovine brain were estimated using target theory analysis of data from radiation inactivation experiments. Whether crude or highly purified samples were irradiated, the following results were obtained. Low doses of radiation caused a 10 to 15% increase in basal activity, which, with further irradiation, decayed with an apparent target size of approx.60,000 daltons. Calmodulin-dependent activity decayed with an apparent target size of approx.105,000 daltons. The percentage stimulation of enzyme activity by calmodulin decreased markedly as a function of radiation dosage. These observations are consistent with results predicted by computer-assisted modeling based on the assumptions that: 1) the calmodulin-activated phosphodiesterase exists as a mixture of monomers which are fully active in the absence of calmodulin and dimers which are inactive in the absence of calmodulin; 2) in the presence of calmodulin, a dimer exhibits activity equal to that of two monomers; 3) on radiation destruction of a dimer, an active monomer is generated. This monomer-dimer hypothesis provides a plausible explanation for and definition of basal and calmodulin-dependent phosphodiesterase activity

  4. 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).

    Science.gov (United States)

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

    2008-10-01

    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.

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

    OpenAIRE

    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.

    2012-01-01

    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 resveratrol result from competitive inhibition of cAMP-degrading phosphodiesterases, leading to elevated cAMP levels. The resulting activation of Epac1, a cAMP effector protein, increases intracellular Ca2...

  6. Analogues of Cucurbita maxima trypsin inhibitor III (CMTI-III) with elastase inhibitory activity.

    Science.gov (United States)

    Rózycki, J; Kupryszewski, G; Rolka, K; Ragnarsson, U; Zbyryt, T; Krokoszyńska, I; Wilusz, T

    1994-04-01

    Three new CMTI-III analogues containing the Val residue in the reactive site (position 5) were synthesized by the solid-phase method. The analogues displayed an elastase inhibitory activity. It is shown that the removal of the N-terminal Arg residue and the introduction of the Gly-Pro-Gln tripeptide in the region 23-25 decreases the antielastase activity by two orders of magnitude. The removal of the disulfide bridge in positions 16-28 and the substitution of Ala for Cys16 and Gly for Cys28 decreases the activity (measured as Ka with HLE) by five orders of magnitude as compared with [Val5]CMTI-III.

  7. Transient Kinetics of a cGMP-dependent cGMP-specific Phosphodiesterase from Dictyostelium discoideum

    NARCIS (Netherlands)

    Haastert, Peter J.M. van; Lookeren Campagne, Michiel M. van

    1984-01-01

    Chemotactic stimulation of Dictyostelium discoideum cells induces a fast transient increase of cGMP levels which reach a peak at 10 s. Prestimulation levels are recovered in ~30 s, which is achieved mainly by the action of a guanosine 3',5'-monophosphate cGMP-specific phosphodiesterase. This enzyme

  8. A Rhodium(III)-Based Inhibitor of Lysine-Specific Histone Demethylase 1 as an Epigenetic Modulator in Prostate Cancer Cells.

    Science.gov (United States)

    Yang, Chao; Wang, Wanhe; Liang, Jia-Xin; Li, Guodong; Vellaisamy, Kasipandi; Wong, Chun-Yuen; Ma, Dik-Lung; Leung, Chung-Hang

    2017-03-23

    We report herein a novel rhodium(III) complex 1 as a new LSD1 targeting agent and epigenetic modulator. Complex 1 disrupted the interaction of LSD1-H3K4me2 in human prostate carcinoma cells and enhanced the amplification of p21, FOXA2, and BMP2 gene promoters. Complex 1 was selective for LSD1 over other histone demethylases, such as KDM2b, KDM7, and MAO activities, and also showed antiproliferative activity toward human cancer cells. To date, complex 1 is the first metal-based inhibitor of LSD1 activity.

  9. Fragment-Based Discovery of Pyrimido[1,2-b]indazole PDE10A Inhibitors.

    Science.gov (United States)

    Chino, Ayaka; Seo, Ryushi; Amano, Yasushi; Namatame, Ichiji; Hamaguchi, Wataru; Honbou, Kazuya; Mihara, Takuma; Yamazaki, Mayako; Tomishima, Masaki; Masuda, Naoyuki

    2018-01-01

    In this study, we report the identification of potent pyrimidoindazoles as phosphodiesterase10A (PDE10A) inhibitors by using the method of fragment-based drug discovery (FBDD). The pyrazolopyridine derivative 2 was found to be a fragment hit compound which could occupy a part of the binding site of PDE10A enzyme by using the method of the X-ray co-crystal structure analysis. On the basis of the crystal structure of compound 2 and PDE10A protein, a number of compounds were synthesized and evaluated, by means of structure-activity relationship (SAR) studies, which culminated in the discovery of a novel pyrimidoindazole derivative 13 having good physicochemical properties.

  10. Immunohistochemical distribution of cAMP- and cGMP-phosphodiesterase (PDE) isoenzymes in the human prostate

    NARCIS (Netherlands)

    Uckert, Stefan; Oelke, Matthias; Stief, Christian G.; Andersson, K.-E.; Jonas, Udo; Hedlund, Petter

    2006-01-01

    With the introduction of sildenafil citrate (Viagra), the concept of phosphodiesterase (PDE) inhibition has gained tremendous interest in the field of urology. Cyclic nucleotide second messengers cGMP and cAMP have been assumed to be involved in the control of the normal function of the prostate.

  11. 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

    2009-01-01

    -dependent hydrolase of the ß-lactamase superfamily. Screening with a wide array of hydrolytically sensitive substrates indicated that PhnP is an enzyme with phosphodiesterase activity, having the greatest specificity toward bis(p-nitrophenyl)phosphate and 2',3'-cyclic nucleotides. No activity was observed toward RNA...

  12. Novel benzimidazole derivatives as phosphodiesterase 10A (PDE10A) inhibitors with improved metabolic stability.

    Science.gov (United States)

    Chino, Ayaka; Masuda, Naoyuki; Amano, Yasushi; Honbou, Kazuya; Mihara, Takuma; Yamazaki, Mayako; Tomishima, Masaki

    2014-07-01

    In this study, we report the identification of potent benzimidazoles as PDE10A inhibitors. We first identified imidazopyridine 1 as a high-throughput screening hit compound from an in-house library. Next, optimization of the imidazopyridine moiety to improve inhibitory activity gave imidazopyridinone 10b. Following further structure-activity relationship development by reducing lipophilicity and introducing substituents, we acquired 35, which exhibited both improved metabolic stability and reduced CYP3A4 time-dependent inhibition. Copyright © 2014. Published by Elsevier Ltd.

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

    Directory of Open Access Journals (Sweden)

    Fu L

    2015-05-01

    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

  14. Synergism of antifungal activity between mitochondrial respiration inhibitors and kojic acid.

    Science.gov (United States)

    Kim, Jong H; Campbell, Bruce C; Chan, Kathleen L; Mahoney, Noreen; Haff, Ronald P

    2013-01-25

    Co-application of certain types of compounds to conventional antimicrobial drugs can enhance the efficacy of the drugs through a process termed chemosensitization. We show that kojic acid (KA), a natural pyrone, is a potent chemosensitizing agent of complex III inhibitors disrupting the mitochondrial respiratory chain in fungi. Addition of KA greatly lowered the minimum inhibitory concentrations of complex III inhibitors tested against certain filamentous fungi. Efficacy of KA synergism in decreasing order was pyraclostrobin > kresoxim-methyl > antimycin A. KA was also found to be a chemosensitizer of cells to hydrogen peroxide (H₂O₂), tested as a mimic of reactive oxygen species involved in host defense during infection, against several human fungal pathogens and Penicillium strains infecting crops. In comparison, KA-mediated chemosensitization to complex III inhibitors/H₂O₂ was undetectable in other types of fungi, including Aspergillus flavus, A. parasiticus, and P. griseofulvum, among others. Of note, KA was found to function as an antioxidant, but not as an antifungal chemosensitizer in yeasts. In summary, KA could serve as an antifungal chemosensitizer to complex III inhibitors or H₂O₂ against selected human pathogens or Penicillium species. KA-mediated chemosensitization to H₂O₂ seemed specific for filamentous fungi. Thus, results indicate strain- and/or drug-specificity exist during KA chemosensitization.

  15. Delayed-type hypersensitivity lesions in the central nervous system are prevented by inhibitors of matrix metalloproteinases.

    Science.gov (United States)

    Matyszak, M K; Perry, V H

    1996-09-01

    We have studied the effect of an inhibitor of matrix metalloproleinases, BB-1101, on a delayed-type hypersensitivity (DTH) response in the CNS. We used a recently described model in which heat-killed bacillus Calmette-Guérin (BCG) sequestered behind the blood-brain barrier (BBB) is targeted by a T-cell mediated response after subcutaneous injection of BCG (Matyszak and Perry, 1995). The DTH lesions are characterised by breakdown of the BBB, macrophage and lymphocyte infiltration and tissue damage including myelin loss. Treatment with BB-1101, which is not only a potent inhibitor of matrix metalloproteinases but also strongly inhibits TNF-alpha release, dramatically attenuated the CNS lesions. Breakdown of the BBB and the recruitment of T-cells into the site of the lesion were significantly reduced. There were many fewer inflammatory macrophages in DTH lesions than in comparable lesions from untreated animals. There was also significantly less myelin damage (assessed by staining with anti-MBP antibody). The DTH response in animals treated with dexamethasone was also reduced, but to a lesser degree. No significant effect was seen after administration of pentoxifylline, a phosphodiesterase inhibitor with effects including the inhibition of TNF-alpha production. Our results suggest that inhibitors of matrix metalloproteinases may be of considerable therapeutic benefit in neuroinflammatory diseases.

  16. Identification of small-molecule inhibitors of Yersinia pestis Type III secretion system YscN ATPase.

    Directory of Open Access Journals (Sweden)

    Wieslaw Swietnicki

    Full Text Available Yersinia pestis is a gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. The pathogen uses a type III secretion system (T3SS to deliver virulence factors directly from bacterium into host mammalian cells. The system contains a single ATPase, YscN, necessary for delivery of virulence factors. In this work, we show that deletion of the catalytic domain of the yscN gene in Y. pestis CO92 attenuated the strain over three million-fold in the Swiss-Webster mouse model of bubonic plague. The result validates the YscN protein as a therapeutic target for plague. The catalytic domain of the YscN protein was made using recombinant methods and its ATPase activity was characterized in vitro. To identify candidate therapeutics, we tested computationally selected small molecules for inhibition of YscN ATPase activity. The best inhibitors had measured IC(50 values below 20 µM in an in vitro ATPase assay and were also found to inhibit the homologous BsaS protein from Burkholderia mallei animal-like T3SS at similar concentrations. Moreover, the compounds fully inhibited YopE secretion by attenuated Y. pestis in a bacterial cell culture and mammalian cells at µM concentrations. The data demonstrate the feasibility of targeting and inhibiting a critical protein transport ATPase of a bacterial virulence system. It is likely the same strategy could be applied to many other common human pathogens using type III secretion system, including enteropathogenic E. coli, Shigella flexneri, Salmonella typhimurium, and Burkholderia mallei/pseudomallei species.

  17. Identification of small-molecule inhibitors of Yersinia pestis Type III secretion system YscN ATPase.

    Science.gov (United States)

    Swietnicki, Wieslaw; Carmany, Daniel; Retford, Michael; Guelta, Mark; Dorsey, Russell; Bozue, Joel; Lee, Michael S; Olson, Mark A

    2011-01-01

    Yersinia pestis is a gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. The pathogen uses a type III secretion system (T3SS) to deliver virulence factors directly from bacterium into host mammalian cells. The system contains a single ATPase, YscN, necessary for delivery of virulence factors. In this work, we show that deletion of the catalytic domain of the yscN gene in Y. pestis CO92 attenuated the strain over three million-fold in the Swiss-Webster mouse model of bubonic plague. The result validates the YscN protein as a therapeutic target for plague. The catalytic domain of the YscN protein was made using recombinant methods and its ATPase activity was characterized in vitro. To identify candidate therapeutics, we tested computationally selected small molecules for inhibition of YscN ATPase activity. The best inhibitors had measured IC(50) values below 20 µM in an in vitro ATPase assay and were also found to inhibit the homologous BsaS protein from Burkholderia mallei animal-like T3SS at similar concentrations. Moreover, the compounds fully inhibited YopE secretion by attenuated Y. pestis in a bacterial cell culture and mammalian cells at µM concentrations. The data demonstrate the feasibility of targeting and inhibiting a critical protein transport ATPase of a bacterial virulence system. It is likely the same strategy could be applied to many other common human pathogens using type III secretion system, including enteropathogenic E. coli, Shigella flexneri, Salmonella typhimurium, and Burkholderia mallei/pseudomallei species.

  18. Antithrombin III in animal models of sepsis and organ failure.

    Science.gov (United States)

    Dickneite, G

    1998-01-01

    Antithrombin III (AT III) is the physiological inhibitor of thrombin and other serine proteases of the clotting cascade. In the development of sepsis, septic shock and organ failure, the plasma levels of AT III decrease considerably, suggesting the concept of a substitution therapy with the inhibitor. A decrease of AT III plasma levels might also be associated with other pathological disorders like trauma, burns, pancreatitis or preclampsia. Activation of coagulation and consumption of AT III is the consequence of a generalized inflammation called SIRS (systemic inflammatory response syndrome). The clotting cascade is also frequently activated after organ transplantation, especially if organs are grafted between different species (xenotransplantation). During the past years AT III has been investigated in numerous corresponding disease models in different animal species which will be reviewed here. The bulk of evidence suggests, that AT III substitution reduces morbidity and mortality in the diseased animals. While gaining more experience with AT III, the concept of substitution therapy to maximal baseline plasma levels (100%) appears to become insufficient. Evidence from clinical and preclinical studies now suggests to adjust the AT III plasma levels to about 200%, i.e., doubling the normal value. During the last few years several authors proposed that AT III might not only be an anti-thrombotic agent, but to have in addition an anti-inflammatory effect.

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

    Directory of Open Access Journals (Sweden)

    Selvakumar Subbian

    2011-09-01

    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.

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

    Science.gov (United States)

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

    2016-04-05

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

  1. Isolation of natural inhibitors of papain obtained from Carica papaya latex

    Directory of Open Access Journals (Sweden)

    Rubens Monti

    2004-09-01

    Full Text Available Studies were carried out to natural papain inhibitor from papaya latex. Fresh latex from green fruits of Carica papaya was collected and immediately transported in ice bath to the lab, from which three fractions with inhibitor effect of esterase papain activity were isolated by latex dialysis, Sephadex G-25 gel filtration and ionic exchange chromatography in SP-Sephadex C-25. The isolated fractions, identified as inhibitors I and II, showed a negative reaction with ninhydrin; however, the fraction identified as P-III showed positive reaction with ninhydrin. Kinetics data showed non-competitive inhibition (inhibitor I and uncompetitive (inhibitors II and P-III.Este trabalho apresenta novos dados sobre inibidores naturais de papaína. O látex fresco de frutos verdes de Carica papaya foi coletado pela manhã em plantações da região de Araraquara, SP, Brasil e imediatamente transportado ao laboratório em banho de gelo. Três frações com efeito inibitório da atividade esterásica da papaína foram isoladas a partir do látex fresco, através de diálise, filtração em Sephadex G-25 e cromatografia em SP-Sephadex C-25. As frações isoladas identificadas como inibidores I e II, mostraram reação negativa à ninidrina; entretanto, a fração identificada como P-III mostrou reação positiva. Dados cinéticos revelaram inibição não-competitiva (inibidor I e incompetitiva (inibidores II e P-III.

  2. Synergism of Antifungal Activity between Mitochondrial Respiration Inhibitors and Kojic Acid

    Directory of Open Access Journals (Sweden)

    Ronald P. Haff

    2013-01-01

    Full Text Available Co-application of certain types of compounds to conventional antimicrobial drugs can enhance the efficacy of the drugs through a process termed chemosensitization. We show that kojic acid (KA, a natural pyrone, is a potent chemosensitizing agent of complex III inhibitors disrupting the mitochondrial respiratory chain in fungi. Addition of KA greatly lowered the minimum inhibitory concentrations of complex III inhibitors tested against certain filamentous fungi. Efficacy of KA synergism in decreasing order was pyraclostrobin > kresoxim-methyl > antimycin A. KA was also found to be a chemosensitizer of cells to hydrogen peroxide (H2O2, tested as a mimic of reactive oxygen species involved in host defense during infection, against several human fungal pathogens and Penicillium strains infecting crops. In comparison, KA-mediated chemosensitization to complex III inhibitors/H2O2 was undetectable in other types of fungi, including Aspergillus flavus, A. parasiticus, and P. griseofulvum, among others. Of note, KA was found to function as an antioxidant, but not as an antifungal chemosensitizer in yeasts. In summary, KA could serve as an antifungal chemosensitizer to complex III inhibitors or H2O2 against selected human pathogens or Penicillium species. KA-mediated chemosensitization to H2O2 seemed specific for filamentous fungi. Thus, results indicate strain- and/or drug-specificity exist during KA chemosensitization.

  3. Distinct Molecular Effects of Angiotensin II and Angiotensin III in Rat Astrocytes

    Directory of Open Access Journals (Sweden)

    Michelle A. Clark

    2013-01-01

    Full Text Available It is postulated that central effects of angiotensin (Ang II may be indirect due to rapid conversion to Ang III by aminopeptidase A (APA. Previously, we showed that Ang II and Ang III induced mitogen-activated protein (MAP kinases ERK1/2 and stress-activated protein kinase/Jun-terminal kinases (SAPK/JNK phosphorylation in cultured rat astrocytes. Most importantly, both peptides were equipotent in causing phosphorylation of these MAP kinases. In these studies, we used brainstem and cerebellum astrocytes to determine whether Ang II’s phosphorylation of these MAP kinases is due to the conversion of the peptide to Ang III. We pretreated astrocytes with 10 μM amastatin A or 100 μM glutamate phosphonate, selective APA inhibitors, prior to stimulating with either Ang II or Ang III. Both peptides were equipotent in stimulating ERK1/2 and SAPK/JNK phosphorylation. The APA inhibitors failed to prevent Ang II- and Ang III-mediated phosphorylation of the MAP kinases. Further, pretreatment of astrocytes with the APA inhibitors did not affect Ang II- or Ang III-induced astrocyte growth. These findings suggest that both peptides directly induce phosphorylation of these MAP kinases as well as induce astrocyte growth. These studies establish both peptides as biologically active with similar intracellular and physiological effects.

  4. PDE5 Inhibitors As Potential Tools In The Treatment Of Cystic Fibrosis

    Directory of Open Access Journals (Sweden)

    Sabrina eNoel

    2012-09-01

    Full Text Available Despite great advances in the understanding of the genetics and pathophysiology of cystic fibrosis (CF, there is still no cure for the disease. Using phosphodiesterase type 5 (PDE5 inhibitors, we and others have provided evidence of rescued F508del-CFTR trafficking and corrected deficient chloride transport activity. Studies using PDE5 inhibitors in mice homozygous for the clinically relevant F508del mutation have been conducted with the aim of restoring F508del-CFTR protein function. We demonstrated, by measuring transepithelial nasal potential difference in F508del mice following intraperitoneal injection of sildenafil, vardenafil or taladafil at clinical doses are able to restore the decreased CFTR-dependent chloride transport across the nasal mucosa. Moreover, vardenafil, but not sildenafil, stimulates chloride transport through the normal CFTR protein. We developed a specific nebulizer setup for mice, with which we demonstrated, through a single inhalation of PDE5 inhibitors, local activation of CFTR protein in CF. Significant potential advantages of inhalation drug therapy over oral or intravenous routes include rapid onset of pharmacological action, reduced systemic secondary effects and reduced effective drug doses compared to the drug delivered orally; this underlines the relevance and impact of our work for translational science. More recently, we analyzed the bronchoalveolar lavage of CF and wild-type mice for cell infiltrates and expression of pro-inflammatory cytokines and chemokines; we found that the CFTR activating effect of vardenafil, selected as a representative long-lasting PDE5 inhibitor, breaks the vicious circle of lung inflammation which plays a major role in morbi-mortality in CF. Our data highlight the potential use of PDE5 inhibitors in CF. Therapeutic approaches using clinically approved PDE5 inhibitors to address F508del-CFTR defects could speed up the development of new therapies for CF.

  5. Avanafil for erectile dysfunction in elderly and younger adults: differential pharmacology and clinical utility

    Directory of Open Access Journals (Sweden)

    Katz EG

    2014-08-01

    Full Text Available Eric G Katz,1 Ronny BW Tan,2 Daniel Rittenberg,1 Wayne J Hellstrom3 1Tulane University School of Medicine, New Orleans, LA, USA; 2Department of Urology, Tan Tock Seng Hospital, Singapore; 3Section of Andrology, Department of Urology, Tulane University School of Medicine, New Orleans, LA, USA Abstract: The treatment modalities of erectile dysfunction range from oral pharmacotherapy to intracavernosal injections, intraurethral pellets, vacuum erectile devices, and the surgical option of penile prosthesis insertion. Oral phosphodiesterase 5 inhibitors still remain the preferred treatment for patients since they are the least invasive, not to mention that they can be prescribed by non-urologists. Due to these factors, there has been development of newer drugs with fewer side effects. This is a review of the second generation phosphodiesterase 5 inhibitor, avanafil, looking into its pharmacology as well as its clinical utility. Avanafil's faster onset and shorter duration of action has made it preferred as compared to other PDE5 inhibitors for patients with multiple comorbidities. Keywords: phosphodiesterase 5 inhibitors, impotence, sildenafil, sexual dysfunction, nitric oxide

  6. Immunotherapy (excluding checkpoint inhibitors) for stage I to III non-small cell lung cancer treated with surgery or radiotherapy with curative intent.

    Science.gov (United States)

    Zhu, Jianwei; Li, Rui; Tiselius, Eva; Roudi, Raheleh; Teghararian, Olivia; Suo, Chen; Song, Huan

    2017-12-16

    Non-small cell lung cancer (NSCLC) is the most common lung cancer, accounting for approximately 80% to 85% of all cases. For patients with localised NSCLC (stages I to III), it has been speculated that immunotherapy may be helpful for reducing postoperative recurrence rates, or improving the clinical outcomes of current treatment for unresectable tumours. While several new agents have now entered phase III clinical trials, we felt a systematic review was needed to address the question of the effectiveness and safety of immunotherapy in patients with stages I to III NSCLC. To evaluate the effectiveness and safety of immunotherapy (excluding checkpoint inhibitors) in patients with localised NSCLC (stages I to III) who received surgery or radiotherapy with curative intent. We searched the following databases (from inception to 20 January 2017): CENTRAL, MEDLINE, Embase, and CINAHL, and five trial registers. We also manually checked abstracts or reports from relevant conference proceedings and the reference lists of included trials. We searched for randomised controlled trials (RCTs) in adults (≥ 18 years) with histologically-confirmed early-stage (stages I to III) NSCLC after surgical resection, and those with unresectable locally advanced stage III NSCLC who had received radiotherapy with curative intent. For patients who had received primary surgical treatment, postoperative radiotherapy or chemoradiotherapy was allowed if it was used for both experimental and control groups. Two review authors independently selected eligible trials, assessed risk of bias, and extracted data. We used survival analysis to pool time-to-event data, expressing the intervention effect as a hazard ratio (HR). We calculated risk ratios (RR) for dichotomous data, and mean differences for continuous data, with 95% confidence intervals (CI). Due to clinical heterogeneity (immunotherapeutic agents with different underlying mechanisms), we used random-effects models for our meta-analyses. We

  7. Women taking the “blue pill” (sildenafil citrate: such a big deal?

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    Lo Monte G

    2014-11-01

    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

  8. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

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    Lynch Tadhg

    2009-04-01

    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.

  9. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries.

    LENUS (Irish Health Repository)

    Maharaj, Chrisen H

    2009-01-01

    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.

  10. Inhibition of Cyclic Adenosine Monophosphate-Specific Phosphodiesterase by Various Food Plant-Derived Phytotherapeutic Agents.

    Science.gov (United States)

    Röhrig, Teresa; Pacjuk, Olga; Hernández-Huguet, Silvia; Körner, Johanna; Scherer, Katharina; Richling, Elke

    2017-11-04

    Background: Phosphodiesterases (PDEs) play a major role in the regulation of cyclic adenosine monophosphate (cAMP)- and cyclic guanosine monophosphate (cGMP)-mediated pathways. Their inhibitors exhibit anti-inflammatory, vasodilatory and antithrombotic effects. Therefore, consumption of foods with PDE-inhibiting potential may possess beneficial influence on the risk of cardiovascular diseases. Methods: Four plant extracts ( Arbutus unedo , Camellia sinensis , Cynara scolymus , Zingiber officinale ) with promising ingredient profiles and physiological effects were tested for their ability to inhibit cAMP-specific PDE in vitro in a radioactive assay. Results: Strawberry tree fruit ( Arbutus unedo ) and tea ( Camellia sinensis ) extracts did not inhibit PDE markedly. Alternatively, artichoke ( Cynara scolymus ) extract had a significant inhibitory influence on PDE activity (IC 50 = 0.9 ± 0.1 mg/mL) as well as its flavone luteolin (IC 50 = 41 ± 10 μM) and 3,4-dicaffeoylquinic acid (IC 50 > 1.0 mM). Additionally, the ginger ( Zingiber officinale ) extract and one of its constituents, [6]-gingerol, significantly inhibited PDE (IC 50 = 1.7 ± 0.2 mg/mL and IC 50 > 1.7 mM, respectively). Crude fractionation of ginger extract showed that substances responsible for PDE inhibition were in the lipoid fraction (IC 50 = 455 ± 19 μg/mL). Conclusions: A PDE-inhibitory effect was shown for artichoke and ginger extract. Whether PDE inhibition in vivo can be achieved through ingestion of artichoke or ginger extracts leading to physiological effects concerning cardiovascular health should be addressed in future research.

  11. Inhibition of Cyclic Adenosine Monophosphate-Specific Phosphodiesterase by Various Food Plant-Derived Phytotherapeutic Agents

    Directory of Open Access Journals (Sweden)

    Teresa Röhrig

    2017-11-01

    Full Text Available Background: Phosphodiesterases (PDEs play a major role in the regulation of cyclic adenosine monophosphate (cAMP- and cyclic guanosine monophosphate (cGMP-mediated pathways. Their inhibitors exhibit anti-inflammatory, vasodilatory and antithrombotic effects. Therefore, consumption of foods with PDE-inhibiting potential may possess beneficial influence on the risk of cardiovascular diseases. Methods: Four plant extracts (Arbutus unedo, Camellia sinensis, Cynara scolymus, Zingiber officinale with promising ingredient profiles and physiological effects were tested for their ability to inhibit cAMP-specific PDE in vitro in a radioactive assay. Results: Strawberry tree fruit (Arbutus unedo and tea (Camellia sinensis extracts did not inhibit PDE markedly. Alternatively, artichoke (Cynara scolymus extract had a significant inhibitory influence on PDE activity (IC50 = 0.9 ± 0.1 mg/mL as well as its flavone luteolin (IC50 = 41 ± 10 μM and 3,4-dicaffeoylquinic acid (IC50 > 1.0 mM. Additionally, the ginger (Zingiber officinale extract and one of its constituents, [6]-gingerol, significantly inhibited PDE (IC50 = 1.7 ± 0.2 mg/mL and IC50 > 1.7 mM, respectively. Crude fractionation of ginger extract showed that substances responsible for PDE inhibition were in the lipoid fraction (IC50 = 455 ± 19 μg/mL. Conclusions: A PDE-inhibitory effect was shown for artichoke and ginger extract. Whether PDE inhibition in vivo can be achieved through ingestion of artichoke or ginger extracts leading to physiological effects concerning cardiovascular health should be addressed in future research.

  12. Phosphodiesterase-4 inhibition as a therapeutic approach to treat capillary leakage in systemic inflammation.

    Science.gov (United States)

    Schick, Martin Alexander; Wunder, Christian; Wollborn, Jakob; Roewer, Norbert; Waschke, Jens; Germer, Christoph-Thomas; Schlegel, Nicolas

    2012-06-01

    In sepsis and systemic inflammation, increased microvascular permeability and consecutive breakdown of microcirculatory flow significantly contribute to organ failure and death. Evidence points to a critical role of cAMP levels in endothelial cells to maintain capillary endothelial barrier properties in acute inflammation. However, approaches to verify this observation in systemic models are rare. Therefore we tested here whether systemic application of the phosphodiesterase-4-inhibitors (PD-4-Is) rolipram or roflumilast to increase endothelial cAMP was effective to attenuate capillary leakage and breakdown of microcirculatory flow in severe lipopolysaccharide (LPS)-induced systemic inflammation in rats. Measurements of cAMP in mesenteric microvessels demonstrated significant LPS-induced loss of cAMP levels which was blocked by application of rolipram. Increased endothelial cAMP by application of either PD-4-I rolipram or roflumilast led to stabilization of endothelial barrier properties as revealed by measurements of extravasated FITC-albumin in postcapillary mesenteric venules. Accordingly, microcirculatory flow in mesenteric venules was significantly increased following PD-4-I treatment and blood gas analyses indicated improved metabolism. Furthermore application of PD-4-I after manifestation of LPS-induced systemic inflammation and capillary leakage therapeutically stabilized endothelial barrier properties as revealed by significantly reduced volume resuscitation for haemodynamic stabilization. Accordingly microcirculation was significantly improved following treatment with PD-4-Is. Our results demonstrate that inflammation-derived loss of endothelial cAMP contributes to capillary leakage which was blocked by systemic PD-4-I treatment. Therefore these data suggest a highly clinically relevant and applicable approach to stabilize capillary leakage in sepsis and systemic inflammation.

  13. Kinase inhibitors: a new class of antirheumatic drugs

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    Kyttaris VC

    2012-09-01

    Full Text Available Vasileios C KyttarisDivision of Rheumatology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USAAbstract: The outlook for patients with rheumatoid arthritis has improved significantly over the last three decades with the use of disease-modifying antirheumatic drugs. However, despite the use of methotrexate, cytokine inhibitors, and molecules targeting T and B cells, a percentage of patients do not respond or lose their response over time. The autoimmune process in rheumatoid arthritis depends on activation of immune cells, which utilize intracellular kinases to respond to external stimuli such as cytokines, immune complexes, and antigens. In the past decade, small molecules targeting several kinases, such as p38 MAPK, Syk, and JAK have been developed. Several p38 MAPK inhibitors proved ineffective in treating rheumatoid arthritis. The Syk inhibitor, fostamatinib, proved superior to placebo in Phase II trials and is currently under Phase III investigation. Tofacitinib, a JAK1/3 inhibitor, was shown to be efficacious in two Phase III trials, while VX-509, a JAK3 inhibitor, showed promising results in a Phase II trial. Fostamatinib and tofacitinib were associated with increased rates of infection, elevation of liver enzymes, and neutropenia. Moreover, fostamatinib caused elevations of blood pressure and diarrhea, while tofacitinib was associated with an increase in creatinine and elevation of lipid levels.Keywords: rheumatoid arthritis, kinase inhibitors, mitogen-activated phosphokinase p38, spleen tyrosine kinase, Janus kinases

  14. A Rhodium(III) Complex as an Inhibitor of Neural Precursor Cell Expressed, Developmentally Down-Regulated 8-Activating Enzyme with in Vivo Activity against Inflammatory Bowel Disease.

    Science.gov (United States)

    Zhong, Hai-Jing; Wang, Wanhe; Kang, Tian-Shu; Yan, Hui; Yang, Yali; Xu, Lipeng; Wang, Yuqiang; Ma, Dik-Lung; Leung, Chung-Hang

    2017-01-12

    We report herein the identification of the rhodium(III) complex [Rh(phq) 2 (MOPIP)] + (1) as a potent and selective ATP-competitive neural precursor cell expressed, developmentally down-regulated 8 (NEDD8)-activating enzyme (NAE) inhibitor. Structure-activity relationship analysis indicated that the overall organometallic design of complex 1 was important for anti-inflammatory activity. Complex 1 showed promising anti-inflammatory activity in vivo for the potential treatment of inflammatory bowel disease.

  15. Discovery of plant phenolic compounds that act as type III secretion system inhibitors or inducers of the fire blight pathogen, Erwinia amylovora.

    Science.gov (United States)

    Khokhani, Devanshi; Zhang, Chengfang; Li, Yan; Wang, Qi; Zeng, Quan; Yamazaki, Akihiro; Hutchins, William; Zhou, Shan-Shan; Chen, Xin; Yang, Ching-Hong

    2013-09-01

    Erwinia amylovora causes a devastating disease called fire blight in rosaceous plants. The type III secretion system (T3SS) is one of the important virulence factors utilized by E. amylovora in order to successfully infect its hosts. By using a green fluorescent protein (GFP) reporter construct combined with a high-throughput flow cytometry assay, a library of phenolic compounds and their derivatives was studied for their ability to alter the expression of the T3SS. Based on the effectiveness of the compounds on the expression of the T3SS pilus, the T3SS inhibitors 4-methoxy-cinnamic acid (TMCA) and benzoic acid (BA) and one T3SS inducer, trans-2-(4-hydroxyphenyl)-ethenylsulfonate (EHPES), were chosen for further study. Both the T3SS inhibitors (TMCA and BA) and the T3SS inducer (EHPES) were found to alter the expression of T3SS through the HrpS-HrpL pathway. Additionally, TMCA altered T3SS expression through the rsmBEa-RsmAEa system. Finally, we found that TMCA and BA weakened the hypersensitive response (HR) in tobacco by suppressing the T3SS of E. amylovora. In our study, we identified phenolic compounds that specifically targeted the T3SS. The T3SS inhibitor may offer an alternative approach to antimicrobial therapy by targeting virulence factors of bacterial pathogens.

  16. [Cardiovascular repercussion of lodenafil carbonate, a new PDE5 inhibitor, with and without alcohol consumption].

    Science.gov (United States)

    Silva, Adauto Carvalho; Toffoletto, Odaly; Lucio, Luiz Antonio Galvão; Santos, Paula Ferreira Dos; Afiune, Jorge Barros; Massud Filho, João; Tufik, Sergio

    2010-02-01

    Millions of men around the world suffer from erectile dysfunction, for which phosphodiesterase 5 inhibitors (PDE-5 inhibitors) are currently the first treatment option. Sexual activity and alcohol consumption are closely related, and the simultaneous use of alcohol and PDE-5 inhibitors can happen. Lodenafil carbonate is a new PDE-5 inhibitor, developed by a Brazilian pharmaceutical company. This work aimed at evaluating the cardiovascular safety of lodenafil carbonate, with and without simultaneous alcohol consumption. Fifteen male volunteers received 160 mg lodenafil carbonate (LC), in three different moments. Participants were assigned to three groups, treated with LC in fasting condition, with alcohol or receiving only placebo. The volunteers were continuously monitored during 24 hours for physical impairment, blood pressure, heart rate, QT interval and lodenafil's pharmacokinetic parameters. Lodenafil carbonate alone or with alcohol did not induce clinically relevant modifications in arterial blood pressure or heart rate. A statistically significant decrease in blood pressure was seen four hours after LC and alcohol intake, and an increase in heart rate six hours after intake of lodenafil carbonate alone. The QTc interval was not significantly modified. Lodenafil carbonate bioavailability was increased in 74% when drug intake was associated with alcohol. These results show that the use of lodenafil carbonate did not have clinically relevant effects on blood pressure or heart rate, and was not associated with QT interval prolongation. The association of lodenafil carbonate and alcohol affected its pharmacokinetic properties, increasing the bioavailability of the drug.

  17. Comparison of tamsulosin vs tamsulosin/sildenafil effectiveness in the treatment of erectile dysfunction in patients affected by type III chronic prostatitis.

    Science.gov (United States)

    Cantoro, Ubaldo; Catanzariti, Francesco; Lacetera, Vito; Quaresima, Luigi; Muzzonigro, Giovanni; Polito, Massimo

    2013-09-26

    We evaluated the effectiveness of tamsulosin monotherapy versus tamsulosin plus sildenafil combination therapy on erectile dysfunction (ED) in young patients with type III chronic prostatitis and ED by using symptom score scales. 44 male patients were divided into 2 groups: the first group (20 patients) was treated with tamsulosin 0,4 mg monotherapy and the second one 24 patients) was treated with tamsulosin 0,4 mg plus sildenafil 50 mg combination therapy. “International Prostate Symptom Score, “National Institute of Health Chronic Prostatitis Symptom Index" (NIH-CPSI) and “International Index of Erectile Function" (IIEF-5) were investigated in each group of patients, and scores calculated during the first medical examination. Both groups were treated with tamsulosin once daily for 60 days, while sildenafil 50 mg was given on demand (at least 2 times per week) for 60 days. During the second medical examination IPSS, NIH-CPSI and IIEF-5 scores were analyzed once more. Afterwards, the alterations of scores among medical examinations in each group and between both groups were statistically compared. The age average of the 44 cases included was 32.04 3.15 years. Both groups present a statistically significant decrease, between the first and the second medical examination, in IPSS, NIH-CPSI scores and statistically significant increase in IIEF-5 score. In addition, there is no statistically significant difference, in all scores, between mono and combination therapy. tamsulosin monotherapy, as well as a combination therapy (tamsulosin plus sildenafil) has an improving effect on symptoms and on ED in patients with type III prostatitis. In the near future alpha-blockers monotherapy could be used in the treatment of chronic prostatitis and ED cases instead of phosphodiesterase type 5 (PDE-5) inhibitors combination therapy.

  18. Partial reconstitution of photoreceptor cGMP phosphodiesterase characteristics in cGMP phosphodiesterase-5.

    Science.gov (United States)

    Granovsky, A E; Artemyev, N O

    2001-06-15

    Photoreceptor cGMP phosphodiesterases (PDE6) are uniquely qualified to serve as effector enzymes in the vertebrate visual transduction cascade. In the dark-adapted photoreceptors, the activity of PDE6 is blocked via tight association with the inhibitory gamma-subunits (Pgamma). The Pgamma block is removed in the light-activated PDE6 by the visual G protein, transducin. Transducin-activated PDE6 exhibits an exceptionally high catalytic rate of cGMP hydrolysis ensuring high signal amplification. To identify the structural determinants for the inhibitory interaction with Pgamma and the remarkable cGMP hydrolytic ability, we sought to reproduce the PDE6 characteristics by mutagenesis of PDE5, a related cyclic GMP-specific, cGMP-binding PDE. PDE5 is insensitive to Pgamma and has a more than 100-fold lower k(cat) for cGMP hydrolysis. Our mutational analysis of chimeric PDE5/PDE6alpha' enzymes revealed that the inhibitory interaction of cone PDE6 catalytic subunits (PDE6alpha') with Pgamma is mediated primarily by three hydrophobic residues at the entry to the catalytic pocket, Met(758), Phe(777), and Phe(781). The maximal catalytic rate of PDE5 was enhanced by at least 10-fold with substitutions of PDE6alpha'-specific glycine residues for the corresponding PDE5 alanine residues, Ala(608) and Ala(612). The Gly residues are adjacent to the highly conserved metal binding motif His-Asn-X-X-His, which is essential for cGMP hydrolysis. Our results suggest that the unique Gly residues allow the PDE6 metal binding site to adopt a more favorable conformation for cGMP hydrolysis.

  19. Insulin alters the target size of the peripheral cyclic AMP phosphodiesterase but not the integral cyclic GMP-stimulated cyclic AMP phosphodiesterase in liver plasma membranes

    International Nuclear Information System (INIS)

    Wallace, A.V.; Martin, B.R.; Houslay, M.D.

    1990-01-01

    Radiation inactivation of the two high affinity cyclic AMP phosphodiesterases (PDE) found in liver plasma membranes afforded an estimation of their molecular target sizes in situ. The activity of the peripheral plasma membrane PDE decayed as a single exponential with a target size corresponding to a monomer of circa 54 kDa. The integral, cyclic GMP-stimulated PDE decayed as a dimer of circa 125 kDa. Preincubation of plasma membranes with insulin (10nM), prior to irradiation, caused the target size of only the peripheral plasma membrane PDE to increase. We suggest that insulin addition causes the peripheral plasma membrane PDE to alter its coupling to an integral plasma membrane protein with a target size of circa 90 kDa

  20. Effects of sevoflurane on adenylate cyclase and phosphodiesterases activity in brain of rats

    International Nuclear Information System (INIS)

    Feng Changdong; Yang Jianping; Dai Tijun

    2009-01-01

    Objective: To investigate the effects of sevoflurane on c adenylate cyclase (AC) and phosphodiesterases (PDE) activity in the cerebrocortex, hippocampus and brain stem of rats, and to examine the role of cAMP in sevoflurane anesthesia. Methods: Fourty SD rats were delaminately designed and allocated randomly to 5 groups inhaling 1.5% sevoflurane i.e., no recovery (recovery group, n=8) and one hour after righting reflexrecovery (aware group, n=8). The brain tissues were rapidly dissected into cerebrocortex and hippocampus and brain stem.Then the adenylate cyclase and phosphodiesterases activity were assessed. Results: So far as the activity of AC is concerned, compared with the control group, the activity of AC in the cerebrocortex, hippocampus and brain stem brain stem of induction group and anesthesia group, the cerebrocortex, and hippocampus in the recovery group were significantly increased; compared with those in the anesthesia group, the activity of AC in the cerebrocortex, hippocampus and brain stem of aware group were significantly decreased (P<0.05); For the activity of PDE, compared with the control group, the activity of PDE in the cerebrocortex, hippocampus and brain stem in the induction group and anesthesia group was significantly decreased, compared with that in anesthesia group, the activity of PDE in the cerebrocortex, hippocampus and brain stem of recovery group and aware group was significantly increased (P<0.05). Conclusion: cAMP may play an important role in sevoflurane anesthesia. (authors)

  1. Genetic deletion and pharmacological inhibition of phosphodiesterase 10A protects mice from diet-induced obesity and insulin resistance.

    Science.gov (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

    2014-01-01

    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.

  2. JAK Inhibitors: Treatment Efficacy and Safety Profile in Patients with Psoriasis

    Directory of Open Access Journals (Sweden)

    Leeyen Hsu

    2014-01-01

    Full Text Available Janus kinase (JAK pathways are key mediators in the immunopathogenesis of psoriasis. Psoriasis treatment has evolved with the advent of targeted therapies, which inhibit specific components of the psoriasis proinflammatory cascade. JAK inhibitors have been studied in early phase trials for psoriasis patients, and the data are promising for these agents as potential treatment options. Tofacitinib, an oral or topically administered JAK1 and JAK3 inhibitor, and ruxolitinib, a topical JAK1 and JAK2 inhibitor, have been most extensively studied in psoriasis, and both improved clinical symptoms of psoriasis. Additional JAK1 or JAK3 inhibitors are being studied in clinical trials. In phase III trials for rheumatoid arthritis, tofacitinib was efficacious in patients with inadequate responses to tumor necrosis factor inhibitors, methotrexate monotherapy, or disease-modifying antirheumatic drugs. The results of phase III trials are pending for these therapies in psoriasis, and these agents may represent important alternatives for patients with inadequate responses to currently available agents. Further investigations with long-term clinical trials are necessary to verify their utility in psoriasis treatment and assess their safety in this patient population.

  3. Discovery of novel PDE9 inhibitors capable of inhibiting Aβ aggregation as potential candidates for the treatment of Alzheimer’s disease

    Science.gov (United States)

    Su, Tao; Zhang, Tianhua; Xie, Shishun; Yan, Jun; Wu, Yinuo; Li, Xingshu; Huang, Ling; Luo, Hai-Bin

    2016-02-01

    Recently, phosphodiesterase-9 (PDE9) inhibitors and biometal-chelators have received much attention as potential therapeutics for the treatment of Alzheimer’s disease (AD). Here, we designed, synthesized, and evaluated a novel series of PDE9 inhibitors with the ability to chelate metal ions. The bioassay results showed that most of these molecules strongly inhibited PDE9 activity. Compound 16 showed an IC50 of 34 nM against PDE9 and more than 55-fold selectivity against other PDEs. In addition, this compound displayed remarkable metal-chelating capacity and a considerable ability to halt copper redox cycling. Notably, in comparison to the reference compound clioquinol, it inhibited metal-induced Aβ1-42 aggregation more effectively and promoted greater disassembly of the highly structured Aβ fibrils generated through Cu2+-induced Aβ aggregation. These activities of 16, together with its favorable blood-brain barrier permeability, suggest that 16 may be a promising compound for treatment of AD.

  4. Pharmacotherapy of erectile dysfunction: Current standards

    Directory of Open Access Journals (Sweden)

    Kew-Kim Chew

    2006-01-01

    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.

  5. Purine analogs as phosphatidylinositol 4-kinase III beta inhibitors

    Czech Academy of Sciences Publication Activity Database

    Šála, Michal; Kögler, Martin; Plačková, Pavla; Mejdrová, Ivana; Hřebabecký, Hubert; Procházková, Eliška; Strunin, Dmytro; Lee, G.; Birkuš, G.; Weber, Jan; Mertlíková-Kaiserová, Helena; Nencka, Radim

    2016-01-01

    Roč. 26, č. 11 (2016), s. 2706-2712 ISSN 0960-894X R&D Projects: GA ČR GA15-09310S; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : phosphatidylinositol 4-kinase * purine * PI4K III beta * antiviral agent * hepatitis C virus Subject RIV: CC - Organic Chemistry Impact factor: 2.454, year: 2016

  6. Oligopeptidase B from Serratia proteamaculans. III. Inhibition analysis. Specific interactions with metalloproteinase inhibitors.

    Science.gov (United States)

    Mikhailova, A G; Khairullin, R F; Kolomijtseva, G Ya; Rumsh, L D

    2012-03-01

    Inhibition of the novel oligopeptidase B from Serratia proteamaculans (PSP) by basic pancreatic trypsin inhibitor, Zn2+ ions, and o- and m-phenanthroline was investigated. A pronounced effect of calcium ions on the interaction of PSP with inhibitors was demonstrated. Inversion voltamperometry and atomic absorption spectrometry revealed no zinc ions in the PSP molecule. Hydrophobic nature of the enzyme inhibition by o- and m-phenanthroline was established.

  7. The role of initial success rates and other factors in determining reliability of outcomes of phosphodiesterase inhibitor therapy for erectile dysfunction: a pooled analysis of 17 placebo-controlled trials of tadalafil for use as needed.

    Science.gov (United States)

    Sontag, Angelina; Rosen, Raymond C; Litman, Heather J; Ni, Xiao; Araujo, Andre B

    2013-02-01

    Reliability of successful outcomes in men with erectile dysfunction (ED) on phosphodiesterase type 5 inhibitors is an important aspect of patient management. We examined reliability of successful outcomes in a large integrated dataset of randomized tadalafil trials. Success rates, time to success, subsequent success after first success, and probability of success were analyzed based on Sexual Encounter Profile questions 2 and 3. Data from 3,254 ED patients treated with tadalafil 10 mg (N = 510), 20 mg (N = 1,772), or placebo (N = 972) were pooled from 17 placebo-controlled studies. Tadalafil patients had significantly higher first-attempt success rates vs. placebo. This effect was consistent across most subgroups; however, patients with severe ED experienced a greater response to tadalafil than patients with mild-moderate ED. Approximately 80% of patients achieved successful penile insertion within two attempts with either tadalafil dose and successful intercourse within eight attempts for tadalafil 10 mg and four attempts for tadalafil 20 mg. However, approximately 70% of tadalafil-treated patients achieved successful intercourse even by the second attempt. Subsequent success rates were higher for patients with first-attempt success (81.5% for 10 mg and 86.1% for 20 mg vs. 66.2% for placebo, P success (53.2% for 10 mg and 56.4% for 20 mg vs. 39.9% for placebo, P success rates at early attempts were similar to rates at later attempts (i.e., attempts 5 and 10 vs. 25), although insertion success rates were significantly lower earlier in treatment. The findings affirm the reliability of successful outcomes with tadalafil treatment and that first-attempt success is a critical factor affecting subsequent outcomes. The results further show that even among men who did not succeed on first attempt, a substantial proportion will have successful outcomes if treatment is maintained. © 2012 International Society for Sexual Medicine.

  8. Design, chemical synthesis and kinetic studies of trypsin chromogenic substrates based on the proteinase binding loop of Cucurbita maxima trypsin inhibitor (CMTI-III).

    Science.gov (United States)

    Lesner, A; Brzozowski, K; Kupryszewski, G; Rolka, K

    2000-03-05

    A series of trypsin chromogenic substrates with formula: Y-Ala-X-Abu-Pro-Lys-pNA, where X = Gly, Ala, Abu, Val, Leu, Phe, Ser, Glu and Y = Ac, H; pNA = p-nitroanilide was synthesized. The Cucurbita maxima trypsin inhibitor CMTI-III molecule was used as a vehicle to design the trypsin substrates. To evaluate the influence of position P(4) on the substrate-enzyme interaction, kinetic parameters of newly synthesized substrates with bovine beta-trypsin were determined. The increasing hydrophobicity of the amino acid residue (Gly, Ala, Abu, Val) introduced in position P(4) significantly enhanced the substrate specificity (k(cat)/K(m)) which was over 8 times higher for the last residue than that for the first one. The introduction of residues with more hydrophilic side chain (Glu, Ser) in this position reduced the value of this parameter. These results correspond well with those obtained using molecular dynamics of bovine beta-trypsin with monosubstituted CMTI-I analogues, indicating that in both trypsin substrate and inhibitor position 4 plays an important role in the interaction with the enzyme. Copyright 2000 Academic Press.

  9. Mutation of the cyclic di-GMP phosphodiesterase gene in Burkholderia lata SK875 attenuates virulence and enhances biofilm formation.

    Science.gov (United States)

    Jung, Hae-In; Kim, Yun-Jung; Lee, Yun-Jung; Lee, Hee-Soo; Lee, Jung-Kee; Kim, Soo-Ki

    2017-10-01

    Burkholderia sp. is a gram-negative bacterium that commonly exists in the environment, and can cause diseases in plants, animals, and humans. Here, a transposon mutant library of a Burkholderia lata isolate from a pig with swine respiratory disease in Korea was screened for strains showing attenuated virulence in Caenorhabditis elegans. One such mutant was obtained, and the Tn5 insertion junction was mapped to rpfR, a gene encoding a cyclic di-GMP phosphodiesterase that functions as a receptor. Mutation of rpfR caused a reduction in growth on CPG agar and swimming motility as well as a rough colony morphology on Congo red agar. TLC analysis showed reduced AHL secretion, which was in agreement with the results from plate-based and bioluminescence assays. The mutant strain produced significantly more biofilm detected by crystal violet staining than the parent strain. SEM of the mutant strain clearly showed that the overproduced biofilm contained a filamentous structure. These results suggest that the cyclic di-GMP phosphodiesterase RpfR plays an important role in quorum sensing modulation of the bacterial virulence and biofilm formation.

  10. JAK/STAT inhibitors and other small molecule cytokine antagonists for the treatment of allergic disease.

    Science.gov (United States)

    Howell, Michael D; Fitzsimons, Carolyn; Smith, Paul A

    2018-04-01

    To provide an overview of janus kinase (JAK), chemoattractant receptor homologous molecule expressed on T H 2 cells (CRTH2), and phosphodiesterase 4 (PDE4) inhibitors in allergic disorders. PubMed literature review. Articles included in this review discuss the emerging mechanism of action of small molecule inhibitors and their use in the treatment of atopic dermatitis (AD), asthma, and allergic rhinitis (AR). Allergic diseases represent a spectrum of diseases, including AD, asthma, and AR. For decades, these diseases have been primarily characterized by increased T H 2 signaling and downstream inflammation. In recent years, additional research has identified disease phenotypes and subsets of patients with non-Th2 mediated inflammation. The increasing heterogeneity of disease has prompted investigators to move away from wide-ranging treatment approaches with immunosuppressive agents, such as corticosteroids, to consider more targeted immunomodulatory approaches focused on specific pathways. In the past decade, inhibitors that target JAK signaling, PDE4, and CRTH2 have been explored for their potential activity in models of allergic disease and therapeutic benefit in clinical trials. Interestingly, although JAK inhibitors provide an opportunity to interfere with cytokine signaling and could be beneficial in a broad range of allergic diseases, current clinical trials are focused on the treatment of AD. Conversely, both PDE4 and CRTH2 inhibitors have been evaluated in a spectrum of allergic diseases. This review summarizes the varying degrees of success that these small molecules have demonstrated across allergic diseases. Emerging therapies currently in development may provide more consistent benefit to patients with allergic diseases by specifically targeting inflammatory pathways important for disease pathogenesis. Copyright © 2018 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  11. Specific binding of [3H]LY186126, an analogue of indolidan (LY195115), to cardiac membranes enriched in sarcoplasmic reticulum vesicles

    International Nuclear Information System (INIS)

    Kauffman, R.F.; Utterback, B.G.; Robertson, D.W.

    1989-01-01

    LY186126 was found to be a potent inhibitor of type IV cyclic AMP phosphodiesterase located in the sarcoplasmic reticulum of canine cardiac muscle. This compound, a close structural analogue of indolidan (LY195115), was prepared in high specific activity, tritiated form to study the positive inotropic receptor(s) for cardiotonic phosphodiesterase inhibitors such as indolidan and milrinone. A high-affinity binding site for [ 3 H]LY186126 was observed (Kd = 4 nM) in purified preparations of canine cardiac sarcoplasmic reticulum vesicles. Binding was proportional to vesicle protein, was inactivated by subjecting membranes to proteolysis or boiling, and was dependent on added Mg2+. Scatchard analysis suggested the presence of a single class of binding sites in the membrane preparation. Indolidan, milrinone, and LY186126 (all at 1 microM) produced essentially complete displacement of bound [ 3 H]LY186126, while nifedipine, propranolol, and prazosin had little or no effect at this concentration. This represents the first reported use of a radioactive analogue to label the inotropic receptor for cardiotonic phosphodiesterase inhibitors. The results suggest that [ 3 H]LY186126 is a useful radioligand for examining the subcellular site(s) responsible for positive inotropic effects of these drugs

  12. Phosphodiesterase 9A regulates central cGMP and modulates responses to cholinergic and monoaminergic perturbation in vivo.

    Science.gov (United States)

    Kleiman, Robin J; Chapin, Douglas S; Christoffersen, Curt; Freeman, Jody; Fonseca, Kari R; Geoghegan, Kieran F; Grimwood, Sarah; Guanowsky, Victor; Hajós, Mihály; Harms, John F; Helal, Christopher J; Hoffmann, William E; Kocan, Geralyn P; Majchrzak, Mark J; McGinnis, Dina; McLean, Stafford; Menniti, Frank S; Nelson, Fredrick; Roof, Robin; Schmidt, Anne W; Seymour, Patricia A; Stephenson, Diane T; Tingley, Francis David; Vanase-Frawley, Michelle; Verhoest, Patrick R; Schmidt, Christopher J

    2012-05-01

    Cyclic nucleotides are critical regulators of synaptic plasticity and participate in requisite signaling cascades implicated across multiple neurotransmitter systems. Phosphodiesterase 9A (PDE9A) is a high-affinity, cGMP-specific enzyme widely expressed in the rodent central nervous system. In the current study, we observed neuronal staining with antibodies raised against PDE9A protein in human cortex, cerebellum, and subiculum. We have also developed several potent, selective, and brain-penetrant PDE9A inhibitors and used them to probe the function of PDE9A in vivo. Administration of these compounds to animals led to dose-dependent accumulation of cGMP in brain tissue and cerebrospinal fluid, producing a range of biological effects that implied functional significance for PDE9A-regulated cGMP in dopaminergic, cholinergic, and serotonergic neurotransmission and were consistent with the widespread distribution of PDE9A. In vivo effects of PDE9A inhibition included reversal of the respective disruptions of working memory by ketamine, episodic and spatial memory by scopolamine, and auditory gating by amphetamine, as well as potentiation of risperidone-induced improvements in sensorimotor gating and reversal of the stereotypic scratching response to the hallucinogenic 5-hydroxytryptamine 2A agonist mescaline. The results suggested a role for PDE9A in the regulation of monoaminergic circuitry associated with sensory processing and memory. Thus, PDE9A activity regulates neuronal cGMP signaling downstream of multiple neurotransmitter systems, and inhibition of PDE9A may provide therapeutic benefits in psychiatric and neurodegenerative diseases promoted by the dysfunction of these diverse neurotransmitter systems.

  13. 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

    2015-01-01

    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......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 camptothecin family (CPT). TDP1 has in cell line based assays been shown to counteract the effect of CPT. We have quantified the enzymatic activities of TOP1 and TDP1 in paired (tumor and adjacent non-tumor) samples from non-small cell lung cancer (NSCLC) patients and show that in NSCLC TOP1 and TDP1...... activities are significantly upregulated in the tumor tissue. Furthermore, we found a positive correlation between the TDP1 activity and the tumor percentage (TOP1 activity did not correlate with the tumor percentage) as well as between the activities of TOP1 and TDP1 both within the tumor and the non...

  14. Catalytic enhancement of the heme-based oxygen-sensing phosphodiesterase EcDOS by hydrogen sulfide is caused by changes in heme coordination structure

    Czech Academy of Sciences Publication Activity Database

    Yang, F.; Fojtíková, V.; Man, Petr; Stráňava, M.; Martínková, M.; Du, Y.; Huang, D.; Shimizu, T.

    2015-01-01

    Roč. 28, č. 4 (2015), s. 637-652 ISSN 0966-0844 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 Keywords : Heme * O-2 sensor * Phosphodiesterase Subject RIV: CE - Biochemistry Impact factor: 2.134, year: 2015

  15. Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production

    Directory of Open Access Journals (Sweden)

    Shohei Sakuda

    2014-03-01

    Full Text Available Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control.

  16. Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production

    Science.gov (United States)

    Sakuda, Shohei; Prabowo, Diyan Febri; Takagi, Keiko; Shiomi, Kazuro; Mori, Mihoko; Ōmura, Satoshi; Nagasawa, Hiromichi

    2014-01-01

    Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A) inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III) and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control. PMID:24674936

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Osthol attenuates neutrophilic oxidative stress and hemorrhagic shock-induced lung injury via inhibition of phosphodiesterase 4.

    Science.gov (United States)

    Tsai, Yung-Fong; Yu, Huang-Ping; Chung, Pei-Jen; Leu, Yann-Lii; Kuo, Liang-Mou; Chen, Chun-Yu; Hwang, Tsong-Long

    2015-12-01

    Oxidative stress caused by neutrophils is an important pathogenic factor in trauma/hemorrhagic (T/H)-induced acute lung injury (ALI). Osthol, a natural coumarin found in traditional medicinal plants, has therapeutic potential in various diseases. However, the pharmacological effects of osthol in human neutrophils and its molecular mechanism of action remain elusive. In this study, our data showed that osthol potently inhibited the production of superoxide anion (O2(•-)) and reactive oxidants derived therefrom as well as expression of CD11b in N-formylmethionylleucylphenylalanine (FMLP)-activated human neutrophils. However, osthol inhibited neutrophil degranulation only slightly and it failed to inhibit the activity of subcellular NADPH oxidase. FMLP-induced phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) was inhibited by osthol. Notably, osthol increased the cAMP concentration and protein kinase A (PKA) activity in activated neutrophils. PKA inhibitors reversed the inhibitory effects of osthol, suggesting that these are mediated through cAMP/PKA-dependent inhibition of ERK and Akt activation. Furthermore, the activity of cAMP-specific phosphodiesterase (PDE) 4, but not PDE3 or PDE7, was significantly reduced by osthol. In addition, osthol reduced myeloperoxidase activity and pulmonary edema in rats subjected to T/H shock. In conclusion, our data suggest that osthol has effective anti-inflammatory activity in human neutrophils through the suppression of PDE4 and protects significantly against T/H shock-induced ALI in rats. Osthol may have potential for future clinical application as a novel adjunct therapy to treat lung inflammation caused by adverse circulatory conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Increase of Intracellular Cyclic AMP by PDE4 Inhibitors Affects HepG2 Cell Cycle Progression and Survival.

    Science.gov (United States)

    Massimi, Mara; Cardarelli, Silvia; Galli, Francesca; Giardi, Maria Federica; Ragusa, Federica; Panera, Nadia; Cinque, Benedetta; Cifone, Maria Grazia; Biagioni, Stefano; Giorgi, Mauro

    2017-06-01

    Type 4 cyclic nucleotide phosphodiesterases (PDE4) are major members of a superfamily of enzymes (PDE) involved in modulation of intracellular signaling mediated by cAMP. Broadly expressed in most human tissues and present in large amounts in the liver, PDEs have in the last decade been key therapeutic targets for several inflammatory diseases. Recently, a significant body of work has underscored their involvement in different kinds of cancer, but with no attention paid to liver cancer. The present study investigated the effects of two PDE4 inhibitors, rolipram and DC-TA-46, on the growth of human hepatoma HepG2 cells. Treatment with these inhibitors caused a marked increase of intracellular cAMP level and a dose- and time-dependent effect on cell growth. The concentrations of inhibitors that halved cell proliferation to about 50% were used for cell cycle experiments. Rolipram (10 μM) and DC-TA-46 (0.5 μM) produced a decrease of cyclin expression, in particular of cyclin A, as well as an increase in p21, p27 and p53, as evaluated by Western blot analysis. Changes in the intracellular localization of cyclin D1 were also observed after treatments. In addition, both inhibitors caused apoptosis, as demonstrated by an Annexin-V cytofluorimetric assay and analysis of caspase-3/7 activity. Results demonstrated that treatment with PDE4 inhibitors affected HepG2 cell cycle and survival, suggesting that they might be useful as potential adjuvant, chemotherapeutic or chemopreventive agents in hepatocellular carcinoma. J. Cell. Biochem. 118: 1401-1411, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. PDE 7 inhibitors: new potential drugs for the therapy of spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Irene Paterniti

    Full Text Available BACKGROUND: Primary traumatic mechanical injury to the spinal cord (SCI causes the death of a number of neurons that to date can neither be recovered nor regenerated. During the last years our group has been involved in the design, synthesis and evaluation of PDE7 inhibitors as new innovative drugs for several neurological disorders. Our working hypothesis is based on two different facts. Firstly, neuroinflammation is modulated by cAMP levels, thus the key role for phosphodiesterases (PDEs, which hydrolyze cAMP, is undoubtedly demonstrated. On the other hand, PDE7 is expressed simultaneously on leukocytes and on the brain, highlighting the potential crucial role of PDE7 as drug target for neuroinflammation. METHODOLOGY/PRINCIPAL FINDINGS: Here we present two chemically diverse families of PDE7 inhibitors, designed using computational techniques such as virtual screening and neuronal networks. We report their biological profile and their efficacy in an experimental SCI model induced by the application of vascular clips (force of 24 g to the dura via a four-level T5-T8 laminectomy. We have selected two candidates, namely S14 and VP1.15, as PDE7 inhibitors. These compounds increase cAMP production both in macrophage and neuronal cell lines. Regarding drug-like properties, compounds were able to cross the blood brain barrier using parallel artificial membranes (PAMPA methodology. SCI in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and production of a range of inflammatory mediators, tissue damage, and apoptosis. Treatment of the mice with S14 and VP1.15, two PDE7 inhibitors, significantly reduced the degree of spinal cord inflammation, tissue injury (histological score, and TNF-α, IL-6, COX-2 and iNOS expression. CONCLUSIONS/SIGNIFICANCE: All these data together led us to propose PDE7 inhibitors, and specifically S14 and VP1.15, as potential drug candidates to be further studied for the treatment of SCI.

  1. Does a single dose of the phosphodiesterase 4 inhibitor, cilomilast (15 mg), induce bronchodilation in patients with chronic obstructive pulmonary disease?

    NARCIS (Netherlands)

    Grootendorst, D. C.; Gauw, S. A.; Baan, R.; Kelly, J.; Murdoch, R. D.; Sterk, P. J.; Rabe, K. F.

    2003-01-01

    Maintenance treatment with PDE(4) inhibitor cilomilast improves FEV(1) in chronic obstructive pulmonary disease (COPD) patients. We investigated the acute bronchodilating effects of a single dose of cilomilast with or without concomitant administration of inhaled salbutamol and/or ipratropium

  2. Sequential treatment of tyrosine kinase inhibitors and chemotherapy for EGFR-mutated non-small cell lung cancer: a meta-analysis of Phase III trials

    Directory of Open Access Journals (Sweden)

    Zhang Y

    2013-11-01

    Full Text Available Yiliang Zhang,1,* Yihua Sun,1,* Lei Wang,1 Ting Ye,1 Yunjian Pan,1 Haichuan Hu,1 Yongfu Yu,2 Naiqing Zhao,2 Yanyan Song,3 David Garfield,4 Haiquan Chen1 1Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, 2Department of Biostatistics, School of Public Health, Fudan University, 3Department of Pharmacology and Biostatistics, Institute of Medical Science, Shanghai Jiaotong University School of Medicine, 4ProMed Cancer Centers, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: This aim of this study was to compare the efficacy of first-line tyrosine kinase inhibitor therapy followed, upon progression, by chemotherapy with the reverse sequence in patients with EGFR-mutated non-small cell lung cancer (NSCLC in terms of overall survival. Methods: We performed a meta-analysis of studies that met the following criteria: Phase III clinical trial comparing the sequencing of epidermal growth factor receptor (EGFR tyrosine kinase inhibitors with chemotherapy in the treatment of advanced EGFR-mutated NSCLC; activating mutations reported; and availability of hazard ratio estimates with 95% confidence intervals (CIs for overall survival. Results: Six clinical trials were included in this study. The pooled hazard ratio for overall survival of the EGFR-mutated population that completed sequential treatment was 1.03 (95% CI 0.86–1.22, P=0.776. There was no statistically significant heterogeneity between the studies (tau2 =0; I2=0, 95% CI 0–0.37, P=0.548. Evidence of marked publication bias for the two treatment sequences was insufficient (P=0.145. Conclusion: In patients with advanced NSCLC and activating EGFR mutations, first-line chemotherapy followed upon progression by a tyrosine kinase inhibitor was not inferior in terms of overall survival compared with the inverse sequence. This may serve as an indication that

  3. Cyclic AMP-specific phosphodiesterase, PDE8A1, is activated by protein kinase A-mediated phosphorylation

    OpenAIRE

    Brown, Kim M.; Lee, Louisa C.Y; Findlay, Jane E.; Day, Jonathan P.; Baillie, George S.

    2012-01-01

    The cyclic AMP-specific phosphodiesterase PDE8 has been shown to play a pivotal role in important processes such as steroidogenesis, T cell adhesion, regulation of heart beat and chemotaxis. However, no information exists on how the activity of this enzyme is regulated. We show that under elevated cAMP conditions, PKA acts to phosphorylate PDE8A on serine 359 and this action serves to enhance the activity of the enzyme. This is the first indication that PDE8 activity can be modulated by a kin...

  4. Phosphodiesterase profile of human B lymphocytes from normal and atopic donors and the effects of PDE inhibition on B cell proliferation

    Science.gov (United States)

    Gantner, Florian; Götz, Christine; Gekeler, Volker; Schudt, Christian; Wendel, Albrecht; Hatzelmann, Armin

    1998-01-01

    CD19+ B lymphocytes were purified from the peripheral blood of normal and atopic subjects to analyse and compare the phosphodiesterase (PDE) activity profile, PDE mRNA expression and the importance of PDE activity for the regulation of B cell function.The majority of cyclic AMP hydrolyzing activity of human B cells was cytosolic PDE4, followed by cytosolic PDE7-like activity; marginal PDE3 activity was found only in the particulate B cell fraction. PDE1, PDE2 and PDE5 activities were not detected.By cDNA-PCR analysis mRNA of the PDE4 subtypes A, B (splice variant PDE4B2) and D were detected. In addition, a weak signal for PDE3A was found.No differences in PDE activities or mRNA expression of PDE subtypes were found in B cells from either normal or atopic subjects.Stimulation of B lymphocytes with the polyclonal stimulus lipopolysaccharide (LPS) induced a proliferative response in a time- and concentration-dependent manner, which was increased in the presence of interleukin-4 (IL-4). PDE4 inhibitors (rolipram, piclamilast) led to an increase in the cellular cyclic AMP concentration and to an augmentation of proliferation, whereas a PDE3 inhibitor (motapizone) was ineffective, which is in accordance with the PDE profile found. The proliferation enhancing effect of the PDE4 inhibitors was partly mimicked by the cyclic AMP analogues dibutyryl (db) cyclic AMP and 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole-3′,5′-cyclic monophosphorothioate, Sp-isomer (dcl-cBIMPS), respectively. However, at concentrations exceeding 100 μM db-cyclic AMP suppressed B lymphocyte proliferation, probably as a result of cytotoxicity. Prostaglandin E2 (PGE2, 1 μM) and forskolin (10 μM) did not affect B cell proliferation, even when given in combination with rolipram.Inhibition of protein kinase A (PKA) by differentially acting selective inhibitors (KT 5720, Rp-8-Br-cyclic AMPS) decreased the proliferative response of control cells and reversed the proliferation enhancing effects

  5. Off-Label Use of Phosphodiesterase Type 5 Inhibitor Erectile Dysfunction Medication to Enhance Sex Among Gay and Bisexual Men in Australia: Results From the FLUX Study.

    Science.gov (United States)

    Hammoud, Mohamed A; Jin, Fengyi; Lea, Toby; Maher, Lisa; Grierson, Jeffrey; Prestage, Garrett

    2017-06-01

    be representative of all GBMs in Australia. GBMs who used an oral EDM in the previous 6 months often used it for recreational purposes, but many of those who used it on a weekly basis also might have used it for therapeutic reasons. GBMs often use EDMs to enhance their sexual experiences often in the context of intensive sex partying (which can include risky sexual behavior). Hammoud MA, Jin F, Lea T, et al. Off-Label Use of Phosphodiesterase Type 5 Inhibitor Erectile Dysfunction Medication to Enhance Sex Among Gay and Bisexual Men in Australia: Results From the FLUX Study. J Sex Med 2017;14:774-784. Copyright © 2017 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  6. PDE5 inhibitors blunt inflammation in human BPH: a potential mechanism of action for PDE5 inhibitors in LUTS.

    Science.gov (United States)

    Vignozzi, Linda; Gacci, Mauro; Cellai, Ilaria; Morelli, Annamaria; Maneschi, Elena; Comeglio, Paolo; Santi, Raffaella; Filippi, Sandra; Sebastianelli, Arcangelo; Nesi, Gabriella; Serni, Sergio; Carini, Marco; Maggi, Mario

    2013-09-01

    Metabolic syndrome (MetS) and benign prostate hyperplasia (BPH)/low urinary tract symptoms (LUTS) are often comorbid. Chronic inflammation is one of the putative links between these diseases. Phosphodiesterase type 5 inhibitors (PDE5i) are recognized as an effective treatment of BPH-related LUTS. One proposed mechanism of action of PDE5 is the inhibition of intraprostatic inflammation. In this study we investigate whether PDE5i could blunt inflammation in the human prostate. Evaluation of the effect of tadalafil and vardenafil on secretion of interleukin 8 (IL-8, a surrogate marker of prostate inflammation) by human myofibroblast prostatic cells (hBPH) exposed to different inflammatory stimuli. We preliminary evaluate histological features of prostatic inflammatory infiltrates in BPH patients enrolled in a randomized, double bind, placebo controlled study aimed at investigating the efficacy of vardenafil (10 mg/day, for 12 weeks) on BPH/LUTS. In vitro treatment with tadalafil or vardenafil on hBPH reduced IL-8 secretion induced by either TNFα or metabolic factors, including oxidized low-density lipoprotein, oxLDL, to the same extent as a PDE5-insensitive PKG agonist Sp-8-Br-PET-cGMP. These effects were reverted by the PKG inhibitor KT5823, suggesting a cGMP/PKG-dependency. Treatment with tadalafil or vardenafil significantly suppressed oxLDL receptor (LOX-1) expression. Histological evaluation of anti-CD45 staining (CD45 score) in prostatectomy specimens of BPH patients showed a positive association with MetS severity. Reduced HDL-cholesterol and elevated triglycerides were the only MetS factors significantly associated with CD45 score. In the MetS cohort there was a significant lower CD45 score in the vardenafil-arm versus the placebo-one. © 2013 Wiley Periodicals, Inc.

  7. Interaction of divalent metal ions with Zn(2+)-glycerophosphocholine cholinephosphodiesterase from ox brain.

    Science.gov (United States)

    Lee, K J; Kim, M R; Kim, Y B; Myung, P K; Sok, D E

    1997-12-01

    The effect of divalent metal ions on the activity of glycerophosphocholine cholinephosphodiesterse from ox brain was examined. Zn(2+)- and Co(2+)-glycerophosphocholine cholinephosphodiesterases were prepared from the exposure of apoenzyme to Zn2+ and Co2+, respectively, and the properties of two metallo-phosphodiesterases were compared to those of native phosphodiesterase. Although two metallo-enzymes were similar in expressing Km value, optimum pH or sensitivity to Cu2+, they differed in the susceptibility to the inhibition by thiocholine or tellurite; while Co(2+)-phosphodiesterase was more sensitive to tellurites, Zn(2+)-phosphodiesterase was more susceptible to inhibition by thiocholine. In addition, Zn(2+)-phosphodiesterase was more thermo-stable than Co2+ enzyme. Separately, when properties of native phosphodiesterase were compared to those of each metallo-phosphodiesterase, native phosphodiesterase was found to be quite similar to Zn(2+)-phosphodiesterase in many respects. Even in thermo-stability, native enzyme resembled Zn(2+)-phosphodiesterase rather than Co(2+)-enzyme. Consistent with this, the stability of native phosphodiesterase was maintained in the presence of Zn2+, but not Co2+, Mn2+ was also as effective as Zn2+ in the stabilization of the enzyme. Noteworthy, the native enzyme was found to be inhibited competitively by Cu2+ with a Ki value of 20 microM, and its inhibitory action was antagonized effectively by Zn2+ or Co2+. Also, choline, another competitive inhibitor of the enzyme, appeared to antagonize the inhibitory action of Cu2+. Taken together, it is suggested that there may be multiple binding sites for divalent metal ions in the molecule of glycerophosphocholine cholinephosphodiesterase.

  8. The pharmacological management of erectile dysfunction – Update ...

    African Journals Online (AJOL)

    Erectile dysfunction (ED) is a trivial condition with a prevailing incidence worldwide. Phosphodiesterase-5 inhibitors (PDE-5) have revolutionised the treatment of ED and are regarded as one of the most successful drug groups in modern medicine. Generally PDE-5 inhibitors are well tolerated and the incidence of ...

  9. Discovery of a novel orally active PDE-4 inhibitor effective in an ovalbumin-induced asthma murine model.

    Science.gov (United States)

    Kwak, Hyun Jeong; Nam, Ji Yeon; Song, Jin Sook; No, Zaesung; Yang, Sung Don; Cheon, Hyae Gyeong

    2012-06-15

    Phosphodiesterase-4 (PDE-4) is responsible for metabolizing adenosine 3',5'-cyclic monophosphate that reduces the activation of a wide range of inflammatory cells including eosinophils. PDE-4 inhibitors are under development for the treatment of respiratory diseases such as asthma and chronic obstructive pulmonary disease. Herein, we report a novel PDE-4 inhibitor, PDE-423 (3-[1-(3-cyclopropylmethoxy-4-difluoromethoxybenzyl)-1H-pyrazol-3-yl]-benzoic acid), which shows good in vitro and in vivo oral activities. PDE-423 exhibited in vitro IC(50)s of 140 nM and 550 nM in enzyme assay and cell-based assay, respectively. In vivo study using ovalbumin-induced asthmatic mice revealed that PDE-423 reduced methacholine-stimulated airway hyperreactivity in a dose-dependent manner by once daily oral administration (ED(50)=18.3 mg/kg), in parallel with decreased eosinophil peroxidase activity and improved lung histology. In addition, PDE-423 was effective in diminishing lipopolysaccharide-induced neutrophilia in vivo as well as in vitro. Oral administration of PDE-423 (100 mg/kg) had no effect on the duration of xylazine/ketamine-induced anesthesia and did not induce vomiting incidence in ferrets up to the dose of 1000 mg/kg. The present study indicates that a novel PDE-4 inhibitor, PDE-423, has good pharmacological profiles implicating this as a potential candidate for the development of a new anti-asthmatic drug. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Carmela Giampà

    2010-10-01

    Full Text Available 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.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.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 be a primary driver of these secondary pathological events. More

  11. Specific binding of (/sup 3/H)LY186126, an analogue of indolidan (LY195115), to cardiac membranes enriched in sarcoplasmic reticulum vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Kauffman, R.F.; Utterback, B.G.; Robertson, D.W.

    1989-05-01

    LY186126 was found to be a potent inhibitor of type IV cyclic AMP phosphodiesterase located in the sarcoplasmic reticulum of canine cardiac muscle. This compound, a close structural analogue of indolidan (LY195115), was prepared in high specific activity, tritiated form to study the positive inotropic receptor(s) for cardiotonic phosphodiesterase inhibitors such as indolidan and milrinone. A high-affinity binding site for (/sup 3/H)LY186126 was observed (Kd = 4 nM) in purified preparations of canine cardiac sarcoplasmic reticulum vesicles. Binding was proportional to vesicle protein, was inactivated by subjecting membranes to proteolysis or boiling, and was dependent on added Mg2+. Scatchard analysis suggested the presence of a single class of binding sites in the membrane preparation. Indolidan, milrinone, and LY186126 (all at 1 microM) produced essentially complete displacement of bound (/sup 3/H)LY186126, while nifedipine, propranolol, and prazosin had little or no effect at this concentration. This represents the first reported use of a radioactive analogue to label the inotropic receptor for cardiotonic phosphodiesterase inhibitors. The results suggest that (/sup 3/H)LY186126 is a useful radioligand for examining the subcellular site(s) responsible for positive inotropic effects of these drugs.

  12. Insights into the molecular evolution of peptidase inhibitors in arthropods.

    Science.gov (United States)

    Alonso, Joaquin; Martinez, Manuel

    2017-01-01

    Peptidase inhibitors are key proteins involved in the control of peptidases. In arthropods, peptidase inhibitors modulate the activity of peptidases involved in endogenous physiological processes and peptidases of the organisms with which they interact. Exploring available arthropod genomic sequences is a powerful way to obtain the repertoire of peptidase inhibitors in every arthropod species and to understand the evolutionary mechanisms involved in the diversification of this kind of proteins. A genomic comparative analysis of peptidase inhibitors in species belonging to different arthropod taxonomic groups was performed. The results point out: i) species or clade-specific presence is shown for several families of peptidase inhibitors; ii) multidomain peptidase inhibitors are commonly found in many peptidase inhibitor families; iii) several families have a wide range of members in different arthropod species; iv) several peptidase inhibitor families show species-specific (or clade-specific) gene family expansions; v) functional divergence may be assumed for particular clades; vi) passive expansions may be used by natural selection to fix adaptations. In conclusion, conservation and divergence of duplicated genes and the potential recruitment as peptidase inhibitors of proteins from other families are the main mechanisms used by arthropods to fix diversity. This diversity would be associated to the control of target peptidases and, as consequence, to adapt to specific environments.

  13. Potential role for epidermal growth factor receptor inhibitors in combined-modality therapy for non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Kim, Dong Wook; Choy, Hak

    2004-01-01

    There has been a surge of interest in the translation of discoveries in molecular biology into clinically relevant therapies in the field of hematology/oncology. The epidermal growth factor receptor (EGFR) has been a molecular target of significant interest and investigation, and preclinical and clinical studies support a role for targeted therapy in a variety of cancers, including non-small-cell lung cancer (NSCLC) via compounds that specifically inhibit EGFR. ZD1839, IMC-C225, and OSI-774 are the most clinically developed of these compounds. Interestingly, preclinical studies have demonstrated that EGFR inhibitors may have radiation-sensitizing properties, as well as increased cytotoxic activity in combination with chemotherapeutic agents, suggesting a potential role for EGFR inhibitors as an adjunct to the current combined-modality approach for therapy of Stage III NSCLC. Therefore, clinical trials have been proposed and initiated to address the issue of determining the impact of the addition of EGFR inhibitors to the standard combined-modality regimen (chemotherapy/radiation therapy ± surgery) for Stage III NSCLC. This article reviews preclinical and clinical data supporting the role for EGFR inhibitors alone or in combination with chemotherapy/radiation therapy for locally advanced NSCLC. Also, it will provide an overview of ongoing and proposed clinical studies investigating the potential role for EGFR inhibitors in Stage III NSCLC

  14. mTOR inhibitors alone and in combination with JAK2 inhibitors effectively inhibit cells of myeloproliferative neoplasms.

    Directory of Open Access Journals (Sweden)

    Costanza Bogani

    Full Text Available BACKGROUND: Dysregulated signaling of the JAK/STAT pathway is a common feature of chronic myeloproliferative neoplasms (MPN, usually associated with JAK2V617F mutation. Recent clinical trials with JAK2 inhibitors showed significant improvements in splenomegaly and constitutional symptoms in patients with myelofibrosis but meaningful molecular responses were not documented. Accordingly, there remains a need for exploring new treatment strategies of MPN. A potential additional target for treatment is represented by the PI3K/AKT/mammalian target of rapamycin (mTOR pathway that has been found constitutively activated in MPN cells; proof-of-evidence of efficacy of the mTOR inhibitor RAD001 has been obtained recently in a Phase I/II trial in patients with myelofibrosis. The aim of the study was to characterize the effects in vitro of mTOR inhibitors, used alone and in combination with JAK2 inhibitors, against MPN cells. FINDINGS: Mouse and human JAK2V617F mutated cell lines and primary hematopoietic progenitors from MPN patients were challenged with an allosteric (RAD001 and an ATP-competitive (PP242 mTOR inhibitor and two JAK2 inhibitors (AZD1480 and ruxolitinib. mTOR inhibitors effectively reduced proliferation and colony formation of cell lines through a slowed cell division mediated by changes in cell cycle transition to the S-phase. mTOR inhibitors also impaired the proliferation and prevented colony formation from MPN hematopoietic progenitors at doses significantly lower than healthy controls. JAK2 inhibitors produced similar antiproliferative effects in MPN cell lines and primary cells but were more potent inducers of apoptosis, as also supported by differential effects on cyclinD1, PIM1 and BcLxL expression levels. Co-treatment of mTOR inhibitor with JAK2 inhibitor resulted in synergistic activity against the proliferation of JAK2V617F mutated cell lines and significantly reduced erythropoietin-independent colony growth in patients with

  15. Radiosynthesis and in vivo evaluation of [{sup 11}C]MP-10 as a positron emission tomography radioligand for phosphodiesterase 10A

    Energy Technology Data Exchange (ETDEWEB)

    Plisson, Christophe, E-mail: Christophe.2.plisson@gsk.com [GlaxoSmithKline, Clinical Imaging Centre Hammersmith Hospital, London, W12 0NN (United Kingdom); Salinas, Cristian [GlaxoSmithKline, Clinical Imaging Centre Hammersmith Hospital, London, W12 0NN (United Kingdom); Weinzimmer, David; Labaree, David; Lin, Shu-Fei; Ding, Yu-Shin [Yale University PET Center, Yale University School of Medicine, PO Box 208048 New Haven, CT (United States); Jakobsen, Steen [Aarhus PET Centre, Aarhus Sygehus, Norrebrogade 44, DK-8000 Aarhus C (Denmark); Smith, Paul W. [GlaxoSmithKline, Clinical Imaging Centre Hammersmith Hospital, London, W12 0NN (United Kingdom); Eiji, Kawanishi [Medicinal Chemistry Research Laboratories II, Research Division, Mitsubishi Tanabe Pharma Corporation, Saitama 335-8505 (Japan); Carson, Richard E. [Yale University PET Center, Yale University School of Medicine, PO Box 208048 New Haven, CT (United States); Gunn, Roger N.; Rabiner, Eugenii A. [GlaxoSmithKline, Clinical Imaging Centre Hammersmith Hospital, London, W12 0NN (United Kingdom)

    2011-08-15

    Introduction: The aim of this study was to evaluate a newly reported positron emission tomography (PET) radioligand [{sup 11}C]MP-10, a potent and selective inhibitor of the central phosphodiesterase 10A enzyme (PDE10A) in vivo, using PET. Methods: A procedure was developed for labeling MP-10 with carbon-11. [{sup 11}C]MP-10 was evaluated in vivo both in the pig and baboon brain. Results: Alkylation of the corresponding desmethyl compound with [{sup 11}C]methyl iodide produced [{sup 11}C]MP-10 with good radiochemical yield and specific activity. PET studies in the pig showed that [{sup 11}C]MP-10 rapidly entered the brain reaching peak tissue concentration at 1-2 min postadministration, followed by washout from the tissue. Administration of a selective PDE10A inhibitor reduced the binding in all brain regions to the levels of the cerebellum, demonstrating the saturability and selectivity of [{sup 11}C]MP-10 binding. In the nonhuman primate, the brain tissue kinetics of [{sup 11}C]MP-10 were slower, reaching peak tissue concentrations at 30-60 min postadministration. In both species, the observed rank order of regional brain signal was striatum>diencephalon>cortical regions=cerebellum, consistent with the known distribution and concentration of PDE10A. [{sup 11}C]MP-10 brain kinetics were well described by a two-tissue compartment model, and estimates of total volume of distribution (V{sub T}) were obtained. Blocking studies with unlabeled MP-10 revealed the suitability of the cerebellum as a reference tissue and enabled the estimation of regional binding potential (BP{sub ND}) as the outcome measure of specific binding. Quantification of [{sup 11}C]MP-10 binding using the simplified reference tissue model with cerebellar input function produced BP{sub ND} estimates consistent with those obtained by the two-tissue compartment model. Conclusion: We demonstrated that [{sup 11}C]MP-10 possesses good characteristics for the in vivo quantification of the PDE10A in the

  16. Sexual function in hypertensive patients receiving treatment

    Directory of Open Access Journals (Sweden)

    Thorsten Reffelmann

    2006-12-01

    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

  17. Novel environment friendly corrosion inhibitor pigments based on naturally occurring clay minerals

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, S.; McMurray, H.N.; Worsley, D.A. [University of Wales, Swansea (United Kingdom). Dept. of Materials Engineering; Powell, S.M. [University of Wales, Swansea (United Kingdom). Engineering Doktorate Centre

    2001-12-01

    Novel, ceramic, corrosion inhibitor pigments consisting of cerium (III) and calcium (II) cation exchanged bentonites have been shown to provide effective cut-edge corrosion resistance in organic coated galvanised steel. The bentonite pigments were prepared from a naturally occurring (Wyoming) bentonite with a cation-exchange-capacity of 0.7 milli-equivalents per gram. Cation exchange was carried out by repeated washing with aqueous solutions of cerium (III) chloride and calcium (II) chloride to produce bentonites containing 31500 ppm exchangeable cerium (III) and 13500 ppm exchangeable calcium (II) respectively. The resulting bentonite pigments were dispersed in a polyester-resin based primer paint system to give a pigment volume concentration of 19%. For comparison, two similar primer systems were prepared containing a commercial calcium (II) exchanged silica pigment Shieldex: 60 000 ppm calcium (II) and a strontium chromate dispersion, both with a 19% pigment volume concentration. All three primer systems were applied (5 {mu}m) to the zinc surface of galvanised 0.7 mm gauge sheet steel and overcoated with an architectural polyester topcoat (18 {mu}m). The performance of the inhibitor pigments was compared by measuring the rate of corrosion-driven organic coating delamination from the cut edge of samples during 1000 h of salt-spray testing. The calcium (II) bentonite pigment exhibited an anti-delamination performance similar to that of strontium chromate but superior to that of Shieldex. However, the cerium (III) bentonite pigment was superior in performance to both strontium chromate and Shieldex. Thus, the bentonite pigments represent promising, environmentally friendly, ion-exchange corrosion inhibitors which exhibit good anti-delamination performance by comparison with current commercial systems. (orig.)

  18. Analysis of proton wires in the enzyme active site suggests a mechanism of c-di-GMP hydrolysis by the EAL domain phosphodiesterases.

    Science.gov (United States)

    Grigorenko, Bella L; Knyazeva, Marina A; Nemukhin, Alexander V

    2016-11-01

    We report for the first time a hydrolysis mechanism of the cyclic dimeric guanosine monophosphate (c-di-GMP) by the EAL domain phosphodiesterases as revealed by molecular simulations. A model system for the enzyme-substrate complex was prepared on the base of the crystal structure of the EAL domain from the BlrP1 protein complexed with c-di-GMP. The nucleophilic hydroxide generated from the bridging water molecule appeared in a favorable position for attack on the phosphorus atom of c-di-GMP. The most difficult task was to find a pathway for a proton transfer to the O3' atom of c-di-GMP to promote the O3'P bond cleavage. We show that the hydrogen bond network extended over the chain of water molecules in the enzyme active site and the Glu359 and Asp303 side chains provides the relevant proton wires. The suggested mechanism is consistent with the structural, mutagenesis, and kinetic experimental studies on the EAL domain phosphodiesterases. Proteins 2016; 84:1670-1680. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Women taking the "blue pill" (sildenafil citrate): such a big deal?

    Science.gov (United States)

    Lo Monte, Giuseppe; Graziano, Angela; Piva, Isabella; Marci, Roberto

    2014-01-01

    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.

  20. Women taking the “blue pill” (sildenafil citrate): such a big deal?

    Science.gov (United States)

    Lo Monte, Giuseppe; Graziano, Angela; Piva, Isabella; Marci, Roberto

    2014-01-01

    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. PMID:25422584

  1. Methylated trivalent arsenicals are potent inhibitors of glucose stimulated insulin secretion by murine pancreatic islets

    International Nuclear Information System (INIS)

    Douillet, Christelle; Currier, Jenna; Saunders, Jesse; Bodnar, Wanda M.; Matoušek, Tomáš; Stýblo, Miroslav

    2013-01-01

    Epidemiologic evidence has linked chronic exposure to inorganic arsenic (iAs) with an increased prevalence of diabetes mellitus. Laboratory studies have identified several mechanisms by which iAs can impair glucose homeostasis. We have previously shown that micromolar concentrations of arsenite (iAs III ) or its methylated trivalent metabolites, methylarsonite (MAs III ) and dimethylarsinite (DMAs III ), inhibit the insulin-activated signal transduction pathway, resulting in insulin resistance in adipocytes. Our present study examined effects of the trivalent arsenicals on insulin secretion by intact pancreatic islets isolated from C57BL/6 mice. We found that 48-hour exposures to low subtoxic concentrations of iAs III , MAs III or DMAs III inhibited glucose-stimulated insulin secretion (GSIS), but not basal insulin secretion. MAs III and DMAs III were more potent than iAs III as GSIS inhibitors with estimated IC 50 ≤ 0.1 μM. The exposures had little or no effects on insulin content of the islets or on insulin expression, suggesting that trivalent arsenicals interfere with mechanisms regulating packaging of the insulin transport vesicles or with translocation of these vesicles to the plasma membrane. Notably, the inhibition of GSIS by iAs III , MAs III or DMAs III could be reversed by a 24-hour incubation of the islets in arsenic-free medium. These results suggest that the insulin producing pancreatic β-cells are among the targets for iAs exposure and that the inhibition of GSIS by low concentrations of the methylated metabolites of iAs may be the key mechanism of iAs-induced diabetes. - Highlights: ► Trivalent arsenicals inhibit glucose stimulated insulin secretion by pancreatic islets. ► MAs III and DMAs III are more potent inhibitors than arsenite with IC 50 ∼ 0.1 μM. ► The arsenicals have little or no effects on insulin expression in pancreatic islets. ► The inhibition of insulin secretion by arsenite, MAs III or DMAs III is reversible. ► Thus

  2. Adenoviral short hairpin RNA therapy targeting phosphodiesterase 5a relieves cardiac remodeling and dysfunction following myocardial infarction

    Science.gov (United States)

    Li, Longhu; Haider, Husnain Kh.; Wang, Linlin; Lu, Gang

    2012-01-01

    We previously showed that treatment with tadalafil, a long-acting phosphodiesterase-5a (PDE5a) inhibitor, effectively prevented adverse left ventricular (LV) remodeling of the infarcted heart. We hypothesized that short-hairpin RNA (shRNA) therapy targeting PDE5a would simulate the effects of pharmacological intervention for treatment of postinfarction LV remodeling and dysfunction. Experimental model of myocardial infarction was developed in female mice by permanent ligation of left coronary artery. Immediately after that, an adenoviral vector encoding for shRNA sequence targeting PDE5a (Ad-shPDE5a) was injected intramyocardially, which specifically inhibited PDE5a in the heart. Four weeks later, Ad-shPDE5a treated mice showed significant mitigation of the left ventricle (LV) dilatation and dysfunction as indicated by smaller LV cavity and more preserved ejection fraction and fractional shortening. Infarction size and fibrosis were significantly reduced in Ad-shPDE5a-treated mice. Additionally, more salvaged cardiomyocytes, significantly reduced collagen contents, and higher blood vessel density were observed in Ad-shPDE5a-treated mice. The cytoprotective effects of Ad-shPDE5a were demonstrated in vitro in Ad-shPDE5a transfected cardiomyocytes cultured under oxygen glucose deprivation. Among downstream mediators of PDE5a signaling, cyclic GMP (cGMP) and cGMP-dependent protein kinase G (PKG) were activated with concomitant reduction in caspase-3 activity. However, no significant change in PKA and cAMP activities were observed in Ad-shPDE5a-treated hearts. Inhibition with shRNA improved cardiac remodeling and dysfunction by reducing infarction size and cardiac fibrosis and increased cGMP and PKG activity. These findings suggest that PDE5 inhibition with Ad-shPDE5a is a novel approach for treatment of myocardial infarction. PMID:22447941

  3. Selective Sensing of Tyrosine Phosphorylation in Peptides Using Terbium(III Complexes

    Directory of Open Access Journals (Sweden)

    Jun Sumaoka

    2016-01-01

    Full Text Available Phosphorylation of tyrosine residues in proteins, as well as their dephosphorylation, is closely related to various diseases. However, this phosphorylation is usually accompanied by more abundant phosphorylation of serine and threonine residues in the proteins and covers only 0.05% of the total phosphorylation. Accordingly, highly selective detection of phosphorylated tyrosine in proteins is an urgent subject. In this review, recent developments in this field are described. Monomeric and binuclear TbIII complexes, which emit notable luminescence only in the presence of phosphotyrosine (pTyr, have been developed. There, the benzene ring of pTyr functions as an antenna and transfers its photoexcitation energy to the TbIII ion as the emission center. Even in the coexistence of phosphoserine (pSer and phosphothreonine (pThr, pTyr can be efficintly detected with high selectivity. Simply by adding these TbIII complexes to the solutions, phosphorylation of tyrosine in peptides by protein tyrosine kinases and dephosphorylation by protein tyrosine phosphatases can be successfully visualized in a real-time fashion. Furthermore, the activities of various inhibitors on these enzymes are quantitatively evaluated, indicating a strong potential of the method for efficient screening of eminent inhibitors from a number of candidates.

  4. Dgroup: DG01062 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ceptor antagonist, Phosphodiesterase (PDE) inhibitor, Xanthine cardiodiuretics; X...anthine bronchodilator; Cardiac diuretics ADORA1 [HSA:134] [KO:K04265] ADORA2A [HSA:135] [KO:K04266] PDE [HS

  5. Heart Failure Treated with Low-dose Milrinone in a Full-term Newborn

    Directory of Open Access Journals (Sweden)

    S. Šebková

    2012-01-01

    Full Text Available A term newborn with a hypocontractile myocardium complicating persistent pulmonary hypertension of the newborn was successfully treated with a low-dose phosphodiesterase III inhibitor milrinone. Echocardiography diagnosed heart failure with a left ventricular ejection fraction of 35% and a left ventricular shortening fraction of 18% and severe persistent pulmonary hypertension of the newborn with oxygenation index of 28. Milrinone was started at an initial dose of 50 mcg/kg, followed by continuous infusion of 0.20 mcg/kg/min. With lowdose milrinone oxygenation index decreased to 3 within 6 hours, left ventricular ejection fraction and left ventricular shortening fraction increased to 57%, and 30%, respectively. Low doses of milrinone might be promising in the treatment of heart failure and persistent pulmonary hypertension of the newborn in term newborns.

  6. Milrinone in Enterovirus 71 Brain Stem Encephalitis

    Directory of Open Access Journals (Sweden)

    SHIH-MIN eWANG

    2016-03-01

    Full Text Available 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.

  7. Heart failure treated with low-dose milrinone in a full-term newborn.

    Science.gov (United States)

    Sebková, S; Tomek, V; Zemanová, P; Janota, J

    2012-01-01

    A term newborn with a hypocontractile myocardium complicating persistent pulmonary hypertension of the newborn was successfully treated with a low-dose phosphodiesterase III inhibitor milrinone. Echocardiography diagnosed heart failure with a left ventricular ejection fraction of 35% and a left ventricular shortening fraction of 18% and severe persistent pulmonary hypertension of the newborn with oxygenation index of 28. Milrinone was started at an initial dose of 50 mcg/kg, followed by continuous infusion of 0.20 mcg/kg/min. With lowdose milrinone oxygenation index decreased to 3 within 6 hours, left ventricular ejection fraction and left ventricular shortening fraction increased to 57%, and 30%, respectively. Low doses of milrinone might be promising in the treatment of heart failure and persistent pulmonary hypertension of the newborn in term newborns.

  8. Impact of aging and comorbidity on the efficacy of low-intensity shock wave therapy for erectile dysfunction.

    Science.gov (United States)

    Hisasue, Shin-ichi; China, Toshiyuki; Horiuchi, Akira; Kimura, Masaki; Saito, Keisuke; Isotani, Shuji; Ide, Hisamitsu; Muto, Satoru; Yamaguchi, Raizo; Horie, Shigeo

    2016-01-01

    To evaluate the efficacy of low-intensity shock wave therapy and to identify the predictive factors of its efficacy in Japanese patients with erectile dysfunction. The present study included 57 patients with erectile dysfunction who satisfied all the following conditions: more than 6-months history of erectile dysfunction, sexual health inventory for men score of ≤ 12 without phosphodiesterase type-5 inhibitor, erection hardness score grade 1 or 2, mean penile circumferential change by erectometer assessing sleep related erection of energy shock waves generator (ED1000; Medispec, Gaithersburg, MD, USA). A total of 12 shock wave treatments were applied. Sexual health inventory for men score, erection hardness score with or without phosphodiesterase type-5 inhibitor, and mean penile circumferential change were assessed at baseline, 1, 3 and 6 months after the termination of low-intensity shock wave therapy. Of 57 patients who were assigned for the low-intensity shock wave therapy trial, 56 patients were analyzed. Patients had a median age of 64 years. The sexual health inventory for men and erection hardness score (with and without phosphodiesterase type-5 inhibitor) were significantly increased (P wave therapy (P wave therapy seems to be an effective physical therapy for erectile dysfunction. Age and comorbidities are negative predictive factors of therapeutic response. © 2015 The Japanese Urological Association.

  9. Computation-based virtual screening for designing novel antimalarial drugs by targeting falcipain-III: a structure-based drug designing approach.

    Science.gov (United States)

    Kesharwani, Rajesh Kumar; Singh, Durg Vijay; Misra, Krishna

    2013-01-01

    Cysteine proteases (falcipains), a papain-family of enzymes of Plasmodium falciparum, are responsible for haemoglobin degradation and thus necessary for its survival during asexual life cycle phase inside the human red blood cells while remaining non-functional for the human body. Therefore, these can act as potential targets for designing antimalarial drugs. The P. falciparum cysteine proteases, falcipain-II and falcipain- III are the enzymes which initiate the haemoglobin degradation, therefore, have been selected as targets. In the present study, we have designed new leupeptin analogues and subjected to virtual screening using Glide at the active site cavity of falcipain-II and falcipain-III to select the best docked analogues on the basis of Glide score and also compare with the result of AutoDock. The proposed analogues can be synthesized and tested in vivo as future potent antimalarial drugs. Protein falcipain-II and falcipain-III together with bounds inhibitors epoxysuccinate E64 (E64) and leupeptin respectively were retrieved from protein data bank (PDB) and latter leupeptin was used as lead molecule to design new analogues by using Ligbuilder software and refined the molecules on the basis of Lipinski rule of five and fitness score parameters. All the designed leupeptin analogues were screened via docking simulation at the active site cavity of falcipain-II and falcipain-III by using Glide software and AutoDock. The 104 new leupeptin-based antimalarial ligands were designed using structure-based drug designing approach with the help of Ligbuilder and subjected for virtual screening via docking simulation method against falcipain-II and falcipain-III receptor proteins. The Glide docking results suggest that the ligands namely result_037 shows good binding and other two, result_044 and result_042 show nearly similar binding than naturally occurring PDB bound ligand E64 against falcipain-II and in case of falcipain-III, 15 designed leupeptin analogues having

  10. The majority of patients with metastatic melanoma are not represented in pivotal phase III immunotherapy trials

    DEFF Research Database (Denmark)

    Donia, Marco; Kimper-Karl, Marie Louise; Høyer, Katrine Lundby

    2017-01-01

    BACKGROUND: Recent randomised phase III trials have led to the approval of several immune checkpoint inhibitors for unresectable or metastatic melanoma (MM). These trials all employed strict patient selection criteria, and it is currently unknown how large proportion of 'real-world' patients diag...... a huge knowledge gap regarding the usefulness of new immunotherapies in the 'real-world' patient population, and urge additional testing of known regimens in selected poor prognosis cohorts.......BACKGROUND: Recent randomised phase III trials have led to the approval of several immune checkpoint inhibitors for unresectable or metastatic melanoma (MM). These trials all employed strict patient selection criteria, and it is currently unknown how large proportion of 'real-world' patients...... in 2014, were included in the analysis. Seven pre-defined eligibility criteria, all used to select patients for enrolment in five recent randomised phase III immunotherapy trials, were analysed. RESULTS: Fifty-five percent of the total population with MM did not meet one or more eligibility criteria ('not...

  11. Administration of PDE4 Inhibitors Suppressed the Pannus-Like Inflammation by Inhibition of Cytokine Production by Macrophages and Synovial Fibroblast Proliferation

    Directory of Open Access Journals (Sweden)

    Katsuya Kobayashi

    2007-01-01

    Full Text Available A marked proliferation of synovial fibroblasts in joints leads to pannus formation in rheumatoid arthritis (RA. Various kinds of cytokines are produced in the pannus. The purpose of this study is to elucidate the effects of phosphodiesterase 4 (PDE4 inhibitors in a new animal model for the evaluation of pannus formation and cytokine production in the pannus. Mice sensitized with methylated bovine serum albumin (mBSA were challenged by subcutaneous implantation of a membrane filter soaked in mBSA solution in the back of the mice. Drugs were orally administered for 10 days. The granuloma formed around the filter was collected on day 11. It was chopped into pieces and cultured in vitro for 24 hr. The cytokines were measured in the supernatants. The type of cytokines produced in the granuloma was quite similar to those produced in pannus in RA. Both PDE4 inhibitors, KF66490 and SB207499, suppressed the production of IL-1β, TNF-α, and IL-12, and the increase in myeloperoxidase activity, a marker enzyme for neutrophils and hydroxyproline content. Compared to leflunomide, PDE4 inhibitors more strongly suppressed IL-12 production and the increase in myeloperoxidase activity. PDE4 inhibitors also inhibited lipopolysaccharide-induced TNF-α and IL-12 production from thioglycolate-induced murine peritoneal macrophages and the proliferation of rat synovial fibroblasts. These results indicate this model makes it easy to evaluate the effect of drugs on various cytokine productions in a granuloma without any purification step and may be a relevant model for evaluating novel antirheumatic drugs on pannus formation in RA. PDE4 inhibitors could have therapeutic effects on pannus formation in RA by inhibition of cytokine production by macrophages and synovial fibroblast proliferation.

  12. Administration of PDE4 inhibitors suppressed the pannus-like inflammation by inhibition of cytokine production by macrophages and synovial fibroblast proliferation.

    Science.gov (United States)

    Kobayashi, Katsuya; Suda, Toshio; Manabe, Haruhiko; Miki, Ichiro

    2007-01-01

    A marked proliferation of synovial fibroblasts in joints leads to pannus formation in rheumatoid arthritis (RA). Various kinds of cytokines are produced in the pannus. The purpose of this study is to elucidate the effects of phosphodiesterase 4 (PDE4) inhibitors in a new animal model for the evaluation of pannus formation and cytokine production in the pannus. Mice sensitized with methylated bovine serum albumin (mBSA) were challenged by subcutaneous implantation of a membrane filter soaked in mBSA solution in the back of the mice. Drugs were orally administered for 10 days. The granuloma formed around the filter was collected on day 11. It was chopped into pieces and cultured in vitro for 24 hr. The cytokines were measured in the supernatants. The type of cytokines produced in the granuloma was quite similar to those produced in pannus in RA. Both PDE4 inhibitors, KF66490 and SB207499, suppressed the production of IL-1beta, TNF-alpha, and IL-12, and the increase in myeloperoxidase activity, a marker enzyme for neutrophils and hydroxyproline content. Compared to leflunomide, PDE4 inhibitors more strongly suppressed IL-12 production and the increase in myeloperoxidase activity. PDE4 inhibitors also inhibited lipopolysaccharide-induced TNF-alpha and IL-12 production from thioglycolate-induced murine peritoneal macrophages and the proliferation of rat synovial fibroblasts. These results indicate this model makes it easy to evaluate the effect of drugs on various cytokine productions in a granuloma without any purification step and may be a relevant model for evaluating novel antirheumatic drugs on pannus formation in RA. PDE4 inhibitors could have therapeutic effects on pannus formation in RA by inhibition of cytokine production by macrophages and synovial fibroblast proliferation.

  13. Inhibition of Phosphodiesterase 4 by FCPR03 Alleviates Lipopolysaccharide-Induced Depressive-Like Behaviors in Mice: Involvement of p38 and JNK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Hui Yu

    2018-02-01

    Full Text Available Inflammatory responses induced by peripheral administration of lipopolysaccharide (LPS triggers depressive-like behavioral syndrome in rodents. Inhibition of phosphodiesterase 4 (PDE4 produces a robust anti-inflammatory effect in inflammatory cells. Unfortunately, archetypal PDE4 inhibitors cause intolerable gastrointestinal side-effects, such as vomiting and nausea. N-isopropyl-3-(cyclopropylmethoxy-4-difluoromethoxy benzamide (FCPR03 is a novel, selective PDE4 inhibitor with little, or no, emetic potency. Our previous studies show that FCPR03 is effective in attenuating neuroinflammation in mice treated with LPS. However, whether FCPR03 could exert antidepressant-like effect induced by LPS is largely unknown. In the present study, mice injected intraperitoneally (i.p. with LPS was established as an in vivo animal model of depression. The antidepressant-like activities of FCPR03 were evaluated using a tail suspension test, forced swimming test, and sucrose preference test. We demonstrated that administration of FCPR03 (1 mg/kg produced antidepressant-like effects in mice challenged by LPS, as evidenced by decreases in the duration of immobility in the forced swim and tail suspension tests, while no significant changes in locomotor activity were observed. FCPR03 also increased sucrose preference in mice treated with LPS. In addition, treatment with FCPR03 abolished the downregulation of brain-derived neurotrophic factor induced by LPS and decreased the level of corticosterone in plasma. Meanwhile, periphery immune challenge by LPS induced enhanced phosphorylation of p38-mitogen activated protein kinase (p38 and c-Jun N-terminal kinase (JNK in both the cerebral cortex and hippocampus in mice. Interestingly, treatment with FCPR03 significantly blocked the role of LPS and reduced the levels of phosphorylated p38 and JNK. Collectively, these results indicate that FCPR03 shows antidepressant-like effects in mice challenged by LPS, and the p38/JNK

  14. [Acute monocular loss of vision : Differential diagnostic considerations apart from the internistic etiological clarification].

    Science.gov (United States)

    Rickmann, A; Macek, M A; Szurman, P; Boden, K

    2017-08-03

    We report the case of acute painless monocular loss of vision in a 53-year-old man. An interdisciplinary etiological evaluation remained without pathological findings with respect to arterial branch occlusion. A reevaluation of the patient history led to a possible association with the administration of phosphodiesterase type 5 inhibitor (PDE5 inhibitor). A critical review of the literature on PDE5 inhibitor administration with ocular participation was performed.

  15. Methylated trivalent arsenicals are potent inhibitors of glucose stimulated insulin secretion by murine pancreatic islets

    Energy Technology Data Exchange (ETDEWEB)

    Douillet, Christelle [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Currier, Jenna [Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Saunders, Jesse [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Bodnar, Wanda M. [Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7431 (United States); Matoušek, Tomáš [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic); Stýblo, Miroslav, E-mail: styblo@med.unc.edu [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States)

    2013-02-15

    Epidemiologic evidence has linked chronic exposure to inorganic arsenic (iAs) with an increased prevalence of diabetes mellitus. Laboratory studies have identified several mechanisms by which iAs can impair glucose homeostasis. We have previously shown that micromolar concentrations of arsenite (iAs{sup III}) or its methylated trivalent metabolites, methylarsonite (MAs{sup III}) and dimethylarsinite (DMAs{sup III}), inhibit the insulin-activated signal transduction pathway, resulting in insulin resistance in adipocytes. Our present study examined effects of the trivalent arsenicals on insulin secretion by intact pancreatic islets isolated from C57BL/6 mice. We found that 48-hour exposures to low subtoxic concentrations of iAs{sup III}, MAs{sup III} or DMAs{sup III} inhibited glucose-stimulated insulin secretion (GSIS), but not basal insulin secretion. MAs{sup III} and DMAs{sup III} were more potent than iAs{sup III} as GSIS inhibitors with estimated IC{sub 50} ≤ 0.1 μM. The exposures had little or no effects on insulin content of the islets or on insulin expression, suggesting that trivalent arsenicals interfere with mechanisms regulating packaging of the insulin transport vesicles or with translocation of these vesicles to the plasma membrane. Notably, the inhibition of GSIS by iAs{sup III}, MAs{sup III} or DMAs{sup III} could be reversed by a 24-hour incubation of the islets in arsenic-free medium. These results suggest that the insulin producing pancreatic β-cells are among the targets for iAs exposure and that the inhibition of GSIS by low concentrations of the methylated metabolites of iAs may be the key mechanism of iAs-induced diabetes. - Highlights: ► Trivalent arsenicals inhibit glucose stimulated insulin secretion by pancreatic islets. ► MAs{sup III} and DMAs{sup III} are more potent inhibitors than arsenite with IC{sub 50} ∼ 0.1 μM. ► The arsenicals have little or no effects on insulin expression in pancreatic islets. ► The inhibition of

  16. 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

    2010-01-01

    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...

  17. Comparing acquired angioedema with hereditary angioedema (types I/II): findings from the Icatibant Outcome Survey.

    Science.gov (United States)

    Longhurst, H J; Zanichelli, A; Caballero, T; Bouillet, L; Aberer, W; Maurer, M; Fain, O; Fabien, V; Andresen, I

    2017-04-01

    Icatibant is used to treat acute hereditary angioedema with C1 inhibitor deficiency types I/II (C1-INH-HAE types I/II) and has shown promise in angioedema due to acquired C1 inhibitor deficiency (C1-INH-AAE). Data from the Icatibant Outcome Survey (IOS) were analysed to evaluate the effectiveness of icatibant in the treatment of patients with C1-INH-AAE and compare disease characteristics with those with C1-INH-HAE types I/II. Key medical history (including prior occurrence of attacks) was recorded upon IOS enrolment. Thereafter, data were recorded retrospectively at approximately 6-month intervals during patient follow-up visits. In the icatibant-treated population, 16 patients with C1-INH-AAE had 287 attacks and 415 patients with C1-INH-HAE types I/II had 2245 attacks. Patients with C1-INH-AAE versus C1-INH-HAE types I/II were more often male (69 versus 42%; P = 0·035) and had a significantly later mean (95% confidence interval) age of symptom onset [57·9 (51·33-64·53) versus 14·0 (12·70-15·26) years]. Time from symptom onset to diagnosis was significantly shorter in patients with C1-INH-AAE versus C1-INH-HAE types I/II (mean 12·3 months versus 118·1 months; P = 0·006). Patients with C1-INH-AAE showed a trend for higher occurrence of attacks involving the face (35 versus 21% of attacks; P = 0·064). Overall, angioedema attacks were more severe in patients with C1-INH-HAE types I/II versus C1-INH-AAE (61 versus 40% of attacks were classified as severe to very severe; P types I/II, respectively. © 2016 British Society for Immunology.

  18. HDAC inhibitor L-carnitine and proteasome inhibitor bortezomib synergistically exert anti-tumor activity in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Hongbiao Huang

    Full Text Available Combinations of proteasome inhibitors and histone deacetylases (HDAC inhibitors appear to be the most potent to produce synergistic cytotoxicity in preclinical trials. We have recently confirmed that L-carnitine (LC is an endogenous HDAC inhibitor. In the current study, the anti-tumor effect of LC plus proteasome inhibitor bortezomib (velcade, Vel was investigated both in cultured hepatoma cancer cells and in Balb/c mice bearing HepG2 tumor. Cell death and cell viability were assayed by flow cytometry and MTS, respectively. Gene, mRNA expression and protein levels were detected by gene microarray, quantitative real-time PCR and Western blot, respectively. The effect of Vel on the acetylation of histone H3 associated with the p21(cip1 gene promoter was examined by using ChIP assay and proteasome peptidase activity was detected by cell-based chymotrypsin-like (CT-like activity assay. Here we report that (i the combination of LC and Vel synergistically induces cytotoxicity in vitro; (ii the combination also synergistically inhibits tumor growth in vivo; (iii two major pathways are involved in the synergistical effects of the combinational treatment: increased p21(cip1 expression and histone acetylation in vitro and in vivo and enhanced Vel-induced proteasome inhibition by LC. The synergistic effect of LC and Vel in cancer therapy should have great potential in the future clinical trials.

  19. Nitrato-complexes of Y(III), La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl) benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A; Singh, M P; Singh, V K

    1982-05-01

    The nitrato-complexes, (Y(PyBzH)/sub 2/(NO/sub 3/)/sub 2/)NO/sub 3/.H/sub 2/O and Nd, Sm, Gd, Tb, Dy, Ho ; n=1-3, m=0-0.5 ; PyBzh=2-(2 -pyridyl)benzimidazole) are formed on interaction of the ligand with metal nitrates in ethanol. The electrical conductance values (116-129 ohm/sup -1/cm/sup 2/mol/sup -1/) suggest 1:1 electrolyte-nature of the complexes. Magnetic moment values of Ce(2.53 B.M.), Pr(3.62 B.M.), Nd(3.52 B.M.), Sm(1.70 B.M.), Gd(8.06 B.M.), Tb(9.44 B.M.), Dy(10.56 B.M.) and Ho(10.51 B.M.) in the complexes confirm the positive state of the metals. Infrared evidences are obtained for the existance of both coordinated (C/sub 2/v) and uncoordinated (D/sub 3/h) nitrate groups. Electronic absorption spectra of Pr(III)-, Nd(III)-, Sm(III)-, Tb(III)-, Dy(III)- and Ho(III)-complexes have been analysed in the light of LSJ terms.

  20. Nitrato-complexes of Y(III), La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl) benzimidazole

    International Nuclear Information System (INIS)

    Mishra, A.; Singh, M.P.; Singh, V.K.

    1982-01-01

    The nitrato-complexes, [Y(PyBzH) 2 (NO 3 ) 2 ]NO 3 .H 2 O and Nd, Sm, Gd, Tb, Dy, Ho ; n=1-3, m=0-0.5 ; PyBzh=2-(2 -pyridyl)benzimidazole] are formed on interaction of the ligand with metal nitrates in ethanol. The electrical conductance values (116-129 ohm -1 cm 2 mol -1 ) suggest 1:1 electrolyte-nature of the complexes. Magnetic moment values of Ce(2.53 B.M.), Pr(3.62 B.M.), Nd(3.52 B.M.), Sm(1.70 B.M.), Gd(8.06 B.M.), Tb(9.44 B.M.), Dy(10.56 B.M.) and Ho(10.51 B.M.) in the complexes confirm the terpositive state of the metals. Infrared evidences are obtained for the existance of both coordinated (C 2 v) and uncoordinated (D 3 h) nitrate groups. Electronic absorption spectra of Pr(III)-, Nd(III)-, Sm(III)-, Tb(III)-, Dy(III)- and Ho(III)-complexes have been analysed in the light of LSJ terms. (author)

  1. Novel Inhibitor Cystine Knot Peptides from Momordica charantia

    Science.gov (United States)

    Clark, Richard J.; Tang, Jun; Zeng, Guang-Zhi; Franco, Octavio L.; Cantacessi, Cinzia; Craik, David J.; Daly, Norelle L.; Tan, Ning-Hua

    2013-01-01

    Two new peptides, MCh-1 and MCh-2, along with three known trypsin inhibitors (MCTI-I, MCTI-II and MCTI-III), were isolated from the seeds of the tropical vine Momordica charantia. The sequences of the peptides were determined using mass spectrometry and NMR spectroscopy. Using a strategy involving partial reduction and stepwise alkylation of the peptides, followed by enzymatic digestion and tandem mass spectrometry sequencing, the disulfide connectivity of MCh-1 was elucidated to be CysI-CysIV, CysII-CysV and CysIII-CysVI. The three-dimensional structures of MCh-1 and MCh-2 were determined using NMR spectroscopy and found to contain the inhibitor cystine knot (ICK) motif. The sequences of the novel peptides differ significantly from peptides previously isolated from this plant. Therefore, this study expands the known peptide diversity in M. charantia and the range of sequences that can be accommodated by the ICK motif. Furthermore, we show that a stable two-disulfide intermediate is involved in the oxidative folding of MCh-1. This disulfide intermediate is structurally homologous to the proposed ancestral fold of ICK peptides, and provides a possible pathway for the evolution of this structural motif, which is highly prevalent in nature. PMID:24116036

  2. Novel inhibitor cystine knot peptides from Momordica charantia.

    Directory of Open Access Journals (Sweden)

    Wen-Jun He

    Full Text Available Two new peptides, MCh-1 and MCh-2, along with three known trypsin inhibitors (MCTI-I, MCTI-II and MCTI-III, were isolated from the seeds of the tropical vine Momordica charantia. The sequences of the peptides were determined using mass spectrometry and NMR spectroscopy. Using a strategy involving partial reduction and stepwise alkylation of the peptides, followed by enzymatic digestion and tandem mass spectrometry sequencing, the disulfide connectivity of MCh-1 was elucidated to be CysI-CysIV, CysII-CysV and CysIII-CysVI. The three-dimensional structures of MCh-1 and MCh-2 were determined using NMR spectroscopy and found to contain the inhibitor cystine knot (ICK motif. The sequences of the novel peptides differ significantly from peptides previously isolated from this plant. Therefore, this study expands the known peptide diversity in M. charantia and the range of sequences that can be accommodated by the ICK motif. Furthermore, we show that a stable two-disulfide intermediate is involved in the oxidative folding of MCh-1. This disulfide intermediate is structurally homologous to the proposed ancestral fold of ICK peptides, and provides a possible pathway for the evolution of this structural motif, which is highly prevalent in nature.

  3. Purification, partial characterization, and immunological relationships of multiple low molecular weight protease inhibitors of soybean

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, D L.R.; Lin, K T.D.; Yang, W K; Foard, D E

    1977-01-01

    Five protease inhibitors, I-V, in the molecular weight range 7000-8000 were purified from Tracy soybeans by ammonium sulfate precipitation, gel filtration on Sephadex G-100 and G-75, and column chromatography on DEAE-cellulose. In common with previously described trypsin inhibitors from legumes, I-V have a high content of half-cystine and lack tryptophan. By contrast with other legume inhibitors, inhibitor II contains 3 methionine residues. Isoelectric points range from 6.2 to 4.2 in order from inhibitor I to V. Molar ratios (inhibitor/enzyme) for 50% trypsin inhibition are I = 4.76, II = 1.32, III = 3.22, IV = 2.17, V = 0.97. Only V inhibits chymotrypsin significantly (molar ratio = 1.33 for 50% inhibition). The sequence of the first 16 N-terminal amino acid residues of inhibitor V is identical to that of the Bowman-Birk inhibitor; all other observations also indicate that inhibitor V and Bowman-Birk are identical. The first 20 N-terminal amino acid residues of inhibitor II show high homology to those of Bowman-Birk inhibitor, differing by 1 deletion and 5 substitutions. Immunological tests show that inhibitors I through IV are fully cross-reactive with each other but are distinct from inhibitor V.

  4. The glycomic effect of N-acetylglucosaminyltransferase III overexpression in metastatic melanoma cells. GnT-III modifies highly branched N-glycans.

    Science.gov (United States)

    Link-Lenczowski, Paweł; Bubka, Monika; Balog, Crina I A; Koeleman, Carolien A M; Butters, Terry D; Wuhrer, Manfred; Lityńska, Anna

    2018-04-01

    N-acetylglucosaminyltransferase III (GnT-III) is known to catalyze N-glycan "bisection" and thereby modulate the formation of highly branched complex structures within the Golgi apparatus. While active, it inhibits the action of other GlcNAc transferases such as GnT-IV and GnT-V. Moreover, GnT-III is considered as an inhibitor of the metastatic potential of cancer cells both in vitro and in vivo. However, the effects of GnT-III may be more diverse and depend on the cellular context. We describe the detailed glycomic analysis of the effect of GnT-III overexpression in WM266-4-GnT-III metastatic melanoma cells. We used MALDI-TOF and ESI-ion-trap-MS/MS together with HILIC-HPLC of 2-AA labeled N-glycans to study the N-glycome of membrane-attached and secreted proteins. We found that the overexpression of GnT-III in melanoma leads to the modification of a broad range of N-glycan types by the introduction of the "bisecting" GlcNAc residue with highly branched complex structures among them. The presence of these unusual complex N-glycans resulted in stronger interactions of cellular glycoproteins with the PHA-L. Based on the data presented here we conclude that elevated activity of GnT-III in cancer cells does not necessarily lead to a total abrogation of the formation of highly branched glycans. In addition, the modification of pre-existing N-glycans by the introduction of "bisecting" GlcNAc can modulate their capacity to interact with carbohydrate-binding proteins such as plant lectins. Our results suggest further studies on the biological function of "bisected" oligosaccharides in cancer cell biology and their interactions with carbohydrate-binding proteins.

  5. Model-Informed Drug Development for Ixazomib, an Oral Proteasome Inhibitor.

    Science.gov (United States)

    Gupta, Neeraj; Hanley, Michael J; Diderichsen, Paul M; Yang, Huyuan; Ke, Alice; Teng, Zhaoyang; Labotka, Richard; Berg, Deborah; Patel, Chirag; Liu, Guohui; van de Velde, Helgi; Venkatakrishnan, Karthik

    2018-02-15

    Model-informed drug development (MIDD) was central to the development of the oral proteasome inhibitor ixazomib, facilitating internal decisions (switch from body surface area (BSA)-based to fixed dosing, inclusive phase III trials, portfolio prioritization of ixazomib-based combinations, phase III dose for maintenance treatment), regulatory review (model-informed QT analysis, benefit-risk of 4 mg dose), and product labeling (absolute bioavailability and intrinsic/extrinsic factors). This review discusses the impact of MIDD in enabling patient-centric therapeutic optimization during the development of ixazomib. © 2017 The Authors. Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  6. Association of the polymorphism of codon 121 in the ecto-nucleotide pyrophosphatase/phosphodiesterase 1 gene with polycystic ovary syndrome in Chinese woman

    International Nuclear Information System (INIS)

    Shi, Y.; Chen, Z.; Zhang, P.; Zhao, Y.; You, L.; Sun, X.

    2008-01-01

    Objective was to determine the association of polymorphism of codon 121 in the ecto-nucleotide pyrophosphastase/phosphodiesterase 1 (E-NPP1/PC-1) gene in Chinese women with polycystic ovary syndrome (PCOS). A total of 51 PCOS patients and 61 healthy women from Chinese Han population from the Center Reproductive Medicine of Provincial Hospital affiliated to Shandong University from June 2005 to July 2006 were recruited for the determination of the polymorphism of the E-NPP/PC-1 gene. Genomic DNA was extracted from peripheral blood monocytes of patients and controls and genotyping of the gene was performed by using polymerase chain reaction, which was followed by sequencing. The frequency of the 121Q allele was 13 and 18%, respectively, in PCOS patients and healthy women, while the frequency of the 121K allele was 87 and 82% in the 2 groups. There is no significant difference in the E-NPP1/PC-1 polymorphism between PCOS patients and healthy controls among Chinese Han women. ecto-nucleotide pyrophosphatase/phosphodiesterase 1 polymorphism has no association with PCOS. Further studies are still needed to elucidate whether or not the E-NPP1/PC-1 gene has a functional role in PCOS. (author)

  7. Dysregulated human Tyrosyl-DNA phosphodiesterase I acts as cellular toxin

    Science.gov (United States)

    Cuya, Selma M.; Comeaux, Evan Q.; Wanzeck, Keith; Yoon, Karina J.; van Waardenburg, Robert C.A.M.

    2016-01-01

    Tyrosyl-DNA phosphodiesterase I (TDP1) hydrolyzes the drug-stabilized 3’phospho-tyrosyl bond formed between DNA topoisomerase I (TOPO1) and DNA. TDP1-mediated hydrolysis uses a nucleophilic histidine (Hisnuc) and a general acid/base histidine (Hisgab). A Tdp1Hisgab to Arg mutant identified in patients with the autosomal recessive neurodegenerative disease SCAN1 causes stabilization of the TDP1-DNA intermediate. Based on our previously reported Hisgab-substitutions inducing yeast toxicity (Gajewski et al. J. Mol. Biol. 415, 741-758, 2012), we propose that converting TDP1 into a cellular poison by stabilizing the covalent enzyme-DNA intermediate is a novel therapeutic strategy for cancer treatment. Here, we analyzed the toxic effects of two TDP1 catalytic mutants in HEK293 cells. Expression of human Tdp1HisnucAla and Tdp1HisgabAsn mutants results in stabilization of the covalent TDP1-DNA intermediate and induces cytotoxicity. Moreover, these mutants display reduced in vitro catalytic activity compared to wild type. Co-treatment of Tdp1mutant with topotecan shows more than additive cytotoxicity. Overall, these results support the hypothesis that stabilization of the TDP1-DNA covalent intermediate is a potential anti-cancer therapeutic strategy. PMID:27893431

  8. A metal-based inhibitor of NEDD8-activating enzyme.

    Directory of Open Access Journals (Sweden)

    Hai-Jing Zhong

    Full Text Available A cyclometallated rhodium(III complex [Rh(ppy(2(dppz](+ (1 (where ppy=2-phenylpyridine and dppz=dipyrido[3,2-a:2',3'-c]phenazine dipyridophenazine has been prepared and identified as an inhibitor of NEDD8-activating enzyme (NAE. The complex inhibited NAE activity in cell-free and cell-based assays, and suppressed the CRL-regulated substrate degradation and NF-κB activation in human cancer cells with potency comparable to known NAE inhibitor MLN4924. Molecular modeling analysis suggested that the overall binding mode of 1 within the binding pocket of the APPBP1/UBA3 heterodimer resembled that for MLN4924. Complex 1 is the first metal complex reported to suppress the NEDDylation pathway via inhibition of the NEDD8-activating enzyme.

  9. The pde2 gene of Saccharomyces cerevisiae is allelic to rca1 and encodes a phosphodiesterase which protects the cell from extracellular cAMP.

    Science.gov (United States)

    Wilson, R B; Renault, G; Jacquet, M; Tatchell, K

    1993-07-05

    The high affinity cAMP phosphodiesterase, encoded by PDE2, is an important component of the cAMP-dependent protein kinase signaling system in Saccharomyces cerevisiae. An unexpected phenotype of pde2 mutants is sensitivity to external cAMP. This trait has been found independently for rca1 mutants and has been used to monitor the effects of cAMP on several biological processes. We demonstrate here that RCA1 is identical to PDE2. Further analysis of the phenotype of pde2 deletions reveal that exogenously added cAMP results in an increase in the internal level of cAMP. This increase slows down the rate of cell division by increasing the length of the G1 phase of the cell cycle and leads to increased cell volume. Also, cells with a disrupted PDE2 gene previously arrested by nutrient starvation rapidly lose thermotolerance when incubated with exogenous cAMP. From these observations we propose that a role of the PDE2-encoded phosphodiesterase may be to help insulate the internal cAMP pools from the external environment. This protective role might also be important in other eukaryotic organisms where cAMP is a key second messenger.

  10. Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

    DEFF Research Database (Denmark)

    Clemmesen, Jens-Otto; Giraldi, Annamaria; Ott, Peter

    2008-01-01

    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 liv...... type-5 inhibitor sildenafil, the present study could not demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG....

  11. Multiple Behavior Phenotypes of the Fragile-X Syndrome Mouse Model Respond to Chronic Inhibition of Phosphodiesterase-4D (PDE4D)

    OpenAIRE

    Gurney, Mark E.; Cogram, Patricia; Deacon, Robert M; Rex, Christopher; Tranfaglia, Michael

    2017-01-01

    Fragile-X syndrome (FXS) patients display intellectual disability and autism spectrum disorder due to silencing of the X-linked, fragile-X mental retardation-1 (FMR1) gene. Dysregulation of cAMP metabolism is a consistent finding in patients and in the mouse and fly FXS models. We therefore explored if BPN14770, a prototypic phosphodiesterase-4D negative allosteric modulator (PDE4D-NAM) in early human clinical trials, might provide therapeutic benefit in the mouse FXS model. Daily treatment o...

  12. Hesperidin-3′-O-Methylether Is More Potent than Hesperidin in Phosphodiesterase Inhibition and Suppression of Ovalbumin-Induced Airway Hyperresponsiveness

    Directory of Open Access Journals (Sweden)

    You-Lan Yang

    2012-01-01

    Full Text Available Hesperidin is present in the traditional Chinese medicine, “Chen Pi,” and recently was reported to have anti-inflammatory effects. Therefore, we were interested in comparing the effects of hesperidin and hesperidin-3′-O-methylether on phosphodiesterase inhibition and airway hyperresponsiveness (AHR in a murine model of asthma. In the present results, hesperidin-3′-O-methylether, but not hesperidin, at 30 μmol/kg (p.o. significantly attenuated the enhanced pause (Penh value, suppressed the increases in numbers of total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils, suppressed total and OVA-specific immunoglobulin (IgE levels in the serum and BALF, and enhanced the level of total IgG2a in the serum of sensitized and challenged mice, suggesting that hesperidin-3′-O-methylether is more potent than hesperidin in suppression of AHR and immunoregulation. The different potency between them may be due to their aglycons, because these two flavanone glycosides should be hydrolyzed by β-glucosidase after oral administration. Neither influenced xylazine/ketamine-induced anesthesia, suggesting that they may have few or no adverse effects, such as nausea, vomiting, and gastric hypersecretion. In conclusion, hesperidin-3′-O-methylether is more potent in phosphodiesterase inhibition and suppression of AHR and has higher therapeutic (PDE4H/PDE4L ratio than hesperidin. Thus, hesperidin-3′-O-methylether may have more potential for use in treating allergic asthma and chronic obstructive pulmonary disease.

  13. Sexual function in patients with chronic angina pectoris.

    Science.gov (United States)

    Kloner, Robert A; Henderson, Luana

    2013-06-01

    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. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Otezla, Warts and All, Racks Up Sales and Eyes Blockbuster Status.

    Science.gov (United States)

    Reinke, Thomas

    2017-10-01

    Otezla-the generic name is apremilast-also exploited a new mechanism of action as the first inhibitor of phosphodiesterase 4 (PDE4) that results in increased expression of both anti-inflammatory proteins and reduced expression of their pro-inflammatory counterparts.

  15. Phosphodiesterase-1b (Pde1b) knockout mice are resistant to forced swim and tail suspension induced immobility and show upregulation of Pde10a.

    Science.gov (United States)

    Hufgard, Jillian R; Williams, Michael T; Skelton, Matthew R; Grubisha, Olivera; Ferreira, Filipa M; Sanger, Helen; Wright, Mary E; Reed-Kessler, Tracy M; Rasmussen, Kurt; Duman, Ronald S; Vorhees, Charles V

    2017-06-01

    Major depressive disorder is a leading cause of suicide and disability. Despite this, current antidepressants provide insufficient efficacy in more than 60% of patients. Most current antidepressants are presynaptic reuptake inhibitors; postsynaptic signal regulation has not received as much attention as potential treatment targets. We examined the effects of disruption of the postsynaptic cyclic nucleotide hydrolyzing enzyme, phosphodiesterase (PDE) 1b, on depressive-like behavior and the effects on PDE1B protein in wild-type (WT) mice following stress. Littermate knockout (KO) and WT mice were tested in locomotor activity, tail suspension (TST), and forced swim tests (FST). FST was also used to compare the effects of two antidepressants, fluoxetine and bupropion, in KO versus WT mice. Messenger RNA (mRNA) expression changes were also determined. WT mice underwent acute or chronic stress and markers of stress and PDE1B expression were examined. Pde1b KO mice exhibited decreased TST and FST immobility. When treated with antidepressants, both WT and KO mice showed decreased FST immobility and the effect was additive in KO mice. Mice lacking Pde1b had increased striatal Pde10a mRNA expression. In WT mice, acute and chronic stress upregulated PDE1B expression while PDE10A expression was downregulated after chronic but not acute stress. PDE1B is a potential therapeutic target for depression treatment because of the antidepressant-like phenotype seen in Pde1b KO mice.

  16. Efficacy and tolerability of lodenafil carbonate for oral therapy of erectile dysfunction: a phase III clinical trial.

    Science.gov (United States)

    Glina, Sidney; Fonseca, Gilvan N; Bertero, Eduardo B; Damião, Ronaldo; Rocha, Luíz C A; Jardim, Carlos R F; Cairoli, Carlos E; Teloken, Cláudio; Torres, Luiz O; Faria, Geraldo E; da Silva, Marcelo B; Pagani, Eduardo

    2010-05-01

    This is a phase III, prospective, randomized, double-blind, placebo-controlled clinical trial on lodenafil carbonate (LC), a novel phosphodiesterase 5 inhibitor developed in Brazil. Expanding information on LC efficacy and safety. International Index of Erectile Function (IIEF) erectile domain, positive answers to the sexual encounter profile (SEP)-2 and SEP-3 questions and incidence of adverse events (AEs). A total of 350 men with erectile dysfunction (ED) of all degrees were randomized to placebo, LC 40 mg or LC 80 mg and followed for 4 weeks. They completed the IIEF and answered the SEP questions 2 and 3 after each intercourse without and with the use of LC. IIEF Erectile Domain scores without and with the use of medication were the following (mean [M] +/- standard deviation [SD]): placebo = 13.9 +/- 5.2 and 14.8 +/- 7.8; LC 40 mg = 13.6 +/- 5.3 and 18.6 +/- 8.0; LC 80 mg = 13.4 +/- 4.9 and 20.6 +/- 7.7 (analysis of variance [ANOVA] P < 0.01). Positive answers to SEP-2 without and with the use of medication were the following (M +/- SD): placebo = 55.3 +/- 43.2% and 52.1 +/- 41.4%; LC 40 mg = 46.4 +/- 44.3% and 63.5 +/- 42.0%; LC 80 mg = 50.2 +/- 40.9% and 80.8 +/- 32.3% (ANOVA P < 0.01). Positive answers to SEP-3 were the following: placebo = 20.2 +/- 32.3% and 29.7 +/- 38.1%; LC 40 mg = 19.6 +/- 34.3% and 50.8 +/- 44.4%; LC 80 mg = 20.8 +/- 33.2% and 66.0 +/- 39.3% (ANOVA P < 0.01). The patients with at least one AE were placebo = 28.7%, LC 40 mg = 40.9%, and LC 80 mg = 49.5%. AEs whose incidence was significantly higher with LC than with placebo included rhinitis, headache, flushing, visual disorder, and dizziness. LC showed a satisfactory efficacy-safety profile for oral therapy of ED.

  17. Synthesis and biological evaluation of 5-carbamoyl-2-phenylpyrimidine derivatives as novel and potent PDE4 inhibitors.

    Science.gov (United States)

    Goto, Taiji; Shiina, Akiko; Yoshino, Toshiharu; Mizukami, Kiyoshi; Hirahara, Kazuki; Suzuki, Osamu; Sogawa, Yoshitaka; Takahashi, Tomoko; Mikkaichi, Tsuyoshi; Nakao, Naoki; Takahashi, Mizuki; Hasegawa, Masashi; Sasaki, Shigeki

    2013-11-15

    5-Carbamoyl-2-phenylpyrimidine derivative 2 has been identified as a phosphodiesterase 4 (PDE4) inhibitor with moderate PDE4B inhibitory activity (IC50=200 nM). Modification of the carboxylic acid moiety of 2 gave N-neopentylacetamide derivative 10f, which had high in vitro PDE4B inhibitory activity (IC50=8.3 nM) and in vivo efficacy against lipopolysaccharide (LPS)-induced pulmonary neutrophilia in mice (ID50=16 mg/kg, ip). Furthermore, based on the X-ray crystallography of 10f bound to the human PDE4B catalytic domain, we designed 7,8-dihydro-6H-pyrido[4,3-d]pyrimidin-5-one derivative 39 which has a fused bicyclic lactam scaffold. Compound 39 exhibited excellent inhibitory activity against LPS-induced tumor necrosis factor alpha (TNF-α) production in mouse splenocytes (IC50=0.21 nM) and in vivo anti-inflammatory activity against LPS-induced pulmonary neutrophilia in mice (41% inhibition at a dose of 1.0 mg/kg, i.t.). Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. 3,7-Bis(2-hydroxyethyl)icaritin, a potent inhibitor of phosphodiesterase-5, prevents monocrotaline-induced pulmonary arterial hypertension via NO/cGMP activation in rats.

    Science.gov (United States)

    Lan, Tao-Hua; Chen, Xiao-Ling; Wu, Yun-Shan; Qiu, Hui-Liang; Li, Jun-Zhe; Ruan, Xin-Min; Xu, Dan-Ping; Lin, Dong-Qun

    2018-06-15

    Pulmonary arterial hypertension (PAH) is a chronic progressive disease which leads to elevated pulmonary arterial pressure and right heart failure. 3,7-Bis(2-hydroxyethyl)icaritin (ICT), an icariin derivatives, was reported to have potent inhibitory activity on phosphodiesterase type 5 (PDE5) which plays a crucial role in the pathogenesis of PAH. The present study was designed to investigate the effects of ICT on monocrotaline (MCT)-induced PAH rat model and reveal the underlying mechanism. MCT-induced PAH rat models were established with intragastric administration of ICT (10, 20, 40 mg/kg/d), Icariin (ICA) (40 mg/kg/d) and Sildenafil (25 mg/kg/d). The mean pulmonary arterial pressure (mPAP) and right ventricle hypertrophy index (RVHI) were measured. Pulmonary artery remodeling was assessed by H&E staining. Blood and lung tissue were collected to evaluate the level of endothelin 1 (ET-1), nitric oxide (NO), and cyclic guanosine monophosphate (cGMP). The expressions endothelial nitric oxide synthase (eNOS) and PDE5A in lung tissues were determined by Western blot analysis. The results showed that ICT reduced RVHI and mPAP, and reversed lung vascular remodeling in rats with MCT-induced PAH. ICT also reversed MCT-induced ET-1 elevation, NO and cGMP reduction in serum or lung tissue. Moreover, ICT administration significantly induced eNOS activation and PDE5A inhibition. ICT with lower dose had better effects than ICA. In summary, ICT is more effective in preventing MCT-induced PAH in rats via NO/cGMP activation compared with ICA. These findings demonstrate a novel mechanism of the action of ICT that may have value in prevention of PAH. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Structural consequences of the natural substitution, E9K, on reactive-site-hydrolyzed squash (Cucurbita maxima) trypsin inhibitor (CMTI), as studied by two-dimensional NMR.

    Science.gov (United States)

    Krishnamoorthi, R; Lin, C L; VanderVelde, D

    1992-06-02

    Sequence-specific hydrogen-1 NMR assignments were made to all of the 29 amino acid residues of reactive-site-hydrolyzed Cucurbita maxima trypsin inhibitor I (CMTI-I*) by the application of two-dimensional NMR (2D NMR) techniques, and its secondary structural elements (two tight turns, a 3(10)-helix, and a triple-stranded beta-sheet) were identified on the basis of short-range NOESY cross peaks and deuterium-exchange kinetics. These secondary structural elements are present in the intact inhibitor [Holak, T. A., Gondol, D., Otlewski, J., & Wilusz, T. (1989) J. Mol. Biol. 210, 635-648] and are unaffected by the hydrolysis of the reactive-site peptide bond between Arg5 and Ile6, in accordance with the earlier conclusion reached for CMTI-III* [Krishnamoorthi, R., Gong, Y.-X., Lin, C. S., & VanderVelde, D. (1992) Biochemistry 31, 898-904]. Chemical shifts of backbone hydrogen atoms, peptide NH's, and C alpha H's, of CMTI-I* were compared with those of the intact inhibitor, CMTI-I, and of the reactive-site-hydrolyzed, natural, E9K variant, CMTI-III*. Cleavage of the Arg5-Ile6 peptide bond resulted in changes of chemical shifts of most of the backbone atoms of CMTI-I, in agreement with the earlier results obtained for CMTI-III. Comparison of chemical shifts of backbone hydrogen atoms of CMTI-I* and CMTI-III* revealed no changes, except for residues Glu9 and His25. However, the intact forms of the same two proteins, CMTI-I and CMTI-III, showed small but significant perturbations of chemical shifts of residues that made up the secondary structural elements of the inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Comparison of efficacy and satisfaction profile, between penile prosthesis implantation and oral PDE5 inhibitor tadalafil therapy, in men with nerve-sparing radical prostatectomy erectile dysfunction.

    Science.gov (United States)

    Megas, Georgios; Papadopoulos, Georgios; Stathouros, Georgios; Moschonas, Dimitrios; Gkialas, Ioannis; Ntoumas, Konstantinos

    2013-07-01

    WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Erectile dysfunction after nerve-sparing radical retropubic prostatectomy constitutes a challenge to the urologist. The mainstay of medical treatment after radical prostatectomy to restore spontaneous erectile function remains phosphodiesterase (PDE5) inhibitors, despite the fact that data from animal studies suggesting that PDE5 inhibitors can prevent smooth muscle apoptosis and fibrosis have not yet been extrapolated to humans because of a lack of standardized protocols. If the above treatment fails, second-line therapies such as intraurethral prostaglandins, penile injection therapy and vacuum devices are offered. When less invasive therapies are ineffective, interventions that preserve sexual function such as penile prosthesis implantation become the treatment of choice. Our study reveals the alternative of penile prosthesis implantation as first-line treatment in erectile dysfunction after nerve-sparing radical prostatectomy. It also highlights its superiority to the oral PDE5 inhibitor treatment, regarding the erection, frequency, firmness, maintenance and penetration ability. This suggests that a concept of an early penile intervention in the future would be promising for those patients who wish to remain sexually active without depending on oral formulations with doubtful and delayed results. To evaluate the outcome of penile prosthesis surgery in comparison to oral phosphodiesterase type 5 (PDE5) inhibitor administration, in men with erectile dysfunction after nerve-sparing radical prostatectomy, as early penile intervention therapy. A total of 174 patients treated by nerve-sparing retropubic radical prostatectomy (RRP) for clinically localized prostate cancer, between January 2006 and September 2009 enrolled in the study, 153 patients fulfilled the inclusion criteria, and 69 (45%) patients presented with post-RRP erectile dysfunction 6 months after primary surgery. Fifty-four patients were disease

  1. Effects of co-administration of dietary sodium arsenite and an NADPH oxidase inhibitor on the rat bladder epithelium

    International Nuclear Information System (INIS)

    Suzuki, Shugo; Arnold, Lora L.; Pennington, Karen L.; Kakiuchi-Kiyota, Satoko; Cohen, Samuel M.

    2009-01-01

    Arsenite (As III ), an inorganic arsenical, is a known human carcinogen, inducing tumors of the skin, urinary bladder and lung. It is metabolized to organic methylated arsenicals. Oxidative stress has been suggested as a mechanism for arsenic-induced carcinogenesis. Reactive oxygen species (ROS) can be important factors for carcinogenesis and tumor progression. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is known to produce intracellular ROS, therefore, we investigated the ability of apocynin (acetovanillone), an NADPH oxidase inhibitor, to inhibit the cytotoxicity and regenerative cell proliferation of arsenic in vitro and in vivo. Apocynin had similar effects in reducing the cytotoxicity of As III and dimethylarsinous acid (DMA III ) in rat urothelial cells in vitro. When tested at the same concentrations as apocynin, other antioxidants, such as L-ascorbate and N-acetylcysteine, did not inhibit As III -induced cytotoxicity but they were more effective at inhibiting DMA III -induced cytotoxicity compared with apocynin. In vivo, female rats were treated for 3 weeks with 100 ppm As III . Immunohistochemical staining for 8-hydroxy-2'-deoxyguanosine (8-OHdG) showed that apocynin reduced oxidative stress partially induced by As III treatment on rat urothelium, and significantly reduced the cytotoxicity of superficial cells detected by scanning electron microscopy (SEM). However, based on the incidence of simple hyperplasia and the bromodeoxyuridine (BrdU) labeling index, apocynin did not inhibit As III -induced urothelial cell proliferation. These data suggest that the NADPH oxidase inhibitor, apocynin, may have the ability to partially inhibit arsenic-induced oxidative stress and cytotoxicity of the rat bladder epithelium in vitro and in vivo. However, apocynin did not inhibit the regenerative cell proliferation induced by arsenite in a short-term study.

  2. Effects of PDE5 Inhibitors and sGC Stimulators in a Rat Model of Artificial Ureteral Calculosis.

    Directory of Open Access Journals (Sweden)

    Peter Sandner

    Full Text Available Urinary colics from calculosis are frequent and intense forms of pain whose current pharmacological treatment remains unsatisfactory. New and more effective drugs are needed to control symptoms and improve stone expulsion. Recent evidence suggested that the Nitric Oxide (NO / cyclic guanosine monophosphate (cGMP/phosphodiesterase type 5 (PDE5 system may contribute to ureteral motility influencing stone expulsion. We investigated if PDE5 inhibitors and sGC stimulators influence ureteral contractility, pain behaviour and stone expulsion in a rat model of ureteral calculosis. We investigated: a the sex-specific PDE5 distribution in the rat ureter; b the functional in vitro effects of vardenafil and sildenafil (PDE5 inhibitors and BAY41-2272 (sGC stimulator on induced ureteral contractility in rats and c the in vivo effectiveness of vardenafil and BAY41-2272, alone and combined with ketoprofen, vs hyoscine-N-butylbromide alone or combined with ketoprofen, on behavioural pain indicators and stone expulsion in rats with artificial calculosis in one ureter. PDE5 was abundantly expressed in male and female rats' ureter. In vitro, both vardenafil and BAY41-2272 significantly relaxed pre-contracted ureteral strips. In vivo, all compounds significantly reduced number and global duration of "ureteral crises" and post-stone lumbar muscle hyperalgesia in calculosis rats. The highest level of reduction of the pain behaviour was observed with BAY41-2272 among all spasmolytics administered alone, and with the combination of ketoprofen with BAY41-2272. The percentage of stone expulsion was maximal in the ketoprofen+BAY41-2272 group. The NO/cGMP/PDE5 pathway is involved in the regulation of ureteral contractility and pain behaviour in urinary calculosis. PDE5 inhibitors and sGC stimulators could become a potent new option for treatment of urinary colic pain.

  3. Does tadalafil prevent erectile dysfunction in patients undergoing radiation therapy for prostate cancer?

    NARCIS (Netherlands)

    L. Incrocci (Luca)

    2014-01-01

    textabstractA recently published paper addressed the interesting topic of prevention of erectile dysfunction (ED) with tadalafil, a phosphodiesterase-type 5 inhibitor (PDE5i) in patients undergoing radiation therapy for localized prostate cancer. [1]Tadalafil 5 mg or placebo was

  4. Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

    DEFF Research Database (Denmark)

    Clemmesen, Jens-Otto; Giraldi, Annamaria; Ott, Peter

    2008-01-01

    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...

  5. Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

    DEFF Research Database (Denmark)

    Clemmesen, J.O.; Giraldi, A.; Ott, P.

    2008-01-01

    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 liv...... type-5 inhibitor sildenafil, the present study could not demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG Udgivelsesdato: 2008/10/28...

  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

    2009-01-01

    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...

  7. 2'-phosphodiesterase and 2',5'-oligoadenylate synthetase activities in the lowest metazoans, sponge [porifera].

    Science.gov (United States)

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

    2009-01-01

    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.

  8. 2',3'-cyclic nucleotide 3'-phosphodiesterases inhibit hepatitis B virus replication.

    Directory of Open Access Journals (Sweden)

    Hui Ma

    Full Text Available 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP is a member of the interferon-stimulated genes, which includes isoforms CNP1 and CNP2. CNP1 is locally expressed in the myelin sheath but CNP2 is additionally expressed at low levels outside the nervous system. CNPs regulate multiple cellular functions and suppress protein production by association with polyadenylation of mRNA. Polyadenylation of Hepatitis B virus (HBV RNAs is crucial for HBV replication. Whether CNPs interact with polyadenylation signal of HBV RNAs and interfere HBV replication is unknown. In this study, we evaluated expressions of CNP isoforms in hepatoma cell lines and their effects on HBV replication. We found that CNP2 is moderately expressed and gently responded to interferon treatment in HepG2, but not in Huh7 cells. The CNP1 and CNP2 potently inhibited HBV production by blocking viral proteins synthesis and reducing viral RNAs, respectively. In chronic hepatitis B patients, CNP was expressed in most of HBV-infected hepatocytes of liver specimens. Knockdown of CNP expression moderately improved viral production in the HepG2.2.15 cells treated with IFN-α. In conclusion, CNP might be a mediator of interferon-induced response against HBV.

  9. Structural Basis for Inhibitor-Induced Hydrogen Peroxide Production by Kynurenine 3-Monooxygenase.

    Science.gov (United States)

    Kim, Hyun Tae; Na, Byeong Kwan; Chung, Jiwoung; Kim, Sulhee; Kwon, Sool Ki; Cha, Hyunju; Son, Jonghyeon; Cho, Joong Myung; Hwang, Kwang Yeon

    2018-04-19

    Kynurenine 3-monooxygenase (KMO) inhibitors have been developed for the treatment of neurodegenerative disorders. The mechanisms of flavin reduction and hydrogen peroxide production by KMO inhibitors are unknown. Herein, we report the structure of human KMO and crystal structures of Saccharomyces cerevisiae (sc) and Pseudomonas fluorescens (pf) KMO with Ro 61-8048. Proton transfer in the hydrogen bond network triggers flavin reduction in p-hydroxybenzoate hydroxylase, but the mechanism triggering flavin reduction in KMO is different. Conformational changes via π-π interactions between the loop above the flavin and substrate or non-substrate effectors lead to disorder of the C-terminal α helix in scKMO and shifts of domain III in pfKMO, stimulating flavin reduction. Interestingly, Ro 61-8048 has two different binding modes. It acts as a competitive inhibitor in scKMO and as a non-substrate effector in pfKMO. These findings provide understanding of the catalytic cycle of KMO and insight for structure-based drug design of KMO inhibitors. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Sildenafil enhances systolic adaptation, but does not prevent diastolic dysfunction, in the pressure-loaded right ventricle

    NARCIS (Netherlands)

    Borgdorff, Marinus A. J.; Bartelds, Beatrijs; Dickinson, Michael G.; Weij, Michel; Zandvoort, Andre; Sillje, Herman H. W.; Steendijk, Paul; de Vroomen, Maartje; Berger, Rolf M. F.; Boersma, B.

    Right ventricular (RV) failure due to pressure or volume overload is a major risk factor for early mortality in congenital heart disease and pulmonary hypertension, but currently treatments are lacking. We aimed to demonstrate that the phosphodiesterase 5A inhibitor sildenafil can prevent adverse

  11. Heart protection by combination therapy with esmolol and milrinone at late-ischemia and early reperfusion.

    Science.gov (United States)

    Huang, Ming-He; Wu, Yewen; Nguyen, Vincent; Rastogi, Saurabh; McConnell, Bradley K; Wijaya, Cori; Uretsky, Barry F; Poh, Kian-Keong; Tan, Huay-Cheem; Fujise, Kenichi

    2011-06-01

    The present study determined whether late-ischemia/early reperfusion therapy with the β(1)-adrenergic receptor (AR) blocker esmolol and phosphodiesterase III inhibitor milrinone reduced left ventricular (LV) myocardial infarct size (IS). In an ischemia/reperfusion rat model (30-min ischemia/4-hr reperfusion), esmolol, milrinone or esmolol + milrinone were intravenous (IV) infused over 10 min (from the last 5 min of ischemia to the first 5 min of reperfusion). LV-IS were 48.9 ± 8.9%, 41.5 ± 5.4%, 25.8 ± 7.7% and 16.8 ± 7.3% for saline, esmolol, milrinone, and esmolol + milrinone, respectively (n = 12/group). Esmolol + milrinone further reduced LV-IS compared with esmolol or milrinone alone (p milrinone was eliminated in the presence of protein kinase A-(PKA)-inhibitor (Rp-cAMPS) or Akt-inhibitor (AKT 1/2 kinase inhibitor). In mixed rat ventricular cardiomyocyte cultures, intra-ischemic application of esmolol, milrinone or esmolol + milrinone reduced myocyte death rates by 5.5%, 13.3%, and 16.8%, respectively, compared with saline (p milrinone was abrogated in the presence of PKA-inhibitor or Akt-inhibitor. Esmolol, milrinone or esmolol + milrinone increased myocardial PKA activity by 22%, 28% and 59%, respectively, compared with saline (n = 6, p milrinone or esmolol + milrinone, there were 1.7-, 2.7-, and 6-fold increase in tissue pAkt levels, respectively. This esmolol + milrinone induced pAkt activation was abolished in the presence of PKA inhibitor. Esmolol, milrinone and esmolol + milrinone reduced myocyte apoptosis rates by 22%, 37% and 60%, respectively, compared with saline (p milrinone additively reduces LV-IS associated with robust activation of myocardial PKA and subsequent Akt-antiapoptotic pathway.

  12. Efficacy and gastrointestinal tolerability of ML3403, a selective inhibitor of p38 MAP kinase and CBS-3595, a dual inhibitor of p38 MAP kinase and phosphodiesterase 4 in CFA-induced arthritis in rats.

    Science.gov (United States)

    Koch, Diana A; Silva, Rodrigo B M; de Souza, Alessandra H; Leite, Carlos E; Nicoletti, Natália F; Campos, Maria M; Laufer, Stefan; Morrone, Fernanda B

    2014-03-01

    Mitogen-activated protein kinase (MAPK) p38 inhibitors have entered the clinical phase, although many of them have failed due to high toxicity and lack of efficacy. In the present study we compared the effects of the selective p38 inhibitor ML3403 and the dual p38-PDE4 inhibitor CBS-3595, on inflammatory and nociceptive parameters in a model of polyarthritis in rats. Male Wistar rats (180-200 g) were used for the complete Freund's adjuvant (CFA)-induced arthritis model and they were evaluated at 14-21 days. We also analysed the effects of these pharmacological tools on liver and gastrointestinal toxicity and on cytokine levels. Repeated CBS-3595 (3 mg/kg) or ML3403 (10 mg/kg) administration produced significant anti-inflammatory actions in the chronic arthritis model induced by CFA. CBS-3595 and ML3403 treatment also markedly reduced the production of the proinflammatory cytokine IL-6 in the paw tissue, whereas it widely increased the levels of the anti-inflammatory cytokine IL-10. Moreover, CBS-3595 produced partial anti-allodynic effects in the CFA model at 4 and 8 days after treatment. Notably, ML3403 and CBS-3595 did not show marked signs of hepatoxicity, as supported by unaltered histological observations in the liver sections. Finally, both compounds were safe in the gastrointestinal tract, according to evaluation of intestinal biopsies. CBS-3595 displayed a superior profile regarding its anti-inflammatory effects. Thus p38 MAPK/PDE4 blocking might well constitute a relevant strategy for the treatment of RA.

  13. β-secretase inhibitor; a promising novel therapeutic drug in AD

    Directory of Open Access Journals (Sweden)

    Kelly Willemijn Menting

    2014-07-01

    Full Text Available Alzheimer’s disease (AD and vascular dementia are responsible for up to 90% of dementia cases. According to the World Health Organization (WHO, a staggering number of 35.6 million people are currently diagnosed with dementia. Blocking disease progression or preventing AD altogether is desirable for both social and economic reasons and recently focus has shifted to a new and promising drug: the β-secretase inhibitor. Much of AD research has investigated the amyloid cascade hypothesis, which postulates that AD is caused by changes in amyloid beta (Aβ stability and aggregation. Blocking Aβ production by inhibiting the first protease required for its generation, β-secretase/BACE1, may be the next step in blocking AD progression. In April 2012, promising phase I data on inhibitor MK-8931 was presented. This drug reduced Aβ CSF levels up to 92% and was well tolerated by patients. In March 2013 data was added from a one week trial in 32 mild to moderate AD patients, showing CSF Aβ levels decreased up to 84%. However, BACE1 inhibitors require further research. First, greatly reducing Aβ levels through BACE1 inhibition may have harmful side effects. Second, BACE1 inhibitors have yet to pass clinical trial phase II/III and no data on possible side effects on AD patients are available. And third, there remains doubt about the clinical efficacy of BACE1 inhibitors. In moderate AD patients, Aβ plaques have already been formed. BACE1 inhibitors prevent production of new Aβ plaques, but hypothetically do not influence already existing Aβ peptides. Therefore, BACE1 inhibitors are potentially better at preventing AD instead of having therapeutic use.

  14. Tyrosyl-DNA Phosphodiesterase I a critical survival factor for neuronal development and homeostasis.

    Science.gov (United States)

    van Waardenburg, Robert C A M

    2016-01-01

    Tyrosyl-DNA phosphodiesterase I (TDP1), like most DNA repair associated proteins, is not essential for cell viability. However, dysfunctioning TDP1 or ATM (ataxia telangiectasia mutated) results in autosomal recessive neuropathology with similar phenotypes, including cerebellar atrophy. Dual inactivation of TDP1 and ATM causes synthetic lethality. A TDP1H 493 R catalytic mutant is associated with spinocerebellar ataxia with axonal neuropathy (SCAN1), and stabilizes the TDP1 catalytic obligatory enzyme-DNA covalent complex. The ATM kinase activates proteins early on in response to DNA damage. Tdp1-/- and Atm-/- mice exhibit accumulation of DNA topoisomerase I-DNA covalent complexes (TOPO1-cc) explicitly in neuronal tissue during development. TDP1 resolves 3'- and 5'-DNA adducts including trapped TOPO1-cc and TOPO1 protease resistant peptide-DNA complex. ATM appears to regulate the response to TOPO1-cc via a noncanonical function by regulating SUMO/ubiquitin-mediated TOPO1 degradation. In conclusion, TDP1 and ATM are critical factors for neuronal cell viability via two independent but cooperative pathways.

  15. Roles of A-Kinase Anchoring Proteins and Phosphodiesterases in the Cardiovascular System

    Science.gov (United States)

    Ercu, Maria; Klussmann, Enno

    2018-01-01

    A-kinase anchoring proteins (AKAPs) and cyclic nucleotide phosphodiesterases (PDEs) are essential enzymes in the cyclic adenosine 3′-5′ monophosphate (cAMP) signaling cascade. They establish local cAMP pools by controlling the intensity, duration and compartmentalization of cyclic nucleotide-dependent signaling. Various members of the AKAP and PDE families are expressed in the cardiovascular system and direct important processes maintaining homeostatic functioning of the heart and vasculature, e.g., the endothelial barrier function and excitation-contraction coupling. Dysregulation of AKAP and PDE function is associated with pathophysiological conditions in the cardiovascular system including heart failure, hypertension and atherosclerosis. A number of diseases, including autosomal dominant hypertension with brachydactyly (HTNB) and type I long-QT syndrome (LQT1), result from mutations in genes encoding for distinct members of the two classes of enzymes. This review provides an overview over the AKAPs and PDEs relevant for cAMP compartmentalization in the heart and vasculature and discusses their pathophysiological role as well as highlights the potential benefits of targeting these proteins and their protein-protein interactions for the treatment of cardiovascular diseases. PMID:29461511

  16. Population pharmacokinetics of olprinone in healthy male volunteers

    Directory of Open Access Journals (Sweden)

    Kunisawa T

    2014-03-01

    Full Text Available Takayuki Kunisawa,1 Hidefumi Kasai,2 Makoto Suda,2 Manabu Yoshimura,3 Ami Sugawara,3 Yuki Izumi,3 Takafumi Iida,3 Atsushi Kurosawa,3 Hiroshi Iwasaki3 1Surgical Operation Department, Asahikawa Medical University Hospital, Hokkaido, Japan; 2Clinical Study Management Division, Bell Medical Solutions Inc, Tokyo, Japan; 3Department of Anesthesiology and Critical Care Medicine, Asahikawa Medical University, Hokkaido, Japan Background: Olprinone decreases the cardiac preload and/or afterload because of its vasodilatory effect and increases myocardial contractility by inhibiting phosphodiesterase III. Purpose: The objective of this study was to characterize the population pharmacokinetics of olprinone after a single continuous infusion in healthy male volunteers. Methods: We used 500 plasma concentration data points collected from nine healthy male volunteers for the study. The population pharmacokinetic analysis was performed using the nonlinear mixed effect model (NONMEM® software. Results: The time course of plasma concentration of olprinone was best described using a two-compartment model. The final pharmacokinetic parameters were total clearance (7.37 mL/minute/kg, distribution volume of the central compartment (134 mL/kg, intercompartmental clearance (7.75 mL/minute/kg, and distribution volume of the peripheral compartment (275 mL/kg. The interindividual variability in the total clearance was 12.4%, and the residual error variability (exponential and additive were 22.2% and 0.129 (standard deviation. The final pharmacokinetic model was assessed using a bootstrap method and visual predictive check. Conclusion: We developed a population pharmacokinetic model of olprinone in healthy male adults. The bootstrap method and visual predictive check showed that this model was appropriate. Our results might be used to develop the population pharmacokinetic model in patients. Keywords: phosphodiesterase III inhibitor, men, pharmacokinetic model

  17. Isothiocyanato complexes of Gd(III), Tb(III), Dy(III) and Ho(III) with 2-(2'-pyridyl)benzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A; Singh, V K

    1982-01-01

    Six-coordinated complexes of the type (Ln(PyBzH)/sub 2/NCS.H/sub 2/O) (NCS)/sub 2/.nH/sub 2/O/mC/sub 2/H/sub 5/OH (Ln = Gd(III), Tb(III), Dy(III) and Ho(III), n=1-2; m=1) have been prepared from Ln(NCS)/sub 6//sup 3 -/. The room temperature magnetic moment values confirm the terpositive state of the lanthanide ions. Infrared spectra suggest the N-coordination of thiocyanate group. Electronic spectral studies of Tb(III), Dy(III) and Ho(III) complexes have been made in terms of LSJ term energies. 13 refs.

  18. 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

    2010-01-01

    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...... by measurements of inulin- and para-amino hippuric acid (PAH) clearances, respectively. RESULTS: The basal PRC was reduced in nNOS⁻(/)⁻ compared to the wild types. Administration of milrinone caused a more pronounced PRC increase in nNOS⁻(/)⁻, resulting in normalized renin levels, whereas PDE5 inhibition did...... not affect PRC in any genotype. The blood pressure was similar in both genotypes, and milrinone did not affect blood pressure compared to vehicle. GFR and RPF were similar at baseline and were reduced by milrinone. CONCLUSIONS: The present study provides in vivo evidence supporting the view that NO...

  19. Decision tree analyses of key patient characteristics in Middle Eastern/North African and Latin American men treated with long-acting and short-acting PDE5 inhibitors for erectile dysfunction.

    Science.gov (United States)

    Rubio-Aurioles, Eusebio; El-Meliegy, Amr; Abdulwahed, Samer; Henneges, Carsten; Sorsaburu, Sebastian; Gurbuz, Sirel

    2015-02-01

    Phosphodiesterase type 5 (PDE5) inhibitors have discontinuation rates as high as 60% in men with erectile dysfunction. Treatment satisfaction has been significantly associated with treatment continuation. Understanding key characteristics in terms of treatment preference, relationship, and lifestyle issues could provide direction on how to improve compliance with PDE5 inhibitor treatment globally. The objective was to identify subgroups of interest in the pooled database of two observational studies conducted in Latin America (LA) and Middle East/North Africa (MENA) exploring patient characteristics and prescription of either a long- or short-acting PDE5 inhibitor at baseline. Two identical prospective, non-interventional, observational, studies in MENA (N = 493) and LA (N = 511) treated men with an 'on demand' (pro re nata, PRN) PDE5 inhibitor (sildenafil, tadalafil, vardenafil, or lodenafil) during 6 months. In this post-hoc meta-analysis of two observational studies with equal design, pooled data were analyzed to determine patient characteristics and PDE5 inhibitor prescribed/used most likely to be associated with patient expectations, satisfaction, self-esteem, and patient-partner relationships. Decision tree analyses, with and without weighting, were used to identify and describe key features. In each analysis of patient expectations, patient-partner relationship, and self-esteem, we describe the two major subgroups at baseline for each decision tree. Analyses of patient expectations and sexual self-esteem revealed that patients prescribed long-acting PDE5 inhibitors (59%) highlighted the importance of treatment effect duration, second to partner satisfaction with treatment, while patients prescribed short-acting PDE5 inhibitors (32%) placed less importance on treatment effect duration but considerable importance on treatment effect lasting until intercourse completion. Further insights regarding patients, partner relationship characteristics, and

  20. Low-dose aspirin, non-steroidal anti-inflammatory drugs, selective COX-2 inhibitors and breast cancer recurrence

    DEFF Research Database (Denmark)

    Cronin-Fenton, Deirdre P; Heide-Jørgensen, Uffe; Ahern, Thomas P

    2016-01-01

    BACKGROUND: Aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and selective COX-2 inhibitors may improve outcomes in breast cancer patients. We investigated the association of aspirin, NSAIDs, and use of selective COX-2 inhibitors with breast cancer recurrence. METHODS: We identified incident...... stage I-III Danish breast cancer patients in the Danish Breast Cancer Cooperative Group registry, who were diagnosed during 1996-2008. Prescriptions for aspirin (>99% low-dose aspirin), NSAIDs, and selective COX-2 inhibitors were ascertained from the National Prescription Registry. Follow-up began....... RESULTS: We identified 34,188 breast cancer patients with 233,130 person-years of follow-up. Median follow-up was 7.1 years; 5,325 patients developed recurrent disease. Use of aspirin, NSAIDs, or selective COX-2 inhibitors was not associated with the rate of recurrence (HRadjusted aspirin = 1.0, 95% CI...

  1. Smoothened inhibitors in the treatment of advanced basal cell carcinomas.

    Science.gov (United States)

    Kunstfeld, Rainer

    2014-03-01

    The Hedgehog pathway has been identified as a key element in the development of many forms of cancer. Smoothened (Smo) inhibitors are known to beneficially interfere with the Hedgehog pathway and are currently under investigation as anticancer drugs for many tumor entities. Reviewed here are the most recent developments in clinical research on Smo inhibitors for the treatment of advanced basal cell carcinoma (BCC). When reviewing the literature of the past 12 months, it is striking to see the rapid evolution of the field. Compounds that have been presented as powerful new drug candidates 12 months ago have now been discontinued, whereas new ones have emerged. Reports on 13 drug candidates have been identified: one marketed, vismodegib, eight currently under development (phase I-II) and four for which clinical investigation for BCC is currently not being pursued. Smo inhibitors are a promising drug class for the treatment of BCC. To date, most candidates are in early stage development and are expected to enter the market in approximately 5-8 years, if successful.

  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.

    Science.gov (United States)

    Bilodeau-Goeseels, Sylvie

    2011-01-01

    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. Copyright © 2011 Wiley Periodicals, Inc.

  3. Mænd med rejsningsbesvær efter radikal prostatektomi bør behandles efter sædvanlige retningslinjer

    DEFF Research Database (Denmark)

    Fode, Mikkel; Hansen, Rikke Bølling; Maigaard, Thomas

    2014-01-01

    Penile rehabilitation programmes aim to improve long-term sexual function after nerve-sparing radical prostatectomy. Programmes aim to improve cavernous oxygenation to avoid structural damage in penile tissue. Especially, daily use of phosphodiesterase type 5 (PDE5) inhibitors has been studied. T......, urethral suppositories and penile implants....

  4. Mænd med rejsningsbesvær efter radikal prostatektomi bør behandles efter sædvanlige retningslinjer

    DEFF Research Database (Denmark)

    Fode, Mikkel; Hansen, Rikke Bølling; Maigaard, Thomas

    2015-01-01

    Penile rehabilitation programmes aim to improve long-term sexual function after nerve-sparing radical prostatectomy. Programmes aim to improve cavernous oxygenation to avoid structural damage in penile tissue. Especially, daily use of phosphodiesterase type 5 (PDE5) inhibitors has been studied. T......, urethral suppositories and penile implants....

  5. Lapatinib versus hormone therapy in patients with advanced renal cell carcinoma: a randomized phase III clinical trial

    DEFF Research Database (Denmark)

    Ravaud, Alain; Hawkins, Robert; Gardner, Jason P

    2008-01-01

    PURPOSE: Lapatinib is an orally reversible inhibitor of epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor 2 (HER-2) tyrosine kinases with demonstrated activity in patients with HER-2-positive breast cancer. In the current phase III open-label trial, lapatinib was comp...

  6. Effects of cholera toxin and isobutylmethylxanthine on growth of human fibroblasts

    International Nuclear Information System (INIS)

    Espinoza, B.; Wharton, W.

    1986-01-01

    Cholera toxin produced a dose-dependent decrease in the restimulation of G 0 /G 1 traverse in density-arrested human fibroblasts but did not inhibit the stimulation of cells arrested in G 0 after serum starvation at low density. In addition, cholera toxin did not inhibit the proliferation of sparse logarithmically growing human fibroblasts, even when low concentrations of the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) were also present. However, the final density to which sparse cells grew was limited by cholera toxin, when added either alone or together with low concentrations of IBMX. In contrast, high concentrations of the phosphodiesterase inhibitor alone produced a profound inhibition in the growth of sparse human fibrobasts. IBMX produced an inhibition both in the G 1 and in the G 2 phases of the cell cycle by a mechanism(s) that was not related to the magnitude of the increases in adenosine 3,5-cyclic monophosphate concentrations

  7. Complexation of trivalent actinides and lanthanides with hydrophilic N-donor ligands for Am(III)/Cm(III) and An(III)/Ln(III) separation; Komplexierung von trivalenten Actiniden und Lanthaniden mit hydrophilen N-Donorliganden zur Am(III)/Cm(III)- bzw. An(III)/Ln(III)-Trennung

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Christoph

    2017-07-24

    The implementation of actinide recycling processes is considered in several countries, aiming at the reduction of long-term radiotoxicity and heat load of used nuclear fuel. This requires the separation of the actinides from the fission and corrosion products. The separation of the trivalent actinides (An(III)) Am(III) and Cm(III), however, is complicated by the presence of the chemically similar fission lanthanides (Ln(III)). Hydrophilic N-donor ligands are employed as An(III) or Am(III) selective complexing agents in solvent extraction to strip An(III) or Am(III) from an organic phase loaded with An(III) and Ln(III). Though they exhibit excellent selectivity, the complexation chemistry of these ligands and the complexes formed during solvent extraction are not sufficiently characterized. In the present thesis the complexation of An(III) and Ln(III) with hydrophilic N-donor ligands is studied by time resolved laser fluorescence spectroscopy (TRLFS), UV/Vis, vibronic sideband spectroscopy and solvent extraction. TRLFS studies on the complexation of Cm(III) and Eu(III) with the Am(III) selective complexing agent SO{sub 3}-Ph-BTBP (tetrasodium 3,3{sup '},3'',3{sup '''}-([2,2{sup '}-bipyridine]-6,6{sup '}-diylbis(1,2,4-triazine-3,5,6-triyl)) tetrabenzenesulfonate) revealed the formation of [M(SO{sub 3}-Ph-BTBP){sub n}]{sup (4n-3)-} complexes (M = Cm(III), Eu(III); n = 1, 2). The conditional stability constants were determined in different media yielding two orders of magnitude larger β{sub 2}-values for the Cm(III) complexes, independently from the applied medium. A strong impact of ionic strength on the stability and stoichiometry of the formed complexes was identified, resulting from the stabilization of the pentaanionic [M(SO{sub 3}-Ph-BTBP){sub 2}]{sup 5-} complex with increasing ionic strength. Thermodynamic studies of Cm(III)-SO{sub 3}-Ph-BTBP complexation showed that the proton concentration of the applied medium impacts

  8. Complexes of 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III)

    International Nuclear Information System (INIS)

    Ferenc, W.; Bernat, M; Gluchowska, H.W.; Sarzynski, J.

    2010-01-01

    The complexes of 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III) have been synthesized as polycrystalline hydrated solids, and characterized by elemental analysis, spectroscopy, magnetic studies and also by X-ray diffraction and thermogravimetric measurements. The analysed complexes have the following colours: violet for Nd(III), white for Gd(III) and cream for Ho(III) compounds. The carboxylate groups bind as bidentate chelating (Ho) or bridging ligands (Nd, Gd). On heating to 1173K in air the complexes decompose in several steps. At first, they dehydrate in one step to form anhydrous salts, that next decompose to the oxides of respective metals. The gaseous products of their thermal decomposition in nitrogen were also determined and the magnetic susceptibilities were measured over the temperature range of 76-303K and the magnetic moments were calculated. The results show that 4-chlorophenoxyacetates of Nd(III), Gd(III) and Ho(III) are high-spin complexes with weak ligand fields. The solubility value in water at 293K for analysed 4-chlorophenoxyacetates is in the order of 10 -4 mol/dm 3 . (author)

  9. Angiotensin II increases phosphodiesterase 5A expression in vascular smooth muscle cells: A mechanism by which angiotensin II antagonizes cGMP signaling

    Science.gov (United States)

    Kim, Dongsoo; Aizawa, Toru; Wei, Heng; Pi, Xinchun; Rybalkin, Sergei D.; Berk, Bradford C.; Yan, Chen

    2014-01-01

    Angiotensin II (Ang II) and nitric oxide (NO)/natriuretic peptide (NP) signaling pathways mutually regulate each other. Imbalance of Ang II and NO/NP has been implicated in the pathophysiology of many vascular diseases. cGMP functions as a key mediator in the interaction between Ang II and NO/NP. Cyclic nucleotide phosphodiesterase 5A (PDE5A) is important in modulating cGMP signaling by hydrolyzing cGMP in vascular smooth muscle cells (VSMC). Therefore, we examined whether Ang II negatively modulates intracellular cGMP signaling in VSMC by regulating PDE5A. Ang II rapidly and transiently increased PDE5A mRNA levels in rat aortic VSMC. Upregulation of PDE5A mRNA was associated with a time-dependent increase of both PDE5 protein expression and activity. Increased PDE5A mRNA level was transcription-dependent and mediated by the Ang II type 1 receptor. Ang II-mediated activation of extracellular signal-regulated kinases 1/2 (ERK1/2) was essential for Ang II-induced PDE5A upregulation. Pretreatment of VSMC with Ang II inhibited C-type NP (CNP) stimulated cGMP signaling, such as cGMP dependent protein kinase (PKG)-mediated phosphorylation of vasodilator-stimulated-phosphoprotein (VASP). Ang II-mediated inhibition of PKG was blocked when PDE5 activity was decreased by selective PDE5 inhibitors, suggesting that upregulation of PDE5A expression is an important mechanism for Ang II to attenuate cGMP signaling. PDE5A may also play a critical role in the growth promoting effects of Ang II because inhibition of PDE5A activity significantly decreased Ang II-stimulated VSMC growth. These observations establish a new mechanism by which Ang II antagonizes cGMP signaling and stimulates VSMC growth. PMID:15623434

  10. Sildenafil citrate-restored eNOS and PDE5 regulation in sickle cell mouse penis prevents priapism via control of oxidative/nitrosative stress.

    Science.gov (United States)

    Bivalacqua, Trinity J; Musicki, Biljana; Hsu, Lewis L; Berkowitz, Dan E; Champion, Hunter C; Burnett, Arthur L

    2013-01-01

    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.

  11. Interaction of fucoidan with proteases and inhibitors of coagulation and fibrinolysis.

    Science.gov (United States)

    Minix, R; Doctor, V M

    1997-09-01

    The interactions of fucoidan with glutamic plasminogen (Glu-Plg), two-chain tissue plasminogen activator (t-PA), LMwt-urokinase, thrombin, and antithrombin III (AT-III) were investigated using fucoidan-sepharose affinity chromatography. The results showed 1) a high degree of affinity between fucoidan-sepharose and Glu-Plg; Lmwt-urokinase and thrombin while t-Pa and AT-III did not bind with fucoidan-sepharose. 2) The double reciprocal plot for the LMwt-urokinase activation of Glu-Plg showed that plasminogen activator inhibitor (PAI-1) inhibited this reaction in a noncompetitive manner and that the presence of fucoidan decreased Km for this interaction by 50% and increased Kcat by 30-fold, 3) The double reciprocal plot for the t-PA activation of Glu-Plg showed that PAI-1 inhibited this reaction in a competitive manner and that fucoidan in conjunction with 6-aminohexanoic acid (6-AH) increased Kcat for this interaction by 5-fold without affecting Km. 4) Fucoidan enhanced the interaction of thrombin with both AT-III and heparin cofactor II (HC-II) and it was more effective than unfractionated heparin of LMwt-heparin in enhancing the interaction of HC-II with thrombin.

  12. Changes in soluble CEA and TIMP-1 levels during adjuvant chemotherapy for stage III colon cancer

    DEFF Research Database (Denmark)

    Aldulaymi, Bahir; Christensen, Ib Jarle; Sölétormos, György

    2010-01-01

    Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been suggested to be a valuable marker in colorectal cancer (CRC), but the effects of chemotherapy on TIMP-1 levels are unknown. The present study evaluated the effect of chemotherapy on TIMP-1 levels in comparison with carcinoembryonic antige...... (CEA) levels in patients with stage III colon cancer.......Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been suggested to be a valuable marker in colorectal cancer (CRC), but the effects of chemotherapy on TIMP-1 levels are unknown. The present study evaluated the effect of chemotherapy on TIMP-1 levels in comparison with carcinoembryonic antigen...

  13. Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-[(1H-benzimidazol-2-yl-methylene) amino] phenol

    International Nuclear Information System (INIS)

    Omprakash, K.L.; Chandra Pal, A.V.; Reddy, M.L.N.

    1982-01-01

    A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO 4 ) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (logβ 2 ) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III). (author)

  14. Formation constants of Sm(III), Dy(III), Gd(III), Pr(III) and Nd(III) complexes of tridentate schiff base, 2-((1H-benzimidazol-2-yl-methylene) amino) phenol

    Energy Technology Data Exchange (ETDEWEB)

    Omprakash, K L; Chandra Pal, A V; Reddy, M L.N. [Osmania Univ., Hyderabad (India). Dept. of Chemistry

    1982-03-01

    A new tridentate schiff base, 2- (1H-benzimidazol-2-yl-methylene)amino phenol derived from benzimididazole-2-carbo-xaldehyde and 2-aminophenol has been synthesised and characterised by spectral and analytical data. Proton-ligand formation constants of the schiff base and metal-ligand formation constants of its complexes with Sm(III), Dy(III), Gd(III), Nd(III) and Pr(III) have been determined potentiometrically in 50% (v/v) aqueous dioxane at an ionic strength of 0.1M (NaClO/sub 4/) and at 25deg C using the Irving-Rossotti titration technique. The order of stability constants (log..beta../sub 2/) is found to be Sm(III)>Dy(III)>Gd(III)>Pr(III)>Nd(III).

  15. Treatment of esophageal motility disorders based on the chicago classification.

    Science.gov (United States)

    Maradey-Romero, Carla; Gabbard, Scott; Fass, Ronnie

    2014-12-01

    The Chicago Classification divides esophageal motor disorders based on the recorded value of the integrated relaxation pressure (IRP). The first group includes those with an elevated mean IRP that is associated with peristaltic abnormalities such as achalasia and esophagogastric junction outflow obstruction. The second group includes those with a normal mean IRP that is associated with esophageal hypermotility disorders such as distal esophageal spasm, hypercontractile esophagus (jackhammer esophagus), and hypertensive peristalsis (nutcracker esophagus). The third group includes those with a normal mean IRP that is associated with esophageal hypomotility peristaltic abnormalities such as absent peristalsis, weak peristalsis with small or large breaks, and frequent failed peristalsis. The therapeutic options vary greatly between the different groups of esophageal motor disorders. In achalasia patients, potential treatment strategies comprise medical therapy (calcium channel blockers, nitrates, and phosphodiesterase 5 inhibitors), endoscopic procedures (botulinum toxin A injection, pneumatic dilation, or peroral endoscopic myotomy) or surgery (Heller myotomy). Patients with a normal IRP and esophageal hypermotility disorder are candidates for medical therapy (nitrates, calcium channel blockers, phosphodiesterase 5 inhibitors, cimetropium/ipratropium bromide, proton pump inhibitors, benzodiazepines, tricyclic antidepressants, trazodone, selective serotonin reuptake inhibitors, and serotonin-norepinephrine reuptake inhibitors), endoscopic procedures (botulinum toxin A injection and peroral endoscopic myotomy), or surgery (Heller myotomy). Lastly, in patients with a normal IRP and esophageal hypomotility disorder, treatment is primarily focused on controlling the presence of gastroesophageal reflux with proton pump inhibitors and lifestyle modifications (soft and liquid diet and eating in the upright position) to address patient's dysphagia.

  16. Spectrophotometric and pH-Metric Studies of Ce(III, Dy(III, Gd(III,Yb(III and Pr(III Metal Complexes with Rifampicin

    Directory of Open Access Journals (Sweden)

    A. N. Sonar

    2011-01-01

    Full Text Available The metal-ligand and proton-ligand stability constant of Ce(III, Dy(III, Gd(III,Yb(III and Pr(III metals with substituted heterocyclic drug (Rifampicin were determined at various ionic strength by pH metric titration. NaClO4 was used to maintain ionic strength of solution. The results obtained were extrapolated to the zero ionic strength using an equation with one individual parameter. The thermodynamic stability constant of the complexes were also calculated. The formation of complexes has been studied by Job’s method. The results obtained were of stability constants by pH metric method is confirmed by Job’s method.

  17. Complexes of lanthanum(III), cerium(III), samarium(III) and dysprosium(III) with substituted piperidines

    Energy Technology Data Exchange (ETDEWEB)

    Manhas, B S; Trikha, A K; Singh, H; Chander, M

    1983-11-01

    Complexes of the general formulae M/sub 2/Cl/sub 6/(L)/sub 3/.C/sub 2/H/sub 5/OH and M/sub 2/(NO/sub 3/)/sub 6/(L)/sub 2/.CH/sub 3/OH have been synthesised by the reactions of chlorides and nitrates of La(III), Ce(III), Sm(III) and Dy(III) with 2-methylpiperidine, 3-methylpiperidine and 4-methylpiperidine. These complexes have been characterised on the basis of their elemental analysis, and IR and electronic reflectance spectra. IR spectral data indicate the presence of coordinated ethanol and methanol molecules and bidentate nitrate groups. Coordination numbers of the metal ions vary from 5 to 8. 19 refs.

  18. Precipitation of plutonium (III) oxalate and calcination to plutonium oxide

    International Nuclear Information System (INIS)

    Esteban, A.; Orosco, E.H.; Cassaniti, P.; Greco, L.; Adelfang, P.

    1989-01-01

    The plutonium based fuel fabrication requires the conversion of the plutonium nitrate solution from nuclear fuel reprocessing into pure PuO2. The conversion method based on the precipitation of plutonium (III) oxalate and subsequent calcination has been studied in detail. In this procedure, plutonium (III) oxalate is precipitated, at room temperature, by the slow addition of 1M oxalic acid to the feed solution, containing from 5-100 g/l of plutonium in 1M nitric acid. Before precipitation, the plutonium is adjusted to trivalent state by addition of 1M ascorbic acid in the presence of an oxidation inhibitor such as hydrazine. Finally, the precipitate is calcinated at 700 deg C to obtain PuO2. A flowsheet is proposed in this paper including: a) A study about the conditions to adjust the plutonium valence. b) Solubility data of plutonium (III) oxalate and measurements of plutonium losses to the filtrate and wash solution. c) Characterization of the obtained products. Plutonium (III) oxalate has several potential advantages over similar conversion processes. These include: 1) Formation of small particle sizes powder with good pellets fabrication characteristics. 2) The process is rather insensitive to most process variables, except nitric acid concentration. 3) Ambient temperature operations. 4) The losses of plutonium to the filtrate are less than in other conversion processes. (Author) [es

  19. Inner-sphere and outer-sphere complexes of yttrium(III), lanthanum (III), neodymium(III), terbium(III) and thulium(III) with halide ions in N,N-dimethylformamide

    International Nuclear Information System (INIS)

    Takahashi, Ryouta; Ishiguro, Shin-ichi

    1991-01-01

    The formation of chloro, bromo and iodo complexes of yttrium(III), and bromo and iodo complexes of lanthanum(III), neodymium(III), terbium(III) and thulium(III) has been studied by precise titration calorimetry in N,N-dimethylformamide (DMF) at 25 o C. The formation of [YCl] 2+ , [YCl 2 ] + , [YCl 3 ] and [YCl 4 ] - , and [MBr] 2+ and [MBr 2 ] + (M = Y, La, Nd, Tb, Tm) was revealed, and their formation constants, enthalpies and entropies were determined. It is found that the formation enthalpies change in the sequence ΔH o (Cl) > ΔH o (l), which is unusual for hard metal (III) ions. This implies that, unlike the chloride ion, the bromide ion forms outer-sphere complexes with the lanthanide(III) and yttrium(III) ions in DMF. Evidence for either an inner- or outer-sphere complex was obtained from 89 Y NMR spectra for Y(ClO 4 ) 3 , YCl 3 and YBr 3 DMF solutions at room temperature. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Histone deacetylase inhibitors: can we consider potent anti-neoplastic agents for the treatment of asthma?

    Science.gov (United States)

    Royce, Simon G; Ververis, Katherine; Karagiannis, Tom C

    2012-01-01

    Histone deacetylase inhibitors have emerged as a new class of anti-cancer therapeutics due to their potent anti-proliferative and apoptotic effects in malignant cells. Accumulating evidence is indicating that histone deacetylase inhibitors may also have potential clinical utility in non-oncological applications, including asthma. However, the potential of histone deacetylase inhibitors in asthma remains controversial. For example, the mechanisms of action of the broad-spectrum histone deacetylase inhibitor, Trichostatin A, in animal models of allergic airways disease are conflicting. Further, there is evidence suggesting potential problems associated with histone deacetylase 2 inhibition and conventional glucocorticosteroid therapy. Similarly, disparate findings are emerging following modulation of the class III, sirtuin 1 enzyme. Indeed, it is becoming apparent that the mechanism of action may not be related to histone deacetylase inhibition activity per se. Further, there is only limited evidence that these compounds possess anti-inflammatory effects in models of asthma. In this review, we provide an overview of the biology of the metal-dependent and sirtuin deacetylases in the context of asthma. The controversies surrounding the potential use of histone deacetylase inhibitors in asthma are discussed and future directions involving the investigation of more specific analogues are explored.

  2. Acquired resistance to EGFR inhibitors: mechanisms and prevention strategies

    International Nuclear Information System (INIS)

    Viloria-Petit, Alicia M.; Kerbel, Robert S.

    2004-01-01

    Potent and specific, or relatively specific, inhibitors of epidermal growth factor receptor (EGFR) signaling, including monoclonal antibodies and small molecular weight compounds, have been successfully developed. Both types of agent have been found to have significant antitumor activity, especially when used in combination with radio- hormone- and chemotherapy in preclinical studies. Because of the potentiation of the conventional drug activity in these combination settings, inhibitors of EGFR signaling have often been referred to as sensitizers for chemotherapy or radiation, as well as drug resistance reversal agents. Phase II clinical trials in head-and-neck as well as lung cancer suggested this concept of chemosensitization might translate into the clinic, but this remains to be definitively proven in randomized, double-blind Phase III trials. Given the extensive preclinical literature on EGFR blocking drugs and the advanced clinical development of such agents, it is surprising that the possibility of development of acquired resistance to the EGFR inhibitors themselves, a common clinical problem with virtually all other currently used anticancer drugs, remains a largely unexplored subject of investigation. Here we summarize some of the possible mechanisms that can result in acquired resistance to EGFR-targeting drugs. Alternative combination therapies to circumvent and delay this problem are suggested

  3. Grafting of a novel gold(III) complex on nanoporous MCM-41 and evaluation of its toxicity in Saccharomyces cerevisiae.

    Science.gov (United States)

    Fazaeli, Yousef; Amini, Mostafa M; Ashourion, Hamed; Heydari, Homayoun; Majdabadi, Abbas; Jalilian, Amir Reza; Abolmaali, Shamsozoha

    2011-01-01

    The goal of this research was to investigate the potential of newly synthesized gold complex trichloro(2,4,6-trimethylpyridine)Au(III) as an anticancer agent. The gold(III) complex was synthesized and grafted on nanoporous silica, MCM-41, to produce AuCl(3)@PF-MCM- 41 (AuCl(3) grafted on pyridine-functionalized MCM-41). The toxicity of trichloro(2,4,6- trimethylpyridine)Au(III) and AuCl(3)@PF-MCM-41 in Saccharomyces cerevisiae (as a model system) was studied. The gold(III) complex showed a mid cytotoxic effect on yeast viability. Using the drug delivery system, nanoporous MCM-41, the gold(III) complex became a strong inhibitor for growth of yeast cells at a very low concentration. Furthermore, the animal tests revealed a high uptake of AuCl(3)@PF-MCM-41 in tumor cells. The stability of the compound was confirmed in human serum.

  4. Radical prostatectomy

    DEFF Research Database (Denmark)

    Fode, Mikkel; Sønksen, Jens; Jakobsen, Henrik

    2014-01-01

    surgery and at follow-up and they were asked to report their use of pads/diapers. Potency was defined as an IIEF-5 score of at least 17 with or without phosphodiesterase-5 inhibitors. Patients using up to one pad daily for security reasons only were considered continent. Positive surgical margins, blood...

  5. Clinical utility of the oral JAK inhibitor tofacitinib in the treatment of rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Cutolo M

    2013-11-01

    Full Text Available Maurizio Cutolo, Marianna Meroni Research Laboratories and Academic Division of Clinical Rheumatology, Department of Internal Medicine, University of Genova, Genova, Italy Abstract: Immune/inflammatory cells act in rheumatoid arthritis (RA-affected patients by synthesizing several inflammatory mediators, including cytokines that initiate intracellular signaling. Recently, small molecule inhibitors of transduction and transcription signals that influence the intracellular pathways (such as the Janus kinase [JAK] family of tyrosine kinases have been tested for RA treatment. Four members of the JAK family are known: JAK1, JAK2, JAK3, and TyK2. JAK1/JAK3 constitutively binds to the cytoplasmic portion of the cytokine receptor – the common gamma chain – that represents a common subunit of several cytokines involved in T-cell and natural killer cell development, as well as in B-cell activation. Tofacitinib is an oral JAK inhibitor that is now available and effective in RA treatment, as shown in multiple Phase II and Phase III clinical trials. However, long-term safety data and comparisons with other disease-modifying antirheumatic drugs and small molecule inhibitors are necessary to better determine the role of tofacitinib in RA. Keywords: Janus kinase inhibitors, tofacitinib, rheumatoid arthritis, kinases, small molecules inhibitors, intracellular signaling

  6. Phosphodiesterase 4 inhibition as a potential new therapeutic target in obese women with polycystic ovary syndrome.

    Science.gov (United States)

    Jensterle, Mojca; Kocjan, Tomaz; Janez, Andrej

    2014-08-01

    Phosphodiesterase (PDE) enzymes, including members of PDE4, have been investigated in the regulation of endocrine and reproductive functions of ovaries. In addition, selective inhibition of PDE4 enzyme has recently been implicated in the regulation of metabolism with positive effects on glucose homeostasis and weight reduction. The aim of this study was to evaluate whether the PDE4 inhibitor roflumilast affects body weight and hormonal and metabolic status in obese women with polycystic ovary syndrome (PCOS). Design/Participants/Main Outcome Measures: A 12-week prospective randomized open-label study was conducted with 36 obese women with PCOS diagnosed by the National Eunice Kennedy Shriver Institute of Child Health and Human Development criteria that had been pretreated with metformin (MET). They were randomized to MET 1000 mg twice a day or combined treatment (COM) with MET 1000 mg twice a day and roflumilast 500 μg every day. The primary outcome was change in anthropometric measures of obesity. Thirty-one patients (aged 33.8 ± 7.4 y, twice a day 36.4 ± 5.1 kg/m(2), mean ± SD) completed the study: 16 on MET and 15 on COM. Subjects treated with COM lost on average 4.2 ± 2.8 kg compared with a 0.9 ± 2.5 kg weight gain in the MET group (P = .025). Body mass index decreased for 1.6 ± 1.1 kg/m(2) in COM arm compared with increase for 0.9 ± 2.4 kg/m(2) in the MET arm (P = .046). Visceral adipose tissue area as assessed by dual-energy x-ray absorptiometry decreased from 136.7 ± 37.8 to 121.2 ± 36.2 cm(2) in the COM arm compared with an increase from 155.3 ± 61.9 to 166.7 ± 67.2 cm(2) in the MET arm (P = .02). From baseline to study end, both treatment interventions resulted in a significant reduction of androstenedione (P = .013), free T (P = .002), and homeostasis model assessment for insulin resistance score (P = .027) and a significant increase in SHBG (P = .024), although the between-treatment differences of the changes have not been statistically

  7. Engineering the substrate and inhibitor specificities of human coagulation Factor VIIa

    DEFF Research Database (Denmark)

    Larsen, Katrine S; Østergaard, Henrik; Bjelke, Jais R

    2007-01-01

    The remarkably high specificity of the coagulation proteases towards macromolecular substrates is provided by numerous interactions involving the catalytic groove and remote exosites. For FVIIa [activated FVII (Factor VII)], the principal initiator of coagulation via the extrinsic pathway, several...... for FVIIa by marked changes in primary substrate specificity and decreased rates of antithrombin III inhibition. Interestingly, these changes do not necessarily coincide with an altered ability to activate Factor X, demonstrating that inhibitor and macromolecular substrate selectivity may be engineered...

  8. Interstitial Lung Disease Associated with mTOR Inhibitors in Solid Organ Transplant Recipients: Results from a Large Phase III Clinical Trial Program of Everolimus and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Patricia Lopez

    2014-01-01

    Full Text Available Interstitial lung disease (ILD has been reported with the use of mammalian target of rapamycin inhibitors (mTORi. The clinical and safety databases of three Phase III trials of everolimus in de novo kidney (A2309, heart (A2310, and liver (H2304 transplant recipients (TxR were searched using a standardized MedDRA query (SMQ search for ILD followed by a case-by-case medical evaluation. A literature search was conducted in MEDLINE and EMBASE. Out of the 1,473 de novo TxR receiving everolimus in Phase III trials, everolimus-related ILD was confirmed in six cases (one kidney, four heart, and one liver TxR representing an incidence of 0.4%. Everolimus was discontinued in three of the four heart TxR, resulting in ILD improvement or resolution. Outcome was fatal in the kidney TxR (in whom everolimus therapy was continued and in the liver TxR despite everolimus discontinuation. The literature review identified 57 publications on ILD in solid organ TxR receiving everolimus or sirolimus. ILD presented months or years after mTORi initiation and symptoms were nonspecific and insidious. The event was more frequent in patients with a late switch to mTORi. In most cases, ILD was reversed after prompt mTORi discontinuation. ILD induced by mTORi is an uncommon and potentially fatal event warranting early recognition and drug discontinuation.

  9. Size-Controlled Production of Gold Bionanoparticles Using the Extremely Acidophilic Fe(III-Reducing Bacterium, Acidocella aromatica

    Directory of Open Access Journals (Sweden)

    Intan Nurul Rizki

    2018-02-01

    Full Text Available Recycling of gold-bearing “urban mine” resources, such as waste printed circuit boards (PCBs, is attracting an increasing interest. Some of the gold leaching techniques utilize acidic lixiviants and in order to eventually target such acidic leachates, the utility of the acidophilic Fe(III-reducing heterotrophic bacterium, Acidocella (Ac. aromatica PFBC was evaluated for production of Au(0 bionanoparticles (bio-AuNPs. Au(III ions (as AuCl4−, initially 10 mg/L, were readily adsorbed onto the slightly-positively charged Ac. aromatica cell surface and transported into cytoplasm to successfully form intracellular bio-AuNPs in a simple one-step microbiological reaction. Generally, increasing the initial concentration of formate as e-donor corresponded to faster Au(III bioreduction and a greater number of Au(0 nucleation sites with less crystal growth within 40–60 h: i.e., use of 1, 5, 10, or 20 mM formate led to production of bio-AuNPs of 48, 24, 13, or 12 nm in mean particle size with 2.3, 17, 62, and 97 particles/cell, respectively. Addition of Cu2+ as an enzymatic inhibitor significantly decreased the number of Au(0 nucleation sites but enhanced crystal growth of individual particles. As a result, the manipulation of the e-donor concentration combined with an enzyme inhibitor enabled the 3-grade size-control of bio-AuNPs (nearly within a normal distribution at 48, 26 or 13 nm by use of 1 mM formate, 20 mM formate (+Cu2+ or 10 mM formate, respectively, from highly acidic, dilute Au(III solutions.

  10. Complex I and complex III inhibition specifically increase cytosolic hydrogen peroxide levels without inducing oxidative stress in HEK293 cells

    NARCIS (Netherlands)

    Forkink, M.; Basit, F.; Teixeira, J.; Swarts, H.G.; Koopman, W.J.H.; Willems, P.H.G.M.

    2015-01-01

    Inhibitor studies with isolated mitochondria demonstrated that complex I (CI) and III (CIII) of the electron transport chain (ETC) can act as relevant sources of mitochondrial reactive oxygen species (ROS). Here we studied ROS generation and oxidative stress induction during chronic (24h) inhibition

  11. Solvent extraction of anionic chelate complexes of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) with 2-thenoyltrifluoroacetone as ion-pairs with tetrabutylammonium ions

    International Nuclear Information System (INIS)

    Noro, Junji; Sekine, Tatsuya.

    1992-01-01

    The solvent extraction of lanthanum(III), europium(III), lutetium(III), scandium(III), and indium(III) in 0.1 mol dm -3 sodium nitrate solutions with 2-thenoyltrifluoroacetone (Htta) in the absence and presence of tetrabutylammonium ions (tba + ) into carbon tetrachloride was measured. The extraction of lanthanum(III), europium(III), and lutetium(III) was greatly enhanced by the addition of tba + ; this could be explained in terms of the extraction of a ternary complex, M(tta) 4 - tba + . However, the extractions of scandium(III) and indium(III) were nearly the same when tba + was added. The data were treated on the basis of the formation equilibrium of the ternary complex from the neutral chelate, M(tta) 3 , with the extracted ion-pairs of the reagents, tta - tba + , in the organic phase. It was concluded that the degree of association of M(tta) 3 with the ion-pair, tta - tba + , is greater in the order La(tta) 3 ≅ Eu(tta) 3 > Lu(tta) 3 , or that the stability of the ternary complex in the organic phase is higher in the order La(tta) 4 - tba + ≅ Eu(tta) 4 - tba + > Lu(tta) 4 - tba + . This is similar to those of adduct metal chelates of Htta with tributylphosphate (TBP) in synergistic extraction systems. (author)

  12. [Prospect and Current Situation of Immune Checkpoint Inhibitors 
in First-line Treatment in Advanced Non-small Cell Lung Cancer Patients].

    Science.gov (United States)

    Wang, Haiyang; Yu, Xiaoqing; Fan, Yun

    2017-06-20

    With the breakthroughs achieved of programmed death-1 (PD-1)/PD-L1 inhibitors monotherapy as first-line and second-line treatment in advanced non-small cell lung cancer (NSCLC), the treatment strategy is gradually evolving and optimizing. Immune combination therapy expands the benefit population and improves the curative effect. A series of randomized phase III trials are ongoing. In this review, we discuss the prospect and current situation of immune checkpoint inhibitors in first-line treatment in advanced NSCLC patients.

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

    Directory of Open Access Journals (Sweden)

    Mohsen Zhaleh

    2014-07-01

    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.

  14. Mechanistic insights into the role of prenyl-binding protein PrBP/δ in membrane dissociation of phosphodiesterase 6

    KAUST Repository

    Qureshi, Bilal M.

    2018-01-02

    Isoprenylated proteins are associated with membranes and their inter-compartmental distribution is regulated by solubilization factors, which incorporate lipid moieties in hydrophobic cavities and thereby facilitate free diffusion during trafficking. Here we report the crystal structure of a solubilization factor, the prenyl-binding protein (PrBP/δ), at 1.81 Å resolution in its ligand-free apo-form. Apo-PrBP/δ harbors a preshaped, deep hydrophobic cavity, capacitating apo-PrBP/δ to readily bind its prenylated cargo. To investigate the molecular mechanism of cargo solubilization we analyzed the PrBP/δ-induced membrane dissociation of rod photoreceptor phosphodiesterase (PDE6). The results suggest that PrBP/δ exclusively interacts with the soluble fraction of PDE6. Depletion of soluble species in turn leads to dissociation of membrane-bound PDE6, as both are in equilibrium. This

  15. Mechanistic insights into the role of prenyl-binding protein PrBP/δ in membrane dissociation of phosphodiesterase 6

    KAUST Repository

    Qureshi, Bilal M.; Schmidt, Andrea; Behrmann, Elmar; Bü rger, Jö rg; Mielke, Thorsten; Spahn, Christian M. T.; Heck, Martin; Scheerer, Patrick

    2018-01-01

    Isoprenylated proteins are associated with membranes and their inter-compartmental distribution is regulated by solubilization factors, which incorporate lipid moieties in hydrophobic cavities and thereby facilitate free diffusion during trafficking. Here we report the crystal structure of a solubilization factor, the prenyl-binding protein (PrBP/δ), at 1.81 Å resolution in its ligand-free apo-form. Apo-PrBP/δ harbors a preshaped, deep hydrophobic cavity, capacitating apo-PrBP/δ to readily bind its prenylated cargo. To investigate the molecular mechanism of cargo solubilization we analyzed the PrBP/δ-induced membrane dissociation of rod photoreceptor phosphodiesterase (PDE6). The results suggest that PrBP/δ exclusively interacts with the soluble fraction of PDE6. Depletion of soluble species in turn leads to dissociation of membrane-bound PDE6, as both are in equilibrium. This

  16. Lysine Deacetylase Inhibitors in Parasites: Past, Present, and Future Perspectives.

    Science.gov (United States)

    Hailu, Gebremedhin S; Robaa, Dina; Forgione, Mariantonietta; Sippl, Wolfgang; Rotili, Dante; Mai, Antonello

    2017-06-22

    Current therapies for human parasite infections rely on a few drugs, most of which have severe side effects, and their helpfulness is being seriously compromised by the drug resistance problem. Globally, this is pushing discovery research of antiparasitic drugs toward new agents endowed with new mechanisms of action. By using a "drug repurposing" strategy, histone deacetylase inhibitors (HDACi), which are presently clinically approved for cancer use, are now under investigation for various parasite infections. Because parasitic Zn 2+ - and NAD + -dependent HDACs play crucial roles in the modulation of parasite gene expression and many of them are pro-survival for several parasites under various conditions, they are now emerging as novel potential antiparasitic targets. This Perspective summarizes the state of knowledge of HDACi (both class I/II HDACi and sirtuin inhibitors) targeted to the main human parasitic diseases (schistosomiasis, malaria, trypanosomiasis, leishmaniasis, and toxoplasmosis) and provides visions into the main issues that challenge their development as antiparasitic agents.

  17. The PDE10A inhibitor MP-10 and haloperidol produce distinct gene expression profiles in the striatum and influence cataleptic behavior in rodents.

    Science.gov (United States)

    Gentzel, Renee C; Toolan, Dawn; Roberts, Rhonda; Koser, Amy Jo; Kandebo, Monika; Hershey, James; Renger, John J; Uslaner, Jason; Smith, Sean M

    2015-12-01

    Phosphodiesterase 10A (PDE10A) has garnered attention as a potential therapeutic target for schizophrenia due to its prominent striatal expression and ability to modulate striatal signaling. The present study used the selective PDE10A inhibitor MP-10 and the dopamine D2 antagonist haloperidol to compare effects of PDE10A inhibition and dopamine D2 blockade on striatopallidal (D2) and striatonigral (D1) pathway activation. Our studies confirmed that administration of MP-10 significantly elevates expression of the immediate early genes (IEG) c-fos, egr-1, and arc in rat striatum. Furthermore, we demonstrated that MP-10 induced egr-1 expression was distributed evenly between enkephalin-containing D2-neurons and substance P-containing D1-neurons. In contrast, haloperidol (3 mg/kg) selectively activated egr-1 expression in enkephalin neurons. Co-administration of MP-10 and haloperidol (0.5 mg/kg) increased IEG expression to a greater extent than either compound alone. Similarly, in a rat catalepsy assay, administration of haloperidol (0.5 mg/kg) or MP-10 (3-30 mg/kg) did not produce cataleptic behavior when dosed alone, but co-administration of haloperidol with MP-10 (3 and 10 mg/kg) induced cataleptic behaviors. Interestingly, co-administration of haloperidol with a high dose of MP-10 (30 mg/kg) failed to produce cataleptic behavior. These findings are important for understanding the neural circuits involved in catalepsy and suggest that the behavioral effects produced by PDE10A inhibitors may be influenced by concomitant medication and the level of PDE10A inhibition achieved by the dose of the inhibitor. Copyright © 2015. Published by Elsevier Ltd.

  18. Improvement of spatial memory function in APPswe/PS1dE9 mice after chronic inhibition of phosphodiesterase type 4D.

    Science.gov (United States)

    Sierksma, A S R; van den Hove, D L A; Pfau, F; Philippens, M; Bruno, O; Fedele, E; Ricciarelli, R; Steinbusch, H W M; Vanmierlo, T; Prickaerts, J

    2014-02-01

    Phosphodiesterase type 4 inhibitors (PDE4-Is) have received increasing attention as cognition-enhancers and putative treatment strategies for Alzheimer's disease (AD). By preventing cAMP breakdown, PDE4-Is can enhance intracellular signal transduction and increase the phosphorylation of cAMP response element-binding protein (CREB) and transcription of proteins related to synaptic plasticity and associated memory formation. Unfortunately, clinical development of PDE4-Is has been seriously hampered by emetic side effects. The new isoform-specific PDE4D-I, GEBR-7b, has shown to have beneficial effects on memory at non-emetic doses. The aim of the current study was to investigate chronic cognition-enhancing effects of GEBR-7b in a mouse model of AD. To this extent, 5-month-old (5M) APPswe/PS1dE9 mice received daily subcutaneous injections with GEBR-7b (0.001 mg/kg) or vehicle for a period of 3 weeks, and were tested on affective and cognitive behavior at 7M. We demonstrated a cognition-enhancing potential in APPswe/PS1dE9 mice as their spatial memory function at 7M in the object location test was improved by prior GEBR-7b treatment. APPswe/PS1dE9 mice displayed lower levels of CREB phosphorylation, which remained unaltered after chronic GEBR-7b treatment, and higher levels of tau in the hippocampus. Hippocampal brain-derived neurotrophic factor levels and synaptic densities were not different between experimental groups and no effects were observed on hippocampal GSK3β and tau phosphorylation or Aβ levels. In conclusion, GEBR-7b can enhance spatial memory function in the APPswe/PS1dE9 mouse model of AD. Although the underlying mechanisms of its cognition-enhancing potential remain to be elucidated, PDE4D inhibition appears an interesting novel therapeutic option for cognitive deficits in AD. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Sparkle/PM3 for the modeling of europium(III), gadolinium(III), and terbium(III) complexes

    International Nuclear Information System (INIS)

    Freire, Ricardo O.; Rocha, Gerd B.; Simas, Alfredo M.

    2009-01-01

    The Sparkle/PM3 model is extended to europium(III), gadolinium(III), and terbium(III) complexes. The validation procedure was carried out using only high quality crystallographic structures, for a total of ninety-six Eu(III) complexes, seventy Gd(III) complexes, and forty-two Tb(III) complexes. The Sparkle/PM3 unsigned mean error, for all interatomic distances between the trivalent lanthanide ion and the ligand atoms of the first sphere of coordination, is: 0.080 A for Eu(III); 0.063 A for Gd(III); and 0.070 A for Tb(III). These figures are similar to the Sparkle/AM1 ones of 0.082 A, 0.061 A, and 0.068 A respectively, indicating they are all comparable parameterizations. Moreover, their accuracy is similar to what can be obtained by present-day ab initio effective core potential full geometry optimization calculations on such lanthanide complexes. Finally, we report a preliminary attempt to show that Sparkle/PM3 geometry predictions are reliable. For one of the Eu(III) complexes, BAFZEO, we created hundreds of different input geometries by randomly varying the distances and angles of the ligands to the central Eu(III) ion, which were all subsequently fully optimized. A significant trend was unveiled, indicating that more accurate local minima geometries cluster at lower total energies, thus reinforcing the validity of sparkle model calculations. (author)

  20. Sildenafil citrate-restored eNOS and PDE5 regulation in sickle cell mouse penis prevents priapism via control of oxidative/nitrosative stress.

    Directory of Open Access Journals (Sweden)

    Trinity J Bivalacqua

    Full Text Available 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.

  1. Inhibitors

    Science.gov (United States)

    ... JM, and the Hemophilia Inhibitor Research Study Investigators. Validation of Nijmegen-Bethesda assay modifications to allow inhibitor ... webinars on blood disorders Language: English (US) Español (Spanish) File Formats Help: How do I view different ...

  2. Uranium (III)-Plutonium (III) co-precipitation in molten chloride

    Science.gov (United States)

    Vigier, Jean-François; Laplace, Annabelle; Renard, Catherine; Miguirditchian, Manuel; Abraham, Francis

    2018-02-01

    Co-management of the actinides in an integrated closed fuel cycle by a pyrochemical process is studied at the laboratory scale in France in the CEA-ATALANTE facility. In this context the co-precipitation of U(III) and Pu(III) by wet argon sparging in LiCl-CaCl2 (30-70 mol%) molten salt at 705 °C is studied. Pu(III) is prepared in situ in the molten salt by carbochlorination of PuO2 and U(III) is then introduced as UCl3 after chlorine purge by argon to avoid any oxidation of uranium up to U(VI) by Cl2. The oxide conversion yield through wet argon sparging is quantitative. However, the preferential oxidation of U(III) in comparison to Pu(III) is responsible for a successive conversion of the two actinides, giving a mixture of UO2 and PuO2 oxides. Surprisingly, the conversion of sole Pu(III) in the same conditions leads to a mixture of PuO2 and PuOCl, characteristic of a partial oxidation of Pu(III) to Pu(IV). This is in contrast with coconversion of U(III)-Pu(III) mixtures but in agreement with the conversion of Ce(III).

  3. Design, optimization, and biological evaluation of novel keto-benzimidazoles as potent and selective inhibitors of phosphodiesterase 10A (PDE10A).

    Science.gov (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

    2013-11-14

    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.

  4. Role of Ru(IlI) as an inhibitor in oxidation of lactose by (Cu(bipy)2)2+ in alkaline medium: spectrophotometric and kinetic studies

    International Nuclear Information System (INIS)

    Singh, Ashok Kumar; Singh, Manjula; Srivastava, Jaya; Rahmani, Shahla

    2013-01-01

    Kinetics of oxidation of lactose by (Cu(bipy) 2 ) 2+ in alkaline medium using Ru(III) as an inhibitor has been studied spectrophotometrically at 40 °C. The studies show that the rate of the reaction is zero order with respect to (Cu(bipy) 2 ) 2+ and first order with respect to (lactose). The order of reaction is found to be two at low concentrations of OH - (from 1.48×10 5 to 3.47×10 5 M) and less than two at its high concentrations (from 4.27×10 5 to 6.31×10 5 M). There is a substantial decrease in the pseudo-zero order rate constant with increase in the concentration of Ru(III) chloride, indicating the role of Ru(III) chloride as an inhibitor. Decrease in the rate with increase in dielectric constant of the medium is observed, while ionic strength of the medium and bipyridyl concentration has no influence on the rate. Based on kinetic data and spectrophotometric evidences, a suitable mechanism is proposed for the studied reaction. (author)

  5. Repair of DNA treated with γ-irradiation and chemical carcinogens. Comprehensive report of entire period of ERDA support from June 1, 1975--January 15, 1978

    International Nuclear Information System (INIS)

    Goldthwait, D.A.

    1978-01-01

    A partially purified enzyme fraction isolated from E. coli showed an N-glycosidase activity as well as a phosphodiesterase activity on DNA treated with methylnitrosourea, and with 7-bromomethylbenz(a)anthracene and a phosphodiesterase activity against γ-irradiated DNA. Both 0-6 methyl guanine and 3-methyladenine were released from DNA treated with MNU; the adenine and guanine derivatives from the DNA treated with 7-bromomethyl-12-methylbenz(a)anthracene were also liberated. Progress is also reported on studies on Endonucleases II and VI and Exonuclease III of E. coli; methods for assay and for synthesis of substrates; attempts at purification of repair enzymes from mammalian tissues; and β-propiolactone reactions with deoxynucleosides and with DNA

  6. Chemical Space of FLT3 Inhibitors as Potential Anti-AML Drugs.

    Science.gov (United States)

    Lan, Qing-Yuan; Zhi, Yan-Le; Heng, Hao; Tian, Jie-Yi; Guo, Xiao-Xing; Liu, Hai-Chun; Chen, Ya-Dong; Lu, Tao; Lu, Shuai

    2017-11-20

    FLT3 is a member of receptor tyrosine kinase III family, mainly expressed in hematopoietic cells. The aberrant expression and function of FLT3 are strongly related to leukemia, especially acute myeloid leukemia. Its varieties of amino-acid residues mutations, such as FLT3-ITDs and -TKDs, can induce constant proliferation of hematological tumor cells with poor prognosis. Hence FLT3 serves as a promising target in AML chemotherapy. This review focused on the progress of FLT3 inhibitors study including those that have entered clinical trials or were reported in numerous patents all over the world. Thus, we provided a useful reference for the development of new anti-leukemia drugs. Through a comprehensive retrospective study, FLT3 inhibitors in several patent applications were identified and classified into five categories, including quinolone-related, indole-related, ureas, pyrimidines and other compounds. For each category of compounds, the structural feature, SAR, biological activity and current research status were thoroughly reviewed and analyzed. Although some of those compounds expressed potent bioactivities and have reached the advanced clinical trials for the treatment of leukemia, there are still several problems need to be faced before they enter the market eventually, especially the drug resistance issue. The improvement of therapeutic potency for FLT3 inhibitors might depend on the useful combination therapy and further refinement of the intrinsic properties of FLT3 inhibitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Mice deficient in phosphodiesterase-4A display anxiogenic-like behavior.

    Science.gov (United States)

    Hansen, Rolf T; Conti, Marco; Zhang, Han-Ting

    2014-08-01

    Phosphodiesterases (PDEs) are a super family of enzymes responsible for the halting of intracellular cyclic nucleotide signaling and may represent novel therapeutic targets for treatment of cognitive disorders. PDE4 is of considerable interest to cognitive research because it is highly expressed in the brain, particularly in the cognition-related brain regions. Recently, the functional role of PDE4B and PDE4D, two of the four PDE4 subtypes (PDE4A, B, C, and D), in behavior has begun to be identified; however, the role of PDE4A in the regulation of behavior is still unknown. The purpose of this study was to characterize the functional role of PDE4A in behavior. The role of PDE4A in behavior was evaluated through a battery of behavioral tests using PDE4A knockout (KO) mice; urine corticosterone levels were also measured. PDE4A KO mice exhibited improved memory in the step-through-passive-avoidance test. They also displayed anxiogenic-like behavior in elevated-plus maze, holeboard, light-dark transition, and novelty suppressed feeding tests. Consistent with the anxiety profile, PDE4A KO mice had elevated corticosterone levels compared with wild-type controls post-stress. Interestingly, PDE4A KO mice displayed no change in object recognition, Morris water maze, forced swim, tail suspension, and duration of anesthesia induced by co-administration of xylazine and ketamine (suggesting that PDE4A KO may not be emetic). These results suggest that PDE4A may be important in the regulation of emotional memory and anxiety-like behavior, but not emesis. PDE4A could possibly represent a novel therapeutic target in the future for anxiety or disorders affecting memory.

  8. Pharmacologic Therapy in Men's Health: Hypogonadism, Erectile Dysfunction, and Benign Prostatic Hyperplasia.

    Science.gov (United States)

    Berkseth, Kathryn E; Thirumalai, Arthi; Amory, John K

    2016-07-01

    This article reviews current pharmacologic treatment options for 3 common men's health concerns: hypogonadism, erectile dysfunction (ED), and benign prostatic hyperplasia (BPH). Specific topics addressed include: management of male hypogonadism using testosterone replacement therapy, use of oral phosphodiesterase inhibitors as first-line therapy for men with ED and the utility of intraurethral and intrapenile alprostadil injections for patients who do not respond to oral medications, and the role of alpha1-adrenergic antagonists, 5-alpha-reductase inhibitors, anticholinergic agents, and herbal therapies in the management of BPH. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. PdeH, a high-affinity cAMP phosphodiesterase, is a key regulator of asexual and pathogenic differentiation in Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Ravikrishna Ramanujam

    2010-05-01

    Full Text Available Cyclic AMP-dependent pathways mediate the communication between external stimuli and the intracellular signaling machinery, thereby influencing important aspects of cellular growth, morphogenesis and differentiation. Crucial to proper function and robustness of these signaling cascades is the strict regulation and maintenance of intracellular levels of cAMP through a fine balance between biosynthesis (by adenylate cyclases and hydrolysis (by cAMP phosphodiesterases. We functionally characterized gene-deletion mutants of a high-affinity (PdeH and a low-affinity (PdeL cAMP phosphodiesterase in order to gain insights into the spatial and temporal regulation of cAMP signaling in the rice-blast fungus Magnaporthe oryzae. In contrast to the expendable PdeL function, the PdeH activity was found to be a key regulator of asexual and pathogenic development in M. oryzae. Loss of PdeH led to increased accumulation of intracellular cAMP during vegetative and infectious growth. Furthermore, the pdeHDelta showed enhanced conidiation (2-3 fold, precocious appressorial development, loss of surface dependency during pathogenesis, and highly reduced in planta growth and host colonization. A pdeHDelta pdeLDelta mutant showed reduced conidiation, exhibited dramatically increased (approximately 10 fold cAMP levels relative to the wild type, and was completely defective in virulence. Exogenous addition of 8-Br-cAMP to the wild type simulated the pdeHDelta defects in conidiation as well as in planta growth and development. While a fully functional GFP-PdeH was cytosolic but associated dynamically with the plasma membrane and vesicular compartments, the GFP-PdeL localized predominantly to the nucleus. Based on data from cAMP measurements and Real-Time RTPCR, we uncover a PdeH-dependent biphasic regulation of cAMP levels during early and late stages of appressorial development in M. oryzae. We propose that PdeH-mediated sustenance and dynamic regulation of cAMP signaling

  10. A Phase III, Randomized, Controlled Trial of Apremilast in Patients with Psoriatic Arthritis: Results of the PALACE 2 Trial.

    Science.gov (United States)

    Cutolo, Maurizio; Myerson, Gary E; Fleischmann, Roy M; Lioté, Frédéric; Díaz-González, Federico; Van den Bosch, Filip; Marzo-Ortega, Helena; Feist, Eugen; Shah, Kamal; Hu, ChiaChi; Stevens, Randall M; Poder, Airi

    2016-09-01

    Apremilast, an oral phosphodiesterase 4 inhibitor, downregulates intracellular inflammatory mediator synthesis by elevating cyclic adenosine monophosphate levels. The PALACE 2 trial evaluated apremilast efficacy and safety in patients with active psoriatic arthritis (PsA) despite prior conventional disease-modifying antirheumatic drugs and/or biologic therapy. Eligible patients were randomized (1:1:1) to placebo, apremilast 20 mg BID, or apremilast 30 mg BID. At Week 16, patients with swollen and tender joint count improvement 20% improvement in American College of Rheumatology response criteria (ACR20) at Week 16. In the intent-to-treat population (N = 484), ACR20 at Week 16 was achieved by more patients receiving apremilast 20 mg BID [37.4% (p = 0.0002)] and 30 mg BID [32.1% (p = 0.0060)] versus placebo (18.9%). Clinically meaningful improvements in signs and symptoms of PsA, physical function, and psoriasis were observed with apremilast through Week 52. The most common adverse events were diarrhea, nausea, headache, and upper respiratory tract infection. Diarrhea and nausea generally occurred early and usually resolved spontaneously with continued treatment. Laboratory abnormalities were infrequent and transient. Apremilast demonstrated clinical improvements in PsA for up to 52 weeks, including signs and symptoms, physical function, and psoriasis. No new safety signals were observed. ClinicalTrials.gov identifier: NCT01212757.

  11. Usb1 controls U6 snRNP assembly through evolutionarily divergent cyclic phosphodiesterase activities.

    Science.gov (United States)

    Didychuk, Allison L; Montemayor, Eric J; Carrocci, Tucker J; DeLaitsch, Andrew T; Lucarelli, Stefani E; Westler, William M; Brow, David A; Hoskins, Aaron A; Butcher, Samuel E

    2017-09-08

    U6 small nuclear ribonucleoprotein (snRNP) biogenesis is essential for spliceosome assembly, but not well understood. Here, we report structures of the U6 RNA processing enzyme Usb1 from yeast and a substrate analog bound complex from humans. Unlike the human ortholog, we show that yeast Usb1 has cyclic phosphodiesterase activity that leaves a terminal 3' phosphate which prevents overprocessing. Usb1 processing of U6 RNA dramatically alters its affinity for cognate RNA-binding proteins. We reconstitute the post-transcriptional assembly of yeast U6 snRNP in vitro, which occurs through a complex series of handoffs involving 10 proteins (Lhp1, Prp24, Usb1 and Lsm2-8) and anti-cooperative interactions between Prp24 and Lhp1. We propose a model for U6 snRNP assembly that explains how evolutionarily divergent and seemingly antagonistic proteins cooperate to protect and chaperone the nascent snRNA during its journey to the spliceosome.The mechanism of U6 small nuclear ribonucleoprotein (snRNP) biogenesis is not well understood. Here the authors characterize the enzymatic activities and structures of yeast and human U6 RNA processing enzyme Usb1, reconstitute post-transcriptional assembly of yeast U6 snRNP in vitro, and propose a model for U6 snRNP assembly.

  12. Cell line with endogenous EGFRvIII expression is a suitable model for research and drug development purposes.

    Science.gov (United States)

    Stec, Wojciech J; Rosiak, Kamila; Siejka, Paulina; Peciak, Joanna; Popeda, Marta; Banaszczyk, Mateusz; Pawlowska, Roza; Treda, Cezary; Hulas-Bigoszewska, Krystyna; Piaskowski, Sylwester; Stoczynska-Fidelus, Ewelina; Rieske, Piotr

    2016-05-31

    Glioblastoma is the most common and malignant brain tumor, characterized by high cellular heterogeneity. About 50% of glioblastomas are positive for EGFR amplification, half of which express accompanying EGFR mutation, encoding truncated and constitutively active receptor termed EGFRvIII. Currently, no cell models suitable for development of EGFRvIII-targeting drugs exist, while the available ones lack the intratumoral heterogeneity or extrachromosomal nature of EGFRvIII.The reports regarding the biology of EGFRvIII expressed in the stable cell lines are often contradictory in observations and conclusions. In the present study, we use DK-MG cell line carrying endogenous non-modified EGFRvIII amplicons and derive a sub-line that is near depleted of amplicons, whilst remaining identical on the chromosomal level. By direct comparison of the two lines, we demonstrate positive effects of EGFRvIII on cell invasiveness and populational growth as a result of elevated cell survival but not proliferation rate. Investigation of the PI3K/Akt indicated no differences between the lines, whilst NFκB pathway was over-active in the line strongly expressing EGFRvIII, finding further supported by the effects of NFκB pathway specific inhibitors. Taken together, these results confirm the important role of EGFRvIII in intrinsic and extrinsic regulation of tumor behavior. Moreover, the proposed models are stable, making them suitable for research purposes as well as drug development process utilizing high throughput approach.

  13. Secretory leukocyte protease inhibitor protein regulates the penetrance of frontotemporal lobar degeneration in progranulin mutation carriers.

    Science.gov (United States)

    Ghidoni, Roberta; Flocco, Rosa; Paterlini, Anna; Glionna, Michela; Caruana, Loredana; Tonoli, Elisa; Binetti, Giuliano; Benussi, Luisa

    2014-01-01

    The discovery that mutations in the gene encoding for progranulin (GRN) cause frontotemporal lobar degeneration (FTLD) and other neurodegenerative diseases leading to dementia has brought renewed interest in progranulin and its functions in the central nervous system. Full length progranulin is preserved from cleavage by secretory leukocyte protease inhibitor (SLPI), one of the smallest serine protease inhibitor circulating in plasma. Herein, we investigated the relationship between circulating SLPI and progranulin in affected and unaffected subjects belonging to 26 Italian pedigrees carrying GRN null mutations. In GRN null mutation carriers, we demonstrated: i) an increase of circulating SLPI levels in affected subjects; ii) an age-related upregulation of the serine-protease inhibitor in response to lifetime progranulin shortage; and iii) a delay in the age of onset in subjects with the highest SLPI protein levels. The study of SLPI and its relation to progranulin suggests the existence of unexpected molecular players in progranulin-associated neurodegeneration.

  14. Old and new acetylcholinesterase inhibitors for Alzheimer's disease.

    Science.gov (United States)

    Galimberti, Daniela; Scarpini, Elio

    2016-10-01

    To date, pharmacological treatment of Alzheimer's disease (AD) includes Acetylcholinesterase Inhibitors (AChEIs) for mild-to-moderate AD, and memantine for moderate-to-severe AD. AChEIs reversibly inhibit acetylcholinesterase (AChE), thus increasing the availability of acetylcholine in cholinergic synapses, enhancing cholinergic transmission. These drugs provide symptomatic short-term benefits, without clearly counteracting the progression of the disease. On the wake of successful clinical trials which lead to the marketing of AChEIs donepezil, rivastigmine and galantamine, many compounds with AChEI properties have been developed and tested mainly in Phase I-II clinical trials in the last twenty years. Here, we review clinical trials initiated and interrupted, and those ongoing so far. Despite many clinical trials with novel AChEIs have been carried out after the registration of those currently used to treat mild to moderate AD, none so far has been successful in a Phase III trial and marketed. Alzheimer's disease is a complex multifactorial disorder, therefore therapy should likely address not only the cholinergic system but also additional neurotransmitters. Moreover, such treatments should be started in very mild phases of the disease, and preventive strategies addressed in elderly people.

  15. Valproic Acid, a Histone Deacetylase Inhibitor, in Combination with Paclitaxel for Anaplastic Thyroid Cancer: Results of a Multicenter Randomized Controlled Phase II/III Trial

    Directory of Open Access Journals (Sweden)

    Maria Graziella Catalano

    2016-01-01

    Full Text Available Anaplastic thyroid cancer (ATC has a median survival less than 5 months and, to date, no effective therapy exists. Taxanes have recently been stated as the main drug treatment for ATC, and the histone deacetylase inhibitor valproic acid efficiently potentiates the effects of paclitaxel in vitro. Based on these data, this trial assessed the efficacy and safety of the combination of paclitaxel and valproic acid for the treatment of ATC. This was a randomized, controlled phase II/III trial, performed on 25 ATC patients across 5 centers in northwest Italy. The experimental arm received the combination of paclitaxel (80 mg/m2/weekly and valproic acid (1,000 mg/day; the control arm received paclitaxel alone. Overall survival and disease progression, evaluated in terms of progression-free survival, were the primary outcomes. The secondary outcome was the pharmacokinetics of paclitaxel. The coadministration of valproic acid did not influence the pharmacokinetics of paclitaxel. Neither median survival nor median time to progression was statistically different in the two arms. Median survival of operated-on patients was significantly better than that of patients who were not operated on. The present trial demonstrates that the addition of valproic acid to paclitaxel has no effect on overall survival and disease progression of ATC patients. This trial is registered with EudraCT 2008-005221-11.

  16. Thermodecomposition of lanthanides (III) and ytrium (III) glucoheptonates

    International Nuclear Information System (INIS)

    Giolito, J.

    1987-01-01

    The lanthanides (III) and yttrium (III) glucoheptonates as well the D-glucoheptono 1-4 lactone were studied using common analytical methods, elemental microanalysis of carbon and hydrogen, thermogravimetry and differential scanning calorimetry. These compounds were prepared from the reaction between the lanthanides (III) and yttrium (III) hydroxides and glucoheptonic acid aqueous solution obtained by means of the delta lactone hydrolysis of this acid. After stoichiometric reaction the compounds were precipitated by the addition of absolute ethanol, washed with the same solvent and dried in desiccator. Thermogravimetric the (TG) curves of the lanthanides glucoheptonates of the ceric group present thermal profiles with enough differences permitting an easy caracterization of each compound and the yttrium (III) glucoheptonate TG curve showed a great similarity with the erbium (III) compound TG curve. The differential scanning calometry (DSC) curves showed endothermic and exothermic peaks by their shape, height and position (temperature) permit an easy and rapid identification of each compound specially if DSC and TG curves were examined simultaneously. (author) [pt

  17. The Moessbauer effect in Fe(III) HEDTA, Fe(III) EDTA, and Fe(III) CDTA compounds

    International Nuclear Information System (INIS)

    Prado, F.R.

    1989-01-01

    The dependence of Moessbauer spectra with pH value of Fe(III)HEDTA and Fe(III)CDTA compounds is studied. Informations on formation processes of LFe-O-FeL (L=ligand) type dimers by the relation of titration curves of Fe(III)EDTA, Fe(III)HEDTA and Fe(III)CDTA compounds with the series of Moessbauer spectra, are obtained. Some informations on Fe-O-Fe bond structure are also obtained. Comparing the titration curves with the series of Moessbauer spectra, it is concluded that the dimerization process begins when a specie of the form FeXOH α (X = EDTA, HEDTA, CDTA; α = -1, -2) arises. (M.C.K.) [pt

  18. Acute dysphonia secondary to vocal fold hemorrhage after vardenafil use.

    Science.gov (United States)

    Singh, Vikas; Cohen, Seth M; Rousseau, Bernard; Noordzij, J Pieter; Garrett, C Gaelyn; Ossoff, Robert H

    2010-06-01

    Owing to their vasodilatory effects, the phosphodiesterase-5 inhibitors have become widely used for the treatment of erectile dysfunction. Among the reported adverse events of these agents are epistaxis, variceal bleeding, intracranial hemorrhage, and hemorrhoidal bleeding. We report a case of vocal fold hemorrhage that occurred after vardenafil use in a 31-year-old man who was a professional singer.

  19. Phosphodiesterase inhibitor KMUP-3 displays cardioprotection via protein kinase G and increases cardiac output via G-protein-coupled receptor agonist activity and Ca2+ sensitization

    Directory of Open Access Journals (Sweden)

    Chung-Pin Liu

    2016-02-01

    Full Text Available KMUP-3 (7-{2-[4-(4-nitrobenzene piperazinyl]ethyl}-1, 3-dimethylxanthine displays cardioprotection and increases cardiac output, and is suggested to increase cardiac performance and improve myocardial infarction. To determine whether KMUP-3 improves outcomes in hypoperfused myocardium by inducing Ca2+ sensitization to oppose protein kinase (PKG-mediated Ca2+ blockade, we measured left ventricular systolic blood pressure, maximal rates of pressure development, mean arterial pressure and heart rate in rats, and measured contractility and expression of PKs/RhoA/Rho kinase (ROCKII in beating guinea pig left atria. Hemodynamic changes induced by KMUP-3 (0.5–3.0 mg/kg, intravenously were inhibited by Y27632 [(R-(+-trans-4-1-aminoethyl-N-(4-Pyridyl cyclohexane carboxamide] and ketanserin (1 mg/kg, intravenously. In electrically stimulated left guinea pig atria, positive inotropy induced by KMUP-3 (0.1–100μM was inhibited by the endothelial NO synthase (eNOS inhibitors N-nitro-l-arginine methyl ester (L-NAME and 7-nitroindazole, cyclic AMP antagonist SQ22536 [9-(terahydro-2-furanyl-9H-purin-6-amine], soluble guanylyl cyclase (sGC antagonist ODQ (1H-[1,2,4] oxadiazolo[4,3-a] quinoxalin-1-one, RhoA inhibitor C3 exoenzyme, β-blocker propranolol, 5-hydroxytryptamine 2A antagonist ketanserin, ROCK inhibitor Y27632 and KMUP-1 (7-{2-[4-(2-chlorobenzene piperazinyl]ethyl}-1, 3-dimethylxanthine at 10μM. Western blotting assays indicated that KMUP-3 (0.1–10μM increased PKA, RhoA/ROCKII, and PKC translocation and CIP-17 (an endogenous 17-kDa inhibitory protein activation. In spontaneous right atria, KMUP-3 induced negative chronotropy that was blunted by 7-nitroindazole and atropine. In neonatal myocytes, L-NAME inhibited KMUP-3-induced eNOS phosphorylation and RhoA/ROCK activation. In H9c2 cells, Y-27632 (50μM and PKG antagonist KT5823 [2,3,9,10,11,12-hexahydro-10R- methoxy-2,9-dimethyl-1-oxo-9S,12R-epoxy-1H-diindolo(1,2,3-fg:3′,2′,1

  20. The endoplasmic reticulum is a target organelle for trivalent dimethylarsinic acid (DMA{sup III})-induced cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Naranmandura, Hua, E-mail: narenman@zju.edu.cn [Department of Pharmacology, Toxicology, and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Xu, Shi [Department of Pharmacology, Toxicology, and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Koike, Shota [Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675 (Japan); Pan, Li Qiang [Department of Pharmacology, Toxicology, and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Chen, Bin [Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030 (China); Wang, Yan Wei; Rehman, Kanwal; Wu, Bin [Department of Pharmacology, Toxicology, and Biochemical Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Chen, Zhe [Zhejiang Hospital of Traditional Chinese Medicine, Zhejiang Chinese Medical University, Hangzhou (China); Suzuki, Noriyuki, E-mail: n-suzuki@p.chiba-u.ac.jp [Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675 (Japan)

    2012-05-01

    The purpose of present study was to characterize the endoplasmic reticulum stress and generation of ROS in rat liver RLC-16 cells by exposing to trivalent dimethylarsinous acid (DMA{sup III}) and compared with that of trivalent arsenite (iAs{sup III}) and monomethylarsonous acid (MMA{sup III}). Protein kinase-like endoplasmic reticulum kinase (PERK) phosphorylation was significantly induced in cells exposed to DMA{sup III}, while there was no change in phosphorylated PERK (P-PERK) detected in cells after exposure to iAs{sup III} or MMA{sup III}. The generation of reactive oxygen species (ROS) after DMA{sup III} exposure was found to take place specifically in the endoplasmic reticulum (ER), while previous reports showed that ROS was generated in mitochondria following exposure to MMA{sup III}. Meanwhile, cycloheximide (CHX) which is an inhibitor of protein biosynthesis strongly inhibited the DMA{sup III}-induced intracellular ROS generation in the ER and the phosphorylation of PERK, suggesting the induction of ER stress probably occurs through the inhibition of the protein folding process. Activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP) mRNA were induced by all three arsenic species, however, evidence suggested that they might be induced by different pathways in the case of iAs{sup III} and MMA{sup III}. In addition, ER resident molecular chaperone glucose-regulated protein78 (GRP78) was not affected by trivalent arsenicals, while it was induced in positive control only at high concentration (Thapsigargin;Tg), suggesting the GRP78 is less sensitive to low levels of ER stress. In summary, our findings demonstrate that the endoplasmic reticulum is a target organelle for DMA{sup III}-induced cytotoxicity. Highlights: ►ER is a target organelle for trivalent DMA{sup III}-induced cytotoxicity. ►Generation of ROS in ER can be induced specially by trivalent DMA{sup III}. ►ER-stress and generation of ROS are caused by the increase in

  1. Mechanisms of topoisomerase I (TOP1) gene copy number increase in a stage III colorectal cancer patient cohort

    DEFF Research Database (Denmark)

    Smith, David Hersi; Christensen, Ib Jarle; Jensen, Niels Frank

    2013-01-01

    Topoisomerase I (Top1) is the target of Top1 inhibitor chemotherapy. The TOP1 gene, located at 20q12-q13.1, is frequently detected at elevated copy numbers in colorectal cancer (CRC). The present study explores the mechanism, frequency and prognostic impact of TOP1 gene aberrations in stage III C...

  2. SGLT2-inhibitors: a novel class for the treatment of type 2 diabetes introduction of SGLT2-inhibitors in clinical practice.

    Science.gov (United States)

    Cuypers, J; Mathieu, C; Benhalima, K

    2013-01-01

    Treatment of type 2 diabetes (T2DM) continues to present challenges, with significant proportion of patients failing to achieve and maintain glycemic targets. Despite the availability of many oral antidiabetic agents, therapeutic efficacy is offset by side effects such as weight gain and hypoglycemia. Therefore, the search for novel therapeutic agents with an improved benefit-risk profile continues. Recent research has focused on the kidney as a potential therapeutic target, especially because maximal renal glucose reabsorption is increased in T2DM. Under normal physiological conditions, nearly all filtered glucose is reabsorbed in the proximal tubule of the nephron, principally via the sodium-glucose cotransporter 2 (SGLT2). SGLT2-inhibitors are a new class of oral antidiabetics, which reduce hyperglycemia by increasing urinary glucose excretion independently of insulin secretion or action. Clinical results are promising with significant lowering of HbA1c without increased risk of hypoglycemia, reduction of body weight and reduction of systolic blood pressure. Dapagliflozin is the first highly selective SGLT2-inhibitor approved by the European Medecine Agency. Canagliflozin and empagliflozin are undergoing phase III trials. Actual safety issues are an increased risk for genital- and urinary tract infections and a possible increased risk for bladder and breast cancer. This led to refusal of dapagliflozin by the Food and Drug Administration (FDA). A large randomized control trial is therefore warranted by the FDA. This review provides an overview of the current evidence available so far on the therapeutic potential of the SGLT2-inhibitors for the treatment of T2DM.

  3. Sorption of trace amounts of gallium (III) on iron (III) oxide

    International Nuclear Information System (INIS)

    Music, S.; Gessner, M.; Wolf, R.H.H.

    1979-01-01

    The sorption of trace amounts of gallium(III) on iron(III) oxide has been studied as a function of pH. Optimum conditions have been found for the preconcentration of traces of gallium(III) by iron(III) oxide. The influence of surface active substances and of complexing agents on the sorption of trace amounts of gallium(III) on iron(III) oxide has been also studied. (orig.) [de

  4. Sorption of trace amounts of gallium (III) on iron (III) oxide

    Energy Technology Data Exchange (ETDEWEB)

    Music, S; Gessner, M; Wolf, R H.H. [Institut Rudjer Boskovic, Zagreb (Yugoslavia)

    1979-01-01

    The sorption of trace amounts of gallium(III) on iron(III) oxide has been studied as a function of pH. Optimum conditions have been found for the preconcentration of traces of gallium(III) by iron(III) oxide. The influence of surface active substances and of complexing agents on the sorption of trace amounts of gallium(III) on iron(III) oxide has been also studied.

  5. Diminished responsiveness to dobutamine as an inotrope in mice with cecal ligation and puncture-induced sepsis: attribution to phosphodiesterase 4 upregulation.

    Science.gov (United States)

    Sakai, Mari; Suzuki, Tokiko; Tomita, Kengo; Yamashita, Shigeyuki; Palikhe, Sailesh; Hattori, Kohshi; Yoshimura, Naoki; Matsuda, Naoyuki; Hattori, Yuichi

    2017-06-01

    Dobutamine has been used in septic shock for many years as an only inotrope, but its benefit has been questioned. We weighed the effects of dobutamine and milrinone as inotropes in mice with cecal ligation and puncture (CLP)-induced polymicrobial sepsis. CLP-induced septic mice exhibited significant cardiac inflammation, as indicated by greatly increased mRNAs of proinflammatory cytokines and robust infiltration of inflammatory cells in the ventricular myocardium. Elevations of plasma cardiac troponin-I showed cardiac injury in CLP mice. Noninvasive echocardiographic assessment of cardiac function revealed that despite preserved left ventricular function in the presence of fluid replacement, the dobutamine inotropic response was significantly impaired in CLP mice compared with sham-operated controls. By contrast, milrinone exerted inotropic effects in sham-operated and CLP mice in an equally effective manner. Surface expression levels of β 1 -adrenoceptors and α-subunits of three main G protein families in the myocardium were unaffected by CLP-induced sepsis. Plasma cAMP levels were significantly elevated in both sham-operated and CLP mice in response to milrinone but only in sham-operated controls in response to dobutamine. Of phosphodiesterase (PDE) isoforms, PDE4D, but not PDE3A, both of which are responsible for cardiac cAMP hydrolysis, was significantly upregulated in CLP mouse myocardium. We define a novel mechanism for the impaired responsiveness to dobutamine as an inotrope in sepsis, and understanding the role of PDE4D in modulating cardiac functional responsiveness in sepsis may open the potential of a PDE4D-targeted therapeutic option in septic patients with low cardiac output who have a need for inotropic support. NEW & NOTEWORTHY Advisability of the usefulness of dobutamine in septic shock management is limited. Here, we reveal that the effect of dobutamine as a positive inotrope is impaired in mice with cecal ligation and puncture-induced sepsis

  6. WISC-III e WAIS-III na avaliação da inteligência de cegos WISC-III/WAIS-III en ciegos WISC-III and WAIS-III in intellectual assessment of blind people

    Directory of Open Access Journals (Sweden)

    Elizabeth do Nascimento

    2007-12-01

    Full Text Available Diante da escassez de pesquisas nacionais e de testes psicológicos destinados a avaliar pessoas cegas, desenvolveu-se um estudo psicométrico com as escalas verbais dos testes WISC-III e WAIS-III. Após as adaptações de alguns estímulos e das instruções, os testes foram aplicados em crianças (N = 120 e adultos (N = 52 residentes em Belo Horizonte. Os resultados indicaram que as escalas verbais modificadas apresentam uma boa consistência interna (alfa> 0,80. Além disso, a investigação da validade fatorial identifica a presença clara de apenas um componente. Este componente explica 81% e 64% para o WISC-III e WAIS-III, respectivamente. Conclui-se que as adaptações a que se procedeu não afetaram a estrutura fatorial das escalas. Deste modo, os profissionais poderão utilizar as escalas modificadas para avaliar a inteligência de pessoas cegas.Frente a la escasez de investigaciones nacionales asi como la ausencia de tests psicológicos que evaluen personas ciegas, se ha desarrollado un estudio psicometrico com la escalas verbales del WISC-III y WAIS-III. Posteriormente a las adaptaciones de algunos estímulos y de las instrucciones, las escalas fueron aplicadas a una muestra de niños (n=120 y de adultos (n=52 residentes en la ciudad de Belo Horizonte-Brasil. Los resultados indican que las escalas verbales modificadas presentan una alta fiabilidad (alpha >0,80 asi como la presencia clara de un unico componente responsable por 81% y 64% de la variancia del WIC-III e WAIS-III respectivamente. Se ha concluido que las modificaciones efectuadas no han comprometido la estructura factorial de las escalas verbales. Por tanto, los profesionales psicólogos pueden utilizar las escalas modificadas para la evaluación de la inteligencia de personas portadoras de ceguera.Owing to the almost lack of a national research on psychological testing for the evaluation of blind people, a psychometric study has been developed with the WISC-III and WAIS-III

  7. Determination of disulfide bridges of two spider toxins: hainantoxin-III and hainantoxin-IV

    Directory of Open Access Journals (Sweden)

    W Wang

    2009-01-01

    Full Text Available Peptide toxins are usually highly bridged proteins with multipairs of intrachain disulfide bonds. Analysis of disulfide connectivity is an important facet of protein structure determination. In this paper, we successfully assigned the disulfide linkage of two novel peptide toxins, called HNTX-III and HNTX-IV, isolated from the venom of Ornithoctonus hainana spider. Both peptides are useful inhibitors of TTX-sensitive voltage-gated sodium channels and are composed of six cysteine residues that form three disulfide bonds, respectively. Firstly, the peptides were partially reduced by tris(2-carboxyethyl-phosphine (TCEP in 0.1 M citrate buffer containing 6 M guanidine-HCl at 40° C for ten minutes. Subsequently, the partially reduced intermediates containing free thiols were separated by reversed-phase high-performance liquid chromatography (RP-HPLC and alkylated by rapid carboxamidomethylation. Then, the disulfide bonds of the intermediates were analyzed by Edman degradation. By using the strategy above, disulfide linkages of HNTX-III and HNTX-IV were determined as I-IV, II-V and III-VI pattern. In addition, this study also showed that this method may have a great potential for determining the disulfide bonds of spider peptide toxins.

  8. Synthesis and biological evaluation of lycorine derivatives as dual inhibitors of human acetylcholinesterase and butyrylcholinesterase

    Directory of Open Access Journals (Sweden)

    Wang Yue-Hu

    2012-09-01

    Full Text Available Abstract Background Alzheimer’s disease (AD is a neurologically degenerative disorder that affects more than 20 million people worldwide. The selective butyrylcholinesterase (BChE inhibitors and bivalent cholinesterase (ChE inhibitors represent new treatments for AD. Findings A series of lycorine derivatives (1–10 were synthesized and evaluated for anti-cholinesterase activity. Result showed that the novel compound 2-O-tert-butyldimethylsilyl-1-O-(methylthiomethyllycorine (7 was a dual inhibitor of human acetylcholinesterase (hAChE and butyrylcholinesterase (hBChE with IC50 values of 11.40 ± 0.66 μM and 4.17 ± 0.29 μM, respectively. The structure-activity relationships indicated that (i the 1-O-(methylthiomethyl substituent in lycorine was better than the 1-O-acetyl group for the inhibition of cholinesterase; (ii the acylated or etherified derivatives of lycorine and lycorin-2-one were more potent against hBChE than hAChE; and (iii the oxidation of lycorine at C-2 decreases the activity. Conclusion Acylated or etherified derivatives of lycorine are potential dual inhibitors of hBChE and hAChE. Hence, further study on the modification of lycorine for ChE inhibition is necessary.

  9. Pharmacological preconditioning by milrinone: memory preserving and neuroprotective effect in ischemia-reperfusion injury in mice.

    Science.gov (United States)

    Saklani, Reetu; Jaggi, Amteshwar; Singh, Nirmal

    2010-07-01

    We tested the neuroprotective effect of milrinone, a phosphodiesterase III inhibitor, in pharmacological preconditioning. Bilateral carotid artery occlusion for 12 min followed by reperfusion for 24 h produced ischemia-reperfusion (I/R) cerebral injury in male Swiss albino mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was assessed using the Morris water maze test, and motor coordination was evaluated using the inclined beam walking test, rota-rod test, and lateral push test. Milrinone (50 microg/kg & 100 microg/kg i.v.) was administered 24 h before surgery in a separate group of animals to induce pharmacological preconditioning. I/R increased cerebral infarct size and impaired memory and motor coordination. Milrinone treatment significantly decreased cerebral infarct size and reversed I/R-induced impairments in memory and motor coordination. This neuroprotective effect was blocked by ruthenium red (3 mg/kg, s.c.), an intracellular ryanodine receptor blocker. These findings indicate that milrinone preconditioning exerts a marked neuroprotective effect on the ischemic brain, putatively due to increased intracellular calcium levels activating calcium-sensitive signal transduction cascades.

  10. SGLT2 inhibitors to control glycemia in type 2 diabetes mellitus: a new approach to an old problem.

    Science.gov (United States)

    Jabbour, Serge A

    2014-01-01

    Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of antidiabetic agents with a novel insulin-independent mechanism of action. The SGLT2 is a transporter found in the proximal tubule of the kidney and is responsible for approximately 90% of renal glucose reabsorption. The SGLT2 inhibitors reduce reabsorption of glucose in the kidney, resulting in glucose excretion in the urine (50-90 g of ~180 g filtered by the kidneys daily), which in turn lowers plasma glucose levels in people with diabetes. The insulin-independent mechanism of action of SGLT2 inhibitors dictates that they are associated with a very low risk of hypoglycemia and can be used in patients with any degree of β-cell function or insulin sensitivity. Clinical trials have shown that SGLT2 inhibitors are effective at reducing blood glucose levels, body weight, and blood pressure when used as monotherapy or in combination with other antidiabetic agents in patients with type 2 diabetes mellitus. Treatment with SGLT2 inhibitors is generally well tolerated, although these agents have been associated with an increased incidence of genital infections. The SGLT2 inhibitors have become a valuable addition to the armory of drugs used to treat patients with type 2 diabetes mellitus, and several agents within the class are currently under investigation in phase III clinical trials.

  11. Extraction and separation studies of Ga(III, In(III and Tl(III using the neutral organophosphorous extractant, Cyanex-923

    Directory of Open Access Journals (Sweden)

    P. M. DHADKE

    2003-07-01

    Full Text Available The neutral extractant, Cyanes-923 has been used for the extraction and separation of gallium(III, indium(III and thallium(III from acidic solution. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the pH range 4.5–5.5, 5.0–6.5 and 1.5–3.0, respectively, and from the organic phase they can be stripped with 2.0 mol dm-3 HNO3, 3.0 mol dm-3 HNO3 and 3.0 mol dm-3 HCl, respectively. The effect of pH equilibration period, diluents, diverse ions and stripping agents on the extraction of Ga(III, In(III and Tl(III has been studied. The stroichiometry of the extracted species of these metal ions was determined on the basis of the slope analysis method. The reaction proceed by solvation and the probable extracted species found were [MCl3. 3Cyanex-923] [where M = Ga(III or In(III ] and [HTlCl4. 3Cyanex-923]. Based on these results a sequential procedure for the separation of Ga(III, In(III and Tl(III from each other was developed.

  12. Potentiometric studies on some ternary complexes of Nd(III), Sm(III), Gd(III) and Ho(III) with cyclohexanediaminetetraacetic acid as primary ligand

    International Nuclear Information System (INIS)

    Marathe, D.G.; Munshi, K.N.

    1983-01-01

    The formation constants of the ternary complexes of neodymium(III), samarium(III), gadlonium(III) and holmium(III) with cyclohexanediaminetetraacetic acid (CyDTA) as primary ligand and dihydroxynaphthalene (DHN), dihydroxynaphthalene-6-sulphonic acid (DHNSA) and cateechol-3,5-disulphonic acid (CDSA) as secondary ligands have been investigated by potentiometric titration technique. The secondary ligands have been investigated by potentiometric titration technique. The values of formation constants of 1:1:1 ternary chelates are reported at three different temperatures, and at a fixed ionic strength, μ = 0.1 M (NaClO 4 ). (author)

  13. Small-molecule inhibitors of toxT expression in Vibrio cholerae.

    Science.gov (United States)

    Anthouard, Rebecca; DiRita, Victor J

    2013-08-06

    identified in a high-throughput screen, (ii) targeting virulence gene production is an effective therapeutic strategy, and (iii) small-molecule inhibitors can uncover unknown layers of gene regulation, even in well-studied regulatory cascades.

  14. Solvent effects on extraction of aluminum(III), gallium(III), and indium(III), with decanoic acid

    International Nuclear Information System (INIS)

    Yamada, Hiromichi; Hayashi, Hisao; Fujii, Yukio; Mizuta, Masateru

    1986-01-01

    Extraction of aluminum(III) and indium(III) with decanoic acid in 1-octanol was carried out at 25 deg C and at an aqueous ionic strength of 0.1 mol dm -3 (NaClO 4 ). Monomeric and tetrameric aluminum(III) decanoates and monomeric indium(III) decanoate are responsible for the extraction. From a comparison of the present results with those obtained from the previous works, the polymerization of the extracted species was found to be more extensive in benzene than in 1-octanol, and the metal decanoates were highly polymerized in the following order in both solvents: Al > Ga > In. (author)

  15. Antithrombin III prevents deleterious effects of remote ischemia-reperfusion injury on healing of colonic anastomoses.

    Science.gov (United States)

    Tekin, Koray; Aytekin, Faruk; Ozden, Akin; Bilgihan, Ayşe; Erdem, Ergün; Sungurtekin, Ugur; Güney, Yildiz

    2002-08-01

    Antithrombin III is known as the most important natural inhibitor of thrombin activity and has been shown to attenuate local harmful effects of ischemia-reperfusion injury in many organs. In recent animal studies, delaying effect of remote organ ischemia-reperfusion injury on healing of intestinal anastomoses has been demonstrated. In this study, we investigated whether antithrombin III reduces deleterious systemic effects of ischemia-reperfusion injury on healing of colonic anastomoses in rats. Anastomosis of the left colon was performed in 24 rats that were divided into three groups: sham operated control (group I, n = 8), 30 minutes of intestinal ischemia-reperfusion by superior mesenteric artery occlusion (group II, n = 8), antithrombin III treated group (250 U/kg before and after the ischemia-reperfusion, group III, n = 8). On postoperative day 6, all animals were sacrificed, and bursting pressure and tissue hydroxyproline content of the anastomoses were assessed and compared. On postoperative day 6 the mean bursting pressures were 149.6 +/- 4.8, 69.8 +/- 13.5, and 121.8 +/- 8.7 mm Hg for groups I, II, and III, respectively (P = 0.000). Mean tissue hydroxyproline concentration values were 389.5 +/- 29.6, 263.1 +/- 10.0, and 376.0 +/- 33.8 microg/mg for groups I, II, III respectively (P = 0.005). This study showed that, antithrombin III treatment significantly prevented the delaying effect of remote organ ischemia-reperfusion injury on anastomotic healing in the colon. Further clinical studies are needed to clarify whether antithrombin may be a useful therapeutic agent to increase the safety of the anastomosis during particular operations where remote organ ischemia-reperfusion injury takes place.

  16. Carbon- versus sulphur-based zinc binding groups for carbonic anhydrase inhibitors?

    Science.gov (United States)

    Supuran, Claudiu T

    2018-12-01

    A set of compounds incorporating carbon-based zinc-binding groups (ZBGs), of the type PhX (X = COOH, CONH 2 , CONHNH 2 , CONHOH, CONHOMe), and the corresponding derivatives with sulphur(VI)-based ZBGs (X = SO 3 H, SO 2 NH 2 , SO 2 NHNH 2 , SO 2 NHOH, SO 2 NHOMe) were tested as inhibitors of all mammalian isoforms of carbonic anhydrase (CA, EC 4.2.1.1), CA I-XV. Three factors connected with the ZBG influenced the efficacy as CA inhibitor (CAI) of the investigated compounds: (i) the pKa of the ZBG; (ii) its geometry (tetrahedral, i.e. sulphur-based, versus trigonal, i.e. carbon-based ZBGs), and (iii) orientation of the organic scaffold induced by the nature of the ZBG. Benzenesulphonamide was the best inhibitor of all isoforms, but other ZBGs led to interesting inhibition profiles, although with an efficacy generally reduced when compared to the sulphonamide. The nature of the ZBG also influenced the CA inhibition mechanism. Most of these derivatives were zinc binders, but some of them (sulfonates, carboxylates) may interact with the enzyme by anchoring to the zinc-coordinated water molecule or by other inhibition mechanisms (occlusion of the active site entrance, out of the active site binding, etc.). Exploring structurally diverse ZBGs may lead to interesting new developments in the field of CAIs.

  17. Characterization of ["1"1C]Lu AE92686 as a PET radioligand for phosphodiesterase 10A in the nonhuman primate brain

    International Nuclear Information System (INIS)

    Yang, Kai-Chun; Stepanov, Vladimir; Amini, Nahid; Martinsson, Stefan; Takano, Akihiro; Halldin, Christer; Nielsen, Jacob; Bundgaard, Christoffer; Bang-Andersen, Benny; Grimwood, Sarah; Farde, Lars; Finnema, Sjoerd J.

    2017-01-01

    ["1"1C]Lu AE92686 is a positron emission tomography (PET) radioligand that has recently been validated for examining phosphodiesterase 10A (PDE10A) in the human striatum. ["1"1C]Lu AE92686 has high affinity for PDE10A (IC_5_0 = 0.39 nM) and may also be suitable for examination of the substantia nigra, a region with low density of PDE10A. Here, we report characterization of regional ["1"1C]Lu AE92686 binding to PDE10A in the nonhuman primate (NHP) brain. A total of 11 PET measurements, seven baseline and four following pretreatment with unlabeled Lu AE92686 or the structurally unrelated PDE10A inhibitor MP-10, were performed in five NHPs using a high resolution research tomograph (HRRT). ["1"1C]Lu AE92686 binding was quantified using a radiometabolite-corrected arterial input function and compartmental and graphical modeling approaches. Regional time-activity curves were best described with the two-tissue compartment model (2TCM). However, the distribution volume (V_T) values for all regions were obtained by the Logan plot analysis, as reliable cerebellar V_T values could not be derived by the 2TCM. For cerebellum, a proposed reference region, V_T values increased by ∝30 % with increasing PET measurement duration from 63 to 123 min, while V_T values in target regions remained stable. Both pretreatment drugs significantly decreased ["1"1C]Lu AE92686 binding in target regions, while no significant effect on cerebellum was observed. Binding potential (BP_N_D) values, derived with the simplified reference tissue model (SRTM), were 13-17 in putamen and 3-5 in substantia nigra and correlated well to values from the Logan plot analysis. The method proposed for quantification of ["1"1C]Lu AE92686 binding in applied studies in NHP is based on 63 min PET data and SRTM with cerebellum as a reference region. The study supports that ["1"1C]Lu AE92686 can be used for PET examinations of PDE10A binding also in substantia nigra. (orig.)

  18. Characterization of [{sup 11}C]Lu AE92686 as a PET radioligand for phosphodiesterase 10A in the nonhuman primate brain

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Kai-Chun; Stepanov, Vladimir; Amini, Nahid; Martinsson, Stefan; Takano, Akihiro; Halldin, Christer [Karolinska Institutet, Karolinska University Hospital, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm (Sweden); Nielsen, Jacob [H. Lundbeck A/S, Synaptic Transmission, Valby (Denmark); Bundgaard, Christoffer; Bang-Andersen, Benny [H. Lundbeck A/S, Discovery Chemistry and DMPK, Valby (Denmark); Grimwood, Sarah [Pfizer Inc., Neuroscience and Pain Research Unit, Cambridge, MA (United States); Farde, Lars [Karolinska Institutet, Karolinska University Hospital, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm (Sweden); AstraZeneca PET Science Center at Karolinska Institutet, Personalized Health Care and Biomarkers, Stockholm (Sweden); Finnema, Sjoerd J. [Karolinska Institutet, Karolinska University Hospital, Department of Clinical Neuroscience, Center for Psychiatric Research, Stockholm (Sweden); Yale University, Department of Radiology and Biomedical Imaging, New Haven, CT (United States)

    2017-02-15

    [{sup 11}C]Lu AE92686 is a positron emission tomography (PET) radioligand that has recently been validated for examining phosphodiesterase 10A (PDE10A) in the human striatum. [{sup 11}C]Lu AE92686 has high affinity for PDE10A (IC{sub 50} = 0.39 nM) and may also be suitable for examination of the substantia nigra, a region with low density of PDE10A. Here, we report characterization of regional [{sup 11}C]Lu AE92686 binding to PDE10A in the nonhuman primate (NHP) brain. A total of 11 PET measurements, seven baseline and four following pretreatment with unlabeled Lu AE92686 or the structurally unrelated PDE10A inhibitor MP-10, were performed in five NHPs using a high resolution research tomograph (HRRT). [{sup 11}C]Lu AE92686 binding was quantified using a radiometabolite-corrected arterial input function and compartmental and graphical modeling approaches. Regional time-activity curves were best described with the two-tissue compartment model (2TCM). However, the distribution volume (V{sub T}) values for all regions were obtained by the Logan plot analysis, as reliable cerebellar V{sub T} values could not be derived by the 2TCM. For cerebellum, a proposed reference region, V{sub T} values increased by ∝30 % with increasing PET measurement duration from 63 to 123 min, while V{sub T} values in target regions remained stable. Both pretreatment drugs significantly decreased [{sup 11}C]Lu AE92686 binding in target regions, while no significant effect on cerebellum was observed. Binding potential (BP{sub ND}) values, derived with the simplified reference tissue model (SRTM), were 13-17 in putamen and 3-5 in substantia nigra and correlated well to values from the Logan plot analysis. The method proposed for quantification of [{sup 11}C]Lu AE92686 binding in applied studies in NHP is based on 63 min PET data and SRTM with cerebellum as a reference region. The study supports that [{sup 11}C]Lu AE92686 can be used for PET examinations of PDE10A binding also in substantia

  19. Microbial reduction of Fe(III) in the presence of oxygen under low pH conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kusel, K.; Roth, U.; Drake, H.L. [University of Bayreuth, Bayreuth (Germany)

    2002-07-01

    In acidic, coal mining lake sediments, facultatively anaerobic Acidiphilium species are probably involved in the reduction of Fe(III). Previous results indicate that these bacteria can co-respire O{sub 2} and Fe(III). In this study, we investigated the capacity of the sediment microbiota to reduce Fe(III) in the presence of O{sub 2} at pH 3. In sediment microcosms with 4% O{sub 2} in the headspace, the concentration of Fe(II) increased at a rate of 1.03 {mu}mol (g wet sediment){sup -1} day{sup -1} within the first 7 days of incubation which was similar to the rate obtained with controls incubated under anoxic conditions. However, in microcosms incubated under air, Fe(II) was consumed after a lag phase of 8 h with a rate of 2.66 {mu}mol (g wet sediment){sup -1} day{sup -1}. Acidiphilium cryptum JF-5, isolated from this sediment, reduced soluble Fe(III) with either 4 or 21% O{sub 2} in the headspace, and concomitantly consumed O{sub 2}. However, the rate of Fe(II) formation normalized for cell density decreased under oxic conditions. Schwertmannite, the predominant Fe(III)-mineral of this sediment, was also reduced by A. cryptum JF-5 under oxic conditions. The rate of Fe(II) formation by A. cryptum JF-5 decreased after transfer from preincubation under air in medium lacking Fe(III). Acidiphilium cryptum JF-5 did not form Fe(II) when preincubated under air and transferred to anoxic medium containing Fe(III) and chloramphenicol, an inhibitor of protein synthesis. These results indicate that: (i) the reduction of Fe(III) can occur at low O{sub 2} concentrations in acidic sediments; (ii) Fe(II) can be oxidized at O{sub 2} concentrations near saturation; and (iii) the enzyme(s) responsible for the reduction of Fe(III) in A. cryptum JF-5 are not constitutive.

  20. A mouse model of mitochondrial complex III dysfunction induced by myxothiazol

    Energy Technology Data Exchange (ETDEWEB)

    Davoudi, Mina [Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185 (Sweden); Kallijärvi, Jukka; Marjavaara, Sanna [Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, 00014 (Finland); Kotarsky, Heike; Hansson, Eva [Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185 (Sweden); Levéen, Per [Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185 (Sweden); Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, 00014 (Finland); Fellman, Vineta, E-mail: Vineta.Fellman@med.lu.se [Pediatrics, Department of Clinical Sciences, Lund, Lund University, Lund 22185 (Sweden); Folkhälsan Research Center, Biomedicum Helsinki, University of Helsinki, 00014 (Finland); Children’s Hospital, Helsinki University Hospital, University of Helsinki, Helsinki 00029 (Finland)

    2014-04-18

    Highlights: • Reversible chemical inhibition of complex III in wild type mouse. • Myxothiazol causes decreased complex III activity in mouse liver. • The model is useful for therapeutic trials to improve mitochondrial function. - Abstract: Myxothiazol is a respiratory chain complex III (CIII) inhibitor that binds to the ubiquinol oxidation site Qo of CIII. It blocks electron transfer from ubiquinol to cytochrome b and thus inhibits CIII activity. It has been utilized as a tool in studies of respiratory chain function in in vitro and cell culture models. We developed a mouse model of biochemically induced and reversible CIII inhibition using myxothiazol. We administered myxothiazol intraperitoneally at a dose of 0.56 mg/kg to C57Bl/J6 mice every 24 h and assessed CIII activity, histology, lipid content, supercomplex formation, and gene expression in the livers of the mice. A reversible CIII activity decrease to 50% of control value occurred at 2 h post-injection. At 74 h only minor histological changes in the liver were found, supercomplex formation was preserved and no significant changes in the expression of genes indicating hepatotoxicity or inflammation were found. Thus, myxothiazol-induced CIII inhibition can be induced in mice for four days in a row without overt hepatotoxicity or lethality. This model could be utilized in further studies of respiratory chain function and pharmacological approaches to mitochondrial hepatopathies.

  1. The Cyclic Di-GMP Phosphodiesterase Gene Rv1357c/BCG1419c Affects BCG Pellicle Production and In Vivo Maintenance.

    Science.gov (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

    2015-02-01

    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. © 2015 International Union of Biochemistry and Molecular Biology.

  2. Mitochondrial Membrane Permeability Inhibitors in Acute Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Cory Trankle, MD

    2016-10-01

    Full Text Available Despite therapeutic advances, acute myocardial infarction (AMI remains a leading cause of morbidity and mortality worldwide. One potential limitation of the current treatment paradigm is the lack of effective therapies to optimize reperfusion after ischemia and prevent reperfusion-mediated injury. Experimental studies indicate that this process accounts for up to 50% of the final infarct size, lending it importance as a potential target for cardioprotection. However, multiple therapeutic approaches have shown potential in pre-clinical and early phase trials but a paucity of clear clinical benefit when expanded to larger studies. Here we explore this history of trials and errors of the studies of cyclosporine A and other mitochondrial membrane permeability inhibitors, agents that appeared to have a promising pre-clinical record yet provided disappointing results in phase III clinical trials.

  3. Synthesis and characterization of La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III) and Dy(III) complexes of 2-acetylfuran-2-thenoylhydrazone

    International Nuclear Information System (INIS)

    Singh, B.; Singh, Praveen K.

    1998-01-01

    The reaction of 2-acetylfuran-2-thenoylhydrazone(afth) with Ln(III) trichlorides yields complexes of the type [Ln(afth)Cl 2 (H 2 O)(EtOH)]Cl, [Ln(III) = La, Pr, Nd, Sm, Eu, Gd, Tb and Dy]. The complexes have been characterized by molar conductance, magnetic susceptibility and TGA and DTA measurements, magnetic susceptibility and TGA and DTA measurements, FAB mass, infrared, proton NMR, electronic absorption and emission spectra. The terbium complex is found to be monomer from the FAB mass spectrum. The IR and NMR spectra suggest neutral tridentate behaviour of the Schiff base. A coordination number seven is proposed around the metal ions. Emission spectra suggest C 3v , symmetry around the metal ion with capped octahedron geometry for the europium complex. (author)

  4. Golimumab in patients with active rheumatoid arthritis after treatment with tumour necrosis factor alpha inhibitors (GO-AFTER study): a multicentre, randomised, double-blind, placebo-controlled, phase III trial

    NARCIS (Netherlands)

    Smolen, Josef S.; Kay, Jonathan; Doyle, Mittie K.; Landewé, Robert; Matteson, Eric L.; Wollenhaupt, Jürgen; Gaylis, Norman; Murphy, Frederick T.; Neal, Jeffrey S.; Zhou, Yiying; Visvanathan, Sudha; Hsia, Elizabeth C.; Rahman, Mahboob U.; Ahern, Michael John; Hall, Stephen; Nash, Peter Thomas; Graninger, Winfried; Ebner, Wolfgang; Machold, Klaus; Zamani, Omid; Atkins, Christopher; Beaulieu, André; Bell, Mary; Fitzcharles, Mary Ann; Keystone, Edward; Khraishi, Majed; McKendry, Robert J. R.; Rahman, Proton; Thomason, Glen T. D.; Thorne, J. Carter; Bookman, Arthur; Faraawi, Rafat; Hannonen, Pekka; Leirisalo-Repo, Marjetta; Järvinen, Pentti; Braun, Jürgen; Burmester, Gerd; Fiehn, Christoph; Gruenke, Mathias; Bäuerle, Michael; Hauer, Rolf-Walter; Kellner, Herbert; Rubbert, Andrea; Schewe, Stefan; Sieper, Joachim; Tony, Hans-Peter; Kekow, Jörn; Ching, Daniel Wai Tho; Jones, Peter Brian Barrie; Singh, Gagrath Pradeep

    2009-01-01

    Tumour necrosis factor alpha (TNFalpha) inhibitors are frequently used to treat rheumatoid arthritis, but whether use of a different TNFalpha inhibitor can improve patient response is unknown. We assess the efficacy and safety of the TNFalpha inhibitor golimumab in patients with active rheumatoid

  5. Preparation and characterisation of mixed ligand complexes of Co(III), Fe(III) and Cr(III) containing phthalimide and phenols

    International Nuclear Information System (INIS)

    Miah, M.A.J.; Islam, M.S.; Pal, S.C.; Barma, T.K.

    1996-01-01

    Some novel mixed ligand complexes of Co(III), Fe(III) and Cr(III) containing phthalimide as primary and 2-aminophenol and 3-aminophenol as secondary ligands have been synthesized and characterised on the basis of elemental analyses, conductivity and magnetic measurements and infrared and electronic spectral studies. Complexes containing 2-aminophenol are 1:1 electrolyte in N,N dimethylformamide. Spectral studies indicate that all the complexes exhibit octahedral geometry. The complexes have the general composition; K[M(pim)/sub 2/(L)/sub 2/]; where m=Co(III), Fe(III) and Cr(III), pim-anion of phthalimamide and L=anion of 2-aminophenol and 3-aminophenol. (author)

  6. Highly Selective Phosphatidylinositol 4-Kinase III beta Inhibitors and Structural Insight into Their Mode of Action

    Czech Academy of Sciences Publication Activity Database

    Mejdrová, Ivana; Chalupská, Dominika; Kögler, Martin; Šála, Michal; Plačková, Pavla; Bäumlová, Adriana; Hřebabecký, Hubert; Procházková, Eliška; Dejmek, Milan; Guillon, Rémi; Strunin, Dmytro; Weber, Jan; Lee, G.; Birkuš, G.; Mertlíková-Kaiserová, Helena; Bouřa, Evžen; Nencka, Radim

    2015-01-01

    Roč. 58, č. 9 (2015), s. 3767-3793 ISSN 0022-2623 R&D Projects: GA MŠk LO1302; GA ČR GA15-09310S; GA ČR GJ15-21030Y EU Projects: European Commission(XE) 333916 - STARPI4K Institutional support: RVO:61388963 Keywords : phosphatidylinositol 4-kinase III beta * broad-spectrum antiviral agents * positive-sense RNA viruses Subject RIV: CC - Organic Chemistry Impact factor: 5.589, year: 2015

  7. Discovery of natural mouse serum derived HIV-1 entry inhibitor(s).

    Science.gov (United States)

    Wei, M; Chen, Y; Xi, J; Ru, S; Ji, M; Zhang, D; Fang, Q; Tang, B

    Among rationally designed human immunodeficiency virus 1 (HIV-1) inhibitors, diverse natural factors have showed as potent anti-HIV activity in human blood. We have discovered that the boiled supernatant of healthy mouse serum could suppress HIV-1 entry, and exhibited reduced inhibitory activity after trypsin digestion. Further analysis demonstrated that only the fraction containing 10-25 K proteins could inhibit HIV-1 mediated cell-cell fusion. These results suggest that the 10-25 K protein(s) is novel natural HIV-1 entry inhibitor(s). Our findings provide important information about novel natural HIV entry inhibitors in mouse serum.

  8. Non‑Hormonal treatment of BPH/BOO

    Directory of Open Access Journals (Sweden)

    Nadir I Osman

    2014-01-01

    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.

  9. Myocardial repair with long-term and low-dose administration of a nitric oxide synthesis inhibitor. Myofibroblasts, type III collagen and fibronectin

    Directory of Open Access Journals (Sweden)

    Pessanha Mônica Gomes

    1999-01-01

    Full Text Available OBJECTIVE: To study the healing process of the myocardium in hypertensive rats undergoing inhibition of nitric oxide synthesis. METHODS: Two groups of animals were studied: one received L-NAME, 12mg/kg/day, and the other was a control group. The presence of type III collagen, fibronectin, and alpha-smooth muscle actin-positive cells was assessed by immunohistochemistry. RESULTS: Fibronectin was seen in both early and late lesions, while type III collagen was seen mainly in areas of incomplete healing, situated among myocytes and around the intramyocardial branches of the coronary arteries. Areas representing early and late lesions showed a population of spindle-shaped cells. Immunohistochemistry showed that these cells were positive for alpha-smooth muscle actin. CONCLUSION: In the myocardium of hypertensive rats, the alpha-smooth muscle actin-positive cells are related to the accumulation of type III collagen and fibronectin in the areas of myocardial damage.

  10. Continuous Intravenous Milrinone Therapy in Pediatric Outpatients

    OpenAIRE

    Curley, Michelle; Liebers, Jill; Maynard, Roy

    2017-01-01

    Milrinone is a phosphodiesterase 3 inhibitor with both positive inotropic and vasodilator properties. Administered as a continuous infusion, milrinone is indicated for the short-term treatment of patients with acute decompensated heart failure. Despite limited data supporting long-term milrinone therapy in adults with congestive heart failure, children managed as outpatients may benefit from continuous milrinone as a treatment for cardiac dysfunction, as a destination therapy for cardiac tran...

  11. Non pigmenting mucosal fixed drug eruption due to tadalafil: A report of two cases

    Directory of Open Access Journals (Sweden)

    Sudip Das

    2014-01-01

    Full Text Available Various ′sex-stimulant′ medicines with fancy names and attractive packaging are available over the counter. Most contain phosphodiesterase 5 inhibitors in various strengths, often with herbal additions. These drugs are used erratically by the lay public, driven by folklore that such usage leads to increase in the length, girth or firmness of the penis. Such indiscriminate use by an otherwise healthy population leads to undue side effects.

  12. New Drugs and Treatment Targets in Psoriasis

    DEFF Research Database (Denmark)

    Kofoed, Kristian; Skov, Lone; Zachariae, Claus

    2015-01-01

    , and phosphodiesterase inhibitors. We review published clinical trials, and conference abstracts presented during the last years, concerned with new drugs under development for the treatment of psoriasis. In conclusion, our psoriasis armamentarium will be filled with several new effective therapeutic options the coming...... years. We need to be aware of the limitations of drug safety data when selecting new novel treatments. Monitoring and clinical registries are still important tools....

  13. Theobromine up-regulates cerebral brain-derived neurotrophic factor and facilitates motor learning in mice

    OpenAIRE

    Yoneda, Mitsugu; Sugimoto, Naotoshi; Katakura, Masanori; Matsuzaki, Kentaro; Tanigami, Hayate; Yachie, Akihiro; Ohno-Shosaku, Takako; Shido, Osamu

    2017-01-01

    Theobromine, which is a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. Theobromine works as a phosphodiesterase (PDE) inhibitor to increase intracellular cyclic adenosine monophosphate (cAMP). cAMP activates the cAMP-response element-binding protein (CREB), which is involved in a large variety of brain processes, including the induction of the brain-derived neurotrophic factor (BDNF). BDNF supports cell survival and neuronal functions, including learning and m...

  14. Pharmacological Prevention and Reversion of Erectile Dysfunction after Radical Prostatectomy, By Modulation of Nitric Oxide/Cgmp Pathways

    Science.gov (United States)

    2008-03-01

    and intensified CVOD (10); d) iNOS knock out mice had an increased collagen deposition in the penile corpora cavernosa with aging (35), and adult ...Xi L, Kukreja RC. Phosphodiesterase-5 inhibitor sildenafil preconditions adult cardiac myocytes against necrosis and apoptosis. Essential role of...in hypothyroidism . Am J Physiol Endocrinol Metab. 2007 292(1):E175-86 33. Ferrini MG, Kovanecz I, Sanchez S, Vernet D, Davila HH, Rajfer J,Gonzalez

  15. Phase I-II study of everolimus and low-dose oral cyclophosphamide in patients with metastatic renal cell cancer

    International Nuclear Information System (INIS)

    Huijts, Charlotte M; Santegoets, Saskia J; Eertwegh, Alfons J van den; Pijpers, Laura S; Haanen, John B; Gruijl, Tanja D de; Verheul, Henk M; Vliet, Hans J van der

    2011-01-01

    For patients with metastatic renal cell cancer (mRCC) who progressed on vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor therapy, the orally administered mammalian target of rapamycin (mTOR) inhibitor everolimus has been shown to prolong progression free survival. Intriguingly, inhibition of mTOR also promotes expansion of immunosuppressive regulatory T cells (Tregs) that can inhibit anti-tumor immune responses in a clinically relevant way in various tumor types including RCC. This study intends to investigate whether the antitumor efficacy of everolimus can be increased by preventing the detrimental everolimus induced expansion of Tregs using a metronomic schedule of cyclophosphamide. This phase I-II trial is a national multi-center study of different doses and schedules of low-dose oral cyclophosphamide in combination with a fixed dose of everolimus in patients with mRCC not amenable to or progressive after a VEGF-receptor tyrosine kinase inhibitor containing treatment regimen. In the phase I part of the study the optimal Treg-depleting dose and schedule of metronomic oral cyclophosphamide when given in combination with everolimus will be determined. In the phase II part of the study we will evaluate whether the percentage of patients progression free at 4 months of everolimus treatment can be increased from 50% to 70% by adding metronomic cyclophosphamide (in the dose and schedule determined in the phase I part). In addition to efficacy, we will perform extensive immune monitoring with a focus on the number, phenotype and function of Tregs, evaluate the safety and feasibility of the combination of everolimus and cyclophosphamide, perform monitoring of selected angiogenesis parameters and analyze everolimus and cyclophosphamide drug levels. This phase I-II study is designed to determine whether metronomic cyclophosphamide can be used to counter the mTOR inhibitor everolimus induced Treg expansion in patients with metastatic renal cell

  16. Phase I-II study of everolimus and low-dose oral cyclophosphamide in patients with metastatic renal cell cancer

    Directory of Open Access Journals (Sweden)

    Huijts Charlotte M

    2011-11-01

    Full Text Available Abstract Background For patients with metastatic renal cell cancer (mRCC who progressed on vascular endothelial growth factor (VEGF receptor tyrosine kinase inhibitor therapy, the orally administered mammalian target of rapamycin (mTOR inhibitor everolimus has been shown to prolong progression free survival. Intriguingly, inhibition of mTOR also promotes expansion of immunosuppressive regulatory T cells (Tregs that can inhibit anti-tumor immune responses in a clinically relevant way in various tumor types including RCC. This study intends to investigate whether the antitumor efficacy of everolimus can be increased by preventing the detrimental everolimus induced expansion of Tregs using a metronomic schedule of cyclophosphamide. Methods/design This phase I-II trial is a national multi-center study of different doses and schedules of low-dose oral cyclophosphamide in combination with a fixed dose of everolimus in patients with mRCC not amenable to or progressive after a VEGF-receptor tyrosine kinase inhibitor containing treatment regimen. In the phase I part of the study the optimal Treg-depleting dose and schedule of metronomic oral cyclophosphamide when given in combination with everolimus will be determined. In the phase II part of the study we will evaluate whether the percentage of patients progression free at 4 months of everolimus treatment can be increased from 50% to 70% by adding metronomic cyclophosphamide (in the dose and schedule determined in the phase I part. In addition to efficacy, we will perform extensive immune monitoring with a focus on the number, phenotype and function of Tregs, evaluate the safety and feasibility of the combination of everolimus and cyclophosphamide, perform monitoring of selected angiogenesis parameters and analyze everolimus and cyclophosphamide drug levels. Discussion This phase I-II study is designed to determine whether metronomic cyclophosphamide can be used to counter the mTOR inhibitor everolimus

  17. Selective inhibition of influenza virus protein synthesis by inhibitors of DNA function

    International Nuclear Information System (INIS)

    Minor, P.D.; Dimmock, N.J.

    1977-01-01

    Various known inhibitors of cellular DNA function were shown to inhibit cellular RNA synthesis and influenza (fowl plague) virus multiplication. The drugs were investigated for their effect upon the synthesis of influenza virus proteins. According to this effect they could be classified with previously studied compounds as follows: Group I (ethidium bromide, proflavine, and N-nitroquinoline-N-oxide) inhibited both viral and cellular protein synthesis; Group II (nogalomycin, daunomycin and α-amanitin) inhibited viral but not cellular protein synthesis, and all viral proteins were inhibited coordinately; Group III (mithramycin, echinomycin, and actinomycin D) inhibited all viral but not cellular protein synthesis at high concentrations, but at a lower critical concentration inhibited the synthesis of viral haemagglutinin, neuraminidase, and M protein preferentially; Group IV(uv irradiation and camptothecin) inhibited the synthesis of viral haemagglutinin, neuraminidase, and M protein, but not other viral proteins, even at high doses. The mode of action of these inhibitors is discussed in relation to the mechanism of the nuclear events upon which influenza virus multiplication is dependent

  18. Structural asymmetry of phosphodiesterase-9, potential protonation of a glutamic acid, and role of the invariant glutamine.

    Directory of Open Access Journals (Sweden)

    Jing Hou

    2011-03-01

    Full Text Available PDE9 inhibitors show potential for treatment of diseases such as diabetes. To help with discovery of PDE9 inhibitors, we performed mutagenesis, kinetic, crystallographic, and molecular dynamics analyses on the active site residues of Gln453 and its stabilizing partner Glu406. The crystal structures of the PDE9 Q453E mutant (PDE9Q453E in complex with inhibitors IBMX and (S-BAY73-6691 showed asymmetric binding of the inhibitors in two subunits of the PDE9Q453E dimer and also the significant positional change of the M-loop at the active site. The kinetic analysis of the Q453E and E406A mutants suggested that the invariant glutamine is critical for binding of substrates and inhibitors, but is unlikely to play a key role in the differentiation between substrates of cGMP and cAMP. The molecular dynamics simulations suggest that residue Glu406 may be protonated and may thus explain the hydrogen bond distance between two side chain oxygens of Glu453 and Glu406 in the crystal structure of the PDE9Q453E mutant. The information from these studies may be useful for design of PDE9 inhibitors.

  19. RVX-297- a novel BD2 selective inhibitor of BET bromodomains

    Energy Technology Data Exchange (ETDEWEB)

    Kharenko, Olesya A., E-mail: olesya@zenithepigenetics.com [Zenith Epigenetics, Suite 300, 4820 Richard Road SW, Calgary, Alberta, T3E 6L1 (Canada); Gesner, Emily M.; Patel, Reena G.; Norek, Karen [Zenith Epigenetics, Suite 300, 4820 Richard Road SW, Calgary, Alberta, T3E 6L1 (Canada); White, Andre; Fontano, Eric; Suto, Robert K. [Xtal BioStructures, Inc., 12 Michigan Dr., Natick, MA 01760 (United States); Young, Peter R.; McLure, Kevin G.; Hansen, Henrik C. [Zenith Epigenetics, Suite 300, 4820 Richard Road SW, Calgary, Alberta, T3E 6L1 (Canada)

    2016-08-12

    Bromodomains are epigenetic readers that specifically bind to the acetyl lysine residues of histones and transcription factors. Small molecule BET bromodomain inhibitors can disrupt this interaction which leads to potential modulation of several disease states. Here we describe the binding properties of a novel BET inhibitor RVX-297 that is structurally related to the clinical compound RVX-208, currently undergoing phase III clinical trials for the treatment of cardiovascular diseases, but is distinctly different in its biological and pharmacokinetic profiles. We report that RVX-297 preferentially binds to the BD2 domains of the BET bromodomain and Extra Terminal (BET) family of protein. We demonstrate the differential binding modes of RVX-297 in BD1 and BD2 domains of BRD4 and BRD2 using X-ray crystallography, and describe the structural differences driving the BD2 selective binding of RVX-297. The isothermal titration calorimetry (ITC) data illustrate the related differential thermodynamics of binding of RVX-297 to single as well as dual BET bromodomains. - Highlights: • A novel inhibitor of BET bromodomains, RVX-297 is described. • The differential binding modes of RVX-297 in BD1 and BD2 domains of BRD4 and BRD2 using X-ray crystallography are described. • RVX-297 preferentially binds to the BD2 domains of the BET bromodomains. • The structural and thermodynamic properties of the BD2 selective binding of RVX-297 are characterized.

  20. Thermodynamic data for predicting concentrations of Pu(III), Am(III), and Cm(III) in geologic environments

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Dhanpat; Rao, Linfeng; Weger, H.T.; Felmy, A.R. [Pacific Northwest National Laboratory, WA (United States); Choppin, G.R. [Florida State University, Florida (United States); Yui, Mikazu [Japan Nuclear Cycle Development Inst., Tokai Works, Tokai, Ibaraki (Japan)

    1999-01-01

    This report provides thermodynamic data for predicting concentrations of Pu(III), Am(III), and Cm(III) in geologic environments, and contributes to an integration of the JNC chemical thermodynamic database, JNC-TDB (previously PNC-TDB), for the performance analysis of geological isolation system for high-level radioactive wastes. Thermodynamic data for the formation of complexes or compounds with hydroxide, chloride, fluoride, carbonate, nitrate, sulfate and phosphate are discussed in this report. Where data for specific actinide(III) species are lacking, the data were selected based on chemical analogy to other trivalent actinides. In this study, the Pitzer ion-interaction model is mainly used to extrapolate thermodynamic constants to zero ionic strength at 25degC. (author)

  1. Luminescence study on solvation of americium(III), curium(III) and several lanthanide(III) ions in nonaqueous and binary mixed solvents

    International Nuclear Information System (INIS)

    Kimura, T.; Nagaishi, R.; Kato, Y.; Yoshida, Z.

    2001-01-01

    The luminescence lifetimes of An(III) and Ln(III) ions [An=Am and Cm; Ln=Nd, Sm, Eu, Tb and Dy] were measured in dimethyl sulfoxide(DMSO), N,N-dimethylformamide(DMF), methanol(MeOH), water and their perdeuterated solvents. Nonradiative decay rates of the ions were in the order of H 2 O > MeOH > DMF > DMSO, indicating that O-H vibration is more effective quencher than C-H, C=O, and S=O vibrations in the solvent molecules. Maximal lifetime ratios τ D /τ H were observed for Eu(III) in H 2 O, for Sm(III) in MeOH and DMF, and for Sm(III) and Dy(III) in DMSO. The solvent composition in the first coordination sphere of Cm(III) and Ln(III) in binary mixed solvents was also studied by measuring the luminescence lifetime. Cm(III) and Ln(III) were preferentially solvated by DMSO in DMSO-H 2 O, by DMF in DMF-H 2 O, and by H 2 O in MeOH-H 2 O over the whole range of the solvent composition. The order of the preferential solvation, i.e., DMSO > DMF > H 2 O > MeOH, correlates with the relative basicity of these solvents. The Gibbs free energy of transfer of ions from water to nonaqueous solvents was further estimated from the degree of the preferential solvation. (orig.)

  2. Luminescence studies of Sm(III) and Cm(III) complexes in NaSCN/DHDECMP extraction systems

    CERN Document Server

    Chung, D Y; Kimura, T

    1999-01-01

    Laser-induced fluorescence (LIF) studies of Sm(III) and Cm(III) complexes in the NaSCN/DHDECMP solvent extraction system were carried out. Luminescence lifetimes were measured to determine the number of water molecules coordinated to Sm(III), Tb(III), Dy(III), and Cm(III) in the sodium thiocyanate solution and in the DHDECMP phase. The hydration number of Sm(III), Tb(III), Dy(III), and Cm(III) in the sodium thiocyanate solution decreased linearly with increasing sodium thiocyanate concentration. The hydration numbers of Sm(III), Dy(III), and Cm(III) in the DHDECMP phase decreased with increasing sodium thiocyanate concentration. The water molecules in the inner coordination sphere of Sm(III) and Dy(III) extracted into the DHDECMP were not completely removed at low sodium thiocyanate concentration but decreased with increasing sodium thiocyanate concentration. However, in the case of Cm(III) extracted into the DHDECMP phase from the sodium thiocyanate solution, there was no water in the inner coordination sphe...

  3. In Silico Docking of Small-Molecule Inhibitors to the Escherichia coli Type III Secretion System EscN ATPase

    Science.gov (United States)

    2014-07-01

    Adenosine triphosphatase (ATPase) Broad-spectrum antibiotic Drug discovery Enzyme inhibitors Enzyme structure Injectosome Molecular modeling Protein...Kagawa, Y.; Yoshida, M. The Crystal Structure of the Nucleotide- Free Alpha 3 Beta 3 Subcomplex of F1-ATPase from the Thermophilic Bacillus PS3 is...Kinases and other ATP- Requiring Enzymes and a Common Nucleotide Binding Fold. EMBO J. 1982, 1, 945–951. Zarivach, R.; Vuckovic, M.; Deng, W

  4. Association of Eu(III) and Cm(III) with Bacillus subtilis and Halobacterium salinarum

    International Nuclear Information System (INIS)

    Ozaki, Takuo; Kimura, Takaumi; Ohnuki, Toshihiko; Yoshida, Zenko

    2002-01-01

    Adsorption behavior of Eu(III) and Cm(III) by Bacillus subtilis and Halobacterium salinarum was investigated. Both microorganisms showed almost identical pH dependence on the distribution ratio (K d ) of the metals examined, i.e., K d of Eu(III) and Cm(III) increased with an increase of pH. The coordination state of Eu(III) adsorbed on the microorganisms was studied by time-resolved laser-induced fluorescence spectroscopy (TRLFS). The coordination states of Eu(III) adsorbed on the B. subtilis and H. salinarum was of different characteristics. H. salinarum exhibited more outer-spherical interaction with Eu(III) than B. subtilis. (author)

  5. Inhibitor candidates's identification of HCV's RNA polymerase NS5B using virtual screening against iPPI-library

    Science.gov (United States)

    Sulistyawati, Indah; Sulistyo Dwi K., P.; Ichsan, Mochammad

    2016-03-01

    Hepatitis C is one of the major causes of chronic liver failure that caused by Hepatitis C Virus (HCV). Preventing the progression of HCV's replication through the inhibition of The RNA polymerase NS5B of Hepatitis C virus (NS5B) can be achieved via 4 binding regions: Site I (Thumb I), Site II (Thumb II), Site III (Palm I), and Site IV (Palm II). The aim of this research is to identify a candidate of NS5B inhibitor as an alternative for Hepatitis C treatment. An NS5B's 3D structure (PDB ID = 3D5M) used in this study has met some criteria of a good model to be used in virtual screening againts iPPI-lib using MTiOpenScreen webserver. The top two natural compounds resulted here then docked using Pyrix 0.8 and discovered trans-6-Benzamido-2-methyldecahydroisoquinoline (-9,1kcal/mol) and 2,4-dichloro-5-[4-(2 methoxyphenyl) piperazine-1-carbonyl]-N-[3-(trifluoromethyl)phenyl] benzenesulfonamide (9,4 kcal/mol) can bind to Tyr448 similar with all three established inhibitors, such as setrobuvir (-11,4 kcal/mol; site 3 inhibitor), CHEMBL379677 (-9,1 kcal/mol; site 1 inhibitor), and nesbuvir (-7,7 kcal/mol; site 4 inhibitor). The results of this study are relatively still needs to be tested, both in vitro and in vivo, in order to obtain more comprehensive knowledges as a follow-up of this predictive study.

  6. Enzymatic activity of granulations tissues under low doses of radiation. Biochemical analysis in rats

    International Nuclear Information System (INIS)

    Tosoni, Guilherme Monteiro; Boscolo, Frab Norberto; Cury, Jaime Aparecido; Watanabe, Plauto Christopher Aranha

    1994-01-01

    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)

  7. Sorption of small amounts of europium(III) on iron(III) hydroxide and oxide

    International Nuclear Information System (INIS)

    Music, S.; Gessner, M.; Wolf, R.H.H.

    1979-01-01

    The sorption of small amounts of europium(III) on iron(III) hydroxide and oxide has been studied as a function of pH. The mechanism of sorption is discussed. Optimum conditions have been found for the preconcentration of small or trace amounts of europium(III) by iron(III) hydroxide and oxide. The influence of complexing agents (EDTA, oxalate, tartrate and 5-sulfosalicylic acid) on the sorption of small amounts of europium(III) on iron(III) oxide has also been studied. (author)

  8. Stress history increases alcohol intake in relapse: relation to phosphodiesterase 10A.

    Science.gov (United States)

    Logrip, Marian L; Zorrilla, Eric P

    2012-09-01

    Stressful experiences can result in elevated alcohol drinking, as exemplified in many individuals with post-traumatic stress disorder. However, how stress history, rather than acute stressors, influences alcohol intake remains uncertain. To model the protracted effects of past stress, male Wistar rats were subjected to light-cued footshock (stress history) or light cues alone (control) prior to acquisition of alcohol self-administration (1-hour sessions, fixed ratio 1-3, 100 µl of 10% v/v alcohol as reinforcer). Stress history did not alter mean alcohol intake during acquisition of self-administration, but it increased preference for the alcohol-paired lever over the inactive lever. Following an extinction period, rats with a history of stress exposure and low baseline alcohol intake showed a twofold elevation in alcohol self-administration, as compared with low-drinking rats with no stress history. Similar effects were not seen in rats self-administering 0.1% sucrose. Analysis of mRNA levels of phosphodiesterase 10A (PDE10A), a dual-specificity cyclic adenosine monophosphate and cyclic guanosine monophosphate hydrolyzing enzyme, showed that stress history increased Pde10a mRNA levels in the basolateral amygdala and, in low-drinking rats, the prelimbic prefrontal cortex (plPFC). Pde10a mRNA levels in the plPFC correlated directly with greater alcohol self-administration during the relapse-like phase, and greater BLA Pde10a mRNA levels correlated with increased ethanol preference after acquisition. The data demonstrate that stress history sensitizes otherwise low alcohol drinkers to consume more alcohol in a relapse-like situation and identify stress-induced neuroadaptations in amygdala and prefrontal cortical Pde10a expression as changes that may drive heightened alcohol intake and preference in susceptible individuals. © 2012 The Authors. Addiction Biology © 2012 Society for the Study of Addiction.

  9. Antitumor effects of a sirtuin inhibitor, tenovin-6, against gastric cancer cells via death receptor 5 up-regulation.

    Directory of Open Access Journals (Sweden)

    Sachiko Hirai

    Full Text Available Up-regulated sirtuin 1 (SIRT1, an NAD+-dependent class III histone deacetylase, deacetylates p53 and inhibits its transcriptional activity, leading to cell survival. SIRT1 overexpression has been reported to predict poor survival in some malignancies, including gastric cancer. However, the antitumor effect of SIRT1 inhibition remains elusive in gastric cancer. Here, we investigated the antitumor mechanisms of a sirtuin inhibitor, tenovin-6, in seven human gastric cancer cell lines (four cell lines with wild-type TP53, two with mutant-type TP53, and one with null TP53. Interestingly, tenovin-6 induced apoptosis in all cell lines, not only those with wild-type TP53, but also mutant-type and null versions, accompanied by up-regulation of death receptor 5 (DR5. In the KatoIII cell line (TP53-null, DR5 silencing markedly attenuated tenovin-6-induced apoptosis, suggesting that the pivotal mechanism behind its antitumor effects is based on activation of the death receptor signal pathway. Although endoplasmic reticulum stress caused by sirtuin inhibitors was reported to induce DR5 up-regulation in other cancer cell lines, we could not find marked activation of its related molecules, such as ATF6, PERK, and CHOP, in gastric cancer cells treated with tenovin-6. Tenovin-6 in combination with docetaxel or SN-38 exerted a slight to moderate synergistic cytotoxicity against gastric cancer cells. In conclusion, tenovin-6 has potent antitumor activity against human gastric cancer cells via DR5 up-regulation. Our results should be helpful for the future clinical development of sirtuin inhibitors.

  10. A multifaceted approach to maximize erectile function and vascular health.

    Science.gov (United States)

    Meldrum, David R; Gambone, Joseph C; Morris, Marge A; Ignarro, Louis J

    2010-12-01

    To review the role of various factors influencing vascular nitric oxide (NO) and cyclic GMP, and consequently, erectile function and vascular health. Pertinent publications are reviewed. Daily moderate exercise stimulates vascular NO production. Maintenance of normal body weight and waist/hip ratio allows NO stimulation by insulin. Decreased intake of fat, sugar, and simple carbohydrates rapidly converted to sugar reduces the adverse effects of fatty acids and sugar on endothelial NO production. Omega-3 fatty acids stimulate endothelial NO release. Antioxidants boost NO production and prevent NO breakdown. Folic acid, calcium, vitamin C, and vitamin E support the biochemical pathways leading to NO release. Cessation of smoking and avoidance of excessive alcohol preserve normal endothelial function. Moderate use of alcohol and certain proprietary supplements may favorably influence erectile and vascular function. Treatment of any remaining testosterone deficit will both increase erectile function and reduce any associated metabolic syndrome. After production of NO and cyclic GMP are improved, use of phosphodiesterase-5 inhibitors should result in greater success in treating remaining erectile dysfunction. Recent studies have also suggested positive effects of phosphodiesterase-5 inhibitors on vascular function. A multifaceted approach will maximize both erectile function and vascular health. Copyright © 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  11. Update on the clinical utility of sildenafil in the treatment of pulmonary arterial hypertension

    Directory of Open Access Journals (Sweden)

    Gautam V Ramani

    2010-05-01

    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

  12. The effect of chemical anti-inhibitors on fibrinolytic enzymes and inhibitors

    DEFF Research Database (Denmark)

    Sidelmann, Johannes Jakobsen; Jespersen, J; Kluft, C

    1997-01-01

    proteases. We studied the influence of chemical anti-inhibitors (chloramine T, flufenamate, sodium lauryl sulfate, and methylamine) on fibrinolytic serine proteases and fibrinolytic enzyme inhibitors using the physiological substrate fibrin as plasmin substrate. Low concentrations of chloramine T (0.01 mmol......%) and plasminogen activators (apparent recovery > 200%). Sodium lauryl sulfate eliminates the major fibrinolytic enzyme inhibitors, but increases the activity of plasmin (apparent recovery > 200%) and plasminogen activator, urokinase type (apparent recovery 130%). Methylamine affects only plasmin inhibition. We...

  13. The emerging role of ALK inhibitors in the treatment of advanced non-small cell lung cancer.

    Science.gov (United States)

    Galetta, Domenico; Rossi, Antonio; Pisconti, Salvatore; Colucci, Giuseppe

    2012-04-01

    Most NSCLC patients are diagnosed in the advanced stage of the disease. Recently, chemotherapeutic agents have reached a plateau of effectiveness. Increased understanding of cancer biology has revealed several potential therapeutic strategies that have led to marketing of new biologic agents. The echinoderm microtubule-associated protein like-4-anaplastic lymphoma kinase (EML4-ALK) fusion oncogene represents one of the newest molecular targets in NSCLC, identifying a subset of NSCLC patients characterized by distinct clinicopathological features. The available results concerning ALK inhibitors for the treatment of advanced NSCLC patients. An electronic search was used to retrieve the articles addressing this topic. In a pivotal Phase I clinical trial, crizotinib (PF-02341066), a small-molecule ALK inhibitor, demonstrated impressive antitumor activity in the majority of NSCLC patients with ALK fusions. Phase III randomized trials investigating crizotinib in this subgroup of patients are ongoing. If the results from these large international trials confirm the efficacy of crizotinib in the subset of patients, the next few years could see the treatment of advanced NSCLC patients with ALK fusions. Specific inhibitors would realize the so called personalized medicine in subsets of this disease.

  14. Combined effects of EGFR tyrosine kinase inhibitors and vATPase inhibitors in NSCLC cells

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hyeon-Ok [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Hong, Sung-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Kim, Chang Soon [Department of Microbiological Engineering, Kon-Kuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143–701 (Korea, Republic of); Park, Jin-Ah; Kim, Jin-Hee; Kim, Ji-Young; Kim, Bora [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Chang, Yoon Hwan; Hong, Seok-Il; Hong, Young Jun [Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Park, In-Chul, E-mail: parkic@kirams.re.kr [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Lee, Jin Kyung, E-mail: jklee@kirams.re.kr [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of)

    2015-08-15

    Despite excellent initial clinical responses of non-small cell lung cancer (NSCLC) patients to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), many patients eventually develop resistance. According to a recent report, vacuolar H + ATPase (vATPase) is overexpressed and is associated with chemotherapy drug resistance in NSCLC. We investigated the combined effects of EGFR TKIs and vATPase inhibitors and their underlying mechanisms in the regulation of NSCLC cell death. We found that combined treatment with EGFR TKIs (erlotinib, gefitinib, or lapatinib) and vATPase inhibitors (bafilomycin A1 or concanamycin A) enhanced synergistic cell death compared to treatments with each drug alone. Treatment with bafilomycin A1 or concanamycin A led to the induction of Bnip3 expression in an Hif-1α dependent manner. Knock-down of Hif-1α or Bnip3 by siRNA further enhanced cell death induced by bafilomycin A1, suggesting that Hif-1α/Bnip3 induction promoted resistance to cell death induced by the vATPase inhibitors. EGFR TKIs suppressed Hif-1α and Bnip3 expression induced by the vATPase inhibitors, suggesting that they enhanced the sensitivity of the cells to these inhibitors by decreasing Hif-1α/Bnip3 expression. Taken together, we conclude that EGFR TKIs enhance the sensitivity of NSCLC cells to vATPase inhibitors by decreasing Hif-1α/Bnip3 expression. We suggest that combined treatment with EGFR TKIs and vATPase inhibitors is potentially effective for the treatment of NSCLC. - Highlights: • Co-treatment with EGFR TKIs and vATPase inhibitors induces synergistic cell death • EGFR TKIs enhance cell sensitivity to vATPase inhibitors via Hif-1α downregulation • Co-treatment of these inhibitors is potentially effective for the treatment of NSCLC.

  15. ROS inhibitor N-acetyl-L-cysteine antagonizes the activity of proteasome inhibitors.

    Science.gov (United States)

    Halasi, Marianna; Wang, Ming; Chavan, Tanmay S; Gaponenko, Vadim; Hay, Nissim; Gartel, Andrei L

    2013-09-01

    NAC (N-acetyl-L-cysteine) is commonly used to identify and test ROS (reactive oxygen species) inducers, and to inhibit ROS. In the present study, we identified inhibition of proteasome inhibitors as a novel activity of NAC. Both NAC and catalase, another known scavenger of ROS, similarly inhibited ROS levels and apoptosis associated with H₂O₂. However, only NAC, and not catalase or another ROS scavenger Trolox, was able to prevent effects linked to proteasome inhibition, such as protein stabilization, apoptosis and accumulation of ubiquitin conjugates. These observations suggest that NAC has a dual activity as an inhibitor of ROS and proteasome inhibitors. Recently, NAC was used as a ROS inhibitor to functionally characterize a novel anticancer compound, piperlongumine, leading to its description as a ROS inducer. In contrast, our own experiments showed that this compound depicts features of proteasome inhibitors including suppression of FOXM1 (Forkhead box protein M1), stabilization of cellular proteins, induction of ROS-independent apoptosis and enhanced accumulation of ubiquitin conjugates. In addition, NAC, but not catalase or Trolox, interfered with the activity of piperlongumine, further supporting that piperlongumine is a proteasome inhibitor. Most importantly, we showed that NAC, but not other ROS scavengers, directly binds to proteasome inhibitors. To our knowledge, NAC is the first known compound that directly interacts with and antagonizes the activity of proteasome inhibitors. Taken together, the findings of the present study suggest that, as a result of the dual nature of NAC, data interpretation might not be straightforward when NAC is utilized as an antioxidant to demonstrate ROS involvement in drug-induced apoptosis.

  16. Synergistic apoptosis induction in leukemic cells by the phosphatase inhibitor salubrinal and proteasome inhibitors.

    Directory of Open Access Journals (Sweden)

    Hannes C A Drexler

    Full Text Available Cells adapt to endoplasmic reticulum (ER-stress by arresting global protein synthesis while simultaneously activating specific transcription factors and their downstream targets. These processes are mediated in part by the phosphorylation-dependent inactivation of the translation initiation factor eIF2alpha. Following restoration of homeostasis protein synthesis is resumed when the serine/threonine-protein phosphatase PP1 dephosphorylates and reactivates eIF2alpha. Proteasome inhibitors, used to treat multiple myeloma patients evoke ER-stress and apoptosis by blocking the ER-associated degradation of misfolded proteins (ERAD, however, the role of eIF2alpha phosphorylation in leukemic cells under conditions of proteasome inhibitor-mediated ER stress is currently unclear.Bcr-Abl-positive and negative leukemic cell lines were used to investigate the functional implications of PP1-related phosphatase activities on eIF2alpha phosphorylation in proteasome inhibitor-mediated ER stress and apoptosis. Rather unexpectedly, salubrinal, a recently identified PP1 inhibitor capable to protect against ER stress in various model systems, strongly synergized with proteasome inhibitors to augment apoptotic death of different leukemic cell lines. Salubrinal treatment did not affect the phosphorlyation status of eIF2alpha. Furthermore, the proapoptotic effect of salubrinal occurred independently from the chemical nature of the proteasome inhibitor, was recapitulated by a second unrelated phosphatase inhibitor and was unaffected by overexpression of a dominant negative eIF2alpha S51A variant that can not be phosphorylated. Salubrinal further aggravated ER-stress and proteotoxicity inflicted by the proteasome inhibitors on the leukemic cells since characteristic ER stress responses, such as ATF4 and CHOP synthesis, XBP1 splicing, activation of MAP kinases and eventually apoptosis were efficiently abrogated by the translational inhibitor cycloheximide.Although PP1

  17. Differential effects of buffer pH on Ca2+-induced ROS emission with inhibited mitochondrial complex I and III

    Directory of Open Access Journals (Sweden)

    Daniel P Lindsay

    2015-03-01

    Full Text Available Excessive mitochondrial reactive oxygen species (ROS emission is a critical component in the etiolo-gy of ischemic injury. Complex I and complex III of the electron transport chain are considered the primary sources of ROS emission during cardiac ischemia and reperfusion (IR injury. Several factors modulate ischemic ROS emission, such as an increase in extra-matrix Ca2+, a decrease in extra-matrix pH, and a change in substrate utilization. Here we examined the combined effects of these factors on ROS emission from respiratory complex I and III under conditions of simulated IR injury. Guinea pig heart mitochondria were suspended in experimental buffer at a given pH and incubated with or without CaCl2. Mitochondria were then treated with either pyruvate, a complex I substrate, followed by rote-none, a complex I inhibitor, or succinate, a complex II substrate, followed by antimycin A, a complex III inhibitor. H2O2 release rate and matrix volume were compared with and without adding CaCl2 and at pH 7.15, 6.9, or 6.5 with pyruvate + rotenone or succinate + antimycin A to simulate conditions that may occur during in vivo cardiac IR injury. We found a large increase in H2O2 release with high [CaCl2] and pyruvate + rotenone at pH 6.9, but not at pHs 7.15 or 6.5. Large increases in H2O2 release rate also occurred at each pH with high [CaCl2] and succinate + antimycin A, with the highest levels observed at pH 7.15. The increases in H2O2 release were associated with significant mitochondrial swelling, and both H2O2 release and swelling were abolished by cyclosporine A, a desensitizer of the mitochondrial permeability transition pore. These results indicate that ROS production by complex I and by III is differently affected by buffer pH and Ca2+ loading with mPTP opening. The study sug-gests that changes in the levels of cytosolic Ca2+ and pH during IR alter the relative amounts of ROS produced at mitochondrial respiratory complex I and complex III.

  18. First steps in the direction of synthetic, allosteric, direct inhibitors of thrombin and factor Xa.

    Science.gov (United States)

    Verghese, Jenson; Liang, Aiye; Sidhu, Preet Pal Singh; Hindle, Michael; Zhou, Qibing; Desai, Umesh R

    2009-08-01

    Designing non-saccharide functional mimics of heparin is a major challenge. In this work, a library of small, aromatic molecules based on the sulfated DHP scaffold was synthesized and screened against thrombin and factor Xa. The results reveal that (i) selected monomeric benzofuran derivatives inhibit the two enzymes, albeit weakly; (ii) the two enzymes recognize different structural features in the benzofurans studied suggesting significant selectivity of recognition; and (iii) the mechanism of inhibition is allosteric. The molecules represent the first allosteric small molecule inhibitors of the two enzymes.

  19. First Steps in the Direction of Synthetic, Allosteric, Direct Inhibitors of Thrombin and Factor Xa

    Science.gov (United States)

    Verghese, Jenson; Liang, Aiye; Sidhu, Preet Pal Singh; Hindle, Michael; Zhou, Qibing; Desai, Umesh R.

    2009-01-01

    Designing non-saccharide functional mimics of heparin is a major challenge. In this work, a library of small, aromatic molecules based on the sulfated DHP scaffold was synthesized and screened against thrombin and factor Xa. The results reveal that i) selected monomeric benzofuran derivatives inhibit the two enzymes, albeit weakly; ii) the two enzymes recognize different structural features in the benzofurans studied suggesting significant selectivity of recognition; and iii) the mechanism of inhibition is allosteric. The molecules represent the first allosteric small molecule inhibitors of the two enzymes. PMID:19540113

  20. Identification of small molecule inhibitors of Pseudomonas aeruginosa exoenzyme S using a yeast phenotypic screen.

    Directory of Open Access Journals (Sweden)

    Anthony Arnoldo

    2008-02-01

    Full Text Available Pseudomonas aeruginosa is an opportunistic human pathogen that is a key factor in the mortality of cystic fibrosis patients, and infection represents an increased threat for human health worldwide. Because resistance of Pseudomonas aeruginosa to antibiotics is increasing, new inhibitors of pharmacologically validated targets of this bacterium are needed. Here we demonstrate that a cell-based yeast phenotypic assay, combined with a large-scale inhibitor screen, identified small molecule inhibitors that can suppress the toxicity caused by heterologous expression of selected Pseudomonas aeruginosa ORFs. We identified the first small molecule inhibitor of Exoenzyme S (ExoS, a toxin involved in Type III secretion. We show that this inhibitor, exosin, modulates ExoS ADP-ribosyltransferase activity in vitro, suggesting the inhibition is direct. Moreover, exosin and two of its analogues display a significant protective effect against Pseudomonas infection in vivo. Furthermore, because the assay was performed in yeast, we were able to demonstrate that several yeast homologues of the known human ExoS targets are likely ADP-ribosylated by the toxin. For example, using an in vitro enzymatic assay, we demonstrate that yeast Ras2p is directly modified by ExoS. Lastly, by surveying a collection of yeast deletion mutants, we identified Bmh1p, a yeast homologue of the human FAS, as an ExoS cofactor, revealing that portions of the bacterial toxin mode of action are conserved from yeast to human. Taken together, our integrated cell-based, chemical-genetic approach demonstrates that such screens can augment traditional drug screening approaches and facilitate the discovery of new compounds against a broad range of human pathogens.

  1. Palbociclib: A Novel Cyclin-Dependent Kinase Inhibitor for Hormone Receptor-Positive Advanced Breast Cancer.

    Science.gov (United States)

    Mangini, Neha S; Wesolowski, Robert; Ramaswamy, Bhuvaneswari; Lustberg, Maryam B; Berger, Michael J

    2015-11-01

    To review palbociclib, a novel small-molecule inhibitor of cyclin-dependent kinases 4 and 6, and its current place in therapy for the treatment of hormone receptor (HMR)-positive, human epidermal growth factor receptor 2 (Her2)-negative advanced breast cancer. Four phase I trials, 2 phase II trials, and 1 phase III trial were identified from May 2004 to May 2015 using PubMed, American Society of Clinical Oncology (ASCO) abstracts, and European Society of Medical Oncology (ESMO) abstracts. In the first-line setting, the phase II PALbociclib: Ongoing trials in the Management of breast cAncer (PALOMA)-1 trial randomized patients to receive letrozole alone or letrozole plus palbociclib 125 mg daily for 3 weeks, followed by 1 week off, as initial therapy for advanced breast cancer. The investigator-assessed median progression-free survival (PFS) was 20. 2 months for the combination versus 10.2 months for letrozole alone (hazard ratio [HR] = 0.488; 95% CI = 0.319-0.748; 1-sided P = 0.0004). The ensuing Food and Drug Administration approval of palbociclib was given a "breakthrough therapy" designation, where preliminary evidence suggests substantial improvement over existing therapies for a serious or life-threatening disease. A confirmatory phase III trial, PALOMA-2, is under way. In patients who were previously treated with endocrine therapy for advanced breast cancer, the phase III PALOMA-3 trial randomized patients to fulvestrant plus palbociclib versus fulvestrant plus placebo. The investigator-assessed median PFS at the time of a preplanned analysis was 9.2 months with palbociclib-fulvestrant compared with 3.8 months with placebo-fulvestrant (HR = 0.42; 95% CI = 0.32-0.56; P < 0.001). Palbociclib, the first-in-class CDK4/6 inhibitor, significantly extended PFS in combination with endocrine therapy in the first and subsequent lines of treatment for HMR-positive, Her2-negative advanced breast cancer. © The Author(s) 2015.

  2. Effects upon metabolic pathways and energy production by Sb(III and As(III/Sb(III-oxidase gene aioA in Agrobacterium tumefaciens GW4.

    Directory of Open Access Journals (Sweden)

    Jingxin Li

    Full Text Available Agrobacterium tumefaciens GW4 is a heterotrophic arsenite [As(III]/antimonite [Sb(III]-oxidizing strain. The As(III oxidase AioAB is responsible for As(III oxidation in the periplasm and it is also involved in Sb(III oxidation in Agrobacterium tumefaciens 5A. In addition, Sb(III oxidase AnoA and cellular H2O2 are also responsible for Sb(III oxidation in strain GW4. However, the deletion of aioA increased the Sb(III oxidation efficiency in strain GW4. In the present study, we found that the cell mobility to Sb(III, ATP and NADH contents and heat release were also increased by Sb(III and more significantly in the aioA mutant. Proteomics and transcriptional analyses showed that proteins/genes involved in Sb(III oxidation and resistance, stress responses, carbon metabolism, cell mobility, phosphonate and phosphinate metabolism, and amino acid and nucleotide metabolism were induced by Sb(III and were more significantly induced in the aioA mutant. The results suggested that Sb(III oxidation may produce energy. In addition, without periplasmic AioAB, more Sb(III would enter bacterial cells, however, the cytoplasmic AnoA and the oxidative stress response proteins were significantly up-regulated, which may contribute to the increased Sb(III oxidation efficiency. Moreover, the carbon metabolism was also activated to generate more energy against Sb(III stress. The generated energy may be used in Sb transportation, DNA repair, amino acid synthesis, and cell mobility, and may be released in the form of heat.

  3. Mixed ligand complexes of some of the rare earths. La(III)-, Pr(III)- or Nd-(III)-CDTA-Hydroxy Acids

    Energy Technology Data Exchange (ETDEWEB)

    Rana, H S; Tandon, J P [Rajasthan Univ., Jaipur (India). Chemical Labs.

    1975-11-01

    Biligand complexes of the 1:1 Ln(III)-1,2-diaminocyclohexane-tetraacetic acid (CDTA) chelate with hydroxy acids (where hydroxy acids = salicylic acid (SA); Sulphosalicylic acid (SSA) and 8-hydroxyquinoline-5-sulphonic acid (HQSA)) have been investigated by potentiometric titration. Their formation constants have been calculated (..mu..=0.1M-KNO/sub 3/; and t=30+-1 deg C) as 4.60 +-0.03, 5.46+-0.03, 5.87+-0.05; 3.12+-0.04, 3.95+-0.05, 4.42+-0.07; 2.73+-0.06, 3.45+-0.05 and 3.90+-0.08 for Ln(III)-CDTA-SA,-SSA, and -HQSA respectively (where Ln=La, Pr or Nd). The value of log Ksub(MAB) follows the order: La(III)).

  4. Screening of protein kinase inhibitors identifies PKC inhibitors as inhibitors of osteoclastic acid secretion and bone resorption

    Directory of Open Access Journals (Sweden)

    Boutin Jean A

    2010-10-01

    Full Text Available Abstract Background Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts. Methods Human osteoclasts were generated from CD14+ monocytes. The effect of different kinase inhibitors on lysosomal acidification in human osteoclasts was investigated using acridine orange for different incubation times (45 minutes, 4 and 24 hours. The inhibitors were tested in an acid influx assay using microsomes isolated from human osteoclasts. Bone resorption by human osteoclasts on bone slices was measured by calcium release. Cell viability was measured using AlamarBlue. Results Of the 51 compounds investigated only few inhibitors were positive in both acidification and resorption assays. Rottlerin, GF109203X, Hypericin and Ro31-8220 inhibited acid influx in microsomes and bone resorption, while Sphingosine and Palmitoyl-DL-carnitine-Cl showed low levels of inhibition. Rottlerin inhibited lysosomal acidification in human osteoclasts potently. Conclusions In conclusion, a group of inhibitors all indicated to inhibit PKC reduced acidification in human osteoclasts, and thereby bone resorption, indicating that acid secretion by osteoclasts may be specifically regulated by PKC in osteoclasts.

  5. A rhodium(III) complex inhibits LPS-induced nitric oxide production and angiogenic activity in cellulo.

    Science.gov (United States)

    Liu, Li-Juan; Lin, Sheng; Chan, Daniel Shiu-Hin; Vong, Chi Teng; Hoi, Pui Man; Wong, Chun-Yuen; Ma, Dik-Lung; Leung, Chung-Hang

    2014-11-01

    Metal-containing complexes have arisen as viable alternatives to organic molecules as therapeutic agents. Metal complexes possess a number of advantages compared to conventional carbon-based compounds, such as distinct geometries, interesting electronic properties, variable oxidation states and the ability to arrange different ligands around the metal centre in a precise fashion. Meanwhile, nitric oxide (NO) plays key roles in the regulation of angiogenesis, vascular permeability and inflammation. We herein report a novel cyclometalated rhodium(III) complex as an inhibitor of lipopolysaccharides (LPS)-induced NO production in RAW264.7 macrophages. Experiments suggested that the inhibition of NO production in cells by complex 1 was mediated through the down-regulation of nuclear factor-κB (NF-κB) activity. Furthermore, complex 1 inhibited angiogenesis in human umbilical vein endothelial cells (HUVECs) as revealed by an endothelial tube formation assay. This study demonstrates that kinetically inert rhodium(III) complexes may be potentially developed as effective anti-angiogenic agents. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Comparison of the effects of isobutylmethylxanthine and milrinone on ischaemia-induced arrhythmias and platelet aggregation in anaesthetized rabbits.

    Science.gov (United States)

    Holbrook, M.; Coker, S. J.

    1989-01-01

    1. The aim of this study was to compare the effects of the non-selective phosphodiesterase (PDE) inhibitor, isobutylmethylxanthine (IBMX) and the selective PDE III inhibitor, milrinone, in a rabbit model of acute myocardial ischaemia. 2. Coronary artery occlusion caused changes in the ST-segment of the ECG and ectopic activity in all control rabbits. Ventricular fibrillation occurred in 10 out of 14 (71%) of these animals. Pretreatment with IBMX 100 micrograms kg-1 plus 10 micrograms kg-1 min-1, starting 10 min before coronary artery occlusion, reduced ischaemia-induced ST-segment changes and ventricular fibrillation occurred in only 10% of this group (n = 10). A similar dose of milrinone had no antiarrhythmic activity, whereas with a lower dose of milrinone, 30 micrograms kg-1 plus 3 micrograms kg-1 min-1 (n = 10), only 30% of rabbits fibrillated and ST-segment changes were attenuated. 3. Acute administration of both IBMX and milrinone reduced arterial blood pressure. With the higher dose of milrinone a significant effect was still present after 10 min of drug infusion. A greater hypotensive response to the higher dose of milrinone was observed in the rabbits which subsequently fibrillated during ischaemia. A marked tachycardia was also observed after administration of the higher dose of milrinone. 4. At the end of the experiment platelet aggregation was studied ex vivo. ADP-induced aggregation was reduced by pretreatment of the rabbits with milrinone but not IBMX. Both PDE inhibitors enhanced the ability of isoprenaline to inhibit ADP-induced platelet aggregation but milrinone was more effective, particularly at the higher dose.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2478245

  7. Cellular mechanisms underlying the effects of milrinone and cilostazol to suppress arrhythmogenesis associated with Brugada syndrome.

    Science.gov (United States)

    Szél, Tamás; Koncz, István; Antzelevitch, Charles

    2013-11-01

    Brugada syndrome is an inherited disease associated with vulnerability to ventricular tachycardia and sudden cardiac death in young adults. Milrinone and cilostazol, oral phosphodiesterase (PDE) type III inhibitors, have been shown to increase L-type calcium channel current (ICa) and modestly increase heart rate by elevating the level of intracellular cyclic adenosine monophosphate. To examine the effectiveness of these PDE inhibitors to suppress arrhythmogenesis in an experimental model of Brugada syndrome. Action potential (AP) and electrocardiographic recordings were obtained from epicardial and endocardial sites of coronary-perfused canine right ventricular wedge preparations. The Ito agonist NS5806 (5 μM) and Ca(2+) channel blocker verapamil (2 μM) were used to pharmacologically mimic Brugada phenotype. The combination induced all-or-none repolarization at some epicardial sites but not others, leading to ST-segment elevation as well as an increase in both epicardial and transmural dispersion of repolarization. Under these conditions, phase 2 reentry developed as the epicardial AP dome propagated from sites where it was maintained to sites at which it was lost, generating closely coupled extrasystoles and ventricular tachycardia. The addition of the PDE inhibitor milrinone (2.5 μM) or cilostazol (5-10 μM) to the coronary perfusate restored the epicardial AP dome, reduced dispersion, and abolished phase 2 reentry-induced extrasystoles and ventricular tachycardia. Our study identifies milrinone as a more potent alternative to cilostazol for reversing the repolarization defects responsible for the electrocardiographic and arrhythmic manifestations of Brugada syndrome. Both drugs normalize ST-segment elevation and suppress arrhythmogenesis in experimental models of Brugada syndrome. © 2013 Heart Rhythm Society. All rights reserved.

  8. Enhancement of the fluorescence of the samarium (III) complex by gadolinium (III)

    International Nuclear Information System (INIS)

    Yun-Xiang, C.; Zhang-Hua, L.

    1988-01-01

    The increase in sensitivity and selectivity of reactions in which colored species are formed by the addition of different metal ions is an area of research that has recently been developed. This phenomenon, which is sometimes called cocolaration effect, has been explained by the formation of mixed metal complex. The authors found an analogous phenomenon of reactions forming fluorescent complexes. The complexes of Sm(III)-thenoyltrifluoroacetone (TTA)-phenanthroline (Phen)-Triton-X-100 (TX-100) and Gd(III) (or La(III), Lu(III) and Y(III))-TTA-Phen-TX-100 had practically no fluorescence separately. Instead, a fluorescence-enhancement phenomenon caused by adding Gd or La, Lu and Y ions to the system was observed for the first time. The intensity of the enhanced fluorescence of Sm(III) complex was increased in the following order: La< Y< Lu< Gd. By analogy with cocoloration effect, the authors call this new fluorescence-enhancement phenomenon the co-fluorescence effect. The object of this work was to study the enhancement effect of Gd(III) on the fluorescence of the Sm(III)-TTA-Phen-TX-100 system. The recommended fluorimetric method has been applied to the determination of trace amounts of samarium in ytterbium oxide with satisfactory results. A general reaction mechanism for the system studied was proposed

  9. Phenolic Amides Are Potent Inhibitors of De Novo Nucleotide Biosynthesis.

    Science.gov (United States)

    Pisithkul, Tippapha; Jacobson, Tyler B; O'Brien, Thomas J; Stevenson, David M; Amador-Noguez, Daniel

    2015-09-01

    An outstanding challenge toward efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. Elucidating the mechanisms that underlie their toxicity is critical for developing strategies to overcome them. Here, using Escherichia coli as a model system, we investigated the metabolic effects and toxicity mechanisms of feruloyl amide and coumaroyl amide, the predominant phenolic compounds in ammonia-pretreated biomass hydrolysates. Using metabolomics, isotope tracers, and biochemical assays, we showed that these two phenolic amides act as potent and fast-acting inhibitors of purine and pyrimidine biosynthetic pathways. Feruloyl or coumaroyl amide exposure leads to (i) a rapid buildup of 5-phosphoribosyl-1-pyrophosphate (PRPP), a key precursor in nucleotide biosynthesis, (ii) a rapid decrease in the levels of pyrimidine biosynthetic intermediates, and (iii) a long-term generalized decrease in nucleotide and deoxynucleotide levels. Tracer experiments using (13)C-labeled sugars and [(15)N]ammonia demonstrated that carbon and nitrogen fluxes into nucleotides and deoxynucleotides are inhibited by these phenolic amides. We found that these effects are mediated via direct inhibition of glutamine amidotransferases that participate in nucleotide biosynthetic pathways. In particular, feruloyl amide is a competitive inhibitor of glutamine PRPP amidotransferase (PurF), which catalyzes the first committed step in de novo purine biosynthesis. Finally, external nucleoside supplementation prevents phenolic amide-mediated growth inhibition by allowing nucleotide biosynthesis via salvage pathways. The results presented here will help in the development of strategies to overcome toxicity of phenolic compounds and facilitate engineering of more efficient microbial producers of biofuels and chemicals. Copyright © 2015, Pisithkul et al.

  10. Phenolic Amides Are Potent Inhibitors of De Novo Nucleotide Biosynthesis

    Science.gov (United States)

    Pisithkul, Tippapha; Jacobson, Tyler B.; O'Brien, Thomas J.; Stevenson, David M.

    2015-01-01

    An outstanding challenge toward efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. Elucidating the mechanisms that underlie their toxicity is critical for developing strategies to overcome them. Here, using Escherichia coli as a model system, we investigated the metabolic effects and toxicity mechanisms of feruloyl amide and coumaroyl amide, the predominant phenolic compounds in ammonia-pretreated biomass hydrolysates. Using metabolomics, isotope tracers, and biochemical assays, we showed that these two phenolic amides act as potent and fast-acting inhibitors of purine and pyrimidine biosynthetic pathways. Feruloyl or coumaroyl amide exposure leads to (i) a rapid buildup of 5-phosphoribosyl-1-pyrophosphate (PRPP), a key precursor in nucleotide biosynthesis, (ii) a rapid decrease in the levels of pyrimidine biosynthetic intermediates, and (iii) a long-term generalized decrease in nucleotide and deoxynucleotide levels. Tracer experiments using 13C-labeled sugars and [15N]ammonia demonstrated that carbon and nitrogen fluxes into nucleotides and deoxynucleotides are inhibited by these phenolic amides. We found that these effects are mediated via direct inhibition of glutamine amidotransferases that participate in nucleotide biosynthetic pathways. In particular, feruloyl amide is a competitive inhibitor of glutamine PRPP amidotransferase (PurF), which catalyzes the first committed step in de novo purine biosynthesis. Finally, external nucleoside supplementation prevents phenolic amide-mediated growth inhibition by allowing nucleotide biosynthesis via salvage pathways. The results presented here will help in the development of strategies to overcome toxicity of phenolic compounds and facilitate engineering of more efficient microbial producers of biofuels and chemicals. PMID:26070680

  11. Avanafil for the treatment of erectile dysfunction: initial data and clinical key properties.

    Science.gov (United States)

    Kedia, George T; Uckert, Stefan; Assadi-Pour, Farhang; Kuczyk, Markus A; Albrecht, Knut

    2013-02-01

    Orally active, selective inhibitors of phosphodiesterase type 5 (PDE 5, cyclic GMP PDE), such as sildenafil, tadalafil and vardenafil, are currently the first-choice treatment options for the clinical management of erectile dysfunction (ED) of various etiologies and severities. However, a significant number of patients remain dissatisfied with the available therapies due a lack of efficacy or discomfort arising from adverse events. Several new PDE5 inhibitors, among which are avanafil (TA-1790), lodenafil, mirodenafil, udenafil, SLX-2101, JNJ-10280205 and JNJ-10287069, have recently been approved and introduced into the market or are in the final stages of their clinical development. Avanafil (marketed in the US under the brand name STENDRA(™)) has been developed by VIVUS Inc. (Mountain View, CA, USA) and has recently received approval from the US Food and Drug Administration (FDA) for use in the treatment of male ED. The drug has demonstrated improved selectivity for PDE5, is rapidly absorbed after oral administration with a fast onset of action and a plasma half-life that is comparable to sildenfil and vardenafil. In phase II and phase III clinical trials that included a large number of patients, avanafil has been shown to be effective and well tolerated. Owing to its favorable pharmacodynamic and pharmacokinetic profile, avanafil is considered as a promising new option in the treatment of ED. The present article summarizes the initial data and clinical key properties of avanafil.

  12. Involvement of NO-cGMP pathway in anti-hyperalgesic effect of PDE5 inhibitor tadalafil in experimental hyperalgesia.

    Science.gov (United States)

    Otari, K V; Upasani, C D

    2015-08-01

    The association of elevated level of cyclic guanosine monophosphate (cGMP) with inhibition of hyperalgesia and involvement of nitric oxide (NO)-cGMP pathway in the modulation of pain perception was previously reported. Phosphodiesterases 5 (PDE5) inhibitors, sildenafil and tadalafil (TAD) used in erectile dysfunction, are known to act via the NO-cGMP pathway. TAD exerts its action by increasing the levels of intracellular cGMP. Hence, the present study investigated the effect of TAD 5, 10, or 20 mg/kg, per os (p.o.) or L-NAME 20 mg/kg, intraperitoneally (i.p.) and TAD (20 mg/kg, p.o.) in carrageenan- and diabetes-induced hyperalgesia in rats using hot plate test at 55 ± 2 °C. In carrageenan- and diabetes-induced hyperalgesia, TAD (10 and 20 mg/kg, p.o.) significantly increased paw withdrawal latencies (PWLs) as compared to the control group. L-NAME significantly decreased PWLs as compared to the normal group and aggravated the hyperalgesia. Moreover, significant difference in PWLs of L-NAME and TAD 20 was evident. Co-administration of L-NAME (20 mg/kg) with TAD (20 mg/kg) showed significant difference in PWLs as compared to the TAD (20 mg/kg), indicating L-NAME reversed and antagonized TAD-induced anti-hyperalgesia. This suggested an important role of NO-cGMP pathway in TAD-induced anti-hyperalgesic effect.

  13. Metallothionein (MT)-III

    DEFF Research Database (Denmark)

    Carrasco, J; Giralt, M; Molinero, A

    1999-01-01

    Metallothionein-III is a low molecular weight, heavy-metal binding protein expressed mainly in the central nervous system. First identified as a growth inhibitory factor (GIF) of rat cortical neurons in vitro, it has subsequently been shown to be a member of the metallothionein (MT) gene family...... injected rats. The specificity of the antibody was also demonstrated in immunocytochemical studies by the elimination of the immunostaining by preincubation of the antibody with brain (but not liver) extracts, and by the results obtained in MT-III null mice. The antibody was used to characterize...... the putative differences between the rat brain MT isoforms, namely MT-I+II and MT-III, in the freeze lesion model of brain damage, and for developing an ELISA for MT-III suitable for brain samples. In the normal rat brain, MT-III was mostly present primarily in astrocytes. However, lectin staining indicated...

  14. Phase II study of imatinib mesylate and hydroxyurea for recurrent grade III malignant gliomas.

    Science.gov (United States)

    Desjardins, Annick; Quinn, Jennifer A; Vredenburgh, James J; Sathornsumetee, Sith; Friedman, Allan H; Herndon, James E; McLendon, Roger E; Provenzale, James M; Rich, Jeremy N; Sampson, John H; Gururangan, Sridharan; Dowell, Jeannette M; Salvado, August; Friedman, Henry S; Reardon, David A

    2007-05-01

    Recent reports demonstrate the activity of imatinib mesylate, an ATP-mimetic, tyrosine kinase inhibitor, plus hydroxyurea, a ribonucleotide reductase inhibitor, in patients with recurrent glioblastoma multiforme. We performed the current phase 2 study to evaluate this regimen among patients with recurrent WHO grade III malignant glioma (MG). Patients with grade III MG at any recurrence, received imatinib mesylate plus hydroxyurea (500 mg twice a day) orally on a continuous, daily schedule. The imatinib mesylate dose was 500 mg twice a day for patients on enzyme inducing anti-epileptic drugs (EIAEDs) and 400 mg once a day for those not on EIAEDs. Clinical assessments were performed monthly and radiographic assessments were obtained at least every 2 months. The primary endpoint was 6-month progression-free survival (PFS) rate. Thirty-nine patients were enrolled. All patients had progressive disease after prior radiotherapy and at least temozolomide-based chemotherapy. The median number of episodes of prior progression was 2 (range, 1-7) and the median number of prior treatment regimens was 3 (range, 1-8). With a median follow-up of 82.9 weeks, 24% of patients were progression-free at 6 months. The radiographic response rate was 10%, while 33% achieved stable disease. Among patients who achieved at least stable disease at first evaluation, the 6-month and 12-month PFS rates were 53% and 29%, respectively. The most common grade 3 or greater toxicities were hematologic and complicated less than 4% of administered courses. Imatinib mesylate plus hydroxyurea, is well tolerated and associated with anti-tumor activity in some patients with recurrent grade 3 MG.

  15. Milrinone therapeutic drug monitoring in a pediatric population: Development and validation of a quantitative liquid chromatography-tandem mass spectrometry method.

    Science.gov (United States)

    Raizman, Joshua E; Taylor, Katherine; Parshuram, Christopher; Colantonio, David A

    2017-05-01

    Milrinone is a potent selective phosphodiesterase type III inhibitor which stimulates myocardial function and improves myocardial relaxation. Although therapeutic monitoring is crucial to maintain therapeutic outcome, little data is available. A proof-of-principle study has been initiated in our institution to evaluate the clinical impact of optimizing milrinone dosing through therapeutic drug monitoring (TDM) in children following cardiac surgery. We developed a robust LC-MS/MS method to quantify milrinone in serum from pediatric patients in real-time. A liquid-liquid extraction procedure was used to prepare samples for analysis prior to measurement by LC-MS/MS. Performance characteristics, such as linearity, limit of quantitation (LOQ) and precision, were assessed. Patient samples were acquired post-surgery and analyzed to determine the concentration-time profile of the drug as well as to track turn-around-times. Within day precision was milrinone levels were either sub-therapeutic or in the toxic range, highlighting the importance for milrinone TDM. This simplified and quick method proved to be analytically robust and able to provide therapeutic monitoring of milrinone in real-time in patients post-cardiac surgery. Copyright © 2017. Published by Elsevier B.V.

  16. Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms

    International Nuclear Information System (INIS)

    Ozaki, T.; Kimura, T.; Ohnuki, T.; Yoshida, Z.; Gillow, J.B.; Francis, A.J.

    2004-01-01

    We investigated the association of europium(III) and curium(III) with the microorganisms Chlorella vulgaris, Bacillus subtilis, Pseudomonas fluorescens, Halomonas sp., Halobacterium salinarum, and Halobacterium halobium. We determined the kinetics and distribution coefficients (K d ) for Eu(III) and Cm(III) sorption at pH 3-5 by batch experiments, and evaluated the number of water molecules in the inner-sphere (N H 2 O ) and the degree of strength of ligand field (R E/M ) for Eu(III) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Exudates from C. vulgaris, Halomonas sp., and H. halobium had an affinity for Eu(III) and Cm(III). The log K d of Eu(III) and Cm(III) showed that their sorption was not fully due to the exchange with three protons on the functional groups on cell surfaces. The halophilic microorganisms (Halomonas sp., Halobacterium salinarum, H. halobium) showed almost no pH dependence in log K d , indicating that an exchange with Na + on the functional groups was involved in their sorption. The ΔN H 2 O (= 9 - N H 2 O ) for Eu(III) on C. vulgaris was 1-3, while that for the other microorganisms was over 3, demonstrating that the coordination of Eu(III) with C. vulgaris was predominantly an outer-spherical process. The R E/M for Eu(III) on halophilic microorganisms was 2.5-5, while that for non-halophilic ones was 1-2.5. This finding suggests that the coordination environment of Eu(III) on the halophilic microorganisms is more complicated than that on the other three non-halophilic ones. (orig.)

  17. Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, T.; Kimura, T.; Ohnuki, T.; Yoshida, Z. [Advanced Science Research Center, Japan Atomic Energy Research Inst., Ibaraki (Japan); Gillow, J.B.; Francis, A.J. [Environmental Sciences Dept., Brookhaven National Lab., Upton, NY (United States)

    2004-07-01

    We investigated the association of europium(III) and curium(III) with the microorganisms Chlorella vulgaris, Bacillus subtilis, Pseudomonas fluorescens, Halomonas sp., Halobacterium salinarum, and Halobacterium halobium. We determined the kinetics and distribution coefficients (K{sub d}) for Eu(III) and Cm(III) sorption at pH 3-5 by batch experiments, and evaluated the number of water molecules in the inner-sphere (N{sub H{sub 2}O}) and the degree of strength of ligand field (R{sub E/M}) for Eu(III) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Exudates from C. vulgaris, Halomonas sp., and H. halobium had an affinity for Eu(III) and Cm(III). The log K{sub d} of Eu(III) and Cm(III) showed that their sorption was not fully due to the exchange with three protons on the functional groups on cell surfaces. The halophilic microorganisms (Halomonas sp., Halobacterium salinarum, H. halobium) showed almost no pH dependence in log K{sub d}, indicating that an exchange with Na{sup +} on the functional groups was involved in their sorption. The {delta}N{sub H{sub 2}O} (= 9 - N{sub H{sub 2}O}) for Eu(III) on C. vulgaris was 1-3, while that for the other microorganisms was over 3, demonstrating that the coordination of Eu(III) with C. vulgaris was predominantly an outer-spherical process. The R{sub E/M} for Eu(III) on halophilic microorganisms was 2.5-5, while that for non-halophilic ones was 1-2.5. This finding suggests that the coordination environment of Eu(III) on the halophilic microorganisms is more complicated than that on the other three non-halophilic ones. (orig.)

  18. Characterization and Thermodynamic Relationship of Three Polymorphs of a Xanthine Oxidase Inhibitor, Febuxostat.

    Science.gov (United States)

    Patel, Jinish; Jagia, Moksh; Bansal, Arvind Kumar; Patel, Sarsvatkumar

    2015-11-01

    Febuxostat (FXT), a xanthine oxidase inhibitor, is an interesting and unique molecule, which exhibits extensive polymorphism, with over 15 polymorphic forms reported to date. The primary purpose of the study was to characterize the three polymorphic forms with respect to their thermodynamic quantities and establish thermodynamic relationship between them. The polymorphs were characterized by thermal and powder X-ray diffraction methods. Three different methods were used to calculate the transition temperatures (Ttr) and thereby their thermodynamic relationships. Although the first and second method used calorimetric data (melting point and heat of fusion), the third method employed the use of configurational free energy phase diagram. The onset melting points of three polymorphic forms were found to be 482.89 ± 0.37 K for form I, 476.30 ± 1.21 K for form II, and 474.19 ± 0.11 K for form III. Moreover, the powder X-ray diffraction patterns for each form were also unique. The polymorphic pair of form I and II and of form I and III was found to be enantiotropic, whereas pair of form II and III was monotropic. Besides the relative thermodynamic aspects (free energy differences, enthalpy, entropy contributions) using different methods, the pharmaceutical implications and phase transformation aspects have also been covered. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  19. Hesperetin-7,3'-O-dimethylether selectively inhibits phosphodiesterase 4 and effectively suppresses ovalbumin-induced airway hyperresponsiveness with a high therapeutic ratio

    Directory of Open Access Journals (Sweden)

    Yang You-Lan

    2011-11-01

    Full Text Available Abstract Background Hesperetin was reported to selectively inhibit phosphodiesterase 4 (PDE4. While hesperetin-7,3'-O-dimethylether (HDME is a synthetic liposoluble hesperetin. Therefore, we were interested in investigating its selectivity on PDE4 and binding ability on high-affinity rolipram-binding sites (HARBs in vitro, and its effects on ovalbumin-induced airway hyperresponsiveness in vivo, and clarifying its potential for treating asthma and chronic obstructive pulmonary disease (COPD. Methods PDE1~5 activities were measured using a two-step procedure. The binding of HDME on high-affinity rolipram-binding sites was determined by replacing 2 nM [3H]-rolipram. AHR was assessed using the FlexiVent system and barometric plethysmography. Inflammatory cells were counted using a hemocytometer. Cytokines were determined using mouse T helper (Th1/Th2 cytokine CBA kits, and total immunoglobulin (IgE or IgG2a levels were done using ELISA method. Xylazine (10 mg/kg/ketamine (70 mg/kg-induced anesthesia was performed. Results HDME revealed selective phosphodiesterase 4 (PDE4 inhibition with a therapeutic (PDE4H/PDE4L ratio of 35.5 in vitro. In vivo, HDME (3~30 μmol/kg, orally (p.o. dose-dependently and significantly attenuated the airway resistance (RL and increased lung dynamic compliance (Cdyn, and decreased enhanced pause (Penh values induced by methacholine in sensitized and challenged mice. It also significantly suppressed the increases in the numbers of total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils, and levels of cytokines, including interleukin (IL-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF of these mice. In addition, HDME (3~30 μmol/kg, p.o. dose-dependently and significantly suppressed total and ovalbumin-specific immunoglobulin (IgE levels in the BALF and serum, and enhanced IgG2a level in the serum of these mice. Conclusions HDME exerted anti

  20. Transuranium perrhenates: Np(IV), Pu(IV) and (III), Am (III)

    International Nuclear Information System (INIS)

    Silvestre, Jean-Paul; Freundlich, William; Pages, Monique

    1977-01-01

    Synthesis in aqueous solution and by solid state reactions, crystallographical characterization and study of the stability of some transuranium perrhenates: Asup(n+)(ReO 4 - )sub(n) (A=Np(IV), Pu(IV), Pu(III), Am(III) [fr

  1. RNA polymerase II mediated transcription from the polymerase III promoters in short hairpin RNA expression vector

    International Nuclear Information System (INIS)

    Rumi, Mohammad; Ishihara, Shunji; Aziz, Monowar; Kazumori, Hideaki; Ishimura, Norihisa; Yuki, Takafumi; Kadota, Chikara; Kadowaki, Yasunori; Kinoshita, Yoshikazu

    2006-01-01

    RNA polymerase III promoters of human ribonuclease P RNA component H1, human U6, and mouse U6 small nuclear RNA genes are commonly used in short hairpin RNA (shRNA) expression vectors due their precise initiation and termination sites. During transient transfection of shRNA vectors, we observed that H1 or U6 promoters also express longer transcripts enough to express several reporter genes including firefly luciferase, green fluorescent protein EGFP, and red fluorescent protein JRed. Expression of such longer transcripts was augmented by upstream RNA polymerase II enhancers and completely inhibited by downstream polyA signal sequences. Moreover, the transcription of firefly luciferase from human H1 promoter was sensitive to RNA polymerase II inhibitor α-amanitin. Our findings suggest that commonly used polymerase III promoters in shRNA vectors are also prone to RNA polymerase II mediated transcription, which may have negative impacts on their targeted use

  2. SINE transcription by RNA polymerase III is suppressed by histone methylation but not by DNA methylation

    Science.gov (United States)

    Varshney, Dhaval; Vavrova-Anderson, Jana; Oler, Andrew J.; Cowling, Victoria H.; Cairns, Bradley R.; White, Robert J.

    2015-01-01

    Short interspersed nuclear elements (SINEs), such as Alu, spread by retrotransposition, which requires their transcripts to be copied into DNA and then inserted into new chromosomal sites. This can lead to genetic damage through insertional mutagenesis and chromosomal rearrangements between non-allelic SINEs at distinct loci. SINE DNA is heavily methylated and this was thought to suppress its accessibility and transcription, thereby protecting against retrotransposition. Here we provide several lines of evidence that methylated SINE DNA is occupied by RNA polymerase III, including the use of high-throughput bisulphite sequencing of ChIP DNA. We find that loss of DNA methylation has little effect on accessibility of SINEs to transcription machinery or their expression in vivo. In contrast, a histone methyltransferase inhibitor selectively promotes SINE expression and occupancy by RNA polymerase III. The data suggest that methylation of histones rather than DNA plays a dominant role in suppressing SINE transcription. PMID:25798578

  3. EGFR and its mutant EGFRvIII as modulators of tumor cell radiosensitivity

    International Nuclear Information System (INIS)

    Lammering, G.; Hewit, T.H.; Contessa, J.N.; Hawkins, W.; Lin, P.S.; Valerie, K.; Mikkelsen, R.; Dent, P.; Schmidt-Ullrich, R.K.

    2001-01-01

    tumors for MDA-MB-231 and U-87 MG tumors, with dose enhancement ratios of 1.9. U-373 MG tumors expressing EGFR-CD533 demonstrated a 4-fold increase in the tumor doubling time after IR (3 x 3 Gy) compared with LacZ transduced tumors. EGF treatment activated EGFR, as quantified by tyrosine phosphorylation (Tyr-P) and mediated activation of its downstream target mitogen activated protein kinase (MAPK), but had no effect on EGFRvIII. In contrast, IR stimulated a 4-fold increase in Tyr-P of EGFRvIII, resulting in a maximum 9-fold activation of MAPK and a 3-fold activation of the PI3K signal transduction pathway. A specific tyrphostin inhibitor of EGFR and EGFRvIII, AG1478, reduced the radiation-induced activation of MAPK and PI3K to a maximum of 2-fold, similar to the activation profile observed in CHO cells transfected with null vectors. Colony formation and cell growth assays verified that cells expressing EGFRvIII are markedly protected against the cytotoxic effects of IR. Finally, Ad-EGFR-CD533 transduction of U-373 MG cells expressing EGFRvIII significantly reduced basal Tyr-P and IR-induced activation of EGFRvIII. Conclusion: The effects of in vivo expression of constitutively active EGFRvIII on cellular radiosensitivity have not previously been considered. We demonstrate here that expression of EGFRvIII enhances the relative radioresistance of tumor cells in vitro and in vivo. This resistance is mediated by the significantly greater radiation-induced activation of EGFRvIII relative to EGFR and as a consequence a greater stimulation of both the MAPK and PI3K cytoprotective pathways. Importantly, the genetic disruption of EGFR function by expression of EGFR-CD533 is equally effective with either EGFR or EGFRvIII

  4. Isolation and characterization of a specific endogenous Na+, K+-ATPase inhibitor from bovine adrenal

    International Nuclear Information System (INIS)

    Tamura, M.; Lam, T.T.; Inagami, T.

    1988-01-01

    In order to identify a specific endogenous Na + ,K + -ATPase inhibitor which could possibly be related to salt-dependent hypertension, the authors looked for substances in the methanol extract of bovine whole adrenal which show all of the following properties: (i) inhibitory activity for Na + ,K + -ATPase; (ii) competitive displacing activity against [ 3 H]ouabain binding to the enzyme; (iii) inhibitory activity for 86 Rb uptake into intact human erythrocytes; and (iv) cross-reactivity with sheep anti-digoxin-specific antibody. After stepwise fractionation of the methanol extract of bovine adrenal glands by chromatography on a C 18 open column, a 0-15% acetonitrile fraction was fractionated by high-performance liquid chromatography on a Zorbax octadecylsilane column. One of the most active fractions in 0-15% acetonitrile was found to exhibit all of the four types of the activities. It was soluble in water and was distinct from various substances which have been known to inhibit Na + ,K + -ATPase. These results strongly suggest that this water-soluble nonpeptidic Na + ,K + -ATPase inhibitor may be a specific endogenous regulator for the ATPase

  5. Enhancement of fracture healing in the rat, modulated by compounds that stimulate inducible nitric oxide synthase

    OpenAIRE

    Rajfer, R. A.; Kilic, A.; Neviaser, A. S.; Schulte, L. M.; Hlaing, S. M.; Landeros, J.; Ferrini, M. G.; Ebramzadeh, E.; Park, S-H.

    2017-01-01

    Objectives We investigated the effects on fracture healing of two up-regulators of inducible nitric oxide synthase (iNOS) in a rat model of an open femoral osteotomy: tadalafil, a phosphodiesterase inhibitor, and the recently reported nutraceutical, COMB-4 (consisting of L-citrulline, Paullinia cupana, ginger and muira puama), given orally for either 14 or 42 days. Materials and Methods Unilateral femoral osteotomies were created in 58 male rats and fixed with an intramedullary compression na...

  6. Allosteric small-molecule kinase inhibitors

    DEFF Research Database (Denmark)

    Wu, Peng; Clausen, Mads Hartvig; Nielsen, Thomas E.

    2015-01-01

    current barriers of kinase inhibitors, including poor selectivity and emergence of drug resistance. In spite of the small number of identified allosteric inhibitors in comparison with that of inhibitors targeting the ATP pocket, encouraging results, such as the FDA-approval of the first small...

  7. 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

    2006-01-01

    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......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...... 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...

  8. Ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) and adenosine deaminase (ADA) activities in prostate cancer patients: influence of Gleason score, treatment and bone metastasis.

    Science.gov (United States)

    Battisti, Vanessa; Maders, Liési D K; Bagatini, Margarete D; Battisti, Iara E; Bellé, Luziane P; Santos, Karen F; Maldonado, Paula A; Thomé, Gustavo R; Schetinger, Maria R C; Morsch, Vera M

    2013-04-01

    The relation between adenine nucleotides and cancer has already been described in literature. Considering that the enzymes ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) and adenosine deaminase (ADA) act together to control nucleotide levels, we aimed to investigate the role of these enzymes in prostate cancer (PCa). E-NPP and ADA activities were determined in serum and platelets of PCa patients and controls. We also verified the influence of the Gleason score, bone metastasis and treatment in the enzyme activities. Platelets and serum E-NPP activity increased, whereas ADA activity in serum decreased in PCa patients. In addition, Gleason score, metastasis and treatment influenced E-NPP and ADA activities. We may propose that E-NPP and ADA are involved in the development of PCa. Moreover, E-NPP and ADA activities are modified in PCa patients with distinct Gleason score, with bone metastasis, as well as in patients under treatment. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Genetic Ablation of Type III Adenylyl Cyclase Exerts Region-Specific Effects on Cilia Architecture in the Mouse Nose.

    Directory of Open Access Journals (Sweden)

    Rosemary C Challis

    Full Text Available We recently reported that olfactory sensory neurons in the dorsal zone of the mouse olfactory epithelium exhibit drastic location-dependent differences in cilia length. Furthermore, genetic ablation of type III adenylyl cyclase (ACIII, a key olfactory signaling protein and ubiquitous marker for primary cilia, disrupts the cilia length pattern and results in considerably shorter cilia, independent of odor-induced activity. Given the significant impact of ACIII on cilia length in the dorsal zone, we sought to further investigate the relationship between cilia length and ACIII level in various regions throughout the mouse olfactory epithelium. We employed whole-mount immunohistochemical staining to examine olfactory cilia morphology in phosphodiesterase (PDE 1C-/-;PDE4A-/- (simplified as PDEs-/- hereafter and ACIII-/- mice in which ACIII levels are reduced and ablated, respectively. As expected, PDEs-/- animals exhibit dramatically shorter cilia in the dorsal zone (i.e., where the cilia pattern is found, similar to our previous observation in ACIII-/- mice. Remarkably, in a region not included in our previous study, ACIII-/- animals (but not PDEs-/- mice have dramatically elongated, comet-shaped cilia, as opposed to characteristic star-shaped olfactory cilia. Here, we reveal that genetic ablation of ACIII has drastic, location-dependent effects on cilia architecture in the mouse nose. These results add a new dimension to our current understanding of olfactory cilia structure and regional organization of the olfactory epithelium. Together, these findings have significant implications for both cilia and sensory biology.

  10. Maintenance of EGFR and EGFRvIII expressions in an in vivo and in vitro model of human glioblastoma multiforme

    DEFF Research Database (Denmark)

    Stockhausen, Marie-Thérése; Broholm, Helle; Villingshøj, Mette

    2011-01-01

    Glioblastoma multiforme (GBM) is the most common, and most aggressive primary brain tumor among adults. A vast majority of the tumors express high levels of the epidermal growth factor receptor (EGFR) as a consequence of gene amplification. Furthermore, gene amplification is often associated...... with mutation of EGFR, and the constitutive activated deletion variant EGFRvIII is the most common EGFR mutation found in GBM. Activated EGFR signaling, through overexpression and/or mutation, is involved in increased tumorigenic potential. As such, EGFR is an attractive target for GBM therapy. However......, clinical studies with EGFR inhibitors have shown inconsistent results, and as such, further knowledge regarding the role of EGFR and EGFRvIII in GBM is needed. For this, an appropriate in vivo/in vitro tumor model is required. Here, we report the establishment of an experimental GBM model in which...

  11. TGF-β-stimulated aberrant expression of class III β-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

    International Nuclear Information System (INIS)

    Chung, Eun Jee; Chun, Ji Na; Jung, Sun-Ah; Cho, Jin Won; Lee, Joon H.

    2011-01-01

    Highlights: ► TGF-β induces aberrant expression of βIII in RPE cells via the ERK pathway. ► TGF-β increases O-GlcNAc modification of βIII in RPE cells. ► Mature RPE cells have the capacity to express a neuron-associated gene by TGF-β. -- Abstract: The class III β-tubulin isotype (β III ) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III β-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-β (TGF-β) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-β on the aberrant expression of class III β-tubulin and the intracellular signaling pathway mediating these changes. TGF-β-induced aberrant expression and O-linked-β-N-acetylglucosamine (O-GlcNac) modification of class III β-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-β also stimulated phosphorylation of ERK. TGF-β-induced aberrant expression of class III β-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-β stimulated aberrant expression of class III β-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-β stimulation and provide useful information towards understanding the pathogenesis of proliferative vitreoretinal diseases.

  12. TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

    2011-11-18

    Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

  13. SGLT2 inhibitors.

    Science.gov (United States)

    Dardi, I; Kouvatsos, T; Jabbour, S A

    2016-02-01

    Diabetes mellitus is a serious health issue and an economic burden, rising in epidemic proportions over the last few decades worldwide. Although several treatment options are available, only half of the global diabetic population achieves the recommended or individualized glycemic targets. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of antidiabetic agents with a novel insulin-independent action. SGLT2 is a transporter found in the proximal renal tubules, responsible for the reabsorption of most of the glucose filtered by the kidney. Inhibition of SGLT2 lowers the blood glucose level by promoting the urinary excretion of excess glucose. Due to their insulin-independent action, SGLT2 inhibitors can be used with any degree of beta-cell dysfunction or insulin resistance, related to a very low risk of hypoglycemia. In addition to improving glycemic control, SGLT2 inhibitors have been associated with a reduction in weight and blood pressure when used as monotherapy or in combination with other antidiabetic agents in patients with type 2 diabetes mellitus (T2DM). Treatment with SGLT2 inhibitors is usually well tolerated; however, they have been associated with an increased incidence of urinary tract and genital infections, although these infections are usually mild and easy to treat. SGLT2 inhibitors are a promising new option in the armamentarium of drugs for patients with T2DM. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Basel III D: Swiss Finish to Basel III

    OpenAIRE

    Christian M. McNamara; Natalia Tente; Andrew Metrick

    2014-01-01

    After the Basel Committee on Banking Supervision (BCBS) introduced the Basel III framework in 2010, individual countries confronted the question of how best to implement the framework given their unique circumstances. Switzerland, with a banking industry that is both heavily concentrated and very large relative to the size of its overall economy, faced a special challenge. It ultimately adopted what is sometimes referred to as the “Swiss Finish” to Basel III – enhanced requirements applicable...

  15. Proton NMR studies of Cucurbita maxima trypsin inhibitors: Evidence for pH-dependent conformational change and his25 - try27 interaction

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamoorthi, R.; Chanlan Sun Lin; Yuxi Gong (Kansas State Univ., Manhattan (United States)); VanderVelde, D. (Univ. of Kansas, Lawrence (United States)); Hahn, K. (Univ. of Colorado, Denver (United States))

    1992-01-28

    A pH-dependent His25-Tyr27 interaction was demonstrated in the case of Cucurbita maxima trypsin inhibitors (CMTI-I and CMTI-III) by means of nuclear magnetic resonance (NMR) spectroscopy. pH titration, line widths, peak shapes, deuterium exchange kinetics, and two-dimensional nuclear Overhauser effect spectroscopy (NOESY) were employed to characterize a conformational change involving Tyr27, which was shown to be triggered by deprotonation of His25 around pH 6. A hydrogen bond is proposed to be formed between N{sub {epsilon}} of His25 and OH of Tyr27, as a distance between the atoms, His25 N{epsilon} and Tyr25 OH, of 3.02 {angstrom} is consistent with a model built with NOE-derived distance constraints. The presently characterized relative orientati