Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.1.4.1 (phosphodiesterase)
18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The aim of this study was to investigate the effects of IL-10, a cell permeable analogue of cyclic AMP, dibutyryl-cAMP (db-cAMP), modulators of intracellular cyclic AMP such as phosphodiesterase (PDE) inhibitors and a beta 2-adrenoceptor agonist, salmeterol, on pulmonary inflammation following acute lung injury induced by endotoxin exposure in rats. Pulmonary inflammation was induced in adult Wistar rats by a 60-min exposure to endotoxin (lipopolysaccharide, LPS, 100 micrograms/mL). 4 h later bronchoalveolar lavage (BAL) was performed. The PDE inhibitors, rolipram (3 and 5 mg/kg) and theophylline (30 and 100 mg/kg) inhibited neutrophil recruitment, TNF-alpha release and cellular activation in BAL. Salmeterol (0.5 mg/mL) and IL-10 (0.1 microgram) only inhibit TNF-alpha increase in the BAL fluid and db-AMPc (2.5 micrograms/rat) was ineffective. The present data show that the selective PDE4 inhibitor, rolipram, and the non-selective PDE inhibitor, theophylline, markedly reduced the pulmonary inflammation associated with acute lung injury in the rat. These effects may be mediated in part by IL-10 rather than by cyclic AMP, as demonstrated by the potent inhibitory activity of exogenous IL-10 on the increase in TNF-alpha release in BAL fluid of rats exposed to LPS.
...
PMID:Effects of interleukin-10 and modulators of cyclic AMP formation on endotoxin-induced inflammation in rat lung. 1002 94

TNF-alpha mediates both protective and detrimental manifestations of the host immune response. Our previous work has shown thalidomide to be a relatively selective inhibitor of TNF-alpha production in vivo and in vitro. Additionally, we have recently reported that thalidomide exerts a costimulatory effect on T cell responses. To develop thalidomide analogues with increased anti-TNF-alpha activity and reduced or absent toxicities, novel TNF-alpha inhibitors were designed and synthesized. When a selected group of these compounds was examined for their immunomodulatory activities, different patterns of cytokine modulation were revealed. The tested compounds segregated into two distinct classes: one class of compounds, shown to be potent phosphodiesterase 4 inhibitors, inhibited TNF-alpha production, increased IL-10 production by LPS-induced PBMC, and had little effect on T cell activation; the other class of compounds, similar to thalidomide, were not phosphodiesterase 4 inhibitors and markedly stimulated T cell proliferation and IL-2 and IFN-gamma production. These compounds inhibited TNF-alpha, IL-1beta, and IL-6 and greatly increased IL-10 production by LPS-induced PBMC. Similar to thalidomide, the effect of these agents on IL-12 production was dichotomous; IL-12 was inhibited when PBMC were stimulated with LPS but increased when cells were stimulated by cross-linking the TCR. The latter effect was associated with increased T cell CD40 ligand expression. The distinct immunomodulatory activities of these classes of thalidomide analogues may potentially allow them to be used in the clinic for the treatment of different immunopathological disorders.
...
PMID:Differential cytokine modulation and T cell activation by two distinct classes of thalidomide analogues that are potent inhibitors of TNF-alpha. 1038 39

15-Deoxy-Delta12,14-PGJ2 (dPGJ2) is a bioactive metabolite of the J2 series that has been identified as a ligand for peroxisome proliferator-activated receptor gamma (PPARgamma) and has received attention for its potential antiinflammatory effects. Because neutrophils express cell-surface receptors for PGs, the effect of dPGJ2 was tested on an inflammatory response that should not require PPARgamma, the oxidative burst made by adherent human neutrophils. dPGJ2 inhibited adhesion-dependent H2O2 production with an IC50 of 1. 5 microM when neutrophils were stimulated with TNF, N-formylnorleucylleucylphenylalanine, or LPS. Inhibition by dPGJ2 occurred during the lag phase, before generation of peroxide, suggesting blockade of an early signaling step. Indeed, dPGJ2 blocked adhesion of neutrophils to fibrinogen in response to TNF or LPS with an IC50 of 3-5 micro+dPGJ2 was more potent at inhibiting the adhesion-dependent oxidative burst than several other PGs tested. Further, dPGJ2 did not appear to act through either the DP receptor or receptors for PGE2. PG receptors modulate cAMP levels, and the inhibition of adhesion and oxidative burst by dPGJ2 was enhanced in the presence of 3-isobutyl-1-methylxanthine, a cAMP phosphodiesterase inhibitor. A potent PPARgamma agonist (AD-5075) did not inhibit peroxide production or adhesion, nor did it change the IC50 for dPGJ2 inhibition. These studies suggest that dPGJ2 may interact with an unknown receptor on neutrophils, distinct from PPARgamma, to modulate the production of reactive oxygen intermediates.
...
PMID:15-Deoxy-Delta12,1412,14-prostaglandin J2 inhibits the beta2 integrin-dependent oxidative burst: involvement of a mechanism distinct from peroxisome proliferator-activated receptor gamma ligation. 1057 Mar 10

Adenosine (ADO) exerts potent anti-inflammatory and immunosuppressive effects. In this paper we address the possibility that these effects are partly mediated by inhibition of the secretion of IL-12, a proinflammatory cytokine and a major inducer of Th1 responses. We demonstrate that 5'-N-ethylcarboxamidoadenosine (NECA), a nonspecific ADO analogue, and 2-p-(2-carbonyl-ethyl)phenylethylamino-5'-N-ethylcarboxamidoadenos ine (CGS-21680), a specific A2a receptor agonist, dose-dependently inhibited, in whole blood ex vivo and monocyte cultures, the production of human IL-12 induced by LPS and Stapholococcus aureus Cowan strain 1. However, the A1 receptor agonist 2-Chloro-N6-cyclopentyladenosine and the A3 receptor agonists N6-Benzyl-NECA and 1-deoxy-1-[6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-N-methyl-be ta-d -ribofuranuronamide expressed only weak inhibitory effects. On the other hand, NECA and CGS-21680 dose-dependently potentiated the production of IL-10. The differential effect of these drugs on monocyte IL-12 and IL-10 production implies that these effects are mediated by A2a receptor signaling rather than by intracellular toxicity of ADO analogue's metabolites. Moreover, CGS-21680 inhibited IL-12 production independently of endogenous IL-10 induction, because anti-IL-10 Abs failed to prevent its effect. The selective A2a antagonist 8-(3-Chlorostyryl) caffeine prevented the inhibitory effect of CGS-21680 on IL-12 production. The phosphodiesterase inhibitor Ro 20-1724 dose-dependently potentiated the inhibitory effect of CGS-21680 and, furthermore, Rp-cAMPS, a protein kinase A inhibitor, reversed the inhibitory effect of CGS-21680, implicating a cAMP/protein kinase A pathway in its action. Thus, ligand activation of A2a receptors simultaneously inhibits IL-12 and stimulates IL-10 production by human monocytes. Through this mechanism, ADO released in excess during inflammatory and ischemic conditions, or tissue injury, may contribute to selective suppression of Th1 responses and cellular immunity.
...
PMID:Ligand-activation of the adenosine A2a receptors inhibits IL-12 production by human monocytes. 1060 40

Adenosine exerts potent anti-inflammatory activities through inhibition of cytokine synthesis by activated monocytes. Adenosine is rapidly phosphorylated intracellularly by adenosine kinase. GP515, an adenosine kinase inhibitor, prevents the phosphorylation of adenosine to AMP and thereby locally enhances the adenosine concentration. GP515 has exhibited significant anti-inflammatory effects in several murine models of inflammation. In this study we investigated the effect of GP515 alone and in combination with exogenous adenosine or with rolipram, a phosphodiesterase inhibitor, on tumor necrosis factor alpha (TNF-alpha) synthesis in human peripheral blood mononuclear cells (PBMC) or whole blood. Lipopolysaccharide (LPS; 10 ng/mL)-stimulated PBMC were incubated in the absence or presence of these substances. GP515 alone showed a dose-dependent suppression of TNF-alpha production with an IC50 of 80 microM. The TNF-alpha-inhibiting effects of adenosine and GP515 were reversed in the presence of the cAMP antagonist (Rp)-cAMPS, supporting the hypothesis of a cAMP-mediated pathway. Combinations of GP515 with either adenosine or rolipram led to an additive inhibition of TNF-alpha synthesis. These experiments are the first to demonstrate efficacy of an adenosine kinase inhibitor in TNF-alpha suppression in cells of human origin. The findings form a basis to investigate these strategies in animal models of TNF-alpha-mediated chronic inflammatory diseases.
...
PMID:Suppression of TNF-alpha production in human mononuclear cells by an adenosine kinase inhibitor. 1091 95

We have investigated the bronchodilator and anti-inflammatory properties of roflumilast (3-cyclopropylmethoxy-4-difluoromethoxy-N-[3,5-dichloropyrid-4-yl]-benzamide), a novel, highly potent, and selective phosphodiesterase 4 (PDE4) inhibitor. Additionally, we compared the effects of roflumilast and its N-oxide, the primary metabolite in vivo, with those of the PDE4 inhibitors piclamilast, rolipram, and cilomilast. Roflumilast inhibited the ovalbumin-evoked contractions of tracheal chains prepared from sensitized guinea pigs (EC(50) = 2 x 10(-7) M) but showed no relaxant effect on tissues contracted spontaneously. In spasmogen-challenged rats and guinea pigs, intravenously administered roflumilast displayed bronchodilatory activity (ED(50) = 4.4 and 7.1 micromol/kg, respectively). Furthermore, roflumilast dose dependently attenuated allergen-induced bronchoconstriction in guinea pigs (ED(50) = 0.1 micromol/kg i.v.). Roflumilast given orally (ED(50) = 1.5 micromol/kg) showed equal potency to its N-oxide (ED(50) = 1.0 micromol/kg) but was superior to piclamilast (ED(50) = 8.3 micromol/kg), rolipram (ED(50) = 32.5 micromol/kg), and cilomilast (ED(50) = 52.2 micromol/kg) in suppressing allergen-induced early airway reactions. To assess the anti-inflammatory potential of orally administered roflumilast, antigen-induced cell infiltration, total protein, and TNFalpha concentration in bronchoalveolar lavage fluid of Brown Norway rats were determined. Roflumilast and its N-oxide equally inhibited eosinophilia (ED(50) = 2.7 and 2.5 micromol/kg, respectively), whereas the reference inhibitors displayed lower potency (ED(50) = 17-106 micromol/kg). Besides, orally administered roflumilast abrogated LPS-induced circulating TNFalpha in the rat (ED(50) = 0.3 micromol/kg), an effect shared by its N-oxide, with both molecules exhibiting 8-, 25-, and 310-fold superiority to piclamilast, rolipram, and cilomilast, respectively. These results, coupled with the in vitro effects of roflumilast on inflammatory cells, suggest that roflumilast represents a potential new drug for the treatment of asthma and chronic obstructive pulmonary disease.
...
PMID:In vivo efficacy in airway disease models of roflumilast, a novel orally active PDE4 inhibitor. 1125 55

The effect of phosphodiesterase-inhibiting anti-inflammatory drug pentoxifylline (PTX) on LPS-induced IL-18 synthesis and IL-18-mediated IFN-gamma-induction were investigated. In a dose-dependent manner PTX inhibited production of IL-18 in LPS-treated cultures of murine spleen cells and bone marrow-derived macrophages. Similarly, PTX treatment significantly reduced blood IL-18 levels and expression of spleen IL-18 mRNA in LPS-challenged mice. The inhibitory effect of PTX was specific for IL-18, since LPS-induced IL-12 p40 release was not suppressed either in splenocyte cultures or blood of LPS-injected animals. Synergistic induction of IFN-gamma by combined IL-12/IL-18 treatment was also inhibited by PTX in vitro and in vivo. Experiments with IL-12 pretreatment of splenocytes, followed by IL-18 stimulation, revealed that PTX suppressed both IL-12 and IL-18 signals responsible for IFN-gamma induction. These results suggest that interference with IL-18 synthesis and IFN-gamma-inducing activity might contribute to anti-inflammatory actions of PTX.
...
PMID:Pentoxifylline inhibits the synthesis and IFN-gamma-inducing activity of IL-18. 1142 5

1. Rolipram, a selective phosphodiesterase (PDE) type 4 inhibitor, was used to characterize leukocyte recruitment mechanisms in models of acute and subacute inflammation. Intravital microscopy within the rat mesenteric microcirculation was employed. 2. Mesentery superfusion with PAF (0.1 microM) induced a significant increase in leukocyte rolling flux, adhesion and emigration at 60 min. Rolipram pretreatment, markedly inhibited these parameters by 100, 95 and 95% respectively. 3. Similar effects were observed when the mesentery was superfused with LPS (1 microg ml(-1)) for the same time period and these leukocyte parameters were nearly abrogated by rolipram pretreatment. 4. LPS exposure of the mesentery for 4 h caused a greater increase in leukocyte rolling flux, adhesion and emigration which were inhibited by rolipram administration by 51, 71 and 81% respectively. 5. Immunohistochemistry revealed a significant increase in P-selectin expression after 60 min superfusion with PAF which was attenuated by rolipram. 6. LPS exposure of the mesentery for 4 h caused a significant increase in P- and E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression. Rolipram pretreatment down-regulated both P- and E-selectin expression but had no effect on ICAM-1 and VCAM-1 expression. 7. Significant increases in plasma cyclic AMP levels were detected at 4.5 h after rolipram administration. 8. In conclusion, we have demonstrated that rolipram is a potent in vivo inhibitor of leukocyte-endothelial cell interactions. The effects observed are mediated through endothelial P- and E-selectin downregulation. Therefore, selective PDE-4 inhibitors may be useful in the control of different inflammatory disorders.
...
PMID:Rolipram inhibits leukocyte-endothelial cell interactions in vivo through P- and E-selectin downregulation. 1195 89

This paper describes the synthesis and anti-inflammatory activity of new N-phenyl-phthalimide sulfonamides (3a-e) and the isosters N-phenyl-phthalimide amides (4a-e), designed as hybrids of thalidomide (1) and aryl sulfonamide phosphodiesterase inhibitor (2). In these series, compound 3e (LASSBio 468), having a sulfonyl-thiomorpholine moiety, showed potent inhibitory activity on LPS-induced neutrophil recruitment with ED(50)=2.5mg kg(-1), which was correlated with its inhibitory effect on TNF-alpha level.
...
PMID:Synthesis and anti-inflammatory activity of phthalimide derivatives, designed as new thalidomide analogues. 1211 Mar 31

The signalling pathways mediating neutrophil spontaneous apoptosis are still largely unknown. We report that the indolocarbazole compound KT5823, a specific inhibitor of cGMP-dependent protein kinases (cGK), dose-dependently inhibited spontaneous apoptosis of neutrophils. At the concentration eliciting the maximum effect (8 microM), it decreased apoptosis from 72.42+/-12.79% to 45.86+/-7.22% (p=0.0002, n=6). Similarly, the isoquinoline sulfonamide compound H89, another cGK inhibitor, prevented neutrophil apoptosis. At the concentration eliciting the maximum effect (20 microM), it decreased apoptosis from 72.42+/-12.79% to 31.84+/-10.70% (p=0.0004, n=6). The maximum effect of KT5823 and H89 was comparable to that of GM-CSF and LPS, respectively. Moreover, YC-1, a soluble guanylate cyclase activator, and 4-([3',4',-(methylenedioxy)benzyl]amino)-6-methoxyquinazoline, a specific phosphodiesterase 5 inhibitor, enhanced neutrophil apoptosis, and their effect was antagonised by KT5823. Taken together, these observations highlight a new role of cGK as important mediators of neutrophil spontaneous apoptosis.
...
PMID:Inhibition of cGMP-dependent protein kinases potently decreases neutrophil spontaneous apoptosis. 1227 Jan 21


<< Previous 1 2 3 4 5 6 7 8 9 Next >>

---