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1
Bloom, Timothy J. "Cyclic nucleotide phosphodiesterase isozymes expressed in mouse skeletal muscle." Canadian Journal of Physiology and Pharmacology 80, no. 12 (December 1, 2002): 1132–35. http://dx.doi.org/10.1139/y02-149.
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To understand changes in cyclic nucleotide metabolism in muscle disease states, the expression of phosphodiesterase (PDE) isozymes in normal mouse leg muscle was examined. Four subcellular fractions were generated by differential centrifugation at 10 000 × g and 100 000 × g. cAMP PDE activity was found predominately in the soluble fractions, while cGMP PDE activity was more evenly distributed amongst soluble and particulate fractions. Pharmacological inhibitors demonstrate that PDE4 represents the major cAMP hydrolyzing activity and PDE2 represents the major cGMP hydrolyzing activity in mouse leg muscle. PDE1 is expressed at low levels, while PDE3 and PDE5 are intermediate. Between 20 and 40% of total PDE activity remained in the presence of inhibitors for PDE1PDE5, indicating that other PDE families contribute to the total PDE pool. Reverse-transcription PCR with family-specific primers showed expression of mRNA for PDE7PDE9, supporting this conclusion. Total PDE activity was found to be elevated in tissue extracts from a mouse model of Duchenne's muscular dystrophy.Key words: cyclic nucleotide, phosphodiesterase, skeletal muscle, pharmacological inhibitors, muscular dystrophy.
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DAY, Jonathan P., Julian A. T. DOW, Miles D. HOUSLAY, and Shireen-A. DAVIES. "Cyclic nucleotide phosphodiesterases in Drosophila melanogaster." Biochemical Journal 388, no. 1 (May 10, 2005): 333–42. http://dx.doi.org/10.1042/bj20050057.
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Cyclic nucleotide PDEs (phosphodiesterases) are important enzymes that regulate intracellular levels of cAMP and cGMP. In the present study, we identify and characterize novel PDEs in the genetic model, Drosophila melanogaster. The Drosophila genome encodes five novel PDE genes in addition to dunce. Predicted PDE sequences of Drosophila show highly conserved critical domains when compared with human PDEs. Thus PDE-encoding genes of D. melanogaster are CG14940-PDE1C, CG8279-PDE6β, CG5411-PDE8A, CG32648-PDE9 and CG10231-PDE11. Reverse transcriptase–PCRs of adult tissues reveal widespread expression of PDE genes. Drosophila Malpighian (renal) tubules express all the six PDEs: Drosophila PDE1, dunce (PDE4), PDE6, PDE8, PDE9 and PDE11. Antipeptide antibodies were raised against PDE1, PDE6, PDE9 and PDE11. Verification of antibody specificity by Western blotting of cloned and expressed PDE constructs allowed the immunoprecipitation studies of adult Drosophila lysates. Biochemical characterization of immunoprecipitated endogenous PDEs showed that PDE1 is a dual-specificity PDE (Michaelis constant Km for cGMP: 15.3±1 μM; Km cAMP: 20.5±1.5 μM), PDE6 is a cGMP-specific PDE (Km cGMP: 37±13 μM) and PDE11 is a dual-specificity PDE (Km cGMP: 6±2 μM; Km cAMP: 18.5±5.5 μM). Drosophila PDE1, PDE6 and PDE11 display sensitivity to vertebrate PDE inhibitors, zaprinast (IC50 was 71±39 μM for PDE1, 0.65±0.015 μM for PDE6 and 1.6±0.5 μM for PDE11) and sildenafil (IC50 was 1.3±0.9 μM for PDE1, 0.025±0.005 μM for PDE6 and 0.12±0.06 μM for PDE11). We provide the first characterization of a cGMP-specific PDE and two dual-specificity PDEs in Drosophila, and show a high degree of similarity in structure and function between human and Drosophila PDEs.
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Wright, Lyndon C., Joachim Seybold, Annette Robichaud, Ian M. Adcock, and Peter J. Barnes. "Phosphodiesterase expression in human epithelial cells." American Journal of Physiology-Lung Cellular and Molecular Physiology 275, no. 4 (October 1, 1998): L694—L700. http://dx.doi.org/10.1152/ajplung.1998.275.4.l694.
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Epithelial cells play a critical role in airway inflammation and have the capacity to produce many inflammatory mediators, including bioactive lipids and proinflammatory cytokines. Intracellular levels of cAMP and cGMP are important in the control of inflammatory cell function. These cyclic nucleotides are inactivated via a family of phosphodiesterase (PDE) enzymes, providing a possible site for drug intervention in chronic inflammatory conditions. We studied the expression of PDE activity in an epithelial cell line (A549) and in primary human airway epithelial cells (HAECs). We measured PDE function using specific inhibitors to identify the PDE families present and used RT-PCR to elucidate the expression of PDE isogenes. Both A549 cells and HAECs predominantly expressed PDE4 activity, with lesser PDE1, PDE3, and PDE5 activity. RT-PCR identified HSPDE4A5 and HSPDE4D3 together with HSPDE7. Inhibition of PDE4 and PDE3 reduced secretion by these cells. Epithelial PDE may be an important target for PDE4 inhibitors in the development of the control of asthmatic inflammation, particularly when delivered via the inhaled route.
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Sasseville, M., F. K. Albuz, F. J. Richard, and R. B. Gilchrist. "254. Evidences for a novel cAMP-phosphodiesterase expressed in the bovine ovarian follicle." Reproduction, Fertility and Development 20, no. 9 (2008): 54. http://dx.doi.org/10.1071/srb08abs254.
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3′5’-Cyclic adenosine monophosphate (cAMP) is an important second messenger in the mammalian ovarian follicle implicated in gonadotrophin signalling as well as oocyte meiotic arrest. Cyclic AMP-degrading phosphodiesterases (PDE) modulate cAMP levels in the ovarian follicle, but the specific PDE subtypes responsible for this degradation in the different cellular compartments within the bovine follicle remain unknown. The current dogma, established principally in rodent, presents PDE3A as the ‘oocyte PDE’, while PDE4D is the ‘granulosa/cumulus PDE’. Our PDE activity measurements suggested that a PDE3 (cilostamide-sensitive, 10µM) was representing 79% of the total cAMP-PDE activity in the bovine oocyte, in agreement with the dogma. However, our results suggested that PDE4 (rolipram-sensitive, 10µM) is representing only 19% of the cAMP-PDE activity in the cumulus cells, while 65% of the activity was due to PDE8 (IBMX-insensitive, 500µM), a result in direct opposition with the accepted PDE distribution in the ovarian follicle. Mural granulosa cells were displaying equal amounts of PDE4 (31%) and PDE8 (30%) cAMP-PDE activities. Interestingly, cAMP-PDE activities were not varying during the first 9 h of IVM in the bovine cumulus-oocyte complexes (COC), as seen in rat. COCs treated with an adenylyl cyclase stimulator (forkolin 100µM) in combinaison with the only known inhibitor for the PDE8 family, dipyridamole, are showing a dose-dependant increase of cAMP levels and a significant delay nuclear maturation, whereas a potent PDE4 inhibitor, rolipram (up to 100µM), was ineffective. This study provides the first insight into subtype-specific PDE cAMP degrading activities in the bovine ovarian follicle, especially around oocyte nuclear maturation. It demonstrates dramatic differential PDE subtype compartmentalisation between ovarian somatic cells and the germ cell, including the important contribution of a new PDE family member in the ovarian follicle, PDE8. PDE8 could be a novel pharmacological target to improve bovine oocyte IVM conditions and to increase developmental competence.
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Neumann, Joachim, Rafaela Voss, Ulrich Laufs, Christian Werner, and Ulrich Gergs. "Phosphodiesterases 2, 3 and 4 can decrease cardiac effects of H2-histamine-receptor activation in isolated atria of transgenic mice." Naunyn-Schmiedeberg's Archives of Pharmacology 394, no. 6 (February 12, 2021): 1215–29. http://dx.doi.org/10.1007/s00210-021-02052-y.
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AbstractHistamine exerts cAMP-dependent positive inotropic effects (PIE) and positive chronotropic effects (PCE) on isolated left and right atria, respectively, of transgenic mice which overexpress the human H2-receptor in the heart (=H2-TG). To determine whether these effects are antagonized by phosphodiesterases (PDEs), contractile studies were done in isolated left and right atrial preparations of H2-TG. The contractile effects of histamine were tested in the additional presence of the PDE-inhibitorserythro-9-(2-hydroxy-3-nonyl)adenine hydrochloride (EHNA, 1 μM, PDE2-inhibitor) or cilostamide (1 μM, PDE3-inhibitor), rolipram (10 μM, a PDE4-inhibitor), and their combinations. Cilostamide (1 μM) and EHNA (1 μM), rolipram (1 μM), and EHNA (1 μM) and the combination of rolipram (0.1 μM) and cilostamide (1 μM) each increased the potency of histamine to elevate the force of contraction (FOC) in H2-TG. Cilostamide (1 μM) and rolipram (10 μM) alone increased and EHNA (1 μM) decreased alone, and their combination increased the potency of histamine to increase the FOC in H2-TG indicating that PDE3 and PDE4 regulate the inotropic effects of histamine in H2-TG. The PDE inhibitors (EHNA, cilostamide, rolipram) alone did not alter the potency of histamine to increase the heart beat in H2-TG whereas a combination of rolipram, cilostamide, and EHNA, or of rolipram and EHNA increased the potency of histamine to act on the beating rate. In summary, the data suggest that the PCE of histamine in H2-TG atrium involves PDE 2 and 4 activities, whereas the PIE of histamine are diminished by activity of PDE 3 and 4.
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Tarpey, Siobhán B., Darrell R. Sawmiller, Claire Kelly, W. Joseph Thompson, and Mary I. Townsley. "Phosphodiesterase 3 activity is reduced in dog lung following pacing-induced heart failure." American Journal of Physiology-Lung Cellular and Molecular Physiology 284, no. 5 (May 1, 2003): L766—L773. http://dx.doi.org/10.1152/ajplung.00373.2002.
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We hypothesized that decreases in expression and/or activity of cAMP-specific phosphodiesterases (PDE) contribute to protective adaptations observed in lung after heart failure. In this study, we compared PDE activity in lung parenchyma isolated from control dogs and those paced to heart failure by assaying cyclic nucleotide hydrolysis in fractions of homogenate supernatant eluted from DEAE-Trisacryl columns. Cyclic nucleotide hydrolysis due to PDE3, PDE4, and PDE5 isoforms was predominant in both control and paced groups. The ratio of PDE3 activity to total cAMP PDE activity was decreased in the paced group compared with control ( P< 0.05), whereas PDE4 or PDE5 activity ratios were not different between the two groups. With the use of RT-PCR, message expression for PDE3A or PDE3B did not differ between the two groups. Cilostamide, a selective PDE3 inhibitor, and forskolin, a nonspecific agonist for adenylyl cyclase, both inhibited thapsigargin-induced increases in endothelial permeability in control lung. We conclude that PDE3 activity, but not mRNA expression, is reduced in lung from dogs paced to heart failure, a change that could contribute to heart failure-induced attenuation of the lung endothelial permeability response to injury.
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Phillips, Peter G., Lu Long, Martin R. Wilkins, and Nicholas W. Morrell. "cAMP phosphodiesterase inhibitors potentiate effects of prostacyclin analogs in hypoxic pulmonary vascular remodeling." American Journal of Physiology-Lung Cellular and Molecular Physiology 288, no. 1 (January 2005): L103—L115. http://dx.doi.org/10.1152/ajplung.00095.2004.
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We investigated the effects of prostacyclin analogs and isoform-selective phosphodiesterase (PDE) inhibitors, alone and in combination, on pulmonary vascular remodeling in vitro and in vivo. Vascular smooth muscle cells (VSMC) isolated from pulmonary (proximal and distal) and systemic circulations demonstrated subtle variations in expression of PDE isoform mRNA. However, using biochemical assays, we found PDE3 and PDE4 isoforms to be responsible for the majority of cAMP hydrolysis in all VSMC. In growth assays, the prostacyclin analogs cicaprost and iloprost inhibited mitogen-induced proliferation of VSMC in a cAMP-dependent manner. In addition, isoform-selective antagonists of PDEs 1, 3, or 4 inhibited VSMC proliferation, an effect that synergized with the effect of prostacyclin analogs. The inhibitory effects were greater in cells isolated from pulmonary circulation. In an in situ perfused rat lung preparation, administration of prostacyclin analogs or the PDE inhibitors vinpocetine (PDE1), cilostamide (PDE3), or rolipram (PDE4), but not EHNA (PDE2), attenuated acute hypoxic vasoconstriction (HPV). Combinations of agents led to a greater reduction in HPV. Furthermore, during exposure to hypoxia for 13 days, Wistar rats were treated with iloprost, rolipram, cilostamide, or combinations of these agents. Compared with normoxic controls, hypoxic animals developed pulmonary hypertension and distal pulmonary artery muscularization. These parameters were attenuated by iloprost+cilostamide, iloprost+rolipram, and cilostamide+rolipram but were not significantly affected by single agents. Together, these findings provide a greater understanding of the role of cAMP PDEs in VSMC proliferation and provide rationale for combined use of prostacylcin analogs plus PDE3/4 inhibitors in treatment of pulmonary vascular remodeling.
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ERDOGAN, Suat, and Miles D. HOUSLAY. "Challenge of human Jurkat T-cells with the adenylate cyclase activator forskolin elicits major changes in cAMP phosphodiesterase (PDE) expression by up-regulating PDE3 and inducing PDE4D1 and PDE4D2 splice variants as well as down-regulating a novel PDE4A splice variant." Biochemical Journal 321, no. 1 (January 1, 1997): 165–75. http://dx.doi.org/10.1042/bj3210165.
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The cAMP phosphodiesterase (PDE) 3 and PDE4 isoforms provide the major cAMP-hydrolysing PDE activities in Jurkat T-cells, with additional contributions from the PDE1 and PDE2 isoforms. Challenge of cells with the adenylate cyclase activator forskolin led to a rapid, albeit transient, increase in PDE3 activity occurring over the first 45 min, followed by a sustained increase in PDE3 activity which began after ∼3 h and continued for at least 24 h. Only this second phase of increase in PDE3 activity was blocked by the transcriptional inhibitor actinomycin D. After ∼3 h of exposure to forskolin, PDE4 activity had increased, via a process that could be inhibited by actinomycin D, and it remained elevated for at least a 24 h period. Such actions of forskolin were mimicked by cholera toxin and 8-bromo-cAMP. Forskolin increased intracellular cAMP concentrations in a time-dependent fashion and its action was enhanced when PDE induction was blocked with actinomycin D. Reverse transcription (RT)-PCR analysis, using generic primers designed to detect transcripts representing enzymically active products of the four PDE4 genes, identified transcripts for PDE4A and PDE4D but not for PDE4B or PDE4C in untreated Jurkat T-cells. Forskolin treatment did not induce transcripts for either PDE4B or PDE4C; however, it reduced the RT-PCR signal for PDE4A transcripts and markedly enhanced that for PDE4D transcripts. Using RT-PCR primers for PDE4 splice variants, a weak signal for PDE4D1 was evident in control cells whereas, in forskolin-treated cells, clear signals for both PDE4D1 and PDE4D2 were detected. RT-PCR analysis of the PDE4A species indicated that it was not the PDE4A isoform PDE-46 (PDE4A4B). Immunoblotting of control cells for PDE4 forms identified a single PDE4A species of ∼118 kDa, which migrated distinctly from the PDE4A4B isoform PDE-46, with immunoprecipitation analyses showing that it provided all of the PDE4 activity in control cells. Forskolin treatment led to a marked decrease of this novel PDE4A species and allowed the detection of a strong signal for an ∼67 kDa PDE4D species, suggested to be PDE4D1, but did not induce PDE4B and PDE4C isoforms. Elevation of intracellular cAMP concentrations in Jurkat T-cells thus exerts a highly selective effect on the transcriptional activity of the genes encoding the various PDE4 isoforms. This leads to the down-regulation of a novel PDE4A splice variant and the induction of PDE4D1 and PDE4D2 splice variants, leading to a net increase in the total PDE4 activity of Jurkat T-cells.
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Szczypka, Marianna. "Role of Phosphodiesterase 7 (PDE7) in T Cell Activity. Effects of Selective PDE7 Inhibitors and Dual PDE4/7 Inhibitors on T Cell Functions." International Journal of Molecular Sciences 21, no. 17 (August 25, 2020): 6118. http://dx.doi.org/10.3390/ijms21176118.
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Phosphodiesterase 7 (PDE7), a cAMP-specific PDE family, insensitive to rolipram, is present in many immune cells, including T lymphocytes. Two genes of PDE7 have been identified: PDE7A and PDE7B with three or four splice variants, respectively. Both PDE7A and PDE7B are expressed in T cells, and the predominant splice variant in these cells is PDE7A1. PDE7 is one of several PDE families that terminates biological functions of cAMP—a major regulating intracellular factor. However, the precise role of PDE7 in T cell activation and function is still ambiguous. Some authors reported its crucial role in T cell activation, while according to other studies PDE7 activity was not pivotal to T cells. Several studies showed that inhibition of PDE7 by its selective or dual PDE4/7 inhibitors suppresses T cell activity, and consequently T-mediated immune response. Taken together, it seems quite likely that simultaneous inhibition of PDE4 and PDE7 by dual PDE4/7 inhibitors or a combination of selective PDE4 and PDE7 remains the most interesting therapeutic target for the treatment of some immune-related disorders, such as autoimmune diseases, or selected respiratory diseases. An interesting direction of future studies could also be using a combination of selective PDE7 and PDE3 inhibitors.
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Teng, Bunyan, Daniel N. Darlington, and Andrew P. Cap. "Adenosine Regulation of cAMP through Phosphodiesterases." Blood 132, Supplement 1 (November 29, 2018): 2424. http://dx.doi.org/10.1182/blood-2018-99-114929.
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Abstract Introduction: Adenosine, an autacoid and metabolite of ATP, has been known to have anti-platelet properties. Of the 4 adenosine receptors (ARs), only A2A AR have been implicated in adenosines anti-platelet properties in human. A2A AR is a G-Protein Coupled Receptors associated with a stimulatory G-Protein (Gs) that can activate adenylyl cyclase (AC) and increase intracellular cAMP. An elevation of cAMP has been shown to inhibit platelet aggregation to natural stimuli. Regulation of intracellular cAMP is balanced between synthesis by adenylate cyclase and degradation by phosphdiesterases (PDE). There are 3 PDE subtypes found in platelets: PDE2, PDE3, and PDE5. However, it is not know which subtype(s) is (are) responsible for regulating cAMP level in human platelets after adenosine stimulation. Materials and Methods: Platelet-rich plasma (PRP) was isolated from whole blood of human volunteers, and centrifuged at 200g for 10min. Light transmission aggregometry was performed after stimulation of platelets with 100uM ADP, with or without NECA (non-specific AR agonist), DPCPX (A1 AR antagonist), and Sch 58261 (A2A AR antagonist). PRP treated with NECA, DPCPX, Sch 58261, and PDE inhibitors (EHNA, E in figures, for PDE2, Trequinsin, T in figures, for PDE3, and 4-{[3'4'-(methylenedioxy) benzyl]amino}-6-methoxyqunazolin, 4 in figures, for PDE 5). Cyclic AMP was measured in platelets after treatment by liquid chromatography/ Tandem Mass Spectroscopy (Quantiva, ThrermoFisher) after treated with these drugs. Results: ADP-induced platelet aggregation was inhibited in a dose dependent manner by the non-specific adenosine agonist, NECA (Figure 1) and the effect was blocked by A2A specific antagonist Sch 58261, not by the A1 AR antagonist, DPCPX (Figure 2). NECA inhibition of platelet aggregation was likely due to an elevation of intracellular cAMP (1 uM, 5min incubation, Figure 3). Inhibition of PDE3 alone, significantly increased intracellular cAMP, suggesting that basal PDE3 activity is present. PDE 3 inhibition combined with NECA elevated cAMP even higher than PDE inhibition or NECA alone (Figure 3), suggesting that NECA (A2A stimulation) effects PDE activity. Inhibition of PDE2 or 5 had no effect on basal or NECA stimulated cAMP (Figure 3). Inhibition of all 3 PDE (2,3,5) combined with NECA elevated cAMP to levels higher then NECA+ PDE3 inhibition, again suggesting that NECA maybe effecting the activity of the PDEs (Figure 3). The potentiation of cAMP by PDE3 inhibition + NECA was block by A2A, but not A1 antagonist (Figure 4) suggesting that the nonspecific adenosine agonist is elevating cAMP through A2A. Conclusion: 1. In human platelets, NECA stimulates cAMP through A2A receptors and this elevation is likely due to an elevation in adenylate cyclase via Gs coupled to A2A. PDE3 is basally active and likely regulated by adenosine receptors. Disclosures No relevant conflicts of interest to declare.
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Granovski, Olexiy, and Olena Boiarchuk. "FUNCTIONAL AND MUTATIONAL ANALYSIS OF THE IDENTIFICATION OF Pγ-BINDING RESIDUES ON PDE6α'." Grail of Science, no. 28 (June 22, 2023): 157–61. http://dx.doi.org/10.36074/grail-of-science.09.06.2023.23.
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Photoreceptor cGMP phosphodiesterase (PDE 6) is an effector enzyme in the G-protein mediated visual transduction cascade. In the dark, PDE6 activity is turned off by an inhibitory γ- subunit (Pγ). To study the mechanism of PDE6 catalytic activity inhibition by Pγ chimeric proteins PDE6α’/PDE5 were created. The catalytic properties of chimeric PDE remained the same as those of PDE5. Mutational analysis of the Pg-binding region, PDE6α' - (750-760), using ala-scan revealed PDE6α’ residues required for interaction. The M758A mutation markedly impaired and the Q752A mutation moderately impaired Pγ inhibition of the chimeric PDE. Analysis of the catalytic properties of the mutant PDE and the PDE6 catalytic domain model suggest that the Met758 and Gln752 residues bind Pγ directly. The PDE6 catalytic site model shows that PDE6α’-(750–760) forms a loop at the entrance to the cGMP-binding pocket. Binding of Pγ to Met758 effectively blocks cGMP access to the catalytic cavity, providing a structural basis for the PDE6 inhibition mechanism.
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Seybold, Joachim, Dirk Thomas, Martin Witzenrath, Şengül Boral, Andreas C. Hocke, Alexander Bürger, Armin Hatzelmann, et al. "Tumor necrosis factor-α–dependent expression of phosphodiesterase 2: role in endothelial hyperpermeability." Blood 105, no. 9 (May 1, 2005): 3569–76. http://dx.doi.org/10.1182/blood-2004-07-2729.
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AbstractThe pleiotropic cytokine tumor necrosis factor-α (TNF-α) and thrombin lead to increased endothelial permeability in sepsis. Numerous studies demonstrated the significance of intracellular cyclic nucleotides for the maintenance of endothelial barrier function. Actions of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) are terminated by distinct cyclic nucleotide phosphodiesterases (PDEs). We hypothesized that TNF-α could regulate PDE activity in endothelial cells, thereby impairing endothelial barrier function. In cultured human umbilical vein endothelial cells (HUVECs), we found a dramatic increase of PDE2 activity following TNF-α stimulation, while PDE3 and PDE4 activities remained unchanged. Significant PDE activities other than PDE2, PDE3, and PDE4 were not detected. TNF-α increased PDE2 expression in a p38 mitogen-activated protein kinase (MAPK)–dependent manner. Endothelial barrier function was investigated in HUVECs and in isolated mice lungs. Selective PDE2 up-regulation sensitized HUVECs toward the permeability-increasing agent thrombin. In isolated mice lungs, we demonstrated that PDE2 inhibition was effective in preventing thrombin-induced lung edema, as shown with a reduction in both lung wet-to-dry ratio and albumin flux from the vascular to bronchoalveolar compartment. Our findings suggest that TNF-α–mediated up-regulation of PDE2 may destabilize endothelial barrier function in sepsis. Inhibition of PDE2 is therefore of potential therapeutic interest in sepsis and acute respiratory distress syndrome (ARDS).
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Manns, J. M., K. J. Brennan, S. B. Sheth, and R. W. Colman. "Differential Regulation of Human Platelet Responses by cGMP Inhibited and Stimulated cAMP Phosphodiesterases." Thrombosis and Haemostasis 87, no. 05 (2002): 873–79. http://dx.doi.org/10.1055/s-0037-1613099.
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SummaryPlatelets contain two cAMP phosphodiesterases (PDEs) which regulate intracellular cAMP levels, cGMP-inhibited cAMP PDE (PDE3A) and cGMP-stimulated PDE (PDE2A). Using the PDE3 inhibitor, milrinone and the PDE2 inhibitor, erythro-9-(2-hydroxyl-3-nonyl)adenine (EHNA), we have explored the contribution of each PDE to the regulation of platelet function. Inhibition of PDE2 resulted in higher levels of intracellular cAMP than inhibition of PDE3A suggesting this PDE may be the more important regulator of cAMP in human platelets. However, a concentration-dependent inhibition of agonist-induced aggregation was observed with milrinone while little effect was seen with EHNA. In addition, we observed a concentration-dependent inhibition in the increase of intracellular Ca2+ with PDE3 inhibition and significantly less with PDE2 inhibition. PDE3 inhibition also resulted in a concentration-dependent increase in cAMP-mediated phosphorylation of the vasodilator-stimulated phospho-protein (VASP) whereas there was no significant increase with PDE2 inhibition. In each of these experiments, synergism was noted with the combination of milrinone and EHNA. These results suggest that cAMP pools may be localized and the various PDEs regulate specific pools. These data also suggest that inhibitors of PDE3A may be more effective antiplatelet agents.
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Germain, Nöella, Elisabeth Boichot, Jean-Michel Planquois, and Vincent Lagente. "Reduced Airway Hyperresponsiveness by Phosphodiesterase 3 and 4 Inhibitors in Guinea-Pigs." Mediators of Inflammation 8, no. 3 (1999): 153–57. http://dx.doi.org/10.1080/09629359990487.
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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.
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Świerczek, Artur, Krzysztof Pociecha, Hanna Plutecka, Marietta Ślusarczyk, Grażyna Chłoń-Rzepa, and Elżbieta Wyska. "Pharmacokinetic/Pharmacodynamic Evaluation of a New Purine-2,6-Dione Derivative in Rodents with Experimental Autoimmune Diseases." Pharmaceutics 14, no. 5 (May 19, 2022): 1090. http://dx.doi.org/10.3390/pharmaceutics14051090.
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Current treatment strategies of autoimmune diseases (ADs) display a limited efficacy and cause numerous adverse effects. Phosphodiesterase (PDE)4 and PDE7 inhibitors have been studied recently as a potential treatment of a variety of ADs. In this study, a PK/PD disease progression modeling approach was employed to evaluate effects of a new theophylline derivative, compound 34, being a strong PDE4 and PDE7 inhibitor. Activity of the studied compound against PDE1 and PDE3 in vitro was investigated. Animal models of multiple sclerosis (MS), rheumatoid arthritis (RA), and autoimmune hepatitis were utilized to assess the efficacy of this compound, and its pharmacokinetics was investigated in mice and rats. A new PK/PD disease progression model of compound 34 was developed that satisfactorily predicted the clinical score-time courses in mice with experimental encephalomyelitis that is an animal model of MS. Compound 34 displayed a high efficacy in all three animal models of ADs. Simultaneous inhibition of PDE types located in immune cells may constitute an alternative treatment strategy of ADs. The PK/PD encephalomyelitis and arthritis progression models presented in this study may be used in future preclinical research, and, upon modifications, may enable translation of the results of preclinical investigations into the clinical settings.
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Sarfati, Marika, Véronique Mateo, Sylvie Baudet, Manuel Rubio, Christine Fernandez, Fréderic Davi, Jacques-Louis Binet, Jozo Delic, and Hélène Merle-Béral. "Sildenafil and vardenafil, types 5 and 6 phosphodiesterase inhibitors, induce caspase-dependent apoptosis of B-chronic lymphocytic leukemia cells." Blood 101, no. 1 (January 1, 2003): 265–69. http://dx.doi.org/10.1182/blood-2002-01-0075.
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Abstract Type 4 phosphodiesterase (PDE4) inhibitors reportedly induce apoptosis in chronic lymphocytic leukemia (CLL) cells. Following clinical improvement of one previously untreated CLL patient with sildenafil therapy, we evaluated the in vitro induction of apoptosis in CLL cells by 4 PDE5/6 inhibitors, including sildenafil, vardenafil, zaprinast, and methoxyquinazoline (MQZ). After 24 hours of culture, the various PDE inhibitors differed in their ability to induce apoptosis, with zaprinast displaying no killing effect. Normal B cells isolated from control donors were totally resistant to PDE-induced apoptosis. Vardenafil was 3 and 30 times more potent an inducer of apoptosis than sildenafil and MQZ, respectively. Both vardenafil and sildenafil failed to elevate adenosine 3′5′ cyclic monophosphate (cAMP) levels, largely excluding an inhibitory effect on cAMP-PDE3, -PDE4, and -PDE7. Vardenafil- or sildenafil-treated B-CLL cells displayed up to 30% intracellular active caspase 3. Drug-induced apoptosis was inhibited by the caspase inhibitor z-VAD.fmk, prevented by interleukin-4 (IL-4), and significantly reduced by stromal-derived factor1-α (SDF-1α). We conclude that vardenafil and sildenafil induce caspase-dependent apoptosis of B-CLL cells in vitro and thus might be considered in the treatment of CLL patients. However, further in vivo investigations should be warranted.
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Reid, Ian A. "Role of Phosphodiesterase Isoenzymes in the Control of Renin Secretion: Effects of Selective Enzyme Inhibitors." Current Pharmaceutical Design 5, no. 9 (January 1999): 725–35. http://dx.doi.org/10.2174/1381612805666230111201536.
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<p>In most cells, the steady-state level of cAMP ultimately depends on the rate of cAMP synthesis by adenylyl cyclase and the rate of cAMP hydrolysis by cyclic nucleotide phosphodiesterases (PDEs). PDEs exist in multiple forms that have been grouped into seven families based on their substrate specificity, mode of regulation and kinetic properties. Selective inhibitors of many PDE families are now available. Examples are milrinone and trequinsin (PDE3); rolipram and Ro 20-1724 (PDE4); and zaprinast, sildenafil and didyridamole (PDE5). These inhibitors have proven to be valuable tools to investigate the role of PDEs in cell function.</p> <p> Representatives of most PDE families are present in the kidneys, and recent studies in this and other laboratories have provided evidence that some of them participate in the regulation of renin secretion. In particular, administration of selective PDE inhibitors has marked effects on renin secretion. For example, the PDE3 inhibitors milrinone and trequinsin increase resting renin in conscious rabbits and enhance the renin secretory response to beta-adrenergic stimulation. Milrinone also increases renin secretion in human subjects. The PDE4 inhibitors rolipram and Ro 20-1724 both increase renin secretion in rabbits and also enhance the renin response to beta-adrenergic stimulation. Studies in other laboratories have implicated other PDE families in the control of renin secretion. The aim of this review is to present current concepts concerning the PDEs and to discuss their role in the control of renin secretion by the kidneys.</p>
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Abusnina, Abdurazzag, Thérèse Keravis, Qingwei Zhou, Hélène Justiniano, Annelise Lobstein, and Claire Lugnier. "Tumour growth inhibition and anti-angiogenic effects using curcumin correspond to combined PDE2 and PDE4 inhibition." Thrombosis and Haemostasis 113, no. 02 (March 2015): 319–28. http://dx.doi.org/10.1160/th14-05-0454.
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SummaryVascular endothelial growth factor (VEGF) plays a major role in angiogenesis by stimulating endothelial cells. Increase in cyclic AMP (cAMP) level inhibits VEGF-induced endothelial cell proliferation and migration. Cyclic nucleotide phosphodiesterases (PDEs), which specifically hydrolyse cyclic nucleotides, are critical in the regulation of this signal transduction. We have previously reported that PDE2 and PDE4 up-regulations in human umbilical vein endothelial cells (HUVECs) are implicated in VEGF-induced angiogenesis and that inhibition of PDE2 and PDE4 activities prevents the development of the in vitro angiogenesis by increasing cAMP level, as well as the in vivo chicken embryo angiogenesis. We have also shown that polyphenols are able to inhibit PDEs. The curcumin having anti-cancer properties, the present study investigated whether PDE2 and PDE4 inhibitors and curcumin could have similar in vivo anti-tumour properties and whether the anti-angiogenic effects of curcumin are mediated by PDEs. Both PDE2/PDE4 inhibitor association and curcumin significantly inhibited in vivo tumour growth in C57BL/6N mice. In vitro, curcumin inhibited basal and VEGF-stimulated HUVEC proliferation and migration and delayed cell cycle progression at G0/G1, similarly to the combination of selective PDE2 and PDE4 inhibitors. cAMP levels in HUVECs were significantly increased by curcumin, similarly to rolipram (PDE4 inhibitor) and BAY-60–550 (PDE2 inhibitor) association, indicating cAMP-PDE inhibitions. Moreover, curcumin was able to inhibit VEGF-induced cAMP-PDE activity without acting on cGMP-PDE activity and to modulate PDE2 and PDE4 expressions in HUVECs. The present results suggest that curcumin exerts its in vitro anti-angiogenic and in vivo antitumour properties through combined PDE2 and PDE4 inhibition.
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Lee, Dong I., and David A. Kass. "Phosphodiesterases and Cyclic GMP Regulation in Heart Muscle." Physiology 27, no. 4 (August 2012): 248–58. http://dx.doi.org/10.1152/physiol.00011.2012.
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The cyclic nucleotide cGMP and its corresponding activated kinase cGK-1 serve as a counterbalance to acute and chronic myocardial stress. cGMP hydrolysis by several members of the phosphodiesterase (PDE) superfamily, PDE1, PDE2, and PDE5, regulate this signaling in the heart. This review details new insights regarding how these PDEs modulate cGMP and cGK-1 to influence heart function and chronic stress responses, and how their inhibition may provide potential therapeutic benefits.
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Favot, Laure, Thérèse Keravis, Vincent Holl, Alain Bec, and Claire Lugnier. "VEGF-induced HUVEC migration and proliferation are decreased by PDE2 and PDE4 inhibitors." Thrombosis and Haemostasis 90, no. 08 (2003): 334–43. http://dx.doi.org/10.1160/th03-02-0084.
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SummaryMigration and proliferation of endothelial cells in response to VEGF play an important role in angiogenesis associated to pathologies such as atherosclerosis, diabetes and tumor development. Elevation of cAMP in endothelial cells has been shown to inhibit growth factor-induced proliferation. Our hypothesis was that inactivation of cAMP-specific phosphodiesterases (PDEs) would inhibit angiogenesis. The purpose of this study was to evaluate the effect of PDE inhibitors on in vitro and in vivo angiogenesis, using human umbilical vein endothelial cell (HUVEC) and chick chorioallantoic membrane (CAM) models respectively. Here, we report that: 1) PDE2, PDE3, PDE4 and PDE5 are expressed in HUVEC; 2) EHNA (20 µM), PDE2 selective inhibitor, and RP73401 (10 µM), PDE4 selective inhibitor, are able to increase the intracellular cAMP level in HUVEC; 3) EHNA and RP73401 are able to inhibit proliferation, cell cycle progression and migration of HUVEC stimulated by VEGF; 4) these in vitro effects can be mimic by treating HUVEC with the cAMP analogue, 8-Br-cAMP (600 µM); 5) only the association of EHNA and RP73401 inhibits in vivo angiogenesis, indicating that both migration and proliferation must be inhibited. These data strongly suggest that PDE2 and PDE4 represent new potential therapeutic targets in pathological angiogenesis.
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Mokra, Daniela, and Juraj Mokry. "Phosphodiesterase Inhibitors in Acute Lung Injury: What Are the Perspectives?" International Journal of Molecular Sciences 22, no. 4 (February 16, 2021): 1929. http://dx.doi.org/10.3390/ijms22041929.
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Despite progress in understanding the pathophysiology of acute lung damage, currently approved treatment possibilities are limited to lung-protective ventilation, prone positioning, and supportive interventions. Various pharmacological approaches have also been tested, with neuromuscular blockers and corticosteroids considered as the most promising. However, inhibitors of phosphodiesterases (PDEs) also exert a broad spectrum of favorable effects potentially beneficial in acute lung damage. This article reviews pharmacological action and therapeutical potential of nonselective and selective PDE inhibitors and summarizes the results from available studies focused on the use of PDE inhibitors in animal models and clinical studies, including their adverse effects. The data suggest that xanthines as representatives of nonselective PDE inhibitors may reduce acute lung damage, and decrease mortality and length of hospital stay. Various (selective) PDE3, PDE4, and PDE5 inhibitors have also demonstrated stabilization of the pulmonary epithelial–endothelial barrier and reduction the sepsis- and inflammation-increased microvascular permeability, and suppression of the production of inflammatory mediators, which finally resulted in improved oxygenation and ventilatory parameters. However, the current lack of sufficient clinical evidence limits their recommendation for a broader use. A separate chapter focuses on involvement of cyclic adenosine monophosphate (cAMP) and PDE-related changes in its metabolism in association with coronavirus disease 2019 (COVID-19). The chapter illuminates perspectives of the use of PDE inhibitors as an add-on treatment based on actual experimental and clinical trials with preliminary data suggesting their potential benefit.
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Cheng, Jingfei, Michael A. Thompson, Henry J. Walker, Catherine E. Gray, Gina M. Warner, Wei Zhou, and Joseph P. Grande. "Lixazinone Stimulates Mitogenesis of Madin-Darby Canine Kidney Cells." Experimental Biology and Medicine 231, no. 3 (March 2006): 288–95. http://dx.doi.org/10.1177/153537020623100308.
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Polycystic kidney diseases (PKD) are characterized by excessive proliferation of renal tubular epithelial cells, development of fluid-filled cysts, and progressive renal insufficiency. cAMP inhibits proliferation of normal renal tubular epithelial cells but stimulates proliferation of renal tubular epithelial cells derived from patients with PKD. Madin-Darby canine kidney (MDCK) epithelial cells, which are widely used as an in vitro model of cystogenesis, also proliferate in response to cAMP. Intracellular cAMP levels are tightly regulated by phosphodiesterases (PDE). Isoform-specific PDE inhibitors have been developed as therapeutic agents to regulate signaling pathways directed by cAMP. In other renal cell types, we have previously demonstrated that cAMP is hydrolyzed by PDE3 and PDE4, but only PDE3 inhibitors suppress proliferation by inhibiting Raf-1 activity (Cheng J, Thompson MA, Walker HJ, Gray CE, Diaz Encarnacion MM, Warner GM, Grande JP. Am J Physiol Renal Physiol 287:F940-F953, 2004.) A potential role for PDE isoform(s) in cAMP-mediated proliferation of MDCK cells has not previously been established. Similar to what we have previously found in several other renal cell types, cAMP hydrolysis in MDCK cells is directed primarily by PDE4 (85% of total activity) and PDE3 (15% of total activity). PDE4 inhibitors are more effective than PDE3 inhibitors in increasing intracellular cAMP levels in MDCK cells. However, only PDE3 inhibitors, and not PDE4 inhibitors, stimulate mitogenesis of MDCK cells. PDE3 but not PDE4 inhibitors activate B-Raf but not Raf-1, as assessed by an in vitro kinase assay. PDE3 but not PDE4 inhibitors activate the ERK pathway and activate cyclins D and E, as assessed by histone H1 kinase assay. We conclude that mitogenesis of MDCK cells is regulated by a functionally compartmentalized intracellular cAMP pool directed by PDE3. Pharmacologic agents that stimulate PDE3 activity may provide the basis for new therapies directed toward reducing cystogenesis in patients with PKD.
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Ogawa, Ryosuke, Michael B. Streiff, Artem Bugayenko, and Gregory J. Kato. "Inhibition of PDE4 phosphodiesterase activity induces growth suppression, apoptosis, glucocorticoid sensitivity, p53, and p21WAF1/CIP1 proteins in human acute lymphoblastic leukemia cells." Blood 99, no. 9 (May 1, 2002): 3390–97. http://dx.doi.org/10.1182/blood.v99.9.3390.
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Abstract Glucocorticoids are integral to successful treatment of childhood acute lymphoblastic leukemia (ALL) and other lymphoid malignancies. A large body of data indicates that in various model systems, elevation of cyclic adenosine monophosphate (cAMP) can potentiate glucocorticoid response, although this has not been well evaluated as a potential leukemia treatment. Although cAMP analogs have been studied, little data exist regarding the potential toxicity to leukemia cells of pharmacologic elevation of cAMP levels in leukemic blasts. Using MTT assays of cell proliferation on CEM ALL cells, we found that aminophylline and other nonspecific phosphodiesterase (PDE) inhibitors suppress cell growth. This effect is replicated by the PDE4-specific PDE inhibitor rolipram, but not by specific inhibitors of the PDE1 or PDE3 classes. We found that PDE inhibitors cause increased dexamethasone sensitivity and a synergistic effect with the adenylyl cyclase activator forskolin. We observed several important cellular characteristics associated with this treatment, including elevation of cAMP, induction of p53 and p21WAF1/CIP1proteins, G1 and G2/M cell cycle arrest, and increased apoptosis. Sensitivity to forskolin and rolipram is shared by at least 2 pediatric ALL cell lines, CEM and Reh cells. Some cell lines derived from adult-type lymphoid malignancies also show sensitivity to this treatment. These findings suggest that PDE inhibitors have therapeutic potential in human ALL and characterize the molecular mechanisms that may be involved in this response.
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Cote, R. H. "Characteristics of Photoreceptor PDE (PDE6): similarities and differences to PDE5." International Journal of Impotence Research 16, S1 (June 2004): S28—S33. http://dx.doi.org/10.1038/sj.ijir.3901212.
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Bloom, Timothy J. "Age-related alterations in cyclic nucleotide phosphodiesterase activity in dystrophic mouse leg muscle." Canadian Journal of Physiology and Pharmacology 83, no. 11 (November 1, 2005): 1055–60. http://dx.doi.org/10.1139/y05-085.
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Previous reports have described both increased and decreased cyclic nucleotide phosphodiesterase (PDE) activity in dystrophic muscle. Total PDE activity was measured in hind leg muscle from a mouse model of Duchenne muscular dystrophy (mdx) and a genetic control strain at 5, 8, 10, and 15 weeks of age. Total PDE activity declined in fractions isolated from mdx muscle over this time period, but was stable in fractions from control mice. Compared with age-matched controls, younger mdx muscle had higher cAMP and cGMP PDE activity. However, at 15 weeks, fractions from both strains had similar cGMP PDE activity and mdx fractions had lower cAMP PDE activity than controls. Particulate fractions from mdx muscle showed an age-related decline in sensitivity to the PDE4 inhibitor RO 20-1724. A similar loss of sensitivity to the PDE2 inhibitor erythro-9-(2-hydroxyl-3-nonyl)-adenine (EHNA) was seen in a particulate fraction from mdx muscle and to a lesser degree in control muscle. These results suggest that the earlier disagreement regarding altered cyclic nucleotide metabolism in dystrophic muscle may be due to changes with age in PDE activity of dystrophic tissue. The age-related decline in particulate PDE activity seen in dystrophic muscle appears to be isozyme-specific and not due to a generalized decrease in total PDE activity.Key words: cyclic nucleotide phosphodiesterase, muscular dystrophy, mouse, RO 20-1724, EHNA.
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Spence, S., G. Rena, G. Sweeney, and M. D. Houslay. "Induction of Ca2+/calmodulin-stimulated cyclic AMP phosphodiesterase (PDE1) activity in Chinese hamster ovary cells (CHO) by phorbol 12-myristate 13-acetate and by the selective overexpression of protein kinase C isoforms." Biochemical Journal 310, no. 3 (September 15, 1995): 975–82. http://dx.doi.org/10.1042/bj3100975.
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The cAMP phosphodiesterase (PDE) activity of CHO cells was unaffected by the addition of Ca2+ +calmodulin (CaM), indicating the absence of any PDE1 (Ca2+/CaM-stimulated PDE) activity. Treatment with the tumour promoting phorbol ester phorbol 12-myristate 13-acetate (PMA) led to the rapid transient induction of PDE1 activity which attained a maximum value after about 13 h before slowly decreasing. Such induction was attenuated by actinomycin D. PCR primers were designed to hybridize with two regions identified as being characteristic of PDE1 forms found in various species and predicted to amplify a 601 bp fragment. RT-PCR using degenerate primers allowed an approx. 600 bp fragment to be amplified from RNA preparations of rat brain but not from CHO cells unless they had been treated with PMA. CHO cells transfected to overexpress protein kinase C (PKC)-alpha and PKC-epsilon, but not those transfected to overexpress PKC-beta I or PKC-gamma, exhibited a twofold higher PDE activity. They also expressed a PDE1 activity, with Ca2+/CaM effecting a 1.8-2.8-fold increase in total PDE activity. RT-PCR, with PDE1-specific primers, identified an approx. 600 bp product in CHO cells transfected to overexpress PKC-alpha and PKC-epsilon, but not in those overexpressing PKC-beta I or PKC-gamma. Treatment of PKC-alpha transfected cells with PMA caused a rapid, albeit transient, increase in PDE1 activity, which reached a maximum some 1 h after PMA challenge, before returning to resting levels some 2 h later. The residual isobutylmethylxanthine (IBMX)-insensitive PDE activity was dramatically reduced (approx. 4-fold) in the PKC-gamma transfectants, suggesting that the activity of the cyclic AMP-specific IBMX-insensitive PDE7 activity was selectively reduced by overexpression of this particular PKC isoform. These data identify a novel point of ‘cross-talk’ between the lipid and cyclic AMP signalling systems where the action of specific PKC isoforms is shown to cause the induction of Ca2+/CaM-stimulated PDE (PDE1) activity. It is suggested that this protein kinase C-mediated process might involve regulation of PDE1 gene expression by the AP-1 (fos/jun) system.
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Wang, Ya-Juan, Shun-De Song, Jun-Chun Chen, Xue-Feng Wang, Ya-Li Jiang, Qiang-Min Xie, Ji-Qiang Chen, Zi-Gang Li, and Hui-Fang Tang. "Effects of InactivatedBordetella pertussison Phosphodiesterase in the Lung of Ovalbumin Sensitized and Challenged Rats." Pulmonary Medicine 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/581738.
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This paper indicated that inactivatedBordetella pertussis(iBp) can enhance the lung airway hyperreactivity of the rats sensitized and challenged with OVA. The mechanisms were involved in the upregulation of cAMP-PDE activity and PDE4A, PDE4D, and PDE3 gene expression in the lungs. But only PDE4 activity was different between the OVA and OVA+iBp groups, and PDE4D expression was significantly increased in iBp rats alone. So, our data suggested that cosensitization with OVA and iBp affects lung airway reactivity by modulating the lung cAMP-PDE activity and PDE4D gene expression.
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Mussen, Femke, Jana Van Broeckhoven, Niels Hellings, Melissa Schepers, and Tim Vanmierlo. "Unleashing Spinal Cord Repair: The Role of cAMP-Specific PDE Inhibition in Attenuating Neuroinflammation and Boosting Regeneration after Traumatic Spinal Cord Injury." International Journal of Molecular Sciences 24, no. 9 (May 2, 2023): 8135. http://dx.doi.org/10.3390/ijms24098135.
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Traumatic spinal cord injury (SCI) is characterized by severe neuroinflammation and hampered neuroregeneration, which often leads to permanent neurological deficits. Current therapies include decompression surgery, rehabilitation, and in some instances, the use of corticosteroids. However, the golden standard of corticosteroids still achieves minimal improvements in functional outcomes. Therefore, new strategies tackling the initial inflammatory reactions and stimulating endogenous repair in later stages are crucial to achieving functional repair in SCI patients. Cyclic adenosine monophosphate (cAMP) is an important second messenger in the central nervous system (CNS) that modulates these processes. A sustained drop in cAMP levels is observed during SCI, and elevating cAMP is associated with improved functional outcomes in experimental models. cAMP is regulated in a spatiotemporal manner by its hydrolyzing enzyme phosphodiesterase (PDE). Growing evidence suggests that inhibition of cAMP-specific PDEs (PDE4, PDE7, and PDE8) is an important strategy to orchestrate neuroinflammation and regeneration in the CNS. Therefore, this review focuses on the current evidence related to the immunomodulatory and neuroregenerative role of cAMP-specific PDE inhibition in the SCI pathophysiology.
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Hovmöller, Sven, Linus Hovmöller Zou, Xiaodong Zou, and Benjamin Grushko. "Structures of pseudo-decagonal approximants in Al−Co−Ni." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1969 (June 28, 2012): 2949–59. http://dx.doi.org/10.1098/rsta.2011.0310.
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Quasi-crystals shocked the crystallographic world when they were reported in 1984. We now know that they are not a rare exception, and can be found in many alloy systems. One of the richer systems for quasi-crystals and their approximants is Al−Co−Ni. A large series of pseudo-decagonal (PD) approximants have been found. Only two of them, PD4 and PD8, have been solved by X-ray crystallography. We report here the structures of PD1, PD2, PD3 and PD5, solved from the limited information that is provided by electron diffraction patterns, unit cell dimensions and high-resolution electron microscopy images.
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Ivey, F. Douglas, Lili Wang, Didem Demirbas, Christina Allain, and Charles S. Hoffman. "Development of a Fission Yeast-Based High-Throughput Screen to Identify Chemical Regulators of cAMP Phosphodiesterases." Journal of Biomolecular Screening 13, no. 1 (November 26, 2007): 62–71. http://dx.doi.org/10.1177/1087057107312127.
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Cyclic nucleotide phosphodiesterases (PDEs) comprise a superfamily of enzymes that serve as drug targets in many human diseases. There is a continuing need to identify high-specificity inhibitors that affect individual PDE families or even subtypes within a single family. The authors describe a fission yeast-based high-throughput screen to detect inhibitors of heterologously expressed adenosine 3′,5′-cyclic monophosphate (cAMP) PDEs. The utility of this system is demonstrated by the construction and characterization of strains that express mammalian PDE2A, PDE4A, PDE4B, and PDE8A and respond appropriately to known PDE2A and PDE4 inhibitors. High-throughput screens of 2 bioactive compound libraries for PDE inhibitors using strains expressing PDE2A, PDE4A, PDE4B, and the yeast PDE Cgs2 identified known PDE inhibitors and members of compound classes associated with PDE inhibition. The authors verified that the furanocoumarin imperatorin is a PDE4 inhibitor based on its ability to produce a PDE4-specific elevation of cAMP levels. This platform can be used to identify PDE activators, as well as genes encoding PDE regulators, which could serve as targets for future drug screens. ( Journal of Biomolecular Screening 2008:62-71)
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Tulsian, Nikhil K., Valerie Jia-En Sin, Hwee-Ling Koh, and Ganesh S. Anand. "Development of Phosphodiesterase–Protein-Kinase Complexes as Novel Targets for Discovery of Inhibitors with Enhanced Specificity." International Journal of Molecular Sciences 22, no. 10 (May 15, 2021): 5242. http://dx.doi.org/10.3390/ijms22105242.
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Phosphodiesterases (PDEs) hydrolyze cyclic nucleotides to modulate multiple signaling events in cells. PDEs are recognized to actively associate with cyclic nucleotide receptors (protein kinases, PKs) in larger macromolecular assemblies referred to as signalosomes. Complexation of PDEs with PKs generates an expanded active site that enhances PDE activity. This facilitates signalosome-associated PDEs to preferentially catalyze active hydrolysis of cyclic nucleotides bound to PKs and aid in signal termination. PDEs are important drug targets, and current strategies for inhibitor discovery are based entirely on targeting conserved PDE catalytic domains. This often results in inhibitors with cross-reactivity amongst closely related PDEs and attendant unwanted side effects. Here, our approach targeted PDE–PK complexes as they would occur in signalosomes, thereby offering greater specificity. Our developed fluorescence polarization assay was adapted to identify inhibitors that block cyclic nucleotide pockets in PDE–PK complexes in one mode and disrupt protein-protein interactions between PDEs and PKs in a second mode. We tested this approach with three different systems—cAMP-specific PDE8–PKAR, cGMP-specific PDE5–PKG, and dual-specificity RegA–RD complexes—and ranked inhibitors according to their inhibition potency. Targeting PDE–PK complexes offers biochemical tools for describing the exquisite specificity of cyclic nucleotide signaling networks in cells.
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Rickles, Richard J., Laura Pierce, Thomas Giordano, Winnie F. Tam, Douglas W. McMillin, Kenneth C. Anderson, Constantine Mitsiades, and Margaret S. Lee. "Adenosine A2A Receptor Agonism and PDE Inhibition: A Synergistic Multi-Target Mechanism Discovered through Systematic Combination Screening in Multiple Myeloma." Blood 112, no. 11 (November 16, 2008): 847. http://dx.doi.org/10.1182/blood.v112.11.847.847.
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Abstract Using a combination high throughput screening technology, we have discovered an unexpected synergistic interaction between adenosine A2A receptor (A2A) agonism and phosphodiesterase (PDE) inhibition that displays substantial activity in preclinical Multiple Myeloma (MM) models. High throughput combination screening allows the systematic testing of combinations of approved drugs and other biologically active molecules in cell based assays of tumor cell proliferation and viability. In this approach we generate a dose matrix for each chemical combination, capturing the combined activity of two compounds over a broad range of single agent concentrations. Quantitative scoring of dose response matrices using models of drug interactions allows insight into the biological mechanism of action of drug combinations and the discovery of novel therapeutic applications. Using a panel of 4 MM cell lines (H929, MM.1S, MM.1R and RPMI-8226) we evaluated a defined set of combinations of approved drugs and molecular probes. A total of 2841 unique combinations were evaluated, 648 of which were assayed in all 4 cell lines. Multiple combinations were identified that exceeded the Loewe additivity model including enhancers of known anti-cancer drugs and combinations of targets not previously know in multiple myeloma. Multiple classes of drugs and targeted agents were identified that synergize with dexamethasone. Backcrosses of these active agents revealed multiple dexamethasone enhancers that also synergized with each other. Two of these classes, A2A agonists and PDE inhibitors demonstrated high levels of synergy and good breadth of activity across several MM cell lines. Interestingly, while the majority of the combinations screened had little or no synergistic effect in the glucocorticoid resistant MM.1R cell line, combinations of PDE inhibitors and A2A agonists demonstrated substantial efficacy (>90% inhibition of proliferation) and striking synergy (combination indices<0.3) in this cell line. We have used panels of selective adenosine receptor agonists, antagonists and PDE inhibitors as well as siRNAs targeting specific molecular isoforms of these proteins to dissect the molecular mechanism of this synergy. All adenosine receptor agonists tested synergize with the multi-PDE isoform inhibitor trequinsin. Synergy between the A2A agonist Chloro-IB-MECA and trequinsin is suppressed by the adenosine A2A antagonist SCH58261 at 78 nM but not by the A1, A2B or A3 antagonists DPCPX, MRS1754 and MRS1523 respectively, demonstrating that A2A agonism is the necessary component of the synergistic multi-target mechanism. Furthermore, siRNA knockdown of adenosine A2A but not A1, A2B or A3 receptors blocks the activity of all adenosine receptor agonists examined. Similarly, using 22 subtype specific PDE inhibitors, we find that the specific subset of PDE2, 3, 4 and 7, are able to synergize with A2A agonists. By combining subtype inhibitors and/or siRNAs targeting specific PDE isoforms we find that maximal activity is observed when more than one PDE is targeted. Inhibition of both PDE3 and 4 results in the greatest synergy, with further enhancement from the addition of PDE2 and/or PDE7 inhibition. During treatment with A2A agonists and PDE inhibitors there is a compensatory 13-fold up-regulation of PDE4B, as measured by qPCR, suggesting that inhibition of this isoform is particularly important for maximal antiproliferative activity. We find that neither A2A agonism nor PDE inhibition alone induces cAMP accumulation in MM cell lines. However, the combination of A2A activation and PDE inhibition leads to elevated intracellular cAMP and cell death. Notably, the activity of A2A agonists is enhanced in the presence of 10 ng/mL interleukin-6 and HS-5 human bone marrow stromal cells and the synergy between A2A agonists and PDE inhibitors is preserved under these conditions. In summary, we describe the use of cHTS screening to discover new synergistic multi-target mechanisms and prioritize synergistic anti-proliferative combinations for preclinical evaluation. This approach has resulted in the discovery of adenosine A2A receptor agonism and PDE inhibition as a highly selective and synergistic multi-target mechanism with therapeutic potential in MM.
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Foureau, Anna V. Ivanina, David M. Foureau, Carol J. Farhangfar, and Kathryn F. Mileham. "Abstract 281: Phosphodiesterase 8/9 inhibition to sensitize squamous non-small cell lung cancer (NSCLC) to pemetrexed (PMX): A double-edge strategy." Cancer Research 83, no. 7_Supplement (April 4, 2023): 281. http://dx.doi.org/10.1158/1538-7445.am2023-281.
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Abstract Introduction. Phosphosidesterases (PDE) are key regulators of cyclic nucleotide (cAMP/cGMP) signaling regulating many cellular processes including cell proliferation, growth arrest and apoptosis. In squamous NSCLC (SCC), PDE inhibitors (PDEi) have shown anti-tumor activity both as single agent and in combination with chemotherapy. A strong putative synergistic mechanistic activity exists between pemetrexed (PMX) and PDEi through cAMP/Protein kinase A (PKA) and cGMP/Protein Kinase G signaling. We therefore thought to investigate whether SCC, classically resistance to PMX can be sensitized to the drug through PDE inhibition. Methods. Whole exome sequencing and survival data from TCGA was surveyed to identify PDEs most closely associated with clinical outcome in NSCLC. Whole exome sequencing data from GEmiCCL database were used to select SCC cell lines with unaltered PDE genes. Two SCC cell lines (H226, H1703) were evaluated for viability (WST8 assay), proliferation and apoptosis (Apo-Tox-Glo assay) after treatment with PMX with or without sildenafil citrate, PF-04671536 or PF-04447943 (PDE5i, PDE8i and PDE9i respectively). PDE expression was quantified by qPCR and Western Blot (WB). PDE activity and downstream signaling was quantified by measuring PKA/PKG target activation (PKA/pVASP157, PKG/pVAP239). Results. Presence of function altering mutations in PDE8 (cAMP/PKA signaling) and PDE9 (cGMP/PKG signaling) improved NSCLC overall survival (P<0.1). PDE5 (cGMP/PKG signaling) mutations had no significant clinical impact. Both SCC cell lines investigated expressed high level of PDE8-9, but H1703 had only trace levels of PDE5. Endogenous PKA activity and PKG activity was significantly lower in H1703 cells compared with H226. PDEi stimulated SCC cell growth (30-60% increase). PDE8i and PDE9i (EC50<40nM, significant PKA/PKG activation) were more potent than PDE5i (>1.5µM, no PKA/PKG activation). PMX also displayed a pro-mitotic activity toward SCC (40% increase at 250µM) coupled with significant PKA activation in H226 and PKG activation in H1703 cells. Combination of PDE5i, 8i or 9i (2X EC50 concentrations) with low dose PMX (0.025µM) inhibited SCC cell growth, H1703 showing greater response than H226 (30-37% vs 8-11% growth reduction). No cell death, necrosis or apoptosis, was detected. This cytostatic activity of PDEi combination treatment was not observed at high dose PMX (250µM). Conclusions. In the absence of PDE mutations, single agent PDE5i, 8i and 9i promote SCC growth with PDE8,9i displaying a far greater potency than PDE5i. PMX is also pro-mitotic toward SCC cells but PDE5i, 8i, and PDE9i can sensitize SCC cells to the drug. SCC cells with lower endogenous PKA/PKG activity are more sensitive to PDEi+PMX treatment. This combination is not cytotoxic though, rather is cytostatic, and displays a very narrow window of therapeutic activity. Citation Format: Anna V. Ivanina Foureau, David M. Foureau, Carol J. Farhangfar, Kathryn F. Mileham. Phosphodiesterase 8/9 inhibition to sensitize squamous non-small cell lung cancer (NSCLC) to pemetrexed (PMX): A double-edge strategy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 281.
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Zheng, Yang, Susanne Schroeder, Georgi K. Kanev, Sanaa S. Botros, Samia William, Abdel-Nasser A. Sabra, Louis Maes, et al. "To Target or Not to Target Schistosoma mansoni Cyclic Nucleotide Phosphodiesterase 4A?" International Journal of Molecular Sciences 24, no. 7 (April 6, 2023): 6817. http://dx.doi.org/10.3390/ijms24076817.
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Schistosomiasis is a neglected tropical disease with high morbidity. Recently, the Schistosoma mansoni phosphodiesterase SmPDE4A was suggested as a putative new drug target. To support SmPDE4A targeted drug discovery, we cloned, isolated, and biochemically characterized the full-length and catalytic domains of SmPDE4A. The enzymatically active catalytic domain was crystallized in the apo-form (PDB code: 6FG5) and in the cAMP- and AMP-bound states (PDB code: 6EZU). The SmPDE4A catalytic domain resembles human PDE4 more than parasite PDEs because it lacks the parasite PDE-specific P-pocket. Purified SmPDE4A proteins (full-length and catalytic domain) were used to profile an in-house library of PDE inhibitors (PDE4NPD toolbox). This screening identified tetrahydrophthalazinones and benzamides as potential hits. The PDE inhibitor NPD-0001 was the most active tetrahydrophthalazinone, whereas the approved human PDE4 inhibitors roflumilast and piclamilast were the most potent benzamides. As a follow-up, 83 benzamide analogs were prepared, but the inhibitory potency of the initial hits was not improved. Finally, NPD-0001 and roflumilast were evaluated in an in vitro anti-S. mansoni assay. Unfortunately, both SmPDE4A inhibitors were not effective in worm killing and only weakly affected the egg-laying at high micromolar concentrations. Consequently, the results with these SmPDE4A inhibitors strongly suggest that SmPDE4A is not a suitable target for anti-schistosomiasis therapy.
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Nikawa, J., P. Sass, and M. Wigler. "Cloning and characterization of the low-affinity cyclic AMP phosphodiesterase gene of Saccharomyces cerevisiae." Molecular and Cellular Biology 7, no. 10 (October 1987): 3629–36. http://dx.doi.org/10.1128/mcb.7.10.3629-3636.1987.
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Saccharomyces cerevisiae contains two genes which encode cyclic AMP (cAMP) phosphodiesterase. We previously isolated and characterized PDE2, which encodes a high-affinity cAMP phosphodiesterase. We have now isolated the PDE1 gene of S. cerevisiae, which encodes a low-affinity cAMP phosphodiesterase. These two genes represent highly divergent branches in the evolution of phosphodiesterases. High-copy-number plasmids containing either PDE1 or PDE2 can reverse the growth arrest defects of yeast cells carrying the RAS2(Val-19) mutation. PDE1 and PDE2 appear to account for the aggregate cAMP phosphodiesterase activity of S. cerevisiae. Disruption of both PDE genes results in a phenotype which resembles that induced by the RAS2(Val-19) mutation. pde1- pde2- ras1- ras2- cells are viable.
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Nikawa, J., P. Sass, and M. Wigler. "Cloning and characterization of the low-affinity cyclic AMP phosphodiesterase gene of Saccharomyces cerevisiae." Molecular and Cellular Biology 7, no. 10 (October 1987): 3629–36. http://dx.doi.org/10.1128/mcb.7.10.3629.
Full textAbstract:
Saccharomyces cerevisiae contains two genes which encode cyclic AMP (cAMP) phosphodiesterase. We previously isolated and characterized PDE2, which encodes a high-affinity cAMP phosphodiesterase. We have now isolated the PDE1 gene of S. cerevisiae, which encodes a low-affinity cAMP phosphodiesterase. These two genes represent highly divergent branches in the evolution of phosphodiesterases. High-copy-number plasmids containing either PDE1 or PDE2 can reverse the growth arrest defects of yeast cells carrying the RAS2(Val-19) mutation. PDE1 and PDE2 appear to account for the aggregate cAMP phosphodiesterase activity of S. cerevisiae. Disruption of both PDE genes results in a phenotype which resembles that induced by the RAS2(Val-19) mutation. pde1- pde2- ras1- ras2- cells are viable.
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Xin, Wenkuan, Wei P. Feinstein, Andrea L. Britain, Cristhiaan D. Ochoa, Bing Zhu, Wito Richter, Silas J. Leavesley, and Thomas C. Rich. "Estimating the magnitude of near-membrane PDE4 activity in living cells." American Journal of Physiology-Cell Physiology 309, no. 6 (September 15, 2015): C415—C424. http://dx.doi.org/10.1152/ajpcell.00090.2015.
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Recent studies have demonstrated that functionally discrete pools of phosphodiesterase (PDE) activity regulate distinct cellular functions. While the importance of localized pools of enzyme activity has become apparent, few studies have estimated enzyme activity within discrete subcellular compartments. Here we present an approach to estimate near-membrane PDE activity. First, total PDE activity is measured using traditional PDE activity assays. Second, known cAMP concentrations are dialyzed into single cells and the spatial spread of cAMP is monitored using cyclic nucleotide-gated channels. Third, mathematical models are used to estimate the spatial distribution of PDE activity within cells. Using this three-tiered approach, we observed two pharmacologically distinct pools of PDE activity, a rolipram-sensitive pool and an 8-methoxymethyl IBMX (8MM-IBMX)-sensitive pool. We observed that the rolipram-sensitive PDE (PDE4) was primarily responsible for cAMP hydrolysis near the plasma membrane. Finally, we observed that PDE4 was capable of blunting cAMP levels near the plasma membrane even when 100 μM cAMP were introduced into the cell via a patch pipette. Two compartment models predict that PDE activity near the plasma membrane, near cyclic nucleotide-gated channels, was significantly lower than total cellular PDE activity and that a slow spatial spread of cAMP allowed PDE activity to effectively hydrolyze near-membrane cAMP. These results imply that cAMP levels near the plasma membrane are distinct from those in other subcellular compartments; PDE activity is not uniform within cells; and localized pools of AC and PDE activities are responsible for controlling cAMP levels within distinct subcellular compartments.
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Kopanitsa, Liliya, Maksym V. Kopanitsa, Dewi Safitri, Graham Ladds, and David S. Bailey. "Suppression of Proliferation of Human Glioblastoma Cells by Combined Phosphodiesterase and Multidrug Resistance-Associated Protein 1 Inhibition." International Journal of Molecular Sciences 22, no. 18 (September 7, 2021): 9665. http://dx.doi.org/10.3390/ijms22189665.
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The paucity of currently available therapies for glioblastoma multiforme requires novel approaches to the treatment of this brain tumour. Disrupting cyclic nucleotide-signalling through phosphodiesterase (PDE) inhibition may be a promising way of suppressing glioblastoma growth. Here, we examined the effects of 28 PDE inhibitors, covering all the major PDE classes, on the proliferation of the human U87MG, A172 and T98G glioblastoma cells. The PDE10A inhibitors PF-2545920, PQ10 and papaverine, the PDE3/4 inhibitor trequinsin and the putative PDE5 inhibitor MY-5445 potently decreased glioblastoma cell proliferation. The synergistic suppression of glioblastoma cell proliferation was achieved by combining PF-2545920 and MY-5445. Furthermore, a co-incubation with drugs that block the activity of the multidrug resistance-associated protein 1 (MRP1) augmented these effects. In particular, a combination comprising the MRP1 inhibitor reversan, PF-2545920 and MY-5445, all at low micromolar concentrations, afforded nearly complete inhibition of glioblastoma cell growth. Thus, the potent suppression of glioblastoma cell viability may be achieved by combining MRP1 inhibitors with PDE inhibitors at a lower toxicity than that of the standard chemotherapeutic agents, thereby providing a new combination therapy for this challenging malignancy.
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Day, Jonathan P., Miles D. Houslay, and Shireen-A. Davies. "A novel role for a Drosophila homologue of cGMP-specific phosphodiesterase in the active transport of cGMP." Biochemical Journal 393, no. 2 (December 23, 2005): 481–88. http://dx.doi.org/10.1042/bj20051505.
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cGMP was first discovered in urine, demonstrating that kidney cells extrude this cyclic nucleotide. Drosophila Malpighian tubules provide a model renal system in which a homologue of mammalian PDE (phosphodiesterase) 6 is expressed. In humans, this cG-PDE (cGMP-specific PDE) is specifically expressed in the retinal system, where it controls visual signal transduction. In order to gain insight into the functional role of DmPDE6 (Drosophila PDE6-like enzyme) in epithelial function, we generated transgenic animals with targeted expression of DmPDE6 to tubule Type I (principal) cells. This revealed localization of DmPDE6 primarily at the apical membranes. As expected, overexpression of DmPDE6 resulted in elevated cG-PDE activity and decreased tubule cGMP content. However, such targeted overexpression of DmPDE6 creates a novel phenotype that manifests itself in inhibition of the active transport and efflux of cGMP by tubules. This effect is specific to DmPDE6 action, as no effect on cGMP transport is observed in tubules from a bovine PDE5 transgenic line which display reduced rates of fluid secretion, an effect not seen in DmPDE6 transgenic animals. Specific ablation of DmPDE6 in tubule principal cells, via expression of a targeted DmPDE6 RNAi (RNA interference) transgene, conferred increased active transport of cGMP, confirming a direct role for DmPDE6 in regulating cGMP transport in tubule principal cells. Pharmacological inhibition of DmPDE6 in wild-type tubules using the cG-PDE inhibitor, zaprinast, similarly results in stimulated cGMP transport. We provide the first demonstration of a novel role for a cG-PDE in modulating cGMP transport and efflux.
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Meima, Marcel E., Ricardo M. Biondi, and Pauline Schaap. "Identification of a Novel Type of cGMP Phosphodiesterase That Is Defective in the ChemotacticstmFMutants." Molecular Biology of the Cell 13, no. 11 (November 2002): 3870–77. http://dx.doi.org/10.1091/mbc.e02-05-0285.
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StmF mutants are chemotactic mutants that are defective in a cGMP phosphodiesterase (PDE) activity. We identified a novel gene, PdeD, that harbors two cyclic nucleotide–binding domains and a metallo-β-lactamase homology domain. Similar to stmF mutants,pdeD-null mutants displayed extensively streaming aggregates, prolonged elevation of cGMP levels after chemotactic stimulation, and reduced cGMP-PDE activity. PdeDtranscripts were lacking in stmF mutant NP377, indicating that this mutant carries a PdeD lesion. Expression of a PdeD-YFP fusion protein in pdeD-null cells restored the normal cGMP response and showed that PdeD resides in the cytosol. When purified by immunoprecipitation, the PdeD-YFP fusion protein displayed cGMP-PDE activity, which was retained in a truncated construct that contained only the metallo-β-lactamase domain.
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Hanson, Kimberly A., James W. Ziegler, Sergei D. Rybalkin, Jim W. Miller, Steven H. Abman, and William R. Clarke. "Chronic pulmonary hypertension increases fetal lung cGMP phosphodiesterase activity." American Journal of Physiology-Lung Cellular and Molecular Physiology 275, no. 5 (November 1, 1998): L931—L941. http://dx.doi.org/10.1152/ajplung.1998.275.5.l931.
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An experimental ovine fetal model for perinatal pulmonary hypertension of the neonate (PPHN) was characterized by altered pulmonary vasoreactivity and structure. Because past studies had suggested impaired nitric oxide-cGMP cascade in this experimental model, we hypothesized that elevated phosphodiesterase (PDE) activity may contribute to altered vascular reactivity and structure in experimental PPHN. Therefore, we studied the effects of the PDE inhibitors zaprinast and dipyridamole on fetal pulmonary vascular resistance and PDE5 activity, protein, mRNA, and localization in normal and pulmonary hypertensive fetal lambs. Infusion of dipyridamole and zaprinast lowered pulmonary vascular resistance by 55 and 35%, respectively, in hypertensive animals. In comparison with control animals, lung cGMP PDE activity was elevated in hypertensive fetal lambs (150%). Increased PDE5 activity was not associated with either an increased PDE5 protein or mRNA level. Immunocytochemistry demonstrated that PDE5 was localized to vascular smooth muscle. We concluded that PDE5 activity was increased in experimental PPHN, possibly by posttranslational phosphorylation. We speculated that these increases in cGMP PDE activity contributed to altered pulmonary vasoreactivity in experimental perinatal pulmonary hypertension.
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Murray, Fiona, Hemal H. Patel, Ryan Y. S. Suda, Shen Zhang, Patricia A. Thistlethwaite, Jason X. J. Yuan, and Paul A. Insel. "Expression and activity of cAMP phosphodiesterase isoforms in pulmonary artery smooth muscle cells from patients with pulmonary hypertension: role for PDE1." American Journal of Physiology-Lung Cellular and Molecular Physiology 292, no. 1 (January 2007): L294—L303. http://dx.doi.org/10.1152/ajplung.00190.2006.
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Pulmonary hypertension (PHT) is associated with increased vascular resistance due to sustained contraction and enhanced proliferation of pulmonary arterial smooth muscle cells (PASMC); the abnormal tone and remodeling in the pulmonary vasculature may relate, at least in part, to decreased cyclic nucleotide levels. Cyclic nucleotide phosphodiesterases (PDEs), of which 11 families have been identified, catalyze the hydrolysis of cAMP and cGMP. We tested the hypothesis that PASMC isolated from patients with PHT, either idiopathic pulmonary arterial hypertension (IPAH) or secondary pulmonary hypertension (SPH), have increased expression and activity of PDE isoforms that reduce the responsiveness of agents that raise cellular cAMP. Real-time PCR and immunoblotting demonstrated that the expression of PDE1A, PDE1C, PDE3B, and PDE5A was enhanced in PASMC from both IPAH and SPH patients compared with control PASMC. Consistent with this enhanced expression of PDEs, agonist-stimulated cAMP levels were significantly reduced in IPAH and SPH PASMC unless a PDE inhibitor was present. The use of specific PDE inhibitors revealed that an increase in PDE1 and PDE3 activity largely accounted for reduced agonist-induced cAMP levels and increased proliferation in IPAH and SPH PASMC. Treatment with PDE1C-targeted small interference RNA enhanced cAMP accumulation and inhibited cellular proliferation to a greater extent in PHT PASMC than controls. The results imply that an increase in PDE isoforms, in particular PDE1C, contributes to decreased cAMP and increased proliferation of PASMC in patients with PHT. PDE1 isoforms may provide novel targets for the treatment of both primary and secondary forms of the disease.
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Blanco-Rivero, Javier, and Fabiano E. Xavier. "Therapeutic Potential of Phosphodiesterase Inhibitors for Endothelial Dysfunction- Related Diseases." Current Pharmaceutical Design 26, no. 30 (September 4, 2020): 3633–51. http://dx.doi.org/10.2174/1381612826666200403172736.
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Cardiovascular diseases (CVD) are considered a major health problem worldwide, being the main cause of mortality in developing and developed countries. Endothelial dysfunction, characterized by a decline in nitric oxide production and/or bioavailability, increased oxidative stress, decreased prostacyclin levels, and a reduction of endothelium-derived hyperpolarizing factor is considered an important prognostic indicator of various CVD. Changes in cyclic nucleotides production and/ or signalling, such as guanosine 3', 5'-monophosphate (cGMP) and adenosine 3', 5'-monophosphate (cAMP), also accompany many vascular disorders that course with altered endothelial function. Phosphodiesterases (PDE) are metallophosphohydrolases that catalyse cAMP and cGMP hydrolysis, thereby terminating the cyclic nucleotide-dependent signalling. The development of drugs that selectively block the activity of specific PDE families remains of great interest to the research, clinical and pharmaceutical industries. In the present review, we will discuss the effects of PDE inhibitors on CVD related to altered endothelial function, such as atherosclerosis, diabetes mellitus, arterial hypertension, stroke, aging and cirrhosis. Multiple evidences suggest that PDEs inhibition represents an attractive medical approach for the treatment of endothelial dysfunction-related diseases. Selective PDE inhibitors, especially PDE3 and PDE5 inhibitors are proposed to increase vascular NO levels by increasing antioxidant status or endothelial nitric oxide synthase expression and activation and to improve the morphological architecture of the endothelial surface. Thereby, selective PDE inhibitors can improve the endothelial function in various CVD, increasing the evidence that these drugs are potential treatment strategies for vascular dysfunction and reinforcing their potential role as an adjuvant in the pharmacotherapy of CVD.
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Shen, Kunyu, David W. Johnson, and Glenda C. Gobe. "The role of cGMP and its signaling pathways in kidney disease." American Journal of Physiology-Renal Physiology 311, no. 4 (October 1, 2016): F671—F681. http://dx.doi.org/10.1152/ajprenal.00042.2016.
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Cyclic nucleotide signal transduction pathways are an emerging research field in kidney disease. Activated cell surface receptors transduce their signals via intracellular second messengers such as cAMP and cGMP. There is increasing evidence that regulation of the cGMP-cGMP-dependent protein kinase 1-phosphodiesterase (cGMP-cGK1-PDE) signaling pathway may be renoprotective. Selective PDE5 inhibitors have shown potential in treating kidney fibrosis in patients with chronic kidney disease (CKD), via their downstream signaling, and these inhibitors also have known activity as antithrombotic and anticancer agents. This review gives an outline of the cGMP-cGK1-PDE signaling pathways and details the downstream signaling and regulatory functions that are modulated by cGK1 and PDE inhibitors with regard to antifibrotic, antithrombotic, and antitumor activity. Current evidence that supports the renoprotective effects of regulating cGMP-cGK1-PDE signaling is also summarized. Finally, the effects of icariin, a natural plant extract with PDE5 inhibitory function, are discussed. We conclude that regulation of cGMP-cGK1-PDE signaling might provide novel, therapeutic strategies for the worsening global public health problem of CKD.
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Okatan, Esma N., and Belma Turan. "The contribution of phosphodiesterases to cardiac dysfunction in rats with metabolic syndrome induced by a high-carbohydrate diet." Canadian Journal of Physiology and Pharmacology 97, no. 11 (November 2019): 1064–72. http://dx.doi.org/10.1139/cjpp-2019-0006.
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Metabolic syndrome (MetS) is a cluster of risk factors, including insulin resistance among others, underlying the development of diabetes and (or) cardiovascular diseases. Studies show a close relationship between cardiac dysfunction and abnormal cAMP catabolism, which contributes to pathological remodelling. Stimulating the synthesis of cAMP via suppression of phosphodiesterases (PDEs) has positive therapeutic effects. Therefore, we examined the role of PDEs on cardiac dysfunction in high-carbohydrate diet-induced MetS rats. We first demonstrated significantly high expression levels of PDE3 and PDE4, the most highly expressed subtypes, together with depressed cAMP levels in heart tissue from MetS rats. Second, we demonstrated the activity of these PDEs by using either their basal or PDE inhibitor-induced intracellular levels of cAMP and Ca2+, the transient intracellular Ca2+ changes under electrical stimulation, isometric contractions in papillary muscle strips and some key signalling proteins (such as RyR2, PLN, PP1A, and PKA) are responsible for the Ca2+ homeostasis in isolated cardiomyocytes from MetS rats. The clear recovery in decreased basal cAMP levels, increased protein expression levels of PDE3 and PDE4, and positive responses in the altered Ca2+ homeostasis to PDE inhibitors as seen in our study can provide important insights about the roles of activated PDEs in depressed contractile activity in hearts from MetS rats.
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Wang, Huanchen, Stefan Kunz, Gong Chen, Thomas Seebeck, Yiqian Wan, Howard Robinson, Sibylla Martinelli, and Hengming Ke. "Biological and Structural Characterization of Trypanosoma cruzi Phosphodiesterase C and Implications for Design of Parasite Selective Inhibitors." Journal of Biological Chemistry 287, no. 15 (February 21, 2012): 11788–97. http://dx.doi.org/10.1074/jbc.m111.326777.
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Trypanosoma cruzi phosphodiesterase C (TcrPDEC) is a potential new drug target for the treatment of Chagas disease but has not been well studied. This study reports the enzymatic properties of various kinetoplastid PDECs and the crystal structures of the unliganded TcrPDEC1 catalytic domain and its complex with an inhibitor. Mutations of PDEC during the course of evolution led to inactivation of PDEC in Trypanosoma brucei/Trypanosoma evansi/Trypanosoma congolense, whereas the enzyme is active in all other kinetoplastids. The TcrPDEC1 catalytic domain hydrolyzes both cAMP and cGMP with a Km of 23.8 μm and a kcat of 31 s−1 for cAMP and a Km of 99.1 μm and a kcat of 17 s−1 for cGMP, thus confirming its dual specificity. The crystal structures show that the N-terminal fragment wraps around the TcrPDEC catalytic domain and may thus regulate its enzymatic activity via direct interactions with the active site residues. A PDE5 selective inhibitor that has an IC50 of 230 nm for TcrPDEC1 binds to TcrPDEC1 in an orientation opposite to that of sildenafil. This observation, together with the screen of the inhibitory potency of human PDE inhibitors against TcrPDEC, implies that the scaffold of some human PDE inhibitors might be used as the starting model for design of parasite PDE inhibitors. The structural study also identified a unique parasite pocket that neighbors the active site and may thus be valuable for the design of parasite-specific inhibitors.
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Maronde, Erik. "Influence of Phosphodiesterase Inhibition on CRE- and EGR1-Dependent Transcription in a Mouse Hippocampal Cell Line." International Journal of Molecular Sciences 21, no. 22 (November 17, 2020): 8658. http://dx.doi.org/10.3390/ijms21228658.
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Signaling pathways, depending on the second messenger molecule cAMP, modulate hippocampal cell signaling via influencing transcription factors like cAMP-regulated element-binding protein (CREB) or early growth response 1 EGR1/Krox24/zif268/ZENK (EGR1). Here, we investigated two reporter cell lines derived from an immortalized hippocampal neuronal cell line stably expressing a CRE- or EGR1-luciferase reporter gene (HT22CREluc and HT22EGR1luc, respectively). The cells were subjected to phosphodiesterase inhibitors and other cAMP-modulating agents to investigate dose- and time-dependent phosphodiesterase (PDE)-mediated fine-tuning of cAMP-dependent transcriptional signaling. The non-isoform-specific cyclic nucleotide phosphodiesterase (PDE) inhibitor isobutyl-methyl-xanthine (IBMX), as well as selective inhibitors of PDE3 (milrinone) and PDE4 (rolipram), were tested for their ability to elevate CRE- and EGR1-luciferase activity. Pharmacological parameters like onset of activity, maximum activity, and offset of activity were determined. In summary, phosphodiesterase inhibition appeared similarly potent in comparison to adenylate cyclase stimulation or direct activation of protein kinase A (PKA) via specific cAMP agonists and was at least partly mediated by PKA as shown by the selective PKA inhibitor Rp-8-Br-cAMPS. Moreover, transcriptional activation by PDE inhibition was also influenced by organic anion-exchanger action and interacted with fibroblast growth factor (FGF) receptor-mediated pathways.
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Su, Yi-Hsien, and Victor D. Vacquier. "Cyclic GMP-specific Phosphodiesterase-5 Regulates Motility of Sea Urchin Spermatozoa." Molecular Biology of the Cell 17, no. 1 (January 2006): 114–21. http://dx.doi.org/10.1091/mbc.e05-08-0820.
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Motility, chemotaxis, and the acrosome reaction of animal sperm are all regulated by cyclic nucleotides and protein phosphorylation. One of the cyclic AMP-dependent protein kinase (PKA) substrates in sea urchin sperm is a member of the phosphodiesterase (PDE) family. The molecular identity and in vivo function of this PDE remained unknown. Here we cloned and characterized this sea urchin sperm PDE (suPDE5), which is an ortholog of human PDE5. The recombinant catalytic domain of suPDE5 hydrolyzes only cyclic GMP (cGMP) and the activity is pH-dependent. Phospho-suPDE5 localizes mainly to sperm flagella and the phosphorylation increases when sperm contact the jelly layer surrounding eggs. In vitro dephosphorylation of suPDE5 decreases its activity by ∼50%. PDE5 inhibitors such as Viagra block the activity of suPDE5 and increase sperm motility. This is the first PDE5 protein to be discovered in animal sperm. The data are consistent with the hypothesis that suPDE5 regulates cGMP levels in sperm, which in turn modulate sperm motility.
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Mendoza, G. A., and F. Treves. "linear PDE." Duke Mathematical Journal 63, no. 2 (July 1991): 355–77. http://dx.doi.org/10.1215/s0012-7094-91-06315-5.
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Oliveira, Tiago Roux, and Miroslav Krstic. "Extremum seeking boundary control for PDE–PDE cascades." Systems & Control Letters 155 (September 2021): 105004. http://dx.doi.org/10.1016/j.sysconle.2021.105004.
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