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Stefan Uckert - One of the best experts on this subject based on the ideXlab platform.
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Phosphodiesterase isoenzymes in the human urethra: A molecular biology and functional study
European Journal of Pharmacology, 2014Co-Authors: George T. Kedia, Mattias Oelke, Markus A. Kuczyk, Joachim E. Sonnenberg, Michael Sohn, Andreas Bannowsky, Stefan UckertAbstract:Abstract Experimental and clinical studies have suggested a role for phosphodiesterase (PDE) isoenzymes in the control of the human lower urinary tract. This study aimed to investigate the expression of PDE isoenzymes and the effects of PDE inhibitors (PDE-Is) in isolated human urethral smooth muscle (USM). The expression of messenger ribonucleic acid (mRNA) specifically encoding for PDE isoenzymes and isoforms (1A, 1B, 1C, 2A, 4A, 4B, 4C, 4D, 5A and 11A) was analyzed by means of reverse transcriptase polymerase chain reaction (RT-PCR). Using a tissue bath technique, the effects of vinpocetine (PDE1-I), erythro-9-(2-hydroxy-3-nonyl)adenine hydrochloride (EHNA-HCl=MEP1) (PDE2-I), rolipram (PDE4-I), sildenafil, vardenafil and tadalafil (PDE5-Is) (0.01–10 µM) on the tension of USM induced by norepinephrine were investigated. The production of cyclic guanosine monophosphate (cyclic GMP) and cyclic adenosine monophosphate (cyclic AMP) was measured by means of radioimmunoassays. RT-PCR analysis revealed the expression of PDE1B, PDE1C, PDE4A, PDE4C, PDE4D, PDE5A and PDE11A. The tension induced by norepinephrine (NE) was reversed by the PDE inhibitors with the following rank order of efficacy: rolipram (mean: −39%)≥sildenafil (−35%)>vardenafil (−26%)>tadalafil (−20%)>vinpocetine (−16%)>MEP1 (−2%). The relaxing effects of the drugs were paralleled by an elevation in tissue levels of cyclic AMP and cyclic GMP. Selective inhibitors of PDE4 and PDE5 can antagonize the tension induced by alpha-adrenergic stimulation of USM. PDE inhibition might represent an interesting option to facilitate the relaxation of the human outflow region.
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The role of phosphodiesterases in bladder pathophysiology
Nature Reviews Urology, 2013Co-Authors: Mohammad S. Rahnama'i, Stefan Uckert, Ramona Hohnen, Gommert A. Van KoeveringeAbstract:Phosphodiesterases (PDEs) hydrolyse cAMP and cGMP, and are thought to have a crucial role in bladder physiology Inhibition of PDEs raises cAMP and cGMP levels and relaxes urinary bladder muscles Although PDEs 1–5 and 7–9 occur in the human urinary bladder, only PDE1 and PDE5 inhibitors have been clinically tested for the treatment of storage and voiding disorders PDE1 inhibition improves micturition frequency PDE5 inhibition alleviates lower urinary tract symptoms in men, including those with and without BPH and erectile dysfunction Rahnama'i and colleagues highlight the emerging role of selective phosphodiesterase (PDE) inhibitors in the management of functional voiding disorders. Although much remains unknown about the role of these enzymes in the human bladder, accumulating evidence suggests that PDE5 inhibitors alleviate lower urinary tract symptoms in men, and could be a useful adjunct to α blocker therapy. Nitric oxide and the cyclic nucleotide monophosphates cAMP and cGMP have a role in control of the micturition process and hence, are suggested to be involved in the pathophysiology of storage and voiding disorders. Phosphodiesterase enzymes (PDEs) hydrolyse cAMP and cGMP. Inhibition of PDEs increases cAMP and cGMP levels and relaxes urinary bladder smooth musculature. Although many preclinical studies have been conducted, to date, only PDE1 and PDE5 inhibitors have been tested clinically for the management of storage and voiding disorders. Treatment with PDE1 inhibitors might improve micturition frequency in patients with overactive bladder, whereas inhibition of PDE5 improves lower urinary tract symptoms in men, either with or without BPH and erectile dysfunction (ED). Furthermore, the combination of a PDE5 inhibitor and an α-adrenoceptor antagonist has superior efficacy to monotherapy with either agent. However, the role of PDE5 inhibitors in the treatment of women with detrusor overactivity remains unclear. The clinical application of agents that inhibit other PDEs, including PDE4, also certainly merits scientific attention. PDE inhibitors seem likely to become a valuable alternative treatment for patients with storage and voiding disorders in the future.
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expression and distribution of key enzymes of the cyclic gmp signaling in the human clitoris relation to phosphodiesterase type 5 pde5
International Journal of Impotence Research, 2011Co-Authors: Stefan Uckert, Mattias Oelke, K Albrecht, Markus A. Kuczyk, D. Breitmeier, Petter HedlundAbstract:The clitoris contributes to the normal female sexual response cycle. A significance of cyclic guanosine monophosphate (GMP) has been assumed in the control of clitoral vascular smooth muscle. As only a few investigations on the physiology of the vascular and non-vascular clitoral tissue have been carried out, knowledge on the mechanisms controlling this particular female genital organ is still vague. It has been suggested that human clitoral corpus cavernosum smooth muscle is regulated by nitric oxide (NO)/cyclic GMP and related key enzymes, such as NO synthases (NOSs) and the phosphodiesterase type 5 (PDE5). The present study evaluated in the human clitoris, by means of immunohistochemistry, the expression and distribution of key enzymes of the cyclic GMP pathway, such as the endothelial NOS, PDE2, PDE11 and cyclic GMP-dependent protein kinase type I (cGKI) in relation to the PDE5. Immunohistochemistry revealed the presence of PDE2, PDE5 and cGKI in the smooth muscle wall of blood vessels transversing the supepithelial and stromal space. Immunosignals specific for PDE2 were also identified in interstitial-like cells located in the basal epithelial layer. Staining for PDE11A was observed in single nerve trunks located in the clitoral stroma. The results are in favor of a role of the cyclic GMP signaling in the control of clitoral blood flow. It seems likely that PDE2 and PDE11 are also involved in the mechanism of local (neuro)transmission in the clitoris.
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Bedeutung von Phosphodiesteraseisoenzymen in der Kontrolle der humanen Detrusormuskulatur
Der Urologe, 2009Co-Authors: Stefan Uckert, Mattias Oelke, Christian G. Stief, Peter Sandner, Ernst Ulbrich, Katja Sigl, Eginhard S. Waldkirch, Markus A. KuczykAbstract:Hintergrund Klinische Studien zeigten positive Effekte der Phosphodiesterase- (PDE-)5-Inhibitoren Sildenafil, Tadalafil und Vardenafil auf die irritative Symptomatik des benigen Prostatasyndroms. Unklar ist bisher, ob diese Substanzen auf die glatte Muskulatur in der Transitionalzone der Prostata und/oder auf den Detrusormuskel wirken. Das Ziel der Studie war die Darstellung der Expression der PDE-Isoenzyme 1, 4 und 5 in der Detrusormuskulatur und die Untersuchung der Effekte selektiver PDE-Inhibitoren auf die muskarinerge Tension isolierter glatter Muskulatur des humanen Detrusors. Methoden Die Darstellung der Expression von PDE-Isoenzymen erfolgte mit immunhistochemischen Methoden. Mit der Organbad-Technik wurden die Effekte der PDE-Inhibitoren Vinpocetin, Rolipram, Sildenafil, Vardenafil und Tadalafil auf die durch Carbachol induzierte tonische Kontraktion isolierter Streifenpräparate des Detrusors untersucht. Ergebnisse Immunreaktionen gegen die PDE-Isoenzyme stellten sich ausschließlich in der glatten Muskulatur dar. Intensiven Signalen, die spezifisch für die PDE4 und PDE5 waren, standen nur schwache Signale, welche die Expression der PDE1 zeigten, gegenüber. Die muskarinerge Kontraktion isolierter Streifenpräparate der Detrusormuskulatur wurde lediglich durch supraphysiologische Konzentrationen der PDE-Inhibitoren antagonisiert. Schlussfolgerung Die Studie zeigt die Expression der PDE-Isoenzyme 1, 4 und 5 im humanen Detrusor. Die relativ schwachen funktionellen Effekte der PDE-Inhibitoren lässt jedoch nicht zwangsläufig auf eine Bedeutung der PDE-Isoenzyme 1, 4 oder 5 in der Kontrolle der Relaxation der Detrusormuskulatur schließen. Objectives The use of inhibitors of phosphodiesterase (PDE) isoenzymes 1 and 5 to treat overactive bladder has been suggested. To further evaluate the significance of PDE isoenzymes in detrusor smooth muscle relaxation, we investigated the effects of selective PDE inhibitors on the tension induced by carbachol of isolated human detrusor tissue. Using immunohistochemical methods, the expression of PDE1, PDE4, and PDE5 in human detrusor was also investigated. Material and Methods The expression of PDE1, PDE4, and PDE5 was evaluated by means of conventional immunohistochemistry (IHC). Using the organ bath technique, the effects of the PDE inhibitors vinpocetine, rolipram, sildenafil, tadalafil, and vardenafil on the tension induced by the muscarinic agonist carbachol (1 µM) were investigated. Results The tension induced by carbachol was dose-dependently reversed by the PDE inhibitors; the maximum reversal of tension ranged from 7% (tadalafil) to 34% (vardenafil). IHC revealed that the expression of PDE isoenzymes was limited to the smooth musculature of the detrusor. While there was prominent expression of PDE4 and PDE5, immunoreactions indicating the presence of PDE1 were less abundant. Conclusion Despite the fact that inhibitors of PDE1, PDE4, and PDE5 exerted only a weak relaxant response on detrusor strips precontracted by carbachol, our findings indicate that both the cAMP and cGMP pathways might be involved in the relaxation mechanism of human detrusor smooth muscle.
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Significance of phosphodiesterase isoenzymes in the control of human detrusor smooth muscle function. An immunohistochemical and functional study
Der Urologe, 2009Co-Authors: Stefan Uckert, Mattias Oelke, Christian G. Stief, Peter Sandner, Ernst Ulbrich, Katja Sigl, Eginhard S. Waldkirch, Markus A. KuczykAbstract:OBJECTIVES The use of inhibitors of phosphodiesterase (PDE) isoenzymes 1 and 5 to treat overactive bladder has been suggested. To further evaluate the significance of PDE isoenzymes in detrusor smooth muscle relaxation, we investigated the effects of selective PDE inhibitors on the tension induced by carbachol of isolated human detrusor tissue. Using immunohistochemical methods, the expression of PDE1, PDE4, and PDE5 in human detrusor was also investigated. MATERIAL AND METHODS The expression of PDE1, PDE4, and PDE5 was evaluated by means of conventional immunohistochemistry (IHC). Using the organ bath technique, the effects of the PDE inhibitors vinpocetine, rolipram, sildenafil, tadalafil, and vardenafil on the tension induced by the muscarinic agonist carbachol (1 microM) were investigated. RESULTS The tension induced by carbachol was dose-dependently reversed by the PDE inhibitors; the maximum reversal of tension ranged from 7% (tadalafil) to 34% (vardenafil). IHC revealed that the expression of PDE isoenzymes was limited to the smooth musculature of the detrusor. While there was prominent expression of PDE4 and PDE5, immunoreactions indicating the presence of PDE1 were less abundant. CONCLUSION Despite the fact that inhibitors of PDE1, PDE4, and PDE5 exerted only a weak relaxant response on detrusor strips precontracted by carbachol, our findings indicate that both the cAMP and cGMP pathways might be involved in the relaxation mechanism of human detrusor smooth muscle.
Chen Yan - One of the best experts on this subject based on the ideXlab platform.
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Cyclic Nucleotide Phosphodiesterase 1 Regulates Lysosome-Dependent Type I Collagen Protein Degradation in Vascular Smooth Muscle Cells
Arteriosclerosis Thrombosis and Vascular Biology, 2011Co-Authors: Yu-jun Cai, Kye-im Jeon, Clint L. Miller, Soyeon Lim, Pingjin Gao, David J. Nagel, Peter A. Knight, Chen YanAbstract:Objective— The phenotypic modulation of vascular smooth muscle cells (VSMCs) to a synthetic phenotype is vital during pathological vascular remodeling and the development of various vascular diseases. An increase in type I collagen (collagen I) has been implicated in synthetic VSMCs, and cyclic nucleotide signaling is critical in collagen I regulation. Herein, we investigate the role and underlying mechanism of cyclic nucleotide phosphodiesterase 1 (PDE1) in regulating collagen I in synthetic VSMCs. Methods and Results— The PDE1 inhibitor IC86340 significantly reduced collagen I in human saphenous vein explants undergoing spontaneous remodeling via ex vivo culture. In synthetic VSMCs, high basal levels of intracellular and extracellular collagen I protein were markedly decreased by IC86340. This attenuation was due to diminished protein but not mRNA. Inhibition of lysosome function abolished the effect of IC86340 on collagen I protein expression. PDE1C but not PDE1A is the major isoform responsible for mediating the effects of IC86340. Bicarbonate-sensitive soluble adenylyl cyclase/cAMP signaling was modulated by PDE1C, which is critical in collagen I degradation in VSMCs. Conclusion— These data demonstrate that PDE1C regulates soluble adenylyl cyclase/cAMP signaling and lysosome-mediated collagen I protein degradation, and they suggest that PDE1C plays a critical role in regulating collagen homeostasis during pathological vascular remodeling.
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ca2 calmodulin stimulated PDE1 regulates the beta catenin tcf signaling through pp2a b56 gamma subunit in proliferating vascular smooth muscle cells
FEBS Journal, 2010Co-Authors: Kye-im Jeon, Hirofumi Jono, Clint L. Miller, Yu-jun Cai, Soyeon Lim, Xuan Liu, Pingjin Gao, Jun Ichi Abe, Chen YanAbstract:The phenotypic change of vascular smooth muscle cells (VSMCs), from a ‘contractile’ phenotype to a ‘synthetic’ phenotype, is crucial for pathogenic vascular remodeling in vascular diseases such as atherosclerosis and restenosis. Ca2+/calmodulin-stimulated phosphodiesterase 1 (PDE1) isozymes, including PDE1A and PDE1C, play integral roles in regulating the proliferation of synthetic VSMCs. However, the underlying molecular mechanism(s) remain unknown. In this study, we explore the role and mechanism of PDE1 isoforms in regulating β-catenin/T-cell factor (TCF) signaling in VSMCs, a pathway important for vascular remodeling through promoting VSMC growth and survival. We found that inhibition of PDE1 activity markedly attenuated β-catenin/TCF signaling by downregulating β-catenin protein. The effect of PDE1 inhibition on β-catenin protein reduction is exerted via promoting glycogen synthase kinase 3 (GSK3)β activation, β-catenin phosphorylation and subsequent β-catenin protein degradation. Moreover, PDE1 inhibition specifically upregulated phosphatase protein phosphatase 2A (PP2A) B56γ subunit gene expression, which is responsible for the effects of PDE1 inhibition on GSK3β and β-catenin/TCF signaling. Furthermore, the effect of PDE1 inhibition on β-catenin was specifically mediated by PDE1A but not PDE1C isozyme. Interestingly, in synthetic VSMCs, PP2A B56γ, phospho-GSK3β and phospho-β-catenin were all found in the nucleus, suggesting that PDE1A regulates nuclear β-catenin protein stability through the nuclear PP2A–GSK3β–β-catenin signaling axis. Taken together, these findings provide direct evidence for the first time that PP2A B56γ is a critical mediator for PDE1A in the regulation of β-catenin signaling in proliferating VSMCs.
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Ca2+/calmodulin-stimulated PDE1 regulates the beta-catenin/TCF signaling through PP2A B56 gamma subunit in proliferating vascular smooth muscle cells.
FEBS Journal, 2010Co-Authors: Kye-im Jeon, Hirofumi Jono, Clint L. Miller, Yu-jun Cai, Soyeon Lim, Xuan Liu, Pingjin Gao, Jun Ichi Abe, Chen YanAbstract:The phenotypic change of vascular smooth muscle cells (VSMCs), from a ‘contractile’ phenotype to a ‘synthetic’ phenotype, is crucial for pathogenic vascular remodeling in vascular diseases such as atherosclerosis and restenosis. Ca2+/calmodulin-stimulated phosphodiesterase 1 (PDE1) isozymes, including PDE1A and PDE1C, play integral roles in regulating the proliferation of synthetic VSMCs. However, the underlying molecular mechanism(s) remain unknown. In this study, we explore the role and mechanism of PDE1 isoforms in regulating β-catenin/T-cell factor (TCF) signaling in VSMCs, a pathway important for vascular remodeling through promoting VSMC growth and survival. We found that inhibition of PDE1 activity markedly attenuated β-catenin/TCF signaling by downregulating β-catenin protein. The effect of PDE1 inhibition on β-catenin protein reduction is exerted via promoting glycogen synthase kinase 3 (GSK3)β activation, β-catenin phosphorylation and subsequent β-catenin protein degradation. Moreover, PDE1 inhibition specifically upregulated phosphatase protein phosphatase 2A (PP2A) B56γ subunit gene expression, which is responsible for the effects of PDE1 inhibition on GSK3β and β-catenin/TCF signaling. Furthermore, the effect of PDE1 inhibition on β-catenin was specifically mediated by PDE1A but not PDE1C isozyme. Interestingly, in synthetic VSMCs, PP2A B56γ, phospho-GSK3β and phospho-β-catenin were all found in the nucleus, suggesting that PDE1A regulates nuclear β-catenin protein stability through the nuclear PP2A–GSK3β–β-catenin signaling axis. Taken together, these findings provide direct evidence for the first time that PP2A B56γ is a critical mediator for PDE1A in the regulation of β-catenin signaling in proliferating VSMCs.
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Cyclic GMP Phosphodiesterases and Regulation of Smooth Muscle Function
Circulation Research, 2003Co-Authors: Sergei D. Rybalkin, Chen Yan, Karin E. Bornfeldt, Joseph A. BeavoAbstract:Cyclic GMP (cGMP) made in response to atrial natriuretic peptide (ANP) or nitric oxide (NO) is an important regulator of short-term changes in smooth muscle tone and longer-term responses to chronic drug treatment or proliferative signals. The ability of smooth muscle cells (SMCs) to utilize different combinations of phosphodiesterase (PDE) isozymes allows cGMP to mediate these multiple processes. For example, PDE5 as a major cGMP-hydrolyzing PDE effectively controls the development of smooth muscle relaxation. In order for contraction to occur, PDE5 is activated and cGMP falls. Conversely, blockade of PDE5 activity allows the relaxation cycle to be prolonged and enhanced. A recently shown direct activation of PDE5 by cGMP binding to the GAF A domain suggests that this regulatory site might be a target for new drug development. The calcium surge associated with vasoconstrictor initiated contraction also activates a calcium/calmodulin-dependent PDE (PDE1A). Together, PDE5 and PDE1A lower cGMP sufficiently to allow contraction. Longer term, both PDE5 and PDE1A mRNA are induced by chronic stimulation of guanylyl cyclase. This induction is a major cause of the tolerance that develops to NO-releasing drugs. Finally, high levels of cGMP or cAMP also act as a brake to attenuate the proliferative response of SMCs to many mitogens. After vessel damage, in order for SMC proliferation to occur, the levels of cGMP and cAMP must be decreased. In humans, this decrease is caused in large part by induction of another Ca2+/calmodulin-dependent PDE (PDE1C) that allows the brake to be released and proliferation to start.
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Stage and Cell-Specific Expression of Calmodulin-Dependent Phosphodiesterases in Mouse Testis
Biology of Reproduction, 2001Co-Authors: Chen Yan, Allan Z. Zhao, William K. Sonnenburg, Joseph A. BeavoAbstract:Calcium and cyclic nucleotides are second messengers that regulate the development and functional activity of spermatozoa. Calcium/calmodulin-dependent phosphodiesterases (CaM-PDEs) are abundant in testicular cells and in mature spermatozoa and provide one means by which calcium regulates cellular cyclic nucleotide content. We examined the spatial and temporal expression profiles of three knownCaM-PDE genes, PDE1A, PDE1B, and PDE1C, in the testis. In situ hybridization and immunofluorescent staining showed that both PDE1A and PDE1C are highly expressed but at different stages in developing germ cells. However, a very low hybridization signal of PDE1B exists uniformly throughout the seminiferous epithelium and the interstitium. More specifically, PDE1A mRNA is found in round to elongated spermatids, with protein expression in the tails of elongated and maturing spermatids. In contrast, PDE1C mRNA accumulates during early meiotic prophase and throughout meiotic and postmeiotic stages. Immunocytochemistry showed a diffuse, presumably cytosolic distribution of the expressed protein. The distinct spatial and temporal expression patterns of CaM-PDEs suggest important but different physiological roles for these CaM-PDEs in developing and mature spermatozoa.
Marc Bickle - One of the best experts on this subject based on the ideXlab platform.
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Protective efficacy of phosphodiesterase-1 inhibition against alpha-synuclein toxicity revealed by compound screening in LUHMES cells
Scientific Reports, 2017Co-Authors: Matthias Höllerhage, Claudia Moebius, Johannes Melms, Wei-hua Chiu, Joachim N. Goebel, Tasnim Chakroun, Thomas Koeglsperger, Wolfgang H. Oertel, Thomas W. Rösler, Marc BickleAbstract:α-synuclein-induced neurotoxicity is a core pathogenic event in neurodegenerative synucleinopathies such as Parkinson’s disease, dementia with Lewy bodies, or multiple system atrophy. There is currently no disease-modifying therapy available for these diseases. We screened 1,600 FDA-approved drugs for their efficacy to protect LUHMES cells from degeneration induced by wild-type α-synuclein and identified dipyridamole, a non-selective phosphodiesterase inhibitor, as top hit. Systematic analysis of other phosphodiesterase inhibitors identified a specific phosphodiesterase 1 inhibitor as most potent to rescue from α-synuclein toxicity. Protection was mediated by an increase of cGMP and associated with the reduction of a specific α-synuclein oligomeric species. RNA interference experiments confirmed PDE1A and to a smaller extent PDE1C as molecular targets accounting for the protective efficacy. PDE1 inhibition also rescued dopaminergic neurons from wild-type α-synuclein induced degeneration in the substantia nigra of mice. In conclusion, this work identifies inhibition of PDE1A in particular as promising target for neuroprotective treatment of synucleinopathies.
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Protective efficacy of phosphodiesterase-1 inhibition against alpha-synuclein toxicity revealed by compound screening in LUHMES cells.
Scientific Reports, 2017Co-Authors: Matthias Höllerhage, Claudia Moebius, Johannes Melms, Wei-hua Chiu, Joachim N. Goebel, Tasnim Chakroun, Thomas Koeglsperger, Wolfgang H. Oertel, Thomas W. Rösler, Marc BickleAbstract:α-synuclein-induced neurotoxicity is a core pathogenic event in neurodegenerative synucleinopathies such as Parkinson’s disease, dementia with Lewy bodies, or multiple system atrophy. There is currently no disease-modifying therapy available for these diseases. We screened 1,600 FDA-approved drugs for their efficacy to protect LUHMES cells from degeneration induced by wild-type α-synuclein and identified dipyridamole, a non-selective phosphodiesterase inhibitor, as top hit. Systematic analysis of other phosphodiesterase inhibitors identified a specific phosphodiesterase 1 inhibitor as most potent to rescue from α-synuclein toxicity. Protection was mediated by an increase of cGMP and associated with the reduction of a specific α-synuclein oligomeric species. RNA interference experiments confirmed PDE1A and to a smaller extent PDE1C as molecular targets accounting for the protective efficacy. PDE1 inhibition also rescued dopaminergic neurons from wild-type α-synuclein induced degeneration in the substantia nigra of mice. In conclusion, this work identifies inhibition of PDE1A in particular as promising target for neuroprotective treatment of synucleinopathies.
Matthias Höllerhage - One of the best experts on this subject based on the ideXlab platform.
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Protective efficacy of phosphodiesterase-1 inhibition against alpha-synuclein toxicity revealed by compound screening in LUHMES cells
Scientific Reports, 2017Co-Authors: Matthias Höllerhage, Claudia Moebius, Johannes Melms, Wei-hua Chiu, Joachim N. Goebel, Tasnim Chakroun, Thomas Koeglsperger, Wolfgang H. Oertel, Thomas W. Rösler, Marc BickleAbstract:α-synuclein-induced neurotoxicity is a core pathogenic event in neurodegenerative synucleinopathies such as Parkinson’s disease, dementia with Lewy bodies, or multiple system atrophy. There is currently no disease-modifying therapy available for these diseases. We screened 1,600 FDA-approved drugs for their efficacy to protect LUHMES cells from degeneration induced by wild-type α-synuclein and identified dipyridamole, a non-selective phosphodiesterase inhibitor, as top hit. Systematic analysis of other phosphodiesterase inhibitors identified a specific phosphodiesterase 1 inhibitor as most potent to rescue from α-synuclein toxicity. Protection was mediated by an increase of cGMP and associated with the reduction of a specific α-synuclein oligomeric species. RNA interference experiments confirmed PDE1A and to a smaller extent PDE1C as molecular targets accounting for the protective efficacy. PDE1 inhibition also rescued dopaminergic neurons from wild-type α-synuclein induced degeneration in the substantia nigra of mice. In conclusion, this work identifies inhibition of PDE1A in particular as promising target for neuroprotective treatment of synucleinopathies.
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Protective efficacy of phosphodiesterase-1 inhibition against alpha-synuclein toxicity revealed by compound screening in LUHMES cells.
Scientific Reports, 2017Co-Authors: Matthias Höllerhage, Claudia Moebius, Johannes Melms, Wei-hua Chiu, Joachim N. Goebel, Tasnim Chakroun, Thomas Koeglsperger, Wolfgang H. Oertel, Thomas W. Rösler, Marc BickleAbstract:α-synuclein-induced neurotoxicity is a core pathogenic event in neurodegenerative synucleinopathies such as Parkinson’s disease, dementia with Lewy bodies, or multiple system atrophy. There is currently no disease-modifying therapy available for these diseases. We screened 1,600 FDA-approved drugs for their efficacy to protect LUHMES cells from degeneration induced by wild-type α-synuclein and identified dipyridamole, a non-selective phosphodiesterase inhibitor, as top hit. Systematic analysis of other phosphodiesterase inhibitors identified a specific phosphodiesterase 1 inhibitor as most potent to rescue from α-synuclein toxicity. Protection was mediated by an increase of cGMP and associated with the reduction of a specific α-synuclein oligomeric species. RNA interference experiments confirmed PDE1A and to a smaller extent PDE1C as molecular targets accounting for the protective efficacy. PDE1 inhibition also rescued dopaminergic neurons from wild-type α-synuclein induced degeneration in the substantia nigra of mice. In conclusion, this work identifies inhibition of PDE1A in particular as promising target for neuroprotective treatment of synucleinopathies.
Sergei D. Rybalkin - One of the best experts on this subject based on the ideXlab platform.
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luteinizing hormone causes phosphorylation and activation of the cgmp phosphodiesterase pde5 in rat ovarian follicles contributing together with PDE1 activity to the resumption of meiosis
Biology of Reproduction, 2016Co-Authors: Jeremy R Egbert, Robin J. Kleiman, Tracy F Uliasz, Leia C Shuhaibar, Andreas Geerts, Frank Wunder, John M Humphrey, Paul D Lampe, Nikolai O Artemyev, Sergei D. RybalkinAbstract:The meiotic cell cycle of mammalian oocytes in preovulatory follicles is held in prophase arrest by diffusion of cGMP from the surrounding granulosa cells into the oocyte. Luteinizing hormone (LH) then releases meiotic arrest by lowering cGMP in the granulosa cells. The LH-induced reduction of cGMP is caused in part by a decrease in guanylyl cyclase activity, but the observation that the cGMP phosphodiesterase PDE5 is phosphorylated during LH signaling suggests that an increase in PDE5 activity could also contribute. To investigate this idea, we measured cGMP-hydrolytic activity in rat ovarian follicles. Basal activity was due primarily to PDE1A and PDE5, and LH increased PDE5 activity. The increase in PDE5 activity was accompanied by phosphorylation of PDE5 at serine 92, a protein kinase A/G consensus site. Both the phosphorylation and the increase in activity were promoted by elevating cAMP and opposed by inhibiting protein kinase A, supporting the hypothesis that LH activates PDE5 by stimulating its phosphorylation by protein kinase A. Inhibition of PDE5 activity partially suppressed LH-induced meiotic resumption as indicated by nuclear envelope breakdown, but inhibition of both PDE5 and PDE1 activities was needed to completely inhibit this response. These results show that activities of both PDE5 and PDE1 contribute to the LH-induced resumption of meiosis in rat oocytes, and that phosphorylation and activation of PDE5 is a regulatory mechanism.
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Role of Ca2+/Calmodulin-Stimulated Cyclic Nucleotide Phosphodiesterase 1 in Mediating Cardiomyocyte Hypertrophy
Circulation Research, 2009Co-Authors: Clint L. Miller, Yu-jun Cai, Masayoshi Oikawa, Andrew P. Wojtovich, David J. Nagel, Vince Florio, Sergei D. Rybalkin, Joseph A. BeavoAbstract:Rationale: Cyclic nucleotide phosphodiesterases (PDEs) through the degradation of cGMP play critical roles in maintaining cardiomyocyte homeostasis. Ca2+/calmodulin (CaM)-activated cGMP-hydrolyzing PDE1 family may play a pivotal role in balancing intracellular Ca2+/CaM and cGMP signaling; however, its function in cardiomyocytes is unknown. Objective: Herein, we investigate the role of Ca2+/CaM-stimulated PDE1 in regulating pathological cardiomyocyte hypertrophy in neonatal and adult rat ventricular myocytes and in the heart in vivo. Methods and Results: Inhibition of PDE1 activity using a PDE1-selective inhibitor, IC86340, or downregulation of PDE1A using siRNA prevented phenylephrine induced pathological myocyte hypertrophy and hypertrophic marker expression in neonatal and adult rat ventricular myocytes. Importantly, administration of the PDE1 inhibitor IC86340 attenuated cardiac hypertrophy induced by chronic isoproterenol infusion in vivo. Both PDE1A and PDE1C mRNA and protein were detected in human h...
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Cyclic GMP Phosphodiesterases and Regulation of Smooth Muscle Function
Circulation Research, 2003Co-Authors: Sergei D. Rybalkin, Chen Yan, Karin E. Bornfeldt, Joseph A. BeavoAbstract:Cyclic GMP (cGMP) made in response to atrial natriuretic peptide (ANP) or nitric oxide (NO) is an important regulator of short-term changes in smooth muscle tone and longer-term responses to chronic drug treatment or proliferative signals. The ability of smooth muscle cells (SMCs) to utilize different combinations of phosphodiesterase (PDE) isozymes allows cGMP to mediate these multiple processes. For example, PDE5 as a major cGMP-hydrolyzing PDE effectively controls the development of smooth muscle relaxation. In order for contraction to occur, PDE5 is activated and cGMP falls. Conversely, blockade of PDE5 activity allows the relaxation cycle to be prolonged and enhanced. A recently shown direct activation of PDE5 by cGMP binding to the GAF A domain suggests that this regulatory site might be a target for new drug development. The calcium surge associated with vasoconstrictor initiated contraction also activates a calcium/calmodulin-dependent PDE (PDE1A). Together, PDE5 and PDE1A lower cGMP sufficiently to allow contraction. Longer term, both PDE5 and PDE1A mRNA are induced by chronic stimulation of guanylyl cyclase. This induction is a major cause of the tolerance that develops to NO-releasing drugs. Finally, high levels of cGMP or cAMP also act as a brake to attenuate the proliferative response of SMCs to many mitogens. After vessel damage, in order for SMC proliferation to occur, the levels of cGMP and cAMP must be decreased. In humans, this decrease is caused in large part by induction of another Ca2+/calmodulin-dependent PDE (PDE1C) that allows the brake to be released and proliferation to start.
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Cyclic Nucleotide Phosphodiesterases and Human Arterial Smooth Muscle Cell Proliferation
Thrombosis and Haemostasis, 1999Co-Authors: Sergei D. Rybalkin, Karin E. BornfeldtAbstract:IntroductionSmooth muscle cells (SMCs) in the arterial wall are normally found in a contractile, nonproliferative state. These SMCs are continuously exposed to agents that elevate cyclic AMP (cAMP) and cyclic GMP (cGMP), such as prostacyclin and nitric oxide (NO) released from the endothelium. Both cAMP and cGMP potently inhibit SMC proliferation by antagonizing major signaling pathways induced by growth factors, such as platelet-derived growth factor. Different forms of injury to the endothelium result in proliferation of the SMCs and can develop into atherosclerosis, restenosis, or arterial thickening associated with neonatal pulmonary hypertension. In human adult aorta, cAMP and cGMP levels are tightly regulated by synthesis and degradation. The latter is mediated by at least two different cAMP phosphodiesterases (PDEs), PDE3 and PDE4, and three different PDEs that degrade mainly cGMP, PDE1A, PDE1B, and PDE5. Strikingly, expression of a new PDE that degrades both cAMP and cGMP, PDE1C, is markedly induced in proliferating SMCs from the same aorta in culture, whereas its expression is nondetectable in contractile aorta. We propose that, for a human arterial SMC to be able to efficiently proliferate, and perhaps even to undergo a phenotypic change from a quiescent to a proliferative phenotype, it has to efficiently degrade inhibitory cAMP and cGMP. In human SMCs, PDE1C is induced to degrade these cyclic nucleotides. Understanding the role of PDE1C in SMC proliferation may provide the basic information necessary for development of highly specific PDE1C inhibitors that target proliferating SMCs in cardiovascular disease.