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Boivin B, Roet KCD, Huang X, Karhohs KW, Rohban MH, Sandoe J, Wiskow O, Maeda R, Grantham A, Dornon MK, Shao J, Frost D, Baker D, Eggan K, Carpenter AE, Woolf CJ. A multiparametric activity profiling platform for neuron disease phenotyping and drug screening. Mol Biol Cell 2022; 33:ar54. [PMID: 34910584 PMCID: PMC9265164 DOI: 10.1091/mbc.e21-10-0481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Patient stem cell-derived models enable imaging of complex disease phenotypes and the development of scalable drug discovery platforms. Current preclinical methods for assessing cellular activity do not, however, capture the full intricacies of disease-induced disturbances and instead typically focus on a single parameter, which impairs both the understanding of disease and the discovery of effective therapeutics. Here, we describe a cloud-based image processing and analysis platform that captures the intricate activity profile revealed by GCaMP fluorescence recordings of intracellular calcium changes and enables the discovery of molecules that correct 153 parameters that define the amyotrophic lateral sclerosis motor neuron disease phenotype. In a high-throughput screen, we identified compounds that revert the multiparametric disease profile to that found in healthy cells, a novel and robust measure of therapeutic potential quite distinct from unidimensional screening. This platform can guide the development of therapeutics that counteract the multifaceted pathological features of diseased cellular activity.
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Affiliation(s)
- Bruno Boivin
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115.,Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Kasper C D Roet
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115.,Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Xuan Huang
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115.,Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Kyle W Karhohs
- Broad Institute of Harvard and MIT, Imaging Platform, Cambridge, MA 02142
| | - Mohammad H Rohban
- Broad Institute of Harvard and MIT, Imaging Platform, Cambridge, MA 02142
| | - Jack Sandoe
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Ole Wiskow
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Rie Maeda
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115
| | - Alyssa Grantham
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115
| | - Mary K Dornon
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115
| | - Jenny Shao
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115
| | - Devlin Frost
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115
| | - Dylan Baker
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Kevin Eggan
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Anne E Carpenter
- Broad Institute of Harvard and MIT, Imaging Platform, Cambridge, MA 02142
| | - Clifford J Woolf
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115.,Department of Neurobiology, Harvard Medical School, Boston, MA 02115
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2
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Yu YH, Kim SW, Kang J, Song Y, Im H, Kim SJ, Yoo DY, Lee MR, Park DK, Oh JS, Kim DS. Phosphodiesterase-5 Inhibitor Attenuates Anxious Phenotypes and Movement Disorder Induced by Mild Ischemic Stroke in Rats. J Korean Neurosurg Soc 2022; 65:665-679. [PMID: 35430790 PMCID: PMC9452378 DOI: 10.3340/jkns.2021.0101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 02/03/2022] [Indexed: 11/27/2022] Open
Abstract
Objective Patients with mild ischemic stroke experience various sequela and residual symptoms, such as anxious behavior and deficits in movement. Few approaches have been proved to be effective and safe therapeutic approaches for patients with mild ischemic stroke by acute stroke. Sildenafil (SIL), a phosphodiesterase-5 inhibitor (PDE5i), is a known remedy for neurodegenerative disorders and vascular dementia through its angiogenesis and neurogenesis effects. In this study, we investigated the efficacy of PDE5i in the emotional and behavioral abnormalities in rats with mild ischemic stroke.
Methods We divided the rats into four groups as follows (n=20, respectively) : group 1, naïve; group 2, middle cerebral artery occlusion (MCAo30); group 3, MCAo30+SIL-pre; and group 4, MCAo30+SIL-post. In the case of drug administration groups, single dose of PDE5i (sildenafil citrate, 20 mg/kg) was given at 30-minute before and after reperfusion of MCAo in rats. After surgery, we investigated and confirmed the therapeutic effect of sildenafil on histology, immunofluorescence, behavioral assays and neural oscillations.
Results Sildenafil alleviated a neuronal loss and reduced the infarction volume. And results of behavior task and immunofluorescence shown possibility that anti-inflammation process and improve motor deficits sildenafil treatment after mild ischemic stroke. Furthermore, sildenafil treatment attenuated the alteration of theta-frequency rhythm in the CA1 region of the hippocampus, a known neural oscillatory marker for anxiety disorder in rodents, induced by mild ischemic stroke.
Conclusion PDE5i as effective therapeutic agents for anxiety and movement disorders and provide robust preclinical evidence to support the development and use of PDE5i for the treatment of mild ischemic stroke residual disorders.
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Minor Allele Frequencies and Molecular Pathways Differences for SNPs Associated with Amyotrophic Lateral Sclerosis in Subjects Participating in the UKBB and 1000 Genomes Project. J Clin Med 2021; 10:jcm10153394. [PMID: 34362180 PMCID: PMC8348602 DOI: 10.3390/jcm10153394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/12/2021] [Accepted: 07/28/2021] [Indexed: 12/25/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a complex disease with a late onset and is characterized by the progressive loss of muscular and respiratory functions. Although recent studies have partially elucidated ALS's mechanisms, many questions remain such as what the most important molecular pathways involved in ALS are and why there is such a large difference in ALS onset among different populations. In this study, we addressed this issue with a bioinformatics approach, using the United Kingdom Biobank (UKBB) and the European 1000 Genomes Project (1KG) in order to analyze the most ALS-representative single nucleotide polymorphisms (SNPs) that differ for minor allele frequency (MAF) between the United Kingdom population and some European populations including Finnish in Finland, Iberian population in Spain, and Tuscans in Italy. We found 84 SNPs associated with 46 genes that are involved in different pathways including: "Ca2+ activated K+ channels", "cGMP effects", "Nitric oxide stimulates guanylate cyclase", "Proton/oligopeptide cotransporters", and "Signaling by MAPK mutants". In addition, we revealed that 83% of the 84 SNPs can alter transcription factor-motives binding sites of 224 genes implicated in "Regulation of beta-cell development", "Transcription-al regulation by RUNX3", "Transcriptional regulation of pluripotent stem cells", and "FOXO-mediated transcription of cell death genes". In conclusion, the genes and pathways analyzed could explain the cause of the difference of ALS onset.
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Oprişoreanu AM, Smith HL, Krix S, Chaytow H, Carragher NO, Gillingwater TH, Becker CG, Becker T. Automated in vivo drug screen in zebrafish identifies synapse-stabilising drugs with relevance to spinal muscular atrophy. Dis Model Mech 2021; 14:259422. [PMID: 33973627 PMCID: PMC8106959 DOI: 10.1242/dmm.047761] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 03/10/2021] [Indexed: 12/14/2022] Open
Abstract
Synapses are particularly vulnerable in many neurodegenerative diseases and often the first to degenerate, for example in the motor neuron disease spinal muscular atrophy (SMA). Compounds that can counteract synaptic destabilisation are rare. Here, we describe an automated screening paradigm in zebrafish for small-molecule compounds that stabilize the neuromuscular synapse in vivo. We make use of a mutant for the axonal C-type lectin chondrolectin (chodl), one of the main genes dysregulated in SMA. In chodl-/- mutants, neuromuscular synapses that are formed at the first synaptic site by growing axons are not fully mature, causing axons to stall, thereby impeding further axon growth beyond that synaptic site. This makes axon length a convenient read-out for synapse stability. We screened 982 small-molecule compounds in chodl chodl-/- mutants and found four that strongly rescued motor axon length. Aberrant presynaptic neuromuscular synapse morphology was also corrected. The most-effective compound, the adenosine uptake inhibitor drug dipyridamole, also rescued axon growth defects in the UBA1-dependent zebrafish model of SMA. Hence, we describe an automated screening pipeline that can detect compounds with relevance to SMA. This versatile platform can be used for drug and genetic screens, with wider relevance to synapse formation and stabilisation.
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Affiliation(s)
- Ana-Maria Oprişoreanu
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Hannah L Smith
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Sophia Krix
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
| | - Helena Chaytow
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Neil O Carragher
- Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, EH4 2XR Edinburgh, UK
| | - Thomas H Gillingwater
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Catherina G Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB.,Euan MacDonald Centre for Motor Neurone Disease Research, University of Edinburgh, EH16 4SB Edinburgh, UK
| | - Thomas Becker
- Centre for Discovery Brain Sciences, University of Edinburgh, The Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB
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Uboldi AD, Wilde ML, Bader SM, Tonkin CJ. Environmental sensing and regulation of motility in Toxoplasma. Mol Microbiol 2020; 115:916-929. [PMID: 33278047 DOI: 10.1111/mmi.14661] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 12/28/2022]
Abstract
Toxoplasma and other apicomplexan parasites undergo a unique form of cellular locomotion referred to as "gliding motility." Gliding motility is crucial for parasite survival as it powers tissue dissemination, host cell invasion and egress. Distinct environmental cues lead to activation of gliding motility and have become a prominent focus of recent investigation. Progress has been made toward understanding what environmental cues are sensed and how these signals are transduced in order to regulate the machinery and cellular events powering gliding motility. In this review, we will discuss new findings and integrate these into our current understanding to propose a model of how environmental sensing is achieved to regulate gliding motility in Toxoplasma. Collectively, these findings also have implications for the understanding of gliding motility across Apicomplexa more broadly.
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Affiliation(s)
- Alessandro D Uboldi
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Mary-Louise Wilde
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Stefanie M Bader
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia
| | - Christopher J Tonkin
- Division of Infectious Disease and Immune Defense, The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,The Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
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6
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Duarte-Silva E, Peixoto CA. Molecular Mechanisms of Phosphodiesterase-5 Inhibitors on Neuronal Apoptosis. DNA Cell Biol 2018; 37:861-865. [PMID: 30234372 DOI: 10.1089/dna.2018.4410] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Phosphodiesterase-5 inhibitors (PDE5Is) have been shown to modulate cell death/cell survival in different in vivo and in vitro models of disease by activating many signaling pathways. This review aimed at elucidating how PDE5Is can inhibit apoptosis. In this study, we describe many signaling pathways involved with the mechanism of action of PDE5Is that ultimately inhibit apoptosis and thus promote cell survival.
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Affiliation(s)
- Eduardo Duarte-Silva
- 1 Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM) , Recife, Brazil .,2 Postgraduate Program in Biosciences and Biotechnology for Health (PPGBBS), Oswaldo Cruz Foundation (FIOCRUZ-PE)/Aggeu Magalhães Institute (IAM) , Recife, Brazil
| | - Christina Alves Peixoto
- 1 Laboratory of Ultrastructure, Aggeu Magalhães Institute (IAM) , Recife, Brazil .,3 Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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7
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Zaprinast diminished pain and enhanced opioid analgesia in a rat neuropathic pain model. Eur J Pharmacol 2018; 839:21-32. [PMID: 30213497 DOI: 10.1016/j.ejphar.2018.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 08/25/2018] [Accepted: 09/04/2018] [Indexed: 01/11/2023]
Abstract
The mechanism of neuropathic pain is complex and unclear. Based on our results, we postulate that an intensification of the kynurenine pathway occurs as a consequence of nerve injury. The G protein-coupled receptor 35 (GPR35) is important for kynurenine pathway activation. Cyclic GMP-specific phosphodiesterase inhibitors have also been shown to have beneficial effects on neuropathic pain. Therefore, the aims of our research were to elucidate how a substance that acts as both an agonist of GPR35 and an inhibitor of phosphodiesterase influences neuropathic pain in a rat model. Here, we demonstrated that preemptive and repeated intrathecal (i.t.) administration (16 h and 1 h before injury and then after nerve ligation daily for 7 days) of zaprinast (1 μg/5 μl) significantly attenuated mechanical (von Frey test) and thermal (cold plate test) hypersensitivity measured on day 7 after chronic constriction injury, and the effect of even a single injection lasted up to 24 h. Our data indicate that zaprinast diminished the number of IBA1-positive cells and consequently attenuated the levels of IL-1beta, IL-6, IL-18, and NOS2 in the lumbar spinal cord and/or dorsal root ganglia. Our results also demonstrated that zaprinast potentiated the analgesic properties of morphine and buprenorphine. In summary, in a neuropathic pain model, zaprinast significantly reduced pain symptoms and enhanced the effectiveness of opioids. Our data provide new evidence that modulation of both GPR35 and phosphodiesterase could be an important strategy for innovative pharmacological treatments designed to decrease hypersensitivity evoked by nerve injury.
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8
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Wareham LK, Buys ES, Sappington RM. The nitric oxide-guanylate cyclase pathway and glaucoma. Nitric Oxide 2018; 77:75-87. [PMID: 29723581 DOI: 10.1016/j.niox.2018.04.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/18/2018] [Accepted: 04/23/2018] [Indexed: 01/12/2023]
Abstract
Glaucoma is a prevalent optic neuropathy characterized by the progressive dysfunction and loss of retinal ganglion cells (RGCs) and their optic nerve axons, which leads to irreversible visual field loss. Multiple risk factors for the disease have been identified, but elevated intraocular pressure (IOP) remains the primary risk factor amenable to treatment. Reducing IOP however does not always prevent glaucomatous neurodegeneration, and many patients progress with the disease despite having IOP in the normal range. There is increasing evidence that nitric oxide (NO) is a direct regulator of IOP and that dysfunction of the NO-Guanylate Cyclase (GC) pathway is associated with glaucoma incidence. NO has shown promise as a novel therapeutic with targeted effects that: 1) lower IOP; 2) increase ocular blood flow; and 3) confer neuroprotection. The various effects of NO in the eye appear to be mediated through the activation of the GC- guanosine 3:5'-cyclic monophosphate (cGMP) pathway and its effect on downstream targets, such as protein kinases and Ca2+ channels. Although NO-donor compounds are promising as therapeutics for IOP regulation, they may not be ideal to harness the neuroprotective potential of NO signaling. Here we review evidence that supports direct targeting of GC as a novel pleiotrophic treatment for the disease, without the need for direct NO application. The identification and targeting of other factors that contribute to glaucoma would be beneficial to patients, particularly those that do not respond well to IOP-dependent interventions.
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Affiliation(s)
- Lauren K Wareham
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Rebecca M Sappington
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.
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9
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Ma Q, Zhang L. C-type natriuretic peptide functions as an innate neuroprotectant in neonatal hypoxic-ischemic brain injury in mouse via natriuretic peptide receptor 2. Exp Neurol 2018; 304:58-66. [PMID: 29501420 DOI: 10.1016/j.expneurol.2018.02.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 02/22/2018] [Accepted: 02/27/2018] [Indexed: 12/22/2022]
Abstract
Neonatal hypoxia-ischemia (HI) is the most common cause of brain injury in neonates, which leads to high neonatal mortality and severe neurological morbidity in later life (Vannucci, 2000; Volpe, 2001). Yet the molecular mechanisms of neuronal death and brain damage induced by neonatal HI remain largely elusive. Herein, using both in vivo and in vitro models, we determine an endogenous neuroprotectant role of c-type natriuretic peptide (CNP) in preserving neuronal survival after HI brain injury in mouse pups. Postnatal day 7 (P7) mouse pups with CNP deficiency (Nppclbab/lbab) exhibit increased brain infarct size and worsened long-term locomotor function after neonatal HI compared with wildtype control (Nppc+/+). In isolated primary cortical neurons, recombinant CNP dose-dependently protects primary neurons from oxygen-glucose deprivation (OGD) insult. This neuroprotective effect appears to be mediated through its cognate natriuretic peptide receptor 2 (NPR2), in that antagonization of NPR2, but not NPR3, exacerbates neuronal death and counteracts the protective effect of CNP on primary neurons exposed to OGD insult. Immunoblot and confocal microscopy demonstrate the abundant expression of NPR2 in neurons of the neonatal brain and in isolated primary cortical neurons as well. Moreover, similar to CNP deficiency, administration of NPR2 antagonist P19 via intracerebroventricular injection prior to HI results in exacerbated neuronal death and brain injury after HI. Altogether, the present study indicates that CNP and its cognate receptor NPR2 mainly expressed in neurons represent an innate neuroprotective mechanism in neonatal HI brain injury.
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Affiliation(s)
- Qingyi Ma
- The Lawrence D. Longo, MD Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Lubo Zhang
- The Lawrence D. Longo, MD Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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10
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Graetz C, Groppa S, Zipp F, Siller N. Preservation of neuronal function as measured by clinical and MRI endpoints in relapsing-remitting multiple sclerosis: how effective are current treatment strategies? Expert Rev Neurother 2018; 18:203-219. [PMID: 29411688 DOI: 10.1080/14737175.2018.1438190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Approved medications for relapsing-remitting multiple sclerosis have shown to be effective in terms of their anti-inflammatory potential. However, it is also crucial to evaluate what long-term effects a patient can expect from current MS drugs in terms of preventing neurodegeneration. Here we aim to provide an overview of the current treatment strategies in MS with a specific focus on potential neuroprotective effects. Areas covered: Randomized, double-blind and placebo or referral-drug controlled phase 2a/b and phase 3 trials were examined; non-blinded phase 4 studies (extension studies) were included to provide long-term data, if not otherwise available. Endpoints considered were expanded disability status scale, various neuropsychological tests, percent brain volume change and T1-hypointense lesions as well as multiple sclerosis functional composite, confirmed disease progression, and no evidence of disease activity. Expert commentary: Overall, neuroprotective functions of classical MS therapeutics are not sufficiently investigated, but available data show limited effects. Thus, further research and development in neuroprotection are warranted. When counselling patients, potential long-term beneficial effects should be presented more conservatively.
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Affiliation(s)
- Christiane Graetz
- a Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2) , University Medical Center of the Johannes Gutenberg University Mainz , Mainz , Germany
| | - Sergiu Groppa
- a Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2) , University Medical Center of the Johannes Gutenberg University Mainz , Mainz , Germany
| | - Frauke Zipp
- a Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2) , University Medical Center of the Johannes Gutenberg University Mainz , Mainz , Germany
| | - Nelly Siller
- a Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2) , University Medical Center of the Johannes Gutenberg University Mainz , Mainz , Germany
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11
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Chen J, Li X, Li X, Chen D. The environmental pollutant BDE-209 regulates NO/cGMP signaling through activation of NMDA receptors in neurons. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:3397-3407. [PMID: 29151189 DOI: 10.1007/s11356-017-0651-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/31/2017] [Indexed: 06/07/2023]
Abstract
The common flame retardant decabrominated diphenyl ether (BDE-209) is a persistent organic pollutant. Epidemiological studies have revealed that prenatal or postnatal exposure to BDE-209 can result in delayed cognitive development, and BDE-209 has been shown to be toxic to cultured neurons with maturation interference effects. However, its neurotoxic mechanism remains unclear. Nitric oxide/cyclic guanosine monophosphate (NO/cGMP) signaling plays an important role in regulating neuronal maturation. We examined the influence of BDE-209 (100, 200, and 400 nM) on NO production and cGMP levels signaling in rodent neurons in vitro, with or without pretreatment N-methyl-D-aspartate (NMDA) receptor antagonism. We found that nanomolar concentrations of BDE-209 affected levels of the second messengers NO and cGMP, and that these effects could be blocked by NMDA receptor antagonism. Moreover, BDE-209 activation of NMDA receptors inhibited the expression of phosphodiesterases (PDEs), which modulate intracellular cGMP levels, and increased the Bcl-2/Bax ratio, favoring apoptosis induction. Our studies implicate the NMDA-NO/cGMP pathway in the pathogenic mechanism through which BDE-209 induces neurotoxicity.
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Affiliation(s)
- Jingsi Chen
- Department of Fetal Medicine and Prenatal Diagnosis, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
- Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou, People's Republic of China, Guangzhou, 510150, China
- Key Laboratories for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, China
| | - Xiuying Li
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
| | - Xiaomei Li
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
| | - Dunjin Chen
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China.
- Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou, People's Republic of China, Guangzhou, 510150, China.
- Key Laboratories for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, China.
- , No.63, Duobao Road, Guangzhou, 510150, China.
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12
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Mackenzie AE, Milligan G. The emerging pharmacology and function of GPR35 in the nervous system. Neuropharmacology 2017; 113:661-671. [DOI: 10.1016/j.neuropharm.2015.07.035] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 07/20/2015] [Accepted: 07/27/2015] [Indexed: 02/07/2023]
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13
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Heckman PRA, Blokland A, Prickaerts J. From Age-Related Cognitive Decline to Alzheimer's Disease: A Translational Overview of the Potential Role for Phosphodiesterases. ADVANCES IN NEUROBIOLOGY 2017; 17:135-168. [PMID: 28956332 DOI: 10.1007/978-3-319-58811-7_6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Phosphodiesterase inhibitors (PDE-Is) are pharmacological compounds enhancing cAMP and/or cGMP signaling. Both these substrates affect neural communication by influencing presynaptic neurotransmitter release and postsynaptic intracellular pathways after neurotransmitter binding to its receptor. Both cAMP and cGMP play an important role in a variety of cellular functions including neuroplasticity and neuroprotection. This chapter provides a translational overview of the effects of different classes of PDE-Is on cognition enhancement in age-related cognitive decline and Alzheimer's disease (AD). The most effective PDE-Is in preclinical models of aging and AD appear to be PDE2-Is, PDE4-Is and PDE5-Is. Clinical studies are relatively sparse and so far PDE1-Is and PDE4-Is showed some promising results. In the future, the demonstration of clinical proof of concept and the generation of isoform selective PDE-Is are the hurdles to overcome in developing safe and efficacious novel PDE-Is for the treatment of age-related cognitive decline and cognitive dysfunction in AD.
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Affiliation(s)
- Pim R A Heckman
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
- Department of Neuropsychology and Psychopharmacology, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - Arjan Blokland
- Department of Neuropsychology and Psychopharmacology, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, PO Box 616, 6200, MD, Maastricht, The Netherlands.
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Fox RJ, Coffey CS, Cudkowicz ME, Gleason T, Goodman A, Klawiter EC, Matsuda K, McGovern M, Conwit R, Naismith R, Ashokkumar A, Bermel R, Ecklund D, Koepp M, Long J, Natarajan S, Ramachandran S, Skaramagas T, Thornell B, Yankey J, Agius M, Bashir K, Cohen B, Coyle P, Delgado S, Dewitt D, Flores A, Giesser B, Goldman M, Jubelt B, Lava N, Lynch S, Miravalle A, Moses H, Ontaneda D, Perumal J, Racke M, Repovic P, Riley C, Severson C, Shinnar S, Suski V, Weinstock-Gutman B, Yadav V, Zabeti A. Design, rationale, and baseline characteristics of the randomized double-blind phase II clinical trial of ibudilast in progressive multiple sclerosis. Contemp Clin Trials 2016; 50:166-77. [PMID: 27521810 DOI: 10.1016/j.cct.2016.08.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/02/2016] [Accepted: 08/09/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Primary and secondary progressive multiple sclerosis (MS), collectively called progressive multiple sclerosis (PMS), is characterized by gradual progression of disability. The current anti-inflammatory treatments for MS have little or no efficacy in PMS in the absence of obvious active inflammation. Optimal biomarkers for phase II PMS trials is unknown. Ibudilast is an inhibitor of macrophage migration inhibitor factor and phosphodiesterases-4 and -10 and exhibits possible neuroprotective properties. The goals of SPRINT-MS study are to evaluate the safety and efficacy of ibudilast in PMS and to directly compare several imaging metrics for utility in PMS trials. METHODS SPRINT-MS is a randomized, placebo-controlled, phase II trial of ibudilast in patients with PMS. Eligible subjects were randomized 1:1 to receive either ibudilast (100mg/day) or placebo for 96weeks. Imaging is conducted every 24weeks for whole brain atrophy, magnetization transfer ratio, diffusion tensor imaging, cortical brain atrophy, and retinal nerve fiber layer thickness. Clinical outcomes include neurologic disability and patient reported quality of life. Safety assessments include laboratory testing, electrocardiography, and suicidality screening. RESULTS A total of 331 subjects were enrolled, of which 255 were randomized onto active study treatment. Randomized subjects were 53.7% female and mean age 55.7 (SD 7.3) years. The last subject is projected to complete the study in May 2017. CONCLUSION SPRINT-MS is designed to evaluate the safety and efficacy of ibudilast as a treatment for PMS while simultaneously validating five different imaging biomarkers as outcome metrics for use in future phase II proof-of-concept PMS trials.
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Affiliation(s)
- Robert J Fox
- Cleveland Clinic, Neurological Institute, Cleveland, OH, United States.
| | - Christopher S Coffey
- Data Coordinating Center, NeuroNEXT, University of Iowa, Iowa City, IA, United States
| | - Merit E Cudkowicz
- Clinical Coordinating Center, NeuroNEXT, Harvard Partners, Boston, MA, United States
| | | | - Andrew Goodman
- University of Rochester Medical Center, Rochester, NY, United States
| | | | | | - Michelle McGovern
- Clinical Coordinating Center, NeuroNEXT, Harvard Partners, Boston, MA, United States
| | - Robin Conwit
- National Institutes of Neurological Disease and Stroke, Bethesda, MD, United States
| | - Robert Naismith
- Washington University School of Medicine, St. Louis, MO, United States
| | - Akshata Ashokkumar
- Data Coordinating Center, NeuroNEXT, University of Iowa, Iowa City, IA, United States
| | - Robert Bermel
- Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Dixie Ecklund
- Data Coordinating Center, NeuroNEXT, University of Iowa, Iowa City, IA, United States
| | - Maxine Koepp
- Data Coordinating Center, NeuroNEXT, University of Iowa, Iowa City, IA, United States
| | - Jeffrey Long
- Data Coordinating Center, NeuroNEXT, University of Iowa, Iowa City, IA, United States
| | - Sneha Natarajan
- Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | | | - Thomai Skaramagas
- Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Brenda Thornell
- Clinical Coordinating Center, NeuroNEXT, Harvard Partners, Boston, MA, United States
| | - Jon Yankey
- Data Coordinating Center, NeuroNEXT, University of Iowa, Iowa City, IA, United States
| | - Mark Agius
- University of California at Davis, Sacramento, CA; currently at Barrows Neurological Institute, Phoenix, AZ, United States
| | - Khurram Bashir
- University of Alabama at Birmingham, Birmingham, AL, United States
| | - Bruce Cohen
- Northwestern University, Chicago, IL, United States
| | - Patricia Coyle
- State University of New York, Stony Brook, NY, United States
| | - Silvia Delgado
- University of Miami School of Medicine, Miami, FL, United States
| | - Dana Dewitt
- University of Utah, Salt Lake City, UT, United States
| | - Angela Flores
- University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Barbara Giesser
- University of California at Los Angeles, Los Angeles, CA, United States
| | - Myla Goldman
- University of Virginia at Charlottesville, Charlottesville, VA, United States
| | - Burk Jubelt
- State University of New York Upstate Medical University, Syracuse, NY, United States
| | - Neil Lava
- Emory University, Atlanta, GA, United States
| | - Sharon Lynch
- University of Kansas Medical Center, Kansas City, KS, United States
| | | | - Harold Moses
- Vanderbilt University, Nashville, TN, United States
| | - Daniel Ontaneda
- Cleveland Clinic, Neurological Institute, Cleveland, OH, United States
| | - Jai Perumal
- Weill Cornell Medical College, New York, NY, United States
| | - Michael Racke
- The Ohio State University, Columbus, OH, United States
| | - Pavle Repovic
- Swedish Medical Center at Seattle, Seattle, WA, United States
| | - Claire Riley
- Columbia University Medical Center, New York, NY, United States
| | | | | | - Valerie Suski
- University of Pittsburgh Medical Center, Pittsburgh, PA, United States
| | | | - Vijayshree Yadav
- Oregon Health and Science University, Portland, OR, United States
| | - Aram Zabeti
- University of Cincinnati, Cincinnati, OH, United States
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Protein Kinase G facilitates EGFR-mediated cell death in MDA-MB-468 cells. Exp Cell Res 2016; 346:224-32. [PMID: 27381222 DOI: 10.1016/j.yexcr.2016.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 06/30/2016] [Accepted: 07/02/2016] [Indexed: 02/06/2023]
Abstract
The Epidermal Growth Factor Receptor (EGFR) is a transmembrane receptor tyrosine kinase with critical implications in cell proliferation, migration, wound healing and the regulation of apoptosis. However, the EGFR has been shown to be hyper-expressed in a number of human malignancies. The MDA-MB-468 metastatic breast cell line is one example of this. This particular cell line hyper-expresses the EGFR and undergoes EGFR-mediated apoptosis in response to EGF ligand. The goal of this study was to identify the kinases that could be potential intermediates for the EGFR-mediated induction of apoptosis intracellularly. After identifying Cyclic GMP-dependent Protein Kinase G (PKG) as a plausible intermediate, we wanted to determine the temporal relationship of these two proteins in the induction of apoptosis. We observed a dose-dependent decrease in MDA-MB-468 cell viability, which was co-incident with increased PKG activity as measured by VASPSer239 phosphorylation. In addition, we observed a dose dependent decrease in cell viability, as well as an increase in apoptosis, in response to two different PKG agonists, 8-Bromo-cGMP and 8-pCPT-cGMP. MDA-MB-468 cells with reduced PKG activity had attenuated EGFR-mediated apoptosis. These findings indicate that PKG does not induce cell death via transphosphorylation of the EGFR. Instead, PKG activity occurs following EGFR activation. Together, these data indicate PKG as an intermediary in EGFR-mediated cell death, likely via apoptotic pathway.
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16
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Kara H, Degirmenci S, Ak A, Bayir A, Kayis SA, Uyar M, Akinci M, Acar D, Kocacan M, Akyurek F. Neuroprotective effects of sildenafil in experimental spinal cord injury in rabbits. Bosn J Basic Med Sci 2015; 15:38-44. [PMID: 25725143 DOI: 10.17305/bjbms.2015.1.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 10/10/2014] [Accepted: 10/08/2014] [Indexed: 01/03/2023] Open
Abstract
Neuroprotective agents such as methylprednisolone and sildenafil may limit damage after spinal cord injury. We evaluated the effects of methylprednisolone and sildenafil on biochemical and histologic changes after spinal cord injury in a rabbit model. Female New Zealand rabbits (32 rabbits) were allocated to 4 equal groups: laminectomy only (sham control) or laminectomy and spinal trauma with no other treatment (trauma control) or treatment with either methylprednisolone or sildenafil. Gelsolin and caspase-3 levels in cerebrospinal fluid and plasma were determined, and spinal cord histology was evaluated at 24 hours after trauma. There were no differences in mean cerebrospinal fluid or plasma levels of caspase-3 between the groups or within the groups from 0 to 24 hours after injury. From 0 to 24 hours after trauma, mean cerebrospinal fluid gelsolin levels significantly increased in the sildenafil group and decreased in the sham control and the trauma control groups. Mean plasma gelsolin level was significantly higher at 8 and 24 hours after trauma in the sildenafil than other groups. Histologic examination indicated that general structural integrity was better in the methylprednisolone in comparison with the trauma control group. General structural integrity, leptomeninges, white and grey matter hematomas, and necrosis were significantly improved in the sildenafil compared with the trauma control group. Caspase-3 levels in the cerebrospinal fluid and blood were not increased but gelsolin levels were decreased after spinal cord injury in trauma control rabbits. Sildenafil caused an increase in gelsolin levels and may be more effective than methylprednisolone at decreasing secondary damage to the spinal cord.
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Affiliation(s)
- Hasan Kara
- Department of Emergency Medicine, Faculty of Medicine, Selcuk University, Konya.
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17
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Peixoto CA, Nunes AKS, Garcia-Osta A. Phosphodiesterase-5 Inhibitors: Action on the Signaling Pathways of Neuroinflammation, Neurodegeneration, and Cognition. Mediators Inflamm 2015; 2015:940207. [PMID: 26770022 PMCID: PMC4681825 DOI: 10.1155/2015/940207] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 11/08/2015] [Indexed: 12/16/2022] Open
Abstract
Phosphodiesterase type 5 inhibitors (PDE5-Is) have recently emerged as a potential therapeutic strategy for neuroinflammatory, neurodegenerative, and memory loss diseases. Mechanistically, PDE5-Is produce an anti-inflammatory and neuroprotection effect by increasing expression of nitric oxide synthases and accumulation of cGMP and activating protein kinase G (PKG), the signaling pathway of which is thought to play an important role in the development of several neurodiseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). The aim of this paper was to review present knowledge of the signaling pathways that underlie the use of PDE5-Is in neuroinflammation, neurogenesis, learning, and memory.
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Affiliation(s)
- Christina Alves Peixoto
- 1Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), 50.740-465 Recife, PE, Brazil
- *Christina Alves Peixoto:
| | - Ana Karolina Santana Nunes
- 1Laboratório de Ultraestrutura, Centro de Pesquisa Aggeu Magalhães (FIOCRUZ), 50.740-465 Recife, PE, Brazil
- 2Universidade Federal de Pernambuco, 50.670-901 Recife, PE, Brazil
| | - Ana Garcia-Osta
- 3Neurobiology of Alzheimer's disease, Neurosciences Division, Center for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain
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Tsai CP, Lin FC, Lee JKW, Lee CTC. Aspirin use associated with amyotrophic lateral sclerosis: a total population-based case-control study. J Epidemiol 2014; 25:172-7. [PMID: 25721071 PMCID: PMC4310879 DOI: 10.2188/jea.je20140070] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background The association of aspirin use and nonsteroid anti-inflammatory drug (NSAID) use with amyotrophic lateral sclerosis (ALS) risk is unclear. This study determined whether use of any individual compound is associated with ALS risk by conducting a total population-based case-control study in Taiwan. Methods A total of 729 patients with newly diagnosed ALS who had a severely disabling disease certificate between January 1, 2002, and December 1, 2008, comprised the case group. These cases were compared with 7290 sex-, age-, residence-, and insurance premium-matched controls. Drug use by each Anatomical Therapeutic Chemical code was analyzed using conditional logistic regression models. False discovery rate (FDR)-adjusted P values were reported in order to avoid inflating false positives. Results Of the 1336 compounds, only the 266 with use cases exceeding 30 in our database were included in the screening analysis. Without controlling for steroid use, the analysis failed to reveal any compound that was inversely associated with ALS risk according to FDR criteria. After controlling for steroid use, we found use of the following compounds to be associated with ALS risk: aspirin, diphenhydramine (one of the antihistamines), and mefenamic acid (one of the NSAIDs). A multivariate analysis revealed that aspirin was independently inversely associated with ALS risk after controlling for diphenhydramine, mefenamic acid, and steroid use. The inverse association between aspirin and ALS was present predominately in patients older than 55 years. Conclusions The results of this study suggested that aspirin use might reduce the risk of ALS, and the benefit might be more prominent for older people.
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Affiliation(s)
- Ching-Piao Tsai
- Neurology, Neurological Institute, Taipei Veterans General Hospital and National Yang-Ming University
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19
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Protective effects of phosphodiesterase 2 inhibitor on depression- and anxiety-like behaviors: involvement of antioxidant and anti-apoptotic mechanisms. Behav Brain Res 2014; 268:150-158. [PMID: 24694839 DOI: 10.1016/j.bbr.2014.03.042] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/18/2014] [Accepted: 03/24/2014] [Indexed: 12/31/2022]
Abstract
Stress occurs in everyday life, but the relationship between stress and the onset or development of depression/anxiety remains unknown. Increasing evidence suggests that the impairment of antioxidant defense and the neuronal cell death are important in the process of emotional disorders. Chronic stress impairs the homeostasis of antioxidants/oxidation, which results in the aberrant stimulation of the cell cycle proteins where cGMP-PKG signaling is thought to have an inhibitory role. Phosphodiesterase 2 (PDE2) is linked to cGMP-PKG signaling and highly expressed in the limbic brain regions including hippocampus and amygdala, which may play important roles in the treatment of depression and anxiety. To address the possible effects of PDE2 inhibitors on depression-/anxiety-like behaviors and the underlying mechanisms, Bay 60-7550 (0.75, 1.5 and 3 mg/kg, i.p.) was administered 30 min before chronic stress. The results suggested that Bay 60-7550 not only restored the behavioral changes but also regulated Cu/Zn superoxide dismutase (SOD) levels differentially in hippocampus and amygdala, which were increased in the hippocampus while decreased in the amygdala. It was also significant that Bay 60-7550 regulated the abnormalities of pro- and anti-apoptotic components, such as Bax, Caspase 3 and Bcl-2, and the indicator of PKG signaling characterized by pVASP(ser239), in these two brain regions. The results suggested that Bay 60-7550 is able to alleviate oxidative stress and mediate part of the apoptotic machinery in neuronal cells possibly through SOD-cGMP/PKG-anti-apoptosis signaling and that inhibition of PDE2 may represent a novel therapeutic target for psychiatric disorders, such as depression and anxiety.
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20
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Presence of Phosphodiesterase Type 5 in the Spinal Cord and its Involvement in Bladder Outflow Obstruction Related Bladder Overactivity. J Urol 2013; 190:1430-5. [DOI: 10.1016/j.juro.2013.03.112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2013] [Indexed: 12/15/2022]
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21
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Liu C, Sherpa T, Varnum MD. Disease-associated mutations in CNGB3 promote cytotoxicity in photoreceptor-derived cells. Mol Vis 2013; 19:1268-81. [PMID: 23805033 PMCID: PMC3692405 DOI: 10.1167/13.9.1268] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 06/07/2013] [Indexed: 01/10/2023] Open
Abstract
Purpose To determine if achromatopsia associated F525N and T383fsX mutations in the CNGB3 subunit of cone photoreceptor cyclic nucleotide-gated (CNG) channels increases susceptibility to cell death in photoreceptor-derived cells. Methods Photoreceptor-derived 661W cells were transfected with cDNA encoding wild-type (WT) CNGA3 subunits plus WT or mutant CNGB3 subunits, and incubated with the membrane-permeable CNG channel activators 8-(4-chlorophenylthio) guanosine 3′,5′-cyclic monophosphate (CPT-cGMP) or CPT-adenosine 3′,5′-cyclic monophosphate (CPT-cAMP). Cell viability under these conditions was determined by measuring lactate dehydrogenase release. Channel ligand sensitivity was calibrated by patch-clamp recording after expression of WT or mutant channels in Xenopus oocytes. Results Coexpression of CNGA3 with CNGB3 subunits containing F525N or T383fsX mutations produced channels exhibiting increased apparent affinity for CPT-cGMP compared to WT channels. Consistent with these effects, cytotoxicity in the presence of 0.1 μM CPT-cGMP was enhanced relative to WT channels, and the increase in cell death was more pronounced for the mutation with the largest gain-of-function effect on channel gating, F525N. Increased susceptibility to cell death was prevented by application of the CNG channel blocker L-cis-diltiazem. Increased cytotoxicity was also found to be dependent on the presence of extracellular calcium. Conclusions These results indicate a connection between disease-associated mutations in cone CNG channel subunits, altered CNG channel-activation properties, and photoreceptor cytotoxicity. The rescue of cell viability via CNG channel block or removal of extracellular calcium suggests that cytotoxicity in this model depends on calcium entry through hyperactive CNG channels.
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Affiliation(s)
- Chunming Liu
- College of Optometry, Western University of Health Sciences, Pomona, CA, USA
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22
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Albrecht P, Henke N, Tien MLT, Issberner A, Bouchachia I, Maher P, Lewerenz J, Methner A. Extracellular cyclic GMP and its derivatives GMP and guanosine protect from oxidative glutamate toxicity. Neurochem Int 2013; 62:610-9. [PMID: 23357478 DOI: 10.1016/j.neuint.2013.01.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 01/13/2013] [Accepted: 01/18/2013] [Indexed: 11/15/2022]
Abstract
Cell death in response to oxidative stress plays a role in a variety of neurodegenerative diseases and can be studied in detail in the neuronal cell line HT22, where extracellular glutamate causes glutathione depletion by inhibition of the glutamate/cystine antiporter system xc(-), elevation of reactive oxygen species and eventually programmed cell death caused by cytotoxic calcium influx. Using this paradigm, we screened 54 putative extracellular peptide or small molecule ligands for effects on cell death and identified extracellular cyclic guanosine monophosphate (cGMP) as a protective substance. Extracellular cGMP was protective, whereas the cell-permeable cGMP analog 8-pCPT-cGMP or the inhibition of cGMP degradation by phosphodiesterases was toxic. Interestingly, metabolites GMP and guanosine were even more protective than cGMP and the inhibition of the conversion of GMP to guanosine attenuated its effect, suggesting that GMP offers protection through its conversion to guanosine. Guanosine increased system xc(-) activity and cellular glutathione levels in the presence of glutamate, which can be explained by transcriptional upregulation of xCT, the functional subunit of system xc(-). However, guanosine also provided protection when added late in the cell death cascade and significantly reduced the number of calcium peaking cells, which was most likely not mediated by transcriptional mechanisms. We observed no changes in the classical protective pathways such as phosphorylation of Akt, ERK1/2 or induction of Nrf2 or ATF4. We conclude that extracellular guanosine protects against endogenous oxidative stress by two probably independent mechanisms involving system xc(-) induction and inhibition of cytotoxic calcium influx.
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Affiliation(s)
- Philipp Albrecht
- Department of Neurology, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
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23
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Metallothioneins I/II are involved in the neuroprotective effect of sildenafil in focal brain injury. Neurochem Int 2012. [PMID: 23178801 DOI: 10.1016/j.neuint.2012.11.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We recently reported that administration of the non-selective cyclic GMP-phosphodiesterase (cGMP-PDE) inhibitor zaprinast to cortically cryoinjured rats results three days post-lesion in reduced neuronal cell death that was associated to decreased macrophage/microglial activation and oxidative stress and increased astrogliosis and angiogenesis. Similar effects have been observed in cryoinjured animals overexpressing metallothioneins I/II (MT-I/II), metal-binding cysteine-rich proteins that are up-regulated in response to injury. In this work we have examined the effect of administration of the selective PDE5 inhibitor sildenafil (10mg/kg, sc) 2h before and 24 and 48h after induction of cortical cryolesion in wild-type and MT-I/II-deficient mice. Our results show that in wild-type animals sildenafil induces similar changes in glial reactivity, angiogenesis and antioxidant and antiapoptotic effects in the cryolesioned cortex as those observed in rats with zaprinast, indicating that inhibition of PDE5 is responsible for the neuroprotective actions. However, these effects were not observed in mice deficient in MT-I/II. We further show that sildenafil significantly increases MT-I/II protein levels in homogenates of lesioned cortex and MT-I/II immunostaining in glial cells around the lesion. Taken together these results indicate that cGMP-mediated pathways regulate expression of MT-I/II and support the involvement of these proteins in the neuroprotective effects of sildenafil in focal brain lesion.
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Bollen E, Prickaerts J. Phosphodiesterases in neurodegenerative disorders. IUBMB Life 2012; 64:965-70. [PMID: 23129425 DOI: 10.1002/iub.1104] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 09/27/2012] [Indexed: 01/21/2023]
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) are responsible for the breakdown of cyclic nucleotides, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). As such, they are crucial regulators of levels of cyclic nucleotide-mediated signaling. cAMP signaling and cGMP signaling have been associated with neuroplasticity and protection, and influencing their levels in the cell by inhibition of PDEs has become a much studied target for treatment in a wide array of disorders, including neurodegenerative disorders. In this review, we will focus on the involvement of PDEs in neurodegenerative disorders. In comparison with preclinical work, data on human patients are scarce. Alzheimer's disease is associated with changes in PDE4, PDE7, and PDE8 expression in the brain. Altered functioning of PDE4 as well as PDE11 is associated with major depressive disorder. In multiple sclerosis, there are indications of alterations in expression of several PDE subtypes in the central nervous system; however, evidence is indirect. In Huntington's disease and Parkinson's disease, most research has focused on PDE1B and PDE10, because of their abundant presence in striatal neurons. In another rare, neurodegenerative striatal motor disorder, that is, autosomal-dominant striatal degeneration, genetic defects in PDE8B gene are thought to underlie the neurodegenerative processes. Although the latter disorder has showed a causative dysfunction of PDEs, this does not hold for the neurodegenerative disorders discussed above, in which changes in PDE levels seemingly rather represent secondary changes and compensation to prior existing dysfunction. However, normalizing cyclic nucleotide signaling via PDE inhibition remains interesting for the treatment of neurodegenerative disorders.
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Affiliation(s)
- Eva Bollen
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
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25
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Saito Y, Yanagawa Y. Ca(2+)-activated ion currents triggered by ryanodine receptor-mediated Ca(2+) release control firing of inhibitory neurons in the prepositus hypoglossi nucleus. J Neurophysiol 2012; 109:389-404. [PMID: 23100137 DOI: 10.1152/jn.00617.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Spontaneous miniature outward currents (SMOCs) are known to exist in smooth muscles and peripheral neurons, and evidence for the presence of SMOCs in central neurons has been accumulating. SMOCs in central neurons are induced through Ca(2+)-activated K(+) (K(Ca)) channels, which are activated through Ca(2+)-induced Ca(2+) release from the endoplasmic reticulum via ryanodine receptors (RyRs). Previously, we found that some neurons in the prepositus hypoglossi nucleus (PHN) showed spontaneous outward currents (SOCs). In the present study, we used whole cell recordings in slice preparations of the rat brain stem to investigate the following: 1) the ionic mechanisms of SOCs, 2) the types of neurons exhibiting frequent SOCs, and 3) the effect of Ca(2+)-activated conductance on neuronal firing. Pharmacological analyses revealed that SOCs were induced via the activation of small-conductance-type K(Ca) (SK) channels and RyRs, indicating that SOCs correspond to SMOCs. An analysis of the voltage responses to current pulses of the fluorescence-expressing inhibitory neurons of transgenic rats revealed that inhibitory neurons frequently exhibited SOCs. Abolition of SOCs via blockade of SK channels enhanced the frequency of spontaneous firing of inhibitory PHN neurons. However, abolition of SOCs via blockade of RyRs reduced the firing frequency and hyperpolarized the membrane potential. Similar reductions in firing frequency and hyperpolarization were also observed when Ca(2+)-activated nonselective cation (CAN) channels were blocked. These results suggest that, in inhibitory neurons in the PHN, Ca(2+) release via RyRs activates SK and CAN channels, and these channels regulate spontaneous firing in a complementary manner.
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Affiliation(s)
- Yasuhiko Saito
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
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Reneerkens OA, Rutten K, Akkerman S, Blokland A, Shaffer CL, Menniti FS, Steinbusch HW, Prickaerts J. Phosphodiesterase type 5 (PDE5) inhibition improves object recognition memory: Indications for central and peripheral mechanisms. Neurobiol Learn Mem 2012; 97:370-9. [DOI: 10.1016/j.nlm.2012.02.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 02/16/2012] [Accepted: 02/27/2012] [Indexed: 01/10/2023]
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The role of adrenergic and cholinergic receptors on the antinociception of sildenafil in the spinal cord of rats. Neurosci Lett 2011; 502:99-102. [PMID: 21820036 DOI: 10.1016/j.neulet.2011.07.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 07/18/2011] [Accepted: 07/19/2011] [Indexed: 11/22/2022]
Abstract
The role played by spinal adrenergic and cholinergic receptors in the antinociceptive effects of intrathecal sildenafil in formalin-induced nociception was examined. Intrathecal catheters were inserted into the subarachnoid space of male Sprague-Dawley rats, and nociception was assessed using the formalin test, consisting of a subcutaneous injection of 50μL of 5% formalin solution into the hind paw. We examined the effects of an alpha 1 adrenergic receptor antagonist (prazosin), an alpha 2 adrenergic receptor antagonist (yohimbine), a muscarinic acetylcholine receptor antagonist (atropine), and a nicotinic acetylcholine receptor antagonist (mecamylamine) on sildenafil-induced antinociception. Intrathecal sildenafil (3, 10, and 30μg) suppressed, in a dose-dependent manner, formalin-induced flinching during phases 1 and 2 of the test. Intrathecal sildenafil (30μg) could not show any effects against intrathecal prazosin (3μg), yohimbine (10μg), atropine (10μg), and mecamylamine (10μg) pretreatment during both phases of the formalin test. These results suggest that intrathecal sildenafil effectively attenuated the pain evoked by formalin injection. Additionally, spinal alpha 1, alpha 2, muscarinic and nicotinic receptors might play a role in sildenafil-induced antinociception.
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Pifarre P, Prado J, Baltrons MA, Giralt M, Gabarro P, Feinstein DL, Hidalgo J, Garcia A. Sildenafil (Viagra) ameliorates clinical symptoms and neuropathology in a mouse model of multiple sclerosis. Acta Neuropathol 2011; 121:499-508. [PMID: 21234581 DOI: 10.1007/s00401-010-0795-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 12/21/2010] [Accepted: 12/30/2010] [Indexed: 12/14/2022]
Abstract
Cyclic GMP (cGMP)-mediated pathways regulate inflammatory responses in immune and CNS cells. Recently, cGMP phosphodiesterase inhibitors such as sildenafil, commonly used to treat sexual dysfunction in humans including multiple sclerosis (MS) patients, have been reported to be neuroprotective in animal models of stroke, Alzheimer's disease, and focal brain lesion. In this work, we have examined if sildenafil ameliorates myelin oligodendrocyte glycoprotein peptide (MOG₃₅₋₅₅)-induced experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. We show for the first time that treatment with sildenafil after disease onset markedly reduces the clinical signs of EAE by preventing axonal loss and promoting remyelination. Furthermore, sildenafil decreases CD3+ leukocyte infiltration and microglial/macrophage activation in the spinal cord, while increasing forkhead box transcription factor 3-expressing T regulatory cells (Foxp3 Tregs). However, sildenafil treatment did not significantly affect MOG₃₅₋₅₅-stimulated proliferation or release of Th1/Th2 cytokines in splenocytes but decreased ICAM-1 in spinal cord infiltrated cells. The presence of reactive astrocytes forming scar-like structures around infiltrates was enhanced by sildenafil suggesting a possible mechanism for restriction of leukocyte spread into healthy parenchyma. These results highlight novel actions of sildenafil that may contribute to its beneficial effects in EAE and suggest that treatment with this widely used and well-tolerated drug may be a useful therapeutic intervention to ameliorate MS neuropathology.
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Affiliation(s)
- Paula Pifarre
- Institute of Biotechnology and Biomedicine, Universitat Autonoma de Barcelona, 08193 Bellaterra, Spain
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29
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Francis SH, Sekhar KR, Ke H, Corbin JD. Inhibition of cyclic nucleotide phosphodiesterases by methylxanthines and related compounds. Handb Exp Pharmacol 2011:93-133. [PMID: 20859794 DOI: 10.1007/978-3-642-13443-2_4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Naturally occurring methylxanthines were the first inhibitors of cyclic nucleotide (cN) phosphodiesterases (PDEs) to be discovered. To improve potency and specificity for inhibition of various PDEs in research and for treatment of diseases, thousands of compounds with related structures have now been synthesized. All known PDE inhibitors contain one or more rings that mimic the purine in the cN substrate and directly compete with cN for access to the catalytic site; this review focuses on inhibitors that contain a nucleus that is closely related to the xanthine ring of theophylline and caffeine and the purine ring of cNs. The specificity and potency of these compounds for blocking PDE action have been improved by appending groups at positions on the rings as well as by modification of the number and distribution of nitrogens and carbons in those rings. Several of these inhibitors are highly selective for particular PDEs; potent and largely selective PDE5 inhibitors are used clinically for treatment of erectile dysfunction [sildenafil (Viagra™), tadalafil (Cialis™) and vardenafil (Levitra™)] and pulmonary hypertension [sildenafil (Revatio™) and tadalafil (Adenocirca)]. Related compounds target other PDEs and show therapeutic promise for a number of maladies.
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Affiliation(s)
- Sharron H Francis
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232-0615, USA.
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30
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Francis SH, Busch JL, Corbin JD, Sibley D. cGMP-dependent protein kinases and cGMP phosphodiesterases in nitric oxide and cGMP action. Pharmacol Rev 2010; 62:525-63. [PMID: 20716671 DOI: 10.1124/pr.110.002907] [Citation(s) in RCA: 710] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To date, studies suggest that biological signaling by nitric oxide (NO) is primarily mediated by cGMP, which is synthesized by NO-activated guanylyl cyclases and broken down by cyclic nucleotide phosphodiesterases (PDEs). Effects of cGMP occur through three main groups of cellular targets: cGMP-dependent protein kinases (PKGs), cGMP-gated cation channels, and PDEs. cGMP binding activates PKG, which phosphorylates serines and threonines on many cellular proteins, frequently resulting in changes in activity or function, subcellular localization, or regulatory features. The proteins that are so modified by PKG commonly regulate calcium homeostasis, calcium sensitivity of cellular proteins, platelet activation and adhesion, smooth muscle contraction, cardiac function, gene expression, feedback of the NO-signaling pathway, and other processes. Current therapies that have successfully targeted the NO-signaling pathway include nitrovasodilators (nitroglycerin), PDE5 inhibitors [sildenafil (Viagra and Revatio), vardenafil (Levitra), and tadalafil (Cialis and Adcirca)] for treatment of a number of vascular diseases including angina pectoris, erectile dysfunction, and pulmonary hypertension; the PDE3 inhibitors [cilostazol (Pletal) and milrinone (Primacor)] are used for treatment of intermittent claudication and acute heart failure, respectively. Potential for use of these medications in the treatment of other maladies continues to emerge.
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Affiliation(s)
- Sharron H Francis
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, 2215 Garland Avenue, Nashville, TN 37232-0615, USA.
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31
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Sildenafil and glyceryl trinitrate reduce tactile allodynia in streptozotocin-injected rats. Eur J Pharmacol 2010; 631:17-23. [DOI: 10.1016/j.ejphar.2010.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 12/08/2009] [Accepted: 01/06/2010] [Indexed: 11/18/2022]
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32
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Menniti FS, Ren J, Coskran TM, Liu J, Morton D, Sietsma DK, Som A, Stephenson DT, Tate BA, Finklestein SP. Phosphodiesterase 5A inhibitors improve functional recovery after stroke in rats: optimized dosing regimen with implications for mechanism. J Pharmacol Exp Ther 2009; 331:842-50. [PMID: 19729580 DOI: 10.1124/jpet.109.156919] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Phosphodiesterase 5A (PDE5A) inhibitors improve functional recovery after middle cerebral artery occlusion (MCA-o) in rats. We used the PDE5A inhibitor 3-(4-(2-hydroxyethyl)piperazin-1-yl)-7-(6-methoxypyridin-3-yl)-1-(2-propoxyethyl)pyrido[3,4-b]pyrazin-2(1H)-one hydrochloride (PF-5) to determine the timing, duration, and degree of inhibition that yields maximum efficacy. We also investigated the localization of PDE5A to determine the tissues and cells that would be targets for PDE5 inhibition and that may mediate efficacy. Nearly complete inhibition of PDE5A, starting 24 h after MCA-o and continued for 7 days, resulted in nearly complete recovery of sensorimotor function that was sustained for 3 months. Delaying administration until 72 h after MCA-o resulted in equivalent efficacy, whereas delaying treatment for 14 days was ineffective. Treatment for 7 days was equivalently efficacious to 28 or 84 days of treatment, whereas treatment for 1 day was less effective. In the normal forebrain, PDE5A immunoreactivity was prominent in smooth muscle of meningeal arteries and a few smaller blood vessels, with weak staining in a few widely scattered cortical neurons and glia. At 24 and 48 h after MCA-o, the number and intensity of blood vessel staining increased in the infarcted cortex and striatum. PDE5A immunoreactivity also was increased at 48 h in putative microglia in penumbra, whereas there was no change in staining of the scattered cortical neurons. Given the window for efficacy and the PDE5A distribution, we hypothesize that efficacy results from an effect on vasculature, and perhaps modulation of microglial function, both of which may facilitate recovery of neuronal function.
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Affiliation(s)
- Frank S Menniti
- Neuroscience Biology, Pfizer Global Research & Development, Groton, Connecticut, USA.
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33
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Adenosine modulates ERK1/2, PI3K/Akt, and p38MAPK activation in the brain of the anoxia-tolerant turtle Trachemys scripta. J Cereb Blood Flow Metab 2008; 28:1469-77. [PMID: 18506199 DOI: 10.1038/jcbfm.2008.45] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The fate of cells under anoxic or ischemic stress is determined by intracellular signaling pathways including the mitogen-activated protein kinases (MAPKs) and phosphatidylinositol 3-kinase (PI3K/Akt), which affect downstream members of the apoptotic cascade. The freshwater turtle Trachemys scripta is extremely tolerant of anoxia, surviving up to 48 h at room temperature and for weeks at 3 degrees C in the complete absence of oxygen. We investigated the relationship between the neuroprotective purine adenosine, which increases greatly in the anoxic turtle brain, and MAPK and Akt activation during both short (1 h) and long-term (4 h) anoxia. ERK1/2 and Akt were significantly upregulated during the first hour of transition to full anoxia, but returned to baseline by 4 h anoxia. Conversely, p38MAPK levels were suppressed by a mean 71% at 1 h anoxia but also returned to baseline by 4 h anoxia. Systemic administration of the general adenosine receptor antagonist aminophylline abrogated the increases in both phosphorylated ERK1/2 and Akt, as well as the initial suppression of p38MAPK. The differential modulation of the MAPK/Akt pathways may be critical for neuronal protection during the initial transition to the hypometabolic state during anoxia, when physiologic stress is likely to be greatest.
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34
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Randomized, double-blind, placebo-controlled study of postoperative nightly sildenafil citrate for the prevention of erectile dysfunction after bilateral nerve-sparing radical prostatectomy. Int J Impot Res 2008; 20:479-86. [PMID: 18650827 DOI: 10.1038/ijir.2008.33] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Four weeks after bilateral nerve-sparing radical retropubic prostatectomy, men with normal erectile function before surgery were randomized to double-blind sildenafil (50 or 100 mg) or placebo nightly for 36 weeks, followed by an 8-week drug-free period before assessment of erectile function. Enrollment was prematurely ceased and only 76 men completed because, assuming a placebo response rate similar to the published literature (for example, 34% in meta-analysis), the 25% response at blinded interim review suggested a lack of treatment effect. On the contrary, spontaneous erectile function (a combined score of >or=8 for questions 3 and 4 of the International Index of Erectile Function and a positive response to 'Were erections good enough for satisfactory sexual activity?') occurred in only 4% of the placebo group (n=1 of 25) versus 27% (n=14 of 51, P=0.0156, Fisher's exact test) of the sildenafil group. Nightly sildenafil administration for 36 weeks after surgery markedly increased the return of normal spontaneous erections.
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35
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Caretti A, Bianciardi P, Ronchi R, Fantacci M, Guazzi M, Samaja M. Phosphodiesterase-5 inhibition abolishes neuron apoptosis induced by chronic hypoxia independently of hypoxia-inducible factor-1alpha signaling. Exp Biol Med (Maywood) 2008; 233:1222-30. [PMID: 18641057 DOI: 10.3181/0802-rm-73] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Exposure to hypoxia triggers a variety of adverse effects in the brain that arise from metabolic stress and induce neuron apoptosis. Overexpression of the hypoxia-inducible factor-1alpha (HIF-1alpha) is believed to be a major candidate in orchestrating the cell's defense against stress. To test the impact of HIF-1alpha on apoptosis during chronic hypoxia in vivo, we examined the protective effect of modulating the nitric oxide (NO)/cGMP pathway by sildenafil, a selective inhibitor of phosphodiesterase-5 (PDE-5). Male ICR/CD-1 mice were divided into 3 groups (n = 6/group): normoxic (21% O(2)), hypoxic (9.5% O(2)), and hypoxic with sildenafil (1.4-mg/kg intraperitoneal injections daily). At the end of the 8-day treatment period, the mice were euthanized and cerebral cortex biopsies were harvested for analyses. We found that sildenafil: (1) did not significantly alter the hypoxia-induced weight loss and hemoglobin increase, but did augment plasma nitrates+nitrites and the tissue content of cGMP and phosphorylated (P) NO synthase III; (2) reversed the hypoxia-induced neuron apoptosis (terminal deoxynucleotidyl transferase positivity and double-staining immunofluorescence, P = 0.009), presumably through increased bcl-2/Bax (P = 0.0005); and (3) did not affect HIF-1alpha, but rather blunted the hypoxia-induced increase in P-ERK1/2 (P = 0.0002) and P-p38 (P = 0.004). We conclude that upregulating the NO/cGMP pathway by PDE-5 inhibition during hypoxia reduces neuron apoptosis, regardless of HIF-1alpha, through an interaction involving ERK1/2 and p38.
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Affiliation(s)
- Anna Caretti
- University of Milan, San Paolo Hospital, via di Rudinì 8 I-20142 Milan, Italy
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36
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Masood A, Nadeem A, Mustafa SJ, O'Donnell JM. Reversal of oxidative stress-induced anxiety by inhibition of phosphodiesterase-2 in mice. J Pharmacol Exp Ther 2008; 326:369-79. [PMID: 18456873 DOI: 10.1124/jpet.108.137208] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The pathogenesis of several neuropsychiatric disorders, including anxiety and depression, has been linked to oxidative stress, in part via alterations in cyclic nucleotide signaling. Phosphodiesterase-2 (PDE2), which regulates cGMP and cAMP signaling, may affect anxiety-related behavior through reduction of oxidative stress. The present study evaluated the effects of oxidative stress on behavior and assessed the anxiolytic effects of the PDE2 inhibitor Bay 60-7550 [(2-(3,4-dimethoxybenzyl)-7-{(1R)-1-[(1R)-1-hydroxyethyl]-4-phenylbutyl}-5-methyl imidazo-[5,1-f][1,2,4]triazin-4(3H)-one)]. Treatment of mice with L-buthionine-(S,R)-sulfoximine (300 mg/kg), an inducer of oxidative stress, caused anxiety-like behavioral effects in elevated plusmaze, open-field, and hole-board tests through the NADPH oxidase pathway; these effects were antagonized by Bay 60-7550 (3 mg/kg) and apocynin (3 mg/kg), an inhibitor of NADPH oxidase. The Bay 60-7550-mediated decrease in oxidative stress (i.e., superoxide anion and reactive oxygen species generation in cultured neurons and total antioxidant capacity and lipid peroxides in amygdala and hypothalamus) and expression of NADPH oxidase subunits (i.e., p47 phox and gp91 phox expression in amygdala, hypothalamus, and cultured neurons) was associated with increased cGMP and phosphorylation of vasodilator-stimulated phosphoprotein at Ser239, suggesting an important role of cGMP-protein kinase G signaling in reduction of anxiety. Overall, the present results indicate that oxidative stress induces anxiety-like behavior in mice and that PDE2 inhibition reverses it through an increase in cGMP signaling. Thus, PDE2 may be a novel pharmacological target for treatment of anxiety in neuropsychiatric and neurodegenerative disorders that involve oxidative stress.
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Affiliation(s)
- Anbrin Masood
- Department of Behavioral Medicine and Psychiatry and Neurobiology and Anatomy, West Virginia University Health Sciences Center, P.O. Box 9128, Morgantown, WV 26506, USA.
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37
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Are multiple sclerosis and amyotrophic lateral sclerosis autoimmune disorders of endogenous vasoactive neuropeptides? Med Hypotheses 2008; 70:413-8. [DOI: 10.1016/j.mehy.2007.04.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Accepted: 04/27/2007] [Indexed: 12/11/2022]
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38
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PDE inhibitors in psychiatry--future options for dementia, depression and schizophrenia? Drug Discov Today 2007; 12:870-8. [PMID: 17933689 DOI: 10.1016/j.drudis.2007.07.023] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 07/21/2007] [Accepted: 07/23/2007] [Indexed: 02/07/2023]
Abstract
Phosphodiesterases are key enzymes in cellular signalling pathways. They degrade cyclic nucleotides and their inhibition via specific inhibitors offers unique 'receptor-independent' opportunities to modify cellular function. An increasing number of in vitro and animal model studies point to innovative treatment options in neurology and psychiatry. This review critiques a selection of recent studies and developments with a focus on dementia/neuroprotection, depression and schizophrenia. Despite increased interest among the clinical neurosciences, there are still no approved PDE inhibitors for clinical use in neurology or psychiatry. Adverse effects are a major impediment for clinical approval. It is therefore necessary to search for more specific inhibitors at the level of different PDE sub-families and isoforms.
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Chen RW, Williams AJ, Liao Z, Yao C, Tortella FC, Dave JR. Broad spectrum neuroprotection profile of phosphodiesterase inhibitors as related to modulation of cell-cycle elements and caspase-3 activation. Neurosci Lett 2007; 418:165-9. [PMID: 17398001 DOI: 10.1016/j.neulet.2007.03.033] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2006] [Revised: 03/06/2007] [Accepted: 03/09/2007] [Indexed: 10/23/2022]
Abstract
Cellular injury can involve the aberrant stimulation of cell cycle proteins in part through activation of phosphodiesterases (PDEs) and downstream expression of cell-cycle components such as cyclin D1. In mature non-proliferating cells activation of the cell cycle can lead to the induction of programmed cell death. In the present study, we investigated the in vitro neuroprotective efficacy and mechanism of action of vinpocetine (PDE1 inhibitor), trequinsin (PDE3 inhibitor), and rolipram (PDE4 inhibitor) in four mechanistically-distinct models of injury to primary rat cortical neurons as related to cell cycle regulation and apoptosis. Cellular injury was induced by hypoxia/hypoglycemia, veratridine (10 microM), staurosporine (1 microM), or glutamate (100 microM), resulting in average neuronal cell death rates of 43-48% as determined by MTT assay. Treatment with each PDE inhibitor (PDEI) resulted in a similar concentration-dependent neuroprotection profile with maximal effective concentrations of 5-10 microM (55-77% neuroprotection) in all four neurotoxicity models. Direct cytotoxicity due to PDE inhibition alone was not observed at concentrations below 100 microM. Further studies indicated that PDEIs can suppress the excitotoxic upregulation of cyclin D1 similar to the effects of flavopiridol, a cyclin-dependent kinase inhibitor, including suppression of pro-apoptotic caspase-3 activity. Overall, these data indicate that PDEIs are broad-spectrum neuroprotective agents acting through modulation of cell cycle elements and may offer a novel mode of therapy against acute injury to the brain.
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Affiliation(s)
- Ren-Wu Chen
- Department of Applied Neurobiology, Division of Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
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40
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Taniguchi Y, Tonai-Kachi H, Shinjo K. Zaprinast, a well-known cyclic guanosine monophosphate-specific phosphodiesterase inhibitor, is an agonist for GPR35. FEBS Lett 2006; 580:5003-8. [PMID: 16934253 DOI: 10.1016/j.febslet.2006.08.015] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 08/09/2006] [Accepted: 08/09/2006] [Indexed: 11/21/2022]
Abstract
We found that zaprinast, a well-known cyclic guanosine monophosphate-specific phosphodiesterase inhibitor, acted as an agonist for a G protein-coupled receptor, GPR35. In our intracellular calcium mobilization assay, zaprinast activated rat GPR35 strongly (geometric mean EC(50) value of 16nM), whereas it activated human GPR35 moderately (geometric mean EC(50) value of 840nM). We also demonstrated that GPR35 acted as a Galpha(i/o)- and Galpha(16)-coupled receptor for zaprinast when heterologously expressed in human embryonic kidney 293 (HEK 293) cells. These findings will facilitate the research on GPR35 and the drug discovery of the GPR35 modulators.
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Affiliation(s)
- Yasuhito Taniguchi
- Discovery Biology Research, Pfizer Global Research and Development, Nagoya Laboratories, Pfizer Inc., 5-2 Taketoyo, Aichi 470-2393, Japan
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41
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de Vente J, Markerink-van Ittersum M, Vles JSH. The role of phosphodiesterase isoforms 2, 5, and 9 in the regulation of NO-dependent and NO-independent cGMP production in the rat cervical spinal cord. J Chem Neuroanat 2006; 31:275-303. [PMID: 16621445 DOI: 10.1016/j.jchemneu.2006.02.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2005] [Revised: 02/17/2006] [Accepted: 02/20/2006] [Indexed: 10/24/2022]
Abstract
NO-responsive, cGMP-producing structures are abundantly present in the cervical spinal cord. NO-mediated cGMP synthesis has been implicated in nociceptive signaling and it has been demonstrated that cGMP has a role establishing synaptic connections in the spinal cord during development. As cGMP levels are controlled by the activity of soluble guanylyl cyclase (synthesis) and the phosphodiesterase (PDE) activity (breakdown), we studied the influence of PDE activity on NO-stimulated cGMP levels in the rat cervical spinal cord. cGMP-immunoreactivity (cGMP-IR) was localized in sections prepared from slices incubated in vitro. A number of reported PDE isoform-selective PDE inhibitors was studied in combination with diethylamineNONOate (DEANO) as a NO-donor including isobutyl-methylxanthine (IBMX) as a non-selective PDE inhibitor. We studied 8-methoxy-IBMX as a selective PDE1 inhibitor, erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and BAY 60-7550 as selective PDE2 inhibitors, sildenafil as a selective PDE5 inhibitor, dipyridamole as a mixed type PDE5 and PDE10 inhibitor, rolipram as a PDE4 inhibitor, and SCH 81566 as a selective PDE9 inhibitor. cGMP-IR structures (nerve fibers, axons, and terminals) were characterized using the following neurochemical markers: vesicular transporter molecules for acetylcholine, GABA, and glutamate (type 1 and type 2), parvalbumin, glutamate transporter molecule EAAT3, synaptophysin, substance P, calcitonin gene-related peptide, and isolectin B4. Most intense cGMP-IR was observed in the dorsal lamina. Ventral motor neurons were devoid of cGMP-IR. cGMP-IR was observed in GABAergic, and glutamatergic terminals in all gray matter laminae. cGMP-IR was abundantly colocalized with anti-vesicular glutamate transporter 2 (vGLUT2), however not with the anti-vesicular glutamate transporter 1 (vGLUT1), suggesting a functional difference between structures expressing vGLUT1 or vGLUT2. cGMP-IR did not colocalize with substance P- or calcitonin-gene related peptide-IR structures, however did partially colocalize with isolectin B4 in the dorsal horn. cGMP-IR in cholinergic structures was observed in dorsal root fibers entering the spinal cord, occasionally in laminae 1-3, in laminae 8 and 9 in isolated boutons and in the C-type terminals, and in small cells and varicosities in lamina 10. This latter observation suggests that the proprioceptive interneurons arising in lamina 10 are also NO-responsive. No region-specific nor a constant co-expression of cGMP-IR with various neuronal markers was observed after incubation of the slices with one of the selected PDE inhibitors. Expression of the mRNA of PDE2, 5, and 9 was observed in all lamina. The ventral motor neurons and the ependymal cells lining the central canal expressed all three PDE isoforms. Incubation of the slices in the presence of IBMX, DEANO in combination with BAY 41-2272, a NO-independent activator of soluble guanylyl cyclase, provided evidence for endogenous NO synthesis in the slice preparations and enhanced cGMP-IR in all lamina. Under these conditions cGMP-IR colocalized with substance P in a subpopulation of substance P-IR fibers. It is concluded that NO functions as a retrograde neurotransmitter in the spinal cord but that also postsynaptic structures are NO-responsive by producing cGMP. cGMP-IR in a subpopulation of isolectin B4 positive fibers and boutons is indicative for a role of NO-cGMP signaling in nociceptive processing. cGMP levels in the spinal cord are controlled by the concerted action of a number of PDE isoforms, which can be present in the same cell.
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MESH Headings
- 3',5'-Cyclic-AMP Phosphodiesterases/drug effects
- 3',5'-Cyclic-AMP Phosphodiesterases/genetics
- 3',5'-Cyclic-AMP Phosphodiesterases/metabolism
- 3',5'-Cyclic-GMP Phosphodiesterases/drug effects
- 3',5'-Cyclic-GMP Phosphodiesterases/genetics
- 3',5'-Cyclic-GMP Phosphodiesterases/metabolism
- Animals
- Biomarkers/metabolism
- Cervical Vertebrae
- Cyclic GMP/biosynthesis
- Cyclic Nucleotide Phosphodiesterases, Type 1
- Cyclic Nucleotide Phosphodiesterases, Type 2
- Cyclic Nucleotide Phosphodiesterases, Type 5
- Enzyme Inhibitors/pharmacology
- Immunohistochemistry
- Male
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Neurotransmitter Agents/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Donors/pharmacology
- Pain/metabolism
- Pain/physiopathology
- Phosphoric Diester Hydrolases/drug effects
- Phosphoric Diester Hydrolases/genetics
- Phosphoric Diester Hydrolases/metabolism
- Plant Lectins
- Presynaptic Terminals/drug effects
- Presynaptic Terminals/metabolism
- Protein Isoforms/drug effects
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Rats
- Rats, Inbred Lew
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Spinal Cord/cytology
- Spinal Cord/metabolism
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Affiliation(s)
- J de Vente
- European Graduate School of Neuroscience (EURON), Maastricht University, Department of Psychiatry and Neuropsychology, UNS50, POB 616, 6200 MD Maastricht, The Netherlands.
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42
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Araiza-Saldaña CI, Reyes-García G, Bermúdez-Ocaña DY, Pérez-Severiano F, Granados-Soto V. Effect of diabetes on the mechanisms of intrathecal antinociception of sildenafil in rats. Eur J Pharmacol 2005; 527:60-70. [PMID: 16305795 DOI: 10.1016/j.ejphar.2005.10.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 09/27/2005] [Accepted: 10/05/2005] [Indexed: 11/19/2022]
Abstract
The mechanism of intrathecal antinociceptive action of the phosphodiesterase 5 inhibitor sildenafil was assessed in diabetic rats using the formalin test. Intrathecal administration of sildenafil (12.5-50 microg) produced a dose-related antinociception during both phases of the formalin test in non-diabetic and diabetic rats. Intrathecal pretreatment with N-L-nitro-arginine methyl ester (L-NAME, nitric oxide (NO) synthase inhibitor, 1-50 microg), 1H-(1,2,4)-oxadiazolo(4,2-a)quinoxalin-1-one (ODQ, guanylyl cyclase inhibitor, 1-10 microg), KT5823 (protein kinase G (PKG) inhibitor, 5-500 ng), charybdotoxin (large-conductance Ca2+-activated K+ channel blocker, 0.01-1 ng), apamin (small-conductance Ca2+-activated K+ channel blocker, 0.1-3 ng) and glibenclamide (ATP-sensitive K+ channel blocker, 12.5-50 microg), but not N-D-nitro-arginine methyl ester (D-NAME, 50 microg) or saline, significantly diminished sildenafil (50 microg)-induced antinociception in non-diabetic rats. Intrathecal administration of ODQ, KT5823, apamin and glibenclamide, but not L-NAME nor charybdotoxin, reversed intrathecal antinociception induced by sildenafil in diabetic rats. Results suggest that sildenafil produces its intrathecal antinociceptive effect via activation of NO-cyclic GMP-PKG-K+ channels pathway in non-diabetic rats. Data suggest that diabetes leads to a dysfunction in NO and large-conductance Ca2+-activated K+ channels. Sildenafil could have a role in the pharmacotherapy of diabetes-associated pain.
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Affiliation(s)
- Claudia Ivonne Araiza-Saldaña
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Coapa, Calzada de los Tenorios 235, Colonia Granjas Coapa, 14330 México, D.F., Mexico
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Shi X, Li X, Clark JD. Formalin injection causes a coordinated spinal cord CO/NO-cGMP signaling system response. Mol Pain 2005; 1:33. [PMID: 16297238 PMCID: PMC1310513 DOI: 10.1186/1744-8069-1-33] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Accepted: 11/18/2005] [Indexed: 12/02/2022] Open
Abstract
Background The CO/NO-cGMP signalling system participates in the regulation of many physiological processes. The roles this system plays in spinal cord nociceptive signalling are particularly important. While individual components have been examined in isolation, little study has been dedicated to understanding the regulation and functioning of the system as a whole. Results In these studies we examined the time course of expression of 13 genes coding for components of this system including isoforms of the heme oxygenase (HO), nitric oxide synthase (NOS), soluble guanylate cyclase (sGC), cGMP dependent protein kinase (PKG) and phosphodiesterase (PDE) enzyme systems. Of the 13 genes studied, 11 had spinal cord mRNA levels elevated at one or more time points up to 48 hours after hindpaw formalin injection. Of the 11 with elevated mRNA, 8 had elevated protein levels 48 hours after formalin injection when mechanical allodynia was maximal. No component had an increased protein level which did not have an increased mRNA level at one or more time points. Injection of morphine 10 mg/kg prior to formalin completely abolished the acute nociceptive behaviours, but did not alter the degree of sensitivity which developed in the formalin treated hind paws during the subsequent 48 hours. Morphine treatment did, however, eliminate formalin induced increases in enzyme protein levels. Conclusion Our results indicate that the expression of the components of the CO/NO-cGMP signalling system seems to be coordinated in such a way that a generalized multi-level enhancement rather than a tightly limited step specific response occurs with noxious stimulation. Furthermore, the analgesic morphine administered prior to noxious stimulation can prevent long-term changes in gene expression though not necessarily nociceptive sensitisation.
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Affiliation(s)
- Xiaoyou Shi
- Stanford University Department of Anesthesiology, Stanford, CA, USA
| | - Xiangqi Li
- Stanford University Department of Anesthesiology, Stanford, CA, USA
| | - J David Clark
- Stanford University Department of Anesthesiology, Stanford, CA, USA
- Veterans Affairs Palo Alto Healthcare System, Palo Alto, CA, USA
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Kume T, Kawai Y, Yoshida K, Nakamizo T, Kanki R, Sawada H, Katsuki H, Shimohama S, Sugimoto H, Akaike A. Protective effect of serofendic acid on glutamate-induced neurotoxicity in rat cultured motor neurons. Neurosci Lett 2005; 383:199-202. [PMID: 15955411 DOI: 10.1016/j.neulet.2005.04.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Revised: 04/04/2005] [Accepted: 04/04/2005] [Indexed: 10/25/2022]
Abstract
We have previously reported that a sulfur-containing neuroprotective substance named serofendic acid was purified and isolated from lipophilic extract of fetal calf serum (FCS). In the present study, we investigated the effect of serofendic acid on glutamate neurotoxicity using embryonic rat spinal cord culture. When cultures were exposed to glutamate (20 microM) with a glutamate transporter inhibitor L-trans-pyrrolidine-2,4-decarboxylate (PDC; 40 microM) for 24 h, motor neurons were injured through both N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methylisoxazole/kainate receptors. This glutamate neurotoxicity was attenuated by nitric oxide (NO) synthase inhibitors. Serofendic acid (0.1-5 microM) prevented glutamate neurotoxicity in a concentration-dependent manner. S-Nitrosocysteine (SNOC; 10 microM), an NO donor, induced motor neuronal death. Serofendic acid (5 microM) also prevented SNOC-induced neurotoxicity. These results indicate that serofendic acid protects cultured motor neurons from glutamate neurotoxicity by reducing the cytotoxic action of NO.
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Affiliation(s)
- Toshiaki Kume
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-shimoadachi-cho, Kyoto 606-8501, Japan
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Thippeswamy T, McKay JS, Morris R, Quinn J, Wong LF, Murphy D. Glial-mediated neuroprotection: evidence for the protective role of the NO-cGMP pathway via neuron-glial communication in the peripheral nervous system. Glia 2005; 49:197-210. [PMID: 15390094 DOI: 10.1002/glia.20105] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The NO-cGMP pathway has emerged as a neuroprotective signaling system involved in communication between neurons and glia. We have previously shown that axotomy or nerve growth factor (NGF)-deprivation of dorsal root ganglion (DRG) neurons leads to increased production of NO and at the same time an increase in cGMP production in their satellite glia cells. Blockade of NO or its receptor, the cGMP synthesizing enzyme soluble guanylate cyclase (sGC), results in apoptosis of neurons and glia. We now show that co-culture of neonatal DRG neurons with either Schwann cells pre-treated with an NO donor or a membrane-permeant cGMP analogue; or neurons maintained in the medium from Schwann cell cultures treated in the same way, prevents neuronal apoptosis. Both NO donor and cGMP treatment of Schwann cells results in synthesis of NGF and NT3. Furthermore, if the Schwann cells are previously infected with adenoviral vectors expressing a dominant negative sGC mutant transgene, treatment of these Schwann cells with an NO donor now fails to prevent neuronal apoptosis. Schwann cells treated in this way also fail to express neither cGMP nor neurotrophins. These findings suggest NO-sGC-cGMP-mediated NGF and NT3 synthesis by Schwann cells protect neurons.
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MESH Headings
- Animals
- Animals, Newborn
- Apoptosis/drug effects
- Apoptosis/physiology
- Cell Communication/physiology
- Cells, Cultured
- Coculture Techniques
- Culture Media, Conditioned/pharmacology
- Cyclic GMP/analogs & derivatives
- Cyclic GMP/metabolism
- Cyclic GMP/pharmacology
- Cytoprotection
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/metabolism
- Guanylate Cyclase
- Nerve Degeneration/metabolism
- Nerve Degeneration/prevention & control
- Neuroglia/metabolism
- Neurons/metabolism
- Neurons, Afferent/drug effects
- Neurons, Afferent/metabolism
- Neuroprotective Agents/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Donors/pharmacology
- Peripheral Nervous System/cytology
- Peripheral Nervous System/metabolism
- Rats
- Rats, Wistar
- Receptor, Nerve Growth Factor/drug effects
- Receptor, Nerve Growth Factor/metabolism
- Receptor, trkC/drug effects
- Receptor, trkC/metabolism
- Receptors, Cytoplasmic and Nuclear/genetics
- Schwann Cells/drug effects
- Schwann Cells/metabolism
- Signal Transduction/genetics
- Signal Transduction/physiology
- Soluble Guanylyl Cyclase
- Transfection
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Sival DA, van Weerden TW, Vles JSH, Timmer A, den Dunnen WFA, Staal-Schreinemachers AL, Hoving EW, Sollie KM, Kranen-Mastenbroek VJM, Sauer PJJ, Brouwer OF. Neonatal loss of motor function in human spina bifida aperta. Pediatrics 2004; 114:427-34. [PMID: 15286226 DOI: 10.1542/peds.114.2.427] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE In neonates with spina bifida aperta (SBA), leg movements innervated by spinal segments located caudal to the meningomyelocele are transiently present. This study in neonates with SBA aimed to determine whether the presence of leg movements indicates functional integrity of neuronal innervation and whether these leg movements disappear as a result of dysfunction of upper motor neurons (axons originating cranial to the meningomyelocele) and/or of lower motor neurons (located caudal to the meningomyelocele). METHODS Leg movements were investigated in neonates with SBA at postnatal day 1 (n = 18) and day 7 (n = 10). Upper and lower motor neuron dysfunction was assessed by neurologic examination (n = 18; disinhibition or inhibition of reflexes, respectively) and by electromyography (n = 12; absence or presence of denervation potentials, respectively). RESULTS Movements, related to spinal segments caudal to the meningomyelocele, were present in all neonates at postnatal day 1. At day 1, leg movements were associated with signs of both upper (10 of 18) and lower (17 of 18) motor neuron dysfunction caudal to the meningomyelocele. In 7 of 10 neonates restudied after the first postnatal week, leg movements had disappeared. The absence of leg movements coincided with loss of relevant reflexes, which had been present at day 1, indicating progression of lower motor neuron dysfunction. CONCLUSIONS We conclude that the presence of neonatal leg movements does not indicate integrity of functional lower motor neuron innervation by spinal segments caudal to the meningomyelocele. Present observations could explain why fetal surgery at the level of the meningomyelocele does not prevent loss of leg movements.
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Affiliation(s)
- Deborah A Sival
- Pediatric Neurology, Department of Pediatrics, University Hospital Groningen, PO Box 30.001, 9713 GZ Groningen, Netherlands.
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Kanki R, Nakamizo T, Yamashita H, Kihara T, Sawada H, Uemura K, Kawamata J, Shibasaki H, Akaike A, Shimohama S. Effects of mitochondrial dysfunction on glutamate receptor-mediated neurotoxicity in cultured rat spinal motor neurons. Brain Res 2004; 1015:73-81. [PMID: 15223368 DOI: 10.1016/j.brainres.2004.04.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2004] [Indexed: 12/11/2022]
Abstract
Glutamate-induced excitotoxicity is implicated as playing a key role in the pathogenesis of amyotrophic lateral sclerosis (ALS), and mitochondrial dysfunction is also found in ALS patients. We investigated the relationship between glutamate excitotoxicity and mitochondrial dysfunction elicited by rotenone (a complex I inhibitor), malonate (a complex II inhibitor), or antimycin (a complex III inhibitor), in primary cultures of the embryonic rat spinal cord. Rotenone and malonate induced relatively selective toxicity against motor neurons as compared to non-motor neurons, whereas antimycin caused non-selective toxicity. The toxicity of rotenone was prevented by a non-N-methyl-D-aspartate (NMDA) receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) but not by an NMDA receptor antagonist, 5-methyl-10, 11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate (MK-801). The toxicity of malonate was blocked by both CNQX and MK-801. The toxicity of antimycin was affected by neither CNQX nor MK-801. When mitochondrial complex I was mildly inhibited by a sub-lethal concentration of rotenone, AMPA-induced motor neuron death was significantly exacerbated. A sub-lethal concentration of malonate exacerbated both NMDA- and AMPA-induced motor neuron death. These data suggest that mitochondrial dysfunction predisposes motor neurons to ionotropic glutamate receptor-mediated excitotoxicity.
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Affiliation(s)
- Rie Kanki
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawaharacho, Sakyoku, Kyoto 606-8507, Japan
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Francis SH, Corbin JD. Molecular mechanisms and pharmacokinetics of phosphodiesterase-5 antagonists. Curr Urol Rep 2004; 4:457-65. [PMID: 14622499 DOI: 10.1007/s11934-003-0027-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The prominence of phosphodiesterase-5 (PDE-5) inhibitors in the treatment of male erectile dysfunction and other diseases related to vascular dysfunction mandates a comprehensive understanding of the properties and effects of these compounds. Three potent and selective PDE-5 inhibitors (sildenafil, tadalafil, and vardenafil) have been approved for clinical use. The clinical efficacy and safety profiles of these medications are related to their molecular mode of action, the selectivity for PDE-5, and the pharmacokinetic properties (absorption, bioavailability, time to onset of action, distribution, metabolism, and elimination). These PDE-5 inhibitors share some common properties with regard to mechanisms of action and selectivities for PDE-5. They also have distinctive characteristics that may impact their clinical use. This article focuses on the basic biochemistry of cyclic guanosine monophosphate signaling and the pharmacokinetic parameters that describe characteristics of drug action of these PDE-5 inhibitors in facilitating smooth muscle relaxation, leading to improved penile erectile response or causing side effects.
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Affiliation(s)
- Sharron H Francis
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Light Hall Room 702, Nashville, TN 37232-0615, USA.
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