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Vo KC, Ruga L, Psathaki OE, Franzkoch R, Distler U, Tenzer S, Hensel M, Hegemann P, Gupta N. Plasticity and therapeutic potential of cAMP and cGMP-specific phosphodiesterases in Toxoplasma gondii. Comput Struct Biotechnol J 2022; 20:5775-5789. [PMID: 36382189 PMCID: PMC9619220 DOI: 10.1016/j.csbj.2022.09.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/03/2022] Open
Abstract
Toxoplasma gondii is a common zoonotic protozoan pathogen adapted to intracellular parasitism in many host cells of diverse organisms. Our previous work has identified 18 cyclic nucleotide phosphodiesterase (PDE) proteins encoded by the parasite genome, of which 11 are expressed during the lytic cycle of its acutely-infectious tachyzoite stage in human cells. Here, we show that ten of these enzymes are promiscuous dual-specific phosphodiesterases, hydrolyzing cAMP and cGMP. TgPDE1 and TgPDE9, with a Km of 18 μM and 31 μM, respectively, are primed to hydrolyze cGMP, whereas TgPDE2 is highly specific to cAMP (Km, 14 μM). Immuno-electron microscopy revealed various subcellular distributions of TgPDE1, 2, and 9, including in the inner membrane complex, apical pole, plasma membrane, cytosol, dense granule, and rhoptry, indicating spatial control of signaling within tachyzoites. Notably, despite shared apical location and dual-catalysis, TgPDE8 and TgPDE9 are fully dispensable for the lytic cycle and show no functional redundancy. In contrast, TgPDE1 and TgPDE2 are individually required for optimal growth, and their collective loss is lethal to the parasite. In vitro phenotyping of these mutants revealed the roles of TgPDE1 and TgPDE2 in proliferation, gliding motility, invasion and egress of tachyzoites. Moreover, our enzyme inhibition assays in conjunction with chemogenetic phenotyping underpin TgPDE1 as a target of commonly-used PDE inhibitors, BIPPO and zaprinast. Finally, we identified a retinue of TgPDE1 and TgPDE2-interacting kinases and phosphatases, possibly regulating the enzymatic activity. In conclusion, our datasets on the catalytic function, physiological relevance, subcellular localization and drug inhibition of key phosphodiesterases highlight the previously-unanticipated plasticity and therapeutic potential of cyclic nucleotide signaling in T. gondii.
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Key Words
- 3′IT, 3′-insertional tagging
- Apicomplexa
- COS, crossover sequence
- CRISPR, clustered regularly interspaced short palindromic repeats
- DHFR-TS, dihydrofolate reductase – thymidylate synthase
- HFF, human foreskin fibroblast
- HXGPRT, hypoxanthine-xanthine-guanine phosphoribosyl transferase
- IMC, inner membrane complex
- Lytic cycle
- MoI, multiplicity of infection
- PDE, phosphodiesterase
- PKA, protein kinase A
- PKG, protein kinase G
- PM, plasma membrane
- Phosphodiesterase
- S. C., selection cassette
- TEM, transmission electron microscopy
- Tachyzoite
- cAMP & cGMP signaling
- sgRNA, single guide RNA
- smHA, spaghetti monster-HA
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Affiliation(s)
- Kim Chi Vo
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Liberta Ruga
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Olympia Ekaterini Psathaki
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Rico Franzkoch
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Ute Distler
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes-Gutenberg University Mainz, Mainz, Germany
| | - Michael Hensel
- University of Osnabrück, Center of Cellular Nanoanalytics (CellNanOs), Integrated Bioimaging Faciltiy (iBiOs), Germany
| | - Peter Hegemann
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS-P), Hyderabad, India
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Bozkurt B, Nair AP, Misra A, Scott CZ, Mahar JH, Fedson S. Neprilysin Inhibitors in Heart Failure: The Science, Mechanism of Action, Clinical Studies, and Unanswered Questions. JACC Basic Transl Sci 2022; 8:88-105. [PMID: 36777165 PMCID: PMC9911324 DOI: 10.1016/j.jacbts.2022.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022]
Abstract
This article provides a contemporary review and a new perspective on the role of neprilysin inhibition in heart failure (HF) in the context of recent clinical trials and addresses potential mechanisms and unanswered questions in certain HF patient populations. Neprilysin is an endopeptidase that cleaves a variety of peptides such as natriuretic peptides, bradykinin, adrenomedullin, substance P, angiotensin I and II, and endothelin. It has a broad role in cardiovascular, renal, pulmonary, gastrointestinal, endocrine, and neurologic functions. The combined angiotensin receptor and neprilysin inhibitor (ARNi) has been developed with an intent to increase vasodilatory natriuretic peptides and prevent counterregulatory activation of the angiotensin system. ARNi therapy is very effective in reducing the risks of death and hospitalization for HF in patients with HF and New York Heart Association functional class II to III symptoms, but studies failed to show any benefits with ARNi when compared with angiotensin-converting enzyme inhibitors or angiotensin receptor blocker in patients with advanced HF with reduced ejection fraction or in patients following myocardial infarction with left ventricular dysfunction but without HF. These raise the questions about whether the enzymatic breakdown of natriuretic peptides may not be a very effective solution in advanced HF patients when there is downstream blunting of the response to natriuretic peptides or among post-myocardial infarction patients in the absence of HF when there may not be a need for increased natriuretic peptide availability. Furthermore, there is a need for additional studies to determine the long-term effects of ARNi on albuminuria, obesity, glycemic control and lipid profile, blood pressure, and cognitive function in patients with HF.
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Key Words
- ACE, angiotensin-converting enzyme
- ANP, atrial natriuretic peptide
- ARB, angiotensin receptor blocker
- ARN, angiotensin receptor–neprilysin
- ARNi
- Aβ, amyloid beta
- BNP, brain natriuretic peptide
- BP, blood pressure
- CSF, cerebrospinal fluid
- EF, ejection fraction
- FDA, U.S. Food and Drug Administration
- GFR, glomerular filtration rate
- HF, heart failure
- HFpEF, heart failure with preserved ejection fraction
- HFrEF, heart failure with reduced ejection fraction
- LV, left ventricular
- LVEF, left ventricular ejection fraction
- MI, myocardial infarction
- NEP inhibitor
- NT-proBNP, N-terminal pro–brain natriuretic peptide
- NYHA, New York Heart Association
- PDE, phosphodiesterase
- RAAS, renin-angiotensin-aldosterone system
- UACR, urinary albumin/creatine ratio
- angiotensin receptor–neprilysin inhibitor
- cGMP, cyclic guanosine monophosphate
- eGFR, estimated glomerular filtration rate
- heart failure
- neprilysin
- neprilysin inhibitor
- sacubitril
- sacubitril/valsartan
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Affiliation(s)
- Biykem Bozkurt
- Winters Center for Heart Failure Research, Cardiovascular Research Institute, Baylor College of Medicine, DeBakey Veterans Affairs Medical Center, Houston Texas, USA
- Cardiology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
- Michael E. DeBakey Veterans Affairs Medical Center, Houston Texas, USA
- Address for correspondence: Dr Biykem Bozkurt, MEDVAMC, 2002 Holcombe Boulevard, Houston, Texas, 77030, USA.
| | - Ajith P. Nair
- Cardiology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Arunima Misra
- Cardiology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
- Michael E. DeBakey Veterans Affairs Medical Center, Houston Texas, USA
| | - Claire Z. Scott
- Cardiology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Jamal H. Mahar
- Cardiology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Savitri Fedson
- Cardiology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
- Michael E. DeBakey Veterans Affairs Medical Center, Houston Texas, USA
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Wu D, Zheng X, Liu R, Li Z, Jiang Z, Zhou Q, Huang Y, Wu XN, Zhang C, Huang YY, Luo HB. Free energy perturbation (FEP)-guided scaffold hopping. Acta Pharm Sin B 2022; 12:1351-1362. [PMID: 35530128 PMCID: PMC9072250 DOI: 10.1016/j.apsb.2021.09.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/03/2021] [Accepted: 09/24/2021] [Indexed: 12/01/2022] Open
Abstract
Scaffold hopping refers to computer-aided screening for active compounds with different structures against the same receptor to enrich privileged scaffolds, which is a topic of high interest in organic and medicinal chemistry. However, most approaches cannot efficiently predict the potency level of candidates after scaffold hopping. Herein, we identified potent PDE5 inhibitors with a novel scaffold via a free energy perturbation (FEP)-guided scaffold-hopping strategy, and FEP shows great advantages to precisely predict the theoretical binding potencies ΔG FEP between ligands and their target, which were more consistent with the experimental binding potencies ΔG EXP (the mean absolute deviations| Δ G FEP - Δ G EXP | < 2 kcal/mol) than those ΔG MM-PBSA or ΔG MM-GBSA predicted by the MM-PBSA or MM-GBSA method. Lead L12 had an IC50 of 8.7 nmol/L and exhibited a different binding pattern in its crystal structure with PDE5 from the famous starting drug tadalafil. Our work provides the first report via the FEP-guided scaffold hopping strategy for potent inhibitor discovery with a novel scaffold, implying that it will have a variety of future applications in rational molecular design and drug discovery.
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Key Words
- ABFE, absolute binding free energy
- BAR, Bennet acceptance ratio
- Binding potencies
- DCM, dichloromethane
- DMF, N,N-dimethylformamide
- DMSO, dimethyl sulfoxide
- Drug discovery
- FEP, free energy perturbation
- Free energy perturbation
- GAFF, general AMBER force field
- HPLC, high performance liquid chromatography
- HRMS, High resolution mass spectra
- IC50, half-inhibitory concentration
- IPTG, isopropyl b-d-thiogalactopyranoside
- LV, left ventricle
- MAD, mean absolute deviations
- MD, molecular dynamics
- MM-GBSA, molecular mechanics/generalized born surface area
- Molecular design
- PAH, pulmonary arterial hypertension
- PDB, protein data bank
- PDE, phosphodiesterase
- PDE5 inhibitors
- PDE5, phosphodiesterase-5
- PME, particle mesh Ewald
- Privileged scaffolds
- Pulmonary arterial hypertension
- RBFE, relative binding free energy
- RED, restraint energy distribution
- RESP, restrained electrostatic potential
- RV, right ventricle
- RVHI, right ventricle hypertrophy index
- SARs, structure–activity relationships
- Scaffold hopping
- THF, tetrahydrofuran
- TLC, thin-layer chromatography
- WT, wall thickness
- ip, intraperitoneal injection
- iv, intravenous administration
- mPAP, pulmonary artery pressure
- po, oral administration (per os)
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Affiliation(s)
- Deyan Wu
- School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xuehua Zheng
- School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, China
| | - Runduo Liu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhe Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zan Jiang
- School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, China
| | - Qian Zhou
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Yue Huang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xu-Nian Wu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Chen Zhang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Yi-You Huang
- School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Hai-Bin Luo
- School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
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Iwakiri Y, Trebicka J. Portal hypertension in cirrhosis: Pathophysiological mechanisms and therapy. JHEP Rep 2021; 3:100316. [PMID: 34337369 DOI: 10.1016/j.jhepr.2021.100316] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 04/19/2021] [Accepted: 05/12/2021] [Indexed: 12/14/2022] Open
Abstract
Portal hypertension, defined as increased pressure in the portal vein, develops as a consequence of increased intrahepatic vascular resistance due to the dysregulation of liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs), frequently arising from chronic liver diseases. Extrahepatic haemodynamic changes contribute to the aggravation of portal hypertension. The pathogenic complexity of portal hypertension and the unsuccessful translation of preclinical studies have impeded the development of effective therapeutics for patients with cirrhosis, while counteracting hepatic and extrahepatic mechanisms also pose a major obstacle to effective treatment. In this review article, we will discuss the following topics: i) cellular and molecular mechanisms of portal hypertension, focusing on dysregulation of LSECs, HSCs and hepatic microvascular thrombosis, as well as changes in the extrahepatic vasculature, since these are the major contributors to portal hypertension; ii) translational/clinical advances in our knowledge of portal hypertension; and iii) future directions.
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Key Words
- ACE2, angiogenesis-converting enzyme 2
- ACLF, acute-on-chronic liver failure
- AT1R, angiotensin II type I receptor
- CCL2, chemokine (C-C motif) ligand 2
- CCl4, carbon tetrachloride
- CLD, chronic liver disease
- CSPH, clinically significant portal hypertension
- Dll4, delta like canonical Notch ligand 4
- ECM, extracellular matrix
- EUS, endoscopic ultrasound
- FXR
- FXR, farnesoid X receptor
- HCC, hepatocellular carcinoma
- HRS, hepatorenal syndrome
- HSC
- HSCs, hepatic stellate cells
- HVPG, hepatic venous pressure gradient
- Hsp90, heat shock protein 90
- JAK2, Janus kinase 2
- KO, knockout
- LSEC
- LSEC, liver sinusoidal endothelial cells
- MLCP, myosin light-chain phosphatase
- NET, neutrophil extracellular trap
- NO
- NO, nitric oxide
- NSBB
- NSBBs, non-selective beta blockers
- PDE, phosphodiesterase
- PDGF, platelet-derived growth factor
- PIGF, placental growth factor
- PKG, cGMP-dependent protein kinase
- Rho-kinase
- TIPS
- TIPS, transjugular intrahepatic portosystemic shunt
- VCAM1, vascular cell adhesion molecule 1
- VEGF
- VEGF, vascular endothelial growth factor
- angiogenesis
- eNOS, endothelial nitric oxide synthase
- fibrosis
- liver stiffness
- statins
- β-Arr2, β-arrestin 2
- β1-AR, β1-adrenergic receptor
- β2-AR, β2-adrenergic receptor
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Hammerschmid D, Germani F, Drusin SI, Fagnen C, Schuster CD, Hoogewijs D, Marti MA, Venien-Bryan C, Moens L, Van Doorslaer S, Sobott F, Dewilde S. Structural modeling of a novel membrane-bound globin-coupled sensor in Geobacter sulfurreducens. Comput Struct Biotechnol J 2021; 19:1874-1888. [PMID: 33995893 PMCID: PMC8076648 DOI: 10.1016/j.csbj.2021.03.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/24/2021] [Accepted: 03/24/2021] [Indexed: 12/12/2022] Open
Abstract
Globin-coupled sensors (GCS) usually consist of three domains: a sensor/globin, a linker, and a transmitter domain. The globin domain (GD), activated by ligand binding and/or redox change, induces an intramolecular signal transduction resulting in a response of the transmitter domain. Depending on the nature of the transmitter domain, GCSs can have different activities and functions, including adenylate and di-guanylate cyclase, histidine kinase activity, aerotaxis and/or oxygen sensing function. The gram-negative delta-proteobacterium Geobacter sulfurreducens expresses a protein with a GD covalently linked to a four transmembrane domain, classified, by sequence similarity, as GCS (GsGCS). While its GD is fully characterized, not so its transmembrane domain, which is rarely found in the globin superfamily. In the present work, GsGCS was characterized spectroscopically and by native ion mobility-mass spectrometry in combination with cryo-electron microscopy. Although lacking high resolution, the oligomeric state and the electron density map were valuable for further rational modeling of the full-length GsGCS structure. This model demonstrates that GsGCS forms a transmembrane domain-driven tetramer with minimal contact between the GDs and with the heme groups oriented outward. This organization makes an intramolecular signal transduction less likely. Our results, including the auto-oxidation rate and redox potential, suggest a potential role for GsGCS as redox sensor or in a membrane-bound e-/H+ transfer. As such, GsGCS might act as a player in connecting energy production to the oxidation of organic compounds and metal reduction. Database searches indicate that GDs linked to a four or seven helices transmembrane domain occur more frequently than expected.
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Key Words
- AfGcHK, Anaeromyxobacter sp. Fw109-5 GcHK
- AsFRMF, Ascaris suum FRMF-amide receptor
- AvGReg, Azotobacter vinilandii Greg
- BpGReg, Bordetella pertussis Greg
- BsHemAT, Bacillus subtilis HemAT
- CCS, collision cross section
- CIU, collision-induced unfolding
- CMC, critical micelle concentration
- CV, cyclic voltammetry
- CeGLB26, Caenorhabditis elegans globin 26
- CeGLB33, Caenorhabditis elegans globin 33
- CeGLB6, Caenorhabditis elegans globin 6
- DDM, n-dodecyl-β-d-maltoside
- DPV, differential pulse voltammetry
- EcDosC, Escherichia coli Dos with DGC activity
- FMRF, H-Phe-Met-Arg-Phe-NH2 neuropeptide
- GCS, globin-coupled sensor
- GD, globin domain
- GGDEF, Gly-Gly-Asp-Glu-Phe motive
- Gb, globin
- Geobacter sulfurreducens
- GintHb, hemoglobin from Gasterophilus intestinalis
- Globin-coupled sensor
- GsGCS, Geobacter sulfurreducens GCS
- GsGCS162, GD of GsGCS
- IM-MS, ion mobility-mass spectrometry
- LmHemAC, Leishmania major HemAC
- MaPgb, Methanosarcina acetivorans protoglobin
- MtTrHbO, Mycobacterium tuberculosis truncated hemoglobin O
- NH4OAc, ammonium acetate
- OG, n-octyl-β-d-glucopyranoside
- PDE, phosphodiesterase
- PcMb, Physether catodon myoglobin
- PccGCS, Pectobacterium carotivorum GCS
- PsiE, phosphate-starvation-inducible E
- RR, resonance Raman
- SCE, saturated calomel electrode
- SHE, standard hydrogen electrode
- SaktrHb, Streptomyces avermitilis truncated hemoglobin-antibiotic monooxygenase
- SwMb, myoglobin from sperm whale
- TD, Transmitter domain
- TmD, Transmembrane domain
- Transmembrane domain
- Transmembrane-coupled globins
- mNgb, mouse neuroglobin
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Affiliation(s)
- Dietmar Hammerschmid
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
- Biomolecular & Analytical Mass Spectrometry, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Francesca Germani
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Salvador I. Drusin
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellòn 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - Charline Fagnen
- Sorbonne Université, UMR 7590, CNRS, Muséum National d’Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, IMPMC, 75005 Paris, France
| | - Claudio D. Schuster
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellòn 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - David Hoogewijs
- Section of Medicine, Department of Endocrinology, Metabolism and Cardiovascular System, University of Fribourg, Switzerland
| | - Marcelo A. Marti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellòn 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - Catherine Venien-Bryan
- Sorbonne Université, UMR 7590, CNRS, Muséum National d’Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, IMPMC, 75005 Paris, France
| | - Luc Moens
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Sabine Van Doorslaer
- Biophysics and Biomedical Physics, Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Frank Sobott
- Biomolecular & Analytical Mass Spectrometry, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, United Kingdom
| | - Sylvia Dewilde
- Proteinchemistry, Proteomics and Epigenetic Signalling, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
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Vo KC, Günay-Esiyok Ö, Liem N, Gupta N. The protozoan parasite Toxoplasma gondii encodes a gamut of phosphodiesterases during its lytic cycle in human cells. Comput Struct Biotechnol J 2020; 18:3861-3876. [PMID: 33335684 PMCID: PMC7720076 DOI: 10.1016/j.csbj.2020.11.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 01/21/2023] Open
Abstract
Toxoplasma genome harbors at least 18 phosphodiesterases encoded by distinct genes. Most parasite PDEs lack regulatory modules and are quite divergent from their human orthologs. Acutely-infectious tachyzoite stage of T. gondii expresses 11 PDEs with varied localizations. PDE8 and PDE9 are closely-related dual-substrate specific proteins residing in the apical pole. Homology modeling of PDE8 and PDE9 reveals a conserved 3D topology and substrate pocket. PDE9 is dispensable in tachyzoites, signifying a functional redundancy with PDE8.
Cyclic nucleotide signaling is pivotal to the asexual reproduction of Toxoplasma gondii, however little do we know about the phosphodiesterase enzymes in this widespread obligate intracellular parasite. Here, we identified 18 phosphodiesterases (TgPDE1-18) in the parasite genome, most of which form apicomplexan-specific clades and lack archetypal regulatory motifs often found in mammalian PDEs. Genomic epitope-tagging in the tachyzoite stage showed the expression of 11 phosphodiesterases with diverse subcellular distributions. Notably, TgPDE8 and TgPDE9 are located in the apical plasma membrane to regulate cAMP and cGMP signaling, as suggested by their dual-substrate catalysis and structure modeling. TgPDE9 expression can be ablated with no apparent loss of growth fitness in tachyzoites. Likewise, the redundancy in protein expression, subcellular localization and predicted substrate specificity of several other PDEs indicate significant plasticity and spatial control of cyclic nucleotide signaling during the lytic cycle. Our findings shall enable a rational dissection of signaling in tachyzoites by combinatorial mutagenesis. Moreover, the phylogenetic divergence of selected Toxoplasma PDEs from human counterparts can be exploited to develop parasite-specific inhibitors and therapeutics.
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Key Words
- 3′IT, 3′-insertional tagging
- AC, adenylate cyclase
- Apicomplexa
- Bradyzoite
- COS, crossover sequence
- CRISPR, clustered regularly interspaced short palindromic repeats
- EES, entero-epithelial stages
- FPKM, fragments per kilobase of exon model per million
- GC, guanylate cyclase
- GMQE, Global Model Quality Estimation
- HFF, human foreskin fibroblast
- HXGPRT, hypoxanthine-xanthine-guanine phosphoribosyltransferase
- IMC, inner membrane complex
- Lytic cycle
- MAEBL, merozoite adhesive erythrocytic binding ligand
- MOI, multiplicity of infection
- OCRE, octamer repeat
- PDE, phosphodiesterase
- PKA, protein kinase A
- PKG, protein kinase G
- PM, plasma membrane
- QMEAN, Quality Model Energy Analysis
- Tachyzoite
- cAMP and cGMP signaling
- sgRNA, single guide RNA
- smHA, spaghetti monster-HA
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Affiliation(s)
- Kim Chi Vo
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Özlem Günay-Esiyok
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nicolas Liem
- Experimental Biophysics, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany
| | - Nishith Gupta
- Department of Molecular Parasitology, Institute of Biology, Faculty of Life Sciences, Humboldt University, Berlin, Germany.,Department of Biological Sciences, Birla Institute of Technology and Science Pilani (BITS-P), Hyderabad, India
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Azouz AA, Saleh E, Abo-Saif AA. Aliskiren, tadalafil, and cinnamaldehyde alleviate joint destruction biomarkers; MMP-3 and RANKL; in complete Freund's adjuvant arthritis model: Downregulation of IL-6/JAK2/STAT3 signaling pathway. Saudi Pharm J 2020; 28:1101-1111. [PMID: 32922141 PMCID: PMC7474170 DOI: 10.1016/j.jsps.2020.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/28/2020] [Indexed: 12/29/2022] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune inflammatory disease, which is accompanied by progressive joint damage and disability. The intolerability of conventional antirheumatic drugs by some patients necessitates the search for effective antirheumatic agents having better tolerability. In the current work, we aimed to investigate the efficacy of cinnamaldehyde, tadalafil, and aliskiren as potential antirheumatic candidates and to explore their modulatory effects on joint destruction, inflammatory response, and intracellular signaling. Arthritis was induced in female Wistar rats by complete Freund's adjuvant (CFA) 0.4 ml s.c. on days 1, 4, and 7. Treated groups received their respective drugs, starting from day 13, daily for 3 weeks. Methotrexate and prednisolone were the standard antirheumatic drugs, while cinnamaldehyde, tadalafil, and aliskiren were the test agents. Treatment with cinnamaldehyde, tadalafil, or aliskiren reduced serum levels of rheumatoid factor, and pro-inflammatory cytokines; tumor necrosis factor-alpha and interleukin-6 (IL-6), along with elevated level of IL-10 which is an anti-inflammatory cytokine. Besides, cartilage and bone destruction biomarkers; matrix metalloproteinase-3 (MMP-3) and receptor activator of nuclear factor-kappa B ligand (RANKL); were significantly reduced after treatment with the test agents, which was further confirmed by histopathological investigation. The elevated protein expressions of phosphorylated-Janus kinase 2 (p-JAK2), phosphorylated-signal transducer and activator of transcription 3 (p-STAT3), and inducible nitric oxide synthase (iNOS) in articular tissue were markedly attenuated after treatment with cinnamaldehyde, tadalafil, or aliskiren, while that of endothelial nitric oxide synthase (eNOS) was greatly enhanced. In addition, oxidative stress and inflammatory markers such as malondialdehyde, nitric oxide, and myeloperoxidase were reduced in joint tissue after treatment with the test agents, while glutathione content was elevated. Furthermore, the renin inhibitor aliskiren produced effects close to those of the normal and methotrexate, the gold standard antirheumatic drug, in most of the measured parameters. Collectively, these findings led to the assumption that the downregulation of IL-6/JAK2/STAT3 signaling by cinnamaldehyde, tadalafil, and aliskiren could alleviate joint destruction by MMP-3 and RANKL, reduce iNOS, and enhance eNOS expressions. Moreover, aliskiren could be a promising therapeutic agent for RA, because of its ability to normalize most of the measured parameters after CFA-induced arthritis.
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Key Words
- Aliskiren
- CFA, complete Freund's adjuvant
- CFA-induced arthritis
- DMARD, disease-modifying antirheumatic drug
- GSH, reduced glutathione
- H&E, hematoxylin and eosin
- IL-10, interleukin-10
- IL-6, interleukin-6
- IL-6/JAK2/STAT3 signaling
- JAK2, Janus kinase 2
- MDA, malondialdehyde
- MMP-3
- MMP-3, matrix metalloproteinase-3
- MPO, myeloperoxidase
- NO, nitric oxide
- PDE, phosphodiesterase
- RA, rheumatoid arthritis
- RANKL
- RANKL, receptor activator of nuclear factor-kappa B ligand
- RAS, renin angiotensin system
- STAT3, signal transducer and activator of transcription 3
- TNF-α, tumor necrosis factor-alpha
- eNOS, endothelial nitric oxide synthase
- iNOS, inducible nitric oxide synthase
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Affiliation(s)
- Amany A Azouz
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt
| | - Esraa Saleh
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt.,Operations Pharmacy, General Fayoum Hospital, Fayoum, Egypt
| | - Ali A Abo-Saif
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Nahda University, Beni-Suef, Egypt
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Abstract
The understanding of the molecular basis of sea urchin behavior and sensory and motor systems lags far behind that of many other animal species. To investigate whole-animal behavior pharmacologically, we first demonstrated that immersion in drug solution is an effective drug administration route for sea urchins, whereas oral drug administration was found to be ineffective. Although intracoelomic injection was found to be effective at administering drugs, it was also found that injection itself can disrupt normal sea urchin behavior. Using the drug immersion procedure, we demonstrate that sea urchin locomotion and the sea urchin righting response are inhibited in a dose-dependent manner by the phosphodiesterase inhibitor theophylline and the transient receptor potential channel inhibitor 2-aminoethoxydiphenyl borate. The sea urchin righting response was also inhibited by the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester and the Ca2+ channel inhibitor diltiazem, which, along with theophylline and 2-aminoethoxydiphenyl borate, would all be expected to disrupt smooth muscle function, based on studies in other animals. In addition, the removal of extracellular Ca2+ also inhibited the righting response, whereas an inhibitor of intracellular Ca2+ release, thapsigargin, did not affect the righting response, indicating that extracellular Ca2+ rather than intracellular Ca2+ stores are required for righting.
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Key Words
- 2-APB, 2-aminoethoxydiphenyl borate
- DMSO, dimethyl sulfoxide
- L-NAME, N(G)-nitro-l-arginine methyl ester
- NO, nitric oxide
- PDE, phosphodiesterase
- SERCA, sarco/endoplasmic reticulum Ca2+-ATPase
- TRP, transient receptor potential
- TRPC, canonical-type TRP
- TRPM, melastatin-type TRP
- TRPV, vanilloid-type TRP
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9
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Nesbitt NM, Arora DP, Johnson RA, Boon EM. Modification of a bi-functional diguanylate cyclase-phosphodiesterase to efficiently produce cyclic diguanylate monophosphate. ACTA ACUST UNITED AC 2015; 7:30-7. [PMID: 28626712 DOI: 10.1016/j.btre.2015.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cyclic-diGMP is a bacterial messenger that regulates many physiological processes, including many attributed to pathogenicity. Bacteria synthesize cyclic-diGMP from GTP using diguanylate cyclases; its hydrolysis is catalyzed by phosphodiesterases. Here we report the over-expression and purification of a bi-functional diguanylate cyclase-phosphodiesterase from Agrobacterium vitis S4. Using homology modeling and primary structure alignment, we identify several amino acids predicted to participate in the phosphodiesterase reaction. Upon altering selected residues, we obtain variants of the enzyme that efficiently and quantitatively catalyze the synthesis of cyclic-diGMP from GTP without hydrolysis to pGpG. Additionally, we identify a variant that produces cyclic-diGMP while immobilized to NiNTA beads and can catalyze the conversion of [α-32P]-GTP to [32P]-cyclic-diGMP. In short, we characterize a novel cyclic-diGMP processing enzyme and demonstrate its utility for efficient and cost-effective production of cyclic-diGMP, as well as modified cyclic-diGMP molecules, for use as probes in studying the many important biological processes mediated by cyclic-diGMP.
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10
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Abstract
The second messenger cyclic di-GMP (c-di-GMP) regulates numerous phenotypes in response to environmental stimuli to enable bacteria to transition between different lifestyles. Here we discuss our recent findings that the human pathogen Vibrio cholerae recognizes 2 host-specific signals, bile and bicarbonate, to regulate intracellular c-di-GMP. We have demonstrated that bile acids increase intracellular c-di-GMP to promote biofilm formation. We have also shown that this bile-mediated increase of intracellular c-di-GMP is negated by bicarbonate, and that this interaction is dependent on pH, suggesting that V. cholerae uses these 2 environmental cues to sense and adapt to its relative location in the small intestine. Increased intracellular c-di-GMP by bile is attributed to increased c-di-GMP synthesis by 3 diguanylate cyclases (DGCs) and decreased expression of one phosphodiesterase (PDE) in the presence of bile. The molecular mechanisms by which bile controls the activity of the 3 DGCs and the regulators of bile-mediated transcriptional repression of the PDE are not yet known. Moreover, the impact of varying concentrations of bile and bicarbonate at different locations within the small intestine and the response of V. cholerae to these cues remains unclear. The native microbiome and pharmaceuticals, such as omeprazole, can impact bile and pH within the small intestine, suggesting these are potential unappreciated factors that may alter V. cholerae pathogenesis.
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Affiliation(s)
- Benjamin J Koestler
- Department of Microbiology and Molecular Genetics; Michigan State University; East Lansing, MI USA
| | - Christopher M Waters
- Department of Microbiology and Molecular Genetics; Michigan State University; East Lansing, MI USA,Correspondence to: Christopher Waters;
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Nassar NN, Abdel-Rahman AA. Brain stem adenosine receptors modulate centrally mediated hypotensive responses in conscious rats: A review. J Adv Res 2014; 6:331-40. [PMID: 26257930 PMCID: PMC4522583 DOI: 10.1016/j.jare.2014.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 02/07/2023] Open
Abstract
Adenosine is implicated in the modulation of cardiovascular responses either at the peripheral or at central level in experimental animals. However, there are no dedicated reviews on the involvement of adenosine in mediating the hypotensive response of centrally administered clonidine in general and specifically in aortically barodenervated rats (ABD). The conscious ABD rat model exhibits surgically induced baroreflex dysfunction and exaggerated hypotensive response, compared with conscious sham-operated (SO) rats. The current review focuses on, the role of adenosine receptors in blood pressure (BP) regulation and their possible crosstalk with other receptors e.g. imidazoline (I1) and alpha (α2A) adrenergic receptor (AR). The former receptor is a molecular target for clonidine, whose hypotensive effect is enhanced approx. 3-fold in conscious ABD rats. We also discussed how the balance between the brain stem adenosine A1 and A2A receptors is regulated by baroreceptors and how such balance influences the centrally mediated hypotensive responses. The use of the ABD rat model yielded insight into the downstream signaling cascades following clonidine-evoked hypotension in a surgical model of baroreflex dysfunction.
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Key Words
- 8-SPT, 8-(p-sulfophenyl)-theophylline. Non-selective adenosine receptor blocker
- A1, adenosine subtype A1 receptor
- A2A, adenosine subtype A2A receptor
- ABC, avidin biotin complex
- ABD rat, aortic barodenervated rat
- ATP, adenosine triphosphate
- BP, blood pressure
- CGS21680, 2-[4-[(2-carboxyethyl)phenyl]ethylaminophenyl]ethylamino]-5′-N-ethylcarboxamidoadenosine. Selective A2A receptor agonist
- CNS, central nervous system
- CPA, N6-cyclopentyladenosine. Selective A1 receptor agonist
- Central adenosine receptors
- Centrally mediated hypotension
- Clonidine
- Conscious rats
- DAG, diacylglycerol
- DPCPX, 8-cyclopentyl-1,3-dipropylxanthine. Selective A1 receptor antagonist
- ERK1/2, extracellular signal regulated kinase
- I.C., intracisternal
- I.V., intravenous
- I1, imidazoline subtype 1 receptor
- IP3, Inositol Triphosphate
- Imidazoline I1-receptor
- JNK, C-Jun N-terminal kinase
- L-NAME, Nω-nitro-l-arginine methyl ester hydrochloride. Non-selective nitric oxide synthase inhibitor
- MAPK-NOS signaling
- NO, nitric oxide
- NOS, nitric oxide synthase
- NTS, nucleus tractus solitarius
- PC-PLC, phosphatidyl choline-selective phospholipase C
- PC12 cells, pheochromocytoma cells
- PD98059, selective extracellular signal regulated kinase inhibitor
- PDE, phosphodiesterase
- PKA, protein kinase A
- RVLM, rostral ventrolateral medulla
- SAPK, stress activated protein kinase
- SCH58261, 5-amino-7-(2-phenylethyl)-2-(2-furyl)-pyrazolo[4,3-[Formula: see text]]-1,2,4-triazolo[1,5-c]pyrimidine. Selective adenosine A2A antagonist
- SHR, spontaneously hypertensive rat
- SND, sympathetic neuronal discharge
- SO, sham operated = conscious normotensive rats
- WKY, Wistar Kyoto rat
- cAMP, cyclic adenosine monophosphate
- α2 AR, alpha 2 adrenergic receptor
- αMNE, alpha methyl norepinephrine
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Affiliation(s)
- Noha N Nassar
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Egypt
| | - Abdel A Abdel-Rahman
- Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, NC, USA
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12
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Saad F, Yassin AA, Haider A, Gooren L. Effects of testosterone on the lower urinary tract go beyond the prostate: New insights, new treatment options. Arab J Urol 2011; 9:147-52. [PMID: 26579287 PMCID: PMC4150581 DOI: 10.1016/j.aju.2011.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 01/29/2011] [Accepted: 02/05/2011] [Indexed: 11/27/2022] Open
Abstract
The traditional assumption that the prostate is an organ exquisitely sensitive to androgen action still holds true, but with lower-than-normal circulating levels of testosterone, all androgen receptors are saturated and a further increase in circulating levels of testosterone has no effect on the prostate (saturation model). Prostate disease (prostate cancer and benign prostatic hyperplasia, BPH) usually occur at an age when circulating levels of testosterone are declining, so it is unlikely that they are to be attributed to an excess of testosterone. The bother of BPH is presently subsumed under ‘pathology of the lower urinary tract’. Surprisingly, these structures have androgen receptors, and depend for their relaxation on nitric oxide, for which the mechanism, in turn, is aided by androgens. This explains why phosphodiesterase type-5 inhibitors also benefit erectile function and symptoms of the lower urinary tract. Normalisation of testosterone in hypogonadal men favours this action. During the development of the prostate, epithelium and mesenchyme are under the control of testicular androgens, and interact to form an organised secretory organ. Furthermore, many of the disease processes of the prostate have been attributed to androgen action, and consequently, therapies have been aimed at manipulating androgen activity.
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Affiliation(s)
- Farid Saad
- Scientific Affairs Men's Healthcare, Bayer Schering Pharma, Berlin, Germany ; Research Department, Gulf Medical University School of Medicine, Ajman, United Arab Emirates
| | - Aksam A Yassin
- Clinic of Urology and Andrology, Segeberger Kliniken, Norderstedt-Hamburg, Germany ; Department of Urology, Gulf Medical University School of Medicine, Ajman, United Arab Emirates
| | | | - Louis Gooren
- Department of Internal Medicine, Section of Endocrinology, Free University Medical Center, Amsterdam, The Netherlands
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Al-Adl AM, Abdel-Wahab O, El-Karamany T, Aal AA. Combined intracavernous vasoactive drugs and sildenafil citrate in treatment of severe erectile dysfunction not responding to on-demand monotherapy. Arab J Urol 2011; 9:153-8. [PMID: 26579288 PMCID: PMC4150578 DOI: 10.1016/j.aju.2011.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 06/27/2011] [Indexed: 12/01/2022] Open
Abstract
Objective To investigate the effect of chronic use of sildenafil and intracavernous injection (ICI) with trimix in men not responding to on-demand monotherapy with sildenafil or ICI with prostaglandin-E1 (PGE1). Patients and methods The study included 40 patients with erectile dysfunction (ED), with a mean (SD) age of 50.7 (11.3) years and unresponsive to on-demand sildenafil or ICI with PGE1 as monotherapy. They were assessed using the Sexual Health in Men (SHIM)-5 score for ED severity, penile colour Doppler ultrasonography (CDUS) for peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI) with an ICI test using 0.25 mL of trimix of papaverine, PGE1 and phentolamine. Testosterone, prolactin and cholesterol levels were assessed. Patients received 25 mg sildenafil daily for 8 weeks, combined with twice weekly ICI with 0.25 mL of trimix. After treatment, the Erection Hardness Score (EHS), penile CDUS with ICI and ED Inventory of Treatment Satisfaction were assessed. Results The mean (SD) SHIM-5 score before treatment was 8.3 (0.5) in 15 of the 40 men and 6.3 (0.4) in 25. Penile haemodynamics were normal in five (13%), showed arterial insufficiency in five (13%), venous occlusive disease in 26 (65%) and mixed vascular in four (10%). There was an improved SHIM-5 score in 28 (70%) patients, as shown by their haemodynamic values, duration of erection and EHS with therapy, and 66% satisfaction with treatment. Adverse effects (penile pain, headache, facial flushing, dyspepsia, nasal congestion, dizziness) were reported in 17 patients (43%). Conclusion Chronic use of trimix plus daily low-dose sildenafil improved penile haemodynamics in these patients with ED not responding to on-demand phosphodiesterase-5 inhibitors or ICI with PGE1 monotherapy.
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Key Words
- CDUS, colour Doppler ultrasonography
- ED, erectile dysfunction
- EDITS, Erectile Dysfunction Inventory of Treatment Satisfaction
- EDV, end-diastolic velocity
- EH(S), Erection Hardness (Score)
- Erectile dysfunction
- ICI, intracavernous injection
- Intracavernous
- NO, nitric oxide
- PDE, phosphodiesterase
- PDE-5I
- PGE1
- PGE1, prostaglandin E1
- PSV, peak systolic velocity
- RI, resistance index
- SHIM, Sexual Health Inventory for Men
- Therapy
- VOD, veno-occlusive dysfunction
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Affiliation(s)
| | | | | | - Ashraf A Aal
- Urology Department, Benha Faculty of Medicine, Egypt
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