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Colin M, Delaitre C, Foulquier S, Dupuis F. The AT 1/AT 2 Receptor Equilibrium Is a Cornerstone of the Regulation of the Renin Angiotensin System beyond the Cardiovascular System. Molecules 2023; 28:5481. [PMID: 37513355 PMCID: PMC10383525 DOI: 10.3390/molecules28145481] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
The AT1 receptor has mainly been associated with the pathological effects of the renin-angiotensin system (RAS) (e.g., hypertension, heart and kidney diseases), and constitutes a major therapeutic target. In contrast, the AT2 receptor is presented as the protective arm of this RAS, and its targeting via specific agonists is mainly used to counteract the effects of the AT1 receptor. The discovery of a local RAS has highlighted the importance of the balance between AT1/AT2 receptors at the tissue level. Disruption of this balance is suggested to be detrimental. The fine tuning of this balance is not limited to the regulation of the level of expression of these two receptors. Other mechanisms still largely unexplored, such as S-nitrosation of the AT1 receptor, homo- and heterodimerization, and the use of AT1 receptor-biased agonists, may significantly contribute to and/or interfere with the settings of this AT1/AT2 equilibrium. This review will detail, through several examples (the brain, wound healing, and the cellular cycle), the importance of the functional balance between AT1 and AT2 receptors, and how new molecular pharmacological approaches may act on its regulation to open up new therapeutic perspectives.
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Affiliation(s)
- Mélissa Colin
- CITHEFOR, Université de Lorraine, F-54000 Nancy, France
- Department of Pharmacology and Toxicology, MHeNS-School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands
| | | | - Sébastien Foulquier
- Department of Pharmacology and Toxicology, MHeNS-School for Mental Health and Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University, 6200 MD Maastricht, The Netherlands
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Hoare SRJ. The Problems of Applying Classical Pharmacology Analysis to Modern In Vitro Drug Discovery Assays: Slow Binding Kinetics and High Target Concentration. SLAS DISCOVERY 2021; 26:835-850. [PMID: 34112012 DOI: 10.1177/24725552211019653] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The analysis framework used to quantify drug potency in vitro (e.g., Kd or Ki) was initially developed for classical pharmacology bioassays, for example, organ bath experiments testing moderate-affinity natural products. Modern drug discovery can infringe the assumptions of the classical pharmacology analysis equations, owing to the reduction of assay volume in miniaturization, target overexpression, and the increase of compound-target affinity in medicinal chemistry. These assumptions are that (1) the compound concentration greatly exceeds the target concentration (i.e., minimal ligand depletion), and (2) the compound is at equilibrium with the receptor (i.e., rapid ligand binding kinetics). Unappreciated infringement of these assumptions can lead to substantial underestimation of compound affinity, which negatively impacts the drug discovery process, from early-stage lead optimization to prediction of human dosing. This study evaluates the real-world impact of these factors on the target interaction assays used in drug discovery using literature examples, database searches, and simulations. The ranges of compound affinity and the assay types that are prone to depletion and equilibration artifacts are identified. Importantly, the highest-affinity compounds, usually the highest value chemical matter in drug discovery, are the most affected. Methods and simulation tools are provided to enable investigators to evaluate, manage, and minimize depletion or equilibration artifacts. This study enables the correct application of pharmacological data analysis to accurately quantify affinity using modern drug discovery assay technology.
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Evaluation of the high affinity [ 18F]fluoropyridine-candesartan in rats for PET imaging of renal AT 1 receptors. Nucl Med Biol 2021; 96-97:41-49. [PMID: 33798796 DOI: 10.1016/j.nucmedbio.2021.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/01/2021] [Accepted: 03/11/2021] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Alterations in the expression of the Angiotensin II type 1 receptors (AT1R) have been demonstrated in the development of several heart and renal diseases. The aim of this study was to evaluate the novel compound [18F]fluoropyridine-candesartan as a PET imaging tracer of AT1R in rat kidneys. METHODS Competition binding assays were carried out with membranes from CHO-K1 cells expressing human AT1R. Binding to plasma proteins was assessed by ultrafiltration. Radiolabeled metabolites in rat plasma and kidneys of control and pretreated animals (candesartan 10 mg/kg or losartan 30 mg/kg) were analyzed by column-switch HPLC. Dynamic PET/CT images of [18F]fluoropyridine-candesartan in male Sprague-Dawley rats were acquired for 60 min at baseline, pre-treatment with the AT1R antagonist losartan (30 mg/kg) or the AT2R antagonist PD123,319 (5 mg/kg). RESULTS Fluoropyridine-candesartan bound with a high affinity for AT1R (Ki = 5.9 ± 1.1 nM), comparable to fluoropyridine-losartan but lower than the parent compound candesartan (Ki = 0.4 ± 0.1 nM). [18F]Fluoropyridine-candesartan bound strongly to plasma proteins (99.3%) and was mainly metabolized to radiolabeled hydrophilic compounds, displaying minimal interference on renal AT1R binding with 82% of unchanged tracer in the kidneys at 20 min post-injection. PET imaging displayed high renal and liver accumulations and slow clearances, with maximum tissue-to-blood ratios of 14 ± 3 and 54 ± 12 in kidney cortex and liver, respectively, at 10 min post-injection. Binding specificity for AT1R was demonstrated with marked reductions in kidney cortex (-84%) and liver (-93%) tissue-to-blood ratios at 20 min post-injection, when blocking with AT1R antagonist losartan (30 mg/kg). No change was observed in kidney cortex of rats pre-treated with AT2R antagonist PD 123,319 (5 mg/kg), confirming binding selectivity for AT1 over AT2 receptors. CONCLUSION High kidney-to-blood ratios and binding selectivity to renal AT1R combined with tracer in vivo stability displaying minimal interference from labeled metabolites support further PET imaging studies with [18F]fluoropyridine-candesartan.
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Abreu Diaz AM, Drumeva GO, Petrenyov DR, Carrier JF, DaSilva JN. Synthesis of the Novel AT 1 Receptor Tracer [ 18F]Fluoropyridine-Candesartan via Click Chemistry. ACS OMEGA 2020; 5:20353-20362. [PMID: 32832788 PMCID: PMC7439361 DOI: 10.1021/acsomega.0c02310] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
A novel 7-((4-(3-((2-[18F]fluoropyridin-3-yl)oxy)propyl)-1H-1,2,3-triazol-1-yl)methyl)-1H-benzo[d]imidazole derivative of the angiotensin II type-1 receptor (AT1R) blocker candesartan, [18F]fluoropyridine-candesartan, was synthesized via the copper-catalyzed azide-alkyne cycloaddition click reaction between 2-[18F]fluoro-3-(pent-4-yn-1-yloxy)pyridine ([18F]FPyKYNE) and the tetrazole-protected azido-candesartan derivative, followed by acid deprotection. This three-step, two-pot, and two-step purification synthesis was done within 2 h. The use of tris[(1-hydroxypropyl-1H-1,2,3-triazol-4-yl)methyl]amine (THPTA) as a Cu(I) stabilizing agent increased the overall radiochemical yield by 4-fold (10 ± 2%, n = 13) compared to the reaction without THPTA (2.4 ± 0.2%, n = 3; decay-corrected from 18F produced at the end-of-beam). Complete separation of [18F]FPyKYNE from its nitro precursor and [18F]fluoropyridine-candesartan from the deprotected azido-candesartan allowed for high molar activities (>380 GBq/μmol) of the tracer. The use of 0.1% trifluoroacetic acid in water for reformulation and the addition of sodium ascorbate to the final formulation (1.6 ± 0.2 GBq/mL, n = 3) prevented tracer radiolysis with >97% radiochemical purity for a period of up to 10 h after the end-of-synthesis. A significant reduction in the uptake (86 ± 3%, n = 8) of the tracer was observed ex vivo in rats (at 20 min postinjection) in the AT1R-rich kidney cortex following pretreatment with saturating doses of the AT1R antagonist candesartan or losartan. This specific binding to AT1R was confirmed in vitro in the rat renal cortex (autoradiography) by a reduction of 26 ± 5% (n = 12) with losartan coincubation (10 μM). These favorable binding properties support further studies to assess the potential of [18F]fluoropyridine-candesartan as a tracer for the positron emission tomography imaging of renal AT1R.
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Affiliation(s)
- Aida M. Abreu Diaz
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Département
de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Institut
de Génie Biomédicale, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Departamento
de Radioquímica, Instituto Superior de Tecnologías y
Ciencias Aplicadas, Universidad de la Habana, Ave. Salvador Allende y Luaces,
Quinta de los Molinos, La Habana 10400, Cuba
| | - Gergana O. Drumeva
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Département
de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
| | - Daniil R. Petrenyov
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
| | - Jean-François Carrier
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Institut
de Génie Biomédicale, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Département
de Physique, Faculté des Arts et des Sciences, Université de Montréal, Complexe des Sciences, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Québec H2V 0B3, Canada
- Département
de Radiologie, Radio-Oncologie et Médecine Nucléaire,
Faculté de Médecine, Université
de Montréal, Pavillon
Roger-Gaudry, 2900 Boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
| | - Jean N. DaSilva
- Centre
de Recherche du CHUM, 900 rue Saint-Denis, Montréal, Québec H2X 0A9, Canada
- Département
de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Institut
de Génie Biomédicale, Faculté de Médecine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960
chemin de la Tour, Montréal, Québec H3T 1J4, Canada
- Département
de Radiologie, Radio-Oncologie et Médecine Nucléaire,
Faculté de Médecine, Université
de Montréal, Pavillon
Roger-Gaudry, 2900 Boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
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Evaluating the benefits of renin-angiotensin system inhibitors as cancer treatments. Pharmacol Ther 2020; 211:107527. [PMID: 32173557 DOI: 10.1016/j.pharmthera.2020.107527] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/08/2020] [Indexed: 02/07/2023]
Abstract
G-protein-coupled receptors (GPCRs) are the largest and most diverse group of cellular membrane receptors identified and characterized. It is estimated that 30 to 50% of marketed drugs target these receptors. The angiotensin II receptor type 1 (AT1R) is a GPCR which signals in response to systemic alterations of the peptide hormone angiotensin II (AngII) in circulation. The enzyme responsible for converting AngI to AngII is the angiotensin-converting enzyme (ACE). Specific inhibitors for the AT1R (more commonly known as AT1R blockers or antagonists) and ACE are well characterized for their effects on the cardiovascular system. Combined with the extensive clinical data available on patient tolerance of AT1R blockers (ARBs) and ACE inhibitors (ACEIs), as well as their non-classical roles in cancer, the notion of repurposing this class of medications as cancer treatment(s) is explored in the current review. Given that AngII-dependent AT1R activity directly regulates angiogenesis, remodeling of vasculature, pro-inflammatory responses, stem cell programming and hematopoiesis, and electrolyte balance; the modulation of these processes with pharmacologically well characterized medications could present a valuable complementary treatment option for cancer patients.
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Systematic characterization of AT1 receptor antagonists with label-free dynamic mass redistribution assays. J Pharmacol Toxicol Methods 2020; 102:106682. [PMID: 32087363 DOI: 10.1016/j.vascn.2020.106682] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 12/23/2019] [Accepted: 02/07/2020] [Indexed: 11/23/2022]
Abstract
INTRODUCTION In the drug discovery field, the binding affinities and binding kinetics of drug candidates are very important. Angiotensin II type 1 (AT1) receptor antagonists, e.g., candesartan, telmisartan, irbesartan, losartan and valsartan, show high affinities and long-lasting bindings to the receptor, making them preferred medications for hypertension treatment. However, the molecular binding properties of AT1 receptor antagonists are controversial. METHODS In this work, we established a profile to study the phenotypic properties of AT1 receptor antagonists with label-free dynamic mass redistribution (DMR) assays in native human cells. With noninvasive features, DMR assay were conducted in multiple formats. Eleven antagonists were systematically evaluated with angiotensin II as an agonist probe in the Hep G2 cell line, which endogenously expresses the AT1 receptor. RESULTS The IC50 values to the AT1 receptor of individual antagonist varied with different incubation times. The antagonists showed competitive behavior with angiotensin II. Schild analysis was used to analyze the competitive behavior of the antagonist. All of the antagonist showed long-lasting possession of the AT1 receptor, except telmisartan. The systematic evaluation of the antagonists implied that 11 antagonists showed high binding affinity but distinct binding modes to AT1 receptor. DISCUSSION This study demonstrated that the DMR assay has great potential for determining the pharmacological parameters of ligands. This work may serve as guidance for other receptor and ligand assays.
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Planes N, Vanderheyden PPML, Gratton E, Caballero-George C. Image mean square displacement to study the lateral mobility of Angiotensin II type 1 and Endothelin 1 type A receptors on living cells. Microsc Res Tech 2019; 83:381-392. [PMID: 31837080 DOI: 10.1002/jemt.23425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 12/02/2019] [Indexed: 11/10/2022]
Abstract
The lateral mobility of membrane receptors provides insights into the molecular interactions of protein binding and the complex dynamic plasma membrane. The image mean square displacement (iMSD) analysis is a method used to extract qualitative and quantitative information of the protein diffusion law and infers how diffusion dynamic processes may change when the cellular environment is modified. The aim of the study was to describe the membrane diffusing properties of two G-protein-coupled receptors namely Angiotensin II type 1 (AT1 ) and Endothelin 1 type A (ETA ) receptors and their corresponding receptor-ligand complexes in living cells using total internal reflection fluorescent microscopy and iMSD analysis. This study showed that both AT1 and ETA receptors displayed a mix of three modes of diffusion: free, confined, and partially confined. The confined mode was the predominant at the plasma membrane of living cells and was not affected by ligand binding. However, the local diffusivity and the confinement zone of AT1 receptors were reduced by the binding of its antagonist losartan, and the long-range diffusion with the local diffusivity coefficient of ETA receptors was reduced upon exposure to its antagonist BQ123. To the best of our knowledge, this is the first study addressing the protein diffusion laws of these two receptors on living cells using total internal reflection fluorescence microscopy and iMSD.
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Affiliation(s)
- Nadir Planes
- Center of Innovation and Technology Transfer, Institute of Scientific Research and High Technology Services (INDICASAT AIP), Panama City, Panama.,Department of Biotechnology, Acharya Nagarjuna University, Guntur, Andhra Pradesh, India
| | | | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, California
| | - Catherina Caballero-George
- Center of Innovation and Technology Transfer, Institute of Scientific Research and High Technology Services (INDICASAT AIP), Panama City, Panama
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Rizwan F, Yesmine S, Banu SG, Chowdhury IA, Hasan R, Chatterjee TK. Renoprotective effects of stevia ( Stevia rebaudiana Bertoni), amlodipine, valsartan, and losartan in gentamycin-induced nephrotoxicity in the rat model: Biochemical, hematological and histological approaches. Toxicol Rep 2019; 6:683-691. [PMID: 31372346 PMCID: PMC6656923 DOI: 10.1016/j.toxrep.2019.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/05/2019] [Accepted: 07/06/2019] [Indexed: 12/29/2022] Open
Abstract
The current study investigated the renoprotective effects of stevia, angiotensin-II type 1 receptor (AT1) blocker and calcium (Ca2+) channel blocker in gentamycin-induced nephrotoxicity in rat models. Six groups of male Sprague-Dawley rats of eight weeks old were taken for the experiment: sham control, nephrotoxicity, treatment with amlodipine (4 mg/kg/day); stevia (200 mg/kg/day); losartan (15 mg/kg/day) and valsartan (5 mg/kg/day), accordingly. The blood sample was taken for the assessment of renal and hepatic-functional variables like serum creatinine, blood urea, BUN and SGPT, SGOT, and total serum bilirubin. Hematological parameters were also examined. Histological examination has been done on kidneys and liver. Alterations of the body weight and the organ's weight were documented. Treatment with stevia and valsartan significantly decreased serum creatinine levels. A reduction of liver enzymes, and total serum bilirubin levels were observed in all the treatment groups. Treatment with valsartan and amlodipine, remarkably and stevia, mildly reduced the renal tissue damage, inflammation, and tubular necrosis. However, the present study demonstrated that losartan treatment aggravated kidney damage by increasing protein cast, calcification, tubular necrosis, and injury. This comparison indicated that both stevia and valsartan have beneficial renoprotective effect and valsartan offers a better treatment option in renal damage over losartan.
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Key Words
- ACE, angiotensin converting enzyme
- ARB
- ARB, angiotensin-II type 1 receptor (AT1) blockers
- AT1, angiotensin-II type 1 receptor
- AT2, angiotensin-II type 2 receptor
- BUN, blood urea nitrogen
- CCB
- CCB, calcium (Ca2+) channel blocker
- CKD, chronic kidney disease
- EDTA, ethylene diamine tetra acetate
- Gentamycin-induced
- HCT, hematocrit
- HDL, high density lipoprotein
- Hb, hemoglobin
- LDL, low density lipoprotein
- MCH, mean corpuscular hemoglobin
- MCHC, mean corpuscular hemoglobin concentration
- MCV, mean corpuscular volume
- Nephrotoxicity
- RBC, red blood cells
- RBS, random blood sugar
- RDW-CV, red blood cell distribution width-CV
- RDW-SD, red blood cell distribution width-SD
- ROS, reactive oxygen species
- Renoprotective effects
- SGOT, serum glutamic oxaloacetic transaminase
- SGPT, serum glutamic pyruvic transaminase
- Stevia
- TG, triglycerides
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Affiliation(s)
- Farhana Rizwan
- Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
- Department of Pharmacy, East West University, Aftabnagar, Dhaka, 1212, Bangladesh
| | - Saquiba Yesmine
- Department of Pharmacy, Jahangirnagar University, Savar, Dhaka, Bangladesh
| | - Sultana Gulshan Banu
- Department of Pathology, Bangabandhu Sheikh Mujib Medical University, Shahbag, Dhaka, Bangladesh
| | | | - Rajibul Hasan
- Department of Biochemistry and Cell Biology, Bangladesh University of Health Sciences, Mirpur, 1216, Dhaka, Bangladesh
| | - Tapan Kumar Chatterjee
- Department of Pharmaceutical Technology, Jadavpur University, Kolkata, 700032, India
- Department of Pharmaceutical Science and Technology, JIS University, Agarpara, Kolkata, 700109, West Bengal, India
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McKinnell RM, Fatheree P, Choi SK, Gendron R, Jendza K, Olson Blair B, Budman J, Hill CM, Hegde LG, Yu C, McConn D, Hegde SS, Marquess DG, Klein U. Discovery of TD-0212, an Orally Active Dual Pharmacology AT 1 Antagonist and Neprilysin Inhibitor (ARNI). ACS Med Chem Lett 2019; 10:86-91. [PMID: 30655952 DOI: 10.1021/acsmedchemlett.8b00462] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 12/03/2018] [Indexed: 01/02/2023] Open
Abstract
Dual inhibition of angiotensin-converting enzyme (ACE) and neprilysin (NEP) by drugs such as omapatrilat produces superior antihypertensive efficacy relative to ACE inhibitors but is associated with a higher risk of life-threatening angioedema due to bradykinin elevations. We hypothesized that dual AT1 (angiotensin II type 1 receptor) blockade and NEP inhibition with a single molecule would produce similar antihypertensive efficacy to omapatrilat without the risk of angioedema since ACE (the rate limiting enzyme in bradykinin metabolism) would remain uninhibited. Merging the structures of losartan (an AT1 antagonist) and thiorphan (a NEP inhibitor) led to the discovery of a novel series of orally active, dual AT1 antagonist/NEP inhibitors (ARNIs) exemplified by compound 35 (TD-0212). In models of renin-dependent and -independent hypertension, 35 produced blood pressure reductions similar to omapatrilat and combinations of AT1 receptor antagonists and NEP inhibitors. Upper airway angioedema risk was assessed in a rat tracheal plasma extravasation (TPE) model. Unlike omapatrilat, 35 did not increase TPE at antihypertensive doses. Compound 35 therefore provides the enhanced activity of dual AT1/NEP inhibition with a potentially lower risk of angioedema relative to dual ACE/NEP inhibition.
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Affiliation(s)
- R. Murray McKinnell
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Paul Fatheree
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Seok-Ki Choi
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Roland Gendron
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Keith Jendza
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Brooke Olson Blair
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Joe Budman
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Craig M. Hill
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Laxminarayan G. Hegde
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Cecile Yu
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Donavon McConn
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Sharath S. Hegde
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Daniel G. Marquess
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
| | - Uwe Klein
- Theravance Biopharma US Inc., 901 Gateway Boulevard, South San Francisco, California 94080, United States
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Ostroumova OD, Kochetkov AI, Cherniaeva MS. Arterial Hypertension in Older Adults in the Light of New European Guidelines 2018. RATIONAL PHARMACOTHERAPY IN CARDIOLOGY 2018. [DOI: 10.20996/1819-6446-2018-14-5-774-784] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- O. D. Ostroumova
- A.I. Evdokimov Moscow State University of Medicine and Dentistry; Pirogov Russian National Research Medical University
| | - A. I. Kochetkov
- A.I. Evdokimov Moscow State University of Medicine and Dentistry; Pirogov Russian National Research Medical University
| | - M. S. Cherniaeva
- Central State Medical Academy of Administrative Department of the President of the Russian Federation
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11
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Garton DR, Ross SG, Maldonado-Hernández R, Quick M, Lasalde-Dominicci JA, Lizardi-Ortiz JE. Amphetamine enantiomers inhibit homomeric α7 nicotinic receptor through a competitive mechanism and within the intoxication levels in humans. Neuropharmacology 2018; 144:172-183. [PMID: 30359640 DOI: 10.1016/j.neuropharm.2018.10.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 10/10/2018] [Accepted: 10/21/2018] [Indexed: 11/28/2022]
Abstract
Amphetamine-type stimulants (ATS) are the second most consumed illicit drug worldwide and lack good treatments for associated substance use disorders, lagging behind other addictive drugs. For this reason, a deeper understanding of the pharmacodynamics of ATS is required. The present study seeks to determine amphetamine (AMPH) enantiomers' effects on the homomeric α7 nicotinic acetylcholine receptor (α7 nAChR). Here we have shown that AMPH enantiomers bind to the α7 nAChR and competitively inhibit acetylcholine responses. Our in silico docking analysis suggests that AMPH binds close to the β7 strand of the B-loop of a chimera comprising of the human α7 nAChR and the acetylcholine binding protein from Lymnaea stagnalis. This may inhibit the required movement of the C-loop for channel opening, due to steric hindrance, providing a structural mechanism for its antagonist effect. Finally, we have shown that, in α7 nAChR full knockout mice, the behavioral response to D-AMPH is attenuated, providing direct evidence for the role of α7 nAChRs on the physiological response to D-AMPH. Importantly, D-AMPH exerts these effects at concentrations predicted to be pharmacologically relevant for chronic methamphetamine users and during binges. In conclusion, our data present new findings that implicate the α7 nAChR on the pharmacodynamics of ATS, which may be important for behavioral responses to these drugs, indicating a potential role for α7 nAChRs in ATS substance-use disorders.
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Affiliation(s)
- Daniel R Garton
- Columbia College of Columbia University, New York, NY, 10027, USA
| | - Sharmaine G Ross
- Department of Biobehavioral Sciences, Teachers College Columbia University, New York, NY, 10027, USA
| | | | - Matthias Quick
- Department of Psychiatry, Molecular Therapeutics Division, Columbia University Medical Center, New York, NY, 10032, USA
| | - José A Lasalde-Dominicci
- Departments of Biology and Chemistry, University of Puerto Rico, Río Piedras Campus, San Juan, PR, 00931, USA; Molecular Sciences Research Center, University of Puerto Rico, San Juan, PR, 00927, USA
| | - José E Lizardi-Ortiz
- Molecular Sciences Research Center, University of Puerto Rico, San Juan, PR, 00927, USA; Departments of Neurology and Psychiatry, Columbia University Medical Center, New York, NY, 10032, USA.
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12
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Takezako T, Unal H, Karnik SS, Node K. Current topics in angiotensin II type 1 receptor research: Focus on inverse agonism, receptor dimerization and biased agonism. Pharmacol Res 2017. [PMID: 28648738 DOI: 10.1016/j.phrs.2017.06.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Although the octapeptide hormone angiotensin II (Ang II) regulates cardiovascular and renal homeostasis through the Ang II type 1 receptor (AT1R), overstimulation of AT1R causes various human diseases, such as hypertension and cardiac hypertrophy. Therefore, AT1R blockers (ARBs) have been widely used as therapeutic drugs for these diseases. Recent basic research and clinical studies have resulted in the discovery of interesting phenomena associated with AT1R function. For example, ligand-independent activation of AT1R by mechanical stress and agonistic autoantibodies, as well as via receptor mutations, has been shown to decrease the inverse agonistic efficacy of ARBs, though the molecular mechanisms of such phenomena had remained elusive until recently. Furthermore, although AT1R is believed to exist as a monomer, recent studies have demonstrated that AT1R can homodimerize and heterodimerize with other G-protein coupled receptors (GPCR), altering the receptor signaling properties. Therefore, formation of both AT1R homodimers and AT1R-GPCR heterodimer may be involved in the pathogenesis of human disease states, such as atherosclerosis and preeclampsia. Finally, biased AT1R ligands that can preferentially activate the β-arrestin-mediated signaling pathway have been discovered. Such β-arrestin-biased AT1R ligands may be better therapeutic drugs for cardiovascular diseases. New findings on AT1R described herein could provide a conceptual framework for application of ARBs in the treatment of diseases, as well as for novel drug development. Since AT1R is an extensively studied member of the GPCR superfamily encoded in the human genome, this review is relevant for understanding the functions of other members of this superfamily.
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Affiliation(s)
- Takanobu Takezako
- Department of Advanced Heart Research, Saga University, Saga, Japan; Medical Center for Student Health, Kobe University, Kobe, Japan.
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Koichi Node
- Department of Cardiovascular Medicine, Saga University, Japan
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13
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Vanderheyden PML, Benachour N. Influence of the cellular environment on ligand binding kinetics at membrane-bound targets. Bioorg Med Chem Lett 2017; 27:3621-3628. [PMID: 28666735 DOI: 10.1016/j.bmcl.2017.06.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 06/13/2017] [Accepted: 06/19/2017] [Indexed: 10/19/2022]
Abstract
While historically 'in vitro' binding data were obtained by analyzing equilibrium experiments, kinetic data are increasingly appreciated to provide information on the time a particular compound remains bound to its target. This information is of biological importance to understand the molecular mechanism of a drug not only to evaluate the time a particular receptor/enzyme is blocked in the case of antagonists/inhibitors but also to investigate its contribution to the efficacy to mediate signaling in the case of agonists. There is accumulating evidence that many drugs binding to either membrane-bound receptors or enzymes are found to display long duration of action which can be ascribed to slow dissociation from their target proteins. In the present review three such examples are discussed which encompass ligands that bind to membrane-bound proteins and from which it appears that the tight binding kinetics is influenced by the cellular/membrane environment of the target protein.
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Affiliation(s)
- Patrick M L Vanderheyden
- Research Group of Molecular and Biochemical Pharmacology, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, VUB-MBFA, Pleinlaan 2, B-1050 Brussels, Belgium.
| | - Nerdjes Benachour
- Research Group of Molecular and Biochemical Pharmacology, Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, VUB-MBFA, Pleinlaan 2, B-1050 Brussels, Belgium
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14
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Vauquelin G, Fierens FLP, Gáborik Z, Le Minh T, De Backer JP, Hunyady L, Vanderheyden PML. Role of basic amino acids of the human angiotensin type 1 receptor in the binding of the non-peptide antagonist candesartan. J Renin Angiotensin Aldosterone Syst 2016; 2:S32-S36. [DOI: 10.1177/14703203010020010501] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
To explain the insurmountable/long-lasting binding of biphenyltetrazole-containing AT1-receptor antagonists such as candesartan, to the human angiotensin II type 1-receptor, a model is proposed in which the basic amino acids Lys199 and Arg 167 of the receptor interact respectively with the carboxylate and the tetrazole group of the antagonists. To validate this model, we have investigated the impact of substitution of Lys199 by Ala or Gln and of Arg167 by Ala on the binding properties of [3H]candesartan and on competition binding by candesartan, EXP3174, irbesartan, losartan, angiotensin II (Ang II) and [Sar1-Ile8]angiotensin. Our results indicate that both amino acids play an important role in the AT1-receptor ligand binding. Whereas the negative charge of Lys 199 is involved in an ionic bond with the end-standing carboxylate group of the peptide ligands, its polarity also contributes to the non-peptide antagonist binding. Substitution of Arg167 by Ala completely abolished [3H]Ang II, as well as [3H] candesartan, binding. Whereas these results are in line with the proposed model, it cannot be excluded that both amino acid residues are important for the structural integrity of the AT1-receptor with respect to its ligand binding properties.
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Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium, gvauquel@ vub.ac.be
| | - Frederik LP Fierens
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
| | - Zsuzsanna Gáborik
- Department of Physiology, Semmelweis University Medical
School, H-1444 Budapest, PO Box 259, Hungary
| | - Tam Le Minh
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
| | - Jean-Paul De Backer
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
| | - László Hunyady
- Department of Physiology, Semmelweis University Medical
School, H-1444 Budapest, PO Box 259, Hungary
| | - Patrick ML Vanderheyden
- Department of Molecular and Biochemical Pharmacology,
Institute for Molecular Biology and Biotechnology, Free University of Brussels
(VUB), B-1640 Sint-Genesius Rode, Belgium
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15
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van Rodijnen WF, van Lambalgen TA, van Teijlingen ME, Tangelder GJ, ter Wee PM. Comparison of the AT1-receptor blockers candesartan, irbesartan and losartan for inhibiting renal microvascular constriction. J Renin Angiotensin Aldosterone Syst 2016; 2:S204-S210. [DOI: 10.1177/14703203010020013601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Angiotensin II (Ang II) type 1 (AT1) receptor blockers differ in their affinity for the AT1-receptor, suggesting a dissimilar potency for inhibiting Ang II-induced vascular constriction. In the present study, we compared the effects of candesartan, irbesartan and losartan on the renal microvascular constriction to locally-formed Ang II, using isolated, perfused hydronephrotic rat kidneys. Addition of 1 nmol/L angiotensin I (Ang I, the precursor of Ang II) significantly reduced the diameters of interlobular arteries (ILAs; -47.6±2.6%), afferent arterioles (AAs; -43.6±2.3%) and efferent arterioles (EAs; -31.6±2.4%). Candesartan and irbesartan were more potent in antagonising the constriction to Ang I than losartan. By contrast, candesartan and irbesartan differed only slightly in potency. After a washing period of 60 minutes with drug-free medium, a second application of Ang I failed to induce vasoconstriction only in candesartan-treated kidneys. Pretreatment of hydronephrotic kidneys with candesartan, to further explore its antagonistic properties, shifted the dose-response curves of Ang II approximately 2 log units to the right without reducing the maximal Ang II-induced constriction of ILAs, AAs or EAs. Additionally, dose-response curves of Ang II were similar after short (10 minutes) and prolonged (60 minutes) preincubation with candesartan. Our findings indicate that candesartan and irbesartan are more potent inhibitors of renal microvascular constriction to locally-formed Ang II than losartan. The inhibitory effect of candesartan is more prolonged, suggesting a slow dissociation from the AT1-receptor. Additionally, candesartan was found to block the Ang II-induced constriction of renal microvessels in a surmountable manner.
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Affiliation(s)
| | | | | | | | - Piet M ter Wee
- Department of Nephrology, Institute for Cardiovascular
Research (ICaR-VU), Vrije Universiteit, Amsterdam, The Netherlands
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16
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Ytterberg H, Edvinsson L. Characterisation of angiotensin II receptors in isolated human subcutaneous resistance arteries. J Renin Angiotensin Aldosterone Syst 2016; 2:S37-S41. [DOI: 10.1177/14703203010020010601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Subcutaneous arteries have been used as a model for resistance arteries, which are potentially involved in enhanced blood pressure (BP) regulation in man. Angiotensin II (Ang II) is an important regulator of tone, acting via type 1 (AT1-) and type 2 (AT2-) receptor subtypes. The aim of this study was to characterise the Ang II receptors in isolated human subcutaneous arteries, using pharmacological and molecular methods. Subcutaneous arteries were obtained from patients undergoing elective gut surgery and were carefully dissected from the abdominal wall. Cylindrical segments were mounted on two L-shaped metal prongs, one of which was connected to a force-displacement transducer for continuous recording of isometric tension. Concentration-response curves to Ang II were constructed in the presence and absence of various selective AT1-receptor antagonists, candesartan, EXP3174, irbesartan and losartan, and the AT2-receptor antagonist, PD 123319. Responses to Ang II were measured as increases in force (mN) and expressed as a percentage of the response to 60 mM of KCl. Ang II caused a concentration-dependent contraction (pEC50=9.45±0.48, Emax=120±13%). Candesartan and EXP3174 caused concentration-dependent depression of the Emax of Ang II without any major shift of pEC50. Losartan and irbesartan caused a significant, dose-dependent rightward shift of the Ang II contraction-response curve in human subcutaneous arteries. The results show that contractile responses of human subcutaneous arteries are mediated via the AT1-receptor. The AT1-receptor antagonists, candesartan and EXP3174, acted in an insurmountable manner, while losartan and irbesartan were surmountable AT1-receptor antagonists. The AT2-receptor antagonist, PD 123319, (10, 100 nM) had no effect on Ang II-induced contraction. This is supported by the positive identification of mRNA for the human AT 1-receptor by RT-PCR.
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Affiliation(s)
- Hoa Ytterberg
- Department of Experimental Vascular Research, Department
of Internal Medicine, Lund University Hospital, Lund, Sweden,
| | - Lars Edvinsson
- Department of Experimental Vascular Research, Department
of Internal Medicine, Lund University Hospital, Lund, Sweden
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17
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Distinctions between non-peptide angiotensin II AT1-receptor antagonists. J Renin Angiotensin Aldosterone Syst 2016; 2:S24-S31. [DOI: 10.1177/14703203010020010401] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A far-reaching understanding of the molecular action mechanism of AT1-receptor antagonists (AIIAs) was obtained by using CHO cells expressing transfected human AT 1-receptors. In this model, direct [3H]-antagonist binding and inhibition of agonist-induced responses (inositol phosphate accumulation) can be measured under identical experimental conditions. Whereas preincubation with a surmountable AIIA (losartan) causes parallel shifts of the angiotensin II (Ang II) concentration-response curve, insurmountable antagonists also cause partial (i.e., 30% for irbesartan, 50% for valsartan, 70% for EXP3174,) to almost complete (95% for candesartan) reductions of the maximal response. The main conclusions are that all investigated antagonists are competitive with respect to Ang II. They bind to a common or overlapping site on the receptor in a mutually exclusive way. Insurmountable inhibition is related to the slow dissociation rate of the antagonist-receptor complex (t 1/2 of 7 minutes for irbesartan, 17 minutes for valsartan, 30 minutes for EXP3174 and 120 minutes for candesartan). Antagonist-bound AT1-receptors can adopt a fast and a slow reversible state. This is responsible for the partial nature of the insurmountable inhibition. The long-lasting effect of candesartan, the active metabolite of candesartan cilexetil, in vascular smooth muscle contraction studies, as well as in in vivo experiments on rat and in clinical studies, is compatible with its slow dissociation from, and continuous recycling between AT1-receptors. This recycling, or `rebinding' takes place because of the very high affinity of candesartan for the AT1-receptor.
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18
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Jugdutt BI, Menon V. Upregulation of Angiotensin II Type 2 Receptor and Limitation of Myocardial Stunning by Angiotensin II Type 1 Receptor Blockers during Reperfused Myocardial Infarction in the Rat. J Cardiovasc Pharmacol Ther 2016; 8:217-26. [PMID: 14506547 DOI: 10.1177/107424840300800307] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Background: We have previously shown that angiotensin II type 1 receptor blockers induce cardioprotection and upregulate angiotensin II type 2 receptor during in vivo postischemicreperfusion in dogs. Whether angiotensin II type 1 receptor blockers upregulate angiotensin II type 2 receptors in rats is controversial, and whether surmountable and insurmountable angiotensin II type 1 receptor blockers exert similar protective effects during reperfused myocardial infarction is not known. Methods: We assessed the effects of the surmountable angiotensin receptor blocker valsartan, and the insurmountable angiotensin receptor blocker irbesartan, on hemodynamics and left ventricular systolic and diastolic function (echocardiography/Doppler) in vivo and infarct size (triphenyl tetrazolium chloride method), and regional angiotensin II type 1 receptor and angiotensin II type 2 receptor expression (immunoblots) ex vivo, after anterior reperfused myocardial infarction in rats. The rats were randomized to four groups: intravenous valsartan (10 mg/kg, n = 8), irbesartan (10 mg/kg, n = 8), or saline vehicle (controls, n = 14) over 30 minutes before reperfused myocardial infarction, and sham (n = 8). Angiotensin II type 1 receptor blockade was assessed by the inhibition of angiotensin II pressor responses. Results: Compared with the control group, both angiotensin receptor blockers significantly decreased infarct size, limited the increase in left atrial pressure, improved positive left ventricular dP/dtm,x and dP/dtm,,, improved left ventricular ejection fraction and diastolic function, and limited infarct expansion after reperfused myocardial infarction. Both angiotensin receptor blockers increased angiotensin II type 2 receptor protein in the postischemic-reperfused zone, with no change in angiotensin II type 1 receptor protein. There were no changes in the sham group. Conclusion: The overall results indicate that the angiotensin receptor blockers valsartan and irbesartan both induce cardioprotection, limit myocardial stunning, and upregulate angiotensin II type 2 receptor protein expression after reperfused myocardial infarction in the rat. Patients who are already receiving angiotensin receptor blockers and develop acute coronary syndromes might benefit from these cardioprotective effects during reperfusion therapy.
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Affiliation(s)
- Bodh I Jugdutt
- Division of Cardiology, Department of Medicine and the Cardiovascular Research Group, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada.
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19
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Hachem M, Tiberi M, Ismail B, Hunter CR, Arksey N, Hadizad T, Beanlands RS, deKemp RA, DaSilva JN. Characterization of 18F-FPyKYNE-Losartan for Imaging AT1 Receptors. J Nucl Med 2016; 57:1612-1617. [DOI: 10.2967/jnumed.115.170951] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 04/11/2016] [Indexed: 12/25/2022] Open
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20
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Michel MC, Brunner HR, Foster C, Huo Y. Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease. Pharmacol Ther 2016; 164:1-81. [PMID: 27130806 DOI: 10.1016/j.pharmthera.2016.03.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 02/07/2023]
Abstract
We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.
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Affiliation(s)
- Martin C Michel
- Dept. Pharmacology, Johannes Gutenberg University, Mainz, Germany; Dept. Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim, Ingelheim, Germany.
| | | | - Carolyn Foster
- Retiree from Dept. of Research Networking, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, USA
| | - Yong Huo
- Dept. Cardiology & Heart Center, Peking University First Hospital, Beijing, PR China
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21
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Keller M, Kuhn KK, Einsiedel J, Hübner H, Biselli S, Mollereau C, Wifling D, Svobodová J, Bernhardt G, Cabrele C, Vanderheyden PML, Gmeiner P, Buschauer A. Mimicking of Arginine by Functionalized N(ω)-Carbamoylated Arginine As a New Broadly Applicable Approach to Labeled Bioactive Peptides: High Affinity Angiotensin, Neuropeptide Y, Neuropeptide FF, and Neurotensin Receptor Ligands As Examples. J Med Chem 2016; 59:1925-45. [PMID: 26824643 DOI: 10.1021/acs.jmedchem.5b01495] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Derivatization of biologically active peptides by conjugation with fluorophores or radionuclide-bearing moieties is an effective and commonly used approach to prepare molecular tools and diagnostic agents. Whereas lysine, cysteine, and N-terminal amino acids have been mostly used for peptide conjugation, we describe a new, widely applicable approach to peptide conjugation based on the nonclassical bioisosteric replacement of the guanidine group in arginine by a functionalized carbamoylguanidine moiety. Four arginine-containing peptide receptor ligands (angiotensin II, neurotensin(8-13), an analogue of the C-terminal pentapeptide of neuropeptide Y, and a neuropeptide FF analogue) were subject of this proof-of-concept study. The N(ω)-carbamoylated arginines, bearing spacers with a terminal amino group, were incorporated into the peptides by standard Fmoc solid phase peptide synthesis. The synthesized chemically stable peptide derivatives showed high receptor affinities with Ki values in the low nanomolar range, even when bulky fluorophores had been attached. Two new tritiated tracers for angiotensin and neurotensin receptors are described.
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Affiliation(s)
- Max Keller
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Kilian K Kuhn
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Jürgen Einsiedel
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University , Schuhstrasse 19, D-91052 Erlangen, Germany
| | - Harald Hübner
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University , Schuhstrasse 19, D-91052 Erlangen, Germany
| | - Sabrina Biselli
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Catherine Mollereau
- Institut de Pharmacologie et Biologie Structurale, CNRS/IPBS , 205 route de Narbonne, 31077 Toulouse cedex 5, France
| | - David Wifling
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Jaroslava Svobodová
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Günther Bernhardt
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - Chiara Cabrele
- Department of Molecular Biology, University of Salzburg , Billrothstrasse 11, A-5020 Salzburg, Austria
| | - Patrick M L Vanderheyden
- Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel , Pleinlaan 2, B-1050 Brussels, Belgium
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich Alexander University , Schuhstrasse 19, D-91052 Erlangen, Germany
| | - Armin Buschauer
- Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg , Universitätsstrasse 31, D-93053 Regensburg, Germany
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22
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Vauquelin G, Van Liefde I, Swinney DC. Radioligand binding to intact cells as a tool for extended drug screening in a representative physiological context. DRUG DISCOVERY TODAY. TECHNOLOGIES 2015; 17:28-34. [PMID: 26724334 DOI: 10.1016/j.ddtec.2015.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 09/04/2015] [Accepted: 09/09/2015] [Indexed: 06/05/2023]
Abstract
Radioligand binding assays on intact cells offer distinct advantages to those on membrane suspensions. Major pharmacological properties like drug affinity and binding kinetics are more physiologically relevant. Complex mechanisms can be studied with a wider choice of experimental approaches and so provide insights into induced-fit type binding, receptor internalisation and even into pharmacomicrokinetic phenomena like drug rebinding and partitioning into the membrane. Hence, intact cell binding constitutes a valuable addition to the pharmacologist's toolbox.
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Affiliation(s)
- Georges Vauquelin
- Dept. of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
| | - Isabelle Van Liefde
- Dept. of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - David C Swinney
- Institute for Rare and Neglected Diseases Drug Discovery, 897 Independence Ave, Suite 2C, Mountain View, CA 94043, United States
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23
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Bolaños J, De León LF, Ochoa E, Darias J, Raja HA, Shearer CA, Miller AN, Vanderheyden P, Porras-Alfaro A, Caballero-George C. Phylogenetic Diversity of Sponge-Associated Fungi from the Caribbean and the Pacific of Panama and Their In Vitro Effect on Angiotensin and Endothelin Receptors. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2015; 17:533-564. [PMID: 26026948 DOI: 10.1007/s10126-015-9634-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 04/17/2015] [Indexed: 06/04/2023]
Abstract
Fungi occupy an important ecological niche in the marine environment, and marine fungi possess an immense biotechnological potential. This study documents the fungal diversity associated with 39 species of sponges and determines their potential to produce secondary metabolites capable of interacting with mammalian G-protein-coupled receptors involved in blood pressure regulation. Total genomic DNA was extracted from 563 representative fungal strains obtained from marine sponges collected by SCUBA from the Caribbean and the Pacific regions of Panama. A total of 194 operational taxonomic units were found with 58% represented by singletons based on the internal transcribed spacer (ITS) and partial large subunit (LSU) rDNA regions. Marine sponges were highly dominated by Ascomycota fungi (95.6%) and represented by two major classes, Sordariomycetes and Dothideomycetes. Rarefaction curves showed no saturation, indicating that further efforts are needed to reveal the entire diversity at this site. Several unique clades were found during phylogenetic analysis with the highest diversity of unique clades in the order Pleosporales. From the 65 cultures tested to determine their in vitro effect on angiotensin and endothelin receptors, the extracts of Fusarium sp. and Phoma sp. blocked the activation of these receptors by more than 50% of the control and seven others inhibited between 30 and 45%. Our results indicate that marine sponges from Panama are a "hot spot" of fungal diversity as well as a rich resource for capturing, cataloguing, and assessing the pharmacological potential of substances present in previously undiscovered fungi associated with marine sponges.
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Affiliation(s)
- Jessica Bolaños
- Institute of Scientific Research and High Technology Services, Bld. 219, City of Knowledge, Clayton, Panama, Republic of Panama
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24
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Dabul S, Bathgate-Siryk A, Valero TR, Jafferjee M, Sturchler E, McDonald P, Koch WJ, Lymperopoulos A. Suppression of adrenal βarrestin1-dependent aldosterone production by ARBs: head-to-head comparison. Sci Rep 2015; 5:8116. [PMID: 25631300 PMCID: PMC4309955 DOI: 10.1038/srep08116] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 11/26/2014] [Indexed: 12/22/2022] Open
Abstract
The known angiotensin II (AngII) physiological effect of aldosterone synthesis and secretion is mediated by either Gq/11 proteins or βarrestin1 (βarr1), both of which can couple to its type 1 receptors (AT₁Rs), present in adrenocortical zona glomerulosa (AZG) cell membranes. In the present study, we examined the relative potencies of all the currently used in the clinic AT₁R antagonist drugs (angiotensin receptor blockers, ARBs, or sartans) at preventing activation of these two signaling mediators (G proteins and βarrs) at the AngII-bound AT1R and, consequently, at suppression of aldosterone in vitro. All ARBs were found to be potent inhibitors of G protein activation at the AT₁R. However, candesartan and valsartan were the most potent at blocking AngII-induced βarr activation at this receptor, among the tetrazolo-biphenyl-methyl derivatives, translating into excellent efficacies at aldosterone suppression in H295R cells. Conversely, irbesartan and losartan were largely G protein-selective inhibitors at the AT₁R, with very low potency towards βarr inhibition. As a result, they were very weak suppressors of βarr1-dependent aldosterone production in H295R cells. These findings provide important pharmacological insights into the drug class of ARBs and medicinal chemistry insights for future drug development in the field of AngII antagonism.
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Affiliation(s)
- Samalia Dabul
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL 33328, USA
| | - Ashley Bathgate-Siryk
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL 33328, USA
| | - Thairy Reyes Valero
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL 33328, USA
| | - Malika Jafferjee
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL 33328, USA
| | - Emmanuel Sturchler
- Translational Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Patricia McDonald
- Translational Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Walter J Koch
- Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Anastasios Lymperopoulos
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL 33328, USA
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Nikolaou A, Stijlemans B, Laoui D, Schouppe E, Tran HTT, Tourwé D, Chai SY, Vanderheyden PML, Van Ginderachter JA. Presence and regulation of insulin-regulated aminopeptidase in mouse macrophages. J Renin Angiotensin Aldosterone Syst 2014; 15:466-79. [DOI: 10.1177/1470320313507621] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Alexandros Nikolaou
- Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Belgium
- Cellular and Molecular Immunology Unit, Vrije Universiteit Brussel, Belgium
| | - Benoit Stijlemans
- Myeloid Cell Immunology Laboratory, VIB, Belgium
- Cellular and Molecular Immunology Unit, Vrije Universiteit Brussel, Belgium
| | - Damya Laoui
- Myeloid Cell Immunology Laboratory, VIB, Belgium
- Cellular and Molecular Immunology Unit, Vrije Universiteit Brussel, Belgium
| | - Elio Schouppe
- Myeloid Cell Immunology Laboratory, VIB, Belgium
- Cellular and Molecular Immunology Unit, Vrije Universiteit Brussel, Belgium
| | - Huyen TT Tran
- Myeloid Cell Immunology Laboratory, VIB, Belgium
- Cellular and Molecular Immunology Unit, Vrije Universiteit Brussel, Belgium
| | - Dirk Tourwé
- Laboratory of Organic Chemistry, Vrije Universiteit Brussel, Belgium
| | - Siew Y Chai
- Department of Physiology, Monash University, Australia
| | | | - Jo A Van Ginderachter
- Myeloid Cell Immunology Laboratory, VIB, Belgium
- Cellular and Molecular Immunology Unit, Vrije Universiteit Brussel, Belgium
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Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: G protein-coupled receptors. Br J Pharmacol 2013; 170:1459-581. [PMID: 24517644 PMCID: PMC3892287 DOI: 10.1111/bph.12445] [Citation(s) in RCA: 505] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. G protein-coupled receptors are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
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Affiliation(s)
- Stephen PH Alexander
- School of Life Sciences, University of Nottingham Medical SchoolNottingham, NG7 2UH, UK
| | - Helen E Benson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Elena Faccenda
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Adam J Pawson
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | - Joanna L Sharman
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
| | | | - John A Peters
- Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of DundeeDundee, DD1 9SY, UK
| | - Anthony J Harmar
- The University/BHF Centre for Cardiovascular Science, University of EdinburghEdinburgh, EH16 4TJ, UK
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Bergmayr C, Thurner P, Keuerleber S, Kudlacek O, Nanoff C, Freissmuth M, Gruber CW. Recruitment of a cytoplasmic chaperone relay by the A2A adenosine receptor. J Biol Chem 2013; 288:28831-44. [PMID: 23965991 PMCID: PMC3789979 DOI: 10.1074/jbc.m113.464776] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The adenosine A2A receptor is a prototypical rhodopsin-like G protein-coupled receptor but has several unique structural features, in particular a long C terminus (of >120 residues) devoid of a palmitoylation site. It is known to interact with several accessory proteins other than those canonically involved in signaling. However, it is evident that many more proteins must interact with the A2A receptor, if the trafficking trajectory of the receptor is taken into account from its site of synthesis in the endoplasmic reticulum (ER) to its disposal by the lysosome. Affinity-tagged versions of the A2A receptor were expressed in HEK293 cells to identify interacting partners residing in the ER by a proteomics approach based on tandem affinity purification. The receptor-protein complexes were purified in quantities sufficient for analysis by mass spectrometry. We identified molecular chaperones (heat-shock proteins HSP90α and HSP70-1A) that interact with and retain partially folded A2A receptor prior to ER exit. Complex formation between the A2A receptor and HSP90α (but not HSP90β) and HSP70-1A was confirmed by co-affinity precipitation. HSP90 inhibitors also enhanced surface expression of the receptor in PC12 cells, which endogenously express the A2A receptor. Finally, proteins of the HSP relay machinery (e.g. HOP/HSC70-HSP90 organizing protein and P23/HSP90 co-chaperone) were recovered in complexes with the A2A receptor. These observations are consistent with the proposed chaperone/coat protein complex II exchange model. This posits that cytosolic HSP proteins are sequentially recruited to folding intermediates of the A2A receptor. Release of HSP90 is required prior to recruitment of coat protein complex II components. This prevents premature ER export of partially folded receptors.
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Affiliation(s)
- Christian Bergmayr
- From the Institute for Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Waehringerstrasse 13a, A-1090 Vienna, Austria
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Michel MC, Foster C, Brunner HR, Liu L. A systematic comparison of the properties of clinically used angiotensin II type 1 receptor antagonists. Pharmacol Rev 2013; 65:809-48. [PMID: 23487168 DOI: 10.1124/pr.112.007278] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Angiotensin II type 1 receptor antagonists (ARBs) have become an important drug class in the treatment of hypertension and heart failure and the protection from diabetic nephropathy. Eight ARBs are clinically available [azilsartan, candesartan, eprosartan, irbesartan, losartan, olmesartan, telmisartan, valsartan]. Azilsartan (in some countries), candesartan, and olmesartan are orally administered as prodrugs, whereas the blocking action of some is mediated through active metabolites. On the basis of their chemical structures, ARBs use different binding pockets in the receptor, which are associated with differences in dissociation times and, in most cases, apparently insurmountable antagonism. The physicochemical differences between ARBs also manifest in different tissue penetration, including passage through the blood-brain barrier. Differences in binding mode and tissue penetration are also associated with differences in pharmacokinetic profile, particularly duration of action. Although generally highly specific for angiotensin II type 1 receptors, some ARBs, particularly telmisartan, are partial agonists at peroxisome proliferator-activated receptor-γ. All of these properties are comprehensively reviewed in this article. Although there is general consensus that a continuous receptor blockade over a 24-hour period is desirable, the clinical relevance of other pharmacological differences between individual ARBs remains to be assessed.
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Affiliation(s)
- Martin C Michel
- Department of Clinical Development & Medical Affairs, Boehringer Ingelheim, 55216 Ingelheim, Germany.
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Nikolaou A, Eynde IVD, Tourwé D, Vauquelin G, Tóth G, Mallareddy JR, Poglitsch M, Van Ginderachter JA, Vanderheyden PM. [3H]IVDE77, a novel radioligand with high affinity and selectivity for the insulin-regulated aminopeptidase. Eur J Pharmacol 2013; 702:93-102. [DOI: 10.1016/j.ejphar.2013.01.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 01/14/2013] [Accepted: 01/16/2013] [Indexed: 10/27/2022]
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Efficacy/safety of olmesartan medoxomil versus losartan potassium in naïve versus previously treated subjects with hypertension. Adv Ther 2012; 29:524-37. [PMID: 22763801 DOI: 10.1007/s12325-012-0029-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Indexed: 01/13/2023]
Abstract
INTRODUCTION A predefined exploratory analysis of a prospective, randomized, double-blind, forced-titration study of olmesartan medoxomil (OM) versus losartan potassium (LOS) in subjects with hypertension not previously or previously treated with antihypertensive medication is reported. METHODS The study included a 3-4-week placebo run-in and an 8-week active treatment period: OM (weeks 1-4, OM 20 mg; weeks 5-8, OM 40 mg); placebo + OM (weeks 1-2, placebo; weeks 3-4, OM 20 mg; weeks 5-8, OM 40 mg); and LOS (weeks 1-4, LOS 50 mg; weeks 5-8, LOS 100 mg). Analyses focused on comparison of OM and placebo + OM combined versus LOS. Efficacy endpoints were mean change from baseline in seated cuff diastolic blood pressure (SeDBP) at week 8 (primary); seated cuff systolic blood pressure (SeSBP) at weeks 4 and 8, and SeDBP at week 4 (secondary), and BP target achievement (tertiary). RESULTS The randomized population (n = 941) had a mean ± SD age of 51.9 ± 9.7 years, 54.5% were male, and 20.1% were naïve to antihypertensive medication. For treatmentnaïve subjects, baseline seated BP (SeBP) (±SD) was 157.4 (±10.9)/101.8 (±4.3) mmHg with OM and 156.3 (±10.8)/101.1 (±3.9) mmHg with LOS, while non-naïve subjects had 158.4 (±10.2)/100.9 (±4.0) mmHg with OM and 158.8 (±10.1)/101.3 (±4.2) mmHg with LOS. OM monotherapy produced significantly greater changes in least-squares mean (±SE) SeDBP compared with LOS in both treatment-naïve (-9.7 [1.0] vs. -6.6 [1.0] mmHg; P = 0.0232 vs. LOS) and non-naïve subjects (-9.6 [0.5] vs. -7.3 [0.5] mmHg; P = 0.0013 vs. LOS). A significantly greater proportion of patients achieved the SeBP goal of <140/90 mmHg with OM compared with LOS in treatment-naïve (34.1% vs. 19.0%, respectively; P = 0.0109) and non-naïve subjects (31.0% vs. 19.6%; P = 0.0008). CONCLUSION Overall, OM monotherapy resulted in significantly greater SeBP reductions and greater SeBP goal achievement than LOS, irrespective of previous medication use. Both OM and LOS therapy were well tolerated.
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Ramsey SJ, Attkins NJ, Fish R, van der Graaf PH. Quantitative pharmacological analysis of antagonist binding kinetics at CRF1 receptors in vitro and in vivo. Br J Pharmacol 2012; 164:992-1007. [PMID: 21449919 DOI: 10.1111/j.1476-5381.2011.01390.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE A series of novel non-peptide corticotropin releasing factor type-1 receptor (CRF(1)) antagonists were found to display varying degrees of insurmountable and non-competitive behaviour in functional in vitro assays. We describe how we attempted to relate this behaviour to ligand receptor-binding kinetics in a quantitative manner and how this resulted in the development and implementation of an efficient pharmacological screening method based on principles described by Motulsky and Mahan. EXPERIMENTAL APPROACH A non-equilibrium binding kinetic assay was developed to determine the receptor binding kinetics of non-peptide CRF(1) antagonists. Nonlinear, mixed-effects modelling was used to obtain estimates of the compounds association and dissociation rates. We present an integrated pharmacokinetic-pharmacodynamic (PKPD) approach, whereby the time course of in vivo CRF(1) receptor binding of novel compounds can be predicted on the basis of in vitro assays. KEY RESULTS The non-competitive antagonist behaviour appeared to be correlated to the CRF(1) receptor off-rate kinetics. The integrated PKPD model suggested that, at least in a qualitative manner, the in vitro assay can be used to triage and select compounds for further in vivo investigations. CONCLUSIONS AND IMPLICATIONS This study provides evidence for a link between ligand offset kinetics and insurmountable/non-competitive antagonism at the CRF(1) receptor. The exact molecular pharmacological nature of this association remains to be determined. In addition, we have developed a quantitative framework to study and integrate in vitro and in vivo receptor binding kinetic behaviour of CRF(1) receptor antagonists in an efficient manner in a drug discovery setting.
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Doi N, Yamakawa N, Matsumoto H, Yamamoto Y, Nagano T, Matsumura N, Horisawa K, Yanagawa H. DNA display selection of peptide ligands for a full-length human G protein-coupled receptor on CHO-K1 cells. PLoS One 2012; 7:e30084. [PMID: 22253889 PMCID: PMC3254644 DOI: 10.1371/journal.pone.0030084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 12/09/2011] [Indexed: 12/25/2022] Open
Abstract
The G protein-coupled receptors (GPCRs), which form the largest group of transmembrane proteins involved in signal transduction, are major targets of currently available drugs. Thus, the search for cognate and surrogate peptide ligands for GPCRs is of both basic and therapeutic interest. Here we describe the application of an in vitro DNA display technology to screening libraries of peptide ligands for full-length GPCRs expressed on whole cells. We used human angiotensin II (Ang II) type-1 receptor (hAT1R) as a model GPCR. Under improved selection conditions using hAT1R-expressing Chinese hamster ovary (CHO)-K1 cells as bait, we confirmed that Ang II gene could be enriched more than 10,000-fold after four rounds of selection. Further, we successfully selected diverse Ang II-like peptides from randomized peptide libraries. The results provide more precise information on the sequence-function relationships of hAT1R ligands than can be obtained by conventional alanine-scanning mutagenesis. Completely in vitro DNA display can overcome the limitations of current display technologies and is expected to prove widely useful for screening diverse libraries of mutant peptide and protein ligands for receptors that can be expressed functionally on the surface of CHO-K1 cells.
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Affiliation(s)
- Nobuhide Doi
- Department of Biosciences and Informatics, Keio University, Yokohama, Japan.
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Catalano A, Carocci A, Di Mola A, Bruno C, Vanderheyden PML, Franchini C. 1-Pentanoyl-N-{[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl}-pyrrolidine-2-carboxamide: Investigation of Structural Variations. Arch Pharm (Weinheim) 2011; 344:617-26. [DOI: 10.1002/ardp.201000296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 01/17/2011] [Accepted: 01/20/2011] [Indexed: 11/12/2022]
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Demaegdt H, Gard P, De Backer JP, Lukaszuk A, Szemenyei E, Tóth G, Tourwé D, Vauquelin G. Binding of "AT4 receptor" ligands to insulin regulated aminopeptidase (IRAP) in intact Chinese hamster ovary cells. Mol Cell Endocrinol 2011; 339:34-44. [PMID: 21457753 DOI: 10.1016/j.mce.2011.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 03/17/2011] [Accepted: 03/22/2011] [Indexed: 01/03/2023]
Abstract
Insulin regulated aminopeptidase (IRAP) recognises "AT(4)-receptor" ligands like angiotensin IV (Ang IV) and peptidomimetics like AL-11. The metabolic stability and high affinity of [(3)H]AL-11 for catalytically active IRAP allowed its detection in Chinese hamster ovary (CHO-K1) cell membranes in the absence of chelators (Demaegdt et al., 2009). Here, we show that, contrary to [(3)H]Ang IV, [(3)H]AL-11 displays high affinity and specificity for IRAP in intact CHO-K1 cells as well. After binding to IRAP at the surface, [(3)H]AL-11 is effectively internalized by an endocytotic process. Unexpectedly, surface binding and internalization of [(3)H]AL-11 was not affected by pretreating the cells with Ang IV but declined with AL-11. In the latter case surface expression of IRAP even increased. After elimination of simpler explanations, it is proposed that metabolically stable "AT(4)-receptor" ligands undergo semi-continuous cycling between the cell surface and endosomal compartments. The in vivo efficacy of stable and unstable "AT(4)-receptor" ligands could therefore differ.
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Affiliation(s)
- Heidi Demaegdt
- Department of Molecular and Biochemical Pharmacology, Research Group of Experimental Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
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Lukaszuk A, Demaegdt H, Van den Eynde I, Vanderheyden P, Vauquelin G, Tourwé D. Conformational constraints in angiotensin IV to probe the role of Tyr2, Pro5 and Phe6. J Pept Sci 2011; 17:545-53. [DOI: 10.1002/psc.1365] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 01/27/2011] [Accepted: 01/27/2011] [Indexed: 12/16/2022]
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Charlton SJ, Vauquelin G. Elusive equilibrium: the challenge of interpreting receptor pharmacology using calcium assays. Br J Pharmacol 2010; 161:1250-65. [PMID: 20977466 PMCID: PMC3000651 DOI: 10.1111/j.1476-5381.2010.00863.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 03/29/2010] [Accepted: 04/12/2010] [Indexed: 11/28/2022] Open
Abstract
UNLABELLED Calcium is a key intracellular signal that controls manifold cellular processes over a wide temporal range. The development of calcium-sensitive fluorescent dyes and proteins revolutionized our ability to visualize this important second messenger and its complex signalling characteristics. The subsequent advent of high throughput plate-based fluorescence readers has resulted in the calcium assay becoming the most widely utilized assay system for the characterization of novel receptor ligands. In this review we discuss common approaches to calcium assays, paying particular attention to the potential issues associated with interpretation of receptor pharmacology using this system. Topics covered include dye saturation and forced-coupling of receptors to the calcium pathway, but special consideration is given to the influence of non-equilibrium conditions in this rapid signalling system. Modelling the calcium transient in a kinetic mode allows the influence of ligand kinetics, receptor reserve and read time to be explored. This demonstrates that observed ligand pharmacology at very early time points can be quite different to that determined after longer incubations, even resulting in reversal of agonist potency orders that may be misinterpreted as agonist biased signalling. It also shows that estimates of antagonist affinity, whether by Schild analysis or inhibition curves, are similarly affected by hemi-equilibrium conditions. Finally we end with a discussion on practical approaches to accurately estimate the affinity of insurmountable antagonists using calcium assays. LINKED ARTICLES This article is part of a themed section on Analytical Receptor Pharmacology in Drug Discovery. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2010.161.issue-6.
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Zwier JM, Roux T, Cottet M, Durroux T, Douzon S, Bdioui S, Gregor N, Bourrier E, Oueslati N, Nicolas L, Tinel N, Boisseau C, Yverneau P, Charrier-Savournin F, Fink M, Trinquet E. A fluorescent ligand-binding alternative using Tag-lite® technology. ACTA ACUST UNITED AC 2010; 15:1248-59. [PMID: 20974902 DOI: 10.1177/1087057110384611] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
G-protein-coupled receptors (GPCRs) are crucial cell surface receptors that transmit signals from a wide range of extracellular ligands. Indeed, 40% to 50% of all marketed drugs are thought to modulate GPCR activity, making them the major class of targets in the drug discovery process. Binding assays are widely used to identify high-affinity, selective, and potent GPCR drugs. In this field, the use of radiolabeled ligands has remained so far the gold-standard method. Here the authors report a less hazardous alternative for high-throughput screening (HTS) applications by the setup of a nonradioactive fluorescence-based technology named Tag-lite(®). Selective binding of various fluorescent ligands, either peptidic or not, covering a large panel of GPCRs from different classes is illustrated, particularly for chemokine (CXCR4), opioid (δ, µ, and κ), and cholecystokinin (CCK1 and CCK2) receptors. Affinity constants of well-known pharmacological agents of numerous GPCRs are in line with values published in the literature. The authors clearly demonstrate that the Tag-lite binding assay format can be successfully and reproducibly applied by using different cellular materials such as transient or stable recombinant cells lines expressing SNAP-tagged GPCR. Such fluorescent-based binding assays can be performed with adherent cells or cells in suspension, in 96- or 384-well plates. Altogether, this new technology offers great advantages in terms of flexibility, rapidity, and user-friendliness; allows easy miniaturization; and makes it completely suitable for HTS applications.
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Vauquelin G, Charlton SJ. Long-lasting target binding and rebinding as mechanisms to prolong in vivo drug action. Br J Pharmacol 2010; 161:488-508. [PMID: 20880390 PMCID: PMC2990149 DOI: 10.1111/j.1476-5381.2010.00936.x] [Citation(s) in RCA: 206] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 05/17/2010] [Accepted: 06/10/2010] [Indexed: 11/28/2022] Open
Abstract
An increasing number of examples in the literature suggest that the in vivo duration of drug action not only depends on macroscopic pharmacokinetic properties like plasma half-life and the time needed to equilibrate between the plasma and the effect compartments, but is also influenced by long-lasting target binding and rebinding. The present review combines information from different research areas and simulations to explore the nature of these mechanisms and the conditions in which they are most prevalent. Simulations reveal that these latter phenomena become especially influential when there is no longer sufficient free drug around to maintain high levels of receptor occupancy. There is not always a direct link between slow dissociation and long-lasting in vivo target protection, as the rate of free drug elimination from the effect compartment is also a key influencing factor. Local phenomena that hinder the diffusion of free drug molecules away from their target may allow them to consecutively bind to the same target and/or targets nearby (denoted as 'rebinding') even when their concentration in the bulk phase has already dropped to insignificant levels. The micro-anatomic properties of many effect compartments are likely to intensify this phenomenon. By mimicking the complexity of tissues, intact cells offer the opportunity to investigate both mechanisms under the same, physiologically relevant conditions.
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Affiliation(s)
- Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium.
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Detection of angiotensin II type 1 receptor ligands by a cell-based assay. Anal Bioanal Chem 2010; 395:1937-40. [PMID: 19760406 DOI: 10.1007/s00216-009-3074-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 08/14/2009] [Accepted: 08/17/2009] [Indexed: 10/20/2022]
Abstract
This work describes a cell-based assay that does not depend on radioactivity or laboratory animals for the detection of ligands of angiotensin II type 1 receptor (AT1R). The assay makes use of stable transfected Chinese hamster ovary cells (CHO-AT1R) expressing the AT1R. A sequential saturation assay principle was used in which receptor binding sites of the CHO-AT1R cells are blocked by the analyte in a concentration-dependent manner. Afterwards, TAMRA-angiotensin II, a fluorescence-labeled ligand, was added to bind to the remaining free binding sites of the receptor. In consequence, the fluorescence signal determined is inversely proportional to the concentration of the analyte.
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De Bundel D, Demaegdt H, Lahoutte T, Caveliers V, Kersemans K, Ceulemans AG, Vauquelin G, Clinckers R, Vanderheyden P, Michotte Y, Smolders I. Involvement of the AT1 receptor subtype in the effects of angiotensin IV and LVV-haemorphin 7 on hippocampal neurotransmitter levels and spatial working memory. J Neurochem 2009; 112:1223-34. [PMID: 20028450 DOI: 10.1111/j.1471-4159.2009.06547.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Intracerebroventricular (i.c.v.) administration of angiotensin IV (Ang IV) or Leu-Val-Val-haemorphin 7 (LVV-H7) improves memory performance in normal rats and reverses memory deficits in rat models for cognitive impairment. These memory effects were believed to be mediated via the putative 'AT4 receptor'. However, this binding site was identified as insulin-regulated aminopeptidase (IRAP). Correspondingly, Ang IV and LVV-H7 were characterised as IRAP inhibitors. This study investigates whether and how IRAP may be involved in the central effects of Ang IV and LVV-H7. We determined the effects of i.c.v. administration of Ang IV or LVV-H7 on hippocampal neurotransmitter levels using microdialysis in rats. We observed that Ang IV modulates hippocampal acetylcholine levels, whereas LVV-H7 does not. This discrepancy was reflected in the observation that Ang IV binds with micromolar affinity to the AT1 receptor whereas no binding affinity was observed for LVV-H7. Correspondingly, we demonstrated that the AT1 receptor is involved in the effects of Ang IV on hippocampal neurotransmitter levels and on spatial working memory in a plus maze spontaneous alternation task. However, the AT1 receptor was not involved in the spatial memory facilitating effect of LVV-H7. Finally, we demonstrated that Ang IV did not diffuse to the hippocampus following i.c.v. injection, suggesting an extrahippocampal site of action. We propose that AT1 receptors are implicated in the neurochemical and cognitive effects of Ang IV, whereas LVV-H7 may mediate its effects via IRAP.
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Affiliation(s)
- Dimitri De Bundel
- Research Group Experimental Pharmacology, Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Vrije Universiteit Brussel, Brussels, Belgium
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Lukaszuk A, Demaegdt H, Feytens D, Vanderheyden P, Vauquelin G, Tourwé D. The Replacement of His(4) in Angiotensin IV by Conformationally Constrained Residues Provides Highly Potent and Selective Analogues. J Med Chem 2009; 52:5612-8. [DOI: 10.1021/jm900651p] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Aneta Lukaszuk
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Heidi Demaegdt
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Debby Feytens
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Patrick Vanderheyden
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Georges Vauquelin
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Dirk Tourwé
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
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42
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RUILOPE LUIS. Improving Prognosis in Hypertension: Exploring the Benefits of Angiotensin II Type 1 Receptor Blockade. Blood Press 2009; 9:31-35. [DOI: 10.1080/080370500439209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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43
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JOHNSTON COLINI. Angiotensin II Type 1 Receptor Blockade: a Novel Therapeutic Concept. Blood Press 2009; 9:9-13. [DOI: 10.1080/080370500439155] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Van Liefde I, Vauquelin G. Sartan-AT1 receptor interactions: in vitro evidence for insurmountable antagonism and inverse agonism. Mol Cell Endocrinol 2009; 302:237-43. [PMID: 18620019 DOI: 10.1016/j.mce.2008.06.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 06/09/2008] [Accepted: 06/12/2008] [Indexed: 10/21/2022]
Abstract
Sartans are non-peptide AT(1) receptor antagonists used to treat hypertension and related pathologies. Their effects on the G protein-dependent responses of angiotensin II (Ang II) were the same in vascular tissues and in isolated cell systems. All are competitive but, when pre-incubated, they act surmountably (only rightward shift of the Ang II concentration-response curve) or insurmountably (also decreasing the maximal response). Insurmountable behaviour reflects the formation of tight sartan-receptor complexes; it is often partial due to the co-existence of tight and loose complexes. Their ratio positively correlates with the dissociation half-life of the tight complexes and depends on the sartan: i.e. candesartan>olmesartan>telmisartan approximately equal EXP3174>valsartan>irbesartan>>losartan. When AT(1) receptors display sufficient basal activity (in case of receptor over-expression, mutation and, especially, tissue stretching) sartans may also act as inverse agonists. This rather affects long-term, G protein-independent hypertrophic responses leading to cardiovascular remodelling.
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Affiliation(s)
- I Van Liefde
- Department of Molecular and Biochemical Pharmacology, Institute for Molecular Biology and Biotechnology, Vrije Universiteit Brussel (VUB), Brussel, Belgium
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45
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Akazawa H, Yasuda N, Komuro I. Mechanisms and functions of agonist-independent activation in the angiotensin II type 1 receptor. Mol Cell Endocrinol 2009; 302:140-7. [PMID: 19059460 DOI: 10.1016/j.mce.2008.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 11/06/2008] [Accepted: 11/06/2008] [Indexed: 11/23/2022]
Abstract
The angiotensin II (AngII) type 1 (AT(1)) receptor is a seven-transmembrane G protein-coupled receptor, and is involved in regulating the physiological and pathological process of the cardiovascular system. Systemically and locally generated AngII has agonistic action on AT(1) receptor, but recent studies have demonstrated that AT(1) receptor inherently shows spontaneous activity even in the absence of AngII. Furthermore, mechanical stress can activate AT(1) receptor by inducing conformational switch without the involvement of AngII, and induce cardiac hypertrophy in vivo. These agonist-independent activities of AT(1) receptor can be inhibited by inverse agonists, but not by neutral antagonists. Considerable attention has been directed to molecular mechanisms and clinical implications of agonist-independent AT(1) receptor activation, and inverse agonist activity emerges as an important pharmacological parameter for AT(1) receptor blockers that will improve efficacy and expand therapeutic potentials in cardiovascular medicine.
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Affiliation(s)
- Hiroshi Akazawa
- Division of Cardiovascular Pathophysiology, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan
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46
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Duvernay MT, Dong C, Zhang X, Robitaille M, Hébert TE, Wu G. A single conserved leucine residue on the first intracellular loop regulates ER export of G protein-coupled receptors. Traffic 2009; 10:552-66. [PMID: 19220814 DOI: 10.1111/j.1600-0854.2009.00890.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The intrinsic structural determinants for export trafficking of G protein-coupled receptors (GPCRs) have been mainly identified in the termini of the receptors. In this report, we determined the role of the first intracellular loop (ICL1) in the transport from the endoplasmic reticulum (ER) to the cell surface of GPCRs. The alpha(2B)-adrenergic receptor (AR) mutant lacking the ICL1 is unable to traffic to the cell surface and to initiate signaling measured as ERK1/2 activation. Mutagenesis studies identify a single Leu48 residue in the ICL1 modulates alpha(2B)-AR export from the ER. The ER export function of the Leu48 residue can be substituted by Phe, but not Ile, Val, Tyr and Trp, and is unlikely involved in correct folding or dimerization of alpha(2B)-AR in the ER. Importantly, the isolated Leu residue is remarkably conserved in the center of the ICL1s among the family A GPCRs and is also required for the export to the cell surface of beta(2)-AR, alpha(1B)-AR and angiotensin II type 1 receptor. These data indicate a crucial role for a single Leu residue within the ICL1 in ER export of GPCRs.
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Affiliation(s)
- Matthew T Duvernay
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, USA
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47
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White M, Rouleau JL, Afzal R, Floras J, Yusuf S, McKelvie RS. Effects of enalapril, candesartan or both on neurohumoral activation and LV volumes and function in patients with heart failure not treated with a beta-blocker. Ther Adv Cardiovasc Dis 2009; 3:113-21. [DOI: 10.1177/1753944708103658] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: The long-term effects of the angiotensin-receptor blocker candesartan, the angiotensin-converting enzyme inhibitor enalapril or their combination have been incompletely studied in a large cohort of patients with heart failure not treated with beta-blockers. The objective of this study was to investigate the changes in neurohormones and LV volumes and ejection fraction in patients treated with enalapril, candesartan, or enalapril plus candesartan without concomitant beta-blocker therapy. Methods: Three hundred and ninety-two patients from the RESOLVD pilot study not treated with a beta-blocker at baseline or at any time during the trial were analyzed. Norepinephrine, endothelin-1, big endothelin-1, angiotensin-II, aldosterone, N-terminal proANP, BNP, and radionuclide angiography were measured before and after 43 weeks of treatment with candesartan alone ( n = 162), or enalapril alone ( n = 45), or candesartan plus enalapril ( n = 185). Endpoints were assessed at baseline and after 43 weeks of therapy. Results: LV end-diastolic and end-systolic volumes increased significantly at 43 weeks in all groups except for patients treated with enalapril plus candesartan. BNP decreased at 43 weeks only in patients receiving dual angiotensin-II suppression (-6.1 ± 37.8 pmol/l). Angiotensin-II levels were significantly increased in patients treated with candesartan (+23.6 ± 47.1 pg/ml; p<0.05). Conclusion: We conclude that angiotensin-II modulation, with enalapril and candesartan, without concomitant utilization of beta-blocker lead to a decrease in BNP and an attenuation of the increase in LV end-diastolic and end-systolic volumes without a reversal of this process in the long term.
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Affiliation(s)
- Michel White
- Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada,
| | - Jean-Lucien Rouleau
- Research Center, Montreal Heart Institute and Université de Montréal, Montreal, Quebec, Canada
| | - Rizwan Afzal
- Department of Medicine, McMaster Hospital, Hamilton, Ontario, Canada
| | - John Floras
- Division of Cardiology, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Salim Yusuf
- Department of Medicine, McMaster Hospital, Hamilton, Ontario, Canada
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48
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Demaegdt H, Smitz L, De Backer JP, Le MT, Bauwens M, Szemenyei E, Tóth G, Michotte Y, Vanderheyden P, Vauquelin G. Translocation of the insulin-regulated aminopeptidase to the cell surface: detection by radioligand binding. Br J Pharmacol 2008; 154:872-81. [PMID: 18536739 PMCID: PMC2439846 DOI: 10.1038/bjp.2008.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 02/20/2008] [Accepted: 02/27/2008] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Insulin-regulated aminopeptidase (IRAP) and the insulin-dependent glucose transporter GLUT4 colocalize in specific intracellular vesicles (that is, GLUT4 vesicles). These vesicles move slowly to the cell surface, but their translocation is markedly enhanced by insulin, resulting in higher glucose uptake. Previous studies of the insulin-mediated translocation of IRAP to the cell surface have been hampered by the laborious detection of IRAP at the cell surface. We aimed to develop a more direct and faster method to detect IRAP. To this end, we used model systems with well-characterized IRAP: CHO-K1 cells expressing endogenous IRAP and recombinant HEK293 cells expressing human IRAP. A more widespread application of the method was demonstrated by the use of 3T3-L1 adipocytes. EXPERIMENTAL APPROACH After stimulation of the cells with insulin, internalization of IRAP was inhibited by the addition of phenyl arsine oxide (PAO). Then, cell-surface IRAP was detected by the high-affinity binding of radiolabelled angiotensin (Ang) IV (either 125I or 3H). KEY RESULTS We monitored the time- and concentration dependence of insulin-mediated translocation of IRAP in both cell lines and 3T3-L1 adipocytes. A plateau was reached between 6 and 8 min, and 10(-7) M insulin led to the highest amount of IRAP at the cell surface. CONCLUSIONS AND IMPLICATIONS Based on the capacity of the IRAP apoenzyme to display high affinity for radiolabelled Ang IV and on the ability of PAO to inhibit IRAP internalization, we developed a more direct and faster method to measure insulin-mediated translocation of IRAP to the cell surface.
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Affiliation(s)
- H Demaegdt
- Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Brussels, Belgium.
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49
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Cook JL, Re RN, deHaro DL, Abadie JM, Peters M, Alam J. The trafficking protein GABARAP binds to and enhances plasma membrane expression and function of the angiotensin II type 1 receptor. Circ Res 2008; 102:1539-47. [PMID: 18497328 DOI: 10.1161/circresaha.108.176594] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Proteins that bind to the intracellular expanses, particularly cytoplasmic tail regions, of heptahelical integral membrane receptors are of particular interest in that they can mediate or modulate trafficking or intracellular signaling. In an effort to distinguish new proteins that might promote angiotensin II type 1 (AT(1)) receptor intracellular events, we screened a yeast 2-hybrid mouse brain library with the rat AT(1A) receptor (AT(1)R) carboxyl terminus and identified GABARAP, a protein involved in intracellular trafficking of the GABA(A) receptor, as a binding partner for the AT(1)R. Interaction of GABARAP with the AT(1)R carboxyl terminus was further substantiated using GST pull-down assays, and binding of the full-length tagged AT(1)R to GABARAP was verified using coimmunoprecipitation. Bioluminescence resonance energy transfer assays further confirmed specific interaction of GABARAP with AT(1)R. Moreover, GABARAP clearly increased the steady-state level of plasma membrane-associated AT(1)R in PC-12 cells. Cotransfection of GABARAP with an AT(1)R fluorescent fusion protein increased PC-12 cell surface expression of the AT(1)R more than 6-fold when standardized to the level of intracellular expression. Furthermore, GABARAP overexpression in CHO-K1 cells engineered to express AT(1)R increased angiotensin II binding sites 3.7-fold and angiotensin II-induced phospho-extracellular signal-regulated kinase 1/2 and cellular proliferation significantly over levels obtained with AT(1)R overexpression alone. In addition, small interfering RNA-mediated knockdown of GABARAP reduced the steady-state levels of the AT(1)R fluorescent fusion protein by 43% and its cell surface expression by 84%. Immunoblot analyses confirmed the quantitative image data. We conclude that GABARAP binds to and promotes trafficking of the AT(1)R to the plasma membrane.
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Affiliation(s)
- Julia L Cook
- Division of Research, Ochsner Clinic Foundation, Ochsner Health System, 1514 Jefferson Hwy, New Orleans, LA 70121, USA.
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50
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Lukaszuk A, Demaegdt H, Szemenyei E, Tóth G, Tymecka D, Misicka A, Karoyan P, Vanderheyden P, Vauquelin G, Tourwé D. β-Homo-amino Acid Scan of Angiotensin IV. J Med Chem 2008; 51:2291-6. [DOI: 10.1021/jm701490g] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aneta Lukaszuk
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Heidi Demaegdt
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Erzsebet Szemenyei
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Géza Tóth
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Dagmara Tymecka
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Aleksandra Misicka
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Philippe Karoyan
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Patrick Vanderheyden
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Georges Vauquelin
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
| | - Dirk Tourwé
- Department of Organic Chemistry, Department of Molecular and Biochemical Pharmacology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium, Biological Research Center, Institute of Biochemistry, Temesvari krt. 62, 6726 Szeged, Hungary, Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland, Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106 Warsaw, Poland, and CNRS/UMR 7613, Université Pierre & Marie Curie, Place Jussieu 4, Paris, France
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