Anthony P. Davenport

Imaging Atherosclerotic Plaque Inflammation With [18F]-Fluorodeoxyglucose Positron Emission Tomography

Background—Atherosclerotic plaque rupture is usually a consequence of inflammatory cell activity within the plaque. Current imaging techniques provide anatomic data but no indication of plaque inflammation. The glucose analogue [18F]-fluorodeoxyglucose (18FDG) can be used to image inflammatory cell activity non-invasively by PET. In this study we tested whether 18FDG-PET imaging can identify inflammation within carotid artery atherosclerotic plaques. Methods and Results—Eight patients with symptomatic carotid atherosclerosis were imaged using 18FDG-PET and co-registered CT. Symptomatic carotid plaques were visible in 18FDG-PET images acquired 3 hours post-18FDG injection. The estimated net 18FDG accumulation rate (plaque/integral plasma) in symptomatic lesions was 27% higher than in contralateral asymptomatic lesions. There was no measurable 18FDG uptake into normal carotid arteries. Autoradiography of excised plaques confirmed accumulation of deoxyglucose in macrophage-rich areas of the plaque. Conclusions—This study demonstrates that atherosclerotic plaque inflammation can be imaged with 18FDG-PET, and that symptomatic, unstable plaques accumulate more 18FDG than asymptomatic lesions.

The IUPHAR/BPS Guide to PHARMACOLOGY in 2016: towards curated quantitative interactions between 1300 protein targets and 6000 ligands

The IUPHAR/BPS Guide to PHARMACOLOGY (GtoPdb, http://www.guidetopharmacology.org) provides expert-curated molecular interactions between successful and potential drugs and their targets in the human genome. Developed by the International Union of Basic and Clinical Pharmacology (IUPHAR) and the British Pharmacological Society (BPS), this resource, and its earlier incarnation as IUPHAR-DB, is described in our 2014 publication. This update incorporates changes over the intervening seven database releases. The unique model of content capture is based on established and new target class subcommittees collaborating with in-house curators. Most information comes from journal articles, but we now also index kinase cross-screening panels. Targets are specified by UniProtKB IDs. Small molecules are defined by PubChem Compound Identifiers (CIDs); ligand capture also includes peptides and clinical antibodies. We have extended the capture of ligands and targets linked via published quantitative binding data (e.g. Ki, IC50 or Kd). The resulting pharmacological relationship network now defines a data-supported druggable genome encompassing 7% of human proteins. The database also provides an expanded substrate for the biennially published compendium, the Concise Guide to PHARMACOLOGY. This article covers content increase, entity analysis, revised curation strategies, new website features and expanded download options.

The IUPHAR/BPS Guide to PHARMACOLOGY: an expert-driven knowledgebase of drug targets and their ligands

The International Union of Basic and Clinical Pharmacology/British Pharmacological Society (IUPHAR/BPS) Guide to PHARMACOLOGY (http://www.guidetopharmacology.org) is a new open access resource providing pharmacological, chemical, genetic, functional and pathophysiological data on the targets of approved and experimental drugs. Created under the auspices of the IUPHAR and the BPS, the portal provides concise, peer-reviewed overviews of the key properties of a wide range of established and potential drug targets, with in-depth information for a subset of important targets. The resource is the result of curation and integration of data from the IUPHAR Database (IUPHAR-DB) and the published BPS ‘Guide to Receptors and Channels’ (GRAC) compendium. The data are derived from a global network of expert contributors, and the information is extensively linked to relevant databases, including ChEMBL, DrugBank, Ensembl, PubChem, UniProt and PubMed. Each of the ∼6000 small molecule and peptide ligands is annotated with manually curated 2D chemical structures or amino acid sequences, nomenclature and database links. Future expansion of the resource will complete the coverage of all the targets of currently approved drugs and future candidate targets, alongside educational resources to guide scientists and students in pharmacological principles and techniques.

The Concise Guide to PHARMACOLOGY 2015/16: G protein-coupled receptors.

The Concise Guide to PHARMACOLOGY 2015/16 provides concise overviews of the key properties of over 1750 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.13348/full . G protein‐coupled receptors are one of the eight major pharmacological targets into which the Guide is divided, with the others being: ligand‐gated ion channels, voltage‐gated ion channels, other ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The Concise Guide is published in landscape format in order to facilitate comparison of related targets. It is a condensed version of material contemporary to late 2015, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org , superseding data presented in the previous Guides to Receptors & Channels and the Concise Guide to PHARMACOLOGY 2013/14. 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 GRAC and provides a permanent, citable, point‐in‐time record that will survive database updates.

International Union of Pharmacology. XLVI. G Protein-Coupled Receptor List

NC-IUPHAR (International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification) and its subcommittees provide authoritative reports on the nomenclature and pharmacology of G protein-coupled receptors (GPCRs) that summarize their structure, pharmacology, and roles in physiology and pathology. These reports are published in Pharmacological Reviews (http://www.iuphar.org/nciuphar_arti.html) and through the International Union of Pharmacology (IUPHAR) Receptor Database web site (http://www.iuphar-db.org/iuphar-rd). The essentially complete sequencing of the human genome has allowed the cataloging of all of the human gene sequences potentially encoding GPCRs. The IUPHAR Receptor List (http://www.iuphar-db.org/iuphar-rd/list/index.htm) presents this catalog giving IUPHAR-approved nomenclature (where available), known ligands, and gene names for all of these potential receptors (excluding sensory receptors and pseudogenes) together with links to curated sequence, descriptive information, and additional links in the Entrez Gene database (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=gene). This list is a major new initiative of NC-IUPHAR that, through continuing curation, defines the target of our ongoing receptor classification and invites further input from the scientific community.

The IUPHAR/BPS Guide to PHARMACOLOGY in 2018: updates and expansion to encompass the new guide to IMMUNOPHARMACOLOGY

Abstract The IUPHAR/BPS Guide to PHARMACOLOGY (GtoPdb, www.guidetopharmacology.org) and its precursor IUPHAR-DB, have captured expert-curated interactions between targets and ligands from selected papers in pharmacology and drug discovery since 2003. This resource continues to be developed in conjunction with the International Union of Basic and Clinical Pharmacology (IUPHAR) and the British Pharmacological Society (BPS). As previously described, our unique model of content selection and quality control is based on 96 target-class subcommittees comprising 512 scientists collaborating with in-house curators. This update describes content expansion, new features and interoperability improvements introduced in the 10 releases since August 2015. Our relationship matrix now describes ∼9000 ligands, ∼15 000 binding constants, ∼6000 papers and ∼1700 human proteins. As an important addition, we also introduce our newly funded project for the Guide to IMMUNOPHARMACOLOGY (GtoImmuPdb, www.guidetoimmunopharmacology.org). This has been ‘forked’ from the well-established GtoPdb data model and expanded into new types of data related to the immune system and inflammatory processes. This includes new ligands, targets, pathways, cell types and diseases for which we are recruiting new IUPHAR expert committees. Designed as an immunopharmacological gateway, it also has an emphasis on potential therapeutic interventions.

Characterization and localization of endothelin receptor subtypes in the human atrioventricular conducting system and myocardium.

The characterization and localization of endothelin A (ETA) and endothelin B (ETB) receptors have been determined in tissue sections of the human atrioventricular conducting system, surrounding regions of atrial and ventricular myocardium, and the left ventricular free wall by use of radioligand binding, polymerase chain reaction, and in situ hybridization. Selective ETA (BQ123) and ETB (BQ3020) compounds in conjunction with [125I]endothelin-1 revealed the presence of ETA and ETB receptors in the left ventricular free wall (BQ123: 57 +/- 5% ETA, 43 +/- 2% ETB, n = 3; BQ3020: 67 +/- 3% ETA, 33 +/- 3% ETB, n = 3). Autoradiography using [125I]endothelin-1 in the absence or presence of BQ3020, BQ123, or endothelin-1 showed ETA and ETB receptors localized to atrial and ventricular myocardium, the atrioventricular conducting system, and endocardial cells. There was a higher proportion of ETB receptors in the atrioventricular node and the penetrating and branching bundles of His than in the surrounding intervent...

Orphan‐receptor ligand human urotensin II: receptor localization in human tissues and comparison of vasoconstrictor responses with endothelin‐1

We have determined the distribution of receptors for human urotensin‐II (U‐II) in human and rat CNS and peripheral tissues. In rat, [125I]‐U‐II binding density was highest in the abducens nucleus of brainstem (139.6±14 amol mm−2). Moderate levels were detected in dorsal horn of spinal cord and lower levels in aorta (22.5±6 amol mm−2). In human tissues density was highest in skeletal muscle and cerebral cortex (∼30 amol mm−2), with lower levels (<15 amol mm−2) in kidney cortex and left ventricle. Little binding was identified in atria, conducting system of the heart and lung parenchyma. Receptor density was less in human coronary artery smooth muscle (14.6±3 amol mm−2, n=10) than rat aorta with no significant difference between normal and atherosclerotic vessels. In human skeletal muscle [125I]‐U‐II bound to a single receptor population with KD=0.24±0.17 nM and Bmax=1.97±1.1 fmol mg−1 protein (n=4). U‐II contracted human coronary, mammary and radial arteries, saphenous and umbilical veins with sub‐nanomolar EC50 values. U‐II was 50 times more potent in arteries and <10 times more potent in veins than endothelin‐1 (ET‐1). The maximum response to U‐II (∼20% of control KCl) was significantly less than to ET‐1 (∼80% KCl). In contrast, in rat aorta, U‐II and ET‐1 were equipotent with similar maximum responses. This is the first report of high affinity receptors for [125I]‐U‐II in human CNS and peripheral tissues. This peptide produces potent, low efficacy, vasoconstriction in human arteries and veins. These data suggest a potential role for U‐II in human physiology.

International Union of Pharmacology. XXIX. Update on Endothelin Receptor Nomenclature

In mammals, the endothelin (ET) family comprises three endogenous isoforms, ET-1, ET-2, and ET-3. ET-1 is the principal isoform in the human cardiovascular system and remains the most potent and long-lasting constrictor of human vessels discovered. In humans, endothelins mediate their actions via only two receptor types that have been cloned and classified as the ETA and ETBreceptors in the first NC-IUPHAR (International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification) report on nomenclature in 1994. This report was compiled before the discovery of the majority of endothelin receptor antagonists (particularly nonpeptides) currently used in the characterization of receptors and now updated in the present review. Endothelin receptors continue to be classified according to their rank order of potency for the three endogenous isoforms of endothelin. A selective ETA receptor agonist has not been discovered, but highly selective antagonists include peptides (BQ123, cyclo-[d-Asp-l-Pro-d-Val-l-Leu-d-Trp-]; FR139317, N- [(hexahydro-1-azepinyl)carbonyl]l-Leu(1-Me)d-Trp-3 (2-pyridyl)-d-Ala) and the generally more potent nonpeptides, such as PD156707, SB234551, L754142, A127722, and TBC11251. Sarafotoxin S6c, BQ3020 ([Ala11,15]Ac-ET-1(6–21)), and IRL1620 [Suc-(Glu9, Ala11,15)-ET-1(8–21)] are widely used synthetic ETB receptor agonists. A limited number of peptide (BQ788) and nonpeptide (A192621) ETB antagonists have also been developed. They are generally less potent than ETA antagonists and display lower selectivity (usually only 1 to 2 orders of magnitude) for the ETB receptor. Radioligands highly selective for either ETA(125I-PD151242, 125I-PD164333, and3H-BQ123) or ETB receptors (125I-BQ3020 and 125I-IRL1620) have further consolidated classification into only these two types, with no strong molecular or pharmacological evidence to support the existence of further receptors in mammals.

Chronic Apoptosis of Vascular Smooth Muscle Cells Accelerates Atherosclerosis and Promotes Calcification and Medial Degeneration

Vascular smooth muscle cell (VSMC) accumulation is implicated in plaque development. In contrast, VSMC apoptosis is implicated in plaque rupture, coagulation, vessel remodeling, medial atrophy, aneurysm formation, and calcification. Although VSMC apoptosis accompanies multiple pathologies, there is little proof of direct causality, particularly with the low levels of VSMC apoptosis seen in vivo. Using a mouse model of inducible VSMC–specific apoptosis, we demonstrate that low-level VSMC apoptosis during either atherogenesis or within established plaques of apolipoprotein (Apo)E−/− mice accelerates plaque growth by two-fold, associated with features of plaque vulnerability including a thin fibrous cap and expanded necrotic core. Chronic VSMC apoptosis induced development of calcified plaques in younger animals and promoted calcification within established plaques. In addition, VSMC apoptosis induced medial expansion, associated with increased elastic lamina breaks, and abnormal matrix deposition reminiscent of cystic medial necrosis in humans. VSMC apoptosis prevented outward remodeling associated with atherosclerosis resulting in marked vessel stenosis. We conclude that VSMC apoptosis is sufficient to accelerate atherosclerosis, promote plaque calcification and medial degeneration, prevent expansive remodeling, and promote stenosis in atherosclerosis.