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  • ItemPublished versionOpen Access
    THE CONCISE GUIDE TO PHARMACOLOGY 2017/18: Overview.
    (Wiley-Blackwell, 2017-12) Alexander, Stephen Ph; Kelly, Eamonn; Marrion, Neil V; Peters, John A; Faccenda, Elena; Harding, Simon D; Pawson, Adam J; Sharman, Joanna L; Southan, Christopher; Buneman, O Peter; Cidlowski, John A; Christopoulos, Arthur; Davenport, Anthony P; Fabbro, Doriano; Spedding, Michael; Striessnig, Jörg; Davies, Jamie A; CGTP Collaborators; Davenport, Anthony [0000-0002-2096-3117]
    The Concise Guide to PHARMACOLOGY 2017/18 is the third in this series of biennial publications. This version provides concise overviews of the key properties of nearly 1800 human drug targets with an emphasis on selective pharmacology (where available), 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. Although the Concise Guide represents approximately 400 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.13882/full. In addition to this overview, in which are identified 'Other protein targets' which fall outside of the subsequent categorisation, there are eight areas of focus: G protein-coupled receptors, 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 landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2017, and supersedes data presented in the 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature Committee of the Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate.
  • ItemPublished versionOpen Access
    THE CONCISE GUIDE TO PHARMACOLOGY 2017/18: G protein-coupled receptors.
    (Wiley-Blackwell, 2017-12) Alexander, Stephen Ph; Christopoulos, Arthur; Davenport, Anthony P; Kelly, Eamonn; Marrion, Neil V; Peters, John A; Faccenda, Elena; Harding, Simon D; Pawson, Adam J; Sharman, Joanna L; Southan, Christopher; Davies, Jamie A; CGTP Collaborators; Davenport, Anthony [0000-0002-2096-3117]
    The Concise Guide to PHARMACOLOGY 2017/18 provides concise overviews of the key properties of nearly 1800 human drug targets with an emphasis on selective pharmacology (where available), 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. Although the Concise Guide represents approximately 400 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.13878/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 landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2017, and supersedes data presented in the 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature Committee of the Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate.
  • ItemOpen Access
    Chemerin Elicits Potent Constrictor Actions via Chemokine-Like Receptor 1 (CMKLR1), not G-Protein-Coupled Receptor 1 (GPR1), in Human and Rat Vasculature
    (Wiley, 2016-10-14) Kennedy, AJ; Yang, P; Read, C; Kuc, RE; Yang, L; Taylor, EJA; Taylor, CW; Maguire, JJ; Davenport, AP; Taylor, Colin [0000-0001-7771-1044]; Maguire, Janet [0000-0002-9254-7040]; Davenport, Anthony [0000-0002-2096-3117]
    BACKGROUND: Circulating levels of chemerin are significantly higher in hypertensive patients and positively correlate with blood pressure. Chemerin activates chemokine-like receptor 1 (CMKLR1 or ChemR23) and is proposed to activate the "orphan" G-protein-coupled receptor 1 (GPR1), which has been linked with hypertension. Our aim was to localize chemerin, CMKLR1, and GPR1 in the human vasculature and determine whether 1 or both of these receptors mediate vasoconstriction. METHODS AND RESULTS: Using immunohistochemistry and molecular biology in conduit arteries and veins and resistance vessels, we localized chemerin to endothelium, smooth muscle, and adventitia and found that CMKLR1 and GPR1 were widely expressed in smooth muscle. C9 (chemerin149-157) contracted human saphenous vein (pD2=7.30±0.31) and resistance arteries (pD2=7.05±0.54) and increased blood pressure in rats by 9.1±1.0 mm Hg at 200 nmol. Crucially, these in vitro and in vivo vascular actions were blocked by CCX832, which we confirmed to be highly selective for CMKLR1 over GPR1. C9 inhibited cAMP accumulation in human aortic smooth muscle cells and preconstricted rat aorta, consistent with the observed vasoconstrictor action. Downstream signaling was explored further and, compared to chemerin, C9 showed a bias factor=≈5000 for the Gi protein pathway, suggesting that CMKLR1 exhibits biased agonism. CONCLUSIONS: Our data suggest that chemerin acts at CMKLR1, but not GPR1, to increase blood pressure. Chemerin has an established detrimental role in metabolic syndrome, and these direct vascular actions may contribute to hypertension, an additional risk factor for cardiovascular disease. This study provides proof of principle for the therapeutic potential of selective CMKLR1 antagonists.
  • ItemPublished versionOpen Access
    [Pyr¹]Apelin-13(₁-₁₂) Is a Biologically Active ACE2 Metabolite of the Endogenous Cardiovascular Peptide [Pyr¹]Apelin-13
    (Frontiers Media, 2017-02-28) Yang, P; Kuc, RE; Brame, AL; Dyson, A; Singer, M; Glen, RC; Cheriyan, J; Wilkinson, IB; Davenport, AP; Maguire, JJ; Glen, Robert [0000-0003-1759-2914]; Cheriyan, Joseph [0000-0001-6921-1592]; Wilkinson, Ian [0000-0001-6598-9399]; Davenport, Anthony [0000-0002-2096-3117]; Maguire, Janet [0000-0002-9254-7040]
    Aims: Apelin is a predicted substrate for ACE2, a novel therapeutic target. Our aim was to demonstrate the endogenous presence of the putative ACE2 product [Pyr(1)]apelin-13(1-12) in human cardiovascular tissues and to confirm it retains significant biological activity for the apelin receptor in vitro and in vivo. The minimum active apelin fragment was also investigated. Methods and Results: [Pyr(1)]apelin-13 incubated with recombinant human ACE2 resulted in de novo generation of [Pyr(1)]apelin-13(1-12) identified by mass spectrometry. Endogenous [Pyr(1)]apelin-13(1-12) was detected by immunostaining in human heart and lung localized to the endothelium. Expression was undetectable in lung from patients with pulmonary arterial hypertension. In human heart [Pyr(1)]apelin-13(1-12) (pKi = 8.04 ± 0.06) and apelin-13(F13A) (pKi = 8.07 ± 0.24) competed with [(125)I]apelin-13 binding with nanomolar affinity, 4-fold lower than for [Pyr(1)]apelin-13 (pKi = 8.83 ± 0.06) whereas apelin-17 exhibited highest affinity (pKi = 9.63 ± 0.17). The rank order of potency of peptides to inhibit forskolin-stimulated cAMP was apelin-17 (pD2 = 10.31 ± 0.28) > [Pyr(1)]apelin-13 (pD2 = 9.67 ± 0.04) ≥ apelin-13(F13A) (pD2 = 9.54 ± 0.05) > [Pyr(1)]apelin-13(1-12) (pD2 = 9.30 ± 0.06). The truncated peptide apelin-13(R10M) retained nanomolar potency (pD2 = 8.70 ± 0.04) but shorter fragments exhibited low micromolar potency. In a β-arrestin recruitment assay the rank order of potency was apelin-17 (pD2 = 10.26 ± 0.09) > [Pyr(1)]apelin-13 (pD2 = 8.43 ± 0.08) > apelin-13(R10M) (pD2 = 8.26 ± 0.17) > apelin-13(F13A) (pD2 = 7.98 ± 0.04) ≥ [Pyr(1)]apelin-13(1-12) (pD2 = 7.84 ± 0.06) > shorter fragments (pD2 < 6). [Pyr(1)]apelin-13(1-12) and apelin-13(F13A) contracted human saphenous vein with similar sub-nanomolar potencies and [Pyr(1)]apelin-13(1-12) was a potent inotrope in paced mouse right ventricle and human atria. [Pyr(1)]apelin-13(1-12) elicited a dose-dependent decrease in blood pressure in anesthetized rat and dose-dependent increase in forearm blood flow in human volunteers. Conclusions: We provide evidence that ACE2 cleaves [Pyr(1)]apelin-13 to [Pyr(1)]apelin-13(1-12) and this cleavage product is expressed in human cardiovascular tissues. We have demonstrated biological activity of [Pyr(1)]apelin-13(1-12) at the human and rodent apelin receptor in vitro and in vivo. Our data show that reported enhanced ACE2 activity in cardiovascular disease should not significantly compromise the beneficial effects of apelin based therapies for example in PAH.
  • ItemPublished versionOpen Access
    Inotropic action of the puberty hormone kisspeptin in rat, mouse and human: cardiovascular distribution and characteristics of the kisspeptin receptor
    (PLoS, 2011-11-22) Maguire, JJ; Kirby, HR; Mead, EJ; Kuc, RE; d'Anglemont de Tassigny, X; Colledge, WH; Davenport, AP; Maguire, Janet [0000-0002-9254-7040]; Colledge, Bill [0000-0002-9603-4429]; Davenport, Anthony [0000-0002-2096-3117]
    Kisspeptins, the ligands of the kisspeptin receptor known for its roles in reproduction and cancer, are also vasoconstrictor peptides in atherosclerosis-prone human aorta and coronary artery. The aim of this study was to further investigate the cardiovascular localisation and function of the kisspeptins and their receptor in human compared to rat and mouse heart. Immunohistochemistry and radioligand binding techniques were employed to investigate kisspeptin receptor localisation, density and pharmacological characteristics in cardiac tissues from all three species. Radioimmunoassay was used to detect kisspeptin peptide levels in human normal heart and to identify any pathological changes in myocardium from patients transplanted for cardiomyopathy or ischaemic heart disease. The cardiac function of kisspeptin receptor was studied in isolated human, rat and mouse paced atria, with a role for the receptor confirmed using mice with targeted disruption of Kiss1r. The data demonstrated that kisspeptin receptor-like immunoreactivity localised to endothelial and smooth muscle cells of intramyocardial blood vessels and to myocytes in human and rodent tissue. [¹²⁵I]KP-14 bound saturably, with subnanomolar affinity to human and rodent myocardium (K(D) = 0.12 nM, human; K(D) = 0.44 nM, rat). Positive inotropic effects of kisspeptin were observed in rat, human and mouse. No response was observed in mice with targeted disruption of Kiss1r. In human heart a decrease in cardiac kisspeptin level was detected in ischaemic heart disease. Kisspeptin and its receptor are expressed in the human, rat and mouse heart and kisspeptins possess potent positive inotropic activity. The cardiovascular actions of the kisspeptins may contribute to the role of these peptides in pregnancy but the consequences of receptor activation must be considered if kisspeptin receptor agonists are developed for use in the treatment of reproductive disorders or cancer.
  • ItemPublished versionOpen Access
    The Concise Guide to PHARMACOLOGY 2015/16: G protein-coupled receptors
    (Wiley-Blackwell, 2015-12-09) Alexander, SP; Davenport, AP; Kelly, E; Marrion, N; Peters, JA; Benson, HE; Faccenda, E; Pawson, AJ; Sharman, JL; Southan, C; Davies, JA; CGTP Collaborators; Davenport, Anthony [0000-0002-2096-3117]
    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.
  • ItemPublished versionOpen Access
    The Concise Guide to PHARMACOLOGY 2015/16: Overview
    (Wiley-Blackwell, 2015-12-09) Alexander, SP; Kelly, E; Marrion, N; Peters, JA; Benson, HE; Faccenda, E; Pawson, AJ; Sharman, JL; Southan, C; Buneman, OP; Catterall, WA; Cidlowski, JA; Davenport, AP; Fabbro, D; Fan, G; McGrath, JC; Spedding, M; Davies, JA; CGTP Collaborators; Davenport, Anthony [0000-0002-2096-3117]
    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.13347/full. This compilation of the major pharmacological targets is divided into eight areas of focus: G protein-coupled receptors, 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.
  • ItemPublished versionOpen Access
    Detection of Atherosclerotic Inflammation by $^{68}$Ga-DOTATATE PET Compared to [$^{18}$F]FDG PET Imaging
    (Elsevier, 2017-04-11) Tarkin, JM; Joshi, FR; Evans, NR; Chowdhury, MM; Figg, NL; Shah, AV; Starks, LT; Martin-Garrido, A; Manavaki, R; Yu, E; Kuc, RE; Grassi, L; Kreuzhuber, R; Kostadima, MA; Frontini, M; Kirkpatrick, PJ; Coughlin, PA; Gopalan, D; Fryer, TD; Buscombe, JR; Groves, AM; Ouwehand, WH; Bennett, MR; Warburton, EA; Davenport, AP; Rudd, JHF; Tarkin, Jason [0000-0002-9132-120X]; Evans, Nicholas [0000-0002-7640-4701]; Manavaki, Roido [0000-0002-4384-6626]; Grassi, Luigi [0000-0002-6308-7540]; Frontini, Mattia [0000-0001-8074-6299]; Ouwehand, Willem [0000-0002-7744-1790]; Bennett, Martin [0000-0002-2565-1825]; Davenport, Anthony [0000-0002-2096-3117]; Rudd, James [0000-0003-2243-3117]
    $\textbf{Background}$ Inflammation drives atherosclerotic plaque rupture. Although inflammation can be measured using fluorine-18-labeled fluorodeoxyglucose positron emission tomography ([$^{18}$F]FDG PET), [$^{18}$F]FDG lacks cell specificity, and coronary imaging is unreliable because of myocardial spillover. $\textbf{Objectives}$ Objectives This study tested the efficacy of gallium-68-labeled DOTATATE ($^{68}$Ga-DOTATATE), a somatostatin receptor subtype-2 (SST2)-binding PET tracer, for imaging atherosclerotic inflammation. $\textbf{Methods}$ We confirmed $^{68}$Ga-DOTATATE binding in macrophages and excised carotid plaques. $^{68}$Ga-DOTATATE PET imaging was compared to [$^{18}$F]FDG PET imaging in 42 patients with atherosclerosis. $\textbf{Results}$ Target $\textit{SSTR2}$ gene expression occurred exclusively in “proinflammatory” M1 macrophages, specific $^{68}$Ga-DOTATATE ligand binding to SST$_{2}$ receptors occurred in CD68-positive macrophage-rich carotid plaque regions, and carotid $\textit{SSTR2}$ mRNA was highly correlated with in vivo $^{68}$Ga-DOTATATE PET signals (r = 0.89; 95% confidence interval [CI]: 0.28 to 0.99; p = 0.02). $^{68}$Ga-DOTATATE mean of maximum tissue-to-blood ratios (mTBR$_{max}$) correctly identified culprit versus nonculprit arteries in patients with acute coronary syndrome (median difference: 0.69; interquartile range [IQR]: 0.22 to 1.15; p = 0.008) and transient ischemic attack/stroke (median difference: 0.13; IQR: 0.07 to 0.32; p = 0.003). $^{68}$Ga-DOTATATE mTBR$_{max}$ predicted high-risk coronary computed tomography features (receiver operating characteristics area under the curve [ROC AUC]: 0.86; 95% CI: 0.80 to 0.92; p < 0.0001), and correlated with Framingham risk score (r = 0.53; 95% CI: 0.32 to 0.69; p <0.0001) and [$^{18}$F]FDG uptake (r = 0.73; 95% CI: 0.64 to 0.81; p < 0.0001). [$^{18}$F]FDG mTBR$_{max}$ differentiated culprit from nonculprit carotid lesions (median difference: 0.12; IQR: 0.0 to 0.23; p = 0.008) and high-risk from lower-risk coronary arteries (ROC AUC: 0.76; 95% CI: 0.62 to 0.91; p = 0.002); however, myocardial [$^{18}$F]FDG spillover rendered coronary [$^{18}$F]FDG scans uninterpretable in 27 patients (64%). Coronary $^{68}$Ga-DOTATATE PET scans were readable in all patients. $\textbf{Conclusions}$ We validated $^{68}$Ga-DOTATATE PET as a novel marker of atherosclerotic inflammation and confirmed that $^{68}$Ga-DOTATATE offers superior coronary imaging, excellent macrophage specificity, and better power to discriminate high-risk versus low-risk coronary lesions than [$^{18}$F]FDG. (Vascular Inflammation Imaging Using Somatostatin Receptor Positron Emission Tomography [VISION]; NCT02021188)
  • ItemPublished versionOpen Access
    Vascular Imaging With $^{18}$F-Fluorodeoxyglucose Positron Emission Tomography Is Influenced by Hypoxia
    (Elsevier, 2017-04-11) Joshi, FR; Manavaki, R; Fryer, TD; Figg, NL; Sluimer, JC; Aigbirhio, FI; Davenport, AP; Kirkpatrick, PJ; Warburton, EA; Rudd, JHF; Manavaki, Roido [0000-0002-4384-6626]; Aigbirhio, Franklin [0000-0001-9453-5257]; Davenport, Anthony [0000-0002-2096-3117]; Rudd, James [0000-0003-2243-3117]
  • ItemAccepted versionOpen Access
    Nondiabetic Glucometabolic Status and Progression of Aortic Stiffness: The Whitehall II Study
    (American Diabetes Association, 2017-04-01) McEniery, CM; Wilkinson, IB; Johansen, NB; Witte, DR; Singh-Manoux, A; Kivimaki, M; Tabak, AG; Brunner, EJ; Shipley, MJ; McEniery, Carmel [0000-0003-3636-0705]; Wilkinson, Ian [0000-0001-6598-9399]
    OBJECTIVE Aortic stiffness is an important predictor of future morbidity and mortality. Diabetes is associated with increased aortic stiffness, but the importance of nondiabetic glucometabolic status for accelerated aortic stiffening is unclear. We tested the hypothesis that adverse glucometabolic status is associated with accelerated aortic stiffening in individuals without diabetes, independently of known risk factors for arterial stiffening. RESEARCH DESIGN AND METHODS Glucometabolic status and other cardiovascular risk factors were assessed at baseline in 2008–09, and carotid femoral pulse wave velocity (cfPWV) at baseline and follow-up in 2012–13, in 4,386 participants without diabetes of the Whitehall II Study. RESULTS The mean age of the cohort at cfPWV baseline was 60 years, and 74% were male. cfPWV increased from (mean ± SE) 8.30 ± 0.03 to 8.98 ± 0.04 m/s during 4 years of follow-up. At baseline, cfPWV was associated with fasting and 2-h postload glucose, HbA1c, and HOMA-insulin resistance (HOMA-IR). HbA1c and HOMA-IR were associated with progression of cfPWV after adjusting for physiological confounders and cardiovascular risk factors. A 1 SD higher HbA1c and HOMA-IR were associated with greater increases in cfPWV (0.11 m/s per 5 years [95% CI 0.04, 0.18], P = 0.003 and 0.09 m/s per 5 years [0.01, 0.17], P = 0.03, respectively). Additional adjustment for BMI weakened the association with HOMA-IR but not with HbA1c. CONCLUSIONS HbA1c is independently associated with accelerated progression of aortic stiffness in individuals without diabetes. These findings suggest that long-term glucometabolic status, even in individuals without diabetes, could be an important target for preventative strategies against vascular aging.
  • ItemPublished versionOpen Access
    $^{18}$F-Fluoride and $^{18}$F-Fluorodeoxyglucose Positron Emission Tomography After Transient Ischemic Attack or Minor Ischemic Stroke: Case-Control Study.
    (American Heart Association, 2017-03-14) Vesey, AT; Jenkins, WSA; Irkle, A; Moss, A; Sng, G; Forsythe, RO; Clark, T; Roberts, G; Fletcher, A; Lucatelli, C; Rudd, JHF; Davenport, AP; Mills, NL; Al-Shahi Salman, R; Dennis, M; Whiteley, WN; van Beek, EJR; Dweck, MR; Newby, DE; Rudd, James [0000-0003-2243-3117]; Davenport, Anthony [0000-0002-2096-3117]
    BACKGROUND: Combined positron emission tomography (PET) and computed tomography (CT) can assess both anatomy and biology of carotid atherosclerosis. We sought to assess whether $^{18}$F-fluoride or $^{18}$F-fluorodeoxyglucose can identify culprit and high-risk carotid plaque. METHODS AND RESULTS: We performed $^{18}$F-fluoride and $^{18}$F-fluorodeoxyglucose PET/CT in 26 patients after recent transient ischemic attack or minor ischemic stroke: 18 patients with culprit carotid stenosis awaiting carotid endarterectomy and 8 controls without culprit carotid atheroma. We compared standardized uptake values in the clinically adjudicated culprit to the contralateral asymptomatic artery, and assessed the relationship between radiotracer uptake and plaque phenotype or predicted cardiovascular risk (ASSIGN score [Assessing Cardiovascular Risk Using SIGN Guidelines to Assign Preventive Treatment]). We also performed micro PET/CT and histological analysis of excised plaque. On histological and micro PET/CT analysis, $^{18}$F-fluoride selectively highlighted microcalcification. Carotid $^{18}$F-fluoride uptake was increased in clinically adjudicated culprit plaques compared with asymptomatic contralateral plaques (log$_{10}$ standardized uptake value$_{mean}$ 0.29±0.10 versus 0.23±0.11, P=0.001) and compared with control patients (log$_{10}$ standardized uptake value$_{mean}$ 0.29±0.10 versus 0.12±0.11, P=0.001). $^{18}$F-Fluoride uptake correlated with high-risk plaque features (remodeling index [r=0.53, P=0.003], plaque burden [r=0.51, P=0.004]), and predicted cardiovascular risk [r=0.65, P=0.002]). Carotid $^{18}$F-fluorodeoxyglucose uptake appeared to be increased in 7 of 16 culprit plaques, but no overall differences in uptake were observed in culprit versus contralateral plaques or control patients. However, $^{18}$F-fluorodeoxyglucose did correlate with predicted cardiovascular risk (r=0.53, P=0.019), but not with plaque phenotype. CONCLUSIONS: $^{18}$F-Fluoride PET/CT highlights culprit and phenotypically high-risk carotid plaque. This has the potential to improve risk stratification and selection of patients who may benefit from intervention.
  • ItemAccepted versionOpen Access
    Elabela/Toddler is an Endogenous Agonist of the Apelin APJ Receptor in the Adult Cardiovascular System, and Exogenous Administration of the Peptide Compensates for the Downregulation of its Expression in Pulmonary Arterial Hypertension
    (Wolters Kluwer, 2017-03-21) Yang, P; Read, C; Kuc, RE; Buonincontri, G; Southwood, M; Torella, R; Upton, PD; Crosby, A; Sawiak, SJ; Carpenter, TA; Glen, RC; Morrell, NW; Maguire, JJ; Davenport, AP; Upton, Paul [0000-0003-2716-4921]; Sawiak, Stephen [0000-0003-4210-9816]; Carpenter, Adrian [0000-0002-2939-8222]; Glen, Robert [0000-0003-1759-2914]; Morrell, Nicholas [0000-0001-5700-9792]; Maguire, Janet [0000-0002-9254-7040]; Davenport, Anthony [0000-0002-2096-3117]
    BACKGROUND: -Elabela/Toddler (ELA) is a critical cardiac developmental peptide that acts through the G protein-coupled apelin receptor, despite lack of sequence similarity to the established ligand apelin. Our aim was to investigate the receptor pharmacology, expression pattern and in vivo function of ELA peptides in the adult cardiovascular system, to seek evidence for alteration in pulmonary arterial hypertension (PAH) in which apelin signaling is down-regulated, and to demonstrate attenuation of PAH severity with exogenous administration of ELA in a rat model. METHODS: -In silico docking analysis, competition binding experiments and down-stream assays were used to characterize ELA receptor binding in human heart and signaling in cells expressing the apelin receptor. ELA expression in human cardiovascular tissues and plasma was determined using RT-qPCR, dual-labelling immunofluorescent staining and immunoassays. Acute cardiac effects of ELA-32 and [Pyr(1)]apelin-13 were assessed by magnet resonance imaging and cardiac catheterization in anesthetized rats. Cardiopulmonary human and rat tissues from PAH patients and monocrotaline (MCT) and Sugen/hypoxia exposed rats were used to show changes in ELA expression in PAH. The effect of ELA treatment on cardiopulmonary remodeling in PAH was investigated in the MCT rat model. RESULTS: -ELA competed for binding of apelin in human heart with overlap for the two peptides indicated by in silico modeling. ELA activated G protein- and Β-arrestin-dependent pathways. We detected ELA expression in human vascular endothelium and plasma. Comparable to apelin, ELA increased cardiac contractility, ejection fraction, cardiac output and elicited vasodilatation in rat in vivo ELA expression was reduced in cardiopulmonary tissues from PAH patients and PAH rat models, respectively. ELA treatment significantly attenuated elevation of right ventricular systolic pressure and right ventricular hypertrophy and pulmonary vascular remodeling in MCT exposed rats. CONCLUSIONS: -These results show ELA is an endogenous agonist of the human apelin receptor, exhibits a cardiovascular profile comparable to apelin, is down-regulated in human disease and rodent PAH models and exogenous peptide can reduce the severity of cardiopulmonary remodeling and function in PAH in rats. This study provides additional proof of principle that an apelin receptor agonist may be of therapeutic use in PAH in man.
  • ItemPublished versionOpen Access
    Smooth Muscle Endothelin B Receptors Regulate Blood Pressure but Not Vascular Function or Neointimal Remodeling
    (American Heart Association, 2017-02-01) Miller, E; Czopek, A; Duthie, KM; Kirkby, NS; van de Putte, EEF; Christen, S; Kimmitt, RA; Moorhouse, R; Castellan, RFP; Kotelevtsev, YV; Kuc, RE; Davenport, AP; Dhaun, N; Webb, DJ; Hadoke, PWF; Davenport, Anthony [0000-0002-2096-3117]
    The role of smooth muscle endothelin$_{B}$ (ET$_{B}$) receptors in regulating vascular function, blood pressure (BP), and neointimal remodeling has not been established. Selective knockout mice were generated to address the hypothesis that loss of smooth muscle ET$_{B}$ receptors would reduce BP, alter vascular contractility, and inhibit neointimal remodeling. ET$_{B}$ receptors were selectively deleted from smooth muscle by crossing floxed ET$_{B}$ mice with those expressing cre-recombinase controlled by the transgelin promoter. Functional consequences of ET$_{B}$ deletion were assessed using myography. BP was measured by telemetry, and neointimal lesion formation induced by femoral artery injury. Lesion size and composition (day 28) were analyzed using optical projection tomography, histology, and immunohistochemistry. Selective deletion of ET$_{B}$ was confirmed by genotyping, autoradiography, polymerase chain reaction, and immunohistochemistry. ET$_{B}$-mediated contraction was reduced in trachea, but abolished from mesenteric veins, of knockout mice. Induction of ET$_{B}$-mediated contraction in mesenteric arteries was also abolished in these mice. Femoral artery function was unaltered, and baseline BP modestly elevated in smooth muscle ET$_{B}$ knockout compared with controls (+4.2±0.2 mm Hg; $\textit{P}$<0.0001), but salt-induced and ET$_{B}$ blockade-mediated hypertension were unaltered. Circulating endothelin-1 was not altered in knockout mice. ET$_{B}$-mediated contraction was not induced in femoral arteries by incubation in culture medium or lesion formation, and lesion size was not altered in smooth muscle ET$_{B}$ knockout mice. In the absence of other pathology, ET$_{B}$ receptors in vascular smooth muscle make a small but significant contribution to ET$_{B}$-dependent regulation of BP. These ET$_{B}$ receptors have no effect on vascular contraction or neointimal remodeling.
  • ItemPublished versionOpen Access
    WNK signalling pathways in blood pressure regulation.
    (Springer Science and Business Media LLC, 2017-04) Murthy, Meena; Kurz, Thimo; O'Shaughnessy, Kevin M; O'Shaughnessy, Kevin M [0000-0002-1476-7566]
    Hypertension (high blood pressure) is a major public health problem affecting more than a billion people worldwide with complications, including stroke, heart failure and kidney failure. The regulation of blood pressure is multifactorial reflecting genetic susceptibility, in utero environment and external factors such as obesity and salt intake. In keeping with Arthur Guyton's hypothesis, the kidney plays a key role in blood pressure control and data from clinical studies; physiology and genetics have shown that hypertension is driven a failure of the kidney to excrete excess salt at normal levels of blood pressure. There is a number of rare Mendelian blood pressure syndromes, which have shed light on the molecular mechanisms involved in dysregulated ion transport in the distal kidney. One in particular is Familial hyperkalemic hypertension (FHHt), an autosomal dominant monogenic form of hypertension characterised by high blood pressure, hyperkalemia, hyperchloremic metabolic acidosis, and hypercalciuria. The clinical signs of FHHt are treated by low doses of thiazide diuretic, and it mirrors Gitelman syndrome which features the inverse phenotype of hypotension, hypokalemic metabolic alkalosis, and hypocalciuria. Gitelman syndrome is caused by loss of function mutations in the thiazide-sensitive Na/Cl cotransporter (NCC); however, FHHt patients do not have mutations in the SCL12A3 locus encoding NCC. Instead, mutations have been identified in genes that have revealed a key signalling pathway that regulates NCC and several other key transporters and ion channels in the kidney that are critical for BP regulation. This is the WNK kinase signalling pathway that is the subject of this review.
  • ItemPublished versionOpen Access
    The Role of the Autonomic Nervous System in the Regulation of Aortic Stiffness.
    (Ovid Technologies (Wolters Kluwer Health), 2016-11) Mäki-Petäjä, Kaisa M; Barrett, Sharon ML; Evans, Sarah V; Cheriyan, Joseph; McEniery, Carmel M; Wilkinson, Ian B; Cheriyan, Joseph [0000-0001-6921-1592]; McEniery, Carmel [0000-0003-3636-0705]; Wilkinson, Ian [0000-0001-6598-9399]
    The autonomic nervous system is important in regulating blood pressure, but whether it regulates aortic stiffness is more contentious. We conducted 3 studies in young, healthy individuals to address this important question. Study 1 was a cross-sectional study of 347 subjects with detailed measurements of hemodynamics and heart rate variability. In study 2, 9 subjects were given a bolus of intravenous nicotinic ganglion blocker, pentolinium, or saline in a random order and hemodynamics and heart rate variability were assessed before and after. In study 3, changes in hemodynamics and heart rate variability were assessed during stimulation of the sympathetic nervous system with the use of isometric handgrip exercise in 12 subjects. Study 1: aortic pulse wave velocity (P=0.003) was lowest in the subjects with the highest parasympathetic activity, but after adjusting for mean arterial pressure, the effect was abolished (P=0.3). Study 2: after pentolinium, sympathetic and parasympathetic activity fell (P=0.001 for both), mean arterial pressure, and heart rate increased (P=0.004 and P=0.04, respectively), but there was no change in pulse wave velocity in comparison to placebo (P=0.1). Study 3: during handgrip exercise, sympathetic activity (P=0.003), mean arterial pressure (P<0.0001), and aortic pulse wave velocity increased (P=0.013). However, pulse wave velocity adjusted for mean arterial pressure did not change (P=0.1). The main finding of these studies is that in young healthy subjects, the autonomic nervous system does not have a pressure-independent role in the regulation of aortic stiffness. However, these findings may not apply to patients with increased sympathetic tone or hypertension.
  • ItemAccepted versionOpen Access
    Feeling the pressure: (patho) physiological mechanisms of weight gain and weight loss in humans.
    (Springer Science and Business Media LLC, 2017-03) Middlemiss, Jessica E; McEniery, Carmel M; McEniery, Carmel [0000-0003-3636-0705]
    Obesity is an ongoing global epidemic and has adverse consequences for cardiovascular health. Obesity is often associated with hypertension, which is, itself, a common condition and an important cause of morbidity and mortality worldwide. Although animal models of obesity have provided extensive data on the links between obesity and hypertension, a greater understanding of the pathways linking obesity and hypertension in humans is likely to assist translation of animal data, and may, itself, identify important treatment strategies. Ultimately, this could have a substantial impact on human health, both at an individual and population level. The current review will focus specifically on studies of experimental weight gain and weight loss in humans and the following key areas, which are strongly related to blood pressure: cardiovascular function, autonomic nervous system function, metabolic function and the impact of cardiorespiratory fitness.
  • ItemPublished versionOpen Access
    Cardiac action of the first G protein biased small molecule apelin agonist.
    (elsevier, 2016-09-15) Read, C; Fitzpatrick, CM; Yang, P; Kuc, RE; Maguire, JJ; Glen, RC; Foster, RE; Davenport, AP; Maguire, Janet [0000-0002-9254-7040]; Glen, Robert [0000-0003-1759-2914]; Davenport, Anthony [0000-0002-2096-3117]
    Apelin peptide analogues displaying bias towards G protein signalling pathways have beneficial cardiovascular actions compared with the native peptide in humans in vivo. Our aim was to determine whether small molecule agonists could retain G protein bias. We have identified a biased small molecule, CMF-019, and characterised it in vitro and in vivo. In competition radioligand binding experiments in heart homogenates, CMF-019 bound to the human, rat and mouse apelin receptor with high affinity (pKi=8.58±0.04, 8.49±0.04 and 8.71±0.06 respectively). In cell-based functional assays, whereas, CMF-019 showed similar potency for the Gαi pathway to the endogenous agonist [Pyr(1)]apelin-13 (pD2=10.00±0.13 vs 9.34±0.15), in β-arrestin and internalisation assays it was less potent (pD2=6.65±0.15 vs 8.65±0.10 and pD2=6.16±0.21 vs 9.28±0.10 respectively). Analysis of these data demonstrated a bias of ∼400 for the Gαi over the β-arrestin pathway and ∼6000 over receptor internalisation. CMF-019 was tested for in vivo activity using intravenous injections into anaesthetised male Sprague-Dawley rats fitted with a pressure-volume catheter in the left ventricle. CMF-019 caused a significant increase in cardiac contractility of 606±112mmHg/s (p<0.001) at 500nmol. CMF-019 is the first biased small molecule identified at the apelin receptor and increases cardiac contractility in vivo. We have demonstrated that Gαi over β-arrestin/internalisation bias can be retained in a non-peptide analogue and predict that such bias will have the therapeutic benefit following chronic use. CMF-019 is suitable as a tool compound and provides the basis for design of biased agonists with improved pharmacokinetics for treatment of cardiovascular conditions such as pulmonary arterial hypertension.
  • ItemAccepted versionOpen Access
    Isolated Systolic Hypertension in Young People Is Not Spurious and Should Be Treated: Pro Side of the Argument.
    (Ovid Technologies (Wolters Kluwer Health), 2016-08) McEniery, Carmel M; Franklin, Stanley S; Cockcroft, John R; Wilkinson, Ian B; McEniery, Carmel [0000-0003-3636-0705]; Wilkinson, Ian [0000-0001-6598-9399]
  • ItemAccepted versionOpen Access
    Influence of the central-to-peripheral arterial stiffness gradient on the timing and amplitude of wave reflections.
    (Springer Science and Business Media LLC, 2016-10) Hickson, Stacey S; Nichols, Wilmer W; Yasmin; McDonnell, Barry J; Cockcroft, John R; Wilkinson, Ian B; McEniery, Carmel M; Wilkinson, Ian [0000-0001-6598-9399]; McEniery, Carmel [0000-0003-3636-0705]
    In individuals with compliant aortas, peripheral muscular artery stiffness exceeds central elastic artery stiffness. With aging, central stiffness increases with little change in peripheral stiffness, resulting in a reversal of the normal stiffness gradient. This reversal may reduce the wave reflection amplitude due to the movement of the major 'effective' reflection site further from the heart. To test this phenomenon, we investigated the relationship among arterial stiffness gradients (normal and reversed), wave reflection amplitude and reflection site distance. Subjects aged ⩾50 years were recruited from the Anglo-Cardiff Collaborative Trial. Central stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). In Study 1, peripheral PWV was also measured in the arm (carotid-radial pulse wave velocity) and, in Study 2, in the leg (femoral-dorsalis pedis). Reflection site distance was calculated from cfPWV and the reflected wave Tr. Subjects were dichotomized into those with a normal stiffness gradient (peripheral >central PWV) or a reversed gradient (peripheral
  • ItemOpen Access
    The Prodomain-bound Form of Bone Morphogenetic Protein 10 Is Biologically Active on Endothelial Cells.
    (Elsevier BV, 2016-02-05) Jiang, He; Salmon, Richard M; Upton, Paul D; Wei, Zhenquan; Lawera, Aleksandra; Davenport, Anthony P; Morrell, Nicholas W; Li, Wei; Upton, Paul [0000-0003-2716-4921]; Davenport, Anthony [0000-0002-2096-3117]; Morrell, Nicholas [0000-0001-5700-9792]; Li, Wei [0000-0002-1924-3120]
    BMP10 is highly expressed in the developing heart and plays essential roles in cardiogenesis. BMP10 deletion in mice results in embryonic lethality because of impaired cardiac development. In adults, BMP10 expression is restricted to the right atrium, though ventricular hypertrophy is accompanied by increased BMP10 expression in a rat hypertension model. However, reports of BMP10 activity in the circulation are inconclusive. In particular, it is not known whether in vivo secreted BMP10 is active or whether additional factors are required to achieve its bioactivity. It has been shown that high-affinity binding of the BMP10 prodomain to the mature ligand inhibits BMP10 signaling activity in C2C12 cells, and it was proposed that prodomain-bound BMP10 (pBMP10) complex is latent. In this study, we demonstrated that the BMP10 prodomain did not inhibit BMP10 signaling activity in multiple endothelial cells, and that recombinant human pBMP10 complex, expressed in mammalian cells and purified under native conditions, was fully active. In addition, both BMP10 in human plasma and BMP10 secreted from the mouse right atrium were fully active. Finally, we confirmed that active BMP10 secreted from mouse right atrium was in the prodomain-bound form. Our data suggest that circulating BMP10 in adults is fully active and that the reported vascular quiescence function of BMP10 in vivo is due to the direct activity of pBMP10 and does not require an additional activation step. Moreover, being an active ligand, recombinant pBMP10 may have therapeutic potential as an endothelial-selective BMP ligand, in conditions characterized by loss of BMP9/10 signaling.