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Measom ND, Down KD, Hirst DJ, Jamieson C, Manas ES, Patel VK, Somers DO. Investigation of a Bicyclo[1.1.1]pentane as a Phenyl Replacement within an LpPLA 2 Inhibitor. ACS Med Chem Lett 2017; 8:43-48. [PMID: 28105273 DOI: 10.1021/acsmedchemlett.6b00281] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/15/2016] [Indexed: 02/07/2023] Open
Abstract
We describe the incorporation of a bicyclo[1.1.1]pentane moiety within two known LpPLA2 inhibitors to act as bioisosteric phenyl replacements. An efficient synthesis to the target compounds was enabled with a dichlorocarbene insertion into a bicyclo[1.1.0]butane system being the key transformation. Potency, physicochemical, and X-ray crystallographic data were obtained to compare the known inhibitors to their bioisosteric counterparts, which showed the isostere was well tolerated and positively impacted on the physicochemical profile.
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Affiliation(s)
- Nicholas D. Measom
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K
- Department
of Pure and Applied Chemistry, University of Strathclyde, Thomas
Graham Building, 295 Cathedral Street, Glasgow, G1 1XL, U.K
| | - Kenneth D. Down
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K
| | - David J. Hirst
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K
| | - Craig Jamieson
- Department
of Pure and Applied Chemistry, University of Strathclyde, Thomas
Graham Building, 295 Cathedral Street, Glasgow, G1 1XL, U.K
| | - Eric S. Manas
- GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, United States
| | - Vipulkumar K. Patel
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K
| | - Don O. Somers
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, U.K
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Affiliation(s)
- Diana M Stafforini
- Department of Internal Medicine University of Utah, Salt Lake City, UT 84112 Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112
| | - Guy A Zimmerman
- Department of Internal Medicine University of Utah, Salt Lake City, UT 84112
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Bogdanov AA, Mazzanti ML. Fluorescent macromolecular sensors of enzymatic activity for in vivo imaging. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 113:349-87. [PMID: 23244795 DOI: 10.1016/b978-0-12-386932-6.00009-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Macromolecular imaging probes (or sensors) of enzymatic activity have a unique place in the armamentarium of modern optical imaging techniques. Such probes were initially developed by attaching optically "silent" fluorophores via enzyme-sensitive linkers to large copolymers of biocompatible poly(ethylene glycol) and poly(amino acids). In diseased tissue, where the concentration of enzymes is high, the fluorophores are freed from the macromolecular carrier and regain their initial ability to fluoresce, thus allowing in vivo optical localization of the diseased tissue. This chapter describes the design and application of these probes and their alternatives in various areas of experimental medicine and gives an overview of currently available techniques that allow imaging of animals using visible and near-infrared light.
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Affiliation(s)
- Alexei A Bogdanov
- Laboratory of Molecular Imaging Probes, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Rosenson RS, Stafforini DM. Modulation of oxidative stress, inflammation, and atherosclerosis by lipoprotein-associated phospholipase A2. J Lipid Res 2012; 53:1767-82. [PMID: 22665167 DOI: 10.1194/jlr.r024190] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), also known as platelet-activating factor acetylhydrolase (PAF-AH), is a unique member of the phospholipase A(2) superfamily. This enzyme is characterized by its ability to specifically hydrolyze PAF as well as glycerophospholipids containing short, truncated, and/or oxidized fatty acyl groups at the sn-2 position of the glycerol backbone. In humans, Lp-PLA(2) circulates in active form as a complex with low- and high-density lipoproteins. Clinical studies have reported that plasma Lp-PLA(2) activity and mass are strongly associated with atherogenic lipids and vascular risk. These observations led to the hypothesis that Lp-PLA(2) activity and/or mass levels could be used as biomarkers of cardiovascular disease and that inhibition of the activity could offer an attractive therapeutic strategy. Darapladib, a compound that inhibits Lp-PLA(2) activity, is anti-atherogenic in mice and other animals, and it decreases atherosclerotic plaque expansion in humans. However, disagreement continues to exist regarding the validity of Lp-PLA(2) as an independent marker of atherosclerosis and a scientifically justified target for intervention. Circulating Lp-PLA(2) mass and activity are associated with vascular risk, but the strength of the association is reduced after adjustment for basal concentrations of the lipoprotein carriers with which the enzyme associates. Genetic studies in humans harboring an inactivating mutation at this locus indicate that loss of Lp-PLA(2) function is a risk factor for inflammatory and vascular conditions in Japanese cohorts. Consistently, overexpression of Lp-PLA(2) has anti-inflammatory and anti-atherogenic properties in animal models. This thematic review critically discusses results from laboratory and animal studies, analyzes genetic evidence, reviews clinical work demonstrating associations between Lp-PLA(2) and vascular disease, and summarizes results from animal and human clinical trials in which administration of darapladib was tested as a strategy for the management of atherosclerosis.
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Sternberg Z, Drake A, Sternberg DS, Benedict RHB, Li F, Hojnacki D, Weinstock-Guttmann B, Munschauer FE. Lp-PLA2: Inflammatory Biomarker of Vascular Risk in Multiple Sclerosis. J Clin Immunol 2012; 32:497-504. [DOI: 10.1007/s10875-011-9642-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 12/22/2011] [Indexed: 10/14/2022]
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Katan M, Elkind MSV. Inflammatory and neuroendocrine biomarkers of prognosis after ischemic stroke. Expert Rev Neurother 2011; 11:225-39. [PMID: 21306210 DOI: 10.1586/ern.10.200] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Stroke is the third leading cause of mortality in the USA and one of the leading causes of severe morbidity. It is important to provide stroke patients and physicians with the most accurate prognostic information to optimize care and allocation of healthcare resources. Reliable prognostic markers available during the initial phase after acute stroke may aid clinical decision-making. Several interesting candidate biomarkers have been studied to address prognostic questions; this article will focus on selected inflammatory and neuroendocrine markers. The utility of a biomarker is defined by its ability to improve clinical decision-making and add timely information beyond that readily available from clinical examination and routine imaging. This aim has not been completely achieved yet for any biomarkers, but promising data are available and further studies are ongoing.
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Affiliation(s)
- Mira Katan
- Stroke Division, Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
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Dullaart RPF, Constantinides A, Perton FG, van Leeuwen JJJ, van Pelt JL, de Vries R, van Tol A. Plasma cholesteryl ester transfer, but not cholesterol esterification, is related to lipoprotein-associated phospholipase A2: possible contribution to an atherogenic lipoprotein profile. J Clin Endocrinol Metab 2011; 96:1077-84. [PMID: 21252249 DOI: 10.1210/jc.2010-2139] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
CONTEXT Plasma lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) predicts incident cardiovascular disease and is associated preferentially with negatively charged apolipoprotein B-containing lipoproteins. The plasma cholesteryl ester transfer (CET) process, which contributes to low high-density lipoprotein cholesterol and small, dense low-density lipoproteins, is affected by the composition and concentration of apolipoprotein B-containing cholesteryl ester acceptor lipoproteins. OBJECTIVE We tested relationships of CET with Lp-PLA(2) in subjects with and without metabolic syndrome (MetS). DESIGN AND SETTING In 68 subjects with MetS and 74 subjects without MetS, plasma Lp-PLA(2) mass, cholesterol esterification (EST), lecithin:cholesterol acyltransferase (LCAT) activity level, CET, CET protein (CETP) mass, and lipoproteins were measured. RESULTS EST, LCAT activity, CET (P < 0.001 for all), and CETP (P = 0.030) were increased, and Lp-PLA(2) was decreased (P = 0.043) in MetS. CET was correlated positively with Lp-PLA(2) in subjects with and without MetS (P < 0.05 for both). EST and LCAT activity were unrelated to Lp-PLA(2), despite a positive correlation between EST and CET (P < 0.001). After controlling for age, sex, and diabetes status, CET was determined by Lp-PLA(2) in the whole group (β = 0.245; P < 0.001), and in subjects with (β = 0.304; P = 0.001) and without MetS (β = 0.244; P = 0.006) separately, independently of triglycerides and CETP. CONCLUSIONS Plasma CET is related to Lp-PLA(2) in subjects with and without MetS. The process of CET, but not EST, may be influenced by Lp-PLA(2). These findings provide a rationale to evaluate whether maneuvers that inhibit Lp-PLA(2) will reduce CET, and vice versa to document effects of CETP inhibition on Lp-PLA(2).
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Affiliation(s)
- Robin P F Dullaart
- Department of Endocrinology, University of Groningen and University Medical Center Groningen, 9700 RB Groningen, The Netherlands.
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Onyimba JA, Coronado MJ, Garton AE, Kim JB, Bucek A, Bedja D, Gabrielson KL, Guilarte TR, Fairweather D. The innate immune response to coxsackievirus B3 predicts progression to cardiovascular disease and heart failure in male mice. Biol Sex Differ 2011; 2:2. [PMID: 21338512 PMCID: PMC3049118 DOI: 10.1186/2042-6410-2-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 02/21/2011] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Men are at an increased risk of dying from heart failure caused by inflammatory heart diseases such as atherosclerosis, myocarditis and dilated cardiomyopathy (DCM). We previously showed that macrophages in the spleen are phenotypically distinct in male compared to female mice at 12 h after infection. This innate immune profile mirrors and predicts the cardiac immune response during acute myocarditis. METHODS In order to study sex differences in the innate immune response, five male and female BALB/c mice were infected intraperitoneally with coxsackievirus B3 (CVB3) or phosphate buffered saline and their spleens were harvested 12 h later for microarray analysis. Gene expression was determined using an Affymetrix Mouse Gene 1.0 ST Array. Significant gene changes were verified by quantitative real-time polymerase chain reaction or ELISA. RESULTS During the innate immune response to CVB3 infection, infected males had higher splenic expression of genes which are important in regulating the influx of cholesterol into macrophages, such as phospholipase A2 (PLA2) and the macrophage scavenger receptor compared to the infected females. We also observed a higher expression in infected males compared to infected females of squalene synthase, an enzyme used to generate cholesterol within cells, and Cyp2e1, an enzyme important in metabolizing cholesterol and steroids. Infected males also had decreased levels of the translocator protein 18 kDa (TSPO), which binds PLA2 and is the rate-limiting step for steroidogenesis, as well as decreased expression of the androgen receptor (AR), which indicates receptor activation. Gene differences were not due to increased viral replication, which was unaltered between sexes. CONCLUSIONS We found that, compared to females, male mice had a greater splenic expression of genes which are important for cholesterol metabolism and activation of the AR at 12 h after infection. Activation of the AR has been linked to increased cardiac hypertrophy, atherosclerosis, myocarditis/DCM and heart failure in male mice and humans.
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Affiliation(s)
- Jennifer A Onyimba
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Michael J Coronado
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Amanda E Garton
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Joseph B Kim
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Adriana Bucek
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Djahida Bedja
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kathleen L Gabrielson
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tomas R Guilarte
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - DeLisa Fairweather
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Jayaraman S, Gantz DL, Gursky O. Effects of phospholipase A(2) and its products on structural stability of human LDL: relevance to formation of LDL-derived lipid droplets. J Lipid Res 2011; 52:549-57. [PMID: 21220788 DOI: 10.1194/jlr.m012567] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hydrolysis and oxidation of LDL stimulate LDL entrapment in the arterial wall and promote inflammation and atherosclerosis via various mechanisms including lipoprotein fusion and lipid droplet formation. To determine the effects of FFA on these transitions, we hydrolyzed LDL by phospholipase A(2) (PLA(2)), removed FFA by albumin, and analyzed structural stability of the modified lipoproteins. Earlier, we showed that heating induces LDL remodeling, rupture, and coalescence into lipid droplets resembling those found in atherosclerotic lesions. Here, we report how FFA affect these transitions. Circular dichroism showed that mild LDL lipolysis induces partial β-sheet unfolding in apolipoprotein B. Electron microscopy, turbidity, and differential scanning calorimetry showed that mild lipolysis promotes LDL coalescence into lipid droplets. FFA removal by albumin restores LDL stability but not the protein conformation. Consequently, FFA enhance LDL coalescence into lipid droplets. Similar effects of FFA were observed in minimally oxidized LDL, in LDL enriched with exogenous FFA, and in HDL and VLDL. Our results imply that FFA promote lipoprotein coalescence into lipid droplets and explain why LDL oxidation enhances such coalescence in vivo but hampers it in vitro. Such lipid droplet formation potentially contributes to the pro-atherogenic effects of FFA.
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Affiliation(s)
- Shobini Jayaraman
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA.
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Aggarwal A, Singh S. Newer antiatherosclerosis treatment strategies. HEART ASIA 2011; 3:26-30. [PMID: 27325976 DOI: 10.1136/ha.2010.003129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/19/2010] [Indexed: 11/04/2022]
Abstract
Atherosclerosis has been a target of much clinical and molecular research. As a result of this extensive research, it is amply clear that atherogenesis is a multifactorial process involving an interplay of metabolic, immune and inflammatory mechanisms. Antiatherosclerotic strategies are today aiming for a multipronged approach targeting each arm of this multifactorial process. The newer agents under development can be divided into three broad categories: anti-inflammatory agents, modulators of intermediary metabolism and antiatherosclerosis vaccines. Potential targets for anti-inflammatory agents include inhibition of conversion of low-density lipoprotein (LDL) to oxidised LDL, blocking or downregulation of cell adhesion molecules, chemokine modulation and macrophage receptor blockade. Beyond inhibition of plaque formation, efforts are also ongoing to develop agents which stabilise the plaque by increasing its fibrous content and inhibiting its disruption. So far as research in the sphere of intermediary metabolism is concerned, the focus is now primarily on raising high-density lipoprotein and promoting reverse cholesterol transport; potential targets include cholesteryl ester transfer protein, liver X-receptor, lecithin cholesterol acyltransferase and high-density lipoprotein mimetics. Acyl-coenzymeA: cholesterol acyltransferase is another enzyme whose selective and differential inhibition is under active investigation. The concept of immunisation against a non-communicable disease such as atherosclerosis is still in its nascent stages. However, with increasing evidence to suggest the role of antigen-specific T-cell-mediated immunity in atherogenesis, this approach is potentially promising. Possible antigens under evaluation include oxidised LDL and its subparticles, heat-shock proteins and cholesteryl ester transfer protein. With cardiovascular disease being the single leading cause of death worldwide, the development of a safe and successful antiatherosclerosis strategy (possibly employing a combination of agents acting at various levels) will indeed be a major 21st-century achievement.
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Affiliation(s)
- Amitesh Aggarwal
- Department of Medicine, University College of Medical Sciences, University of Delhi & GTB Hospital, Delhi, India; Department of Preventive Cardiology, University College of Medical Sciences, University of Delhi & GTB Hospital, Delhi, India
| | - Safal Singh
- Department of Medicine, University College of Medical Sciences, University of Delhi & GTB Hospital, Delhi, India; Department of Preventive Cardiology, University College of Medical Sciences, University of Delhi & GTB Hospital, Delhi, India
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White H. Darapladib and its potential for plaque stabilization and prevention of cardiac events. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/clp.10.45] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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