201
|
Dietary indicaxanthin from cactus pear (Opuntia ficus-indicaL. Mill) fruit prevents eryptosis induced by oxysterols in a hypercholesterolaemia-relevant proportion and adhesion of human erythrocytes to endothelial cell layers. Br J Nutr 2015; 114:368-75. [DOI: 10.1017/s0007114515002111] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Toxic oxysterols in a hypercholesterolaemia-relevant proportion cause suicidal death of human erythrocytes or eryptosis. This process proceeds through early production of reactive oxygen species (ROS), release of prostaglandin (PGE2) and opening of PGE2-dependent Ca channels, membrane phosphatidylserine (PS) externalisation, and cell shrinkage. The present study was the first to reveal that a bioavailable phytochemical, indicaxanthin (Ind) from cactus pear fruit, in a concentration range (1·0–5·0 μM) consistent with its plasma level after a fruit meal, prevents PS externalisation and cell shrinkage in a dose-dependent manner when incubated with isolated healthy human erythrocytes exposed to an oxysterol mixture for 48 h. Dietary Ind inhibited ROS production, glutathione (GSH) depletion, PGE2 release and Ca2+entry. Ind alone did not modify the erythrocyte redox environment or affect other parameters.Ex vivospiking of normal human blood with the oxysterol mixture for 48 h induced eryptosis, resulting in the production of ROS and decreased levels of GSH, which was prevented by concurrent exposure to 5 μm-Ind. The adherence of eryptotic erythrocytes to the endothelium causes vascular tissue injury. Erythrocytes isolated from blood incubated with the oxysterol mixture plus 5 μm-Ind did not adhere to endothelial cell monolayers. Eryptotic erythrocytes may contribute to thrombotic complications in hypercholesterolaemia. Our findings suggest the positive effects of diets containing Ind on erythrocytes in hypercholesterolaemic subjects.
Collapse
|
202
|
Luchetti F, Canonico B, Cesarini E, Betti M, Galluzzi L, Galli L, Tippins J, Zerbinati C, Papa S, Iuliano L. 7-Ketocholesterol and 5,6-secosterol induce human endothelial cell dysfunction by differential mechanisms. Steroids 2015; 99:204-11. [PMID: 25697053 DOI: 10.1016/j.steroids.2015.02.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/05/2015] [Accepted: 02/06/2015] [Indexed: 11/16/2022]
Abstract
7-Ketocholesterol and 5,6-secosterol are cholesterol autoxidation products generated under oxidative stress by two distinct mechanisms. They are present in atherosclerotic plaques and are candidate players in the disease initiation and progression. While 7-ketocholesterol affects at cellular level, in particular apoptosis, are well known and reported on diverse cell lines, 5,6-secosterol is a recently discovered oxysterol with relatively few reports on the potential to affect endothelial cell functions. Endothelial cells have a central role in cardiovascular disease as they provide the barrier between blood and the vessel wall where atherosclerosis starts and progresses. Insults to endothelial cells provoke their dysfunction favoring pro-atherogenic and pro-thrombotic effects. In the present work, we tested 7-ketocholesterol and 5,6-secosterol on endothelial cells - focusing on apoptosis and the associated mitochondrial/lysosome alterations - and on endothelial function using the in vitro model of arterial relaxation of aortic rings. Our data provide evidence that 7-ketocholesterol and 5,6-secosterol are efficient instigators of apoptosis, which for 5,6-secosterol is associated to PKC and p53 up-regulation. In addition 5,6-secosterol is a potent inhibitor of endothelial-dependent arterial relaxation through PKC-dependent mechanisms. This may contribute to pro-atherogenic and pro-thrombotic mechanisms of 5,6-secosterol and highlights the role of cholesterol autoxidation in cardiovascular disease.
Collapse
Affiliation(s)
- Francesca Luchetti
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy.
| | - Barbara Canonico
- Department of Earth, Life and Environmental Science, University of Urbino "Carlo Bo", Urbino, Italy
| | - Erica Cesarini
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
| | - Michele Betti
- Department of Earth, Life and Environmental Science, University of Urbino "Carlo Bo", Urbino, Italy
| | - Luca Galluzzi
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
| | - Laura Galli
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
| | - John Tippins
- Division of Cell & Molecular Biology, Biochemistry Building, Imperial College, London, UK
| | - Chiara Zerbinati
- Department of Medico-Surgical Sciences and Biotechnologies Vascular Biology, Atherothrombosis & Mass Spectrometry, Sapienza University of Rome, Latina, Italy
| | - Stefano Papa
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
| | - Luigi Iuliano
- Department of Medico-Surgical Sciences and Biotechnologies Vascular Biology, Atherothrombosis & Mass Spectrometry, Sapienza University of Rome, Latina, Italy
| |
Collapse
|
203
|
Schött HF, Lütjohann D. Validation of an isotope dilution gas chromatography-mass spectrometry method for combined analysis of oxysterols and oxyphytosterols in serum samples. Steroids 2015; 99:139-50. [PMID: 25701095 DOI: 10.1016/j.steroids.2015.02.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/05/2015] [Accepted: 02/07/2015] [Indexed: 11/17/2022]
Abstract
We describe the validation of a method for the analysis of oxysterols, i.e. oxycholesterols and oxyphytosterols, in human serum using gas chromatography-mass spectrometry selected ion monitoring (GC-MS-SIM). Concentrations of 7α- and 7β-hydroxy-, and 7oxo-cholesterol, -campesterol, and -sitosterol as well as 4β-hydroxycholesterol and side-chain oxygenated 24S-, 25-, and 27-hydroxycholesterol were determined by isotope dilution methodology. After saponification at room temperature the oxysterols were extracted, separated from their substrates, cholesterol, campesterol, and sitosterol, by solid phase extraction, and subsequently derivatised to their corresponding trimethylsilyl-ethers prior to GC-MS-SIM. In order to prevent artificial autoxidation butylated hydroxytoluene and ethylenediaminetetraacetic acid were added. The validation of the method was performed according to the International Conference on Harmonisation guidance, including limits of detection and quantification, ranges, recovery and precision. Due to improved instrumental settings and work-up procedure, limits of detection and quantification ranged between 8.0-202.0pg/mL and 28.0-674pg/mL, respectively. Recovery data in five calibration points varied between 91.9% and 116.8% and in serum samples between 93.1% and 118.1%. The mean coefficient of variation (CV) for the recovery of all compounds was <10%. Well satisfying CVs for within-day precision (2.1-10.8%) and for between-day precision (2.3-12.1%) were obtained. More than 20 samples could be processed in a single routine day and test series of about 300 samples can be realised without impairment of the validation parameters during a sequence. Comparison of oxysterol and oxyphytosterol content in serum and plasma revealed no difference. A fully validated isotope dilution methodology for the quantification of oxycholesterols and oxyphytosterols from human serum or plasma is presented.
Collapse
Affiliation(s)
- Hans-Frieder Schött
- Institute for Clinical Chemistry and Clinical Pharmacology, University Clinics Bonn, 53105 Bonn, Germany.
| | - Dieter Lütjohann
- Institute for Clinical Chemistry and Clinical Pharmacology, University Clinics Bonn, 53105 Bonn, Germany.
| |
Collapse
|
204
|
Filomenko R, Fourgeux C, Bretillon L, Gambert-Nicot S. Oxysterols: Influence on plasma membrane rafts microdomains and development of ocular diseases. Steroids 2015; 99:259-65. [PMID: 25683893 DOI: 10.1016/j.steroids.2015.02.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/26/2015] [Accepted: 02/02/2015] [Indexed: 01/27/2023]
Abstract
Oxidation of cholesterol into oxysterols is a major way of elimination of cholesterol from the liver and extrahepatic tissues, including the brain and the retina. Oxysterols are involved in various cellular processes. Numerous links have been established between oxysterols and several disorders such as neurodegenerative pathologies, retinopathies and atherosclerosis. Different components of the lipid layer such as sphingolipids, sterols and proteins participate to membrane fluidity and forme lipid rafts microdomains. Few data are available on the links between lipids rafts and oxysterols. The purpose of this review is to suggest the potential role of lipid rafts microdomains in the development of retinopathies with special emphasis and opening perspectives of their interactions with oxysterols. Actually cholesterol oxidation mechanism may have deleterious effect on its ability to support rafts formation .This review suggest that the effect of oxysterols of lipid rafts would probably depend on the oxysterol molecule and cell type.
Collapse
Affiliation(s)
- Rodolphe Filomenko
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Equipe Œil, Nutrition et Signalisation Cellulaire, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Cynthia Fourgeux
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Equipe Œil, Nutrition et Signalisation Cellulaire, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Lionel Bretillon
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Equipe Œil, Nutrition et Signalisation Cellulaire, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.
| | - Ségolène Gambert-Nicot
- INRA, UMR1324 Centre des Sciences du Goût et de l'Alimentation, Equipe Œil, Nutrition et Signalisation Cellulaire, F-21000 Dijon, France; CNRS, UMR6265 Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France; CHU Dijon, Service de Biochimie Clinique, F-21000 Dijon, France
| |
Collapse
|
205
|
Kulig W, Olżyńska A, Jurkiewicz P, Kantola AM, Komulainen S, Manna M, Pourmousa M, Vazdar M, Cwiklik L, Rog T, Khelashvili G, Harries D, Telkki VV, Hof M, Vattulainen I, Jungwirth P. Cholesterol under oxidative stress-How lipid membranes sense oxidation as cholesterol is being replaced by oxysterols. Free Radic Biol Med 2015; 84:30-41. [PMID: 25795515 DOI: 10.1016/j.freeradbiomed.2015.03.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 02/06/2023]
Abstract
The behavior of oxysterols in phospholipid membranes and their effects on membrane properties were investigated by means of dynamic light scattering, fluorescence spectroscopy, NMR, and extensive atomistic simulations. Two families of oxysterols were scrutinized-tail-oxidized sterols, which are mostly produced by enzymatic processes, and ring-oxidized sterols, formed mostly via reactions with free radicals. The former family of sterols was found to behave similar to cholesterol in terms of molecular orientation, roughly parallel to the bilayer normal, leading to increasing membrane stiffness and suppression of its membrane permeability. In contrast, ring-oxidized sterols behave quantitatively differently from cholesterol. They acquire tilted orientations and therefore disrupt the bilayer structure with potential implications for signaling and other biochemical processes in the membranes.
Collapse
Affiliation(s)
- Waldemar Kulig
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland.
| | - Agnieszka Olżyńska
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejskova 3, 18223 Prague 8, Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejskova 3, 18223 Prague 8, Czech Republic.
| | - Anu M Kantola
- Department of Physics and Chemistry, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
| | - Sanna Komulainen
- Department of Physics and Chemistry, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
| | - Moutusi Manna
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
| | - Mohsen Pourmousa
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
| | - Mario Vazdar
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland; Rudjer Bošković Institute, Division of Organic Chemistry and Biochemistry, POB 180, HR-10002 Zagreb, Croatia
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejskova 3, 18223 Prague 8, Czech Republic; Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic.
| | - Tomasz Rog
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
| | | | - Daniel Harries
- Institute of Chemistry and the Fritz Haber Research Center, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ville-Veikko Telkki
- Department of Physics and Chemistry, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejskova 3, 18223 Prague 8, Czech Republic
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland; MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, Odense, Denmark
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague 6, Czech Republic; Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
| |
Collapse
|
206
|
27-Hydroxycholesterol contributes to disruptive effects on learning and memory by modulating cholesterol metabolism in the rat brain. Neuroscience 2015; 300:163-73. [PMID: 25987203 DOI: 10.1016/j.neuroscience.2015.05.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/21/2015] [Accepted: 05/08/2015] [Indexed: 12/30/2022]
Abstract
Cholesterol metabolism is important for neuronal function in the central nervous system (CNS). The oxysterol 27-hydroxycholesterol (27-OHC) is a cholesterol metabolite that crosses the blood-brain barrier (BBB) and may be a useful substitutive marker for neurodegenerative diseases. However, the effects of 27-OHC on learning and memory and the underlying mechanisms are unclear. To determine this mechanism, we investigated learning and memory and cholesterol metabolism in rat brain following the injection of various doses of 27-OHC into the caudal vein. We found that 27-OHC increased cholesterol levels and upregulated the expression of liver X receptor-α (LXR-α) and adenosine triphosphate (ATP)-binding cassette transporter protein family member A1 (ABCA1). In addition, 27-OHC decreased the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CR) and low-density lipoprotein receptor (LDLR) in rat brain tissues. These findings suggest that 27-OHC may negatively modulate cognitive effects and cholesterol metabolism in the brain.
Collapse
|
207
|
Scholz B, Guth S, Engel KH, Steinberg P. Phytosterol oxidation products in enriched foods: Occurrence, exposure, and biological effects. Mol Nutr Food Res 2015; 59:1339-52. [DOI: 10.1002/mnfr.201400922] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 03/06/2015] [Accepted: 03/06/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Birgit Scholz
- Technische Universität München, Chair of General Food Technology; Freising-Weihenstephan Germany
| | - Sabine Guth
- Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover; Foundation Hannover Germany
| | - Karl-Heinz Engel
- Technische Universität München, Chair of General Food Technology; Freising-Weihenstephan Germany
| | - Pablo Steinberg
- Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover; Foundation Hannover Germany
| |
Collapse
|
208
|
Hammann S, Wendlinger C, Vetter W. Analysis of Intact Cholesteryl Esters of Furan Fatty Acids in Cod Liver. Lipids 2015; 50:611-20. [DOI: 10.1007/s11745-015-4019-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 04/02/2015] [Indexed: 10/23/2022]
|
209
|
Medina ME, Galano A, Trigos Á. Theoretical study on the oxidative damage to cholesterol induced by peroxyl radicals. J PHYS ORG CHEM 2015. [DOI: 10.1002/poc.3449] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Manuel E. Medina
- Centro de Investigaciones Biomédicas; Universidad Veracruzana; Av. Luis Castelazo s/n, Col. Industrial Animas Xalapa Veracruz 91190 Mexico
| | - Annia Galano
- Departamento de Química, División de Ciencias Básica e Ingeniería; Universidad Autónoma Metropolitana-Iztapalapa; Av. San Rafael Atlixco No. 186, Col. Vicentina México D. F. 09340 Mexico
| | - Ángel Trigos
- Laboratorio de Alta Tecnología de Xalapa; Universidad Veracruzana; Calle Médicos 5, Col. Unidad del Bosque Xalapa Veracruz 91010 Mexico
| |
Collapse
|
210
|
Kim SM, Kim BY, Eo SK, Kim CD, Kim K. 27-Hydroxycholesterol up-regulates CD14 and predisposes monocytic cells to superproduction of CCL2 in response to lipopolysaccharide. Biochim Biophys Acta Mol Basis Dis 2015; 1852:442-50. [DOI: 10.1016/j.bbadis.2014.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 12/01/2014] [Accepted: 12/03/2014] [Indexed: 11/16/2022]
|
211
|
Radwan NL, Eldin TS, Zaiat AEL, Mostafa MA. Effect of Dietary Nano-Selenium Supplementation on Selenium Content and Oxidative Stability in Table Eggs and Productive Performance of Laying Hens. ACTA ACUST UNITED AC 2015. [DOI: 10.3923/ijps.2015.161.176] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
212
|
Dubland JA, Francis GA. Lysosomal acid lipase: at the crossroads of normal and atherogenic cholesterol metabolism. Front Cell Dev Biol 2015; 3:3. [PMID: 25699256 PMCID: PMC4313778 DOI: 10.3389/fcell.2015.00003] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 01/07/2015] [Indexed: 01/01/2023] Open
Abstract
Unregulated cellular uptake of apolipoprotein B-containing lipoproteins in the arterial intima leads to the formation of foam cells in atherosclerosis. Lysosomal acid lipase (LAL) plays a crucial role in both lipoprotein lipid catabolism and excess lipid accumulation as it is the primary enzyme that hydrolyzes cholesteryl esters derived from both low density lipoprotein (LDL) and modified forms of LDL. Evidence suggests that as atherosclerosis progresses, accumulation of excess free cholesterol in lysosomes leads to impairment of LAL activity, resulting in accumulation of cholesteryl esters in the lysosome as well as the cytosol in foam cells. Impaired metabolism and release of cholesterol from lysosomes can lead to downstream defects in ATP-binding cassette transporter A1 regulation, needed to offload excess cholesterol from plaque foam cells. This review focuses on the role LAL plays in normal cholesterol metabolism and how the associated changes in its enzymatic activity may ultimately contribute to atherosclerosis progression.
Collapse
Affiliation(s)
- Joshua A Dubland
- Department of Medicine, Centre for Heart Lung Innovation, Providence Health Care Research Institute at St. Paul's Hospital, University of British Columbia Vancouver, BC, Canada
| | - Gordon A Francis
- Department of Medicine, Centre for Heart Lung Innovation, Providence Health Care Research Institute at St. Paul's Hospital, University of British Columbia Vancouver, BC, Canada
| |
Collapse
|
213
|
Son Y, Chun W, Ahn YT, Kim K, Lee CW, Kim JM, Lee C, An WG. 7-Ketocholesterol induces the reduction of KCNMB1 in atherosclerotic blood vessels. Biochem Biophys Res Commun 2015; 457:324-7. [DOI: 10.1016/j.bbrc.2014.12.109] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 12/26/2014] [Indexed: 10/24/2022]
|
214
|
Rosales C, Tang D, Geng YJ. CD1d serves as a surface receptor for oxidized cholesterol induction of peroxisome proliferator-activated receptor-γ. Atherosclerosis 2015; 239:224-31. [PMID: 25618030 DOI: 10.1016/j.atherosclerosis.2015.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 12/17/2014] [Accepted: 01/05/2015] [Indexed: 02/08/2023]
Abstract
OBJECTIVE The cluster of differentiation-1d (CD1d) recognizes and presents the lipid antigens to NK-T lymphocytes. Atherosclerotic lesions contain atherogenic lipids, mainly cholesterol and its oxides. Peroxisome proliferator-activated receptor-γ (PPARγ) is also known to exist in atherosclerotic lesions, participating in regulation of lipid metabolism. The current study tested whether CD1d acts as a surface receptor that mediates induction and activation of PPARγ by oxysterols commonly found in atherosclerotic lesions. METHODS AND RESULTS CD1d overexpression in HEK 293 cells transfected with CD1d cDNA was confirmed by fluorescence, flow cytometry, Western blotting and mRNA expression. Tritiated ((3)H) 7-ketocholesterol (7K) was used for lipid binding assays. Radioactive assessment demonstrated an increased 7K-binding activity HEK 293 cells with CD1d overexpression. The 7K binding could be blocked by another oxysterol, 25-hydroxycholesterol, but not by native free cholesterol. Addition of CD1d:IgG dimer protein or an anti-CD1d antibody, but not control IgG, significantly diminished 7K binding to CD1d-expressing HEK 293 cells. CD1d deficiency markedly diminished the 7K-binding in macrophages and smooth muscle cells. Western blot and gel shift assays demonstrated that CD1d-mediated 7K binding induced expression and activation of PPARγ. The PPARγ agonist PGJ2 enhances the 7K stimulatory effect on PPARγ expression and activity but the antagonist GW9662 inhibits the 7K effect on the CD1d-expressing cells. CONCLUSIONS CD1d acts as a cell surface receptor that recognizes and binds oxysterols and initializes a pathway connecting oxysterol binding to PPARγ activation.
Collapse
Affiliation(s)
- Corina Rosales
- Center for Cardiovascular Biology and Atherosclerosis Research, University of Texas Health Science Center at Houston, USA
| | - Daming Tang
- Texas Heart Institute, Houston, TX 77030, USA
| | - Yong-Jian Geng
- Center for Cardiovascular Biology and Atherosclerosis Research, University of Texas Health Science Center at Houston, USA; Texas Heart Institute, Houston, TX 77030, USA.
| |
Collapse
|
215
|
Orsó E, Matysik S, Grandl M, Liebisch G, Schmitz G. Human native, enzymatically modified and oxidized low density lipoproteins show different lipidomic pattern. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:299-306. [PMID: 25583048 DOI: 10.1016/j.bbalip.2015.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 12/23/2014] [Accepted: 01/03/2015] [Indexed: 11/26/2022]
Abstract
In the present paper we have performed comparative lipidomic analysis of two prototypic atherogenic LDL modifications, oxidized LDL and enzymatically modified LDL. Oxidization of LDL was carried out with different chemical modifications starting from the same native LDL preparations: (i) by copper oxidation leading to terminally oxidized LDL (oxLDL), (ii) by moderate oxidization with HOCl (HOCl LDL), (iii) by long term storage of LDL at 4°C to produce minimally modified LDL (mmLDL), or (iv) by 15-lipoxygenase, produced by a transfected fibroblast cell line (LipoxLDL). The enzymatic modification of LDL was performed by treatment of native LDL with trypsin and cholesteryl esterase (eLDL). Free cholesterol (FC) and cholesteryl esters (CE) represent the predominant lipid classes in all LDL preparations. In contrast to native LDL, which contains about two-thirds of total cholesterol as CE, enzymatic modification of LDL decreased the proportion of CE to about one-third. Free cholesterol and CE in oxLDL are reduced by their conversion to oxysterols. Oxidization of LDL preferentially influences the content of polyunsaturated phosphatidylcholine (PC) and polyunsaturated plasmalogen species, by reducing the total PC fraction in oxLDL. Concomitantly, a strong rise of the lysophosphatidylcholine (LPC) fraction can be found in oxLDL as compared to native LDL. This effect is less pronounced in eLDL. The mild oxidation of LDL with hypochlorite and/or lipoxygenase does not alter the content of the analyzed lipid classes and species in a significant manner. The lipidomic characterization of modified LDLs contributes to the better understanding their diverse cellular effects.
Collapse
Affiliation(s)
- Evelyn Orsó
- University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Silke Matysik
- University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Margot Grandl
- University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Gerhard Liebisch
- University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
| | - Gerd Schmitz
- University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
| |
Collapse
|
216
|
Sterol metabolism controls T(H)17 differentiation by generating endogenous RORγ agonists. Nat Chem Biol 2015; 11:141-7. [PMID: 25558972 DOI: 10.1038/nchembio.1714] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 10/23/2014] [Indexed: 01/06/2023]
Abstract
Retinoic acid receptor-related orphan receptor γ (RORγt) controls the differentiation of naive CD4(+) T cells into the TH17 lineage, which are critical cells in the pathogenesis of autoimmune diseases. Here we report that during TH17 differentiation, cholesterol biosynthesis and uptake programs are induced, whereas their metabolism and efflux programs are suppressed. These changes result in the accumulation of the cholesterol precursor, desmosterol, which functions as a potent endogenous RORγ agonist. Generation of cholesterol precursors is essential for TH17 differentiation as blocking cholesterol synthesis with chemical inhibitors at steps before the formation of active precursors reduces differentiation. Upon activation, metabolic changes also lead to production of specific sterol-sulfate conjugates that favor activation of RORγ over the TH17-inhibiting sterol receptor LXR. Thus, TH17 differentiation is orchestrated by coordinated sterol synthesis, mobilization and metabolism to selectively activate RORγ.
Collapse
|
217
|
Yoshida Y, Umeno A, Akazawa Y, Shichiri M, Murotomi K, Horie M. Chemistry of Lipid Peroxidation Products and Their Use as Biomarkers in Early Detection of Diseases. J Oleo Sci 2015; 64:347-56. [DOI: 10.5650/jos.ess14281] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Yasukazu Yoshida
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST)
| | - Aya Umeno
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST)
| | - Yoko Akazawa
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST)
| | - Mototada Shichiri
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST)
| | - Kazutoshi Murotomi
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST)
| | - Masanori Horie
- Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST)
| |
Collapse
|
218
|
Seo HC, Kim SM, Eo SK, Rhim BY, Kim K. 7α-Hydroxycholesterol Elicits TLR6-Mediated Expression of IL-23 in Monocytic Cells. Biomol Ther (Seoul) 2015; 23:84-9. [PMID: 25593648 PMCID: PMC4286754 DOI: 10.4062/biomolther.2014.067] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/26/2014] [Accepted: 09/01/2014] [Indexed: 11/21/2022] Open
Abstract
We investigated the question of whether 7-oxygenated cholesterol derivatives could affect inflammatory and/or immune responses in atherosclerosis by examining their effects on expression of IL-23 in monocytic cells. 7α-Hydroxycholesterol (7αOHChol) induced transcription of the TLR6 gene and elevated the level of cell surface TLR6 protein in THP-1 monocytic cells. Addition of an agonist of TLR6, FSL-1, to TLR6-expressing cells by treatment with 7αOHChol resulted in enhanced production of IL-23 and transcription of genes encoding the IL-23 subunit α (p19) and the IL-12 subunit β (p40). However, treatment with 7-ketocholesterol (7K) and 7β-hydroxycholesterol (7βOHChol) did not affect TLR6 expression, and addition of FSL-1 to cells treated with either 7K or 7βOHChol did not influence transcription of the genes. Pharmacological inhibition of ERK, Akt, or PI3K resulted in attenuated transcription of TLR6 induced by 7αOHChol as well as secretion of IL-23 enhanced by 7αOHChol plus FSL-1. Inhibition of p38 MAPK or JNK resulted in attenuated secretion of IL-23. These results indicate that a certain type of 7-oxygenated cholesterol like 7αOHChol can elicit TLR6-mediated expression of IL-23 by monocytic cells via PI3K/Akt and MAPKs pathways.
Collapse
Affiliation(s)
- Hyun Chul Seo
- Department of Pharmacology, Pusan National University - School of Medicine, Yangsan 626-870
| | - Sun-Mi Kim
- Department of Pharmacology, Pusan National University - School of Medicine, Yangsan 626-870
| | - Seong-Kug Eo
- College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Iksan 570-752, Republic of Korea
| | - Byung-Yong Rhim
- Department of Pharmacology, Pusan National University - School of Medicine, Yangsan 626-870
| | - Koanhoi Kim
- Department of Pharmacology, Pusan National University - School of Medicine, Yangsan 626-870
| |
Collapse
|
219
|
Heo W, Kim SM, Eo SK, Rhim BY, Kim K. FSL-1, a Toll-like Receptor 2/6 Agonist, Induces Expression of Interleukin-1α in the Presence of 27-hydroxycholesterol. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 18:475-80. [PMID: 25598661 PMCID: PMC4296036 DOI: 10.4196/kjpp.2014.18.6.475] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/04/2014] [Accepted: 08/25/2014] [Indexed: 11/29/2022]
Abstract
We investigated the question of whether cholesterol catabolite can influence expression of inflammatory cytokines via Toll-like receptors (TLR) in monocytic cells. Treatment of THP-1 monocytic cells with 27-hydroxycholesterol (27OHChol) resulted in induction of gene transcription of TLR6 and elevated level of cell surface TLR6. Addition of FSL-1, a TLR6 agonist, to 27OHChol-treated cells resulted in transcription of the IL-1α gene and enhanced secretion of the corresponding gene product. However, cholesterol did not affect TLR6 expression, and addition of FSL-1 to cholesterol-treated cells did not induce expression of IL-1α. Using pharmacological inhibitors, we investigated molecular mechanisms underlying the expression of TLR6 and IL-1α. Treatment with Akt inhibitor IV or U0126 resulted in significantly attenuated expression of TLR6 and IL-1α induced by 27OHChol and 27OHChol plus FSL-1, respectively. In addition, treatment with LY294002, SB202190, or SP600125 resulted in significantly attenuated secretion of IL-1α. These results indicate that 27OHChol can induce inflammation by augmentation of TLR6-mediated production of IL-1α in monocytic cells via multiple signaling pathways.
Collapse
Affiliation(s)
- Weon Heo
- Department of Pharmacology, Pusan National University School of Medicine, Yangsan, 626-870, Korea
| | - Sun-Mi Kim
- Department of Pharmacology, Pusan National University School of Medicine, Yangsan, 626-870, Korea
| | - Seong-Kug Eo
- College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Iksan, 570-752, Korea
| | - Byung-Yong Rhim
- Department of Pharmacology, Pusan National University School of Medicine, Yangsan, 626-870, Korea
| | - Koanhoi Kim
- Department of Pharmacology, Pusan National University School of Medicine, Yangsan, 626-870, Korea
| |
Collapse
|
220
|
Bandaru VVR, Haughey NJ. Quantitative detection of free 24S-hydroxycholesterol, and 27-hydroxycholesterol from human serum. BMC Neurosci 2014; 15:137. [PMID: 25539717 PMCID: PMC4304132 DOI: 10.1186/s12868-014-0137-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 12/17/2014] [Indexed: 03/25/2023] Open
Abstract
Background Cholesterol metabolism is important for the maintenance of myelin and neuronal membranes in the central nervous system. Blood concentrations of the brain specific cholesterol metabolite 24S-hydroxysterol to the peripheral metabolite 27-hydroxycholesterol may be useful surrogate markers for neurodegenerative diseases including Alzheimer’s disease, Huntington’s disease, HIV-Associated Neurocognitive Disorders, and Multiple Sclerosis. However, current methods to isolate hydroxycholesterols are labor intensive, prone to produce variable extraction efficiencies and do not discriminate between free and esterfied forms of hydroxycholesterols. Since free hydroxycholesterols are the biologically active form of these sterols, separating free from esterfied forms may provide a sensitive measure to identify disease-associated differences in brain sterol metabolism. Results We found that average human serum concentrations were 12.3 ± 4.79 ng/ml for free 24(s)-hydroxycholesterol and 17.7 ± 8.5 ng/ml for 27-hydroxycholesterol. Conclusion Serum measurements of these biologically active oxysterols may be useful surrogate measures for brain health in a variety of neurodegenerative conditions.
Collapse
Affiliation(s)
- Veera Venkata Ratnam Bandaru
- Department of Neurology, Richard T. Johnson Division of Neuroimmunology and Neurological Infections, The Johns Hopkins University School of Medicine, Carnegie 616A, 600 North Wolfe Street, Baltimore, 21287, MD, USA.
| | - Norman J Haughey
- Department of Neurology, Richard T. Johnson Division of Neuroimmunology and Neurological Infections, The Johns Hopkins University School of Medicine, Carnegie 616A, 600 North Wolfe Street, Baltimore, 21287, MD, USA. .,Department of Psychiatry, Division of Geriatric Psychiatry and Neuropsychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
221
|
Xu L, Porter NA. Free radical oxidation of cholesterol and its precursors: Implications in cholesterol biosynthesis disorders. Free Radic Res 2014; 49:835-49. [PMID: 25381800 DOI: 10.3109/10715762.2014.985219] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Free radical oxidation of cholesterol and its precursors contribute significantly to the pathophysiology of a number of human diseases. This review intends to summarize recent developments and provide a perspective on the reactivities of sterols toward free radical oxidation, the free radical reaction mechanism, and the biological consequences of oxysterols derived from the highly oxidizable cholesterol precursor, 7-dehydrocholesterol. We propose that the rigid structures, additional substituents on the double bonds, and the well-aligned reactive C-H bonds in sterols make them more prone to free radical oxidation than their acyclic analogs found in unsaturated fatty acids. The mechanism of sterol peroxidation follows some well-established reaction pathways found in the free radical peroxidation of polyunsaturated fatty acids, but sterols also undergo some reactions that are unique to these compounds. Peroxidation of 7-dehydrocholesterol gives arguably the most diverse set of oxysterol products that have been observed to date. The metabolism of these oxysterols in cells and the biological consequences of their formation will be discussed in the context of the pathophysiology of the human disease Smith-Lemli-Opitz syndrome. Considering the high reactivity of sterols, we propose that a number of other cholesterol biosynthesis disorders may be associated with oxidative stress.
Collapse
Affiliation(s)
- L Xu
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University , Nashville, TN , USA
| | | |
Collapse
|
222
|
Lee WR, Ishikawa T, Umetani M. The interaction between metabolism, cancer and cardiovascular disease, connected by 27-hydroxycholesterol. ACTA ACUST UNITED AC 2014; 9:617-624. [PMID: 25632306 DOI: 10.2217/clp.14.53] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxysterols are metabolites of cholesterol that are produced in liver and other peripheral tissues as a means to eliminate cholesterol to bile acid. Recent studies have revealed that the most abundant circulating oxysterol 27-hydroxycholesterol (27HC) is the first identified endogenous selective estrogen receptor modulator. 27HC levels correlate well with that of cholesterol, and also rise progressively with age. 27HC affects estrogen receptor function by the antagonism of estrogen action and also by the direct modulation of the receptor function, and similar to estrogen/estrogen receptors, 27HC has many actions in various tissues. This review article introduces the recent progress in the understanding of the role of 27HC in breast cancer and cardiovascular dysfunction.
Collapse
Affiliation(s)
- Wan-Ru Lee
- Division of Pulmonary & Vascular Biology, Departments of Pediatrics & Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Tomonori Ishikawa
- Division of Pulmonary & Vascular Biology, Departments of Pediatrics & Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA ; Comprehensive Reproductive Medicine, Graduate School of Medical & Dental Sciences, Tokyo Medical & Dental University, Tokyo, Japan
| | - Michihisa Umetani
- Division of Pulmonary & Vascular Biology, Departments of Pediatrics & Pharmacology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| |
Collapse
|
223
|
Muchalski H, Xu L, Porter NA. Tunneling in tocopherol-mediated peroxidation of 7-dehydrocholesterol. Org Biomol Chem 2014; 13:1249-53. [PMID: 25435103 DOI: 10.1039/c4ob02377c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The peroxidation of 7-dehydrocholesterol (7-DHC), a biosynthetic precursor to vitamin D3 and cholesterol, has been linked to the pathophysiology of Smith-Lemli-Optiz syndrome (SLOS), a devastating human disorder. In SLOS, 7-DHC plasma and tissue levels are elevated because of defects in the enzyme that convert it to cholesterol. α-Tocopherol can mediate the peroxidation of 7-DHC under certain circumstances and this prompted us to investigate the kinetic isotope effect (KIE) during this process. Thus, 9,14-d2-7-DHC was synthesized using a photochemical cyclization of deuterium-reinforced previtamin D3 (retro to its biosynthesis). Subsequently, we carried out co-oxidation of 9,14-h2-25,26,26,26,27,27,27-d7- and 9,14-d2-7-DHC in the presence of α-tocopherol under conditions that favor TMP. By monitoring the products formed from each precursor using mass spectrometry, the KIE for the hydrogen (deuterium) atom removal at C9 was found to be 21 ± 1. This large KIE value indicates that tunneling plays a role in the hydrogen atom transfer step in the tocopherol-mediated peroxidation of 7-DHC.
Collapse
Affiliation(s)
- H Muchalski
- Department of Chemistry, Vanderbilt University, 7330 Stevenson Center, Station B 351822, Nashville, TN 37235, USA.
| | | | | |
Collapse
|
224
|
Lizard G. Highlight on transient activation of red/ox-dependent survival signals involving MEK/ERK and PI3/Akt signaling pathways in 27-hydroxycholesterol treated-U937 Human monocytic cells: commentary on "Survival signaling elicited by 27-hydroxycholesterol through the combined modulation of cellular redox state and ERK/Akt phosphorylation," by Beyza Vurusaner et al. Free Radic Biol Med 2014; 77:386-7. [PMID: 25236738 DOI: 10.1016/j.freeradbiomed.2014.07.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 07/31/2014] [Indexed: 10/24/2022]
Affiliation(s)
- Gérard Lizard
- Université de Bourgogne, Laboratoire Bio-PeroxIL "Biochimie du Peroxysome, Inflammation et Métabolisme Lipidique" (EA7270)/INSERM, 6 Bd Gabriel, Dijon, F-21000, France.
| |
Collapse
|
225
|
Development of a Reliable Analytical Protocol for the Isolation of Cholesterol Oxidation Products—a Comparison of Different Lipid Extraction and Saponification Methods. FOOD ANAL METHOD 2014. [DOI: 10.1007/s12161-014-0034-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
226
|
Zarrouk A, Vejux A, Mackrill J, O’Callaghan Y, Hammami M, O’Brien N, Lizard G. Involvement of oxysterols in age-related diseases and ageing processes. Ageing Res Rev 2014; 18:148-62. [PMID: 25305550 DOI: 10.1016/j.arr.2014.09.006] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/23/2014] [Accepted: 09/30/2014] [Indexed: 12/15/2022]
Abstract
Ageing is accompanied by increasing vulnerability to major pathologies (atherosclerosis, Alzheimer's disease, age-related macular degeneration, cataract, and osteoporosis) which can have similar underlying pathoetiologies. All of these diseases involve oxidative stress, inflammation and/or cell death processes, which are triggered by cholesterol oxide derivatives, also named oxysterols. These oxidized lipids result either from spontaneous and/or enzymatic oxidation of cholesterol on the steroid nucleus or on the side chain. The ability of oxysterols to induce severe dysfunctions in organelles (especially mitochondria) plays key roles in RedOx homeostasis, inflammatory status, lipid metabolism, and in the control of cell death induction, which may at least in part contribute to explain the potential participation of these molecules in ageing processes and in age related diseases. As no efficient treatments are currently available for most of these diseases, which are predicted to become more prevalent due to the increasing life expectancy and average age, a better knowledge of the biological activities of the different oxysterols is of interest, and constitutes an important step toward identification of pharmacological targets for the development of new therapeutic strategies.
Collapse
|
227
|
Abstract
Cholesterol and components of the cholesterol biosynthetic pathway have fundamental roles in all mammalian cells. Hydroxylated forms of cholesterol are now emerging as important regulators of immune function. This involves effects on the cholesterol biosynthetic pathway and cell membrane properties, which can have antiviral and anti-inflammatory influences. In addition, a dihydroxylated form of cholesterol functions as an immune cell guidance cue by engaging the G protein-coupled receptor EBI2, and it is required for mounting adaptive immune responses. In this Review, we summarize the current understanding of the closely related oxysterols 25-hydroxycholesterol and 7α,25-dihydroxycholesterol, and the growing evidence that they have wide-ranging influences on innate and adaptive immunity.
Collapse
|
228
|
Hu S, Liu H, Pan Z, Xia L, Dong X, Li L, Xu F, He H, Wang J. Molecular cloning, expression profile and transcriptional modulation of two splice variants of very low density lipoprotein receptor during ovarian follicle development in geese (Anser cygnoide). Anim Reprod Sci 2014; 149:281-96. [DOI: 10.1016/j.anireprosci.2014.06.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/19/2014] [Accepted: 06/20/2014] [Indexed: 10/25/2022]
|
229
|
Marwarha G, Ghribi O. Does the oxysterol 27-hydroxycholesterol underlie Alzheimer's disease-Parkinson's disease overlap? Exp Gerontol 2014; 68:13-8. [PMID: 25261765 DOI: 10.1016/j.exger.2014.09.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 09/19/2014] [Accepted: 09/22/2014] [Indexed: 01/13/2023]
Abstract
Alzheimer's disease (AD), the most common form of dementia, is characterized histopathologically by the deposition of β-amyloid (Aβ) plaques and neurofibrillary tangles-containing hyperphosphorylated tau protein in the brain. Parkinson's disease (PD), the most common movement disorder, is characterized by the aggregation of α-synuclein protein in Lewy body inclusions and the death of dopaminergic neurons in the substantia nigra. Based on their pathological signatures, AD and PD can be considered as two different disease entities. However, a subpopulation of PD patients also exhibit Aβ plaques, and AD patients exhibit α-synuclein aggregates. This overlap between PD and AD suggests that common pathological pathways exist for the two diseases. Identification of factors and cellular mechanisms by which these factors can trigger pathological hallmarks for AD/PD overlap may help in designing disease-modifying therapies that can reverse or stop the progression of AD and PD. For the last decade, work in our laboratory has shown that fluctuations in the levels of cholesterol oxidation products (oxysterols) may correlate with the onset of AD and PD. In this review, we will provide results from our laboratory and data from literature that converge to strongly suggest the involvement of cholesterol and cholesterol oxidation products in the pathogenesis of AD and PD. We will specifically delineate the role of and the underlying mechanisms by which increased levels of the oxysterol 27-hydroxycholesterol contribute to the pathogenesis of AD, PD, and AD/PD overlap.
Collapse
Affiliation(s)
- Gurdeep Marwarha
- Department of Basic Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, United States
| | - Othman Ghribi
- Department of Basic Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, United States.
| |
Collapse
|
230
|
Rao X, Zhong J, Maiseyeu A, Gopalakrishnan B, Villamena FA, Chen LC, Harkema JR, Sun Q, Rajagopalan S. CD36-dependent 7-ketocholesterol accumulation in macrophages mediates progression of atherosclerosis in response to chronic air pollution exposure. Circ Res 2014; 115:770-780. [PMID: 25186795 DOI: 10.1161/circresaha.115.304666] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE Air pollution exposure has been shown to potentiate plaque progression in humans and animals. Our previous studies have suggested a role for oxidized lipids in mediating adverse vascular effect of air pollution. However, the types of oxidized lipids formed in response to air pollutants and how this occurs and their relevance to atherosclerosis are not fully understood. OBJECTIVE To investigate the mechanisms by which particulate matter <2.5 μm (PM2.5) induces progression of atherosclerosis. METHODS AND RESULTS Atherosclerosis-prone ApoE(-/-) or LDLR(-/-) mice were exposed to filtered air or concentrated ambient PM2.5 using a versatile aerosol concentrator enrichment system for 6 months. PM2.5 increased 7-ketocholesterol (7-KCh), an oxidatively modified form of cholesterol, in plasma intermediate density lipoprotein/low-density lipoprotein fraction and in aortic plaque concomitant with progression of atherosclerosis and increased CD36 expression in plaque macrophages from PM2.5-exposed mice. Macrophages isolated from PM2.5-exposed mice displayed increased uptake of oxidized lipids without alterations in their efflux capacity. Consistent with these finding, CD36-positive macrophages displayed a heightened capacity for oxidized lipid uptake. Deficiency of CD36 on hematopoietic cells diminished the effect of air pollution on 7-KCh accumulation, foam cell formation, and atherosclerosis. CONCLUSIONS Our results suggest a potential role for CD36-mediated abnormal accumulations of oxidized lipids, such as 7-KCh, in air pollution-induced atherosclerosis progression.
Collapse
Affiliation(s)
- Xiaoquan Rao
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
| | - Jixin Zhong
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
| | - Andrei Maiseyeu
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
| | - Bhavani Gopalakrishnan
- Department of Pharmacology, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Frederick A Villamena
- Department of Pharmacology, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Lung-Chi Chen
- The Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, USA
| | - Jack R Harkema
- Center for Integrative Toxicology and Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, Michigan, USA
| | - Qinghua Sun
- Department of Pharmacology, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA.,College of Public Health, The Ohio State University, Columbus, Ohio, USA
| | - Sanjay Rajagopalan
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
| |
Collapse
|
231
|
Huang JD, Amaral J, Lee JW, Rodriguez IR. 7-Ketocholesterol-induced inflammation signals mostly through the TLR4 receptor both in vitro and in vivo. PLoS One 2014; 9:e100985. [PMID: 25036103 PMCID: PMC4103802 DOI: 10.1371/journal.pone.0100985] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/01/2014] [Indexed: 12/23/2022] Open
Abstract
The cholesterol oxide 7-ketocholesterol (7KCh) has been implicated in numerous age-related diseases such as atherosclerosis, Alzheimer's disease, Parkinson's disease, cancer and age-related macular degeneration. It is formed by the autooxidation of cholesterol and especially cholesterol-fatty acid esters found in lipoprotein deposits. This molecule causes complex and potent inflammatory responses in vitro and in vivo. It is suspected of causing chronic inflammation in tissues exposed to oxidized lipoprotein deposits. In this study we have examined the inflammatory pathways activated by 7KCh both in cultured ARPE19 cells and in vivo using 7KCh-containing implants inserted into the anterior chamber of the rat eye. Our results indicate that 7KCh-induced inflammation is mediated mostly though the TLR4 receptor with some cross-activation of EGFR-related pathways. The majority of the cytokine inductions seem to signal via the TRIF/TRAM side of the TLR4 receptor. The MyD88/TIRAP side only significantly effects IL-1β inductions. The 7KCh-induced inflammation also seems to involve a robust ER stress response. However, this response does not seem to involve a calcium efflux-mediated UPR. Instead the ER stress response seems to be mediated by yet identified kinases activated through the TLR4 receptor. Some of the kinases identified are the RSKs which seem to mediate the cytokine inductions and the cell death pathway but do not seem to be involved in the ER stress response.
Collapse
Affiliation(s)
- Jiahn-Dar Huang
- Mechanisms of Retinal Diseases Section, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Juan Amaral
- Mechanisms of Retinal Diseases Section, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jung Wha Lee
- Mechanisms of Retinal Diseases Section, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ignacio R. Rodriguez
- Mechanisms of Retinal Diseases Section, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| |
Collapse
|
232
|
Umetani M, Ghosh P, Ishikawa T, Umetani J, Ahmed M, Mineo C, Shaul PW. The cholesterol metabolite 27-hydroxycholesterol promotes atherosclerosis via proinflammatory processes mediated by estrogen receptor alpha. Cell Metab 2014; 20:172-82. [PMID: 24954418 PMCID: PMC4098728 DOI: 10.1016/j.cmet.2014.05.013] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 02/11/2014] [Accepted: 05/05/2014] [Indexed: 01/25/2023]
Abstract
Oxysterols are cholesterol metabolites that serve multiple functions in lipid metabolism, including as liver X receptor (LXR) ligands. 27-hydroxycholesterol (27HC) is an abundant oxysterol metabolized by CYP7B1. How 27HC impacts vascular health is unknown. We show that elevations in 27HC via cyp7b1 deletion promote atherosclerosis in apoe(-/-) mice without altering lipid status; furthermore, estrogen-related atheroprotection is attenuated. In wild-type mice, leukocyte-endothelial cell adhesion is increased by 27HC via estrogen receptor (ER)-dependent processes. In monocytes/macrophages, 27HC upregulates proinflammatory genes and increases adhesion via ERα. In endothelial cells, 27HC is also proadhesive via ERα, and in contrast to estrogen, which blunts NF-κB activation, 27HC stimulates NF-κB activation via Erk1,2 and JNK-dependent IκBα degradation. Whereas 27HC administration to apoe(-/-) mice increases atherosclerosis, apoe(-/-);erα(-/-) are unaffected. Thus, 27HC promotes atherosclerosis via proinflammatory processes mediated by ERα, and it attenuates estrogen-related atheroprotection. Strategies to lower 27HC may complement approaches targeting cholesterol to prevent vascular disease.
Collapse
Affiliation(s)
- Michihisa Umetani
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Pritam Ghosh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tomonori Ishikawa
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Junko Umetani
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Mohamed Ahmed
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chieko Mineo
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
233
|
Liu F, Wang W, Xu Y, Wang Y, Chen LF, Fang Q, Yan XW. ABCG1 rs57137919G>a polymorphism is functionally associated with varying gene expression and apoptosis of macrophages. PLoS One 2014; 9:e97044. [PMID: 24972087 PMCID: PMC4074052 DOI: 10.1371/journal.pone.0097044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 04/14/2014] [Indexed: 01/16/2023] Open
Abstract
ATP-binding cassette transporter G1 (ABCG1) is a transmembrane cholesterol transporter involved in macrophage sterol homeostasis, reverse cholesterol transport (RCT), and atherosclerosis. The role of ABCG1 in atherosclerosis remains controversial, especially in animal models. Our previous study showed that single nucleotide polymorphism rs57137919 (-367G>A) in the ABCG1 promoter region was associated with reduced risk for atherosclerotic coronary artery disease (CAD). This study was designed to provide functional evidence for the role of rs57137919G>A in atherosclerosis in humans. We combined in vitro and ex vivo studies using cell lines and human monocyte-derived macrophages to investigate the functional consequences of the promoter polymorphism by observing the effects of the rs57137919A allele on promoter activity, transcription factor binding, gene expression, cholesterol efflux, and apoptosis levels. The results showed that the rs57137919A allele was significantly associated with decreased ABCG1 gene expression possibly due to the impaired ability of protein-DNA binding. ABCG1-mediated cholesterol efflux decreased by 23% with rs57137919 A/A versus the G/G genotype. Cholesterol-loaded macrophage apoptosis was induced 2-fold with the A/A genotype compared with the G/G genotype. Proapoptotic genes Bok and Bid mRNA levels were significantly increased in macrophages from the A/A genotype compared with those from the G/G genotype. These findings demonstrated that the ABCG1 promoter rs57137919G>A variant had an allele-specific effect on ABCG1 expression and was associated with an increased apoptosis in cholesterol-loaded macrophages, providing functional evidence to explain the reduced risk for atherosclerosis in subjects with the ABCG1 promoter rs57137919A allele as reported in our previous study.
Collapse
Affiliation(s)
- Fang Liu
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wei Wang
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yan Xu
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yu Wang
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lian-Feng Chen
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Quan Fang
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao-Wei Yan
- Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail:
| |
Collapse
|
234
|
Miyazaki-Anzai S, Masuda M, Demos-Davies KM, Keenan AL, Saunders SJ, Masuda R, Jablonski K, Cavasin MA, Kendrick J, Chonchol M, McKinsey TA, Levi M, Miyazaki M. Endoplasmic reticulum stress effector CCAAT/enhancer-binding protein homologous protein (CHOP) regulates chronic kidney disease-induced vascular calcification. J Am Heart Assoc 2014; 3:e000949. [PMID: 24963104 PMCID: PMC4309099 DOI: 10.1161/jaha.114.000949] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Background Cardiovascular diseases such as atherosclerosis and vascular calcification are a major cause of death in patients with chronic kidney disease (CKD). Recently, the long‐awaited results of the Study of Heart and Renal Protection trial were reported. This large randomized clinical trial found that an extensive cholesterol‐lowering therapy through the combination of simvastatin and ezetimibe significantly reduced cardiovascular diseases in a wide range of patients with CKD. However, the mechanism by which this cholesterol‐lowering therapy reduces CKD‐dependent vascular diseases remains elusive. The objective of the present study was to determine the contribution of the oxysterol‐induced pro‐apoptotic transcription factor CCAAT/enhancer‐binding protein homologous protein (CHOP) on the pathogenesis of CKD‐dependent cardiovascular diseases through endoplasmic reticulum stress signaling. Methods and Results CKD increased levels of serum oxysterols such as 7‐ketocholesterol in human patients and ApoE−/− mice. Treatment with simvastatin plus ezetimibe strongly reduced levels of serum oxysterols and attenuated CKD‐dependent atherosclerosis, vascular cell death, vascular calcification, and cardiac dysfunction. This therapy also reduced aortic endoplasmic reticulum stress induced by CKD. The short hairpin RNA‐mediated knockdown of CHOP and activating transcription factor‐4 in vascular smooth muscle cells attenuated oxysterol‐induced mineralization, osteogenic differentiation, and endoplasmic reticulum stress. In addition, CHOP deficiency protected ApoE−/− mice from CKD‐dependent vascular calcification, cardiac dysfunction, and vascular cell death. Conclusions These data reveal that the cholesterol‐lowering therapy of simvastatin plus ezetimibe attenuates CKD‐dependent vascular diseases through a reduction of oxysterol‐mediated endoplasmic reticulum stress. CHOP plays a crucial role in the pathogenesis of CKD‐dependent vascular calcification.
Collapse
Affiliation(s)
- Shinobu Miyazaki-Anzai
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Masashi Masuda
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Kimberly M Demos-Davies
- Division of Cardiology, University of Colorado Denver, Aurora, CO (K.M.D.D., M.A.C., T.A.M.K.)
| | - Audrey L Keenan
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Sommer J Saunders
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Rumiko Masuda
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Kristen Jablonski
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Maria A Cavasin
- Division of Cardiology, University of Colorado Denver, Aurora, CO (K.M.D.D., M.A.C., T.A.M.K.)
| | - Jessica Kendrick
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Michel Chonchol
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Timothy A McKinsey
- Division of Cardiology, University of Colorado Denver, Aurora, CO (K.M.D.D., M.A.C., T.A.M.K.)
| | - Moshe Levi
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.)
| | - Makoto Miyazaki
- Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO (S.M.A., M.M., A.L.K., S.J.S., R.M., K.J., J.K., M.C., M.L., M.M.) Division of Endocrinology, Diabetes and Metabolism, University of Colorado Denver, Aurora, CO (M.M.)
| |
Collapse
|
235
|
Daugvilaite V, Arfelt KN, Benned-Jensen T, Sailer AW, Rosenkilde MM. Oxysterol-EBI2 signaling in immune regulation and viral infection. Eur J Immunol 2014; 44:1904-12. [PMID: 24810762 PMCID: PMC4209795 DOI: 10.1002/eji.201444493] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/27/2014] [Accepted: 05/05/2014] [Indexed: 01/16/2023]
Abstract
The seven transmembrane G protein-coupled receptor Epstein-Barr virus (EBV) induced gene 2 (EBI2; also known as GPR183) was identified in 1993 on the basis of its substantial upregulation in EBV-infected cells. It is primarily expressed in lymphoid cells; most abundantly in B cells. EBI2 is central for the positioning of B cells within the lymphoid organs, a process that is regulated in part by a chemotactic gradient formed by the endogenous lipid agonists, and in part by a fine-tuned regulation of EBI2 cell surface expression. The most potent endogenous EBI2 agonist is 7α, 25-dihydroxyxcholesterol (7α,25-OHC), yet many structurally related oxysterols can bind to an EBI2 pocket that is defined by the upper parts of the transmembrane helices and extracellular receptor regions. EBI2 signals via Gαi, as well as via G protein-independent pathways like β-arrestin recruitment. The concerted action of these pathways leads to cell migration. By genetically interfering with its up- and downregulation, EBI2 was also recently shown to induce cell proliferation, an action that could be inhibited by small molecule antagonists. Here, we focus on the oxysterol-EBI2 axis in immune control, including its role in the EBV life cycle. We also summarize the structural and functional properties of EBI2 interaction with oxysterol agonists and small molecule antagonists and discuss EBI2 as therapeutic target for diseases of the immune system.
Collapse
Affiliation(s)
- Viktorija Daugvilaite
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | | |
Collapse
|
236
|
Tempel W, Grabovec I, MacKenzie F, Dichenko YV, Usanov SA, Gilep AA, Park HW, Strushkevich N. Structural characterization of human cholesterol 7α-hydroxylase. J Lipid Res 2014; 55:1925-32. [PMID: 24927729 DOI: 10.1194/jlr.m050765] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Hepatic conversion to bile acids is a major elimination route for cholesterol in mammals. CYP7A1 catalyzes the first and rate-limiting step in classic bile acid biosynthesis, converting cholesterol to 7α-hydroxycholesterol. To identify the structural determinants that govern the stereospecific hydroxylation of cholesterol, we solved the crystal structure of CYP7A1 in the ligand-free state. The structure-based mutation T104L in the B' helix, corresponding to the nonpolar residue of CYP7B1, was used to obtain crystals of complexes with cholest-4-en-3-one and with cholesterol oxidation product 7-ketocholesterol (7KCh). The structures reveal a motif of residues that promote cholest-4-en-3-one binding parallel to the heme, thus positioning the C7 atom for hydroxylation. Additional regions of the binding cavity (most distant from the access channel) are involved to accommodate the elongated conformation of the aliphatic side chain. Structural complex with 7KCh shows an active site rigidity and provides an explanation for its inhibitory effect. Based on our previously published data, we proposed a model of cholesterol abstraction from the membrane by CYP7A1 for metabolism. CYP7A1 structural data provide a molecular basis for understanding of the diversity of 7α-hydroxylases, on the one hand, and cholesterol-metabolizing enzymes adapted for their specific activity, on the other hand.
Collapse
Affiliation(s)
- Wolfram Tempel
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Irina Grabovec
- Institute of Bioorganic Chemistry NAS of Belarus, Minsk, 220141 Belarus
| | - Farrell MacKenzie
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | | | - Sergey A Usanov
- Institute of Bioorganic Chemistry NAS of Belarus, Minsk, 220141 Belarus
| | - Andrei A Gilep
- Institute of Bioorganic Chemistry NAS of Belarus, Minsk, 220141 Belarus
| | - Hee-Won Park
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112
| | | |
Collapse
|
237
|
Irvin MR, Zhi D, Aslibekyan S, Claas SA, Absher DM, Ordovas JM, Tiwari HK, Watkins S, Arnett DK. Genomics of post-prandial lipidomic phenotypes in the Genetics of Lipid lowering Drugs and Diet Network (GOLDN) study. PLoS One 2014; 9:e99509. [PMID: 24905834 PMCID: PMC4048279 DOI: 10.1371/journal.pone.0099509] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 05/15/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Increased postprandial lipid (PPL) response to dietary fat intake is a heritable risk factor for cardiovascular disease (CVD). Variability in postprandial lipids results from the complex interplay of dietary and genetic factors. We hypothesized that detailed lipid profiles (eg, sterols and fatty acids) may help elucidate specific genetic and dietary pathways contributing to the PPL response. METHODS AND RESULTS We used gas chromatography mass spectrometry to quantify the change in plasma concentration of 35 fatty acids and 11 sterols between fasting and 3.5 hours after the consumption of a high-fat meal (PPL challenge) among 40 participants from the GOLDN study. Correlations between sterols, fatty acids and clinical measures were calculated. Mixed linear regression was used to evaluate associations between lipidomic profiles and genomic markers including single nucleotide polymorphisms (SNPs) and methylation markers derived from the Affymetrix 6.0 array and the Illumina Methyl450 array, respectively. After the PPL challenge, fatty acids increased as well as sterols associated with cholesterol absorption, while sterols associated with cholesterol synthesis decreased. PPL saturated fatty acids strongly correlated with triglycerides, very low-density lipoprotein, and chylomicrons. Two SNPs (rs12247017 and rs12240292) in the sorbin and SH3 domain containing 1 (SORBS1) gene were associated with b-Sitosterol after correction for multiple testing (P≤4.5*10(-10)). SORBS1 has been linked to obesity and insulin signaling. No other markers reached the genome-wide significance threshold, yet several other biologically relevant loci are highlighted (eg, PRIC285, a co-activator of PPARa). CONCLUSIONS Integration of lipidomic and genomic data has the potential to identify new biomarkers of CVD risk.
Collapse
Affiliation(s)
- Marguerite R. Irvin
- Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail:
| | - Degui Zhi
- Department of Biostatistics, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Stella Aslibekyan
- Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Steven A. Claas
- Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Devin M. Absher
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, United States of America
| | - Jose M. Ordovas
- Department of Epidemiology, Atherothrombosis and Imaging, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Instituto Madrileño de Estudios Avanzados Alimentacion, Madrid, Spain
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, United States of America
| | - Hemant K. Tiwari
- Department of Biostatistics, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Steve Watkins
- Metabolon, Lipomics Division, Research Triangle Park, North Carolina, United States of America
| | - Donna K. Arnett
- Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| |
Collapse
|
238
|
Miyamoto S, Martinez GR, Medeiros MHG, Di Mascio P. Singlet molecular oxygen generated by biological hydroperoxides. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 139:24-33. [PMID: 24954800 DOI: 10.1016/j.jphotobiol.2014.03.028] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/19/2014] [Accepted: 03/27/2014] [Indexed: 11/19/2022]
Abstract
The chemistry behind the phenomenon of ultra-weak photon emission has been subject of considerable interest for decades. Great progress has been made on the understanding of the chemical generation of electronically excited states that are involved in these processes. Proposed mechanisms implicated the production of excited carbonyl species and singlet molecular oxygen in the mechanism of generation of chemiluminescence in biological system. In particular, attention has been focused on the potential generation of singlet molecular oxygen in the recombination reaction of peroxyl radicals by the Russell mechanism. In the last ten years, our group has demonstrated the generation of singlet molecular oxygen from reactions involving the decomposition of biologically relevant hydroperoxides, especially from lipid hydroperoxides in the presence of metal ions, peroxynitrite, HOCl and cytochrome c. In this review we will discuss details on the chemical aspects related to the mechanism of singlet molecular oxygen generation from different biological hydroperoxides.
Collapse
Affiliation(s)
- Sayuri Miyamoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP26077, CEP 05513-970 São Paulo, SP, Brazil.
| | - Glaucia R Martinez
- Departamento de Bioquímica e Biologia Molecular, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba-PR, Brazil
| | - Marisa H G Medeiros
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP26077, CEP 05513-970 São Paulo, SP, Brazil
| | - Paolo Di Mascio
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP26077, CEP 05513-970 São Paulo, SP, Brazil.
| |
Collapse
|
239
|
Sekiya M, Yamamuro D, Ohshiro T, Honda A, Takahashi M, Kumagai M, Sakai K, Nagashima S, Tomoda H, Igarashi M, Okazaki H, Yagyu H, Osuga JI, Ishibashi S. Absence of Nceh1 augments 25-hydroxycholesterol-induced ER stress and apoptosis in macrophages. J Lipid Res 2014; 55:2082-92. [PMID: 24891333 DOI: 10.1194/jlr.m050864] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
An excess of cholesterol and/or oxysterols induces apoptosis in macrophages, contributing to the development of advanced atherosclerotic lesions. In foam cells, these sterols are stored in esterified forms, which are hydrolyzed by two enzymes: neutral cholesterol ester hydrolase 1 (Nceh1) and hormone-sensitive lipase (Lipe). A deficiency in either enzyme leads to accelerated growth of atherosclerotic lesions in mice. However, it is poorly understood how the esterification and hydrolysis of sterols are linked to apoptosis. Remarkably, Nceh1-deficient thioglycollate-elicited peritoneal macrophages (TGEMs), but not Lipe-deficient TGEMs, were more susceptible to apoptosis induced by oxysterols, particularly 25-hydroxycholesterol (25-HC), and incubation with 25-HC caused massive accumulation of 25-HC ester in the endoplasmic reticulum (ER) due to its defective hydrolysis, thereby activating ER stress signaling such as induction of CCAAT/enhancer-binding protein-homologous protein (CHOP). These changes were nearly reversed by inhibition of ACAT1. In conclusion, deficiency of Nceh1 augments 25-HC-induced ER stress and subsequent apoptosis in TGEMs. In addition to reducing the cholesteryl ester content of foam cells, Nceh1 may protect against the pro-apoptotic effect of oxysterols and modulate the development of atherosclerosis.
Collapse
Affiliation(s)
- Motohiro Sekiya
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Daisuke Yamamuro
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Taichi Ohshiro
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Akira Honda
- Joint Research Center, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0395, Japan
| | - Manabu Takahashi
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Masayoshi Kumagai
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Kent Sakai
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Shuichi Nagashima
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Hiroshi Tomoda
- Department of Microbial Chemistry, Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo 108-8641, Japan
| | - Masaki Igarashi
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Hiroaki Okazaki
- Departments of Diabetes and Metabolic Diseases, University of Tokyo, Tokyo 113-8655, Japan
| | - Hiroaki Yagyu
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Jun-ichi Osuga
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| | - Shun Ishibashi
- Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical University, Tochigi 329-0498, Japan
| |
Collapse
|
240
|
Fu X, Huang X, Li P, Chen W, Xia M. 7-Ketocholesterol inhibits isocitrate dehydrogenase 2 expression and impairs endothelial function via microRNA-144. Free Radic Biol Med 2014; 71:1-15. [PMID: 24642088 DOI: 10.1016/j.freeradbiomed.2014.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 02/15/2014] [Accepted: 03/10/2014] [Indexed: 11/30/2022]
Abstract
Oxysterol is associated with the induction of endothelial oxidative stress and impaired endothelial function. Mitochondria play a central role in oxidative energy metabolism and the maintenance of proper redox status. The purpose of this study was to determine the effects and mechanisms of 7-ketocholesterol (7-KC) on isocitrate dehydrogenase 2 (IDH2) and its impact on endothelial function in both human aortic endothelial cells (HAECs) and C57BL/6J mice. HAECs treated with 7-KC showed significant reductions of IDH2 mRNA and protein levels and enzyme activity, leading to decreased NADPH concentration and an increased ratio of reduced-to-oxidized glutathione in the mitochondria. 7-KC induced the expression of a specific microRNA, miR-144, which in turn targets and downregulates IDH2. In silico analysis predicted that miR-144 could bind to the 3'-untranslated region of IDH2 mRNA. Overexpression of miR-144 decreased the expression of IDH2 and the levels of NADPH. A complementary finding is that a miR-144 inhibitor increased the mRNA and protein expression levels of IDH2. Furthermore, miR-144 level was elevated in HAECs in response to 7-KC. Anti-Ago1/2 immunoprecipitation coupled with a real-time polymerase chain reaction assay revealed that 7-KC increased the functional targeting of miR-144/IDH2 mRNA in HAECs. Infusion of 7-KC in vivo decreased vascular IDH2 expression and impaired vascular reactivity via miR-144. 7-KC controls miR-144 expression, which in turn decreases IDH2 expression and attenuates NO bioavailability to impair endothelial homeostasis. The newly identified 7-KC-miR-144-IDH2 pathway may contribute to atherosclerosis progression and provides new insight into 7-KC function and microRNA biology in cardiovascular disease.
Collapse
Affiliation(s)
- Xiaodong Fu
- Department of Physiology, School of Basic Science, Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Xiuwei Huang
- Guangdong Provincial Key Laboratory of Food, Nutrition, and Health, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China; Department of Nutrition, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China
| | - Ping Li
- Department of Physiology, School of Basic Science, Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Weiyu Chen
- Department of Physiology, School of Basic Science, Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Min Xia
- Guangdong Provincial Key Laboratory of Food, Nutrition, and Health, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China; Department of Nutrition, School of Public Health, Sun Yat-sen University (Northern Campus), Guangzhou, Guangdong Province, China.
| |
Collapse
|
241
|
A Comparison of the Potential Unfavorable Effects of Oxycholesterol and Oxyphytosterol in Mice: Different Effects, on Cerebral 24S-Hydroxychoelsterol and Serum Triacylglycerols Levels. Biosci Biotechnol Biochem 2014; 72:3128-33. [DOI: 10.1271/bbb.80256] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
242
|
|
243
|
Engel T, Fobker M, Buchmann J, Kannenberg F, Rust S, Nofer JR, Schürmann A, Seedorf U. 3β,5α,6β-Cholestanetriol and 25-hydroxycholesterol accumulate in ATP-binding cassette transporter G1 (ABCG1)-deficiency. Atherosclerosis 2014; 235:122-9. [PMID: 24833118 DOI: 10.1016/j.atherosclerosis.2014.04.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 04/08/2014] [Accepted: 04/17/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Oxysterols are oxidized derivatives of sterols that have cytotoxic effects and are potent regulators of diverse cellular functions. Efficient oxysterol removal by the sub-family G member 1 of the ATP-binding cassette transporters (ABCG1) is essential for cell survival and control of cellular processes. However, the specific role of ABCG1 in the transport of various oxysterol species has been not systematically investigated to date. Here, we examined the involvement of ABCG1 in the oxysterol metabolism by studying oxysterol tissue levels in a mouse model of Abcg1-deficiency. METHODS AND RESULTS Analysis of lung tissue of Abcg1(-/-) mice on a standard diet revealed that 3β,5α,6β-cholestanetriol (CT) and 25-hydroxycholesterol (HC) accumulated at more than 100-fold higher levels in comparison to wild-type mice. 24S-HC and 27-HC levels were also elevated, but were minor constituents. A radiolabeled assay employing regulable ABCG1-expressing HeLa cell lines revealed that 25-HC export to albumin was dependent on functional ABCG1 expression and could be blocked by an excess of unlabeled 25-HC or 27-HC. In this cell line, 25-HC at low doses triggered mitochondrial membrane potential, and reactive oxygen species production, which are both indirect indicators of cellular energy expenditure. CONCLUSION Our results suggest that 25-HC and CT are physiologic substrates for ABCG1. Excessive accumulation of these oxysterols may explain the increased rate of cell death and the inflammatory phenotype observed in Abcg1-deficient animals and cells.
Collapse
Affiliation(s)
- Thomas Engel
- Leibniz-Institute for Arteriosclerosis Research at The Westphalian Wilhelms-University, 48149 Muenster, Germany.
| | - Manfred Fobker
- Center for Laboratory Medicine, University Hospital Muenster, 48149 Muenster, Germany
| | - Jana Buchmann
- German Institute of Human Nutrition, Department of Experimental Diabetology, 14558 Potsdam-Rehbruecke, Germany
| | - Frank Kannenberg
- Center for Laboratory Medicine, University Hospital Muenster, 48149 Muenster, Germany
| | - Stephan Rust
- Leibniz-Institute for Arteriosclerosis Research at The Westphalian Wilhelms-University, 48149 Muenster, Germany
| | - Jerzy-Roch Nofer
- Center for Laboratory Medicine, University Hospital Muenster, 48149 Muenster, Germany
| | - Annette Schürmann
- German Institute of Human Nutrition, Department of Experimental Diabetology, 14558 Potsdam-Rehbruecke, Germany
| | - Udo Seedorf
- Leibniz-Institute for Arteriosclerosis Research at The Westphalian Wilhelms-University, 48149 Muenster, Germany
| |
Collapse
|
244
|
Leung KS, Chen X, Zhong W, Yu AC, Lee CYJ. Microbubble-mediated sonoporation amplified lipid peroxidation of Jurkat cells. Chem Phys Lipids 2014; 180:53-60. [DOI: 10.1016/j.chemphyslip.2014.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 02/12/2014] [Accepted: 02/16/2014] [Indexed: 12/21/2022]
|
245
|
Gessier F, Preuss I, Yin H, Rosenkilde MM, Laurent S, Endres R, Chen YA, Marsilje TH, Seuwen K, Nguyen DG, Sailer AW. Identification and Characterization of Small Molecule Modulators of the Epstein–Barr Virus-Induced Gene 2 (EBI2) Receptor. J Med Chem 2014; 57:3358-68. [DOI: 10.1021/jm4019355] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Hong Yin
- Genomics
Institute of the Novartis Research Foundation (GNF), San Diego, California 92121, United States
| | - Mette M. Rosenkilde
- Laboratory
for Molecular Pharmacology, Department of Neuroscience and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | | | | | - Yu A. Chen
- Genomics
Institute of the Novartis Research Foundation (GNF), San Diego, California 92121, United States
| | - Thomas H. Marsilje
- Genomics
Institute of the Novartis Research Foundation (GNF), San Diego, California 92121, United States
| | | | - Deborah G. Nguyen
- Genomics
Institute of the Novartis Research Foundation (GNF), San Diego, California 92121, United States
| | | |
Collapse
|
246
|
Matysik S, Schmitz G, Bauer S, Kiermaier J, Matysik FM. Potential of gas chromatography–atmospheric pressure chemical ionization–time-of-flight mass spectrometry for the determination of sterols in human plasma. Biochem Biophys Res Commun 2014; 446:751-5. [DOI: 10.1016/j.bbrc.2014.01.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Accepted: 01/12/2014] [Indexed: 11/26/2022]
|
247
|
Petrova NL, Shanahan CM. Neuropathy and the vascular-bone axis in diabetes: lessons from Charcot osteoarthropathy. Osteoporos Int 2014; 25:1197-207. [PMID: 24091593 DOI: 10.1007/s00198-013-2511-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/09/2013] [Indexed: 10/26/2022]
Abstract
Emerging evidence from the last two decades has shown that vascular calcification (VC) is a regulated, cell-mediated process orchestrated by vascular smooth muscle cells (VSMCs) and that this process bears many similarities to bone mineralization. While many of the mechanisms driving VSMC calcification have been well established, it remains unclear what factors in specific disease states act to promote vascular calcification and in parallel, bone loss. Diabetes is a condition most commonly associated with VC and bone abnormalities. In this review, we describe how factors associated with the diabetic milieu impact on VSMCs, focusing on the role of oxidative stress, inflammation, impairment of the advanced glycation end product (AGE)/receptor for AGE system and, importantly, diabetic neuropathy. We also explore the link between bone and VC in diabetes with a specific emphasis on the receptor activator of nuclear factor κβ ligand/osteoprotegerin system. Finally, we describe what insights can be gleaned from studying Charcot osteoarthropathy, a rare complication of diabetic neuropathy, in which the occurrence of VC is frequent and where bone lysis is extreme.
Collapse
Affiliation(s)
- N L Petrova
- Diabetic Foot Clinic, King's College Hospital, Denmark Hill, London, SE5 9RS, UK
| | | |
Collapse
|
248
|
Saito Y, Noguchi N. 7-Hydroxycholestrol as a possible biomarker of cellular lipid peroxidation: Difference between cellular and plasma lipid peroxidation. Biochem Biophys Res Commun 2014; 446:741-4. [PMID: 24380859 DOI: 10.1016/j.bbrc.2013.12.083] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 12/16/2013] [Indexed: 02/08/2023]
|
249
|
Helmschrodt C, Becker S, Thiery J, Ceglarek U. Preanalytical standardization for reactive oxygen species derived oxysterol analysis in human plasma by liquid chromatography–tandem mass spectrometry. Biochem Biophys Res Commun 2014; 446:726-30. [DOI: 10.1016/j.bbrc.2013.12.087] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 12/17/2013] [Indexed: 01/09/2023]
|
250
|
Abstract
![]()
7-Dehydrocholesterol (7-DHC) is the
most oxidizable lipid molecule
reported to date, with a propagation rate constant for free radical
peroxidation that is 200 times that of cholesterol. To better understand
the high reactivity of 7-DHC and elucidate the reaction mechanism,
we synthesized conjugated and skipped nonconjugated cholestadienols
that would give one of the two putative pentadienyl-radical intermediates
formed in 7-DHC peroxidation. The additional dienols include 6,8(9)-dienol,
5,8(14)-dienol, 6,8(14)-dienol, and the biologically important 8-dehydrocholesterol
(8-DHC; 5,8(9)-dienol). We found that all of the dienols are significantly
(at least 40 times) more reactive than cholesterol. Among them, dienols
leading to the formation of the pentadienyl radical in ring B (termed endo-B) of the sterol are more reactive than
those leading to the pentadienyl radical spanning rings B and C (termed exo-B). By comparing the oxysterol profile
formed from 7-DHC and those formed from 8-DHC and 5,8(14)-dienol,
products formed from abstraction of the hydrogen atoms at C-9 and
C-14 (H-9 or H-14 mechanism) were
clearly differentiated. When the oxidation was carried out in the
presence of the good hydrogen atom donor α-tocopherol, the oxysterol
profile of 7-DHC peroxidation differed distinctly from the profile
observed in the absence of the antioxidant and resembles more closely
the profile observed in biological systems. This study suggests that
oxidative stress and the accumulation of oxysterols should be considered
as two key factors in cholesterol biosynthesis or metabolism disorders,
where dienyl sterol intermediates are accumulated.
Collapse
Affiliation(s)
- Libin Xu
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University , Nashville, Tennessee 37235, United States
| | | |
Collapse
|