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Yutuc E, Dickson AL, Pacciarini M, Griffiths L, Baker PRS, Connell L, Öhman A, Forsgren L, Trupp M, Vilarinho S, Khalil Y, Clayton PT, Sari S, Dalgic B, Höflinger P, Schöls L, Griffiths WJ, Wang Y. Deep mining of oxysterols and cholestenoic acids in human plasma and cerebrospinal fluid: Quantification using isotope dilution mass spectrometry. Anal Chim Acta 2021; 1154:338259. [PMID: 33736801 PMCID: PMC7988461 DOI: 10.1016/j.aca.2021.338259] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 01/25/2021] [Indexed: 01/01/2023]
Abstract
Both plasma and cerebrospinal fluid (CSF) are rich in cholesterol and its metabolites. Here we describe in detail a methodology for the identification and quantification of multiple sterols including oxysterols and sterol-acids found in these fluids. The method is translatable to any laboratory with access to liquid chromatography – tandem mass spectrometry. The method exploits isotope-dilution mass spectrometry for absolute quantification of target metabolites. The method is applicable for semi-quantification of other sterols for which isotope labelled surrogates are not available and approximate quantification of partially identified sterols. Values are reported for non-esterified sterols in the absence of saponification and total sterols following saponification. In this way absolute quantification data is reported for 17 sterols in the NIST SRM 1950 plasma along with semi-quantitative data for 8 additional sterols and approximate quantification for one further sterol. In a pooled (CSF) sample used for internal quality control, absolute quantification was performed on 10 sterols, semi-quantification on 9 sterols and approximate quantification on a further three partially identified sterols. The value of the method is illustrated by confirming the sterol phenotype of a patient suffering from ACOX2 deficiency, a rare disorder of bile acid biosynthesis, and in a plasma sample from a patient suffering from cerebrotendinous xanthomatosis, where cholesterol 27-hydroxylase is deficient. Absolute quantification of oxysterols and cholestenoic acids. Methodology applicable to plasma and cerebrospinal fluid. Data generated for non-esterified and total sterols. Diastereoisomers at C-24 and C-25 separated and quantified.
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Affiliation(s)
- Eylan Yutuc
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Alison L Dickson
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Manuela Pacciarini
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Lauren Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | | | | | - Anders Öhman
- Department of Integrative Medical Biology, Umeå University, SE-901 87, Umeå, Sweden
| | - Lars Forsgren
- Department of Clinical Science, Neurosciences, Umeå University, SE-901 85, Umeå, Sweden
| | - Miles Trupp
- Department of Clinical Science, Neurosciences, Umeå University, SE-901 85, Umeå, Sweden
| | - Sílvia Vilarinho
- Departments of Internal Medicine, Section of Digestive Diseases, and of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Youssef Khalil
- Inborn Errors of Metabolism, Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
| | - Peter T Clayton
- Inborn Errors of Metabolism, Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
| | - Sinan Sari
- Department of Pediatrics, Division of Gastroenterology, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Buket Dalgic
- Department of Pediatrics, Division of Gastroenterology, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Philip Höflinger
- Department of Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Ludger Schöls
- Department of Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK.
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
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Kloudova-Spalenkova A, Ueng YF, Wei S, Kopeckova K, Peter Guengerich F, Soucek P. Plasma oxysterol levels in luminal subtype breast cancer patients are associated with clinical data. J Steroid Biochem Mol Biol 2020; 197:105566. [PMID: 31874216 PMCID: PMC7015808 DOI: 10.1016/j.jsbmb.2019.105566] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 12/11/2019] [Accepted: 12/16/2019] [Indexed: 02/06/2023]
Abstract
Oxygenated metabolites of cholesterol (oxysterols) have been previously demonstrated to contribute to progression of various cancers and to modulate resistance to breast cancer endocrine therapy in vitro. We measured prognostic roles of circulating levels of seven major oxysterols in the progression of luminal subtype breast carcinoma. Liquid chromatography coupled with tandem mass spectrometry was used for determination of levels of non-esterified 25-hydroxycholesterol, 27-hydroxycholesterol, 7α-hydroxycholesterol, 7-ketocholesterol, cholesterol-5α,6α-epoxide, cholesterol-5β,6β-epoxide, and cholestane-3β,5α,6β-triol in plasma samples collected from patients (n = 58) before surgical removal of tumors. Oxysterol levels were then associated with clinical data of patients. All oxysterols except cholesterol-5α,6α-epoxide were detected in patient plasma samples. Circulating levels of 7α-hydroxycholesterol and 27-hydroxycholesterol were significantly lower in patients with small tumors (pT1) and cholesterol-5β,6β-epoxide and cholestane-3β,5α,6β-triol were lower in patients with stage IA disease compared to larger tumors or more advanced stages. Patients with higher than median cholestane-3β,5α,6β-triol levels had significantly worse disease-free survival than patients with lower levels (p = 0.037 for all patients and p = 0.015 for subgroup treated only with tamoxifen). In conclusion, this study shows, for the first time, that circulating levels of oxysterols, especially cholestane-3β,5α,6β-triol, may have prognostic roles in patients with luminal subtype breast cancer.
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Affiliation(s)
- Alzbeta Kloudova-Spalenkova
- Department of Toxicogenomics, National Institute of Public Health, Srobarova 48, Prague 10, 10042, Czech Republic; Biomedical Centre, Faculty of Medicine Pilsen, Charles University, alej Svobody 1655/76, Pilsen, 32300, Czech Republic; Third Faculty of Medicine, Charles University, Ruska 2411/87, Prague 10, 10000, Czech Republic
| | - Yune-Fang Ueng
- National Research Institute of Chinese Medicine, Taipei, Taiwan, ROC; Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan, ROC; Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan, ROC
| | - Shouzou Wei
- Department of Medicine, Vanderbilt University Medical Center, 2200 Pierce Avenue, Nashville, TN, 37235, United States
| | - Katerina Kopeckova
- Department of Oncology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84/1, 15000, Prague 5, Czech Republic
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, 2200 Pierce Avenue, Nashville, TN, 37232-0146, United States
| | - Pavel Soucek
- Biomedical Centre, Faculty of Medicine Pilsen, Charles University, alej Svobody 1655/76, Pilsen, 32300, Czech Republic.
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Griffiths WJ, Wang Y. Oxysterols as lipid mediators: Their biosynthetic genes, enzymes and metabolites. Prostaglandins Other Lipid Mediat 2019; 147:106381. [PMID: 31698146 PMCID: PMC7081179 DOI: 10.1016/j.prostaglandins.2019.106381] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/29/2019] [Accepted: 09/09/2019] [Indexed: 02/07/2023]
Abstract
Pathways of oxysterol biosynthesis. Pathways of oxysterol metabolism. Oxysterols as bioactive molecules. Disorders of oxysterol metabolism.
There is growing evidence that oxysterols are more than simple metabolites in the pathway from cholesterol to bile acids. Recent data has shown oxysterols to be ligands to nuclear receptors and to G protein-coupled receptors, modulators of N-methyl-d-aspartate receptors and regulators of cholesterol biosynthesis. In this mini-review we will discuss the biosynthetic mechanisms for the formation of different oxysterols and the implication of disruption of these mechanisms in health and disease.
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Affiliation(s)
- William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP Wales, UK.
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP Wales, UK.
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Mutemberezi V, Buisseret B, Masquelier J, Guillemot-Legris O, Alhouayek M, Muccioli GG. Oxysterol levels and metabolism in the course of neuroinflammation: insights from in vitro and in vivo models. J Neuroinflammation 2018. [PMID: 29523207 PMCID: PMC5845224 DOI: 10.1186/s12974-018-1114-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background Oxysterols are cholesterol derivatives that have been suggested to play a role in inflammatory diseases such as obesity, atherosclerosis, or neuroinflammatory diseases. However, the effect of neuroinflammation on oxysterol levels has only been partially studied so far. Methods We used an HPLC-MS method to quantify over ten oxysterols both in in vitro and in vivo models of neuroinflammation. In the same models, we used RT-qPCR to analyze the expression of the enzymes responsible for oxysterol metabolism. Using the BV2 microglial cell line, we explored the effect of lipopolysaccharide (LPS)-induced (M1-type) and IL-4-induced (M2-type) cell activation on oxysterol levels. We also used LPS-activated co-cultures of mouse primary microglia and astrocytes. In vivo, we induced a neuroinflammation by administering LPS to mice. Finally, we used a mouse model of multiple sclerosis, namely the experimental autoimmune encephalomyelitis (EAE) model, that is characterized by demyelination and neuroinflammation. Results In vitro, we found that LPS activation induces profound alterations in oxysterol levels. Interestingly, we could discriminate between control and LPS-activated cells based on the changes in oxysterol levels both in BV2 cells and in the primary co-culture of glial cells. In vivo, the changes in oxysterol levels were less marked than in vitro. However, we found in both models increased levels of the GPR183 agonist 7α,25-dihydroxycholesterol. Furthermore, we studied in vitro the effect of 14 oxysterols on the mRNA expression of inflammatory markers in LPS-activated co-culture of microglia and astrocytes. We found that several oxysterols decreased the LPS-induced expression of pro-inflammatory markers. Conclusions These data demonstrate that inflammation profoundly affects oxysterol levels and that oxysterols can modulate glial cell activation. This further supports the interest of a large screening of oxysterol levels when studying the interplay between neuroinflammation and bioactive lipids. Electronic supplementary material The online version of this article (10.1186/s12974-018-1114-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Valentin Mutemberezi
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Av. E. Mounier, 72 (B1.72.01), 1200, Bruxelles, Belgium
| | - Baptiste Buisseret
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Av. E. Mounier, 72 (B1.72.01), 1200, Bruxelles, Belgium
| | - Julien Masquelier
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Av. E. Mounier, 72 (B1.72.01), 1200, Bruxelles, Belgium
| | - Owein Guillemot-Legris
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Av. E. Mounier, 72 (B1.72.01), 1200, Bruxelles, Belgium
| | - Mireille Alhouayek
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Av. E. Mounier, 72 (B1.72.01), 1200, Bruxelles, Belgium
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute (LDRI), Université catholique de Louvain (UCL), Av. E. Mounier, 72 (B1.72.01), 1200, Bruxelles, Belgium.
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Dias IHK, Milic I, Lip GYH, Devitt A, Polidori MC, Griffiths HR. Simvastatin reduces circulating oxysterol levels in men with hypercholesterolaemia. Redox Biol 2018; 16:139-145. [PMID: 29501047 PMCID: PMC5952874 DOI: 10.1016/j.redox.2018.02.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/13/2018] [Accepted: 02/15/2018] [Indexed: 11/17/2022] Open
Abstract
Oxysterols (OHC) are biologically active cholesterol metabolites circulating in plasma that may be formed enzymatically (e.g. 24S-OHC, 25-OHC and 27-OHC) or by autoxidative mechanisms (e.g. 7-ketocholesterol, 7β-OHC and 25-OHC). Oxysterols are more soluble than cholesterol and are reported to exert inflammatory, cytoprotective and apoptotic effects according to concentration and species. Esterified oxysterols have been analysed in people with dementia and cardiovascular diseases although there is no consistent relationship between oxysterol esters and disease. However, oxysterol esters are held in lipoprotein core and may not relate to the concentration and activity of plasma free oxysterols. Methodological limitations have challenged the analysis of free oxysterols to date. We have developed a fast, sensitive and specific quantitative LC-MS/MS, multiple reaction monitoring (MRM) method to target five oxysterols in human plasma with analyte recoveries between 72% and 82% and sensitivities between 5 and 135 pg/ml. A novel method was used to investigate the hypothesis that simvastatin may reduce the concentrations of specific plasma free oxysterols in hypercholesterolaemia. Twenty healthy male volunteers were recruited (aged 41-63 years); ten were asymptomatic with high plasma cholesterol > 6.5 mM and ten were healthy with normal plasma cholesterol (< 6.5 mM). Simvastatin (40 mg/day) was prescribed to those with hypercholesterolaemia. Plasma samples were taken from both groups at baseline and after three months. Simvastatin reduced plasma cholesterol by ~35% (p < 0.05) at the end of three months. Oxysterols generated by autoxidation (but not enzymatically) were elevated up to 45 fold in hypercholesterolaemic midlife men. Plasma oxysterols were restored to those of healthy controls after simvastatin intervention suggesting that autoxidation is either prevented by simvastatin directly or that autoxidation is less prevalent when plasma cholesterol concentrations are within the normal range.
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Affiliation(s)
- Irundika H K Dias
- Aston Research Centre for Healthy Ageing, School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK
| | - Ivana Milic
- Aston Research Centre for Healthy Ageing, School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK
| | - Gregory Y H Lip
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Andrew Devitt
- Aston Research Centre for Healthy Ageing, School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK
| | - M Cristina Polidori
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University, Duesseldorf, Germany; Ageing Clinical Research, Department Medicine II, University Hospital of Cologne, Cologne, Germany
| | - Helen R Griffiths
- Aston Research Centre for Healthy Ageing, School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK; Faculty of Health and Medical Sciences, University of Surrey, Stag Hill, Guildford GU2 7XH, UK
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Griffiths WJ, Hearn T, Crick PJ, Abdel-Khalik J, Dickson A, Yutuc E, Wang Y. Charge-tagging liquid chromatography-mass spectrometry methodology targeting oxysterol diastereoisomers. Chem Phys Lipids 2017; 207:69-80. [PMID: 28411018 PMCID: PMC5630687 DOI: 10.1016/j.chemphyslip.2017.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 04/10/2017] [Indexed: 12/14/2022]
Abstract
EADSA and LC–MS allows the differentiation of sterol diastereoisomers. 24S- and 24R-hydroxycholesterol are present in human plasma. Four diastereoisomers of 3β,7-dihydroxycholest-5-enoic acid are found in human plasma. 3β,7α- and 3β,7β-dihydroxychol-5-enoic acids are found in human plasma. 7α- and 7β- epimers give distinguishable MS3 spectra.
The introduction of a hydroxy group to the cholesterol skeleton introduces not only the possibility for positional isomers but also diastereoisomers, where two or more isomers have different configurations at one or more of the stereocentres but are not mirror images. The differentiation of diastereoisomers is important as differing isomers can have differing biochemical properties and are formed via different biochemical pathways. Separation of diasterioisomers is not always easy by chromatographic methods Here we demonstrate, by application of charge-tagging and derivatisation with the Girard P reagent, the separation and detection of biologically relevant diastereoisomers using liquid chromatography − mass spectrometry with multistage fragmentation.
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Affiliation(s)
- William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK.
| | - Thomas Hearn
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Peter J Crick
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Jonas Abdel-Khalik
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Alison Dickson
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Eylan Yutuc
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK.
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Mutemberezi V, Guillemot-Legris O, Muccioli GG. Oxysterols: From cholesterol metabolites to key mediators. Prog Lipid Res 2016; 64:152-169. [PMID: 27687912 DOI: 10.1016/j.plipres.2016.09.002] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/13/2016] [Accepted: 09/23/2016] [Indexed: 12/13/2022]
Abstract
Oxysterols are cholesterol metabolites that can be produced through enzymatic or radical processes. They constitute a large family of lipids (i.e. the oxysterome) involved in a plethora of physiological processes. They can act through GPCR (e.g. EBI2, SMO, CXCR2), nuclear receptors (LXR, ROR, ERα) and through transporters or regulatory proteins. Their physiological effects encompass cholesterol, lipid and glucose homeostasis. Additionally, they were shown to be involved in other processes such as immune regulatory functions and brain homeostasis. First studied as precursors of bile acids, they quickly emerged as interesting lipid mediators. Their levels are greatly altered in several pathologies and some oxysterols (e.g. 4β-hydroxycholesterol or 7α-hydroxycholestenone) are used as biomarkers of specific pathologies. In this review, we discuss the complex metabolism and molecular targets (including binding properties) of these bioactive lipids in human and mice. We also discuss the genetic mouse models currently available to interrogate their effects in pathophysiological settings. We also summarize the levels of oxysterols reported in two key organs in oxysterol metabolism (liver and brain), plasma and cerebrospinal fluid. Finally, we consider future opportunities and directions in the oxysterol field in order to gain a better insight and understanding of the complex oxysterol system.
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Affiliation(s)
- Valentin Mutemberezi
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium
| | - Owein Guillemot-Legris
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium
| | - Giulio G Muccioli
- Bioanalysis and Pharmacology of Bioactive Lipids Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Belgium.
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Griffiths WJ, Abdel-Khalik J, Crick PJ, Yutuc E, Wang Y. New methods for analysis of oxysterols and related compounds by LC-MS. J Steroid Biochem Mol Biol 2016; 162:4-26. [PMID: 26639636 DOI: 10.1016/j.jsbmb.2015.11.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 12/21/2022]
Abstract
Oxysterols are oxygenated forms of cholesterol or its precursors. They are formed enzymatically and via reactive oxygen species. Oxysterols are intermediates in bile acid and steroid hormone biosynthetic pathways and are also bioactive molecules in their own right, being ligands to nuclear receptors and also regulators of the processing of steroid regulatory element-binding proteins (SREBPs) to their active forms as transcription factors regulating cholesterol and fatty acid biosynthesis. Oxysterols are implicated in the pathogenesis of multiple disease states ranging from atherosclerosis and cancer to multiple sclerosis and other neurodegenerative diseases including Alzheimer's and Parkinson's disease. Analysis of oxysterols is challenging on account of their low abundance in biological systems in comparison to cholesterol, and due to the propensity of cholesterol to undergo oxidation in air to generate oxysterols with the same structures as those present endogenously. In this article we review the mass spectrometry-based methods for oxysterol analysis paying particular attention to analysis by liquid chromatography-mass spectrometry (LC-MS).
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Affiliation(s)
- William J Griffiths
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
| | - Jonas Abdel-Khalik
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Peter J Crick
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Eylan Yutuc
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Yuqin Wang
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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.
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Karuna R, Christen I, Sailer AW, Bitsch F, Zhang J. Detection of di hydroxycholesterols in human plasma using HPLC-ESI-MS/MS. Steroids 2015; 99:131-8. [PMID: 25683891 DOI: 10.1016/j.steroids.2015.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/27/2015] [Accepted: 02/02/2015] [Indexed: 11/21/2022]
Abstract
We report a straightforward sample preparation procedure and a direct liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method for the analysis of 7alpha,25-dihydroxycholesterol (7α25-OHC) and 7alpha,27-dihydroxycholesterol (7α27-OHC). By applying a slow protein precipitation approach using cold ethanol, we were able to detect and quantify 7α25-OHC and 7α27-OHC in a fast and reliable manner. The average concentrations from 20 healthy individuals were determined to be 0.21±0.05nM for 7α25-OHC and 3.4±0.1nM for 7α27-OHC. In addition, we are the first to report the average degrees of esterification (n=8) to be 73.8% and 82% for 7α25-OHC and 7α27-OHC, respectively. Using the established method, we achieved the sensitivity sufficient for detecting low abundant dihydroxylated oxysterols in healthy individuals. This result should enable extension of these studies towards a comprehensive analysis of oxysterol levels under disease conditions.
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Affiliation(s)
- Ratna Karuna
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland.
| | - Isabelle Christen
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Andreas W Sailer
- Developmental & Molecular Pathways, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Francis Bitsch
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland
| | - Juan Zhang
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Basel, Switzerland.
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Hokugo A, Saito T, Li A, Sato K, Tabata Y, Jarrahy R. Stimulation of bone regeneration following the controlled release of water-insoluble oxysterol from biodegradable hydrogel. Biomaterials 2014; 35:5565-71. [PMID: 24731715 DOI: 10.1016/j.biomaterials.2014.03.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 03/11/2014] [Indexed: 12/30/2022]
Abstract
Recently bone graft substitutes using bone morphogenetic proteins (BMPs) have been heralded as potential alternatives to traditional bone reconstruction procedures. BMP-based products, however, are associated with significant and potentially life-threatening side effects when used in the head and neck region and furthermore, are exorbitantly priced. Oxysterols, products of cholesterol oxidation, represent a class of molecules that are favorable alternatives or adjuncts to BMP therapy due to their low side effect profile and cost. In order to establish the optimal clinical utility of oxysterol, an optimal scaffold must be developed, one that allows the release of oxysterol in a sustained and efficient manner. In this study, we prepare a clinically applicable bone graft substitute engineered for the optimal release of oxysterol. We first solubilized oxysterol in water by making use of polymeric micelles using l-lactic acid oligomer (LAo) grafted gelatin. Then, the water-solubilized oxysterol was incorporated into a biodegradable hydrogel that was enzymatically degraded intracorporeally. In this manner, oxysterol could be released from the hydrogel in a degradation-driven manner. The water-solubilized oxysterol incorporated biodegradable hydrogel was implanted into rat calvarial defects and induced successful bone regeneration. The innovative significance of this study lies in the development of a bone graft substitute that couples the osteogenic activity of oxysterol with a scaffold designed for optimized oxysterol release kinetics, all of which lead to better repair of bone defects.
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Affiliation(s)
- Akishige Hokugo
- Division of Plastic and Reconstructive Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90025, USA
| | - Takashi Saito
- Department of Biomaterials, Field of Tissue Engineering, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Andrew Li
- Division of Plastic and Reconstructive Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90025, USA
| | - Keisuke Sato
- Department of Biomaterials, Field of Tissue Engineering, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Yasuhiko Tabata
- Department of Biomaterials, Field of Tissue Engineering, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Reza Jarrahy
- Division of Plastic and Reconstructive Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90025, USA.
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Chen C, Yang HC, Lee IS. Immobilizing hydroxycholesterol with apatite on titanium surfaces to induce ossification. Biomater Res 2014; 18:16. [PMID: 26331067 PMCID: PMC4552360 DOI: 10.1186/2055-7124-18-16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/05/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Immobilizing bioactive molecules and osteoconductive apatite on titanium implants have investigated direct ossification. In this study, hydroxycholesterol (HC) was immobilized with apatite on titanium through simply adsorption or sandwich-like coating. Three kinds of hydroxycholesterol were chosen to induce ossification: 20α-hydroxycholesterol (20α- HC), 22(S)-hydroxycholesterol (22(S)-HC) and 25-hydroxycholesterol (25-HC).The effects of HC/apatite coating on ossification abilities were evaluated in vitro and in vivo. RESULTS At 6 d, adsorbed apatite/25-HC and apatite/22(S)-HC coating exhibited some cytotoxicity, while the cell viability of apatite/20α-HC coating was similar as apatite coating. Immobilizing HC with apatite significantly enhanced the ALP activities compared with apatite coating. There was no significant difference in ALP value between adsorbed apatite/HC coating and sandwich-like apatite/HC/apatite coating. When compared with apatite coating, the mineral deposition improved by adsorbed HC with apatite at higher concentration in vivo. CONCLUSIONS When compared with apatite coating, immobilizing HC with apatite coating induced the ossification in vitro and in vivo.
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Affiliation(s)
- Cen Chen
- Bio-X Center, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018 China
| | - Hyeong Cheol Yang
- Department of Dental Biomaterials Science, Seoul National University, Seoul, 110-749 Korea
| | - In-Seop Lee
- Bio-X Center, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018 China ; Institute of Natural Sciences, Yonsei University, Seoul, 120-749 Korea
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