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Grooms A, Nordmann AN, Badu-Tawiah AK. Plasma-Droplet Reaction Systems: A Direct Mass Spectrometry Approach for Enhanced Characterization of Lipids at Multiple Isomer Levels. ACS MEASUREMENT SCIENCE AU 2023; 3:32-44. [PMID: 36817012 PMCID: PMC9936802 DOI: 10.1021/acsmeasuresciau.2c00051] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 06/18/2023]
Abstract
Neutral triacylglyceride (TG) lipids are critical in cellular function, signaling, and energy storage. Multiple molecular pathways control TG structure via nonselective routes making them structurally complex and analytically challenging to characterize. The presence of C=C bond positional isomers exacerbates this challenge as complete structural elucidation is not possible by conventional tandem mass spectrometric methods such as collision-induced dissociation (CID), alone. Herein, we report a custom-made coaxial contained-electrospray ionization (ESI) emitter that allows the fusion of plasma discharge with charged microdroplets during electrospray (ES). Etched capillaries were incorporated into this contained-ES emitter, facilitating the generation of reactive oxygen species (ROS) at low (3 kV) ESI voltages and allowing stable ESI ion signal to be achieved at an unprecedented high (7 kV) spray voltage. The analytical utility of inducing plasma discharge during electrospray was investigated using online ionization of neutral TGs, in situ epoxidation of unsaturation sites, and C=C bond localization via conventional CID mass spectrometry. Collisional activation of the lipid epoxide generated during the online plasma-droplet fusion experiment resulted in a novel fragmentation pattern that showed a quadruplet of diagnostic ions for confident assignment of C=C bond positions and subsequent isomer differentiation. This phenomenon enabled the identification of a novel TG lipid, composed of conjugated linoleic acid, that is isomeric with two other TG lipids naturally found in extra virgin olive oil. To validate our findings, we analyzed various standards of TG lipids, including triolein, trilinolein, and trilinolenin, and isomeric mixtures in the positive-ion mode, each of which produced the expected quadruplet diagnostic fragment ions. Further validation was obtained by analyzing standards of free fatty acids expected from the hydrolysis of the TG lipids in the negative-ion mode, together with isomeric mixtures. The chemistry governing the gas-phase fragmentation of the lipid epoxides was carefully elucidated for each TG lipid analyzed. This comprehensive shotgun lipidomic approach has the potential to impact biomedical research since it can be accomplished on readily available mass spectrometers without the need for instrument modification.
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Liu X, Jiao B, Cao W, Ma X, Xia Y, Blanksby SJ, Zhang W, Ouyang Z. Development of a Miniature Mass Spectrometry System for Point-of-Care Analysis of Lipid Isomers Based on Ozone-Induced Dissociation. Anal Chem 2022; 94:13944-13950. [PMID: 36176011 DOI: 10.1021/acs.analchem.2c03112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Disorder of lipid homeostasis is closely associated with a variety of diseases. Although mass spectrometry (MS) approaches have been well developed for the characterization of lipids, it still lacks an integrated and compact MS system that is capable of rapid and detailed lipid structural characterization and can be conveniently transferred into different laboratories. In this work, we describe a novel miniature MS system with the capability of both ozone-induced dissociation (OzID) and collision-induced dissociation (CID) for the assignment of sites of unsaturation and sn-positions in glycerolipids. A miniature ozone generator was developed, which can be operated at a relatively high pressure. By maintaining high-concentration ozone inside the linear ion trap, OzID efficiency was significantly improved for the identification of C═C locations in unsaturated lipids, with reaction times as short as 10 ms. Finally, the miniature OzID MS system was applied to the analysis of C═C locations and sn-positions of lipids from biological samples. Direct sampling and fast detection of changes in phospholipid isomers were demonstrated for the rapid discrimination of breast cancer tissue samples, showing the potential of the miniature OzID MS system for point-of-care analysis of lipid isomer biomarkers in complex samples.
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Affiliation(s)
- Xinwei Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Bin Jiao
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Wenbo Cao
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Xiaoxiao Ma
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Yu Xia
- Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Stephen J Blanksby
- Central Analytical Research Facility and School of Chemistry and Physics, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Wenpeng Zhang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
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3
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Zhang W, Jian R, Zhao J, Liu Y, Xia Y. Deep-lipidotyping by mass spectrometry: recent technical advances and applications. J Lipid Res 2022; 63:100219. [PMID: 35489417 PMCID: PMC9213770 DOI: 10.1016/j.jlr.2022.100219] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/18/2022] Open
Abstract
In-depth structural characterization of lipids is an essential component of lipidomics. There has been a rapid expansion of mass spectrometry methods that are capable of resolving lipid isomers at various structural levels over the past decade. These developments finally make deep-lipidotyping possible, which provides new means to study lipid metabolism and discover new lipid biomarkers. In this review, we discuss recent advancements in tandem mass spectrometry (MS/MS) methods for identification of complex lipids beyond the species (known headgroup information) and molecular species (known chain composition) levels. These include identification at the levels of carbon-carbon double bond (C=C) location and sn-position as well as characterization of acyl chain modifications. We also discuss the integration of isomer-resolving MS/MS methods with different lipid analysis workflows and their applications in lipidomics. The results showcase the distinct capabilities of deep-lipidotyping in untangling the metabolism of individual isomers and sensitive phenotyping by using relative fractional quantitation of the isomers.
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Affiliation(s)
- Wenpeng Zhang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, P. R. China
| | - Ruijun Jian
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biological, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Jing Zhao
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biological, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Yikun Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, P. R. China
| | - Yu Xia
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biological, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
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4
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Feng G, Hao Y, Wu L, Chen S. A visible-light activated [2 + 2] cycloaddition reaction enables pinpointing carbon-carbon double bonds in lipids. Chem Sci 2020; 11:7244-7251. [PMID: 34123010 PMCID: PMC8159383 DOI: 10.1039/d0sc01149e] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 06/20/2020] [Indexed: 12/11/2022] Open
Abstract
The precise location of C[double bond, length as m-dash]C bonds in bioactive molecules is critical for a deep understanding of the relationship between their structures and biological roles. However, the traditional ultraviolet light-based approaches exhibited great limitations. Here, we discovered a new type of visible-light activated [2 + 2] cycloaddition of carbonyl with C[double bond, length as m-dash]C bonds. We found that carbonyl in anthraquinone showed great reactivities towards C[double bond, length as m-dash]C bonds in lipids to form oxetanes under the irradiation of visible-light. Combined with tandem mass spectrometry, this site-specific dissociation of oxetane enabled precisely locating the C[double bond, length as m-dash]C bonds in various kinds of monounsaturated and polyunsaturated lipids. The proof-of-concept applicability of this new type of [2 + 2] photocycloaddition was validated in the global identification of unsaturated lipids in a complex human serum sample. 86 monounsaturated and polyunsaturated lipids were identified with definitive positions of C[double bond, length as m-dash]C bonds, including phospholipids and fatty acids even with up to 6 C[double bond, length as m-dash]C bonds. This study provides new insights into both the photocycloaddition reactions and the structural lipidomics.
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Affiliation(s)
- Guifang Feng
- Institute for Advanced Studies, Wuhan University Wuhan Hubei 430072 China
| | - Yanhong Hao
- Institute for Advanced Studies, Wuhan University Wuhan Hubei 430072 China
| | - Liang Wu
- Institute for Advanced Studies, Wuhan University Wuhan Hubei 430072 China
| | - Suming Chen
- Institute for Advanced Studies, Wuhan University Wuhan Hubei 430072 China
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5
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Comprehensive Characterization of Phospholipid Isomers in Human Platelets. JOURNAL OF ANALYSIS AND TESTING 2020. [DOI: 10.1007/s41664-020-00137-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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6
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Zhang W, Shang B, Ouyang Z, Xia Y. Enhanced Phospholipid Isomer Analysis by Online Photochemical Derivatization and RPLC-MS. Anal Chem 2020; 92:6719-6726. [PMID: 32271544 DOI: 10.1021/acs.analchem.0c00690] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Mapping the complete molecular composition of a lipidome is considered an important goal of lipidomics for unraveling pathways and mechanisms behind lipid homeostasis. Conventional dissociation methods of mass spectrometry (MS) usually cannot give detailed structural information on lipids such as locations of carbon-carbon double bonds (C═C) in acyl chains. Double-bond derivatization via the Paternò-Büchi (PB) reaction has been demonstrated as a simple and highly efficient method for identification of C═C locations of different classes of lipids when paired with tandem mass spectrometry (MS/MS). In this work, reversed-phase lipid chromatography (RPLC)-MS was coupled with an online PB reaction to achieve enhanced analysis of isomers and isobars of phospholipids. A new acetone-containing mobile phase was developed that showed good elution performance for the separation of phospholipids by C18 columns. An improved flow microreactor was developed, enabling online derivatization of phospholipid C═C in 20 s. The workflow of RPLC-PB-MS/MS was developed and optimized for identification of C═C locations in isobaric ether-linked and diacyl phospholipids, 13C isobars, and acyl chain isomers in biological lipid extracts. Separation and identification of C═C locations of cis/trans phospholipid isomers were achieved for lipid standards. The incorporation of the PB reaction into the RPLC-MS workflow enabled analysis of phospholipid isomers and isobars with high confidence, demonstrating its potential for high-throughput phospholipid identification from complex mixtures.
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Affiliation(s)
- Wenpeng Zhang
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biological, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.,Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Bing Shang
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biological, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, P. R. China
| | - Yu Xia
- MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biological, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
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7
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Nagatomo N, Yoshimoto M. High Permeability of Polyunsaturated Lipid Bilayers As Applied to Attoliter Enzyme Reactors. ACS APPLIED BIO MATERIALS 2019; 2:2453-2463. [DOI: 10.1021/acsabm.9b00165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Naoyuki Nagatomo
- Department of Applied Chemistry, Yamaguchi University, Tokiwadai 2-16-1, Ube 755-8611, Japan
| | - Makoto Yoshimoto
- Department of Applied Chemistry, Yamaguchi University, Tokiwadai 2-16-1, Ube 755-8611, Japan
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8
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Benzophenone used as the photochemical reagent for pinpointing C=C locations in unsaturated lipids through shotgun and liquid chromatography-mass spectrometry approaches. Anal Chim Acta 2018; 1028:32-44. [PMID: 29884351 DOI: 10.1016/j.aca.2018.04.046] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/17/2018] [Accepted: 04/18/2018] [Indexed: 01/08/2023]
Abstract
Unsaturated lipids exhibit different physiological significances due to the different locations of the carbon-carbon double bond (C=C). Identifying lipid isomers with mass-based methods remains challenging. Xia's group has been successfully employed Paternò-Büchi (PB) reaction, a photochemical reaction with UV irradiation, coupled with tandem mass spectrometry (MS/MS) to identify and quantify unsaturated lipids in complex mixtures. However, the existing PB reagents possess certain demerits. In this regard, a new PB reagent that is compatible with various lipidomic analysis platforms must be screened. In this study, we comprehensively evaluated the conditions of the PB reaction and screened benzophenone as a new PB reagent. Benzophenone possesses unique advantages, such as a relative high PB yield; the PB products could be readily distinguished from the reacted lipids based on the added high molecular weight (182 Da); and the benzophenone does not affect the lipids appearance interval for reversed-phase column separation. Furthermore, we optimized the reaction conditions by using benzophenone as a PB reagent and summarized the molecular formulas of the diagnostic ions according to the fragment rules. The proposed PB method has been implemented in shotgun and LC-MS lipidomics. To our best knowledge, this work is the first to report the integrated PB reaction with LC-MS lipidomics for identification of lipid isomers.
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9
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Physicochemical interactions among α-eleostearic acid-loaded liposomes applied to the development of drug delivery systems. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2017.10.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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10
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Shen W, McIntosh MK. Nutrient Regulation: Conjugated Linoleic Acid's Inflammatory and Browning Properties in Adipose Tissue. Annu Rev Nutr 2017; 36:183-210. [PMID: 27431366 DOI: 10.1146/annurev-nutr-071715-050924] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Obesity is the most widespread nutritional disease in the United States. Developing effective and safe strategies to manage excess body weight is therefore of paramount importance. One potential strategy to reduce obesity is to consume conjugated linoleic acid (CLA) supplements containing isomers cis-9, trans-11 and trans-10, cis-12, or trans-10, cis-12 alone. Proposed antiobesity mechanisms of CLA include regulation of (a) adipogenesis, (b) lipid metabolism, (c) inflammation, (d) adipocyte apoptosis, (e) browning or beiging of adipose tissue, and (f) energy metabolism. However, causality of CLA-mediated responses to body fat loss, particularly the linkage between inflammation, thermogenesis, and energy metabolism, is unclear. This review examines whether CLA's antiobesity properties are due to inflammatory signaling and considers CLA's linkage with lipogenesis, lipolysis, thermogenesis, and browning of white and brown adipose tissue. We propose a series of questions and studies to interrogate the role of the sympathetic nervous system in mediating CLA's antiobesity properties.
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Affiliation(s)
- Wan Shen
- Department of Nutrition, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402; ,
| | - Michael K McIntosh
- Department of Nutrition, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402; ,
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11
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de Sousa RS, de Moraes Nogueira AO, Marques VG, Clementin RM, de Lima VR. Effects of α-eleostearic acid on asolectin liposomes dynamics: relevance to its antioxidant activity. Bioorg Chem 2013; 51:8-15. [PMID: 24076476 DOI: 10.1016/j.bioorg.2013.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 11/27/2022]
Abstract
In this study, the effect of α-eleostearic acid (α-ESA) on the lipid peroxidation of soybean asolectin (ASO) liposomes was investigated. This effect was correlated to changes caused by the fatty acid in the membrane dynamics. The influence of α-ESA on the dynamic properties of liposomes, such as hydration, mobility and order, were followed by horizontal attenuated total reflection Fourier transform infrared spectroscopy (HATR-FTIR), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and UV-vis techniques. The α-ESA showed an in vitro antioxidant activity against the damage induced by hydroxyl radical (OH) in ASO liposomes. The analysis of HATR-FTIR frequency shifts and bandwidths and (1)H NMR spin-lattice relaxation times, related to specific lipid groups, showed that α-ESA causes an ordering effect on the polar and interfacial regions of ASO liposomes, which may restrict the OH diffusion in the membrane. The DSC enthalpy variation analysis suggested that the fatty acid promoted a disordering effect on lipid hydrophobic regions, which may facilitate interactions between the reactive specie and α-ESA. Turbidity results showed that α-ESA induces a global disordering effect on ASO liposomes, which may be attributed to a change in the lipid geometry and shape. Results of this study may allow a more complete view of α-ESA antioxidant mode of action against OH, considering its influence on the membrane dynamics.
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Affiliation(s)
- Robson Simplício de Sousa
- Research Group of Membrane Molecular Interactions, School of Chemical and Food Engineering, Post-graduation Program in Technological and Environmental Chemistry, Federal University of Rio Grande, Av. Itália, km 8, Campus Carreiros, Rio Grande-RS 96203-900, Brazil
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12
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El Roz A, Bard JM, Huvelin JM, Nazih H. The anti-proliferative and pro-apoptotic effects of the trans9, trans11 conjugated linoleic acid isomer on MCF-7 breast cancer cells are associated with LXR activation. Prostaglandins Leukot Essent Fatty Acids 2013; 88:265-72. [PMID: 23375583 DOI: 10.1016/j.plefa.2012.12.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 12/17/2012] [Accepted: 12/31/2012] [Indexed: 12/29/2022]
Abstract
Conjugated linoleic acids (CLA), naturally found in dairy products and ruminant meat, are positional and geometric isomers (trans: t or cis: c) of linoleic acid, and have been widely reported to possess anti-tumoral activity against breast cancer both in vitro and in vivo. CLA isomer t9,t11 was recently proposed as an agonist of the transcriptional factor LXR, which is known for inducing genes implicated in cholesterol efflux. In this study, the growth inhibitory effect of three CLA isomers (c9,t11-CLA, t9,t11-CLA and t10,c12-CLA) was investigated on MCF-7 breast cancer cells, as well as their effect on LXR target genes. Our results revealed that t9,t11-CLA was the most efficient isomer by decreasing MCF-7 proliferation, inhibiting migration, and inducing apoptosis after 24h of treatment. t9,t11-CLA treatment led to an increase in the mRNA levels of LXR target genes involved in cholesterol efflux (ABCG1 and ARL7), as well as an increase of HMG-CoA-reductase which is the rate-limiting step of cholesterol biosynthesis. Interestingly, confocal microscopy analysis showed that t9,t11-CLA treatment remarkably reduced the intracellular and membrane-associated cholesterol levels. LXR activation through t9,t11-CLA isomer could lead to cholesterol cell deprivation by stimulating its efflux, which results in the inhibition of cell proliferation and stimulation of apoptosis.
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Affiliation(s)
- A El Roz
- EA2160, Mer, Molécules, Santé, IUML: Institut Universitaire Mer et Littoral FR3473 CNRS, Faculty of Pharmacy, Nantes, France
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13
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Carro M, Buschiazzo J, Ríos G, Oresti G, Alberio R. Linoleic acid stimulates neutral lipid accumulation in lipid droplets of maturing bovine oocytes. Theriogenology 2013; 79:687-94. [DOI: 10.1016/j.theriogenology.2012.11.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 11/24/2012] [Accepted: 11/24/2012] [Indexed: 01/22/2023]
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Effects of conjugated linoleic acid isomers on monocyte, macrophage and foam cell phenotype in atherosclerosis. Prostaglandins Other Lipid Mediat 2012; 98:56-62. [DOI: 10.1016/j.prostaglandins.2011.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 01/24/2023]
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15
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Shinohara N, Tsuduki T, Ito J, Honma T, Kijima R, Sugawara S, Arai T, Yamasaki M, Ikezaki A, Yokoyama M, Nishiyama K, Nakagawa K, Miyazawa T, Ikeda I. Jacaric acid, a linolenic acid isomer with a conjugated triene system, has a strong antitumor effect in vitro and in vivo. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:980-8. [PMID: 22521763 DOI: 10.1016/j.bbalip.2012.04.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 03/05/2012] [Accepted: 04/02/2012] [Indexed: 10/28/2022]
Abstract
In this study, we compared the cytotoxic effects of natural conjugated linolenic acids (CLnAs) on human adenocarcinoma cells (DLD-1) in vitro, with the goal of finding CLnA isomers with strong cytotoxic effects. The antitumor effect of the CLnA with the strongest cytotoxic effect was then examined in mice. The results showed that all CLnA isomers have strong cytotoxic effects on DLD-1 cells, with jacaric acid (JA) having the strongest effect. Examination of the mechanism of cell death showed that CLnAs induce apoptosis in DLD-1 cells via lipid peroxidation. The intracellular levels of incorporated CLnAs were measured to examine the reason for differences in cytotoxic effects. These results showed that JA was taken into cells efficiently. Collectively, these results suggest that the cytotoxic effect of CLnAs is dependent on intracellular incorporation and induction of apoptosis via lipid peroxidation. JA also had a strong preventive antitumor effect in vivo in nude mice into which DLD-1 cells were transplanted. These results suggest that JA can be used as a dietary constituent for prevention of cancer.
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Affiliation(s)
- Nahoko Shinohara
- Laboratory of Food and Biomolecular Science, Graduate School of Agriculture, Tohoku University, Japan
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16
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Zhao G, Subbaiah PV, Mintzer E, Chiu SW, Jakobsson E, Scott HL. Molecular dynamic simulation study of cholesterol and conjugated double bonds in lipid bilayers. Chem Phys Lipids 2011; 164:811-8. [PMID: 21982866 DOI: 10.1016/j.chemphyslip.2011.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 09/21/2011] [Accepted: 09/23/2011] [Indexed: 01/23/2023]
Abstract
Conjugated linoleic acids (CLA) are found naturally in dairy products. Two isomers of CLA, that differ only in the location of cis and trans double bonds, are found to have distinct and different biological effects. The cis 9 trans 11 (C9T11) isomer is believed to have anti-carcinogenic effects, while the trans 10 cis 12 (T10C12) isomer is believed to be associated with anti-obesity effects. In this paper we extend earlier molecular dynamics (MD) simulations of pure CLA-phosphatidylcholine bilayers to investigate the comparative effects of cholesterol on bilayers composed of the two respective isomers. Simulations of phosphatidylcholine lipid bilayers in which the sn-2 chains contained one of the two isomers of CLA were performed in which, for each isomer, the simulated bilayers contained 10% and 30% cholesterol (Chol). From MD trajectories we calculate and compare structural properties of the bilayers, including areas per molecule, thickness of bilayers, tilt angle of cholesterols, order parameter profiles, and one and two-dimensional radial distribution function (RDF), as functions of Chol concentration. While the structural effect of cholesterol is approximately the same for both isomers, we find differences at an atomistic level in order parameter profiles and in two-dimensional radial distribution functions.
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Affiliation(s)
- Guijun Zhao
- Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
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17
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Zhao G, Subbaiah PV, Chiu SW, Jakobsson E, Scott HL. Conjugated double bonds in lipid bilayers: a molecular dynamics simulation study. Chem Phys Lipids 2011; 164:251-7. [PMID: 21320475 DOI: 10.1016/j.chemphyslip.2011.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Revised: 02/03/2011] [Accepted: 02/04/2011] [Indexed: 11/16/2022]
Abstract
Conjugated linoleic acids (CLA) are found naturally in dairy products. Two isomers of CLA, that differ only in the location of cis and trans double bonds, are found to have distinct and different biological effects. The cis 9 trans 11 (C9T11) isomer is attributed to have the anti-carcinogenic effects, while the trans 10 cis 12 (T10C12) isomer is believed to be responsible for the anti-obesity effects. Since dietary CLA are incorporated into membrane phospholipids, we have used Molecular Dynamics (MD) simulations to investigate the comparative effects of the two isomers on lipid bilayer structure. Specifically, simulations of phosphatidylcholine lipid bilayers in which the sn-2 chains contained one of the two isomers of CLA were performed. Force field parameters for the torsional potential of double bonds were obtained from ab initio calculations. From the MD trajectories we calculated and compared structural properties of the two lipid bilayers, including areas per molecule, density profiles, thickness of bilayers, tilt angle of tail chains, order parameters profiles, radial distribution function (RDF) and lateral pressure profiles. The main differences found between bilayers of the two CLA isomers, are (1) the order parameter profile for C9T11 has a dip in the middle of sn-2 chain while the profile for T10C12 has a deeper dip close to terminal of sn-2 chain, and (2) the lateral pressure profiles show differences between the two isomers. Our simulation results reveal localized physical structural differences between bilayers of the two CLA isomers that may contribute to different biological effects through differential interactions with membrane proteins or cholesterol.
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Affiliation(s)
- Guijun Zhao
- Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, Chicago, 60616, United States
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18
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Subbaiah PV, Gould IG, Lal S, Aizezi B. Incorporation profiles of conjugated linoleic acid isomers in cell membranes and their positional distribution in phospholipids. BIOCHIMICA ET BIOPHYSICA ACTA 2011; 1811:17-24. [PMID: 20920595 PMCID: PMC2997919 DOI: 10.1016/j.bbalip.2010.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 09/20/2010] [Accepted: 09/27/2010] [Indexed: 10/19/2022]
Abstract
Although the conjugated linoleic acids (CLA) have several isomer-specific biological effects including anti-carcinogenic and anti-adipogenic effects, their mechanisms of action remain unclear. To determine their potential effects on membrane structure and function, we studied the incorporation profiles of four CLA isomers (trans-10 cis-12 (A), trans-9 trans-11 (B), cis-9 trans-11 (C), and cis-9 cis-11 (D)) in CHO and HepG2 cells. All four isomers were incorporated into cellular lipids as efficiently as linoleic acid (LA), with the majority of the incorporated CLA present in membrane rafts. Of the four isomers, only CLA-A increased the cholesterol content of the raft fraction. Over 50% of the incorporated CLAs were recovered in phosphatidylcholine of CHO cells, but in HepG2 the neutral lipids contained the majority of CLA. The desaturation index (18:1/18:0 and 16:1/16:0) was reduced by CLA-A, but increased by CLA-B, the effects being apparent mostly in raft lipids. The Δ⁹ desaturase activity was inhibited by CLAs A and C. Unlike LA, which was mostly found in the sn-2 position of phospholipids, most CLAs were also incorporated significantly into the sn-1 position in both cell types. These studies show that the incorporation profiles of CLA isomers differ significantly from that of LA, and this could lead to alterations in membrane function, especially in the raft-associated proteins.
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Belda BJ, Lee Y, Vanden Heuvel JP. Conjugated linoleic acids and inflammation: isomer- and tissue-specific responses. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/clp.10.54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nakamura YK, Omaye ST. Lipophilic compound-mediated gene expression and implication for intervention in reactive oxygen species (ROS)-related diseases: mini-review. Nutrients 2010; 2:725-36. [PMID: 22254050 PMCID: PMC3257678 DOI: 10.3390/nu2070725] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 07/02/2010] [Accepted: 07/05/2010] [Indexed: 12/31/2022] Open
Abstract
In addition to exhibiting antioxidant properties, conjugated linoleic acid (CLA) and vitamin E may modulate gene expression of endogenous antioxidant enzymes. Depending on cellular microenvironments, such modulation reflects either antioxidant or prooxidant outcomes. Although epidemiological/experimental studies have indicated that CLA and vitamin E have health promoting properties, recent findings from clinical trials have been inconclusive. Discrepancies between the results found from prospective studies and recent clinical trials might be attributed to concentration-dependent cellular microenvironment alterations. We give a perspective of possible molecular mechanisms of actions of these lipophilic compounds and their implications for interventions of reactive oxygen species (ROS)-related diseases.
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Affiliation(s)
- Yukiko K Nakamura
- Department of Nutrition, University of Nevada, Reno, Nevada 89557-0208, USA.
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