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Poli G, Biasi F, Leonarduzzi G. Oxysterols in the pathogenesis of major chronic diseases. Redox Biol 2013; 1:125-30. [PMID: 24024145 PMCID: PMC3757713 DOI: 10.1016/j.redox.2012.12.001] [Citation(s) in RCA: 217] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 12/03/2012] [Indexed: 02/04/2023] Open
Abstract
Pathological accumulation of 27-carbon intermediates or end-products of cholesterol metabolism, named oxysterols, may contribute to the onset and especially to the development of major chronic diseases in which inflammation, but also oxidative damage and to a certain extent cell death, are hallmarks and primary mechanisms of progression. Indeed, certain oxysterols exercise strong pro-oxidant and pro-inflammatory effects at concentrations detectable in the lesions typical of atherosclerosis, neurodegenerative diseases, inflammatory bowel diseases, age-related macular degeneration, and other pathological conditions characterized by altered cholesterol uptake and/or metabolism.
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Key Words
- 24-OH, 24-hydroxycholesterol
- 27-OH, 27-hydroxycholesterol
- 7-K, 7-ketocholesterol
- 7α-OH, 7α-hydroxycholesterol
- 7β-OH, 7β-hydroxycholesterol
- AMD, Age-related macular degeneration
- AP-1, Activator protein-1
- Aβ, Amyloid-β
- ERK1/2, Extracellular signaling-regulated kinase 1/2
- FXR, Farnesoid X receptor
- Human chronic diseases
- IBD, Inflammatory bowel diseases
- ICAM, Intercellular adhesion molecule-1
- IL, Interleukin
- Inflammation
- JNK, c-Jun N-terminal
- LDL, Low density lipoprotein
- LXR, Liver X receptor
- MAPK, Mitogen-activated protein kinase
- MCP-1, Monocyte chemotactic protein-1
- MIP-1β, Monocyte inflammatory protein-1β
- MMP, Matrix metalloproteinase
- NF-κB, Nuclear factor-κB
- Oxidative stress
- Oxysterols
- PKC, Protein kinase C
- ROS, Reactive oxygen species
- TGFβ1, Transforming growth factor β1
- TIMP, Tissue inhibitors of metalloproteinases
- TNF-α, Tumor necrosis factor-α
- VCAM-1, Vascular cell adhesion molecule-1
- α-EPOX, 5α,6α-epoxycholesterol
- β-EPOX, 5β,6β-epoxycholesterol
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Affiliation(s)
- Giuseppe Poli
- Department of Clinical and Biological Sciences, University of Torino, 10043 Orbassano, Torino, Italy
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Trapecar M, Cencic A. Application of Gut Cell Models for Toxicological and Bioactivity Studies of Functional and Novel Foods. Foods 2012; 1:40-51. [PMID: 28239090 PMCID: PMC5302223 DOI: 10.3390/foods1010040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 11/30/2012] [Accepted: 12/04/2012] [Indexed: 12/16/2022] Open
Abstract
The concept of functional and novel foods undoubtedly bears great potential as an asset to human health. However, this very same quest for ever new bioactive ingredients calls for reliable and distinct risk assessment as they may be potentially hazardous to human health. Most of today's methodologies still rely on decades old routines of animal trials and use of tumor-derived cell lines. Since such methodologies are not in line with the actual processes in the human body and with the 3R (replacement, reduction, refinement) concept, the results are often unreliable and misleading. Therefore, in this paper we propose the utilization of available untransformed small intestinal cell lines derived from human and pig tissue of non-tumor origin and describe several available cell models of the gut that offer a functional, close resemblance with the in vivo environment.
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Affiliation(s)
- Martin Trapecar
- Department of Biochemistry and Nutrition, University of Maribor, Faculty of Medicine, Slomskov trg 15, Maribor 2000, Slovenia.
| | - Avrelija Cencic
- Department of Biochemistry and Nutrition, University of Maribor, Faculty of Medicine, Slomskov trg 15, Maribor 2000, Slovenia.
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Evidence of cell damage induced by major components of a diet-compatible mixture of oxysterols in human colon cancer CaCo-2 cell line. Biochimie 2012; 95:632-40. [PMID: 23092829 DOI: 10.1016/j.biochi.2012.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 10/15/2012] [Indexed: 01/29/2023]
Abstract
Cholesterol oxidation products, termed oxysterols, have been shown to be more reactive than unoxidized cholesterol, possessing marked pro-inflammatory and cytotoxic effects in a number of cells and tissues. Oxysterols, absorbed with the diet as products of cholesterol auto-oxidation, have recently been suggested to potentially interfere with homeostasis of the mucosal intestinal epithelium, by promoting and sustaining irreversible damage. However, the treatment of colon cancer cells with a diet-compatible mixture of oxysterols does not elicit the same responses than individual components added to the cells at the same concentrations at which they are present in the mixture. Sixty μM oxysterol mixture showed a slight pro-apoptotic effect on human colon cancer CaCo-2 cell line, evaluated in terms of caspase-3 and caspase-7 activation; conversely, 7α-hydroxycholesterol, 7β-hydroxycholesterol and 5α,6α-epoxycholesterol were identified to be able to induce a significant pro-apoptotic effect if added to cell culture singly; 7β-hydroxycholesterol had stronger action than other compounds. The enhanced production of reactive oxygen species through up-regulation of the colonic NADPH-oxidase isoform NOX1 appeared to be the key event in oxysterol-induced apoptosis in these colon cancer cells. As regards pro-inflammatory effects of oxysterols, IL-8 and MCP-1 were evaluated for their chemotactic activity. Only MCP-1 production was significantly induced by 7β-hydroxycholesterol, as well as by cholesterol and oxysterol mixture. However, oxysterol-induced inflammation appeared to be NOX1-independent, suggesting a secondary role of this enzyme in inducing inflammation in colon cancer cells. A selective cell death induced by specific oxysterols against colon cancer cells, mainly exploiting their ability to activate NOX1 in generating oxidative reactions, might represent a promising field of investigation in colorectal cancer, and might bring new insights on strategies in anticancer therapy.
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Kenny O, O'Callaghan Y, O'Connell NM, McCarthy FO, Maguire AR, O'Brien NM. Oxidized derivatives of dihydrobrassicasterol: cytotoxic and apoptotic potential in U937 and HepG2 cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:5952-5961. [PMID: 22594485 DOI: 10.1021/jf204737e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The ability of phytosterol compounds to reduce plasma serum cholesterol levels in humans is well investigated. However, phytosterols are structurally similar to cholesterol with a double bond at the C5-6 position and are therefore susceptible to oxidation. Much research has been carried out on the biological effects of cholesterol oxidation products (COPs) in vitro. In contrast, there is less known about phytosterol oxidation products (POPs). From previous studies, it is apparent that oxidized derivatives of the phytosterols, β-sitosterol and stigmasterol, are cytotoxic in vitro but are less potent than their COP counterparts. In the present study, the cytotoxic and apoptotic potential of oxidized derivatives of dihydrobrassicasterol (DHB) including 5α,6α-epoxyergostan-3β-ol (α-epoxide), 5β,6β-epoxyergostan-3β-ol (β-epoxide), ergost-5-en-7-on-3β-ol (7-keto), ergost-5-ene-3β,7β-diol (7-β-OH), and ergostane-3β,5α,6β-triol (triol) were evaluated in the U937 and HepG2 cell lines. In general, 7-keto, 7-β-OH, and triol derivatives had a significant cytotoxic impact on U937 and HepG2 cells. The oxides appear to be more toxic toward U937 cells. In line with previous findings, the POPs investigated in this study were less potent than the equivalent COPs. The results add to the body of data on the toxicity of individual POPs.
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Affiliation(s)
- Olivia Kenny
- School of Food and Nutritional Sciences, ‡Department of Chemistry, Analytical and Biological Chemistry Research Facility, and §School of Pharmacy, Analytical and Biological Chemistry Research Facility, University College Cork , Cork, Ireland
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Langerholc T, Maragkoudakis PA, Wollgast J, Gradisnik L, Cencic A. Novel and established intestinal cell line models - An indispensable tool in food science and nutrition. Trends Food Sci Technol 2011; 22:S11-S20. [PMID: 32336880 PMCID: PMC7172287 DOI: 10.1016/j.tifs.2011.03.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This review presents the applications of intestinal cell models of human and pig origin in food and nutritional sciences and highlights their potential as in vitro platforms for preclinical research. Intestinal cell models are used in studies of bioavailability, adsorption and transport in nutritional or toxicological settings, allergic effects of food components, as well as probiotics and/or host-pathogen gut interactions. In addition, this review discusses the advantages of using specialized and functional cell models over generic cancer-derived cell lines.
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Affiliation(s)
- Tomaz Langerholc
- Dep. of Microbiology, Biochemistry, Molecular Biology and Biotechnology, Faculty of Agriculture and Life Science, University of Maribor, Pivola 10, 2311 Hoce, Slovenia
| | - Petros A Maragkoudakis
- European Commission - Joint Research Centre - Institute for Health and Consumer Protection, Via Enrico Fermi 2749, 21027 Ispra (VA), Italy
| | - Jan Wollgast
- European Commission - Joint Research Centre - Institute for Health and Consumer Protection, Via Enrico Fermi 2749, 21027 Ispra (VA), Italy
| | - Lidija Gradisnik
- Dep. of Biochemistry and Nutrition, Faculty of Medicine, University of Maribor, Slomskov trg 15, 2000 Maribor, Slovenia
| | - Avrelija Cencic
- Dep. of Microbiology, Biochemistry, Molecular Biology and Biotechnology, Faculty of Agriculture and Life Science, University of Maribor, Pivola 10, 2311 Hoce, Slovenia
- Dep. of Biochemistry and Nutrition, Faculty of Medicine, University of Maribor, Slomskov trg 15, 2000 Maribor, Slovenia
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Jusakul A, Loilome W, Namwat N, Haigh WG, Kuver R, Dechakhamphu S, Sukontawarin P, Pinlaor S, Lee SP, Yongvanit P. Liver fluke-induced hepatic oxysterols stimulate DNA damage and apoptosis in cultured human cholangiocytes. Mutat Res 2011; 731:48-57. [PMID: 22044627 DOI: 10.1016/j.mrfmmm.2011.10.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 10/12/2011] [Accepted: 10/18/2011] [Indexed: 12/12/2022]
Abstract
Oxysterols are cholesterol oxidation products that are generated by enzymatic reactions through cytochrome P450 family enzymes or by non-enzymatic reactions involving reactive oxygen and nitrogen species. Oxysterols have been identified in bile in the setting of chronic inflammation, suggesting that biliary epithelial cells are chronically exposed to these compounds in certain clinical settings. We hypothesized that biliary oxysterols resulting from liver fluke infection participate in cholangiocarcinogenesis. Using gas chromatography/mass spectrometry, we identified oxysterols in livers from hamsters infected with Opisthorchis viverrini that develop cholangiocarcinoma. Five oxysterols were found: 7-keto-cholesta-3,5-diene (7KD), 3-keto-cholest-4-ene (3K4), 3-keto-cholest-7-ene (3K7), 3-keto-cholesta-4,6-diene (3KD), and cholestan-3β,5α,6β-triol (Triol). Triol and 3K4 were found at significantly higher levels in the livers of hamsters with O. viverrini-induced cholangiocarcinoma. We therefore investigated the effects of Triol and 3K4 on induction of cholangiocarcinogenesis using an in vitro human cholangiocyte culture model. Triol- and 3K4-treated cells underwent apoptosis. Western blot analysis showed significantly increased levels of Bax and decreased levels of Bcl-2 in these cells. Increased cytochrome c release from mitochondria was found following treatment with Triol and 3K4. Triol and 3K4 also induced formation of the DNA adducts 1,N(6)-etheno-2'-deoxyadenosine, 3,N(4)-etheno-2'-deoxycytidine and 8-oxo-7,8-dihydro-2'-deoxyguanosine in cholangiocytes. The data suggest that Triol and 3K4 cause DNA damage via oxidative stress. Chronic liver fluke infection increases production of the oxysterols Triol and 3K4 in the setting of chronic inflammation in the biliary system. These oxysterols induce apoptosis and DNA damage in cholangiocytes. Insufficient and impaired DNA repair of such mutated cells may enhance clonal expansion and further drive the change in cellular phenotype from normal to malignant.
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Affiliation(s)
- Apinya Jusakul
- Department of Biochemistry, Khon Kaen University, Khon Kaen, Thailand
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Jusakul A, Yongvanit P, Loilome W, Namwat N, Kuver R. Mechanisms of oxysterol-induced carcinogenesis. Lipids Health Dis 2011; 10:44. [PMID: 21388551 PMCID: PMC3061933 DOI: 10.1186/1476-511x-10-44] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 03/09/2011] [Indexed: 12/28/2022] Open
Abstract
Oxysterols are oxidation products of cholesterol that are generated by enzymatic reactions mediated by cytochrome P450 family enzymes or by non-enzymatic reactions involving reactive oxygen and nitrogen species. Oxysterols play various regulatory roles in normal cellular processes such as cholesterol homeostasis by acting as intermediates in cholesterol catabolism. Pathological effects of oxysterols have also been described, and various reports have implicated oxysterols in several disease states, including atherosclerosis, neurological disease, and cancer. Numerous studies show that oxysterols are associated with various types of cancer, including cancers of the colon, lung, skin, breast and bile ducts. The molecular mechanisms whereby oxysterols contribute to the initiation and progression of cancer are an area of active investigation. This review focuses on the current state of knowledge regarding the role of oxysterols in carcinogenesis. Mutagenicity of oxysterols has been described in both nuclear and mitochondrial DNA. Certain oxysterols such as cholesterol-epoxide and cholestanetriol have been shown to be mutagenic and genotoxic. Oxysterols possess pro-oxidative and pro-inflammatory properties that can contribute to carcinogenesis. Oxysterols can induce the production of inflammatory cytokines such as interleukin-8 and interleukin-1β. Certain oxysterols are also involved in the induction of cyclo-oxygenase-2 expression. Inflammatory effects can also be mediated through the activation of liver-X-receptor, a nuclear receptor for oxysterols. Thus, several distinct molecular mechanisms have been described showing that oxysterols contribute to the initiation and progression of cancers arising in various organ systems.
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Affiliation(s)
- Apinya Jusakul
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Khaen, Thailand
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Benesch MG, Mannock DA, McElhaney RN. Sterol chemical configuration influences the thermotropic phase behaviour of dipalmitoylphosphatidylcholine bilayers containing 5α-cholestan-3β- and 3α-ol. Chem Phys Lipids 2011; 164:62-9. [DOI: 10.1016/j.chemphyslip.2010.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/20/2010] [Accepted: 10/27/2010] [Indexed: 10/18/2022]
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Sterol chemical configuration and conformation influence the thermotropic phase behaviour of dipalmitoylphosphatidylcholine mixtures containing 5β-cholestan-3β- and -3α-ol. Chem Phys Lipids 2011; 164:70-7. [DOI: 10.1016/j.chemphyslip.2010.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Revised: 10/20/2010] [Accepted: 10/27/2010] [Indexed: 01/27/2023]
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Mascia C, Maina M, Chiarpotto E, Leonarduzzi G, Poli G, Biasi F. Proinflammatory effect of cholesterol and its oxidation products on CaCo-2 human enterocyte-like cells: effective protection by epigallocatechin-3-gallate. Free Radic Biol Med 2010; 49:2049-57. [PMID: 20923702 DOI: 10.1016/j.freeradbiomed.2010.09.033] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/24/2010] [Accepted: 09/28/2010] [Indexed: 10/19/2022]
Abstract
Cholesterol and its oxidation products, namely oxysterols, have very recently been shown to potentially interfere with homeostasis of the human digestive tract, by promoting and sustaining irreversible damage of the colonic epithelial layer. This report concerns the strong proinflammatory action that a dietary oxysterol mixture and, to a lesser extent, an identical concentration of unoxidized cholesterol exert on CaCo-2 colonic epithelial cells by up-regulating both expression and synthesis of interleukin 8. The oxysterol mixture and its most effective component, 7β-hydroxycholesterol, are also shown to markedly enhance the expression of key inflammatory and chemotactic cytokines in colonic epithelial cells, more efficiently than unoxidized cholesterol. The sterols' proinflammatory effect seems to be mediated by enhanced activation of NOX1, because it is prevented by pretreatment of the cells with DPI, a selective inhibitor of this oxidase. Importantly, NOX1 hyperactivation by the oxysterol mixture or cholesterol was fully prevented by CaCo-2 cell preincubation with epigallocatechin-3-gallate. Consistently, supplementation with this compound fully protected colonic epithelial cells against overexpression of inflammatory and chemotactic genes induced by the sterols investigated.
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Affiliation(s)
- Cinzia Mascia
- Department of Clinical and Biological Sciences, University of Turin at San Luigi Gonzaga Hospital, Turin, Italy
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