1
|
The content of carotenoids and tocochromanols in bitter, semi-sweet and sweet apricots depending on different harvest times and geographical regions. Eur Food Res Technol 2021. [DOI: 10.1007/s00217-021-03688-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
2
|
Bakkalbasi E, Meral R, Dogan IS. Bioactive Compounds, Physical and Sensory Properties of Cake Made with Walnut Press-Cake. J FOOD QUALITY 2015. [DOI: 10.1111/jfq.12169] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Emre Bakkalbasi
- Department of Food Engineering; Yüzüncü Yıl University; 65080 Van Turkey
| | - Raciye Meral
- Department of Food Engineering; Yüzüncü Yıl University; 65080 Van Turkey
| | - Ismail S. Dogan
- Department of Food Engineering; Yüzüncü Yıl University; 65080 Van Turkey
| |
Collapse
|
3
|
Mathur P, Ding Z, Saldeen T, Mehta JL. Tocopherols in the Prevention and Treatment of Atherosclerosis and Related Cardiovascular Disease. Clin Cardiol 2015; 38:570-6. [PMID: 26272221 DOI: 10.1002/clc.22422] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 01/19/2023] Open
Abstract
Oxidants/antioxidants play an important role in cellular homeostasis. The human body has endogenous molecules that work as antioxidants, such as glutathione, superoxide dismutase, peroxidases, and catalase. Exogenous substances in the diet, such as β-carotene, ascorbate, and vitamin E, are vital antioxidants. Of these, vitamin E is likely the most important antioxidant in the human diet, and many studies have been performed to elucidate its role in health and disease. Vitamin E is a family of several compounds, of which α-tocopherol is the most widely known analog. α-Tocopherol exhibits antioxidative property in vitro and inhibits oxidation of low-density lipoprotein cholesterol. In addition, α-tocopherol shows anti-inflammatory activity and modulates expression of proteins involved in the uptake, transport, and degradation of atherogenic lipids. Though α-tocopherol exhibits important antioxidant, anti-inflammatory, and antiatherogenic features in vitro, α-tocopherol supplements have failed to consistently reduce atherosclerosis-related events in human trials. The conflicting results have led to reconsideration of the importance previously given to α-tocopherol and led to interest in other members of vitamin E family, especially γ-tocopherol, which exerts a much more potent antioxidant, anti-inflammatory, and cardioprotective effect than α-tocopherol. This reconsideration has been backed by solid laboratory and clinical research. We suggest that the absence of γ-tocopherol in traditional preparations may be one reason for the lack of consistent salutary effects of vitamin E preparations in clinical trials. This review summarizes our current understanding of tocopherols as antioxidant molecules and emerging evidence of an important role of γ-tocopherol in the pathophysiology of atherosclerosis-related cardiovascular disease.
Collapse
Affiliation(s)
- Pankaj Mathur
- Department of Cardiovascular Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Zufeng Ding
- Department of Cardiovascular Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Tom Saldeen
- Department of Cardiovascular Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Jawahar L Mehta
- Department of Cardiovascular Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| |
Collapse
|
4
|
Xu Z, Harvey KA, Pavlina TM, Zaloga GP, Siddiqui RA. Tocopherol and tocotrienol homologs in parenteral lipid emulsions. EUR J LIPID SCI TECH 2014; 117:15-22. [PMID: 25685054 PMCID: PMC4315900 DOI: 10.1002/ejlt.201400182] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/17/2014] [Accepted: 07/09/2014] [Indexed: 11/09/2022]
Abstract
Parenteral lipid emulsions, which are made of oils from plant and fish sources, contain different types of tocopherols and tocotrienols (vitamin E homologs). The amount and types of vitamin E homologs in various lipid emulsions vary considerably and are not completely known. The objective of this analysis was to develop a quantitative method to determine levels of all vitamin E homologs in various lipid emulsions. An HPLC system was used to measure vitamin E homologs using a Pinnacle DB Silica normal phase column and an isocratic, n-hexane:1,4 dioxane (98:2) mobile phase. An optimized protocol was used to report vitamin E homolog concentrations in soybean oil-based (Intralipid®, Ivelip®, Lipofundin® N, Liposyn® III, and Liposyn® II), medium- and long-chain fatty acid-based (Lipofundin®, MCT and Structolipid®), olive oil-based (ClinOleic®), and fish oil-based (Omegaven®) and mixture of these oils-based (SMOFlipid®, Lipidem®) commercial parenteral lipid emulsions. Total content of all vitamin E homologs varied greatly between different emulsions, ranging from 57.9 to 383.9 µg/mL. Tocopherols (α, β, γ, δ) were the predominant vitamin E homologs for all emulsions, with tocotrienol content < 0.3%. In all of the soybean emulsions, except for Lipofundin® N, the predominant vitamin E homolog was γ-tocopherol, which ranged from 57–156 µg/mL. ClinOleic® predominantly contained α-tocopherol (32 µg/mL), whereas α-tocopherol content in Omegaven® was higher than most of the other lipid emulsions (230 µg/mL).
Collapse
Affiliation(s)
- Zhidong Xu
- Cellular Biochemistry Laboratory, Methodist Research Institute, Indiana University Health
| | - Kevin A Harvey
- Cellular Biochemistry Laboratory, Methodist Research Institute, Indiana University Health
| | | | - Gary P Zaloga
- Baxter Healthcare Corporation Deerfield, IL 60015, USA
| | - Rafat A Siddiqui
- Cellular Biochemistry Laboratory, Methodist Research Institute, Indiana University Health ; Department of Medicine, Indiana University School of Medicine Indianapolis, IN 46202, USA
| |
Collapse
|
5
|
Bakkalbaşi E, Menteş Yilmaz Ö, Poyrazoğlu ES, Artik N. Tocopherol Contents of Walnut Varieties Grown in Turkey and the Effect of Storage on Tocopherol Content. J FOOD PROCESS PRES 2012. [DOI: 10.1111/j.1745-4549.2012.00802.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Emre Bakkalbaşi
- Department of Food Engineering; Engineering and Architecture Faculty; Yüzüncü Yıl University; Zeve Campus 65080 Van Turkey
| | - Özay Menteş Yilmaz
- Department of Chemistry; Science Faculty; Ankara University; Ankara Turkey
| | | | - Nevzat Artik
- Department of Food Engineering; Engineering Faculty; Ankara University; Ankara Turkey
| |
Collapse
|
6
|
Lu J, Mitra S, Wang X, Khaidakov M, Mehta JL. Oxidative stress and lectin-like ox-LDL-receptor LOX-1 in atherogenesis and tumorigenesis. Antioxid Redox Signal 2011; 15:2301-33. [PMID: 21338316 DOI: 10.1089/ars.2010.3792] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been identified as a major receptor for oxidized low-density lipoprotein (ox-LDL) in endothelial cells, monocytes, platelets, cardiomyocytes, and vascular smooth muscle cells. Its expression is minimal under physiological conditions but can be induced under pathological conditions. The upregulation of LOX-1 by ox-LDL appears to be important for physiologic processes, such as endothelial cell proliferation, apoptosis, and endothelium remodeling. Pathophysiologic effects of ox-LDL in atherogenesis have also been firmly established, including endothelial cell dysfunction, smooth muscle cell growth and migration, monocyte transformation into macrophages, and finally platelet aggregation-seen in atherogenesis. Recent studies show a positive correlation between increased serum ox-LDL levels and an increased risk of colon, breast, and ovarian cancer. As in atherosclerosis, ox-LDL and its receptor LOX-1 activate the inflammatory pathway through nuclear factor-kappa B, leading to cell transformation. LOX-1 is important for maintaining the transformed state in developmentally diverse cancer cell lines and for tumor growth, suggesting a molecular connection between atherogenesis and tumorigenesis.
Collapse
Affiliation(s)
- Jingjun Lu
- Cardiovascular Division, VA Medical Center, University of Arkansas for Medical Sciences, Little Rock, AR 72212, USA
| | | | | | | | | |
Collapse
|
7
|
Kirmizis D, Papagianni A, Belechri AM, Memmos D. Effects of vitamin E-coated membrane dialyser on markers of oxidative stress and inflammation in patients on chronic haemodialysis. Nephrol Dial Transplant 2011; 26:2296-2301. [DOI: 10.1093/ndt/gfq715] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
|
8
|
Liu H, Zhang C, Huang K. Lanthanum chloride suppresses oxysterol-induced ECV-304 cell apoptosis via inhibition of intracellular Ca(2+) concentration elevation, oxidative stress, and activation of ERK and NF-κB signaling pathways. J Biol Inorg Chem 2011; 16:671-81. [PMID: 21359969 DOI: 10.1007/s00775-011-0766-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 02/16/2011] [Indexed: 02/05/2023]
Abstract
Experimental studies have demonstrated that oral administration of lanthanum chloride (LaCl(3)) inhibits the development of atherosclerosis, but the related mechanism has not been fully elucidated. Oxysterols are toxic to the vascular endothelial cells which are important in preventing the formation and progression of atheromatous plaque. In this study, we examined the effect of LaCl(3) on oxysterol cholestane-3β,5α,6β-triol (Triol)-induced apoptosis and the related mechanisms in ECV-304 cells, a presumptive endothelial cell line. Incubation with Triol resulted in apoptosis of ECV-304 cells, as determined by Hoechst 33342 staining, fluorescein isothiocyanate labeled annexin V/propidium iodide double staining, and the loss of mitochondrial membrane potential. Triol activated extracellular-signal-regulated kinase (ERK) and nuclear factor κB (NF-κB), and inhibition of Triol-activated ERK and NF-κB signaling by specific inhibitors attenuated apoptosis induction by Triol in ECV-304 cells. Pretreatment with LaCl(3) (1 μM) for 12 h before exposure to Triol decreased Triol-mediated apoptosis as well as activation of ERK and NF-κB. In addition, Triol induced oxidative stress in ECV-304 cells, manifested by the increase of intracellular reactive oxygen species generation and malondialdehyde level, and the reduction of the content of total protein thiols and the activity of antioxidant glutathione peroxidases; LaCl(3) pretreatment significantly reversed these effects. Finally, LaCl(3) pretreatment significantly inhibited the increases of intracellular Ca(2+) concentration induced by Triol. Our study suggests that Triol induced ECV-304 cell apoptosis, and LaCl(3) could suppress this effect probably by inhibiting intracellular Ca(2+) concentration elevation, oxidative stress, as well as activation of ERK and NF-κB signaling pathways.
Collapse
Affiliation(s)
- Hongmei Liu
- Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
| | | | | |
Collapse
|
9
|
ÖZOGUL F, ÖZOGUL Y, KULEY E. Simple Extraction and Rapid HPLC Method for Tocopherol Analysis in Marine and Fresh-water Fish Species. FOOD SCIENCE AND TECHNOLOGY RESEARCH 2011. [DOI: 10.3136/fstr.17.595] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
10
|
Hudthagosol C, Haddad EH, McCarthy K, Wang P, Oda K, Sabaté J. Pecans acutely increase plasma postprandial antioxidant capacity and catechins and decrease LDL oxidation in humans. J Nutr 2011; 141:56-62. [PMID: 21106921 DOI: 10.3945/jn.110.121269] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Bioactive constituents of pecan nuts such as γ-tocopherol and flavan-3-ol monomers show antioxidant properties in vitro, but bioavailability in humans is not known. We examined postprandial changes in plasma oxygen radical absorbance capacity (ORAC) and in concentrations of tocopherols, catechins, oxidized LDL, and malondialdehyde (MDA) in response to pecan test meals. Sixteen healthy men and women (23-44 y, BMI 22.7 ± 3.4) were randomly assigned to 3 sequences of test meals composed of whole pecans, blended pecans, or an isocaloric meal of equivalent macronutrient composition but formulated of refined ingredients in a crossover design with a 1-wk washout period between treatments. Blood was sampled at baseline and at intervals up to 24 h postingestion. Following the whole and blended pecan test meals, plasma concentrations of γ-tocopherols doubled at 8 h (P < 0.001) and hydrophilic- and lipophilic-ORAC increased 12 and 10% at 2 h, respectively. Post whole pecan consumption, oxidized LDL decreased 30, 33, and 26% at 2, 3, and 8 h, respectively (P < 0.05), and epigallocatechin-3-gallate concentrations at 1 h (mean ± SEM; 95.1 ± 30.6 nmol/L) and 2 h (116.3 ± 80.5 nmol/L) were higher than at baseline (0 h) and after the control test meal at 1 h (P < 0.05). The postprandial molar ratio of MDA:triglycerides decreased by 37, 36, and 40% at 3, 5, and 8 h, respectively (P < 0.05), only when whole and blended pecan data were pooled. These results show that bioactive constituent of pecans are absorbable and contribute to postprandial antioxidant defenses.
Collapse
Affiliation(s)
- Chatrapa Hudthagosol
- Department of Nutrition, School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA
| | | | | | | | | | | |
Collapse
|
11
|
Fluctuation of serum vitamin E (alpha-tocopherol) concentrations during exacerbation and remission phases in patients with chronic fatigue syndrome. Heart Vessels 2010; 25:319-23. [PMID: 20676841 DOI: 10.1007/s00380-009-1206-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 09/11/2009] [Indexed: 10/19/2022]
Abstract
The etiology of chronic fatigue syndrome remains unknown. Oxidative stress may be involved in its pathogenesis. Vitamin E is a major endogenous lipid-soluble antioxidative substance, and is consumed during the lipid peroxidation process. We studied a population comprising 27 patients with chronic fatigue syndrome (10 men and 17 women, 29 +/- 6 years of age) and 27 age- and sex-matched control subjects. Serum vitamin E (alpha-tocopherol) concentrations were determined and expressed as mg/g total lipids (total cholesterol and triglyceride) to evaluate oxidative stress. Serum alpha-tocopherol concentrations (mg/g lipids) were significantly (P < 0.001) lower in the patients with chronic fatigue syndrome (2.81 +/- 0.73) than in the control subjects (3.88 +/- 0.65). The patients with chronic fatigue syndrome were re-examined during a follow-up interval. After 8 +/- 2 months, 16 patients exhibited a status that warranted re-examination during remission of the symptoms at a regular visit to our hospital (Group 1), while the remaining 11 did not (Group 2). The serum alpha-tocopherol levels were significantly elevated during remission as compared with those at baseline in Group 1 (2.71 +/- 0.62 --> 3.24 +/- 0.83, P < 0.001). The levels did not significantly change after the interval in Group 2 (2.97 +/- 0.86 --> 2.85 +/- 0.73, not significant). In conclusion, serum alpha-tocopherol concentrations were significantly lower in the patients with chronic fatigue syndrome as compared with the control subjects, suggesting increased oxidative stress in the former. The low level of serum alpha-tocopherol was ameliorated during the remission phase as compared with the exacerbation phase in the patients with chronic fatigue syndrome, suggesting that increased oxidative stress may be involved in the pathogenesis of chronic fatigue syndrome and might also be directly related to the severity of the symptoms of chronic fatigue syndrome.
Collapse
|
12
|
Abstract
Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Thus, regulated inflammatory responses are essential to remain healthy and maintain homeostasis. However, inflammatory responses that fail to regulate themselves can become chronic and contribute to the perpetuation and progression of disease. Characteristics typical of chronic inflammatory responses underlying the pathophysiology of several disorders include loss of barrier function, responsiveness to a normally benign stimulus, infiltration of inflammatory cells into compartments where they are not normally found in such high numbers, and overproduction of oxidants, cytokines, chemokines, eicosanoids and matrix metalloproteinases. The levels of these mediators amplify the inflammatory response, are destructive and contribute to the clinical symptoms. Various dietary components including long chain ω-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy. These components act through a variety of mechanisms including decreasing inflammatory mediator production through effects on cell signaling and gene expression (ω-3 fatty acids, vitamin E, plant flavonoids), reducing the production of damaging oxidants (vitamin E and other antioxidants), and promoting gut barrier function and anti-inflammatory responses (prebiotics and probiotics). However, in general really strong evidence of benefit to human health through anti-inflammatory actions is lacking for most of these dietary components. Thus, further studies addressing efficacy in humans linked to studies providing greater understanding of the mechanisms of action involved are required.
Collapse
|
13
|
Liu X, Zhao J, Xu J, Zhao B, Zhang Y, Zhang S, Miao J. Protective effects of a benzoxazine derivative against oxidized LDL-induced apoptosis and the increases of integrin beta4, ROS, NF-kappaB and P53 in human umbilical vein endothelial cells. Bioorg Med Chem Lett 2009; 19:2896-900. [PMID: 19362839 DOI: 10.1016/j.bmcl.2009.03.070] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 02/27/2009] [Accepted: 03/09/2009] [Indexed: 11/29/2022]
Abstract
To investigate whether 6-amino-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine (ABO) inhibits oxidized low-density lipoprotein (oxLDL)-induced human umbilical vein endothelial cell (HUVEC) apoptosis, we treated HUVECs with oxLDL in the absence or presence of ABO. The results showed that ABO could act as an effective inhibitor of oxLDL-elicited HUVEC apoptosis by inhibiting the levels of integrin beta4, reactive oxygen species (ROS), NF-kappaB and P53, and suppressing NF-kappaB nuclear translocation.
Collapse
Affiliation(s)
- Xia Liu
- Institute of Developmental Biology, Shandong University, Jinan, China
| | | | | | | | | | | | | |
Collapse
|
14
|
Reiter E, Jiang Q, Christen S. Anti-inflammatory properties of alpha- and gamma-tocopherol. Mol Aspects Med 2007; 28:668-91. [PMID: 17316780 PMCID: PMC2613571 DOI: 10.1016/j.mam.2007.01.003] [Citation(s) in RCA: 209] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2006] [Indexed: 01/01/2023]
Abstract
Natural vitamin E consists of four different tocopherol and four different tocotrienol homologues (alpha,beta, gamma, delta) that all have antioxidant activity. However, recent data indicate that the different vitamin E homologues also have biological activity unrelated to their antioxidant activity. In this review, we discuss the anti-inflammatory properties of the two major forms of vitamin E, alpha-tocopherol (alphaT) and gamma-tocopherol (gammaT), and discuss the potential molecular mechanisms involved in these effects. While both tocopherols exhibit anti-inflammatory activity in vitro and in vivo, supplementation with mixed (gammaT-enriched) tocopherols seems to be more potent than supplementation with alphaT alone. This may explain the mostly negative outcomes of the recent large-scale interventional chronic disease prevention trials with alphaT only and thus warrants further investigation.
Collapse
Affiliation(s)
- Elke Reiter
- Institute for Infectious Diseases, University of Berne, Friedbühlstrasse 51, CH-3010 Berne, Switzerland
| | - Qing Jiang
- Interdepartmental Nutrition Program, Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907, USA
| | - Stephan Christen
- Institute for Infectious Diseases, University of Berne, Friedbühlstrasse 51, CH-3010 Berne, Switzerland
- *Corresponding author. Tel.: +41 31 632 8707, fax +41 31 632 3550, E-mail addresses: (E. Reiter), (Q. Jiang), (S. Christen)
| |
Collapse
|
15
|
Abstract
Nuclear factor (NF-kappaB)(1) is a eukaryotic transcription factor that may be activated by oxidative stress. Because of this hypothesis, the effect of vitamin E on NF-kappaB activation has been examined in many studies, using both in vivo and in vitro models. Most of these studies have observed that vitamin E inhibits the activation of NF-kappaB, with the greatest inhibition seen with the succinate form. Vitamin E may be inhibiting NF-kappaB by reducing oxidative stress or through one of its nonantioxidant functions; this is not clear at the present time. It also is not known if the inhibition of NF-kappaB is necessary for any of vitamin E's effects on gene expression and the resulting physiological effects.
Collapse
Affiliation(s)
- Howard P Glauert
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, Kentucky 40506, USA
| |
Collapse
|
16
|
Harris LK, Mann GE, Ruiz E, Mushtaq S, Leake DS. Ascorbate does not protect macrophages against apoptosis induced by oxidised low density lipoprotein. Arch Biochem Biophys 2006; 455:68-76. [PMID: 17049479 DOI: 10.1016/j.abb.2006.07.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 07/04/2006] [Accepted: 07/13/2006] [Indexed: 02/05/2023]
Abstract
Apoptosis of macrophages and smooth muscle cells is observed in atherosclerotic lesions and may play an important role in the disease progression. Oxidised low density lipoprotein (LDL) is cytotoxic and induces apoptosis in a variety of cell types. We reported previously that ascorbate protects arterial smooth muscle cells from apoptosis induced by oxidised LDL containing the peak levels of lipid hydroperoxides. We now demonstrate that macrophages undergo apoptosis when treated with this species of oxidised LDL, as detected by increased annexin V binding and DNA fragmentation. Ascorbate treatment of macrophages did not protect against the cytotoxicity of oxidised LDL, and modestly increased the levels of annexin V binding and DNA fragmentation. Oxidised LDL treatment also increased the expression of the antioxidant stress protein heme oxygenase-1 in macrophages; however, this increase was markedly attenuated by ascorbate pretreatment. Although apoptosis induced by oxidised LDL was modestly promoted by ascorbate, ascorbate apparently decreased the levels of oxidative stress in macrophages, suggesting that this pro-apoptotic effect was not mediated by a pro-oxidant mechanism, but may instead have been due to intracellular protection of the apoptotic machinery by ascorbate.
Collapse
Affiliation(s)
- Lynda K Harris
- Cell and Molecular Biology Research Division, School of Biological Sciences, The University of Reading, Whiteknights, P.O. Box 228, Reading, Berkshire RG6 6AJ, UK
| | | | | | | | | |
Collapse
|
17
|
Clarke MW, Ward NC, Wu JHY, Hodgson JM, Puddey IB, Croft KD. Supplementation with mixed tocopherols increases serum and blood cell gamma-tocopherol but does not alter biomarkers of platelet activation in subjects with type 2 diabetes. Am J Clin Nutr 2006; 83:95-102. [PMID: 16400056 DOI: 10.1093/ajcn/83.1.95] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Some studies have shown potential benefit of vitamin E on platelet function, but several clinical trials failed to show improved cardiovascular outcome with alpha-tocopherol supplementation. Gamma-tocopherol, a major dietary form of vitamin E, may have protective properties different from those of alpha-tocopherol. OBJECTIVE We compared the effects of supplementation with alpha-tocopherol (500 mg) and a gamma-tocopherol-rich compound (500 mg, containing 60% gamma-tocopherol) on serum and cellular tocopherol concentrations, urinary tocopherol metabolite excretion, and in vivo platelet activation in subjects with type 2 diabetes. DESIGN Fifty-eight subjects were randomly assigned to receive either 500 mg alpha-tocopherol/d, 500 mg mixed tocopherols/d, or matching placebo. Serum, erythrocyte, and platelet tocopherol and urinary metabolite concentrations were measured at baseline and after the 6-wk intervention. Soluble CD40 ligand, urinary 11-dehydro-thromboxane B2, serum thromboxane B2, soluble P-selectin, and von Willebrand factor were measured as biomarkers of in vivo platelet activation. RESULTS Serum alpha-tocopherol increased with both tocopherol treatments. Serum and cellular gamma-tocopherol increased 4-fold (P < 0.001) in the mixed tocopherol group, whereas red blood cell gamma-tocopherol decreased significantly after alpha-tocopherol supplementation. Excretion of alpha-carboxyethyl-hydroxychroman increased significantly after supplementation with alpha-tocopherol and mixed tocopherols. Excretion of gamma-carboxyethyl-hydroxychroman increased significantly after supplementation with mixed tocopherols and after that with alpha-tocopherol, which may reflect the displacement of gamma-tocopherol by alpha-tocopherol due to incorporation of the latter into lipoproteins in the liver. Neither treatment had any significant effect on markers of platelet activation. CONCLUSIONS Supplementation with alpha-tocopherol decreased red blood cell gamma-tocopherol, whereas mixed tocopherols increased both serum alpha-tocopherol and serum and cellular gamma-tocopherol. Changes in serum tocopherol closely reflect changes in cellular concentrations of tocopherols after supplementation.
Collapse
Affiliation(s)
- Michael W Clarke
- Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, University of Western Australia, Perth, Australia
| | | | | | | | | | | |
Collapse
|
18
|
Saldeen K, Saldeen T. Importance of tocopherols beyond α-tocopherol: evidence from animal and human studies. Nutr Res 2005. [DOI: 10.1016/j.nutres.2005.09.019] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
19
|
Deby-Dupont G, Mouithys-Mickalad A, Serteyn D, Lamy M, Deby C. Resveratrol and curcumin reduce the respiratory burst of Chlamydia-primed THP-1 cells. Biochem Biophys Res Commun 2005; 333:21-7. [PMID: 15939398 DOI: 10.1016/j.bbrc.2005.05.073] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Accepted: 05/14/2005] [Indexed: 11/26/2022]
Abstract
The intracellular bacterium Chlamydia pneumoniae is involved in the inflammation process of atherosclerosis. We previously demonstrated that C. pneumonia infected monocytes (THP-1 cells) responded to stimulation by an increased respiratory burst linked to an increased NADPH oxidase (NOX) activity. We now tested agents acting on the assembly of the NOX subunits or on protein kinase C, a trigger of NOX activity. Apocynin, resveratrol, rutin, quercetin, curcumin, and tocopherols were tested. The cells were pre-incubated with Chlamydia and the agent for 19 h, and then stimulated with phorbol myristate acetate. The NOX activity was monitored by measuring the hydrogen peroxide production. Resveratrol and curcumin (10(-4)-10(-6) M) were better inhibitors than apocynin. alpha-Tocopherol was inactive, and gamma-tocopherol inhibitor at 10(-4) M only. Quercetin was inactive, and rutin a moderate but significant inhibitor. The inhibition by resveratrol was increased by 10(-6) M rutin or quercetin. Resveratrol and curcumin thus appeared to be interesting for atherosclerosis treatment.
Collapse
Affiliation(s)
- Ginette Deby-Dupont
- Center for Oxygen, Research and Development (CORD), Institut de Chimie, B6a, University of Liège, Sart Tilman, Belgium
| | | | | | | | | |
Collapse
|
20
|
Gao X, Bermudez OI, Tucker KL. Plasma C-Reactive Protein and Homocysteine Concentrations Are Related to Frequent Fruit and Vegetable Intake in Hispanic and Non-Hispanic White Elders. J Nutr 2004. [DOI: 10.1093/jn/134.4.913 [doi]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Xiang Gao
- The Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Odilia I. Bermudez
- The Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Katherine L. Tucker
- The Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| |
Collapse
|
21
|
|
22
|
Chen J, Li D, Zhang X, Mehta JL. Tumor necrosis factor-alpha-induced apoptosis of human coronary artery endothelial cells: modulation by the peroxisome proliferator-activated receptor-gamma ligand pioglitazone. J Cardiovasc Pharmacol Ther 2004; 9:35-41. [PMID: 15094967 DOI: 10.1177/107424840400900i106] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The cytokine tumor necrosis factor-alpha (TNF-alpha) plays an important role in endothelial injury, which is associated with the release of reactive oxygen species and the induction of apoptosis. We report on our study of TNF-alpha-induced apoptosis in human coronary artery endothelial cells and its modulation by the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligand pioglitazone. Treatment of cells with TNF-alpha (40 ng/mL) resulted in apoptosis as measured by DNA laddering and caspase-3 activation. TNF-alpha treatment decreased the expression of antiapoptotic protein Bcl-2 (P <.05 vs control), but not the expression of Fas or FLIP, in human coronary artery endothelial cells. Treatment of cells with TNF-alpha also enhanced lipid peroxidation (P <.01 vs control). Pretreatment of cells with the PPAR-gamma ligand pioglitazone blocked TNF-alpha-mediated apoptosis, caspase-3 activation, expression of Bcl-2, and lipid peroxidation (P <.01 vs TNF-alpha alone). These results indicate that TNF-alpha induces oxidative stress in human coronary artery endothelial cells, resulting in apoptosis through a reduction in Bcl-2 expression and the subsequent activation of caspase-3. The PPAR-gamma ligand pioglitazone modulates lipid peroxidation, alters Bcl-2 expression and caspase-3 activation, and finally reduces apoptosis. The antioxidant and antiapoptotic effects of pioglitazone may be the mechanism by which this agent reduces endothelial injury.
Collapse
Affiliation(s)
- Jiawei Chen
- Department of Internal Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205-7199, USA
| | | | | | | |
Collapse
|
23
|
Wagner KH, Kamal-Eldin A, Elmadfa I. Gamma-tocopherol--an underestimated vitamin? ANNALS OF NUTRITION AND METABOLISM 2004; 48:169-88. [PMID: 15256801 DOI: 10.1159/000079555] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The main research activities of the last decades on tocopherols were mainly focused on alpha-tocopherol, in particular when considering the biological activities. However, recent studies have increased the knowledge on gamma-tocopherol, which is the major form of vitamin E in the diet in the USA, but not in Europe. gamma-Tocopherol provides different antioxidant activities in food and in-vitro studies and showed higher activity in trapping lipophilic electrophiles and reactive nitrogen and oxygen species. The lower plasma levels of gamma- compared to alpha-tocopherol might be discussed in the light of different bioavailability, but also in a potential transformation from gamma- into alpha-tocopherol. From the metabolism end product, only that of gamma-tocopherol (2,7,8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman), but not that of alpha-tocopherol, was identified to provide natriuretic activity. Studies also indicate that only the gamma-tocopherol plasma level served as biomarker for cancer and cardiovascular risk. Therefore, this paper provides a comprehensive review on gamma-tocopherol with emphasis on its chemistry, biosynthesis, occurrence in food, different intake linking to different plasma levels in USA and Europe, absorption and metabolism, biological activities, and possible role in human health.
Collapse
Affiliation(s)
- Karl-Heinz Wagner
- Institute of Nutritional Sciences, University of Vienna, Vienna, Austria.
| | | | | |
Collapse
|
24
|
Gao X, Bermudez OI, Tucker KL. Plasma C-reactive protein and homocysteine concentrations are related to frequent fruit and vegetable intake in Hispanic and non-Hispanic white elders. J Nutr 2004; 134:913-8. [PMID: 15051846 DOI: 10.1093/jn/134.4.913] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Elevated C-reactive protein (CRP) and plasma total homocysteine (Hcy) were recently identified as risk factors for cardiovascular disease. However, few studies have related fruit and vegetable consumption to these markers of inflammation and B vitamin deficiency, particularly in the Hispanic population. We examined the relation of fruit and vegetable intake with plasma CRP and Hcy concentrations in a cross-sectional study. Subjects were 445 Hispanic elders and 154 neighborhood-based non-Hispanic white elders living in Massachusetts. Diet was assessed with a FFQ designed for this population. There were significant inverse dose-response associations between fruit and vegetable intake and plasma CRP (P for trend = 0.010) and Hcy (P for trend = 0.033) concentrations, after adjustment for potential confounders. The prevalence of high plasma CRP (> 10 mg/L), and high Hcy (>10.4 micromol/L for women and >11.4 micromol/L for men), was significantly greater among subjects in the lowest quartile of fruit and vegetable consumption relative to those in the highest quartile, 17.9 vs. 9.1% and 58.7 vs. 44.4%, respectively. With each additional serving of fruit and vegetable intake, adjusted odd ratios for high plasma CRP and Hcy were 0.79 (95% CI: 0.65 to 0.97) and 0.83 (95% CI: 0.72 to 0.96), respectively. Greater frequency of fruit and vegetable intake was associated with significantly lower plasma CRP and Hcy concentrations. Because both of these metabolites are known risk factors for CVD, these findings contribute to the evidence that a higher intake of fruit and vegetables may reduce the risk of CVD.
Collapse
Affiliation(s)
- Xiang Gao
- The Jean Mayer U S Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA
| | | | | |
Collapse
|
25
|
Sánchez-Moreno C, Dorfman SE, Lichtenstein AH, Martín A. Dietary fat type affects vitamins C and E and biomarkers of oxidative status in peripheral and brain tissues of golden Syrian hamsters. J Nutr 2004; 134:655-60. [PMID: 14988463 DOI: 10.1093/jn/134.3.655] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Oxidative stress is an important trigger in the complex chain of events leading to neurodegenerative diseases. On the other hand, dietary fatty acids play an essential role in brain function. The objectives of this study were to assess the effect of dietary fat type on vitamin C and vitamin E (alpha-and gamma-tocopherol) concentrations in peripheral and brain tissues and its effect on 8-epiPGF(2)alpha (F(2)-isoprostanes). Male Golden Syrian hamsters (n = 120, 8 wk old) were fed diets enriched in butter, hydrogenated fat (margarine), and canola and soybean oils. After 12 wk, hamsters were deprived of food, anesthetized with isoflurane, and killed via terminal exsanguination. Analyses of vitamins C, E, and 8-epiPGF(2)alpha were performed in peripheral tissues and brain. Hamsters consuming the margarine-enriched diet had lower (P < 0.05) vitamin C and alpha-tocopherol concentrations in liver, plasma, and brain, and higher (P < 0.02) plasma 8-epiPGF(2)alpha than groups fed the butter, and the canola and soybean oil diets. Liver and plasma gamma-tocopherol concentration was higher (P < 0.001) among the groups fed the soybean- and margarine-enriched diets compared with the other groups. alpha-Tocopherol was higher (P < 0.05) and 8-epiPGF(2)alpha lower (P < 0.01) among the groups fed the canola and soybean oil diets compared with the other groups. Across the groups, an inverse correlation between plasma levels of vitamin C and 8-epiPGF(2)alpha (r = -0.37, P = 0.03) and a positive correlation between plasma levels of vitamin C and alpha-tocopherol were observed (r = 0.341, P = 0.003). Hamsters fed the butter-enriched diet had a higher (P < 0.03) plasma uric acid concentration than the other groups. The results of this study provide new evidence concerning the effect of dietary fat on antioxidant status, which is important for the maintenance of good health.
Collapse
Affiliation(s)
- Concepción Sánchez-Moreno
- Nutrition and Neurocognition Laboratory, Cardiovascular Nutrition Research Laboratory, Jean Mayer U.S. Department of Agriculture-Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA
| | | | | | | |
Collapse
|
26
|
Abstract
Apoptosis-inducing factor (AIF), which exerts its effect via a caspase-independent pathway, has been suggested to be a mediator of cell injury. We have recently identified the expression of AIF in human coronary artery endothelial cells (HCAECs). The present study was designed to determine the pathophysiological role of AIF in oxidized low-density lipoprotein (ox-LDL)-induced apoptosis of HCAECs. The cells were cultured and treated with ox-LDL (40 microg/ml) for 24 h. Ox-LDL increased AIF expression, caused apoptosis of HCAECs (determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining and large-scale DNA fragmentation), and induced translocation of AIF from the cytoplasm to the nucleus (fluorescence immunocytochemistry). Pretreatment of HCAECs with a caspase inhibitor (ZVAD-fmk) did not influence AIF-mediated apoptosis in response to ox-LDL. We developed a specific antisense oligonucleotide targeted to the 5'-TCG CCG AAA TGT TCC GGT GTG GA-3' portion of the human AIF mRNA sequence (AIF-AS) to bind a complementary sequence overlapping the translational start site. Pretreatment of cells with the AIF-AS for 24 h resulted in suppression of ox-LDL-upregulated AIF protein, as measured by immunoblot analysis. AIF-AS also reduced apoptosis and AIF translocation (P < 0.01 vs. ox-LDL alone). Next, we constructed a recombinant AIF plasmid by inserting whole-length AIF cDNA into the expression vector pcDNA3.1 with a cytomegalovirus promoter. HCAECs transfected with plasmid showed a two- to fourfold increase in AIF expression, extensive apoptosis, and translocation of AIF from the cytoplasm to the nucleus. These results from two approaches indicate that AIF plays an important role in ox-LDL-induced endothelial injury.
Collapse
Affiliation(s)
- Wenguang Zhang
- Div. of Cardiovascular Medicine, Univ. of Arkansas for Medical Sciences, 4301 W. Markham St., No. 532, Little Rock, AR 72205, USA
| | | | | |
Collapse
|
27
|
Hammer S, Sauer B, Spika I, Schraut C, Kleuser B, Schäfer-Korting M. Glucocorticoids mediate differential anti-apoptotic effects in human fibroblasts and keratinocytes via sphingosine-1-phosphate formation. J Cell Biochem 2004; 91:840-51. [PMID: 14991774 DOI: 10.1002/jcb.10766] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Glucocorticoids are potent anti-inflammatory and immunomodulatory drugs which also induce growth inhibition in a variety of cell types. For this reason long-term treatment of inflammatory skin diseases may result in irreversible skin atrophy. To elucidate whether the antiproliferative action of glucocorticoids in fibroblasts is accompanied by induction of apoptosis we investigated the influence of dexamethasone (DEX) on both parameters. Interestingly, we revealed that growth inhibitory concentrations of this glucocorticoid did not induce fibroblast apoptosis. Moreover, DEX protected these cells from apoptosis induced by tumor necrosis factor alpha (TNFalpha)/actinomycin, UV-irradiation, and cell permeable ceramides. These findings are in contrast to the lack of anti-apoptotic effects detected in keratinocytes. Although DEX inhibited TNFalpha mediated nuclear factor-kappa (NF-kappaB) activity in fibroblasts, this mechanism was not involved in its cytoprotection as it was verified by specific NF-kappaB inhibitors. Therefore, we looked for alternative intracellular mediators. Coincubation of fibroblasts with the sphingosine kinase inhibitor N,N-dimethylsphingosine, which blocks formation of the sphingolipid degradation product sphingosine-1-phosphate (S1P), abrogated the protective glucocorticoid effect almost completely. As preincubation with S1P reduced the number of apoptotic cells after stimulation with TNFalpha/actinomycin and moreover DEX increased the intracellular S1P content a role of this sphingolipid in the cytoprotection by DEX is suggested.
Collapse
Affiliation(s)
- S Hammer
- Institut für Pharmazie, Abteilung für Pharmakologie und Toxikologie, Freie Universität Berlin, Berlin, Germany
| | | | | | | | | | | |
Collapse
|
28
|
Chen J, Mehta JL, Haider N, Zhang X, Narula J, Li D. Role of caspases in Ox-LDL-induced apoptotic cascade in human coronary artery endothelial cells. Circ Res 2003; 94:370-6. [PMID: 14684629 DOI: 10.1161/01.res.0000113782.07824.be] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Oxidized low-density lipoprotein (ox-LDL) induces apoptosis in endothelial cells. However, steps leading to ox-LDL-induced apoptosis remain unclear. We examined the role of ox-LDL and its newly described receptor LOX-1 in the expression of intracellular pro- and antiapoptotic proteins and caspase pathways in human coronary artery endothelial cells (HCAECs). Cells were cultured and treated with different concentrations (10 to 80 microg/mL) of ox-LDL for different times (2 to 24 hours). Ox-LDL induced apoptosis in HCAECs in a concentration- and time-dependent manner. Ox-LDL also activated caspase-9 and caspase-3, but not caspase-8. After ox-LDL treatment, there was a significant release of activators of caspase-9, including cytochrome c and Smac from mitochondria to cytoplasmic compartment, and their release was not affected by treatment of cells with inhibitors of either caspase-8 or caspase-9. Ox-LDL also decreased expression of antiapoptotic proteins Bcl-2 and c-IAP (inhibitory apoptotic protein)-1, which are involved in the release of cytochrome c and Smac and activation of caspase-9, in a concentration- and time-dependent manner. On the other hand, ox-LDL did not change the expression of Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (FLIP) and proapoptotic protein Fas, which are required for the activation of caspase-8. Further, ox-LDL did not cause the truncation of Bid, which implies the activation of caspase-8. In other experiments, pretreatment of HCAECs with the caspase-9 inhibitor z-LEHD-fmk, but not the caspase-8 inhibitor z-IETD-fmk, blocked ox-LDL-induced activation of caspase-3 and apoptosis. As expected, pretreatment with the caspase-3 inhibitor DEVD-CHO inhibited ox-LDL-induced activation of caspase-3 and resultant apoptosis. The proapoptotic effects of ox-LDL were mediated by its receptor LOX-1, because pretreatment of HCAECs with antisense-LOX-1, but not sense-LOX-1, blocked these effects of ox-LDL. These findings suggest that ox-LDL through its receptor LOX-1 decreases the expression of antiapoptotic proteins Bcl-2 and c-IAP-1. This is followed by activation of apoptotic signaling pathway, involving release of cytochrome c and Smac and activation of caspase-9 and then caspase-3.
Collapse
Affiliation(s)
- Jiawei Chen
- Department of Internal Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR 72205, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Campbell S, Stone W, Whaley S, Krishnan K. Development of gamma (gamma)-tocopherol as a colorectal cancer chemopreventive agent. Crit Rev Oncol Hematol 2003; 47:249-59. [PMID: 12962899 DOI: 10.1016/s1040-8428(03)00042-8] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Nutritional factors play an important role in the prevention and promotion of colorectal cancer. Vitamin E is a generic term that describes a group of lipid-soluble chain-breaking antioxidants that includes tocopherols and tocotrienols. Vitamin E occurs in nature as eight structurally related forms that include four tocopherols and four tocotrienols. Vitamin E is a potent membrane-soluble antioxidant. Antioxidants like vitamin E (tocopherols) may prevent colon cancer through several different cellular and molecular mechanisms. Vitamin E in the American diet is primarily available in plant-oil rich foods such as vegetable oils, seeds and nuts and these foods vary widely in their content of alpha-tocopherol and gamma-tocopherol. Vitamin E may help prevent colon cancer by decreasing the formation of mutagens arising from the oxidation of fecal lipids, by decreasing oxidative stress in the epithelial cells of the colon and by molecular mechanisms that influence cell death, cell cycle and transcriptional events. Most epidemiological, experimental and clinical studies have evaluated the alpha-isoform and not the gamma-isoform of vitamin E. Recent epidemiological, experimental and mechanistic evidence suggests that gamma-tocopherol may be a more potent cancer chemopreventive agent than alpha-tocopherol. The differences in chemical reactivity, metabolism and biological activity may contribute to these differences in the effects of gamma-tocopherol when compared with alpha-tocopherol. The rationale supporting the development of gamma-tocopherol as a colorectal cancer preventive agent is reviewed here.
Collapse
Affiliation(s)
- Sharon Campbell
- Division of Hematology-Oncology, Department of Internal Medicine, James H. Quillen College of Medicine, East Tennessee State University, Box 70622, Johnson City, TN 37614, USA
| | | | | | | |
Collapse
|
30
|
Uemura M, Manabe H, Yoshida N, Fujita N, Ochiai J, Matsumoto N, Takagi T, Naito Y, Yoshikawa T. Alpha-tocopherol prevents apoptosis of vascular endothelial cells via a mechanism exceeding that of mere antioxidation. Eur J Pharmacol 2002; 456:29-37. [PMID: 12450566 DOI: 10.1016/s0014-2999(02)02639-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Alpha-tocopherol has been reported to exert an anti-atherogenesis effect. We attempted to clarify the effect of alpha-tocopherol-both as an antioxidant and as a nonantioxidant--on apoptosis induced by oxidized low-density lipoprotein (LDL) or oxysterols. Oxidized LDL and oxysterols induced necrosis and/or apoptosis of vascular endothelial cells. The induction of apoptosis was associated with increased caspase-3 activity and the generation of intracellular reactive oxygen species, both the effects of which were attenuated by alpha-tocopherol. Apoptosis was also decreased by beta-tocopherol or intracellular radical scavengers, but these suppressive effects were less than those of alpha-tocopherol. Neither beta-tocopherol nor the scavengers had pronounced effect on caspase-3 activity, but each of them decreased the generation of reactive oxygen species to the same extent as alpha-tocopherol. Our study suggests that alpha-Toc protects against apoptosis not only by scavenging reactive oxygen species, but also by inhibiting caspase activity, which means that its activity may exceed that of a mere antioxidant.
Collapse
Affiliation(s)
- Manabu Uemura
- First Department of Internal Medicine, Kyoto Prefectural University of Medicine, Kamigyo, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Saldeen TGP, Mehta JL. Dietary modulations in the prevention of coronary artery disease: a special emphasis on vitamins and fish oil. Curr Opin Cardiol 2002; 17:559-67. [PMID: 12357135 DOI: 10.1097/00001573-200209000-00018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Coronary artery disease (CAD) is the most common cause of death in most countries. The etiology of CAD is complex, and many risk factors have been described. Traditional risk factors for CAD can only explain about half of the clinical events; therefore, interest in nutritional factors, such as vitamins and fish oil, has been maintained.
Collapse
Affiliation(s)
- Tom G P Saldeen
- Department of Surgical Sciences, University of Uppsala, Uppsala, Sweden.
| | | |
Collapse
|
32
|
Affiliation(s)
- Hervé Benoist
- Inserm U466, Institut Louis Bugnard, CHU Rangueil, 31403 Toulouse, France
| | | | | |
Collapse
|
33
|
Li DY, Chen HJ, Staples ED, Ozaki K, Annex B, Singh BK, Vermani R, Mehta JL. Oxidized low-density lipoprotein receptor LOX-1 and apoptosis in human atherosclerotic lesions. J Cardiovasc Pharmacol Ther 2002; 7:147-53. [PMID: 12232563 DOI: 10.1177/107424840200700304] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Lectin-like oxidized LDL receptor-1 (LOX-1), a novel receptor for oxidized low-density lipoprotein, mediates oxidized low-density lipoprotein-induced apoptosis of endothelial cells, monocyte adhesion to endothelium, and phagocytosis of aged cells. The present study examined the role of LOX-1 and apoptosis in human atherosclerotic lesions. METHODS AND RESULTS Grafted vein (n = 8), human carotid artery endarterectomy (n = 11), and normal human internal mammary artery (n = 8) specimens were used to study the expression of LOX-1 and apoptosis. LOX-1 expression was determined by reverse transcriptase-polymerase chain reaction, Western analysis, and immunostaining. Presence of apoptosis was determined by fluorescent in situ nick end-labeling staining and by the presence of poly (ADP-ribose) polymerase protein (an apoptotic marker). Expression of LOX-1 was significantly increased in atherosclerotic grafted vein and carotid artery specimens compared with that in normal arteries. LOX-1 was expressed in endothelial cells, macrophages, and smooth muscle cells. LOX-1 was extensively expressed in the new blood vessels in the core of advanced atherosclerotic lesions. Double immunostaining showed LOX-1 expression to be colocalized with apoptotic cells. Fluorescent in situ nick end-labeling staining showed that the apoptotic cells were present mostly in the rupture-prone regions of the atherosclerotic plaque. CONCLUSION These observations indicate that LOX-1 is extensively expressed in the proliferated intima of grafted veins and in advanced atherosclerotic carotid arteries. Further, LOX-1 is colocalized with apoptotic cells. These observations may relate to the phenomenon of plaque rupture, and provide targets for developing new therapies.
Collapse
Affiliation(s)
- D Y Li
- Department of Surgery, University of Florida and the VA Medical Center, Gainesville, FL, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Chen H, Li D, Mehta JL. Modulation of matrix metalloproteinase-1, its tissue inhibitor, and nuclear factor-kappa B by losartan in hypercholesterolemic rabbits. J Cardiovasc Pharmacol 2002; 39:332-9. [PMID: 11862111 DOI: 10.1097/00005344-200203000-00003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Upregulation of angiotensin II receptor, may be involved in the initiation and progression of atherosclerosis. To examine the contribution of AT1 receptor in the expression of matrix metalloproteinase-1 (MMP-1) and its tissue inhibitor (TIMP-2) in lipid-deposited arterial tissues, New Zealand white rabbits were given high-cholesterol chow (with losartan 25 mg/d or vehicle) for 10 weeks. Losartan reduced the areas of sudanophilia in the aorta of rabbits fed high-cholesterol diet (p < 0.01 vs. control). Losartan also significantly decreased the enhanced mRNA expression of MMP-1 and TIMP-2 in aortas of rabbits with high-cholesterol diet. Losartan-treated rabbits revealed a reduction in immunohistochemical expression of MMP-1, whereas TIMP-2 expression became localized to the intima. In addition, losartan treatment reduced the activation of NF-kappa B by inhibiting the degradation of its inhibitor I kappa-B alpha. These observations demonstrate that AT1 receptor blockade with losartan reduces lipid deposition and exerts potent inhibitory effects on NF-kappa B activation and modulates the expression of MMP-1 and TIMP-2 in hypercholesterolemic rabbits.
Collapse
Affiliation(s)
- Hongjiang Chen
- Division of Cardiovascular Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Health Care System, Little Rock, AR 72205-7199, USA
| | | | | |
Collapse
|
35
|
Liu W, Itoigawa M, Miki T, Nishikawa H, Sugiyama S, Ishikawa N. 1-O-hexyl-2,3,5-trimethylhydroquinone inhibits IkappaB phosphorylation and degradation-linked inducible nitric oxide synthase expression: beyond antioxidant function. J Pharm Pharmacol 2002; 54:383-9. [PMID: 11902804 DOI: 10.1211/0022357021778628] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Inducible nitric oxide (NO) production in macrophages plays an important role in atherosclerosis, the protective effects of vitamin E and its derivatives perhaps being partly mediated by alteration in this parameter. We have investigated the influence of a novel synthesized vitamin E derivative, 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), on NO production in the RAW 264.7 mouse macrophage cell line. HTHQ dose-dependently inhibited lipopolysaccharide (LPS)-induced NO production through reducing LPS-triggered inducible nitric oxide synthase (iNOS) expression. The phosphorylation and subsequent degradation of IkappaB caused by LPS in RAW 264.7 cells was markedly blocked. The free radical scavenging activity of HTHQ was only 2-fold that of vitamin E, whereas its inhibition of NO production was found to be nearly 500-fold stronger. Our results indicated that HTHQ suppressed NO production in macrophages by blocking IkappaB degradation and thus inhibiting iNOS expression. The inhibitory activity of HTHQ on NO production did not parallel its free radical scavenging activity, implying a possible involvement of additional functions.
Collapse
Affiliation(s)
- Wei Liu
- Department of Pharmacology, Aichi Medical University School of Medicine, Nagakute, Japan
| | | | | | | | | | | |
Collapse
|
36
|
Chen H, Li D, Saldeen T, Romeo F, Mehta JL. Mixed tocopherol preparation is superior to alpha-tocopherol alone against hypoxia-reoxygenation injury. Biochem Biophys Res Commun 2002; 291:349-53. [PMID: 11846411 DOI: 10.1006/bbrc.2002.6439] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxia-reoxygenation (H-R) is associated with alterations in oxidant-antioxidant balance and L-arginine-nitric oxide system. Tocopherols decrease the activity of reactive oxygen species (ROS) and yet are not beneficial in clinical trials. It has been proposed that mixed tocopherols as found in nature may be more tissue protective than alpha-tocopherol alone found in commercial preparations. We compared the effect of a mixed tocopherol preparation with that of alpha-tocopherol alone on superoxide dismutase (SOD) activity and iNOS expression in cultured myocytes exposed to H-R. Myocytes from Sprague-Dawley rat hearts were subjected to hypoxia for 24 h followed by reoxygenation for 3 h H-R. Parallel groups of myocytes were pretreated with alpha-tocopherol alone or a mixed-tocopherol preparation (containing alpha-, gamma-, and delta-tocopherols) (50 microM) for 30 min. H-R resulted in myocyte injury (determined by LDH release), a decrease in SOD activity and an upregulation of iNOS expression/activity. Both tocopherol preparations attenuated cell injury and markedly decreased the effects of H-R on SOD activity and iNOS expression/activity (all P < 0.05 vs H-R group, n = 5). However, mixed-tocopherol preparation was much superior to alpha-tocopherol in terms of myocyte protection from the adverse effect of H-R (P < 0.05). Lack of efficacy of commercial tocopherol preparations in clinical trials may reflect absence of gamma- and delta-tocopherols.
Collapse
Affiliation(s)
- Hongjiang Chen
- Department of Medicine and Physiology, University of Arkansas for Medical Science and Central Arkansas Veterans Health Care System, Little Rock, Arkansas 72205-7199, USA
| | | | | | | | | |
Collapse
|
37
|
Bochkov VN, Mechtcheriakova D, Lucerna M, Huber J, Malli R, Graier WF, Hofer E, Binder BR, Leitinger N. Oxidized phospholipids stimulate tissue factor expression in human endothelial cells via activation of ERK/EGR-1 and Ca(++)/NFAT. Blood 2002; 99:199-206. [PMID: 11756172 DOI: 10.1182/blood.v99.1.199] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Activation of endothelial cells by lipid oxidation products is a key event in the initiation and progression of the atherosclerotic lesion. Minimally modified low-density lipoprotein (MM-LDL) induces the expression of certain inflammatory molecules such as tissue factor (TF) in endothelial cells. This study examined intracellular signaling pathways leading to TF up-regulation by oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (OxPAPC), a biologically active component of MM-LDL. OxPAPC induced TF activity and protein expression in human umbilical vein endothelial cells (HUVECs). However, OxPAPC neither induced phosphorylation or degradation of I kappa B alpha nor DNA binding of nuclear factor-kappa B (NF-kappa B). Furthermore, OxPAPC-induced TF expression was not inhibited by overexpression of I kappa B alpha. These results strongly indicate that OxPAPC-induced TF expression is independent of the classical NF-kappa B pathway. However, OxPAPC stimulated phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and expression of early growth response factor 1 (EGR-1). Inhibitors of mitogen-activated kinase/ERK (MEK) or protein kinase C (PKC) blocked elevation of both EGR-1 and TF. Furthermore, overexpression of NAB2, a corepressor of EGR-1, inhibited effects of OxPAPC. In addition, OxPAPC induced rapid and reversible elevation of free cytosolic Ca(++) levels and nuclear factor of activated T cells (NFAT)/DNA binding. Induction of TF expression by OxPAPC was partially inhibited by cyclosporin A, known to block calcineurin, a Ca(++)-dependent phosphatase upstream of NFAT. Treatment of OxPAPC with phospholipase A(2) destroyed its biologic activity and 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphorylcholine was identified as one biologically active component of OxPAPC that induces TF expression. Together, the results demonstrate that OxPAPC induces TF expression in HUVECs through activation of PKC/ERK/EGR-1 and Ca(++)/calcineurin/NFAT pathways rather than by NF-kappa B-mediated transcription. Thus, oxidized phospholipids may contribute to inflammation by activating pathways alternative to the classical NF-kappa B pathway.
Collapse
Affiliation(s)
- Valery N Bochkov
- Department of Vascular Biology and Thrombosis Research, University of Vienna, Austria
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Jenkins MY, Mitchell GV, Grundel E. Natural tocopherols in a dietary supplement of lutein affect tissue distribution of tocopherols in young rats. Nutr Cancer 2001; 37:207-14. [PMID: 11142095 DOI: 10.1207/s15327914nc372_14] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The effects of graded levels of Flora GLO (FG), a dietary supplement containing lutein derived from marigold flowers, on tissue concentrations of lutein and alpha- and gamma-tocopherol were determined. Six groups of male weanling Fischer 344 rats (15/group) were fed ad libitum modified AIN-93G diets containing 0%, 0.30%, 0.60%, 1.20%, 2.40%, or 4.80% FG for eight weeks. FG provided 0%, 0.015%, 0.030%, 0.060%, 0.120%, or 0.240% lutein; corresponding levels of tocopherols were approximately 0%, 0.006%, 0.012%, 0.023%, 0.046%, and 0.092%, respectively. Maximal uptakes of lutein in plasma, spleen, and liver were observed with 4.8% FG. Lutein was not detectable in brain, heart, lung, testes, and kidney. Concentrations of alpha-tocopherol in the plasma (microgram/mg triglycerides) were reduced in all rats fed FG (p < 0.05). alpha-Tocopherol increased nonlinearly in lung, heart, and spleen with increased FG level. alpha-Tocopherol in liver increased with increased dietary FG; alpha-tocopherol in kidney, testes, and brain did not increase. At each dietary level of FG, the spleen had a higher percentage of gamma-tocopherol, and testes and brain had a lower percentage of gamma-tocopherol than all other tissues. For all tissues, the concentrations of alpha-tocopherol were always higher than those of gamma-tocopherol. Tocopherols added to the dietary supplement for functional purposes appeared to have a significant effect on tissue levels of tocopherols. Therefore, changes in alpha- and gamma-tocopherol levels in tissues of rats fed FG cannot be attributed solely to effects of lutein.
Collapse
Affiliation(s)
- M Y Jenkins
- Office of Nutritional Products, Labeling, and Dietary Supplements, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA.
| | | | | |
Collapse
|
39
|
Lyons NM, Woods JA, O'Brien NM. alpha-Tocopherol, but not gamma-tocopherol inhibits 7 beta-hydroxycholesterol-induced apoptosis in human U937 cells. Free Radic Res 2001; 35:329-39. [PMID: 11697131 DOI: 10.1080/10715760100300861] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Oxysterols, particularly those oxidised at position 7, are toxic to cells in culture and have been shown to induce apoptosis in cell types such as vascular endothelial cells, smooth muscle cells and monocytes. The precise mechanism by which oxysterols induce apoptosis is unknown but may involve the generation of oxidative stress. In the present study we examined the ability of alpha-TOC, alpha-TOC acetate (alpha-TOCA) and gamma-TOC to protect against 7 beta-hydroxycholesterol (7 beta-OHC)-induced apoptosis of human monocytic U937 cells. 7 beta-OHC is one of the most commonly detected oxysterols in foods and its level in plasma has been positively associated with an increased risk of atherosclerosis. The present study demonstrates a significant decrease in cell membrane integrity and cellular glutathione levels when U937 cells were treated with 30 microM 7 beta-OHC. DNA fragmentation also occurred, as measured by agarose gel electrophoresis, and the number of apoptotic cells increased as assessed by nuclear morphology. Analysis by HPLC showed that there was a greater incorporation of gamma-TOC into U937 cells after a 48 h incubation, than either alpha-TOC or alpha-TOCA. However, despite the increased uptake of gamma-TOC, only alpha-TOC, and not gamma-TOC or alpha-TOCA was effective at inhibiting 7 beta-OHC-induced apoptosis in U937 cells.
Collapse
Affiliation(s)
- N M Lyons
- Department of Food Science, Food Technology and Nutrition, University College Cork, Republic of Ireland
| | | | | |
Collapse
|
40
|
Neuzil J, Weber C, Kontush A. The role of vitamin E in atherogenesis: linking the chemical, biological and clinical aspects of the disease. Atherosclerosis 2001; 157:257-83. [PMID: 11472726 DOI: 10.1016/s0021-9150(00)00741-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Atherosclerosis is a disease involving both oxidative modifications and disbalance of the immune system. Vitamin E, an endogenous redox-active component of circulating lipoproteins and (sub)cellular membranes whose levels can be manipulated by supplementation, has been shown to play a role in the initiation and progression of the disease. Recent data reveal that the activities of vitamin E go beyond its redox function. Moreover, it has been shown that vitamin E can exacerbate certain processes associated with atherogenesis. In this essay we review the role of biology of atherosclerosis, and suggest that these two facets decide the clinical manifestation and outcome of the disease.
Collapse
Affiliation(s)
- J Neuzil
- Institute for Prevention of Cardiovascular Diseases, Ludwig-Maximilians-University, Pettenkoferstr. 9, 80336 Munich, Germany.
| | | | | |
Collapse
|
41
|
Abstract
Normal embryonic development, tissue differentiation and repair in the eukaryote requires a tightly regulated apoptosis, or programmed cell death. Apoptosis also plays an essential role in different pathological processes including atherosclerosis, in which it affects all cell types in the atherosclerotic lesion, including endothelial cells, vascular smooth muscle cells, and macrophages. During atherosclerosis progression, pro- and anti-apoptotic signals abound in the evolving lesion. Apoptosis limits the number of a particular cell type that accumulates in the lesion and slows down the overall progression of the lesion. On the other hand, it contributes to the production of unstable plaques. Many pharmacological agents used to treat cardiovascular and lipid disorders have pro- or/and anti-apoptotic effects. Pharmaceuticals that modulate apoptosis in specific types of cell can potentially serve as anti-atherogenic agents. However, to develop agents for clinical use requires a thorough knowledge of the pathophysiology of apoptosis in atheromatous lesions, a highly cell-specific process. Here we review our current understanding of the process to provide a background for future pharmacological research in the area.
Collapse
Affiliation(s)
- N V Guevara
- Department of Physical Science, University of Texas at Brownsville, Brownsville, TX 78520, USA
| | | | | |
Collapse
|
42
|
Abstract
A range of compounds in or derived from the diet modulates apoptosis in cell cultures in vitro. These observations have important implications concerning the mechanisms whereby dietary components affect health. Proapoptotic compounds could protect against cancer by enhancing elimination of initiated, precancerous cells, and antiapoptotic compounds could promote tumor formation by inhibiting apoptosis in genetically damaged cells. Proapoptotic compounds could also contribute to age-related degenerative diseases by activating cell death in postmitotic cells or shifting the normal balance of mitosis and apoptosis in tissues with regenerative capacity. Many age-related diseases, for example macular degeneration and Parkinson's disease, appear to have oxidative stress as an underlying component that interacts with genetic, dietary, and environmental factors to determine relative risk in an individual. Oxidative stress activates apoptosis, and antioxidants protect against apoptosis in vitro; thus, a central role of dietary antioxidants may be to protect against apoptosis. However, little in vivo data are available to directly link diet with altered apoptosis as an underlying determinant of disease. Moreover, the possible antagonistic effects of different dietary components and the uncertainty about whether proapoptotic compounds that may protect against cancer could contribute to degenerative diseases and vice versa indicate that there is a great need for better in vivo assessment of apoptosis and that caution should be exercised when extrapolating in vitro data on apoptosis to in vivo dietary recommendations.
Collapse
Affiliation(s)
- W H Watson
- Departments of Biochemistry and Ophthalmology, Emory University School of Medicine, Atlanta, Georgia 30322, USA
| | | | | |
Collapse
|
43
|
Song JM, Kim HS, Park SJ, Chae IH, Oh BH, Lee MM, Park YB. Effect of hypercholesterolemia on macrophage infiltration after balloon injury to rabbit iliac artery. JAPANESE CIRCULATION JOURNAL 2001; 65:117-22. [PMID: 11216820 DOI: 10.1253/jcj.65.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Both hypercholesterolemia and vascular injury have been reported to induce macrophage infiltration, but their combined effect and the mechanism by which hypercholesterolemia enhances the infiltration remain to be clarified in vivo. To evaluate the effect of hypercholesterolemia on macrophage infiltration after vascular injury, the iliac arteries of hypercholesterolemic (HC) and normocholesterolemic (NC) rabbits were examined 2h, 1 day, 3 days, 7 days, and 14 days after balloon injury using immunohistochemical staining for macrophages, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1. Nuclear factor kappa-B (NF-kappaB) activation was also evaluated in fresh frozen iliac arteries using the electrophoretic mobility shift assay method. The fundamental difference between HC and NC was the amount of macrophage infiltration seen in HC from 7 days after balloon injury. Two out of 4 HC iliac arteries on the 7th day, and 3 out of 4 HC iliac arteries on the 14th day were positively stained with ICAM-1 in regenerated endothelium and neointima, whereas there were no positively stained NC iliac arteries. Neither HC nor NC tissues showed positive staining with VCAM-1. NF-kappaB was activated in HC 7 and 14 days after balloon injury, but not in NC. In conclusion, in vivo hypercholesterolemia induces macrophage infiltration after balloon injury and it is mediated by increased NF-kappaB activation promoting ICAM-1 expression.
Collapse
Affiliation(s)
- J M Song
- Department of Internal Medicine, Seoul National University College of Medicine, Heart Research Institute, Medical Research Center, Korea
| | | | | | | | | | | | | |
Collapse
|
44
|
Li D, Saldeen T, Romeo F, Mehta JL. Oxidized LDL upregulates angiotensin II type 1 receptor expression in cultured human coronary artery endothelial cells: the potential role of transcription factor NF-kappaB. Circulation 2000; 102:1970-6. [PMID: 11034947 DOI: 10.1161/01.cir.102.16.1970] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND We demonstrated earlier that angiotensin II (Ang II), by AT(1) receptor activation, upregulates oxidized LDL (ox-LDL) endothelial receptor LOX-1 gene expression and uptake of ox-LDL in human coronary artery endothelial cells (HCAECs). In this study, we investigated the regulation of Ang II receptors (AT1R and AT2R) by ox-LDL and the role of the redox-sensitive transcription factor NF-kappaB in this process. METHODS AND RESULTS HCAECs were incubated with ox-LDL for 24 hours. Ox-LDL (10 to 40 microg protein/mL) upregulated AT1R but not AT2R, mRNA, or protein. Ox-LDL degraded IkappaBalpha in cytoplasm and activated transcription factor NF-kappaB (P65) in HCAEC nuclear extract. Treatment of cells with the antioxidant alpha-tocopherol (10 to 50 micromol/L) attenuated ox-LDL-mediated degradation of IkappaBalpha and activation of NF-kappaB (P65) and inhibited the upregulation of AT1R mRNA and protein. The role of NF-kappaB signal transduction was further examined by use of an NF-kappaB inhibitor, caffeic acid phenethyl ester (CAPE). Pretreatment of cells with CAPE inhibited ox-LDL-mediated degradation of IkappaBalpha and NF-kappaB activation and inhibited ox-LDL-induced upregulation of AT1R expression. Incubation of cells with both ox-LDL and Ang II increased cell injury, measured as cell viability and LDH release, compared with either ox-LDL or Ang II alone. alpha-Tocopherol as well as the specific AT1R blocker CV11974 (candesartan) attenuated the cell-injurious effects of ox-LDL. CONCLUSIONS These observations suggest an important role of ox-LDL-mediated AT1R upregulation in cell injury. In this process, NF-kappaB activation seems to play a critical role in signal transduction. These findings provide a basis for the use of antioxidants and AT1R blockers in designing therapy of atherosclerosis.
Collapse
MESH Headings
- Angiotensin II/metabolism
- Angiotensin II/pharmacology
- Angiotensin Receptor Antagonists
- Arteries/cytology
- Arteries/metabolism
- Caffeic Acids/pharmacology
- Cell Survival/drug effects
- Cells, Cultured
- Coronary Vessels/cytology
- Coronary Vessels/metabolism
- DNA-Binding Proteins/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Humans
- I-kappa B Proteins
- L-Lactate Dehydrogenase/metabolism
- Lipoproteins, LDL/metabolism
- Lipoproteins, LDL/pharmacology
- NF-KappaB Inhibitor alpha
- NF-kappa B/antagonists & inhibitors
- NF-kappa B/metabolism
- Phenylethyl Alcohol/analogs & derivatives
- Phenylethyl Alcohol/pharmacology
- RNA, Messenger/metabolism
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
- Up-Regulation/drug effects
- Up-Regulation/physiology
- Vitamin E/metabolism
- Vitamin E/pharmacology
Collapse
Affiliation(s)
- D Li
- Departments of Medicine and Physiology, University of Arkansas and VA Medical Center, Little Rock, USA
| | | | | | | |
Collapse
|
45
|
Li D, Saldeen T, Mehta JL. Effects of alpha-tocopherol on ox-LDL-mediated degradation of IkappaB and apoptosis in cultured human coronary artery endothelial cells. J Cardiovasc Pharmacol 2000; 36:297-301. [PMID: 10975585 DOI: 10.1097/00005344-200009000-00003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Experimental studies have demonstrated that vitamin E (alpha-tocopherol) may provide significant cytoprotection during cell injury. In this study, we examined the effects of alpha-tocopherol on oxidized low-density lipoprotein (ox-LDL)-induced apoptosis in human coronary artery endothelial cells (HCAECs). In addition, we examined the activation of NF-kappaB pathway in this process. Cultured HCAECs were treated with ox-LDL for 24 h. Incubation of HCAECs with ox-LDL resulted in apoptosis of HCAECs in a concentration-dependent manner, as determined by TUNEL and DNA laddering. Ox-LDL degraded IkappaB and activated NF-kappaB in HCAECs, as determined by Western blot analysis. Treatment with alpha-tocopherol (10 and 50 microM) decreased ox-LDL-mediated apoptosis as well as degradation of IkappaB and activation of NF-kappaB in HCAECs. High concentration of alpha-tocopherol (50 microM) was more effective than the low concentration of alpha-tocopherol (10 microM). Thus, ox-LDL induces apoptosis of HCAECs, in concurrence with degradation of IkappaB and activation of NF-kappaB. Alpha-tocopherol markedly decreases ox-LDL-induced effects.
Collapse
Affiliation(s)
- D Li
- Department of Medicine, University of Florida and VA Medical Center, Gainesville, USA
| | | | | |
Collapse
|
46
|
de Nigris F, Franconi F, Maida I, Palumbo G, Anania V, Napoli C. Modulation by alpha- and gamma-tocopherol and oxidized low-density lipoprotein of apoptotic signaling in human coronary smooth muscle cells. Biochem Pharmacol 2000; 59:1477-87. [PMID: 10751558 DOI: 10.1016/s0006-2952(00)00275-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Apoptosis may play an important role in atherogenesis. Oxidized low-density lipoprotein (oxLDL) promotes apoptosis in the arterial wall in addition to several other proatherogenic effects. Tocopherol supplements have been suggested to protect against coronary heart disease (CHD) in epidemiological studies. The effects of oxLDL and alpha- and gamma-tocopherol on apoptotic signaling pathways are poorly understood. Thus, the goal of the study was to investigate these pathways in the presence of copper-oxidized LDL and tocopherols in human coronary smooth muscle cells (SMC). We showed that oxLDL-mediated apoptosis, assessed by DNA fragmentation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, and caspase activation stimulated several transcription factors and proapoptotic dynamic movements of the Bcl-2 family proteins through the mitogen-activated protein kinase (MAPK) and Jun kinase pathways. alpha-Tocopherol and gamma-tocopherol significantly reduced these molecular events and cell death effectors caspase-3 and -8. Under our experimental conditions, alpha-tocopherol was significantly more effective than gamma-tocopherol, and oxLDL-mediated apoptosis increased c-Jun, cyclic AMP-responsive element-binding, Ets-like element kinase-dependent 7, and activating transcription factor-2 proteins as well as nuclear activity of the activated protein-1 complex in human coronary SMC. Moreover, our results demonstrate that tocopherols may exert their antiatherogenic effects at least in part via reduction of the MAPK and JunK cascade together with a protective profile of apoptotic genes of the Bcl-2 family. These data are consistent with the beneficial effects of tocopherols on atherogenesis seen in experimental studies and on CHD in epidemiological surveys.
Collapse
Affiliation(s)
- F de Nigris
- Department of Clinical and Experimental Medicine, University of Naples, Naples, Italy
| | | | | | | | | | | |
Collapse
|
47
|
Abstract
The oxidation of LDL is thought to be a major contributor to the development of atherosclerosis. Considerable descriptive evidence has been accumulated showing that oxidized LDL promotes pro-atherogenic events. However, direct evidence that oxidized LDL causes atherosclerosis is lacking. This article summarizes the results of recent studies that demonstrate how oxidized LDL affects cellular function, and highlights key issues that should be addressed to link LDL oxidation with atherosclerosis.
Collapse
Affiliation(s)
- M J Thomas
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1016, USA.
| |
Collapse
|
48
|
Li D, Mehta JL. Upregulation of endothelial receptor for oxidized LDL (LOX-1) by oxidized LDL and implications in apoptosis of human coronary artery endothelial cells: evidence from use of antisense LOX-1 mRNA and chemical inhibitors. Arterioscler Thromb Vasc Biol 2000; 20:1116-22. [PMID: 10764682 DOI: 10.1161/01.atv.20.4.1116] [Citation(s) in RCA: 255] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A specific lectin-like endothelial receptor for oxidized low density lipoprotein (LOX-1), distinct from the scavenger receptor in monocytes/macrophages, has been identified and cloned. In this study, we examined the regulation of LOX-1 by oxidized low density lipoprotein (ox-LDL) and determined the role of LOX-1 in ox-LDL-induced apoptosis of cultured human coronary artery endothelial cells (HCAECs). Incubation of HCAECs with ox-LDL (40 microg/mL), but not native LDL, for 24 hours markedly increased LOX-1 expression (mRNA and protein). After 48 hours of preincubation of HCAECs with a specific antisense to LOX-1 mRNA (antisense LOX-1), ox-LDL-mediated upregulation of LOX-1 was suppressed (P<0.01). In contrast, treatment of HCAECs with sense LOX-1 had no effect. Ox-LDL also induced apoptosis (determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling and DNA laddering) of HCAECs in a concentration- and time-dependent fashion. LOX-1 played an important role in ox-LDL-mediated apoptosis of HCAECs because antisense LOX-1 inhibited this effect of ox-LDL. Polyinosinic acid and carrageenan, 2 different chemical inhibitors of LOX-1, also decreased ox-LDL-mediated apoptosis of HCAECs. Nuclear factor (NF)-kappaB was markedly activated in ox-LDL-treated HCAECs. The critical role of NF-kappaB activation became evident in experiments with antisense LOX-1, which abolished ox-LDL-mediated NF-kappaB activation. In this process, an NF-kappaB inhibitor, caffeic acid phenethyl ester, also inhibited ox-LDL-mediated apoptosis of HCAECs. These findings indicate that ox-LDL upregulates its own endothelial receptor. Ox-LDL-induced apoptosis is mediated by the action of LOX-1. In this process, NF-kappaB activation may play an important role as a signal transduction mechanism.
Collapse
Affiliation(s)
- D Li
- Department of Medicine, University of Florida, Gainesville 32610, USA
| | | |
Collapse
|