1
|
Lee MJ, Kim EH, Lee SA, Kang YM, Jung CH, Yoon HK, Seol SM, Lee YL, Lee WJ, Park JY. Dehydroepiandrosterone prevents linoleic acid-induced endothelial cell senescence by increasing autophagy. Metabolism 2015; 64:1134-45. [PMID: 26051603 DOI: 10.1016/j.metabol.2015.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 04/28/2015] [Accepted: 05/04/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Autophagy has emerged as a potentially important factor in the pathogenesis of atherosclerosis. Dehydroepiandrosterone (DHEA) is an adrenal steroid of great recent interest due to its anti-aging and anti-atherogenic effects; however, little is known about its role in autophagy and endothelial senescence. OBJECTIVE The aim of this study was to investigate whether DHEA prevents linoleic acid (LA)-induced endothelial senescence by enhancing autophagy. MATERIALS/METHODS After pre-treatement with or without DHEA prior to LA treatment in human aortic endothelial cells (HAECs), the level of senescence was compared by senescence-associated acidic β-galactosidase (SA-β-Gal) staining and hyperphosphorylated pRB (ppRB) protein level. Autophagy was detected by LC3 conversion and measuring the level of p62/SQSTM1 (sequestosome 1), a protein degraded by autophagy. The fusion of autophagosome and lysosome was confirmed by fluorescence microscopy. RESULTS Pre-treatment with DHEA inhibited LA-induced endothelial senescence. DHEA increased the conversion of LC3-I to LC3-II and decreased the level of p62 in a time- and dose-dependent manner. Although both DHEA and LA treatment increased the conversion of LC3-I to LC3-II, treatment of LA increased p62 and decreased fusion of autophagosome and lysosome, which reflected decreased autophagic flux. However, pre-treatment with DHEA restored autophagic flux inhibited by LA. When we evaluated signaling pathways, we found that JNK activation involved in LC3 conversion induced by DHEA. CONCLUSION DHEA prevents LA-induced endothelial senescence by restoring autophagy and autophagic flux through JNK activation.
Collapse
Affiliation(s)
- Min Jung Lee
- Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Eun Hee Kim
- Department of Health Screening and Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang Ah Lee
- Department of Internal Medicine, Jeju National University Hospital, Jeju National School of Medicine, Jeju, Republic of Korea
| | - Yu Mi Kang
- Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Chang Hee Jung
- Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hae Kyeong Yoon
- Asan Institute of Life Sciences, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - So Mi Seol
- Asan Institute of Life Sciences, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yoo La Lee
- Asan Institute of Life Sciences, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Woo Je Lee
- Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
| | - Joong-Yeol Park
- Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
| |
Collapse
|
2
|
Gousiadou C, Gotfredsen CH, Matsa M, Hadjipavlou-Litina D, Skaltsa H. Minor iridoids from Scutellaria albida ssp. albida. Inhibitory potencies on lipoxygenase, linoleic acid lipid peroxidation and antioxidant activity of iridoids from Scutellaria sp. J Enzyme Inhib Med Chem 2013; 28:704-10. [PMID: 22630074 DOI: 10.3109/14756366.2012.672415] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A new iridoid glycoside, 6'-O-E-caffeoyl-mussaenosidic acid , in addition to one known aglycon, four known triterpenes and one known flavonoid, were isolated from the aerial parts of Scutellaria albida subsp. albida. Furthermore, 12 iridoids with similar structures isolated from Scutellaria sp., were examined for their inhibitory potency on lipoxygenase and lipid peroxidation, as well as their antioxidant activity, in comparison to known antioxidants e.g. caffeic acid, nordihydroguaretic acid (NDGA) and trolox. AAPH, DPPH and soybean lipoxygenase (LOX) assays were used for the tests. This investigation led to interesting observations considering the Structure-Activity Relationship. According to our results, the presence of a p-coumaroyl group optimized and even dramatically changed the biological responses of the investigated iridoids.
Collapse
Affiliation(s)
- Chrysoula Gousiadou
- Department of Pharmacognosy and Chemistry of Natural Products, School of Pharmacy, University of Athens, Panepistimiopolis, Zografou, Athens, Greece.
| | | | | | | | | |
Collapse
|
3
|
Zhou H, Chen X, Wang C, Ye J, Chen H. Purification and characterization of a novel ~18 kDa antioxidant protein from Ginkgo biloba seeds. Molecules 2012; 17:14778-94. [PMID: 23519252 PMCID: PMC6268451 DOI: 10.3390/molecules171214778] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 11/30/2012] [Accepted: 12/07/2012] [Indexed: 01/09/2023] Open
Abstract
Ginkgo biloba seeds are widely used as a food and traditional medicine in China. In the present study, a novel antioxidant protein named GBSP was purified from Ginkgo biloba seeds. The protein (GBSP) was purified by homogenization of Ginkgo biloba seed powder in saline solution, 70% ammonium sulphate precipitation, filtration on a DEAE-Cellulose52 anion exchange column, gel filtration on a Sephadex G-50 column, and preparative chromatography on a C18 column using RP-HPLC. GBSP showed an apparent molecular weight of 18 kDa by SDS-PAGE and MALDI-TOF/MS analyses. The amino acid sequence obtained by MALDI-TOF/TOF MS analysis showed GBSP was a novel protein, as no matching protein in was found the database. The protein exhibited significant antioxidant activities against free radicals such as DPPH, ABTS and superoxide anion and showed higher activity than α-tocopherol in a linoleic acid emulsion assay system. Furthermore, GBSP exhibited notable reducing power and a strong chelating effect on Cu2+ and Fe2+. Therefore, the present study demonstrates, for the first time, that this novel protein from Ginkgo biloba seeds is an excellent antioxidant.
Collapse
Affiliation(s)
- Hao Zhou
- Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, Jiangsu, China
- National Engineering Lab for Biomass Chemical Utilization, Nanjing 210042, Jiangsu, China
- Key and Open Lab on Forest Chemical Engineering, SFA, Nanjing 210042, Jiangsu, China
- Key Lab of Biomass Energy and Material, Nanjing 210042, Jiangsu, China
- Institute of New Technology of Forestry, CAF, Beijing 100091, China
| | - Xijuan Chen
- Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, Jiangsu, China
- National Engineering Lab for Biomass Chemical Utilization, Nanjing 210042, Jiangsu, China
- Key and Open Lab on Forest Chemical Engineering, SFA, Nanjing 210042, Jiangsu, China
- Key Lab of Biomass Energy and Material, Nanjing 210042, Jiangsu, China
| | - Chengzhang Wang
- Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, Jiangsu, China
- National Engineering Lab for Biomass Chemical Utilization, Nanjing 210042, Jiangsu, China
- Key and Open Lab on Forest Chemical Engineering, SFA, Nanjing 210042, Jiangsu, China
- Key Lab of Biomass Energy and Material, Nanjing 210042, Jiangsu, China
- Institute of New Technology of Forestry, CAF, Beijing 100091, China
- Author to whom correspondence should be addressed; E-Mail: ; Tel./Fax: +86-25-8548-2471
| | - Jianzhong Ye
- Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, Jiangsu, China
- National Engineering Lab for Biomass Chemical Utilization, Nanjing 210042, Jiangsu, China
- Key and Open Lab on Forest Chemical Engineering, SFA, Nanjing 210042, Jiangsu, China
- Key Lab of Biomass Energy and Material, Nanjing 210042, Jiangsu, China
| | - Hongxia Chen
- Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, Jiangsu, China
- National Engineering Lab for Biomass Chemical Utilization, Nanjing 210042, Jiangsu, China
- Key and Open Lab on Forest Chemical Engineering, SFA, Nanjing 210042, Jiangsu, China
- Key Lab of Biomass Energy and Material, Nanjing 210042, Jiangsu, China
| |
Collapse
|
4
|
Litinas KE, Mangos A, Nikkou TE, Hadjipavlou-Litina DJ. Synthesis and biological evaluation of fused oxepinocoumarins as free radicals scavengers. J Enzyme Inhib Med Chem 2011; 26:805-12. [PMID: 21381887 DOI: 10.3109/14756366.2011.555944] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Some fused dihydrooxepino[f]-, [g]-, and [h]coumarins were obtained from the ring-closing metathesis of the corresponding o-allyl-allyloxycoumarins under the treatment with the first generation Grubbs' catalyst. These compounds were tested in vitro for their antioxidant activity, and they present significant scavenging activity. They were also showed to inhibit in vitro soybean lipoxygenase.
Collapse
Affiliation(s)
- Konstantinos E Litinas
- Laboratory of Organic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | | | | | | |
Collapse
|
5
|
Dauchy RT, Blask DE, Dauchy EM, Davidson LK, Tirrell PC, Greene MW, Tirrell RP, Hill CR, Sauer LA. Antineoplastic effects of melatonin on a rare malignancy of mesenchymal origin: melatonin receptor-mediated inhibition of signal transduction, linoleic acid metabolism and growth in tissue-isolated human leiomyosarcoma xenografts. J Pineal Res 2009; 47:32-42. [PMID: 19486272 DOI: 10.1111/j.1600-079x.2009.00686.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Melatonin provides a circadian signal that regulates linoleic acid (LA)-dependent tumor growth. In rodent and human cancer xenografts of epithelial origin in vivo, melatonin suppresses the growth-stimulatory effects of linoleic acid (LA) by blocking its uptake and metabolism to the mitogenic agent, 13-hydroxyoctadecadienoic acid (13-HODE). This study tested the hypothesis that both acute and long-term inhibitory effects of melatonin are exerted on LA transport and metabolism, and growth activity in tissue-isolated human leiomyosarcoma (LMS), a rare, mesenchymally-derived smooth muscle tissue sarcoma, via melatonin receptor-mediated inhibition of signal transduction activity. Melatonin added to the drinking water of female nude rats bearing tissue-isolated LMS xenografts and fed a 5% corn oil (CO) diet caused the rapid regression of these tumors (0.17 +/- 0.02 g/day) versus control xenografts that continued to grow at 0.22 +/- 0.03 g/day over a 10-day period. LMS perfused in situ for 150 min with arterial donor blood augmented with physiological nocturnal levels of melatonin showed a dose-dependent suppression of tumor cAMP production, LA uptake, 13-HODE release, extracellular signal-regulated kinase (ERK 1/2), mitogen activated protein kinase (MEK), Akt activation, and [(3)H]thymidine incorporation into DNA and DNA content. The inhibitory effects of melatonin were reversible and preventable with either melatonin receptor antagonist S20928, pertussis toxin, forskolin, or 8-Br-cAMP. These results demonstrate that, as observed in epithelially-derived cancers, a nocturnal physiological melatonin concentration acutely suppress the proliferative activity of mesenchymal human LMS xenografts while long-term treatment of established tumors with a pharmacological dose of melatonin induced tumor regression via a melatonin receptor-mediated signal transduction mechanism involving the inhibition of tumor LA uptake and metabolism.
Collapse
Affiliation(s)
- Robert T Dauchy
- Laboratory of Chrono-Neuroendocrine Oncology, Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Louisiana Cancer Research Consortium, New Orleans, LA 70112-2699, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Gülçin I. Antioxidant activity of L-adrenaline: a structure-activity insight. Chem Biol Interact 2008; 179:71-80. [PMID: 18929549 DOI: 10.1016/j.cbi.2008.09.023] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2008] [Revised: 09/16/2008] [Accepted: 09/17/2008] [Indexed: 11/18/2022]
Abstract
L-adrenaline belongs to a group of the compounds known as catecholamines, which play an important role in the regulation of physiological process in living organisms. The antioxidant activity and antioxidant mechanism of L-adrenaline was clarified using various in vitro antioxidant assays including 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), N,N-dimethyl-p-phenylenediamine (DMPD(+)), and superoxide anion radicals (O(2)(-)) scavenging activity, hydrogen peroxide (H(2)O(2)), total antioxidant activity, ferric ions (Fe(3+)) and cupric ions (Cu(2+)) reducing ability, ferrous ions (Fe(2+)) chelating activity. L-adrenaline inhibited 74.2% lipid peroxidation of a linoleic acid emulsion at 30 microg/mL concentration. On the other hand, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), alpha-tocopherol and trolox displayed 83.3, 82.1, 68.1 and 81.3% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. BHA, BHT, alpha-tocopherol and trolox were used as reference antioxidants and radical scavenger compounds. Moreover, this study will bring an innovation for further studies related to antioxidant properties of L-adrenaline. According to present study, L-adrenaline had effective in vitro antioxidant and radical scavenging activity.
Collapse
Affiliation(s)
- Ilhami Gülçin
- Atatürk University, Faculty of Sciences, Department of Chemistry, TR-25240-Erzurum, Turkey.
| |
Collapse
|
7
|
Abstract
Japanese horse chestnut seed extract (HCSE) dose-dependently inhibited the autooxidation of linoleic acid (IC(50): 0.2 mg/ml), and the inhibition was almost complete at a concentration of 1 mg/ml. The HCSE scavenged DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals and superoxide anions with EC(50)s of 0.65 and 0.21 mg/ml, respectively. However, it had no effect on hydrogen peroxide. The HCSE inhibited the genotoxicities of furylfuramide, N-methyl-N-nitrosourea, methyl methanesulfonate, mitomycin C, 2-aminoanthracene and aflatoxin B1 at a concentration of 1 mg/ml or more. Total polyphenol content of the HCSE was 21 mg/g (13 mg/g-seeds). These results indicate that the Japanese horse chestnut seed is an antioxidative and antimutagenic botanical resource.
Collapse
Affiliation(s)
- Itaru Sato
- Laboratories of Veterinary Public Health, Faculty of Agriculture, Iwate University, Japan
| | | | | | | |
Collapse
|
8
|
Farkas O, Jakus J, Héberger K. Quantitative structure-antioxidant activity relationships of flavonoid compounds. Molecules 2004; 9:1079-88. [PMID: 18007505 DOI: 10.3390/91201079] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Revised: 06/18/2004] [Accepted: 06/21/2004] [Indexed: 11/16/2022] Open
Abstract
A quantitative structure-antioxidant activity relationship (QSAR) study of 36 flavonoids was performed using the partial least squares projection of latent structures (PLS) method. The chemical structures of the flavonoids have been characterized by constitutional descriptors, two-dimensional topological and connectivity indices. Our PLS model gave a proper description and a suitable prediction of the antioxidant activities of a diverse set of flavonoids having clustering tendency.
Collapse
Affiliation(s)
- Orsolya Farkas
- Bio-oxidation Group, Chemical Research Center, Hungarian Academy of Sciences, H-1525 Budapest, P.O. Box 17, Hungary
| | | | | |
Collapse
|
9
|
Kim EJ, Holthuizen PE, Park HS, Ha YL, Jung KC, Park JHY. Trans-10,cis-12-conjugated linoleic acid inhibits Caco-2 colon cancer cell growth. Am J Physiol Gastrointest Liver Physiol 2002; 283:G357-67. [PMID: 12121883 DOI: 10.1152/ajpgi.00495.2001] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A commercially available mixture of conjugated linoleic acid (CLA) isomers decreases colon cancer cell growth. We compared the individual potencies of the two main isomers in this mixture [cis-9,trans-11 (c9t11) and trans-10,cis-12 (t10c12)] and assessed whether decreased cell growth is related to changes in secretion of insulin-like growth factor II (IGF-II) and/or IGF-binding proteins (IGFBPs), which regulate Caco-2 cell proliferation. Cells were incubated in serum-free medium with different concentrations of the individual CLA isomers. t10c12 CLA dose dependently decreased viable cell number (55 +/- 3% reduction 96 h after adding 5 microM t10c12 CLA). t10c12 CLA induced apoptosis and decreased DNA synthesis, whereas c9t11 CLA had no effect. Immunoblot analysis of 24-h serum-free conditioned medium using a monoclonal anti-IGF-II antibody revealed that Caco-2 cells secreted both a mature 7,500 molecular weight (M(r)) IGF-II and higher M(r) forms of IGF-II. The levels of the higher M(r) and the mature form of IGF-II were decreased 50 +/- 3% and 22 +/- 2%, respectively, by 5 microM t10c12 CLA. c9t11 CLA had no effect. Ligand blot analysis of conditioned medium using 125I-labeled IGF-II revealed that t10c12 CLA slightly decreased IGFBP-2 production; c9t11 CLA had no effect. Exogenous IGF-II reversed t10c12 CLA-induced growth inhibition and apoptosis. These results indicate that CLA-inhibited Caco-2 cell growth is caused by t10c12 CLA and may be mediated by decreasing IGF-II secretion in Caco-2 cells.
Collapse
Affiliation(s)
- Eun J Kim
- Division of Life Sciences, Hallym University, Chunchon 200-702, Korea
| | | | | | | | | | | |
Collapse
|
10
|
Nakagawa H, Tsuta K, Kiuchi K, Senzaki H, Tanaka K, Hioki K, Tsubura A. Induction of histone acetylation in rat liver and hepatoma by organosulfur compounds including diallyl disulfide. Anticancer Res 2001; 22:891-7. [PMID: 11375895 DOI: 10.1093/carcin/22.6.891] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In previous studies, diallyl disulfide induced histone acetylation and differentiation in DS19 mouse erythroleukemic cells. In the present work the potential induction of histone acetylation in tumor-bearing rats was examined. Increased acetylation of histones in liver and Morris hepatoma 7777 was induced by treatment of rats with diallyl disulfide (200 mg/kg body weight), allyl mercaptan (100 mg/kg body weight) and butanethiol (100 mg/kg body weight). The level of histone acetylation was greater in liver than in the hepatoma and the response to the organosulfur compounds tended to be less in the tumor. The data suggested that compounds in garlic or their metabolites may increase the acetylation of core nucleosomal histones and thereby favor cell differentiation.
Collapse
Affiliation(s)
- H Nakagawa
- Department of Pathology II and Department of Surgery II, Kansai Medical University, Moriguchi, Osaka 570-8506, Japan
| | | | | | | | | | | | | |
Collapse
|
11
|
Nakagawa H, Kiyozuka Y, Uemura Y, Senzaki H, Shikata N, Hioki K, Tsubura A. Resveratrol inhibits human breast cancer cell growth and may mitigate the effect of linoleic acid, a potent breast cancer cell stimulator. J Cancer Res Clin Oncol 2001; 127:258-64. [PMID: 11315261 DOI: 10.1007/s004320000190] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Resveratrol is a naturally occurring product found in grapes and wine. The effect of synthetic resveratrol on the growth of estrogen receptor (ER)-positive (KPL-1 and MCF-7) and -negative (MKL-F) human breast cancer cell lines was examined. Resveratrol at low concentrations caused cell proliferation in ER-positive lines (KPL-1, < or = 22 microM; MCF-7, < or = 4 microM) whereas at high concentrations (> or = 44 microM) it caused suppression of cell growth in all three cell lines examined. Growth suppression was due to apoptosis as seen by the appearance of a sub-G1 fraction. The apoptosis cascade up-regulated Bax and Bak protein, down-regulated Bcl-xL protein, and activated caspase-3. Resveratrol (52-74 microM) antagonized the effect of linoleic acid, a potent breast cancer cell stimulator, and suppressed the growth of both ER-positive and -negative cell lines. Thus, resveratrol could be a promising anticancer agent for both hormone-dependent and hormone-independent breast cancers, and may mitigate the growth stimulatory effect of linoleic acid in the Western-style diet.
Collapse
Affiliation(s)
- H Nakagawa
- Department of Pathology II, Kansai Medical University, Moriguchi, Osaka 570-8506, Japan
| | | | | | | | | | | | | |
Collapse
|
12
|
Meerarani P, Ramadass P, Toborek M, Bauer HC, Bauer H, Hennig B. Zinc protects against apoptosis of endothelial cells induced by linoleic acid and tumor necrosis factor alpha. Am J Clin Nutr 2000; 71:81-7. [PMID: 10617950 DOI: 10.1093/ajcn/71.1.81] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Zinc requirements of the vascular endothelium may be increased in inflammatory conditions, ie, atherosclerosis, in which apoptotic cell death is prevalent. OBJECTIVE We hypothesized that zinc deficiency may potentiate disruption of endothelial cell integrity mediated by fatty acids and inflammatory cytokines by enhancing pathways that lead to apoptosis and up-regulation of caspase genes. DESIGN Endothelial cells were maintained in low-serum medium or grown in culture media containing selected chelators, ie, diethylenetriaminepentaacetate or N,N,N', N'-tetrakis(2-pyridylmethyl)-ethylenediamine (TPEN), with or without zinc supplementation. Subsequently, cells were treated with linoleic acid, tumor necrosis factor alpha (TNF-alpha), or both. We studied the effect of zinc deficiency and supplementation on the induction of apoptosis by measuring caspase-3 activity, cell binding of annexin V, and DNA fragmentation. RESULTS Our results indicated that linoleic acid and TNF-alpha independently, but more markedly in concert, up-regulated caspase-3 activity and induced annexin V binding and DNA fragmentation. Zinc deficiency, especially when induced by TPEN, dramatically increased apoptotic cell death induced by cytokines and lipids compared with control cultures. Supplementation of low-serum- or chelator-treated endothelial cells with physiologic amounts of zinc caused a marked attenuation of apoptosis induced by linoleic acid and TNF-alpha. Morphologic changes of cells observed during zinc deficiency were prevented by zinc supplementation. Media supplementation with other divalent cations (eg, calcium and magnesium) did not mimic the protective role of zinc against apoptosis. CONCLUSIONS Our data indicate that zinc is vital to vascular endothelial cell integrity, possibly by regulating signaling events to inhibit apoptotic cell death.
Collapse
Affiliation(s)
- P Meerarani
- Departments of Nutrition and Food Science and Surgery, University of Kentucky, Lexington, and the Molecular Biology Institute, Austrian Academy of Sciences, Salzburg
| | | | | | | | | | | |
Collapse
|
13
|
Abstract
The oxidation of linoleic acid catalyzed by Fe(II) is strongly inhibited by phosvitin, while chelation with EDTA, NTA or deferoxamine produced only partial inhibition. Interestingly, the DNA degradation catalyzed by Fe(II) in the presence of H2O2 is also inhibited by phosvitin or deferoxamine. In contrast, chelation of the metal ion with EDTA or NTA enhanced the DNA degradation. The results suggest that the nature of interaction between the metal ion and the complexing agent may be an important factor in the generation of active oxygen intermediates.
Collapse
Affiliation(s)
- S U Maheswari
- Vittal Mallya Scientific Research Foundation, Bangalore, India
| | | | | |
Collapse
|