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The potential role of nutrition on lens pathology: a systematic review and meta-analysis. Surv Ophthalmol 2019; 64:668-678. [DOI: 10.1016/j.survophthal.2019.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/27/2019] [Accepted: 03/04/2019] [Indexed: 11/23/2022]
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Xu Z, Sun T, Li W, Sun X. Inhibiting effects of dietary polyphenols on chronic eye diseases. J Funct Foods 2017. [DOI: 10.1016/j.jff.2017.10.031] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Elbay A, Ozer OF, Altinisik M, Elbay AE, Sezer T, Bayraktar H, Ozdemir H. A novel tool reflecting the role of oxidative stress in the cataracts: thiol/disulfide homeostasis. Scandinavian Journal of Clinical and Laboratory Investigation 2017; 77:223-227. [PMID: 28276726 DOI: 10.1080/00365513.2017.1292539] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We investigated serum and aqueous humor thiol/disulfide (T-D) homeostasis in patients with cataracts versus healthy controls. In total, 56 patients with cataracts and 49 healthy controls were enrolled in this case-control study. Serum total thiol (TT), native thiol (NT), and disulfide (DS) concentrations were determined using a novel automated measurement method. Additionally, DS/TT, DS/NT and NT/TT percentage ratios were compared between the groups. In comparison with the control group, serum NT levels and aqueous humor TT and NT levels were significantly lower (p < .05, p < .05 and p < .001, respectively), whereas serum and aqueous humor DS levels were significantly higher in cataract patients (p < .01 and p < .001). DS/TT and DS/NT ratios were significantly higher and the NT/TT ratio was lower in cataract patients in serum (p < .005) and aqueous humor samples (p < .001). In conclusion, serum T-D homeostasis may be useful as biochemical markers, indicating the role of oxidative stress in the development of cataracts. Further studies are needed to confirm the pathophysiological role of T-D homeostasis in cataractogenesis.
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Affiliation(s)
- Ahmet Elbay
- a Department of Ophthalmology , Bezmialem University School of Medicine , Istanbul , Turkey
| | - Omer Faruk Ozer
- b Department of Biochemistry , Bezmialem University School of Medicine , Istanbul , Turkey
| | - Muhammed Altinisik
- c Department of Ophthalmology , Nevsehir State Hospital , Nevsehir , Turkey
| | - Arif Emre Elbay
- d Department of Ophthalmology , Samsun Gazi State Hospital , Samsun , Turkey
| | - Taha Sezer
- a Department of Ophthalmology , Bezmialem University School of Medicine , Istanbul , Turkey
| | - Havvanur Bayraktar
- a Department of Ophthalmology , Bezmialem University School of Medicine , Istanbul , Turkey
| | - Hakan Ozdemir
- a Department of Ophthalmology , Bezmialem University School of Medicine , Istanbul , Turkey
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Abstract
AbstractObjectiveWe conducted a meta-analysis to evaluate the relationship between vitamin E and age-related cataract (ARC).DesignThe fixed- or random-effect model was selected based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Begg’s test. The dose–response relationship was assessed by a restricted cubic spline model.SettingRelevant studies were identified by a search of PubMed and the Cochrane Library to May 2014, without language restrictions.SubjectsStudies involved samples of people of all ages.ResultsDietary vitamin E intake, dietary and supplemental vitamin E intake, and high serum tocopherol levels were significantly associated with decreased risk of ARC, the pooled relative risk was 0·73 (95 % CI 0·58, 0·92), 0·86 (95 % CI 0·75, 0·99) and 0·77 (95 % CI 0·66, 0·91), respectively. Supplemental vitamin E intake was non-significantly associated with ARC risk (relative risk=0·92; 95 % CI 0·78, 1·07). The findings from dose–response analysis showed evidence of a non-linear association between dietary vitamin E intake and ARC. The risk of ARC decreased with dietary vitamin E intake from 7 mg/d (relative risk=0·94; 95 % CI 0·90, 0·97).ConclusionsThe findings of the meta-analysis indicated that dietary vitamin E intake, dietary and supplemental vitamin E intake, and high level of serum tocopherol might be significantly associated with reduced ARC risk.
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Boeing H, Bechthold A, Bub A, Ellinger S, Haller D, Kroke A, Leschik-Bonnet E, Müller MJ, Oberritter H, Schulze M, Stehle P, Watzl B. Critical review: vegetables and fruit in the prevention of chronic diseases. Eur J Nutr 2012; 51:637-63. [PMID: 22684631 PMCID: PMC3419346 DOI: 10.1007/s00394-012-0380-y] [Citation(s) in RCA: 996] [Impact Index Per Article: 83.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 05/09/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND Vegetables and fruit provide a significant part of human nutrition, as they are important sources of nutrients, dietary fibre, and phytochemicals. However, it is uncertain whether the risk of certain chronic diseases can be reduced by increased consumption of vegetables or fruit by the general public, and what strength of evidence has to be allocated to such an association. METHODS Therefore, a comprehensive analysis of the studies available in the literature and the respective study results has been performed and evaluated regarding obesity, type 2 diabetes mellitus, hypertension, coronary heart disease (CHD), stroke, cancer, chronic inflammatory bowel disease (IBD), rheumatoid arthritis (RA), chronic obstructive pulmonary disease (COPD), asthma, osteoporosis, eye diseases, and dementia. For judgement, the strength of evidence for a risk association, the level of evidence, and the number of studies were considered, the quality of the studies and their estimated relevance based on study design and size. RESULTS For hypertension, CHD, and stroke, there is convincing evidence that increasing the consumption of vegetables and fruit reduces the risk of disease. There is probable evidence that the risk of cancer in general is inversely associated with the consumption of vegetables and fruit. In addition, there is possible evidence that an increased consumption of vegetables and fruit may prevent body weight gain. As overweight is the most important risk factor for type 2 diabetes mellitus, an increased consumption of vegetables and fruit therefore might indirectly reduces the incidence of type 2 diabetes mellitus. Independent of overweight, there is probable evidence that there is no influence of increased consumption on the risk of type 2 diabetes mellitus. There is possible evidence that increasing the consumption of vegetables and fruit lowers the risk of certain eye diseases, dementia and the risk of osteoporosis. Likewise, current data on asthma, COPD, and RA indicate that an increase in vegetable and fruit consumption may contribute to the prevention of these diseases. For IBD, glaucoma, and diabetic retinopathy, there was insufficient evidence regarding an association with the consumption of vegetables and fruit. CONCLUSIONS This critical review on the associations between the intake of vegetables and fruit and the risk of several chronic diseases shows that a high daily intake of these foods promotes health. Therefore, from a scientific point of view, national campaigns to increase vegetable and fruit consumption are justified. The promotion of vegetable and fruit consumption by nutrition and health policies is a preferable strategy to decrease the burden of several chronic diseases in Western societies.
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Affiliation(s)
- Heiner Boeing
- Department of Epidemiology, German Institute of Human Nutrition, Potsdam-Rehbrücke, Germany
| | | | - Achim Bub
- Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Karlsruhe, Germany
| | - Sabine Ellinger
- Department of Nutrition and Food Science, University of Bonn, Bonn, Germany
| | - Dirk Haller
- Nutrition and Food Research Centre, Chair for the Biofunctionality of Food, Technical University of Munich, Freising-Weihenstephan, Germany
| | - Anja Kroke
- Department of Nutritional, Food and Consumer Sciences, Fulda University of Applied Sciences, Fulda, Germany
| | | | - Manfred J. Müller
- Institute of Human Nutrition and Food Science, Christian-Albrechts-University Kiel, Kiel, Germany
| | | | - Matthias Schulze
- Department of Molecular Epidemiology, German Institute of Human Nutrition, Potsdam-Rehbrücke, Germany
| | - Peter Stehle
- Department of Nutrition and Food Science, University of Bonn, Bonn, Germany
| | - Bernhard Watzl
- Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Karlsruhe, Germany
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Ladurner A, Schmitt CA, Schachner D, Atanasov AG, Werner ER, Dirsch VM, Heiss EH. Ascorbate stimulates endothelial nitric oxide synthase enzyme activity by rapid modulation of its phosphorylation status. Free Radic Biol Med 2012; 52:2082-90. [PMID: 22542797 PMCID: PMC3377995 DOI: 10.1016/j.freeradbiomed.2012.03.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 03/09/2012] [Accepted: 03/12/2012] [Indexed: 02/06/2023]
Abstract
Long-term exposure to ascorbate is known to enhance endothelial nitric oxide synthase (eNOS) activity by stabilizing the eNOS cofactor tetrahydrobiopterin (BH4). We investigated acute effects of ascorbate on eNOS function in primary (HUVEC) and immortalized human endothelial cells (EA.hy926), aiming to provide a molecular explanation for the rapid vasodilatation seen in vivo upon administration of ascorbate. Enzymatic activity of eNOS and intracellular BH4 levels were assessed by means of an arginine-citrulline conversion assay and HPLC analysis, respectively. Over a period of 4h, ascorbate steadily increased eNOS activity, although endothelial BH4 levels remained unchanged compared to untreated control cells. Immunoblot analyses revealed that as early as 5 min after treatment ascorbate dose-dependently increased phosphorylation at eNOS-Ser1177 and concomitantly decreased phosphorylation at eNOS-Thr495, a phosphorylation pattern indicative of increased eNOS activity. By employing pharmacological inhibitors, siRNA-mediated knockdown approaches, and overexpression of the catalytic subunit of protein phosphatase 2A (PP2A), we show that this effect was at least partly owing to reduction of PP2A activity and subsequent activation of AMP-activated kinase. In this report, we unravel a novel mechanism for how ascorbate rapidly activates eNOS independent of its effects on BH4 stabilization.
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Key Words
- ampk, amp-activated protein kinase
- bh4, tetrahydrobiopterin
- dmem, dulbecco's modified eagle's medium
- dmso, dimethyl sulfoxide
- enos, endothelial nitric oxide synthase
- fbs, fetal bovine serum
- ha-tag, hemagglutinin tag
- hepes, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- hiv, human immunodeficiency virus
- hplc, high-performance liquid chromatography
- huvec, human umbilical vein endothelial cell
- pi3k, phosphatidylinositol 3-kinases
- pkc, protein kinase c
- pp2a, protein phosphatase 2a
- sds–page, sodium dodecyl sulfate–polyacrylamide gel electrophoresis
- tlc, thin-layer chromatography
- ascorbate
- endothelial no synthase activity
- endothelial no synthase phosphorylation
- amp-activated kinase
- protein phosphatase 2a
- free radicals
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Affiliation(s)
- Angela Ladurner
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
| | - Christoph A. Schmitt
- University College London, Wolfson Institute for Biomedical Research, London, UK
| | - Daniel Schachner
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
| | - Atanas G. Atanasov
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
| | - Ernst R. Werner
- Biocenter, Division of Biological Chemistry, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Verena M. Dirsch
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
| | - Elke H. Heiss
- Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
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Fletcher AE. Controversy over "contradiction": Should randomized trials always trump observational studies? Am J Ophthalmol 2009; 147:384-6. [PMID: 19217953 DOI: 10.1016/j.ajo.2008.04.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 04/11/2008] [Accepted: 04/14/2008] [Indexed: 11/27/2022]
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Granado F, Olmedilla B, Blanco I. Nutritional and clinical relevance of lutein in human health. Br J Nutr 2007; 90:487-502. [PMID: 14513828 DOI: 10.1079/bjn2003927] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lutein is one of the most widely found carotenoids distributed in fruits and vegetables frequently consumed. Its presence in human tissues is entirely of dietary origin. Distribution of lutein among tissues is similar to other carotenoids but, along with zeaxanthin, they are found selectively at the centre of the retina, being usually referred to as macular pigments. Lutein has no provitamin A activity in man but it displays biological activities that have attracted great attention in relation to human health. Epidemiological studies have shown inconsistent associations between high intake or serum levels of lutein and lower risk for developing cardiovascular disease, several types of cancer, cataracts and age-related maculopathy. Also, lutein supplementation has provided both null and positive results on different biomarkers of oxidative stress although it is effective in increasing macular pigment concentration and in improving visual function in some, but not all, subjects with different eye pathologies. Overall, data suggest that whereas serum levels of lutein have, at present, no predictive, diagnostic or prognostic value in clinical practice, its determination may be very helpful in assessing compliance and efficacy of intervention as well as potential toxicity. In addition, available evidence suggests that a serum lutein concentration between 0·6 and 1·05 μmol/l seems to be a safe, dietary achievable and desirable target potentially associated with beneficial impact on visual function and, possibly, on the development of other chronic diseases. The use of lutein as a biomarker of exposure in clinical practice may provide some rationale for assessing its relationship with human health as well as its potential use within the context of evidence-based medicine.
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Affiliation(s)
- F Granado
- Servicio de Endocrinología y Nutricíon, Hospital Universitario Puerta de Hierro, Madrid, Spain
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Garti N, Amar I, Yaghmur A, Spernath A, Aserin A. Interfacial Modification and Structural Transitions Induced by Guest Molecules Solubilized in U‐Type Nonionic Microemulsions. J DISPER SCI TECHNOL 2007. [DOI: 10.1081/dis-120021797] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Nissim Garti
- a Casali Institute of Applied Chemistry , The Hebrew University of Jerusalem , Givat Ram Campus, 91904 , Jerusalem , Israel
| | - Idit Amar
- a Casali Institute of Applied Chemistry , The Hebrew University of Jerusalem , Givat Ram Campus, 91904 , Jerusalem , Israel
| | - Anan Yaghmur
- a Casali Institute of Applied Chemistry , The Hebrew University of Jerusalem , Givat Ram Campus, 91904 , Jerusalem , Israel
| | - Aviram Spernath
- a Casali Institute of Applied Chemistry , The Hebrew University of Jerusalem , Givat Ram Campus, 91904 , Jerusalem , Israel
| | - Abraham Aserin
- a Casali Institute of Applied Chemistry , The Hebrew University of Jerusalem , Givat Ram Campus, 91904 , Jerusalem , Israel
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Yoshida M, Takashima Y, Inoue M, Iwasaki M, Otani T, Sasaki S, Tsugane S. Prospective study showing that dietary vitamin C reduced the risk of age-related cataracts in a middle-aged Japanese population. Eur J Nutr 2007; 46:118-24. [PMID: 17265171 DOI: 10.1007/s00394-006-0641-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Accepted: 12/19/2006] [Indexed: 11/24/2022]
Abstract
BACKGROUND In Western countries, many epidemiological studies have demonstrated that specific dietary nutrients are associated with the risk of developing age-related cataracts. These reports have suggested that dietary antioxidant vitamins, in particular vitamin C, can play a role in preventing the onset or progression of age-related visual impairment. However, few prospective studies have examined this relationship in a general Asian population. Therefore, in this study, we investigated whether dietary vitamin C was associated with a lower incidence of age-related cataracts by performing a 5-year prospective population-based analysis using data from a cohort of over 30,000 Japanese residents recruited to the Japan Public Health Center-based Prospective Study (JPHC Study) cohort I. AIM OF THE STUDY We carried out a prospective analysis of the association between vitamin C intake and age-related cataracts among middle-aged Japanese, to study the effects of dietary antioxidants in an Asian population. METHODS This 5-year population-based study included 16,415 men and 18,771 women (aged 45-64 years), who were recruited onto the JPHC Study and had not reported cataracts in baseline surveys. Vitamin C was calculated from the nutrient intake assessed by self-administered food-frequency questionnaires (FFQ). Self-reported questionnaires were used to assess two endpoints: diagnosis or extraction of cataracts. RESULTS At follow-up, 216 men and 551 women reported new diagnoses, and 110 men and 187 women reported extractions of cataracts. For both endpoints, a higher vitamin C intake was associated with a reduced incidence of cataracts in both sexes. After adjusting for potential confounding factors, the multivariate odds ratios (ORs) for men and women in the highest quintiles of energy-adjusted vitamin C intake, relative to the lowest quintiles, were 0.65 (95% CI, 0.42-0.97) and 0.59 (95% CI, 0.43-0.89) for cataract diagnoses, and 0.70 (95% CI, 0.44-1.20) and 0.64 (95% CI, 0.41-0.94) for cataract extractions, respectively. CONCLUSIONS Dietary vitamin C intake might lower the risk of age-related cataracts among middle-aged Japanese.
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Affiliation(s)
- Masao Yoshida
- Dept. of Public Health, Kyorin University School of Medicine, Tokyo, Japan
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Abstract
Microemulsions are potentially excellent carriers for bioactive molecules. They offer the advantage of spontaneous formation, ease of manufacture, thermodynamic stability, and improved solubilization of bioactive materials. This review explores some of the new trends in microemulsion research through analysis of some representative studies. The solubilization of different classic drugs, peptides, and nutraceuticals in various oral microemulsion compositions and microstructures was reviewed. It was found that even W/O microemulsions, which are expected to break upon dilution in the digestive tract, increase the permeability and bioavailability of drugs. Thus, it seems that component selection (the use of molecules that can act as permeability enhancers) is of great importance. Structures such as self-microemulsifying drug delivery systems (SMEDDS), W/O, bicontinuous, and O/W microemulsions, were closely examined, and their potential to serve as drug carriers was evaluated. It seems that for microemulsion systems to be used as vehicles for bioactive materials, the formulations should be based on SMEEDS, which form O/W upon dilution to a specific water content. U-type microemulsions are actually an improved SMEDDS formulation, capable of being diluted with any given water concentration. Much research is being conducted on microemulsion microstructure since there is an obvious direct connection between the microstructure, solubilization capacity, and bioavailability of the active molecules.
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Affiliation(s)
- Aviram Spernath
- Casali Institute of Applied Chemistry, The Institute of Chemistry, Givat Ram Campus, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Shang F, Dudek E, Liu Q, Boulton ME, Taylor A. Protein Quality Control by the Ubiquitin Proteolytic Pathway: Roles in Resistance to Oxidative Stress and Disease. Isr J Chem 2006. [DOI: 10.1560/a8aa-y8rp-9drw-y8ax] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Versari D, Herrmann J, Gössl M, Mannheim D, Sattler K, Meyer FB, Lerman LO, Lerman A. Dysregulation of the ubiquitin-proteasome system in human carotid atherosclerosis. Arterioscler Thromb Vasc Biol 2006; 26:2132-9. [PMID: 16778122 DOI: 10.1161/01.atv.0000232501.08576.73] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The ubiquitin-proteasome system is the principal degradation route of intracellular and oxidized proteins, thus regulating many cellular processes conceivably important for atherosclerosis. The aim of this study was to evaluate the activity of ubiquitin-proteasome system in human carotid artery plaques in relation to oxidative stress and clinical manifestation. METHODS AND RESULTS In carotid endarterectomy specimens from 83 asymptomatic and 94 symptomatic patients, content of ubiquitin, ubiquitin conjugates, matrix metalloproteases, and NADPH-oxidase-p67 was evaluated by immunoblotting; proteolytic proteasome activity by fluorometric assay; single and double immunostaining for ubiquitin conjugates, 3-nitrotyrosine, apoptosis, smooth muscle alpha-actin, and macrophage CD-68, as well as Sirius Red staining for collagen were performed. Compared with asymptomatic patients, symptomatic patients showed a more unstable plaque phenotype, an increased degree of apoptosis, a significantly higher ubiquitin conjugates content (17.72+/-1.36 versus 10.99+/-1.04; P<0.001), and lower proteasome activity (5.01+/-0.70 versus 9.41+/-1.19 nmol AMC/mg protein/min; P<0.01). Ubiquitin conjugates content was directly correlated to NADPH-p67 and degree of apoptosis. Immunostaining revealed colocalization of ubiquitin conjugates and 3-nitrotyrosine, and accumulation of ubiquitin conjugates in smooth muscle cells and macrophages. CONCLUSIONS In human carotid plaques increased oxidative stress is associated with inhibition of the proteasome activity and accumulation of ubiquitin conjugates, particularly in symptomatic patients. These results suggest a possible role of the ubiquitin-proteasome system in influencing plaque stability.
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Affiliation(s)
- Daniele Versari
- Division of Cardiovascular Diseases, Mayo Clinic Rochester, 200 First St SW, Rochester, MN 55905, USA
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Nourmohammadi I, Modarress M, Pakdel F. Assessment of Aqueous Humor Zinc Status in Human Age-Related Cataract. ANNALS OF NUTRITION AND METABOLISM 2006; 50:51-3. [PMID: 16276076 DOI: 10.1159/000089565] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Accepted: 07/14/2005] [Indexed: 11/19/2022]
Abstract
Age-related cataract is an ever-increasing health problem among the elderly population worldwide. In recent years, there has been speculation that the levels of micronutrients in ocular tissue may play a role in the pathogenesis of cataract, especially zinc, since it is found in high concentrations in the eye tissues, including the aqueous humor. 44 subjects diagnosed with cataract were chosen for study and matched with 21 healthy controls to determine the concentration of zinc in aqueous humor. The findings revealed that a significantly higher concentration of zinc was present in the aqueous humor of our study population compared to controls (p < 0.001). These findings, in agreement with several previous studies, amplify the need for further investigation to determine if these higher levels are in actuality a consequence of the disease or a factor in the formation of cataract.
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Affiliation(s)
- I Nourmohammadi
- Department of Biochemistry, Cellular and Molecular Research Center, Iran University of Medical Sciences and Health Services, Tehran, Iran.
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Guest PC, Skynner HA, Salim K, Tattersall FD, Knowles MR, Atack JR. Detection of gender differences in rat lens proteins using 2-D-DIGE. Proteomics 2006; 6:667-76. [PMID: 16342238 DOI: 10.1002/pmic.200500213] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The glass-like transparency of the human eye lens is achieved by the tight packing of abundant crystallin proteins. However, the precise role of the accessory non-crystallin proteins is not well understood. We have carried out 2-DE mapping of these proteins in rat lens. This showed the presence of the high molecular weight filamentous structural proteins spectrin, filensin, tubulin, vimentin, actin and phakinin as well as several forms of potential crystallin oligomers comprised of alphaA, betaB1, betaA1 and betaA4 chains. Other proteins that were present include, heat shock protein 71, WD repeat protein 1, and several enzymes including alpha-enolase, pyruvate kinase, transketolase and aldose reductase. 2-D-DIGE analysis revealed several expression differences between the lens proteomes of male and female rats. Female rat lenses contained lower levels of aldose reductase, increased proteolyic fragments of the structural proteins filensin, vimentin and phakinin and higher levels of potential alphaA, betaB1 and betaA1 crystallin oligomers. Taken together these findings suggest that there are potential differences in oxidative stress regulation between male and female rat lenses, which may have implications on susceptibility to cataract formation. Future studies aimed at elucidating pre-cataractic changes in the non-crystallin proteins described here may facilitate identification of novel markers involved in cataractogenesis.
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Affiliation(s)
- Paul C Guest
- Neuroscience Research Centre, Merck Sharp and Dohme Research Laboratories, Harlow, UK.
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Dudek EJ, Shang F, Valverde P, Liu Q, Hobbs M, Taylor A. Selectivity of the ubiquitin pathway for oxidatively modified proteins: relevance to protein precipitation diseases. FASEB J 2005; 19:1707-9. [PMID: 16099947 DOI: 10.1096/fj.05-4049fje] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
There is now consensus that the accumulation of oxidatively modified proteins is cytotoxic and causally related to several age-related diseases, including the amyloid diseases and age-related cataracts. There is also general agreement that proteolytic pathways provide a quality control mechanism to limit accumulation of damaged proteins. Although many researchers assume that the ubiquitin pathway is involved in recognition and proteolytic removal of oxidatively modified proteins, which are produced upon cellular stress, there has been no direct evidence to support this hypothesis. In this work, we used a novel proteolysis-resistant ubiquitin variant to demonstrate that ubiquitin conjugates isolated from oxidatively stressed mammalian cells are enriched 3.3-15-fold for oxidatively modified proteins and that failure to execute ubiquitin-dependent proteolysis renders various cell types more susceptible to oxidative stress-related cytotoxicity. These results were corroborated using several inhibitors of the ubiquitin proteasome pathway, including PS-341, an anticancer drug in clinical use. Taken together the data indicate that the ubiquitin proteolytic pathway recognizes and removes oxidatively modified proteins, and that failure of this system, as occurs upon aging or stress, may be involved in and exacerbate cytotoxicity and age-related syndromes in which accumulation of ubiquitinated and oxidatively modified proteins has an etiologic role.
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Affiliation(s)
- E J Dudek
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111, USA
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Krepler K, Schmid R. Alpha-tocopherol in plasma, red blood cells and lenses with and without cataract. Am J Ophthalmol 2005; 139:266-70. [PMID: 15733987 DOI: 10.1016/j.ajo.2004.09.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2004] [Indexed: 11/20/2022]
Abstract
PURPOSE To compare levels of alpha-tocopherol in human lenses with cataract to clear human lenses and to determine associations between levels of alpha-tocopherol in plasma, red blood cells, and human lenses with cataract. DESIGN Cross-sectional study. METHODS Concentrations of alpha-tocopherol were measured by high-performance liquid chromatography in blood and in human lenses with and without cataract. Lenses were obtained during cataract surgery and from a regional eye bank. Peripheral alpha-tocopherol status in patients was assessed as plasma alpha-tocopherol (total and corrected for low-density lipoproteins) and as red blood cell bound alpha-tocopherol. Data (mean +/- standard error of the mean) are expressed as microM alpha-tocopherol/g lens protein, microM alpha-tocopherol/l plasma, microM alpha-tocopherol/g low-density lipoproteins, and microM alpha-tocopherol/T red blood cells. RESULTS Concentrations of alpha-tocopherol were measured in 27 lenses of cataract patients, 8 cadaver lenses with cataract and in 14 clear cadaver lenses. The concentration of alpha-tocopherol was significantly higher in cataract than in control cadaver lenses (0.49 +/- 0.04 vs 0.35 +/- 0.03, P < .05). The difference between alpha-tocopherol in lenses of cataract patients and control cadaver lenses was even higher (0.7 +/- 0.1 vs 0.35 +/- 0.03, P < .01). No significant correlation was observed between plasma alpha-tocopherol or red blood cell bound alpha-tocopherol and lens alpha-tocopherol in patients. CONCLUSIONS Serum and red blood cell levels of alpha-tocopherol may not reflect the alpha-tocopherol status of the lens itself and therefore may not be clinically relevant markers for cataract risk. Mechanisms leading to increased levels of alpha-tocopherol in cataract lenses need to be explored in future research.
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Affiliation(s)
- Katharina Krepler
- Departments of Ophthalmology and Optometry, Medical University of Vienna, A-1090 Vienna, Austria.
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Shih S, Weng YM, Chen S, Huang SL, Huang CH, Chen W. FT-Raman spectroscopic investigation of lens proteins of tilapia treated with dietary vitamin E. Arch Biochem Biophys 2004; 420:79-86. [PMID: 14622977 DOI: 10.1016/j.abb.2003.09.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
FT-Raman spectroscopy was employed to explore the structural changes of lens proteins in Tilapia lenses affected by dietary vitamin E supplementation. The microenvironment of major lens constituents including thiol compounds, tyrosine, and tryptophan exhibited significant change upon vitamin E treatment, while the protein secondary structure was unaltered and remained as an antiparallel beta-pleated sheet. These structures in the cortex were more susceptible to vitamin E treatment than in the nucleus. Protein sulfhydryls in the cortex were predominantly in the reduced form, while in the nucleus both the oxidized and reduced forms coexisted as evidenced by the vibrational mode of SH (2580 cm(-1)) and SS (507 cm(-1)), respectively. Both tyrosine and tryptophan were more accessible to water or more exposed in the cortex than in the nucleus. The symmetrically inverse response of vitamin E, between Raman intensity of 1090 cm(-1) and the glutathione level, was consistent with a close relationship of GSH and vitamin E in defending the lens from external insults.
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Affiliation(s)
- Shoeher Shih
- Department of Food Science, National Chiayi University, Chiayi, Taiwan
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Amar I, Aserin A, Garti N. Solubilization patterns of lutein and lutein esters in food grade nonionic microemulsions. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2003; 51:4775-4781. [PMID: 14705912 DOI: 10.1021/jf026222t] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Lutein, a naturally occurring carotenoid, is widely distributed in fruits and vegetables and is particularly concentrated in the Tagetes erecta flower. Epidemiological studies suggest that a high lutein intake (6 mg/day) increases serum levels that are associated with a lower risk of cataract and age-related macular degeneration. Lutein can either be free or esterified (myristate, palmitate, or stearate). Both are practically insoluble in aqueous systems, and their solubility in food grade solvents (oils) is very limited, resulting is low bioavailability. To improve its solubility and bioavailability, lutein was solubilized in U-type food grade microemulsions based on ethoxylated sorbitan fatty acid esters, glycerol, R-(+)-limonene, and ethanol. Some of the main findings are as follows: (1) reverse micellar and W/O compositions solubilized both luteins better than an O/W microemulsion, and maximum solubilization is obtained within the bicontinuous phase; (2) free lutein is solubilized better than the esterified one, in the W/O microemulsions, whereas the esterified lutein is better accommodated within the O/W microemulsion; (3) vegetable oils decrease the solubilization of free lutein; (4) glycerol and alcohol enhance the solubilization of both luteins; (5) solubilization is surfactant-dependent in all mesophase structures, but its strongest effect is in the bicontinuous phase.
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Affiliation(s)
- Idit Amar
- Casali Institute of Applied Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
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Bhat SP. Crystallins, genes and cataract. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2003; 60:205-62. [PMID: 12790344 DOI: 10.1007/978-3-0348-8012-1_7] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Far from being a physical entity, assembled of inanimate structural proteins, the ocular lens epitomizes the biological ingenuity that sustains an essential and near-perfect physical system of immaculate optics. Crystallins (alpha, beta, and gamma) provide transparency by dint of their high concentration, but it is debatable whether proteins that provide transparency are any different, biologically or structurally, from those that are present in non-transparent structures or tissues. It is becoming increasingly clear that crystallins may have a plethora of metabolic and regulatory functions, both within the lens as well as outside of it. Alpha-crystallins are members of a small heat shock family of proteins and beta/gamma-crystallins belong to the family of epidermis-specific differentiation proteins. Crystallin gene expression has been studied from the perspective of the lens specificity of their promoters. Mutations in alpha-, beta-, and gamma-crystallins are linked with the phenotype of the loss of transparency. Understanding catalytic, non-structural properties of crystallins may be critical for understanding the malfunction in molecular cascades that lead to cataractogenesis and its eventual therapeutic amelioration.
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Affiliation(s)
- Suraj P Bhat
- Jules Stein Eye Institute and Brain Research Institute, Geffen School of Medicine at UCLA, Los Angeles, CA 90077-7000, USA.
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Goswami S, Sheets NL, Zavadil J, Chauhan BK, Bottinger EP, Reddy VN, Kantorow M, Cvekl A. Spectrum and range of oxidative stress responses of human lens epithelial cells to H2O2 insult. Invest Ophthalmol Vis Sci 2003; 44:2084-93. [PMID: 12714647 PMCID: PMC2080867 DOI: 10.1167/iovs.02-0882] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Oxidative stress (OS) is believed to be a major contributor to age-related cataract and other age-related diseases. METHODS cDNA microarrays were used to identify the spectrum and range of genes with transcript levels that are altered in response to acute H(2)O(2)-induced OS in human lens epithelial (HLE) cells. HLE cells were treated with 50 microM H(2)O(2) for 1 hour in the absence of serum, followed by a return to complete medium. RNAs were prepared from treated and untreated cells at 0, 1, 2, and 8 hours after H(2)O(2) treatment. RESULTS The data showed 1171 genes that were significantly up- and downregulated in response to H(2)O(2) treatment. Several functional subcategories of genes were identified, including those encoding DNA repair proteins, antioxidant defense enzymes, molecular chaperones, protein biosynthesis enzymes, and trafficking and degradation proteins. Differential expression of selected genes was confirmed at the level of RNA and/or protein. Many of the identified genes (e.g., glutathione S-transferase [MGST2], thioredoxin reductase beta, and peroxiredoxin 2) have been identified as participants in OS responses in the lens and other systems. Some genes induced by OS in the current study (e.g., oxygen regulated protein [ORP150] and heat shock protein [HSP40]) are better known to respond to other forms of stress. Two genes (receptor tyrosine kinase [AXL/ARK] and protein phosphatase 2A) are known to be differentially expressed in cataract. Most of the genes point to a novel pathways associated with OS. CONCLUSIONS The present data provide a global perspective on those genes that respond to acute OS, point to novel genes and pathways associated with OS, and set the groundwork for understanding the functions of OS-related genes in lens protection and disease.
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Affiliation(s)
- Sumanta Goswami
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York
| | - Nancy L. Sheets
- Department of Biology, West Virginia University, Morgantown, West Virginia
| | - Jiři Zavadil
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - Bharesh K. Chauhan
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York
| | - Erwin P. Bottinger
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - Venkat N. Reddy
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Marc Kantorow
- Department of Biology, West Virginia University, Morgantown, West Virginia
| | - Aleš Cvekl
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, New York
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York
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Obermuller-Jevic b U, Packer a L. Vitamin E in Disease Prevention and Therapy. Antioxidants (Basel) 2003. [DOI: 10.1201/9781439822173.ch19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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