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Oezer K, Kolibabka M, Gassenhuber J, Dietrich N, Fleming T, Schlotterer A, Morcos M, Wohlfart P, Hammes HP. The effect of GLP-1 receptor agonist lixisenatide on experimental diabetic retinopathy. Acta Diabetol 2023; 60:1551-1565. [PMID: 37423944 PMCID: PMC10520173 DOI: 10.1007/s00592-023-02135-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/10/2023] [Indexed: 07/11/2023]
Abstract
AIMS Glucagon-like peptide-1 receptor agonists are effective treatments for type 2 diabetes, effectively lowering glucose without weight gain and with low risk for hypoglycemia. However, their influence on the retinal neurovascular unit remains unclear. In this study, we analyzed the effects of the GLP-1 RA lixisenatide on diabetic retinopathy. METHODS Vasculo- and neuroprotective effects were assessed in experimental diabetic retinopathy and high glucose-cultivated C. elegans, respectively. In STZ-diabetic Wistar rats, acellular capillaries and pericytes (quantitative retinal morphometry), neuroretinal function (mfERG), macroglia (GFAP western blot) and microglia (immunohistochemistry) quantification, methylglyoxal (LC-MS/MS) and retinal gene expressions (RNA-sequencing) were determined. The antioxidant properties of lixisenatide were tested in C. elegans. RESULTS Lixisenatide had no effect on glucose metabolism. Lixisenatide preserved the retinal vasculature and neuroretinal function. The macro- and microglial activation was mitigated. Lixisenatide normalized some gene expression changes in diabetic animals to control levels. Ets2 was identified as a regulator of inflammatory genes. In C. elegans, lixisenatide showed the antioxidative property. CONCLUSIONS Our data suggest that lixisenatide has a protective effect on the diabetic retina, most likely due to a combination of neuroprotective, anti-inflammatory and antioxidative effects of lixisenatide on the neurovascular unit.
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Affiliation(s)
- Kuebra Oezer
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
| | - Matthias Kolibabka
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | | | - Nadine Dietrich
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Thomas Fleming
- Department of Medicine I and Clinical Chemistry, Heidelberg University, Heidelberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Andrea Schlotterer
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Michael Morcos
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Stoffwechselzentrum Rhein-Pfalz, Belchenstraße 1-5, 68163, Mannheim, Germany
| | - Paulus Wohlfart
- Sanofi, MSAT M&I Bioassays and Compliance, Frankfurt, Germany
| | - Hans-Peter Hammes
- 5th Medical Department, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Luo WM, Zhang ZP, Zhang W, Su JY, Gao XQ, Liu X, Wang WY, Jiang CT, Fang ZZ. The Association of Homocysteine and Diabetic Retinopathy in Homocysteine Cycle in Chinese Patients With Type 2 Diabetes. Front Endocrinol (Lausanne) 2022; 13:883845. [PMID: 35846275 PMCID: PMC9276920 DOI: 10.3389/fendo.2022.883845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/25/2022] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE This study aimed to explore the relationship between homocysteine (Hcy) and diabetic retinopathy (DR) and the impacts of the Hcy pathway on this relationship against this background. METHODS This study retrieved 1979 patients with type 2 diabetes (T2D) from the First Affiliated Hospital of Liaoning Medical University in Jinzhou, Liaoning Province, China. Multiple logistic regression was used to analyze the effects of Hcy cycle on the relationship between Hcy and DR. Spearman's rank correlation analysis was used to analyze the correlation between risk factors related to DR progression and Hcy. Finally, the results of logistic regression were supplemented by mediation analysis. RESULTS We found there was a negative correlation between low concentration of Hcy and DR (OR : 0.83, 95%CI: 0.69-1). After stratifying all patients by cysteine (Cys) or Methionine (Met), this relationship remained significant only in low concentration of Cys (OR: 0.75, 95%CI: 0.61-0.94). Through the RCS curve, we found that the effect of Hcy on DR presents a U-shaped curve relationship. Mediating effect in Met and Hcy cycles was also significant [Total effect c (OR: 0.968, 95%CI: 0.938-0.998), Direct effect path c' (OR: 0.969, 95%CI: 0.940-0.999), Path a (OR: 1.047, 95%CI: 1.004-1.091), Path b (OR: 0.964, 95%CI: 0.932-0.998)]. CONCLUSIONS The relationship between Hcy and DR presents a U-shaped curve and the homocysteine cycle pathway has an impact on it. And too low concentration of Hcy indicates a lack of other substances, such as vitamins. It is suggested that the progression of DR is the result of a combination of many risk factors. Further prospective studies are needed to determine the role of Hcy in the pathogenesis of DR.
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Affiliation(s)
- Wei-Ming Luo
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Zhi-Peng Zhang
- Department of Surgery, Peking University Third Hospital, Beijing, China
| | - Wei Zhang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Jing-Yang Su
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Xiao-Qian Gao
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Xu Liu
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Wan-Ying Wang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Chang-Tao Jiang
- Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Ministry of Education, Peking University, Beijing, China
| | - Zhong-Ze Fang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China
- *Correspondence: Zhong-Ze Fang,
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Gómez X, Sanon S, Zambrano K, Asquel S, Bassantes M, Morales JE, Otáñez G, Pomaquero C, Villarroel S, Zurita A, Calvache C, Celi K, Contreras T, Corrales D, Naciph MB, Peña J, Caicedo A. Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions. NPJ Microgravity 2021; 7:35. [PMID: 34556658 PMCID: PMC8460669 DOI: 10.1038/s41526-021-00162-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 08/03/2021] [Indexed: 02/08/2023] Open
Abstract
Exposure to microgravity and ionizing radiation during spaceflight missions causes excessive reactive oxygen species (ROS) production that contributes to cellular stress and damage in astronauts. Average spaceflight mission time is expected to lengthen as humanity aims to visit other planets. However, longer missions or spaceflights will undoubtedly lead to an increment in microgravity, ionizing radiation and ROS production. Strategies to minimize ROS damage are necessary to maintain the health of astronauts, future space colonists, and tourists during and after spaceflight missions. An antioxidant cocktail formulated to prevent or mitigate ROS damage during space exploration could help maintain the health of space explorers. We propose key points to consider when developing an antioxidant cocktail. We discuss how ROS damages our body and organs, the genetic predisposition of astronauts to its damage, characteristics and evidence of the effectiveness of antioxidants to combat excess ROS, differences in drug metabolism when on Earth and in space that could modify antioxidant effects, and the characteristics and efficacy of common antioxidants. Based on this information we propose a workflow for assessing astronaut resistance to ROS damage, infight monitoring of ROS production, and an antioxidant cocktail. Developing an antioxidant cocktail represents a big challenge to translate current medical practices from an Earth setting to space. The key points presented in this review could promote the development of different antioxidant formulations to maintain space explorers' health in the future.
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Affiliation(s)
- Xavier Gómez
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
- Universidad San Francisco de Quito USFQ, Instituto de Investigaciones en Biomedicina iBioMed, Quito, Ecuador
- Mito-Act Research Consortium, Quito, Ecuador
| | - Serena Sanon
- Universidad San Francisco de Quito USFQ, Instituto de Investigaciones en Biomedicina iBioMed, Quito, Ecuador
- Cornell University, Ithaca, NY, USA
- Mito-Act Research Consortium, Quito, Ecuador
| | - Kevin Zambrano
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
- Universidad San Francisco de Quito USFQ, Instituto de Investigaciones en Biomedicina iBioMed, Quito, Ecuador
- Mito-Act Research Consortium, Quito, Ecuador
- School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, The Netherlands
| | - Samira Asquel
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Mariuxi Bassantes
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Julián E Morales
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Gabriela Otáñez
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Core Pomaquero
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Sarah Villarroel
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Alejandro Zurita
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Carlos Calvache
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Kathlyn Celi
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Terry Contreras
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Dylan Corrales
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - María Belén Naciph
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - José Peña
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador
| | - Andrés Caicedo
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias de la Salud, Escuela de Medicina, Quito, Ecuador.
- Universidad San Francisco de Quito USFQ, Instituto de Investigaciones en Biomedicina iBioMed, Quito, Ecuador.
- Mito-Act Research Consortium, Quito, Ecuador.
- Sistemas Médicos SIME, Universidad San Francisco de Quito USFQ, Quito, Ecuador.
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Dietary antioxidative supplements and diabetic retinopathy; a systematic review. J Diabetes Metab Disord 2019; 18:705-716. [PMID: 31890694 DOI: 10.1007/s40200-019-00434-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 08/20/2019] [Indexed: 12/11/2022]
Abstract
Purpose There is controversial data regarding the effects of dietary antioxidative supplements on diabetic retinopathy (DR). We conducted a systematic review of both observational and randomized controlled clinical trials (RCTs) to clarify whether they are effective or not. Methods All observational and RCTs conducted by antioxidative supplements on DR published up to 1 January 2018 in PubMed, Web of Sciences, Scopus and Cochrane Library databases were included. Exclusion criteria were animal studies, and studies conducted in Type 1 diabetes mellitus (T1DM), children or pregnant women. Main outcome measures were reporting the incidence or progression of DR in T2DM by assessment of visual fields, and measurements of oxidative and antioxidative biomarkers. The quality of reporting of included articles and risk of bias were assessed. Results Finally, we reached 14 observational studies and 7 RCTs that conducted on 256,259 subjects. Due to severe methodological heterogeneity, only qualitative synthesis was carried. All studies were reported a significantly lower level of antioxidants and higher level of oxidative stress biomarkers in DR compared with others. There was an inverse significant correlation between vitamin C and malondialdehyde (MDA) (r = -0.81) or DNA damage (r = -0.41). These figures were statistically significant between vitamin E and MDA (r = 0.77) or superoxide dismutase (r = 0.44). Coefficient of correlation between MDA and zinc (-0.82), coenzyme Q10 (0.56), and magnesium (-0.73) was significant. Multi-oxidants trials were shown non-significant beneficial effects on DR. Conclusions Although our study supports the positive effects of antioxidative supplements on DR, more high quality studies are needed to confirm.
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Park SW, Ghim W, Oh S, Kim Y, Park UC, Kang J, Yu HG. Association of vitreous vitamin C depletion with diabetic macular ischemia in proliferative diabetic retinopathy. PLoS One 2019; 14:e0218433. [PMID: 31216331 PMCID: PMC6583975 DOI: 10.1371/journal.pone.0218433] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 06/02/2019] [Indexed: 12/11/2022] Open
Abstract
Purpose Vitreous vitamin C, as an anti-oxidant, is responsible for regulating oxygen tension and oxidative stress in the eye. Oxidative stress and retinal ischemia are implicated in the development of proliferative diabetic retinopathy (PDR). In this study, we aimed to determine whether vitreous level of vitamin C is compromised in patients with PDR and to investigate the association of diabetic macular ischemia and vitamin C. Methods This prospective study enrolled forty patients who underwent pars plana vitrectomy for the treatment of PDR (PDR group, n = 20) and idiopathic epiretinal membrane (control group, n = 20). Serum, aqueous humor, and the vitreous were collected for the analysis of vitamin C level by HPLC. Diabetic macular ischemia (DMI) in PDR group was evaluated with fluorescein angiography (FA). Results PDR patients (60.4 ± 2.1 y) were younger than non-diabetic control patients (67.4 ± 1.2 y). Serum, aqueous, and vitreous levels of vitamin C in PDR were 38.7%, 22.5%, and 11.1% of non-diabetic control group, respectively. All PDR patients had DMI (grade 1: 25%, grade 2: 30%, grade 3: 30%, grade 4: 15%). DMI grade was inversely correlated with the level of vitreous vitamin C (r = -0.546, P = 0.019), not with HbA1C, serum, or aqueous vitamin C level. In addition, the level of vitreous vitamin C (4.5 ± 2.6 μg/ml) in high DMI group (Gr 3 &4) was lower than that (31.0 ± 9.1 μg/ml) in low DMI group (Gr 1&2) (P = 0.015). Conclusions Vitreous level of vitamin C in PDR patients showed a tenfold decrease, which was associated with the degree of macular ischemia. This suggests that vitreous vitamin C depletion may cause macula ischemia in PDR patients.
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Affiliation(s)
- Sung Wook Park
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul, Republic of Korea
- Retinal Degeneration Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Woonhyung Ghim
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul, Republic of Korea
- Retinal Degeneration Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Sanghyeon Oh
- Retinal Degeneration Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Interdisciplinary Program in Stem Cell Biology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Yejin Kim
- Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Un Chul Park
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul, Republic of Korea
- Retinal Degeneration Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jaeseung Kang
- Department of Anatomy, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyeong Gon Yu
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul, Republic of Korea
- Retinal Degeneration Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- * E-mail:
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Hanna KL, Hepworth LR, Rowe FJ. The treatment methods for post-stroke visual impairment: A systematic review. Brain Behav 2017; 7:e00682. [PMID: 28523224 PMCID: PMC5434187 DOI: 10.1002/brb3.682] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/15/2017] [Accepted: 02/16/2017] [Indexed: 12/23/2022] Open
Abstract
AIM To provide a systematic overview of interventions for stroke related visual impairments. METHOD A systematic review of the literature was conducted including randomized controlled trials, controlled trials, cohort studies, observational studies, systematic reviews, and retrospective medical note reviews. All languages were included and translation obtained. This review covers adult participants (aged 18 years or over) diagnosed with a visual impairment as a direct cause of a stroke. Studies which included mixed populations were included if over 50% of the participants had a diagnosis of stroke and were discussed separately. We searched scholarly online resources and hand searched articles and registers of published, unpublished, and ongoing trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Article selection was performed by two authors independently. Data were extracted by one author and verified by a second. The quality of the evidence and risk of bias was assessed using appropriate tools dependant on the type of article. RESULTS Forty-nine articles (4142 subjects) were included in the review, including an overview of four Cochrane systematic reviews. Interventions appraised included those for visual field loss, ocular motility deficits, reduced central vision, and visual perceptual deficits. CONCLUSION Further high quality randomized controlled trials are required to determine the effectiveness of interventions for treating post-stroke visual impairments. For interventions which are used in practice but do not yet have an evidence base in the literature, it is imperative that these treatments be addressed and evaluated in future studies.
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Affiliation(s)
- Kerry Louise Hanna
- Department of Health Services ResearchUniversity of LiverpoolLiverpoolUK
| | | | - Fiona J. Rowe
- Department of Health Services ResearchUniversity of LiverpoolLiverpoolUK
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Le JT, Hutfless S, Li T, Bressler NM, Heyward J, Bittner AK, Glassman A, Dickersin K. Setting Priorities for Diabetic Retinopathy Clinical Research and Identifying Evidence Gaps. Ophthalmol Retina 2017; 1:94-102. [PMID: 28717786 DOI: 10.1016/j.oret.2016.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE Prioritizing comparative effectiveness research may contribute to obtaining answers that clinicians perceive they need and may minimize research that could be considered wasteful. Our objective was to identify evidence gaps and set priorities for new systematic reviews and randomized controlled trials for managing diabetic retinopathy (DR), including diabetic macular edema (DME). DESIGN Cross-sectional study. PARTICIPANTS Diabetic Retinopathy Clinical Research Network (DRCR.net) investigators. METHODS We provided recommendations from the American Academy of Ophthalmology's 2012 Preferred Practice Patterns for Diabetic Retinopathy as 91 answerable clinical research questions about intervention effectiveness to 410 DRCR.net investigators to rate each question's importance from 0 (not important) to 10 (very important) using a 2-round Delphi survey and to suggest additional questions. We considered questions as high priority if at least 75% of respondents to both rounds assigned an importance rating of 5 or more in round 2. We also extracted outcome measures relevant to DR and asked respondents to identify those that must be measured in all studies. We mapped Cochrane reviews published up to March 2016 to high-priority clinical research questions. MAIN OUTCOME MEASURE Ranking of importance of each clinical question. RESULTS Thirty-two individuals completed rounds 1 and 2 and suggested 15 questions. Among the final list of 106 clinical research questions, 22 questions met our definition of high priority: 9 of 22 concerned the effectiveness of anti-VEGF therapy, and 13 of 22 focused on how often patients should be followed up (re-examination) and treatment effectiveness in patients with specific characteristics (e.g., DME). Outcomes that 75% or more of respondents marked as "must be measured in all studies" included visual acuity and visual loss, death of participants, and intraocular pressure. Only 1 prioritized question was associated with conclusive evidence from a Cochrane systematic review. CONCLUSIONS A limited response rate among DRCR.net members identified 22 comparative effectiveness research questions as high priority for the management of DR, including DME, but few were associated with Cochrane reviews. These results support the need of systematic reviews and randomized controlled trials to address evidence gaps.
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Affiliation(s)
- Jimmy T Le
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Susan Hutfless
- Division of Gastroenterology & Hepatology, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Tianjing Li
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Neil M Bressler
- Retina Division, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland
| | - James Heyward
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Ava K Bittner
- College of Optometry, Nova Southeastern University, Fort Lauderdale, Florida
| | - Adam Glassman
- Diabetic Retinopathy Clinical Research Network, Jaeb Center for Health Research, Tampa, Florida
| | - Kay Dickersin
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Lugo-Radillo A, Amezcua-Portillo A, Valdovinos-Ruiz DE, Perez-Chavira CJ. The consumption of a diet abundant in vegetables and fruits or the performance of non-exhaustive exercise do not protect against diabetic retinopathy: a study in a Mexican population. Int J Diabetes Dev Ctries 2015. [DOI: 10.1007/s13410-015-0360-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Eshaq RS, Wright WS, Harris NR. Oxygen delivery, consumption, and conversion to reactive oxygen species in experimental models of diabetic retinopathy. Redox Biol 2014; 2:661-6. [PMID: 24936440 PMCID: PMC4052533 DOI: 10.1016/j.redox.2014.04.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 04/15/2014] [Accepted: 04/16/2014] [Indexed: 11/30/2022] Open
Abstract
Retinal tissue receives its supply of oxygen from two sources – the retinal and choroidal circulations. Decreases in retinal blood flow occur in the early stages of diabetes, with the eventual development of hypoxia thought to contribute to pathological neovascularization. Oxygen consumption in the retina has been found to decrease in diabetes, possibly due to either a reduction in neuronal metabolism or to cell death. Diabetes also enhances the rate of conversion of oxygen to superoxide in the retina, with experimental evidence suggesting that mitochondrial superoxide not only drives the overall production of reactive oxygen species, but also initiates several pathways leading to retinopathy, including the increased activity of the polyol and hexosamine pathways, increased production of advanced glycation end products and expression of their receptors, and activation of protein kinase C. Diabetes alters oxygen delivery and consumption in the retina. Conversion of oxygen to superoxide increases in the diabetic retina. An initial production of mitochondrial superoxide generates further ROS. ROS have been found to mediate deleterious pathways in the diabetic retina.
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Affiliation(s)
- Randa S Eshaq
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - William S Wright
- Department of Biomedical Sciences, University of South Carolina School of Medicine, Greenville, SC, USA
| | - Norman R Harris
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
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Abstract
The biochemical perturbations in diabetes mellitus (DM) create the conditions for the production of free radicals, the consequence of which is increased oxidative stress. Evidence has accrued over the past 2 decades that suggests that oxidative stress is an important pathogenetic factor in the development of diabetic retinopathy (DR). Experimental data show that the use of strategies that ameliorate oxidative stress can prevent and retard the development of DR in the animal model. Clinical observations also suggest that reducing oxidative stress may help to reverse pathological manifestations of DR. The present article constitutes an examination of the role of antioxidants in the management of DR and the current state of clinically relevant knowledge.
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Affiliation(s)
- Michael Williams
- Medical Ophthalmology, Department of Ophthalmology, Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, BT12 6BA, Northern Ireland, UK
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Badr G, Mahmoud MH, Farhat K, Waly H, Al-Abdin OZ, Rabah DM. Maternal supplementation of diabetic mice with thymoquinone protects their offspring from abnormal obesity and diabetes by modulating their lipid profile and free radical production and restoring lymphocyte proliferation via PI3K/AKT signaling. Lipids Health Dis 2013; 12:37. [PMID: 23506302 PMCID: PMC3608164 DOI: 10.1186/1476-511x-12-37] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/15/2013] [Indexed: 01/12/2023] Open
Abstract
Background Epidemiological studies have shown that the offspring of mothers who experience diabetes mellitus during pregnancy are seven times more likely to develop health complications than the offspring of mothers who do not suffer from diabetes during pregnancy. The present study was designed to investigate whether supplementation of streptozotocin (STZ)-induced diabetic pregnant mice with thymoquinone (TQ) during pregnancy and lactation improves the risk of developing diabetic complications acquired by their offspring. Methods Three groups of pregnant female mice were used: non-diabetic control dams (CD), diabetic dams (DD), and diabetic dams supplemented with TQ (DD + TQ) during pregnancy and lactation (n = 10 female mice in each group). Results Our data demonstrated a marked decrease in the number of neonates born to DD, and these neonates showed a marked increase in their mean body weight (macrosomic pups) compared to those born to CD and DD + TQ. The induction of diabetes during pregnancy and lactation resulted in macrosomic pups with several postpartum complications, such as a marked increase in their levels of blood glucose, free radicals, plasma pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), and lipids, and a tendency toward abnormal obesity compared to the offspring of CD. By contrast, macrosomic offspring born to DD exhibited a marked reduction in plasma cytokine levels (IL-2, -4 and -7), an obvious reduction in the number of circulating lymphocytes, decreased proliferation of superantigen (SEB)-stimulated lymphocytes and aberrant AKT phosphorylation. Interestingly, the supplementation of DD with TQ during pregnancy and lactation had an obvious and significant effect on the number and mean body weight of neonates. Furthermore, TQ significantly restored the levels of blood glucose, insulin, free radicals, plasma cytokines, and lipids as well as lymphocyte proliferation in the offspring. Conclusions Our data suggest that the nutritional supplementation of DD with the natural antioxidant TQ during pregnancy and lactation protects their offspring from developing diabetic complications and preserves an efficient lymphocyte immune response later in life.
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Affiliation(s)
- Gamal Badr
- Princess Al-Johara Al-Ibrahim Center for Cancer Research, Prostate Cancer Research Chair, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
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Fitzpatrick AM, Jones DP, Brown LAS. Glutathione redox control of asthma: from molecular mechanisms to therapeutic opportunities. Antioxid Redox Signal 2012; 17:375-408. [PMID: 22304503 PMCID: PMC3353819 DOI: 10.1089/ars.2011.4198] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 01/22/2012] [Accepted: 01/22/2012] [Indexed: 12/11/2022]
Abstract
Asthma is a chronic inflammatory disorder of the airways associated with airway hyper-responsiveness and airflow limitation in response to specific triggers. Whereas inflammation is important for tissue regeneration and wound healing, the profound and sustained inflammatory response associated with asthma may result in airway remodeling that involves smooth muscle hypertrophy, epithelial goblet-cell hyperplasia, and permanent deposition of airway extracellular matrix proteins. Although the specific mechanisms responsible for asthma are still being unraveled, free radicals such as reactive oxygen species and reactive nitrogen species are important mediators of airway tissue damage that are increased in subjects with asthma. There is also a growing body of literature implicating disturbances in oxidation/reduction (redox) reactions and impaired antioxidant defenses as a risk factor for asthma development and asthma severity. Ultimately, these redox-related perturbations result in a vicious cycle of airway inflammation and injury that is not always amenable to current asthma therapy, particularly in cases of severe asthma. This review will discuss disruptions of redox signaling and control in asthma with a focus on the thiol, glutathione, and reduced (thiol) form (GSH). First, GSH synthesis, GSH distribution, and GSH function and homeostasis are discussed. We then review the literature related to GSH redox balance in health and asthma, with an emphasis on human studies. Finally, therapeutic opportunities to restore the GSH redox balance in subjects with asthma are discussed.
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Affiliation(s)
- Anne M Fitzpatrick
- Department of Pediatrics, Emory University, Atlanta, Georgia 30322, USA.
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Pollock A, Hazelton C, Henderson CA, Angilley J, Dhillon B, Langhorne P, Livingstone K, Munro FA, Orr H, Rowe FJ, Shahani U. Interventions for age-related visual problems in patients with stroke. Cochrane Database Syst Rev 2012:CD008390. [PMID: 22419333 DOI: 10.1002/14651858.cd008390.pub2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The prevalence of eye problems increases with age and, consequently, so does the level of visual impairment. As the incidence of stroke also increases with age, a significant proportion of stroke patients will have age-related visual problems. It is possible that the effect of interventions for age-related visual problems may differ in the population of stroke patients compared to the wider population of older people. The interaction between the problems arising directly from stroke and those arising directly from age-related visual problems will be complex. Interventions for age-related visual problems may also be affected by the presence of other stroke-related co-morbidities. Consequently, the nature and outcome of interventions for age-related visual problems may be different in patients with stroke. OBJECTIVES The aim of this review is to determine if interventions for age-related visual problems improve functional ability following stroke. SEARCH METHODS We searched the Cochrane Stroke Group Trials Register (March 2011), the Cochrane Eyes and Vision Group Trials Register (December 2009) and nine electronic bibliographic databases including: the Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 1), MEDLINE (1950 to February 2011), EMBASE (1980 to February 2011), CINAHL (1982 to February 2011), AMED (1985 to February 2011) and PsycINFO (1967 to February 2011). We also searched reference lists and trials registers, handsearched journals and conference proceedings, and contacted experts. SELECTION CRITERIA Randomised trials in adults after stroke, where the intervention is specifically targeted at assessing, treating or correcting age-related visual problems, or improving the ability of the patient to cope with visual impairment. Primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, visual acuity, visual field, visual function, balance, falls, depression and anxiety, discharge destination/residence after stroke, quality of life and social isolation, adverse events and death. DATA COLLECTION AND ANALYSIS Two review authors independently screened abstracts and planned to extract data and appraise trials. We planned that assessment of methodological quality would be undertaken for allocation concealment, blinding of outcome assessor, method of dealing with missing data and other potential sources of bias. MAIN RESULTS We considered 7357 titles, 460 abstracts and 85 full papers. We identified no studies for inclusion in this review. AUTHORS' CONCLUSIONS There are no implications for practice arising from this review. Evidence relating to the management of patients (from the general population) with age-related visual problems is available from other Cochrane reviews and is likely to be the best evidence available for making treatment decisions about individual patients. Subgroup analyses within these reviews to explore the effect of interventions for age-related visual problems in patients with stroke are recommended. We recommend that the objectives and selection criteria for this Cochrane review are amended and clarified prior to any future updates.
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Affiliation(s)
- Alex Pollock
- Nursing, Midwifery and AlliedHealth Professions Research Unit, Glasgow Caledonian University, Glasgow, UK.
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Akbar S, Bellary S, Griffiths HR. Dietary antioxidant interventions in type 2 diabetes patients: a meta-analysis. ACTA ACUST UNITED AC 2011. [DOI: 10.1177/1474651411407558] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An imbalance between reactive oxygen species (ROS) production and antioxidant scavenging has been implicated in type 2 diabetes. ROS are a byproduct in type 2 diabetes, generated during protein glycation and as a consequence of advanced glycation end-products-receptor binding; they impair insulin signalling pathways and induce cytotoxicity in pancreatic beta cells. Neutralisation of oxidants by increased antioxidant availability may mitigate these effects. Several human intervention studies have been undertaken to determine whether dietary antioxidants exert beneficial effects for type 2 diabetes patients. This paper describes a systematic review and meta-analysis of the effects of dietary supplementation with antioxidant vitamins C or E on (1) plasma glucose and insulin concentrations, as an indicator of the capacity for antioxidant to interfere with disease process and (2) on glycated haemoglobin A1C as a measure of antioxidant effects on posttranslational protein modification implicated in disease complications. Combined analysis of 14 studies that met inclusion criteria revealed that dietary antioxidant supplementation did not affect plasma glucose or insulin levels, suggesting that they could not interfere with the pathogenesis of insulin resistance. However, HbA1C levels were significantly reduced by antioxidant supplementation, suggesting that antioxidants may have some benefit in protecting against the complications of type 2 diabetes.
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Affiliation(s)
- Sarah Akbar
- Life and Health Sciences, Aston Research Centre for Healthy Ageing, Aston University, Birmingham, UK
| | - Srikanth Bellary
- Life and Health Sciences, Aston Research Centre for Healthy Ageing, Aston University, Birmingham, UK
| | - Helen R Griffiths
- Life and Health Sciences, Aston Research Centre for Healthy Ageing, Aston University, Birmingham, UK,
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Badr G, Bashandy S, Ebaid H, Mohany M, Sayed D. Vitamin C supplementation reconstitutes polyfunctional T cells in streptozotocin-induced diabetic rats. Eur J Nutr 2011; 51:623-33. [PMID: 21350934 DOI: 10.1007/s00394-011-0176-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 01/17/2011] [Indexed: 02/08/2023]
Abstract
BACKGROUND Studies have demonstrated that vitamin C supplementation enhances the immune system, prevents DNA damage, and decreases the risk of a wide range of diseases. Other study reported that leukocyte vitamin C level was low in diabetic individuals compared with nondiabetic controls. AIM OF THE WORK To study the effect of vitamin C on oxidative stress, blood lipid profile, and T-cell responsiveness during streptozotocin (STZ)-induced type I diabetes mellitus. METHODS Thirty male Sprague-Dawley rats were randomly split into three groups. The first served as a control group (n = 10) in which rats were injected with the vehicle alone. The second (n = 10) and the third groups (n = 10) were rendered diabetic by intraperitoneal (i.p.) injection of single doses of STZ (60 mg/kg body weight). The third group was supplemented with vitamin C (100 mg/kg body weight) for 2 months. RESULTS T lymphocytes from the diabetic rats were found to be in a stunned state, with a decreased surface expression of the CD28 costimulatory molecule, low levels of phosphorylated AKT, altered actin polymerization, diminished proliferation and cytokine production, and, eventually, a marked decrease in abundance in the periphery. Vitamin C was found to significantly decrease the elevated levels of blood hydroperoxide, glucose, cholesterol, triglycerides and low-density lipoprotein (LDL) in diabetic rats. Furthermore, it was found to restore CD28 expression, AKT phosphorylation, actin polymerization, and polyfunctional T cells (IFN-γ- and IL-2-producing cells that exhibit a high proliferation capacity). CONCLUSION Vitamin C treatment restores and reconstitutes polyfunctional, long-lived T cells in diabetic rats.
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Affiliation(s)
- Gamal Badr
- Zoology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
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Micronutrients and Diabetic Retinopathy. Ophthalmology 2010; 117:71-8. [DOI: 10.1016/j.ophtha.2009.06.040] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/15/2009] [Accepted: 06/19/2009] [Indexed: 01/26/2023] Open
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Abstract
Although ascorbic acid is an important water-soluble antioxidant and enzyme cofactor in plants and animals, humans and some other species do not synthesize ascorbate due to the lack of the enzyme catalyzing the final step of the biosynthetic pathway, and for them it has become a vitamin. This review focuses on the role of ascorbate in various hydroxylation reactions and in the redox homeostasis of subcellular compartments including mitochondria and endoplasmic reticulum. Recently discovered functions of ascorbate in nucleic acid and histone dealkylation and proteoglycan deglycanation are also summarized. These new findings might delineate a role for ascorbate in the modulation of both pro- and anti-carcinogenic mechanisms. Recent advances and perspectives in therapeutic applications are also reviewed. On the basis of new and earlier observations, the advantages of the lost ability to synthesize ascorbate are pondered. The increasing knowledge of the functions of ascorbate and of its molecular sites of action can mechanistically substantiate a place for ascorbate in the treatment of various diseases.
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Affiliation(s)
- J Mandl
- Department of Medical Chemistry, Molecular Biology and Patobiochemistry, Semmelweis University Budapest, Budapest, Hungary.
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