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Pan L, Wu J, Wang N. Association of Gene Polymorphisms with Normal Tension Glaucoma: A Systematic Review and Meta-Analysis. Genes (Basel) 2024; 15:491. [PMID: 38674425 PMCID: PMC11050218 DOI: 10.3390/genes15040491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Normal tension glaucoma (NTG) is becoming a more and more serious problem, especially in Asia. But the pathological mechanisms are still not illustrated clearly. We carried out this research to uncover the gene polymorphisms with NTG. METHODS We searched in Web of Science, Embase, Pubmed and Cochrane databases for qualified case-control studies investigating the association between single nucleotide polymorphisms (SNPs) and NTG risk. Odds ratios (ORs) and 95% confidence intervals (CIs) for each SNP were estimated by fixed- or random-effect models. Sensitivity analysis was also performed to strengthen the reliability of the results. RESULTS Fifty-six studies involving 33 candidate SNPs in 14 genetic loci were verified to be eligible for our meta-analysis. Significant associations were found between 16 SNPs (rs166850 of OPA1; rs10451941 of OPA1; rs735860 of ELOVL5; rs678350 of HK2; c.603T>A/Met98Lys of OPTN; c.412G>A/Thr34Thr of OPTN; rs10759930 of TLR4; rs1927914 of TLR4; rs1927911 of TLR4; c.*70C>G of EDNRA; rs1042522/-Arg72Pro of P53; rs10483727 of SIX1-SIX6; rs33912345 of SIX1-SIX6; rs2033008 of NCK2; rs3213787 of SRBD1 and c.231G>A of EDNRA) with increased or decreased risk of NTG. CONCLUSIONS In this study, we confirmed 16 genetic polymorphisms in 10 genes (OPA1, ELOVL5, HK2, OPTN, TLR4, EDNRA, P53, NCK2, SRBD1 and SIX1-SIX6) were associated with NTG.
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Affiliation(s)
- Lijie Pan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, No. 1 Dong Jiao Min Xiang Street, Dongcheng District, Beijing 100730, China;
| | - Jian Wu
- School of Life Sciences, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871, China
- Henan Academy of Innovations in Medical Science, No. 2 Biotechnology Street, Hangkonggang District, Zhengzhou 450000, China
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, No. 1 Dong Jiao Min Xiang Street, Dongcheng District, Beijing 100730, China;
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2
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Lee JY, Choi JA, Park SP, Jee D. Association Between High Blood Folate Levels and Glaucoma in a Representative Korean Population. Invest Ophthalmol Vis Sci 2024; 65:6. [PMID: 38170538 PMCID: PMC10768708 DOI: 10.1167/iovs.65.1.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 11/19/2023] [Indexed: 01/05/2024] Open
Abstract
Purpose This study aimed to investigate the association between folate levels and the prevalence of glaucoma. Methods This nationwide population-based cross-sectional study included 1790 participants aged ≥40 years. We analyzed data regarding the participants obtained in the 2016-2018 Korean National Health and Nutrition Examination Survey. The diagnosis of glaucoma was defined according to the International Society of Geographical and Epidemiological Ophthalmology criteria. Logistic regression analyses were used to investigate the relationship between blood folate levels and glaucoma. Results There was a significantly lower prevalence of glaucoma in the highest quartile of blood folate levels than in the lowest quartile, after adjusting for confounding factors such as age, sex, systemic hypertension, diabetes, hypercholesterolemia, and smoking (odds ratio [OR] = 0.470; 95% confidence interval [CI], 0.291-0.759; P for trend = 0.017). There was a significantly lower risk of glaucoma in the highest quartile of blood folate levels than in the lowest quartile among women (OR = 0.188; 95% CI, 0.099-0.357; P for trend <0.001) and younger participants (OR =0.443; 95% CI, 0.229-0.856; P for trend = 0.045). Conclusions Our findings indicate a strong inverse correlation between blood folate levels and glaucoma.
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Affiliation(s)
- Ji Young Lee
- Department of Ophthalmology and Visual Science, College of Medicine, Daejeon St. Marys’ Hospital, Catholic University of Korea, Seoul, Korea
| | - Jin A. Choi
- Department of Ophthalmology and Visual Science, College of Medicine, St. Vincent's Hospital, Catholic University of Korea, Seoul, Korea
| | - Sung Pyo Park
- Department of Ophthalmology, Hallym University Kangdong Sacred Heart Hospital, Seoul, Korea
| | - Donghyun Jee
- Department of Ophthalmology and Visual Science, College of Medicine, St. Vincent's Hospital, Catholic University of Korea, Seoul, Korea
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3
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Washington J, Ritch R, Liu Y. Homocysteine and Glaucoma. Int J Mol Sci 2023; 24:10790. [PMID: 37445966 DOI: 10.3390/ijms241310790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 06/10/2023] [Accepted: 06/11/2023] [Indexed: 07/15/2023] Open
Abstract
Elevated levels of homocysteine (Hcy), a non-proteinogenic amino acid, may lead to a host of manifestations across the biological systems, particularly the nervous system. Defects in Hcy metabolism have been associated with many neurodegenerative diseases including glaucoma, i.e., the leading cause of blindness. However, the pathophysiology of elevated Hcy and its eligibility as a risk factor for glaucoma remain unclear. We aimed to provide a comprehensive review of the relationship between elevated Hcy levels and glaucoma. Through a systemic search of the PubMed and Google Scholar databases, we found that elevated Hcy might play an important role in the pathogenesis of glaucoma. Further research will be necessary to help clarify the specific contribution of elevated Hcy in the pathogenesis of glaucoma. A discovery and conceptual understanding of Hcy-associated glaucoma could be the keys to providing better therapeutic treatment, if not prophylactic treatment, for this disease.
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Affiliation(s)
- Joshua Washington
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Robert Ritch
- New York Eye & Ear Infirmary, New York, NY 10003, USA
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- James & Jean Culver Vision Discovery Institute, 4 Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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Hirbo JB, Pasutto F, Gamazon ER, Evans P, Pawar P, Berner D, Sealock J, Tao R, Straub PS, Konkashbaev AI, Breyer MA, Schlötzer-Schrehardt U, Reis A, Brantley MA, Khor CC, Joos KM, Cox NJ. Analysis of genetically determined gene expression suggests role of inflammatory processes in exfoliation syndrome. BMC Genomics 2023; 24:75. [PMID: 36797672 PMCID: PMC9936777 DOI: 10.1186/s12864-023-09179-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 02/09/2023] [Indexed: 02/18/2023] Open
Abstract
BACKGROUND Exfoliation syndrome (XFS) is an age-related systemic disorder characterized by excessive production and progressive accumulation of abnormal extracellular material, with pathognomonic ocular manifestations. It is the most common cause of secondary glaucoma, resulting in widespread global blindness. The largest global meta-analysis of XFS in 123,457 multi-ethnic individuals from 24 countries identified seven loci with the strongest association signal in chr15q22-25 region near LOXL1. Expression analysis have so far correlated coding and a few non-coding variants in the region with LOXL1 expression levels, but functional effects of these variants is unclear. We hypothesize that analysis of the contribution of the genetically determined component of gene expression to XFS risk can provide a powerful method to elucidate potential roles of additional genes and clarify biology that underlie XFS. RESULTS Transcriptomic Wide Association Studies (TWAS) using PrediXcan models trained in 48 GTEx tissues leveraging on results from the multi-ethnic and European ancestry GWAS were performed. To eliminate the possibility of false-positive results due to Linkage Disequilibrium (LD) contamination, we i) performed PrediXcan analysis in reduced models removing variants in LD with LOXL1 missense variants associated with XFS, and variants in LOXL1 models in both multiethnic and European ancestry individuals, ii) conducted conditional analysis of the significant signals in European ancestry individuals, and iii) filtered signals based on correlated gene expression, LD and shared eQTLs, iv) conducted expression validation analysis in human iris tissues. We observed twenty-eight genes in chr15q22-25 region that showed statistically significant associations, which were whittled down to ten genes after statistical validations. In experimental analysis, mRNA transcript levels for ARID3B, CD276, LOXL1, NEO1, SCAMP2, and UBL7 were significantly decreased in iris tissues from XFS patients compared to control samples. TWAS genes for XFS were significantly enriched for genes associated with inflammatory conditions. We also observed a higher incidence of XFS comorbidity with inflammatory and connective tissue diseases. CONCLUSION Our results implicate a role for connective tissues and inflammation pathways in the etiology of XFS. Targeting the inflammatory pathway may be a potential therapeutic option to reduce progression in XFS.
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Affiliation(s)
- Jibril B Hirbo
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
- Vanderbilt Genetics Institute, Nashville, TN, 37232, USA.
| | - Francesca Pasutto
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg FAU, 91054, Erlangen, Germany
| | - Eric R Gamazon
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- Vanderbilt Genetics Institute, Nashville, TN, 37232, USA
- Clare Hall and MRC Epidemiology Unit, University of Cambridge, Cambridge, CB2 0SL, UK
| | - Patrick Evans
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Priyanka Pawar
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Daniel Berner
- Department of Ophthalmology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Julia Sealock
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Ran Tao
- Biostatistics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Peter S Straub
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Anuar I Konkashbaev
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Max A Breyer
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Ursula Schlötzer-Schrehardt
- Department of Ophthalmology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg FAU, 91054, Erlangen, Germany
| | - Milam A Brantley
- Clare Hall and MRC Epidemiology Unit, University of Cambridge, Cambridge, CB2 0SL, UK
| | - Chiea C Khor
- Genome Institute of Singapore, 60 Biopolis St, Singapore, 138672, Singapore
| | - Karen M Joos
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Nancy J Cox
- Genetic Medicine, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- Vanderbilt Genetics Institute, Nashville, TN, 37232, USA
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Effect of long-term chronic hyperhomocysteinemia on retinal structure and function in the cystathionine-β-synthase mutant mouse. Exp Eye Res 2022; 214:108894. [PMID: 34906600 PMCID: PMC9251730 DOI: 10.1016/j.exer.2021.108894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/01/2021] [Accepted: 12/08/2021] [Indexed: 02/03/2023]
Abstract
Elevated levels of the excitatory amino acid homocysteine (Hcy) have been implicated in retinal diseases in humans including glaucoma and macular degeneration. It is not clear whether elevated Hcy levels are pathogenic. Models of hyperhomocysteinemia (Hhcy) have proven useful in addressing this including mice with deficiency in the enzyme cystathionine β-synthase (CBS). Cbs+/- mice have a ∼two-fold increase in plasma and retinal Hcy levels. Previous studies of visual function and structure in Cbs+/- mice during the first 10 months of life revealed mild ganglion cell loss, but minimal electrophysiological alterations. It is not clear whether extended, chronic exposure to moderate Hhcy elevation will lead to visual function loss and retinal pathology. The present study addressed this by performing comprehensive analyses of retinal function/structure in 20 month Cbs+/- and Cbs+/+ (WT) mice including IOP, SD-OCT, scotopic and photopic ERG, pattern ERG (pERG), and visual acuity. Eyes were harvested for histology and immunohistochemical analysis of Brn3a (ganglion cells), dihydroethidium (oxidative stress) and GFAP (gliosis). The analyses revealed no difference in IOP between groups for age/strain. Visual acuity measured ∼0.36c/d for mice at 20 months in Cbs+/- and WT mice; contrast sensitivity did not differ between groups at either age. Similarly SD-OCT, scotopic/photopic ERG and pERG revealed no differences between 20 month Cbs+/- and WT mice. There was minimal disruption in retinal structure when eyes were examined histologically. Morphometric analysis revealed no significant differences in retinal layers. Immunohistochemistry revealed ∼5 RGCs/100 μm retinal length in both Cbs+/- and WT mice at 20 months. While there was greater oxidative stress and gliosis in older (20 month) mice versus young (4 month) mice, there was no difference in these parameters between the 20 month Cbs+/- and WT mice. We conclude that chronic, moderate Hhcy (at least due to deficiency of Cbs) is not accompanied by retinal structural/functional changes that differ significantly from age-matched WT littermates. Despite considerable evidence that severe Hhcy is toxic to retina, moderate Hhcy appears tolerated by retina suggesting compensatory cellular survival mechanisms.
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Yang YM, Liu YP, Li DY, Yu M, Gong B, Wang L, Shuai P. Association of MTHFR C677T polymorphism with primary open angle glaucoma: a Meta-analysis based on 18 case-control studies. Int J Ophthalmol 2021; 14:896-902. [PMID: 34150546 DOI: 10.18240/ijo.2021.06.16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 07/27/2020] [Indexed: 02/07/2023] Open
Abstract
AIM To systematically understand the genetic association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and primary open angle glaucoma (POAG). METHODS A comprehensive literature search in Google Scholar, PubMed, Science Citation Index, Foreign Medical Literature Retrieval Service, Chinese National Knowledge Infrastructure and Wanfang Databases was performed to collect all eligible studies up to August 2019. Study selection, data abstraction and study quality evaluation were performed by two independent investigators. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association. RESULTS Eighteen case-control studies including 2156 cases and 2201 controls were identified. There was no significant difference in the terms of MTHFR C677T polymorphism and POAG in the Caucasian population (for T vs C OR=1.11, 95%CI: 0.88 to 1.39; for TT vs CC OR=1.01, 95%CI: 0.76 to 1.36; for TT+TC vs CC OR=1.15, 95%CI: 0.84 to 1.58 and for TT vs TC+CC OR=1.02, 95%CI: 0.78 to 1.33). However, a significant effect was revealed in the Asian population (for T vs C OR=1.34, 95%CI: 1.12 to 1.59; for TT+TC vs CC OR=1.41, 95%CI: 1.14 to 1.76). CONCLUSION Based on 18 eligible studies, we provide a correlation between MTHFR C677T polymorphism and POAG among the Asians subgroup indicating that the T allele or TT +TC genotype may play a critical role in POAG development in Asians.
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Affiliation(s)
- Yu-Mei Yang
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan Province, China
| | - Yu-Ping Liu
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan Province, China.,School of Medicine, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan Province, China
| | - Dong-Yu Li
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan Province, China.,School of Medicine, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan Province, China
| | - Man Yu
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 611731, Sichuan Province, China
| | - Bo Gong
- School of Medicine, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan Province, China.,Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 611731, Sichuan Province, China
| | - Lin Wang
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan Province, China
| | - Ping Shuai
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, Sichuan Province, China.,School of Medicine, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan Province, China
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7
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Assessing the Performance of Daily Intake of a Homotaurine, Carnosine, Forskolin, Vitamin B2, Vitamin B6, and Magnesium Based Food Supplement for the Maintenance of Visual Function in Patients with Primary Open Angle Glaucoma. J Ophthalmol 2020; 2020:7879436. [PMID: 32411435 PMCID: PMC7201465 DOI: 10.1155/2020/7879436] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 04/07/2019] [Accepted: 12/24/2019] [Indexed: 11/17/2022] Open
Abstract
Background Glaucoma is a multifactorial optic neuropathy, which causes a continuous loss of retinal ganglion cells. Given the neurodegenerative nature of glaucoma, the necessity for neuroprotective intervention still arises, to be added alongside hypotonic therapy. Objective The objective of this study was to assess the effect of daily intake of a homotaurine, carnosine, forskolin, vitamins B1, B2, and B6, folic acid, and magnesium based supplement (GANGLIOLIFE®) on the progression rates of the visual field in patients with progressive POAG despite good tonometric compensation and to assess the most suitable dosage. Methods This is a monocentric nonrandomized experimental clinical study. Patients with mean deviation (MD) ranging from -2 dB to -15 dB with MD progression ≥1 dB in the previous year and IOP values of ≤18 mm Hg were included. All the patients underwent supplement therapy for a period of 6 months. For the first 2 months, they took 2 tablets a day, and for the following 4 months, 1 tablet a day. The patients were assessed before the start of treatment, time 0 (T 0), after 2 months (T 1), and after 6 months (T 2) of therapy. At each check-up, patients were given a full eye test including perimetry, RNFL, and GCC using FD-OCT, PERG, contrast sensitivity, and QoL evaluation using the Glaucoma Symptom Scale questionnaire and National Eye Institute Visual Function Questionnaire 25. Results 31 patients with a mean age of 70.80 ± 8.77 were included. At T 1 and T 2, the mean values of MD were lessened (MD = -5.37 ± -2.91, P < 0.01, and MD = -5.48 ± 3.15, P < 0.05, respectively) compared to T 0 (MD = -5.98 ± 2.83). Patients also demonstrated a significant reduction in IOP (P < 0.01), improved light sensitivity (P < 0.01) and contrast sensitivity (P < 0.05), and a better quality of life (P < 0.05). Conclusions Treatment with a supplement which includes homotaurine, carnosine, forskolin, vitamins B1, B2, and B6, folic acid, and magnesium has been shown to be able to slow down the rate of progression of functional damage and improve visual function after 2 and 6 months of daily intake. Quality of life showed significant improvement.
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Navneet S, Zhao J, Wang J, Mysona B, Barwick S, Ammal Kaidery N, Saul A, Kaddour-Djebbar I, Bollag WB, Thomas B, Bollinger KE, Smith SB. Hyperhomocysteinemia-induced death of retinal ganglion cells: The role of Müller glial cells and NRF2. Redox Biol 2019; 24:101199. [PMID: 31026769 PMCID: PMC6482349 DOI: 10.1016/j.redox.2019.101199] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/05/2019] [Accepted: 04/10/2019] [Indexed: 12/23/2022] Open
Abstract
Hyperhomocysteinemia (Hhcy), or increased levels of the excitatory amino acid homocysteine (Hcy), is implicated in glaucoma, a disease characterized by increased oxidative stress and loss of retinal ganglion cells (RGCs). Whether Hhcy is causative or merely a biomarker for RGC loss in glaucoma is unknown. Here we analyzed the role of NRF2, a master regulator of the antioxidant response, in Hhcy-induced RGC death in vivo and in vitro. By crossing Nrf2−/− mice and two mouse models of chronic Hhcy (Cbs+/- and Mthfr+/- mice), we generated Cbs+/-Nrf2−/− and Mthfr+/-Nrf2−/− mice and performed systematic analysis of retinal architecture and visual acuity followed by assessment of retinal morphometry and gliosis. We observed significant reduction of inner retinal layer thickness and reduced visual acuity in Hhcy mice lacking NRF2. These functional deficits were accompanied by fewer RGCs and increased gliosis. Given the key role of Müller glial cells in maintaining RGCs, we established an ex-vivo indirect co-culture system using primary RGCs and Müller cells. Hhcy-exposure decreased RGC viability, which was abrogated when cells were indirectly cultured with wildtype (WT) Müller cells, but not with Nrf2−/− Müller cells. Exposure of WT Müller cells to Hhcy yielded a robust mitochondrial and glycolytic response, which was not observed in Nrf2−/− Müller cells. Taken together, the in vivo and in vitro data suggest that deleterious effects of Hhcy on RGCs are likely dependent upon the health of retinal glial cells and the availability of an intact retinal antioxidant response mechanism. Oxidative stress is linked to homocysteine (Hcy)-induced retinal ganglion cell death. NRF2's role in protecting ganglion cells from excess Hcy was studied in vitro/vivo. Hyper-Hcy mice were crossed with Nrf2−/− mice to study retinal function/structure. Ganglion cells co-cultured with primary WT Müller glial cells survived Hcy treatment. Nrf2−/− Müller cells did not afford neuroprotective advantage to Hcy-treated cells.
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Affiliation(s)
- Soumya Navneet
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Jing Zhao
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Jing Wang
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Barbara Mysona
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Shannon Barwick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
| | - Navneet Ammal Kaidery
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA
| | - Alan Saul
- James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Ismail Kaddour-Djebbar
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Charlie Norwood VA Medical Center, One Freedom Way, Augusta, GA, 30904, USA
| | - Wendy B Bollag
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Charlie Norwood VA Medical Center, One Freedom Way, Augusta, GA, 30904, USA
| | - Bobby Thomas
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA; Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA; Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA; Department of Drug Discovery, Medical University of South Carolina, Charleston, SC, USA
| | - Kathryn E Bollinger
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA; James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA.
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9
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Wang HW, Sun P, Chen Y, Jiang LP, Wu HP, Zhang W, Gao F. Research progress on human genes involved in the pathogenesis of glaucoma (Review). Mol Med Rep 2018; 18:656-674. [PMID: 29845210 PMCID: PMC6059695 DOI: 10.3892/mmr.2018.9071] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/12/2018] [Indexed: 12/20/2022] Open
Abstract
Glaucoma is the leading cause of irreversible blindness globally. It is known that the incidence of glaucoma is closely associated with inheritance. A large number of studies have suggested that genetic factors are involved in the occurrence and development of glaucoma, and even affect the drug sensitivity and prognosis of glaucoma. In the present review, 22 loci of glaucoma are presented, including the relevant genes (myocilin, interleukin 20 receptor subunit B, optineurin, ankyrin repeat- and SOCS box-containing protein 10, WD repeat-containing protein 36, EGF-containing fibulin-like extracellular matrix protein 1, neurotrophin 4, TANK-binding kinase 1, cytochrome P450 subfamily I polypeptide 1, latent transforming growth factor β binding protein 2 and TEK tyrosine kinase endothelial) and 74 other genes (including toll-like receptor 4, sine oculis homeobox Drosophila homolog of 1, doublecortin-like kinase 1, RE repeats-encoding gene, retinitis pigmentosa GTPase regulator-interacting protein, lysyl oxidase-like protein 1, heat-shock 70-kDa protein 1A, baculoviral IAP repeat-containing protein 6, 5,10-methylenetetrahydrofolate reductase and nitric oxide synthase 3 and nanophthalmos 1) that are more closely associated with glaucoma. The pathogenesis of these glaucoma-associated genes, glaucomatous genetics and genetic approaches, as well as glaucomatous risk factors, including increasing age, glaucoma family history, high myopia, diabetes, ocular trauma, smoking, intraocular pressure increase and/or fluctuation were also discussed.
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Affiliation(s)
- Hong-Wei Wang
- Department of Ophthalmology, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Peng Sun
- Department of Ophthalmology, Longgang District People's Hospital, Shenzhen, Guangdong 518172, P.R. China
| | - Yao Chen
- Department of Ophthalmology, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Li-Ping Jiang
- Department of Ophthalmology, The First Affiliated Hospital of Qiqihar Medical University, Qiqihar, Heilongjiang 161041, P.R. China
| | - Hui-Ping Wu
- Department of The Scientific Research, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Wen Zhang
- Medical School, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Feng Gao
- Department of Hospital Administration, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
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10
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MTHFR and MTHFD1 gene polymorphisms are not associated with pseudoexfoliation syndrome in South Indian population. Int Ophthalmol 2017; 38:599-606. [DOI: 10.1007/s10792-017-0498-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 03/08/2017] [Indexed: 12/29/2022]
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Nailfold capillary morphology in exfoliation syndrome. Eye (Lond) 2017; 31:698-707. [PMID: 28085140 DOI: 10.1038/eye.2016.312] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/26/2016] [Indexed: 02/08/2023] Open
Abstract
PurposeThe purpose of the study was to investigate nailfold microvascular morphology in exfoliation syndrome with or without glaucoma (XFS/XFG) compared with primary open-angle glaucoma (POAG) and control subjects using nailfold capillary videomicroscopy.Patients and methodsWe used a JH-1004 capillaroscope to perform nailfold capillary videomicroscopy on the fourth and fifth digit of the non-dominant hand. We enrolled 56 XFS/XFG patients, 87 POAG patients, and 75 control subjects. Masked observers graded the videos for hemorrhages, avascular zones ≥200 microns (μm), and degree of microvascular tortuosity on a four-point subjective scale. Multivariable odds ratios, 95% confidence intervals and P-for trends for assessing the relation between morphological changes and POAG or XFS/XFG were obtained from logistic regression analyses. We also assessed this relation with XFS/XFG compared with POAG in multivariable models.ResultsAfter adjusting for multiple covariates, nailfold hemorrhages, avascular zones ≥200 μm, and higher degree of vascular tortuosity were more common in XFS/XFG vs controls (P-for trend ≤0.0001) and in POAG vs controls (P-for trend ≤0.01). For each 100 capillaries, the number of hemorrhages was similar (P-for trend=0.91) between XFS/XFG and POAG patients; however, there were more avascular zones per 100 capillaries with borderline significance (P-for trend=0.04) in the XFS/XFG group. XFS/XFG patients had more tortuosity than POAG patients; specifically, having a tortuosity score ≥1.5 was associated with a 4.4-fold increased odds of XFS/XFG (95% confidence interval: 1.5-13.3) relative to a tortuosity score <1.0 (P-for trend=0.005).ConclusionA high degree of nailfold capillary tortuosity is a distinct non-ocular feature associated with XFS/XFG compared with either POAG or controls.
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Aboobakar IF, Johnson WM, Stamer WD, Hauser MA, Allingham RR. Major review: Exfoliation syndrome; advances in disease genetics, molecular biology, and epidemiology. Exp Eye Res 2016; 154:88-103. [PMID: 27845061 DOI: 10.1016/j.exer.2016.11.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/06/2016] [Accepted: 11/10/2016] [Indexed: 12/20/2022]
Abstract
Exfoliation syndrome (XFS) is a common age-related disorder that leads to deposition of extracellular fibrillar material throughout the body. The most recognized disease manifestation is exfoliation glaucoma (XFG), which is a common cause of blindness worldwide. Recent developments in XFS genetics, cell biology and epidemiology have greatly improved our understanding of the etiology of this complex inherited disease. This review summarizes current knowledge of XFS pathogenesis, identifies gaps in knowledge, and discusses areas for future research.
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Affiliation(s)
- Inas F Aboobakar
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - William M Johnson
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - Michael A Hauser
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA.
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Association of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism with primary glaucoma in Saudi population. BMC Ophthalmol 2016; 16:156. [PMID: 27585654 PMCID: PMC5009653 DOI: 10.1186/s12886-016-0337-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 08/23/2016] [Indexed: 11/18/2022] Open
Abstract
Background Methylenetetrahydrofolate reductase (MTHFR), a critical enzyme in folate metabolism is involved in DNA synthesis, DNA repair and DNA methylation. The functional polymorphism of MTHFR gene, C677T has been shown to impact various diseases and implicated as a risk factor for the development of various neurodegenerative disorders including glaucoma. Methods We investigated MTHFR C677T genotypes and alleles frequencies in primary glaucoma [primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG)] patients and matched healthy controls in a case-control study. Two hundred ten primary glaucoma cases were studied for MTHFR C677T polymorphism and compared with 280 controls taken from the healthy population, employing the polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP). The MTHFR gene was amplified using specific primers. The PCR products (294 bp) was subsequently digested with HinfI (New England Biolabs) at 37 °C for 12 h, separated by electrophoresis on 2 % agarose gels, and visualized with ethidium bromide staining. The restriction digestion yielded 168 and 126 bp fragments for TT, 294, 168 and 126 bp fragments for CT and undigested PCR product 294 bp indicating CC genotype. Results We found the frequency of the genotypes and alleles of MTHFR C677T differ significantly between cases and controls. The frequencies of allele T and genotype CT were significantly higher while the frequencies of allele C and genotype CC were lower in primary glaucoma patients as compared to controls (p <0.05). Upon stratification of our results into POAG and PACG, significantly higher frequencies of allele T (19.44 %) and genotype CT (38.89 %) were found in POAG patients compared to controls (12.5 % and 25 % respectively). The frequencies of alleles and genotypes were almost similar in PACG and controls (p = 0.8). Conclusion This study indicates that the allele T and genotype CT of MTHFR C677T polymorphism are significantly associated with POAG while allele C and CC genotype may be protective for it. We conclude that the MTHFR C677T polymorphism increases the risk for POAG development in Saudi population and can be a genetic marker however, further studies are needed with multiple-ethnic populations affected with POAG to strengthen these findings.
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Leibovitzh H, Cohen E, levi A, Kramer M, Shochat T, Goldberg E, Krause I. Relationship between homocysteine and intraocular pressure in men and women: A population-based study. Medicine (Baltimore) 2016; 95:e4858. [PMID: 27661027 PMCID: PMC5044897 DOI: 10.1097/md.0000000000004858] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 08/17/2016] [Accepted: 08/19/2016] [Indexed: 12/12/2022] Open
Abstract
The relationship between homocysteine levels and glaucoma has been questioned in previous studies without conclusive results. In the current study, we assessed the relationship between homocysteine levels and intraocular pressure which is one of the main factors in the development of glaucoma in men and women.A retrospective cross-sectional analysis of a database from a screening center in Israel which assessed 11,850 subjects, within an age range 20 to 80 years. The relationship between homocysteine and intraocular pressure has been investigated by comparing intraocular pressure in subjects with elevated and normal homocysteine and by comparing homocysteine levels in subjects with elevated and normal intraocular pressure. In addition, we compared the levels of homocysteine in subjects with and without a confirmed diagnosis of glaucoma.The mean IOP (±SD) in subjects with normal homocysteine levels(≤15 μmol/L) was 13.2 ± 2.3 mm Hg and 13.4 ± 2.4 mm Hg in those with high homocysteine levels (>15 μmol/L) (P < 0.008, 95% confidence interval [CI] 0.3-0.09).Nonetheless, after multivariate adjustment for age, gender, vitamin B12, and folic acid statistical significance was no longer demonstrated (P = 0.37). Mean homocysteine levels (±SD) in subjects with normal intraocular pressure of ≤ 21 mm Hg was 11.7 ± 5.5 μmol/L and 12.09 ± 3.43 μmol/L in those with elevated intraocular pressure (P = 0.4, 95%CI 1.1-1.8). Mean homocysteine levels (±SD) in subjects with glaucoma were 11.2 ± 3.5 μmol/L compared to 11.7 ± 5.5 μmol/L in subjects without glaucoma and normal intraocular pressure ≤ 21 mm Hg (P = 0.4, 95% CI 1.2-2.1).The current study displays no clinical correlation between the homocysteine level and the intraocular pressure. Homocysteine may not be used as a predictive parameter to recognize those subjects prone to develop elevated intraocular pressure.
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Affiliation(s)
| | - Eytan Cohen
- Department of Medicine F-Recanati
- Clinical Pharmacology Unit
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | | | - Michal Kramer
- Department of Ophthalmology, Rabin Medical Center, Petah Tikva
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | | | - Elad Goldberg
- Department of Medicine F-Recanati
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - Ilan Krause
- Department of Medicine F-Recanati
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
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Plasma Homocysteine, Serum Folic Acid, Serum Vitamin B12, Serum Vitamin B6, MTHFR, and Risk of Normal-Tension Glaucoma. J Glaucoma 2016; 25:e94-8. [PMID: 26171850 DOI: 10.1097/ijg.0000000000000269] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND This meta-analysis aims to comprehensively evaluate the association between total homocysteine (tHcy) levels, serum folic acid, vitamin B12, vitamin B6 levels, methylenetetrahydrofolate reductase (MTHFR) C677T genotype, and risk of normal-tension glaucoma (NTG). MATERIALS AND METHODS A systematic search of the EMBASE and PubMed databases was performed to evaluate plasma tHcy levels, serum folic acid, B vitamins' mean difference, and odds ratios of MTHFR C677T genotype between cases and controls. RESULTS A total of 7 studies including 458 cases and 555 controls meeting the inclusion criteria were involved in this meta-analysis. There were 4 studies for tHcy (149 cases and 148 controls), 2 studies for vitamin B6, vitamin B12, and folate (90 cases and 82 controls), and 4 studies for MTHFR (343 cases and 449 controls). Overall, the mean plasma tHcy levels, serum folic acids, vitamin B12, and vitamin B6 levels were 1.16 μmol/L [95% confidence interval (CI), -0.13, 2.45], -0.62 μmol/L (95% CI, -1.98, 0.74), 5.81 μmol/L (95% CI, -3.53, 15.14), and -16.79 μmol/L (95% CI, -86.09, 52.51). MTHFR TT genotype was found to be unrelated to NTG risk (odds ratio=1.08; 95% CI, 0.69, 1.69). CONCLUSION NTG is not associated with elevated plasma tHcy, serum folic acid, serum vitamin B12, serum vitamin B6, and MTHFR C677T genotype.
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Homocysteine in ocular diseases. Clin Chim Acta 2015; 450:316-21. [PMID: 26343924 DOI: 10.1016/j.cca.2015.09.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/01/2015] [Accepted: 09/03/2015] [Indexed: 11/21/2022]
Abstract
Homocysteine (Hcy) is a derived sulfur-containing and non-proteinogenic amino acid. The metabolism of Hcy occurs either through the remethylation to methionine or transsulfuration to cysteine. Studies have identified hyperhomocysteinemia (HHcy) as one of the possible risk factors for a multitude of diseases including vascular, neurodegenerative and ocular diseases. Association of HHcy with eye diseases such as retinopathy, pseudoexfoliative glaucoma maculopathy, cataract, optic atrophy and retinal vessel atherosclerosis is established. The molecular mechanism underlying these ocular diseases has been reported as impaired vascular endothelial function, apoptosis of retinal ganglion cells, extracellular matrix alterations, decreased lysyl oxidase activity and oxidative stress. The formed homocysteine-thiolactone in HHcy has stronger cytotoxicity and pro-inflammatory properties which can induce lens opacification and optic nerve damage. The metabolism of Hcy requires enzymes with vitamins such as folic acid, vitamins B12 and B6. Despite the mixed conclusion of various studies regarding the level of these vitamins in elder people, studies recommended the treatment with folate and B12 to reduce Hcy levels in subjects with or without any defect in the enzymes involved in its metabolism. The levels of Hcy, folate, B6 as well as B12 should be measured early in patients with visual impairment that would aid to screen patients for life-threatening disorders related with HHcy. Elder patients may supplement with these vitamins in order to attenuate the ocular damages. This article discusses the association of Hcy in ocular diseases and the possible mechanism in the pathogenesis.
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Weisfeld-Adams JD, McCourt EA, Diaz GA, Oliver SC. Ocular disease in the cobalamin C defect: a review of the literature and a suggested framework for clinical surveillance. Mol Genet Metab 2015; 114:537-46. [PMID: 25742969 DOI: 10.1016/j.ymgme.2015.01.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 01/28/2015] [Accepted: 01/28/2015] [Indexed: 01/23/2023]
Abstract
The association between combined methylmalonic acidemia and homocystinuria of cblC type (cobalamin C defect, cblC) and ocular disease is now well recognized, and is a significant component of morbidity and disability associated with the condition. In this review, through collation of historically reported cases of early- and late-onset cblC and previously unreported cases, we have attempted to characterize the epidemiology, clinical features, and pathomechanisms of individual ocular features of cblC. These data suggest that maculopathy and nystagmus with abnormal vision are extremely common and affect the majority of children with early-onset cblC, usually before school age; strabismus and optic atrophy are also seen at relatively high frequency. The timing of progression of macular disease may coincide with a critical period of postnatal foveal development. Maculopathy and retinal disease may be subclinical and show only partial correlation with the extent of visual deficits, and visual deterioration may be relentlessly progressive in spite of aggressive treatment of biochemical abnormalities. In later-onset forms of the disease, visual loss and ocular complications appear to be infrequent. Finally, we discuss investigational strategies in diagnosing and characterizing eye disease in individuals with cblC, explore possible therapeutic avenues that may attenuate progression and severity of eye disease, and propose a clinical surveillance guideline for monitoring progression of ocular disease in children and adults with cblC.
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Affiliation(s)
- James D Weisfeld-Adams
- Children's Hospital Colorado, Aurora, CO, USA; Division of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Emily A McCourt
- Children's Hospital Colorado, Aurora, CO, USA; Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, USA
| | - George A Diaz
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Scott C Oliver
- Children's Hospital Colorado, Aurora, CO, USA; Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, USA
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Zhao R, Yin D, Wang E, Si B. The effect of MTHFR ala222val polymorphism on open-angle glaucoma: a meta-analysis. Ophthalmic Genet 2014; 36:27-30. [PMID: 25317717 DOI: 10.3109/13816810.2014.969379] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Glaucoma is the second leading cause of irreversible blindness worldwide, among which primary open-angle glaucoma (POAG) is the most common form of glaucoma in some populations. To date, published data on the association between MTHFR (Ala222Val) polymorphism and POAG risk are still inconclusive. In this work, we performed a meta-analysis of available case-control study in order to assess the association between MTHFR (Ala222Val) polymorphism and POAG susceptibility. In total we compiled 13 studies (1970 POAG patients and 1712 control subjects) into the meta-analysis. Overall, no obvious associations between MTHFR (Ala222Val) polymorphism and POAG susceptibility was found under all four genetic models (Val/Val versus Ala/Ala: OR = 1.05, 95% CI = 0.77-1.43; Ala/Val versus Ala/Ala: OR = 1.05, 95% CI = 0.86-1.26; Ala/Val + Val/Val versus Ala/Ala: OR = 1.08, 95% CI = 0.87-1.34; Val/Val versus Ala/Val + Ala/Ala: OR = 1.14, 95% CI = 0.67-1.92). In the stratified analysis by ethnicity, significant associations were still not observed in all genetic models. In conclusion, based on 13 eligible studies, the result provided strong evidences that MTHFR Ala222Val polymorphism is not associated with POAG.
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Affiliation(s)
- Rong Zhao
- Ophthalmology Department, General Hospital of Air Force , Beijing , China
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19
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Zacharaki F, Hadjigeorgiou GM, Koliakos GG, Morrison MA, Tsezou A, Chatzoulis DZ, Almpanidou P, Topouridou K, Karabatsas CH, Pefkianaki M, DeAngelis MM, Tsironi EE. Plasma homocysteine and genetic variants of homocysteine metabolism enzymes in patients from central Greece with primary open-angle glaucoma and pseudoexfoliation glaucoma. Clin Ophthalmol 2014; 8:1819-25. [PMID: 25246760 PMCID: PMC4166342 DOI: 10.2147/opth.s64904] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The purpose of this study was to investigate plasma homocysteine levels and polymorphisms in genes encoding enzymes in the metabolic pathway of homocysteine in association with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXFG). METHODS A total of 156 glaucoma patients (76 with POAG and 80 with PXFG) and 135 controls matched for age and sex were enrolled in this study. Plasma homocysteine levels were measured using a commercially available enzyme-linked immunosorbent assay kit. DNA was extracted from peripheral blood leukocytes and real-time polymerase chain reaction was performed for genotyping of the samples. Patients were genotyped using predesigned TaqMan(®) single nucleotide polymorphism genotyping assays for two exon variations (rs1801131, rs1801133) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and one intron variation (rs8006686) in the methylenetetrahydrofolate dehydrogenase (MTHFD1) gene. RESULTS Homocysteine levels were slightly higher in the patient group (POAG and PXFG) compared with controls, but the difference did not reach statistical significance. The minor alleles of the MTHFR single nucleotide polymorphisms showed a protective effect for POAG and showed an increased risk for PXFG, but none of these associations reached statistical significance (P>0.05). The minor allele of MTHFD1 rs8006686 showed a trend for increased risk of both POAG and PXFG (P>0.05). No statistically significant interaction was seen between the genetic variants and homocysteine levels (P>0.05). CONCLUSION Our results show that neither the examined single nucleotide polymorphisms from genes involved in the pathway of homocysteine metabolism nor the measured homocysteine levels were associated with POAG or PXFG in our study cohort.
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Affiliation(s)
- Fani Zacharaki
- Department of Ophthalmology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | | | - Georgios G Koliakos
- Department of Biochemistry, Medical School, Aristotles University of Thessaloniki, Thessaloniki, Greece
| | - Margaux A Morrison
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Aspasia Tsezou
- Department of Biology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Dimitrios Z Chatzoulis
- Department of Ophthalmology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Pavlina Almpanidou
- Department of Ophthalmology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Konstantina Topouridou
- Department of Biochemistry, Medical School, Aristotles University of Thessaloniki, Thessaloniki, Greece
| | | | - Maria Pefkianaki
- Department of Ophthalmology, Faculty of Medicine, University of Thessaly, Larissa, Greece
| | - Margaret M DeAngelis
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Evangelia E Tsironi
- Department of Ophthalmology, Faculty of Medicine, University of Thessaly, Larissa, Greece
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Andrikopoulos GK, Alexopoulos DK, Gartaganis SP. Pseudoexfoliation syndrome and cardiovascular diseases. World J Cardiol 2014; 6:847-854. [PMID: 25228963 PMCID: PMC4163713 DOI: 10.4330/wjc.v6.i8.847] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/09/2014] [Accepted: 06/11/2014] [Indexed: 02/06/2023] Open
Abstract
Pseudoexfoliation (PEX) syndrome is a well-recognized late-onset disease caused by a generalized fibrillopathy. It is linked to a broad spectrum of ocular complications including glaucoma and perioperative problems during cataract surgery. Apart from the long-known intraocular manifestations, PEX deposits have been found in a variety of extraocular locations and they appear to represent a systemic process associated with increased cardiovascular and cerebrovascular morbidity. However, as published results are inconsistent, the clinical significance of the extraocular PEX deposits remains controversial. Identification of PEX deposits in the heart and the vessel wall, epidemiologic studies, as well as, similarities in pathogenetic mechanisms have led to the hypothesis of a possible relation between fibrillar material and cardiovascular disease. Recent studies suggest that PEX syndrome is frequently linked to impaired heart and blood vessels function. Systemic and ocular blood flow changes, altered parasympathetic vascular control and baroreflex sensitivity, increased vascular resistance and decreased blood flow velocity, arterial endothelial dysfunction, high levels of plasma homocysteine and arterial hypertension have all been demonstrated in PEX subjects. Common features in the pathogenesis of both atherosclerosis and PEX, like oxidative stress and inflammation and a possible higher frequency of abdominal aorta aneurysm in PEX patients, could imply that these grey-white deposits and cardiovascular disorders are related or reflect different manifestations of the same process.
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Endothelin-1 levels and biomarkers of oxidative stress in glaucoma patients. Int Ophthalmol 2014; 35:527-32. [DOI: 10.1007/s10792-014-9979-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 07/15/2014] [Indexed: 12/27/2022]
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Choo BJ, Hwang YH, Lee JH, Kim TJ. Comparison of Serum Homocysteine, Vitamin B12, Vitamin B6 and Folate Levels in Different Glaucoma Types. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2013. [DOI: 10.3341/jkos.2013.54.1.104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Byung Ju Choo
- Department of Ophthalmology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Young Hoon Hwang
- Department of Ophthalmology, Kim's Eye Hospital, Myung-Gok Eye Research Institute, Konyang University, Seoul, Korea
| | - Joo Hwa Lee
- Department of Ophthalmology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Tai Jin Kim
- Department of Ophthalmology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
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Xu F, Zhao X, Zeng SM, Li L, Zhong HB, Li M. Homocysteine, B Vitamins, Methylenetetrahydrofolate Reductase Gene, and Risk of Primary Open-Angle Glaucoma. Ophthalmology 2012; 119:2493-9. [DOI: 10.1016/j.ophtha.2012.06.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 06/15/2012] [Accepted: 06/15/2012] [Indexed: 11/25/2022] Open
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Buentello-Volante B, Elizondo-Olascoaga C, Miranda-Duarte A, Guadarrama-Vallejo D, Cabral-Macias J, Zenteno JC. Association study of multiple gene polymorphisms with the risk of adult-onset primary open-angle glaucoma in a Mexican population. Exp Eye Res 2012. [PMID: 23206929 DOI: 10.1016/j.exer.2012.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The aim of this study was to investigate the association of multiple primary open-angle glaucoma (POAG)-risk alleles in a Mexican population for the first time. Genotyping was performed for a total of 26 previously associated alleles located in 11 different genes, including MYOC, CYP1B1, OPTN, IL1A, TNF, OPA1, EDNRA, AGTR2, MTHFR, GSTM1, and GSTT1. The frequencies of these variants were compared in a group of 218 individuals (118 with POAG and 100 adult controls without the disease). Genomic DNA was extracted from blood leukocytes, and genotyping was performed using PCR followed by direct sequencing. GSTM1 and GSTT1 deletion variants were screened by agarose gel analysis. Individual SNP analysis showed that no specific variants conferred an elevated risk for developing POAG. However, the CG genotype for rs5335 polymorphism in EDNRA showed a protective effect against the development of POAG, as it provides an estimated odds ratio of 0.5 (95% CI, 0.3-0.9; p = 0.03). Moreover, one haplotype consisting of rs1056827 and rs100012 in CYP1B1 gene was significantly associated with a protective effect against POAG (p = 0.0045; OR = 0.3; 95% CI, 0.1-0.7). This is the first case-control investigation of POAG-risk alleles in multiple genes in a Latino population. Although our results support that the analyzed variants are not major risk factors for POAG in this ethnic group, they also point toward a protective effect conferred by EDNRA rs5335, as well as by a CYP1B1 haplotype consisting of rs1056827 and rs100012. Our study emphasizes the importance of genotyping ethnic groups with a complex admixture of ancestral populations for contributing to dissecting the genetics of POAG.
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Huo Y, Zou H, Lang M, Ji SX, Yin XL, Zheng Z, Liu W, Chen CL, Yuan RD, Ye J. Association between MTHFR C677T polymorphism and primary open-angle glaucoma: a meta-analysis. Gene 2012; 512:179-84. [PMID: 23123730 DOI: 10.1016/j.gene.2012.10.067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 10/16/2012] [Accepted: 10/25/2012] [Indexed: 10/27/2022]
Abstract
Epidemiological studies have evaluated the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and primary open-angle glaucoma (POAG) risk. However, the results remain conflicting. The aim of this study was to investigate the association between MTHFRC677T polymorphism and POAG risk. All genetic association studies on MTHFR C677T polymorphism and POAG were systematically searched by the electronic databases PubMed, Embase and Web of Science. Study selection, data abstraction and study quality evaluation were conducted in duplicate independently. The strength of association between MTHFR C677T polymorphism and POAG was measured by odds ratios (ORs) and 95% confidence intervals (CIs). Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 10 studies including 1224 cases and 1105 controls were included in our final meta-analysis. There was no evidence of significant association of the overall population (for allelic model: OR=1.17, 95% CI=0.94-1.46; for additive model: OR=1.15, 95% CI=0.85-1.57; for dominant model: OR=1.19, 95% CI=0.92-1.55 and for recessive model: OR=1.11, 95% CI=0.83-1.49). Significant associations were found between MTHFR C677T polymorphisms and POAG in allelic model (OR=1.39, 95% CI=1.05-1.83) and additive model (OR=1.88, 95% CI=1.04-3.43) for population-based (PB) subgroup. This meta-analysis suggested that there were significant associations between MTHFR C677T polymorphism and POAG in allelic model and additive model for PB subgroup which indicated that the T allele or TT genotype might increase the risk of POAG, whereas no evidence of significant association was shown of the overall studied population. However, this conclusion should be interpreted cautiously. More large sample-size and multi-ethnicity studies with well-defined POAG patients and well-study design are needed in the future study.
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Affiliation(s)
- Yan Huo
- Department of Ophthalmology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China
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Sarici AM, Yetik H, Akar S, Arvas S. The Association between Serum Homocysteine Levels and Retinopathy of Prematurity. J Int Med Res 2012. [DOI: 10.1177/030006051204000532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Objective: To evaluate the relationship between serum total homocysteine levels and retinopathy of prematurity (ROP). Methods: This prospective case-control study involved premature infants diagnosed with ROP 4 weeks after birth (cases); controls were premature infants not developing ROP during follow-up. Fasting serum total homocysteine concentrations were determined in all participants 4 weeks after birth, using high performance liquid chromatography. Results: A total of 45 and 35 infants were included in the case and control groups, respectively. The mean ± SD (range) serum total homocysteine levels were 10.36 ± 1.72 μmol/l (7.45 - 14.84) in infants with ROP and 8.41 ± 2.12 μmol/l (5.56 - 13.90) in controls. This difference was statistically significant. Mean ± SD total homocysteine levels were higher in infants with more severe ROP (11.45 ± 1.76 μmol/l) compared with mild ROP (9.92 ± 1.56 μmol/l). Conclusions: Elevated serum total homocysteine levels are associated with the development of ROP in premature infants. Further studies with larger patient populations are required, to improve understanding of the relationship between homocysteine and ROP development.
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Affiliation(s)
- AM Sarici
- Department of Ophthalmology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - H Yetik
- Department of Ophthalmology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - S Akar
- Department of Ophthalmology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - S Arvas
- Department of Ophthalmology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
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Ghanem AA, Mady SM, El awady HE, Arafa LF. Homocysteine and Hydroxyproline Levels in Patients with Primary Open-Angle Glaucoma. Curr Eye Res 2012; 37:712-8. [DOI: 10.3109/02713683.2012.669512] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Age-related changes in visual function in cystathionine-beta-synthase mutant mice, a model of hyperhomocysteinemia. Exp Eye Res 2011; 96:124-31. [PMID: 22197750 DOI: 10.1016/j.exer.2011.12.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 12/06/2011] [Accepted: 12/09/2011] [Indexed: 11/24/2022]
Abstract
Homocysteine is an amino acid required for the metabolism of methionine. Excess homocysteine is implicated in cardiovascular and neurological disease and new data suggest a role in various retinopathies. Mice lacking cystathionine-beta-synthase (cbs(-/-)) have an excess of retinal homocysteine and develop anatomical abnormalities in multiple retinal layers, including photoreceptors and ganglion cells; heterozygous (cbs(+/-)) mice demonstrate ganglion cell loss and mitochondrial abnormalities in the optic nerve. The purpose of the present study was to determine whether elevated homocysteine, due to absent or diminished cbs, alters visual function. We examined cbs(-/-) (3 weeks) and cbs(+/-) mice (5, 10, 15, 30 weeks) and results were compared to those obtained from wild type (WT) littermates. Conventional dark- and light-adapted ERGs were recorded, along with dc-ERG to assess retinal pigment epithelial (RPE) function. The visual evoked potential (VEP) was used to assess transmission to the visual cortex. The amplitudes of the major ERG components were reduced in cbs(-/-) mice at age 3 weeks and VEPs were delayed markedly. These findings are consistent with the early retinal disruption observed anatomically in these mice. In comparison, at 3 weeks of age, responses of cbs(+/-) mice did not differ significantly from those of WT mice. Functional abnormalities were not observed in cbs(+/-) mice until 15 weeks of age, at which time amplitude reductions were noted for the ERG a- and b-wave and the light peak component, but not for other components generated by the RPE. VEP implicit times were delayed in cbs(+/-) mice at 15 and 30 weeks, while VEP amplitudes were unaffected. The later onset of functional defects in cbs(+/-) mice is consistent with a slow loss of ganglion cells reported previously in the heterozygous mutant. Light peak abnormalities indicate that RPE function is also compromised in older cbs(+/-) mice. The data suggest that severe elevations of homocysteine are associated with marked alterations of retinal function while modest homocysteine elevation is reflected in milder and delayed alterations of retinal function. The work lays the foundation to explore the role of homocysteine in retinal diseases such as glaucoma and optic neuropathy.
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Xu F, Zhang L, Li M. Plasma homocysteine, serum folic acid, serum vitamin B12, serum vitamin B6, MTHFR and risk of pseudoexfoliation glaucoma: a meta-analysis. Graefes Arch Clin Exp Ophthalmol 2011; 250:1067-74. [DOI: 10.1007/s00417-011-1877-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 11/06/2011] [Accepted: 11/15/2011] [Indexed: 12/29/2022] Open
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Ganapathy PS, Perry RL, Tawfik A, Smith RM, Perry E, Roon P, Bozard BR, Ha Y, Smith SB. Homocysteine-mediated modulation of mitochondrial dynamics in retinal ganglion cells. Invest Ophthalmol Vis Sci 2011; 52:5551-8. [PMID: 21642619 DOI: 10.1167/iovs.11-7256] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To evaluate the effect of excess homocysteine on the regulation of retinal ganglion cell mitochondrial dynamics. METHODS Mice deficient in cystathionine-β-synthase (cbs) were used as a model of hyperhomocysteinemia. Gene and protein expression analyses of Opa1 and Fis1 were performed on cbs⁺/⁻ neural retinas. Mitochondria within retinal ganglion cell axons underwent systematic ultrastructural analysis to measure area, length, width, and the distance between the mitochondria and the axon wall. Primary mouse ganglion cells were cultured, treated with homocysteine, and assessed for levels of Opa1 and Fis1 protein, the number of mitochondria per length of neurite, and levels of cleaved caspase-3. RESULTS Opa1 and Fis1 protein levels in cbs⁺/⁻ neural retinas were elevated to 191.00% ± 26.40% and 226.20% ± 4.57%, respectively, compared with wild-type. Mitochondria of cbs⁺/⁻ retinas were smaller in all parameters studied, including area (0.32 ± 0.01 μm² vs. 0.42 ± 0.02 μm²), compared with wild-type. Primary ganglion cells treated with homocysteine had elevations in Opa1 and Fis1 proteins, a significantly higher number of mitochondria per length of neurite (0.1781 ± 0.017 vs. 0.1156 ± 0.012), and significantly higher levels of cleaved caspase-3 compared with control. CONCLUSIONS This study provides the first evidence that homocysteine-induced ganglion cell loss involves the dysregulation of mitochondrial dynamics, both in vivo and in vitro. The present data suggest increased mitochondrial fission as a novel mechanism of homocysteine toxicity to neurons. Of particular relevance are glaucoma and Alzheimer's disease, neurodegenerative diseases that are associated with hyperhomocysteinemia and, more recently, have implicated increased mitochondrial fission in their pathogeneses.
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Affiliation(s)
- Preethi S Ganapathy
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia, USA
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31
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Ganapathy PS, White RE, Ha Y, Bozard BR, McNeil PL, Caldwell RW, Kumar S, Black SM, Smith SB. The role of N-methyl-D-aspartate receptor activation in homocysteine-induced death of retinal ganglion cells. Invest Ophthalmol Vis Sci 2011; 52:5515-24. [PMID: 21436276 DOI: 10.1167/iovs.10-6870] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Elevated plasma homocysteine has been implicated in glaucoma, a vision disorder characterized by retinal ganglion cell death. The toxic potential of homocysteine to ganglion cells is known, but the mechanisms are not clear. A mechanism of homocysteine-induced death of cerebral neurons is via N-methyl-D-aspartate (NMDA) receptor overstimulation, leading to excess calcium influx and oxidative stress. This study examined the role of the NMDA receptor in homocysteine-mediated ganglion cell death. METHODS Primary mouse ganglion cells were used for these experiments. NMDA receptor stimulation by homocysteine was determined by patch clamp analysis and fluorescent detection of intracellular calcium. NMDA receptor involvement in homocysteine-mediated cell death was determined through assessment of lactate dehydrogenase release and TUNEL analysis. These experiments used the NMDA receptor blocker MK-801. Induction of reactive species superoxide, nitric oxide, and peroxynitrite was measured by electron paramagnetic resonance spectroscopy, chemiluminescent nitric oxide detection, and immunoblotting for nitrotyrosine, respectively. RESULTS 50 μM homocysteine stimulated the NMDA receptor in presence of 100 μM glycine. Homocysteine induced 59.67 ± 4.89% ganglion cell death that was reduced to 19.87 ± 3.03% with cotreatment of 250 nM MK-801. Homocysteine elevated intracellular calcium ∼7-fold, which was completely prevented by MK-801. Homocysteine treatment increased superoxide and nitric oxide levels by ∼40% and ∼90%, respectively, after 6 hours. Homocysteine treatment elevated peroxynitrite by ∼85% after 9 hours. CONCLUSIONS These experiments provide compelling evidence that homocysteine induces retinal ganglion cell toxicity through direct NMDA receptor stimulation and implicate, for the first time, the induction of oxidative stress as a potent mechanism of homocysteine-mediated ganglion cell death.
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Affiliation(s)
- Preethi S Ganapathy
- Department of Cellular Biology and Anatomy, Georgia Health Sciences, University, Medical College of Georgia, Augusta, GA, USA
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Abstract
Glaucoma, a leading cause of blindness worldwide, is characterized by progressive optic nerve damage, usually associated with intraocular pressure. Although the clinical progression of the disease is well defined, the molecular events responsible for glaucoma are currently poorly understood and current therapeutic strategies are not curative. This review summarizes the human genetics and genomic approaches that have shed light on the complex inheritance of glaucoma genes and the potential for gene-based and cellular therapies that this research makes possible.
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Affiliation(s)
- Bao Jian Fan
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
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Tranchina L, Centofanti M, Oddone F, Tanga L, Roberti G, Liberatoscioli L, Cortese C, Manni G. Levels of plasma homocysteine in pseudoexfoliation glaucoma. Graefes Arch Clin Exp Ophthalmol 2010; 249:443-8. [PMID: 20740289 DOI: 10.1007/s00417-010-1487-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 07/26/2010] [Accepted: 08/03/2010] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND To examine levels of serum homocysteine (Hcy), vitamin B12 and folic acid in patients with pseudoexfoliation glaucoma (PEXG), primary open-angle glaucoma (POAG), and healthy control subjects. METHODS This study included 36 patients with PEXG, 40 with POAG, and 40 age-matched healthy subjects. Fasting plasma Hcy concentrations and levels of serum vitamin B12 and folic acid were measured using competitive chemiluminescent enzyme immunoassay; values exceeding 14 μm/l were considered elevated. RESULTS Mean plasma Hcy was significantly higher in PEXG (16.55 ± 7.23 μm/l) compared with POAG (13.91 ± 3.61 μm/l) and controls (13.12 ± 5.13 μm/l) (p = 0.03 and p = 0.0007 respectively). There were no statistical differences in serum vitamin B12 and folic acid levels among PEXG, POAG and control subjects (p > 0.05). A moderate, although statistically significant, relationship between Hcy and folic acid levels was found in the PEXG group (R(2) = 0.23, p = 0.003). Hcy levels were found not to be related with folic acid or vitamin B12 in either POAG or control subjects. CONCLUSIONS In this study, plasma Hcy is significantly higher in PEXG group than the POAG and control groups. Hyper-Hcy might play a role in the pathogenesis of PEXG. Hyper-Hcy may be an independent factor stressing vasculopathy in addition to pseudoexfoliation, so might be a modifiable risk factor for PEXG.
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Affiliation(s)
- Laura Tranchina
- Department of Biopathology, Ophthalmology Division, University of Rome Tor Vergata and Fondazione PTV Policlinico Tor Vergata, Via Montpellier, 1 - 00133, Rome, Italy.
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Turgut B, Kaya M, Arslan S, Demir T, Güler M, Kaya MK. Levels of circulating homocysteine, vitamin B6, vitamin B12, and folate in different types of open-angle glaucoma. Clin Interv Aging 2010; 5:133-9. [PMID: 20458351 PMCID: PMC2861848 DOI: 10.2147/cia.s9918] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE To compare the levels of plasma homocysteine (Hcy), vitamin B6 (vit-B6), serum vitamin B12 (vit-B12), and folate in healthy individuals and in patients with normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), or primary open-angle glaucoma (POAG). STUDY DESIGN A prospective controlled trial. PARTICIPANTS AND METHODS Forty healthy subjects, 48 patients with NTG, 38 patients with PXG, and 34 patients with POAG were included in the study. Those who used vitamin supplements or medications affecting Hcy and vitamin levels were excluded from the study. The levels of Hcy and vit-B6 were measured by High Performance Liquid Chromatography (HPLC). The levels of serum vit-B12 and folic acid were measured by competitive chemiluminescent enzyme immunoassay (CEI). One-way analysis if variance (ANOVA), analysis of covariance (ANCOVA), and the Tukey honestly significant difference test were used for statistical analysis. RESULTS The mean Hcy level of the PXG group was 15.46+/-9.27 micromol/L which was significantly higher (P=0.03) than that of the control group. There were no statistical differences in serum vit-B12 and folate levels among control subjects and NTG, PXG and POAG groups (P>0.05). It was found that the mean plasma vit-B6 level was significantly higher in subjects with NTG (P=0.03) and POAG (P=0.025) versus controls. Mean vit-B6 levels in NTG and POAG were 30.50+/-11.29 microg/L and 30+/-12.15 microg/L, respectively. CONCLUSIONS The plasma level of Hcy was found to be increased only in PXG patients and the plasma levels of vit-B6 were found to increase in the NTG and POAG sample groups. Using homocysteine and vit-B6 levels as the determinants of hyperhomocysteinemia still needs further research.
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Affiliation(s)
- Burak Turgut
- Firat University School of Medicine, Department of Ophthalmology, Elaziğ, Turkey.
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Ganapathy PS, Dun Y, Ha Y, Duplantier J, Allen JB, Farooq A, Bozard BR, Smith SB. Sensitivity of staurosporine-induced differentiated RGC-5 cells to homocysteine. Curr Eye Res 2010; 35:80-90. [PMID: 20021258 DOI: 10.3109/02713680903421194] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Homocysteine is implicated in ganglion cell death associated with glaucoma. To understand mechanisms of homocysteine-induced cell death, we analyzed the sensitivity of the RGC-5 cell line, differentiated using staurosporine, to physiologically-relevant levels of the excitotoxic amino acid homocysteine. METHODS RGC-5 cells were differentiated 24 hr using 316 nM staurosporine and tested for expression of Thy 1.2 via immunodetection, RT-PCR, and immunoblotting. The sensitivity of staurosporine-differentiated RGC-5 cells to physiological levels of homocysteine (50, 100, 250 microM) and to high levels of homocysteine (1 mM), glutamate (1 mM), and oxidative stress (25 microM:10 mU/ml xanthine:xanthine oxidase) was assessed by TUNEL assay and by immunodetection of cleaved caspase-3. The sensitivity of undifferentiated RGC-5 cells to high (1, 5, and 10 mM) homocysteine was also examined. RESULTS Undifferentiated RGC-5 cells express Thy 1.2 mRNA and protein. Staurosporine-differentiated RGC-5 cells extend neurite processes and express Thy 1.2 after 24 hr differentiation; they express NF-L after 1 and 3 days differentiation. Treatment of staurosporine -differentiated RGC-5 cells with 50, 100, or 250 microM homocysteine did not alter neurite processes nor induce cell death (detected by TUNEL and active caspase-3) to a level greater than that observed in the control (non-homocysteine-treated, staurosporine-differentiated) cells. The 1 mM dosage of homocysteine in staurosporine-differentiated RGC-5 cells also did not induce cell death above control levels, although 18 hr treatment of non-differentiated RGC-5 cells with 5 mM homocysteine decreased survival by 50%. CONCLUSIONS RGC-5 cells differentiated for 24 hr with 316 nM staurosporine project robust neurite processes and are positive for ganglion cell markers consistent with a more neuronal phenotype than non-staurosporine-differentiated RGC-5 cells. However, concentrations of homocysteine known to induce ganglion cell death in vivo and in primary ganglion cells are not sufficient to induce death of RGC-5 cells, even when they are differentiated with staurosporine.
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Affiliation(s)
- Preethi S Ganapathy
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia 30912-2000, USA
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Mossböck G, Weger M, Meinitzer A, Semmelrock J, Schmut O, Faschinger C, Zimmermann C, Renner W, Stanger O. Asymmetrisches Dimethylarginin und Homocystein bei Primärem Offenwinkelglaukom. SPEKTRUM DER AUGENHEILKUNDE 2009. [DOI: 10.1007/s00717-009-0351-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ganapathy PS, Moister B, Roon P, Mysona BA, Duplantier J, Dun Y, Moister TKVE, Farley MJ, Prasad PD, Liu K, Smith SB. Endogenous elevation of homocysteine induces retinal neuron death in the cystathionine-beta-synthase mutant mouse. Invest Ophthalmol Vis Sci 2009; 50:4460-70. [PMID: 19357353 DOI: 10.1167/iovs.09-3402] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the effects of endogenous elevation of homocysteine on the retina using the cystathionine beta-synthase (cbs) mutant mouse. METHODS Retinal homocysteine in cbs mutant mice was measured by high-performance liquid chromatography (HPLC). Retinal cryosections from cbs(-/-) mice and cbs(+/-) mice were examined for histologic changes by light and electron microscopy. Morphometric analysis was performed on retinas of cbs(+/-) mice maintained on a high-methionine diet (cbs(+/-) HM). Changes in retinal gene expression were screened by microarray. RESULTS HPLC analysis revealed an approximate twofold elevation in retinal homocysteine in cbs(+/-) mice and an approximate sevenfold elevation in cbs(-/-) mice. Distinct alterations in the ganglion, inner plexiform, inner nuclear, and epithelial layers were observed in retinas of cbs(-/-) and 1-year-old cbs(+/-) mice. Retinas of cbs(+/-) HM mice demonstrated an approximate 20% decrease in cells of the ganglion cell layer (GCL), which occurred as early as 5-weeks after onset of the HM diet. Microarray analysis revealed alterations in expression of several genes, including increased expression of Aven, Egr1, and Bat3 in retinas of cbs(+/-) HM mice. CONCLUSIONS This study provides the first analysis of morphologic and molecular effects of endogenous elevations of retinal homocysteine in an in vivo model. Increased retinal homocysteine alters inner and outer retinal layers in cbs homozygous mice and older cbs heterozygous mice, and it primarily affects the cells of the GCL in younger heterozygous mice. Elevated retinal homocysteine alters expression of genes involved in endoplasmic reticular stress, N-methyl-d-aspartate (NMDA) receptor activation, cell cycle, and apoptosis.
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Affiliation(s)
- Preethi S Ganapathy
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia 30912-2000, USA
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