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Du R, Wang P, Tian N. CD3ζ-Mediated Signaling Protects Retinal Ganglion Cells in Glutamate Excitotoxicity of the Retina. Cells 2024; 13:1006. [PMID: 38920637 PMCID: PMC11201742 DOI: 10.3390/cells13121006] [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: 03/30/2024] [Revised: 05/28/2024] [Accepted: 06/06/2024] [Indexed: 06/27/2024] Open
Abstract
Excessive levels of glutamate activity could potentially damage and kill neurons. Glutamate excitotoxicity is thought to play a critical role in many CNS and retinal diseases. Accordingly, glutamate excitotoxicity has been used as a model to study neuronal diseases. Immune proteins, such as major histocompatibility complex (MHC) class I molecules and their receptors, play important roles in many neuronal diseases, while T-cell receptors (TCR) are the primary receptors of MHCI. We previously showed that a critical component of TCR, CD3ζ, is expressed by mouse retinal ganglion cells (RGCs). The mutation of CD3ζ or MHCI molecules compromises the development of RGC structure and function. In this study, we investigated whether CD3ζ-mediated molecular signaling regulates RGC death in glutamate excitotoxicity. We show that mutation of CD3ζ significantly increased RGC survival in NMDA-induced excitotoxicity. In addition, we found that several downstream molecules of TCR, including Src (proto-oncogene tyrosine-protein kinase) family kinases (SFKs) and spleen tyrosine kinase (Syk), are expressed by RGCs. Selective inhibition of an SFK member, Hck, or Syk members, Syk or Zap70, significantly increased RGC survival in NMDA-induced excitotoxicity. These results provide direct evidence to reveal the underlying molecular mechanisms that control RGC death under disease conditions.
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Affiliation(s)
- Rui Du
- Department of Ophthalmology and Visual Science, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (R.D.); (P.W.)
| | - Ping Wang
- Department of Ophthalmology and Visual Science, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (R.D.); (P.W.)
| | - Ning Tian
- Department of Ophthalmology and Visual Science, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (R.D.); (P.W.)
- Department of Neurobiology, University of Utah, Salt Lake City, UT 84132, USA
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84132, USA
- Veterans Affairs Medical Center, Salt Lake City, UT 84148, USA
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2
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Abstract
Although diabetic retinopathy (DR) is clinically diagnosed as a vascular disease, many studies find retinal neuronal and visual dysfunction before the onset of vascular DR. This suggests that DR should be viewed as a neurovascular disease. Prior to the onset of DR, human patients have compromised electroretinograms that indicate a disruption of normal function, particularly in the inner retina. They also exhibit reduced contrast sensitivity. These early changes, especially those due to dysfunction in the inner retina, are also seen in rodent models of diabetes in the early stages of the disease. Rodent models of diabetes exhibit several neuronal mechanisms, such as reduced evoked GABA release, increased excitatory glutamate signaling, and reduced dopamine signaling, that suggest specific neuronal deficits. This suggests that understanding neuronal deficits may lead to early diabetes treatments to ameliorate neuronal dysfunction.
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Affiliation(s)
- Erika D Eggers
- Departments of Physiology and Biomedical Engineering, University of Arizona, Tucson, Arizona, USA;
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3
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Cai D, Hou B, Xie SL. Amino acid analysis as a method of discovering biomarkers for diagnosis of diabetes and its complications. Amino Acids 2023:10.1007/s00726-023-03255-8. [PMID: 37067568 DOI: 10.1007/s00726-023-03255-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/21/2023] [Indexed: 04/18/2023]
Abstract
Diabetes mellitus (DM) is a severe chronic diseases with a global prevalence of 9%, leading to poor health and high health care costs, and is a direct cause of millions of deaths each year. The rising epidemic of diabetes and its complications, such as retinal and peripheral nerve disease, is a huge burden globally. A better understanding of the molecular pathways involved in the development and progression of diabetes and its complications can facilitate individualized prevention and treatment. High diabetes mellitus incidence rate is caused mainly by lack of non-invasive and reliable methods for early diagnosis, such as plasma biomarkers. The incidence of diabetes and its complications in the world still grows so it is crucial to develop a new, faster, high specificity and more sensitive diagnostic technologies. With the advancement of analytical techniques, metabolomics can identify and quantify multiple biomarkers simultaneously in a high-throughput manner, and effective biomarkers can greatly improve the efficiency of diabetes and its complications. By providing information on potential metabolic pathways, metabolomics can further define the mechanisms underlying the progression of diabetes and its complications, help identify potential therapeutic targets, and improve the prevention and management of T2D and its complications. The application of amino acid metabolomics in epidemiological studies has identified new biomarkers of diabetes mellitus (DM) and its complications, such as branched-chain amino acids, phenylalanine and arginine metabolites. This study focused on the analysis of metabolic amino acid profiling as a method for identifying biomarkers for the detection and screening of diabetes and its complications. The results presented are all from recent studies, and in all cases analyzed, there were significant changes in the amino acid profile of patients in the experimental group compared to the control group. This study demonstrates the potential of amino acid profiles as a detection method for diabetes and its complications.
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Affiliation(s)
- Dan Cai
- The Affiliated Nanhua Hospital, Department of Hand and Foot Surgery, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Biao Hou
- The Affiliated Nanhua Hospital, Department of Hand and Foot Surgery, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Song Lin Xie
- The Affiliated Nanhua Hospital, Department of Hand and Foot Surgery, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
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4
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Yalcın SO, Kaplan AT, Sobu E. Corneal endothelial cell morphology and optical coherence tomography findings in children with type 1 diabetes mellitus. Eur J Ophthalmol 2022; 33:1331-1339. [PMID: 36544297 DOI: 10.1177/11206721221145983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Purpose To evaluate central macular thickness, retinal nerve fibre layer thickness, corneal endothelial cell density and central corneal thickness in children with Type 1 Diabetes Mellitus (DM). Methods Thirty children with Type 1 DM and 30 age-matched children as controls were examined. Central macular thickness (CMT) and four quadrants of retinal nerve fibre layer thickness (RNFLT) were measured by optical coherence tomography (OCT), while endothelial cell density (ECD), coefficient of variation in cell size (CV), hexagonality (HEX) and central corneal thickness (CCT) were measured by noncontact specular microscopy. Results The mean ECD was 2810.77 ± 273.47 cells/mm2 and the mean hexagonality ratio was 49.77 ± 13.2 both were significantly lower (p < 0.001, p = 0.037 respectively) in the diabetic group compared to the control group. The mean CV was 37.6 ± 7.27, it was significantly higher (p = 0.024) in the diabetic group than the control group. The mean corneal thickness was greater in the DM group than the controls, but the difference was not significant (p = 0.176). There were no significant differences in CMT or RNFLT between the two groups. There was a negative correlation between the HbA1c levels and the thickness of the superior quadrants of RNFL (r = -0.406, p = 0.026). The duration of diabetes had no significant correlations with the corneal and retinal parameters. Conclusion The diabetic children had changes in corneal endothelial morphology and there was a negative correlation between HbA1c levels and superior quadrant of RNFLT.
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Affiliation(s)
- Sibel Oskan Yalcın
- Department of Ophthalmology, Kartal Dr. Lütfi Kırdar City Hospital, İstanbul, Turkey
| | - Aysin Tuba Kaplan
- Department of Ophthalmology, Kartal Dr. Lütfi Kırdar City Hospital, İstanbul, Turkey
| | - Elif Sobu
- Department of Pediatric Endocrinology, Kartal Dr. Lütfi Kırdar City Hospital, İstanbul, Turkey
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Amino Acids Metabolism in Retinopathy: From Clinical and Basic Research Perspective. Metabolites 2022; 12:metabo12121244. [PMID: 36557282 PMCID: PMC9781488 DOI: 10.3390/metabo12121244] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 11/22/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
Retinopathy, including age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinopathy of prematurity (ROP), are the leading cause of blindness among seniors, working-age populations, and children. However, the pathophysiology of retinopathy remains unclear. Accumulating studies demonstrate that amino acid metabolism is associated with retinopathy. This study discusses the characterization of amino acids in DR, AMD, and ROP by metabolomics from clinical and basic research perspectives. The features of amino acids in retinopathy were summarized using a comparative approach based on existing high-throughput metabolomics studies from PubMed. Besides taking up a large proportion, amino acids appear in both human and animal, intraocular and peripheral samples. Among them, some metabolites differ significantly in all three types of retinopathy, including glutamine, glutamate, alanine, and others. Studies on the mechanisms behind retinal cell death caused by glutamate accumulation are on the verge of making some progress. To develop potential therapeutics, it is imperative to understand amino acid-induced retinal functional alterations and the underlying mechanisms. This review delineates the significance of amino acid metabolism in retinopathy and provides possible direction to discover therapeutic targets for retinopathy.
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Li J, Guo C, Wang T, Xu Y, Peng F, Zhao S, Li H, Jin D, Xia Z, Che M, Zuo J, Zheng C, Hu H, Mao G. Interpretable machine learning-derived nomogram model for early detection of diabetic retinopathy in type 2 diabetes mellitus: a widely targeted metabolomics study. Nutr Diabetes 2022; 12:36. [PMID: 35931671 PMCID: PMC9355962 DOI: 10.1038/s41387-022-00216-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 07/10/2022] [Accepted: 07/18/2022] [Indexed: 01/20/2023] Open
Abstract
Objective Early identification of diabetic retinopathy (DR) is key to prioritizing therapy and preventing permanent blindness. This study aims to propose a machine learning model for DR early diagnosis using metabolomics and clinical indicators. Methods From 2017 to 2018, 950 participants were enrolled from two affiliated hospitals of Wenzhou Medical University and Anhui Medical University. A total of 69 matched blocks including healthy volunteers, type 2 diabetes, and DR patients were obtained from a propensity score matching-based metabolomics study. UPLC-ESI-MS/MS system was utilized for serum metabolic fingerprint data. CART decision trees (DT) were used to identify the potential biomarkers. Finally, the nomogram model was developed using the multivariable conditional logistic regression models. The calibration curve, Hosmer–Lemeshow test, receiver operating characteristic curve, and decision curve analysis were applied to evaluate the performance of this predictive model. Results The mean age of enrolled subjects was 56.7 years with a standard deviation of 9.2, and 61.4% were males. Based on the DT model, 2-pyrrolidone completely separated healthy controls from diabetic patients, and thiamine triphosphate (ThTP) might be a principal metabolite for DR detection. The developed nomogram model (including diabetes duration, systolic blood pressure and ThTP) shows an excellent quality of classification, with AUCs (95% CI) of 0.99 (0.97–1.00) and 0.99 (0.95–1.00) in training and testing sets, respectively. Furthermore, the predictive model also has a reasonable degree of calibration. Conclusions The nomogram presents an accurate and favorable prediction for DR detection. Further research with larger study populations is needed to confirm our findings.
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Affiliation(s)
- Jushuang Li
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Chengnan Guo
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Tao Wang
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yixi Xu
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fang Peng
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Shuzhen Zhao
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Huihui Li
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Dongzhen Jin
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhezheng Xia
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Mingzhu Che
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jingjing Zuo
- Center on Clinical Research, School of Ophthalmology & Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Chao Zheng
- The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Honglin Hu
- Department of Endocrinology, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
| | - Guangyun Mao
- Division of Epidemiology and Health Statistics, Department of Preventive Medicine, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China. .,Center on Evidence-Based Medicine & Clinical Epidemiological Research, School of Public Health & Management, Wenzhou Medical University, Wenzhou, Zhejiang, China. .,Center on Clinical Research, School of Ophthalmology & Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.
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7
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Ma C, Yao MD, Han XY, Shi ZH, Yan B, Du JL. Silencing of circular RNA‑ZYG11B exerts a neuroprotective effect against retinal neurodegeneration. Int J Mol Med 2022; 50:106. [PMID: 35730627 PMCID: PMC9239035 DOI: 10.3892/ijmm.2022.5162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 05/27/2022] [Indexed: 11/05/2022] Open
Abstract
Ischemic retinal diseases are the major cause of vision impairment worldwide. Currently, there are no available treatments for ischemia‑induced retinal neurodegeneration. Circular RNAs (circRNAs) have emerged as important regulators of several biological processes and human diseases. The present study investigated the role of circRNA‑ZYG11B (circZYG11B; hsa_circ_0003739) in retinal neurodegeneration. Reverse transcription quantitative polymerase chain reaction (RT‑qPCR) demonstrated that circZYG11B expression was markedly increased during retinal neurodegeneration in vivo and in vitro. Cell Counting Kit‑8, TUNEL and caspase‑3 activity assays revealed that silencing of circZYG11B was able to protect against oxidative stress‑ or hypoxic stress‑induced retinal ganglion cell (RGC) injury. Furthermore, immunofluorescence staining and hematoxylin and eosin staining revealed that silencing of circZYG11B alleviated ischemia/reperfusion‑induced retinal neurodegeneration, as indicated by reduced RGC injury and decreased retinal reactive gliosis. In addition, luciferase reporter, biotin‑coupled miRNA capture and RNA immunoprecipitation assays revealed that circZYG11B could regulate RGC function through circZYG11B/microRNA‑620/PTEN signaling. Clinically, RT‑qPCR assays demonstrated that circZYG11B expression was markedly increased in the aqueous humor of patients with glaucoma. In conclusion, circZYG11B may be considered a promising target for the diagnosis and treatment of retinal ischemic diseases.
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Affiliation(s)
- Cong Ma
- Department of Endocrinology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Mu-Di Yao
- Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200030, P.R. China
| | - Xiao-Yan Han
- Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200030, P.R. China
| | - Ze-Hui Shi
- Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200030, P.R. China
| | - Biao Yan
- Eye Institute, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200030, P.R. China
| | - Jian-Ling Du
- Department of Endocrinology, First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
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8
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Boccuni I, Fairless R. Retinal Glutamate Neurotransmission: From Physiology to Pathophysiological Mechanisms of Retinal Ganglion Cell Degeneration. Life (Basel) 2022; 12:638. [PMID: 35629305 PMCID: PMC9147752 DOI: 10.3390/life12050638] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 12/12/2022] Open
Abstract
Glutamate neurotransmission and metabolism are finely modulated by the retinal network, where the efficient processing of visual information is shaped by the differential distribution and composition of glutamate receptors and transporters. However, disturbances in glutamate homeostasis can result in glutamate excitotoxicity, a major initiating factor of common neurodegenerative diseases. Within the retina, glutamate excitotoxicity can impair visual transmission by initiating degeneration of neuronal populations, including retinal ganglion cells (RGCs). The vulnerability of RGCs is observed not just as a result of retinal diseases but has also been ascribed to other common neurodegenerative and peripheral diseases. In this review, we describe the vulnerability of RGCs to glutamate excitotoxicity and the contribution of different glutamate receptors and transporters to this. In particular, we focus on the N-methyl-d-aspartate (NMDA) receptor as the major effector of glutamate-induced mechanisms of neurodegeneration, including impairment of calcium homeostasis, changes in gene expression and signalling, and mitochondrial dysfunction, as well as the role of endoplasmic reticular stress. Due to recent developments in the search for modulators of NMDA receptor signalling, novel neuroprotective strategies may be on the horizon.
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Affiliation(s)
- Isabella Boccuni
- Institute for Physiology and Pathophysiology, Heidelberg University, 69120 Heidelberg, Germany
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany;
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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9
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Understanding Neurodegeneration from a Clinical and Therapeutic Perspective in Early Diabetic Retinopathy. Nutrients 2022; 14:nu14040792. [PMID: 35215442 PMCID: PMC8877033 DOI: 10.3390/nu14040792] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 02/05/2023] Open
Abstract
Recent evidence indicates that neurodegeneration is a critical element of diabetic retinopathy (DR) pathogenesis. The neuronal cells’ apoptosis contributes to microvascular impairment and blood–retinal barrier breakdown. Therefore, neurodegeneration represents an early intervention target to slow and prevent the development of microvascular alterations visible on clinical examination. Multimodal imaging features and functional assessment can permit the identification of neuronal damage in a subclinical stage before the recognition of DR signs. Clinical features of neurodegeneration are crucial in identifying patients at high risk of developing a vascular impairment and, thus, serve as outcome measures to understand the efficacy of supplementation. The optimal approach for targeting neurodegeneration contemplates the use of topical compounds that possibly act on different elements of the pathogenic cascade. To date, clinical trials available on humans tested three different topical agents, including brimonidine, somatostatin, and citicoline, with promising results.
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10
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Filippov VM, Petrachkov DV, Budzinskaya MV, Sidamonidze AL. [Modern concepts of pathogenesis of diabetic retinopathy]. Vestn Oftalmol 2021; 137:306-313. [PMID: 34669342 DOI: 10.17116/oftalma2021137052306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This literature review presents modern view on the pathogenesis of diabetic retinopathy (DR) paying particular attention to the molecular mechanisms leading to its development, as well as the manifestations of retinal neurodegeneration in such patients. Assessment of this condition and its clinical manifestations makes it possible to diagnose DR at the stage of absent initial vascular changes. Investigating the neurodegeneration mechanisms could supplement the existing understanding of the disease pathogenesis and could possibly help find new ways of treatment and prevention of DR.
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Affiliation(s)
- V M Filippov
- Research Institute of Eye Diseases, Moscow, Russia
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11
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Tonade D, Kern TS. Photoreceptor cells and RPE contribute to the development of diabetic retinopathy. Prog Retin Eye Res 2021; 83:100919. [PMID: 33188897 PMCID: PMC8113320 DOI: 10.1016/j.preteyeres.2020.100919] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/27/2020] [Accepted: 10/31/2020] [Indexed: 12/26/2022]
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness. It has long been regarded as vascular disease, but work in the past years has shown abnormalities also in the neural retina. Unfortunately, research on the vascular and neural abnormalities have remained largely separate, instead of being integrated into a comprehensive view of DR that includes both the neural and vascular components. Recent evidence suggests that the most predominant neural cell in the retina (photoreceptors) and the adjacent retinal pigment epithelium (RPE) play an important role in the development of vascular lesions characteristic of DR. This review summarizes evidence that the outer retina is altered in diabetes, and that photoreceptors and RPE contribute to retinal vascular alterations in the early stages of the retinopathy. The possible molecular mechanisms by which cells of the outer retina might contribute to retinal vascular damage in diabetes also are discussed. Diabetes-induced alterations in the outer retina represent a novel therapeutic target to inhibit DR.
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Affiliation(s)
- Deoye Tonade
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Timothy S Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Veterans Administration Medical Center Research Service, Cleveland, OH, USA; Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA; Veterans Administration Medical Center Research Service, Long Beach, CA, USA.
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12
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Diabetic retinal neurodegeneration as a form of diabetic retinopathy. Int Ophthalmol 2021; 41:3223-3248. [PMID: 33954860 DOI: 10.1007/s10792-021-01864-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE To review the evidence supporting diabetic retinal neurodegeneration (DRN) as a form of diabetic retinopathy. METHOD Review of literature. RESULTS DRN is recognized to be a part of retinopathy in patients with diabetes mellitus (DM), in addition to the well-established diabetic retinal vasculopathy (DRV). DRN has been noted in the early stages of DM, before the onset of clinically evident diabetic retinopathy. The occurrence of DRN has been confirmed in animal models of DM, histopathological examination of donor's eyes from diabetic individuals and assessment of neural structure and function in humans. DRN involves alterations in retinal ganglion cells, photoreceptors, amacrine cells and bipolar cells, and is thought to be driven by glutamate, oxidative stress and dysregulation of neuroprotective factors in the retina. Potential therapeutic options for DRN are under evaluation. CONCLUSIONS Literature is divided on the temporal relation between DRN and DRV, with evidence of both precedence and simultaneous occurrence. The relationship between DRN and multi-system neuropathy in DM is yet to be evaluated critically.
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13
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Porcu E, Gilardi F, Darrous L, Yengo L, Bararpour N, Gasser M, Marques-Vidal P, Froguel P, Waeber G, Thomas A, Kutalik Z. Triangulating evidence from longitudinal and Mendelian randomization studies of metabolomic biomarkers for type 2 diabetes. Sci Rep 2021; 11:6197. [PMID: 33737653 PMCID: PMC7973501 DOI: 10.1038/s41598-021-85684-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
The number of people affected by Type 2 diabetes mellitus (T2DM) is close to half a billion and is on a sharp rise, representing a major and growing public health burden. Given its mild initial symptoms, T2DM is often diagnosed several years after its onset, leaving half of diabetic individuals undiagnosed. While several classical clinical and genetic biomarkers have been identified, improving early diagnosis by exploring other kinds of omics data remains crucial. In this study, we have combined longitudinal data from two population-based cohorts CoLaus and DESIR (comprising in total 493 incident cases vs. 1360 controls) to identify new or confirm previously implicated metabolomic biomarkers predicting T2DM incidence more than 5 years ahead of clinical diagnosis. Our longitudinal data have shown robust evidence for valine, leucine, carnitine and glutamic acid being predictive of future conversion to T2DM. We confirmed the causality of such association for leucine by 2-sample Mendelian randomisation (MR) based on independent data. Our MR approach further identified new metabolites potentially playing a causal role on T2D, including betaine, lysine and mannose. Interestingly, for valine and leucine a strong reverse causal effect was detected, indicating that the genetic predisposition to T2DM may trigger early changes of these metabolites, which appear well-before any clinical symptoms. In addition, our study revealed a reverse causal effect of metabolites such as glutamic acid and alanine. Collectively, these findings indicate that molecular traits linked to the genetic basis of T2DM may be particularly promising early biomarkers.
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Affiliation(s)
- Eleonora Porcu
- grid.9851.50000 0001 2165 4204Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland ,grid.419765.80000 0001 2223 3006Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Federica Gilardi
- grid.150338.c0000 0001 0721 9812Unit of Forensic Toxicology and Chemistry, CURML, Lausanne University Hospital and Geneva University Hospitals, Geneva, Switzerland ,grid.9851.50000 0001 2165 4204Faculty Unit of Toxicology, CURML, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Liza Darrous
- grid.419765.80000 0001 2223 3006Swiss Institute of Bioinformatics, Lausanne, Switzerland ,grid.9851.50000 0001 2165 4204Center for Primary Care and Public Health, University of Lausanne, Lausanne, Switzerland
| | - Loic Yengo
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia
| | - Nasim Bararpour
- grid.150338.c0000 0001 0721 9812Unit of Forensic Toxicology and Chemistry, CURML, Lausanne University Hospital and Geneva University Hospitals, Geneva, Switzerland ,grid.9851.50000 0001 2165 4204Faculty Unit of Toxicology, CURML, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Marie Gasser
- grid.150338.c0000 0001 0721 9812Unit of Forensic Toxicology and Chemistry, CURML, Lausanne University Hospital and Geneva University Hospitals, Geneva, Switzerland ,grid.9851.50000 0001 2165 4204Faculty Unit of Toxicology, CURML, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Pedro Marques-Vidal
- grid.8515.90000 0001 0423 4662Department of Medicine, Internal Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Philippe Froguel
- grid.410463.40000 0004 0471 8845Inserm UMR1283, CNRS UMR8199, European Genomic Institute for Diabetes (EGID), Université de Lille, Institut Pasteur de Lille, Lille University Hospital, Lille, France ,grid.7445.20000 0001 2113 8111Department of Metabolism, Imperial College London, London, UK
| | - Gerard Waeber
- grid.8515.90000 0001 0423 4662Department of Medicine, Internal Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Aurelien Thomas
- grid.150338.c0000 0001 0721 9812Unit of Forensic Toxicology and Chemistry, CURML, Lausanne University Hospital and Geneva University Hospitals, Geneva, Switzerland ,grid.9851.50000 0001 2165 4204Faculty Unit of Toxicology, CURML, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Zoltán Kutalik
- grid.419765.80000 0001 2223 3006Swiss Institute of Bioinformatics, Lausanne, Switzerland ,grid.9851.50000 0001 2165 4204Center for Primary Care and Public Health, University of Lausanne, Lausanne, Switzerland
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14
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Abo El Gheit RE, Soliman NA, Badawi GA, Madi NM, El-Saka MH, Badr SM, Emam MN. Retinoprotective effect of agmatine in streptozotocin-induced diabetic rat model: avenues for vascular and neuronal protection : Agmatine in diabetic retinopathy. J Physiol Biochem 2021; 77:305-320. [PMID: 33635523 DOI: 10.1007/s13105-021-00799-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 02/08/2021] [Indexed: 12/20/2022]
Abstract
Diabetic retinopathy (DR) is the most common diabetic neurovascular complication, and the leading cause of preventable blindness among working-age individuals. Recently, agmatine, the endogenous decarboxylated L-arginine, has gained attention as a pleiotropic agent that modulates the diabetes-associated decline in quality of life, and exhibited varied protective biological effects. Diabetes was induced by a single streptozotocin (STZ, 50 mg/kg, i.p.) injection. When diabetes was verified, the animals were randomly allocated into three groups (16 rat each); diabetic, agmatine-treated diabetic (1 mg/kg, daily, for 12 weeks), and control group. Blood glucose homeostasis, retinal redox status, apoptotic parameters, nitric oxide synthase (NOS), nitric oxide (NO), vascular endothelial growth factor (VEGF), glutamate, glutamine, glutamine synthase (GS) activity, nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and mitogen-activated protein kinase (MAPKs) pathways were assayed biochemically. Retinal vascular permeability was measured. Retinal morphology was evaluated by hematoxylin and eosin staining. Retinal N-methyl-D-aspartic acid receptor1 (NMDAR1) and glutamate aspartate transporter (GLAST) mRNA were quantified. Glucose transporter 1, pro-caspase3, and glial fibrillary acidic protein (GFAP) expression were quantified by immunohistochemistry. Chronic agmatine treatment abrogated STZ-induced retinal neurodegeneration features including gliosis, and neuronal apoptosis, restored retinal vascular permeability, mostly through antioxidant, anti-apoptotic capacity, abolishing glutamate excitotoxicity, modulating the activity of NMDARs, MAPKs/NFκB, and NOS/NO pathways. By restoring the molecular and functional background of retinal neurovascular homeostatic balance, agmatine would be appropriate therapeutic option acting upstream of the DR, impeding its progression.
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Affiliation(s)
| | - Nema A Soliman
- Medical Biochemistry Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Ghada A Badawi
- Pharmacology and Toxicology Department, Faculty of Pharmacy and Pharmaceutical Industries, Sinai University, El-Arish, Egypt
| | - Nermin M Madi
- Physiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Mervat H El-Saka
- Physiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Shimaa M Badr
- Histology Departments, Tanta University, Tanta, Egypt
| | - Marwa N Emam
- Physiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
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15
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Targeted pharmacotherapy against neurodegeneration and neuroinflammation in early diabetic retinopathy. Neuropharmacology 2021; 187:108498. [PMID: 33582150 DOI: 10.1016/j.neuropharm.2021.108498] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/18/2021] [Accepted: 02/06/2021] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR), the most frequent complication of diabetes, is one of the leading causes of irreversible blindness in working-age adults and has traditionally been regarded as a microvascular disease. However, increasing evidence has revealed that synaptic neurodegeneration of retinal ganglion cells (RGCs) and activation of glial cells may represent some of the earliest events in the pathogenesis of DR. Upon diabetes-induced metabolic stress, abnormal glycogen synthase kinase-3β (GSK-3β) activation drives tau hyperphosphorylation and β-catenin downregulation, leading to mitochondrial impairment and synaptic neurodegeneration prior to RGC apoptosis. Moreover, glial cell activation triggers enhanced inflammation and oxidative stress, which may accelerate the deterioration of diabetic RGCs neurodegeneration. These findings have opened up opportunities for therapies, such as inhibition of GSK-3β, glial cell activation, glutamate excitotoxicity and the use of neuroprotective drugs targeting early neurodegenerative processes in the retina and halting the progression of DR before the manifestation of microvascular abnormalities. Such interventions could potentially remedy early neurodegeneration and help prevent vision loss in people suffering from DR.
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16
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Sun Y, Zou H, Li X, Xu S, Liu C. Plasma Metabolomics Reveals Metabolic Profiling For Diabetic Retinopathy and Disease Progression. Front Endocrinol (Lausanne) 2021; 12:757088. [PMID: 34777253 PMCID: PMC8589034 DOI: 10.3389/fendo.2021.757088] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/29/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUNDS Diabetic retinopathy (DR), the main retinal vascular complication of DM, is the leading cause of visual impairment and blindness among working-age people worldwide. The aim of this study was to investigate the difference of plasma metabolic profiles in patients with DR to better understand the mechanism of this disease and disease progression. METHODS We used ultrahigh-performance liquid Q-Exactive mass spectrometry and multivariate statistical analyses to conduct a comprehensive analysis of plasma metabolites in a population with DR and proliferative DR (PDR). A risk score based on the level of the selected metabolite was established and evaluated using the least absolute shrinkage and selection operator regularization logistic regression (LASSO-LR) based machine learning model. RESULTS 22 differentially expressed metabolites which belonged to different metabolic pathway were identified and confirmed to be associated with the occurrence of DR. A risk score based on the level of the selected metabolite pseudouridine was established and evaluated to strongly associated with the occurrence of DR. Four circulating plasma metabolites (pseudouridine, glutamate, leucylleucine and N-acetyltryptophan) were identified to be differentially expressed between patients with PDR and other patients, and a risk score formula based on these plasma metabolites was developed and assessed to be significantly related to PDR. CONCLUSIONS Our work highlights the possible use of the risk score assessment based on the plasma metabolites not only reveal in the early diagnosis of DR and PDR but also assist in enhancing current therapeutic strategies in the clinic.
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Affiliation(s)
- Yu Sun
- Department of Endocrinology, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine, Nanjing, China
- Department of Endocrinology and Metabolism, The Affiliated Suqian Hospital of Xuzhou Medical University, Suqian, China
| | - Huiling Zou
- Department of Endocrinology and Metabolism, The Affiliated Suqian Hospital of Xuzhou Medical University, Suqian, China
| | - Xingjia Li
- Department of Endocrinology, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine, Nanjing, China
- Treatment of Yingbing of State Administration of Traditional Chinese Medicine, Jiangsu Provincial Academy of Traditional Chinese Medicine, Nanjing, China
| | - Shuhang Xu
- Department of Endocrinology, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine, Nanjing, China
- Treatment of Yingbing of State Administration of Traditional Chinese Medicine, Jiangsu Provincial Academy of Traditional Chinese Medicine, Nanjing, China
- *Correspondence: Chao Liu, ; Shuhang Xu,
| | - Chao Liu
- Department of Endocrinology, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Traditional Chinese Medicine, Nanjing, China
- Treatment of Yingbing of State Administration of Traditional Chinese Medicine, Jiangsu Provincial Academy of Traditional Chinese Medicine, Nanjing, China
- *Correspondence: Chao Liu, ; Shuhang Xu,
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17
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Abstract
Diabetic retinopathy is now well understood as a neurovascular disease. Significant deficits early in diabetes are found in the inner retina that consists of bipolar cells that receive inputs from rod and cone photoreceptors, ganglion cells that receive inputs from bipolar cells, and amacrine cells that modulate these connections. These functional deficits can be measured in vivo in diabetic humans and animal models using the electroretinogram (ERG) and behavioral visual testing. Early effects of diabetes on both the human and animal model ERGs are changes to the oscillatory potentials that suggest dysfunctional communication between amacrine cells and bipolar cells as well as ERG measures that suggest ganglion cell dysfunction. These are coupled with changes in contrast sensitivity that suggest inner retinal changes. Mechanistic in vitro neuronal studies have suggested that these inner retinal changes are due to decreased inhibition in the retina, potentially due to decreased gamma aminobutyric acid (GABA) release, increased glutamate release, and increased excitation of retinal ganglion cells. Inner retinal deficits in dopamine levels have also been observed that can be reversed to limit inner retinal damage. Inner retinal targets present a promising new avenue for therapies for early-stage diabetic eye disease.
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18
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Tabassum S, Ahmad S, Madiha S, Shahzad S, Batool Z, Sadir S, Haider S. Free L-glutamate-induced modulation in oxidative and neurochemical profile contributes to enhancement in locomotor and memory performance in male rats. Sci Rep 2020; 10:11206. [PMID: 32641780 PMCID: PMC7343824 DOI: 10.1038/s41598-020-68041-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 05/04/2020] [Indexed: 12/30/2022] Open
Abstract
Glutamate (Glu), the key excitatory neurotransmitter in the central nervous system, is considered essential for brain functioning and has a vital role in learning and memory formation. Earlier it was considered as a harmful agent but later found to be useful for many body functions. However, studies regarding the effects of free l-Glu administration on CNS function are limited. Therefore, current experiment is aimed to monitor the neurobiological effects of free l-Glu in male rats. l-Glu was orally administered to rats for 5-weeks and changes in behavioral performance were monitored. Thereafter, brain and hippocampus were collected for oxidative and neurochemical analysis. Results showed that chronic supplementation of free l-Glu enhanced locomotor performance and cognitive function of animals which may be attributed to the improved antioxidant status and cholinergic, monoaminergic and glutamatergic neurotransmission in brain and hippocampus. Current results showed that chronic supplementation of l-Glu affects the animal behaviour and brain functioning via improving the neurochemical and redox system of brain. Free l-Glu could be a useful therapeutic agent to combat neurological disturbances however this requires further targeted studies.
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Affiliation(s)
- Saiqa Tabassum
- Neurochemistry and Biochemical Neuropharmacology Research Unit, Department of Biochemistry, University of Karachi, Karachi, 75270, Pakistan.,Department of Biosciences, Faculty of Life Science, Shaheed Zulfiqar Ali Bhutto Institute of Science and Technology (Szabist), Karachi, Pakistan
| | - Saara Ahmad
- Department of Biological and Biomedical Sciences, Aga Khan University Hospital, Karachi, Pakistan
| | - Syeda Madiha
- Neurochemistry and Biochemical Neuropharmacology Research Unit, Department of Biochemistry, University of Karachi, Karachi, 75270, Pakistan
| | - Sidrah Shahzad
- Neurochemistry and Biochemical Neuropharmacology Research Unit, Department of Biochemistry, University of Karachi, Karachi, 75270, Pakistan
| | - Zehra Batool
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Sadia Sadir
- Neurochemistry and Biochemical Neuropharmacology Research Unit, Department of Biochemistry, University of Karachi, Karachi, 75270, Pakistan
| | - Saida Haider
- Neurochemistry and Biochemical Neuropharmacology Research Unit, Department of Biochemistry, University of Karachi, Karachi, 75270, Pakistan.
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19
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Zhang Y, Li Q, Guan S, Li H. Methamphetamine causes acute toxicity in the retina of Balb/c mice. Cutan Ocul Toxicol 2020; 39:83-88. [PMID: 31986912 DOI: 10.1080/15569527.2020.1722153] [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: 11/13/2019] [Revised: 01/09/2020] [Accepted: 01/22/2020] [Indexed: 10/25/2022]
Abstract
Purpose: As a powerful psychostimulant with high potential for abuse, methamphetamine (Meth) could cause neurological diseases. METH-induced ophthalmic complications are present, but its underlying mechanism has not been completely elucidated, specifically on the retina. This study was to investigate effects of Meth treatment on the retina. Methods: Balb/c mice were treated with Meth at progressively increasing doses (0-6 mg/kg) intraperitoneally four times per day for five days, mice treated with saline as negative control. Electroretinography (ERG) was used to test the function of retina after Meth treatment. Pathological changes were examined by haematoxylin and eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. Enzyme-linked immunosorbent assay (ELISA) was used to measure the norepinephrine and tumour necrosis factor alpha (TNFα). Real-time PCR and western blot were used to measure expression changes of genes and proteins, respectively. Results: Our data showed that Meth treatment caused photoreceptor cell death and decreased the thickness of retina. Meth treatment also elevated norepinephrine levels in plasma and increased TNFα in the retina. Moreover, Meth treatment decreased platelet endothelial cell adhesion molecule-1 (PECAM-1) protein expression and increased protein expression of matrix metalloproteinases (MMPs) in the retina.Conclusions: Our study indicated that short-term intraperitoneal treatment of Meth induced retinal degeneration of Balb/c mice due to a vascular loss of PECAM-1 and an increase of MMPs.
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Affiliation(s)
- Yanlai Zhang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, People's Republic of China
| | - Qi Li
- The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, People's Republic of China
| | - Siyuan Guan
- The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Hao Li
- Department of Neurology, The First People's Hospital of Yibin, Yibin, People's Republic of China
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20
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Ou K, Copland DA, Theodoropoulou S, Mertsch S, Li Y, Liu J, Schrader S, Liu L, Dick AD. Treatment of diabetic retinopathy through neuropeptide Y-mediated enhancement of neurovascular microenvironment. J Cell Mol Med 2020; 24:3958-3970. [PMID: 32141716 PMCID: PMC7171318 DOI: 10.1111/jcmm.15016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/02/2019] [Accepted: 12/27/2019] [Indexed: 12/12/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the most severe clinical manifestations of diabetes mellitus and a major cause of blindness. DR is principally a microvascular disease, although the pathogenesis also involves metabolic reactive intermediates which induce neuronal and glial activation resulting in disruption of the neurovascular unit and regulation of the microvasculature. However, the impact of neural/glial activation in DR remains controversial, notwithstanding our understanding as to when neural/glial activation occurs in the course of disease. The objective of this study was to determine a potential protective role of neuropeptide Y (NPY) using an established model of DR permissive to N-methyl-D-aspartate (NMDA)-induced excitotoxic apoptosis of retinal ganglion cells (RGC) and vascular endothelial growth factor (VEGF)-induced vascular leakage. In vitro evaluation using primary retinal endothelial cells demonstrates that NPY promotes vascular integrity, demonstrated by maintained tight junction protein expression and reduced permeability in response to VEGF treatment. Furthermore, ex vivo assessment of retinal tissue explants shows that NPY can protect RGC from excitotoxic-induced apoptosis. In vivo clinical imaging and ex vivo tissue analysis in the diabetic model permitted assessment of NPY treatment in relation to neural and endothelial changes. The neuroprotective effects of NPY were confirmed by attenuating NMDA-induced retinal neural apoptosis and able to maintain inner retinal vascular integrity. These findings could have important clinical implications and offer novel therapeutic approaches for the treatment in the early stages of DR.
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Affiliation(s)
- Kepeng Ou
- College of Pharmacy, National and Local Joint Engineering Research Center of Targeted and Innovative Therapeutics, Chongqing Key Laboratory of Kinase Modulators as Innovative Medicine, Chongqing University of Arts and Sciences, Chongqing, China.,Laboratory for Experimental Ophthalmology, University of Düsseldorf, Düsseldorf, Germany.,Academic Unit of Ophthalmology, Bristol Medical School, University of Bristol, Bristol, UK
| | - David A Copland
- Academic Unit of Ophthalmology, Bristol Medical School, University of Bristol, Bristol, UK
| | - Sofia Theodoropoulou
- Academic Unit of Ophthalmology, Bristol Medical School, University of Bristol, Bristol, UK
| | - Sonja Mertsch
- Laboratory for Experimental Ophthalmology, University of Düsseldorf, Düsseldorf, Germany.,Department of Ophthalmology, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Youjian Li
- College of Pharmacy, National and Local Joint Engineering Research Center of Targeted and Innovative Therapeutics, Chongqing Key Laboratory of Kinase Modulators as Innovative Medicine, Chongqing University of Arts and Sciences, Chongqing, China.,Academic Unit of Ophthalmology, Bristol Medical School, University of Bristol, Bristol, UK
| | - Jian Liu
- Academic Unit of Ophthalmology, Bristol Medical School, University of Bristol, Bristol, UK
| | - Stefan Schrader
- Laboratory for Experimental Ophthalmology, University of Düsseldorf, Düsseldorf, Germany.,Department of Ophthalmology, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Lei Liu
- Academic Unit of Ophthalmology, Bristol Medical School, University of Bristol, Bristol, UK
| | - Andrew D Dick
- Academic Unit of Ophthalmology, Bristol Medical School, University of Bristol, Bristol, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital, University College London Institute of Ophthalmology, London, UK
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21
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Effect of diabetes blood-stasis syndrome and Xuefu Zhuyu decoction on ROS-ERK1/2 signaling pathway in rat retina Müller cells. Cytotechnology 2020; 72:303-314. [PMID: 32112164 DOI: 10.1007/s10616-020-00379-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 02/17/2020] [Indexed: 12/20/2022] Open
Abstract
This research aimed to investigate whether diabetic blood-stasis syndrome had a relationship with ROS-ERK1/2 signaling pathway in rat retina Müller cells and explore the effects of traditional Chinese drugs designed for promoting blood circulation to remove blood stasis on diabetic retinopathy (DR) treatment. Immunofluorescence was applied to determine purity of Müller cells. The diabetes was induced in rats by streptozotocin (STZ). Müller cells were stimulated by blood serum obtained from rats with blood-stasis syndrome and then treated by Xuefu Zhuyu decoction. Kits for reactive oxygen species (ROS), superoxide dismutase (SOD) and glutathione (GSH) were used for corresponding detection. Western blot analysis was used to determine the phosphorylation of ERK1/2. The results indicated that stimulation of Müller cells by blood serum of rats with diabetic blood-stasis syndrome increased the expression of ROS, inhibited SOD and GSH, and activated ERK1/2 signaling pathway. Treatment of Xuefu Zhuyu decoction could weaken this phenomenon. What's more, similar effects of ERK1/2 inhibitor U0126 with Xuefu Zhuyu decoction proved the involvement of ERK1/2 signaling pathway. Therefore, our results suggested that traditional Chinese drugs for promoting blood circulation to remove blood stasis would be an effective therapy to treat DR.
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22
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Ma M, Zhao S, Zhang J, Sun T, Fan Y, Zheng Z. High Glucose-Induced TRPC6 Channel Activation Decreases Glutamate Uptake in Rat Retinal Müller Cells. Front Pharmacol 2020; 10:1668. [PMID: 32116675 PMCID: PMC7033573 DOI: 10.3389/fphar.2019.01668] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/20/2019] [Indexed: 12/15/2022] Open
Abstract
High glucose (HG) increases the production of reactive oxygen species (ROS), leading to decreased glutamate uptake in Müller cells. The transient receptor potential cation channel 6 (TRPC6) channel, an oxidative stress-sensitive Ca2+-permeable cationic channel, is readily detected in Müller cells and highly expressed under HG conditions. Yet, the effect of high glucose-induced TRPC6 channel activation in Müller cells is poorly understood. We hypothesized that TRPC6 channel activation mediates high glucose-induced decreases in Müller cell glutamate uptake. We found RNA interference (RNAi) of the TRPC6 channel abolished HG-induced decreases in glutamate uptake and cell death. HG also decreased the expression of the glutamate-aspartate transporter (GLAST), which is the most important transporter involved in glutamate uptake. The mRNA level of ciliary neurotrophic factor (CNTF) in rMC-1 cells and the release of CNTF in the culture media was decreased, but the mRNA levels of IL-6 and vascular endothelial growth factor (VEGF) were increased under HG conditions. After RNAi silencing in rMC-1 cells, the mRNA levels of CNTF increased, but IL-6 and VEGF levels decreased. Furthermore, TRPC6 knockdown (KD) decreased expression of glial fibrillary acidic protein (GFAP) and increased expression of Kir4.1, pointing to inhibition of HG-induced gliosis in rMC-1 cells. ROS and intracellular Ca2+ levels decreased after TRPC6 knockdown. Exposure to Hyp9 (10 μM), a highly selective TRPC6 channel agonist, can aggravate HG-induced pathological changes. Collectively, our results suggest TRPC6 channel activation is involved in HG-induced decreases in glutamate uptake in rMC-1 cells. These findings provide novel insights into the role of TRPC6 in HG-induced retinal neurovasculopathy and suggest TRPC6 is a promising target for drug development for diabetic retinopathy (DR).
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Affiliation(s)
- Mingming Ma
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Shuzhi Zhao
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Jian Zhang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Tao Sun
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Ying Fan
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Zhi Zheng
- Department of Ophthalmology, Shanghai General Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
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23
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Lee M, Leskova W, Eshaq RS, Harris NR. Acute changes in the retina and central retinal artery with methamphetamine. Exp Eye Res 2020; 193:107964. [PMID: 32044305 DOI: 10.1016/j.exer.2020.107964] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 02/05/2020] [Accepted: 02/05/2020] [Indexed: 12/12/2022]
Abstract
Methamphetamine (METH), an addictive stimulant of neurotransmitters, is associated with cardiovascular and neurological diseases. METH-induced ophthalmic complications are also present but have been insufficiently investigated. The purpose of this study is to investigate the retinal effects of METH. C57BL/6 mice were administrated progressively increasing doses of METH (0-6 mg/kg) by repetitive intraperitoneal injections for 5 days (4 times per day). Retinal degeneration was examined by morphological changes and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) assay. Norepinephrine levels were measured by ELISA, protein expression levels were determined by immunoblot and immunostaining, and gelatinase activity was examined by zymography. The thickness of the retina and the number of nuclei in the inner and outer nuclear layers were decreased by METH. Retinal cell death and astrocyte activation by METH treatment were confirmed by TUNEL assay and glial fibrillary acidic protein expression, respectively. Increased tumor necrosis factor-α protein in the retina and elevated norepinephrine levels in plasma were found in METH-treated mice. Platelet endothelial cell adhesion molecule-1 (PECAM-1) protein expression level was decreased in the retina and central retinal artery (CRA) by METH treatment, along with the endothelial proteoglycans glypican-1 and syndecan-1. Moreover, a regulator of the extracellular matrix, matrix metalloproteinase-14 (MMP-14) in the retina, and MMP-2 and MMP-9 in plasma, were increased by METH treatment. In conclusion, METH administration is involved in retinal degeneration with a vascular loss of PECAM-1 and the glycocalyx in the CRA and retina, and an increase of MMPs.
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Affiliation(s)
- Minsup Lee
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, 71103, USA
| | - Wendy Leskova
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, 71103, USA
| | - Randa S Eshaq
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, 71103, USA
| | - Norman R Harris
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, 71103, USA.
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24
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Fathalipour M, Fathalipour H, Safa O, Nowrouzi-Sohrabi P, Mirkhani H, Hassanipour S. The Therapeutic Role of Carotenoids in Diabetic Retinopathy: A Systematic Review. Diabetes Metab Syndr Obes 2020; 13:2347-2358. [PMID: 32753919 PMCID: PMC7342496 DOI: 10.2147/dmso.s255783] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/05/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Carotenoids are a large group of natural pigments that occur in many foods, fruits, and vegetables. Several studies have shown a number of biological properties of carotenoids, particularly beneficial impacts on cancer, metabolic, neurodegenerative, and cardiovascular diseases. However, recent evidence has shown that these compounds could prevent, delay, and ameliorate diabetic retinopathy (DR). The aim of current study was to review the therapeutic effects of carotenoids in the treatment of DR and discuss the molecular mechanisms that are behind these pharmacological activities. METHODS Six online databases (Medline/PubMed, Scopus, Web of Knowledge, Embase, ScienceDirect, and ProQuest) were searched until September 2019. The systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. RESULTS A total of 25 studies were included after the final retrieval. A relationship was observed between carotenoids and management of DR. Findings also demonstrated that the underlying mechanism of beneficial effects of these compounds was antioxidant, anti-inflammatory, anti-angiogenic, and neuroprotective properties. CONCLUSION Carotenoids potentially delay the initiation and prevent the progression of DR; however, ample preclinical studies are required to confirm their effect, and adequate clinical trials are needed to really understand how well these compounds influence DR among humans.
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Affiliation(s)
- Mohammad Fathalipour
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Hadis Fathalipour
- The Student Research Committee, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran
| | - Omid Safa
- Department of Clinical Pharmacy, Faculty of Pharmacy, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | | | - Hossein Mirkhani
- Department of Pharmacology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Soheil Hassanipour
- Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Rasht, Iran
- Correspondence: Soheil Hassanipour Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Razi Hospital, Sardar-Jangle Ave., Rasht41448-95655, IranTel +98(13)33535116Fax +98(13)33534951 Email
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Rostamkhani H, Mellati AA, Tabaei BS, Alavi M, Mousavi SN. Association of Serum Zinc and Vitamin A Levels with Severity of Retinopathy in Type 2 Diabetic Patients: a Cross-Sectional Study. Biol Trace Elem Res 2019; 192:123-128. [PMID: 30790120 DOI: 10.1007/s12011-019-01664-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 02/04/2019] [Indexed: 10/27/2022]
Abstract
Diabetic retinopathy (DR) is a common microvascular disorder which occurs in type 2 diabetes mellitus (T2DM) patients due to chronic hyperglycemia. Previous studies reported that serum zinc (Zn) and vitamin A levels were associated with certain diabetic microvascular complications. However, the relationship between Zn and vitamin A levels with the severity of DR in type 2 diabetic patients is not clear. We aimed to analyze the relationship between serum Zn and vitamin A levels with the severity of DR in T2DM. Sixty T2DM patients were selected from whom attending to the ophthalmology center of hospital from June 2017 and Feb 2018. Patients were categorized as controls, non-proliferative DR (NPDR), and proliferative DR (PDR). Anthropometric, dietary, and physical activity data were gathered. Fasting blood samples were taken to measure biochemical parameters. Serum Zn and vitamin A levels were measured via enzymatic-calorimetric and HPLC methods, respectively. Results showed that serum Zn and vitamin A levels were significantly lower in the PDR group than the controls (p = 0.03 and p = 0.008, respectively). Serum low-density lipoprotein (LDL.C) was significantly higher in the PDR than the control group (p = 0.02). Adjusting for the other variables, increase in serum Zn and vitamin A levels reduced risk of DR by 25.7% and 31.1%, respectively (p = 0.02 and p = 0.007). Higher serum LDL.C increased DR severity by 28.7%, adjusted for the variables (95% CI = 0.002, 0.02; p = 0.01). Lower serum Zn and vitamin A levels, as well as higher LDL.C in the T2DM patients, are related to DR severity.
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Affiliation(s)
- Hadi Rostamkhani
- Department of Clinical Biochemistry, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
- Student Research Center, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Ali Awsat Mellati
- Department of Clinical Biochemistry, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Banafsheh Sadat Tabaei
- Department of Clinical Biochemistry, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Mohammadhossein Alavi
- Department of Biothechnology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Seyedeh Neda Mousavi
- Department of Nutrition, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
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Ghaseminejad F, Kaplan L, Pfaller AM, Hauck SM, Grosche A. The role of Müller cell glucocorticoid signaling in diabetic retinopathy. Graefes Arch Clin Exp Ophthalmol 2019; 258:221-230. [PMID: 31734719 DOI: 10.1007/s00417-019-04521-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/14/2019] [Accepted: 10/22/2019] [Indexed: 12/13/2022] Open
Abstract
Diabetic retinopathy (DR) is a sight-threatening complication associated with the highly prevalent diabetes disorder. Both the microvascular damage and neurodegeneration detected in the retina caused by chronic hyperglycemia have brought special attention to Müller cells, the major macroglia of the retina that are responsible for retinal homeostasis. Given the role of glucocorticoid signaling in anti-inflammatory responses and the almost exclusive expression of glucocorticoid receptors (GRs) in retinal Müller cells, administration of corticosteroid agonists as a potential treatment option has been widely studied. Although these approaches have been moderately efficacious in treating or de-escalating DR pathomechanisms, there are various side effects and gaps of knowledge with regard to introducing exogenous glucocorticoids to the diseased retina. In this paper, we provide a review of the literature concerning the available evidence for the role of Müller cell glucocorticoid signaling in DR and we discuss previously investigated approaches in modulating this system as possible treatment options. Furthermore, we propose a novel alternative to the available choices of treatment by using gene therapy as a tool to regulate the expression of GR in retinal Müller cells. Upregulating GR expression allows for induced glucocorticoid signaling with more enduring effects compared to injection of agonists. Hence, repetitive injections would no longer be required. Lastly, side effects of glucocorticoid therapy such as glucocorticoid resistance of GR following chronic exposure to excess ligands or agonists can be avoided.
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Affiliation(s)
- Farhad Ghaseminejad
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, Martinsried, Germany
| | - Lew Kaplan
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, Martinsried, Germany
| | - Anna M Pfaller
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, Martinsried, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Heidemannstr. 1, Neuherberg, Germany
| | - Antje Grosche
- Department of Physiological Genomics, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, Martinsried, Germany.
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Narayanan SP, Shosha E, D Palani C. Spermine oxidase: A promising therapeutic target for neurodegeneration in diabetic retinopathy. Pharmacol Res 2019; 147:104299. [PMID: 31207342 PMCID: PMC7011157 DOI: 10.1016/j.phrs.2019.104299] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 04/23/2019] [Accepted: 06/05/2019] [Indexed: 12/20/2022]
Abstract
Diabetic Retinopathy (DR), is a significant public health issue and the leading cause of blindness in working-aged adults worldwide. The vision loss associated with DR affects patients' quality of life and has negative social and psychological effects. In the past, diabetic retinopathy was considered as a vascular disease; however, it is now recognized to be a neuro-vascular disease of the retina. Current therapies for DR, such as laser photocoagulation and anti-VEGF therapy, treat advanced stages of the disease, particularly the vasculopathy and have adverse side effects. Unavailability of effective treatments to prevent the incidence or progression of DR is a major clinical problem. There is a great need for therapeutic interventions capable of preventing retinal damage in DR patients. A growing body of evidence shows that neurodegeneration is an early event in DR pathogenesis. Therefore, studies of the underlying mechanisms that lead to neurodegeneration are essential for identifying new therapeutic targets in the early stages of DR. Deregulation of the polyamine metabolism is implicated in various neurodegenerative diseases, cancer, renal failure, and diabetes. Spermine Oxidase (SMOX) is a highly inducible enzyme, and its dysregulation can alter polyamine homeostasis. The oxidative products of polyamine metabolism are capable of inducing cell damage and death. The current review provides insight into the SMOX-regulated molecular mechanisms of cellular damage and dysfunction, and its potential as a therapeutic target for diabetic retinopathy. Structural and functional changes in the diabetic retina and the mechanisms leading to neuronal damage (excitotoxicity, loss of neurotrophic factors, oxidative stress, mitochondrial dysfunction etc.) are also summarized in this review. Furthermore, existing therapies and new approaches to neuroprotection are discussed.
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Affiliation(s)
- S Priya Narayanan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States; Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States; VA Medical Center, Augusta, GA, United States.
| | - Esraa Shosha
- Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States; Clinical Pharmacy Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Chithra D Palani
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, United States; Augusta University Culver Vision Discovery Institute, Augusta, GA, United States; Vascular Biology Center, Augusta University, Augusta, GA, United States
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Nawaz IM, Rezzola S, Cancarini A, Russo A, Costagliola C, Semeraro F, Presta M. Human vitreous in proliferative diabetic retinopathy: Characterization and translational implications. Prog Retin Eye Res 2019; 72:100756. [PMID: 30951889 DOI: 10.1016/j.preteyeres.2019.03.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is one of the leading causes of visual impairment in the working-age population. DR is a progressive eye disease caused by long-term accumulation of hyperglycaemia-mediated pathological alterations in the retina of diabetic patients. DR begins with asymptomatic retinal abnormalities and may progress to advanced-stage proliferative diabetic retinopathy (PDR), characterized by neovascularization or preretinal/vitreous haemorrhages. The vitreous, a transparent gel that fills the posterior cavity of the eye, plays a vital role in maintaining ocular function. Structural and molecular alterations of the vitreous, observed during DR progression, are consequences of metabolic and functional modifications of the retinal tissue. Thus, vitreal alterations reflect the pathological events occurring at the vitreoretinal interface. These events are caused by hypoxic, oxidative, inflammatory, neurodegenerative, and leukostatic conditions that occur during diabetes. Conversely, PDR vitreous can exert pathological effects on the diabetic retina, resulting in activation of a vicious cycle that contributes to disease progression. In this review, we recapitulate the major pathological features of DR/PDR, and focus on the structural and molecular changes that characterize the vitreal structure and composition during DR and progression to PDR. In PDR, vitreous represents a reservoir of pathological signalling molecules. Therefore, in this review we discuss how studying the biological activity of the vitreous in different in vitro, ex vivo, and in vivo experimental models can provide insights into the pathogenesis of PDR. In addition, the vitreous from PDR patients can represent a novel tool to obtain preclinical experimental evidences for the development and characterization of new therapeutic drug candidates for PDR therapy.
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Affiliation(s)
- Imtiaz M Nawaz
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Sara Rezzola
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Anna Cancarini
- Department of Ophthalmology, University of Brescia, Italy
| | - Andrea Russo
- Department of Ophthalmology, University of Brescia, Italy
| | - Ciro Costagliola
- Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy
| | | | - Marco Presta
- Department of Molecular and Translational Medicine, University of Brescia, Italy.
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29
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Christensen I, Lu B, Yang N, Huang K, Wang P, Tian N. The Susceptibility of Retinal Ganglion Cells to Glutamatergic Excitotoxicity Is Type-Specific. Front Neurosci 2019; 13:219. [PMID: 30930737 PMCID: PMC6429039 DOI: 10.3389/fnins.2019.00219] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 02/26/2019] [Indexed: 12/17/2022] Open
Abstract
Retinal ganglion cells (RGCs) are the only output neurons that conduct visual signals from the eyes to the brain. RGC degeneration occurs in many retinal diseases leading to blindness and increasing evidence suggests that RGCs are susceptible to various injuries in a type-specific manner. Glutamate excitotoxicity is the pathological process by which neurons are damaged and killed by excessive stimulation of glutamate receptors and it plays a central role in the death of neurons in many CNS and retinal diseases. The purpose of this study is to characterize the susceptibility of genetically identified RGC types to the excitotoxicity induced by N-methyl-D-aspartate (NMDA). We show that the susceptibility of different types of RGCs to NMDA excitotoxicity varies significantly, in which the αRGCs are the most resistant type of RGCs to NMDA excitotoxicity while the J-RGCs are the most sensitive cells to NMDA excitotoxicity. These results strongly suggest that the differences in the genetic background of RGC types might provide valuable insights for understanding the selective susceptibility of RGCs to pathological insults and the development of a strategy to protect RGCs from death in disease conditions. In addition, our results show that RGCs lose dendrites before death and the sequence of the morphological and molecular events during RGC death suggests that the initial insult of NMDA excitotoxicity might set off a cascade of events independent of the primary insults. However, the kinetics of dendritic retraction in RGCs does not directly correlate to the susceptibility of type-specific RGC death.
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Affiliation(s)
- Ian Christensen
- Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Bo Lu
- VA Salt Lake City Health Care System, Salt Lake City, UT, United States.,Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Ning Yang
- VA Salt Lake City Health Care System, Salt Lake City, UT, United States.,Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Kevin Huang
- VA Salt Lake City Health Care System, Salt Lake City, UT, United States.,Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Ping Wang
- VA Salt Lake City Health Care System, Salt Lake City, UT, United States.,Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Ning Tian
- VA Salt Lake City Health Care System, Salt Lake City, UT, United States.,Department of Ophthalmology & Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, United States
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30
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Shafabakhsh R, Aghadavod E, Ghayour‐Mobarhan M, Ferns G, Asemi Z. Role of histone modification and DNA methylation in signaling pathways involved in diabetic retinopathy. J Cell Physiol 2018; 234:7839-7846. [DOI: 10.1002/jcp.27844] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 11/15/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Rana Shafabakhsh
- Research Center for Biochemistry and Nutrition in Metabolic Diseases Kashan University of Medical Sciences Kashan Iran
| | - Esmat Aghadavod
- Research Center for Biochemistry and Nutrition in Metabolic Diseases Kashan University of Medical Sciences Kashan Iran
| | - Majid Ghayour‐Mobarhan
- Metabolic Syndrome Research Center School of Medicine, Mashhad University of Medical Sciences Mashhad Iran
| | - Gordon Ferns
- Division of Medical Education Brighton & Sussex Medical School Brighton UK
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases Kashan University of Medical Sciences Kashan Iran
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31
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Sahajpal NS, Goel RK, Chaubey A, Aurora R, Jain SK. Pathological Perturbations in Diabetic Retinopathy: Hyperglycemia, AGEs, Oxidative Stress and Inflammatory Pathways. Curr Protein Pept Sci 2018; 20:92-110. [DOI: 10.2174/1389203719666180928123449] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/10/2018] [Accepted: 08/29/2017] [Indexed: 01/02/2023]
Abstract
Diabetic retinopathy (DR) remains the leading cause of blindness in working-aged adults
around the world. The proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME) are
the severe vision threatening stages of the disorder. Although, a huge body of research exists in elaborating
the pathological mechanisms that lead to the development of DR, the certainty and the correlation
amongst these pathways remain ambiguous. The complexity of DR lies in the multifactorial pathological
perturbations that are instrumental in both the disease development and its progression. Therefore, a holistic
perspective with an understanding of these pathways and their correlation may explain the pathogenesis
of DR as a unifying mechanism. Hyperglycemia, oxidative stress and inflammatory pathways
are the crucial components that are implicated in the pathogenesis of DR. Of these, hyperglycemia appears
to be the initiating central component around which other pathological processes operate. Thus,
this review discusses the role of hyperglycemia, oxidative stress and inflammation in the pathogenesis of
DR, and highlights the cross-talk amongst these pathways in an attempt to understand the complex interplay
of these mechanisms. Further, an effort has been made to identify the knowledge gap and the key
players in each pathway that may serve as potential therapeutic drug targets.
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Affiliation(s)
- Nikhil Shri Sahajpal
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Rajesh Kumar Goel
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
| | - Alka Chaubey
- Cytogenetics Laboratory, Greenwood Genetic Center, Greenwood, South Carolina, SC, United States
| | - Rohan Aurora
- The International School Bangalore, Karnataka, India
| | - Subheet Kumar Jain
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
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Time-dependent changes in hypoxia- and gliosis-related factors in experimental diabetic retinopathy. Eye (Lond) 2018; 33:600-609. [PMID: 30401898 PMCID: PMC6461831 DOI: 10.1038/s41433-018-0268-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/21/2018] [Accepted: 08/30/2018] [Indexed: 01/26/2023] Open
Abstract
Diabetes causes various biochemical changes in the retina; long-term changes in the factors associated with hypoxia and gliosis have rarely been reported. The present study was conducted to explore the changes in these factors in a time-dependent manner in experimental diabetic retinopathy (DR). Diabetes was induced in Sprague-Dawley rats by intraperitoneal injection of streptozotocin. The expression of the following factors was examined using immunofluorescence and western blot analysis at 0.5, 1, 2, 4 and 6 months after diabetes onset: hypoxia-inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), erythropoietin (EPO), erythropoietin receptor (EPOR), glial fibrillary acidic protein (GFAP), vimentin, glutamate-aspartate transporter (GLAST) and glutamine synthase (GS). The expression of factors such as HIF-1alpha, VEGF, EPO, EPOR, GFAP and vimentin, was up-regulated with the progression of diabetes in the diabetic rat retinas compared to the expression in normal control retinas, whereas the expression of GS and GLAST was down-regulated. Changes in EPO and EPOR appeared 2 weeks after diabetes onset. HIF-1alpha, VEGF and GFAP started to increase at 1 month and vimentin at 4 months after diabetes onset. GS and GLAST started to decrease at 1 month after diabetes onset. The expression of these factors, which are involved in the processes of hypoxia and gliosis, varied at different stages of DR. The time-course change may be helpful in the evaluation of the progression of DR, and it may indicate the optimal intervention time points for DR.
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Jiang H, Du J, Song J, Li Y, Wu M, Zhou J, Wu S. Loss-of-function mutation of serine racemase attenuates retinal ganglion cell loss in diabetic mice. Exp Eye Res 2018; 175:90-97. [PMID: 29913163 DOI: 10.1016/j.exer.2018.06.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 03/14/2018] [Accepted: 06/14/2018] [Indexed: 10/14/2022]
Abstract
Consistent results suggest the promoting roles of serine racemase (SR)/D-serine in retinal neurodegeneration in diabetic retinopathy (DR). However, the direct evidence connecting SR deficiency with retinal neuroprotection in genetic model of diabetes mellitus has not been reported. In this investigation, we explore the effect of absence of functional SR on the degeneration of retinal ganglion cells (RGCs) with a diabetic murine model, Ins2Akita mice. We established a murine strain with double mutation, termed Ins2Akita-Srr, by mating heterozygous Ins2Akita mice with homozygous Srrochre269 mice. Ins2Akita retained less RGC in posterior, middle, and peripheral retinae than the counterpart from non-diabetic sibling mice at the age of five or seven months. Ins2Akita-Srr mice retained more RGC in middle and peripheral--but not in posterior-- retinae than the counterpart from Ins2Akita sibling mice at the age of five months. By contrast, at the age of seven months, Ins2Akita-Srr mice contained more RGC in peripheral, middle, and posterior retinae than the counterpart from Ins2Akita. RGCs were identified with retrograde labeling in vivo or with immunolabeling against a RGC-specific transcription factor, Brn3a, in retinal flat mounts. Correspondingly, the aqueous humor of Ins2Akita-Srr contained less amount of D-serine than sibling Ins2Akita mice. Thus, SR deficiency significantly prevented RGC loss in diabetic mice. We conclude that D-serine is a critical factor in the degeneration of RGC in DR. Targeting SR expression or activity may be a strategy for ameliorating RGC loss in DR.
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Affiliation(s)
- Haiyan Jiang
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, PR China
| | - Jinlin Du
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, PR China
| | - Juan Song
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, PR China
| | - Yanqi Li
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, PR China
| | - Mengjuan Wu
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, PR China
| | - Jing Zhou
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, PR China
| | - Shengzhou Wu
- School of Optometry and Ophthalmology and the Eye Hospital, Wenzhou Medical University, PR China; State Key Laboratory of Optometry, Ophthalmology, and Visual Science, 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, PR China.
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Kolesnikov AV, Shchul’kin AV, Pisklova MV, Barenina OI, Yakusheva EN, Kudrin VS, Ostrovskaya RU, Uzbekov MG, Shishkin MM. The Influence of Noopept on Morphological, Electrophysiological, and Biochemical Changes in the Retina during the Experimental Thrombosis of Its Vessels. NEUROCHEM J+ 2018. [DOI: 10.1134/s181971241801004x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Carpi-Santos R, Calaza KC. Alterations in System x c- Expression in the Retina of Type 1 Diabetic Rats and the Role of Nrf2. Mol Neurobiol 2018; 55:7941-7948. [PMID: 29488137 DOI: 10.1007/s12035-018-0961-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/12/2018] [Indexed: 12/23/2022]
Abstract
Nrf2 (nuclear factor erythroid 2-related factor 2), a transcription factor that controls expression of several proteins that are related to cellular antioxidant capacity, such as the subunit xCT of the system xc-, is dysregulated in diabetes. Recently, it was described that system xc- is decreased in the retina after 3 weeks of diabetes. So, in the present work, the temporal relationship between xCT and Nrf2 in the retina of diabetic animals was investigated. Diabetes was induced in male Wistar rats (200 g) by a single injection of streptozotocin, and retinas were collected after 1, 2, and 6 months of diabetes induction. Expression of xCT, Nrf2 activity, and binding to antioxidant-responsive element (ARE) sequence were evaluated. Glutathione and reactive oxygen species (ROS) levels were also assessed. After 1 month of diabetes, Nrf2 activity, xCT expression, and glutathione levels were reduced whereas ROS were increased. Although glutathione and ROS levels remain unchanged until later stages, Nrf2 activity and xCT expression returned to normal levels after 2 months. However, they were decreased again at 6 months of diabetes. Accordingly, Nrf2 binding to xCT ARE sequence followed the same pattern of Nrf2 activity and xCT expression. These data showed that retinal xCT expression is regulated by Nrf2 in diabetic condition. The results also demonstrated a temporal relationship between Nrf2 and system xc- which could be implicated in the initiation of oxidative stress in retina in diabetes.
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Affiliation(s)
- Raul Carpi-Santos
- Department of Neurobiology, Neuroscience Program, Institute of biology, Fluminense Federal University, 24020-140, Niterói, Rio de Janeiro, Brazil
| | - Karin C Calaza
- Department of Neurobiology, Neuroscience Program, Institute of biology, Fluminense Federal University, 24020-140, Niterói, Rio de Janeiro, Brazil.
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36
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Rhee SY, Jung ES, Park HM, Jeong SJ, Kim K, Chon S, Yu SY, Woo JT, Lee CH. Plasma glutamine and glutamic acid are potential biomarkers for predicting diabetic retinopathy. Metabolomics 2018; 14:89. [PMID: 29950956 PMCID: PMC6013531 DOI: 10.1007/s11306-018-1383-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 06/06/2018] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Diabetic patients with a long disease duration usually accompanied complication such as diabetic retinopathy, but in some patients had no complication. OBJECTIVES We analyzed differences in plasma metabolites according to the presence or absence of diabetic retinopathy (DR) in type 2 diabetic (T2D) patients with disease duration ≥ 15 years. METHODS A cohort of 183 T2D patients was established. Their biospecimens and clinical information were collected in accordance with the guidelines of the National Biobank of Korea, and the Korean Diabetes Association. DR phenotypes of the subjects were verified by ophthalmologic specialists. Plasma metabolites were analyzed using gas chromatography time-of-flight mass spectrometry and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. And these results were analyzed using multivariate statistics. RESULTS For metabolomic study, propensity score matched case and control subjects were chosen. Mean age of the subjects was 66.4 years and mean T2D duration was 22.2 years. Metabolomic identification revealed various carbohydrates, amino acids, and organic compounds that distinguished between age- and sex-matched non-diabetic controls and T2D subjects. Among these, glutamine and glutamic acid were suggested as the most distinctive metabolites for the presence of DR. Receiver operating characteristics curves showed an excellent diagnostic value of combined (AUC = 0.739) and the ratio (AUC = 0.742) of glutamine and glutamic acid for DR. And these results were consistent in validation analyses. CONCLUSION Our results imply that plasma glutamine, glutamic acid, and their ratio may be valuable as novel biomarkers for anticipating DR in T2D subjects.
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Affiliation(s)
- Sang Youl Rhee
- Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, 23 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Eun Sung Jung
- Department of Systems Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, Republic of Korea
| | - Hye Min Park
- Department of Systems Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, Republic of Korea
| | - Su Jin Jeong
- Statistics Support Department, Kyung Hee University Medical Center Medical Science Research Institute, Seoul, Republic of Korea
| | - Kiyoung Kim
- Department of Ophthalmology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Suk Chon
- Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, 23 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Seung-Young Yu
- Department of Ophthalmology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Jeong-Taek Woo
- Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, 23 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Choong Hwan Lee
- Department of Systems Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, Republic of Korea.
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Amato R, Dal Monte M, Lulli M, Raffa V, Casini G. Nanoparticle-Mediated Delivery of Neuroprotective Substances for the Treatment of Diabetic Retinopathy. Curr Neuropharmacol 2018; 16:993-1003. [PMID: 28714394 PMCID: PMC6120116 DOI: 10.2174/1570159x15666170717115654] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 05/04/2017] [Accepted: 07/14/2017] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a major complication of diabetes, characterized by extensive vascular pathology leading to vision loss. Neuronal suffering and death are also present in the diabetic retina as a result of different molecular mechanisms that are compromised or modified in response to high glucose. The aim of this paper is to highlight recent data indicating that neurodegeneration is likely to play a primary role in the development of DR and that strategies based on nanomedicine may be exploited to deliver neuroprotection to the retina. METHODS An extensive analysis of the publications dealing with the role of neuroprotection in DR and with nanoparticle-mediated drug delivery to the retina has been conducted using PubMed, with particular attention to the most recent papers. RESULTS There are important limitations related to possible systemic side effects of neuroprotective substances and to drug bioavailability in the retina such as, for instance, the amount of drug reaching the retina, the need of keeping to a minimum the number of administrations (especially, for example, in the case of intraocular injections) and the need of assuring a long-lasting, graded intraocular drug delivery. In recent years, a variety of investigations have been aimed at the exploitation of approaches of nanomedicine to enhance the pharmacokinetics and pharmacodynamic activity of intraocularly delivered drugs. In particular, we provide some preliminary results that we have obtained about the feasibility of delivering magnetic nanoparticles functionalized with a neuroprotectant to mouse eyes through intraocular injections. CONCLUSION We propose that nanoparticles functionalized with neuroprotective substances may be used to protect the diabetic retina, thus causing an impact in the design of future pharmacologic treatments for DR.
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Affiliation(s)
| | | | | | | | - Giovanni Casini
- Address correspondence to this author at the Department of Biology, University of Pisa, via S. Zeno 31, I-56127 Pisa, Italy; Tel: ++39-050-2211423; E-mail:
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Neurodegeneration in diabetic retinopathy: Potential for novel therapies. Vision Res 2017; 139:82-92. [PMID: 28988945 DOI: 10.1016/j.visres.2017.06.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/12/2017] [Accepted: 06/14/2017] [Indexed: 11/20/2022]
Abstract
The complex pathology of diabetic retinopathy (DR) affects both vascular and neural tissue. The characteristics of neurodegeneration are well-described in animal models but have more recently been confirmed in the clinical setting, mostly by using non-invasive imaging approaches such as spectral domain optical coherence tomography (SD-OCT). The most frequent observations report loss of tissue in the nerve fiber layer and inner plexiform layer, confirming earlier findings from animal models. In several cases the reduction in inner retinal layers is reported in patients with little evidence of vascular lesions or macular edema, suggesting that degenerative loss of neural tissue in the inner retina can occur after relatively short durations of diabetes. Animal studies also suggest that neurodegeneration leading to retinal thinning is not limited to cell death and tissue loss but also includes changes in neuronal morphology, reduced synaptic protein expression and alterations in neurotransmission, including changes in expression of neurotransmitter receptors as well as neurotransmitter release, reuptake and metabolism. The concept of neurodegeneration as an early component of DR introduces the possibility to explore alternative therapies to prevent the onset of vision loss, including neuroprotective therapies and drugs targeting individual neurotransmitter systems, as well as more general neuroprotective approaches to preserve the integrity of the neural retina. In this review we consider some of the evidence for progressive retinal neurodegeneration in diabetes, and explore potential neuroprotective therapies.
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Karti O, Nalbantoglu O, Abali S, Ayhan Z, Tunc S, Kusbeci T, Ozkan B. Retinal Ganglion Cell Loss in Children With Type 1 Diabetes Mellitus Without Diabetic Retinopathy. Ophthalmic Surg Lasers Imaging Retina 2017; 48:473-477. [PMID: 28613353 DOI: 10.3928/23258160-20170601-05] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE Early diabetic retinal changes in children with type 1 diabetes mellitus (T1DM) without diabetic retinopathy (DR) were examined using spectral-domain optical coherence tomography (SD-OCT). PATIENTS AND METHODS Sixty children with T1DM without DR and 60 normal children were enrolled in the study. SD-OCT was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber (RNFL) thicknesses in all participants. RESULTS The GC-IPL thickness was significantly decreased in all quadrants except the superior-nasal quadrant in children with diabetes (P < .05). However, the RNFL thickness in all quadrants was not significantly different between the groups (P > .05). CONCLUSIONS There was a decreased GC-IPL thickness in children with T1DM without DR, suggesting that T1DM has an early neurodegenerative effect on retinal ganglion cells that occurs when the vascular component of DR is absent. SD-OCT may be more useful than ophthalmoscopic evaluation for detecting the earlier retinal structural changes of diabetes. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:473-477.].
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Welters A, Klüppel C, Mrugala J, Wörmeyer L, Meissner T, Mayatepek E, Heiss C, Eberhard D, Lammert E. NMDAR antagonists for the treatment of diabetes mellitus-Current status and future directions. Diabetes Obes Metab 2017; 19 Suppl 1:95-106. [PMID: 28880473 DOI: 10.1111/dom.13017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/18/2017] [Accepted: 05/20/2017] [Indexed: 12/16/2022]
Abstract
Diabetes mellitus is characterized by chronically elevated blood glucose levels accelerated by a progressive decline of insulin-producing β-cells in the pancreatic islets. Although medications are available to transiently adjust blood glucose to normal levels, the effects of current drugs are limited when it comes to preservation of a critical mass of functional β-cells to sustainably maintain normoglycemia. In this review, we recapitulate recent evidence on the role of pancreatic N-methyl-D-aspartate receptors (NMDARs) in β-cell physiology, and summarize effects of morphinan-based NMDAR antagonists that are beneficial for insulin secretion, glucose tolerance and islet cell survival. We further discuss NMDAR-mediated molecular pathways relevant for neuronal cell survival, which may also be important for the preservation of β-cell function and mass. Finally, we summarize the literature for evidence on the role of NMDARs in the development of diabetic long-term complications, and highlight beneficial pharmacologic aspects of NMDAR antagonists in diabetic nephropathy, retinopathy as well as neuropathy.
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Affiliation(s)
- Alena Welters
- Institute of Metabolic Physiology, Department of Biology, Heinrich Heine University, Düsseldorf, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital Düsseldorf, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Carina Klüppel
- Institute of Metabolic Physiology, Department of Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Jessica Mrugala
- Institute for Beta Cell Biology, German Diabetes Center, Leibniz Center for Diabetes Research, Düsseldorf, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Düsseldorf, Germany
| | - Laura Wörmeyer
- Institute of Metabolic Physiology, Department of Biology, Heinrich Heine University, Düsseldorf, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital Düsseldorf, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Thomas Meissner
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital Düsseldorf, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Ertan Mayatepek
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital Düsseldorf, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Christian Heiss
- Division of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Daniel Eberhard
- Institute of Metabolic Physiology, Department of Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Eckhard Lammert
- Institute of Metabolic Physiology, Department of Biology, Heinrich Heine University, Düsseldorf, Germany
- Institute for Beta Cell Biology, German Diabetes Center, Leibniz Center for Diabetes Research, Düsseldorf, Germany
- German Center for Diabetes Research, Helmholtz Zentrum München, Neuherberg, Düsseldorf, Germany
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Retinal exposure to high glucose condition modifies the GABAergic system: Regulation by nitric oxide. Exp Eye Res 2017; 162:116-125. [PMID: 28734674 DOI: 10.1016/j.exer.2017.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/16/2017] [Accepted: 07/18/2017] [Indexed: 11/20/2022]
Abstract
Diabetic retinopathy is a severe retinal complication that diabetic patients are susceptible to present. Although this disease is currently characterized as a microvascular disease, there is growing evidence that neural changes occur and maybe precede vascular impairments. Using chicken retina, an avascular tissue with no direct contact with blood vessels and neural retina, this study aimed to evaluate the influence of acute exposure to high glucose concentration in the retinal GABAergic system, and the role of nitric oxide (NO) in this modulation. Therefore, in ex vivo experiments, retinas were incubated in control (10 mM glucose) or high glucose condition (35 mM) for 30 min. By using DAF-FM to evaluate NO production, it was possible to show that high glucose (HG) significantly increased NO levels in the outer nuclear layer, inner nuclear layer (outer and inner portion), and inner plexiform layer. It was also observed that HG increased GABA immunoreactivity (IR) in amacrine and horizontal cells. HG did not change glutamic acid decarboxylase-IR, whereas it decreased GABA Transporter (GAT) 1-IR and increased GAT-3-IR. The co-treatment with 7-NI, an inhibitor of neuronal nitric oxide synthase (nNOS), blocked all changes stimulated by HG exposure. The concomitant exposure with SNAP-5114, a GAT-2/3 inhibitor, blocked the increase in GABA-IR caused by HG incubation. Therefore, our data suggest that hyperglycemia induces GABA accumulation in the cytosol by modulating GABA transporters. This response is dependent on NO production and signaling.
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Toft-Kehler AK, Skytt DM, Svare A, Lefevere E, Van Hove I, Moons L, Waagepetersen HS, Kolko M. Mitochondrial function in Müller cells - Does it matter? Mitochondrion 2017; 36:43-51. [PMID: 28179130 DOI: 10.1016/j.mito.2017.02.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 01/26/2017] [Accepted: 02/03/2017] [Indexed: 11/17/2022]
Abstract
Growing evidence suggests that mitochondrial dysfunction might play a key role in the pathogenesis of age-related neurodegenerative inner retinal diseases such as diabetic retinopathy and glaucoma. Therefore, the present review provides a perspective on the impact of functional mitochondria in the most predominant glial cells of the retina, the Müller cells. Müller cells span the entire thickness of the neuroretina and are in close proximity to retinal cells including the retinal neurons that provides visual signaling to the brain. Among multiple functions, Müller cells are responsible for the removal of neurotransmitters, buffering potassium, and providing neurons with essential metabolites. Thus, Müller cells are responsible for a stable metabolic dialogue in the inner retina and their crucial role in supporting retinal neurons is indisputable. Müller cell functions require considerable energy production and previous literature has primarily emphasized glycolysis as the main energy provider. However, recent studies highlight the need of mitochondrial ATP production to upheld Müller cell functions. Therefore, the present review aims to provide an overview of the current evidence on the impact of mitochondrial functions in Müller cells.
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Affiliation(s)
- Anne Katrine Toft-Kehler
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen O, Denmark; Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark.
| | - Dorte Marie Skytt
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen O, Denmark; Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark
| | - Alicia Svare
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark
| | - Evy Lefevere
- Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Inge Van Hove
- Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lieve Moons
- Neural Circuit Development and Regeneration Research Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Helle S Waagepetersen
- Neuromet, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen O, Denmark
| | - Miriam Kolko
- Eye Translational Research Unit, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen O, Denmark; Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen N, Denmark; Zealand University Hospital, Department of Ophthalmology, Vestermarksvej 23, 4000 Roskilde, Denmark.
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Effects of Glutamate and Aspartate on Serum Antioxidative Enzyme, Sex Hormones, and Genital Inflammation in Boars Challenged with Hydrogen Peroxide. Mediators Inflamm 2016; 2016:4394695. [PMID: 27777497 PMCID: PMC5061961 DOI: 10.1155/2016/4394695] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 09/07/2016] [Indexed: 11/17/2022] Open
Abstract
Background. Oxidative stress is associated with infertility. This study was conducted to determine the effects of glutamate and aspartate on serum antioxidative enzymes, sex hormones, and genital inflammation in boars suffering from oxidative stress. Methods. Boars were randomly divided into 4 groups: the nonchallenged control (CON) and H2O2-challenged control (BD) groups were fed a basal diet supplemented with 2% alanine; the other two groups were fed the basal diet supplemented with 2% glutamate (GLU) or 2% aspartate (ASP). The BD, GLU, and ASP groups were injected with hydrogen peroxide (H2O2) on day 15. The CON group was injected with 0.9% sodium chloride solution on the same day. Results. Dietary aspartate decreased the malondialdehyde (MDA) level in serum (P < 0.05) compared with the BD group. Additionally, aspartate maintained serum luteinizing hormone (LH) at a relatively stable level. Moreover, glutamate and aspartate increased transforming growth factor-β1 (TGF-β1) and interleukin-10 (IL-10) levels in the epididymis and testis (P < 0.05) compared with the BD group. Conclusion. Both glutamate and aspartate promoted genital mRNA expressions of anti-inflammatory factors after oxidative stress. Aspartate more effectively decreased serum MDA and prevented fluctuations in serum sex hormones after H2O2 challenge than did glutamate.
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Martínez-Moreno CG, Ávila-Mendoza J, Wu Y, Arellanes-Licea EDC, Louie M, Luna M, Arámburo C, Harvey S. Neuroprotection by GH against excitotoxic-induced cell death in retinal ganglion cells. Gen Comp Endocrinol 2016; 234:68-80. [PMID: 27129619 DOI: 10.1016/j.ygcen.2016.03.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 03/16/2016] [Indexed: 01/13/2023]
Abstract
Retinal growth hormone (GH) has been shown to promote cell survival in retinal ganglion cells (RGCs) during developmental waves of apoptosis during chicken embryonic development. The possibility that it might also against excitotoxicity-induced cell death was therefore examined in the present study, which utilized quail-derived QNR/D cells as an in vitro RGC model. QNR/D cell death was induced by glutamate in the presence of BSO (buthionine sulfoxamide) (an enhancer of oxidative stress), but this was significantly reduced (P<0.01) in the presence of exogenous recombinant chicken GH (rcGH). Similarly, QNR/D cells that had been prior transfected with a GH plasmid to overexpress secreted and non-secreted GH. This treatment reduced the number of TUNEL-labeled cells and blocked their release of lactate dehydrogenase (LDH). In a further experiment with dissected neuroretinal explants from ED (embryonic day) 10 embryos, rcGH treatment of the explants also reduced (P<0.01) the number of glutamate-BSO-induced apoptotic cells and blocked the explant release of LDH. This neuroprotective action was likely mediated by increased STAT5 phosphorylation and increased bcl-2 production, as induced by exogenous rcGH treatment and the media from GH-overexpressing QNR/D cells. As rcGH treatment and GH-overexpression cells also increased the content of IGF-1 and IGF-1 mRNA this neuroprotective action of GH is likely to be mediated, at least partially, through an IGF-1 mechanism. This possibility is supported by the fact that the siRNA knockdown of GH or IGF-1 significantly reduced QNR/D cell viability, as did the immunoneutralization of IGF-1. GH is therefore neuroprotective against excitotoxicity-induced RGC cell death by anti-apoptotic actions involving IGF-1 stimulation.
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Affiliation(s)
| | - José Ávila-Mendoza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Yilun Wu
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
| | - Elvira Del Carmen Arellanes-Licea
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Marcela Louie
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
| | - Maricela Luna
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Carlos Arámburo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro. 76230, Mexico
| | - Steve Harvey
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada.
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Moran EP, Wang Z, Chen J, Sapieha P, Smith LEH, Ma JX. Neurovascular cross talk in diabetic retinopathy: Pathophysiological roles and therapeutic implications. Am J Physiol Heart Circ Physiol 2016; 311:H738-49. [PMID: 27473938 DOI: 10.1152/ajpheart.00005.2016] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 07/18/2016] [Indexed: 12/19/2022]
Abstract
Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population in developed countries, and its prevalence will increase as the global incidence of diabetes grows exponentially. DR begins with an early nonproliferative stage in which retinal blood vessels and neurons degenerate as a consequence of chronic hyperglycemia, resulting in vasoregression and persistent retinal ischemia, metabolic disequilibrium, and inflammation. This is conducive to overcompensatory pathological neovascularization associated with advanced proliferative DR. Although DR is considered a microvascular complication, the retinal microvasculature is intimately associated with and governed by neurons and glia; neurodegeneration, neuroinflammation, and dysregulation of neurovascular cross talk are responsible in part for vascular abnormalities in both early nonproliferative DR and advanced proliferative DR. Neuronal activity directly regulates microvascular dilation and blood flow in the process of neurovascular coupling. Retinal neurons also secrete guidance cues in response to injury, ischemia, or metabolic stress that may either promote or suppress vascular outgrowth, either alleviating or exacerbating DR, contingent on the stage of disease and retinal microenvironment. Neurodegeneration, impaired neurovascular coupling, and dysregulation of neuronal guidance cues are key events in the pathogenesis of DR, and correcting these events may prevent or delay development of advanced DR. The review discusses the mechanisms of neurovascular cross talk and its dysregulation in DR, and their potential therapeutic implications.
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Affiliation(s)
- Elizabeth P Moran
- Depatment of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Harold Hamm Diabetes Center, Oklahoma City, Oklahoma
| | - Zhongxiao Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; and
| | - Jing Chen
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; and
| | - Przemyslaw Sapieha
- Departments of Ophthalmology, Biochemistry & Molecular Medicine, Maisonneuve-Rosemont Hospital Research Centre, University of Montreal, Montreal, Quebec, Canada
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; and
| | - Jian-Xing Ma
- Depatment of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; Harold Hamm Diabetes Center, Oklahoma City, Oklahoma;
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Vindeirinho J, Santiago AR, Cavadas C, Ambrósio AF, Santos PF. The Adenosinergic System in Diabetic Retinopathy. J Diabetes Res 2016; 2016:4270301. [PMID: 27034960 PMCID: PMC4789509 DOI: 10.1155/2016/4270301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/29/2015] [Indexed: 11/18/2022] Open
Abstract
The neurodegenerative and inflammatory environment that is prevalent in the diabetic eye is a key player in the development and progression of diabetic retinopathy. The adenosinergic system is widely regarded as a significant modulator of neurotransmission and the inflammatory response, through the actions of the four types of adenosine receptors (A1R, A2AR, A2BR, and A3R), and thus could be revealed as a potential player in the events unfolding in the early stages of diabetic retinopathy. Herein, we review the studies that explore the impact of diabetic conditions on the retinal adenosinergic system, as well as the role of the said system in ameliorating or exacerbating those conditions. The experimental results described suggest that this system is heavily affected by diabetic conditions and that the modulation of its components could reveal potential therapeutic targets for the treatment of diabetic retinopathy, particularly in the early stages of the disease.
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Affiliation(s)
- J. Vindeirinho
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
- CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal
- *J. Vindeirinho:
| | - A. R. Santiago
- CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
| | - C. Cavadas
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, 3004-504 Coimbra, Portugal
- CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - A. F. Ambrósio
- CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), 3000-548 Coimbra, Portugal
| | - P. F. Santos
- CNC.IBILI, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000-456 Coimbra, Portugal
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Hernández C, Dal Monte M, Simó R, Casini G. Neuroprotection as a Therapeutic Target for Diabetic Retinopathy. J Diabetes Res 2016; 2016:9508541. [PMID: 27123463 PMCID: PMC4830713 DOI: 10.1155/2016/9508541] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/29/2016] [Accepted: 03/16/2016] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy (DR) is a multifactorial progressive disease of the retina and a leading cause of vision loss. DR has long been regarded as a vascular disorder, although neuronal death and visual impairment appear before vascular lesions, suggesting an important role played by neurodegeneration in DR and the appropriateness of neuroprotective strategies. Upregulation of vascular endothelial growth factor (VEGF), the main target of current therapies, is likely to be one of the first responses to retinal hyperglycemic stress and VEGF may represent an important survival factor in early phases of DR. Of central importance for clinical trials is the detection of retinal neurodegeneration in the clinical setting, and spectral domain optical coherence tomography seems the most indicated technique. Many substances have been tested in animal studies for their neuroprotective properties and for possible use in humans. Perhaps, the most intriguing perspective is the use of endogenous neuroprotective substances or nutraceuticals. Together, the data point to the central role of neurodegeneration in the pathogenesis of DR and indicate neuroprotection as an effective strategy for treating this disease. However, clinical trials to determine not only the effectiveness and safety but also the compliance of a noninvasive route of drug administration are needed.
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Affiliation(s)
- Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabolicas Asociadas) and Diabetes and Metabolism Research Unit, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autonoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain
- *Cristina Hernández: and
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, Via San Zeno 31, 56127 Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabolicas Asociadas) and Diabetes and Metabolism Research Unit, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autonoma de Barcelona, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain
| | - Giovanni Casini
- Department of Biology, University of Pisa, Via San Zeno 31, 56127 Pisa, Italy
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
- *Giovanni Casini:
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Yu Y, Zou J, Han Y, Quyang L, He H, Hu P, Shao Y, Tu P. Effects of intravitreal injection of netrin-1 in retinal neovascularization of streptozotocin-induced diabetic rats. DRUG DESIGN DEVELOPMENT AND THERAPY 2015; 9:6363-77. [PMID: 26674395 PMCID: PMC4676508 DOI: 10.2147/dddt.s93166] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background In a previous study, we confirmed that netrin-1 acts as an antiangiogenic factor by inhibiting alkali burn-induced corneal neovascularization in rats. Here, we continue working on the role of netrin-1 in retinal neovascularization. Methods Using an in vitro angiogenesis assay, we detected the effects of netrin-1 on human umbilical vein endothelial cell tube formation, viability and proliferation, migration, and invasion at concentrations of 0.1 μg/mL or 5 μg/mL. We intravitreally injected 0.1 μg/mL or 5 μg/mL netrin-1 into streptozotocin-induced rats to assess retinal neovascularization using retinal electrophysiology and electroretinography, enzyme-linked immunosorbent assay, fundus fluoresce in angiography, measurement of inner blood retinal barrier, retinal hematoxylin-eosin staining, and retinal flat-mount fluorescence assays. Results Human umbilical vein endothelial cell tube formation, viability and proliferation, migration, and invasion were upregulated by netrin-1 at a concentration of 0.1 μg/mL (P<0.05), while 5 μg/mL netrin-1 had an opposite effect (P<0.05) in our in vitro angiogenesis assay. Retinal electrophysiology testing revealed that intravitreal injection of netrin-1 affected the amplitude of a- and b-waves (a-wave: 0.1 μg/mL netrin-1 =17.67±3.39 μm, 5 μg/mL netrin-1 =28.50±1.31 μm, phosphate-buffered saline [PBS]-treated =17.67±3.39 μm; b-wave: 0.1 μg/mL netrin-1 =44.67±4.80 μm, 5 μg/mL netrin-1 =97.17±9.63 μm, PBS-treated =44.67±4.80 μm) and the expression of VEGF-A (no-treatment rats, 9.29±0.80 pg/mL; PBS-treated rats, 19.64±3.77 pg/mL; 0.1 μg/mL netrin-1 treated rats, 21.37±3.64 pg/mL; 5 μg/mL netrin-1 treated rats, 9.85±0.54 pg/mL, at 6 weeks after induction). By comparing fluoresce in angiography, level of inner blood retinal barrier breakdown (% of control), retinal hematoxylin-eosin staining, and collagen-IV fluorescence assays in the retinas of PBS-treated rats, netrin-1 was found to suppress and reverse retinal neovascularization at a concentration of 5 μg/mL (P<0.05), while 0.1 μg/mL netrin-1 (P<0.05) led to an increase in the number of new retinal blood vessels, after 6 weeks’ injection. Conclusion Netrin-1 could play a significant role in retinal neovascularization by dual-direction regulating angiogenesis dependent on dosage.
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Affiliation(s)
- Yao Yu
- Nanchang Key Laboratory of Diabetes, Department of Endocrinology and Metabolism, The Third Hospital of Nanchang, Jiangxi, People's Republic of China ; Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Clinical Ophthalmology Institute, Jiangxi, People's Republic of China
| | - Jing Zou
- Department of Ophthalmology, Xiangya Hospital, Central South University, Hunan, People's Republic of China
| | - Yun Han
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute of Xiamen University, Fujian, People's Republic of China
| | - Luowa Quyang
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute of Xiamen University, Fujian, People's Republic of China
| | - Hui He
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Eye Institute of Xiamen University, Fujian, People's Republic of China
| | - Peihong Hu
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Clinical Ophthalmology Institute, Jiangxi, People's Republic of China
| | - Yi Shao
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Clinical Ophthalmology Institute, Jiangxi, People's Republic of China
| | - Ping Tu
- Nanchang Key Laboratory of Diabetes, Department of Endocrinology and Metabolism, The Third Hospital of Nanchang, Jiangxi, People's Republic of China
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Jiang H, Wang X, Zhang H, Chang Y, Feng M, Wu S. Loss-of-function mutation of serine racemase attenuates excitotoxicity by intravitreal injection of N
-methyl-D-aspartate. J Neurochem 2015; 136:186-93. [PMID: 26485193 DOI: 10.1111/jnc.13400] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/07/2015] [Accepted: 10/12/2015] [Indexed: 02/01/2023]
Affiliation(s)
- Haiyan Jiang
- School of Optometry and Ophthalmology and the Eye Hospital; Wenzhou Medical University; Wenzhou Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Wenzhou Zhejiang China
| | - Xianwei Wang
- School of Optometry and Ophthalmology and the Eye Hospital; Wenzhou Medical University; Wenzhou Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Wenzhou Zhejiang China
| | - He Zhang
- School of Optometry and Ophthalmology and the Eye Hospital; Wenzhou Medical University; Wenzhou Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Wenzhou Zhejiang China
| | - Yuhua Chang
- School of Optometry and Ophthalmology and the Eye Hospital; Wenzhou Medical University; Wenzhou Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Wenzhou Zhejiang China
| | - Meiling Feng
- School of Optometry and Ophthalmology and the Eye Hospital; Wenzhou Medical University; Wenzhou Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Wenzhou Zhejiang China
| | - Shengzhou Wu
- School of Optometry and Ophthalmology and the Eye Hospital; Wenzhou Medical University; Wenzhou Zhejiang China
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science; Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry; Wenzhou Zhejiang China
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Oxidative stress-associated neuroretinal dysfunction and nitrosative stress in diabetic retinopathy. Can J Diabetes 2015; 37:401-7. [PMID: 24321721 DOI: 10.1016/j.jcjd.2013.05.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/18/2013] [Accepted: 05/22/2013] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The present study was intended to investigate whether oxidative stress is the key regulator to alter neuroretinal biochemical homeostasis and in turn aggravate the process of diabetic retinopathy by inducing nitrosative stress in the retinal neurovascular unit. METHODS Peripheral blood mononuclear cell reactive oxygen species level was measured by flow cytometry along with spectrophotometric detection of malondialdehyde (MDA) and glutamate from serum or plasma and a vitreous sample of study groups (i.e. subjects with proliferative diabetic retinopathy [PDR], type 2 diabetes without retinopathy [DNR] and healthy controls [HCs]). Further, nitrosative stress assessment was performed by spectrophotometric and enzyme-linked immunosorbent assay-based detection of serum and vitreous nitrite and nitrotyrosine concentrations, respectively. RESULTS The plasma glutamate level remains insignificant between subjects with PDR and DNR (p=0.505) or in HC (p=0.1344) individuals. However, serum MDA (p=0.0004), nitrite (p=0.0147) and nitrotyrosine (p=0.0129) were found to be strikingly higher among PDR subjects compared with the DNR group. Significantly increased levels of peripheral blood mononuclear cell reactive oxygen species (p<0.0001), vitreous glutamate (p=0.0009, p<0.0001), MDA (p=0.0058, p=0.0003), nitrite (p=0.0014, p<0.0001) and nitrotyrosine (p=0.0008, p<0.0001) were found in PDR subjects compared with DNR and HC subjects, respectively. CONCLUSIONS Our observation suggests that oxidative stress is associated with impairment in neuroretinal biochemical homeostasis among PDR subjects, which further augments retinal nitrosative stress and thus worsens the pathogenic process of retinopathy among PDR subjects.
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