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Cheng YW, Huang YC, Chang KF, Huang XF, Sheu GT, Tsai NM. Protective Effect of Curcumin on the Tight Junction Integrity and Cellular Senescence in Human Retinal Pigment Epithelium of Early Diabetic Retinopathy. JOURNAL OF PHYSIOLOGICAL INVESTIGATION 2024; 67:107-117. [PMID: 38857204 DOI: 10.4103/ejpi.ejpi-d-23-00035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/05/2024] [Indexed: 06/12/2024]
Abstract
Diabetic retinopathy (DR) is a secondary complication of diabetes that can lead to visual impairment and blindness. The retinal pigment epithelium (RPE) is a monolayer of pigment cells that forms the blood-retinal barrier (BRB) via tight junction (TJ) proteins and plays a crucial role in the physiological function of the retina. Hyperglycemia induces RPE death and BRB breakdown, which accelerates the process of DR. Curcumin, an active extract of Curcuma longa , has anti-inflammatory, antioxidant, antiapoptotic, and neuroprotective properties. However, the effect of Curcumin on the BRB under high glucose conditions remains unknown. This study aimed to investigate the protective effects of Curcumin on RPE physiology in vitro and in vivo . Curcumin significantly alleviated cell viability inhibition under high glucose conditions. Moreover, high glucose reduced extracellular signal-regulated kinase and Akt pathways activation to diminish RPE cell growth but reversed by Curcumin treatment. Curcumin protected not only TJ integrity but also retinoid regeneration through TJ proteins and isomerase modulation in diabetic retina. Furthermore, Curcumin decreased the expression of angiogenic factor to inhibit retinal neovascularization. Finally, Curcumin treatment markedly reduced apoptosis during hyperglycemia. In conclusion, Curcumin can alleviate the progression of DR by promoting RPE survival, TJ integrity, retinoid isomerase activity, RPE senescence inhibition, and neovascularization. Therefore, Curcumin exhibits high potential for use as a therapeutic agent for early DR.
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Affiliation(s)
- Yu-Wen Cheng
- Department of Internal Medicine, Lee's General Hospital, Miaoli, Taiwan
| | - Ya-Chih Huang
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Kai-Fu Chang
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Xiao-Fan Huang
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Gwo-Tarng Sheu
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Nu-Man Tsai
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
- Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
- Department of Life-and-Death Studies, Nanhua University, Chiayi, Taiwan
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Ramos H, Hernández C, Simó R, Simó-Servat O. Inflammation: The Link between Neural and Vascular Impairment in the Diabetic Retina and Therapeutic Implications. Int J Mol Sci 2023; 24:ijms24108796. [PMID: 37240138 DOI: 10.3390/ijms24108796] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 04/25/2023] [Accepted: 05/12/2023] [Indexed: 05/28/2023] Open
Abstract
The etiology of diabetic retinopathy (DR) is complex, multifactorial and compromises all the elements of the retinal neurovascular unit (NVU). This diabetic complication has a chronic low-grade inflammatory component involving multiple inflammatory mediators and adhesion molecules. The diabetic milieu promotes reactive gliosis, pro-inflammatory cytokine production and leukocyte recruitment, which contribute to the disruption of the blood retinal barrier. The understanding and the continuous research of the mechanisms behind the strong inflammatory component of the disease allows the design of new therapeutic strategies to address this unmet medical need. In this context, the aim of this review article is to recapitulate the latest research on the role of inflammation in DR and to discuss the efficacy of currently administered anti-inflammatory treatments and those still under development.
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Affiliation(s)
- Hugo Ramos
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Olga Simó-Servat
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
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Patel C, Pande S, Sagathia V, Ranch K, Beladiya J, Boddu SHS, Jacob S, Al-Tabakha MM, Hassan N, Shahwan M. Nanocarriers for the Delivery of Neuroprotective Agents in the Treatment of Ocular Neurodegenerative Diseases. Pharmaceutics 2023; 15:837. [PMID: 36986699 PMCID: PMC10052766 DOI: 10.3390/pharmaceutics15030837] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/25/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Retinal neurodegeneration is considered an early event in the pathogenesis of several ocular diseases, such as diabetic retinopathy, age-related macular degeneration, and glaucoma. At present, there is no definitive treatment to prevent the progression or reversal of vision loss caused by photoreceptor degeneration and the death of retinal ganglion cells. Neuroprotective approaches are being developed to increase the life expectancy of neurons by maintaining their shape/function and thus prevent the loss of vision and blindness. A successful neuroprotective approach could prolong patients' vision functioning and quality of life. Conventional pharmaceutical technologies have been investigated for delivering ocular medications; however, the distinctive structural characteristics of the eye and the physiological ocular barriers restrict the efficient delivery of drugs. Recent developments in bio-adhesive in situ gelling systems and nanotechnology-based targeted/sustained drug delivery systems are receiving a lot of attention. This review summarizes the putative mechanism, pharmacokinetics, and mode of administration of neuroprotective drugs used to treat ocular disorders. Additionally, this review focuses on cutting-edge nanocarriers that demonstrated promising results in treating ocular neurodegenerative diseases.
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Affiliation(s)
- Chirag Patel
- Department of Pharmacology, L. M. College of Pharmacy, Ahmedabad 380009, India
| | - Sonal Pande
- Department of Pharmacology, L. M. College of Pharmacy, Ahmedabad 380009, India
| | - Vrunda Sagathia
- Department of Pharmacology, L. M. College of Pharmacy, Ahmedabad 380009, India
| | - Ketan Ranch
- Department of Pharmaceutics, L. M. College of Pharmacy, Ahmedabad 380009, India
| | - Jayesh Beladiya
- Department of Pharmacology, L. M. College of Pharmacy, Ahmedabad 380009, India
| | - Sai H. S. Boddu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman P.O. Box 346, United Arab Emirates
- Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Shery Jacob
- Department of Pharmaceutical Sciences, College of Pharmacy, Gulf Medical University, Ajman P.O. Box 4184, United Arab Emirates
| | - Moawia M. Al-Tabakha
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman P.O. Box 346, United Arab Emirates
- Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Nageeb Hassan
- Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman P.O. Box 346, United Arab Emirates
- Department of Clinical Sciences, College of Pharmacy & Health Science, Ajman University, Ajman P.O. Box 346, United Arab Emirates
| | - Moyad Shahwan
- Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman P.O. Box 346, United Arab Emirates
- Department of Clinical Sciences, College of Pharmacy & Health Science, Ajman University, Ajman P.O. Box 346, United Arab Emirates
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Wang Y, Liu X, Quan X, Qin X, Zhou Y, Liu Z, Chao Z, Jia C, Qin H, Zhang H. Pigment epithelium-derived factor and its role in microvascular-related diseases. Biochimie 2022; 200:153-171. [DOI: 10.1016/j.biochi.2022.05.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 05/19/2022] [Accepted: 05/30/2022] [Indexed: 01/02/2023]
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Lee JY, Kim M, Oh SB, Kim HY, Kim C, Kim TY, Park YH. Superoxide dismutase 3 prevents early stage diabetic retinopathy in streptozotocin-induced diabetic rat model. PLoS One 2022; 17:e0262396. [PMID: 35015779 PMCID: PMC8751990 DOI: 10.1371/journal.pone.0262396] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 12/23/2021] [Indexed: 12/16/2022] Open
Abstract
Purpose To identify the effects of superoxide dismutase (SOD)3 on diabetes mellitus (DM)-induced retinal changes in a diabetic rat model. Methods Diabetic models were established by a single intraperitoneal injection of streptozotocin (STZ) in Sprague-Dawley rats. After purification of the recombinant SOD3, intravitreal injection of SOD3 was performed at the time of STZ injection, and 1 and 2 weeks following STZ injection. Scotopic and photopic electroretinography (ERG) were recorded. Immunofluorescence staining with ɑ-smooth muscle actin (SMA), glial fibrillary acidic protein (GFAP), pigment epithelium-derived factor (PEDF), Flt1, recoverin, parvalbumin, extracellular superoxide dismutase (SOD3), 8-Hydroxy-2’deoxyguanosine (8-OHdG) and tumor necrosis factor-ɑ (TNF-ɑ) were evaluated. Results In the scotopic ERG, the diabetic group showed reduced a- and b-wave amplitudes compared with the control group. In the photopic ERG, b-wave amplitude showed significant (p < 0.0005) reduction at 8 weeks following DM induction. However, the trend of a- and b-wave reduction was not evident in the SOD3 treated group. GFAP, Flt1, 8-OHdG and TNF-ɑ immunoreactivity were increased, and ɑ-SMA, PEDF and SOD3 immunoreactivity were decreased in the diabetic retina. The immunoreactivity of these markers was partially recovered in the SOD3 treated group. Parvalbumin expression was not decreased in the SOD3 treated group. In the diabetic retinas, the immunoreactivity of recoverin was weakly detected in both of the inner nuclear layer and inner plexiform layer compared to the control group but not in the SOD3 treated group. Conclusions SOD3 treatment attenuated the loss of a/b-wave amplitudes in the diabetic rats, which was consistent with the immunohistochemical evaluation. We also suggest that in rod-dominant rodents, the use of blue on green photopic negative response (PhNR) is effective in measuring the inner retinal function in animal models of diabetic retinopathy. SOD3 treatment ameliorated the retinal Müller cell activation in diabetic rats and pericyte dysfunction. These results suggested that SOD3 exerted protective effects on the development of diabetic retinopathy.
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Affiliation(s)
- Ji-Yeon Lee
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Mirinae Kim
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Ophthalmology and Visual Science, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Su Bin Oh
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hae-Young Kim
- Department of Dermatology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Chongtae Kim
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Tae-Yoon Kim
- Department of Dermatology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Young-Hoon Park
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
- Department of Ophthalmology and Visual Science, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- * E-mail:
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Neurovascular Impairment and Therapeutic Strategies in Diabetic Retinopathy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:ijerph19010439. [PMID: 35010703 PMCID: PMC8744686 DOI: 10.3390/ijerph19010439] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/25/2021] [Accepted: 12/30/2021] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy has recently been defined as a highly specific neurovascular complication of diabetes. The chronic progression of the impairment of the interdependence of neurovascular units (NVUs) is associated with the pathogenesis of diabetic retinopathy. The NVUs consist of neurons, glial cells, and vascular cells, and the interdependent relationships between these cells are disturbed under diabetic conditions. Clinicians should understand and update the current knowledge of the neurovascular impairments in diabetic retinopathy. Above all, neuronal cell death is an irreversible change, and it is directly related to vision loss in patients with diabetic retinopathy. Thus, neuroprotective and vasoprotective therapies for diabetic retinopathy must be established. Understanding the physiological and pathological interdependence of the NVUs is helpful in establishing neuroprotective and vasoprotective therapies for diabetic retinopathy. This review focuses on the pathogenesis of the neurovascular impairments and introduces possible neurovascular protective therapies for diabetic retinopathy.
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Sheemar A, Soni D, Takkar B, Basu S, Venkatesh P. Inflammatory mediators in diabetic retinopathy: Deriving clinicopathological correlations for potential targeted therapy. Indian J Ophthalmol 2021; 69:3035-3049. [PMID: 34708739 PMCID: PMC8725076 DOI: 10.4103/ijo.ijo_1326_21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/10/2021] [Accepted: 09/27/2021] [Indexed: 11/22/2022] Open
Abstract
The role of inflammation in diabetic retinopathy (DR) is well-established and dysregulation of a large number of inflammatory mediators is known. These include cytokines, chemokines, growth factors, mediators of proteogenesis, and pro-apoptotic molecules. This para-inflammation as a response is not directed to a particular pathogen or antigen but is rather directed toward the by-products of the diabetic milieu. The inflammatory mediators take part in cascades that result in cellular level responses like neurodegeneration, pericyte loss, leakage, capillary drop out, neovascularization, etc. There are multiple overlaps between the inflammatory pathways occurring within the diabetic retina due to a large number of mediators, their varied sources, and cross-interactions. This makes understanding the role of inflammation in clinical manifestations of DR difficult. Currently, mediator-based therapy for DR is being evaluated for interventions that target a specific step of the inflammatory cascade. We reviewed the role of inflammation in DR and derived a simplified clinicopathological correlation between the sources and stimuli of inflammation, the inflammatory mediators and pathways, and the clinical manifestations of DR. By doing so, we deliberate mediator-specific therapy for DR. The cross-interactions between inflammatory mediators and the molecular cycles influencing the inflammatory cascades are crucial challenges to such an approach. Future research should be directed to assess the feasibility of the pathology-based therapy for DR.
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Affiliation(s)
- Abhishek Sheemar
- Department of Ophthalmology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
| | - Deepak Soni
- Department of Ophthalmology, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh, India
| | - Brijesh Takkar
- Smt. Kanuri Santhamma Center for Vitreoretinal Diseases, L V Prasad Eye Institute, Hyderabad, India
- Indian Health Outcomes, Public Health and Economics Research (IHOPE) Centre, L V Prasad Eye Institute, Hyderabad, India
| | - Soumyava Basu
- Uveitis Service, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Pradeep Venkatesh
- Dr.R.P.Centre for Ophthalmic Sciences, All India Institute of Medical Science, New Delhi, India
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Filippov VM, Petrachkov DV, Budzinskaya MV, Matyushchenko AG. [The role of neurodegeneration biomarkers in the management of patients with diabetic retinopathy]. Vestn Oftalmol 2021; 137:314-322. [PMID: 34669343 DOI: 10.17116/oftalma2021137052314] [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: 11/18/2022]
Abstract
This literature review focuses on the role of disease biomarkers in the management of patients with diabetic retinopathy (DR) investigating in detail the problem of retinal neurodegeneration in such patients. Identification and assessment of the significance of qualitative and quantitative biomarkers of DR and neurodegeneration can complement screening examination, as well as help predict the course of the disease and the response to therapy. A comprehensive analysis of these factors allows for effective treatment and prevention of complications in patients with DR based on prognostic models and dynamic monitoring of these indicators.
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Affiliation(s)
- V M Filippov
- Research Institute of Eye Diseases, Moscow, Russia
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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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Nian S, Lo ACY, Mi Y, Ren K, Yang D. Neurovascular unit in diabetic retinopathy: pathophysiological roles and potential therapeutical targets. EYE AND VISION 2021; 8:15. [PMID: 33931128 PMCID: PMC8088070 DOI: 10.1186/s40662-021-00239-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 04/02/2021] [Indexed: 02/06/2023]
Abstract
Diabetic retinopathy (DR), one of the common complications of diabetes, is the leading cause of visual loss in working-age individuals in many industrialized countries. It has been traditionally regarded as a purely microvascular disease in the retina. However, an increasing number of studies have shown that DR is a complex neurovascular disorder that affects not only vascular structure but also neural tissue of the retina. Deterioration of neural retina could precede microvascular abnormalities in the DR, leading to microvascular changes. Furthermore, disruption of interactions among neurons, vascular cells, glia and local immune cells, which collectively form the neurovascular unit, is considered to be associated with the progression of DR early on in the disease. Therefore, it makes sense to develop new therapeutic strategies to prevent or reverse retinal neurodegeneration, neuroinflammation and impaired cell-cell interactions of the neurovascular unit in early stage DR. Here, we present current perspectives on the pathophysiology of DR as a neurovascular disease, especially at the early stage. Potential novel treatments for preventing or reversing neurovascular injuries in DR are discussed as well.
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Affiliation(s)
- Shen Nian
- Department of Pathology, Xi'an Medical University, Xi'an, Shaanxi Province, China.
| | - Amy C Y Lo
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Yajing Mi
- Institute of Basic Medicine Science, Xi'an Medical University, Xi'an, Shaanxi Province, China
| | - Kai Ren
- Department of Biochemistry and Molecular Biology, Xi'an Medical University, Xi'an, Shaanxi Province, China
| | - Di Yang
- Department of Ophthalmology, First Affiliated Hospital of Kunming Medical University, Kunming Medical University, Kunming, Yunnan Province, China.
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Retinal Genomic Fabric Remodeling after Optic Nerve Injury. Genes (Basel) 2021; 12:genes12030403. [PMID: 33799827 PMCID: PMC7999523 DOI: 10.3390/genes12030403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/14/2021] [Accepted: 02/19/2021] [Indexed: 12/16/2022] Open
Abstract
Glaucoma is a multifactorial neurodegenerative disease, characterized by degeneration of the retinal ganglion cells (RGCs). There has been little progress in developing efficient strategies for neuroprotection in glaucoma. We profiled the retina transcriptome of Lister Hooded rats at 2 weeks after optic nerve crush (ONC) and analyzed the data from the genomic fabric paradigm (GFP) to bring additional insights into the molecular mechanisms of the retinal remodeling after induction of RGC degeneration. GFP considers three independent characteristics for the expression of each gene: level, variability, and correlation with each other gene. Thus, the 17,657 quantified genes in our study generated a total of 155,911,310 values to analyze. This represents 8830x more data per condition than a traditional transcriptomic analysis. ONC led to a 57% reduction in RGC numbers as detected by retrograde labeling with 1,1'-dioctadecyl-3,3,3,3'-tetramethylindocarbocyanine perchlorate (DiI). We observed a higher relative expression variability after ONC. Gene expression stability was used as a measure of transcription control and disclosed a robust reduction in the number of very stably expressed genes. Predicted protein-protein interaction (PPI) analysis with STRING revealed axon and neuron projection as mostly decreased processes, consistent with RGC degeneration. Conversely, immune response PPIs were found among upregulated genes. Enrichment analysis showed that complement cascade and Notch signaling pathway, as well as oxidative stress and kit receptor pathway were affected after ONC. To expand our studies of altered molecular pathways, we examined the pairwise coordination of gene expressions within each pathway and within the entire transcriptome using Pearson correlations. ONC increased the number of synergistically coordinated pairs of genes and the number of similar profiles mainly in complement cascade and Notch signaling pathway. This deep bioinformatic study provided novel insights beyond the regulation of individual gene expression and disclosed changes in the control of expression of complement cascade and Notch signaling functional pathways that may be relevant for both RGC degeneration and remodeling of the retinal tissue after ONC.
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Mrugacz M, Bryl A, Zorena K. Retinal Vascular Endothelial Cell Dysfunction and Neuroretinal Degeneration in Diabetic Patients. J Clin Med 2021; 10:jcm10030458. [PMID: 33504108 PMCID: PMC7866162 DOI: 10.3390/jcm10030458] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/11/2021] [Accepted: 01/19/2021] [Indexed: 12/13/2022] Open
Abstract
Diabetes mellitus (DM) has become a vital societal problem as epidemiological studies demonstrate the increasing incidence of type 1 and type 2 diabetes. Lesions observed in the retina in the course of diabetes, referred to as diabetic retinopathy (DR), are caused by vascular abnormalities and are ischemic in nature. Vascular lesions in diabetes pertain to small vessels (microangiopathy) and involve precapillary arterioles, capillaries and small veins. Pericyte loss, thickening of the basement membrane, and damage and proliferation of endothelial cells are observed. Endothelial cells (monolayer squamous epithelium) form the smooth internal vascular lining indispensable for normal blood flow. Breaking its continuity initiates blood coagulation at that site. The endothelium controls the process of exchange of chemical substances (nutritional, regulatory, waste products) between blood and the retina, and blood cell passing through the vascular wall. Endothelial cells produce biologically active substances involved in blood coagulation, regulating vascular wall tension and stimulating neoangiogenesis. On the other hand, recent studies have demonstrated that diabetic retinopathy may be not only a microvascular disease, but is a result of neuroretinal degeneration. Neuroretinal degeneration appears structurally, as neural apoptosis of amacrine and Muller cells, reactive gliosis, ganglion cell layer/inner plexiform (GCL) thickness, retinal thickness, and retinal nerve fiber layer thickness, and a reduction of the neuroretinal rim in minimum rim width (MRW) and functionally as an abnormal electroretinogram (ERG), dark adaptation, contrast sensitivity, color vision, and microperimetric test. The findings in early stages of diabetic retinopathy may precede microvascular changes of this disease. Furthermore, the article's objective is to characterize the factors and mechanisms conducive to microvascular changes and neuroretinal apoptosis in diabetic retinopathy. Only when all the measures preventing vascular dysfunction are determined will the risk of complications in the course of diabetes be minimized.
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Affiliation(s)
- Malgorzata Mrugacz
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, 15-089 Białystok, Poland
| | - Anna Bryl
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, 15-089 Białystok, Poland
| | - Katarzyna Zorena
- Department of Immunobiology and Environment Microbiology, Medical University of Gdańsk, 18-211 Gdańsk, Poland
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The innate immune system in diabetic retinopathy. Prog Retin Eye Res 2021; 84:100940. [PMID: 33429059 DOI: 10.1016/j.preteyeres.2021.100940] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/24/2020] [Accepted: 01/03/2021] [Indexed: 12/20/2022]
Abstract
The prevalence of diabetes has been rising steadily in the past half-century, along with the burden of its associated complications, including diabetic retinopathy (DR). DR is currently the most common cause of vision loss in working-age adults in the United States. Historically, DR has been diagnosed and classified clinically based on what is visible by fundoscopy; that is vasculature alterations. However, recent technological advances have confirmed pathology of the neuroretina prior to any detectable vascular changes. These, coupled with molecular studies, and the positive impact of anti-inflammatory therapeutics in DR patients have highlighted the central involvement of the innate immune system. Reminiscent of the systemic impact of diabetes, immune dysregulation has become increasingly identified as a key element of the pathophysiology of DR by interfering with normal homeostatic systems. This review uses the growing body of literature across various model systems to demonstrate the clear involvement of all three pillars of the immune system: immune-competent cells, mediators, and the complement system. It also demonstrates how the relative contribution of each of these requires more extensive analysis, including in human tissues over the continuum of disease progression. Finally, although this review demonstrates how the complex interactions of the immune system pose many more questions than answers, the intimately connected nature of the three pillars of the immune system may also point to possible new targets to reverse or even halt reverse retinopathy.
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Urner S, Ho F, Jha JC, Ziegler D, Jandeleit-Dahm K. NADPH Oxidase Inhibition: Preclinical and Clinical Studies in Diabetic Complications. Antioxid Redox Signal 2020; 33:415-434. [PMID: 32008354 DOI: 10.1089/ars.2020.8047] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Significance: Oxidative stress plays a critical role in the development and progression of serious micro- and macrovascular complications of diabetes. Nicotinamide adenine dinucleotide phosphate oxidase (NOX)-derived reactive oxygen species (ROS) significantly contribute to oxidative stress-associated inflammatory pathways that lead to tissue damage of different organs, including the kidneys, retina, brain, nerves, and the cardiovascular system. Recent Advances: Preclinical studies, including genetic-modified mouse models or cell culture models, have revealed the role of specific NOX isoforms in different diabetic complications, and suggested them as a promising target for the treatment of these diseases. Critical Issues: In this review, we provide an overview of the role of ROS and oxidative stress in macrovascular complications, such as stroke, myocardial infarction, coronary artery disease, and peripheral vascular disease that are all mainly driven by atherosclerosis, as well as microvascular complications, such as diabetic retinopathy, nephropathy, and neuropathy. We summarize conducted genetic deletion studies of different Nox isoforms as well as pharmacological intervention studies using NOX inhibitors in the context of preclinical as well as clinical research on diabetic complications. Future Directions: We outline the isoforms that are most promising for future clinical trials in the context of micro- and macrovascular complications of diabetes.
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Affiliation(s)
- Sofia Urner
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany
| | - Florence Ho
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, Australia
| | - Jay C Jha
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, Australia
| | - Dan Ziegler
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany
| | - Karin Jandeleit-Dahm
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, Australia
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15
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Update on the Effects of Antioxidants on Diabetic Retinopathy: In Vitro Experiments, Animal Studies and Clinical Trials. Antioxidants (Basel) 2020; 9:antiox9060561. [PMID: 32604941 PMCID: PMC7346101 DOI: 10.3390/antiox9060561] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 12/14/2022] Open
Abstract
Current therapies for diabetic retinopathy (DR) incorporate blood glucose and blood pressure control, vitrectomy, photocoagulation, and intravitreal injections of anti-vascular endothelial growth factors or corticosteroids. Nonetheless, these techniques have not been demonstrated to completely stop the evolution of this disorder. The pathophysiology of DR is not fully known, but there is more and more evidence indicating that oxidative stress is an important mechanism in the progression of DR. In this sense, antioxidants have been suggested as a possible therapy to reduce the complications of DR. In this review we aim to assemble updated information in relation to in vitro experiments, animal studies and clinical trials dealing with the effect of the antioxidants on DR.
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16
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Yamagishi SI, Koga Y, Sotokawauchi A, Hashizume N, Fukahori S, Matsui T, Yagi M. Therapeutic Potential of Pigment Epithelium-derived Factor in Cancer. Curr Pharm Des 2020; 25:313-324. [PMID: 30892156 DOI: 10.2174/1381612825666190319112106] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/13/2019] [Indexed: 12/11/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is one of the serine protease inhibitors with multifunctional properties, which is produced by various types of organs and tissues. There is an accumulating body of evidence that PEDF plays an important role in the maintenance of tissue homeostasis. Indeed, PEDF not only works as an endogenous inhibitor of angiogenesis, but also suppresses oxidative stress, inflammatory and thrombotic reactions in cell culture systems, animal models, and humans. Furthermore, we, along with others, have found that PEDF inhibits proliferation of, and induces apoptotic cell death in, numerous kinds of tumors. In addition, circulating as well as tumor expression levels of PEDF have been inversely associated with tumor growth and metastasis. These observations suggest that supplementation of PEDF proteins and/or enhancement of endogenous PEDF expression could be a novel therapeutic strategy for the treatment of cancer. Therefore, in this paper, we review the effects of PEDF on diverse types of cancer, and discuss its therapeutic perspectives.
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Affiliation(s)
- Sho-Ichi Yamagishi
- Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Yoshinori Koga
- Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume 830-0011, Japan.,Department of Pediatric Surgery, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Ami Sotokawauchi
- Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Naoki Hashizume
- Department of Pediatric Surgery, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Suguru Fukahori
- Department of Pediatric Surgery, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Takanori Matsui
- Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume 830-0011, Japan
| | - Minoru Yagi
- Department of Pediatric Surgery, Kurume University School of Medicine, Kurume 830-0011, Japan
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17
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Brook N, Brook E, Dharmarajan A, Chan A, Dass CR. The role of pigment epithelium-derived factor in protecting against cellular stress. Free Radic Res 2019; 53:1166-1180. [PMID: 31760841 DOI: 10.1080/10715762.2019.1697809] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Since its discovery as a neurotrophic factor in retinal pigmented epithelium cells in the late 1980s, there has been an increase in understanding of the role that pigment epithelium-derived factor (PEDF) plays in cellular functions. PEDF plays an important role in mediating cellular protection during exposure to oxidative stress and inflammation by preventing stress-induced angiogenesis and apoptosis. PEDF acts to reduce oxidative stress by promoting mitochondrial stability and by regulating the expression of enzymes involved in ROS accumulation and clearance. PEDF protects against the negative effects of oxidative stress by regulating cell survival pathways and the expression of inflammatory and proangiogenic mediators. PEDF-mediated cellular protection may be of clinical importance in diseases characterised by oxidative stress, chronic inflammation and pathological neovascularization, indicating that targeting PEDF may be a potential focus for therapeutic interventions in chronic diseases. In this review, we provide a historical perspective on the discoveries of PEDF interactions and functions, and discuss recent in vitro, in vivo and clinical findings to provide a current summary of the important protective effects following cellular exposure to stress stimuli and future clinical potential of PEDF.
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Affiliation(s)
- Naomi Brook
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, Australia.,Curtin Health Innovation Research Institute, Bentley, Australia
| | - Emily Brook
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, Australia.,Curtin Health Innovation Research Institute, Bentley, Australia
| | - Arun Dharmarajan
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, Australia.,Curtin Health Innovation Research Institute, Bentley, Australia.,Department of Biomedical Sciences, Sri Ramachandra Institute of Higher Education and Research, Chennai, India
| | - Arlene Chan
- Curtin Medical School, Curtin University, Bentley, Australia.,Hollywood Private Hospital, Breast Clinical Trials Unit, Breast Cancer Research Centre-Western Australia, Nedlands, Australia
| | - Crispin R Dass
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, Australia.,Curtin Health Innovation Research Institute, Bentley, Australia
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18
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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: 29] [Impact Index Per Article: 5.8] [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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19
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Zhang X, Pek SLT, Tavintharan S, Sum CF, Lim SC, Ang K, Yeo D, Ee TW, Yip CC, Kumari N. Leucine-rich α-2-glycoprotein predicts proliferative diabetic retinopathy in type 2 diabetes. J Diabetes Complications 2019; 33:651-656. [PMID: 31256924 DOI: 10.1016/j.jdiacomp.2019.05.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 05/08/2019] [Accepted: 05/26/2019] [Indexed: 12/17/2022]
Abstract
AIM We aim to examine the association of plasma leucine-rich-α-2-glycoprotein 1 (LRG1) with diabetic retinopathy (DR) in type 2 diabetes. METHODS At baseline visit, plasma LRG1 levels were assessed using ELISA. Central arterial stiffness was estimated by carotid-femoral pulse wave velocity (PWV). At follow-up visit (median = 3.2 years), digital color fundus photographs were assessed for DR. DR severity was categorized into non-proliferative DR (NPDR) and proliferative DR (PDR). RESULTS DR was diagnosed in 396 (32.8%) of 1206 patients. DR has higher LRG1 than non-DR (19.5 ± 11.3vs.16.9 ± 8.9 μg/ml, p ≪ 0.001). After adjustment, LRG1 was not associated with DR (OR = 1.2, [95% CI, 0.96-1.30], p = 0.16). LRG1 was higher in PDR (n = 107) than NPDR (n = 270) (23.2 ± 15.4vs.18.1 ± 8.9 μg/ml, n = 270, p ≪ 0.001). After adjustment, with 1-SD increase in LRG1, the relative risk of NPDR and PDR was 0.99 ([0.83-1.18], p = 0.91) and 1.42 ([95% CI, 1.14-1.76], p = 0.002) (p-trend = 0.01), respectively. We didn't observe significant improvement in AUC after adding LRG1 into the model. Baseline PWV mediated 12.0% of the association between LRG1 and PDR (p = 0.03). CONCLUSION Baseline plasma LRG1 is associated with PDR, suggesting it maybe a promising biomarker for prediction for advanced proliferative stages of DR. The mediation result indicates the potential benefit of ameliorating central arterial stiffness to prevent PDR.
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Affiliation(s)
- Xiao Zhang
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore
| | - Sharon L T Pek
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore
| | - Subramaniam Tavintharan
- Diabetes Centre, Khoo Teck Puat Hospital, Singapore; Department of Medicine, Khoo Teck Puat Hospital, Singapore
| | - Chee Fang Sum
- Diabetes Centre, Khoo Teck Puat Hospital, Singapore; Department of Medicine, Khoo Teck Puat Hospital, Singapore
| | - Su Chi Lim
- Diabetes Centre, Khoo Teck Puat Hospital, Singapore; Department of Medicine, Khoo Teck Puat Hospital, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Keven Ang
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore
| | - Darren Yeo
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore
| | - Tang Wern Ee
- National Healthcare Group Polyclinics, Singapore
| | - Chee Chew Yip
- Department of ophthalmology and Visual Sciences, Khoo Teck Puat Hospital, Singapore
| | - Neelam Kumari
- Department of ophthalmology and Visual Sciences, Khoo Teck Puat Hospital, Singapore.
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20
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Sdobnikova SV, Kulybysheva VS, Sidamonidze AL. [The state of ocular neurosensory apparatus in diabetes mellitus]. Vestn Oftalmol 2019; 134:263-269. [PMID: 30499527 DOI: 10.17116/oftalma2018134051263] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diabetes mellitus is one of the most common chronic diseases in the world. Among its late complications that can lead to disability is diabetic neuropathy (DN). Patients diagnosed with DN often also have diabetic retinopathy (DR). According to available data, DR prevalence ranges from 30 to 60%. For a long time, DR has been considered a microvascular disease. However, more data has been emerging recently that indicates the presence of other components in the pathophysiology of DR. Neurodegenerative changes in the retina can be detected in patients with diabetes mellitus before clinical signs of diabetic retinopathy appear. Accumulation of extracellular glutamate, oxidative stress, reduction of neuroprotective factors synthesized by the retina are all believed to lead to neuronal apoptosis and glial cell dysfunction. This cascade of reactions subsequently causes disruption of the hematoretinal barrier and damage to neurovascular apparatus of the retina. This results in the defeat of capillaries of the retinal vascular system, which is consistently characterized by the loss of pericytes and the formation of unperfusable capillaries. The concept of neurodegeneration being an early component of DR provides an opportunity to explore alternative therapies to prevent the onset of vision loss in diabetes mellitus.
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Affiliation(s)
- S V Sdobnikova
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - V S Kulybysheva
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - A L Sidamonidze
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
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21
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Churm R, Dunseath GJ, Prior SL, Thomas RL, Banerjee S, Owens DR. Development and characterization of an in vitro system of the human retina using cultured cell lines. Clin Exp Ophthalmol 2019; 47:1055-1062. [PMID: 31254428 DOI: 10.1111/ceo.13578] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 06/18/2019] [Accepted: 06/24/2019] [Indexed: 12/26/2022]
Abstract
BACKGROUND Previously developed in vitro cultures of the human retina have been solo or dual cell cultures. We developed a triple-cell culture in vitro model utilizing a membrane system to produce a better representation of a functional and morphological human retina. METHODS Retinal microvascular endothelial cells (HRMVEC/ACBRI181, cell systems), retinal pigment epithelium cells (RPE/ARPE-19, ATCC) and Müller glial cells (Moorfield Institute of Ophthalmology-Müller 1, UCL) were grown in a triple culture. Our optimized triple-culture media contained a mix of specific endothelial medium and high glucose Dulbecco's Modified Eagle's medium, where all three layers were viable for up to 5 days. Co-culture effect on morphological changes (cell staining) and gene expression of functional genes (pigment epithelium derived factor [PEDF] and vascular endothelial growth factor [VEGF]) were measured from RNA via real-time polymerase chain reaction. Expression of tight junction protein 1 (TJP1) was measured in RNA isolated from ARPE-19s, to assess barrier stability. RESULTS The triple-culture promotes certain cell functionality through up-regulation of TJP1, increasing PEDF and decreasing VEGF expression highlighting its importance for the assessment of disease mechanisms distinct from a solo culture which would not allow the true effect of the native microenvironment to be elucidated. CONCLUSIONS This model's novelty and reliability allows for the assessment of singular cellular function within the retinal microenvironment and overall assessment of retinal health, while eliminating the requirement of animal-based models.
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Affiliation(s)
- Rachel Churm
- Diabetes Research Group, Swansea University, Swansea, UK
| | | | - Sarah L Prior
- Diabetes Research Group, Swansea University, Swansea, UK
| | | | - Sanjiv Banerjee
- Cardiff and Vale Health Board, University of Wales Hospital, Cardiff, UK
| | - David R Owens
- Diabetes Research Group, Swansea University, Swansea, UK
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22
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Huang KT, Lin CC, Tsai MC, Chen KD, Chiu KW. Pigment epithelium-derived factor in lipid metabolic disorders. Biomed J 2019; 41:102-108. [PMID: 29866598 PMCID: PMC6138776 DOI: 10.1016/j.bj.2018.02.004] [Citation(s) in RCA: 11] [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: 12/13/2017] [Revised: 01/29/2018] [Accepted: 02/13/2018] [Indexed: 01/10/2023] Open
Abstract
Pigment epithelium-derived factor (PEDF) is a secreted glycoprotein that has anti-angiogenic, anti-proliferative, neurotrophic and immunomodulatory properties. PEDF has recently emerged as a critical metabolic regulatory protein since the discovery of its modulatory activities in the lipolytic pathway by binding to adipose triglyceride lipase (ATGL). Despite being beneficial in maintaining the homeostasis of hepatic lipid accumulation, PEDF has been uncovered an unfavorable role associated with insulin resistance. The molecular events that connect these two apparent distinct observations have been controversial and remained largely unknown. Therefore in this short review, we attempt to summarize the current findings of PEDF regarding its lipid metabolic functions and provide perspectives in identifying PEDF as a potential therapeutic target in lipid disorders.
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Affiliation(s)
- Kuang-Tzu Huang
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
| | - Chih-Che Lin
- Liver Transplantation Center, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Ming-Chao Tsai
- Division of Hepato-Gastroenterology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Kuang-Den Chen
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - King-Wah Chiu
- Division of Hepato-Gastroenterology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
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23
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Zafar S, Sachdeva M, Frankfort BJ, Channa R. Retinal Neurodegeneration as an Early Manifestation of Diabetic Eye Disease and Potential Neuroprotective Therapies. Curr Diab Rep 2019; 19:17. [PMID: 30806815 PMCID: PMC7192364 DOI: 10.1007/s11892-019-1134-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Diabetic retinopathy (DR) is a major cause of visual impairment and blindness throughout the world. Microvascular changes have long been regarded central to disease pathogenesis. In recent years, however, retinal neurodegeneration is increasingly being hypothesized to occur prior to the vascular changes classically associated with DR and contribute to disease pathogenesis. RECENT FINDINGS There is growing structural and functional evidence from human and animal studies that suggests retinal neurodegeneration to be an early component of DR. Identification of new therapeutic targets is an ongoing area of research with several different molecules undergoing testing in animal models for their neuroprotective properties and for possible use in humans. Retinal neurodegeneration may play a central role in DR pathogenesis. As new therapies are developed, it will be important to develop criteria for clinically defining retinal neurodegeneration. A standardization of the methods for monitoring neurodegeneration along with more sensitive means of detecting preclinical damage is also needed.
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Affiliation(s)
- Sidra Zafar
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | - Mira Sachdeva
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | | | - Roomasa Channa
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
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24
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Sinclair SH, Schwartz SS. Diabetic Retinopathy-An Underdiagnosed and Undertreated Inflammatory, Neuro-Vascular Complication of Diabetes. Front Endocrinol (Lausanne) 2019; 10:843. [PMID: 31920963 PMCID: PMC6923675 DOI: 10.3389/fendo.2019.00843] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/19/2019] [Indexed: 12/14/2022] Open
Abstract
Diabetes mellitus is a world-wide epidemic and diabetic retinopathy, a devastating, vision-threatening condition, is one of the most common diabetes-specific complications. Diabetic retinopathy is now recognized to be an inflammatory, neuro-vascular complication with neuronal injury/dysfunction preceding clinical microvascular damage. Importantly, the same pathophysiologic mechanisms that damage the pancreatic β-cell (e.g., inflammation, epigenetic changes, insulin resistance, fuel excess, and abnormal metabolic environment), also lead to cell and tissue damage causing organ dysfunction, elevating the risk of all complications, including diabetic retinopathy. Viewing diabetic retinopathy within the context whereby diabetes and all its complications arise from common pathophysiologic factors allows for the consideration of a wider array of potential ocular as well as systemic treatments for this common and devastating complication. Moreover, it also raises the importance of the need for methods that will provide more timely detection and prediction of the course in order to address early damage to the neurovascular unit prior to the clinical observation of microangiopathy. Currently, treatment success is limited as it is often initiated far too late and after significant neurodegeneration has occurred. This forward-thinking approach of earlier detection and treatment with a wider array of possible therapies broadens the physician's armamentarium and increases the opportunity for prevention and early treatment of diabetic retinopathy with preservation of good vision, as well the prevention of similar destructive processes occurring among other organs.
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Affiliation(s)
- Stephen H. Sinclair
- Sinclair Retina Associates, Media, PA, United States
- Main Line Health System, Media, PA, United States
- *Correspondence: Stephen H. Sinclair
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25
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Qiao H, Zhang Y, Lin W, Wang YF, Furdui CM, Jiang Q, Li X, Long T, Wang Y, Qin DN. Decreased expression of pigment epithelium-derived factor within the penile tissues contributes to erectile dysfunction in diabetic rats. Clin Sci (Lond) 2018; 132:2175-2188. [PMID: 30232174 DOI: 10.1042/cs20180192] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/29/2018] [Accepted: 09/18/2018] [Indexed: 02/05/2023]
Abstract
Increased production of reactive oxygen species (ROS) and inflammation are major contributors to the development and progression of diabetes-associated erectile dysfunction (DMED). As an endogenous antioxidant and anti-inflammatory factor, the potential implication of pigment epithelium-derived factor (PEDF) in DMED has not been revealed. To assess the potential antioxidant and anti-inflammatory functions of PEDF in DMED, we first demonstrated that PEDF was significantly decreased at the levels of the mRNA and protein in the penis of diabetic rats compared with normal controls. To test the hypothesis that decreased the penile levels of PEDF are associated with oxidative stress and inflammation in DMED, an adenovirus expressing PEDF (Ad-PEDF) or the same titer of control virus (Ad-GFP) was intracavernously administered at 2 weeks after diabetic onset. After 6 weeks of treatment, we found that administration of Ad-PEDF could significantly increase erectile response to cavernosal nerve stimulation in the diabetic rats by restoring the endothelial NO synthase (eNOS), P-eNOS, and neuronal NO synthase (nNOS) protein levels to the standard levels represented in normal rats and by suppressing the levels of tumor necrosis factor-α (TNF-α) and oxidative stress. In conclusion, the present data indicated that the antioxidant and anti-inflammatory potential of PEDF plays important role in restoring erectile function by the inhibition of oxidative stress and TNF-α production.
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Affiliation(s)
- Hongjie Qiao
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Yuanyuan Zhang
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC 27157, U.S.A
| | - Wenwen Lin
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China
| | - Cristina M Furdui
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, U.S.A
| | - Qiuling Jiang
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Xiao Li
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Ting Long
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Yunguang Wang
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
| | - Da-Nian Qin
- Department of Physiology, Shantou University Medical College, Shantou 515041, China
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26
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Reactive Oxygen Species-Mediated Damage of Retinal Neurons: Drug Development Targets for Therapies of Chronic Neurodegeneration of the Retina. Int J Mol Sci 2018; 19:ijms19113362. [PMID: 30373222 PMCID: PMC6274960 DOI: 10.3390/ijms19113362] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 02/06/2023] Open
Abstract
The significance of oxidative stress in the development of chronic neurodegenerative diseases of the retina has become increasingly apparent in recent years. Reactive oxygen species (ROS) are free radicals produced at low levels as a result of normal cellular metabolism that are ultimately metabolized and detoxified by endogenous and exogenous mechanisms. In the presence of oxidative cellular stress, ROS are produced in excess, resulting in cellular injury and death and ultimately leading to tissue and organ dysfunction. Recent studies have investigated the role of excess ROS in the pathogenesis and development of chronic neurodegenerative diseases of the retina including glaucoma, diabetic retinopathy, and age-related macular degeneration. Findings from these studies are promising insofar as they provide clear rationales for innovative treatment and prevention strategies of these prevalent and disabling diseases where currently therapeutic options are limited. Here, we briefly outline recent developments that have contributed to our understanding of the role of ROS in the pathogenesis of chronic neurodegenerative diseases of the retina. We then examine and analyze the peer-reviewed evidence in support of ROS as targets for therapy development in the area of chronic neurodegeneration of the retina.
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Chakravarthy H, Devanathan V. Molecular Mechanisms Mediating Diabetic Retinal Neurodegeneration: Potential Research Avenues and Therapeutic Targets. J Mol Neurosci 2018; 66:445-461. [PMID: 30293228 DOI: 10.1007/s12031-018-1188-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 09/25/2018] [Indexed: 12/16/2022]
Abstract
Diabetic retinopathy (DR) is a devastating complication of diabetes with a prevalence rate of 35%, and no effective treatment options. Since the most visible clinical features of DR are microvascular irregularities, therapeutic interventions often attempt to reduce microvascular injury, but only after permanent retinal damage has ensued. However, recent data suggests that diabetes initially affects retinal neurons, leading to neurodegeneration as an early occurrence in DR, before onset of the more noticeable vascular abnormalities. In this review, we delineate the sequence of initiating events leading to retinal degeneration in DR, considering neuronal dysfunction as a primary event. Key molecular mechanisms and potential biomarkers associated with retinal neuronal degeneration in diabetes are discussed. In addition to glial reactivity and inflammation in the diabetic retina, the contribution of neurotrophic factors, cell adhesion molecules, apoptosis markers, and G protein signaling to neurodegenerative pathways warrants further investigation. These studies could complement recent developments in innovative treatment strategies for diabetic retinopathy, such as targeting retinal neuroprotection, promoting neuronal regeneration, and attempts to re-program other retinal cell types into functional neurons. Indeed, several ongoing clinical trials are currently attempting treatment of retinal neurodegeneration by means of such novel therapeutic avenues. The aim of this article is to highlight the crucial role of neurodegeneration in early retinopathy progression, and to review the molecular basis of neuronal dysfunction as a first step toward developing early therapeutic interventions that can prevent permanent retinal damage in diabetes. ClinicalTrials.gov: NCT02471651, NCT01492400.
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Affiliation(s)
- Harshini Chakravarthy
- Department of Biology, Indian Institute of Science Education and Research (IISER), Transit campus: C/o. Sree Rama Engineering College Campus, Karakambadi Road, Mangalam, Tirupati, 517507, India
| | - Vasudharani Devanathan
- Department of Biology, Indian Institute of Science Education and Research (IISER), Transit campus: C/o. Sree Rama Engineering College Campus, Karakambadi Road, Mangalam, Tirupati, 517507, India.
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Subirada PV, Paz MC, Ridano ME, Lorenc VE, Vaglienti MV, Barcelona PF, Luna JD, Sánchez MC. A journey into the retina: Müller glia commanding survival and death. Eur J Neurosci 2018; 47:1429-1443. [PMID: 29790615 DOI: 10.1111/ejn.13965] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/19/2018] [Accepted: 05/03/2018] [Indexed: 12/12/2022]
Abstract
Müller glial cells (MGCs) are known to participate actively in retinal development and to contribute to homoeostasis through many intracellular mechanisms. As there are no homologous cells in other neuronal tissues, it is certain that retinal health depends on MGCs. These macroglial cells are located at the centre of the columnar subunit and have a great ability to interact with neurons, astrocytes, microglia and endothelial cells in order to modulate different events. Several investigations have focused their attention on the role of MGCs in diabetic retinopathy, a progressive pathology where several insults coexist. As expected, data suggest that MGCs display different responses according to the severity of the stimulus, and therefore trigger distinct events throughout the course of the disease. Here, we describe physiological functions of MGCs and their participation in inflammation, gliosis, synthesis and secretion of trophic and antioxidant factors in the diabetic retina. We invite the reader to consider the protective/deleterious role of MGCs in the early and late stages of the disease. In the light of the results, we open up the discussion around and ask the question: Is it possible that the modulation of a single cell type could improve or even re-establish retinal function after an injury?
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Affiliation(s)
- Paula V Subirada
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - María C Paz
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Magali E Ridano
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Valeria E Lorenc
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Department of Ophthalmology, The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - María V Vaglienti
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Pablo F Barcelona
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - José D Luna
- Centro Privado de Ojos Romagosa-Fundación VER, Córdoba, Argentina
| | - María C Sánchez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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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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Falero-Perez J, Park S, Sorenson CM, Sheibani N. PEDF expression affects retinal endothelial cell proangiogenic properties through alterations in cell adhesive mechanisms. Am J Physiol Cell Physiol 2017; 313:C405-C420. [PMID: 28747334 PMCID: PMC5668572 DOI: 10.1152/ajpcell.00004.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 07/20/2017] [Accepted: 07/20/2017] [Indexed: 12/17/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is an endogenous inhibitor of angiogenesis. Although various ocular cell types including retinal endothelial cells (EC) produce PEDF, we know very little about cell autonomous effects of PEDF in these cell types. Here we determined how PEDF expression affects retinal EC proangiogenic properties. Retinal EC were prepared from wild-type (PEDF+/+) and PEDF-deficient (PEDF-/-) mice. The identity of EC was confirmed by staining for specific markers including vascular endothelial cadherin, CD31, and B4-lectin. Retinal EC also expressed VEGF receptor 1 and endoglin, as well as ICAM-1, ICAM-2, and VCAM-1. PEDF-/- retinal EC were more proliferative, less apoptotic when challenged with H2O2, less migratory, and less adherent compared with PEDF+/+ EC. These changes could be associated, at least in part, with increased levels of tenascin-C, fibronectin, thrombospondin-1 and collagen IV, and lower amounts of osteopontin. PEDF-/- EC also exhibited alterations in expression of a number of integrins including α2, αv, β1, β8, and αvβ3, and cell-cell adhesion molecules including CD31, zonula occluden-1, and occludin. These observations correlated with attenuation of capillary morphogenesis and increased levels of oxidative stress in PEDF-/- EC. PEDF-/- EC also produced lower levels of VEGF compared with PEDF+/+ cells. Thus, PEDF deficiency has a significant impact on retinal EC adhesion and migration, perhaps through altered production of extracellular matrix and junctional proteins in response to increased oxidative stress affecting their proangiogenic activity.
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Affiliation(s)
- Juliana Falero-Perez
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - SunYoung Park
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Christine M Sorenson
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Nader Sheibani
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin;
- McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin; and
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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Iwona BS. Growth Factors in the Pathogenesis of Retinal Neurodegeneration in Diabetes Mellitus. Curr Neuropharmacol 2017; 14:792-804. [PMID: 27528260 PMCID: PMC5333593 DOI: 10.2174/1570159x14666160813182009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/12/2015] [Accepted: 01/06/2015] [Indexed: 12/13/2022] Open
Abstract
Neurodegeneration is an initial process in the development of diabetic retinopathy (DR). High quantities of glutamate, oxidative stress, induction of the renin-angiotensin system (RAS) and elevated levels of RAGE are crucial elements in the retinal neurodegeneration caused by diabetes mellitus. At least, there is emerging proof to indicate that the equilibrium between the neurotoxic and neuroprotective components will affect the state of the retinal neurons. Somatostatin (SST), pigment epithelium-derived factor (PEDF), and erythropoietin (Epo) are endogenous neuroprotective peptides that are decreased in the eye of diabetic persons and play an essential role in retinal homeostasis. On the other hand, insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF) are pivotal proteins which participate in the development of new capillaries and finally cause damage to the retinal neurons. During recent years, our knowledge about the function of growth factors in the pathogenesis of retinal neurodegeneration has increased. However, intensive investigations are needed to clarify the basic processes that contribute to retinal neurodegeneration and its association with damage to the capillary blood vessels. The objective of this review article is to show new insights on the role of neurotransmitters and growth factors in the pathogenesis of diabetic retinopathy. The information contained in this manuscript may provide the basis for novel strategies based on the factors of neurodegeneration to diagnose, prevent and treat DR in its earliest phases.
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Affiliation(s)
- Ben-Skowronek Iwona
- Department Pediatric Endocrinology and Diabetology, Medical University of Lublin, ul. Prof. A. Gebali 6, 20-093 Lublin, Poland
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Mrugacz M, Bryl A, Bossowski A. Neuroretinal Apoptosis as a Vascular Dysfunction in Diabetic Patients. Curr Neuropharmacol 2017; 14:826-830. [PMID: 27212050 PMCID: PMC5333582 DOI: 10.2174/1570159x14666160523144245] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 11/15/2015] [Accepted: 11/16/2015] [Indexed: 11/24/2022] Open
Abstract
Background Diabetic retinopathy (DR) is an important complication of diabetes and is considered one of the main causes of blindness in moderate-income and highly-developed countries. As it is a major socioeconomic problem, defining all mechanisms that may lead to DR development is of great importance. In the 21st century diabetic lesions occurring in the retina are well known. However what kind of retinal neuronal damage occurs in the course of diabetes remains unclear. Results In this manuscript we present the most recent knowledge about suggested mechanisms of diabetic retinopathy, including neuroretinal apoptosis. Getting a deep insight into the role of apoptosis and degeneration of retinal neurons leading to DR will have vital consequences. Conclusion The findings of this review confirm that it is very likely that in the nearest future diabetic retinopathy treatment will be based on administration of neuroprotective agents. The implementation of neuroprotective drugs may slow down retinopathy progression, making it possible to avoid the currently used therapeutic procedures, such as laser photocoagulation, intravitreous injections or posterior vitrectomy, which are not only risky for the healthy part of the retina but also relatively expensive.
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Affiliation(s)
- Małgorzata Mrugacz
- Department of Ophthalmology and Visual Rehabilitation, Medical University of Bialystok, Poland
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Roy S, Kern TS, Song B, Stuebe C. Mechanistic Insights into Pathological Changes in the Diabetic Retina: Implications for Targeting Diabetic Retinopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 187:9-19. [PMID: 27846381 DOI: 10.1016/j.ajpath.2016.08.022] [Citation(s) in RCA: 145] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 07/27/2016] [Accepted: 08/04/2016] [Indexed: 12/16/2022]
Abstract
Increasing evidence points to inflammation as one of the key players in diabetes-mediating adverse effects to the neuronal and vascular components of the retina. Sustained inflammation induces biochemical and molecular changes, ultimately contributing to retinal complications and vision loss in diabetic retinopathy. In this review, we describe changes involving metabolic abnormalities secondary to hyperglycemia, oxidative stress, and activation of transcription factors, together with neuroglial alterations in the diabetic retina. Changes in biochemical pathways and how they promote pathophysiologic developments involving proinflammatory cytokines, chemokines, and adhesion molecules are discussed. Inflammation-mediated leukostasis, retinal ischemia, and neovascularization and their contribution to pathological and clinical stages leading to vision loss in diabetic retinopathy (DR) are highlighted. In addition, potential treatment strategies involving fibrates, connexins, neuroprotectants, photobiomodulation, and anti-inflammatory agents against the development and progression of DR lesions are reviewed. The importance of appropriate animal models for testing novel strategies against DR lesions is discussed; in particular, a novel nonhuman primate model of DR and the suitability of rodent models are weighed. The purpose of this review is to highlight our current understanding of the pathogenesis of DR and to summarize recent advances using novel approaches or targets to investigate and inhibit the retinopathy.
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Affiliation(s)
- Sayon Roy
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts.
| | - Timothy S Kern
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio; Department of Clinical and Molecular Endocrinology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Brian Song
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts
| | - Caren Stuebe
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts
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Fu X, Gens JS, Glazier JA, Burns SA, Gast TJ. Progression of Diabetic Capillary Occlusion: A Model. PLoS Comput Biol 2016; 12:e1004932. [PMID: 27300722 PMCID: PMC4907516 DOI: 10.1371/journal.pcbi.1004932] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 04/20/2016] [Indexed: 12/14/2022] Open
Abstract
An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions.
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Affiliation(s)
- Xiao Fu
- The Biocomplexity Institute, Indiana University, Bloomington, Indiana, United States of America
- Department of Physics, Indiana University, Bloomington, Indiana, United States of America
| | - John Scott Gens
- The Biocomplexity Institute, Indiana University, Bloomington, Indiana, United States of America
- Department of Physics, Indiana University, Bloomington, Indiana, United States of America
| | - James A. Glazier
- The Biocomplexity Institute, Indiana University, Bloomington, Indiana, United States of America
- Department of Physics, Indiana University, Bloomington, Indiana, United States of America
- Department of Intelligent Systems Engineering, Indiana University, Bloomington, Indiana, United States of America
| | - Stephen A. Burns
- School of Optometry, Indiana University, Bloomington, Indiana, United States of America
| | - Thomas J. Gast
- School of Optometry, Indiana University, Bloomington, Indiana, United States of America
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Calado SM, Diaz-Corrales F, Silva GA. pEPito-driven PEDF Expression Ameliorates Diabetic Retinopathy Hallmarks. Hum Gene Ther Methods 2016; 27:79-86. [PMID: 26942449 DOI: 10.1089/hgtb.2015.169] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the major complications of diabetes mellitus. It is characterized by retinal microvascular changes caused by chronic exposure to hyperglycemia, leading to low tissue oxygenation and ultimately to neovascularization. Laser photocoagulation and vitrectomy are the most efficient treatments for DR, but display severe side effects such as the destruction of the healthy retina. Another clinical approach uses antiangiogenic agents to prevent and delay progression of neovascularization, but these require recurrent local administrations that increase the possibility of retinal detachment, vitreous hemorrhage, and cataract formation. Studies in human diabetic retinas have revealed an imbalance between proangiogenic factors such as the vascular endothelial growth factor (VEGF) and antiangiogenic factors, such as pigment epithelial-derived factor (PEDF). This imbalance favors pathological angiogenesis contributing to DR, and can constitute a therapeutic target. Gene therapy was recently shown to be an adequate intervention for long-term treatment of several retinal pathologies. We have previously shown the newly engineered episomal vector pEPito to be able of sustained gene expression in the mouse retina. We here show that pEPito was able to overexpress PEDF for up to three months, both in in vitro cultures of human retinal pigment epithelial cells and in the retina of diabetic mice after a single subretinal injection. In vivo, in parallel with the increase in PEDF we observed a decrease in VEGF levels in injected compared with noninjected eyes and a significant effect on two hallmarks of DR: reduction of glucose transport (by glucose transporter GLUT1), and reduction of inflammation by decreased reactivity of microglia. Jointly, these results point to a significant therapeutic potential of gene therapy with pEPito-PEDF for the treatment of DR.
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Affiliation(s)
- Sofia M Calado
- 1 Doctoral Program in Biomedical Sciences, Department of Biomedical Sciences and Medicine, University of Algarve , Faro, Portugal .,2 CEDOC, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa , Lisboa, Portugal
| | - Francisco Diaz-Corrales
- 3 Department of Cell Therapy and Regenerative Medicine, Andalusian Molecular Biology and Regenerative Medicine Centre (CABIMER) , Seville, Spain
| | - Gabriela A Silva
- 2 CEDOC, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa , Lisboa, Portugal
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Saxena R, Singh D, Saklani R, Gupta SK. Clinical biomarkers and molecular basis for optimized treatment of diabetic retinopathy: current status and future prospects. Eye Brain 2016; 8:1-13. [PMID: 28539797 PMCID: PMC5398738 DOI: 10.2147/eb.s69185] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Diabetic retinopathy is a highly specific microvascular complication of diabetes and a leading cause of blindness worldwide. It is triggered by hyperglycemia which causes increased oxidative stress leading to an adaptive inflammatory assault to the neuroretinal tissue and microvasculature. Prolonged hyperglycemia causes increased polyol pathway flux, increased formation of advanced glycation end-products, abnormal activation of signaling cascades such as activation of protein kinase C (PKC) pathway, increased hexosamine pathway flux, and peripheral nerve damage. All these changes lead to increased oxidative stress and inflammatory assault to the retina resulting in structural and functional changes. In addition, neuroretinal alterations affect diabetes progression. The most effective way to manage diabetic retinopathy is by primary prevention such as hyperglycemia control. While the current mainstay for the management of severe and proliferative diabetic retinopathy is laser photocoagulation, its role is diminishing with the development of newer drugs including corticosteroids, antioxidants, and antiangiogenic and anti-VEGF agents which work as an adjunct to laser therapy or independently. The current pharmacotherapy of diabetic retinopathy is incomplete as a sole treatment option in view of limited efficacy and short-term effect. There is a definite clinical need to develop new pharmacological therapies for diabetic retinopathy, particularly ones which would be effective through the oral route and help recover lost vision. The increasing understanding of the mechanisms of diabetic retinopathy and its biomarkers is likely to help generate better and more effective medications.
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Affiliation(s)
- Rohit Saxena
- Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi
| | - Digvijay Singh
- Division of Ophthalmology, Medanta-The Medicity, Gurgaon
| | - Ravi Saklani
- Ocular Pharmacology Laboratory, Delhi Institute of Pharmaceutical Sciences and Research, New Delhi, India
| | - Suresh Kumar Gupta
- Ocular Pharmacology Laboratory, Delhi Institute of Pharmaceutical Sciences and Research, New Delhi, India
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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: 53] [Impact Index Per Article: 6.6] [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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Relationship between Oxidative Stress, Circadian Rhythms, and AMD. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:7420637. [PMID: 26885250 PMCID: PMC4738726 DOI: 10.1155/2016/7420637] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/24/2015] [Accepted: 10/26/2015] [Indexed: 12/31/2022]
Abstract
This work reviews concepts regarding oxidative stress and the mechanisms by which endogenous and exogenous factors produce reactive oxygen species (ROS). It also surveys the relationships between oxidative stress, circadian rhythms, and retinal damage in humans, particularly those related to light and photodamage. In the first section, the production of ROS by different cell organelles and biomolecules and the antioxidant mechanisms that antagonize this damage are reviewed. The second section includes a brief review of circadian clocks and their relationship with the cellular redox state. In the third part of this work, the relationship between retinal damage and ROS is described. The last part of this work focuses on retinal degenerative pathology, age-related macular degeneration, and the relationships between this pathology, ROS, and light. Finally, the possible interactions between the retinal pigment epithelium (RPE), circadian rhythms, and this pathology are discussed.
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Maeda S, Matsui T, Ojima A, Suematsu M, Kaseda K, Higashimoto Y, Yamakawa R, Yamagishi SI. DNA Aptamer Raised against Advanced Glycation End Products Prevents Abnormalities in Electroretinograms of Experimental Diabetic Retinopathy. Ophthalmic Res 2015; 54:175-80. [PMID: 26492350 DOI: 10.1159/000440768] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 09/01/2015] [Indexed: 11/19/2022]
Abstract
PURPOSE Abnormalities in electroretinograms (ERG), such as reduced amplitudes and delayed implicit times of a- and b-wave and oscillatory potentials (OPs), are one of the earliest features of diabetic retinopathy prior to obvious vascular changes in diabetic retinas. We have previously shown that serum levels of advanced glycation end products (AGEs) are correlated with a delayed latency of OPs in type 2 diabetic rats. However, the pathological role of AGEs in ERG abnormalities remains unclear. We examined here whether high-affinity DNA aptamer directed against AGEs (AGE-aptamer) prevents ERG abnormalities in experimental type 1 diabetic retinopathy. METHODS Streptozotocin-induced diabetic rats or control rats received continuous intraperitoneal infusion of either AGE-aptamer or control aptamer via an osmotic mini pump for 16 weeks. Anthropometric, metabolic, and hemodynamic variables were measured, and an ERG was performed. RESULTS Although AGE-aptamer did not affect body weight, fasting and random blood glucose, HbA1c, blood pressure, or lipid parameters, it completely prevented the increase in serum AGE levels as well as the reduction of a- and b-wave and OP amplitudes in diabetic rats. CONCLUSION The present study demonstrated for the first time that AGE-aptamer prevents abnormalities in ERG in experimental diabetic retinopathy probably by blocking the harmful effects of AGEs.
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Affiliation(s)
- Satoshi Maeda
- Department of Ophthalmology, Kurume University School of Medicine, Kurume, Japan
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PEDF and its roles in physiological and pathological conditions: implication in diabetic and hypoxia-induced angiogenic diseases. Clin Sci (Lond) 2015; 128:805-23. [PMID: 25881671 PMCID: PMC4557399 DOI: 10.1042/cs20130463] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a broadly expressed multifunctional member of the serine proteinase inhibitor (serpin) family. This widely studied protein plays critical roles in many physiological and pathophysiological processes, including neuroprotection, angiogenesis, fibrogenesis and inflammation. The present review summarizes the temporal and spatial distribution patterns of PEDF in a variety of developing and adult organs, and discusses its functions in maintaining physiological homoeostasis. The major focus of the present review is to discuss the implication of PEDF in diabetic and hypoxia-induced angiogenesis, and the pathways mediating PEDF's effects under these conditions. Furthermore, the regulatory mechanisms of PEDF expression, function and degradation are also reviewed. Finally, the therapeutic potential of PEDF as an anti-angiogenic drug is briefly summarized.
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41
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Simó R, Hernández C. Novel approaches for treating diabetic retinopathy based on recent pathogenic evidence. Prog Retin Eye Res 2015; 48:160-80. [PMID: 25936649 DOI: 10.1016/j.preteyeres.2015.04.003] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/13/2015] [Accepted: 04/21/2015] [Indexed: 12/15/2022]
Abstract
Diabetic retinopathy remains as a leading cause of blindness in developed countries. Current treatments target late stages of DR when vision has already been significantly affected. A better understanding of the pathogenesis of DR would permit the development of more efficient preventional/interventional strategies against early stages of DR. In this article a critical review of the state of the art of this issue is provided along with a discussion of problems which have yet to be overcome. Neuroprotection as a new approach for the treatment of the early stages of DR has been particularly emphasized. The development and progression of DR is not homogeneous and, apart from blood glucose levels and blood pressure, it depends on genetic factors which remain to be elucidated. In addition, the role of the pathogenic pathways is not the same in all patients. All these factors should be taken into account in the near future when an individualized oriented treatment for DR could become feasible. The new techniques in retinal imaging acquisition, the identification of useful circulating biomarkers and the individualized analysis of biological samples could facilitate the development of early and personalized therapy in the setting of DR. Finally, it should be noted that only a coordinated action among ophthalmologists, diabetologists, basic researchers, experts in pharmaco-economics and health care providers addressed to the design of rational strategies targeting prevention and the early stages of DR will be effective in reducing the burden and improving the clinical outcome of this devastating complication of diabetes.
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Affiliation(s)
- Rafael Simó
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
| | - Cristina Hernández
- CIBERDEM (CIBER de Diabetes y Enfermedades Metabólicas Asociadas) and Diabetes and Metabolism Research Unit, Vall Hebron Institut de Recerca (VHIR), Universitat Autónoma de Barcelona, 08035 Barcelona, Spain.
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Thangaraj G, Christophel J, Bachmann G, Greif A, Layer PG. PEDF counteracts DL-α-aminoadipate toxicity and rescues gliotoxic damages in RPE-free chicken retinal explants. Exp Eye Res 2015; 134:111-22. [PMID: 25686916 DOI: 10.1016/j.exer.2015.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 01/21/2015] [Accepted: 02/12/2015] [Indexed: 01/03/2023]
Abstract
Gliotoxic responses complicate human eye diseases, the causes of which often remain obscure. Here, we activated Müller cells (MCs) by the gliotoxin DL-α-aminoadipate (AAA) and assayed possible protective effects by pigment epithelium-derived factor (PEDF) in RPE-free retinal explants of the E6 chick embryo. These models are suited to analyze gliotoxic reactions in vitro, since the avian retina contains only Müller cells (MCs) as glial components, and the RPE-free explants are devoid of a major PEDF source. ChAT- and AChE-immunohistochemistry (IHC) revealed that AAA treatment disrupted the differentiation of cholinergic amacrine cells in the inner plexiform layer. At the applied concentration of 1 mM AAA, apoptosis of MCs was slightly increased, as shown by TUNEL and caspase-3 activity assays. Concomitantly, cell-free gaps emerged in the middle of the retina, where MCs were swollen and amassed glutamine synthetase (shown by GS and Vimentin IHC). AAA treatment strongly activated MCs, as shown by GFAP IHC, and by an increase of stress-related catalase activity. Remarkably, nearly all effects of AAA on MCs were effectively counter-balanced by 50 ng/ml PEDF co-treatment, as also shown by RT-PCR. These findings suggest that supplementation with PEDF can protect the retina against gliotoxic attacks. Further studies should establish whether PEDF similarly protects a gliotoxic human retina.
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Affiliation(s)
- Gopenath Thangaraj
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Jeanette Christophel
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Gesine Bachmann
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Alexander Greif
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany
| | - Paul G Layer
- Technische Universität Darmstadt, Entwicklungsbiologie und Neurogenetik, Schnittspahnstrasse 13, D-64287 Darmstadt, Germany.
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Shin ES, Sorenson CM, Sheibani N. Diabetes and retinal vascular dysfunction. J Ophthalmic Vis Res 2015; 9:362-73. [PMID: 25667739 PMCID: PMC4307665 DOI: 10.4103/2008-322x.143378] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 01/19/2014] [Indexed: 02/06/2023] Open
Abstract
Diabetes predominantly affects the microvascular circulation of the retina resulting in a range of structural changes unique to this tissue. These changes ultimately lead to altered permeability, hyperproliferation of endothelial cells and edema, and abnormal vascularization of the retina with resulting loss of vision. Enhanced production of inflammatory mediators and oxidative stress are primary insults with significant contribution to the pathogenesis of diabetic retinopathy (DR). We have determined the identity of the retinal vascular cells affected by hyperglycemia, and have delineated the cell autonomous impact of high glucose on function of these cells. We discuss some of the high glucose specific changes in retinal vascular cells and their contribution to retinal vascular dysfunction. This knowledge provides novel insight into the molecular and cellular defects contributing to the development and progression of diabetic retinopathy, and will aid in the development of innovative, as well as target specific therapeutic approaches for prevention and treatment of DR.
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Affiliation(s)
- Eui Seok Shin
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Christine M Sorenson
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA ; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Nader Sheibani
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA ; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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Carnagarin R, Dharmarajan AM, Dass CR. PEDF-induced alteration of metabolism leading to insulin resistance. Mol Cell Endocrinol 2015; 401:98-104. [PMID: 25462587 DOI: 10.1016/j.mce.2014.11.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 10/21/2014] [Accepted: 11/10/2014] [Indexed: 02/06/2023]
Abstract
Pigment epithelium-derived factor (PEDF) is an anti-angiogenic, immunomodulatory, and neurotrophic serine protease inhibitor protein. PEDF is evolving as a novel metabolic regulatory protein that plays a causal role in insulin resistance. Insulin resistance is the central pathogenesis of metabolic disorders such as obesity, type 2 diabetes mellitus, polycystic ovarian disease, and metabolic syndrome, and PEDF is associated with them. The current evidence suggests that PEDF administration to animals induces insulin resistance, whereas neutralisation improves insulin sensitivity. Inflammation, lipolytic free fatty acid mobilisation, and mitochondrial dysfunction are the proposed mechanism of PEDF-mediated insulin resistance. This review summarises the probable mechanisms adopted by PEDF to induce insulin resistance, and identifies PEDF as a potential therapeutic target in ameliorating insulin resistance.
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Affiliation(s)
- Revathy Carnagarin
- Curtin Biosciences Research Precinct, Bentley 6102, Australia; School of Pharmacy, Curtin University, Bentley 6102, Australia
| | - Arunasalam M Dharmarajan
- Curtin Biosciences Research Precinct, Bentley 6102, Australia; School of Biomedical Science, Curtin University, Bentley 6102, Australia
| | - Crispin R Dass
- Curtin Biosciences Research Precinct, Bentley 6102, Australia; School of Pharmacy, Curtin University, Bentley 6102, Australia.
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45
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Ibrahim AS, Tawfik AM, Hussein KA, Elshafey S, Markand S, Rizk N, Duh EJ, Smith SB, Al-Shabrawey M. Pigment epithelium-derived factor inhibits retinal microvascular dysfunction induced by 12/15-lipoxygenase-derived eicosanoids. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:290-8. [PMID: 25562624 DOI: 10.1016/j.bbalip.2014.12.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 11/03/2014] [Accepted: 12/29/2014] [Indexed: 01/19/2023]
Abstract
We recently demonstrated that 12/15-lipoxygenase (LOX) derived metabolites, hydroxyeicosatetraenoic acids (HETEs), contribute to diabetic retinopathy (DR) via NADPH oxidase (NOX) and disruption of the balance in retinal levels of the vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF). Here, we test whether PEDF ameliorates retinal vascular injury induced by HETEs and the underlying mechanisms. Furthermore, we pursue the causal relationship between LOX-NOX system and regulation of PEDF expression during DR. For these purposes, we used an experimental eye model in which normal mice were injected intravitreally with 12-HETE with/without PEDF. Thereafter, fluorescein angiography (FA) was used to evaluate the vascular leakage, followed by optical coherence tomography (OCT) to assess the presence of angiogenesis. FA and OCT reported an increased vascular leakage and pre-retinal neovascularization, respectively, in response to 12-HETE that were not observed in the PEDF-treated group. Moreover, PEDF significantly attenuated the increased levels of vascular cell and intercellular adhesion molecules, VCAM-1 and ICAM-1, elicited by 12-HETE injection. Accordingly, the direct relationship between HETEs and PEDF has been explored through in-vitro studies using Müller cells (rMCs) and human retinal endothelial cells (HRECs). The results showed that 12- and 15-HETEs triggered the secretion of TNF-α and IL-6, as well as activation of NFκB in rMCs and significantly increased permeability and reduced zonula occludens protein-1 (ZO-1) immunoreactivity in HRECs. All these effects were prevented in PEDF-treated cells. Furthermore, interest in PEDF regulation during DR has been expanded to include NOX system. Retinal PEDF was significantly restored in diabetic mice treated with NOX inhibitor, apocynin, or lacking NOX2 up to 80% of the control level. Collectively, our findings suggest that interfering with LOX-NOX signaling opens up a new direction for treating DR by restoring endogenous PEDF that carries out multilevel vascular protective functions.
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MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/antagonists & inhibitors
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/pharmacology
- Acetophenones/pharmacology
- Animals
- Arachidonate 12-Lipoxygenase/genetics
- Arachidonate 12-Lipoxygenase/metabolism
- Arachidonate 15-Lipoxygenase/genetics
- Arachidonate 15-Lipoxygenase/metabolism
- Cells, Cultured
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetic Retinopathy/drug therapy
- Diabetic Retinopathy/genetics
- Diabetic Retinopathy/metabolism
- Diabetic Retinopathy/pathology
- Endothelial Cells/drug effects
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Ependymoglial Cells/drug effects
- Ependymoglial Cells/metabolism
- Ependymoglial Cells/pathology
- Eye Proteins/pharmacology
- Gene Expression Regulation
- Humans
- Hydroxyeicosatetraenoic Acids/antagonists & inhibitors
- Hydroxyeicosatetraenoic Acids/pharmacology
- Intercellular Adhesion Molecule-1/genetics
- Intercellular Adhesion Molecule-1/metabolism
- Interleukin-6/genetics
- Interleukin-6/metabolism
- Intravitreal Injections
- Membrane Glycoproteins/antagonists & inhibitors
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Knockout
- NADPH Oxidase 2
- NADPH Oxidases/antagonists & inhibitors
- NADPH Oxidases/genetics
- NADPH Oxidases/metabolism
- NF-kappa B/genetics
- NF-kappa B/metabolism
- Nerve Growth Factors/pharmacology
- Retina/drug effects
- Retina/metabolism
- Retina/pathology
- Retinal Neovascularization/drug therapy
- Retinal Neovascularization/genetics
- Retinal Neovascularization/metabolism
- Retinal Neovascularization/pathology
- Serpins/pharmacology
- Signal Transduction
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/metabolism
- Vascular Cell Adhesion Molecule-1/genetics
- Vascular Cell Adhesion Molecule-1/metabolism
- Zonula Occludens-1 Protein/genetics
- Zonula Occludens-1 Protein/metabolism
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Affiliation(s)
- Ahmed S Ibrahim
- Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Egypt
| | - Amany M Tawfik
- Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA
| | - Khaled A Hussein
- Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA
| | - Sally Elshafey
- Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA
| | - Shanu Markand
- Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA
| | - Nasser Rizk
- Biomedical Science Program, Faculty of Science, Qatar University, Doha, Qatar
| | - Elia J Duh
- Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sylvia B Smith
- Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA; Ophthalmology, MCG, GRU, Augusta, GA, USA
| | - Mohamed Al-Shabrawey
- Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA; Ophthalmology, MCG, GRU, Augusta, GA, USA.
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46
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Zhang XH, Feng ZH, Zhang Y. Pigment epithelium-derived factor protects the morphological structure of retinal Müller cells in diabetic rats. Int J Ophthalmol 2014; 7:941-6. [PMID: 25540743 PMCID: PMC4270985 DOI: 10.3980/j.issn.2222-3959.2014.06.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 06/20/2014] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate if pigment epithelium-derived factor (PEDF) has any protective effect on the retinal Müller cells of Sprague-Dawley rats suffering from diabetes mellitus. METHODS Sixty Sprague-Dawley rats were randomly divided into a negative control group, a group receiving 0.1 µg/µL PEDF, another group receiving 0.2 µg/µL PEDF, and a group receiving balanced salt solution (BSS). Rats in both the PEDF and BSS groups were treated intravitreally based on previously established diabetic models. After 4wk of treatment, morphological alterations of Müller cells and protein expression of glutamine synthase (GS) and glial fibrillary acidic protein (GFAP) were analyzed. RESULTS PEDF at either 0.1 µg/µL or 0.2 µg/µL significantly improved the structures of both nuclei and organelles of Müller cells compared to the BSS-treated group. Expression of GS was significantly higher in the 0.2 µg/µL PEDF group than that in the BSS group (P=0.012), but expression of GFAP was significantly lower in the 0.2 µg/µL PEDF group than that in the BSS group (P=0.000); however, there were no significant differences in expression of these proteins between the 0.1 µg/µL PEDF group and the BSS group (P=0.608, P=0.152). CONCLUSION PEDF protects the morphological ultrastructure of Müller cells, improves the expression of glutamate synthase and prevents cell gliosis.
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Affiliation(s)
- Xiao-Hui Zhang
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an 710004, Shaanxi Province, China
| | - Zhao-Hui Feng
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an 710004, Shaanxi Province, China
| | - Yi Zhang
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Jiaotong University Medical College, Xi'an 710004, Shaanxi Province, China
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Ola MS, Alhomida AS. Neurodegeneration in diabetic retina and its potential drug targets. Curr Neuropharmacol 2014; 12:380-6. [PMID: 25342945 PMCID: PMC4207077 DOI: 10.2174/1570159x12666140619205024] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/27/2014] [Accepted: 06/19/2014] [Indexed: 12/04/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the major complications of diabetes causing vision loss and blindness worldwide. DR is widely recognized as a neurodegenerative disease as evidenced from early changes at cellular and molecular levels in the neuronal component of the diabetic retina, which is further supported by various retinal functional tests indicating functional deficits in the retina soon after diabetes progression. Diabetes alters the level of a number of neurodegenerative metabolites, which increases influx through several metabolic pathways which in turn induce an increase in oxidative stress and a decrease in neurotrophic factors, thereby damage retinal neurons. Loss of neurons may implicate in vascular pathology, a clinical signs of DR observed at later stages of the disease. Here, we discuss diabetes-induced potential metabolites known to be detrimental to neuronal damage and their mechanism of action. In addition, we highlight important neurotrophic factors, whose level have been found to be dysregulated in diabetic retina and may damage neurons. Furthermore, we discuss potential drugs and strategies based on targeting diabetes-induced metabolites, metabolic pathways, oxidative stress, and neurotrophins to protect retinal neurons, which may ameliorate vision loss and vascular damage in DR.
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Affiliation(s)
- Mohammad Shamsul Ola
- Department of Biochemistry, College of Science, King Saud University, Riyadh, KSA, Saudi Arabia
| | - Abdullah S Alhomida
- Department of Biochemistry, College of Science, King Saud University, Riyadh, KSA, Saudi Arabia
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48
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Elahy M, Baindur-Hudson S, Cruzat VF, Newsholme P, Dass CR. Mechanisms of PEDF-mediated protection against reactive oxygen species damage in diabetic retinopathy and neuropathy. J Endocrinol 2014; 222:R129-39. [PMID: 24928938 DOI: 10.1530/joe-14-0065] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is a pluripotent glycoprotein belonging to the serpin family. PEDF can stimulate several physiological processes such as angiogenesis, cell proliferation, and survival. Oxidative stress plays an important role in the occurrence of diabetic retinopathy (DR), which is the major cause of blindness in young diabetic adults. PEDF plays a protective role in DR and there is accumulating evidence of the neuroprotective effect of PEDF. In this paper, we review the role of PEDF and the mechanisms involved in its antioxidative, anti-inflammatory, and neuroprotective properties.
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Affiliation(s)
- Mina Elahy
- College of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Swati Baindur-Hudson
- College of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Vinicius F Cruzat
- College of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, AustraliaCollege of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Philip Newsholme
- College of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, AustraliaCollege of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Crispin R Dass
- College of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, AustraliaCollege of Health and BiomedicineVictoria University, St Albans, Victoria 3021, AustraliaSchool of Biomedical SciencesBiosciences Research PrecinctSchool of PharmacyCurtin University, Bentley, Perth, Western Australia 6102, Australia
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49
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Dorfman D, Aranda ML, González Fleitas MF, Chianelli MS, Fernandez DC, Sande PH, Rosenstein RE. Environmental enrichment protects the retina from early diabetic damage in adult rats. PLoS One 2014; 9:e101829. [PMID: 25004165 PMCID: PMC4086948 DOI: 10.1371/journal.pone.0101829] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 06/11/2014] [Indexed: 11/19/2022] Open
Abstract
Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Available treatments are not completely effective. We analyzed the effect of environmental enrichment on retinal damage induced by experimental diabetes in adult Wistar rats. Diabetes was induced by an intraperitoneal injection of streptozotocin. Three days after vehicle or streptozotocin injection, animals were housed in enriched environment or remained in a standard environment. Retinal function (electroretinogram, and oscillatory potentials), retinal morphology, blood-retinal barrier integrity, synaptophysin, astrocyte and Müller cell glial fibrillary acidic protein, vascular endothelial growth factor, tumor necrosis factor-α, and brain-derived neurotrophic factor levels, as well as lipid peroxidation were assessed in retina from diabetic animals housed in standard or enriched environment. Environmental enrichment preserved scotopic electroretinogram a-wave, b-wave and oscillatory potential amplitude, avoided albumin-Evan's blue leakage, prevented the decrease in retinal synaptophysin and astrocyte glial fibrillary acidic protein levels, the increase in Müller cell glial fibrillary acidic protein, vascular endothelial growth factor and tumor necrosis factor-α levels, as well as oxidative stress induced by diabetes. In addition, enriched environment prevented the decrease in retinal brain-derived neurotrophic factor levels induced by experimental diabetes. When environmental enrichment started 7 weeks after diabetes onset, retinal function was significantly preserved. These results indicate that enriched environment could attenuate the early diabetic damage in the retina from adult rats.
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Affiliation(s)
- Damián Dorfman
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Marcos L. Aranda
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - María Florencia González Fleitas
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Mónica S. Chianelli
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Diego C. Fernandez
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
- Laboratory of Histology, School of Medicine, University of Morón, Buenos Aires, Argentina
| | - Pablo H. Sande
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Ruth E. Rosenstein
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
- * E-mail:
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Pardue MT, Barnes CS, Kim MK, Aung MH, Amarnath R, Olson DE, Thulé PM. Rodent Hyperglycemia-Induced Inner Retinal Deficits are Mirrored in Human Diabetes. Transl Vis Sci Technol 2014; 3:6. [PMID: 24959388 DOI: 10.1167/tvst.3.3.6] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/28/2014] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To evaluate the utility of low luminance stimuli to functionally probe inner retinal rod pathways in the context of diabetes mellitus in both rat and human subjects. METHODS Inner retinal dysfunction was assessed using oscillatory potential (OP) delays in diabetic rats. Scotopic electroretinograms (ERGs) in response to a series of increasing flash luminances were recorded from streptozotocin (STZ)-treated and control Sprague-Dawley rats after 7, 14, 20, and 29 weeks of hyperglycemia. We then evaluated OP delays in human diabetic subjects with (DR) and without (DM) diabetic retinopathy using the International Society for Clinical Electrophysiology in Vision (ISCEV) standard scotopic protocol and two additional dim test flashes. RESULTS Beginning 7 weeks after STZ, OP implicit times in diabetic rats were progressively delayed in response to dim, but not bright stimuli. In many diabetic subjects the standard ISCEV dim flash failed to illicit measureable OPs. However, OPs became measurable using a brighter, nonstandard dim flash (Test Flash 1, -1.43 log cd s/m2), and exhibited prolonged implicit times in the DM group compared with control subjects (CTRL). CONCLUSIONS Delays in scotopic OP implicit times are an early response to hyperglycemia in diabetic rats. A similar, inner retinal, rod-driven response was detected in diabetic human subjects without diabetic retinopathy, only when a nonstandard ISCEV flash intensity was employed during ERG testing. TRANSLATIONAL RELEVANCE The addition of a dim stimulus to standard ISCEV flashes with assessment of OP latency during ERG testing may provide a detection method for early retinal dysfunction in diabetic patients.
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Affiliation(s)
- Machelle T Pardue
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA ; Neuroscience Program, Emory University, Atlanta, GA
| | - Claire S Barnes
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA
| | - Moon K Kim
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA ; Department of Ophthalmology, Emory University, Atlanta, GA
| | - Moe H Aung
- Neuroscience Program, Emory University, Atlanta, GA
| | - Raj Amarnath
- Rehab R&D Center of Excellence, Veterans Affairs Medical Center, Decatur, GA
| | - Darin E Olson
- Medical Service, Veterans Affairs Medical Center, Decatur, GA ; Division of Endocrinology, Metabolism, & Lipids, Emory University, Atlanta, GA
| | - Peter M Thulé
- Medical Service, Veterans Affairs Medical Center, Decatur, GA ; Division of Endocrinology, Metabolism, & Lipids, Emory University, Atlanta, GA
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