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Nesper PL, Fawzi AA. Perfusion Deficits in Diabetes Without Retinopathy Localize to the Perivenular Deep Capillaries Near the Fovea on OCT Angiography. OPHTHALMOLOGY SCIENCE 2024; 4:100482. [PMID: 38751454 PMCID: PMC11090878 DOI: 10.1016/j.xops.2024.100482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 01/07/2024] [Accepted: 01/26/2024] [Indexed: 05/18/2024]
Abstract
Purpose To localize early capillary perfusion deficits in patients with diabetes mellitus (DM) without clinical diabetic retinopathy (DR) using averaged OCT angiography (OCTA). Design Retrospective cross-sectional study. Participants Patients with DM without DR and healthy controls. Methods We measured perfusion deficits in the full retina, superficial capillary plexus (SCP), and deep capillary plexus (DCP) on averaged 3 × 3-mm OCTA images. Perfusion deficits were defined as the percentage of retinal tissue located >30 μm from blood vessels, excluding the foveal avascular zone (FAZ). One eye from each patient was selected based on image quality. We measured deficits in the parafoveal region, the 300 μm surrounding the FAZ, and 300 to 1000 μm surrounding the FAZ. If a capillary layer within one of these regions was significantly different in DM without DR compared with controls, we further characterized the location of perfusion deficit as periarteriolar, perivenular, or the capillaries between these 2 zones. Main Outcome Measures Location of increased perfusion deficits in patients with DM without DR compared with controls. Results Sixteen eyes from 16 healthy controls were compared with 16 eyes from 16 patients with DM without DR (age 45.1 ± 10.7 and 47.4 ± 15.2 years respectively, P = 0.64). Foveal avascular zone area and perfusion deficits in the entire parafovea and the 300 to 1000-μm ring around the FAZ were not significantly different between groups (P > 0.05 for all). Perfusion deficits in 300 μm around the FAZ were significantly increased in patients with DM without DR in full retinal thickness, SCP, and DCP (P < 0.05 for all). When analyzing the perivenular, periarteriolar, and capillary zones, only the perivenular DCP perfusion deficits were significantly increased (5.03 ± 2.92% in DM without DR and 2.73 ± 1.97% in controls, P = 0.014). Conclusions Macular perfusion deficits in patients with DM without DR were significantly increased in the region nearest the FAZ, mainly at the perivenular deep capillaries. Further research on these early changes may improve our understanding of the capillaries most susceptible to vascular injury and disruption during diabetes. Financial Disclosures Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Peter L. Nesper
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Amani A. Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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Hartnett ME, Fickweiler W, Adamis AP, Brownlee M, Das A, Duh EJ, Feener EP, King G, Kowluru R, Luhmann UF, Storti F, Wykoff CC, Aiello LP. Rationale of Basic and Cellular Mechanisms Considered in Updating the Staging System for Diabetic Retinal Disease. OPHTHALMOLOGY SCIENCE 2024; 4:100521. [PMID: 39006804 PMCID: PMC11245984 DOI: 10.1016/j.xops.2024.100521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/12/2024] [Accepted: 03/18/2024] [Indexed: 07/16/2024]
Abstract
Purpose Hyperglycemia is a major risk factor for early lesions of diabetic retinal disease (DRD). Updating the DRD staging system to incorporate relevant basic and cellular mechanisms pertinent to DRD is necessary to better address early disease, disease progression, the use of therapeutic interventions, and treatment effectiveness. Design We sought to review preclinical and clinical evidence on basic and cellular mechanisms potentially pertinent to DRD that might eventually be relevant to update the DRD staging system. Participants Not applicable. Methods The Basic and Cellular Mechanisms Working Group (BCM-WG) of the Mary Tyler Moore Vision Initiative carefully and extensively reviewed available preclinical and clinical evidence through multiple iterations and classified these. Main Outcome Measures Classification was made into evidence grids, level of supporting evidence, and anticipated future relevance to DRD. Results A total of 40 identified targets based on pathophysiology and other parameters for DRD were grouped into concepts or evaluated as specific candidates. VEGFA, peroxisome proliferator-activated receptor-alpha related pathways, plasma kallikrein, and angiopoietin 2 had strong agreement as promising for use as biomarkers in diagnostic, monitoring, predictive, prognostic, and pharmacodynamic responses as well as for susceptibility/risk biomarkers that could underlie new assessments and eventually be considered within an updated DRD staging system or treatment, based on the evidence and need for research that would fit within a 2-year timeline. The BCM-WG found there was strong reason also to pursue the following important concepts regarding scientific research of DRD acknowledging their regulation by hyperglycemia: inflammatory/cytokines, oxidative signaling, vasoprotection, neuroprotection, mitophagy, and nutrients/microbiome. Conclusion Promising targets that might eventually be considered within an updated DRD staging system or treatment were identified. Although the BCM-WG recognizes that at this stage little can be incorporated into a new DRD staging system, numerous potential targets and important concepts deserve continued support and research, as they may eventually serve as biomarkers and/or therapeutic targets with measurable benefits to patients with diabetes. Financial Disclosures Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- M. Elizabeth Hartnett
- Department of Ophthalmology, Byers Eye Institute of Stanford University, Palo Alto, California
| | - Ward Fickweiler
- Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Anthony P. Adamis
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Michael Brownlee
- Departments of Medicine and Pathology, Einstein Diabetes Research Center, Albert Einstein College of Medicine, Bronx, New York
| | - Arup Das
- Department of Surgery, University of New Mexico School of Medicine, Albuquerque, New Mexico
| | - Elia J. Duh
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Edward P. Feener
- Research Division, KalVista Pharmaceuticals, Inc, Cambridge, Massachusetts
| | - George King
- Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Renu Kowluru
- Department of Ophthalmology, Visual & Anatomical Sciences, Wayne State University, Detroit, Michigan
| | - Ulrich F.O. Luhmann
- Roche Pharmaceutical Research and Early Development, Translational Medicine Ophthalmology, Roche Innovation Center Basel, Basel, Switzerland
| | - Federica Storti
- Roche Pharmaceutical Research and Early Development, Translational Medicine Ophthalmology, Roche Innovation Center Basel, Basel, Switzerland
| | - Charles C. Wykoff
- Ophthalmology, Retina Consultants of Texas, Houston, Texas
- Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas
| | - Lloyd Paul Aiello
- Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
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3
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Serikbaeva A, Li Y, Ma S, Yi D, Kazlauskas A. Resilience to diabetic retinopathy. Prog Retin Eye Res 2024; 101:101271. [PMID: 38740254 DOI: 10.1016/j.preteyeres.2024.101271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/16/2024]
Abstract
Chronic elevation of blood glucose at first causes relatively minor changes to the neural and vascular components of the retina. As the duration of hyperglycemia persists, the nature and extent of damage increases and becomes readily detectable. While this second, overt manifestation of diabetic retinopathy (DR) has been studied extensively, what prevents maximal damage from the very start of hyperglycemia remains largely unexplored. Recent studies indicate that diabetes (DM) engages mitochondria-based defense during the retinopathy-resistant phase, and thereby enables the retina to remain healthy in the face of hyperglycemia. Such resilience is transient, and its deterioration results in progressive accumulation of retinal damage. The concepts that co-emerge with these discoveries set the stage for novel intellectual and therapeutic opportunities within the DR field. Identification of biomarkers and mediators of protection from DM-mediated damage will enable development of resilience-based therapies that will indefinitely delay the onset of DR.
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Affiliation(s)
- Anara Serikbaeva
- Department of Physiology and Biophysics, University of Illinois at Chicago, 1905 W Taylor St, Chicago, IL 60612, USA
| | - Yanliang Li
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1905 W Taylor St, Chicago, IL 60612, USA
| | - Simon Ma
- Department of Bioengineering, University of Illinois at Chicago, 1905 W Taylor St, Chicago, IL 60612, USA
| | - Darvin Yi
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1905 W Taylor St, Chicago, IL 60612, USA; Department of Bioengineering, University of Illinois at Chicago, 1905 W Taylor St, Chicago, IL 60612, USA
| | - Andrius Kazlauskas
- Department of Physiology and Biophysics, University of Illinois at Chicago, 1905 W Taylor St, Chicago, IL 60612, USA; Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1905 W Taylor St, Chicago, IL 60612, USA.
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4
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Tang Q, Buonfiglio F, Böhm EW, Zhang L, Pfeiffer N, Korb CA, Gericke A. Diabetic Retinopathy: New Treatment Approaches Targeting Redox and Immune Mechanisms. Antioxidants (Basel) 2024; 13:594. [PMID: 38790699 PMCID: PMC11117924 DOI: 10.3390/antiox13050594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
Diabetic retinopathy (DR) represents a severe complication of diabetes mellitus, characterized by irreversible visual impairment resulting from microvascular abnormalities. Since the global prevalence of diabetes continues to escalate, DR has emerged as a prominent area of research interest. The development and progression of DR encompass a complex interplay of pathological and physiological mechanisms, such as high glucose-induced oxidative stress, immune responses, vascular endothelial dysfunction, as well as damage to retinal neurons. Recent years have unveiled the involvement of genomic and epigenetic factors in the formation of DR mechanisms. At present, extensive research explores the potential of biomarkers such as cytokines, molecular and cell therapies, antioxidant interventions, and gene therapy for DR treatment. Notably, certain drugs, such as anti-VEGF agents, antioxidants, inhibitors of inflammatory responses, and protein kinase C (PKC)-β inhibitors, have demonstrated promising outcomes in clinical trials. Within this context, this review article aims to introduce the recent molecular research on DR and highlight the current progress in the field, with a particular focus on the emerging and experimental treatment strategies targeting the immune and redox signaling pathways.
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Affiliation(s)
- Qi Tang
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (F.B.); (E.W.B.); (L.Z.); (N.P.); (C.A.K.)
| | | | | | | | | | | | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (F.B.); (E.W.B.); (L.Z.); (N.P.); (C.A.K.)
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5
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Tang S, Huang M, Wang R, Li M, Dong N, Wu R, Chi Z, Gao L. Drp1-dependent mitochondrial fragmentation mediates photoreceptor abnormalities in type 1 diabetic retina. Exp Eye Res 2024; 242:109860. [PMID: 38467174 DOI: 10.1016/j.exer.2024.109860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 01/27/2024] [Accepted: 03/08/2024] [Indexed: 03/13/2024]
Abstract
Recent studies have highlighted that retinal neurodegeneration precedes microvascular changes in diabetic retinopathy (DR), but the specific mechanisms remain unclear. Given the pivotal role of dysfunctional mitochondria and oxidative stress in early DR, our objective was to observe mitochondria-related alterations in the neural retina of type one diabetic mellitus mice with no evidence of DR (T1DM-NDR). We aimed to identify the key mitochondrial-related proteins contributing to mitochondrial injury. Our study revealed that T1DM-NDR mice exhibited outer retina thinning, including the ellipsoid zone, inner segment, and outer segment. Additionally, there was an impaired amplitude of the b-wave in electroretinogram (ERG) and a disorganized arrangement of the photoreceptor layer. In both the retina of DM mice and high glucose (HG)-treated 661w cells, mitochondria appeared swollen and fragmented, with disrupted cristae, disorganized or shortened branches in the mitochondrial network, and decreased mitochondrial membrane potential. Among the mitochondrial-related proteins, dynamin-related protein 1 (Drp1) was upregulated, and the ratio of phosphorylated Drp1 protein at serine 616 (S616) and serine 637 (S637) sites significantly increased in the retina of DM mice. The administration of Mdivi-1 ameliorated high-glucose-induced dysfunctional mitochondria, thereby protecting T1DM-NDR mice retina from morphological and functional injuries. Our findings suggest that hyperglycemia promotes Drp1-mediated mitochondrial dysfunction, which may be a significant factor in the development of DR. The inhibition of high-glucose-induced mitochondrial fission emerges as a potential and innovative intervention strategy for preventing DR.
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Affiliation(s)
- Shuyu Tang
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Mengling Huang
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ruixuan Wang
- Bourns Engineering, The University of California, Riverside, Riverside, CA, 92521, United States
| | - Ming Li
- Department of Immunology, College of Basic Medical Immunology, Central South University, Changsha, China
| | - Ning Dong
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ronghan Wu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital of Wenzhou Medical University, Wenzhou, China; National Clinical Research Center for Ocular Diseases, Eye Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zailong Chi
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital of Wenzhou Medical University, Wenzhou, China; National Clinical Research Center for Ocular Diseases, Eye Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Ling Gao
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China; State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital of Wenzhou Medical University, Wenzhou, China; National Clinical Research Center for Ocular Diseases, Eye Hospital of Wenzhou Medical University, Wenzhou, China.
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Cai L, Xia M, Zhang F. Redox Regulation of Immunometabolism in Microglia Underpinning Diabetic Retinopathy. Antioxidants (Basel) 2024; 13:423. [PMID: 38671871 PMCID: PMC11047590 DOI: 10.3390/antiox13040423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/24/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
Diabetic retinopathy (DR) is the leading cause of visual impairment and blindness among the working-age population. Microglia, resident immune cells in the retina, are recognized as crucial drivers in the DR process. Microglia activation is a tightly regulated immunometabolic process. In the early stages of DR, the M1 phenotype commonly shifts from oxidative phosphorylation to aerobic glycolysis for energy production. Emerging evidence suggests that microglia in DR not only engage specific metabolic pathways but also rearrange their oxidation-reduction (redox) system. This redox adaptation supports metabolic reprogramming and offers potential therapeutic strategies using antioxidants. Here, we provide an overview of recent insights into the involvement of reactive oxygen species and the distinct roles played by key cellular antioxidant pathways, including the NADPH oxidase 2 system, which promotes glycolysis via enhanced glucose transporter 4 translocation to the cell membrane through the AKT/mTOR pathway, as well as the involvement of the thioredoxin and nuclear factor E2-related factor 2 antioxidant systems, which maintain microglia in an anti-inflammatory state. Therefore, we highlight the potential for targeting the modulation of microglial redox metabolism to offer new concepts for DR treatment.
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Affiliation(s)
- Luwei Cai
- National Clinical Research Center for Eye Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; (L.C.); (M.X.)
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai 200080, China
| | - Mengxue Xia
- National Clinical Research Center for Eye Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; (L.C.); (M.X.)
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai 200080, China
| | - Fang Zhang
- National Clinical Research Center for Eye Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; (L.C.); (M.X.)
- Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
- Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai 200080, China
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Wang X, Wang T, Kaneko S, Kriukov E, Lam E, Szczepan M, Chen J, Gregg A, Wang X, Fernandez-Gonzalez A, Mitsialis SA, Kourembanas S, Baranov P, Sun Y. Photoreceptors inhibit pathological retinal angiogenesis through transcriptional regulation of Adam17 via c-Fos. Angiogenesis 2024:10.1007/s10456-024-09912-0. [PMID: 38483712 DOI: 10.1007/s10456-024-09912-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/03/2024] [Indexed: 04/11/2024]
Abstract
Pathological retinal angiogenesis profoundly impacts visual function in vascular eye diseases, such as retinopathy of prematurity (ROP) in preterm infants and age-related macular degeneration in the elderly. While the involvement of photoreceptors in these diseases is recognized, the underlying mechanisms remain unclear. This study delved into the pivotal role of photoreceptors in regulating abnormal retinal blood vessel growth using an oxygen-induced retinopathy (OIR) mouse model through the c-Fos/A disintegrin and metalloprotease 17 (Adam17) axis. Our findings revealed a significant induction of c-Fos expression in rod photoreceptors, and c-Fos depletion in these cells inhibited pathological neovascularization and reduced blood vessel leakage in the OIR mouse model. Mechanistically, c-Fos directly regulated the transcription of Adam17 a shedding protease responsible for the production of bioactive molecules involved in inflammation, angiogenesis, and cell adhesion and migration. Furthermore, we demonstrated the therapeutic potential by using an adeno-associated virus carrying a rod photoreceptor-specific short hairpin RNA against c-fos which effectively mitigated abnormal retinal blood vessel overgrowth, restored retinal thickness, and improved electroretinographic (ERG) responses. In conclusion, this study highlights the significance of photoreceptor c-Fos in ROP pathology, offering a novel perspective for the treatment of this disease.
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Affiliation(s)
- Xudong Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Tianxi Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Satoshi Kaneko
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Emil Kriukov
- Department of Ophthalmology, The Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Enton Lam
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Manon Szczepan
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jasmine Chen
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Austin Gregg
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Xingyan Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Angeles Fernandez-Gonzalez
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - S Alex Mitsialis
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Stella Kourembanas
- Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Petr Baranov
- Department of Ophthalmology, The Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Ye Sun
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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Berkowitz BA, Paruchuri A, Stanek J, Podolsky RH, Childers KL, Roberts R. Acetazolamide Challenge Changes Outer Retina Bioenergy-Linked and Anatomical OCT Biomarkers Depending on Mouse Strain. Invest Ophthalmol Vis Sci 2024; 65:21. [PMID: 38488413 PMCID: PMC10946704 DOI: 10.1167/iovs.65.3.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 02/27/2024] [Indexed: 03/19/2024] Open
Abstract
Purpose The purpose of this study was to test the hypothesis that optical coherence tomography (OCT) bioenergy-linked and anatomical biomarkers are responsive to an acetazolamide (ACZ) provocation. Methods C57BL/6J mice (B6J, a strain with relatively inefficient mitochondria) and 129S6/ev mice (S6, a strain with relatively efficient mitochondria) were given a single IP injection of ACZ (carbonic anhydrase inhibitor) or vehicle. In each mouse, the Mitochondrial Configuration within Photoreceptors based on the profile shape Aspect Ratio (MCP/AR) index was determined from the hyper-reflective band immediately posterior to the external limiting membrane (ELM). In addition, we tested for ACZ-induced acidification by measuring contraction of the external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness; the hyporeflective band (HB) signal intensity at the photoreceptor tips was also examined. Finally, the nuclear layer thickness was measured. Results In response to ACZ, MCP/AR was greater-than-vehicle in B6J mice and lower-than-vehicle in S6 mice. ACZ-treated B6J and S6 mice both showed ELM-RPE contraction compared to vehicle-treated mice, consistent with dehydration in response to subretinal space acidification. The HB intensity at the photoreceptor tips and the outer nuclear layer thickness (B6J and S6), as well as the inner nuclear layer thickness of B6J mice, were all lower than vehicle following ACZ. Conclusions Photoreceptor respiratory efficacy can be evaluated in vivo based on distinct rod mitochondria responses to subretinal space acidification measured with OCT biomarkers and an ACZ challenge, supporting and extending our previous findings measured with light-dark conditions.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Anuhya Paruchuri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Josh Stanek
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H. Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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Villa-Fernández E, García AV, Fernández-Fernández A, García-Villarino M, Ares-Blanco J, Pujante P, González-Vidal T, Fraga MF, Torre EM, Delgado E, Lambert C. Metformin and Glucose Concentration as Limiting Factors in Retinal Pigment Epithelial Cell Viability and Proliferation. Int J Mol Sci 2024; 25:2637. [PMID: 38473884 DOI: 10.3390/ijms25052637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Metformin is a well-established drug for the treatment of type 2 diabetes; however, the mechanism of action has not been well described and many aspects of how it truly acts are still unknown. Moreover, regarding in vitro experiments, the glycaemic status when metformin is used is generally not considered, which, added to the suprapharmacological drug concentrations that are commonly employed in research, has resulted in gaps of its mechanism of action. The aim of this study was to determine how glucose and metformin concentrations influence cell culture. Considering that diabetic retinopathy is one of the most common complications of diabetes, a retinal pigment epithelial cell line was selected, and cell viability and proliferation rates were measured at different glucose and metformin concentrations. As expected, glucose concentration by itself positively influenced cell proliferation rates. When the metformin was considered, results were conditioned, as well, by metformin concentration. This conditioning resulted in cell death when high concentrations of metformin were used under physiological concentrations of glucose, while this did not happen when clinically relevant concentrations of metformin were used independently of glucose status. Our study shows the importance of in vitro cell growth conditions when drug effects such as metformin's are being analysed.
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Affiliation(s)
- Elsa Villa-Fernández
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
| | - Ana Victoria García
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
| | | | - Miguel García-Villarino
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Jessica Ares-Blanco
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Pedro Pujante
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
| | - Tomás González-Vidal
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
| | - Mario F Fraga
- Nanomaterials and Nanotechnology Research Center (CINN-CSIC), Health Research Institute of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Institute of Oncology of Asturias (IUOPA), 33006 Oviedo, Asturias, Spain
- Department of Organisms and Systems Biology (B.O.S), University of Oviedo, 33006 Oviedo, Asturias, Spain
| | - Edelmiro Menéndez Torre
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Elias Delgado
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Asturias Central University Hospital, 33011 Oviedo, Asturias, Spain
- Department of Medicine, University of Oviedo, 33006 Oviedo, Asturias, Spain
- Centre for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Carmen Lambert
- Endocrinology, Nutrition, Diabetes and Obesity Group, Health Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Asturias, Spain
- Department of Educational Sciences, University of Oviedo, 33006 Oviedo, Asturias, Spain
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10
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Chen J, Wang Q, Li R, Li Z, Jiang Q, Yan F, Ye J. The role of Keap1-Nrf2 signaling pathway during the progress and therapy of diabetic retinopathy. Life Sci 2024; 338:122386. [PMID: 38159594 DOI: 10.1016/j.lfs.2023.122386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/09/2023] [Accepted: 12/22/2023] [Indexed: 01/03/2024]
Abstract
Diabetic retinopathy is a complex and progressive ocular complication of diabetes mellitus and is a leading cause of blindness in people of working age worldwide. The pathophysiology of diabetic retinopathy involves multifactorial processes, including oxidative stress, inflammation and vascular abnormalities. Understanding the underlying molecular mechanisms involved in its pathogenesis is essential for the development of effective therapeutic interventions. One of the pathways receiving increasing attention is the Keap1-Nrf2 signaling pathway, which regulates the cellular response to oxidative stress by activating Nrf2. In this review, we analyze the current evidence linking Keap1-Nrf2 signaling pathway dysregulation to diabetic retinopathy. In addition, we explore the potential therapeutic implications and the challenges of targeting this pathway for disease management. A comprehensive understanding of the molecular mechanisms of diabetic retinopathy and the therapeutic potential of the Keap1-Nrf2 pathway may pave the way for innovative and effective interventions to combat this vision-threatening disease.
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Affiliation(s)
- Jiawen Chen
- State Key Laboratory of Natural Medicines, Research Center of Biostatistics and Computational Pharmacy, China Pharmaceutical University, Nanjing 211198, China; School of Life Science and Technology, China Pharmaceutical University, Nanjing 210006, China; Department of Ophthalmology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei 434000, China
| | - Qi Wang
- Department of Ophthalmology, The First Affiliated Hospital of Yangtze University, Jingzhou, Hubei 434000, China
| | - Ruiyan Li
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 210006, China
| | - Zhe Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, China; Cardiovascular research Institute, Wuhan University, Wuhan 430060, China
| | - Qizhou Jiang
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 210006, China
| | - Fangrong Yan
- State Key Laboratory of Natural Medicines, Research Center of Biostatistics and Computational Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Junmei Ye
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 210006, China.
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11
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Zhang S, Wei X, Bowers M, Jessberger S, Golczak M, Semenkovich CF, Rajagopal R. Increasing Energetic Demands on Photoreceptors in Diabetes Corrects Retinal Lipid Dysmetabolism and Reduces Subsequent Microvascular Damage. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:2144-2155. [PMID: 37741454 PMCID: PMC10777362 DOI: 10.1016/j.ajpath.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/14/2023] [Accepted: 09/01/2023] [Indexed: 09/25/2023]
Abstract
Mechanisms responsible for the pathogenesis of diabetic retinal disease remain incompletely understood, but they likely involve multiple cellular targets, including photoreceptors. Evidence suggests that dysregulated de novo lipogenesis in photoreceptors is a critical early target of diabetes. Following on this observation, the present study aimed to determine whether two interventions shown to improve diabetic retinopathy in mice-pharmacologic visual cycle inhibition and prolonged dark adaptation-reduce photoreceptor anabolic lipid metabolism. Elevated retinal lipid biosynthetic signaling was observed in two mouse models of diabetes, with both models showing reduced retinal AMP-activated kinase (AMPK) signaling, elevated acetyl CoA carboxylase (ACC) signaling, and increased activity of fatty acid synthase, which promotes lipotoxicity in photoreceptors. Although retinal AMPK-ACC axis signaling was dependent on systemic glucose fluctuations in healthy animals, mice with diabetes lacked such regulation. Visual cycle inhibition and prolonged dark adaptation reversed abnormal retinal AMPK-ACC signaling in mice with diabetes. Although visual cycle inhibition reduced the severity of diabetic retinopathy in control mice, as assessed by retinal capillary atrophy, this intervention was ineffective in fatty acid synthase gain-of-function mice. These results suggest that early diabetic retinopathy is characterized by glucose-driven elevations in retinal lipid biosynthetic activity, and that two interventions known to increase photoreceptor glucose demands alleviate disease by reversing these signals.
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Affiliation(s)
- Sheng Zhang
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Xiaochao Wei
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri
| | - Megan Bowers
- Faculties of Medicine and Science, Laboratory of Neural Plasticity, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Sebastian Jessberger
- Faculties of Medicine and Science, Laboratory of Neural Plasticity, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Marcin Golczak
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri; Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | - Rithwick Rajagopal
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri.
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12
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Ebrahimi M, Thompson P, Lauer AK, Sivaprasad S, Perry G. The retina-brain axis and diabetic retinopathy. Eur J Ophthalmol 2023; 33:2079-2095. [PMID: 37259525 DOI: 10.1177/11206721231172229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Diabetic retinopathy (DR) is a major contributor to permanent vision loss and blindness. Changes in retinal neurons, glia, and microvasculature have been the focus of intensive study in the quest to better understand DR. However, the impact of diabetes on the rest of the visual system has received less attention. There are reports of associations of changes in the visual system with preclinical and clinical manifestations of diabetes. Simultaneous investigation of the retina and the brain may shed light on the mechanisms underlying neurodegeneration in diabetics. Additionally, investigating the links between DR and other neurodegenerative disorders of the brain including Alzheimer's and Parkinson's disease may reveal shared mechanisms for neurodegeneration and potential therapy options.
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Affiliation(s)
- Moein Ebrahimi
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Network of Immunity in Infection, Malignancy, and Autoimmunity, Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Paul Thompson
- Imaging Genetics Center, Mark and Mary Stevens Institute for Neuroimaging and Informatics, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Andreas K Lauer
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Sobha Sivaprasad
- National Institute of Health and Care Research Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, UK
| | - George Perry
- Department of Neuroscience, Developmental and Regenerative Biology, University of Texas and San Antonio, San Antonio, TX, USA
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13
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Mohammad G, Kumar J, Kowluru RA. Mitochondrial Genome-Encoded Long Noncoding RNA Cytochrome B and Mitochondrial Dysfunction in Diabetic Retinopathy. Antioxid Redox Signal 2023; 39:817-828. [PMID: 37464864 PMCID: PMC10654995 DOI: 10.1089/ars.2023.0303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/22/2023] [Indexed: 07/20/2023]
Abstract
Aims: Mitochondrial dysfunction is closely associated with the development of diabetic complications. In diabetic retinopathy, electron transport chain is compromised and mitochondrial DNA (mtDNA) is damaged, downregulating transcription of mtDNA-encoded cytochrome B (CYTB) and its antisense long noncoding RNA, long noncoding RNA cytochrome B (LncCytB). Our goal was to investigate the role of LncCytB in the regulation of CYTB and mitochondrial function in diabetic retinopathy. Methods: Using human retinal endothelial cells, genetically manipulated for LncCytB (overexpression or silencing), the effect of high glucose (20 mM d-glucose) on LncCytB-CYTB interactions (by chromatin isolation by RNA purification), CYTB gene expression (by real-time quantitative polymerase chain reaction), complex III activity, mitochondrial free radicals, and oxygen consumption rate (OCR, by Seahorse XF analyzer) was investigated. Key results were confirmed in the retinal microvessels from streptozotocin-induced diabetic mice. Results: High glucose decreased LncCytB-CYTB interactions, and while LncCytB overexpression ameliorated glucose-induced decrease in CYTB gene transcripts, complex III activity and OCR and increase in mitochondrial reactive oxygen species, LncCytB-siRNA further attenuated CYTB gene transcription, complex III activity, and OCR. Similar decrease in LncCytB-CYTB interactions and CYTB transcription was observed in diabetic mice. Furthermore, maintenance of mitochondrial homeostasis by overexpressing superoxide dismutase or sirtuin 1 in mice ameliorated diabetes-induced decrease in LncCytB-CYTB interactions and CYTB gene transcripts, and also improved complex III activity and mitochondrial respiration. Innovation and Conclusion: LncCytB downregulation in hyperglycemic milieu downregulates CYTB transcription, which inhibits complex III activity and compromises mitochondrial stability and OCR. Thus, preventing LncCytB downregulation in diabetes has potential of inhibiting the development of diabetic retinopathy, possibly via maintaining mitochondrial respiration. Antioxid. Redox Signal. 39, 817-828.
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Affiliation(s)
- Ghulam Mohammad
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, Detroit, Michigan, USA
| | - Jay Kumar
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, Detroit, Michigan, USA
| | - Renu A. Kowluru
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, Detroit, Michigan, USA
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14
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El Saftawy EA, Turkistani SA, Alghabban HM, Albadawi EA, Ibrahim BEA, Morsy S, Farag MF, Al Hariry NS, Shash RY, Elkazaz A, Amin NM. Effects of Lactobacilli acidophilus and/or spiramycin as an adjunct in toxoplasmosis infection challenged with diabetes. Food Waterborne Parasitol 2023; 32:e00201. [PMID: 37719029 PMCID: PMC10504688 DOI: 10.1016/j.fawpar.2023.e00201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 06/25/2023] [Accepted: 06/26/2023] [Indexed: 09/19/2023] Open
Abstract
The current study assessed the anti-parasitic impact of probiotics on Toxoplasma gondii infection either solely or challenged with diabetes in Swiss albino mice. The study design encompassed group-A (diabetic), group-B (non-diabetic), and healthy controls (C). Each group was divided into infected-untreated (subgroup-1); infected and spiramycin-treated (subgroup-2); infected and probiotic-treated (subgroup-3); infected and spiramycin+ probiotic-treated (subgroup-4). Diabetic-untreated animals exhibited acute toxoplasmosis and higher cerebral parasite load. Overall, various treatments reduced intestinal pathology, improved body weight, and decreased mortalities; nevertheless, probiotic + spiramycin exhibited significant differences. On day 7 post-infection both PD-1 and IL-17A demonstrated higher scores in the intestine of diabetic-untreated mice compared with non-diabetics and healthy control; whereas, claudin-1 revealed worsening expression. Likewise, on day 104 post-infection cerebral PD-1 and IL-17A showed increased expressions in diabetic animals. Overall, treatment modalities revealed lower scores of PD-1 and IL-17A in non-diabetic subgroups compared with diabetics. Intestinal and cerebral expressions of IL-17A and PD-1 demonstrated positive correlations with cerebral parasite load. In conclusion, toxoplasmosis when challenged with diabetes showed massive pathological features and higher parasite load in the cerebral tissues. Probiotics are a promising adjunct to spiramycin by ameliorating IL-17A and PD-1 in the intestinal and cerebral tissues, improving the intestinal expression of claudin-1, and efficiently reducing the cerebral parasite load.
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Affiliation(s)
- Enas A. El Saftawy
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
- Medical Parasitology Department, Faculty of Medicine, Armed Forces College of Medicine, Cairo, Egypt
| | | | - Hadel M. Alghabban
- Department of Biochemistry and Molecular Medicine, College of Medicine, Taibah University, Saudi Arabia
| | - Emad A. Albadawi
- Department of Anatomy, College of Medicine, Taibah University, Saudi Arabia
| | - Basma EA Ibrahim
- Physiological Sciences Department, Fakeeh College for Medical Sciences, Saudi Arabia
- Faculty of Medicine, Cairo University, Egypt
| | - Suzan Morsy
- Pathological Sciences Department, Fakeeh College for Medical Sciences, Saudi Arabia
- Department of Clinical Pharmacology, Alexandria, Egypt
| | - Mohamed F. Farag
- Medical Physiology Department, Armed Forces College of Medicine, Cairo, Egypt
| | | | - Rania Y. Shash
- Medical Microbiology and Immunology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Aly Elkazaz
- Pediatric Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Noha M. Amin
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
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15
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Su L, Gong X, Fan R, Ni T, Yang F, Zhang X, Li X. Mechanism of action of platinum nanoparticles implying from antioxidant to metabolic programming in light-induced retinal degeneration model. Redox Biol 2023; 65:102836. [PMID: 37541055 PMCID: PMC10412868 DOI: 10.1016/j.redox.2023.102836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 07/24/2023] [Accepted: 07/31/2023] [Indexed: 08/06/2023] Open
Abstract
Photoreceptors (PRs) degeneration is central to visual impairment and loss in most blind retinal diseases, including age-related macular disease (AMD) and diabetic retinopathy (DR). PRs are susceptible to oxidative stress owing to their unique metabolic features. Accumulating evidence has demonstrated that the targeting oxidative stress is a promising treatment strategy for PR degeneration. Herein, we introduced potent antioxidative platinum nanoparticles (Pt NPs) to treat PRs degeneration in this study. The Pt NPs exhibited multi-enzymatic antioxidant activity and protected PRs from H2O2-induced oxidative damage in vitro assays. Based on the same mechanism, the intravitreal injection of Pt NPs significantly reduced cell apoptosis, maintained retinal structure and preserved retinal function in a mouse model of light-induced retinal degeneration (LIRD). Most importantly, the results of RNA sequencing showed that the transcription of antioxidative genes was upregulated, and metabolic reprogramming occurred in the LIRD-retina after treatment with Pt NPs, both of which benefited retinal survival from oxidative damage. The results indicated that Pt NPs were indeed potent therapeutic candidates for PRs degeneration in blind retinal diseases.
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Affiliation(s)
- Lin Su
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Nankai District, Tianjin, 300384, China
| | - Xiaoqun Gong
- School of Life Sciences, Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, PR China.
| | - Ruiyan Fan
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Nankai District, Tianjin, 300384, China
| | - Tianwen Ni
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Nankai District, Tianjin, 300384, China
| | - Fuhua Yang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Nankai District, Tianjin, 300384, China
| | - Xiaomin Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Nankai District, Tianjin, 300384, China.
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Nankai District, Tianjin, 300384, China.
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16
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Haydinger CD, Oliver GF, Ashander LM, Smith JR. Oxidative Stress and Its Regulation in Diabetic Retinopathy. Antioxidants (Basel) 2023; 12:1649. [PMID: 37627644 PMCID: PMC10451779 DOI: 10.3390/antiox12081649] [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: 07/26/2023] [Revised: 08/09/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
Diabetic retinopathy is the retinal disease associated with hyperglycemia in patients who suffer from type 1 or type 2 diabetes. It includes maculopathy, involving the central retina and characterized by ischemia and/or edema, and peripheral retinopathy that progresses to a proliferative stage with neovascularization. Approximately 10% of the global population is estimated to suffer from diabetes, and around one in 5 of these individuals have diabetic retinopathy. One of the major effects of hyperglycemia is oxidative stress, the pathological state in which elevated production of reactive oxygen species damages tissues, cells, and macromolecules. The retina is relatively prone to oxidative stress due to its high metabolic activity. This review provides a summary of the role of oxidative stress in diabetic retinopathy, including a description of the retinal cell players and the molecular mechanisms. It discusses pathological processes, including the formation and effects of advanced glycation end-products, the impact of metabolic memory, and involvements of non-coding RNA. The opportunities for the therapeutic blockade of oxidative stress in diabetic retinopathy are also considered.
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Affiliation(s)
| | | | | | - Justine R. Smith
- College of Medicine and Public Health, Flinders University, Adelaide, SA 5042, Australia; (C.D.H.); (G.F.O.); (L.M.A.)
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17
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Decker NL, Duffy BV, Boughanem GO, Fukuyama H, Castellanos Canales D, Nesper PL, Gill MK, Fawzi AA. Macular Perfusion Deficits on OCT Angiography Correlate with Nonperfusion on Ultrawide-field Fluorescein Angiography in Diabetic Retinopathy. Ophthalmol Retina 2023; 7:692-702. [PMID: 37061036 PMCID: PMC10524214 DOI: 10.1016/j.oret.2023.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 03/16/2023] [Accepted: 04/07/2023] [Indexed: 04/17/2023]
Abstract
OBJECTIVE To evaluate the correlation between nonperfusion parameters on OCT angiography (OCTA) and ultrawide-field fluorescein angiography (UWF-FA) in subjects with diabetes mellitus (DM). DESIGN Prospective, cross-sectional study. SUBJECTS Subjects with DM and a wide range of diabetic retinopathy (DR) severity seen at a tertiary referral center. METHODS We used averaged 3 × 3 mm OCTA scans to measure geometric perfusion deficit (GPD), vessel density, and vessel length density in the full retina, superficial capillary plexuses (SCPs), and deep capillary plexuses (DCPs). Nonperfusion was manually delineated on UWF-FA to quantify central, peripheral, and total retinal nonperfusion (mm2 and % area). MAIN OUTCOME MEASURES Correlation between OCTA parameters and UWF-FA nonperfusion, and accuracy of these OCTA and UWF-FA parameters in detecting clinically referable eyes, using receiver operating characteristic (ROC) curve analysis, sensitivity, specificity, and area under the ROC curve (AUC). RESULTS The study included 67 eyes (12 eyes with no signs of DR, 8 mild, 22 moderate, 14 severe nonproliferative DR, and 11 treatment-naive proliferative DR). There was a fair-to-moderate correlation between either central or total retinal nonperfusion on UWF-FA (mm2) and GPD in the SCP (r = 0.482 and r = 0.464, respectively) and DCP (r = 0.470 and r = 0.456, respectively). Receiver operating characteristic analysis showed the DCP GPD significantly superior to other OCTA parameters at the DCP with the largest overall AUC on OCTA for distinguishing referable DR (0.905). Furthermore, the GPD parameter had the largest AUC in each respective capillary layer compared with other parameters. Overall, the total UWF-FA nonperfusion area showed a comparable AUC (0.907) and performed significantly better than peripheral nonperfusion (P = 0.041). Comparing the AUC values between GPD and UWF-FA nonperfusion parameters showed no significant difference in discerning referable DR. CONCLUSIONS Nonperfusion as quantified on OCTA (3 × 3 mm) correlated with UWF-FA parameters and both were comparable in detecting referable DR. These macular OCTA metrics, particularly DCP GPD, have the potential for gauging the overall ischemic status of the retina, with an important clinical role in identifying eyes with clinically referable DR. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Nicole L Decker
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Brandon V Duffy
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Ghazi O Boughanem
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Hisashi Fukuyama
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | | | - Peter L Nesper
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Manjot K Gill
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
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18
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García-de-Diego AM. C-subfamily ATP binding cassette transporters extrude the calcium fluorescent probe fluo-4 from a cone photoreceptor cell line. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:1727-1740. [PMID: 36805766 DOI: 10.1007/s00210-023-02422-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 02/07/2023] [Indexed: 02/23/2023]
Abstract
Whole transcriptome sequencing has revealed the existence of mRNAs for multiple membrane transporters in photoreceptors. Except for ATP binding cassette (ABC) member A4, involved in the retinoid cycle, an understanding of the function of most transport proteins in photoreceptors is lacking. In this research paper, extrusion of fluo-4, a Ca2+ fluorescent probe, from 661W cells, a cone photoreceptor murine cell line was studied with online fluorometry and immunocytochemistry. Fluo-4 efflux was temperature dependent, required ATP but not extracellular Na+, was not affected by pH in the range 5.4-8.4, and followed saturating kinetics with a Km of nearly 4 μM, suggesting it was effected by ABC type transporters. A panel of antagonists showed an inhibitory profile typical of the C subfamily of ABC transporters. Immunofluorescence staining was positive for ABCC3, ABCC4 and ABCC5. These experimental results are compatible with fluo-4 being extruded from 661W cones by one or a combination of C-type ABC transporters. Examination of physicochemical descriptors related to drug membrane permeability and ABC substrate binding region further suggested efflux of fluo-4 by C-type ABC transporters. Possible functions of this transport mechanism in photoreceptors are discussed.
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Affiliation(s)
- Antonio-Miguel García-de-Diego
- Instituto Teófilo Hernando de I+D del Medicamento, Madrid, Spain.
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.
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19
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Wang X, Wang T, Lam E, Alvarez D, Sun Y. Ocular Vascular Diseases: From Retinal Immune Privilege to Inflammation. Int J Mol Sci 2023; 24:12090. [PMID: 37569464 PMCID: PMC10418793 DOI: 10.3390/ijms241512090] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
The eye is an immune privileged tissue that insulates the visual system from local and systemic immune provocation to preserve homeostatic functions of highly specialized retinal neural cells. If immune privilege is breached, immune stimuli will invade the eye and subsequently trigger acute inflammatory responses. Local resident microglia become active and release numerous immunological factors to protect the integrity of retinal neural cells. Although acute inflammatory responses are necessary to control and eradicate insults to the eye, chronic inflammation can cause retinal tissue damage and cell dysfunction, leading to ocular disease and vision loss. In this review, we summarized features of immune privilege in the retina and the key inflammatory responses, factors, and intracellular pathways activated when retinal immune privilege fails, as well as a highlight of the recent clinical and research advances in ocular immunity and ocular vascular diseases including retinopathy of prematurity, age-related macular degeneration, and diabetic retinopathy.
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Affiliation(s)
- Xudong Wang
- Department of Ophthalmology, Harvard Medical School, Boston Children’s Hospital, Boston, MA 02115, USA; (X.W.)
| | - Tianxi Wang
- Department of Ophthalmology, Harvard Medical School, Boston Children’s Hospital, Boston, MA 02115, USA; (X.W.)
| | - Enton Lam
- Department of Ophthalmology, Harvard Medical School, Boston Children’s Hospital, Boston, MA 02115, USA; (X.W.)
| | - David Alvarez
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Ye Sun
- Department of Ophthalmology, Harvard Medical School, Boston Children’s Hospital, Boston, MA 02115, USA; (X.W.)
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20
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Le D, Dadzie A, Son T, Lim JI, Yao X. COMPARATIVE ANALYSIS OF OCT AND OCT ANGIOGRAPHY CHARACTERISTICS IN EARLY DIABETIC RETINOPATHY. Retina 2023; 43:992-998. [PMID: 36763982 PMCID: PMC10961166 DOI: 10.1097/iae.0000000000003761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
PURPOSE To assess the quantitative characteristics of optical coherence tomography (OCT) and OCT angiography (OCTA) for the objective detection of early diabetic retinopathy (DR). METHODS This was a retrospective and cross-sectional study, which was carried out at a tertiary academic practice with a subspecialty. Twenty control participants, 15 people with diabetics without retinopathy (NoDR), and 22 people with mild nonproliferative diabetic retinopathy (NPDR) were included in this study. Quantitative OCT characteristics were derived from the photoreceptor hyperreflective bands, i.e., inner segment ellipsoid (ISe) and retinal pigment epithelium (RPE). OCTA characteristics, including vessel diameter index (VDI), vessel perimeter index (VPI), and vessel skeleton density (VSD), were evaluated. RESULTS Quantitative OCT analysis indicated that the ISe intensity was significantly trending downward with DR advancement. Comparative OCTA revealed VDI, VPI, and VSD as the most sensitive characteristics of DR. Correlation analysis of OCT and OCTA characteristics revealed weak variable correlation between the two imaging modalities. CONCLUSION Quantitative OCT and OCTA analyses revealed photoreceptor and vascular distortions in early DR. Comparative analysis revealed that the OCT intensity ratio, ISe/RPE, has the best sensitivity for early DR detection. Weak variable correlation of the OCT and OCTA characteristics suggests that OCT and OCTA are providing supplementary information for DR detection and classification.
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Affiliation(s)
- David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
| | - Albert Dadzie
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
| | - Jennifer I Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL
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21
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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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22
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C. Luu J, Saadane A, Leinonen H, H. Choi E, Gao F, Lewandowski D, Halabi M, L. Sander C, Wu A, Wang JM, Singh R, Gao S, Lessieur EM, Dong Z, Palczewska G, Mullins RF, Peachey NS, Kiser PD, Tabaka M, Kern TS, Palczewski K. Stress resilience-enhancing drugs preserve tissue structure and function in degenerating retina via phosphodiesterase inhibition. Proc Natl Acad Sci U S A 2023; 120:e2221045120. [PMID: 37126699 PMCID: PMC10175720 DOI: 10.1073/pnas.2221045120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 04/02/2023] [Indexed: 05/03/2023] Open
Abstract
Chronic, progressive retinal diseases, such as age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa, arise from genetic and environmental perturbations of cellular and tissue homeostasis. These disruptions accumulate with repeated exposures to stress over time, leading to progressive visual impairment and, in many cases, legal blindness. Despite decades of research, therapeutic options for the millions of patients suffering from these disorders remain severely limited, especially for treating earlier stages of pathogenesis when the opportunity to preserve the retinal structure and visual function is greatest. To address this urgent, unmet medical need, we employed a systems pharmacology platform for therapeutic development. Through integrative single-cell transcriptomics, proteomics, and phosphoproteomics, we identified universal molecular mechanisms across distinct models of age-related and inherited retinal degenerations, characterized by impaired physiological resilience to stress. Here, we report that selective, targeted pharmacological inhibition of cyclic nucleotide phosphodiesterases (PDEs), which serve as critical regulatory nodes that modulate intracellular second messenger signaling pathways, stabilized the transcriptome, proteome, and phosphoproteome through downstream activation of protective mechanisms coupled with synergistic inhibition of degenerative processes. This therapeutic intervention enhanced resilience to acute and chronic forms of stress in the degenerating retina, thus preserving tissue structure and function across various models of age-related and inherited retinal disease. Taken together, these findings exemplify a systems pharmacology approach to drug discovery and development, revealing a new class of therapeutics with potential clinical utility in the treatment or prevention of the most common causes of blindness.
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Affiliation(s)
- Jennings C. Luu
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH44106
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Aicha Saadane
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Henri Leinonen
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
- Department of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio70211, Finland
| | - Elliot H. Choi
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH44106
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Fangyuan Gao
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Dominik Lewandowski
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Maximilian Halabi
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Christopher L. Sander
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH44106
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Arum Wu
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Jacob M. Wang
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH44195
| | - Rupesh Singh
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH44195
| | - Songqi Gao
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH44106
| | - Emma M. Lessieur
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Zhiqian Dong
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Grazyna Palczewska
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Robert F. Mullins
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA52242
| | - Neal S. Peachey
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH44195
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH44106
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH44195
| | - Philip D. Kiser
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
- Department of Physiology & Biophysics, School of Medicine, University of California-Irvine, Irvine, CA92697
- Research Service, VA Long Beach Healthcare System, Long Beach, CA90822
- Department of Clinical Pharmacy Practice, University of California-Irvine, Irvine, CA92697
| | - Marcin Tabaka
- International Centre for Translational Eye Research, Warsaw01224, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw01224, Poland
| | - Timothy S. Kern
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
| | - Krzysztof Palczewski
- Center for Translational Vision Research, Gavin Herbert Eye Institute, Department of Ophthalmology, University of California-Irvine, Irvine, CA92697
- Department of Physiology & Biophysics, School of Medicine, University of California-Irvine, Irvine, CA92697
- International Centre for Translational Eye Research, Warsaw01224, Poland
- Department of Chemistry, University of California-Irvine, Irvine, CA92697
- Department of Molecular Biology and Biochemistry, University of California-Irvine, Irvine, CA92697
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23
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Zhou J, Chen B. Retinal Cell Damage in Diabetic Retinopathy. Cells 2023; 12:cells12091342. [PMID: 37174742 PMCID: PMC10177610 DOI: 10.3390/cells12091342] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/15/2023] Open
Abstract
Diabetic retinopathy (DR), the most common microvascular complication that occurs in diabetes mellitus (DM), is the leading cause of vision loss in working-age adults. The prevalence of diabetic retinopathy is approximately 30% of the diabetic population and untreated DR can eventually cause blindness. For decades, diabetic retinopathy was considered a microvascular complication and clinically staged by its vascular manifestations. In recent years, emerging evidence has shown that diabetic retinopathy causes early neuronal dysfunction and neurodegeneration that may precede vascular pathology and affect retinal neurons as well as glial cells. This knowledge leads to new therapeutic strategies aiming to prevent dysfunction of retinal neurons at the early stage of DR. Early detection and timely treatment to protect retinal neurons are critical to preventing visual loss in DR. This review provides an overview of DR and the structural and functional changes associated with DR, and discusses neuronal degeneration during diabetic retinopathy, the mechanisms underlying retinal neurodegeneration and microvascular complications, and perspectives on current and future clinic therapies.
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Affiliation(s)
- Jing Zhou
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bo Chen
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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24
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Padovani-Claudio DA, Ramos CJ, Capozzi ME, Penn JS. Elucidating glial responses to products of diabetes-associated systemic dyshomeostasis. Prog Retin Eye Res 2023; 94:101151. [PMID: 37028118 PMCID: PMC10683564 DOI: 10.1016/j.preteyeres.2022.101151] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 04/08/2023]
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness in working age adults. DR has non-proliferative stages, characterized in part by retinal neuroinflammation and ischemia, and proliferative stages, characterized by retinal angiogenesis. Several systemic factors, including poor glycemic control, hypertension, and hyperlipidemia, increase the risk of DR progression to vision-threatening stages. Identification of cellular or molecular targets in early DR events could allow more prompt interventions pre-empting DR progression to vision-threatening stages. Glia mediate homeostasis and repair. They contribute to immune surveillance and defense, cytokine and growth factor production and secretion, ion and neurotransmitter balance, neuroprotection, and, potentially, regeneration. Therefore, it is likely that glia orchestrate events throughout the development and progression of retinopathy. Understanding glial responses to products of diabetes-associated systemic dyshomeostasis may reveal novel insights into the pathophysiology of DR and guide the development of novel therapies for this potentially blinding condition. In this article, first, we review normal glial functions and their putative roles in the development of DR. We then describe glial transcriptome alterations in response to systemic circulating factors that are upregulated in patients with diabetes and diabetes-related comorbidities; namely glucose in hyperglycemia, angiotensin II in hypertension, and the free fatty acid palmitic acid in hyperlipidemia. Finally, we discuss potential benefits and challenges associated with studying glia as targets of DR therapeutic interventions. In vitro stimulation of glia with glucose, angiotensin II and palmitic acid suggests that: 1) astrocytes may be more responsive than other glia to these products of systemic dyshomeostasis; 2) the effects of hyperglycemia on glia are likely to be largely osmotic; 3) fatty acid accumulation may compound DR pathophysiology by promoting predominantly proinflammatory and proangiogenic transcriptional alterations of macro and microglia; and 4) cell-targeted therapies may offer safer and more effective avenues for DR treatment as they may circumvent the complication of pleiotropism in retinal cell responses. Although several molecules previously implicated in DR pathophysiology are validated in this review, some less explored molecules emerge as potential therapeutic targets. Whereas much is known regarding glial cell activation, future studies characterizing the role of glia in DR and how their activation is regulated and sustained (independently or as part of retinal cell networks) may help elucidate mechanisms of DR pathogenesis and identify novel drug targets for this blinding disease.
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Affiliation(s)
- Dolly Ann Padovani-Claudio
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, B3321A Medical Center North, 1161 21st Avenue South, Nashville, TN, 37232-0011, USA.
| | - Carla J Ramos
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, AA1324 Medical Center North, 1161 21st Avenue South, Nashville, TN, 37232-0011, USA.
| | - Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University School of Medicine, 300 North Duke Street, Durham, NC, 27701, USA.
| | - John S Penn
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, B3307 Medical Center North, 1161 21st Avenue South, Nashville, TN, 37232-0011, USA.
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25
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Calbiague García V, Cadiz B, Herrera P, Díaz A, Schmachtenberg O. Evaluation of Photobiomodulation and Boldine as Alternative Treatment Options in Two Diabetic Retinopathy Models. Int J Mol Sci 2023; 24:ijms24097918. [PMID: 37175628 PMCID: PMC10178531 DOI: 10.3390/ijms24097918] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/18/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023] Open
Abstract
Diabetic retinopathy causes progressive and irreversible damage to the retina through activation of inflammatory processes, overproduction of oxidative species, and glial reactivity, leading to changes in neuronal function and finally ischemia, edema, and hemorrhages. Current treatments are invasive and mostly applied at advanced stages, stressing the need for alternatives. To this end, we tested two unconventional and potentially complementary non-invasive treatment options: Photobiomodulation, the stimulation with near-infrared light, has shown promising results in ameliorating retinal pathologies and insults in several studies but remains controversial. Boldine, on the other hand, is a potent natural antioxidant and potentially useful to prevent free radical-induced oxidative stress. To establish a baseline, we first evaluated the effects of diabetic conditions on the retina with immunofluorescence, histological, and ultrastructural analysis in two diabetes model systems, obese LepRdb/db mice and organotypic retinal explants, and then tested the potential benefits of photobiomodulation and boldine treatment in vitro on retinal explants subjected to high glucose concentrations, mimicking diabetic conditions. Our results suggest that the principal subcellular structures affected by these conditions were mitochondria in the inner segment of photoreceptors, which displayed morphological changes in both model systems. In retinal explants, lactate metabolism, assayed as an indicator of mitochondrial function, was altered, and decreased photoreceptor viability was observed, presumably as a consequence of increased oxidative-nitrosative stress. The latter was reduced by boldine treatment in vitro, while photobiomodulation improved mitochondrial metabolism but was insufficient to prevent retinal structural damage caused by high glucose. These results warrant further research into alternative and complementary treatment options for diabetic retinopathy.
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Affiliation(s)
- Víctor Calbiague García
- Ph. D. Program in Neuroscience, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Bárbara Cadiz
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Pablo Herrera
- Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Alejandra Díaz
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
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26
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Leng B, Deng L, Tan J, Lee WT, Cao CR, Wang ZP, Huang DJ, Nie XW, Bian JS. Targeting the Na +/K + ATPase DR-region with DR-Ab improves doxorubicin-induced cardiotoxicity. Free Radic Biol Med 2023; 204:38-53. [PMID: 37100355 DOI: 10.1016/j.freeradbiomed.2023.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/04/2023] [Accepted: 04/18/2023] [Indexed: 04/28/2023]
Abstract
Doxorubicin (DOX) is a potent chemotherapeutic drug for various cancers. Yet, the cardiotoxic side effects limit its application in clinical uses, in which ferroptosis serves as a crucial pathological mechanism in DOX-induced cardiotoxicity (DIC). A reduction of Na+/K + ATPase (NKA) activity is closely associated with DIC progression. However, whether abnormal NKA function was involved in DOX-induced cardiotoxicity and ferroptosis remains unknown. Here, we aim to decipher the cellular and molecular mechanisms of dysfunctional NKA in DOX-induced ferroptosis and investigate NKA as a potential therapeutic target for DIC. A decrease activity of NKA further aggravated DOX-triggered cardiac dysfunction and ferroptosis in NKAα1 haploinsufficiency mice. In contrast, antibodies against the DR-region of NKAα-subunit (DR-Ab) attenuated the cardiac dysfunction and ferroptosis induced by DOX. Mechanistically, NKAα1 interacted with SLC7A11 to form a novel protein complex, which was directly implicated in the disease progression of DIC. Furthermore, the therapeutic effect of DR-Ab on DIC was mediated by reducing ferroptosis by promoting the association of NKAα1/SLC7A11 complex and maintaining the stability of SLC7A11 on the cell surface. These results indicate that antibodies targeting the DR-region of NKA may serve as a novel therapeutic strategy to alleviate DOX-induced cardiotoxicity.
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Affiliation(s)
- Bin Leng
- Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore, 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Linquan Street, Suzhou, 215123, Jiangsu, China
| | - Lin Deng
- Department of Pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Jianxin Tan
- Lung Transplant Group, Wuxi People's Hospital Affiliated to Nanjing Medical University, Wuxi, 214023, China
| | - Wei-Thye Lee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Cheng-Rui Cao
- Department of Pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Zi-Ping Wang
- Department of Pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - De-Jian Huang
- Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore, 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Linquan Street, Suzhou, 215123, Jiangsu, China.
| | - Xiao-Wei Nie
- Shenzhen Key Laboratory of Respiratory Diseases, Shenzhen People's Hospital (The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518055, China.
| | - Jin-Song Bian
- Department of Pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China; National University of Singapore (Suzhou) Research Institute, 377 Linquan Street, Suzhou, 215123, Jiangsu, China.
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Polyunsaturated Lipids in the Light-Exposed and Prooxidant Retinal Environment. Antioxidants (Basel) 2023; 12:antiox12030617. [PMID: 36978865 PMCID: PMC10044808 DOI: 10.3390/antiox12030617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
The retina is an oxidative stress-prone tissue due to high content of polyunsaturated lipids, exposure to visible light stimuli in the 400–480 nm range, and high oxygen availability provided by choroidal capillaries to support oxidative metabolism. Indeed, lipids’ peroxidation and their conversion into reactive species promoting inflammation have been reported and connected to retinal degenerations. Here, we review recent evidence showing how retinal polyunsaturated lipids, in addition to oxidative stress and damage, may counteract the inflammatory response triggered by blue light-activated carotenoid derivatives, enabling long-term retina operation despite its prooxidant environment. These two aspects of retinal polyunsaturated lipids require tight control over their synthesis to avoid overcoming their protective actions by an increase in lipid peroxidation due to oxidative stress. We review emerging evidence on different transcriptional control mechanisms operating in retinal cells to modulate polyunsaturated lipid synthesis over the life span, from the immature to the ageing retina. Finally, we discuss the antioxidant role of food nutrients such as xanthophylls and carotenoids that have been shown to empower retinal cells’ antioxidant responses and counteract the adverse impact of prooxidant stimuli on sight.
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28
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Huang H, Saddala MS, Mukwaya A, Mohan RR, Lennikov A. Association of Placental Growth Factor and Angiopoietin in Human Retinal Endothelial Cell-Pericyte co-Cultures and iPSC-Derived Vascular Organoids. Curr Eye Res 2023; 48:297-311. [PMID: 36458540 PMCID: PMC10417885 DOI: 10.1080/02713683.2022.2149808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 11/13/2022] [Accepted: 11/14/2022] [Indexed: 12/05/2022]
Abstract
PURPOSE Placental growth factor (PlGF) and Angiopoietin (Ang)-1 are two proteins that are involved in the regulation of endothelial cell (EC) growth and vasculature formation. In the retina and endothelial cells, pericytes are the major source of both molecules. The purpose of this study is to examine the association of PlGF and Ang-1 with human EC/pericyte co-cultures and iPSC-derived vascular organoids. METHODS In this study, we used co-cultures of human primary retinal endothelial cells (HREC) and primary human retinal pericytes (HRP), western blotting, immunofluorescent analysis, TUNEL staining, LDH-assays, and RNA seq analysis, as well as human-induced pluripotent stem cells (iPSC), derived organoids (VO) to study the association between PlGF and Ang-1. RESULTS Inhibition of PlGF by PlGF neutralizing antibody in HREC-HRP co-cultures resulted in the increased expression of Ang-1 and Tie-2 in a dose-dependent manner. This upregulation was not observed in HREC and HRP monocultures but only in co-cultures suggesting the association of pericytes and endothelial cells. Furthermore, Vascular endothelial growth factor receptor 1 (VEGFR1) inhibition abolished the Ang-1 and Tie-2 upregulation by PlGF inhibition. The pericyte viability in high-glucose conditions was also reduced by VEGFR1 neutralization. Immunofluorescent analysis showed that Ang-1 and Ang-2 were expressed mainly by perivascular cells in the VO. RNA seq analysis of the RNA isolated from VO in high glucose conditions indicated increased PlGF and Ang-2 expressions in the VO. PlGF inhibition increased the expression of Ang-1 and Tie-2 in VO, increasing the pericyte coverage of the VO microvascular network. CONCLUSION Combined, these results suggest PlGF's role in the regulation of Ang-1 and Tie-2 expression through VEGFR1. These findings provide new insights into the neovascularization process in diabetic retinopathy and new targets for potential therapeutic intervention.
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Affiliation(s)
- Hu Huang
- Department of Ophthalmology, University of Missouri School of Medicine, Columbia, MO, USA
| | - Madhu Sudhana Saddala
- Department of Ophthalmology, University of Missouri School of Medicine, Columbia, MO, USA
- Wilmer Bioinformatics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Anthony Mukwaya
- Department of Ophthalmology, Institute for Clinical, and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
- Department of Biochemistry and Molecular Biology, Faculty of Health Sciences, Busitema University, Uganda
| | - Rajiv R. Mohan
- Department of Ophthalmology, University of Missouri School of Medicine, Columbia, MO, USA
| | - Anton Lennikov
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States
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Saadane A, Veenstra AA, Minns MS, Tang J, Du Y, Abubakr Elghazali F, Lessieur EM, Pearlman E, Kern TS. CCR2-positive monocytes contribute to the pathogenesis of early diabetic retinopathy in mice. Diabetologia 2023; 66:590-602. [PMID: 36698021 PMCID: PMC9892100 DOI: 10.1007/s00125-022-05860-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 09/13/2022] [Indexed: 01/27/2023]
Abstract
AIMS/HYPOTHESIS Accumulating evidence suggests that leucocytes play a critical role in diabetes-induced vascular lesions and other abnormalities that characterise the early stages of diabetic retinopathy. However, the role of monocytes has yet to be fully investigated; therefore, we used Ccr2-/- mice to study the role of CCR2+ inflammatory monocytes in the pathogenesis of diabetes-induced degeneration of retinal capillaries. METHODS Experimental diabetes was induced in wild-type and Ccr2-/- mice using streptozotocin. After 2 months, superoxide levels, expression of inflammatory genes, leucostasis, leucocyte- and monocyte-mediated cytotoxicity against retinal endothelial cell death, retinal thickness and visual function were evaluated. Retinal capillary degeneration was determined after 8 months of diabetes. Flow cytometry of peripheral blood for differential expression of CCR2 in monocytes was assessed. RESULTS In nondiabetic mice, CCR2 was highly expressed on monocytes, and Ccr2-/- mice lack CCR2+ monocytes in the peripheral blood. Diabetes-induced retinal superoxide, expression of proinflammatory genes Inos and Icam1, leucostasis and leucocyte-mediated cytotoxicity against retinal endothelial cells were inhibited in diabetic Ccr2-deficient mice and in chimeric mice lacking Ccr2 only from myeloid cells. In order to focus on monocytes, these cells were immuno-isolated after 2 months of diabetes, and they significantly increased monocyte-mediated endothelial cell cytotoxicity ex vivo. Monocytes from Ccr2-deficient mice caused significantly less endothelial cell death. The diabetes-induced retinal capillary degeneration was inhibited in Ccr2-/- mice and in chimeric mice lacking Ccr2 only from myeloid cells. CONCLUSIONS/INTERPRETATION CCR2+ inflammatory monocytes contribute to the pathogenesis of early lesions of diabetic retinopathy.
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Affiliation(s)
- Aicha Saadane
- Department of Ophthalmology, University of California-Irvine, Irvine, CA, USA.
| | | | - Martin S Minns
- Institute for Immunology, University of California-Irvine, Irvine, CA, USA
| | - Jie Tang
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Yunpeng Du
- Department of Ophthalmology, University of California-Irvine, Irvine, CA, USA
| | | | - Emma M Lessieur
- Department of Ophthalmology, University of California-Irvine, Irvine, CA, USA
| | - Eric Pearlman
- Institute for Immunology, University of California-Irvine, Irvine, CA, USA
| | - Timothy S Kern
- Department of Ophthalmology, University of California-Irvine, Irvine, CA, USA
- Veterans Administration Medical Center Research Service, Long Beach, CA, USA
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30
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Towards a New Biomarker for Diabetic Retinopathy: Exploring RBP3 Structure and Retinoids Binding for Functional Imaging of Eyes In Vivo. Int J Mol Sci 2023; 24:ijms24054408. [PMID: 36901838 PMCID: PMC10002987 DOI: 10.3390/ijms24054408] [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: 12/31/2022] [Revised: 02/10/2023] [Accepted: 02/21/2023] [Indexed: 02/25/2023] Open
Abstract
Diabetic retinopathy (DR) is a severe disease with a growing number of afflicted patients, which places a heavy burden on society, both socially and financially. While there are treatments available, they are not always effective and are usually administered when the disease is already at a developed stage with visible clinical manifestation. However, homeostasis at a molecular level is disrupted before visible signs of the disease are evident. Thus, there has been a constant search for effective biomarkers that could signal the onset of DR. There is evidence that early detection and prompt disease control are effective in preventing or slowing DR progression. Here, we review some of the molecular changes that occur before clinical manifestations are observable. As a possible new biomarker, we focus on retinol binding protein 3 (RBP3). We argue that it displays unique features that make it a very good biomarker for non-invasive, early-stage DR detection. Linking chemistry to biological function and focusing on new developments in eye imaging and two-photon technology, we describe a new potential diagnostic tool that would allow rapid and effective quantification of RBP3 in the retina. Moreover, this tool would also be useful in the future to monitor therapeutic effectiveness if levels of RBP3 are elevated by DR treatments.
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Chua SYL, Welsh P, Sun Z, Balaskas K, Warwick A, Steel D, Sivaprasad S, Channa R, Ko T, Sattar N, Khawaja AP, Foster PJ, Patel PJ. Associations Between HbA1c Across the Normal Range, Diagnosed, and Undiagnosed Diabetes and Retinal Layer Thickness in UK Biobank Cohort. Transl Vis Sci Technol 2023; 12:25. [PMID: 36795065 PMCID: PMC9940769 DOI: 10.1167/tvst.12.2.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Purpose The purpose of this study was to investigate the association between glycated hemoglobin (HbA1c) levels and retinal sub-layer thicknesses in people with and without diabetes. Methods We included 41,453 UK Biobank participants aged 40 to 69 years old. Diabetes status was defined by self-report of diagnosis or use of insulin. Participants were categorized into groups: (1) those with HbA1c <48 mmol/mol were subdivided into quintiles according to normal range of HbA1c; (2) those previously diagnosed with diabetes with no evidence of diabetic retinopathy; and (3) undiagnosed diabetes: >48 mmol/mol. Total macular and retinal sub-layer thicknesses were derived from spectral-domain optical coherence tomography (SD-OCT) images. Multivariable linear regression was used to evaluate the associations between diabetes status and retinal layer thickness. Results Compared with participants in the second quintile of the normal HbA1c range, those in the fifth quintile had a thinner photoreceptor layer thickness (-0.33 µm, P = 0.006). Participants with diagnosed diabetes had a thinner macular retinal nerve fiber layer (mRNFL; -0.58 µm, P < 0.001), photoreceptor layer thickness (-0.94 µm, P < 0.001), and total macular thickness (-1.61 µm, P < 0.001), whereas undiagnosed diabetes participants had a reduced photoreceptor layer thickness (-1.22 µm, P = 0.009) and total macular thickness (-2.26 µm, P = 0.005). Compared to participants without diabetes, those with diabetes had a thinner mRNFL (-0.50 µm, P < 0.001), photoreceptor layer thickness (-0.77 µm, P < 0.001), and total macular thickness (-1.36 µm, P < 0.001). Conclusions Participants with higher HbA1c in the normal range had marginally thinner photoreceptor thickness, whereas those with diabetes (including undiagnosed diabetes) had meaningfully thinner retinal sublayer and total macular thickness. Translational Relevance We showed that early retinal neurodegeneration occurs in people whose HbA1c levels are below the current diabetes diagnostic threshold; this might impact the management of pre-diabetes individuals.
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Affiliation(s)
- Sharon Y. L. Chua
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
| | - Paul Welsh
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Zihan Sun
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
| | - Konstantinos Balaskas
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
- School of Biological Sciences, University of Manchester, Manchester, UK
| | - Alasdair Warwick
- UCL Institute of Cardiovascular Science, University College London, London, UK
| | - David Steel
- Sunderland Eye Infirmary, Sunderland, UK
- Bioscience Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Sobha Sivaprasad
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
| | - Roomasa Channa
- Department of Ophthalmology, University of Wisconsin - Madison, Madison, WI, USA
| | - Tony Ko
- Topcon Healthcare Solutions Research & Development, Oakland, NJ, USA
| | - Naveed Sattar
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Anthony P. Khawaja
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
| | - Paul J. Foster
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
| | - Praveen J. Patel
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust & UCL Institute of Ophthalmology, London, UK
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Ong JX, Konopek N, Fukuyama H, Fawzi AA. Deep Capillary Nonperfusion on OCT Angiography Predicts Complications in Eyes with Referable Nonproliferative Diabetic Retinopathy. Ophthalmol Retina 2023; 7:14-23. [PMID: 35803524 PMCID: PMC9813273 DOI: 10.1016/j.oret.2022.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/22/2022] [Accepted: 06/30/2022] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To evaluate the ability of capillary nonperfusion parameters on OCT angiography (OCTA) to predict the development of clinically significant outcomes in eyes with referable nonproliferative diabetic retinopathy (NPDR). DESIGN Prospective longitudinal observational study. SUBJECTS In total, 59 patients (74 eyes) with treatment-naive moderate and severe (referable) NPDR. METHODS Patients were imaged with OCTA at baseline and then followed-up for 1 year. We evaluated 2 OCTA capillary nonperfusion metrics, vessel density (VD) and geometric perfusion deficits (GPDs), in the superficial capillary plexus, middle capillary plexus (MCP), and deep capillary plexus (DCP). We compared the predictive accuracy of baseline OCTA metrics for clinically significant diabetic retinopathy (DR) outcomes at 1 year. MAIN OUTCOME MEASURES Significant clinical outcomes at 1 year, defined as 1 or more of the following-vitreous hemorrhage, center-involving diabetic macular edema, and initiation of treatment with pan-retinal photocoagulation or anti-VEGF injections. RESULTS Overall, 49 patients (61 eyes) returned for the 1-year follow-up. Geometric perfusion deficits and VD in the MCP and DCP correlated with clinically significant outcomes at 1 year (P < 0.001). Eyes with these outcomes had lower VD and higher GPD, indicating worse nonperfusion of the deeper retinal layers than those that remained free from complication. These differences remained significant (P = 0.046 to < 0.001) when OCTA parameters were incorporated into models that also considered sex, baseline corrected visual acuity, and baseline DR severity. Adjusted receiver operating characteristic curve for DCP GPD achieved an area under the curve (AUC) of 0.929, with sensitivity of 89% and specificity of 98%. In a separate analysis focusing on high-risk proliferative diabetic retinopathy outcomes, MCP and DCP GPD and VD remained significantly predictive with comparable AUC and sensitivities to the pooled analysis. CONCLUSIONS Evidence of deep capillary nonperfusion at baseline in eyes with clinically referable NPDR can predict short-term DR complications with high accuracy, suggesting that deep retinal ischemia has an important pathophysiologic role in DR progression. Our results suggest that OCTA may provide additional prognostic benefit to clinical DR staging in eyes with high risk.
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Affiliation(s)
- Janice X Ong
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Nicholas Konopek
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Hisashi Fukuyama
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Department of Ophthalmology, Hyogo College of Medicine, Nishinomiya, Japan
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
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Proinflammatory Cytokines Trigger the Onset of Retinal Abnormalities and Metabolic Dysregulation in a Hyperglycemic Mouse Model. J Ophthalmol 2023; 2023:7893104. [PMID: 36895267 PMCID: PMC9991478 DOI: 10.1155/2023/7893104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/22/2023] [Accepted: 02/03/2023] [Indexed: 03/06/2023] Open
Abstract
Purpose Recent evidence has shown that retinal inflammation is a key player in diabetic retinopathy (DR) pathogenesis. To further understand and validate the metabolic biomarkers of DR, we investigated the effect of intravitreal proinflammatory cytokines on the retinal structure, function, and metabolism in an in vivo hyperglycemic mouse model. Methods C57Bl/6 mice were rendered hyperglycemic within one week of administration of a single high-dose intraperitoneal injection of streptozotocin, while control mice received vehicle injection. After confirming hyperglycemia, the mice received an intravitreal injection of either proinflammatory cytokines (TNF-α and IL-1β) or vehicle. Similarly, control mice received an intravitreal injection of either proinflammatory cytokines or vehicle. The retinal structure was evaluated using fundus imaging and optical coherence tomography, and retinal function was assessed using a focal electroretinogram (ERG), two days after cytokine injection. Retinas were collected for biochemical analysis to determine key metabolite levels and enzymatic activities. Results Hyperglycemic mice intraocularly injected with cytokines developed visible retinal vascular damage and intravitreal and intraretinal hyper-reflective spots two days after the cytokines injection. These mice also developed a significant functional deficit with reduced a-wave and b-wave amplitudes of the ERG at high light intensities compared to control mice. Furthermore, metabolic disruption was evident in these mice, with significantly higher retinal glucose, lactate, ATP, and glutamine levels and a significant reduction in glutamate levels compared with control mice. Minimal or no metabolic changes were observed in hyperglycemic mice without intraocular cytokines or in control mice with intraocular cytokines at 2 days post hyperglycemia. Conclusions Proinflammatory cytokines accelerated the development of vascular damage in the eyes of hyperglycemic mice. Significant changes were observed in retinal structure, function, and metabolic homeostasis. These findings support the idea that with the onset of inflammation in DR, there is a deficit in metabolism. Therefore, early intervention to prevent inflammation-induced retinal changes in diabetic patients may improve the disease outcome.
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Trimethylamine-N-Oxide Promotes High-Glucose-Induced Dysfunction and NLRP3 Inflammasome Activation in Retinal Microvascular Endothelial Cells. J Ophthalmol 2023; 2023:8224752. [PMID: 36895266 PMCID: PMC9991475 DOI: 10.1155/2023/8224752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 02/09/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Introduction Along with blood glucose levels, diabetic retinopathy (DR) development also involves endogenous risk factors, such as trimethylamine-N-oxide (TMAO), a product of intestinal flora metabolic disorder, which exacerbates diabetic microvascular complications. However, the effect of TMAO on retinal cells under high-glucose conditions remains unclear. Therefore, this study examined the effects of TMAO on high-glucose-induced retinal dysfunction in the context of NLRP3 inflammasome activation, which is involved in DR. Materials and Methods TMAO was assessed in the serum and aqueous humor of patients using ELISA. Human retinal microvascular endothelial cells (HRMECs) were treated for 72 h as follows: NG (normal glucose, D-glucose 5.5 mM), NG + TMAO (5 μM), HG (high glucose, D-glucose 30 mM), and HG + TMAO (5 μM). The CCK8 assay was then used to assess cell proliferation; wound healing, cell migration, and tube formation assays were used to verify changes in cell phenotype. ZO-1 expression was determined using immunofluorescence and western blotting. Reactive oxygen species (ROS) formation was assessed using DCFH-DA. NLRP3 inflammasome complex activation was determined using a western blot. Results The serum and aqueous humor from patients with PDR contained higher levels of TMAO compared to patients with nontype 2 diabetes (Control), non-DR (NDR), and non-PDR (NPDR). TMAO showed significant acceleration of high-glucose-induced cell proliferation, wound healing, cell migration, and tube formation. ZO-1 expression decreased remarkably with the combined action of TMAO and a high glucose compared to either treatment alone. TMAO also promoted high-glucose-activated NLRP3 inflammasome complex. Conclusion The combination of TMAO and high-glucose results in increased levels of ROS and NLRP3 inflammasome complex activation in HRMECs, leading to exacerbated retinal dysfunction and barrier failure. Thus, TMAO can accelerate PDR occurrence and development, thus indicating the need for early fundus monitoring in diabetic patients with intestinal flora disorders.
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Titialii-Torres KF, Morris AC. Embryonic hyperglycemia perturbs the development of specific retinal cell types, including photoreceptors. J Cell Sci 2022; 135:jcs259187. [PMID: 34851372 PMCID: PMC8767273 DOI: 10.1242/jcs.259187] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 11/18/2021] [Indexed: 01/12/2023] Open
Abstract
Diabetes is linked to various long-term complications in adults, such as neuropathy, nephropathy and diabetic retinopathy. Diabetes poses additional risks for pregnant women, because glucose passes across the placenta, and excess maternal glucose can result in diabetic embryopathy. While many studies have examined the teratogenic effects of maternal diabetes on fetal heart development, little is known about the consequences of maternal hyperglycemia on the development of the embryonic retina. To address this question, we investigated retinal development in two models of embryonic hyperglycemia in zebrafish. Strikingly, we found that hyperglycemic larvae displayed a significant reduction in photoreceptors and horizontal cells, whereas other retinal neurons were not affected. We also observed reactive gliosis and abnormal optokinetic responses in hyperglycemic larvae. Further analysis revealed delayed retinal cell differentiation in hyperglycemic embryos that coincided with increased reactive oxygen species (ROS). Our results suggest that embryonic hyperglycemia causes abnormal retinal development via altered timing of cell differentiation and ROS production, which is accompanied by visual defects. Further studies using zebrafish models of hyperglycemia will allow us to understand the molecular mechanisms underlying these effects.
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Affiliation(s)
- Kayla F. Titialii-Torres
- Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Ann C. Morris
- Department of Biology, University of Kentucky, Lexington, KY 40506-0225, USA
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Mahmoud ARH, Abdelkawi SA, Ghoneim DF, Hassan AA, Morsy ME. Mitigation of photoreceptors abnormalities after low-level laser therapy and chia seeds supplementation in experimental diabetic retinopathy. Oman J Ophthalmol 2022; 15:347-352. [PMID: 36760936 PMCID: PMC9905903 DOI: 10.4103/ojo.ojo_251_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 04/19/2022] [Accepted: 08/13/2022] [Indexed: 02/11/2023] Open
Abstract
BACKGROUND This study aimed to assess the effect of low-level laser therapy (LLLT) and chia seeds on the mitigation of photoreceptors abnormalities in experimental diabetic retinopathy (DR). MATERIALS AND METHODS A total of 65 female Wistar rats, 5 rats were served as a control group and 60 rats were injected intraperitoneally with one dose of 55 mg/kg of streptozotocin (STZ) to induce DR after 6-8 weeks. The rats were divided into (n = 20 rats each): (a) DR group: did not receive any treatment, (b) DR+ LLLT group was exposed to 670-nm LLLT for 6 weeks (two sessions/week), and (c) DR+ LLLT+ chia seed group, in which rats were exposed to LLLT and administrated with 250 mg/kg/day of chia seeds flour for 2 weeks before STZ injection and continued to the end of the experiment. Blood glucose (BG) levels and retinal histological examination were employed after 1, 2, 4, and 6 weeks. RESULTS The BG level in the DR group and the treated groups were significantly higher (P < 0.001) than in the control group after the four-time periods. Chia seeds group exhibited BG levels less than the DR and the DR+ LLLT groups after 6 weeks (P < 0.01). LLLT improved the degeneration of the photoreceptors after 6 weeks of treatment, while LLLT+ chia seeds supplementation showed early photoreceptors improvement after 2 weeks. CONCLUSION The early improvement in the photoreceptors after LLLT+ chia seed may be attributed to the potent antioxidant properties of chia seeds. Therefore, the combination between LLLT and chia seeds should be employed to protect the retinal photoreceptors against DR.
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Affiliation(s)
- Abdel Rahman Hassan Mahmoud
- Department of Medical Application of Laser, Ophthalmic Unit, National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
| | - Salwa Ahmed Abdelkawi
- Department of Vision Science, Biophysics and Laser Science Unit, Research Institute of Ophthalmology, Giza, Egypt,Address for correspondence: Prof. Salwa Ahmed Abdelkawi, Department of Vision Science, Biophysics and Laser Science Unit, Research Institute of Ophthalmology, Giza, Egypt. E-mail:
| | - Dina Fouad Ghoneim
- Department of Medical Application of Laser, Ophthalmic Unit, National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
| | - Aziza Ahmed Hassan
- Department of Medical Application of Laser, Ophthalmic Unit, National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
| | - Mona Ebrahim Morsy
- Department of Medical Application of Laser, Ophthalmic Unit, National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt
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MicroRNA-150 (miR-150) and Diabetic Retinopathy: Is miR-150 Only a Biomarker or Does It Contribute to Disease Progression? Int J Mol Sci 2022; 23:ijms232012099. [PMID: 36292956 PMCID: PMC9603433 DOI: 10.3390/ijms232012099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 11/18/2022] Open
Abstract
Diabetic retinopathy (DR) is a chronic disease associated with diabetes mellitus and is a leading cause of visual impairment among the working population in the US. Clinically, DR has been diagnosed and treated as a vascular complication, but it adversely impacts both neural retina and retinal vasculature. Degeneration of retinal neurons and microvasculature manifests in the diabetic retina and early stages of DR. Retinal photoreceptors undergo apoptosis shortly after the onset of diabetes, which contributes to the retinal dysfunction and microvascular complications leading to vision impairment. Chronic inflammation is a hallmark of diabetes and a contributor to cell apoptosis, and retinal photoreceptors are a major source of intraocular inflammation that contributes to vascular abnormalities in diabetes. As the levels of microRNAs (miRs) are changed in the plasma and vitreous of diabetic patients, miRs have been suggested as biomarkers to determine the progression of diabetic ocular diseases, including DR. However, few miRs have been thoroughly investigated as contributors to the pathogenesis of DR. Among these miRs, miR-150 is downregulated in diabetic patients and is an endogenous suppressor of inflammation, apoptosis, and pathological angiogenesis. In this review, how miR-150 and its downstream targets contribute to diabetes-associated retinal degeneration and pathological angiogenesis in DR are discussed. Currently, there is no effective treatment to stop or reverse diabetes-caused neural and vascular degeneration in the retina. Understanding the molecular mechanism of the pathogenesis of DR may shed light for the future development of more effective treatments for DR and other diabetes-associated ocular diseases.
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Le D, Son T, Lim JI, Yao X. QUANTITATIVE OPTICAL COHERENCE TOMOGRAPHY REVEALS ROD PHOTORECEPTOR DEGENERATION in EARLY DIABETIC RETINOPATHY. Retina 2022; 42:1442-1449. [PMID: 35316256 PMCID: PMC9329162 DOI: 10.1097/iae.0000000000003473] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE This study is to test the feasibility of optical coherence tomography (OCT) detection of photoreceptor abnormality and to verify that the photoreceptor abnormality is rod predominated in early diabetic retinopathy (DR). METHODS OCT images were acquired from normal eyes, diabetic eyes with no DR, and mild nonproliferative DR (NPDR). Quantitative features, including thickness measurements quantifying band distances and reflectance intensity features among the external limiting membrane, inner segment ellipsoid, interdigitation zone, and retinal pigment epithelium were determined. Comparative OCT analysis of central fovea, parafovea, and perifovea were implemented to verify that the photoreceptor abnormality is rod predominated in early DR. RESULTS Thickness abnormalities between the inner segment ellipsoid and interdigitation zone also showed a decreasing trend among cohorts. Reflectance abnormalities of the external limiting membrane, interdigitation zone, and inner segment ellipsoid were observed between healthy, no DR, and mild NPDR eyes. The normalized inner segment ellipsoid/retinal pigment epithelium intensity ratio revealed a significant decreasing trend in the perifovea, but no detectable difference in central fovea. CONCLUSION Quantitative OCT analysis consistently revealed outer retina, i.e., photoreceptor changes in diabetic patients with no DR and mild NPDR. Comparative analysis of central fovea, parafovea, and perifovea confirmed that the photoreceptor abnormality is rod-predominated in early DR.
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Affiliation(s)
- David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jennifer I. Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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Molins B, Mesquida M, Adan A. Bioengineering approaches for modelling retinal pathologies of the outer blood-retinal barrier. Prog Retin Eye Res 2022:101097. [PMID: 35840488 DOI: 10.1016/j.preteyeres.2022.101097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 05/31/2022] [Accepted: 06/29/2022] [Indexed: 11/18/2022]
Abstract
Alterations of the junctional complex of the outer blood-retinal barrier (oBRB), which is integrated by the close interaction of the retinal pigment epithelium, the Bruch's membrane, and the choriocapillaris, contribute to the loss of neuronal signalling and subsequent vision impairment in several retinal inflammatory disorders such as age-related macular degeneration and diabetic retinopathy. Reductionist approaches into the mechanisms that underlie such diseases have been hindered by the absence of adequate in vitro models using human cells to provide the 3D dynamic architecture that enables expression of the in vivo phenotype of the oBRB. Conventional in vitro cell models are based on 2D monolayer cellular cultures, unable to properly recapitulate the complexity of living systems. The main drawbacks of conventional oBRB models also emerge from the cell sourcing, the lack of an appropriate Bruch's membrane analogue, and the lack of choroidal microvasculature with flow. In the last years, the advent of organ-on-a-chip, bioengineering, and stem cell technologies is providing more advanced 3D models with flow, multicellularity, and external control over microenvironmental properties. By incorporating additional biological complexity, organ-on-a-chip devices can mirror physiologically relevant properties of the native tissue while offering additional set ups to model and study disease. In this review we first examine the current understanding of oBRB biology as a functional unit, highlighting the coordinated contribution of the different components to barrier function in health and disease. Then we describe recent advances in the use of pluripotent stem cells-derived retinal cells, Bruch's membrane analogues, and co-culture techniques to recapitulate the oBRB. We finally discuss current advances and challenges of oBRB-on-a-chip technologies for disease modelling.
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Affiliation(s)
- Blanca Molins
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain.
| | - Marina Mesquida
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain; Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Alfredo Adan
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain; Instituto Clínic de Oftalmología, Hospital Clínic Barcelona, C/ Sabino de Arana 1, 08028, Barcelona, Spain
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Cheung CMG, Fawzi A, Teo KY, Fukuyama H, Sen S, Tsai WS, Sivaprasad S. Diabetic macular ischaemia- a new therapeutic target? Prog Retin Eye Res 2022; 89:101033. [PMID: 34902545 DOI: 10.1016/j.preteyeres.2021.101033] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/25/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022]
Abstract
Diabetic macular ischaemia (DMI) is traditionally defined and graded based on the angiographic evidence of an enlarged and irregular foveal avascular zone. However, these anatomical changes are not surrogate markers for visual impairment. We postulate that there are vascular phenotypes of DMI based on the relative perfusion deficits of various retinal capillary plexuses and choriocapillaris. This review highlights several mechanistic pathways, including the role of hypoxia and the complex relation between neurons, glia, and microvasculature. The current animal models are reviewed, with shortcomings noted. Therefore, utilising the advancing technology of optical coherence tomography angiography (OCTA) to identify the reversible DMI phenotypes may be the key to successful therapeutic interventions for DMI. However, there is a need to standardise the nomenclature of OCTA perfusion status. Visual acuity is not an ideal endpoint for DMI clinical trials. New trial endpoints that represent disease progression need to be developed before irreversible vision loss in patients with DMI. Natural history studies are required to determine the course of each vascular and neuronal parameter to define the DMI phenotypes. These DMI phenotypes may also partly explain the development and recurrence of diabetic macular oedema. It is also currently unclear where and how DMI fits into the diabetic retinopathy severity scales, further highlighting the need to better define the progression of diabetic retinopathy and DMI based on both multimodal imaging and visual function. Finally, we discuss a complete set of proposed therapeutic pathways for DMI, including cell-based therapies that may provide restorative potential.
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Affiliation(s)
- Chui Ming Gemmy Cheung
- Singapore Eye Research Institution, Singapore National Eye Centre, Singapore; Duke-NUS Medical School, National University of Singapore, Singapore
| | | | - Kelvin Yc Teo
- Singapore Eye Research Institution, Singapore National Eye Centre, Singapore
| | | | | | - Wei-Shan Tsai
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom
| | - Sobha Sivaprasad
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom.
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Cung T, Wang H, Hartnett ME. The Effects of Nicotinamide Adenine Dinucleotide Phosphate (NADPH) Oxidase and Erythropoietin, and Their Interactions in Angiogenesis: Implications in Retinopathy of Prematurity. Cells 2022; 11:cells11121951. [PMID: 35741081 PMCID: PMC9222209 DOI: 10.3390/cells11121951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/07/2022] [Accepted: 06/10/2022] [Indexed: 01/27/2023] Open
Abstract
Retinopathy of prematurity (ROP) is a leading cause of vision impairment and blindness in premature infants. Oxidative stress is implicated in its pathophysiology. NADPH oxidase (NOX), a major enzyme responsible for reactive oxygen species (ROS) generation in endothelial cells, has been studied for its involvement in physiologic and pathologic angiogenesis. Erythropoietin (EPO) has gained interest recently due to its tissue protective and angiogenic effects, and it has been shown to act as an antioxidant. In this review, we summarize studies performed over the last five years regarding the role of various NOXs in physiologic and pathologic angiogenesis. We also discuss the effect of EPO in tissue and vasoprotection, and the intersection of EPO and NOX-mediated oxidative stress in angiogenesis and the pathophysiology of ROP.
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Diabetes Aggravates Photoreceptor Pathologies in a Mouse Model for Ocular Vitamin A Deficiency. Antioxidants (Basel) 2022; 11:antiox11061142. [PMID: 35740038 PMCID: PMC9219864 DOI: 10.3390/antiox11061142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/03/2022] [Accepted: 06/08/2022] [Indexed: 02/06/2023] Open
Abstract
Emerging evidence indicates that diabetes disturbs photoreceptor function and vitamin A homeostasis. However, the biochemical basis of this phenotype is not well established. Here, we compared the effects of streptozotocin-induced diabetes in wild-type (WT) mice and Stra6-/- mice, a mouse model for ocular vitamin A deficiency. After 8 weeks, diabetes increased serum retinyl esters in mice of both genotypes. The eyes of diabetic WT mice displayed increased superoxide levels but no changes in retinoid concentrations. Diabetic Stra6-/- mice showed increased ocular retinoid concentrations, but superoxide levels remained unchanged. After 30 weeks, significant alterations in liver and fat retinoid concentrations were observed in diabetic mice. Diabetic WT mice exhibited a decreased expression of visual cycle proteins and a thinning of the photoreceptor layer. Stra6-/- mice displayed significantly lower ocular retinoid concentration than WT mice. An altered retinal morphology and a reduced expression of photoreceptor marker genes paralleled these biochemical changes and were more pronounced in the diabetic animals. Taken together, we observed that diabetes altered vitamin A homeostasis in several organ systems and aggravated photoreceptor pathologies in the vitamin-deficient mouse eyes.
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The inhibitory effects of Dulaglutide on cellular senescence against high glucose in human retinal endothelial cells. Hum Cell 2022; 35:995-1004. [PMID: 35583801 DOI: 10.1007/s13577-022-00703-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 04/13/2022] [Indexed: 01/25/2023]
Abstract
Diabetic nephropathy is one of the most important chronic microvascular complications of diabetes, and its main feature is diabetic glomerulosclerosis. Endothelial sirtuin 1 (SIRT1) expression is related to aging, and reducing SIRT1 expression promotes endothelial cell aging. Plasminogen activator inhibitor-1 (PAI-1) can be synthesized in a variety of cells, such as endothelial cells. Dulaglutide is a glucagon-like peptide-1 (GLP-1) drug, and it can activate the GLP-1 receptor and promote the conversion of intracellular adenosine triphosphate to adenylate cyclase, thereby activating phosphokinase A, and regulating blood glucose levels effectively in the body. We analyzed the effects of Dulaglutide on inhibiting cell senescence by studying the effects of its different concentrations on telomerase activity and senescence-related gene expression. Our results suggest that Dulaglutide can alleviate high-glucose-induced oxidative stress in human retinal endothelial cells by restoring the expressions of SIRT1 and endothelial nitric oxide synthase (eNOS), thereby inhibiting the expression of PAI-1, and restoring telomerase activity. This suggests that the activity of retinal endothelial cells can be controlled by regulating the expression of SIRT1, so as to achieve the effect of treating diabetic retinopathy.
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Calpains as mechanistic drivers and therapeutic targets for ocular disease. Trends Mol Med 2022; 28:644-661. [PMID: 35641420 PMCID: PMC9345745 DOI: 10.1016/j.molmed.2022.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/03/2022] [Accepted: 05/09/2022] [Indexed: 11/18/2022]
Abstract
Ophthalmic neurodegenerative diseases encompass a wide array of molecular pathologies unified by calpain dysregulation. Calpains are calcium-dependent proteases that perpetuate cellular death and inflammation when hyperactivated. Calpain inhibition trials in other organs have faced pharmacological challenges, but the eye offers many advantages for the development and testing of targeted molecular therapeutics, including small molecules, peptides, engineered proteins, drug implants, and gene-based therapies. This review highlights structural mechanisms underlying calpain activation, distinct cellular expression patterns, and in vivo models that link calpain hyperactivity to human retinal and developmental disease. Optimizing therapeutic approaches for calpain-mediated eye diseases can help accelerate clinically feasible strategies for treating calpain dysregulation in other diseased tissues.
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Zhou H, Xu Q, Li H, Hu Y, Kuang H. Proteomics identifies new potential therapeutic targets of diabetic retinopathy. Bioengineered 2022; 13:9916-9927. [PMID: 35412937 PMCID: PMC9161892 DOI: 10.1080/21655979.2022.2062185] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Retinal pigment epithelium (RPE) is an important component of the outer blood-retinal barrier and plays a critical role in maintaining retinal homeostasis. Alterations in RPE can be detected during the early stages of diabetic retinopathy (DR). However, the molecular mechanisms underlying these early changes remain unclear. We investigated the molecular changes induced in the RPE by high glucose concentrations by constructing a high glucose-induced ARPE-19 cell injury model simulating the DR environment in vitro. Proteomic analysis was conducted to measure differences in protein expression between cells treated with normal (5 mM) and high (25 mM) glucose concentrations, and bioinformatics techniques were used to analyze the mechanism of action. The results of the proteomic analyses were validated using western blotting. High glucose levels inhibited the proliferation of ARPE-19 cells. We identified 88 upregulated proteins and 114 downregulated proteins. Six of these proteins were selected for further validation. Changes in the proteome mainly affected the lysosome and cell cycle pathways. Proteomic differences between ARPE-19 cells treated with normal and high glucose concentrations indicate that damage to the RPE in DR may be caused by specific mechanisms. Our study verified protein changes in ARPE-19 cells in a high-glucose environment and may provide new strategies for understanding the molecular mechanisms underlying DR.
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Affiliation(s)
- Huanran Zhou
- Department of Endocrinology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui Province, China.,Department of Endocrinology, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Qian Xu
- Department of Endocrinology, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Hongxue Li
- Department of Endocrinology, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Yuxin Hu
- Department of Endocrinology, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Hongyu Kuang
- Department of Endocrinology, the First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
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Carpi-Santos R, de Melo Reis RA, Gomes FCA, Calaza KC. Contribution of Müller Cells in the Diabetic Retinopathy Development: Focus on Oxidative Stress and Inflammation. Antioxidants (Basel) 2022; 11:antiox11040617. [PMID: 35453302 PMCID: PMC9027671 DOI: 10.3390/antiox11040617] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/01/2022] [Accepted: 03/15/2022] [Indexed: 01/27/2023] Open
Abstract
Diabetic retinopathy is a neurovascular complication of diabetes and the main cause of vision loss in adults. Glial cells have a key role in maintenance of central nervous system homeostasis. In the retina, the predominant element is the Müller cell, a specialized cell with radial morphology that spans all retinal layers and influences the function of the entire retinal circuitry. Müller cells provide metabolic support, regulation of extracellular composition, synaptic activity control, structural organization of the blood–retina barrier, antioxidant activity, and trophic support, among other roles. Therefore, impairments of Müller actions lead to retinal malfunctions. Accordingly, increasing evidence indicates that Müller cells are affected in diabetic retinopathy and may contribute to the severity of the disease. Here, we will survey recently described alterations in Müller cell functions and cellular events that contribute to diabetic retinopathy, especially related to oxidative stress and inflammation. This review sheds light on Müller cells as potential therapeutic targets of this disease.
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Affiliation(s)
- Raul Carpi-Santos
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (R.C.-S.); (F.C.A.G.)
| | - Ricardo A. de Melo Reis
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil;
| | - Flávia Carvalho Alcantara Gomes
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (R.C.-S.); (F.C.A.G.)
| | - Karin C. Calaza
- Instituto de Biologia, Departamento de Neurobiologia, Universidade Federal Fluminense, Niteroi 24210-201, RJ, Brazil
- Correspondence:
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Santos FM, Mesquita J, Castro-de-Sousa JP, Ciordia S, Paradela A, Tomaz CT. Vitreous Humor Proteome: Targeting Oxidative Stress, Inflammation, and Neurodegeneration in Vitreoretinal Diseases. Antioxidants (Basel) 2022; 11:antiox11030505. [PMID: 35326156 PMCID: PMC8944522 DOI: 10.3390/antiox11030505] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 12/12/2022] Open
Abstract
Oxidative stress is defined as an unbalance between pro-oxidants and antioxidants, as evidenced by an increase in reactive oxygen and reactive nitrogen species production over time. It is important in the pathophysiology of retinal disorders such as diabetic retinopathy, age-related macular degeneration, retinal detachment, and proliferative vitreoretinopathy, which are the focus of this article. Although the human organism’s defense mechanisms correct autoxidation caused by endogenous or exogenous factors, this may be insufficient, causing an imbalance in favor of excessive ROS production or a weakening of the endogenous antioxidant system, resulting in molecular and cellular damage. Furthermore, modern lifestyles and environmental factors contribute to increased chemical exposure and stress induction, resulting in oxidative stress. In this review, we discuss the current information about oxidative stress and the vitreous proteome with a special focus on vitreoretinal diseases. Additionally, we explore therapies using antioxidants in an attempt to rescue the body from oxidation, restore balance, and maximize healthy body function, as well as new investigational therapies that have shown significant therapeutic potential in preclinical studies and clinical trial outcomes, along with their goals and strategic approaches to combat oxidative stress.
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Affiliation(s)
- Fátima Milhano Santos
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
- Unidad de Proteomica, Centro Nacional de Biotecnología, CSIC, Campus de Cantoblanco, 28049 Madrid, Spain; (S.C.); (A.P.)
- C4-UBI, Cloud Computing Competence Centre, University of Beira Interior, 6200-501 Covilhã, Portugal
- Correspondence: (F.M.S.); (C.T.T.); Tel.: +351-275-319-700 (C.T.T.)
| | - Joana Mesquita
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
| | - João Paulo Castro-de-Sousa
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
- Department of Ophthalmology, Centro Hospitalar de Leiria, 2410-197 Leiria, Portugal
| | - Sergio Ciordia
- Unidad de Proteomica, Centro Nacional de Biotecnología, CSIC, Campus de Cantoblanco, 28049 Madrid, Spain; (S.C.); (A.P.)
| | - Alberto Paradela
- Unidad de Proteomica, Centro Nacional de Biotecnología, CSIC, Campus de Cantoblanco, 28049 Madrid, Spain; (S.C.); (A.P.)
| | - Cândida Teixeira Tomaz
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
- C4-UBI, Cloud Computing Competence Centre, University of Beira Interior, 6200-501 Covilhã, Portugal
- Chemistry Department, Faculty of Sciences, University of Beira Interior, 6201-001 Covilhã, Portugal
- Correspondence: (F.M.S.); (C.T.T.); Tel.: +351-275-319-700 (C.T.T.)
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Simó R, Simó-Servat O, Bogdanov P, Hernández C. Diabetic Retinopathy: Role of Neurodegeneration and Therapeutic Perspectives. Asia Pac J Ophthalmol (Phila) 2022; 11:160-167. [PMID: 35533335 DOI: 10.1097/apo.0000000000000510] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
ABSTRACT Retinal neurodegeneration plays a significant role in the pathogenesis of diabetic retinopathy, the leading cause of preventable blindness. The hallmarks of diabetes-induced neurodegeneration are neural cell apoptosis and glial activation, which seem even before vascular lesions can be detected by ophthalmoscopic examination. The molecular mediators of retinal neurodegeneration include proinflamma- tory cytokines, oxidative stress, mitochondrial dysfunction, and the molecular pathways closely related to chronic hyperglycemia. In this article, an overview of the main components of neurodegeneration, its key underlying mechanisms, and the more useful experimental models for investigative purposes will be given. In addition, the results of most relevant treatments based on neuroprotection, and the research gaps that should be filled will be critically reviewed.
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Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
| | - Olga Simó-Servat
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
| | - Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- Centro de Investigación Biomedica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
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Ong JX, Fawzi AA. Perspectives on diabetic retinopathy from advanced retinal vascular imaging. Eye (Lond) 2022; 36:319-327. [PMID: 34987198 PMCID: PMC8807653 DOI: 10.1038/s41433-021-01825-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/05/2021] [Accepted: 10/14/2021] [Indexed: 02/03/2023] Open
Abstract
Diabetic retinopathy (DR) is a microvascular complication of diabetes and the most common cause of acquired vision loss in adults worldwide. DR is associated with long-term chronic hyperglycaemia and its detrimental effects on the neurovascular structure and function of the retina. Direct imaging of the retinal vasculature and staging of DR has been traditionally based on fundoscopy and fluorescein angiography, which provide only 2D views of the retina, and in the case of fluorescein angiography, requires an invasive dye injection. In contrast, advanced retinal imaging modalities like optical coherence tomography angiography (OCTA) and adaptive optics (AO) are non-invasive and provide depth-resolved, 3D visualization of retinal vessel structure as well as blood flow. Recent studies utilizing these imaging techniques have shown promise in evaluating quantitative vascular parameters that correlate tightly to clinical DR staging, elucidating functional changes in early diabetes, and monitoring DR treatment response. In this article, we discuss and synthesize the results of advanced retinal imaging studies in DR and their implications for our clinical and pathophysiologic understanding of the disease. Based on the recent literature, we also propose a model to describe the differential changes in vascular structure and flow that have been described on advanced retinal imaging as DR progresses. Future studies of these imaging modalities in larger and more diverse populations, as well as corroboration with histological and functional studies, will be important to further our understanding of DR.
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Affiliation(s)
- Janice X Ong
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Amani A Fawzi
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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50
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Mathew D, Luo Q, Bhatwadekar AD. Circadian Rhythm Disruption Results in Visual Dysfunction. FASEB Bioadv 2022; 4:364-378. [PMID: 35664832 PMCID: PMC9164246 DOI: 10.1096/fba.2021-00125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 01/19/2022] [Accepted: 01/26/2022] [Indexed: 11/14/2022] Open
Abstract
Artificial light has been increasingly in use for the past 70 years. The aberrant light exposure and round‐the‐clock nature of work lead to the disruption of biological clock. Circadian rhythm disruption (CRD) contributes to multiple metabolic and neurodegenerative diseases. However, its effect on vision is not understood. Moreover, the mammalian retina possesses an autonomous clock that could be reset with light exposure. We evaluated the impact of CRD on retinal morphology, physiology, and vision after housing mice in a disruption inducing shorter light/dark cycle (L10:D10). Interestingly, the mice under L10:D10 exhibited three different entrainment behaviors; “entrained,” “free‐running,” and “zigzagging.” These behavior groups under CRD exhibited reduced visual acuity, retinal thinning, and a decrease in the number of photoreceptors. Intriguingly, the electroretinogram response was decreased only in the mice exhibiting “entrained” behavior. The retinal proteome showed distinct changes with each entrainment behavior, and there was a dysfunctional oxidative stress‐antioxidant mechanism. These results demonstrate that CRD alters entrainment behavior and leads to visual dysfunction in mice. Our studies uniquely show the effect of entrainment behavior on retinal physiology. Our data have broader implications in understanding and mitigating the impact of CRD on vision and its potential role in the etiology of retinal diseases.
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Affiliation(s)
- Deepa Mathew
- Department of Ophthalmology Indiana University Indianapolis IN USA
| | - Qianyi Luo
- Department of Ophthalmology Indiana University Indianapolis IN USA
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