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Simó R, Hernández C. Topical ocular administration of DPP-IV inhibitors: a new approach for treating diabetes-induced retinal neurodegeneration. Neural Regen Res 2024; 19:713-714. [PMID: 37843198 PMCID: PMC10664137 DOI: 10.4103/1673-5374.353492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/05/2022] [Accepted: 07/04/2023] [Indexed: 11/19/2022] Open
Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR); Department of Medicine, Autonomous University of Barcelona, Barcelona, Spain; Centro de Investigación Bioméica 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); Department of Medicine, Autonomous University of Barcelona, Barcelona, Spain; Centro de Investigación Bioméica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), Madrid, Spain
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2
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Cubillos S, Kazlauskas A. Manifestation of Pathology in Animal Models of Diabetic Retinopathy Is Delayed from the Onset of Diabetes. Int J Mol Sci 2024; 25:1610. [PMID: 38338889 PMCID: PMC10855501 DOI: 10.3390/ijms25031610] [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: 12/18/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Diabetic retinopathy (DR) is the most common complication that develops in patients with diabetes mellitus (DM) and is the leading cause of blindness worldwide. Fortunately, sight-threatening forms of DR develop only after several decades of DM. This well-documented resilience to DR suggests that the retina is capable of protecting itself from DM-related damage and also that accumulation of such damage occurs only after deterioration of this resilience. Despite the enormous translational significance of this phenomenon, very little is known regarding the nature of resilience to DR. Rodent models of DR have been used extensively to study the nature of the DM-induced damage, i.e., cardinal features of DR. Many of these same animal models can be used to investigate resilience because DR is delayed from the onset of DM by several weeks or months. The purpose of this review is to provide a comprehensive overview of the literature describing the use of rodent models of DR in type-1 and type-2 diabetic animals, which most clearly document the delay between the onset of DM and the appearance of DR. These readily available experimental settings can be used to advance our current understanding of resilience to DR and thereby identify biomarkers and targets for novel, prevention-based approaches to manage patients at risk for developing DR.
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Affiliation(s)
- Samuel Cubillos
- University of Illinois at Chicago, College of Medicine, Chicago, IL 60612, USA;
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3
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Szeto SK, Lai TY, Vujosevic S, Sun JK, Sadda SR, Tan G, Sivaprasad S, Wong TY, Cheung CY. Optical coherence tomography in the management of diabetic macular oedema. Prog Retin Eye Res 2024; 98:101220. [PMID: 37944588 DOI: 10.1016/j.preteyeres.2023.101220] [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: 06/28/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 11/12/2023]
Abstract
Diabetic macular oedema (DMO) is the major cause of visual impairment in people with diabetes. Optical coherence tomography (OCT) is now the most widely used modality to assess presence and severity of DMO. DMO is currently broadly classified based on the involvement to the central 1 mm of the macula into non-centre or centre involved DMO (CI-DMO) and DMO can occur with or without visual acuity (VA) loss. This classification forms the basis of management strategies of DMO. Despite years of research on quantitative and qualitative DMO related features assessed by OCT, these do not fully inform physicians of the prognosis and severity of DMO relative to visual function. Having said that, recent research on novel OCT biomarkers development and re-defined classification of DMO show better correlation with visual function and treatment response. This review summarises the current evidence of the association of OCT biomarkers in DMO management and its potential clinical importance in predicting VA and anatomical treatment response. The review also discusses some future directions in this field, such as the use of artificial intelligence to quantify and monitor OCT biomarkers and retinal fluid and identify phenotypes of DMO, and the need for standardisation and classification of OCT biomarkers to use in future clinical trials and clinical practice settings as prognostic markers and secondary treatment outcome measures in the management of DMO.
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Affiliation(s)
- Simon Kh Szeto
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Timothy Yy Lai
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Stela Vujosevic
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy; Eye Clinic, IRCCS MultiMedica, Milan, Italy
| | - Jennifer K Sun
- Beetham Eye Institute, Harvard Medical School, Boston, USA
| | - SriniVas R Sadda
- Doheny Eye Institute, University of California Los Angeles, Los Angeles, USA
| | - Gavin Tan
- Singapore Eye Research Institute, SingHealth Duke-National University of Singapore, Singapore
| | - Sobha Sivaprasad
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Tien Y Wong
- Tsinghua Medicine, Tsinghua University, Beijing, China; Singapore Eye Research Institute, Singapore
| | - Carol Y Cheung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China.
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4
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Li J, Chen K, Li X, Zhang X, Zhang L, Yang Q, Xia Y, Xie C, Wang X, Tong J, Shen Y. Mechanistic insights into the alterations and regulation of the AKT signaling pathway in diabetic retinopathy. Cell Death Discov 2023; 9:418. [PMID: 37978169 PMCID: PMC10656479 DOI: 10.1038/s41420-023-01717-2] [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: 08/20/2023] [Revised: 11/05/2023] [Accepted: 11/08/2023] [Indexed: 11/19/2023] Open
Abstract
In the early stages of diabetic retinopathy (DR), diabetes-related hyperglycemia directly inhibits the AKT signaling pathway by increasing oxidative stress or inhibiting growth factor expression, which leads to retinal cell apoptosis, nerve proliferation and fundus microvascular disease. However, due to compensatory vascular hyperplasia in the late stage of DR, the vascular endothelial growth factor (VEGF)/phosphatidylinositol 3 kinase (PI3K)/AKT cascade is activated, resulting in opposite levels of AKT regulation compared with the early stage. Studies have shown that many factors, including insulin, insulin-like growth factor-1 (IGF-1), VEGF and others, can regulate the AKT pathway. Disruption of the insulin pathway decreases AKT activation. IGF-1 downregulation decreases the activation of AKT in DR, which abrogates the neuroprotective effect, upregulates VEGF expression and thus induces neovascularization. Although inhibiting VEGF is the main treatment for neovascularization in DR, excessive inhibition may lead to apoptosis in inner retinal neurons. AKT pathway substrates, including mammalian target of rapamycin (mTOR), forkhead box O (FOXO), glycogen synthase kinase-3 (GSK-3)/nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor kappa-B (NF-κB), are a research focus. mTOR inhibitors can delay or prevent retinal microangiopathy, whereas low mTOR activity can decrease retinal protein synthesis. Inactivated AKT fails to inhibit FOXO and thus causes apoptosis. The GSK-3/Nrf2 cascade regulates oxidation and inflammation in DR. NF-κB is activated in diabetic retinas and is involved in inflammation and apoptosis. Many pathways or vital activities, such as the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and mitogen-activated protein kinase (MAPK) signaling pathways, interact with the AKT pathway to influence DR development. Numerous regulatory methods can simultaneously impact the AKT pathway and other pathways, and it is essential to consider both the connections and interactions between these pathways. In this review, we summarize changes in the AKT signaling pathway in DR and targeted drugs based on these potential sites.
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Affiliation(s)
- Jiayuan Li
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
- Department of Cardiology, The Second Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Kuangqi Chen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiang Li
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xuhong Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Liyue Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Qianjie Yang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Yutong Xia
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Chen Xie
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiawei Wang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianping Tong
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China.
| | - Ye Shen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China.
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5
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Zhang J, Ma X, Liu F, Zhang D, Ling J, Zhu Z, Chen Y, Yang P, Yang Y, Liu X, Zhang J, Liu J, Yu P. Role of NLRP3 inflammasome in diabetes and COVID-19 role of NLRP3 inflammasome in the pathogenesis and treatment of COVID-19 and diabetes NLRP3 inflammasome in diabetes and COVID-19 intervention. Front Immunol 2023; 14:1203389. [PMID: 37868953 PMCID: PMC10585100 DOI: 10.3389/fimmu.2023.1203389] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 09/18/2023] [Indexed: 10/24/2023] Open
Abstract
2019 Coronavirus Disease (COVID-19) is a global pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). A "cytokine storm", i.e., elevated levels of pro-inflammatory cytokines in the bloodstream, has been observed in severe cases of COVID-19. Normally, activation of the nucleotide-binding oligomeric domain-like receptor containing pyrin domain 3 (NLRP3) inflammatory vesicles induces cytokine production as an inflammatory response to viral infection. Recent studies have found an increased severity of necrobiosis infection in diabetic patients, and data from several countries have shown higher morbidity and mortality of necrobiosis in people with chronic metabolic diseases such as diabetes. In addition, COVID-19 may also predispose infected individuals to hyperglycemia. Therefore, in this review, we explore the potential relationship between NLRP3 inflammatory vesicles in diabetes and COVID-19. In contrast, we review the cellular/molecular mechanisms by which SARS-CoV-2 infection activates NLRP3 inflammatory vesicles. Finally, we propose several promising targeted NLRP3 inflammatory vesicle inhibitors with the aim of providing a basis for NLRP3-targeted drugs in diabetes combined with noncoronary pneumonia in the clinical management of patients.
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Affiliation(s)
- Jiayu Zhang
- Department of Metabolism and Endocrinology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Huankui Academy, Nanchang University, Jiangxi, Nanchang, China
| | - Xuejing Ma
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Fuwei Liu
- Department of Cardiology, The Affiliated Ganzhou Hospital of Nanchang University, Jiangxi, China
| | - Deju Zhang
- Food and Nutritional Sciences, School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Jitao Ling
- Department of Metabolism and Endocrinology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Zicheng Zhu
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yixuan Chen
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Pingping Yang
- Department of Metabolism and Endocrinology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yanlin Yang
- Department of Metabolism and Endocrinology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiao Liu
- Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jing Zhang
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jianping Liu
- Department of Metabolism and Endocrinology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Peng Yu
- Department of Metabolism and Endocrinology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
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Wang YC, Wang L, Shao YQ, Weng SJ, Yang XL, Zhong YM. Exendin-4 promotes retinal ganglion cell survival and function by inhibiting calcium channels in experimental diabetes. iScience 2023; 26:107680. [PMID: 37680468 PMCID: PMC10481356 DOI: 10.1016/j.isci.2023.107680] [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: 04/04/2023] [Revised: 06/21/2023] [Accepted: 08/14/2023] [Indexed: 09/09/2023] Open
Abstract
Progressive damage of retinal ganglion cells (RGCs) is observed in early diabetic retinopathy. Intracellular Ca2+ overload mediated by Ca2+ influx through voltage-gated Ca2+ channels (VGCCs) is involved in neurodegeneration, whereas glucagon-like peptide-1 (GLP-1) provides neuroprotection. However, whether GLP-1 plays a neuroprotective role in diabetic retinas by modulating VGCCs remains unknown. We found that eye drops of exendin-4, a long-acting GLP-1 receptor (GLP-1R) agonist, prevented the increase of L-type Ca2+ current (ILCa) densities of RGCs induced by 4-week hyperglycemia and promoted RGC survival by suppressing L-type VGCC (L-VGCC) activity in streptozotocin-induced diabetic rats. Moreover, exendin-4-induced suppression of ILCa in RGCs may be mediated by a GLP-1R/Gs/cAMP-PKA/ryanodine/Ca2+/calmodulin/calcineurin/PP1 signaling pathway. Furthermore, exendin-4 functionally improved the light-evoked spiking ability of diabetic RGCs. These results suggest that GLP-1R activation enhances cAMP to PP1 signaling and that PP1 inactivates L-VGCCs by dephosphorylating them, thereby reducing Ca2+ influx, which could protect RGCs against excitotoxic Ca2+ overload.
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Affiliation(s)
- Yong-Chen Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Lu Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Yu-Qi Shao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Shi-Jun Weng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Xiong-Li Yang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Yong-Mei Zhong
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
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7
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Sheth S, Patel A, Foreman M, Mumtaz M, Reddy A, Sharaf R, Sheth S, Lucke-Wold B. The protective role of GLP-1 in neuro-ophthalmology. EXPLORATION OF DRUG SCIENCE 2023; 1:221-238. [PMID: 37711214 PMCID: PMC10501042 DOI: 10.37349/eds.2023.00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/22/2023] [Indexed: 09/16/2023]
Abstract
Despite recent advancements in the field of neuro-ophthalmology, the rising rates of neurological and ophthalmological conditions, mismatches between supply and demand of clinicians, and an aging population underscore the urgent need to explore new therapeutic approaches within the field. Glucagon-like peptide 1 receptor agonists (GLP-1RAs), traditionally used in the treatment of type 2 diabetes, are becoming increasingly appreciated for their diverse applications. Recently, GLP-1RAs have been approved for the treatment of obesity and recognized for their cardioprotective effects. Emerging evidence indicates some GLP-1RAs can cross the blood-brain barrier and may have neuroprotective effects. Therefore, this article aims to review the literature on the neurologic and neuro-ophthalmic role of glucagon-like peptide 1 (GLP-1). This article describes GLP-1 peptide characteristics and the mechanisms mediating its known role in increasing insulin, decreasing glucagon, delaying gastric emptying, and promoting satiety. This article identifies the sources and targets of GLP-1 in the brain and review the mechanisms which mediate its neuroprotective effects, as well as implications for Alzheimer's disease (AD) and Parkinson's disease (PD). Furthermore, the preclinical works which unravel the effects of GLP-1 in ocular dynamics and the preclinical literature regarding GLP-1RA use in the management of several neuro-ophthalmic conditions, including diabetic retinopathy (DR), glaucoma, and idiopathic intracranial hypertension (IIH) are discussed.
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Affiliation(s)
- Sohum Sheth
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Aashay Patel
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Marco Foreman
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Mohammed Mumtaz
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Akshay Reddy
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Ramy Sharaf
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Siddharth Sheth
- College of Medicine, University of Florida, Gainesville, FL 32608, USA
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
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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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Zhao YM, Sun RS, Duan F, Wang FY, Li YJ, Qian XB, Zeng JT, Yang Y, Lin XF. Intravitreal slow-release dexamethasone alleviates traumatic proliferative vitreoretinopathy by inhibiting persistent inflammation and Müller cell gliosis in rabbits. Int J Ophthalmol 2023; 16:22-32. [PMID: 36659954 PMCID: PMC9815969 DOI: 10.18240/ijo.2023.01.04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 10/31/2022] [Indexed: 12/31/2022] Open
Abstract
AIM To evaluate the effects of intravitreal slow-release dexamethasone on traumatic proliferative vitreoretinopathy (PVR) and Müller cell gliosis and preliminarily explored the possible inflammatory mechanism in a rabbit model induced by penetrating ocular trauma. METHODS Traumatic PVR was induced in the right eyes of pigmented rabbits by performing an 8-mm circumferential scleral incision placed 2.5 mm behind the limbus, followed by treatment with a slow-release dexamethasone implant (Ozurdex) or sham injection. Left eyes were used as normal controls. The intraocular pressure (IOP) was monitored using an iCare tonometer. PVR severity was evaluated via anatomical and histopathological examinations every week for 6wk; specific inflammatory cytokine and proliferative marker levels were measured by quantitative real-time polymerase chain reaction, Western blot, protein chip analysis, or immunofluorescence staining. RESULTS During the observation period, PVR severity gradually increased. Intense Müller cell gliosis was observed in the peripheral retina near the wound and in the whole retina of PVR group. Ozurdex significantly alleviated PVR development and Müller cell gliosis. Post-traumatic inflammation fluctuated and was persistent. The interleukin-1β (IL-1β) mRNA level was significantly upregulated, peaking on day 3 and increasing again on day 21 after injury. The expression of nod-like receptor family pyrin domain containing 3 (NLRP3) showed a similar trend that began earlier than that of IL-1β expression. Ozurdex suppressed the expression of IL-1β, NLRP3, and phosphorylated nuclear factor-kappa B (NF-κB). The average IOP after treatment was within normal limits. CONCLUSION The present study demonstrates chronic and fluctuating inflammation in a traumatic PVR rabbit model over 6wk. Ozurdex treatment significantly inhibites inflammatory cytokines expression and Müller cell gliosis, and thus alleviates PVR severity. This study highlights the important role of IL-1β, and Ozurdex inhibites inflammation presumably via the NF-κB/NLRP3/IL-1β inflammatory axis. In summary, Ozurdex provides a potential therapeutic option for traumatic PVR.
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Affiliation(s)
- Yi-Ming Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
| | - Rong-Sha Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
| | - Fang Duan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
| | - Fang-Yu Wang
- Xi'an People's Hospital (Xi'an Fourth Hospital), Shaanxi Eye Hospital, Xi'an 710004, Shaanxi Province, China
| | - Yu-Jie Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
| | - Xiao-Bing Qian
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
| | - Jie-Ting Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
| | - Yao Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
| | - Xiao-Feng Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, Guangdong Province, China
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Yang S, Qi S, Wang C. The role of retinal Müller cells in diabetic retinopathy and related therapeutic advances. Front Cell Dev Biol 2022; 10:1047487. [PMID: 36531955 PMCID: PMC9757137 DOI: 10.3389/fcell.2022.1047487] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 11/24/2022] [Indexed: 11/19/2023] Open
Abstract
Diabetic retinopathy (DR) is a significant complication of diabetes. During the pathogenesis of retinal microangiopathy and neuronopathy, activated retinal Müller cells (RMCs) undergo morphological and structural changes such as increased expression of glial fibrillary acidic protein, disturbance of potassium and water transport regulation, and onset of production of a large number of inflammatory and vascular growth factors as well as chemokines. Evidently, activated RMCs are necessary for the pathogenesis of DR; therefore, exploring the role of RMCs in DR may provide a new target for the treatment thereof. This article reviews the mechanism of RMCs involvement in DR and the progress in related treatments.
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Affiliation(s)
| | - Shounan Qi
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
| | - Chenguang Wang
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, China
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11
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Wołos-Kłosowicz K, Matuszewski W, Rutkowska J, Krankowska K, Bandurska-Stankiewicz E. Will GLP-1 Analogues and SGLT-2 Inhibitors Become New Game Changers for Diabetic Retinopathy? J Clin Med 2022; 11:6183. [PMID: 36294503 PMCID: PMC9604821 DOI: 10.3390/jcm11206183] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/16/2022] [Accepted: 10/18/2022] [Indexed: 09/29/2023] Open
Abstract
Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes mellitus (DM), estimated to affect approximately one-third of the diabetic population, and the most common cause of preventable vision loss. The available treatment options focus on the late stages of this complication, while in the early stages there is no dedicated treatment besides optimizing blood pressure, lipid and glycemic control; DR is still lacking effective preventive methods. glucagon-like peptide 1 receptor agonists (GLP-1 Ras) and sodium-glucose cotransporter 2 (SGLT-2) inhibitors have a proven effect in reducing risk factors of DR and numerous experimental and animal studies have strongly established its retinoprotective potential. Both drug groups have the evident potential to become a new therapeutic option for the prevention and treatment of diabetic retinopathy and there is an urgent need for further comprehensive clinical trials to verify whether these findings are translatable to humans.
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Affiliation(s)
- Katarzyna Wołos-Kłosowicz
- Clinic of Endocrinology, Diabetology and Internal Medicine, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, 10-900 Olsztyn, Poland
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Ramos H, Bogdanov P, Huerta J, Deàs-Just A, Hernández C, Simó R. Antioxidant Effects of DPP-4 Inhibitors in Early Stages of Experimental Diabetic Retinopathy. Antioxidants (Basel) 2022; 11:antiox11071418. [PMID: 35883908 PMCID: PMC9312245 DOI: 10.3390/antiox11071418] [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: 06/30/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 12/03/2022] Open
Abstract
Hyperglycemia-induced oxidative stress plays a key role in the impairment of the retinal neurovascular unit, an early event in the pathogenesis of DR. The aim of this study was to assess the antioxidant properties of topical administration (eye drops) of sitagliptin in the diabetic retina. For this purpose, db/db mice received sitagliptin or vehicle eye drops twice per day for two weeks. Age-matched db/+ mice were used as the control group. We evaluated retinal mRNA (RT-PCR) and protein levels (Western blotting and immunohistochemistry) of different components from both the antioxidant system (NRF2, CAT, GPX, GR, CuZnSOD, and MnSOD) and the prooxidant machinery (PKC and TXNIP). We also studied superoxide levels (dihydroethidium staining) and oxidative damage to DNA/RNA (8-hydroxyguanosine immunostaining) and proteins (nitrotyrosine immunostaining). Finally, NF-кB translocation and IL-1β production were assessed through Western blotting and/or immunohistochemistry. We found that sitagliptin protected against diabetes-induced oxidative stress by reducing superoxide, TXNIP, PKC, and DNA/RNA/protein oxidative damage, and it prevented the downregulation of NRF2 and antioxidant enzymes, with the exception of catalase. Sitagliptin also exerted anti-inflammatory effects, avoiding both NF-кB translocation and IL-1β production. Sitagliptin prevents the diabetes-induced imbalance between ROS production and antioxidant defenses that occurs in diabetic retinas.
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Affiliation(s)
- Hugo Ramos
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (H.R.); (P.B.); (J.H.); (A.D.-J.)
- Center for Networked Biomedical Research of Diabetes and Associated Metabolic Diseases (CIBERDEM), Carlos III Health Institute (ICSIII), 28029 Madrid, Spain
| | - Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (H.R.); (P.B.); (J.H.); (A.D.-J.)
- Center for Networked Biomedical Research of Diabetes and Associated Metabolic Diseases (CIBERDEM), Carlos III Health Institute (ICSIII), 28029 Madrid, Spain
| | - Jordi Huerta
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (H.R.); (P.B.); (J.H.); (A.D.-J.)
| | - Anna Deàs-Just
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (H.R.); (P.B.); (J.H.); (A.D.-J.)
- Center for Networked Biomedical Research of Diabetes and Associated Metabolic Diseases (CIBERDEM), Carlos III Health Institute (ICSIII), 28029 Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (H.R.); (P.B.); (J.H.); (A.D.-J.)
- Center for Networked Biomedical Research of Diabetes and Associated Metabolic Diseases (CIBERDEM), Carlos III Health Institute (ICSIII), 28029 Madrid, Spain
- Department of Medicine, Autonomous University of Barcelona, 08193 Barcelona, Spain
- Correspondence: (C.H.); (R.S.); Tel.: +34-934-894-172 (C.H.)
| | - Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (H.R.); (P.B.); (J.H.); (A.D.-J.)
- Center for Networked Biomedical Research of Diabetes and Associated Metabolic Diseases (CIBERDEM), Carlos III Health Institute (ICSIII), 28029 Madrid, Spain
- Department of Medicine, Autonomous University of Barcelona, 08193 Barcelona, Spain
- Correspondence: (C.H.); (R.S.); Tel.: +34-934-894-172 (C.H.)
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13
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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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Bogdanov P, Ramos H, Valeri M, Deàs-Just A, Huerta J, Simó R, Hernández C. Minimum Effective Dose of DPP-4 Inhibitors for Treating Early Stages of Diabetic Retinopathy in an Experimental Model. Biomedicines 2022; 10:biomedicines10020465. [PMID: 35203674 PMCID: PMC8962353 DOI: 10.3390/biomedicines10020465] [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: 01/14/2022] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 02/04/2023] Open
Abstract
The neurovascular unit (NVU) plays an essential role in the development of diabetic retinopathy (DR). We previously reported that the topical administration (eye drops) of sitagliptin and saxagliptin, two dipeptidyl peptidase-4 inhibitors (DPP-4i), prevents retinal neurodegeneration and vascular leakage in db/db mice. The aim of the present study is to evaluate the minimum effective dose of the topical administration of these DPP-4i. For this purpose, sitagliptin and saxagliptin were tested at different concentrations (sitagliptin: 1 mg/mL, 5 and 10 mg/mL, twice per day; saxagliptin: 1 and 10 mg/mL, once or twice per day) in db/db mice. As end points of efficacy, the hallmarks of NVU impairment were evaluated: reactive gliosis, neural apoptosis, and vascular leakage. These parameters were assessed by immunohistochemistry, cell counting, and the Evans blue method, respectively. Our results demonstrated that the minimum effective dose is 5 mg/mL twice per day for sitagliptin, and 10 mg/mL twice per day for saxagliptin. In conclusion, this study provides useful results for the design of future preclinical regulatory studies and for planning clinical trials.
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Affiliation(s)
- Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute, 08035 Barcelona, Spain; (P.B.); (H.R.); (A.D.-J.); (J.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Hugo Ramos
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute, 08035 Barcelona, Spain; (P.B.); (H.R.); (A.D.-J.); (J.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Marta Valeri
- Unit of High Technology, Vall d’Hebron Research Institute, 08035 Barcelona, Spain;
| | - Anna Deàs-Just
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute, 08035 Barcelona, Spain; (P.B.); (H.R.); (A.D.-J.); (J.H.)
| | - Jordi Huerta
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute, 08035 Barcelona, Spain; (P.B.); (H.R.); (A.D.-J.); (J.H.)
| | - Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute, 08035 Barcelona, Spain; (P.B.); (H.R.); (A.D.-J.); (J.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
- Correspondence: (R.S.); (C.H.); Tel.: +34-934-894-172 (C.H.)
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute, 08035 Barcelona, Spain; (P.B.); (H.R.); (A.D.-J.); (J.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
- Correspondence: (R.S.); (C.H.); Tel.: +34-934-894-172 (C.H.)
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Wei L, Mo W, Lan S, Yang H, Huang Z, Liang X, Li L, Xian J, Xie X, Qin Y, Lin F, Luo Z. GLP-1 RA Improves Diabetic Retinopathy by Protecting the Blood-Retinal Barrier through GLP-1R-ROCK-p-MLC Signaling Pathway. J Diabetes Res 2022; 2022:1861940. [PMID: 36387940 PMCID: PMC9649324 DOI: 10.1155/2022/1861940] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND GLP-1 receptor agonists (GLP-1RA) are common clinical agents that are clinically protective against diabetic complications, such as diabetic retinopathy (DR). Previous studies have shown that the RhoA/ROCK pathway plays an important role in the development of DR. However, the specific mechanism of action between GLP-1RA and DR remains unclear. The aim of this study was thus to investigate the main mechanism involved in the protective effect of GLP-1RA on DR. METHODS Type 2 diabetic mice were fed a high-sugar, high-fat diet. Changes in the retinal structure were observed via HE staining and transmission electron microscopy. The expression of retinal GLP-1R, blood-retinal barrier- (BRB-) related proteins, inflammatory factors, and related pathway proteins were studied via Western blot or immunohistochemistry/immunofluorescence analysis. RESULTS GLP-1RA treatment reduced the blood glucose and lipid levels as well as the body weight of the diabetic mice while also improving retinal thickness, morphology, and vascular ultrastructure. Moreover, restored GLP-1R expression, increased Occludin and ZO-1 levels, and decreased albumin expression led to reduced retinal leakage and improved the BRB by inhibiting the RhoA/ROCK pathway. CONCLUSIONS We found that the protective effect of GLP-1RA on the retina may be realized through the GLP-1R-ROCK-p-MLC signaling pathway.
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Affiliation(s)
- Liufeng Wei
- Department of Laboratory, The First Affiliated Hospital of Guangxi Medical University, No. 22 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Weiwei Mo
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
- Department of Renal Medicine, The Fourth Affiliated Hospital of Guangxi Medical University, No. 1 Liushi Road, Liuzhou, 545000 Guangxi, China
| | - Shanshan Lan
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Haiyan Yang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Zhenxing Huang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Xinghuan Liang
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Li Li
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Jing Xian
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Xuemei Xie
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Yingfen Qin
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Faquan Lin
- Department of Laboratory, The First Affiliated Hospital of Guangxi Medical University, No. 22 Shuangyong Road, Nanning, 530021 Guangxi, China
| | - Zuojie Luo
- Department of Endocrinology, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Nanning, 530021 Guangxi, China
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Xu M, Yang J, Sun J, Xing X, Liu Z, Liu T. A novel mutation in PCK2 gene causes primary angle-closure glaucoma. Aging (Albany NY) 2021; 13:23338-23347. [PMID: 34650006 PMCID: PMC8544327 DOI: 10.18632/aging.203627] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/03/2021] [Indexed: 12/25/2022]
Abstract
Primary angle-closure glaucoma (PACG) is an ophthalmic genetic disease characterized by direct contact between the iris and trabecular meshwork, resulting in an obstructed outflow of aqueous humor from the eye. However, it is unclear as to what role genetics plays in the development of PACG. The present study investigated the disease-causing mutation in a five-generation Chinese PACG family using whole-genome sequencing. A novel heterozygous missense mutation c.977C>T in PCK2 gene was identified in five affected family members, but not in any unaffected and 86 unrelated healthy individuals. This nucleotide substitute is predicted to result in a proline to leucine substitution p.Pro326Leu. Furthermore, the function of this mutation was analyzed through various in vitro assays using the RGC-5 cell line. Our results demonstrate that the p.Pro326Leu mutation induces RGC-5 cell cycle arrest and apoptosis with a decreased BcL-XL. The increasing P53, P27, P21, AKT, and P-GSK3α were also detected in the cells transfected with c.977C>T mutation, suggesting that this mutation within PCK2 gene cause PACG through impairment of AKT/GSK3α signaling pathway.
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Affiliation(s)
- Menghan Xu
- Department of Ophthalmology, 3201 Hospital, Xi'an Jiaotong University Health Science Center, Hanzhong, Shaanxi 723000, China.,The First People's Hospital of Xianyang, Xianyang, Shaanxi 712000, China
| | - Jin Yang
- Department of Ophthalmology, 3201 Hospital, Xi'an Jiaotong University Health Science Center, Hanzhong, Shaanxi 723000, China.,Department of Ophthalmology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, China
| | - Jiayue Sun
- Department of Ophthalmology, 3201 Hospital, Xi'an Jiaotong University Health Science Center, Hanzhong, Shaanxi 723000, China
| | - Xuemei Xing
- Department of Ophthalmology, 3201 Hospital, Xi'an Jiaotong University Health Science Center, Hanzhong, Shaanxi 723000, China
| | - Zheng Liu
- College of Medical Laboratory Science, Guilin Medical University, Guilin, Guangxi 541004, China
| | - Tao Liu
- Department of Ophthalmology, 3201 Hospital, Xi'an Jiaotong University Health Science Center, Hanzhong, Shaanxi 723000, China.,Guihang Guiyang Hospital Affiliated to Zunyi Medical University, Guiyang, Guizhou 550000, China
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17
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Simó R, Simó-Servat O, Bogdanov P, Hernández C. Neurovascular Unit: A New Target for Treating Early Stages of Diabetic Retinopathy. Pharmaceutics 2021; 13:pharmaceutics13081320. [PMID: 34452281 PMCID: PMC8399715 DOI: 10.3390/pharmaceutics13081320] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 01/02/2023] Open
Abstract
The concept of diabetic retinopathy as a microvascular disease has evolved and is now considered a more complex diabetic complication in which neurovascular unit impairment plays an essential role and, therefore, can be considered as a main therapeutic target in the early stages of the disease. However, neurodegeneration is not always the apparent primary event in the natural story of diabetic retinopathy, and a phenotyping characterization is recommendable to identify those patients in whom neuroprotective treatment might be of benefit. In recent years, a myriad of treatments based on neuroprotection have been tested in experimental models, but more interestingly, there are drugs with a dual activity (neuroprotective and vasculotropic). In this review, the recent evidence concerning the therapeutic approaches targeting neurovascular unit impairment will be presented, along with a critical review of the scientific gaps and problems which remain to be overcome before our knowledge can be transferred to clinical practice.
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Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
- Correspondence:
| | - Olga Simó-Servat
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III (ICSIII), 28029 Madrid, Spain
| | - Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- 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 (VHIR), 08035 Barcelona, Spain; (O.S.-S.); (P.B.); (C.H.)
- 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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Effects of the Topical Administration of Semaglutide on Retinal Neuroinflammation and Vascular Leakage in Experimental Diabetes. Biomedicines 2021; 9:biomedicines9080926. [PMID: 34440130 PMCID: PMC8392846 DOI: 10.3390/biomedicines9080926] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND An unexpected increase in the rate of severe diabetic retinopathy was observed in the Semaglutide in Subjects with Type 2 Diabetes (SUSTAIN)-6 clinical trial. Although this effect was attributed to a rapid decrease in blood glucose levels, a direct deleterious effect of semaglutide on the retina could not be ruled out. In order to shed light on this issue, we have performed a study aimed at testing the direct effect of semaglutide administered by eye drops on retinal neuroinflammation and microvascular abnormalities using the db/db mouse model. METHODS Eye drops containing semaglutide (0.33 mg/mL; 5 μL once/daily) or vehicle (PBS; 5 μL once daily) were administered for 15 days. RESULTS We found that semaglutide significantly reduced glial activation, as well as the retinal expression of Nuclear factor kB (NF-κB), proinflammatory cytokines (IL-1β, IL-6, IL-18) and Intercellular Adhesion Molecule (ICAM)-1. In addition, semaglutide prevented the apoptosis of cells from the retinal ganglion layer and activated the protein kinase B (AKT) pathway. Finally, a dramatic decrease in vascular leakage was observed in db/db mice treated with semaglutide. All these findings were observed without any change in blood glucose levels and, therefore, can be directly attributed to semaglutide. CONCLUSIONS These experimental findings point to a beneficial rather than a deleterious effect of semaglutide on the retina of subjects with diabetes.
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Kovács-Valasek A, Pöstyéni E, Dénes V, Mester A, Sétáló G, Gábriel R. Age-Related Alterations of Proteins in Albino Wistar Rat Retina. Cells Tissues Organs 2021; 210:135-150. [PMID: 34218223 DOI: 10.1159/000515447] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/04/2021] [Indexed: 01/05/2023] Open
Abstract
Imbalance of homeostasis causes permanent changes in the body with time. The central nervous system is especially prone to these changes since it possesses limited regenerative capacity. In the retina, neurons are damaged during the aging process, and this eventually leads to deterioration of vision. In our 2-year-long study, we examined genetically closely related rat individuals to disclose the hidden retinal causes of age-associated visual dysfunction. Morphometric analysis showed significant reduction of the retina thickness with aging, particularly that of the inner plexiform layer. To reveal changes between the age groups, we used immunohistochemistry against vesicular glutamate transporter 1 protein for photoreceptor and bipolar cell terminals, Brn3a for ganglion cells, calbindin 28 kDa for horizontal cells, parvalbumin for AII amacrines, protein kinase Cα for rod bipolar cells, tyrosine hydroxylase for dopaminergic cells, glial fibrillary acidic protein for glial cells, and peanut-agglutinin labeling for cones. The most significant decrease was observed in the density of photoreceptor and the ganglion cells in the aging process. By using immunocytochemistry and western blot technique, we observed that calbindin and vesicular glutamate transporter 1 protein staining do not change much with aging; tyrosine hydroxylase, parvalbumin and calretinin showed the highest immunoreactivity during the midlife period. Most interestingly, the level of glial fibrillary acidic protein also changes similarly to the previously named markers. Our results provide further evidence that protein content is modified at least in some cell populations of the rat retina, and the number of retinal cells declined with aging. We conclude that senescence alone may cause structural and functional damage in the retinal tissue.
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Affiliation(s)
- Andrea Kovács-Valasek
- Department of Experimental Zoology and Neurobiology, Institute of Biology, Faculty of Sciences, University of Pécs, Pécs, Hungary.,János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Etelka Pöstyéni
- Department of Experimental Zoology and Neurobiology, Institute of Biology, Faculty of Sciences, University of Pécs, Pécs, Hungary
| | - Viktória Dénes
- Department of Experimental Zoology and Neurobiology, Institute of Biology, Faculty of Sciences, University of Pécs, Pécs, Hungary
| | - Adrienn Mester
- Department of Experimental Zoology and Neurobiology, Institute of Biology, Faculty of Sciences, University of Pécs, Pécs, Hungary
| | - György Sétáló
- Department of Medical Biology, Medical School, University of Pécs, Pécs, Hungary.,János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Róbert Gábriel
- Department of Experimental Zoology and Neurobiology, Institute of Biology, Faculty of Sciences, University of Pécs, Pécs, Hungary.,János Szentágothai Research Centre, University of Pécs, Pécs, Hungary
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20
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Li W, Jin L, Cui Y, Nie A, Xie N, Liang G. Bone marrow mesenchymal stem cells-induced exosomal microRNA-486-3p protects against diabetic retinopathy through TLR4/NF-κB axis repression. J Endocrinol Invest 2021; 44:1193-1207. [PMID: 32979189 DOI: 10.1007/s40618-020-01405-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 08/23/2020] [Indexed: 02/08/2023]
Abstract
AIM Diabetic retinopathy (DR) is a chronic disease causing health and economic burdens on individuals and society. Thus, this study is conducted to figure out the mechanisms of bone marrow mesenchymal stem cells (BMSCs)-induced exosomal microRNA-486-3p (miR-486-3p) in DR. METHODS The putative miR-486-3p binding sites to 3'untranslated region of Toll-like receptor 4 (TLR4) was verified by luciferase reporter assay. High glucose (HG)-treated Muller cells were transfected with miR-486-3p or TLR4-related oligonucleotides and plasmids to explore theirs functions in DR. Additionally, HG-treated Muller cells were co-cultured with BMSC-derived exosomes, exosomes collected from BMSCs that had been transfected with miR-486-3p or TLR4-related oligonucleotides and plasmids to explore their functions in DR. MiR-486-3p, TLR4 and nuclear factor-kappaB (NF-κB) expression, angiogenesis-related factors, oxidative stress factors, viability and apoptosis in HG-treated Muller cells were detected by RT-qPCR, western blot analysis, ELISA, MTT assay and flow cytometry, respectively. RESULTS MiR-486-3p was poorly expressed while TLR4 and NF-κB were highly expressed in HG-treated Muller cells. TLR4 was a target of miR-486-3p. Upregulating miR-486-3p or down-regulating TLR4 inhibited oxidative stress, inflammation and apoptosis, and promoted proliferation of HG-treated Muller cells. Meanwhile, BMSC-derived exosomes inhibited oxidative stress, inflammation and apoptosis, and promoted proliferation of HG-treated Muller cells. Restoring miR-486-3p further enhanced, while up-regulating TLR4 reversed, the improvement of exosomes treatment. CONCLUSION Our study highlights that up-regulation of miR-486-3p induced by BMSC-derived exosomes played a protective role in DR mice via TLR4/NF-κB axis repression.
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Affiliation(s)
- W Li
- Department of Ophthalmology, The Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, 1017 Dongmen North Road, Luohu District, Shenzhen, 518000, Guangdong, China
| | - L Jin
- Department of Ophthalmology, The Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, 1017 Dongmen North Road, Luohu District, Shenzhen, 518000, Guangdong, China
| | - Y Cui
- Department of Ophthalmology, The Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, 1017 Dongmen North Road, Luohu District, Shenzhen, 518000, Guangdong, China
| | - A Nie
- Department of Ophthalmology, The Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, 1017 Dongmen North Road, Luohu District, Shenzhen, 518000, Guangdong, China
| | - N Xie
- Department of Ophthalmology, The Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, 1017 Dongmen North Road, Luohu District, Shenzhen, 518000, Guangdong, China.
| | - G Liang
- Department of Ophthalmology, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, 53300, Guangxi, China.
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21
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Diabetic retinal neurodegeneration as a form of diabetic retinopathy. Int Ophthalmol 2021; 41:3223-3248. [PMID: 33954860 DOI: 10.1007/s10792-021-01864-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE To review the evidence supporting diabetic retinal neurodegeneration (DRN) as a form of diabetic retinopathy. METHOD Review of literature. RESULTS DRN is recognized to be a part of retinopathy in patients with diabetes mellitus (DM), in addition to the well-established diabetic retinal vasculopathy (DRV). DRN has been noted in the early stages of DM, before the onset of clinically evident diabetic retinopathy. The occurrence of DRN has been confirmed in animal models of DM, histopathological examination of donor's eyes from diabetic individuals and assessment of neural structure and function in humans. DRN involves alterations in retinal ganglion cells, photoreceptors, amacrine cells and bipolar cells, and is thought to be driven by glutamate, oxidative stress and dysregulation of neuroprotective factors in the retina. Potential therapeutic options for DRN are under evaluation. CONCLUSIONS Literature is divided on the temporal relation between DRN and DRV, with evidence of both precedence and simultaneous occurrence. The relationship between DRN and multi-system neuropathy in DM is yet to be evaluated critically.
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22
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Nian S, Lo ACY, Mi Y, Ren K, Yang D. Neurovascular unit in diabetic retinopathy: pathophysiological roles and potential therapeutical targets. EYE AND VISION 2021; 8:15. [PMID: 33931128 PMCID: PMC8088070 DOI: 10.1186/s40662-021-00239-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 04/02/2021] [Indexed: 02/06/2023]
Abstract
Diabetic retinopathy (DR), one of the common complications of diabetes, is the leading cause of visual loss in working-age individuals in many industrialized countries. It has been traditionally regarded as a purely microvascular disease in the retina. However, an increasing number of studies have shown that DR is a complex neurovascular disorder that affects not only vascular structure but also neural tissue of the retina. Deterioration of neural retina could precede microvascular abnormalities in the DR, leading to microvascular changes. Furthermore, disruption of interactions among neurons, vascular cells, glia and local immune cells, which collectively form the neurovascular unit, is considered to be associated with the progression of DR early on in the disease. Therefore, it makes sense to develop new therapeutic strategies to prevent or reverse retinal neurodegeneration, neuroinflammation and impaired cell-cell interactions of the neurovascular unit in early stage DR. Here, we present current perspectives on the pathophysiology of DR as a neurovascular disease, especially at the early stage. Potential novel treatments for preventing or reversing neurovascular injuries in DR are discussed as well.
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Affiliation(s)
- Shen Nian
- Department of Pathology, Xi'an Medical University, Xi'an, Shaanxi Province, China.
| | - Amy C Y Lo
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Yajing Mi
- Institute of Basic Medicine Science, Xi'an Medical University, Xi'an, Shaanxi Province, China
| | - Kai Ren
- Department of Biochemistry and Molecular Biology, Xi'an Medical University, Xi'an, Shaanxi Province, China
| | - Di Yang
- Department of Ophthalmology, First Affiliated Hospital of Kunming Medical University, Kunming Medical University, Kunming, Yunnan Province, China.
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Plasma miR-26a-5p is a biomarker for retinal neurodegeneration of early diabetic retinopathy. Eye (Lond) 2021; 35:1587-1599. [PMID: 33931763 DOI: 10.1038/s41433-021-01393-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/24/2020] [Accepted: 01/05/2021] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Retinal neurodegeneration is an early pathological change in diabetic retinopathy (DR). Early-stage retinal neurodegeneration is usually asymptomatic. This study aims to identify circulating microRNAs (miRNAs) as sensitive biomarkers for early retinal neurodegeneration. METHODS We profiled the plasma miRNA expression in three mild nonproliferative diabetic retinopathy (NPDR) cases and three matched non-DR patients using RNA sequencing. The differential miRNAs were validated with qRT-PCR. The retinal nerve fibre layer (RNFL) thickness of the eyes was measured using spectral-domain Optical coherence tomography (SD-OCT). The association between differential miRNAs and RNFL thickness was analysed using the Pearson correlation analysis. Bioinformatics tools were used to predict potential targets of miRNA associated with RNFL thickness and investigate the functions of the potential target genes. RESULTS RNA sequencing identified 69 differential miRNAs and eight of them were reported to be associated with DR. The qRT-PCR for these eight miRNAs validated the down-regulation of circulating miR-26a-5p and miR-126-5p in a larger validating cohort. A positive correlation between plasma miR-26a-5p level and the RNFL thickness of the superior quadrant of both eyes was identified in another cohort, including 33 mild NPDR cases, 33 matched non-DR patients and 20 healthy controls. Furthermore, 367 candidate targets of miR-26a-5p were predicted. The functional studies revealed that these target genes are profoundly involved in various cellular functions and signalling pathways. CONCLUSIONS Circulating miR-26a-5p is a potential biomarker for early-stage retinal neurodegeneration and it may be involved in the development of DR via profoundly influencing the functions of retinal cells.
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Yang X, Wu S, Feng Z, Yi G, Zheng Y, Xia Z. Combination therapy with semaglutide and rosiglitazone as a synergistic treatment for diabetic retinopathy in rodent animals. Life Sci 2021; 269:119013. [PMID: 33417950 DOI: 10.1016/j.lfs.2020.119013] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/22/2020] [Accepted: 12/27/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVE To investigate the protective efficacies and potent mechanisms of combination therapy with semaglutide and rosiglitazone (RSG) on the high-glucose incubated human ARPE-19 cells and diabetic retinopathy (DR) model rats. MAIN METHODS The CCK-8 methods were used to evaluate the protective effects of semaglutide and RSG alone or combination on the cell viability of high-glucose treated ARPE-19 cells. After the DR rat model was established, the effects of combined treatment on general indexes, retinal morphological changes, retinal Müller cells as well as PI3K/Akt/MTOR related factors of DR model rats were investigated. RESULTS The CCK-8 assay showed obviously enhanced protective efficacies of combination therapy with semaglutide and RSG on the ARPE-19 with oxidative stress induced by high-glucose with combination index all below 1.5 demonstrating obvious synergistic effects. Combined incubation could also effectively decrease the expression of inflammatory factors, including TNF-α, IL-1β, IL-6, and the increase of ROS content in ARPE cell culture supernatant induced by high-glucose. Combined use of the antioxidant, PI3K/Akt and mTOR inhibitors, we further demonstrated that combined incubation of semaglutide and RSG could effectively by reduce high glucose-induced inflammatory injury inhibiting ROS/PI3K/Akt/mTOR signaling. Furthermore, chronic combination treatment effectively improved the histopathological characteristics and down-regulated the GFAP expression in Müller cells as well as PI3K/Akt/MTOR signaling pathway-related factors in retina which was better than any monomer treatment group. CONCLUSIONS Combined semaglutide with RSG exhibited synergistically protective efficacies on retinal cells by decreasing the GFAP expression, inhibiting oxidative stress and PI3K/Akt/MTOR signaling-transduction in DR model rats.
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Affiliation(s)
- Xiaoxi Yang
- Department of Ophthalmology, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou 51000, PR China
| | - Shuduan Wu
- Department of Ophthalmology, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou 51000, PR China
| | - Zhizhen Feng
- Department of Ophthalmology, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou 51000, PR China
| | - Guoguo Yi
- Department of Ophthalmology, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou 51000, PR China
| | - Yuxing Zheng
- Department of Ophthalmology, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou 51000, PR China
| | - Zhaoxia Xia
- Department of Ophthalmology, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou 51000, PR China.
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Targeted pharmacotherapy against neurodegeneration and neuroinflammation in early diabetic retinopathy. Neuropharmacology 2021; 187:108498. [PMID: 33582150 DOI: 10.1016/j.neuropharm.2021.108498] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/18/2021] [Accepted: 02/06/2021] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR), the most frequent complication of diabetes, is one of the leading causes of irreversible blindness in working-age adults and has traditionally been regarded as a microvascular disease. However, increasing evidence has revealed that synaptic neurodegeneration of retinal ganglion cells (RGCs) and activation of glial cells may represent some of the earliest events in the pathogenesis of DR. Upon diabetes-induced metabolic stress, abnormal glycogen synthase kinase-3β (GSK-3β) activation drives tau hyperphosphorylation and β-catenin downregulation, leading to mitochondrial impairment and synaptic neurodegeneration prior to RGC apoptosis. Moreover, glial cell activation triggers enhanced inflammation and oxidative stress, which may accelerate the deterioration of diabetic RGCs neurodegeneration. These findings have opened up opportunities for therapies, such as inhibition of GSK-3β, glial cell activation, glutamate excitotoxicity and the use of neuroprotective drugs targeting early neurodegenerative processes in the retina and halting the progression of DR before the manifestation of microvascular abnormalities. Such interventions could potentially remedy early neurodegeneration and help prevent vision loss in people suffering from DR.
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26
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Simó R, Frontoni S. Neuropathic damage in the diabetic eye: clinical implications. Curr Opin Pharmacol 2020; 55:1-7. [PMID: 32932105 DOI: 10.1016/j.coph.2020.08.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/11/2020] [Accepted: 08/25/2020] [Indexed: 02/07/2023]
Abstract
In recent years, emerging evidence support that the eye is target of diabetes neuropathy. There are two components of the eye that are mainly involved in the neurodegenerative process induced by diabetes: the retina and the cornea. The study of functional and structural changes in these components of the eye will provide useful information to identify subjects with diabetes at risk of diabetic peripheral neuropathy and dementia. In this review the state of the art regarding the evidence and clinical implications of this emerging concept will be provided. In addition, the relationship between retinal and corneal neurodegeneration with peripheral neuropathy and cognitive decline will be analyzed. Finally, the scientific gaps than need to be covered and will be critically examined.
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Affiliation(s)
- Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain; CIBERDEM (ISCIII), Madrid, Spain.
| | - Simona Frontoni
- Unit of Endocrinology, Diabetes and Metabolism, S. Giovanni Calibita, Fate Bene Fratelli Hospital, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
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27
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Beneficial Effects of Glucagon-Like Peptide-1 (GLP-1) in Diabetes-Induced Retinal Abnormalities: Involvement of Oxidative Stress. Antioxidants (Basel) 2020; 9:antiox9090846. [PMID: 32927585 PMCID: PMC7554849 DOI: 10.3390/antiox9090846] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/01/2020] [Accepted: 09/07/2020] [Indexed: 12/15/2022] Open
Abstract
Background: Hyperglycemia-induced oxidative stress plays a key role in diabetic complications, including diabetic retinopathy. The main goal of this study was to assess whether the topical administration (eye drops) of glucagon-like peptide-1 (GLP-1) has any effect on oxidative stress in the retina. Methods: db/db mice were treated with eye drops of GLP-1 or vehicle for three weeks, with db/+ mice being used as control. Studies included the assessment by western blot of the antioxidant defense markers CuZnSOD, MnSOD, glutathione peroxidase and reductase; immunofluorescence measurements of DNA/RNA damage, nitro tyrosine and Ki67 and Babam2 proteins. Results: GLP-1 eye drops protected from oxidative stress by increasing the protein levels of glutathione reductase, glutathione peroxidase and CuZnSOD and MnSOD in diabetic retinas. This was associated with a significant reduction of DNA/RNA damage and the activation of proteins involved in DNA repair in the retina (Babam2) and Ki67 (a biomarker of cell proliferation). Conclusions: GLP-1 modulates the antioxidant defense system in the diabetic retina and has a neuroprotective action favoring DNA repair and neuron cells proliferation.
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28
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López-Bernal Á, García-Tejera O, Testi L, Villalobos FJ. Genotypic variability in radial resistance to water flow in olive roots and its response to temperature variations. TREE PHYSIOLOGY 2020; 40:445-453. [PMID: 32031664 DOI: 10.1093/treephys/tpaa010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/30/2019] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
As radial root resistance (Rp) represents one of the key components of the soil-plant-atmosphere continuum resistance catena modulating water transport, understanding its control is essential for physiologists, modelers and breeders. Reports of Rp, however, are still scarce and scattered in the scientific literature. In this study, we assessed genetic variability in Rp and its dependence on temperature in five widely used olive cultivars. In a first experiment, cultivar differences in Rp at 25 °C were evaluated from flow-pressure measurements in excised roots and subsequent analysis of root traits. In a second experiment, similar determinations were performed continually over a 5-h period in which temperature was gradually increased from 12 to 32 °C, enabling the assessment of Rp response to changing temperature. Despite some variability, our results did not show statistical differences in Rp among cultivars in the first experiment. In the second, cultivar differences in Rp were not significant at 12 °C, but they became so as temperature increased. Furthermore, the changes in Rp between 12 and 32 °C were higher than those expected by the temperature-driven decrease in water viscosity, with the degree of that change differing among cultivars. Also, Rp at 25 °C reached momentarily in the second experiment was consistently higher than in the first at that same, but fixed, temperature. Overall, our results suggest that there is limited variability in Rp among the studied cultivars when plants have been exposed to a given temperature for sufficient time. Temperature-induced variation in Rp might thus be partly explained by changes in membrane permeability that occur slowly, which explains why our values at 25 °C differed between experiments. The observed cultivar differences in Rp with warming also indicate faster acclimation of Rp to temperature changes in some cultivars than others.
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Affiliation(s)
- Á López-Bernal
- Departamento de Agronomía, Universidad de Córdoba, Campus de Rabanales, Edificio C4, 14071 Córdoba, Spain
| | - O García-Tejera
- Efficient Use of Water Program, Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Parc de Gardeny, Edifici Fruitcentre, 25003 Lleida, Spain
| | - L Testi
- Instituto de Agricultura Sostenible (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Av. Menéndez Pidal s/n, 14080 Córdoba, Spain
| | - F J Villalobos
- Departamento de Agronomía, Universidad de Córdoba, Campus de Rabanales, Edificio C4, 14071 Córdoba, Spain
- Instituto de Agricultura Sostenible (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Av. Menéndez Pidal s/n, 14080 Córdoba, Spain
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29
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Vujosevic S, Aldington SJ, Silva P, Hernández C, Scanlon P, Peto T, Simó R. Screening for diabetic retinopathy: new perspectives and challenges. Lancet Diabetes Endocrinol 2020; 8:337-347. [PMID: 32113513 DOI: 10.1016/s2213-8587(19)30411-5] [Citation(s) in RCA: 261] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/18/2019] [Accepted: 11/18/2019] [Indexed: 12/15/2022]
Abstract
Although the prevalence of all stages of diabetic retinopathy has been declining since 1980 in populations with improved diabetes control, the crude prevalence of visual impairment and blindness caused by diabetic retinopathy worldwide increased between 1990 and 2015, largely because of the increasing prevalence of type 2 diabetes, particularly in low-income and middle-income countries. Screening for diabetic retinopathy is essential to detect referable cases that need timely full ophthalmic examination and treatment to avoid permanent visual loss. In the past few years, personalised screening intervals that take into account several risk factors have been proposed, with good cost-effectiveness ratios. However, resources for nationwide screening programmes are scarce in many countries. New technologies, such as scanning confocal ophthalmology with ultrawide field imaging and handheld mobile devices, teleophthalmology for remote grading, and artificial intelligence for automated detection and classification of diabetic retinopathy, are changing screening strategies and improving cost-effectiveness. Additionally, emerging evidence suggests that retinal imaging could be useful for identifying individuals at risk of cardiovascular disease or cognitive impairment, which could expand the role of diabetic retinopathy screening beyond the prevention of sight-threatening disease.
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Affiliation(s)
- Stela Vujosevic
- Eye Unit, University Hospital Maggiore della Carità, Novara, Italy
| | - Stephen J Aldington
- Department of Ophthalmology, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, UK
| | - Paolo Silva
- Beetham Eye Institute, Joslin Diabetes Centre, Harvard Medical School, Boston, MA, USA; Philippine Eye Research Institute, University of the Philippines, Manila, Philippines
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Barcelona, Spain; Department of Medicine and Endocrinology, Autonomous University of Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
| | - Peter Scanlon
- Department of Ophthalmology, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, UK
| | - Tunde Peto
- Centre for Public Health, Queen's University Belfast, Belfast, UK
| | - Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Barcelona, Spain; Department of Medicine and Endocrinology, Autonomous University of Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain.
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30
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Pillar S, Moisseiev E, Sokolovska J, Grzybowski A. Recent Developments in Diabetic Retinal Neurodegeneration: A Literature Review. J Diabetes Res 2020; 2020:5728674. [PMID: 34151902 PMCID: PMC7787838 DOI: 10.1155/2020/5728674] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/11/2020] [Accepted: 11/24/2020] [Indexed: 02/08/2023] Open
Abstract
Neurodegeneration plays a significant role in the complex pathology of diabetic retinopathy. Evidence suggests the onset of neurodegeneration occurs early on in the disease, and so a greater understanding of the process is essential for prompt detection and targeted therapies. Neurodegeneration is a common pathway of assorted processes, including activation of inflammatory pathways, reduction of neuroprotective factors, DNA damage, and apoptosis. Oxidative stress and formation of advanced glycation end products amplify these processes and are elevated in the setting of hyperglycemia, hyperlipidemia, and glucose variability. These key pathophysiologic mechanisms are discussed, as well as diagnostic modalities and novel therapeutic avenues, with an emphasis on recent discoveries. The aim of this article is to highlight the crucial role of neurodegeneration in diabetic retinopathy and to review the molecular basis for this neuronal dysfunction, its diagnostic features, and the progress currently made in relevant therapeutic interventions.
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Affiliation(s)
- Shani Pillar
- Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Elad Moisseiev
- Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Andrzej Grzybowski
- Department of Ophthalmology, University of Warmia and Mazury, Olsztyn, Poland
- Institute for Research in Ophthalmology, Foundation for Ophthalmology Development, Poznan, Poland
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31
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Rossino MG, Dal Monte M, Casini G. Relationships Between Neurodegeneration and Vascular Damage in Diabetic Retinopathy. Front Neurosci 2019; 13:1172. [PMID: 31787868 PMCID: PMC6856056 DOI: 10.3389/fnins.2019.01172] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/16/2019] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes and constitutes a major cause of vision impairment and blindness in the world. DR has long been described exclusively as a microvascular disease of the eye. However, in recent years, a growing interest has been focused on the contribution of neuroretinal degeneration to the pathogenesis of the disease, and there are observations suggesting that neuronal death in the early phases of DR may favor the development of microvascular abnormalities, followed by the full manifestation of the disease. However, the mediators that are involved in the crosslink between neurodegeneration and vascular changes have not yet been identified. According to our hypothesis, vascular endothelial growth factor (VEGF) could probably be the most important connecting link between the death of retinal neurons and the occurrence of microvascular lesions. Indeed, VEGF is known to play important neuroprotective actions; therefore, in the early phases of DR, it may be released in response to neuronal suffering, and it would act as a double-edged weapon inducing both neuroprotective and vasoactive effects. If this hypothesis is correct, then any retinal stress causing neuronal damage should be accompanied by VEGF upregulation and by vascular changes. Similarly, any compound with neuroprotective properties should also induce VEGF downregulation and amelioration of the vascular lesions. In this review, we searched for a correlation between neurodegeneration and vasculopathy in animal models of retinal diseases, examining the effects of different neuroprotective substances, ranging from nutraceuticals to antioxidants to neuropeptides and others and showing that reducing neuronal suffering also prevents overexpression of VEGF and vascular complications. Taken together, the reviewed evidence highlights the crucial role played by mediators such as VEGF in the relationship between retinal neuronal damage and vascular alterations and suggests that the use of neuroprotective substances could be an efficient strategy to prevent the onset or to retard the development of DR.
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Affiliation(s)
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Giovanni Casini
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
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32
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Yu X, Hao M, Liu Y, Ma X, Lin W, Xu Q, Zhou H, Shao N, Kuang H. Liraglutide ameliorates non-alcoholic steatohepatitis by inhibiting NLRP3 inflammasome and pyroptosis activation via mitophagy. Eur J Pharmacol 2019; 864:172715. [PMID: 31593687 DOI: 10.1016/j.ejphar.2019.172715] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/26/2019] [Accepted: 10/01/2019] [Indexed: 02/06/2023]
Abstract
Non-alcoholic steatohepatitis (NASH) is a key step in the progression of non-alcoholic fatty liver disease (NAFLD), which causes serious health problems worldwide. The nucleotide-binding oligomerization domain, leucine-rich repeat-containing receptor-containing pyrin domain 3 (NLRP3) inflammasome and pyroptosis play crucial roles in the progression of NASH. Our team has provided clinical evidence of the effects of glucagon-like peptide-1 (GLP-1) on the improvement in liver function and histological resolution of NAFLD. Preliminary work has demonstrated that GLP-1 inhibited NLRP3 inflammasome activation in a mouse model of NAFLD. We further explored the potential molecular mechanisms underlying the anti-inflammatory effect of liraglutide, a long-acting GLP-1 analog, in the treatment of NASH. We established a HepG2 cell model of NASH using double stimulation with palmitic acid and lipopolysaccharide to assess NLRP3 inflammasome and pyroptotic cell activity and to evaluate mitochondrial function and mitophagy. Liraglutide reduced lipid accumulation, inhibited NLRP3 inflammasome and pyroptosis activation, attenuated mitochondrial dysfunction and reactive oxygen species generation, augmented mitophagy in hepatocytes. Mitophagy inhibition with 3-methyladenine/PINK1-directed siRNA weakened the liraglutide-mediated suppression of inflammatory injury. We propose that liraglutide suppresses NLRP3 inflammasome-induced hepatocyte pyroptosis via mitophagy to slow the progression of NASH.
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Affiliation(s)
- Xinyang Yu
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Ming Hao
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Yu Liu
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Xuefei Ma
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Wenjian Lin
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Qian Xu
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Huanran Zhou
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Ning Shao
- Department of Endocrinology, The First Hospital of Harbin, Harbin, Heilongjiang, China
| | - HongYu Kuang
- Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
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Caffeine Modulates Cadmium-Induced Oxidative Stress, Neuroinflammation, and Cognitive Impairments by Regulating Nrf-2/HO-1 In Vivo and In Vitro. J Clin Med 2019; 8:jcm8050680. [PMID: 31091792 PMCID: PMC6572702 DOI: 10.3390/jcm8050680] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/10/2019] [Accepted: 05/12/2019] [Indexed: 02/06/2023] Open
Abstract
Cadmium (Cd), a nonbiodegradable heavy metal and one of the most neurotoxic environmental and industrial pollutants, promotes disturbances in major organs and tissues following both acute and chronic exposure. In this study, we assessed the neuroprotective potential of caffeine (30 mg/kg) against Cd (5 mg/kg)-induced oxidative stress-mediated neuroinflammation, neuronal apoptosis, and cognitive deficits in male C57BL/6N mice in vivo and in HT-22 and BV-2 cell lines in vitro. Interestingly, our findings indicate that caffeine markedly reduced reactive oxygen species (ROS) and lipid peroxidation (LPO) levels and enhanced the expression of nuclear factor-2 erythroid-2 (Nrf-2) and hemeoxygenase-1 (HO-1), which act as endogenous antioxidant regulators. Also, 8-dihydro-8-oxoguanine (8-OXO-G) expression was considerably reduced in the caffeine-treated group as compared to the Cd-treated group. Similarly, caffeine ameliorated Cd-mediated glial activation by reducing the expression of glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), and other inflammatory mediators in the cortical and hippocampal regions of the mouse brain. Moreover, caffeine markedly attenuated Cd-induced neuronal loss, synaptic dysfunction, and learning and cognitive deficits. Of note, nuclear factor-2 erythroid-2 (Nrf-2) gene silencing and nuclear factor-κB (NF-κB) inhibition studies revealed that caffeine exerted neuroprotection via regulation of Nrf-2- and NF-κB-dependent mechanisms in the HT-22 and BV-2 cell lines, respectively. On the whole, these findings reveal that caffeine rescues Cd-induced oxidative stress-mediated neuroinflammation, neurodegeneration, and memory impairment. The present study suggests that caffeine might be a potential antioxidant and neuroprotective agent against Cd-induced neurodegeneration.
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Sinclair SH, Schwartz SS. Diabetic Retinopathy-An Underdiagnosed and Undertreated Inflammatory, Neuro-Vascular Complication of Diabetes. Front Endocrinol (Lausanne) 2019; 10:843. [PMID: 31920963 PMCID: PMC6923675 DOI: 10.3389/fendo.2019.00843] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/19/2019] [Indexed: 12/14/2022] Open
Abstract
Diabetes mellitus is a world-wide epidemic and diabetic retinopathy, a devastating, vision-threatening condition, is one of the most common diabetes-specific complications. Diabetic retinopathy is now recognized to be an inflammatory, neuro-vascular complication with neuronal injury/dysfunction preceding clinical microvascular damage. Importantly, the same pathophysiologic mechanisms that damage the pancreatic β-cell (e.g., inflammation, epigenetic changes, insulin resistance, fuel excess, and abnormal metabolic environment), also lead to cell and tissue damage causing organ dysfunction, elevating the risk of all complications, including diabetic retinopathy. Viewing diabetic retinopathy within the context whereby diabetes and all its complications arise from common pathophysiologic factors allows for the consideration of a wider array of potential ocular as well as systemic treatments for this common and devastating complication. Moreover, it also raises the importance of the need for methods that will provide more timely detection and prediction of the course in order to address early damage to the neurovascular unit prior to the clinical observation of microangiopathy. Currently, treatment success is limited as it is often initiated far too late and after significant neurodegeneration has occurred. This forward-thinking approach of earlier detection and treatment with a wider array of possible therapies broadens the physician's armamentarium and increases the opportunity for prevention and early treatment of diabetic retinopathy with preservation of good vision, as well the prevention of similar destructive processes occurring among other organs.
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Affiliation(s)
- Stephen H. Sinclair
- Sinclair Retina Associates, Media, PA, United States
- Main Line Health System, Media, PA, United States
- *Correspondence: Stephen H. Sinclair
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