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Zhao S, Yan Q, Xu W, Zhang J. Gut microbiome in diabetic retinopathy: A systematic review and meta-analysis. Microb Pathog 2024; 189:106590. [PMID: 38402917 DOI: 10.1016/j.micpath.2024.106590] [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: 12/29/2023] [Accepted: 02/18/2024] [Indexed: 02/27/2024]
Abstract
CONTEXT Changes in the gut microbiome are linked with Type 2diabetes mellitus (T2DM) development, but alterations in patients with diabetic retinopathy (DR) are still being debated. OBJECTIVE To investigate the differences in biodiversity and relative abundance of gut microbiome between patients with DR and T2DM. METHODS A comprehensive search was performed in five electronic databases (PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and CNKI) from the inception of each database through to August 2023. The standardized mean difference (SMD) and its 95% confidence interval (CI) were estimated using Stata 15.1. Furthermore, the alpha diversity index and relative abundance of the gut microbiome were calculated. The Egger test determined publication bias in the literature. RESULTS Seven case-control studies were included in the final dataset, comprising 195 patients with DR and 211 patients with T2DM. Compared to T2DM patients, patients in the DR group had a reduced but not significantly different α-diversity. The analysis of microbial composition at the phylum level revealed a marked increase in the relative abundance of Bacteroidetes(ES = 23.27, 95%CI[8.30, 38.23], P = 0.000) and a decline in Firmicutes(ES = 47.05, 95%CI[36.58, 57.52], P = 0.000), Proteobacteria (ES = 11.08, 95%CI[6.08, 16.07], P = 0.000) and Actinobacteria (ES = 10.43, 95%CI[1.64, 19.22], P = 0.001) in patients with DR when compared to those with T2DM. CONCLUSIONS An association exists between alterations in the gut microbiome of T2DM and the development and progression of DR. This suggests that re-establishing homeostasis of the gut microbiome could be a potential way to prevent or treat DR and requires further confirmation in future studies. REGISTRATION DATABASE Prospero. REGISTRATION NUMBER CRD42023455280.
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Affiliation(s)
- Shuang Zhao
- Shandong First Medical University, Jinan, China.
| | - Qi Yan
- Jiangsu Pei People's Hospital, China.
| | - Wanjing Xu
- Qingpu Branch of Zhongshan Hospital Affiliated to Fudan University, China.
| | - Juanmei Zhang
- The Department of Ophthalmology, Linyi People's Hospital, Linyi, China.
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2
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Oganov AC, Seddon I, Zein M, Yazdanpanah G, Fonoudi H, Jabbehdari S. Composition of the gut microbiome, role of diet, lifestyle, and antioxidant therapies in diabetes mellitus and diabetic retinopathy. Eur J Ophthalmol 2024; 34:367-383. [PMID: 37150930 DOI: 10.1177/11206721231174490] [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] [Indexed: 05/09/2023]
Abstract
The gut microbiome is a complex ecosystem in the gastrointestinal tract composed of trillions of bacteria, viruses, fungi, and protozoa. Disruption of this delicate ecosystem, formally called "dysbiosis", has been linked to a variety of metabolic and inflammatory pathologies. Several studies have focused on abnormal microbiome composition and correlated these findings with the development of type 2 diabetes mellitus (T2DM) and diabetic retinopathy (DR). However, given the complexity of this ecosystem, the current studies are narrow in design and present variable findings. Composition of the gut microbiome in patients with DR significantly differs from patients with diabetes without retinopathy as well as from healthy controls. Additionally, the gut microbiome has been shown to modify effects of medication, diet, exercise, and antioxidant use on the development and progression of DR. In this paper, we present a comprehensive review of literature on the effect of oxidative stress, antioxidant therapies, and dysbiosis on DR.
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Affiliation(s)
- Anthony C Oganov
- Department of Ophthalmology, Renaissance School of Medicine, Stony Brook, NY, USA
| | - Ian Seddon
- College of Osteopathic Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Mike Zein
- Department of Ophthalmology, Cook County Health, Chicago, IL, USA
| | - Ghasem Yazdanpanah
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, IL, USA
| | - Hossein Fonoudi
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
- Iranshahr University of Medical Sciences, Iranshahr, Iran
| | - Sayena Jabbehdari
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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3
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Qiu J, Wu J, Chen W, Ruan Y, Mao J, Li S, Tang X, Zhao L, Li S, Li K, Liu D, Duan Y. NOD1 deficiency ameliorates the progression of diabetic retinopathy by modulating bone marrow-retina crosstalk. Stem Cell Res Ther 2024; 15:38. [PMID: 38336763 PMCID: PMC10858517 DOI: 10.1186/s13287-024-03654-y] [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: 08/28/2023] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
BACKGROUND Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) plays a pivotal role in inducing metabolic inflammation in diabetes. Additionally, the NOD1 ligand disrupts the equilibrium of bone marrow-derived hematopoietic stem/progenitor cells, a process that has immense significance in the development of diabetic retinopathy (DR). We hypothesized that NOD1 depletion impedes the advancement of DR by resolving bone marrow dysfunction. METHODS We generated NOD1-/--Akita double-mutant mice and chimeric mice with hematopoietic-specific NOD1 depletion to study the role of NOD1 in the bone marrow-retina axis. RESULTS Elevated circulating NOD1 activators were observed in Akita mice after 6 months of diabetes. NOD1 depletion partially restored diabetes-induced structural changes and retinal electrical responses in NOD1-/--Akita mice. Loss of NOD1 significantly ameliorated the progression of diabetic retinal vascular degeneration, as determined by acellular capillary quantification. The preventive effect of NOD1 depletion on DR is linked to bone marrow phenotype alterations, including a restored HSC pool and a shift in hematopoiesis toward myelopoiesis. We also generated chimeric mice with hematopoietic-specific NOD1 ablation, and the results further indicated that NOD1 had a protective effect against DR. Mechanistically, loss of hematopoietic NOD1 resulted in reduced bone marrow-derived macrophage infiltration and decreased CXCL1 and CXCL2 secretion within the retina, subsequently leading to diminished neutrophil chemoattraction and NETosis. CONCLUSIONS The results of our study unveil, for the first time, the critical role of NOD1 as a trigger for a hematopoietic imbalance toward myelopoiesis and local retinal inflammation, culminating in DR progression. Targeting NOD1 in bone marrow may be a potential strategy for the prevention and treatment of DR.
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Affiliation(s)
- Jingwen Qiu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jing Wu
- Department of Hematology/Oncology, Chongqing University Cancer Hospital, Chongqing, China
| | - Wenwen Chen
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yu Ruan
- Division of Growth, Development and Mental Health of Children and Adolescence, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Jingning Mao
- Health Medical Center, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Shue Li
- Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xuan Tang
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lei Zhao
- Center for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Shengbing Li
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ke Li
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Dongfang Liu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yaqian Duan
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
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4
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Wang R, Wang QY, Bai Y, Bi YG, Cai SJ. Research progress of diabetic retinopathy and gut microecology. Front Microbiol 2023; 14:1256878. [PMID: 37744925 PMCID: PMC10513461 DOI: 10.3389/fmicb.2023.1256878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/23/2023] [Indexed: 09/26/2023] Open
Abstract
According to the prediction of the International Diabetes Federation, global diabetes mellitus (DM) patients will reach 783.2 million in 2045. The increasing incidence of DM has led to a global epidemic of diabetic retinopathy (DR). DR is a common microvascular complication of DM, which has a significant impact on the vision of working-age people and is one of the main causes of blindness worldwide. Substantial research has highlighted that microangiopathy and chronic low-grade inflammation are widespread in the retina of DR. Meanwhile, with the introduction of the gut-retina axis, it has also been found that DR is associated with gut microecological disorders. The disordered structure of the GM and the destruction of the gut barrier result in the release of abnormal GM flora metabolites into the blood circulation. In addition, this process induced alterations in the expression of various cytokines and proteins, which further modulate the inflammatory microenvironment, vascular damage, oxidative stress, and immune levels within the retina. Such alterations led to the development of DR. In this review, we discuss the corresponding alterations in the structure of the GM flora and its metabolites in DR, with a more detailed focus on the mechanism of gut microecology in DR. Finally, we summarize the potential therapeutic approaches of DM/DR, mainly regulating the disturbed gut microecology to restore the homeostatic level, to provide a new perspective on the prevention, monitoring, and treatment of DR.
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Affiliation(s)
- Rui Wang
- Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi, China
| | - Qiu-Yuan Wang
- Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi, China
| | - Yang Bai
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi, China
| | - Ye-Ge Bi
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi, China
| | - Shan-Jun Cai
- Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi, China
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5
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Gu XM, Lu CY, Pan J, Ye JZ, Zhu QH. Alteration of intestinal microbiota is associated with diabetic retinopathy and its severity: Samples collected from southeast coast Chinese. World J Diabetes 2023; 14:862-882. [PMID: 37383585 PMCID: PMC10294055 DOI: 10.4239/wjd.v14.i6.862] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/09/2023] [Accepted: 04/27/2023] [Indexed: 06/14/2023] Open
Abstract
BACKGROUND Current approaches for the therapy of diabetic retinopathy (DR), which was one of leading causes of visual impairment, have their limitations. Animal experiments revealed that restructuring of intestinal microbiota can prevent retinopathy.
AIM To explore the relationship between intestinal microbiota and DR among patients in the southeast coast of China, and provide clues for novel ways to prevention and treatment methods of DR.
METHODS The fecal samples of non-diabetics (Group C, n = 15) and diabetics (Group DM, n = 30), including 15 samples with DR (Group DR) and 15 samples without DR (Group D), were analyzed by 16S rRNA sequencing. Intestinal microbiota compositions were compared between Group C and Group DM, Group DR and Group D, as well as patients with proliferative diabetic retinopathy (PDR) (Group PDR, n = 8) and patients without PDR (Group NPDR, n = 7). Spearman correlation analyses were performed to explore the associations between intestinal microbiota and clinical indicators.
RESULTS The alpha and beta diversity did not differ significantly between Group DR and Group D as well as Group PDR and Group NPDR. At the family level, Fusobacteriaceae, Desulfovibrionaceae and Pseudomonadaceae were significantly increased in Group DR than in Group D (P < 0.05, respectively). At the genera level, Fusobacterium, Pseudomonas, and Adlercreutzia were increased in Group DR than Group D while Senegalimassilia was decreased (P < 0.05, respectively). Pseudomonas was negatively correlated with NK cell count (r = -0.39, P = 0.03). Further, the abundance of genera Eubacterium (P < 0.01), Peptococcus, Desulfovibrio, Acetanaerobacterium and Negativibacillus (P < 0.05, respectively) were higher in Group PDR compared to Group NPDR, while Pseudomonas, Alloprevotella and Tyzzerella (P < 0.05, respectively) were lower. Acetanaerobacterium and Desulfovibrio were positively correlated with fasting insulin (r = 0.53 and 0.61, respectively, P < 0.05), when Negativibacillus was negatively correlated with B cell count (r = -0.67, P < 0.01).
CONCLUSION Our findings indicated that the alteration of gut microbiota was associated with DR and its severity among patients in the southeast coast of China, probably by multiple mechanisms such as producing short-chain fatty acids, influencing permeability of blood vessels, affecting levels of vascular cell adhesion molecule-1, hypoxia-inducible factor-1, B cell and insulin. Modulating gut microbiota composition might be a novel strategy for prevention of DR, particularly PDR in population above.
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Affiliation(s)
- Xue-Mei Gu
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
- Wenzhou Key Laboratory of Diabetes Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Chao-Yin Lu
- Department of Endocrinology, Taizhou Central Hospital (Taizhou University Hospital), Taizhou 318000, Zhejiang Province, China
| | - Jian Pan
- Department of Ophthalmology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Jian-Zhong Ye
- Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Qi-Han Zhu
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
- Wenzhou Key Laboratory of Diabetes Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
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Serban D, Dascalu AM, Arsene AL, Tribus LC, Vancea G, Pantea Stoian A, Costea DO, Tudosie MS, Stana D, Cristea BM, Nicolae VA, Tudor C, Costea AC, Comandasu M, Faur M, Tanasescu C. Gut Microbiota Dysbiosis in Diabetic Retinopathy-Current Knowledge and Future Therapeutic Targets. Life (Basel) 2023; 13:life13040968. [PMID: 37109497 PMCID: PMC10144923 DOI: 10.3390/life13040968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 03/30/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
Diabetic retinopathy is one of the major causes of blindness today, despite important achievements in diagnosis and therapy. The involvement of a gut-retina axis is thought to be a possible risk factor for several chronic eye disease, such as glaucoma, age-related macular degeneration, uveitis, and, recently, diabetic retinopathy. Dysbiosis may cause endothelial disfunction and alter retinal metabolism. This review analyzes the evidence regarding changes in gut microbiota in patients with DR compared with diabetics and healthy controls (HCs). A systematic review was performed on PubMed, Web of Science, and Google Scholar for the following terms: "gut microbiota" OR "gut microbiome" AND "diabetic retinopathy". Ultimately, 9 articles published between 2020 and 2022 presenting comparative data on a total of 228 T2DM patients with DR, 220 patients with T2DM, and 118 HCs were analyzed. All of the studies found a distinctive microbial beta diversity in DR vs. T2DM and HC, characterized by an altered Firmicutes/Bacteroidetes ratio, a decrease in butyrate producers, and an increase in LPS-expressing and pro-inflammatory species in the Bacteroidetes and Proteobacteria phyla. The probiotic species Bifidobacterium and Lactobacillus were decreased when compared with T2DM. Gut microbiota influence retinal health in multiple ways and may represent a future therapeutic target in DR.
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Affiliation(s)
- Dragos Serban
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Fourth Surgery Department, Emergency University Hospital Bucharest, 050098 Bucharest, Romania
| | - Ana Maria Dascalu
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Ophthalmology Department, Emergency University Hospital Bucharest, 050098 Bucharest, Romania
| | - Andreea Letitia Arsene
- Faculty of Pharmacy, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Laura Carina Tribus
- Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Department of Internal Medicine, Ilfov Emergency Clinic Hospital, 022113 Bucharest, Romania
| | - Geta Vancea
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
- "Victor Babes" Infectious and Tropical Disease Hospital, 030303 Bucharest, Romania
| | - Anca Pantea Stoian
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Daniel Ovidiu Costea
- Faculty of Medicine, Ovidius University Constanta, 900470 Constanta, Romania
- General Surgery Department, Emergency County Hospital Constanta, 900591 Constanta, Romania
| | - Mihail Silviu Tudosie
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Daniela Stana
- Ophthalmology Department, Emergency University Hospital Bucharest, 050098 Bucharest, Romania
| | - Bogdan Mihai Cristea
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Vanessa Andrada Nicolae
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Ophthalmology Department, Emergency University Hospital Bucharest, 050098 Bucharest, Romania
| | - Corneliu Tudor
- Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Fourth Surgery Department, Emergency University Hospital Bucharest, 050098 Bucharest, Romania
| | | | - Meda Comandasu
- Fourth Surgery Department, Emergency University Hospital Bucharest, 050098 Bucharest, Romania
| | - Mihai Faur
- Faculty of Medicine, University "Lucian Blaga", 550169 Sibiu, Romania
- Department of Surgery, Emergency County Hospital Sibiu, 550245 Sibiu, Romania
| | - Ciprian Tanasescu
- Faculty of Medicine, University "Lucian Blaga", 550169 Sibiu, Romania
- Department of Surgery, Emergency County Hospital Sibiu, 550245 Sibiu, Romania
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7
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Wei L, Sun X, Fan C, Li R, Zhou S, Yu H. The pathophysiological mechanisms underlying diabetic retinopathy. Front Cell Dev Biol 2022; 10:963615. [PMID: 36111346 PMCID: PMC9468825 DOI: 10.3389/fcell.2022.963615] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/12/2022] [Indexed: 12/04/2022] Open
Abstract
Diabetic retinopathy (DR) is the most common complication of diabetes mellitus (DM), which can lead to visual impairment and even blindness in severe cases. DR is generally considered to be a microvascular disease but its pathogenesis is still unclear. A large body of evidence shows that the development of DR is not determined by a single factor but rather by multiple related mechanisms that lead to different degrees of retinal damage in DR patients. Therefore, this article briefly reviews the pathophysiological changes in DR, and discusses the occurrence and development of DR resulting from different factors such as oxidative stress, inflammation, neovascularization, neurodegeneration, the neurovascular unit, and gut microbiota, to provide a theoretical reference for the development of new DR treatment strategies.
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Affiliation(s)
- Lindan Wei
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Department of Immunology, Zunyi Medical University, Zunyi, China
| | - Xin Sun
- Special Key Laboratory of Gene Detection and Therapy of Guizhou Province, School of Basic Medical Sciences, Zunyi Medical University, Zunyi, China
| | - Chenxi Fan
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Department of Immunology, Zunyi Medical University, Zunyi, China
| | - Rongli Li
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Department of Immunology, Zunyi Medical University, Zunyi, China
| | - Shuanglong Zhou
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Department of Immunology, Zunyi Medical University, Zunyi, China
| | - Hongsong Yu
- Special Key Laboratory of Ocular Diseases of Guizhou Province, Department of Immunology, Zunyi Medical University, Zunyi, China
- *Correspondence: Hongsong Yu,
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Bai J, Wan Z, Zhang Y, Wang T, Xue Y, Peng Q. Composition and diversity of gut microbiota in diabetic retinopathy. Front Microbiol 2022; 13:926926. [PMID: 36081798 PMCID: PMC9445585 DOI: 10.3389/fmicb.2022.926926] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectiveDiabetic retinopathy (DR) is one of the most common complications of type 2 diabetes mellitus. The current study investigates the composition, structure, and function of gut microbiota in DR patients and explores the correlation between gut microbiota and clinical characteristics of DR.MethodsA total of 50 stool samples were collected from 50 participants, including 25 DR patients and 25 healthy controls (HCs). 16S ribosomal RNA gene sequencing was used to analyze the gut microbial composition in these two groups. DNA was extracted from the fecal samples using the MiSeq platform.ResultsThe microbial structure and composition of DR patients were different from that of HCs. The microbial richness of gut microbiota in DR was higher than that of normal individuals. The alterations of microbiome of DR patients were associated with disrupted Firmicutes, Bacteroidetes, Synergistota, and Desulfobacterota phyla. In addition, increased levels of Bacteroides, Megamonas, Ruminococcus_torques_group, Lachnoclostridium, and Alistipes, and decreased levels of Blautia, Eubacterium_ hallii_group, Collinsella, Dorea, Romboutsia, Anaerostipes, and Fusicatenibacter genera were observed in the DR groups. Additionally, a stochastic forest model was developed to identify a set of biomarkers with seven bacterial genera that can differentiate patients with DR from those HC. The microbial communities exhibited varied functions in these two groups because of the alterations of the above-mentioned bacterial genera.ConclusionThe altered composition and function of gut microbiota in DR patients indicated that gut microbiome could be used as non-invasive biomarkers, improve clinical diagnostic methods, and identify putative therapeutic targets for DR.
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Thakur PS, Aggarwal D, Takkar B, Shivaji S, Das T. Evidence Suggesting the Role of Gut Dysbiosis in Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2022; 63:21. [PMID: 35877085 PMCID: PMC9339698 DOI: 10.1167/iovs.63.8.21] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose Gut dysbiosis has been identified and tested in human trials for its role in diabetes mellitus (DM). The gut-retina axis could be a potential target for retardation of diabetic retinopathy (DR), a known complication of DM. This study reviews the evidence suggesting gut dysbiosis in DR. Methods The published literature in the past 5 years was reviewed using predetermined keywords and articles. The review intended to determine changes in gut microbiome in DR, the hypothesized mechanisms linking to the gut-retina axis, its predictive potential for progression of DR, and the possible therapeutic targets. Results The gut microbiota of people with DM differ from those without it, and the gut microbiota of people with DR differ from those without it. The difference is more significant in the former (DM versus no DM) and less significant in the latter (DM without DR versus DM with DR). Early research has suggested mechanisms of the gut-retina axis, but these are not different from known changes in the gut microbiome of people with DM. The current evidence on the predictive value of the gut microbiome in the occurrence and progression of DR is low. Therapeutic avenues targeting the gut-retina axis include lifestyle changes, pharmacologic inhibitors, probiotics, and fecal microbiota transplantation. Conclusions Investigating the therapeutic utility of the gut ecosystem for DM and its complications like DR is an emerging area of research. The gut-retina axis could be a target for retardation of DR but needs longitudinal regional studies adjusting for dietary habits.
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Affiliation(s)
- Pratima Singh Thakur
- Anant Bajaj Retina Institute-Srimati Kanuri Santhamma Centre for Vitreoretinal Diseases, L V Prasad Eye Institute, Hyderabad, India
| | - David Aggarwal
- Anant Bajaj Retina Institute-Srimati Kanuri Santhamma Centre for Vitreoretinal Diseases, L V Prasad Eye Institute, Hyderabad, India
| | - Brijesh Takkar
- Anant Bajaj Retina Institute-Srimati Kanuri Santhamma Centre for Vitreoretinal Diseases, L V Prasad Eye Institute, Hyderabad, India.,Indian Health Outcomes, Public Health, and Economics Research (IHOPE) Centre, L V Prasad Eye Institute, Hyderabad, India.,https://orcid.org/0000-0001-5779-7645
| | - Sisinthy Shivaji
- Prof. Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India.,https://orcid.org/0000-0003-0376-4658
| | - Taraprasad Das
- Anant Bajaj Retina Institute-Srimati Kanuri Santhamma Centre for Vitreoretinal Diseases, L V Prasad Eye Institute, Hyderabad, India.,https://orcid.org/0000-0002-1295-4528
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10
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Qin X, Zou H. The role of lipopolysaccharides in diabetic retinopathy. BMC Ophthalmol 2022; 22:86. [PMID: 35193549 PMCID: PMC8862382 DOI: 10.1186/s12886-022-02296-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 02/03/2022] [Indexed: 11/29/2022] Open
Abstract
Diabetes mellitus (DM) is a complex metabolic syndrome characterized by hyperglycemia. Diabetic retinopathy (DR) is the most common complication of DM and the leading cause of blindness in the working-age population of the Western world. Lipopolysaccharides (LPS) is an essential ingredient of the outer membrane of gram-negative bacteria, which induces systemic inflammatory responses and cellular apoptotic changes in the host. High-level serum LPS has been found in diabetic patients at the advanced stages, which is mainly due to gut leakage and dysbiosis. In this light, increasing evidence points to a strong correlation between systemic LPS challenge and the progression of DR. Although the underlying molecular mechanisms have not been fully elucidated yet, LPS-related pathobiological events in the retina may contribute to the exacerbation of vasculopathy and neurodegeneration in DR. In this review, we focus on the involvement of LPS in the progression of DR, with emphasis on the blood-retina barrier dysfunction and dysregulated glial activation. Eventually, we summarize the recent advances in the therapeutic strategies for antagonising LPS activity, which may be introduced to DR treatment with promising clinical value.
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Affiliation(s)
- Xinran Qin
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haidong Zou
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Shanghai Eye Diseases Prevention & Treatment Center, Shanghai Eye Hospital, Shanghai, China. .,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China. .,National Clinical Research Center for Eye Diseases, Shanghai, China. .,Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.
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11
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Jiao J, Yu H, Yao L, Li L, Yang X, Liu L. Recent Insights into the Role of Gut Microbiota in Diabetic Retinopathy. J Inflamm Res 2021; 14:6929-6938. [PMID: 34938095 PMCID: PMC8687677 DOI: 10.2147/jir.s336148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/03/2021] [Indexed: 02/06/2023] Open
Abstract
The microbiome has become a hot issue in recent years. The composition, modification, alteration, and disturbance of gut microbiota were found to influence important physiological processes, including energy metabolism and microenvironmental homeostasis, and lead to various diseases, including obesity, type 2 diabetes mellitus and chronic kidney disease. Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus and one of the leading causes of blindness and vision impairment. The underlying mechanisms in DR pathogenesis remain limited. Recently, important insights have been made regarding possible connections between gut microbiome dysbiosis and ocular disease including DR, uveitis, glaucoma, and age-related macular degeneration, and the concept of a "microbiota-gut-retina axis" has been put forward. Hence, we reviewed current understanding of the relationship between DR and gut microbiota. We summarized potential pathophysiological mechanisms that contribute to the role of the gut microbiota on DR, including hyperglycemia, anti-diabetes drugs, microbial metabolites, and inflammatory properties. We aimed to find novel effective therapeutic options to prevent the onset and development of DR.
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Affiliation(s)
- Jinghua Jiao
- Department of Anesthesiology, Central Hospital, Shenyang Medical College, Shenyang, Liaoning, 110024, People's Republic of China
| | - Honghua Yu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510120, People's Republic of China
| | - Litong Yao
- Department of Breast Surgery, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110001, People's Republic of China
| | - Lihua Li
- Department of Ophthalmology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong, 261031, People's Republic of China
| | - Xiaohong Yang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510120, People's Republic of China
| | - Lei Liu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, 510120, People's Republic of China
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12
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Bayan N, Yazdanpanah N, Rezaei N. Role of Toll-Like Receptor 4 in Diabetic Retinopathy. Pharmacol Res 2021; 175:105960. [PMID: 34718133 DOI: 10.1016/j.phrs.2021.105960] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/23/2021] [Accepted: 10/23/2021] [Indexed: 12/11/2022]
Abstract
Diabetic retinopathy (DR) is the most frequent microvascular complication of diabetes mellitus (DM) and a leading cause of blindness worldwide. Evidence has shown that DR is an inflammatory disease with hyperglycemia playing a causative role in the development of its main features, including inflammation, cellular apoptosis, neurodegeneration, oxidative stress, and neovascularization. Toll-like receptors (TLRs) are a well-known family of pattern recognition receptors (PRRs) responsible for the initiation of inflammatory and immune responses. TLR4 identifies both endogenous and exogenous ligands and is associated with various physiological and pathological pathways in the body. While the detailed pathophysiology of DR is still unclear, increasing data suggests a crucial role for TLR4 in the development of DR. Due to hyperglycemia, TLR4 expression increases in diabetic retina, which activates various pathways leading to DR. Considering the role of TLR4 in DR, several studies have focused on the association of TLR4 polymorphisms and risk of DR development. Moreover, evidence concerning the effect of microRNAs in the pathogenesis of DR, through their interaction with TLR4, indicates the determinant role of TLR4 in this disease. Of note, several agents have proven as effective in alleviating DR through the inhibition of the TLR4 pathway, suggesting new avenues in DR treatment. In this review, we provided a brief overview of the TLR4 structure and biological function and a more comprehensive discussion about the mechanisms of TLR4 activation in DR. Furthermore, we summarized the relationship between TLR4 polymorphisms and risk of DR and the relationship between microRNAs and TLR4 in DR. Finally, we discussed the current progress in designing TLR4 inhibitors, which could be helpful in DR clinical management.
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Affiliation(s)
- Nikoo Bayan
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Niloufar Yazdanpanah
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Nima Rezaei
- Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Tehran, Iran; Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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13
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Dando SJ, Kazanis R, McMenamin PG. Myeloid Cells in the Mouse Retina and Uveal Tract Respond Differently to Systemic Inflammatory Stimuli. Invest Ophthalmol Vis Sci 2021; 62:10. [PMID: 34379096 PMCID: PMC8363776 DOI: 10.1167/iovs.62.10.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/03/2021] [Indexed: 01/14/2023] Open
Abstract
Purpose In spite of clear differences in tissue function and significance to ocular disease, little is known about how immune responses differ between the retina and uveal tract. To this end we compared the effects of acute systemic inflammation on myeloid cells within the mouse retina, iris-ciliary body, and choroid. Methods Systemic inflammation was induced in Cx3cr1gfp/gfp and CD11c-eYFP Crb1wt/wtmice by intraperitoneal lipopolysaccharide (LPS). In vivo fundus imaging was performed at two, 24, and 48 hours after LPS, and ocular tissue wholemounts were immunostained and studied by confocal microscopy. Flow cytometry was used to investigate the expression of activation markers (MHC class II, CD80, CD86) on myeloid cell populations at 24 hours. For functional studies, retinal microglia were isolated from LPS-exposed mice and cocultured with naïve OT-II CD4+ T-cells and ovalbumin peptide. T-cell proliferation was measured by flow cytometry and cytokine assays. Results Systemic LPS altered the density and morphology of retinal microglia; however, retinal microglia did not upregulate antigen presentation markers and failed to stimulate naïve CD4+ T-cell proliferation in vitro. In contrast, uveal tract myeloid cells displayed a phenotype consistent with late-activated antigen-presenting cells at 24 hours. Systemic LPS induced remodeling of myeloid populations within the uveal tract, particularly in the choroid, where dendritic cells were partially displaced by macrophages at 24 hours. Conclusions The disparate myeloid cell responses in the retina and uveal tract after systemic LPS highlight differential regulation of innate immunity within these tissue environments, observations that underpin and advance our understanding of ocular immune privilege.
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Affiliation(s)
- Samantha J. Dando
- Queensland University of Technology, Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Brisbane, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia
| | - Renee Kazanis
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia
| | - Paul G. McMenamin
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia
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14
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Huang Y, Wang Z, Ma H, Ji S, Chen Z, Cui Z, Chen J, Tang S. Dysbiosis and Implication of the Gut Microbiota in Diabetic Retinopathy. Front Cell Infect Microbiol 2021; 11:646348. [PMID: 33816351 PMCID: PMC8017229 DOI: 10.3389/fcimb.2021.646348] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 03/02/2021] [Indexed: 12/16/2022] Open
Abstract
The pathogenesis of type 2 diabetes mellitus (T2DM) is commonly associated with altered gut bacteria. However, whether the microbial dysbiosis that exists in human diabetic patients with or without retinopathy is different remains largely unknown. Here, we collected clinical information and fecal samples from 75 participants, including 25 diabetic patients without retinopathy (DM), 25 diabetic patients with retinopathy (DR), and 25 healthy controls (HC). The gut microbial composition in the three groups was analyzed using 16S ribosomal RNA (rRNA) gene sequencing. Microbial structure and composition differed in the three groups. The α and β diversities in both the DM and DR groups were reduced compared with those in the HC group. Blautia was the most abundant genus, especially in the DM group. In addition, increased levels of Bifidobacterium and Lactobacillus and decreased levels of Escherichia-Shigella, Faecalibacterium, Eubacterium_hallii_group and Clostridium genera were observed in the DM and DR groups compared with the HC group. Furthermore, a biomarker set of 25 bacterial families, which could distinguish patients in the DR group from those in the DM and HC groups was identified, with the area under the curve values ranging from 0.69 to 0.85. Of note, Pasteurellaceae, which was increased in DM and decreased in DR compared with HC, generated a high AUC (0.74) as an individual predictive biomarker. Moreover, 14 family biomarkers were associated with fasting blood glucose levels or diabetes, with most of them being negatively correlated. In summary, our study establishes compositional alterations of gut microbiota in DM and DR, suggesting the potential use of gut microbiota as a non-invasive biomarker for clinical and differential diagnosis, as well as identifying potential therapeutic targets of diabetic retinopathy.
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Affiliation(s)
- Yinhua Huang
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China
| | - Zhijie Wang
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China
| | | | | | | | | | - Jiansu Chen
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China.,Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China.,Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
| | - Shibo Tang
- Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Eye Institute, Changsha, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
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15
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Song J, Han D, Lee H, Kim DJ, Cho JY, Park JH, Seok SH. A Comprehensive Proteomic and Phosphoproteomic Analysis of Retinal Pigment Epithelium Reveals Multiple Pathway Alterations in Response to the Inflammatory Stimuli. Int J Mol Sci 2020; 21:ijms21093037. [PMID: 32344885 PMCID: PMC7246457 DOI: 10.3390/ijms21093037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 12/31/2022] Open
Abstract
Overwhelming and persistent inflammation of retinal pigment epithelium (RPE) induces destructive changes in the retinal environment. However, the precise mechanisms remain unclear. In this study, we aimed to investigate RPE-specific biological and metabolic responses against intense inflammation and identify the molecular characteristics determining pathological progression. We performed quantitative analyses of the proteome and phosphoproteome of the human-derived RPE cell line ARPE-19 after treatment with lipopolysaccharide (LPS) for 45 min or 24 h using the latest isobaric tandem-mass tags (TMTs) labeling approach. This approach led to the identification of 8984 proteins, of which 261 showed a 1.5-fold change in abundance after 24 h of treatment with LPS. A parallel phosphoproteome analysis identified 20,632 unique phosphopeptides from 3207 phosphoproteins with 3103 phosphorylation sites. Integrated proteomic and phosphoproteomic analyses showed significant downregulation of proteins related to mitochondrial respiration and cell cycle checkpoint, while proteins related to lipid metabolism, amino acid metabolism, cell-matrix adhesion, and endoplasmic reticulum (ER) stress were upregulated after LPS stimulation. Further, phosphorylation events in multiple pathways, including MAPKK and Wnt/β-catenin signalings, were identified as involved in LPS-triggered pathobiology. In essence, our findings reveal multiple integrated signals exerted by RPE under inflammation and are expected to give insight into the development of therapeutic interventions for RPE disorders.
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Affiliation(s)
- Juha Song
- Department of Microbiology and Immunology, and Institute of Endemic Disease, Seoul National University College of Medicine, Chongno-gu, Seoul 03080, Korea;
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Seoul National University, Gwanak-gu, Seoul 08826, Korea
| | - Dohyun Han
- Proteomics Core Facility, Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea; (D.H.); (H.L.)
| | - Heonyi Lee
- Proteomics Core Facility, Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea; (D.H.); (H.L.)
| | - Da Jung Kim
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea; (D.J.K.); (J.-Y.C.)
- Department of Biomedical Sciences, Seoul National University College of Medicine, Chongno-gu, Seoul 03080, Korea
| | - Joo-Youn Cho
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul 03080, Korea; (D.J.K.); (J.-Y.C.)
- Department of Biomedical Sciences, Seoul National University College of Medicine, Chongno-gu, Seoul 03080, Korea
| | - Jae-Hak Park
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Seoul National University, Gwanak-gu, Seoul 08826, Korea
- Correspondence: (J.-H.P.); (S.H.S.); Tel.: +82-2-880-1256 (J.-H.P.); +82-2-740-8302 (S.H.S.); Fax: +82-2-763-5206 (S.H.S.)
| | - Seung Hyeok Seok
- Department of Microbiology and Immunology, and Institute of Endemic Disease, Seoul National University College of Medicine, Chongno-gu, Seoul 03080, Korea;
- Department of Biomedical Sciences, Seoul National University College of Medicine, Chongno-gu, Seoul 03080, Korea
- Correspondence: (J.-H.P.); (S.H.S.); Tel.: +82-2-880-1256 (J.-H.P.); +82-2-740-8302 (S.H.S.); Fax: +82-2-763-5206 (S.H.S.)
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16
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Kezic JM, McMenamin PG. Systemic exposure to CpG-ODN elicits low-grade inflammation in the retina. Exp Eye Res 2019; 186:107708. [PMID: 31242444 DOI: 10.1016/j.exer.2019.107708] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 01/04/2023]
Abstract
Previous studies have reported that topical exposure to the toll-like receptor (TLR) 9 ligand CpG-ODN causes widespread ocular inflammation, including retinal microglial activation and posterior segment inflammation. Here we sought to determine the effects of systemic exposure to CpG-ODN in the retina and whether this inflammatory response was altered with Cx3cr1 deficiency or hyperglycemia. Male non-diabetic Cx3cr1+/gfp and Cx3cr1gfp/gfp littermates (normoglycemic controls) and Cx3cr1+/gfpIns2Akitaand Cx3cr1gfp/gfpIns2Akita diabetic mice were injected intraperitoneally with 40 μg CpG-ODN. Immunofluorescence staining was performed 1 week later to assess the expression of MHC Class II and glial fibrillary acidic protein (GFAP), as well as to identify morphological changes to microglia and changes in retinal macrophage cell density. Systemic exposure to CpG-ODN induced the upregulated expression of both GFAP on retinal Müller cells and MHC Class II on the retinal vasculature. Additionally, there was an increased accumulation of macrophages in the subretinal space 1 week after exposure to systemic CpG-ODN as well as characteristic morphological changes to microglia indicative of an activated phenotype. These preliminary studies demonstrate that low-grade inflammatory changes were not enhanced in Cx3cr1-deficient or diabetic mice, indicating that the inflammatory response to systemic CpG-ODN in the retina is unaltered in the context of Cx3cr1 deficiency or prolonged hyperglycemia.
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Affiliation(s)
- Jelena M Kezic
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia.
| | - Paul G McMenamin
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
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17
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Francis AW, Wanek J, Shahidi M. Assessment of Global and Local Alterations in Retinal Layer Thickness in Ins2 (Akita) Diabetic Mice by Spectral Domain Optical Coherence Tomography. J Ophthalmol 2018; 2018:7253498. [PMID: 29675273 PMCID: PMC5838457 DOI: 10.1155/2018/7253498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/24/2017] [Indexed: 12/27/2022] Open
Abstract
PURPOSE/AIM The Ins2 (Akita) mouse is a spontaneous diabetic mouse model with a heterozygous mutation in the insulin 2 gene that results in sustained hyperglycemia. The purpose of the study was to assess global and local retinal layer thickness alterations in Akita mice by analysis of spectral domain optical coherence tomography (SD-OCT) images. MATERIALS AND METHODS SD-OCT imaging was performed in Akita and wild-type mice at 12 and 24 weeks of age. Inner retinal thickness (IRT), outer retinal thickness (ORT), total retinal thickness (TRT), and photoreceptor outer segment length (OSL) were measured. Mean global thickness values were compared between Akita and wild-type mice. Local thickness variations in Akita mice were assessed based on normative values in wild-type mice. RESULTS Akita mice had higher blood glucose levels and lower body weights (p < 0.001). On average, IRT, ORT, and TRT were approximately 2% lower in Akita mice than in wild-type mice (p ≤ 0.02). In Akita mice, the percent difference between retinal areas with thickness below and above normative values for IRT, ORT, and TRT was 22%, 32%, and 38%, respectively. CONCLUSIONS These findings support the use of the Akita mouse model to study the retinal neurodegenerative effects of hyperglycemia.
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Affiliation(s)
- Andrew W. Francis
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA
| | - Justin Wanek
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
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18
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Xu WQ, Wang YS. The role of Toll-like receptors in retinal ischemic diseases. Int J Ophthalmol 2016; 9:1343-51. [PMID: 27672603 DOI: 10.18240/ijo.2016.09.19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 03/01/2016] [Indexed: 02/08/2023] Open
Abstract
Toll-like receptors (TLRs) are commonly referred to a series of evolutionary conserved receptors which recognize and respond to various microbes and endogenous ligands. Growing evidence has demonstrated that the expression of TLRs in the retina is regulated during retinal ischemic diseases, including ischemia-reperfusion injury, glaucoma, diabetic retinopathy (DR) and retinopathy of prematurity (ROP). TLRs can be expressed in multiple cells in the retina, such as glial cells, retinal pigment epithelium (RPE), as well as photoreceptor cells and endothelium cells. Activation of TLRs in retina could initiate a complex signal transduction cascade, induce the production of inflammatory cytokines and regulate the level of co-stimulatory molecules, which play prominent roles in the pathogenesis of retinal ischemic diseases. In this review, we summarized current studies about the relationship between TLRs and ischemic retinopathy. A greater understanding of the effect of TLRs on ischemic injuries may contribute to the development of specific TLR targeted therapeutic strategies in these conditions.
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Affiliation(s)
- Wen-Qin Xu
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
| | - Yu-Sheng Wang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China
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19
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Huang NQ, Jin H, Zhou SY, Shi JS, Jin F. TLR4 is a link between diabetes and Alzheimer's disease. Behav Brain Res 2016; 316:234-244. [PMID: 27591966 DOI: 10.1016/j.bbr.2016.08.047] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/23/2016] [Accepted: 08/24/2016] [Indexed: 01/30/2023]
Abstract
Recently, more and more studies have shown that there is an essential link between diabetes mellitus (DM) and Alzheimer's disease (AD). In addition, innate immunity plays an important role in the occurrence and development of DM and AD, which increase the risk of developing type 2 diabetes (T2D) and AD. Although the pathogenesis of those diseases is still a matter of debate, the important role of Toll-like receptor 4 (TLR4) in the two diseases has been receiving much attention at present. TLR4 and insulin resistance do have close ties, and chronic TLR4 activation may contribute to the insulin resistance. Aside from this, TLR4-mediated chronic inflammation also causes many DM complications such as diabetic nephropathy, diabetic retinopathy and diabetic neuropathy and has a profound impact on the internal environment of the body and brain's microenvironment. In parallel, TLR4 is widely distributed in the brain and also has an important role in the central nervous system (CNS) via regulation of neuroinflammation. The cerebrum under the circumstances of insulin resistance may lead to mitochondrial dysfunction in neurons. Interestingly, in the initial stage, the activation of TLR4 has a useful scavenging effect on amyloid beta (Aβ), but chronic long-term activation leads to Aβ deposition in the brain. Therefore we speculate that the TLR4 signaling pathway may be a potential link between DM and AD.
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Affiliation(s)
- Nan-Qu Huang
- Department of Pharmacology and the Key Laboratory of Basic Pharmacology of Guizhou Province, Zunyi Medical College, Guizhou, China
| | - Hai Jin
- Institute of Digestive Diseases of Affiliated Hospital, Zunyi Medical College, Guizhou, China
| | - Shao-Yu Zhou
- Department of Pharmacology and the Key Laboratory of Basic Pharmacology of Guizhou Province, Zunyi Medical College, Guizhou, China; Department of Environmental Health, Indiana University, Bloomington, Indiana, United States
| | - Jing-Shan Shi
- Department of Pharmacology and the Key Laboratory of Basic Pharmacology of Guizhou Province, Zunyi Medical College, Guizhou, China
| | - Feng Jin
- Department of Pharmacology and the Key Laboratory of Basic Pharmacology of Guizhou Province, Zunyi Medical College, Guizhou, China.
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20
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Xu L, Zhang P, Guan H, Huang Z, He X, Wan X, Xiao H, Li Y. Vitamin D and its receptor regulate lipopolysaccharide-induced transforming growth factor-β, angiotensinogen expression and podocytes apoptosis through the nuclear factor-κB pathway. J Diabetes Investig 2016; 7:680-8. [PMID: 27180929 PMCID: PMC5009129 DOI: 10.1111/jdi.12505] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 01/13/2016] [Accepted: 02/20/2016] [Indexed: 12/01/2022] Open
Abstract
AIMS/INTRODUCTION To investigate the effects of vitamin D and its receptor on cytokines expression and podocytes apoptosis. MATERIALS AND METHODS Cultured mouse podocytes were pre-incubated with vitamin D or transiently transfected with small interfering ribonucleic acid (RNA) to knock down the vitamin D receptor. Lipopolysaccharide was used to mimic the inflammation status of diabetes. RESULTS In a lipopolysaccharide-induced state, expressions of transforming growth factor-β, angiotensinogen and vascular endothelial growth factor were similarly increased. Transforming growth factor-β and angiotensinogen levels originally elevated by lipopolysaccharide challenge were distinctly reduced after pre-incubation with vitamin D. Whereas after vitamin D receptor small interfering (si)RNA transfection, the aforementioned cytokines had opposite changes as expected. However, neither vitamin D pretreatment nor vitamin D receptor siRNA transfection influenced the previously increased vascular endothelial growth factor expression at messenger RNA or protein levels. When pretreated with vitamin D, decreases were observed for phosphorylated inhibitor-κB and the inhibitor kinase proteins. After siRNA transfection, those proteins levels were further elevated. The originally increased transforming growth factor-β and angiotensinogen levels as a result of lipopolysaccharide stimulation were reduced at both the messenger RNA and protein levels after the specific inhibition of the nuclear factor-κB pathway with pyrrolidine dithiocarbamate. The apoptosis rate of podocytes was decreased in a parallel manner after vitamin D pre-incubation, and increased after siRNA transfection, which was also suppressed by pyrrolidine dithiocarbamate. CONCLUSIONS Vitamin D and its receptor might be involved in the progression of diabetic nephropathy by regulating transforming growth factor-β, angiotensinogen expression and apoptosis of podocytes. The processes are mediated through the signaling of nuclear factor-κB pathway.
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Affiliation(s)
- Lijuan Xu
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Pengyuan Zhang
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Hongyu Guan
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Zhimin Huang
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xiaoying He
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xuesi Wan
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Haipeng Xiao
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yanbing Li
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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21
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Veenstra A, Liu H, Lee CA, Du Y, Tang J, Kern TS. Diabetic Retinopathy: Retina-Specific Methods for Maintenance of Diabetic Rodents and Evaluation of Vascular Histopathology and Molecular Abnormalities. ACTA ACUST UNITED AC 2015; 5:247-270. [PMID: 26331759 DOI: 10.1002/9780470942390.mo140190] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Diabetic retinopathy is a major cause of visual impairment, which continues to increase in prevalence as more and more people develop diabetes. Despite the importance of vision, the retina is one of the smallest tissues in the body, and specialized techniques have been developed to study retinopathy. This article summarizes several methods used to (i) induce diabetes in mice, (ii) maintain the diabetic animals throughout the months required for development of typical vascular histopathology, (iii) evaluate vascular histopathology of diabetic retinopathy, and (iv) quantitate abnormalities implicated in the development of the retinopathy.
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Affiliation(s)
- Alexander Veenstra
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio.,These authors contributed equally to this work
| | - Haitao Liu
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,These authors contributed equally to this work
| | - Chieh Allen Lee
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio
| | - Yunpeng Du
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio
| | - Jie Tang
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio
| | - Timothy S Kern
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio
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Abstract
SIGNIFICANCE Pattern-recognition receptors (PRRs) are a family of receptors that are used to detect pathogen-associated molecular patterns or damage-associated molecular patterns, which initiate immune responses to resolve infections and repair damaged tissues. Abnormalities in PRR activation will unavoidably lead to excessive inflammation. RECENT ADVANCES Although multiple pathophysiological processes are involved in cardiovascular disease, recent studies have highlighted the importance of innate PRRs, in particular, Toll-like receptors and nucleotide-binding oligomerization domain-like receptors, in mediating inflammatory responses and cardiovascular function. CRITICAL ISSUES The functional roles and regulatory mechanisms of PRRs in cardiovascular diseases are still largely unknown. In particular, controversies exist on the certainty of these detrimental or beneficial effects of some PRRs in different diseased states or different experimental animal models. FUTURE DIRECTIONS Considering that the molecular mechanisms for individual PRR to regulate cellular function are complex and multiple PRRs are activated simultaneously or synergistically, a better understanding of the function of individual PRRs and the interplay of PRRs will provide unexpected opportunities to develop new therapies for cardiovascular disease by modulation of an innate immune system.
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Affiliation(s)
- Xiaojie Wang
- Department of Pharmacology, Shandong University School of Medicine , Jinan, China
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Ha JH, Shil PK, Zhu P, Gu L, Li Q, Chung S. Ocular inflammation and endoplasmic reticulum stress are attenuated by supplementation with grape polyphenols in human retinal pigmented epithelium cells and in C57BL/6 mice. J Nutr 2014; 144:799-806. [PMID: 24699803 PMCID: PMC6611528 DOI: 10.3945/jn.113.186957] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Inflammation and endoplasmic reticulum (ER) stress are common denominators for vision-threatening diseases such as diabetic retinopathy and age-related macular degeneration. Based on our previous study, supplementation with muscadine grape polyphenols (MGPs) alleviated systemic insulin resistance and proinflammatory responses. In this study, we hypothesized that MGPs would also be effective in attenuating ocular inflammation and ER stress. We tested this hypothesis using the human retinal pigmented epithelium (ARPE-19) cells and C57BL/6 mice. In ARPE-19 cells, tumor necrosis factor-α-induced proinflammatory gene expression of interleukin (IL)-1β, IL-6, and monocyte chemotactic protein-1 was decreased by 35.0%, 68.8%, and 62.5%, respectively, with MGP pretreatment, which was primarily due to the diminished mitogen-activated protein kinase activation and subsequent reduction of nuclear factor κ-B activation. Consistently, acute ocular inflammation and leukocyte infiltration were almost completely dampened (>95%) by MGP supplementation (100-200 mg/kg body weight) in C57BL/6 mice. Moreover, MGPs reduced inflammation-mediated loss of tight junctions and retinal permeability. To further investigate the protective roles of MGPs against ER stress, ARPE-19 cells were stimulated with thapsigargin. Pretreatment with MGPs significantly decreased the following: 1) ER stress-mediated vascular endothelial growth factor secretion (3.47 ± 0.06 vs. 1.58 ± 0.02 μg/L, P < 0.0001), 2) unfolded protein response, and 3) early apoptotic cell death (64.4 ± 6.85 vs. 33.7 ± 4.32%, P = 0.0003). Collectively, we have demonstrated that MGP is effective in attenuating ocular inflammation and ER stress. Our work also suggests that MGP may provide a novel dietary strategy to prevent vision-threatening retinal diseases.
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Affiliation(s)
- Jung-Heun Ha
- Department of Food Science and Human Nutrition, University of Florida,
Gainesville, FL
| | | | - Ping Zhu
- Department of Ophthalmology, University of Florida, Gainesville, FL
| | - Liwei Gu
- Department of Food Science and Human Nutrition, University of Florida,
Gainesville, FL
| | - Qiuhong Li
- Department of Ophthalmology, University of Florida, Gainesville, FL
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Hombrebueno JR, Chen M, Penalva RG, Xu H. Loss of synaptic connectivity, particularly in second order neurons is a key feature of diabetic retinal neuropathy in the Ins2Akita mouse. PLoS One 2014; 9:e97970. [PMID: 24848689 PMCID: PMC4029784 DOI: 10.1371/journal.pone.0097970] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 04/26/2014] [Indexed: 11/19/2022] Open
Abstract
Retinal neurodegeneration is a key component of diabetic retinopathy (DR), although the detailed neuronal damage remains ill-defined. Recent evidence suggests that in addition to amacrine and ganglion cell, diabetes may also impact on other retinal neurons. In this study, we examined retinal degenerative changes in Ins2Akita diabetic mice. In scotopic electroretinograms (ERG), b-wave and oscillatory potentials were severely impaired in 9-month old Ins2Akita mice. Despite no obvious pathology in fundoscopic examination, optical coherence tomography (OCT) revealed a progressive thinning of the retina from 3 months onwards. Cone but not rod photoreceptor loss was observed in 3-month-old diabetic mice. Severe impairment of synaptic connectivity at the outer plexiform layer (OPL) was detected in 9-month old Ins2Akita mice. Specifically, photoreceptor presynaptic ribbons were reduced by 25% and postsynaptic boutons by 70%, although the density of horizontal, rod- and cone-bipolar cells remained similar to non-diabetic controls. Significant reductions in GABAergic and glycinergic amacrine cells and Brn3a+ retinal ganglion cells were also observed in 9-month old Ins2Akita mice. In conclusion, the Ins2Akita mouse develops cone photoreceptor degeneration and the impairment of synaptic connectivity at the OPL, predominately resulting from the loss of postsynaptic terminal boutons. Our findings suggest that the Ins2Akita mouse is a good model to study diabetic retinal neuropathy.
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Affiliation(s)
- Jose R. Hombrebueno
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
| | - Mei Chen
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
| | - Rosana G. Penalva
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
| | - Heping Xu
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
- * E-mail:
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25
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Rajamani U, Jialal I. Hyperglycemia induces Toll-like receptor-2 and -4 expression and activity in human microvascular retinal endothelial cells: implications for diabetic retinopathy. J Diabetes Res 2014; 2014:790902. [PMID: 25610879 PMCID: PMC4293793 DOI: 10.1155/2014/790902] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/10/2014] [Indexed: 01/30/2023] Open
Abstract
Diabetic retinopathy (DR) causes visual impairment in working age adults and hyperglycemia-mediated inflammation is central in DR. Toll-like receptors (TLRs) play a key role in innate immune responses and inflammation. However, scanty data is available on their role in DR. Hence, in this study, we examined TLR2 and TLR4 mRNA and protein expression and activity in hyperglycemic human retinal endothelial cells (HMVRECs). HMVRECs were treated with hyperglycemia (HG) or euglycemia and mRNA and protein levels of TLR-2, TLR-4, MyD88, IRF3, and TRIF as well as NF-κB p65 activation were measured. IL-8, IL-1β, TNF-α and MCP-1, ICAM-1, and VCAM-1 as well as monocyte adhesion to HMVRECs were also assayed. HG (25 mM) significantly induced TLR2 and TLR4 mRNA and protein in HMVRECs. It also increased both MyD88 and non-MyD88 pathways, nuclear factor-κB (NF-κB), biomediators, and monocyte adhesion. This inflammation was attenuated by TLR-4 or TLR-2 inhibition, and dual inhibition by a TLR inhibitory peptide as well as TLR2 and 4 siRNA. Additionally, antioxidant treatment reduced TLR-2 and TLR4 expression and downstream inflammatory markers. Collectively, our novel data suggest that hyperglycemia induces TLR-2 and TLR-4 activation and downstream signaling mediating increased inflammation possibly via reactive oxygen species (ROS) and could contribute to DR.
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Affiliation(s)
- Uthra Rajamani
- Laboratory for Atherosclerosis and Metabolic Research, Division of Endocrinology, Diabetes and Metabolism, Department of Pathology, University of California Davis Medical Center, Research Building 1, Room 3000, 4635 Second Avenue, Sacramento, CA 95817, USA
| | - Ishwarlal Jialal
- Laboratory for Atherosclerosis and Metabolic Research, Division of Endocrinology, Diabetes and Metabolism, Department of Pathology, University of California Davis Medical Center, Research Building 1, Room 3000, 4635 Second Avenue, Sacramento, CA 95817, USA
- Veterans Affairs Medical Center, Mather, CA 95655, USA
- *Ishwarlal Jialal:
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