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Samoylov AN, Plotnikov DY, Tumanova PA. [Assessment of environmental and genetic risk factors for the development of primary open-angle glaucoma]. Vestn Oftalmol 2023; 139:74-80. [PMID: 37942600 DOI: 10.17116/oftalma202313905174] [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: 11/10/2023]
Abstract
Primary open-angle glaucoma (POAG) is a multifactorial disease with both environmental and genetic factors involved in its pathogenesis. PURPOSE The study evaluates the role of a number of environmental and genetic risk factors in the risk of POAG development and builds a prognostic model. MATERIAL AND METHODS The study group included 197 patients aged 44 to 90 years (98 - patients with POAG, 99 - the control group), who were treated in the Republican Clinical Ophthalmological Hospital of the Ministry of Health of the Republic of Tatarstan named after Prof. E.V. Adamyuk. RESULTS Age, family history of the disease, presence of type 2 diabetes mellitus, arterial hypertension were revealed to be associated with an increased risk of POAG development. The polymorphisms of matrix metalloproteinase MMP9 and vitamin D receptor (VDR) genes were shown to influence the development of POAG. The prognostic model considering these factors had high sensitivity and specificity (72.0% and 82.6% respectively). CONCLUSION The prognostic model based on environmental and genetic factors is important for assessing the risk of POAG and early detection of the disease.
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Santos FM, Mesquita J, Castro-de-Sousa JP, Ciordia S, Paradela A, Tomaz CT. Vitreous Humor Proteome: Targeting Oxidative Stress, Inflammation, and Neurodegeneration in Vitreoretinal Diseases. Antioxidants (Basel) 2022; 11:antiox11030505. [PMID: 35326156 PMCID: PMC8944522 DOI: 10.3390/antiox11030505] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 03/03/2022] [Accepted: 03/04/2022] [Indexed: 12/12/2022] Open
Abstract
Oxidative stress is defined as an unbalance between pro-oxidants and antioxidants, as evidenced by an increase in reactive oxygen and reactive nitrogen species production over time. It is important in the pathophysiology of retinal disorders such as diabetic retinopathy, age-related macular degeneration, retinal detachment, and proliferative vitreoretinopathy, which are the focus of this article. Although the human organism’s defense mechanisms correct autoxidation caused by endogenous or exogenous factors, this may be insufficient, causing an imbalance in favor of excessive ROS production or a weakening of the endogenous antioxidant system, resulting in molecular and cellular damage. Furthermore, modern lifestyles and environmental factors contribute to increased chemical exposure and stress induction, resulting in oxidative stress. In this review, we discuss the current information about oxidative stress and the vitreous proteome with a special focus on vitreoretinal diseases. Additionally, we explore therapies using antioxidants in an attempt to rescue the body from oxidation, restore balance, and maximize healthy body function, as well as new investigational therapies that have shown significant therapeutic potential in preclinical studies and clinical trial outcomes, along with their goals and strategic approaches to combat oxidative stress.
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Affiliation(s)
- Fátima Milhano Santos
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
- Unidad de Proteomica, Centro Nacional de Biotecnología, CSIC, Campus de Cantoblanco, 28049 Madrid, Spain; (S.C.); (A.P.)
- C4-UBI, Cloud Computing Competence Centre, University of Beira Interior, 6200-501 Covilhã, Portugal
- Correspondence: (F.M.S.); (C.T.T.); Tel.: +351-275-319-700 (C.T.T.)
| | - Joana Mesquita
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
| | - João Paulo Castro-de-Sousa
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
- Department of Ophthalmology, Centro Hospitalar de Leiria, 2410-197 Leiria, Portugal
| | - Sergio Ciordia
- Unidad de Proteomica, Centro Nacional de Biotecnología, CSIC, Campus de Cantoblanco, 28049 Madrid, Spain; (S.C.); (A.P.)
| | - Alberto Paradela
- Unidad de Proteomica, Centro Nacional de Biotecnología, CSIC, Campus de Cantoblanco, 28049 Madrid, Spain; (S.C.); (A.P.)
| | - Cândida Teixeira Tomaz
- CICS-UBI—Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, 6201-001 Covilhã, Portugal; or (J.P.C.-d.-S.)
- C4-UBI, Cloud Computing Competence Centre, University of Beira Interior, 6200-501 Covilhã, Portugal
- Chemistry Department, Faculty of Sciences, University of Beira Interior, 6201-001 Covilhã, Portugal
- Correspondence: (F.M.S.); (C.T.T.); Tel.: +351-275-319-700 (C.T.T.)
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Yin J, Chen X. Edaravone prevents high glucose-induced injury in retinal Müller cells through thioredoxin1 and the PGC-1α/NRF1/TFAM pathway. PHARMACEUTICAL BIOLOGY 2021; 59:1233-1244. [PMID: 34506218 PMCID: PMC8439237 DOI: 10.1080/13880209.2021.1972123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 07/10/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
CONTEXT Oxidative injury in a high-glucose (HG) environment may be a mechanism of diabetic retinopathy (DR) and edaravone can protect retinal ganglion cells by scavenging ROS. OBJECTIVE To explore the effect of edaravone on HG-induced injury. MATERIALS AND METHODS First, Müller cells were cultured by different concentrations of glucose for different durations to obtain a suitable culture concentrations and duration. Müller cells were then divided into Control, HG + Vehicle, HG + Eda-5 μM, HG + Eda-10 μM, HG + Eda-20 μM, and HG + Eda-40 μM groups. Cells were cultured by 20 mM glucose and different concentrations of edaravone for 72 h. RESULTS The IC50 of glucose at 12-72 h is 489.3, 103.5, 27.92 and 20.71 mM, respectively. When Müller cells were cultured in 20 mM glucose for 72 h, the cell viability was 52.3%. Edaravone significantly increased cell viability compared to Vehicle (68.4% vs 53.3%; 78.6% vs 53.3%). The EC50 of edaravone is 34.38 μM. HG induced high apoptosis rate (25.5%), while edaravone (20 and 40 μM) reduced it to 12.5% and 6.89%. HG increased the DCF fluorescence signal (189% of Control) and decreased the mitochondrial membrane potential by 57%. Edaravone significantly decreased the DCF fluorescence signal (144% and 132% of Control) and recovered the mitochondrial membrane potential to 68% and 89% of Control. Furthermore, HG decreased the expression of TRX1, PGC-1α, NRF1 and TFAM, which were restored by edaravone. DISCUSSION AND CONCLUSION These findings provide a new potential approach for the treatment of DR and indicated new molecular targets in the prevention of DR.
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Affiliation(s)
- Juanping Yin
- Department of Ophthalmology, The Fourth Hospital of Changsha, Changsha Hospital of Hunan Normal University, Changsha, China
| | - Xinke Chen
- Department of Ophthalmology, Children’s Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China
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Yu JS, Daw J, Portillo JAC, Subauste CS. CD40 Expressed in Endothelial Cells Promotes Upregulation of ICAM-1 But Not Pro-Inflammatory Cytokines, NOS2 and P2X7 in the Diabetic Retina. Invest Ophthalmol Vis Sci 2021; 62:22. [PMID: 34546322 PMCID: PMC8458989 DOI: 10.1167/iovs.62.12.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose CD40 is an upstream inducer of inflammation in the diabetic retina. CD40 is upregulated in retinal endothelial cells in diabetes. The purpose of this study was to determine whether expression of CD40 in endothelial cells is sufficient to promote inflammatory responses in the retina of diabetic mice. Methods Transgenic mice with CD40 expression restricted to endothelial cells (Trg-CD40 EC), transgenic control mice (Trg-Ctr), B6, and CD40−/− mice were made diabetic using streptozotocin. Leukostasis was assessed using FITC-conjugated ConA. Pro-inflammatory molecule expression was examined by real-time PCR, immunohistochemistry, ELISA, or flow cytometry. Release of ATP was assessed by ATP bioluminescence. Results Diabetic B6 and Trg-CD40 EC mice exhibited increased retinal mRNA levels of ICAM-1, higher ICAM-1 expression in endothelial cells, and increased leukostasis. These responses were not detected in diabetic mice that lacked CD40 (CD40−/− and Trg-Ctr). Diabetic B6 but not Trg-CD40 EC mice upregulated TNF-α, IL-1β, and NOS2 mRNA levels. CD40 stimulation in retinal endothelial cells upregulated ICAM-1 but not TNF-α, IL-1β, or NOS2. CD40 ligation did not trigger ATP release by retinal endothelial cells or pro-inflammatory cytokine production in bystander myeloid cells. In contrast to diabetic B6 mice, diabetic Trg-CD40 EC mice did not upregulate P2X7 mRNA levels in the retina. Conclusions Endothelial cell CD40 promotes ICAM-1 upregulation and leukostasis. In contrast, endothelial cell CD40 does not lead to pro-inflammatory cytokine and NOS2 upregulation likely because it does not activate purinergic-mediated pro-inflammatory molecule expression by myeloid cells or induce expression of these pro-inflammatory molecules in endothelial cells.
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Affiliation(s)
- Jin-Sang Yu
- Division of Infectious Diseases and HIV Medicine, Dept. of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jad Daw
- Division of Infectious Diseases and HIV Medicine, Dept. of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jose-Andres C Portillo
- Division of Infectious Diseases and HIV Medicine, Dept. of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Carlos S Subauste
- Division of Infectious Diseases and HIV Medicine, Dept. of Medicine, Case Western Reserve University, Cleveland, Ohio, United States.,Department of Pathology, Case Western Reserve University, Cleveland, Ohio, United States
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Novel Short-Chain Quinones to Treat Vision Loss in a Rat Model of Diabetic Retinopathy. Int J Mol Sci 2021; 22:ijms22031016. [PMID: 33498409 PMCID: PMC7864174 DOI: 10.3390/ijms22031016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 12/17/2022] Open
Abstract
Diabetic retinopathy (DR), one of the leading causes of blindness, is mainly diagnosed based on the vascular pathology of the disease. Current treatment options largely focus on this aspect with mostly insufficient therapeutic long-term efficacy. Mounting evidence implicates mitochondrial dysfunction and oxidative stress in the central etiology of DR. Consequently, drug candidates that aim at normalizing mitochondrial function could be an attractive therapeutic approach. This study compared the mitoprotective compounds, idebenone and elamipretide, side-by-side against two novel short-chain quinones (SCQs) in a rat model of DR. The model effectively mimicked type 2 diabetes over 21 weeks. During this period, visual acuity was monitored by measuring optokinetic response (OKR). Vision loss occurred 5–8 weeks after the onset of hyperglycemia. After 10 weeks of hyperglycemia, visual function was reduced by 65%. From this point, the right eyes of the animals were topically treated once daily with the test compounds. The left, untreated eye served as an internal control. Only three weeks of topical treatment significantly restored vision from 35% to 58–80%, while visual acuity of the non-treated eyes continued to deteriorate. Interestingly, the two novel SCQs restored visual acuity better than idebenone or elamipretide. This was also reflected by protection of retinal pathology against oxidative damage, retinal ganglion cell loss, reactive gliosis, vascular leakage, and retinal thinning. Overall, mitoprotective and, in particular, SCQ-based compounds have the potential to be developed into effective and fast-acting drug candidates against DR.
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Guo Z, Sun X, Yang J, Xie J, Zhong F, Li X, Zhang Y, Han F, Yang X, Yang S, Zhou W, Chang B. Retinal Neuropathy in IGT Stage of OLETF Rats: Another Characteristic Change of Diabetic Retinopathy. J Diabetes Res 2021; 2021:3181347. [PMID: 34712738 PMCID: PMC8548131 DOI: 10.1155/2021/3181347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/14/2021] [Indexed: 11/18/2022] Open
Abstract
AIMS We investigated the changes of retinal structure in normal glucose tolerance (NGT), impaired glucose tolerance (IGT), diabetes mellitus (DM), and diabetic kidney disease (DKD) stages in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS We assigned OLETF rats to four groups based on their OGTT results and 24 h urinary microalbumin (24 h UMA) levels: NGT, IGT, DM, and DKD groups. We observed the structural and the corresponding pathological changes and quantified the expression of HIF-1α, iNOS, NF-κB, VEGF, ICAM-1, and occludin in the retina. RESULTS Significant damage to the retinal structure, especially in retinal ganglion cells (RGCs), was observed in the IGT stage. The expression of HIF-1α, iNOS, NF-κB, VEGF, and ICAM-1 was significantly upregulated, while that of occludin was downregulated. CONCLUSION Significant retinal neuropathy occurs in the IGT stage. Inflammation and hypoxia may damage the blood retina barrier (BRB), leading to diabetic retinopathy.
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Affiliation(s)
- Zhenhong Guo
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Xiaoyue Sun
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Juhong Yang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Jinlan Xie
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Feifei Zhong
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Xinran Li
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Yi Zhang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Fei Han
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Xiaoyun Yang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin 300000, China
| | - Shaohua Yang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
| | - Wei Zhou
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin 300000, China
| | - Baocheng Chang
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300134, China
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Asano T, Kunikata H, Yasuda M, Nishiguchi KM, Abe T, Nakazawa T. Ocular microcirculation changes, measured with laser speckle flowgraphy and optical coherence tomography angiography, in branch retinal vein occlusion with macular edema treated by ranibizumab. Int Ophthalmol 2020; 41:151-162. [PMID: 32894391 DOI: 10.1007/s10792-020-01562-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/17/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE This study searched for early predictive vascular biomarkers for visual outcomes in eyes with macular edema caused by branch retinal vein occlusion (BRVOME). METHODS Twenty-four eyes of 24 subjects with BRVOME were treated with the intravitreal injection of ranibizumab (IVR) for at least 6 months. We measured mean blur rate (MBR) in the optic nerve head (ONH) and vessel density (VD) in the macula with laser speckle flowgraphy and optical coherence tomography angiography, respectively. RESULTS Six-month post-IVR best-corrected visual acuity (BCVA) was correlated positively with age, pre-IVR BCVA, 1-month post-IVR BCVA, 3-month post-IVR BCVA and pre-IVR systolic blood pressure (P < 0.001, P < 0.001, P < 0.001, P < 0.001 and P = 0.02, respectively) and negatively with pre-IVR overall MBR, 1-month post-IVR overall MBR, 6-month post-IVR overall MBR, 3-month post-IVR deep retinal capillary plexus (DCP) VD and 6-month post-IVR DCP VD (P = 0.03, P = 0.03, P = 0.02, P = 0.01 and P = 0.005, respectively). Furthermore, a multiple regression analysis showed that pre-IVR overall MBR (β = - 0.67, P = 0.009) was among independent prognostic factors predicting 6-month post-IVR BCVA. Six-month post-IVR DCP VD was also correlated with overall MBR at all time points. CONCLUSION ONH blood flow may be a pre-IVR biomarker of both visual outcomes and post-IVR deep macular microcirculation in eyes with BRVOME.
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Affiliation(s)
- Toshifumi Asano
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| | - Hiroshi Kunikata
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan. .,Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
| | - Masayuki Yasuda
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan
| | - Koji M Nishiguchi
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Toshiaki Abe
- Division of Clinical Cell Therapy, United Centers for Advanced Research and Translational Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8574, Japan.,Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Ophthalmic Imaging and Information Analytics, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
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Wright WS, Eshaq RS, Lee M, Kaur G, Harris NR. Retinal Physiology and Circulation: Effect of Diabetes. Compr Physiol 2020; 10:933-974. [PMID: 32941691 PMCID: PMC10088460 DOI: 10.1002/cphy.c190021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
In this article, we present a discussion of diabetes and its complications, including the macrovascular and microvascular effects, with the latter of consequence to the retina. We will discuss the anatomy and physiology of the retina, including aspects of metabolism and mechanisms of oxygenation, with the latter accomplished via a combination of the retinal and choroidal blood circulations. Both of these vasculatures are altered in diabetes, with the retinal circulation intimately involved in the pathology of diabetic retinopathy. The later stages of diabetic retinopathy involve poorly controlled angiogenesis that is of great concern, but in our discussion, we will focus more on several alterations in the retinal circulation occurring earlier in the progression of disease, including reductions in blood flow and a possible redistribution of perfusion that may leave some areas of the retina ischemic and hypoxic. Finally, we include in this article a more recent area of investigation regarding the diabetic retinal vasculature, that is, the alterations to the endothelial surface layer that normally plays a vital role in maintaining physiological functions. © 2020 American Physiological Society. Compr Physiol 10:933-974, 2020.
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Affiliation(s)
- William S Wright
- Department of Biomedical Sciences, University of South Carolina School of Medicine Greenville, Greenville, South Carolina, USA
| | - Randa S Eshaq
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
| | - Minsup Lee
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
| | - Gaganpreet Kaur
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
| | - Norman R Harris
- Department of Molecular and Cellular Physiology, Louisiana State University Health Shreveport, Shreveport, Louisiana, USA
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Dierschke SK, Toro AL, Miller WP, Sunilkumar S, Dennis MD. Diabetes enhances translation of Cd40 mRNA in murine retinal Müller glia via a 4E-BP1/2-dependent mechanism. J Biol Chem 2020; 295:10831-10841. [PMID: 32475820 DOI: 10.1074/jbc.ra120.013711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/27/2020] [Indexed: 11/06/2022] Open
Abstract
Activation of the immune costimulatory molecule cluster of differentiation 40 (CD40) in Müller glia has been implicated in the initiation of diabetes-induced retinal inflammation. Results from previous studies support that CD40 protein expression is elevated in Müller glia of diabetic mice; however, the mechanisms responsible for this increase have not been explored. Here, we evaluated the hypothesis that diabetes augments translation of the Cd40 mRNA. Mice receiving thiamet G (TMG), an inhibitor of the O-GlcNAc hydrolase O-GlcNAcase, exhibited enhanced retinal protein O-GlcNAcylation and increased Cd40 mRNA translation. TMG administration also promoted Cd40 mRNA association with Müller cell-specific ribosomes isolated from the retina of RiboTag mice. Similar effects on O-GlcNAcylation and Cd40 mRNA translation were also observed in the retina of a mouse model of type 1 diabetes. In cultured cells, TMG promoted sequestration of the cap-binding protein eIF4E (eukaryotic translation in initiation factor 4E) by 4E-BP1 (eIF4E-binding protein 1) and enhanced cap-independent Cd40 mRNA translation as assessed by a bicistronic reporter that contained the 5'-UTR of the Cd40 mRNA. Ablation of 4E-BP1/2 prevented the increase in Cd40 mRNA translation in TMG-exposed cells, and expression of a 4E-BP1 variant that constitutively sequesters eIF4E promoted reporter activity. Extending on the cell culture results, we found that in contrast to WT mice, diabetic 4E-BP1/2-deficient mice did not exhibit enhanced retinal Cd40 mRNA translation and failed to up-regulate expression of the inflammatory marker nitric-oxide synthase 2. These findings support a model wherein diabetes-induced O-GlcNAcylation of 4E-BP1 promotes Cd40 mRNA translation in Müller glia.
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Affiliation(s)
- Sadie K Dierschke
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
| | - Allyson L Toro
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
| | - William P Miller
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
| | - Siddharth Sunilkumar
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
| | - Michael D Dennis
- Department of Cellular and Molecular Physiology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA .,Department of Ophthalmology, Pennsylvania State College of Medicine, Hershey, Pennsylvania, USA
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10
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Ramírez-Pérez G, Sánchez-Chávez G, Salceda R. Mitochondrial bound hexokinase type I in normal and streptozotocin diabetic rat retina. Mitochondrion 2020; 52:212-217. [DOI: 10.1016/j.mito.2020.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/24/2020] [Accepted: 04/07/2020] [Indexed: 12/19/2022]
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11
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Liu Y, Xiao J, Zhao Y, Zhao C, Yang Q, Du X, Wang X. microRNA-216a protects against human retinal microvascular endothelial cell injury in diabetic retinopathy by suppressing the NOS2/JAK/STAT axis. Exp Mol Pathol 2020; 115:104445. [PMID: 32335083 DOI: 10.1016/j.yexmp.2020.104445] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/13/2020] [Accepted: 04/22/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Since microRNAs (miRNAs) represent as effective therapeutic targets for diabetic retinopathy (DR), we identified aberrantly expressed miRNAs related to cellular dysfunction in DR and further detected their potential targets. This study aimed to explore the synergistic effect of miR-216a, inducible nitric oxide synthase 2 (NOS2) and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway on human retinal microvascular endothelial cell (HRMEC) injury in DR. METHODS The differentially expressed genes in DR were obtained by GEO database, and the downstream signaling pathways and upstream targeted miRNAs were obtained through bioinformatics analysis. Subsequently, a DR model rat was established, and the target miR-216a was overexpressed to observe the pathological and morphological changes of the rat retina and the levels of inflammatory factors. Then, HRMECs were extracted and added with d-Glucose, and then transfected with miR-216a, NOS2 or adding JAK/STAT signaling pathway specific inhibitor to observe changes in cell activity and inflammatory damage. RESULTS NOS2 was significantly upregulated, and the JAK/STAT signaling pathway was significantly activated in DR. miR-216a targeted NOS2, which played a protective role in the retina of DR rats. Moreover, in cell experiments, overexpression of miR-216a promoted the viability of HRMECs under d-glucose treatment, and inhibited NOS2 expression and the JAK/STAT signaling pathway activation. CONCLUSION This study suggests that miR-216a protects against HRMECs injury in DR by suppressing the NOS2/JAK/STAT axis.
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Affiliation(s)
- Yong Liu
- Department of Ophthalmology, Air Force Medical Center, PLA, Beijing 100142, PR China.
| | - Jianhe Xiao
- Department of Ophthalmology, NO.989 Hospital of the PLA Joint Logistics Support Force, Luoyang 471031, Henan, PR China
| | - Yanyan Zhao
- Department of Ophthalmology, Air Force Medical Center, PLA, Beijing 100142, PR China
| | - Chen Zhao
- Department of Ophthalmology, Air Force Medical Center, PLA, Beijing 100142, PR China
| | - Qinghong Yang
- Department of Ophthalmology, Air Force Medical Center, PLA, Beijing 100142, PR China
| | - Xianghong Du
- Department of Ophthalmology, Air Force Medical Center, PLA, Beijing 100142, PR China
| | - Xin Wang
- Department of Ophthalmology, Air Force Medical Center, PLA, Beijing 100142, PR China
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12
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Subauste CS. The CD40-ATP-P2X 7 Receptor Pathway: Cell to Cell Cross-Talk to Promote Inflammation and Programmed Cell Death of Endothelial Cells. Front Immunol 2019; 10:2958. [PMID: 31921199 PMCID: PMC6928124 DOI: 10.3389/fimmu.2019.02958] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 12/02/2019] [Indexed: 12/15/2022] Open
Abstract
Extracellular adenosine 5′-triphosphate (ATP) functions not only as a neurotransmitter but is also released by non-excitable cells and mediates cell–cell communication involving glia. In pathological conditions, extracellular ATP released by astrocytes may act as a “danger” signal that activates microglia and promotes neuroinflammation. This review summarizes in vitro and in vivo studies that identified CD40 as a novel trigger of ATP release and purinergic-induced inflammation. The use of transgenic mice with expression of CD40 restricted to retinal Müller glia and a model of diabetic retinopathy (a disease where the CD40 pathway is activated) established that CD40 induces release of ATP in Müller glia and triggers in microglia/macrophages purinergic receptor-dependent inflammatory responses that drive the development of retinopathy. The CD40-ATP-P2X7 pathway not only amplifies inflammation but also induces death of retinal endothelial cells, an event key to the development of capillary degeneration and retinal ischemia. Taken together, CD40 expressed in non-hematopoietic cells is sufficient to mediate inflammation and tissue pathology as well as cause death of retinal endothelial cells. This process likely contributes to development of degenerate capillaries, a hallmark of diabetic and ischemic retinopathies. Blockade of signaling pathways downstream of CD40 operative in non-hematopoietic cells may offer a novel means of treating diabetic and ischemic retinopathies.
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Affiliation(s)
- Carlos S Subauste
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH, United States.,Department of Pathology, Case Western Reserve University, Cleveland, OH, United States
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13
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Othman R, Vaucher E, Couture R. Bradykinin Type 1 Receptor - Inducible Nitric Oxide Synthase: A New Axis Implicated in Diabetic Retinopathy. Front Pharmacol 2019; 10:300. [PMID: 30983997 PMCID: PMC6449803 DOI: 10.3389/fphar.2019.00300] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/11/2019] [Indexed: 12/15/2022] Open
Abstract
Compelling evidence suggests a role for the inducible nitric oxide synthase, iNOS, and the bradykinin type 1 receptor (B1R) in diabetic retinopathy, including a possible control of the expression and activity of iNOS by B1R. In diabetic retina, both iNOS and B1R contribute to inflammation, oxidative stress, and vascular dysfunction. The present study investigated whether inhibition of iNOS has any impact on inflammatory/oxidative stress markers and on the B1R-iNOS expression, distribution, and action in a model of type I diabetes. Diabetes was induced in 6-week-old Wistar rats by streptozotocin (65 mg.kg-1, i.p.). The selective iNOS inhibitor 1400W (150 μg.10 μl-1) was administered twice a day by eye-drops during the second week of diabetes. The retinae were collected 2 weeks after diabetes induction to assess the protein and gene expression of markers by Western blot and qRT-PCR, the distribution of iNOS and B1R by fluorescence immunocytochemistry, and the vascular permeability by the Evans Blue dye technique. Diabetic retinae showed enhanced expression of iNOS, B1R, carboxypeptidase M (involved in the biosynthesis of B1R agonists), IL-1β, TNF-α, vascular endothelium growth factor A (VEGF-A) and its receptor, VEGF-R2, nitrosylated proteins and increased vascular permeability. All those changes were reversed by treatment with 1400W. Moreover, the additional increase in vascular permeability in diabetic retina induced by intravitreal injection of R-838, a B1R agonist, was also prevented by 1400W. Immunofluorescence staining highlighted strong colocalization of iNOS and B1R in several layers of the diabetic retina, which was prevented by 1400W. This study suggests a critical role for iNOS and B1R in the early stage of diabetic retinopathy. B1R and iNOS appear to partake in a mutual auto-induction and amplification loop to enhance nitrogen species formation and inflammation in diabetic retina. Hence, B1R-iNOS axis deserves closer scrutiny in targeting diabetic retinopathy.
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Affiliation(s)
- Rahmeh Othman
- School of Optometry, University of Montreal, Montreal, QC, Canada.,Department of Pharmacology and Physiology, University of Montreal, Montreal, QC, Canada
| | - Elvire Vaucher
- School of Optometry, University of Montreal, Montreal, QC, Canada
| | - Réjean Couture
- Department of Pharmacology and Physiology, University of Montreal, Montreal, QC, Canada
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Sahajpal NS, Goel RK, Chaubey A, Aurora R, Jain SK. Pathological Perturbations in Diabetic Retinopathy: Hyperglycemia, AGEs, Oxidative Stress and Inflammatory Pathways. Curr Protein Pept Sci 2018; 20:92-110. [DOI: 10.2174/1389203719666180928123449] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/10/2018] [Accepted: 08/29/2017] [Indexed: 01/02/2023]
Abstract
Diabetic retinopathy (DR) remains the leading cause of blindness in working-aged adults
around the world. The proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME) are
the severe vision threatening stages of the disorder. Although, a huge body of research exists in elaborating
the pathological mechanisms that lead to the development of DR, the certainty and the correlation
amongst these pathways remain ambiguous. The complexity of DR lies in the multifactorial pathological
perturbations that are instrumental in both the disease development and its progression. Therefore, a holistic
perspective with an understanding of these pathways and their correlation may explain the pathogenesis
of DR as a unifying mechanism. Hyperglycemia, oxidative stress and inflammatory pathways
are the crucial components that are implicated in the pathogenesis of DR. Of these, hyperglycemia appears
to be the initiating central component around which other pathological processes operate. Thus,
this review discusses the role of hyperglycemia, oxidative stress and inflammation in the pathogenesis of
DR, and highlights the cross-talk amongst these pathways in an attempt to understand the complex interplay
of these mechanisms. Further, an effort has been made to identify the knowledge gap and the key
players in each pathway that may serve as potential therapeutic drug targets.
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Affiliation(s)
- Nikhil Shri Sahajpal
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Rajesh Kumar Goel
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
| | - Alka Chaubey
- Cytogenetics Laboratory, Greenwood Genetic Center, Greenwood, South Carolina, SC, United States
| | - Rohan Aurora
- The International School Bangalore, Karnataka, India
| | - Subheet Kumar Jain
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
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15
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Opatrilova R, Kubatka P, Caprnda M, Büsselberg D, Krasnik V, Vesely P, Saxena S, Ruia S, Mozos I, Rodrigo L, Kruzliak P, dos Santos KG. Nitric oxide in the pathophysiology of retinopathy: evidences from preclinical and clinical researches. Acta Ophthalmol 2018; 96:222-231. [PMID: 28391624 DOI: 10.1111/aos.13384] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/12/2016] [Indexed: 12/11/2022]
Abstract
Retinopathy is the leading cause of blindness and visual disability in working-aged people. The pathogenesis of retinopathy is an actual and still open query. Alterations contributing to oxidative and nitrosative stress, including elevated nitric oxide and superoxide production, changes in the expression of different isoforms of nitric oxide synthase or endogenous antioxidant system, have been implicated in the mechanisms how this ocular disease develops. In addition, it was documented that renin-angiotensin system has been implicated in the progression of retinopathy. Based on comprehensive preclinical and clinical researches in this area, the role of above-mentioned factors in the pathogenesis of diabetic retinopathy, hypertensive retinopathy and ischaemic proliferative retinopathy is reviewed in this study. Moreover, the genetic susceptibility factors involved in the development of the retinopathy and possible strategies that utilize antioxidants as additive therapy are also highlighted here.
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Affiliation(s)
- Radka Opatrilova
- Department of Chemical Drugs; Faculty of Pharmacy; University of Veterinary and Pharmaceutical Sciences; Brno Czech Republic
| | - Peter Kubatka
- Department of Medical Biology; Jessenius Faculty of Medicine; Comenius University in Bratislava; Martin Slovak Republic
- Division of Oncology; Biomedical Center Martin; Jessenius Faculty of Medicine; Comenius University in Bratislava; Martin Slovak Republic
| | - Martin Caprnda
- 2nd Department of Internal Medicine; Faculty of Pharmacy; Comenius University; Bratislava Slovakia
| | | | - Vladimir Krasnik
- Department of Ophthalmology; Faculty of Medicine; Comenius University; Bratislava Slovakia
| | | | - Sandeep Saxena
- Retina Service; Department of Ophthalmology; King George's Medical University; Lucknow India
| | - Surabhi Ruia
- Retina Service; Department of Ophthalmology; King George's Medical University; Lucknow India
| | - Ioana Mozos
- Department of Functional Sciences; “Victor Babes” University of Medicine and Pharmacy; Timisoara Romania
| | - Luis Rodrigo
- Faculty of Medicine; University of Oviedo; Central University Hospital of Asturias (HUCA); Oviedo Spain
| | - Peter Kruzliak
- Department of Chemical Drugs; Faculty of Pharmacy; University of Veterinary and Pharmaceutical Sciences; Brno Czech Republic
| | - Katia Goncalves dos Santos
- Laboratory of Human Molecular Genetics; Universidade Luterana do Brasil; Canoas Brazil
- Experimental and Molecular Cardiovascular Laboratory; Hospital de Clínicas de Porto Alegre; Porto Alegre Brazil
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Loss of CD40 attenuates experimental diabetes-induced retinal inflammation but does not protect mice from electroretinogram defects. Vis Neurosci 2018; 34:E009. [PMID: 28965505 DOI: 10.1017/s0952523817000074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chronic low grade inflammation is considered to contribute to the development of experimental diabetic retinopathy (DR). We recently demonstrated that lack of CD40 in mice ameliorates the upregulation of inflammatory molecules in the diabetic retina and prevented capillary degeneration, a hallmark of experimental diabetic retinopathy. Herein, we investigated the contribution of CD40 to diabetes-induced reductions in retinal function via the electroretinogram (ERG) to determine if inflammation plays a role in the development of ERG defects associated with diabetes. We demonstrate that diabetic CD40-/- mice are not protected from reduction to the ERG b-wave despite failing to upregulate inflammatory molecules in the retina. Our data therefore supports the hypothesis that retinal dysfunction found in diabetics occurs independent of the induction of inflammatory processes.
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Subauste CS. CD40, a Novel Inducer of Purinergic Signaling: Implications to the Pathogenesis of Experimental Diabetic Retinopathy. Vision (Basel) 2017; 1:vision1030020. [PMID: 31740645 PMCID: PMC6835793 DOI: 10.3390/vision1030020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/08/2017] [Accepted: 08/09/2017] [Indexed: 11/16/2022] Open
Abstract
Diabetic retinopathy is a leading complication of diabetes. Death of capillary cells with resulting capillary degeneration is a central feature of this disease. Chronic low-grade inflammation has been linked to the development of retinal capillary degeneration in diabetes. CD40 is an upstream inducer of a broad range of inflammatory responses in the diabetic retina and is required for death of retinal capillary cells. Recent studies uncovered CD40 as a novel inducer of purinergic signaling and identified the CD40-ATP-P2X7 pathway as having a key role in the induction of inflammation in the diabetic retina and programmed cell death of retinal endothelial cells.
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Affiliation(s)
- Carlos S. Subauste
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; ; Tel.: +1-216-368-2785
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
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Retinal exposure to high glucose condition modifies the GABAergic system: Regulation by nitric oxide. Exp Eye Res 2017; 162:116-125. [PMID: 28734674 DOI: 10.1016/j.exer.2017.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/16/2017] [Accepted: 07/18/2017] [Indexed: 11/20/2022]
Abstract
Diabetic retinopathy is a severe retinal complication that diabetic patients are susceptible to present. Although this disease is currently characterized as a microvascular disease, there is growing evidence that neural changes occur and maybe precede vascular impairments. Using chicken retina, an avascular tissue with no direct contact with blood vessels and neural retina, this study aimed to evaluate the influence of acute exposure to high glucose concentration in the retinal GABAergic system, and the role of nitric oxide (NO) in this modulation. Therefore, in ex vivo experiments, retinas were incubated in control (10 mM glucose) or high glucose condition (35 mM) for 30 min. By using DAF-FM to evaluate NO production, it was possible to show that high glucose (HG) significantly increased NO levels in the outer nuclear layer, inner nuclear layer (outer and inner portion), and inner plexiform layer. It was also observed that HG increased GABA immunoreactivity (IR) in amacrine and horizontal cells. HG did not change glutamic acid decarboxylase-IR, whereas it decreased GABA Transporter (GAT) 1-IR and increased GAT-3-IR. The co-treatment with 7-NI, an inhibitor of neuronal nitric oxide synthase (nNOS), blocked all changes stimulated by HG exposure. The concomitant exposure with SNAP-5114, a GAT-2/3 inhibitor, blocked the increase in GABA-IR caused by HG incubation. Therefore, our data suggest that hyperglycemia induces GABA accumulation in the cytosol by modulating GABA transporters. This response is dependent on NO production and signaling.
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VEGF production and signaling in Müller glia are critical to modulating vascular function and neuronal integrity in diabetic retinopathy and hypoxic retinal vascular diseases. Vision Res 2017; 139:108-114. [PMID: 28601428 DOI: 10.1016/j.visres.2017.05.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 12/21/2022]
Abstract
Müller glia (MG) are major retinal supporting cells that participate in retinal metabolism, function, maintenance, and protection. During the pathogenesis of diabetic retinopathy (DR), a neurovascular disease and a leading cause of blindness, MG modulate vascular function and neuronal integrity by regulating the production of angiogenic and trophic factors. In this article, I will (1) briefly summarize our work on delineating the role and mechanism of MG-modulated vascular function through the production of vascular endothelial growth factor (VEGF) and on investigating VEGF signaling-mediated MG viability and neural protection in diabetic animal models, (2) explore the relationship among VEGF and neurotrophins in protecting Müller cells in in vitro models of diabetes and hypoxia and its potential implication to neuroprotection in DR and hypoxic retinal diseases, and (3) discuss the relevance of our work to the effectiveness and safety of long-term anti-VEGF therapies, a widely used strategy to combat DR, diabetic macular edema, neovascular age-related macular degeneration, retinopathy of prematurity, and other hypoxic retinal vascular disorders.
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20
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Danhong Huayu Koufuye Prevents Diabetic Retinopathy in Streptozotocin-Induced Diabetic Rats via Antioxidation and Anti-Inflammation. Mediators Inflamm 2017. [PMID: 28638179 PMCID: PMC5468776 DOI: 10.1155/2017/3059763] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Danhong Huayu Koufuye (DHK), a traditional Chinese prescription, is used to treat central retinal vein occlusion clinically. We previously reported that DHK prevented diabetic retinopathy (DR) in rats. Moreover, we found that it protected endothelial cells from hyperglycemia-induced apoptosis through antioxidation and anti-inflammation. Here, we investigated whether antioxidative and anti-inflammatory activities of DHK contributed to its therapeutic effect on DR in streptozotocin- (STZ-) induced diabetic rats. DHK significantly blocked the breakdown of the blood-retinal barrier (BRB) and increased the thickness of the inner nuclear layer (INL), as well as suppressed the swelling of the ganglion cell layer (GCL) in diabetic retinas. DHK remarkably increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in plasma, and decreased serum level of nitric oxide (NO). Moreover, DHK markedly reduced the serum levels of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1). Furthermore, DHK significantly downregulated protein expressions of VEGF and inducible NO synthase (iNOS) and mRNA expression of ICAM-1 in retinas. These results suggest that the antioxidative and anti-inflammatory activities of DHK may be important mechanisms involved in the protective effect of DHK on DR in STZ-induced diabetic rats.
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21
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Carr BC, Emigh CE, Bennett LD, Pansick AD, Birch DG, Nguyen C. TOWARDS A TREATMENT FOR DIABETIC RETINOPATHY: Intravitreal Toxicity and Preclinical Safety Evaluation of Inducible Nitric Oxide Synthase Inhibitors. Retina 2017; 37:22-31. [PMID: 27380429 DOI: 10.1097/iae.0000000000001133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The purpose of this study is to determine the maximum tolerated dose of a single intravitreal injection of aminoguanidine and 1400W, 2 inhibitors of inducible nitric oxide synthase, in rabbit eyes. Inhibition of inducible nitric oxide synthase has already been shown to be beneficial in various animal models of diabetic eye disease. METHODS Groups of 4 New Zealand white rabbits were injected with balanced salt solution in the right eye and a single dose of either aminoguanidine (5, 1, 0.25 mg) or 1400W (2 mg and 0.4 mg) in the left eye. Toxicity was assessed by slit-lamp and fundus examination, intraocular pressure and pachymetric measurements, and electrophysiologic and histologic analysis. RESULTS Eyes injected with high doses of aminoguanidine (5 mg) or 1400W (2 mg) demonstrated severe retinal vascular attenuation and infarction. Lower doses of intravitreal aminoguanidine (1 mg) and 1400W (0.4 mg) caused no significant toxic ocular effects in rabbit eyes. CONCLUSION If the difference in vitreal volume between rabbit eyes and human eyes is taken into account, aminoguanidine (2.7 mg) and 1400W (1 mg) would be reasonable intravitreal doses to test for safety and efficacy in early clinical trials.
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Affiliation(s)
- B Cameron Carr
- *Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas; and †Retina Foundation of the Southwest, Dallas, Texas
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Wang Y, Meng X, Yan H. Niaspan inhibits diabetic retinopathy‑induced vascular inflammation by downregulating the tumor necrosis factor‑α pathway. Mol Med Rep 2017; 15:1263-1271. [PMID: 28138697 PMCID: PMC5367335 DOI: 10.3892/mmr.2017.6146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 11/22/2016] [Indexed: 12/22/2022] Open
Abstract
Diabetic retinopathy (DR) is a serious microvascular complication of diabetes and a major cause of blindness in the developing world. Early DR is characterized by vascular neuroinflammation, cell apoptosis and breakdown of the blood‑retinal barrier (BRB). However, optimal treatment options and associated mechanisms remain unclear. Niaspan, which is widely used in the prevention and treatment of hyperlipidemia‑associated diseases, has been reported to inhibit inflammation. However, the effects of Niaspan and the mechanisms underlying the anti‑inflammatory effects of Niaspan on DR have yet to be reported. The present study aimed to investigate the anti‑inflammatory effects and mechanisms of Niaspan in a rat model of DR. Rats with DR exhibited a significant increase in BRB breakdown, retinal apoptosis, and tumor necrosis factor‑α (TNF‑α) and nuclear factor‑κB (NF‑κB) expression. In addition, the expression levels of inducible nitric oxide synthase (iNOS) and intercellular cell adhesion molecule‑1 (ICAM‑1) were increased in the retinas of DR rats compared with in the normal control group. In conclusion, treatment with Niaspan significantly improved clinical and histopathological outcomes; decreased the expression levels of TNF‑α, NF‑κB, iNOS and ICAM‑1; and decreased apoptosis and BRB breakdown, as compared with in the retinas of DR rats. The present study is the first, to the best of our knowledge, to demonstrate that Niaspan treatment ameliorates DR by inhibiting inflammation, and also suggests that the TNF‑α pathway may contribute to the beneficial effects of Niaspan treatment.
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Affiliation(s)
- Yang Wang
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Xiangda Meng
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Hua Yan
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
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Kim J, Jo K, Lee IS, Kim CS, Kim JS. The Extract of Aster Koraiensis Prevents Retinal Pericyte Apoptosis in Diabetic Rats and Its Active Compound, Chlorogenic Acid Inhibits AGE Formation and AGE/RAGE Interaction. Nutrients 2016; 8:nu8090585. [PMID: 27657123 PMCID: PMC5037569 DOI: 10.3390/nu8090585] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/05/2016] [Accepted: 09/13/2016] [Indexed: 12/31/2022] Open
Abstract
Retinal capillary cell loss is a hallmark of early diabetic retinal changes. Advanced glycation end products (AGEs) are believed to contribute to retinal microvascular cell loss in diabetic retinopathy. In this study, the protective effects of Aster koraiensis extract (AKE) against damage to retinal vascular cells were investigated in streptozotocin (STZ)-induced diabetic rats. To examine this issue further, AGE accumulation, nuclear factor-kappaB (NF-κB) and inducible nitric oxide synthase (iNOS) were investigated using retinal trypsin digests from streptozotocin-induced diabetic rats. In the diabetic rats, TUNEL (Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling)-positive retinal microvascular cells were markedly increased. Immunohistochemical studies revealed that AGEs were accumulated within the retinal microvascular cells, and this accumulation paralleled the activation of NF-κB and the expression of iNOS in the diabetic rats. However, AKE prevented retinal microvascular cell apoptosis through the inhibition of AGE accumulation and NF-κB activation. Moreover, to determine the active compounds of AKE, two major compounds, chlorogenic acid and 3,5-di-O-caffeoylquinic acid, were tested in an in vitro assay. Among these compounds, chlorogenic acid significantly reduced AGE formation as well as AGE/RAGE (receptor for AGEs) binding activity. These results suggest that AKE, particularly chlorogenic acid, is useful in inhibiting AGE accumulation in retinal vessels and exerts a preventive effect against the injuries of diabetic retinal vascular cells.
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Affiliation(s)
- Junghyun Kim
- Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Kyuhyung Jo
- Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Ik-Soo Lee
- Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Chan-Sik Kim
- Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
| | - Jin Sook Kim
- Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Korea.
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24
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Hernández C, Bogdanov P, Corraliza L, García-Ramírez M, Solà-Adell C, Arranz JA, Arroba AI, Valverde AM, Simó R. Topical Administration of GLP-1 Receptor Agonists Prevents Retinal Neurodegeneration in Experimental Diabetes. Diabetes 2016; 65:172-87. [PMID: 26384381 DOI: 10.2337/db15-0443] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/08/2015] [Indexed: 11/13/2022]
Abstract
Retinal neurodegeneration is an early event in the pathogenesis of diabetic retinopathy (DR). Since glucagon-like peptide 1 (GLP-1) exerts neuroprotective effects in the central nervous system and the retina is ontogenically a brain-derived tissue, the aims of the current study were as follows: 1) to examine the expression and content of GLP-1 receptor (GLP-1R) in human and db/db mice retinas; 2) to determine the retinal neuroprotective effects of systemic and topical administration (eye drops) of GLP-1R agonists in db/db mice; and 3) to examine the underlying neuroprotective mechanisms. We have found abundant expression of GLP-1R in the human retina and retinas from db/db mice. Moreover, we have demonstrated that systemic administration of a GLP-1R agonist (liraglutide) prevents retinal neurodegeneration (glial activation, neural apoptosis, and electroretinographical abnormalities). This effect can be attributed to a significant reduction of extracellular glutamate and an increase of prosurvival signaling pathways. We have found a similar neuroprotective effect using topical administration of native GLP-1 and several GLP-1R agonists (liraglutide, lixisenatide, and exenatide). Notably, this neuroprotective action was observed without any reduction in blood glucose levels. These results suggest that GLP-1R activation itself prevents retinal neurodegeneration. Our results should open up a new approach in the treatment of the early stages of DR.
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Affiliation(s)
- Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - Patricia Bogdanov
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - Lidia Corraliza
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - Marta García-Ramírez
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Solà-Adell
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
| | - José A Arranz
- Unidad de Metabolopatías, Laboratorios Clínicos, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Ana I Arroba
- CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain Instituto de Investigaciones Biomédicas "Alberto Sols," Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid, Madrid, Spain
| | - Angela M Valverde
- CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain Instituto de Investigaciones Biomédicas "Alberto Sols," Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid, Madrid, Spain
| | - Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain CIBERDEM, Instituto de Salud Carlos III, Madrid, Spain
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Wojcik M, Zieleniak A, Zurawska-Klis M, Cypryk K, Wozniak LA. Increased expression of immune-related genes in leukocytes of patients with diagnosed gestational diabetes mellitus (GDM). Exp Biol Med (Maywood) 2015; 241:457-65. [PMID: 26568332 DOI: 10.1177/1535370215615699] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/14/2015] [Indexed: 12/16/2022] Open
Abstract
Compelling evidence indicates that the immune system is linked to metabolism in gestational diabetes mellitus (GDM), but factors participating in these processes still are awaiting identification. Inducible nitric oxide synthase, encoded by the NOS2 gene, and surfactant protein D, encoded by the SFTPD gene, have been implicated in diabetes. We investigated NOS2 and SFTPD mRNA levels in leukocytes obtained from 125 pregnant women with (n = 87) or without (control group; n = 38) GDM, and, in turn, correlated their expression with clinical parameters of subjects. Leukocytes were isolated from the blood of pregnant women and NOS2 and SFTPD expression in these cells was determined by quantitative real time PCR (qRT-PCR). Univariate correlation analyses were performed to assess an association between leukocyte NOS2 and SFTPD expression and clinical characteristics of patients. qRT-PCR experiments disclosed significantly increased leukocyte NOS2 and SFTPD mRNA levels in hyperglycemic GDM patients (P < 0.05). In the entire study group, there were significant positive associations of leukocyte NOS2 and SFTPD mRNAs with C-reactive protein. Additionally, transcript level of SFTPD also correlated positively with fasting glycemia and insulin resistance. This study demonstrates that an impaired glucose metabolism in GDM may be predominant predictor of leukocyte NOS2 and SFTPD overexpression in diabetic patients. Furthermore, alterations in the expression of these genes are associated with glucose metabolism dysfunction and/or inflammation during pregnancy. In addition, these findings support the utilization of leukocytes as good experimental model to study a relationship between immune-related genes and metabolic changes in women with GDM, as well as to assess the potential mechanisms underlying these alterations.
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Affiliation(s)
- Marzena Wojcik
- Department of Structural Biology, Faculty of Biomedical Sciences and Postgraduate Education, Medical University of Lodz, 90-752 Lodz, Poland
| | - Andrzej Zieleniak
- Department of Structural Biology, Faculty of Biomedical Sciences and Postgraduate Education, Medical University of Lodz, 90-752 Lodz, Poland
| | - Monika Zurawska-Klis
- Diabetology and Metabolic Diseases Department, Medical University of Lodz, 92-213 Lodz, Poland Diabetological Medical Center "OmniMed", 93-338 Lodz, Poland
| | - Katarzyna Cypryk
- Diabetology and Metabolic Diseases Department, Medical University of Lodz, 92-213 Lodz, Poland Diabetological Medical Center "OmniMed", 93-338 Lodz, Poland
| | - Lucyna Alicja Wozniak
- Department of Structural Biology, Faculty of Biomedical Sciences and Postgraduate Education, Medical University of Lodz, 90-752 Lodz, Poland
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Jang H, Choi Y, Ahn HR, Jung SH, Lee CY. Effects of phenolic acid metabolites formed after chlorogenic acid consumption on retinal degeneration in vivo. Mol Nutr Food Res 2015; 59:1918-29. [DOI: 10.1002/mnfr.201400897] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 06/04/2015] [Accepted: 06/26/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Holim Jang
- Department of Food Science; Cornell University; Ithaca NY USA
- Natural Products Research Center; Korea Institute of Science and Technology (KIST); Gangneung Republic of Korea
| | - Yongsoo Choi
- Natural Products Research Center; Korea Institute of Science and Technology (KIST); Gangneung Republic of Korea
| | - Hong Ryul Ahn
- Natural Products Research Center; Korea Institute of Science and Technology (KIST); Gangneung Republic of Korea
| | - Sang Hoon Jung
- Natural Products Research Center; Korea Institute of Science and Technology (KIST); Gangneung Republic of Korea
| | - Chang Yong Lee
- Department of Food Science; Cornell University; Ithaca NY USA
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Nagai N, Yoshioka C, Tanino T, Ito Y, Okamoto N, Shimomura Y. Enhanced Production of Nitric Oxide Leads to ATP Collapse in the Retinas of Otsuka Long-Evans Tokushima Fatty Rats, a Model of Human Diabetes. Curr Eye Res 2015; 41:532-42. [PMID: 25941754 DOI: 10.3109/02713683.2015.1030507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE We determined nitric oxide (NO) production via inducible NO synthase (iNOS) by hyperglycemia using the retina of Otsuka Long-Evans Tokushima Fatty rats (OLETF rats), and investigated the relationship between ATP contents and NO production in the retinas of OLETF rats. METHODS Long-Evans Tokushima Otsuka rats (LETO rats, normal rats) and OLETF rats (model rat for diabetes mellitus) aged 60 weeks of age were used. Plasma glucose (Glu) levels were determined using an Accutrend GCT System, and NO levels were measured by the microdialysis method as nitrite ([Formula: see text]). Cytochrome c oxidase (CCO) activity was measured using a Mitochondrial Isolation Kit and Cytochrome c Oxidase Assay Kit, and ATP levels were determined using a Sigma ATP Bioluminescent Assay Kit and a luminometer AB-2200. RESULTS [Formula: see text] levels in the retinas of OLETF rats were significantly higher than in LETO rats, and the [Formula: see text] levels in the retinas of 60-week-old OLETF rats increased with increasing Glu. CCO activity in the retinas of OLETF rats showed no significant difference from that in LETO rats; however, ATP levels in the retinas of OLETF rats were significantly lower than those in LETO rats. The oral administration of aminoguanidine or disulfiram, an iNOS inhibitor, attenuated the decrease in ATP levels in the retinas of 60-week-old OELTF rats. CONCLUSION The present study demonstrates that NO production via iNOS in the retinas of 60-week-old OLETF rats is caused by hyperglycemia, and that NO causes a decrease in ATP contents in the retinas of 60-week-old OELTF rats. It is possible that the low ATP contents caused by NO may affect the normal functioning of the retina in OLETF rats.
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Affiliation(s)
- Noriaki Nagai
- a Faculty of Pharmacy , Kinki University , Higashi-Osaka, Osaka , Japan and
| | - Chiaki Yoshioka
- a Faculty of Pharmacy , Kinki University , Higashi-Osaka, Osaka , Japan and
| | - Tadatoshi Tanino
- a Faculty of Pharmacy , Kinki University , Higashi-Osaka, Osaka , Japan and
| | - Yoshimasa Ito
- a Faculty of Pharmacy , Kinki University , Higashi-Osaka, Osaka , Japan and
| | - Norio Okamoto
- b Department of Ophthalmology, Faculty of Medicine , Kinki University Osaka-Sayama , Osaka , Japan
| | - Yoshikazu Shimomura
- b Department of Ophthalmology, Faculty of Medicine , Kinki University Osaka-Sayama , Osaka , Japan
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Ghahramani M, Yousefi R, Khoshaman K, Alavianmehr MM. The impact of calcium ion on structure and aggregation propensity of peroxynitrite-modified lens crystallins: New insights into the pathogenesis of cataract disorders. Colloids Surf B Biointerfaces 2015; 125:170-80. [DOI: 10.1016/j.colsurfb.2014.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 09/30/2014] [Accepted: 11/03/2014] [Indexed: 12/24/2022]
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Xiao JR, Do CW, To CH. Potential Therapeutic Effects of Baicalein, Baicalin, and Wogonin in Ocular Disorders. J Ocul Pharmacol Ther 2014; 30:605-14. [DOI: 10.1089/jop.2014.0074] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Jing-Ru Xiao
- Laboratory of Experimental Optometry, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, Hong Kong
| | - Chi-Wai Do
- Laboratory of Experimental Optometry, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, Hong Kong
| | - Chi-Ho To
- Laboratory of Experimental Optometry, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, Hong Kong
- State Key Laboratory of Ophthalmology, Department of Ophthalmology, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
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Portillo JAC, Greene JA, Okenka G, Miao Y, Sheibani N, Kern TS, Subauste CS. CD40 promotes the development of early diabetic retinopathy in mice. Diabetologia 2014; 57:2222-31. [PMID: 25015056 PMCID: PMC4291184 DOI: 10.1007/s00125-014-3321-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 06/09/2014] [Indexed: 11/26/2022]
Abstract
AIMS/HYPOTHESIS Microangiopathy is a leading complication of diabetes that commonly affects the retina. Degenerate capillaries are a central feature of diabetic retinopathy. An inflammatory process has been linked to the development of diabetic retinopathy but its regulation is incompletely understood. Cluster of differentiation (CD) 40 is a member of the TNF receptor superfamily that promotes the development of certain inflammatory disorders. The role of CD40 in diabetic microangiopathy is unknown. METHODS B6 and Cd40−/− mice were administered streptozotocin to induce diabetes. Leucostasis was assessed using fluorescein isothiocyanate-conjugated concanavalin A. Retinal Icam1 and Cd40 mRNA levels were examined using real-time PCR. Protein nitration was assessed by immunohistochemistry. Histopathology was examined in the retinal vasculature. CD40 expression was assessed by flow cytometry and immunohistochemistry. Intercellular adhesion molecule 1 (ICAM-1) and nitric oxide synthase 2 (NOS2) were examined by immunoblot and/or flow cytometry. Nitric oxide production was examined by immunoblot and Griess reaction. RESULTS In mouse models of diabetes, Cd40−/− mice exhibited reduced retinal leucostasis and did not develop capillary degeneration in comparison with B6 mice. Diabetic Cd40−/− mice had diminished ICAM-1 upregulation and decreased protein nitration. Cd40 mRNA levels were increased in the retinas of diabetic B6 mice compared with non-diabetic controls. CD40 expression increased in retinal Müller cells, endothelial cells and microglia of diabetic animals. CD40 stimulation upregulated ICAM-1 in retinal endothelial cells and Müller cells. CD40 ligation upregulated NOS2 and nitric oxide production by Müller cells. CONCLUSIONS/INTERPRETATION CD40-deficient mice were protected fromthe development of diabetic retinopathy. These mice exhibited diminished inflammatory responses linked to diabetic retinopathy. CD40 stimulation of retinal cells triggered these pro-inflammatory responses.
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Nitta F, Kunikata H, Aizawa N, Omodaka K, Shiga Y, Yasuda M, Nakazawa T. The effect of intravitreal bevacizumab on ocular blood flow in diabetic retinopathy and branch retinal vein occlusion as measured by laser speckle flowgraphy. Clin Ophthalmol 2014; 8:1119-27. [PMID: 24959068 PMCID: PMC4061168 DOI: 10.2147/opth.s62022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Background This study evaluated the effect of intravitreal injection of bevacizumab (IVB) on macular edema associated with diabetic retinopathy (DME) or branch retinal vein occlusion (BRVOME) using laser speckle flowgraphy. Methods A comparative interventional study of 25 eyes from 22 patients with macular edema (DME group: 12 eyes; BRVOME group: 13 eyes) who underwent IVB. Mean blur rate (MBR) was measured in the retinal artery, retinal vein, optic nerve head (ONH), and choroid before and after IVB. Results In the BRVOME group, there was no significant change in MBR in the retinal artery, retinal vein or ONH, but choroidal MBR decreased significantly (P=0.04). In the DME group, the MBR in the retinal artery, retinal vein, ONH, and choroid decreased significantly (P=0.02, P=0.04, P<0.001, and P=0.04, respectively). In the DME group, pre-IVB MBR in the ONH was significantly correlated with post-IVB foveal thickness (R= −0.71, P=0.002). There was no such correlation in the BRVOME group in the ONH. Conclusion IVB had a suppressive effect on circulation in eyes with DME but not in those with BRVOME. This suggests that this noninvasive and objective biomarker may be a useful part of pre-IVB evaluations and decision-making in DME.
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Affiliation(s)
- Fumihiko Nitta
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hiroshi Kunikata
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan ; Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Naoko Aizawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kazuko Omodaka
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yukihiro Shiga
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Masayuki Yasuda
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan ; Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Japan ; Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan
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Abu El-Asrar AM, Al-Mezaine HS, Ola MS. Pathophysiology and management of diabetic retinopathy. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.09.52] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Bhat M, Pouliot M, Couture R, Vaucher E. The kallikrein-kinin system in diabetic retinopathy. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2014; 69:111-43. [PMID: 25130041 DOI: 10.1007/978-3-319-06683-7_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Diabetic retinopathy (DR) is a major microvascular complication associated with type 1 and type 2 diabetes mellitus, which can lead to visual impairment and blindness. Current treatment strategies for DR are mostly limited to laser therapies, steroids, and anti-VEGF agents, which are often associated with unwanted side effects leading to further complications. Recent evidence suggests that kinins play a primary role in the development of DR through enhanced vascular permeability, leukocytes infiltration, and other inflammatory mechanisms. These deleterious effects are mediated by kinin B1 and B2 receptors, which are expressed in diabetic human and rodent retina. Importantly, kinin B1 receptor is virtually absent in sane tissue, yet it is induced and upregulated in diabetic retina. These peptides belong to the kallikrein-kinin system (KKS), which contains two separate and independent pathways of regulated serine proteases, namely plasma kallikrein (PK) and tissue kallikrein (TK) that are involved in the biosynthesis of bradykinin (BK) and kallidin (Lys-BK), respectively. Hence, ocular inhibition of kallikreins or antagonism of kinin receptors offers new therapeutic avenues in the treatment and management of DR. Herein, we present an overview of the principal features and known inflammatory mechanisms associated with DR along with the current therapeutic approaches and put special emphasis on the KKS as a new and promising therapeutic target due to its link with key pathways directly associated with the development of DR.
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Leonelli M, Martins DO, Britto LRG. Retinal Cell Death Induced by TRPV1 Activation Involves NMDA Signaling and Upregulation of Nitric Oxide Synthases. Cell Mol Neurobiol 2013; 33:379-92. [DOI: 10.1007/s10571-012-9904-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 12/29/2012] [Indexed: 01/23/2023]
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Bhatwadekar AD, Yan Y, Qi X, Thinschmidt JS, Neu MB, Li Calzi S, Shaw LC, Dominiguez JM, Busik JV, Lee C, Boulton ME, Grant MB. Per2 mutation recapitulates the vascular phenotype of diabetes in the retina and bone marrow. Diabetes 2013; 62. [PMID: 23193187 PMCID: PMC3526035 DOI: 10.2337/db12-0172] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In this study, we assessed whether Per2 clock gene-mutant mice exhibit a vascular phenotype similar to diabetes. Per2 (B6.129-Per2(tm1Drw)/J) or wild-type control mice 4 and 12 months of age were used. To evaluate diabetes-like phenotype in Per2 mutant mice, retina was quantified for mRNA expression, and degree of diabetic retinopathy was evaluated. Bone marrow neuropathy was studied by staining femurs for tyrosine hydroxylase (TH) and neurofilament 200 (NF-200). The rate of proliferation and quantification of bone marrow progenitor cells (BMPCs) was performed, and a threefold decrease in proliferation and 50% reduction in nitric oxide levels were observed in Per2 mutant mice. TH-positive nerve processes and NF-200 staining were reduced in Per2 mutant mice. Both retinal protein and mRNA expression of endothelial nitric oxide synthase were decreased by twofold. Other endothelial function genes (VEGFR2, VEGFR1) were downregulated (1.5-2-fold) in Per2 mutant retinas, whereas there was an upregulation of profibrotic pathway mediated by transforming growth factor-β1. Our studies suggest that Per2 mutant mice recapitulate key aspects of diabetes without the metabolic abnormalities, including retinal vascular damage, neuronal loss in the bone marrow, and diminished BMPC function.
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Affiliation(s)
- Ashay D Bhatwadekar
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, USA
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Mohammad G, Mairaj Siddiquei M, Imtiaz Nawaz M, Abu El-Asrar AM. The ERK1/2 Inhibitor U0126 Attenuates Diabetes-Induced Upregulation of MMP-9 and Biomarkers of Inflammation in the Retina. J Diabetes Res 2013; 2013:658548. [PMID: 23671886 PMCID: PMC3647581 DOI: 10.1155/2013/658548] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 03/25/2013] [Indexed: 12/11/2022] Open
Abstract
This study was conducted to determine the expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in a time-dependent manner and the effect of extracellular-signal-regulated kinases-1/2 (ERK1/2) inhibition on the expressions of MMP-9, TIMP-1, and inflammatory biomarkers in the retinas of diabetic rats. The expression of MMP-9 was quantified by zymography, and the mRNA level of MMP-9 and TIMP-1 was quantified by RT-PCR. The expression of inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF- α ) was examined by Western blot analysis. MMP-9 expression was significantly higher in diabetic rat retinas compared to controls at all time points.TIMP-1 expression was nonsignificantly upregulated at 1week of diabetes and was significantly downregulated at 4 and 12 weeks of diabetes. Intravitreal administration of the ERK1/2 inhibitor U0126 prior to induction of diabetes decreased ERK1/2 activation, attenuated diabetes-induced upregulation of MMP-9, iNOS, IL-6, and TNF- α and upregulated TIMP-1 expression. In MMP-9 knockout mice, diabetes had no effect on retinal iNOS expression and its level remained unchanged. These data provide evidence that ERK1/2 signaling pathway is involved in MMP-9, iNOS, IL-6, and TNF- α induction in diabetic retinas and suggest that ERK1/2 can be a novel therapeutic target in diabetic retinopathy.
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Affiliation(s)
- Ghulam Mohammad
- Department of Ophthalmology, College of Medicine, King Saud University, P.O. Box 245, Riyadh 11411, Saudi Arabia
- *Ghulam Mohammad:
| | - Mohammad Mairaj Siddiquei
- Department of Ophthalmology, College of Medicine, King Saud University, P.O. Box 245, Riyadh 11411, Saudi Arabia
| | - Mohammad Imtiaz Nawaz
- Department of Ophthalmology, College of Medicine, King Saud University, P.O. Box 245, Riyadh 11411, Saudi Arabia
| | - Ahmed M. Abu El-Asrar
- Department of Ophthalmology, College of Medicine, King Saud University, P.O. Box 245, Riyadh 11411, Saudi Arabia
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El-Asrar AMA. Role of inflammation in the pathogenesis of diabetic retinopathy. Middle East Afr J Ophthalmol 2012; 19:70-4. [PMID: 22346117 PMCID: PMC3277027 DOI: 10.4103/0974-9233.92118] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy (DR) remains a major cause of worldwide preventable blindness. The microvasculature of the retina responds to hyperglycemia through a number of biochemical changes, including activation of protein kinase C, increased advanced glycation end products formation, polyol pathway, and oxidative stress, and activation of the renin angiotensin system (RAS). There is an accumulating body of evidence that inflammation plays a prominent role in the pathogenesis of DR.
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Affiliation(s)
- Ahmed M Abu El-Asrar
- Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Park SW, Lee HS, Sung MS, Kim SJ. The effect of melatonin on retinal ganglion cell survival in ischemic retina. Chonnam Med J 2012; 48:116-22. [PMID: 22977753 PMCID: PMC3434791 DOI: 10.4068/cmj.2012.48.2.116] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 07/25/2012] [Accepted: 07/25/2012] [Indexed: 11/06/2022] Open
Abstract
Our objective was to determine whether melatonin increases retinal ganglion cell (RGC) survival in ischemic mouse retina. Transient retinal ischemia was induced by an acute elevation of intraocular pressure in C57BL/6 mice. To evaluate the effect of melatonin on retinal ischemia, an equal amount of either melatonin or vehicle was intraperitoneally injected into the mice 1 hour before ischemia, at the time of ischemia, and 1 hour after ischemia. Hypoxia inducible factor 1α (HIF-1α) and glial fibrillary acidic protein (GFAP) expression were assessed 6, 12, and 24 hours after ischemia-reperfusion by Western blot. RGC survival was measured 2 weeks after ischemia-reperfusion. The expression of HIF-1α and GFAP peaked 24 hours after ischemia-reperfusion in ischemic retina. The treatment of ischemic retina with melatonin resulted in the inhibition of increased expression of HIF-1α and GFAP. RGC survival was greater in retinas treated with melatonin than in retinas treated with vehicle 2 weeks after ischemia-reperfusion. On the basis of our results, we suggest that melatonin treatment increased RGC survival in ischemic mouse retina. The neuroprotective effect of melatonin is mediated by the inhibition of HIF-1α stabilization and reduced activity of glial cells in ischemic mouse retina.
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Affiliation(s)
- Sang-Woo Park
- Department of Ophthalmology, Medical School & Research Institute of Medical Science, Chonnam National University, Gwangju, Korea
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Coorey NJ, Shen W, Chung SH, Zhu L, Gillies MC. The role of glia in retinal vascular disease. Clin Exp Optom 2012; 95:266-81. [PMID: 22519424 DOI: 10.1111/j.1444-0938.2012.00741.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Retinal vascular diseases collectively represent a leading cause of blindness. Unsurprisingly, pathological characterisation and treatment of retinal 'vascular' diseases have primarily focused on the aetiology and consequences of vascular dysfunction. Far less research has addressed the contribution of neuronal and glial dysfunction to the disease process of retinal vascular disorders. Ample evidence now suggests that retinal vasculopathy only uncommonly occurs in isolation, usually existing in concert with neuropathy and gliopathy. Retinal glia (Müller cells, astrocytes and microglia) have been reported to exhibit morphological and functional changes in both early and advanced phases of almost every retinal vascular disease. It is anticipated that identifying the causes of glial activation and dysfunction, and their contribution to loss of vision in retinal vascular disease, will lead to a better understanding of retinal vascular diseases, which might ultimately be translated into novel clinical therapies.
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Affiliation(s)
- Nathan J Coorey
- Save Sight Institute, The University of Sydney, Sydney, Australia
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Pouliot M, Talbot S, Sénécal J, Dotigny F, Vaucher E, Couture R. Ocular application of the kinin B1 receptor antagonist LF22-0542 inhibits retinal inflammation and oxidative stress in streptozotocin-diabetic rats. PLoS One 2012; 7:e33864. [PMID: 22470485 PMCID: PMC3314679 DOI: 10.1371/journal.pone.0033864] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 02/18/2012] [Indexed: 12/19/2022] Open
Abstract
PURPOSE Kinin B(1) receptor (B(1)R) is upregulated in retina of Streptozotocin (STZ)-diabetic rats and contributes to vasodilation of retinal microvessels and breakdown of the blood-retinal barrier. Systemic treatment with B(1)R antagonists reversed the increased retinal plasma extravasation in STZ rats. The present study aims at determining whether ocular application of a water soluble B(1)R antagonist could reverse diabetes-induced retinal inflammation and oxidative stress. METHODS Wistar rats were made diabetic with STZ (65 mg/kg, i.p.) and 7 days later, they received one eye drop application of LF22-0542 (1% in saline) twice a day for a 7 day-period. The impact was determined on retinal vascular permeability (Evans blue exudation), leukostasis (leukocyte infiltration using Fluorescein-isothiocyanate (FITC)-coupled Concanavalin A lectin), retinal mRNA levels (by qRT-PCR) of inflammatory (B(1)R, iNOS, COX-2, ICAM-1, VEGF-A, VEGF receptor type 2, IL-1β and HIF-1α) and anti-inflammatory (B(2)R, eNOS) markers and retinal level of superoxide anion (dihydroethidium staining). RESULTS Retinal plasma extravasation, leukostasis and mRNA levels of B(1)R, iNOS, COX-2, VEGF receptor type 2, IL-1β and HIF-1α were significantly increased in diabetic retinae compared to control rats. All these abnormalities were reversed to control values in diabetic rats treated with LF22-0542. B(1)R antagonist also significantly inhibited the increased production of superoxide anion in diabetic retinae. CONCLUSION B(1)R displays a pathological role in the early stage of diabetes by increasing oxidative stress and pro-inflammatory mediators involved in retinal vascular alterations. Hence, topical application of kinin B(1)R antagonist appears a highly promising novel approach for the treatment of diabetic retinopathy.
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Affiliation(s)
- Mylène Pouliot
- École d'optométrie, Université de Montréal, Montréal, Canada
- Département de Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Canada
| | - Sébastien Talbot
- Département de Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Canada
| | - Jacques Sénécal
- Département de Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Canada
| | | | - Elvire Vaucher
- École d'optométrie, Université de Montréal, Montréal, Canada
| | - Réjean Couture
- Département de Physiologie, Faculté de Médecine, Université de Montréal, Montréal, Canada
- * E-mail:
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The expression of inducible nitric oxide synthase in human retinal pigment epithelial cells under stimulation of proinflammatory cytokine tumor necrosis factor-α. Taiwan J Ophthalmol 2012. [DOI: 10.1016/j.tjo.2011.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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43
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Zhang Y, Li C, Sun X, Kuang X, Ruan X. High glucose decreases expression and activity of p-glycoprotein in cultured human retinal pigment epithelium possibly through iNOS induction. PLoS One 2012; 7:e31631. [PMID: 22363694 PMCID: PMC3281955 DOI: 10.1371/journal.pone.0031631] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 01/14/2012] [Indexed: 11/12/2022] Open
Abstract
Inhibition of p-glycoprotein under hyperglycemic conditions has been reported in various barrier tissues including blood-brain barrier, intestine, and kidney, and has been linked to significant clinical complications. However, whether this is also true for the outer blood-retinal barrier constituted by retinal pigment epithelium, or has a role in pathogenesis of diabetic retinopathy is not yet clear. In this study, using cultured human retinal pigment epithelium cell line D407, we found that high glucose exposure induced a significant decrease in p-glycoprotein expression both at mRNA and at protein levels, accompanied by an attenuated p-glycoprotein activity determined by intracellular rhodamine 123 retention. In marked contrast, the expressions of both mRNA and protein levels of inducible nitrate oxide synthase (iNOS) increased, and were accompanied by increased extracellular nitrate/nitrite production by Griess reaction. In addition, mRNA levels of nuclear receptors revealed a decreased expression of pregnane X receptor after the exposure of high glucose. However, the subsequent alterations in production of nitrate/nitrite, functional expression of p-glycoprotein, and mRNA levels of pregnane X receptor were partially blocked when pretreated with S,S′-1,3-phenylene-bis(1,2-ethanediyl)-bis-isothiourea•2HBr (PBITU), a selective iNOS inhibitor. Moreover, the effects of PBITU were antagonized with the addition of L-arginine, a substrate for NO synthesis. Our in vitro results suggest for the first time that iNOS induction plays a novel role in decreased p-glycoprotein expression and transport function at the human outer blood-retinal barrier under hyperglycemic conditions and further support the concept of inhibiting iNOS pathway as a therapeutic strategy for diabetic retinopathy.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Cell Line
- Cells, Cultured
- Enzyme Induction/drug effects
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation/drug effects
- Glucose/pharmacology
- Humans
- Nitric Oxide/biosynthesis
- Nitric Oxide Synthase Type II/antagonists & inhibitors
- Nitric Oxide Synthase Type II/biosynthesis
- Nitric Oxide Synthase Type II/genetics
- Pregnane X Receptor
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Retinal Pigment Epithelium/cytology
- Retinal Pigment Epithelium/drug effects
- Retinal Pigment Epithelium/enzymology
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Affiliation(s)
- Yuehong Zhang
- Departments of Ophthalmology, and Anesthesiology, First Municipal People's Hospital of Guangzhou, Affiliated Hospital of Guangzhou Medical College, Guangzhou, China
| | - Chunmei Li
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xuerong Sun
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xielan Kuang
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiangcai Ruan
- Departments of Ophthalmology, and Anesthesiology, First Municipal People's Hospital of Guangzhou, Affiliated Hospital of Guangzhou Medical College, Guangzhou, China
- * E-mail:
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44
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Zou MH, Li H, He C, Lin M, Lyons TJ, Xie Z. Tyrosine nitration of prostacyclin synthase is associated with enhanced retinal cell apoptosis in diabetes. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:2835-44. [PMID: 22015457 DOI: 10.1016/j.ajpath.2011.08.041] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 08/08/2011] [Accepted: 08/29/2011] [Indexed: 02/07/2023]
Abstract
The risk of diabetic retinopathy is associated with the presence of both oxidative stress and toxic eicosanoids. Whether oxidative stress actually causes diabetic retinopathy via the generation of toxic eicosanoids, however, remains unknown. The aim of the present study was to determine whether tyrosine nitration of prostacyclin synthase (PGIS) contributes to retinal cell death in vitro and in vivo. Exposure of human retinal pericytes to heavily oxidized and glycated LDL (HOG-LDL), but not native forms of LDL (N-LDL), for 24 hours significantly increased pericyte apoptosis, accompanied by increased tyrosine nitration of PGIS and decreased PGIS activity. Inhibition of the thromboxane receptor or cyclooxygenase-2 dramatically attenuated HOG-LDL-induced apoptosis without restoring PGIS activity. Administration of superoxide dismutase (to scavenge superoxide anions) or L-N(G)-nitroarginine methyl ester (L-NAME, a nonselective nitric oxide synthase inhibitor) restored PGIS activity and attenuated pericyte apoptosis. In Akita mouse retinas, diabetes increased intraretinal levels of oxidized LDL and glycated LDL, induced PGIS nitration, enhanced apoptotic cell death, and impaired blood-retinal barrier function. Chronic administration of tempol, a superoxide scavenger, reduced intraretinal oxidized LDL and glycated LDL levels, PGIS nitration, and retina cell apoptosis, thereby preserving the integrity of blood-retinal barriers. In conclusion, oxidized LDL-mediated PGIS nitration and associated thromboxane receptor stimulation might be important in the initiation and progression of diabetic retinopathy.
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Affiliation(s)
- Ming-Hui Zou
- Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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45
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Omri S, Behar-Cohen F, de Kozak Y, Sennlaub F, Verissimo LM, Jonet L, Savoldelli M, Omri B, Crisanti P. Microglia/macrophages migrate through retinal epithelium barrier by a transcellular route in diabetic retinopathy: role of PKCζ in the Goto Kakizaki rat model. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:942-53. [PMID: 21712024 DOI: 10.1016/j.ajpath.2011.04.018] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 03/31/2011] [Accepted: 04/05/2011] [Indexed: 01/13/2023]
Abstract
Diabetic retinopathy is associated with ocular inflammation, leading to retinal barrier breakdown, macular edema, and visual cell loss. We investigated the molecular mechanisms involved in microglia/macrophages trafficking in the retina and the role of protein kinase Cζ (PKCζ) in this process. Goto Kakizaki (GK) rats, a model for spontaneous type 2 diabetes were studied until 12 months of hyperglycemia. Up to 5 months, sparse microglia/macrophages were detected in the subretinal space, together with numerous pores in retinal pigment epithelial (RPE) cells, allowing inflammatory cell traffic between the retina and choroid. Intercellular adhesion molecule-1 (ICAM-1), caveolin-1 (CAV-1), and PKCζ were identified at the pore border. At 12 months of hyperglycemia, the significant reduction of pores density in RPE cell layer was associated with microglia/macrophages accumulation in the subretinal space together with vacuolization of RPE cells and disorganization of photoreceptors outer segments. The intraocular injection of a PKCζ inhibitor at 12 months reduced iNOS expression in microglia/macrophages and inhibited their migration through the retina, preventing their subretinal accumulation. We show here that a physiological transcellular pathway takes place through RPE cells and contributes to microglia/macrophages retinal trafficking. Chronic hyperglycemia causes alteration of this pathway and subsequent subretinal accumulation of activated microglia/macrophages.
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Affiliation(s)
- Samy Omri
- INSERM, U872 Physiopathology of Ocular Diseases, Therapeutic Innovations, Paris, France
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46
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Ibrahim AS, El-Remessy AB, Matragoon S, Zhang W, Patel Y, Khan S, Al-Gayyar MM, El-Shishtawy MM, Liou GI. Retinal microglial activation and inflammation induced by amadori-glycated albumin in a rat model of diabetes. Diabetes 2011; 60:1122-33. [PMID: 21317295 PMCID: PMC3064086 DOI: 10.2337/db10-1160] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE During diabetes, retinal microglial cells are activated to release inflammatory cytokines that initiate neuronal loss and blood-retinal barrier breakdown seen in diabetic retinopathy (DR). The mechanism by which diabetes activates microglia to release those inflammatory mediators is unclear and was therefore elucidated. RESEARCH DESIGN AND METHODS Microglia activation was characterized in streptozocin-injected rats and in isolated microglial cells using immunofluorescence, enzyme-linked immunosorbent assay, RT-PCR, and Western blot analyses. RESULTS In 8-week diabetic retina, phospho-extracellular signal-related kinase (ERK) and P38 mitogen-activated protein kinases were localized in microglia, but not in Mueller cells or astrocytes. At the same time, Amadori-glycated albumin (AGA)-like epitopes were featured in the regions of microglia distribution, implicating a pathogenic effect on microglial activation. To test this, diabetic rats were treated intravitreally with A717, a specific AGA-neutralizing antibody, or murine IgG. Relative to nondiabetic rats, diabetic rats (IgG-treated) manifested 3.9- and 7.9-fold increases in Iba-1 and tumor necrosis factor (TNF)-α mRNAs, respectively. Treatment of diabetic rats with A717 significantly attenuated overexpression of these mRNAs. Intravitreal injection of AGA per se in normal rats resulted in increases of Iba-1 expression and TNF-α release. Guided by these results, a cultured retinal microglia model was developed to study microglial response after AGA treatment and the mechanistic basis behind this response. The results showed that formation of reactive oxygen species and subsequent activation of ERK and P38, but not Jun NH2-terminal kinase, are molecular events underpinning retinal microglial TNF-α release during AGA treatment. CONCLUSIONS These results provide new insights in understanding the pathogenesis of early DR, showing that the accumulated AGA within the diabetic retina elicits the microglial activation and secretion of TNF-α. Thus, intervention trials with agents that neutralize AGA effects may emerge as a new therapeutic approach to modulate early pathologic pathways long before the occurrence of vision loss among patients with diabetes.
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Affiliation(s)
- Ahmed S. Ibrahim
- Department of Ophthalmology, Medical College of Georgia, Augusta, Georgia
- Vision Discovery Institute, Medical College of Georgia, Augusta, Georgia
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Azza B. El-Remessy
- Department of Ophthalmology, Medical College of Georgia, Augusta, Georgia
- Vision Discovery Institute, Medical College of Georgia, Augusta, Georgia
- Program in Clinical and Experimental Therapeutics, University of Georgia, Athens, Georgia
- VA Medical Center, Augusta, Georgia
| | - Suraporn Matragoon
- Program in Clinical and Experimental Therapeutics, University of Georgia, Athens, Georgia
- VA Medical Center, Augusta, Georgia
| | - Wenbo Zhang
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia
| | - Yogin Patel
- Department of Medicine, Medical College of Georgia, Augusta, Georgia
| | - Sohail Khan
- Department of Ophthalmology, Medical College of Georgia, Augusta, Georgia
| | - Mohammed M. Al-Gayyar
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
- Program in Clinical and Experimental Therapeutics, University of Georgia, Athens, Georgia
- VA Medical Center, Augusta, Georgia
| | | | - Gregory I. Liou
- Department of Ophthalmology, Medical College of Georgia, Augusta, Georgia
- Vision Discovery Institute, Medical College of Georgia, Augusta, Georgia
- Corresponding author: Gregory I. Liou,
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Pannicke T, Wurm A, Iandiev I, Hollborn M, Linnertz R, Binder DK, Kohen L, Wiedemann P, Steinhäuser C, Reichenbach A, Bringmann A. Deletion of aquaporin-4 renders retinal glial cells more susceptible to osmotic stress. J Neurosci Res 2010; 88:2877-88. [PMID: 20544823 DOI: 10.1002/jnr.22437] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The glial water channel aquaporin-4 (AQP4) is implicated in the control of ion and osmohomeostasis in the sensory retina. Using retinal slices from AQP4-deficient and wild-type mice, we investigated whether AQP4 is involved in the regulation of glial cell volume under altered osmotic conditions. Superfusion of retinal slices with a hypoosmolar solution induced a rapid swelling of glial somata in tissues from AQP4 null mice but not from wild-type mice. The swelling was mediated by oxidative stress, inflammatory lipid mediators, and sodium influx into the cells and was prevented by activation of glutamatergic and purinergic receptors. Distinct inflammatory proteins, including interleukin-1 beta, interleukin-6, and inducible nitric oxide synthase, were up-regulated in the retina of AQP4 null mice compared with control, whereas cyclooxygenase-2 was down-regulated. The data suggest that water flux through AQP4 is involved in the rapid volume regulation of retinal glial (Müller) cells in response to osmotic stress and that deletion of AQP4 results in an inflammatory response of the retinal tissue. Possible implications of the data for understanding the pathophysiology of neuromyelitis optica, a human disease that has been suggested to involve serum antibodies to AQP4, are discussed.
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Affiliation(s)
- Thomas Pannicke
- Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany.
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48
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Aqueous humor nitric oxide in patients with central retinal vein occlusion. Nitric Oxide 2010; 23:332-4. [DOI: 10.1016/j.niox.2010.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 09/15/2010] [Accepted: 09/17/2010] [Indexed: 11/17/2022]
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49
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Involvement of oxidative stress and mitochondrial dysfunction in the osmotic swelling of retinal glial cells from diabetic rats. Exp Eye Res 2010; 92:87-93. [PMID: 21111734 DOI: 10.1016/j.exer.2010.11.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 11/16/2010] [Accepted: 11/18/2010] [Indexed: 12/29/2022]
Abstract
Osmotic swelling of retinal glial (Müller) cells may contribute to the development of edema in diabetic retinopathy. Here, we tested whether oxidative stress and mitochondrial dysfunction are pathogenic factors involved in the osmotic swelling of Müller cells in retinal slices from control and streptozotocin-injected hyperglycemic rats. Hypotonic challenge did not change the size of Müller cell somata from control animals but induced soma swelling in Müller cells of diabetic animals. Administration of a reducing agent blocked the osmotic swelling of Müller cell somata. In retinal tissues from control animals, administration of the reducing agent blocked also the swelling-inducing effects of antagonists of P2Y₁ and adenosine A₁ receptors. In tissues from diabetic animals, inhibition of xanthine oxidase decreased the soma swelling by approximately 50% while inhibition of NADPH oxidase and nitric oxide synthase had no effects. Blockade of mitochondrial oxidative stress by perindopril, as well as of mitochondrial permeability transition by cyclosporin A or minocycline, attenuated the swelling. In addition, activation of mitochondrial K(ATP) channels by pinacidil fully prevented the swelling. The data suggest that oxidative stress produced by xanthine oxidase, as well as the mitochondria, are implicated in the induction of osmotic swelling of Müller cells from diabetic rats.
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50
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Wong VHY, Bui BV, Vingrys AJ. Clinical and experimental links between diabetes and glaucoma. Clin Exp Optom 2010; 94:4-23. [PMID: 21091536 DOI: 10.1111/j.1444-0938.2010.00546.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Glaucoma is a leading cause of blindness. It is a multifactorial condition, the risk factors for which are increasingly well defined from large-scale epidemiological studies. One risk factor that remains controversial is the presence of diabetes. It has been proposed that diabetic eyes are at greater risk of injury from external stressors, such as elevated intraocular pressure. Alternatively, diabetes may cause ganglion cell loss, which becomes additive to a glaucomatous ganglion cell injury. Several clinical trials have considered whether a link exists between diabetes and glaucoma. In this review, we outline these studies and consider the causes for their lack of concordant findings. We also review the biochemical and cellular similarities between the two conditions. Moreover, we review the available literature that attempts to answer the question of whether the presence of diabetes increases the risk of developing glaucoma. At present, laboratory studies provide robust evidence for an association between diabetes and glaucoma.
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Affiliation(s)
- Vickie H Y Wong
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
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