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Zhang CJ, Mou H, Yuan J, Wang YH, Sun SN, Wang W, Xu ZH, Yu SJ, Jin K, Jin ZB. Effects of fluorescent protein tdTomato on mouse retina. Exp Eye Res 2024; 243:109910. [PMID: 38663720 DOI: 10.1016/j.exer.2024.109910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 02/26/2024] [Accepted: 04/22/2024] [Indexed: 04/30/2024]
Abstract
Fluorescent proteins (FPs) have been widely used to investigate cellular and molecular interactions and trace biological events in many applications. Some of the FPs have been demonstrated to cause undesirable cellular damage by light-induced ROS production in vivo or in vitro. However, it remains unknown if one of the most popular FPs, tdTomato, has similar effects in neuronal cells. In this study, we discovered that tdTomato expression led to unexpected retinal dysfunction and ultrastructural defects in the transgenic mouse retina. The retinal dysfunction mainly manifested in the reduced photopic electroretinogram (ERG) responses and decreased contrast sensitivity in visual acuity, caused by mitochondrial damages characterized with cellular redistribution, morphological modifications and molecular profiling alterations. Taken together, our findings for the first time demonstrated the retinal dysfunction and ultrastructural defects in the retinas of tdTomato-transgenic mice, calling for a more careful design and interpretation of experiments involved in FPs.
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Affiliation(s)
- Chang-Jun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Hao Mou
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Jing Yuan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Ya-Han Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Shu-Ning Sun
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Wen Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Ze-Hua Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Si-Jian Yu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China
| | - Kangxin Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China.
| | - Zi-Bing Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, 100730, China.
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Sun M, Yu T, Zhao J, Zhu X, Xin W, Zhang F, Zhang L. Role of flavonoids in age-related macular degeneration. Biomed Pharmacother 2023; 159:114259. [PMID: 36652737 DOI: 10.1016/j.biopha.2023.114259] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/11/2023] [Accepted: 01/14/2023] [Indexed: 01/18/2023] Open
Abstract
A common eye disorder known as age-related macular degeneration (AMD) eventually results in blindness and vision loss. AMD has a complicated and poorly understood aetiology. The main pathological processes associated with AMD include oxidative damage, inflammation, and neovascularization. Flavonoids are naturally occurring bioactive substances with extensive distribution and antioxidant, anti-inflammatory, and neovascularization inhibitory properties. Several in vitro and in vivo AMD-related models pertinent to vision and this ocular ailment have been used to assess the mechanisms of action of various flavonoids. This article will discuss the research progress of flavonoids in AMD, especially the characteristics and mechanism of flavonoids in treating AMD.
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Affiliation(s)
- Mengmeng Sun
- Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, School of Pharmacy, Yantai University, Yantai 264005, PR China
| | - Tao Yu
- Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, School of Pharmacy, Yantai University, Yantai 264005, PR China
| | - Jianing Zhao
- Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, School of Pharmacy, Yantai University, Yantai 264005, PR China
| | - Xuan Zhu
- Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, School of Pharmacy, Yantai University, Yantai 264005, PR China
| | - Wenyu Xin
- Key Laboratory of Prescription Effect and Clinical Evaluation of State Administration of Traditional Chinese Medicine of China, School of Pharmacy, Binzhou Medical University, Yantai 264003, PR China.
| | - Fenglan Zhang
- Yantai Yuhuangding Hospital, The Affiliated Hospital of Qingdao University, Yantai 264000, PR China.
| | - Leiming Zhang
- Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, School of Pharmacy, Yantai University, Yantai 264005, PR China.
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Zhao B, Zhu L, Ye M, Lou X, Mou Q, Hu Y, Zhang H, Zhao Y. Oxidative stress and epigenetics in ocular vascular aging: an updated review. Mol Med 2023; 29:28. [PMID: 36849907 PMCID: PMC9972630 DOI: 10.1186/s10020-023-00624-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/16/2023] [Indexed: 03/01/2023] Open
Abstract
Vascular aging is an inevitable process with advancing age, which plays a crucial role in the pathogenesis of cardiovascular and microvascular diseases. Diabetic retinopathy (DR) and age-related macular degeneration (AMD), characterized by microvascular dysfunction, are the common causes of irreversible blindness worldwide, however there is still a lack of effective therapeutic strategies for rescuing the visual function. In order to develop novel treatments, it is essential to illuminate the pathological mechanisms underlying the vascular aging during DR and AMD progression. In this review, we have summarized the recent discoveries of the effects of oxidative stress and epigenetics on microvascular degeneration, which could provide potential therapeutic targets for DR and AMD.
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Affiliation(s)
- Bowen Zhao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Lijia Zhu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Meng Ye
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiaotong Lou
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qianxue Mou
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yuanyuan Hu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Yin Zhao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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Chu YC, Fang HW, Wu YY, Tang YJ, Hsieh EH, She Y, Chang CY, Lin IC, Chen YJ, Liu GS, Tseng CL. Functional Peptide-Loaded Gelatin Nanoparticles as Eyedrops for Cornea Neovascularization Treatment. Int J Nanomedicine 2023; 18:1413-1431. [PMID: 36992821 PMCID: PMC10042260 DOI: 10.2147/ijn.s398769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 03/07/2023] [Indexed: 03/31/2023] Open
Abstract
Background Corneal neovascularization (NV) is a process of abnormal vessel growth into the transparent cornea from the limbus and can disturb the light passing through the cornea, resulting in vision loss or even blindness. The use of nanomedicine as an effective therapeutic formulation in ophthalmology has led to higher drug bioavailability and a slow drug release rate. In this research, we designed and explored the feasibility of a new nanomedicine, gp91 ds-tat (gp91) peptide-encapsulated gelatin nanoparticles (GNP-gp91), for inhibiting corneal angiogenesis. Methods GNP-gp91 were prepared by a two-step desolvation method. The characterization and cytocompatibility of GNP-gp91 were analyzed. The inhibition effect of GNP-gp91 on HUVEC cell migration and tube formation was observed by an inverted microscope. The drug retention test in mouse cornea was observed by in vivo imaging system, fluorescence microscope, and DAPI/TAMRA staining. Finally, the therapeutic efficacy and evaluation of neovascularization-related factors were conducted through the in vivo corneal NV mice model via topical delivery. Results The prepared GNP-gp91 had a nano-scale diameter (550.6 nm) with positive charge (21.7 mV) slow-release behavior (25%, 240hr). In vitro test revealed that GNP-gp91 enhanced the inhibition of cell migration and tube formation capacity via higher internalization of HUVEC. Topical administration (eyedrops) of the GNP-gp91 significantly prolongs the retention time (46%, 20 min) in the mouse cornea. In chemically burned corneal neovascularization models, corneal vessel area with a significant reduction in GNP-gp91 group (7.89%) was revealed when compared with PBS (33.99%) and gp91 (19.67%) treated groups via every two days dosing. Moreover, GNP-gp91 significantly reduced the concentration of Nox2, VEGF and MMP9 in NV's cornea. Conclusion The nanomedicine, GNP-gp91, was successfully synthesized for ophthalmological application. These data suggest that GNP-gp91 contained eyedrops that not only have a longer retention time on the cornea but also can treat mice corneal NV effectively delivered in a low dosing frequency, GNP-gp91 eyedrops provides an alternative strategy for clinical ocular disease treatment in the culture.
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Affiliation(s)
- Ya-Chun Chu
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei City, Taiwan
| | - Hsu-Wei Fang
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei City, Taiwan
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli County, Taiwan
| | - Yu-Yi Wu
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
| | - Yu-Jun Tang
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
| | - Erh-Hsuan Hsieh
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
| | - YiZhou She
- School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
| | - Che-Yi Chang
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
| | - I-Chan Lin
- Department of Ophthalmology, Wan Fang Hospital, Taipei Medical University, Taipei City, Taiwan
- Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan
| | - Yin-Ju Chen
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
- Department of Radiation Oncology, Taipei Medical University Hospital, Taipei City, Taiwan
- International Ph.D. Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
- Center for Precision Medicine and Translational Cancer Research, Taipei Medical University Hospital, Taipei City, Taiwan
| | - Guei-Sheung Liu
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, East Melbourne, VIC, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Ching-Li Tseng
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
- International Ph.D. Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
- Center for Precision Medicine and Translational Cancer Research, Taipei Medical University Hospital, Taipei City, Taiwan
- Research Center of Biomedical Device, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan
- Correspondence: Ching-Li Tseng, Tel +886 2 2736 1661 (ext. 5214), Email
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Harju N. Regulation of oxidative stress and inflammatory responses in human retinal pigment epithelial cells. Acta Ophthalmol 2022; 100 Suppl 273:3-59. [DOI: 10.1111/aos.15275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Niina Harju
- School of Pharmacy University of Eastern Finland Kuopio Finland
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Hydroquinone predisposes for retinal pigment epithelial (RPE) cell degeneration in inflammatory conditions. Immunol Res 2022; 70:678-687. [PMID: 35661979 PMCID: PMC9499922 DOI: 10.1007/s12026-022-09300-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/24/2022] [Indexed: 12/14/2022]
Abstract
In addition to hypoxia, inflammation is capable of inducing vascular endothelial growth factor (VEGF) expression in human retinal pigment epithelial (RPE) cells. Excessive levels of VEGF promote choroidal neovascularization and thereby contribute to the pathogenesis of wet age-related macular degeneration (AMD). Intravitreal anti-VEGF injections ameliorate pathological vessel neoformation in wet AMD but excessive dampening of VEGF can result in a degeneration of the RPE. In the present study, we induced VEGF production by exposing human ARPE-19 cells to the pro-inflammatory IL-1α and subsequently to hydroquinone, a component of tobacco smoke that is a major environmental risk factor for AMD. Effects were monitored by measuring the levels of VEGF and anti-angiogenic pigment epithelium-derived factor (PEDF) using an enzyme-linked immunosorbent assay (ELISA) technique. In addition, we measured the production of reactive oxygen species (ROS) using the 2′,7′-dichlorofluorescin diacetate (H2DCFDA) probe and studied the effects of two anti-oxidants, ammonium pyrrolidinedithiocarbamate (APDC) and N-acetyl-cysteine (NAC), on VEGF production. Cellular and secreted VEGF as well as secreted PEDF levels were reduced at all tested hydroquinone concentrations (10, 50, or 200 µM); these effects were evident prior to any reduction of cell viability evoked by hydroquinone. Cell viability was carefully explored in our previous study and verified by microscoping in the present study. APDC further reduced the VEGF levels, whereas NAC increased them. The 50 μM concentration of hydroquinone increased ROS production in ARPE-19 cells primed with IL-1α. Hydroquinone disturbs the regulatory balance of VEGF and PEDF in inflammatory conditions. These data support the idea that hydroquinone mediates RPE degeneration by reducing VEGF levels and may predispose to dry AMD since VEGF is as well important for retinal integrity.
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Ruan Y, Jiang S, Gericke A. Age-Related Macular Degeneration: Role of Oxidative Stress and Blood Vessels. Int J Mol Sci 2021; 22:ijms22031296. [PMID: 33525498 PMCID: PMC7866075 DOI: 10.3390/ijms22031296] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is a common irreversible ocular disease characterized by vision impairment among older people. Many risk factors are related to AMD and interact with each other in its pathogenesis. Notably, oxidative stress and choroidal vascular dysfunction were suggested to be critically involved in AMD pathogenesis. In this review, we give an overview on the factors contributing to the pathophysiology of this multifactorial disease and discuss the role of reactive oxygen species and vascular function in more detail. Moreover, we give an overview on therapeutic strategies for patients suffering from AMD.
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Affiliation(s)
- Yue Ruan
- Correspondence: (Y.R.); (A.G.); Tel.: +49-6131-178-276 (Y.R. & A.G.)
| | | | - Adrian Gericke
- Correspondence: (Y.R.); (A.G.); Tel.: +49-6131-178-276 (Y.R. & A.G.)
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N-Acetyl-L-cysteine Protects Human Retinal Pigment Epithelial Cells from Oxidative Damage: Implications for Age-Related Macular Degeneration. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:5174957. [PMID: 31485293 PMCID: PMC6710748 DOI: 10.1155/2019/5174957] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 05/27/2019] [Indexed: 01/12/2023]
Abstract
Age-related macular degeneration (AMD) involves the loss of retinal pigment epithelium (RPE) and photoreceptors and is one of the leading causes of blindness in the elderly. Oxidative damage to proteins, lipids, and DNA has been associated with RPE dysfunction and AMD. In this study, we evaluated oxidative stress in AMD and the efficacy of antioxidant, N-acetyl-L-cysteine (NAC), in protecting RPE from oxidative damage. To test this idea, primary cultures of RPE from human donors with AMD (n = 32) or without AMD (No AMD, n = 21) were examined for expression of NADPH oxidase (NOX) genes, a source of reactive oxygen species (ROS). Additionally, the cells were pretreated with NAC for 2 hours and then treated with either hydrogen peroxide (H2O2) or tert-butyl hydroperoxide (t-BHP) to induce cellular oxidation. Twenty-four hours after treatment, ROS production, cell survival, the content of glutathione (GSH) and adenosine triphosphate (ATP), and cellular bioenergetics were measured. We found increased expression of p22phox, a NOX regulator, in AMD cells compared to No AMD cells (p = 0.02). In both AMD and No AMD cells, NAC pretreatment reduced t-BHP-induced ROS production and protected from H2O2-induced cell death and ATP depletion. In the absence of oxidation, NAC treatment improved mitochondrial function in both groups (p < 0.01). Conversely, the protective response exhibited by NAC was disease-dependent for some parameters. In the absence of oxidation, NAC significantly reduced ROS production (p < 0.001) and increased GSH content (p = 0.02) only in RPE from AMD donors. Additionally, NAC-mediated protection from H2O2-induced GSH depletion (p = 0.04) and mitochondrial dysfunction (p < 0.05) was more pronounced in AMD cells compared with No AMD cells. These results demonstrate the therapeutic benefit of NAC by mitigating oxidative damage in RPE. Additionally, the favorable outcomes observed for AMD RPE support NAC's relevance and the potential therapeutic value in treating AMD.
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Li T, Yang S, She X, Yan Q, Zhang P, Zhu H, Wang F, Luo X, Sun X. Modulation of α-adrenoceptor signalling protects photoreceptors after retinal detachment by inhibiting oxidative stress and inflammation. Br J Pharmacol 2019; 176:801-813. [PMID: 30588605 DOI: 10.1111/bph.14565] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 11/20/2018] [Accepted: 11/29/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE Currently available treatments do not halt progression of photoreceptor death and subsequent visual impairment related to retinal detachment (RD) which is observed in various retinal disorders. This study investigated the neuroprotective effects of two adrenoceptor ligands, the α1 -adrenoceptor antagonist doxazosin and the α2 -adrenoceptor agonist guanabenz, against photoreceptor cell death in RD. EXPERIMENTAL APPROACH We used a model of experimental RD in Brown-Norway rats induced by subretinal injection of sodium hyaluronate. Oxidative stress biomarkers and cytokine production were quantified with elisa. Protein expression levels and immunofluorescent labelling were determined in rats with RD and controls for mechanistic elucidation. The effects of systemic (i.p.) administration of doxazosin or guanabenz on photoreceptor apoptosis, retinal histology and electroretinography were evaluated in rats with RD and compared to the effects in vehicle controls. KEY RESULTS Photoreceptors were the major source of RD-induced ROS overproduction in the rat retina through the regulation of NADPH oxidase. Systemic administration of doxazosin or guanabenz decreased the RD-induced production of ROS and proinflammatory cytokines, including IL-1β and the chemokine CCL2, and suppressed retinal gliosis, resulting in attenuation of photoreceptor death and preservation of retinal structures and functions in RD. CONCLUSIONS AND IMPLICATIONS Our findings point to α-adrenoceptors as novel therapeutic targets to provide photoreceptor protection and suggest that both doxazosin and guanabenz, two FDA-approved drugs, could be further explored to treat retinal diseases.
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Affiliation(s)
- Tong Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shiqi Yang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiangjun She
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Quan Yan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Pengfei Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Zhu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Fenghua Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Xueting Luo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Fundus Diseases, Shanghai, China
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Fundus Diseases, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
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11
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Gautam J, Banskota S, Shah S, Jee JG, Kwon E, Wang Y, Kim DY, Chang HW, Kim JA. 4-Hydroxynonenal-induced GPR109A (HCA 2 receptor) activation elicits bipolar responses, G αi -mediated anti-inflammatory effects and G βγ -mediated cell death. Br J Pharmacol 2018; 175:2581-2598. [PMID: 29473951 DOI: 10.1111/bph.14174] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 12/07/2017] [Accepted: 01/30/2018] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE In this study, we examined the possibility that 4-hydroxynonenal (4-HNE) acting as a ligand for the HCA2 receptor (GPR109A) elicits both anti-inflammatory and cell death responses. EXPERIMENTAL APPROACH Agonistic activity of 4-HNE was determined by observing the inhibition of cAMP generation in CHO-K1-GPR109A-Gi cell line, using surface plasmon resonance (SPR) binding and competition binding assays with [3 H]-niacin. 4-HNE-mediated signalling pathways and cellular responses were investigated in cells expressing GPR109A and those not expressing these receptors. KEY RESULTS Agonistic activity of 4-HNE was stronger than that of niacin or 3-OHBA at inhibiting forskolin-induced cAMP production and SPR binding affinity. In ARPE-19 and CCD-841 cells, activation of GPR109A by high concentrations of the agonists 4-HNE (≥10 μM), niacin (≥1000 μM) and 3-OHBA (≥1000 μM) induced apoptosis accompanied by elevated Ca2+ and superoxide levels. This 4-HNE-induced cell death was blocked by knockdown of GPR109A or NOX4 genes, or treatment with chemical inhibitors of Gβγ (gallein), intracellular Ca2+ (BAPTA-AM), NOX4 (VAS2870) and JNK (SP600125), but not by the cAMP analogue 8-CPT-cAMP. By contrast, low concentrations of 4-HNE, niacin and 3-OHBA down-regulated the expression of pro-inflammatory cytokines IL-6 and IL-8. These 4-HNE-induced inhibitory effects were blocked by a cAMP analogue but not by inhibitors of Gβγ -downstream signalling molecules. CONCLUSIONS AND IMPLICATIONS These results revealed that 4-HNE is a strong agonist for GPR109A that induces Gαi -dependent anti-inflammatory and Gβγ -dependent cell death responses. Moreover, the findings indicate that specific intracellular signalling molecules, but not GPR109A, can serve as therapeutic targets to block 4-HNE-induced cell death.
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Affiliation(s)
- Jaya Gautam
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | | | - Sajita Shah
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | - Jun-Goo Jee
- College of Pharmacy, Kyungpook National University, Daegu, Korea
| | - Eunju Kwon
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | - Ying Wang
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | - Dong Young Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | | | - Jung-Ae Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
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Li J, Zhang R, Wang C, Wang X, Xu M, Ma J, Shang Q. Activation of the Small GTPase Rap1 Inhibits Choroidal Neovascularization by Regulating Cell Junctions and ROS Generation in Rats. Curr Eye Res 2018; 43:934-940. [PMID: 29601231 DOI: 10.1080/02713683.2018.1454477] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE Choroidal neovascularization (CNV) is a common vision-threatening complication associated with many fundus diseases. The retinal pigment epithelial (RPE) cell junction barrier has critical functions in preventing CNV, and oxidative stress can cause compromise of barrier integrity and induce angiogenesis. Rap1, a small guanosine triphosphatase (GTPase), is involved in regulating endothelial and epithelial cell junctions. In this work, we explored the function and mechanism of Rap1 in CNV in vivo. METHODS A laser-induced rat CNV model was developed. Rap1 was activated through intravitreal injection of the Rap1 activator 8CPT-2'-O-Me-cAMP (8CPT). At 14 days after laser treatment, CNV size in RPE/choroid flat mounts was measured by fluorescein isothiocyanate-dextran staining. Expression of vascular endothelial growth factor (VEGF) and cell junction proteins in RPE/choroid tissues were analyzed by western blots and quantitative real-time PCR assays. Reactive oxygen species (ROS) in RPE cells were detectedbydichloro-dihydro-fluorescein diacetate assays. The antioxidant apocynin was intraperitoneally injected into rats. RESULTS Activating Rap1 by 8CPT significantly reduced CNV size and VEGF expression in the rat CNV model. Rap1 activation enhanced protein and mRNA levels of ZO-1 and occludin, two tight junction proteins in the RPE barrier. In addition, reducing ROS generation by injection of apocynin, a NADPH oxidase inhibitor, inhibited CNV formation. Rap1 activation reduced ROS generation and expression of NADPH oxidase 4. CONCLUSIONS Rap1 activation inhibits CNV through regulating barrier integrity and ROS generation of RPE in vivo, and selectively activating Rap1 may be a way to reduce vision loss from CNV.
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Affiliation(s)
- Jiajia Li
- a Department of Ophthalmology , The Second Hospital of Hebei Medical University , Shijiazhuang , China
| | - Rong Zhang
- a Department of Ophthalmology , The Second Hospital of Hebei Medical University , Shijiazhuang , China
| | - Caixia Wang
- a Department of Ophthalmology , The Second Hospital of Hebei Medical University , Shijiazhuang , China
| | - Xin Wang
- a Department of Ophthalmology , The Second Hospital of Hebei Medical University , Shijiazhuang , China
| | - Man Xu
- a Department of Ophthalmology , The Second Hospital of Hebei Medical University , Shijiazhuang , China
| | - Jingxue Ma
- a Department of Ophthalmology , The Second Hospital of Hebei Medical University , Shijiazhuang , China
| | - Qingli Shang
- a Department of Ophthalmology , The Second Hospital of Hebei Medical University , Shijiazhuang , China
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Campochiaro PA, Mir TA. The mechanism of cone cell death in Retinitis Pigmentosa. Prog Retin Eye Res 2017; 62:24-37. [PMID: 28962928 DOI: 10.1016/j.preteyeres.2017.08.004] [Citation(s) in RCA: 177] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 12/16/2022]
Abstract
Retinitis Pigmentosa (RP) is a group of diseases in which one of a large number of mutations causes death of rod photoreceptors. After rods die, cone photoreceptors slowly degenerate in a characteristic pattern. The mechanism of rod cell death varies depending upon the gene that is mutated and the rate that rods degenerate is an important prognostic feature, because cones do not begin to degenerate until almost all rods have been eliminated. Rod cell death causes night blindness, but visual disability and blindness result from cone degeneration and therefore it is critical to determine the mechanisms by which it occurs. The death of rods reduces oxygen consumption resulting in high tissue levels of oxygen in the outer retina. The excess oxygen stimulates superoxide radical production by mismatches in the electron transport chain in mitochondria and by stimulation of NADPH oxidase activity in cytoplasm. The high levels of superoxide radicals overwhelm the antioxidant defense system and generate more reactive species including peroxynitrite which is extremely damaging and difficult to detoxify. This results in progressive oxidative damage in cones which contributes to cone cell death and loss of function because drugs or gene transfer that reduce oxidative stress promote cone survival and maintenance of function. Compared with aqueous humor samples from control patients, those from patients with RP show significant elevation of carbonyl content on proteins indicating oxidative damage and a reduction in the ratio of reduced to oxidized glutathione indicating depletion of a major component of the antioxidant defense system from ongoing oxidative stress. The first step in clinical trials will be to identify doses of therapeutic agents that reverse these biomarkers of disease to assist in design of much longer trials with functional and anatomic endpoints.
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Affiliation(s)
- Peter A Campochiaro
- Departments of Ophthalmology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - Tahreem A Mir
- Departments of Ophthalmology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Song H, Vijayasarathy C, Zeng Y, Marangoni D, Bush RA, Wu Z, Sieving PA. NADPH Oxidase Contributes to Photoreceptor Degeneration in Constitutively Active RAC1 Mice. Invest Ophthalmol Vis Sci 2017; 57:2864-75. [PMID: 27233035 PMCID: PMC5113981 DOI: 10.1167/iovs.15-18974] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Purpose The active form of small GTPase RAC1 is required for activation of NADPH oxidase (NOX), which in turn generates reactive oxygen species (ROS) in nonphagocytic cells. We explored whether NOX-induced oxidative stress contributes to rod degeneration in retinas expressing constitutively active (CA) RAC1. Methods Transgenic (Tg)–CA-RAC1 mice were given apocynin (10 mg/kg, intraperitoneal), a NOX inhibitor, or vehicle daily for up to 13 weeks. Superoxide production and oxidative damage were assessed by dihydroethidium staining and by protein carbonyls and malondialdehyde levels, respectively. Outer nuclear layer (ONL) cells were counted and electroretinogram (ERG) amplitudes measured in Tg-CA-RAC1 mice. Outer nuclear layer cells were counted in wild-type (WT) mice after transfer of CA-Rac1 gene by subretinal injection of AAV8-pOpsin-CA Rac1-GFP. Results Transgenic-CA-RAC1 retinas had significantly fewer photoreceptor cells and more apoptotic ONL cells than WT controls from postnatal week (Pw) 3 to Pw13. Superoxide accumulation and protein and lipid oxidation were increased in Tg-CA-RAC1 retinas and were reduced in mice treated with apocynin. Apocynin reduced the loss of photoreceptors and increased the rod ERG a- and b-wave amplitudes when compared with vehicle-injected transgenic controls. Photoreceptor loss was also observed in regions of adult WT retina transduced with AAV8-pOpsin-CA Rac1-GFP but not in neighboring regions that were not transduced or in AAV8-pOpsin-GFP–transduced retinas. Conclusions Constitutively active RAC1 promotes photoreceptor cell death by oxidative damage that occurs, at least partially, through NOX-induced ROS. Reactive oxygen species are likely involved in multiple forms of retinal degenerations, and our results support investigating RAC1 inhibition as a therapeutic approach that targets this disease pathway.
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Affiliation(s)
- Hongman Song
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States
| | - Camasamudram Vijayasarathy
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States
| | - Yong Zeng
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States
| | - Dario Marangoni
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States
| | - Ronald A Bush
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States
| | - Zhijian Wu
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Paul A Sieving
- Section for Translational Research on Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States 3National Eye Institute, National Institutes of Heal
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Mitra RN, Gao R, Zheng M, Wu MJ, Voinov MA, Smirnov AI, Smirnova TI, Wang K, Chavala S, Han Z. Glycol Chitosan Engineered Autoregenerative Antioxidant Significantly Attenuates Pathological Damages in Models of Age-Related Macular Degeneration. ACS NANO 2017; 11:4669-4685. [PMID: 28463509 DOI: 10.1021/acsnano.7b00429] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Age-related macular degeneration (AMD) is the foremost cause of irreversible blindness in people over the age of 65 especially in developing countries. Therefore, an exploration of effective and alternative therapeutic interventions is an unmet medical need. It has been established that oxidative stress plays a key role in the pathogenesis of AMD, and hence, neutralizing oxidative stress is an effective therapeutic strategy for treatment of this serious disorder. Owing to autoregenerative properties, nanoceria has been widely used as a nonenzymatic antioxidant in the treatment of oxidative stress related disorders. Yet, its potential clinical implementation has been greatly hampered by its poor water solubility and lack of reliable tracking methodologies/processes and hence poor absorption, distribution, and targeted delivery. The water solubility and surface engineering of a drug with biocompatible motifs are fundamental to pharmaceutical products and precision medicine. Here, we report an engineered water-soluble, biocompatible, trackable nanoceria with enriched antioxidant activity to scavenge intracellular reactive oxygen species (ROS). Experimental studies with in vitro and in vivo models demonstrated that this antioxidant is autoregenerative and more active in inhibiting laser-induced choroidal neovascularization by decreasing ROS-induced pro-angiogenic vascular endothelial growth factor (VEGF) expression, cumulative oxidative damage, and recruitment of endothelial precursor cells without exhibiting any toxicity. This advanced formulation may offer a superior therapeutic effect to deal with oxidative stress induced pathogeneses, such as AMD.
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Affiliation(s)
| | - Ruijuan Gao
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing 100050, China
| | | | | | - Maxim A Voinov
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695, United States
| | - Alex I Smirnov
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695, United States
| | - Tatyana I Smirnova
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695, United States
| | | | - Sai Chavala
- North Texas Eye Research Institute at University of North Texas Health Science Center , Fort Worth, Texas 76107, United States
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Li Y, Zhu P, Verma A, Prasad T, Deng H, Yu D, Li Q. A novel bispecific molecule delivered by recombinant AAV2 suppresses ocular inflammation and choroidal neovascularization. J Cell Mol Med 2017; 21:1555-1571. [PMID: 28332318 PMCID: PMC5543459 DOI: 10.1111/jcmm.13086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/13/2016] [Indexed: 02/05/2023] Open
Abstract
Elevated vascular endothelial growth factor (VEGF) and complement activation are implicated in the pathogenesis of different ocular diseases. The objective of this study was to investigate the hypothesis that dual inhibition of both VEGF and complement activation would confer better protection against ocular inflammation and neovascularization. In this study, we engineered a secreted chimeric VEGF inhibitor domain (VID), a complement inhibitor domain (CID) and a dual inhibitor (ACVP1). Vectors expressing these three inhibitors were constructed and packaged into AAV2 (sextY-F) particles. The expression and secretion of the proteins were validated by Western blot. The effects of these inhibitors expressed from AAV2 vectors were examined in endotoxin-induced uveitis (EIU), experimental autoimmune uveoretinitis (EAU) and choroidal neovascularization (CNV) mouse models. The AAV2 vectors expressing the CID- and ACVP1-attenuated inflammation in EIU and EAU model, whereas the vector expressing VID showed improved retinal structure damaged by EAU, but not affect the infiltration of inflammatory cells in EAU or EIU eyes. Both VID and CID vectors improved laser-induced retinal and choroid/RPE injuries and CNV, whereas ACVP1 vector provided significantly better protection. Our results suggest that gene therapy targeting VEGF and complement components could provide an innovative and long-term strategy for ocular inflammatory and neovascular diseases.
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Affiliation(s)
- Yiming Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, China.,Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Ping Zhu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Amrisha Verma
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Tuhina Prasad
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Hongxin Deng
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, China
| | - Dechao Yu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan, China
| | - Qiuhong Li
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
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Wang H, Han X, Wittchen ES, Hartnett ME. TNF-α mediates choroidal neovascularization by upregulating VEGF expression in RPE through ROS-dependent β-catenin activation. Mol Vis 2016; 22:116-28. [PMID: 26900328 PMCID: PMC4736754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/01/2016] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Inflammation, oxidative stress, and angiogenesis have been proposed to interact in age-related macular degeneration. It has been postulated that external stimuli that cause oxidative stress can increase production of vascular endothelial growth factor (VEGF) in retinal pigment epithelial (RPE) cells. In this study, we tested the hypothesis that the inflammatory cytokine, tumor necrosis factor alpha (TNF-α), contributed to choroidal neovascularization (CNV) by upregulating VEGF in RPE through intracellular reactive oxygen species (ROS)-dependent signaling and sought to understand the mechanisms involved. METHODS In a murine laser-induced CNV model, 7 days after laser treatment and intravitreal neutralizing mouse TNF-α antibody or isotype immunoglobulin G (IgG) control, the following measurements were made: 1) TNF-α protein and VEGF protein in RPE/choroids with western blot, 2) CNV volume in RPE/choroidal flatmounts, and 3) semiquantification of oxidized phospholipids stained with E06 antibody within CNV with immunohistochemistry (IHC). In cultured human RPE cells treated with TNF-α or PBS control, 1) ROS generation was measured using the 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence assay, and 2) NOX4 protein and VEGF protein or mRNA were measured with western blot or quantitative real-time PCR in cells pretreated with apocynin or nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) inhibitor, VAS 2870, or transfected with p22phox siRNA, and each was compared to its appropriate control. Western blots of phosphorylated p65 (p-p65), total p65 and β-actin, and quantitative real-time PCR of VEGF mRNA were measured in human RPE cells treated with TNF-α and pretreatment with the nuclear factor kappa B inhibitor, Bay 11-7082 or control. Western blots of β-catenin, VEGF, and p22phox and coimmunoprecipitation of β-catenin and T-cell transcriptional factor were performed in human RPE cells treated with TNF-α following pretreatment with β-catenin transcriptional inhibitors, XAV939 or JW67, or transfection with p22phox siRNA and compared to appropriate controls. RESULTS Compared to the non-lasered control, TNF-α and VEGF protein were increased in the RPE/choroids in a murine laser-induced CNV model (p<0.05). An intravitreal neutralizing antibody to mouse TNF-α reduced CNV volume, and VEGF protein in the RPE/choroids (p<0.01) and oxidized phospholipids within CNV compared to IgG control (p<0.05). In cultured RPE cells and compared to controls, TNF-α induced ROS generation and increased activation of NOX4, an isoform of NADPH oxidase; both were prevented by pretreatment with the apocynin or VAS2870 or knockdown of p22phox, a subunit of NADPH oxidase. TNF-α treatment increased VEGF expression (p<0.001) and the formation of a transcriptional complex of β-catenin and T-cell transcriptional factor; both were prevented by pretreatment with apocynin or knockdown of p22phox. Inhibition of β-catenin by XAV939, but not the nuclear factor kappa B inhibitor, Bay 11-7082, prevented TNF-α-induced VEGF upregulation. CONCLUSIONS Our results support the thinking that TNF-α contributes to CNV by upregulating VEGF production in RPE cells through ROS-dependent activation of β-catenin signaling. These results provide mechanisms of crosstalk between inflammatory mediator, TNF-α, and ROS in RPE cells.
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Affiliation(s)
- Haibo Wang
- The John Moran Eye Center, University of Utah, Salt Lake City, UT
| | - Xiaokun Han
- The John Moran Eye Center, University of Utah, Salt Lake City, UT,Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
| | - Erika S. Wittchen
- Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC
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Novel Types of Small RNA Exhibit Sequence- and Target-dependent Angiogenesis Suppression Without Activation of Toll-like Receptor 3 in an Age-related Macular Degeneration (AMD) Mouse Model. MOLECULAR THERAPY. NUCLEIC ACIDS 2015; 4:e258. [PMID: 26484944 PMCID: PMC4881762 DOI: 10.1038/mtna.2015.34] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/15/2015] [Indexed: 12/16/2022]
Abstract
RNA interference (RNAi) has become a powerful tool for suppressing gene expression in vitro and in vivo. A great deal of evidence has demonstrated the potential for the use of synthetic small interfering RNAs (siRNAs) as therapeutic agents. However, the application of siRNA to clinical medicine is still limited, mainly due to sequence-independent suppression of angiogenesis mediated by Toll-like receptor 3 (TLR3). Here, we describe novel types of synthetic RNA, named nkRNA and PnkRNA, that exhibit sequence-specific gene silencing through RNAi without activating TLRs or RIG-I–like receptor signaling. In addition, we confirmed the therapeutic effect for the novel types of RNA in an animal model of age-related macular degeneration (AMD) without retinal degeneration. These data indicate that nkRNA and PnkRNA are of great potential utility as therapies against blinding choroidal neovascularization due to AMD.
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Qiu Y, Tao L, Lei C, Wang J, Yang P, Li Q, Lei B. Downregulating p22phox ameliorates inflammatory response in Angiotensin II-induced oxidative stress by regulating MAPK and NF-κB pathways in ARPE-19 cells. Sci Rep 2015; 5:14362. [PMID: 26415877 PMCID: PMC4586461 DOI: 10.1038/srep14362] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 08/24/2015] [Indexed: 11/24/2022] Open
Abstract
Oxidative stress and inflammation are two interrelated biological events implicated in the pathogenesis of many diseases. Reactive oxygen species (ROS) produced under oxidative stress play a key role in pathological conditions. Inhibition of p22phox, an indispensable component of the NADPH oxidase (NOX) complex comprising the main source of ROS, plays a protective role in many ocular conditions by inhibiting the activation of NOXs and the generation of ROS. However, little is understood regarding the role of p22phox in oxidative stress-related inflammation in the eye. We used a p22phox small interfering RNA (siRNA) to transfect the retinal pigment epithelium (RPE)-derived cell line ARPE-19, and human primary RPE (hRPE) cells, then stimulated with Ang II. We observed a potent anti-inflammatory effect and studied the underlying mechanism. Downregulating p22phox resulted in decreased ROS generation, a reduction of NOXs (NOX1, 2, 4) and a decrease in inflammatory cytokine. In addition, p22phox downregulation reduced the activation of the MAPK and NF-κB signaling pathways. We conclude that inhibition of p22phox has an anti-inflammatory effect in Ang II-induced oxidative stress. Suppressing the MAPK and NF-κB pathways is involved in this protective effect. These results suggest that p22phox may provide a promising therapeutic target for oxidative stress-induced ocular inflammation
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Affiliation(s)
- Yiguo Qiu
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - Lifei Tao
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - Chunyan Lei
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - Jiaming Wang
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - Peizeng Yang
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
| | - Qiuhong Li
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Bo Lei
- Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China
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Hauswirth WW. Retinal gene therapy using adeno-associated viral vectors: multiple applications for a small virus. Hum Gene Ther 2015; 25:671-8. [PMID: 25136913 DOI: 10.1089/hum.2014.2530] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- William W Hauswirth
- Department of Ophthalmology, College of Medicine, University of Florida , Gainesville, FL 32610-0284
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21
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Li H, Wan C, Du L, Li F. Enhanced downregulation of transforming growth factor‑β2 in rat retinal pigment epithelium cells by adeno‑associated virus‑mediated ribonucleic acid interference combined with ultrasound or microbubbles. Mol Med Rep 2014; 11:1099-104. [PMID: 25370502 DOI: 10.3892/mmr.2014.2845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 10/06/2014] [Indexed: 11/06/2022] Open
Abstract
The present study was designed to determine the efficiency and safety of ultrasound (US) and/or US contrast agent microbubbles (MBs) in the delivery of type 2 recombinant adeno-associated virus‑delivered transforming growth factor‑β2 short hairpin ribonucleic acid encoding the enhanced green fluorescent protein gene (rAAV2‑TGFβ2 shRNA‑EGFP) and the downregulation of TGFβ2 in rat retinal pigment epithelium (RPE‑J) cells. The effects of US and/or MBs on the delivery of rAAV2‑EGFP and rAAV2‑TGFβ2 shRNA‑EGFP were evaluated by fluorescence microscopy and flow cytometry. The potential toxicity of cell viability under various US or MB conditions was assessed by CellTiter 96® AQueous One solution cell proliferation assay. The level of TGFβ2 mRNA in RPE‑J cells under various conditions was estimated by reverse transcription‑quantitative polymerase chain reaction analysis. The results obtained demonstrated that low-intensity US (0.5 W/cm2 and 30 sec) or SonoVue (MB:cell ratio, 40:1) increased the delivery efficiency of rAAV2‑EGFP and rAAV2‑TGFβ2 shRNA‑EGFP to RPE‑J cells, whereas the combination of US with MBs did not further increase but instead decreased rAAV transfection. Under the optimal conditions of rAAV delivery, enhanced TGFβ2 gene silencing with a combination of US or SonoVue with rAAV2‑TGFβ2 shRNA resulted in a significant decrease in mRNA levels compared with rAAV2‑TGFβ2 shRNA alone. US or SonoVue was used safely to enhance the delivery of rAAV2‑TGFβ2 shRNA to RPE‑J cells. A combination of the biological (rAAV2‑TGFβ2 shRNA) and physical (US or SonoVue) approaches downregulated the mRNA level of TGFβ2 more effectively.
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Affiliation(s)
- Hongli Li
- Department of Ultrasound, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Caifeng Wan
- Department of Ultrasound, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Lianfang Du
- Department of Ultrasound, Shanghai First People's Hospital, Shanghai 200080, P.R. China
| | - Fenghua Li
- Department of Ultrasound, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
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Wang H, Jiang Y, Shi D, Quilliam LA, Chrzanowska-Wodnicka M, Wittchen ES, Li DY, Hartnett ME. Activation of Rap1 inhibits NADPH oxidase-dependent ROS generation in retinal pigment epithelium and reduces choroidal neovascularization. FASEB J 2013; 28:265-74. [PMID: 24043260 DOI: 10.1096/fj.13-240028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Activation of Rap1 GTPase can improve the integrity of the barrier of the retina pigment epithelium (RPE) and reduce choroidal neovascularization (CNV). Inhibition of NADPH oxidase activation also reduces CNV. We hypothesize that Rap1 inhibits NADPH oxidase-generated ROS and thereby reduces CNV formation. Using a murine model of laser-induced CNV, we determined that reduced Rap1 activity in RPE/choroid occurred with CNV formation and that activation of Rap1 by 2'-O-Me-cAMP (8CPT)-reduced laser-induced CNV via inhibiting NADPH oxidase-generated ROS. In RPE, inhibition of Rap1 by Rap1 GTPase-activating protein (Rap1GAP) increased ROS generation, whereas activation of Rap1 by 8CPT reduced ROS by interfering with the assembly of NADPH oxidase membrane subunit p22phox with NOX4 or cytoplasmic subunit p47phox. Activation of NADPH oxidase with Rap1GAP reduced RPE barrier integrity via cadherin phosphorylation and facilitated choroidal EC migration across the RPE monolayer. Rap1GAP-induced ROS generation was inhibited by active Rap1a, but not Rap1b, and activation of Rap1a by 8CPT in Rap1b(-/-) mice reduced laser-induced CNV, in correlation with decreased ROS generation in RPE/choroid. These findings provide evidence that active Rap1 reduces CNV by interfering with the assembly of NADPH oxidase subunits and increasing the integrity of the RPE barrier.
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Affiliation(s)
- Haibo Wang
- 1John A. Moran Eye Center, University of Utah, 65 N. Mario Capecchi Dr., Salt Lake City, UT 84132.
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Li X, Cai Y, Wang YS, Shi YY, Hou W, Xu CS, Wang HY, Ye Z, Yao LB, Zhang J. Hyperglycaemia exacerbates choroidal neovascularisation in mice via the oxidative stress-induced activation of STAT3 signalling in RPE cells. PLoS One 2012; 7:e47600. [PMID: 23094067 PMCID: PMC3477109 DOI: 10.1371/journal.pone.0047600] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Accepted: 09/18/2012] [Indexed: 12/14/2022] Open
Abstract
Choroidal neovascularisation (CNV) that occurs as a result of age-related macular degeneration (AMD) causes severe vision loss among elderly patients. The relationship between diabetes and CNV remains controversial. However, oxidative stress plays a critical role in the pathogenesis of both AMD and diabetes. In the present study, we investigated the influence of diabetes on experimentally induced CNV and on the underlying molecular mechanisms of CNV. CNV was induced via photocoagulation in the ocular fundi of mice with streptozotocin-induced diabetes. The effect of diabetes on the severity of CNV was measured. An immunofluorescence technique was used to determine the levels of oxidative DNA damage by anti-8-hydroxy-2-deoxyguanosine (8-OHdG) antibody, the protein expression of phosphorylated signal transducer and activator of transcription 3 (p-STAT3) and vascular endothelial growth factor (VEGF), in mice with CNV. The production of reactive oxygen species (ROS) in retinal pigment epithelial (RPE) cells that had been cultured under high glucose was quantitated using the 2′,7′-dichlorofluorescein diacetate (DCFH-DA) method. p-STAT3 expression was examined using Western blot analysis. RT-PCR and ELISA processes were used to detect VEGF expression. Hyperglycaemia exacerbated the development of CNV in mice. Oxidative stress levels and the expression of p-STAT3 and VEGF were highly elevated both in mice and in cultured RPE cells. Treatment with the antioxidant compound N-acetyl-cysteine (NAC) rescued the severity of CNV in diabetic mice. NAC also inhibited the overexpression of p-STAT3 and VEGF in CNV and in RPE cells. The JAK-2/STAT3 pathway inhibitor AG490 blocked VEGF expression but had no effect on the production of ROS in vitro. These results suggest that hyperglycaemia promotes the development of CNV by inducing oxidative stress, which in turn activates STAT3 signalling in RPE cells. Antioxidant supplementation helped attenuate the development of CNV. Thus, our results reveal a potential strategy for the treatment and prevention of diseases involving CNV.
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Affiliation(s)
- Xia Li
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Yan Cai
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Yu-Sheng Wang
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
- * E-mail: (YSW); (JZ)
| | - Yuan-Yuan Shi
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Wei Hou
- Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Chun-Sheng Xu
- State Key Laboratory of Cancer Biology, Department of Gastrointestinal Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Hai-Yan Wang
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Zi Ye
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Li-Bo Yao
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Jian Zhang
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
- * E-mail: (YSW); (JZ)
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Meijles DN, Howlin BJ, Li JM. Consensus in silico computational modelling of the p22phox subunit of the NADPH oxidase. Comput Biol Chem 2012; 39:6-13. [DOI: 10.1016/j.compbiolchem.2012.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/02/2012] [Accepted: 05/02/2012] [Indexed: 11/24/2022]
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Jarrett SG, Boulton ME. Consequences of oxidative stress in age-related macular degeneration. Mol Aspects Med 2012; 33:399-417. [PMID: 22510306 DOI: 10.1016/j.mam.2012.03.009] [Citation(s) in RCA: 368] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 03/31/2012] [Indexed: 12/24/2022]
Abstract
The retina resides in an environment that is primed for the generation of reactive oxygen species (ROS) and resultant oxidative damage. The retina is one of the highest oxygen-consuming tissues in the human body. The highest oxygen levels are found in the choroid, but this falls dramatically across the outermost retina, creating a large gradient of oxygen towards the retina and inner segments of the photoreceptors which contain high levels of polyunsaturated fatty acids. This micro-environment together with abundant photosensitizers, visible light exposure and a high energy demand supports a highly oxidative milieu. However, oxidative damage is normally minimized by the presence of a range of antioxidant and efficient repair systems. Unfortunately, as we age oxidative damage increases, antioxidant capacity decreases and the efficiency of reparative systems become impaired. The result is retinal dysfunction and cell loss leading to visual impairment. It appears that these age-related oxidative changes are a hallmark of early age-related macular degeneration (AMD) which, in combination with hereditary susceptibility and other retinal modifiers, can progress to the pathology and visual morbidity associated with advanced AMD. This review reassesses the consequences of oxidative stress in AMD and strategies for preventing or reversing oxidative damage in retinal tissues.
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Affiliation(s)
- Stuart G Jarrett
- Department of Molecular and Biomedical Pharmacology, College of Medicine, University of Kentucky, Lexington, KY, USA
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Qi X, Cai J, Ruan Q, Liu L, Boye SL, Chen Z, Hauswirth WW, Ryals RC, Shaw L, Caballero S, Grant MB, Boulton ME. γ-Secretase inhibition of murine choroidal neovascularization is associated with reduction of superoxide and proinflammatory cytokines. Invest Ophthalmol Vis Sci 2012; 53:574-85. [PMID: 22205609 DOI: 10.1167/iovs.11-8728] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PURPOSE This study aimed to determine whether upregulation of γ-secretase could inhibit laser-induced choroidal neovascularization (CNV) and if this was associated with a reduction in both oxidative stress and proinflammatory cytokines. METHODS γ-Secretase, or its catalytic subunit presenilin 1 (PS1), were upregulated by exposure to either pigment epithelial derived factor (PEDF) or an AAV2 vector containing a PS1 gene driven by a vascular endothelial-cadherin promoter. Retinal endothelial cells were infected with AAV2 or exposed to PEDF in the presence or absence of VEGF and in vitro angiogenesis determined. Mouse eyes either received intravitreal injection of PEDF, DAPT (a γ-secretase inhibitor) or PEDF + DAPT at the time of laser injury, or AAV2 infection 3 weeks before receiving laser burns. Lesion volume was determined 14 days post laser injury. Superoxide generation, antioxidant activity and the production of proinflammatory mediators were assessed. Knockdown of γ-secretase was achieved using siRNA. RESULTS γ-Secretase upregulation and PS1 overexpression suppressed VEGF-induced in vitro angiogenesis and in vivo laser-induced CNV. This was associated with a reduction in the expression of VEGF and angiogenin 1 together with reduced superoxide anion generation and an increase in MnSOD compared with untreated CNV eyes. PS1 overexpression reduced proinflammatory factors and microglial activation in eyes with CNV compared with control. siRNA inhibition of γ-secretase resulted in increased angiogenesis. CONCLUSIONS γ-Secretase, and in particular PS1 alone, are potent regulators of angiogenesis and this is due in part to stabilizing endogenous superoxide generation and reducing proinflammatory cytokine expression during CNV.
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Affiliation(s)
- Xiaoping Qi
- Departments of Anatomy and Cell Biology, University of Florida, Gainesville, Florida 32610-0235, USA
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Chandrasekhar A, Laloraya M, Kumar PG. Modulation of nicotinamide adenine dinucleotide phosphate oxidase activity through sequential posttranslational modifications of p22 phagocytic oxidase during capacitation and acrosome reaction in goat spermatozoa1. J Anim Sci 2011; 89:2995-3007. [DOI: 10.2527/jas.2010-3731] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Hara R, Inomata Y, Kawaji T, Sagara N, Inatani M, Fukushima M, Tanihara H. Suppression of choroidal neovascularization by N-acetyl-cysteine in mice. Curr Eye Res 2011; 35:1012-20. [PMID: 20958190 DOI: 10.3109/02713683.2010.500112] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE N-acetyl-cysteine (NAC) is a potent antioxidant known to be a precursor of glutathione. The purpose of this study was to investigate the role of NAC in the development of choroidal neovascularization (CNV). METHODS CNV was induced in C57BL/6 mice by laser photocoagulation of the ocular fundus. Mice were injected intraperitoneally with NAC or vehicle alone. The levels of 4-hydoroxy-2-nonenal (4-HNE)-modified protein and nucleus factor (NF)-κB were determined by wester blotting. The recruitment of macrophages and neutrophils after laser injury was analyzed immunohistochemically and in myeloperoxidase (MPO) assays. Enzyme-linked immunosorbent assays (ELISA) were used to measure monocyte chemotactic protein (MCP)-1, CXCL1, vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-1, and VEGFR-2. The extent of CNV was evaluated 7 d after laser injury by lectin staining. RESULTS In NAC-treated mice with laser-induced injuries, the induction of 4-HNE-modified protein after 3 hr and the activation of NF-κB in nuclear extracts after 6 hr were markedly suppressed compared to vehicle-treated mice. Macrophage and neutrophil recruitment were inhibited and the levels of MCP-1, CXCL1, VEGF, and VEGFR-1 were also lower in NAC-treated mice compared to vehicle-treated mice. Furthermore, the extent of CNV induced was significantly lower in NAC-treated compared to vehicle-treated mice (p = 0.027). CONCLUSIONS Our results clearly showed that NAC inhibited indicators of oxidative stress and the activation of NF-κB induced by laser injury, and, consequently, suppressed macrophage and neutrophil infiltration and the development of CNV. This suggests novel preventative and interventional therapeutic strategies for age-related macular degeneration.
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Affiliation(s)
- Ryuhei Hara
- Department of Ophthalmology and Visual Science, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
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Jiang F, Zhang Y, Dusting GJ. NADPH oxidase-mediated redox signaling: roles in cellular stress response, stress tolerance, and tissue repair. Pharmacol Rev 2011; 63:218-42. [PMID: 21228261 DOI: 10.1124/pr.110.002980] [Citation(s) in RCA: 420] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
NADPH oxidase (Nox) has a dedicated function of generating reactive oxygen species (ROS). Accumulating evidence suggests that Nox has an important role in signal transduction in cellular stress responses. We have reviewed the current evidence showing that the Nox system can be activated by a collection of chemical, physical, and biological cellular stresses. In many circumstances, Nox activation fits to the cellular stress response paradigm, in that (1) the response can be initiated by various forms of cellular stresses; (2) Nox-derived ROS may activate mitogen-activated protein kinases (extracellular signal-regulated kinase, p38) and c-Jun NH(2)-terminal kinase, which are the core of the cell stress-response signaling network; and (3) Nox is involved in the development of stress cross-tolerance. Activation of the cell survival pathway by Nox may promote cell adaptation to stresses, whereas Nox may also convey signals toward apoptosis in irreversibly injured cells. At later stage after injury, Nox is involved in tissue repair by modulating cell proliferation, angiogenesis, and fibrosis. We suggest that Nox may have an integral role in cell stress responses and the subsequent tissue repair process. Understanding Nox-mediated redox signaling mechanisms may be of prominent significance at the crossroads of directing cellular responses to stress, aiming at either enhancing the stress resistance (in such situations as preventing ischemia-reperfusion injuries and accelerating wound healing) or sensitizing the stress-induced cytotoxicity for proliferative diseases such as cancer. Therefore, an optimal outcome of interventions on Nox will only be achieved when this is dealt with in a timely and disease-and stage-specific manner.
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Affiliation(s)
- Fan Jiang
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Qilu Hospital, Shandong University, 107 Wen Hua Xi Road, Jinan, Shandong 250012, China.
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Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. It is a multifactorial disease, and current therapy predominantly limits damage only when it has already occurred. The macula is a source of high metabolic activity, and is therefore exposed to correspondingly high levels of reactive oxygen species (ROS). With age, the balance between production of ROS and local antioxidant levels is shifted, and damage ensues. Systemic ROS and antioxidant levels in AMD reflect these local processes. Genetic studies investigating mutations in antioxidant genes in AMD are inconclusive and further studies are indicated, especially to determine the role of mitochondria. Oral antioxidant supplements could be beneficial, and diet modification may help. Future treatments might either increase antioxidant capacity or reduce the production of ROS, using methods such as genetic manipulation. This article reviews the role of oxidative stress in AMD and the potential therapies that might have a role in preventing the blindness resulting from this disease.
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Monaghan-Benson E, Hartmann J, Vendrov AE, Budd S, Byfield G, Parker A, Ahmad F, Huang W, Runge M, Burridge K, Madamanchi N, Hartnett ME. The role of vascular endothelial growth factor-induced activation of NADPH oxidase in choroidal endothelial cells and choroidal neovascularization. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2091-102. [PMID: 20802176 DOI: 10.2353/ajpath.2010.090878] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Rac1, a subunit of NADPH oxidase, plays an important role in directed endothelial cell motility. We reported previously that Rac1 activation was necessary for choroidal endothelial cell migration across the retinal pigment epithelium, a critical step in the development of vision-threatening neovascular age-related macular degeneration. Here we explored the roles of Rac1 and NADPH oxidase activation in response to vascular endothelial growth factor treatment in vitro and in a model of laser-induced choroidal neovascularization. We found that vascular endothelial growth factor induced the activation of Rac1 and of NADPH oxidase in cultured human choroidal endothelial cells. Further, vascular endothelial growth factor led to heightened generation of reactive oxygen species from cultured human choroidal endothelial cells, which was prevented by the NADPH oxidase inhibitors, apocynin and diphenyleneiodonium, or the antioxidant, N-acetyl-L-cysteine. In a model of laser-induced injury, inhibition of NADPH oxidase with apocynin significantly reduced reactive oxygen species levels as measured by dihydroethidium fluorescence and the volume of laser-induced choroidal neovascularization. Mice lacking functional p47phox, a subunit of NADPH oxidase, had reduced dihydroethidium fluorescence and choroidal neovascularization compared with wild-type controls. Taken together, these results indicate that vascular endothelial growth factor activates Rac1 upstream from NADPH oxidase in human choroidal endothelial cells and increases generation of reactive oxygen species, contributing to choroidal neovascularization. These steps may contributed to the pathology of neovascular age-related macular degeneration.
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Affiliation(s)
- Elizabeth Monaghan-Benson
- Department of Cell and Developmental Biology, University of North Carolina, Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, USA
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Salminen A, Kauppinen A, Hyttinen JM, Toropainen E, Kaarniranta K. Endoplasmic reticulum stress in age-related macular degeneration: trigger for neovascularization. Mol Med 2010; 16:535-42. [PMID: 20683548 DOI: 10.2119/molmed.2010.00070] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 07/26/2010] [Indexed: 12/18/2022] Open
Abstract
Age-related macular degeneration (AMD) can be classified into two main categories: the atrophic, dry form and the exudative, wet form. The crucial difference between dry and wet AMD is the development of choroidal neovascularization in wet AMD. One fundamental cause of the neovascularization is the increased expression of VEGF (vascular endothelial growth factor) in retinal pigment epithelial cells. Progression of AMD is linked to augmentation of cellular stress, for example, oxidative stress, proteotoxic stress, inflammation and hypoxia. All these conditions can trigger stress in endoplasmic reticulum (ER), which maintains protein quality control in cells. ER stress induces the unfolded protein response (UPR) via IRE1 (inositol-requiring protein-1), PERK (protein kinase RNA-like ER kinase) and ATF6 (activating transcription factor-6) transducers. UPR signaling is a double-edged sword, that is, it can restore cellular homeostasis as far as possible, but ultimately may lead to chronic, overwhelming stress that can cause apoptotic cell death. Interestingly, ER stress is a well-known inducer of angiogenesis in cancer. Moreover, stress conditions associated with the progress of AMD can induce the expression of VEGF. We discuss the role of ER stress in the regulation of neovascularization and the conversion of dry AMD to its wet, detrimental counterpart.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, University of Eastern Finland, Kuopio, Finland.
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Kosugi T, Nakayama T, Li Q, Chiodo VA, Zhang L, Campbell-Thompson M, Grant M, Croker BP, Nakagawa T. Soluble Flt-1 gene therapy ameliorates albuminuria but accelerates tubulointerstitial injury in diabetic mice. Am J Physiol Renal Physiol 2009; 298:F609-16. [PMID: 20015944 DOI: 10.1152/ajprenal.00377.2009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
VEGF is recognized as a major mediator in the development of diabetic nephropathy. Soluble Flt-1 (sFlt-1) is the endogenous inhibitor of VEGF, and recently genetic overexpression of sFlt-1 in the podocyte was shown to be protective in murine diabetic nephropathy. In this study, we performed a translational study to determine whether an intramuscular gene transfer of sFlt-1 can prevent the progression of renal disease in diabetic db/db mice. Adeno-associated virus-1 (AAV1) encoding human sFlt-1 in two different doses was intramuscularly administrated in db/db and wild-type mice. The sFlt-1-AAV1 treatment significantly increased serum sFlt-1 level at 4 and 8 wk. A dose that was developed in this study caused minimal abnormalities in normal mice but reduced albuminuria in diabetic db/db mice. In renal histology, sFlt-1 treatment at this dose had minimal effects on mesangial expansion in diabetic mice, whereas podocyte injury was significantly improved, at 8 wk. Unfortunately, tubulointerstitial injury was markedly exacerbated by sFlt-1 treatment in association with a reduction in endogenous VEGF expression and peritubular capillary loss. In conclusion, gene therapy with sFlt-1-AAV1 protects podocytes but accelerates tubulointerstitial injury in diabetic db/db mice. These data suggest systemic overexpression of sFlt-1 will not likely be useful for treating diabetic nephropathy.
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Affiliation(s)
- Tomoki Kosugi
- Division of Nephrology, University of Florida, Gainesville, Florida, USA
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Groeger G, Mackey AM, Pettigrew CA, Bhatt L, Cotter TG. Stress-induced activation of Nox contributes to cell survival signalling via production of hydrogen peroxide. J Neurochem 2009; 109:1544-54. [DOI: 10.1111/j.1471-4159.2009.06081.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Usui S, Oveson BC, Lee SY, Jo YJ, Yoshida T, Miki A, Miki K, Iwase T, Lu L, Campochiaro PA. NADPH oxidase plays a central role in cone cell death in retinitis pigmentosa. J Neurochem 2009; 110:1028-37. [PMID: 19493169 DOI: 10.1111/j.1471-4159.2009.06195.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Retinitis pigmentosa (RP) is a collection of diseases in which rod photoreceptors die from a variety of mutations. After rods die, the level of tissue oxygen in the outer retina becomes elevated and there is progressive oxidative damage to cones that ultimately triggers apoptosis. In this study, we investigated the hypothesis that NADPH oxidase (Nox) and/or xanthine oxidase serve as critical intermediaries between increased tissue oxygen and the generation of excessive reactive oxygen species that cause oxidative damage to cones. Apocynin, a blocker of Nox, but not allopurinol, a blocker of xanthine oxidase, markedly reduced the superoxide radicals visualized by hydroethidine in the outer retina in the retinal degeneration-1 (rd1(+/+)) model of RP. Compared to rd1(+/+) mice treated with vehicle, those treated with apocynin, but not those treated with allopurinol, had significantly less oxidative damage in the retina measured by ELISA for carbonyl adducts. Apocynin-treated, but not allopurinol-treated, rd1(+/+) mice had preservation of cone cell density, increased mRNA levels for m- and s-cone opsin, and increased mean photopic b-wave amplitude. In Q344ter mice, a model of dominant RP in which mutant rhodopsin is expressed, apocynin treatment preserved photopic electroretinogram b-wave amplitude compared to vehicle-treated controls. These data indicate that Nox, but not xanthine oxidase, plays a critical role in generation of the oxidative stress that leads to cone cell death in RP and inhibition of Nox provides a new treatment strategy.
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Affiliation(s)
- Shinichi Usui
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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