1
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Bi N, Li N, Liu H, Wang TH. Molecular Network Mechanism Analysis of Urine Stem Cells Against Retinal Aging. Biochem Genet 2024:10.1007/s10528-023-10487-6. [PMID: 38273154 DOI: 10.1007/s10528-023-10487-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/06/2023] [Indexed: 01/27/2024]
Abstract
To investigate the effect and potential mechanism of human-derived urine stem cells (hUSCs) in inhibiting retinal aging by using experimental and bioinformatics. Retinal pigment epithelial cells cultured in vitro, which were randomly divided into normal group, aging group and supernatant of hUSCs group. Cell counting kit-8 detection, senescence-related β-galactosidase, and Annexin V/PI staining were performed to detect cell viability, senescence, and apoptosis. Subsequently, bioinformatics methods were used to explore the underlying mechanisms, in which, targets both hUSCs and aging retina-related targets were obtained from GeneCards. Then, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and protein-protein interaction network were analysis, and the expressional level of hub gene was validated by q-PCR. Supernatant addition of hUSCs promoted markedly cellular proliferation, improved viability and inhibited senescence and apoptosis in vitro. A total of 1476 hUSCs-related targets (Relevance score > 20), 692 retinal disease-related targets, and 732 targets related to disease of aging were selected from GeneCards database, and 289 common targets of hUSCs against aging retina were confirmed through Venn analysis. Enrichment analysis demonstrated that hUSCs might exert its anti-apoptosis efficacy in multiple biological processes, including oxidative stress, inflammation and apoptosis, and core targets were associated with HIF-1, MAPK and PI3K-Akt signal. hUSCs inhibited retinal senescence by regulating multiply targets and signaling pathways, of these, HIF-1, MAPK, and PI3K may be important candidates.
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Affiliation(s)
- Ning Bi
- Institute of Neuroscience, Kunming Medical University, Kunming, 650500, China
| | - Na Li
- Animal Center, Kunming Medical University, Kunming, 650500, China
- Department of Anatomy, College of Basic Medicine, Jinzhou Medical University, Jinzhou, 121000, China
| | - Hua Liu
- Department of Anatomy, College of Basic Medicine, Jinzhou Medical University, Jinzhou, 121000, China.
| | - Ting-Hua Wang
- Institute of Neuroscience, Kunming Medical University, Kunming, 650500, China.
- Animal Center, Kunming Medical University, Kunming, 650500, China.
- Department of Anatomy, College of Basic Medicine, Jinzhou Medical University, Jinzhou, 121000, China.
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2
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Markitantova Y, Simirskii V. Endogenous and Exogenous Regulation of Redox Homeostasis in Retinal Pigment Epithelium Cells: An Updated Antioxidant Perspective. Int J Mol Sci 2023; 24:10776. [PMID: 37445953 DOI: 10.3390/ijms241310776] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
The retinal pigment epithelium (RPE) performs a range of necessary functions within the neural layers of the retina and helps ensure vision. The regulation of pro-oxidative and antioxidant processes is the basis for maintaining RPE homeostasis and preventing retinal degenerative processes. Long-term stable changes in the redox balance under the influence of endogenous or exogenous factors can lead to oxidative stress (OS) and the development of a number of retinal pathologies associated with RPE dysfunction, and can eventually lead to vision loss. Reparative autophagy, ubiquitin-proteasome utilization, the repair of damaged proteins, and the maintenance of their conformational structure are important interrelated mechanisms of the endogenous defense system that protects against oxidative damage. Antioxidant protection of RPE cells is realized as a result of the activity of specific transcription factors, a large group of enzymes, chaperone proteins, etc., which form many signaling pathways in the RPE and the retina. Here, we discuss the role of the key components of the antioxidant defense system (ADS) in the cellular response of the RPE against OS. Understanding the role and interactions of OS mediators and the components of the ADS contributes to the formation of ideas about the subtle mechanisms in the regulation of RPE cellular functions and prospects for experimental approaches to restore RPE functions.
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Affiliation(s)
- Yuliya Markitantova
- Koltsov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Vladimir Simirskii
- Koltsov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
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3
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Zhuang X, Ma J, Xu G, Sun Z. SHP-1 knockdown suppresses mitochondrial biogenesis and aggravates mitochondria-dependent apoptosis induced by all trans retinal through the STING/AMPK pathways. Mol Med 2022; 28:125. [PMID: 36273174 PMCID: PMC9588232 DOI: 10.1186/s10020-022-00554-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 10/06/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Oxidative stress-caused damage to the retinal pigment epithelium (RPE) underlies the onset and progression of age-related macular degeneration (AMD). Impaired mitochondrial biogenesis sensitizes RPE cells to mitochondrial dysfunction, energy insufficiency and death. Src-homology 2 domain-containing phosphatase (SHP)-1 is important in regulating immune responses and cell survival. However, its roles in cell survival are not always consistent. Until now, the effects of SHP-1 on RPE dysfunction, especially mitochondrial homeostasis, remain to be elucidated. We sought to clarify the effects of SHP-1 in RPE cells in response to atRAL-induced oxidative stress and determine the regulatory mechanisms involved. METHODS In the all trans retinal (atRAL)-induced oxidative stress model, we used the vector of lentivirus to knockdown the expression of SHP-1 in ARPE-19 cells. CCK-8 assay, Annexin V/PI staining and JC-1 staining were utilized to determine the cell viability, cell apoptosis and mitochondrial membrane potential. We also used immunoprecipitation to examine the ubiquitination modification of stimulator of interferon genes (STING) and its interaction with SHP-1. The expression levels of mitochondrial marker, proteins related to mitochondrial biogenesis, and signaling molecules involved were examined by western blotting analysis. RESULTS We found that SHP-1 knockdown predisposed RPE cells to apoptosis, aggravated mitochondrial damage, and repressed mitochondrial biogenesis after treatment with atRAL. Immunofluoresent staining and immunoprecipitation analysis confirmed that SHP-1 interacted with the endoplasmic reticulum-resident STING and suppressed K63-linked ubiquitination and activation of STING. Inhibition of STING with the specific antagonist H151 attenuated the effects of SHP-1 knockdown on mitochondrial biogenesis and oxidative damage. The adenosine monophosphate-activated protein kinase (AMPK) pathway acted as the crucial downstream target of STING and was involved in the regulatory processes. CONCLUSIONS These findings suggest that SHP-1 knockdown potentiates STING overactivation and represses mitochondrial biogenesis and cell survival, at least in part by blocking the AMPK pathway in RPE cells. Therefore, restoring mitochondrial health by regulating SHP-1 in RPE cells may be a potential therapeutic strategy for degenerative retinal diseases including AMD.
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Affiliation(s)
- Xiaonan Zhuang
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Jun Ma
- Eye Institute, Eye & ENT Hospital, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Gezhi Xu
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
| | - Zhongcui Sun
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China.
- Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.
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4
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Shao Z, Chwa M, Atilano SR, Park J, Karageozian H, Karageozian V, Kenney MC. The Transcriptome Profile of Retinal Pigment Epithelium and Müller Cell Lines Protected by Risuteganib Against Hydrogen Peroxide Stress. J Ocul Pharmacol Ther 2022; 38:513-526. [PMID: 35731128 PMCID: PMC9508878 DOI: 10.1089/jop.2022.0015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Purpose: Oxidative stress contributes to the pathogenesis of vision-impairing diseases. In the retina, retinal pigment epithelium (RPE) and Müller cells support neuronal homeostasis, but also contribute to pathological development under stressed conditions. Recent studies found that the investigational drug risuteganib (RSG) has a good safety profile, provided protection in experimental models, and improved visual acuity in patients. The present in vitro study evaluated the effects of RSG in RPE and Müller cell lines stressed with the oxidant hydrogen peroxide (H2O2). Methods: Human RPE (ARPE-19) and Müller (MIO-M1) cell lines were treated with various combinations of RSG and H2O2. Trypan blue assay was used to investigate the effect of compounds on cell viability. Gene expression was measured using RNA sequencing to identify regulated genes and the biological processes and pathways involved. Results: Trypan blue assay found RSG pre-treatment significantly protected against H2O2-induced cell death in ARPE-19 and MIO-M1 cells. Transcriptome analysis found H2O2 regulated genes in several disease-relevant biological processes, including cell adhesion, migration, death, and proliferation; ECM organization; angiogenesis; metabolism; and immune system processes. RSG pre-treatment modulated these gene expression profiles in the opposite direction of H2O2. Pathway analysis found genes in integrin, AP-1, and syndecan signaling pathways were regulated. Expression of selected RSG-regulated genes was validated using qRT-PCR. Conclusions: RSG protected cultured human RPE and Müller cell lines against H2O2-induced cell death and mitigated the associated transcriptome changes in biological processes and pathways relevant to the pathogenesis of retinal diseases. These results demonstrate RSG reduced oxidative stress-induced toxicity in two retinal cell lines with potential relevance to the treatment of human diseases.
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Affiliation(s)
- Zixuan Shao
- Allegro Ophthalmics, LLC, San Juan Capistrano, California, USA
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA
| | - Shari R Atilano
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA
| | - John Park
- Allegro Ophthalmics, LLC, San Juan Capistrano, California, USA
| | | | | | - M Cristina Kenney
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA.,Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, California, USA
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5
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Barnstable CJ, Zhang M, Tombran-Tink J. Uncoupling Proteins as Therapeutic Targets for Neurodegenerative Diseases. Int J Mol Sci 2022; 23:5672. [PMID: 35628482 PMCID: PMC9144266 DOI: 10.3390/ijms23105672] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/14/2022] [Accepted: 05/16/2022] [Indexed: 02/05/2023] Open
Abstract
Most of the major retinal degenerative diseases are associated with significant levels of oxidative stress. One of the major sources contributing to the overall level of stress is the reactive oxygen species (ROS) generated by mitochondria. The driving force for ROS production is the proton gradient across the inner mitochondrial membrane. This gradient can be modulated by members of the uncoupling protein family, particularly the widely expressed UCP2. The overexpression and knockout studies of UCP2 in mice have established the ability of this protein to provide neuroprotection in a number of animal models of neurological disease, including retinal diseases. The expression and activity of UCP2 are controlled at the transcriptional, translational and post-translational levels, making it an ideal candidate for therapeutic intervention. In addition to regulation by a number of growth factors, including the neuroprotective factors LIF and PEDF, small molecule activators of UCP2 have been found to reduce mitochondrial ROS production and protect against cell death both in culture and animal models of retinal degeneration. Such studies point to the development of new therapeutics to combat a range of blinding retinal degenerative diseases and possibly other diseases in which oxidative stress plays a key role.
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Affiliation(s)
- Colin J. Barnstable
- Department of Neural and Behavioral Sciences, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA;
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China;
| | - Mingliang Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China;
| | - Joyce Tombran-Tink
- Department of Neural and Behavioral Sciences, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA;
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China;
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6
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Duncan RS, Hurtado DT, Hall CW, Koulen P. Differential Mechanisms of Action and Efficacy of Vitamin E Components in Antioxidant Cytoprotection of Human Retinal Pigment Epithelium. Front Pharmacol 2022; 12:798938. [PMID: 35058783 PMCID: PMC8764263 DOI: 10.3389/fphar.2021.798938] [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: 10/20/2021] [Accepted: 11/17/2021] [Indexed: 12/21/2022] Open
Abstract
The purpose of this study was to determine if different vitamin E components exhibit similar efficacy and mechanism of action in protecting Retinal pigment epithelium (RPE) cells from oxidative damage. We hypothesized that α-tocopherol (αT) is unique among vitamin E components in its cytoprotective mechanism of action against oxidative stress in RPE cells and that it requires protein synthesis for optimal antioxidant effect. We used cell viability assays, fluorescent chemical labeling of DNA and actin and immuno-labeling of the antioxidant proteins Nrf2 and Sod2 and of the tight junction protein, ZO-1, and confocal microscopy to determine the effects of αT and γT against oxidative stress in immortalized human RPE cells (hTERT-RPE). Using the four main vitamin E components, αT, γT, δ-tocopherol (δT) and α-tocotrienol (αTr), we ascertained that they exhibit similar, but not identical, antioxidant activity as αT when used at equimolar concentrations. In addition, we determined that the exposure time of RPE cells to α-tocopherol is critical for its ability to protect against oxidative damage. Lastly, we determined that αT, but not γT, partially requires the synthesis of new proteins within a 24-h period and prior to exposure to tBHP for optimal cytoprotection. We conclude that, unlike γT and δT, αT appears to be unique in its requirement for transport and/or signaling for it to be an effective antioxidant. As a result, more focus should be paid to which vitamin E components are used for antioxidant interventions.
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Affiliation(s)
- R Scott Duncan
- Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Daniel T Hurtado
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Conner W Hall
- Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Peter Koulen
- Vision Research Center, Department of Ophthalmology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States.,Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
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7
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Zhang M, Wang L, Wen D, Ren C, Chen S, Zhang Z, Hu L, Yu Z, Tombran-Tink J, Zhang X, Li X, Barnstable CJ. Neuroprotection of retinal cells by Caffeic Acid Phenylethyl Ester(CAPE) is mediated by mitochondrial uncoupling protein UCP2. Neurochem Int 2021; 151:105214. [PMID: 34710532 DOI: 10.1016/j.neuint.2021.105214] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 09/29/2021] [Accepted: 10/05/2021] [Indexed: 11/27/2022]
Abstract
Oxidative stress due to mitochondrial produced reactive oxygen species is a major cause of damage seen in many retinal degenerative diseases. Caffeic acid phenylethyl ester (CAPE) is protective agent in multiple tissues and is reported to have anti-oxidant properties. Systemically applied CAPE protected retinal ganglion cells from ischemic injury induced by increased intraocular pressure. CAPE provided complete protection for ARPE19 retinal pigment epithelial cells against tert-butyl hydrogen peroxide and reduced both basal and LPS-stimulated ROS production. The major effect of CAPE was mediated by the mitochondrial uncoupling protein UCP2 since both pharmacological inhibition of UCP2 and siRNA-induced knockdown removed the ability of CAPE to block ROS production. Based on common structural features, CAPE may be acting as a mimetic of the natural UCP2 homeostatic regulator 4-hydroxy-2-nonenal. CAPE may provide a valuable tool to treat oxidative stress-related damage in retinal and other degenerative diseases.
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Affiliation(s)
- Mingliang Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Liming Wang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Dejia Wen
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Changjie Ren
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Shuang Chen
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Zhihui Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Lanlan Hu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Zihao Yu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China
| | - Joyce Tombran-Tink
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China; Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Xiaomin Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China.
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China.
| | - Colin J Barnstable
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, 251 Fukang Road, Tianjin 300384, China; Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, PA 17033, USA.
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8
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Davinelli S, Ali S, Scapagnini G, Costagliola C. Effects of Flavonoid Supplementation on Common Eye Disorders: A Systematic Review and Meta-Analysis of Clinical Trials. Front Nutr 2021; 8:651441. [PMID: 34124119 PMCID: PMC8189261 DOI: 10.3389/fnut.2021.651441] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 04/30/2021] [Indexed: 12/13/2022] Open
Abstract
Background: Emerging studies show that certain plant compounds may reduce the severity of most prevalent ocular abnormalities. The aim of this systematic review and meta-analysis was to assess the effect of dietary flavonoids on major eye disorders. Methods: Eligible studies were identified by searching PubMed, Web of Science, Scopus, and Cochrane Library databases for all articles published up to April 2021. The literature search yielded 1,134 articles, and a total of 16 studies were included in the systematic review. A meta-analysis of 11 intervention trials involving a total of 724 participants was performed. Results: Using a random-effects model, the pooled results revealed an overall significant effect of flavonoids on common ophthalmic disorders (standard mean difference = −0.39; 95% CI: −0.56, −0.21, p < 0.01). Of the subclasses of flavonoids, flavan-3-ols (standard mean difference = −0.62; 95% CI: −1.03, −0.22, p < 0.01), and anthocyanins (standard mean difference = −0.42; 95% CI: −0.63, −0.21, p < 0.01) were the only effective intervention for improving the outcomes of ocular conditions. For several of the other flavonoid subclasses, evidence on efficacy was insufficient. Conclusion: Our findings indicate that flavonoids may improve the clinical manifestations associated with ocular disorders. However, further well-constructed clinical trials are required to confirm these results and examine the effect of flavonoids on eye disorders other than those identified in this review. Systematic Review Registration: PROSPERO, identifier CRD42021247332.
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Affiliation(s)
- Sergio Davinelli
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Sawan Ali
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Giovanni Scapagnini
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Ciro Costagliola
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
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9
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Fleckenstein M, Keenan TDL, Guymer RH, Chakravarthy U, Schmitz-Valckenberg S, Klaver CC, Wong WT, Chew EY. Age-related macular degeneration. Nat Rev Dis Primers 2021; 7:31. [PMID: 33958600 DOI: 10.1038/s41572-021-00265-2] [Citation(s) in RCA: 334] [Impact Index Per Article: 111.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/23/2021] [Indexed: 02/07/2023]
Abstract
Age-related macular degeneration (AMD) is the leading cause of legal blindness in the industrialized world. AMD is characterized by accumulation of extracellular deposits, namely drusen, along with progressive degeneration of photoreceptors and adjacent tissues. AMD is a multifactorial disease encompassing a complex interplay between ageing, environmental risk factors and genetic susceptibility. Chronic inflammation, lipid deposition, oxidative stress and impaired extracellular matrix maintenance are strongly implicated in AMD pathogenesis. However, the exact interactions of pathophysiological events that culminate in drusen formation and the associated degeneration processes remain to be elucidated. Despite tremendous advances in clinical care and in unravelling pathophysiological mechanisms, the unmet medical need related to AMD remains substantial. Although there have been major breakthroughs in the treatment of exudative AMD, no efficacious treatment is yet available to prevent progressive irreversible photoreceptor degeneration, which leads to central vision loss. Compelling progress in high-resolution retinal imaging has enabled refined phenotyping of AMD in vivo. These insights, in combination with clinicopathological and genetic correlations, have underscored the heterogeneity of AMD. Hence, our current understanding promotes the view that AMD represents a disease spectrum comprising distinct phenotypes with different mechanisms of pathogenesis. Hence, tailoring therapeutics to specific phenotypes and stages may, in the future, be the key to preventing irreversible vision loss.
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Affiliation(s)
- Monika Fleckenstein
- Department of Ophthalmology and Visual Science, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.
| | - Tiarnán D L Keenan
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, VIC, Australia
| | - Usha Chakravarthy
- Department of Ophthalmology, Centre for Public Health, Queen's University of Belfast, Belfast, UK
| | - Steffen Schmitz-Valckenberg
- Department of Ophthalmology and Visual Science, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Caroline C Klaver
- Department of Ophthalmology, Erasmus MC, Rotterdam, Netherlands.,Department of Epidemiology, Erasmus MC, Rotterdam, Netherlands.,Department of Ophthalmology, Radboud Medical Center, Nijmegen, Netherlands.,Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Wai T Wong
- Section on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Emily Y Chew
- Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
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10
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Beeson C, Peterson YK, Perron N, Bandyopadhyay M, Nasarre C, Beeson G, Comer RF, Lindsey CC, Schnellmann RG, Rohrer B. Newly Identified Chemicals Preserve Mitochondrial Capacity and Decelerate Loss of Photoreceptor Cells in Murine Retinal Degeneration Models. J Ocul Pharmacol Ther 2021; 37:367-378. [PMID: 33945330 DOI: 10.1089/jop.2020.0140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose: Metabolic stress and associated mitochondrial dysfunction are implicated in retinal degeneration irrespective of the underlying cause. We identified seven unique chemicals from a Chembridge DiverSET screen and tested their protection against photoreceptor cell death in cell- and animal-based approaches. Methods: Calcium overload (A23187) was triggered in 661W murine photoreceptor-derived cells, and changes in redox potential and real-time changes in cellular metabolism were assessed using the MTT and Seahorse Biosciences XF assay, respectively. Cheminformatics to compare structures, and biodistribution in the living pig eye aided in selection of the lead compound. In-situ, retinal organ cultures of rd1 mouse and S334ter-line-3 rat were tested, in-vivo the light-induced retinal degeneration in albino Balb/c mice was used, assessing photoreceptor cell numbers histologically. Results: Of the seven chemicals, six were protective against A23187- and IBMX-induced loss of mitochondrial capacity, as measured by viability and respirometry in 661W cells. Cheminformatic analyses identified a unique pharmacophore with 6 physico-chemical features based on two compounds (CB11 and CB12). The protective efficacy of CB11 was further shown by reducing photoreceptor cell loss in retinal explants from two retinitis pigmentosa rodent models. Using eye drops, CB11 targeting to the pig retina was confirmed. The same eye drops decreased photoreceptor cell loss in light-stressed Balb/c mice. Conclusions: New chemicals were identified that protect from mitochondrial damage and lead to improved mitochondrial function. Using ex-vivo and in-vivo models, CB11 decreased the loss of photoreceptor cells in murine models of retinal degeneration and may be effective as treatment for different retinal dystrophies.
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Affiliation(s)
- Craig Beeson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Yuri K Peterson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Nathan Perron
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Mausumi Bandyopadhyay
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Cecile Nasarre
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Gyda Beeson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Richard F Comer
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Christopher C Lindsey
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Rick G Schnellmann
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, Arizona, USA.,Research Service, Southern Arizona VA Healthcare System, Tucson, Arizona, USA
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA.,Research Service, Ralph H Johnson VA Medical Center, Charleston, South Carolina, USA
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Deletion of Mitochondrial Translocator Protein (TSPO) Gene Decreases Oxidative Retinal Pigment Epithelial Cell Death via Modulation of TRPM2 Channel. BIOLOGY 2021; 10:biology10050382. [PMID: 33924902 PMCID: PMC8145237 DOI: 10.3390/biology10050382] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/03/2021] [Accepted: 04/20/2021] [Indexed: 01/11/2023]
Abstract
Simple Summary 18 kDa mitochondrial translocator protein (TSPO) is a mitochondria protein of the cellular outer membrane in the mitochondria of several cells, including ARPE19 is TSPO. Accumulating evince indicates that the presence of TSPO participated the modulations of Ca2+ homeostasis and mitochondrial free reactive oxygen species (fROS) generation. The deletion of TSPO gene provides to study the action of TSPO on the levels of apoptosis, ADP-ribose (ADPR), mitochondria-fROS (Mito-fROS), and apoptosis via the stimulation of Ca2+ permeable channels in the models of cell culture. The stimulations of oxidative stress and ADPR induce the activation of TRPM2 in the ARPE19. For clarifying the involvement of TSPO in retinal human diseases, we used the ARPE19 human cell culture model. The current results demonstrated that the deletion of TSPO induces the regulation of TRPM2 in the TSPO gene knockout ARPE19 (ARPE19-KO) In fact, the present results show that the presence of TSPO increased the upregulations of apoptosis and mitochondria oxidative cytotoxicity values via stimulation of TRPM2 in the ARPE19. Nevertheless, the blockages of PARP-1 (PJ34 and DPQ) and TRPM2 (2APB and ACA) downregulated the values of cell death and oxidative cytotoxicity in the ARPE19. In summary, present results clearly demonstrate that the deletion of TSPO decreases mitochondrial oxidative cytotoxicity-mediated cell death via the modulation of TRPM2 in the ARPE19. Abstract The current results indicated the possible protective actions of 18 kDa mitochondrial translocator protein (TSPO) deletion on TRPM2 stimulation, mitochondrial free ROS (Mito-fROS) and apoptotic harmful actions in the cells of adult retinal pigment epithelial19 (ARPE19). There was a direct relationship between TSPO and the disease of age-related macular degeneration. The nature of TSPO implicates upregulation of Mito-fROS and apoptosis via the activation of Ca2+ channels in ARPE19, although deletion of TSPO gene downregulates the activation. The decrease of oxidative cytotoxicity and apoptosis might induce in TSPO gene deleted cells by the inhibition of Mito-fROS and PARP-1 activation-induced TRPM2 cation channel activation. The ARPE19 cells were divided into two main groups as TSPO expressing (ARPE19) and non-expressing cells (ARPE19-KO). The levels of caspase -3 (Casp -3), caspase -9 (Casp -9), apoptosis, Mito-fROS, TRPM2 current and intracellular free Ca2+ were upregulated in the ARPE19 by the stimulations of H2O2 and ADP-ribose, although their levels were downregulated in the cells by the modulators of PARP-1 (DPQ and PJ34), TRPM2 (ACA and 2APB) and glutathione. However, the H2O2 and ADP-ribose-mediated increases were not observed in the ARPE19-KO. The expression levels of Bax, Casp -3, Casp -9 and PARP-1 were higher in the ARPE19 group as compared to the ARPE19-KO group. In summary, current results confirmed that TRPM2-mediated cell death and oxidative cytotoxicity in the ARPE19 cells were occurred by the presence of TSPO. The deletion of TSPO may be considered as a therapeutic way to TRPM2 activation-mediated retinal oxidative injury.
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Ravichandran G, Raju SV, Sarkar P, N. T. S, Al Olayan EM, Aloufi AS, Elokaby MA, Arshad A, Mala K, Arockiaraj J. Bestrophin‐derived peptide,
WP17
, elicits cell wall disruption‐mediated bactericidal activity against
Micrococcus luteus
and anti‐neoplastic effect against murine melanoma cells. Pept Sci (Hoboken) 2021. [DOI: 10.1002/pep2.24220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Gayathri Ravichandran
- SRM Research Institute, SRM Institute of Science and Technology Chennai Tamil Nadu India
| | - Stefi V. Raju
- SRM Research Institute, SRM Institute of Science and Technology Chennai Tamil Nadu India
| | - Purabi Sarkar
- SRM Research Institute, SRM Institute of Science and Technology Chennai Tamil Nadu India
| | - Saraswathi N. T.
- Molecular Biophysics Lab School of Chemical and Biotechnology, SASTRA Deemed to be University Thanjavur Tamil Nadu India
| | - Ebtesam M. Al Olayan
- Department of Zoology College of Science, King Saud University Riyadh Saudi Arabia
| | - Abeer S. Aloufi
- Department of Zoology College of Science, King Saud University Riyadh Saudi Arabia
| | - Mohamed A. Elokaby
- Aquaculture Division National Institute of Oceanography and Fisheries (NIOF) Alexandria Egypt
| | - Aziz Arshad
- International Institute of Aquaculture and Aquatic Sciences (I‐AQUAS) Universiti Putra Malaysia Port Dickson Negeri Sembilan Malaysia
- Department of Aquaculture, Faculty of Agriculture University Putra Malaysia Serdang Selangor Malaysia
| | - Kanchana Mala
- Department of Medical Research Medical College Hospital & Research Centre, SRM Institute of Science & Technology Chennai Tamil Nadu India
| | - Jesu Arockiaraj
- SRM Research Institute, SRM Institute of Science and Technology Chennai Tamil Nadu India
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Hass DT, Barnstable CJ. Uncoupling proteins in the mitochondrial defense against oxidative stress. Prog Retin Eye Res 2021; 83:100941. [PMID: 33422637 DOI: 10.1016/j.preteyeres.2021.100941] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/28/2020] [Accepted: 01/03/2021] [Indexed: 02/06/2023]
Abstract
Oxidative stress is a major component of most major retinal diseases. Many extrinsic anti-oxidative strategies have been insufficient at counteracting one of the predominant intrinsic sources of reactive oxygen species (ROS), mitochondria. The proton gradient across the inner mitochondrial membrane is a key driving force for mitochondrial ROS production, and this gradient can be modulated by members of the mitochondrial uncoupling protein (UCP) family. Of the UCPs, UCP2 shows a widespread distribution and has been shown to uncouple oxidative phosphorylation, with concomitant decreases in ROS production. Genetic studies using transgenic and knockout mice have documented the ability of increased UCP2 activity to provide neuroprotection in models of a number of diseases, including retinal diseases, indicating that it is a strong candidate for a therapeutic target. Molecular studies have identified the structural mechanism of action of UCP2 and have detailed the ways in which its expression and activity can be controlled at the transcriptional, translational and posttranslational levels. These studies suggest a number of ways in control of UCP2 expression and activity can be used therapeutically for both acute and chronic conditions. The development of such therapeutic approaches will greatly increase the tools available to combat a broad range of serious retinal diseases.
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Affiliation(s)
- Daniel T Hass
- Department of Biochemistry, The University of Washington, Seattle, WA, 98109, USA
| | - Colin J Barnstable
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA.
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Louer EMM, Yi G, Carmone C, Robben J, Stunnenberg HG, den Hollander AI, Deen PMT. Genes Involved in Energy Metabolism Are Differentially Expressed During the Day-Night Cycle in Murine Retinal Pigment Epithelium. Invest Ophthalmol Vis Sci 2020; 61:49. [PMID: 32460311 PMCID: PMC7405837 DOI: 10.1167/iovs.61.5.49] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Purpose The functional interaction between photoreceptors and retinal pigment epithelium (RPE) cells is essential for vision. Phagocytosis of photoreceptor outer segments (POSs) by the RPE follows a circadian pattern; however, it remains unknown whether other RPE processes follow a daily rhythm. Therefore, our aim was to identify RPE processes following a daily rhythm. Methods Murine RPE was isolated at Zeitgeber time (ZT) 0, 2, 4, 9, 14, and 19 (n = 5 per time point), after which RNA was isolated and sequenced. Genes with a significant difference in expression between time points (P < 0.05) were subjected to EnrichR pathway analysis to identify daily rhythmic processes. Results Pathway enrichment revealed 13 significantly enriched KEGG pathways (P < 0.01), including the metabolic pathway (P = 0.002821). Analysis of the metabolic pathway differentially expressed genes revealed that genes involved in adenosine triphosphate production, glycolysis, glycogenolysis, and glycerophospholipid were low at ZT0 (light onset) and high at ZT19 (night). Genes involved in fatty acid degradation and cholesterol synthesis were high at light onset and low at night. Conclusions Our transcriptome data suggest that the highest energy demand of RPE cells is at night, whereas POS phagocytosis and degradation take place in the morning. Furthermore, we identified genes involved in fatty acid and glycerophospholipid synthesis that are upregulated at night, possibly playing a role in generating building blocks for membrane synthesis.
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Handa JT, Bowes Rickman C, Dick AD, Gorin MB, Miller JW, Toth CA, Ueffing M, Zarbin M, Farrer LA. A systems biology approach towards understanding and treating non-neovascular age-related macular degeneration. Nat Commun 2019; 10:3347. [PMID: 31350409 PMCID: PMC6659646 DOI: 10.1038/s41467-019-11262-1] [Citation(s) in RCA: 169] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 07/03/2019] [Indexed: 12/20/2022] Open
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly in the developed world. While treatment is effective for the neovascular or “wet” form of AMD, no therapy is successful for the non-neovascular or “dry” form. Here we discuss the current knowledge on dry AMD pathobiology and propose future research directions that would expedite the development of new treatments. In our view, these should emphasize system biology approaches that integrate omic, pharmacological, and clinical data into mathematical models that can predict disease onset and progression, identify biomarkers, establish disease causing mechanisms, and monitor response to therapy. No effective therapies exist for dry age-related macular degeneration. In this perspective, the authors propose that research should emphasize system biology approaches that integrate various ‘omics’ data into mathematical models to establish pathogenic mechanisms on which to design novel treatments, and identify biomarkers that predict disease progression and therapeutic response.
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Affiliation(s)
- James T Handa
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, 21287, MD, USA.
| | - Cathy Bowes Rickman
- Department of Ophthalmology, Duke University Medical Center, Durham, 27708, NC, USA
| | - Andrew D Dick
- Translational Health Sciences (Ophthalmology), University of Bristol, Bristol, BS8 1TH, UK.,University College London, Institute of Ophthalmology and the National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital and UCL-Institute of Ophthalmology, London, WC1E 6BT, UK
| | - Michael B Gorin
- Department of Ophthalmology, Jules Stein Eye Institute, David Geffen School of Medicine, UCLA, Los Angeles, 90095, CA, USA.,Brain Research Institute, UCLA, Los Angeles, 90095, CA, USA
| | - Joan W Miller
- Retina Service, Massachusetts Eye and Ear, Harvard Ophthalmology AMD Center of Excellence, Department of Ophthalmology, Harvard Medical School, Boston, 02114, MA, USA
| | - Cynthia A Toth
- Department of Ophthalmology, Duke University Medical Center, Durham, 27708, NC, USA
| | - Marius Ueffing
- Department of Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, D-72076, Germany
| | - Marco Zarbin
- Institute of Ophthalmology and Visual Science, New Jersey Medical School, Rutgers University, Newark, 07103, NJ, USA
| | - Lindsay A Farrer
- Departments of Medicine (Biomedical Genetics), Neurology, Ophthalmology, Epidemiology, and Biostatistics, Boston University Schools of Medicine and Public Health, Boston, 02118, MA, USA.
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Liu Y, Ren Y, Wang X, Liu X, Xu Y, He Y. Down regulation of UCP2 expression in retinal pigment epithelium cells under oxidative stress: an in vitro study. Int J Ophthalmol 2019; 12:1089-1094. [PMID: 31341797 DOI: 10.18240/ijo.2019.07.06] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/06/2019] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the expression of uncoupling protein 2 (UCP2) in a retinal pigment epithelium cell line (ARPE-19), under oxidative stress (OS). METHODS ARPE-19 cells were divided into groups treated with various concentrations of hydrogen peroxide (H2O2; 0, 150, 300, 500, 700, and 900 µmol/L) for 24h, to induce oxidative damage and cell viability was assessed by MTT assay. UCP2 mRNA expression in cells treated with H2O2 was investigated by reverse transcription-polymerase chain reaction (RT-PCR). UCP2 protein expression was assessed by Western blotting and ROS levels analyzed by flow cytometry (FCM). Further, UCP2-siRNA treated cultures were exposed to H2O2 (0, 75, 150, and 300 µmol/L) for 2h and cell viability determined by MTT assay. RESULTS Cells treated with higher concentrations of H2O2 appeared shrunken; their adhesion to adjacent cells was disrupted, and the number of dead cells increased. The results of cell viability assays demonstrated that the numbers of cells were decreased in a dose-dependent manner following treatment with H2O2. Compared with untreated controls, cell viability was significantly reduced after treatment with >300 µmol/L H2O2 (P<0.05). Cell metabolic activity was decreased with increased concentrations of H2O2 as detected by MTT assay. Levels of OS were further decreased in cells treated with UCP2-siRNA compared with those treated with H2O2 alone (P<0.05). The results of RT-PCR and Western blotting demonstrated that UCP2 expression was reduced in H2O2-treated groups compared with controls (P<0.05). FCM analysis showed that cell reactive oxygen species (ROS) levels were increased in H2O2-treated groups and further upregulated by UCP2-siRNA treatment (P<0.05). CONCLUSION Expression levels of UCP2 are decreased in ARPE-19 cells treated with H2O2. ROS levels are further increased in cells treated with UCP2-siRNA relative to those treated with H2O2 alone. UCP2 may have a protective role in ARPE-19 cells during oxidative injury.
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Affiliation(s)
- Ying Liu
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Yuan Ren
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Xia Wang
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Xu Liu
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Yun Xu
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Yuan He
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
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Chidlow G, Wood JPM, Sia PI, Casson RJ. Distribution and Activity of Mitochondrial Proteins in Vascular and Avascular Retinas: Implications for Retinal Metabolism. Invest Ophthalmol Vis Sci 2019; 60:331-344. [PMID: 30664793 DOI: 10.1167/iovs.18-25536] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Understanding the energetics of retinal neurons and glia is crucial for developing therapies for diseases that feature deficits in nutrient or oxygen availability. Herein, we performed a detailed characterization of the distribution and activity of mitochondrial proteins in the vascularized retinas of rat and marmoset, and the avascular retinas of rabbit and guinea pig. Further, we delineated expression of ubiquitous mitochondrial creatine kinase (uMtCK). Methods Expression of eight mitochondrial proteins was investigated using Western blotting, single- and double-labeling immunohistochemistry. Activities of cytochrome c oxidase, succinate dehydrgogenase, and isocitrate dehydrogenase were determined by enzyme histochemistry using unfixed tissue sections. Results In vascularized retinas, immunoreactivities were characterized by strong, punctate labeling in the plexiform layers, photoreceptor inner segments, somas of various cell types, notably retinal ganglion cells (RGCs), and the basolateral surface of the retinal pigment epithelium. In avascular retinas, immunoreactivities featured intense labeling of inner segments, together with weak, but unambiguous, staining of both plexiform layers. RGCs were relatively enriched. In Müller cells of avascular retinas, mitochondria were restricted to scleral-end processes. For each species, enzyme activity assays yielded similar results to the protein distributions. Labeling for uMtCK in vascular and avascular retinas was fundamentally similar, being restricted to neuronal populations, most notably inner segments and RGCs. Of all of the mitochondrial proteins, uMtCK displayed the strongest labeling in avascular retinas. uMtCK was not detectable in Müller cells in any species. Conclusions The current findings advance our understanding of the metabolic similarities and differences between vascular and avascular retinas.
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Affiliation(s)
- Glyn Chidlow
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - John P M Wood
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Paul I Sia
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Robert J Casson
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, South Australia, Australia
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Nolte ED, Nolte KA, Yan SS. Anxiety and task performance changes in an aging mouse model. Biochem Biophys Res Commun 2019; 514:246-251. [PMID: 31029428 DOI: 10.1016/j.bbrc.2019.04.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 04/07/2019] [Indexed: 12/13/2022]
Abstract
Due to the increasing focus on aging as an important risk factor for many serious diseases and an emphasis on animal models that have translational value, an increasing number of animal models are being aged. Animal behavior tests can be used to assess effects of aging in mouse models. Female mice begin exhibiting anxiety-like behaviors at 12 months of age which become more serious at 24 months, while males exhibit no age-induced anxiety-like behaviors. Males and females equally demonstrate a failure of daily task performance at 24 months. Despite these cognitive changes, the mice do not show changes in gross motor function. These results suggest cognitive impairment in non-genetically modified aging mice.
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Affiliation(s)
- Erika D Nolte
- Department of Pharmacology and Toxicology, Higuchi Bioscience Center, University of Kansas, Lawrence, KS 66047, USA
| | - Keith A Nolte
- Department of Pharmacology and Toxicology, Higuchi Bioscience Center, University of Kansas, Lawrence, KS 66047, USA
| | - Shirley ShiDu Yan
- Department of Pharmacology and Toxicology, Higuchi Bioscience Center, University of Kansas, Lawrence, KS 66047, USA.
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Interplay between Autophagy and the Ubiquitin-Proteasome System and Its Role in the Pathogenesis of Age-Related Macular Degeneration. Int J Mol Sci 2019; 20:ijms20010210. [PMID: 30626110 PMCID: PMC6337628 DOI: 10.3390/ijms20010210] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/21/2018] [Accepted: 01/02/2019] [Indexed: 12/20/2022] Open
Abstract
Age-related macular degeneration (AMD) is a complex eye disease with many pathogenesis factors, including defective cellular waste management in retinal pigment epithelium (RPE). Main cellular waste in AMD are: all-trans retinal, drusen and lipofuscin, containing unfolded, damaged and unneeded proteins, which are degraded and recycled in RPE cells by two main machineries—the ubiquitin-proteasome system (UPS) and autophagy. Recent findings show that these systems can act together with a significant role of the EI24 (etoposide-induced protein 2.4 homolog) ubiquitin ligase in their action. On the other hand, E3 ligases are essential in both systems, but E3 is degraded by autophagy. The interplay between UPS and autophagy was targeted in several diseases, including Alzheimer disease. Therefore, cellular waste clearing in AMD should be considered in the context of such interplay rather than either of these systems singly. Aging and oxidative stress, two major AMD risk factors, reduce both UPS and autophagy. In conclusion, molecular mechanisms of UPS and autophagy can be considered as a target in AMD prevention and therapeutic perspective. Further work is needed to identify molecules and effects important for the coordination of action of these two cellular waste management systems.
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Wang X, Liu X, Ren Y, Liu Y, Han S, Zhao J, Gou X, He Y. PEDF protects human retinal pigment epithelial cells against oxidative stress via upregulation of UCP2 expression. Mol Med Rep 2018; 19:59-74. [PMID: 30431098 PMCID: PMC6297793 DOI: 10.3892/mmr.2018.9645] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 09/07/2018] [Indexed: 01/23/2023] Open
Abstract
To investigate the protective function of pigment epithelium-derived factor (PEDF) against oxidative stress (OS) in ARPE-19 cells, ARPE-19 cells were divided into different OS groups and treated with various concentrations of H2O2 (0, 75, 150 and 200 µmol/l) for 24 h. To establish the protective group, 200 ng/ml of PEDF was administered to ARPE-19 cells. Cell Counting Kit-8 assays and cell growth curve experiments were performed to determine levels of cell viability; lactate dehydrogenase and propidium iodide (PI) staining assays were also performed. The expression levels of genes associated with apoptosis as well as uncoupling protein 2 (UCP2) were detected by reverse transcription-quantitative, or semi-quantitative polymerase chain reaction. Furthermore, an OS injury animal model was established in both C57BL/6 and BALB/c mice via injection of 5 µg of PEDF in the vitreous cavity and subsequent injection of 150 µM H2O2 following a 24 h time interval. Hematoxylin and eosin (H&E) staining, as well as UCP2 immunofluorescent labeling were also performed. One-way analysis of variance was used to determine statistically significant differences, followed by multiple comparison analysis using the Newman Keuls method. The results of cell viability assays demonstrated that the numbers of apoptotic cells were increased following treatment with H2O2 in a dose-dependent manner; however, this effect was reversed following treatment with PEDF. The expression levels of caspase 3 and B cell lymphoma (Bcl2) associated X genes associated with apoptosis were inhibited, whereas levels of the anti-apoptotic gene Bcl2 were enhanced following treatment with PEDF in different passages of ARPE-19 cells. Significant differences were demonstrated in the levels of UCP2 gene expression between the PEDF+ H2O2 treated group and cells treated with H2O2 alone. Labeling of the UCP2 detector in the confocal images demonstrated decreased UCP2 protein staining in the retinal pigment epithelium (RPE) cells and RPE layers following H2O2 injury; however, this effect was inhibited following treatment with PEDF. H&E staining was performed to investigate the thickness of the RPE layers, and the results revealed that thicknesses were significantly increased in sections treated with PEDF during OS, due to increased numbers of RPE cells. Furthermore, PEDF was demonstrated to increase UCP2 gene expression in ARPE-19 cells and animal RPE layers under OS, which suggested that PEDF may protect RPE cells and tissues during oxidative injury.
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Affiliation(s)
- Xia Wang
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Xu Liu
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Yuan Ren
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Ying Liu
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Shuangyu Han
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Jingkang Zhao
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
| | - Xingchun Gou
- Department of Neurobiology, The Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an, Shaanxi 710021, P.R. China
| | - Yuan He
- Department of Ophthalmology, The Second Affiliated Hospital of Xi'an Medical University, Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an, Shaanxi 710038, P.R. China
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Wang Y, Grenell A, Zhong F, Yam M, Hauer A, Gregor E, Zhu S, Lohner D, Zhu J, Du J. Metabolic signature of the aging eye in mice. Neurobiol Aging 2018; 71:223-233. [PMID: 30172221 DOI: 10.1016/j.neurobiolaging.2018.07.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/28/2018] [Accepted: 07/29/2018] [Indexed: 12/29/2022]
Abstract
Aging is a major risk factor for age-related ocular diseases including age-related macular degeneration in the retina and retinal pigment epithelium (RPE), cataracts in the lens, glaucoma in the optic nerve, and dry eye syndrome in the cornea. We used targeted metabolomics to analyze metabolites from young (6 weeks) and old (73 weeks) eyes in C57 BL6/J mice. Old mice had diminished electroretinogram responses and decreased number of photoreceptors in their retinas. Among the 297 detected metabolites, 45-114 metabolites are significantly altered in aged eye tissues, mostly in the neuronal tissues (retina and optic nerve) and less in cornea, RPE/choroid, and lens. We noted that changes of metabolites in mitochondrial metabolism and glucose metabolism are common features in the aged retina, RPE/choroid, and optic nerve. The aging retina, cornea, and optic nerve also share similar changes in Nicotinamide adenine dinucleotide (NAD), 1-methylnicotinamides, 3-methylhistidine, and other methylated metabolites. Metabolites in taurine metabolism are strikingly influenced by aging in the cornea and lens. In conclusion, the aging eye has both common and tissue-specific metabolic signatures. These changes may be attributed to dysregulated mitochondrial metabolism, reprogrammed glucose metabolism and impaired methylation in the aging eye. Our findings provide biochemical insights into the mechanisms of age-related ocular changes.
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Affiliation(s)
- Yekai Wang
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Allison Grenell
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Fanyi Zhong
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA
| | - Michelle Yam
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Allison Hauer
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Elizabeth Gregor
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Siyan Zhu
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Daniel Lohner
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Jiangjiang Zhu
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH, USA
| | - Jianhai Du
- Department of Ophthalmology, West Virginia University, Morgantown, WV, USA; Department of Biochemistry, West Virginia University, Morgantown, WV, USA.
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Zhang Y, Kittredge A, Ward N, Ji C, Chen S, Yang T. ATP activates bestrophin ion channels through direct interaction. Nat Commun 2018; 9:3126. [PMID: 30087350 PMCID: PMC6081419 DOI: 10.1038/s41467-018-05616-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/09/2018] [Indexed: 11/13/2022] Open
Abstract
Human Bestrophin1 (hBest1) is a Ca2+-activated Cl- channel in retinal pigment epithelium (RPE) essential for retina physiology, and its mutation results in retinal degenerative diseases that have no available treatments. Here, we discover that hBest1's channel activity in human RPE is significantly enhanced by adenosine triphosphate (ATP) in a dose-dependent manner. We further demonstrate a direct interaction between ATP and bestrophins, and map the ATP-binding motif on hBest1 to an intracellular loop adjacent to the channel activation gate. Importantly, a disease-causing mutation of hBest1 located within the ATP-binding motif, p.I201T, diminishes ATP-dependent activation of the channel in patient-derived RPE, while the corresponding mutants in bestrophin homologs display defective ATP binding and a conformational change in the ATP-binding motif. Taken together, our results identify ATP as a critical activator of bestrophins, and reveal the molecular mechanism of an hBest1 patient-specific mutation.
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Affiliation(s)
- Yu Zhang
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Alec Kittredge
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Nancy Ward
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Changyi Ji
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Shoudeng Chen
- Molecular Imaging Center, Department of Experimental Medicine, The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, Guangzhou, 519000, China
| | - Tingting Yang
- Department of Pharmacology and Physiology, University of Rochester, School of Medicine and Dentistry, Rochester, NY, 14642, USA.
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Schottler J, Randoll N, Lucius R, Caliebe A, Roider J, Klettner A. Long-term treatment with anti-VEGF does not induce cell aging in primary retinal pigment epithelium. Exp Eye Res 2018. [DOI: 10.1016/j.exer.2018.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Transcriptome profiling analysis of senescent gingival fibroblasts in response to Fusobacterium nucleatum infection. PLoS One 2017; 12:e0188755. [PMID: 29190775 PMCID: PMC5708803 DOI: 10.1371/journal.pone.0188755] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 10/18/2017] [Indexed: 11/19/2022] Open
Abstract
Periodontal disease is caused by dental plaque biofilms. Fusobacterium nucleatum is an important periodontal pathogen involved in the development of bacterial complexity in dental plaque biofilms. Human gingival fibroblasts (GFs) act as the first line of defense against oral microorganisms and locally orchestrate immune responses by triggering the production of reactive oxygen species and pro-inflammatory cytokines (IL-6 and IL-8). The frequency and severity of periodontal diseases is known to increase in elderly subjects. However, despite several studies exploring the effects of aging in periodontal disease, the underlying mechanisms through which aging affects the interaction between F. nucleatum and human GFs remain unclear. To identify genes affected by infection, aging, or both, we performed an RNA-Seq analysis using GFs isolated from a single healthy donor that were passaged for a short period of time (P4) 'young GFs' or for longer period of time (P22) 'old GFs', and infected or not with F. nucleatum. Comparing F. nucleatum-infected and uninfected GF(P4) cells the differentially expressed genes (DEGs) were involved in host defense mechanisms (i.e., immune responses and defense responses), whereas comparing F. nucleatum-infected and uninfected GF(P22) cells the DEGs were involved in cell maintenance (i.e., TGF-β signaling, skeletal development). Most DEGs in F. nucleatum-infected GF(P22) cells were downregulated (85%) and were significantly associated with host defense responses such as inflammatory responses, when compared to the DEGs in F. nucleatum-infected GF(P4) cells. Five genes (GADD45b, KLF10, CSRNP1, ID1, and TM4SF1) were upregulated in response to F. nucleatum infection; however, this effect was only seen in GF(P22) cells. The genes identified here appear to interact with each other in a network associated with free radical scavenging, cell cycle, and cancer; therefore, they could be potential candidates involved in the aged GF's response to F. nucleatum infection. Further studies are needed to confirm these observations.
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Crooke A, Huete-Toral F, Colligris B, Pintor J. The role and therapeutic potential of melatonin in age-related ocular diseases. J Pineal Res 2017; 63. [PMID: 28658514 DOI: 10.1111/jpi.12430] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/23/2017] [Indexed: 12/20/2022]
Abstract
The eye is continuously exposed to solar UV radiation and pollutants, making it prone to oxidative attacks. In fact, oxidative damage is a major cause of age-related ocular diseases including cataract, glaucoma, age-related macular degeneration, and diabetic retinopathy. As the nature of lens cells, trabecular meshwork cells, retinal ganglion cells, retinal pigment epithelial cells, and photoreceptors is postmitotic, autophagy plays a critical role in their cellular homeostasis. In age-related ocular diseases, this process is impaired, and thus, oxidative damage becomes irreversible. Other conditions such as low-grade chronic inflammation and angiogenesis also contribute to the development of retinal diseases (glaucoma, age-related macular degeneration and diabetic retinopathy). As melatonin is known to have remarkable qualities such as antioxidant/antinitridergic, mitochondrial protector, autophagy modulator, anti-inflammatory, and anti-angiogenic, it can represent a powerful tool to counteract all these diseases. The present review analyzes the role and therapeutic potential of melatonin in age-related ocular diseases, focusing on nitro-oxidative stress, autophagy, inflammation, and angiogenesis mechanisms.
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Affiliation(s)
- Almudena Crooke
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Fernando Huete-Toral
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Basilio Colligris
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Group Ocupharm, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain
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Reductive carboxylation is a major metabolic pathway in the retinal pigment epithelium. Proc Natl Acad Sci U S A 2016; 113:14710-14715. [PMID: 27911769 DOI: 10.1073/pnas.1604572113] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The retinal pigment epithelium (RPE) is a monolayer of pigmented cells that requires an active metabolism to maintain outer retinal homeostasis and compensate for oxidative stress. Using 13C metabolic flux analysis in human RPE cells, we found that RPE has an exceptionally high capacity for reductive carboxylation, a metabolic pathway that has recently garnered significant interest because of its role in cancer cell survival. The capacity for reductive carboxylation in RPE exceeds that of all other cells tested, including retina, neural tissue, glial cells, and a cancer cell line. Loss of reductive carboxylation disrupts redox balance and increases RPE sensitivity to oxidative damage, suggesting that deficiencies of reductive carboxylation may contribute to RPE cell death. Supporting reductive carboxylation by supplementation with an NAD+ precursor or its substrate α-ketoglutarate or treatment with a poly(ADP ribose) polymerase inhibitor protects reductive carboxylation and RPE viability from excessive oxidative stress. The ability of these treatments to rescue RPE could be the basis for an effective strategy to treat blinding diseases caused by RPE dysfunction.
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Nashine S, Chwa M, Kazemian M, Thaker K, Lu S, Nesburn A, Kuppermann BD, Kenney MC. Differential Expression of Complement Markers in Normal and AMD Transmitochondrial Cybrids. PLoS One 2016; 11:e0159828. [PMID: 27486856 PMCID: PMC4972370 DOI: 10.1371/journal.pone.0159828] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 07/09/2016] [Indexed: 12/19/2022] Open
Abstract
Purpose Variations in mitochondrial DNA (mtDNA) and abnormalities in the complement pathways have been implicated in the pathogenesis of age-related macular degeneration (AMD). This study was designed to determine the effects of mtDNA from AMD subjects on the complement pathway. Methods Transmitochondrial cybrids were prepared by fusing platelets from AMD and age-matched Normal subjects with Rho0 (lacking mtDNA) human ARPE-19 cells. Quantitative PCR and Western blotting were performed to examine gene and protein expression profiles, respectively, of complement markers in these cybrids. Bioenergetic profiles of Normal and AMD cybrids were examined using the Seahorse XF24 flux analyzer. Results Significant decreases in the gene and protein expression of complement inhibitors, along with significantly higher levels of complement activators, were found in AMD cybrids compared to Older-Normal cybrids. Seahorse flux data demonstrated that the bioenergetic profiles for Older-Normal and Older-AMD cybrid samples were similar to each other but were lower compared to Young-Normal cybrid samples. Conclusion In summary, since all cybrids had identical nuclei and differed only in mtDNA content, the observed changes in components of complement pathways can be attributed to mtDNA variations in the AMD subjects, suggesting that mitochondrial genome and retrograde signaling play critical roles in this disease. Furthermore, the similar bioenergetic profiles of AMD and Older-Normal cybrids indicate that the signaling between mitochondria and nuclei are probably not via a respiratory pathway.
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Affiliation(s)
- Sonali Nashine
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America
| | - Mina Kazemian
- College of Osteopathic Medicine, Touro University Nevada, Nevada, United States of America
| | - Kunal Thaker
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America
| | - Stephanie Lu
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America
- VA Medical Center Long Beach Hospital, Long Beach, California, United States of America
| | - Anthony Nesburn
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America
- Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Baruch D. Kuppermann
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America
| | - M. Cristina Kenney
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, United States of America
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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Rohrer B, Bandyopadhyay M, Beeson C. Reduced Metabolic Capacity in Aged Primary Retinal Pigment Epithelium (RPE) is Correlated with Increased Susceptibility to Oxidative Stress. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:793-8. [PMID: 26427491 DOI: 10.1007/978-3-319-17121-0_106] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
One of the affected tissues in age-related macular degeneration (AMD) is the retinal pigment epithelium (RPE), a tissue that consists of terminally differentiated cells and that accumulates damage over time. In all tissues, mitochondria (mt), which play an essential role in both cell health (energy) and death (initiator of apoptosis), undergo an aging process through the accumulation of mtDNA damage, changes in mitochondrial dynamics, a reduction in biogenesis, and mitophagy, leading to an overall reduction in mitochondrial energy production and other non-energy-related functions. Here we have compared energy metabolism in primary human RPE cells isolated from aborted fetus or aged donor eyes and grown as stable monolayers. H2O2 treatment resulted in the generation of reactive oxygen species and superoxide, an effect that was significantly augmented by age. Mitochondrial metabolism, as analyzed by Seahorse respirometry, revealed reduced mitochondrial oxygen consumption (ATP production) at baseline and a complete loss of reserve capacity in aged cells. Likewise, glycolysis was blunted in aged cells. Taken together, these studies showed that RPE cells derived from aged donor eyes are more susceptible to oxidative stress, and exhibit a loss in mitochondrial respiratory reserve capacity and a reduction in glycolysis. These data suggest that while old cells may have sufficient energy at rest, they cannot mount a stress response requiring additional ATP and reducing agents. In summary, these data support the hypothesis that mitochondria or energy metabolism is a valid target for therapy in AMD.
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Affiliation(s)
- Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, 167 Ashley Ave, SEI614, 29425, Charleston, SC, USA. .,Research Service, Ralph H. Johnson VA Medical Center, Charleston, SC, USA.
| | - Mausumi Bandyopadhyay
- Department of Ophthalmology, Medical University of South Carolina, 167 Ashley Ave, SEI614, 29425, Charleston, SC, USA
| | - Craig Beeson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, 167 Ashley Ave, SEI614, 29425, Charleston, SC, USA
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Zhang H, Davies KJA, Forman HJ. Oxidative stress response and Nrf2 signaling in aging. Free Radic Biol Med 2015; 88:314-336. [PMID: 26066302 PMCID: PMC4628850 DOI: 10.1016/j.freeradbiomed.2015.05.036] [Citation(s) in RCA: 570] [Impact Index Per Article: 63.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 05/29/2015] [Accepted: 05/31/2015] [Indexed: 12/20/2022]
Abstract
Increasing oxidative stress, a major characteristic of aging, has been implicated in a variety of age-related pathologies. In aging, oxidant production from several sources is increased, whereas antioxidant enzymes, the primary lines of defense, are decreased. Repair systems, including the proteasomal degradation of damaged proteins, also decline. Importantly, the adaptive response to oxidative stress declines with aging. Nrf2/EpRE signaling regulates the basal and inducible expression of many antioxidant enzymes and the proteasome. Nrf2/EpRE activity is regulated at several levels, including transcription, posttranslation, and interactions with other proteins. This review summarizes current studies on age-related impairment of Nrf2/EpRE function and discusses the changes in Nrf2 regulatory mechanisms with aging.
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Affiliation(s)
- Hongqiao Zhang
- Ethel Percy Andrus Gerontology Center, Leonard Davis School of Gerontology
| | - Kelvin J A Davies
- Ethel Percy Andrus Gerontology Center, Leonard Davis School of Gerontology; Division of Molecular & Computational Biology, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Henry Jay Forman
- Ethel Percy Andrus Gerontology Center, Leonard Davis School of Gerontology; School of Natural Science, University of California at Merced, Merced, CA 95344, USA.
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Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E. FEBS Open Bio 2014; 4:1007-14. [PMID: 25473597 PMCID: PMC4250541 DOI: 10.1016/j.fob.2014.11.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 11/09/2014] [Accepted: 11/11/2014] [Indexed: 12/21/2022] Open
Abstract
In this study, we show augmented autophagy in the retinal pigment epithelial cell line ARPE-19 when cultured in the presence of the lipofuscin pigment A2E. A2E alone does not induce RPE cell death, but cell death was induced in the presence of A2E with the autophagy inhibitor 3-methyladenine (3MA), with a concomitant increase in the generation of mitochondrial reactive oxygen species. On the other hand, the ATP production capacity of mitochondria was decreased in the presence of A2E, and pharmacological inhibition of autophagy had no additional effects. The altered mRNA expression level of mitochondrial function markers was confirmed by real-time polymerase chain reaction, which showed that the antioxidant enzymes SOD1 and SOD2 were not reduced in the presence of A2E alone, but significantly suppressed with the addition of 3MA. Furthermore, transmission electron micrography revealed autophagic vacuole formation in the presence of A2E, and inhibition of autophagy resulted in the accumulation of abnormal mitochondria with loss of cristae. Spheroid culture of human RPE cells demonstrated debris accumulation in the presence of A2E, and this accumulation was accelerated in the presence of 3MA. These results indicate that autophagy in RPE cells is a vital cytoprotective process that prevents the accumulation of damaged cellular molecules.
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Schütt F, Aretz S, Auffahrt GU, Kopitz J. [Role of energy metabolism in retinal pigment epithelium]. Ophthalmologe 2013; 110:346-52. [PMID: 23319062 DOI: 10.1007/s00347-012-2752-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The universal energy source adenosine triphosphate (ATP)is reduced by approximately 30 % in the retinal pigment epithelium (RPE) of elderly persons. Increased oxidative stress and decreased antioxidative capacity, such as glutathione in aging eyes cause impairment of energy-dependent RPE processes and lead to loss of visual function. We developed a cell culture model of aging RPE using atractyloside to inhibit mitochondrial ATP synthesis and tert-butyl hydroperoxide as oxidant. The ATP levels were reduced by 30 % and oxidative damaged proteins and DNA increased whereas antioxidative glutathione decreased. Autophagy as an internal cellular repair mechanism and phagocytosis of photoreceptors were impaired. Antioxidative and mitochondria-activating Ginkgo biloba extract EGb 761 increased the intracellular ATP level and antioxidative glutathione. This cell culture model seems to be suitable to investigate in vitro the effect of protective substances and their compounds on aging processes in RPE.
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Affiliation(s)
- F Schütt
- Augenklinik, Universität Heidelberg, INF 400, 69120 Heidelberg.
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Woodell A, Coughlin B, Kunchithapautham K, Casey S, Williamson T, Ferrell WD, Atkinson C, Jones BW, Rohrer B. Alternative complement pathway deficiency ameliorates chronic smoke-induced functional and morphological ocular injury. PLoS One 2013; 8:e67894. [PMID: 23825688 PMCID: PMC3692454 DOI: 10.1371/journal.pone.0067894] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 05/23/2013] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD), a complex disease involving genetic variants and environmental insults, is among the leading causes of blindness in Western populations. Genetic and histologic evidence implicate the complement system in AMD pathogenesis; and smoking is the major environmental risk factor associated with increased disease risk. Although previous studies have demonstrated that cigarette smoke exposure (CE) causes retinal pigment epithelium (RPE) defects in mice, and smoking leads to complement activation in patients, it is unknown whether complement activation is causative in the development of CE pathology; and if so, which complement pathway is required. METHODS Mice were exposed to cigarette smoke or clean, filtered air for 6 months. The effects of CE were analyzed in wildtype (WT) mice or mice without a functional complement alternative pathway (AP; CFB(-/-) ) using molecular, histological, electrophysiological, and behavioral outcomes. RESULTS CE in WT mice exhibited a significant reduction in function of both rods and cones as determined by electroretinography and contrast sensitivity measurements, concomitant with a thinning of the nuclear layers as measured by SD-OCT imaging and histology. Gene expression analyses suggested that alterations in both photoreceptors and RPE/choroid might contribute to the observed loss of function, and visualization of complement C3d deposition implies the RPE/Bruch's membrane (BrM) complex as the target of AP activity. RPE/BrM alterations include an increase in mitochondrial size concomitant with an apical shift in mitochondrial distribution within the RPE and a thickening of BrM. CFB(-/-) mice were protected from developing these CE-mediated alterations. CONCLUSIONS Taken together, these findings provide clear evidence that ocular pathology generated in CE mice is dependent on complement activation and requires the AP. Identifying animal models with RPE/BrM damage and verifying which aspects of pathology are dependent upon complement activation is essential for developing novel complement-based treatment approaches for the treatment of AMD.
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Affiliation(s)
- Alex Woodell
- Division of Research, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Beth Coughlin
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Kannan Kunchithapautham
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Sarah Casey
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Tucker Williamson
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - W. Drew Ferrell
- Moran Eye Center, University of Utah, Salt Lake City, Utah, United States of America
| | - Carl Atkinson
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Bryan W. Jones
- Moran Eye Center, University of Utah, Salt Lake City, Utah, United States of America
| | - Bärbel Rohrer
- Division of Research, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Research Service, Ralph H. Johnson VA Medical Center, Charleston, South Carolina, United States of America
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Devarajan A, Grijalva VR, Bourquard N, Meriwether D, Imaizumi S, Shin BC, Devaskar SU, Reddy ST. Macrophage paraoxonase 2 regulates calcium homeostasis and cell survival under endoplasmic reticulum stress conditions and is sufficient to prevent the development of aggravated atherosclerosis in paraoxonase 2 deficiency/apoE-/- mice on a Western diet. Mol Genet Metab 2012; 107:416-27. [PMID: 22864055 PMCID: PMC3483415 DOI: 10.1016/j.ymgme.2012.06.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Revised: 06/27/2012] [Accepted: 06/28/2012] [Indexed: 01/22/2023]
Abstract
Paraoxonase 2 deficiency (PON2-def) alters mitochondrial function and exacerbates the development of atherosclerosis in mice. PON2 overexpression protects against ER stress in cell culture. In this paper, we examined the role of PON2 in the unexplored link between ER stress and mitochondrial dysfunction and tested whether restoration of PON2 in macrophages is sufficient to reduce aggravated atherosclerosis in PON2-def/apoE(-/-) mice on a Western diet. ER stress response genes, intracellular calcium levels, and apoptotic nuclei were significantly elevated in PON2-def/apoE(-/-) macrophages compared to apoE(-/-) macrophages in response to ER stressors, but not at the basal level. In contrast, PON2-def/apoE(-/-) macrophages exhibited greater mitochondrial stress at the basal level, which was further worsened in response to ER stressors. There was no difference in ER stress response genes and apoptotic nuclei between apoE(-/-) and PON2-def/apoE(-/-) macrophages when pretreated with xestospongin (which blocks the release of calcium from ER) suggesting that PON2 modulates cell survival and ER stress by maintaining calcium homeostasis. Treatment with a mitochondrial calcium uptake inhibitor, RU360, attenuated ER stressor mediated mitochondrial dysfunction in PON2-def/apoE(-/-) macrophages. CHOP expression (ER stress marker) and apoptotic nuclei were significantly higher in aortic lesions of PON2-def/apoE(-/-) mice compared to apoE(-/-) mice fed a Western diet. Restoration of PON2 in macrophages reduced ER stress, mitochondrial dysfunction and apoptosis in response to ER stressors. Furthermore, restoration of PON2 in macrophages reduced lesional apoptosis and atherosclerosis in PON2-def/apoE(-/-) mice on a Western diet. Our data suggest that macrophage PON2 modulates mechanisms that link ER stress, mitochondrial dysfunction and the development of atherosclerosis.
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Affiliation(s)
- Asokan Devarajan
- Division of Cardiology, Department of Medicine, University of California Los Angeles, CA 90095, USA
| | - Victor R Grijalva
- Division of Cardiology, Department of Medicine, University of California Los Angeles, CA 90095, USA
| | - Noam Bourquard
- Division of Cardiology, Department of Medicine, University of California Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, CA 90095, USA
| | - David Meriwether
- Department of Obstetrics and Gynecology, University of California Los Angeles, CA 90095, USA
| | - Satoshi Imaizumi
- Division of Cardiology, Department of Medicine, University of California Los Angeles, CA 90095, USA
| | - Bo-Chul Shin
- Division of Neonatology and Developmental Biology, Neonatal Research Center, Department of Pediatrics, University of California Los Angeles, CA 90095, USA
| | - Sherin U. Devaskar
- Division of Neonatology and Developmental Biology, Neonatal Research Center, Department of Pediatrics, University of California Los Angeles, CA 90095, USA
| | - Srinivasa T. Reddy
- Division of Cardiology, Department of Medicine, University of California Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, CA 90095, USA
- Department of Obstetrics and Gynecology, University of California Los Angeles, CA 90095, USA
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Role of topical nepafenac in prevention and treatment of macular edema after vitreoretinal surgery. Retina 2012; 32:250-5. [PMID: 21926942 DOI: 10.1097/iae.0b013e31821e2057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the effects of topical nepafenac in patients undergoing vitreoretinal surgery. METHODS One hundred and twenty eyes of 120 patients undergoing vitreoretinal surgery were randomized to receive either topical nepafenac 0.1% (60 eyes) or placebo (60 eyes) in this investigator-masked, randomized, comparative case series. Eyes were evaluated for Day 1 postoperative inflammation and 2-, 4-, 6-, and 8-week postoperative retinal thickness and best-corrected visual acuity. RESULTS Mean Day 1 inflammation grades of 0.95 ± 0.6 and 1.78 ± 0.7 were noted in patients taking nepafenac and placebo, respectively (P = 0.002). The nepafenac and placebo groups had mean central macular subfield thickness of 228.44 ± 29.27 μm and 236.21 ± 29.44 μm at 4 weeks (P = 0.172) and 205.35 ± 25.25 μm and 205.37 ± 24.90 μm at 8 weeks (P = 0.971), respectively. At 1 month, there was no statistically significant difference in the mean visual acuity between the nepafenac group (0.55 ± 0.16 decimal units) and placebo group (0.52 ± 0.17 decimal units). CONCLUSION Topical nepafenac was safe and reduced postoperative pain and inflammation in patients undergoing vitreoretinal surgery. However, its effect on reducing postoperative macular edema and improving visual acuity as compared with that of the standard postvitrectomy therapeutic regimen was equivocal.
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Markovets AM, Saprunova VB, Zhdankina AA, Fursova AZ, Bakeeva LE, Kolosova NG. Alterations of retinal pigment epithelium cause AMD-like retinopathy in senescence-accelerated OXYS rats. Aging (Albany NY) 2011; 3:44-54. [PMID: 21191149 PMCID: PMC3047138 DOI: 10.18632/aging.100243] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pathogenesis of age-related macular degeneration (AMD), the leading cause of blindness in the world, remains poorly understood. This makes it necessary to create animal models for studying AMD pathogenesis and to design new therapeutic approaches. Here we showed that retinopathy in OXYS rats is similar to human AMD according to clinical signs, morphology, and vascular endothelium growth factor (VEGF) and pigment epithelium-derived factor (PEDF) genes expression. Clinical signs of retinopathy OXYS rats manifest by the age 3 months against the background of significantly reduced expression level of VEGF and PEDF genes due to the decline of the amount of retinal pigment epithelium (RPE) cells and alteration of choroidal microcirculation. The disruption in OXYS rats' retina starts at the age of 20 days and appears as reduce the area of RPE cells but does not affect their ultrastructure. Ultrastructural pathological alterations of RPE as well as develop forms of retinopathy are observed in OXYS rats from age 12 months and manifested as excessive accumulation of lipofuscin in RPE regions adjacent to the rod cells, whirling extentions of the basement membrane into the cytoplasm. These data suggest that primary cellular degenerative alterations in the RPE cells secondarily lead to choriocapillaris atrophy and results in complete loss of photoreceptor cells in the OXYS rats' retina by the age of 24 months.
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