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Liang C, Li F, Gu C, Xie L, Yan W, Wang X, Shi R, Linghu S, Liu T. Metabolomic profiling of ocular tissues in rabbit myopia: Uncovering differential metabolites and pathways. Exp Eye Res 2024; 240:109796. [PMID: 38244883 DOI: 10.1016/j.exer.2024.109796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/09/2024] [Accepted: 01/16/2024] [Indexed: 01/22/2024]
Abstract
To investigate the metabolic difference among tissue layers of the rabbits' eye during the development of myopia using metabolomic techniques and explore any metabolic links or cascades within the ocular wall. Ultra Performance Liquid Chromatography - Mass Spectrometry (UPLC-MS) was utilized for untargeted metabolite screening (UMS) to identify the significant differential metabolites produced between myopia (MY) and control (CT) (horizontal). Subsequently, we compared those key metabolites among tissues (Sclera, Choroid, Retina) of MY for distribution and variation (longitudinal). A total of 6285 metabolites were detected in the three tissues. The differential metabolites were screened and the metabolic pathways of these metabolites in each myopic tissue were labeled, including tryptophan and its metabolites, pyruvate, taurine, caffeine metabolites, as well as neurotransmitters like glutamate and dopamine. Our study suggests that multiple metabolic pathways or different metabolites under the same pathway, might act on different parts of the eyeball and contribute to the occurrence and development of myopia by affecting the energy supply to the ocular tissues, preventing antioxidant stress, affecting scleral collagen synthesis, and regulating various neurotransmitters mutually.
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Affiliation(s)
- Chengpeng Liang
- Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi Medical University, Zunyi, 563000, Guizhou Province, China.
| | - Fayuan Li
- Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi Medical University, Zunyi, 563000, Guizhou Province, China
| | - Chengqi Gu
- Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi Medical University, Zunyi, 563000, Guizhou Province, China
| | - Ling Xie
- Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi Medical University, Zunyi, 563000, Guizhou Province, China
| | - Wen Yan
- Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi Medical University, Zunyi, 563000, Guizhou Province, China
| | - Xiaoye Wang
- Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi Medical University, Zunyi, 563000, Guizhou Province, China
| | - Rong Shi
- Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, Guizhou Province, China
| | - Shaorong Linghu
- Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, Guizhou Province, China
| | - Taixiang Liu
- Key Laboratory of Ocular Diseases of Guizhou Province, Zunyi Medical University, Zunyi, 563000, Guizhou Province, China; Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, Guizhou Province, China.
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2
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Thomson K, Karouta C, Weber D, Hoffmann N, Morgan I, Kelly T, Ashby R. The role of the serotonergic system in atropine's anti-myopic effects. Biomed Pharmacother 2023; 167:115542. [PMID: 37742601 DOI: 10.1016/j.biopha.2023.115542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/11/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023] Open
Abstract
The muscarinic cholinergic antagonist atropine is the most widely used pharmacological treatment for the visual disorder myopia (short-sightedness), the leading cause of low-vision worldwide. This study sought to better define the mechanism by which atropine inhibits myopic growth. Although classified as a muscarinic-cholinergic antagonist, atropine has been found to bind and modulate the activity of several non-cholinergic systems (e.g., serotonin). Thus, this study investigated whether the serotonergic system could underly atropine's anti-myopic effects. Using a chick model of myopia, we report that atropine's growth-inhibitory effects can be attenuated by pharmacological stimulation of the serotonin system. This may suggest that atropine can slow the development of myopia through inhibiting serotonergic receptor activity. We also observed that pharmacological antagonism of serotonergic receptors inhibits the development of experimental myopia in a dose-dependent manner, further demonstrating that modulation of serotonergic receptor activity can alter ocular growth rates. Finally, we found that neither experimental myopia, nor atropine treatment, induced a significant change in retinal serotonergic output (i.e., synthesis, transport, release and catabolism). This may suggest that, although myopic growth can be inhibited through modulation of serotonergic receptor activity (by atropine or serotonergic antagonists), this does not require a change in serotonin levels. These findings regarding a serotonergic mechanism for atropine may have significant ramifications for the treatment of human myopia. This includes assessing the use of atropine in patients who are also undergoing treatment to upregulate serotonergic signaling (e.g., serotonergic anti-depressants).
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia.
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Daniel Weber
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Nichola Hoffmann
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Ian Morgan
- Research School of Biology, Australian National University, Australia
| | - Tamsin Kelly
- Faculty of Science and Technology, University of Canberra, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia; Research School of Biology, Australian National University, Australia
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3
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Tang YP, Zhang XB, Hu ZX, Lin K, Lin Z, Chen TY, Wu RH, Chi ZL. Vitreous metabolomic signatures of pathological myopia with complications. Eye (Lond) 2023; 37:2987-2993. [PMID: 36841867 PMCID: PMC10516974 DOI: 10.1038/s41433-023-02457-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 01/17/2023] [Accepted: 02/15/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND Pathological myopia (PM) is closely associated with blinding ocular morbidities. Identifying biomarkers can provide clues on pathogeneses. This study aimed to identify metabolic biomarkers and underlying mechanisms in the vitreous humour (VH) of PM patients with complications. METHODS VH samples were collected from 39 PM patients with rhegmatogenous retinal detachment (RRD) (n = 23) or macular hole (MH)/myopic retinoschisis (MRS) (n = 16) and 23 controls (MH with axial length < 26 mm) who underwent surgical treatment. VH metabolomic profiles were investigated using ultra-performance liquid chromatography‒mass spectrometry. The area under the receiver operating characteristic curve (AUC) was computed to identify potential biomarkers for PM diagnosis. RESULTS Bioinformatics analysis identified nineteen and four metabolites altered in positive and negative modes, respectively, and these metabolites were involved in tryptophan metabolism. Receiver operating characteristic analysis showed that seventeen metabolites (AUC > 0.6) in the positive mode and uric acid in the negative mode represent potential biomarkers for PM with complications (AUC = 0.894). Pairwise and pathway analyses among the RRD-PM, MH/MRS-PM and control groups showed that tryptophan metabolism and uric acid were closely correlated with PM. Altered metabolites and pathways in our study were characterized by increased oxidative stress and altered energy metabolism. These results contribute to a better understanding of myopia progression with or without related complications. CONCLUSIONS Our study provides metabolomic signatures and related immunopathological features in the VH of PM patients, revealing new insight into the prevention and treatment of PM and related complications.
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Affiliation(s)
- Yong-Ping Tang
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Xiao-Bo Zhang
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Zhi-Xiang Hu
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Ke Lin
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Zhong Lin
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Tian-Yu Chen
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Rong-Han Wu
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
| | - Zai-Long Chi
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
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4
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Huang Y, Chen X, Zhuang J, Yu K. The Role of Retinal Dysfunction in Myopia Development. Cell Mol Neurobiol 2022:10.1007/s10571-022-01309-1. [DOI: 10.1007/s10571-022-01309-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 11/16/2022] [Indexed: 11/27/2022]
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Thomson K, Kelly T, Karouta C, Morgan I, Ashby R. Insights into the mechanism of atropine's anti-myopia effects: evidence against cholinergic hyperactivity and modulation of dopamine release. Br J Pharmacol 2021; 178:4501-4517. [PMID: 34302355 PMCID: PMC9293064 DOI: 10.1111/bph.15629] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 04/29/2021] [Accepted: 06/25/2021] [Indexed: 11/27/2022] Open
Abstract
Background and Purpose The ability of the muscarinic cholinergic antagonist atropine to inhibit myopia development in humans and animal models would suggest that cholinergic hyperactivity may underlie myopic growth. To test this, we investigated whether cholinergic agonists accelerate ocular growth rates in chickens. Furthermore, we investigated whether atropine alters ocular growth by downstream modulation of dopamine levels, a mechanism postulated to underlie its antimyopic effects. Experimental Approach Muscarinic (muscarine and pilocarpine), nicotinic (nicotine) and non‐specific (oxotremorine and carbachol) cholinergic agonists were administered to chicks developing form‐deprivation myopia (FDM) or chicks that were otherwise untreated. Vitreal levels of dopamine and its primary metabolite 3,4‐dihydroxyphenylacetic acid (DOPAC) were examined using mass spectrometry MS in form‐deprived chicks treated with atropine (360, 15 or 0.15 nmol). Further, we investigated whether dopamine antagonists block atropine's antimyopic effects. Key Results Unexpectedly, administration of each cholinergic agonist inhibited FDM but did not affect normal ocular development. Atropine only affected dopamine and DOPAC levels at its highest dose. Dopamine antagonists did not alter the antimyopia effects of atropine. Conclusion and Implications Muscarinic, nicotinic and non‐specific cholinergic agonists inhibited FDM development. This indicates that cholinergic hyperactivity does not underlie myopic growth and questions whether atropine inhibits myopia via cholinergic antagonism. This study also demonstrates that changes in retinal dopamine release are not required for atropine's antimyopic effects. Finally, nicotinic agonists may represent a novel and more targeted approach for the cholinergic control of myopia as they are unlikely to cause the anterior segment side effects associated with muscarinic treatment.
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Affiliation(s)
- Kate Thomson
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Tamsin Kelly
- National Centre for Forensic Studies, Faculty of Science and Technology, University of Canberra, Australia
| | - Cindy Karouta
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia
| | - Ian Morgan
- Research School of Biology, Australian National University, Australia
| | - Regan Ashby
- Centre for Research in Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Australia.,Research School of Biology, Australian National University, Australia
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6
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Summers JA, Schaeffel F, Marcos S, Wu H, Tkatchenko AV. Functional integration of eye tissues and refractive eye development: Mechanisms and pathways. Exp Eye Res 2021; 209:108693. [PMID: 34228967 DOI: 10.1016/j.exer.2021.108693] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/16/2022]
Abstract
Refractive eye development is a tightly coordinated developmental process. The general layout of the eye and its various components are established during embryonic development, which involves a complex cross-tissue signaling. The eye then undergoes a refinement process during the postnatal emmetropization process, which relies heavily on the integration of environmental and genetic factors and is controlled by an elaborate genetic network. This genetic network encodes a multilayered signaling cascade, which converts visual stimuli into molecular signals that guide the postnatal growth of the eye. The signaling cascade underlying refractive eye development spans across all ocular tissues and comprises multiple signaling pathways. Notably, tissue-tissue interaction plays a key role in both embryonic eye development and postnatal eye emmetropization. Recent advances in eye biometry, physiological optics and systems genetics of refractive error have significantly advanced our understanding of the biological processes involved in refractive eye development and provided a framework for the development of new treatment options for myopia. In this review, we summarize the recent data on the mechanisms and signaling pathways underlying refractive eye development and discuss new evidence suggesting a wide-spread signal integration across different tissues and ocular components involved in visually guided eye growth.
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Affiliation(s)
- Jody A Summers
- Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Frank Schaeffel
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, Tuebingen, Germany; Myopia Research Group, Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
| | - Susana Marcos
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Hao Wu
- Department of Ophthalmology, Columbia University, New York, USA
| | - Andrei V Tkatchenko
- Department of Ophthalmology, Columbia University, New York, USA; Department of Pathology and Cell Biology, Columbia University, New York, USA.
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7
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Najjar RP, Chao De La Barca JM, Barathi VA, Ho CEH, Lock JZ, Muralidharan AR, Tan RKY, Dhand C, Lakshminarayanan R, Reynier P, Milea D. Ocular growth and metabolomics are dependent upon the spectral content of ambient white light. Sci Rep 2021; 11:7586. [PMID: 33828194 PMCID: PMC8026599 DOI: 10.1038/s41598-021-87201-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 03/25/2021] [Indexed: 02/06/2023] Open
Abstract
Myopia results from an excessive axial growth of the eye, causing abnormal projection of remote images in front of the retina. Without adequate interventions, myopia is forecasted to affect 50% of the world population by 2050. Exposure to outdoor light plays a critical role in preventing myopia in children, possibly through the brightness and blue-shifted spectral composition of sunlight, which lacks in artificial indoor lighting. Here, we evaluated the impact of moderate levels of ambient standard white (SW: 233.1 lux, 3900 K) and blue-enriched white (BEW: 223.8 lux, 9700 K) lights on ocular growth and metabolomics in a chicken-model of form-deprivation myopia. Compared to SW light, BEW light decreased aberrant ocular axial elongation and accelerated recovery from form-deprivation. Furthermore, the metabolomic profiles in the vitreous and retinas of recovering form-deprived eyes were distinct from control eyes and were dependent on the spectral content of ambient light. For instance, exposure to BEW light was associated with deep lipid remodeling and metabolic changes related to energy production, cell proliferation, collagen turnover and nitric oxide metabolism. This study provides new insight on light-dependent modulations in ocular growth and metabolomics. If replicable in humans, our findings open new potential avenues for spectrally-tailored light-therapy strategies for myopia.
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Affiliation(s)
- Raymond P Najjar
- Singapore Eye Research Institute, Singapore, Singapore. .,The Ophthalmology and Visual Sciences ACP, Duke-NUS Medical School, Singapore, Singapore.
| | - Juan Manuel Chao De La Barca
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France.,Unité Mixte de Recherche MITOVASC, CNRS 6015, INSERM U1083, Université d'Angers, Angers, France
| | - Veluchamy A Barathi
- Singapore Eye Research Institute, Singapore, Singapore.,The Ophthalmology and Visual Sciences ACP, Duke-NUS Medical School, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | | | | | - Royston K Y Tan
- Department of Ocular Bio-Engineering, National University of Singapore, Singapore, Singapore
| | - Chetna Dhand
- Singapore Eye Research Institute, Singapore, Singapore.,CSIR-Advanced Materials and Processes Research Institute, Hoshangabad Road, Bhopal, 462026, India
| | | | - Pascal Reynier
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers, France.,Unité Mixte de Recherche MITOVASC, CNRS 6015, INSERM U1083, Université d'Angers, Angers, France
| | - Dan Milea
- Singapore Eye Research Institute, Singapore, Singapore. .,The Ophthalmology and Visual Sciences ACP, Duke-NUS Medical School, Singapore, Singapore. .,Singapore National Eye Center, Singapore, Singapore.
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8
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Wang WY, Chen C, Chang J, Chien L, Shih YF, Lin LLK, Pang CP, Wang IJ. Pharmacotherapeutic candidates for myopia: A review. Biomed Pharmacother 2021; 133:111092. [PMID: 33378986 DOI: 10.1016/j.biopha.2020.111092] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/24/2020] [Accepted: 11/28/2020] [Indexed: 01/11/2023] Open
Abstract
This review provides insights into the mechanism underlying the pathogenesis of myopia and potential targets for clinical intervention. Although the etiology of myopia involves both environmental and genetic factors, recent evidence has suggested that the prevalence and severity of myopia appears to be affected more by environmental factors. Current pharmacotherapeutics are aimed at inhibiting environmentally induced changes in visual input and subsequent changes in signaling pathways during myopia pathogenesis and progression. Recent studies on animal models of myopia have revealed specific molecules potentially involved in the regulation of eye development. Among them, the dopamine receptor plays a critical role in controlling myopia. Subsequent studies have reported pharmacotherapeutic treatments to control myopia progression. In particular, atropine treatment yielded favorable outcomes and has been extensively used; however, current studies are aimed at optimizing its efficacy and confirming its safety. Furthermore, future studies are required to assess the efficacy of combinatorial use of low-dose atropine and contact lenses or orthokeratology.
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Affiliation(s)
- Wen-Yi Wang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Camille Chen
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Justine Chang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Lillian Chien
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Yung-Feng Shih
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Luke L K Lin
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, KLN, Hong Kong, China.
| | - I-Jong Wang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Biomedical Sciences, School of Medicine, China Medical University, Taichung, Taiwan.
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9
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Lansky ES. Novel harmala-ocudelic tuning (HOT) for ocular disorders. Med Hypotheses 2020; 143:109834. [PMID: 32498006 DOI: 10.1016/j.mehy.2020.109834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/11/2020] [Indexed: 10/24/2022]
Abstract
The eye contains serotonin, and possesses serotonergic receptors and modulators. Selective serotonin reuptake inhibitors (SSRIs) may impair ocular function, while other serotonin receptor-binding drugs might improve it. A putative vision-improving drug must be safe at therapeutic doses, most preferably with long-lasting benefits from a single or very few administration(s). One drug potentially satisfying these criteria is the common, botanically-occurring indole alkaloid and "major hallucinogen," harmine. Harmine is prominent in the leaves of the Generally Recognized as Safe (GRAS) Passiflora, and in Peganum and Banisteriopsis, the two preeminent "sacred" medicinal plants of India/pre-Islamic Persia/modern Iran and the Amazon respectively. Though the possibility of drug-drug or herb-drug interactions exists, especially with SSRIs, at correct patient-individualized dosages, these plants, used alone, are minimally hallucinogenic, well tolerated, potentially exerting profound therapeutic effects on vision from a single or few administration(s) lasting months or years. The hypothesized mechanism for this extraordinary action is tuning of the serotonergic receptors in the eye in their binding affinity for serotonin, a putative neurochemical "ocudelic" homologue to the psychedelic phenomenon, likely potentiated, according to clinical experience with classical hallucinogens, by therapeutic music, positive psychological "set," and conducive environmental "setting." Blinded research with harmala alkaloid-containing plants in ocular patients using psychedelic therapy accoutrements, viz. eyeshades, high fidelity classical music, headphones, two guides, pre-dosing preparation, and post-dosing integration, could non-invasively assess visual acuity in presbyopia. Significant results would stimulate further exploration of this novel approach to ocular disorders. Deeper benefit, particularly when the retina is compromised, might follow co-ingestion of the harmala alkaloid-containing plants with plants containing dimethyltryptamine.
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Affiliation(s)
- E S Lansky
- Institute of Evolution, University of Haifa, Haifa, Israel.
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10
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Effectiveness and safety of topical levodopa in a chick model of myopia. Sci Rep 2019; 9:18345. [PMID: 31797988 PMCID: PMC6892936 DOI: 10.1038/s41598-019-54789-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/19/2019] [Indexed: 01/18/2023] Open
Abstract
Animal models have demonstrated a link between dysregulation of the retinal dopamine system and the excessive ocular growth associated with the development of myopia. Here we show that intravitreal or topical application of levodopa, which is widely used in the treatment of neurological disorders involving dysregulation of the dopaminergic system, inhibits the development of experimental myopia in chickens. Levodopa slows ocular growth in a dose dependent manner in chicks with a similar potency to atropine, a common inhibitor of ocular growth in humans. Topical levodopa remains effective over chronic treatment periods, with its effectiveness enhanced by coadministration with carbidopa to prevent its premature metabolism. No changes in normal ocular development (biometry and refraction), retinal health (histology), or intraocular pressure were observed in response to chronic treatment (4 weeks). With a focus on possible clinical use in humans, translation of these avian safety findings to a mammalian model (mouse) illustrate that chronic levodopa treatment (9 months) does not induce any observable changes in visual function (electroretinogram recordings), ocular development, and retinal health, suggesting that levodopa may have potential as a therapeutic intervention for human myopia.
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11
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Tkatchenko TV, Tkatchenko AV. Pharmacogenomic Approach to Antimyopia Drug Development: Pathways Lead the Way. Trends Pharmacol Sci 2019; 40:833-852. [PMID: 31676152 DOI: 10.1016/j.tips.2019.09.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/04/2019] [Accepted: 09/16/2019] [Indexed: 12/29/2022]
Abstract
Myopia is the most common eye disorder in the world which is caused by a mismatch between the optical power of the eye and its excessively long axial length. Recent studies revealed that the regulation of the axial length of the eye occurs via a complex signaling cascade, which originates in the retina and propagates across all ocular tissues to the sclera. The complexity of this regulatory cascade has made it particularly difficult to develop effective antimyopia drugs. The current pharmacological treatment options for myopia are limited to atropine and 7-methylxanthine, which have either significant adverse effects or low efficacy. In this review, we focus on the recent advances in genome-wide studies of the signaling pathways underlying myopia development and discuss the potential of systems genetics and pharmacogenomic approaches for the development of antimyopia drugs.
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Affiliation(s)
| | - Andrei V Tkatchenko
- Department of Ophthalmology, Columbia University, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.
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12
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Passos ADCF, Herculano AM, Oliveira KRHM, de Lima SMA, Rocha FAF, Freitas HR, da Silva Sampaio L, Figueiredo DP, da Costa Calaza K, de Melo Reis RA, do Nascimento JLM. Regulation of the Serotonergic System by Kainate in the Avian Retina. Cell Mol Neurobiol 2019; 39:1039-1049. [PMID: 31197744 DOI: 10.1007/s10571-019-00701-8] [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: 02/05/2019] [Accepted: 06/07/2019] [Indexed: 12/20/2022]
Abstract
Serotonin (5-HT) has been recognized as a neurotransmitter in the vertebrate retina, restricted mainly to amacrine and bipolar cells. It is involved with synaptic processing and possibly as a mitogenic factor. We confirm that chick retina amacrine and bipolar cells are, respectively, heavily and faintly immunolabeled for 5-HT. Amacrine serotonergic cells also co-express tyrosine hydroxylase (TH), a marker of dopaminergic cells in the retina. Previous reports demonstrated that serotonin transport can be modulated by neurotransmitter receptor activation. As 5-HT is diffusely released as a neuromodulator and co-localized with other transmitters, we evaluated if 5-HT uptake or release is modulated by several mediators in the avian retina. The role of different glutamate receptors on serotonin transport and release in vitro and in vivo was also studied. We show that L-glutamate induces an inhibitory effect on [3H]5-HT uptake and this effect was specific to kainate receptor activation. Kainate-induced decrease in [3H]5-HT uptake was blocked by CNQX, an AMPA/kainate receptor antagonist, but not by MK-801, a NMDA receptor antagonist. [3H]5-HT uptake was not observed in the presence of AMPA, thus suggesting that the decrease in serotonin uptake is mediated by kainate. 5-HT (10-50 μM) had no intrinsic activity in raising intracellular Ca2+, but addition of 10 μM 5-HT decreased Ca2+ shifts induced by KCl in retinal neurons. Moreover, kainate decreased the number of bipolar and amacrine cells labeled to serotonin in chick retina. In conclusion, our data suggest a highly selective effect of kainate receptors in the regulation of serotonin functions in the retinal cells.
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Affiliation(s)
- Adelaide da Conceição Fonseca Passos
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil
| | - Anderson Manoel Herculano
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil
| | - Karen R H M Oliveira
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil
| | - Silene Maria A de Lima
- Lab de Neurobiologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém-PA, Brazil
| | - Fernando A F Rocha
- Lab de Neurobiologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém-PA, Brazil
| | - Hércules Rezende Freitas
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil.,Escola de Ciências da Saúde, Centro Universitário IBMR, Rio De Janeiro-RJ, Brazil
| | - Luzia da Silva Sampaio
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil
| | - Danniel Pereira Figueiredo
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil
| | - Karin da Costa Calaza
- Lab Neurobiologia da Retina, Programa de Pós-graduação em Neurociências, Universidade Federal Fluminense, Rio De Janeiro-RJ, Brazil
| | - Ricardo Augusto de Melo Reis
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio De Janeiro-RJ, Brazil
| | - José Luiz Martins do Nascimento
- Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Campus Universitário do Guamá, Rua Augusto Correa 01, Belém-PA, 66075-110, Brazil.
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13
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Zhou X, Li G, Zhang S, Wu J. 5-HT1A Receptor Agonist Promotes Retinal Ganglion Cell Function by Inhibiting OFF-Type Presynaptic Glutamatergic Activity in a Chronic Glaucoma Model. Front Cell Neurosci 2019; 13:167. [PMID: 31130845 PMCID: PMC6509153 DOI: 10.3389/fncel.2019.00167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/08/2019] [Indexed: 01/30/2023] Open
Abstract
Serotonin receptors are potential neuroprotective agents in degenerative diseases of the central nervous system. The protective effects of serotonin receptor (5-HT1A) agonists on the survival and function of retinal ganglion cells (RGCs) by regulating the release of the presynaptic neurotransmitter γ-aminobutyric acid (GABA) were confirmed in our previous study of a chronic glaucoma rat model. However, the roles of excitatory amino acids and their interactions with the 5-HT1A receptor in glaucoma remain unknown. Here, we found that ocular hypertension increased glutamine synthetase (GS) and excitatory amino acid transporter 2 (EAAT2) expression in rat retinas. In addition, the high expression of GS and EAAT2 induced by glaucoma was downregulated by the 5-HT1A receptor agonist 8-OH-DPAT and the 5-HT1A receptor antagonist WAY-100635, respectively. Patch-clamp techniques were used to record glutamate receptor-mediated spontaneous and miniature glutamatergic excitatory post-synaptic currents (sEPSCs and mEPSCs) as well as L-glutamate-induced current in OFF-type and ON-type RGCs in rat retinal slices. Although there were no significant differences in the frequency and amplitude of sEPSC and mEPSC release between normal and glaucoma OFF- and ON-type RGCs, exogenous 8-OH-DPAT administration specifically reduced the frequency, but not the amplitude, of sEPSC and mEPSC release in glaucoma OFF-type rather than ON-type RGCs; these effects were completely blocked by WAY-100635. In summary, 8-OH-DPAT decreases and increases GS and EAAT2 expression of glaucomatous retina, respectively, while decreasing sEPSC and mEPSC frequency. In contrast, WAY-100635 increases and decreases GS and EAAT2 expression of glaucomatous retina, respectively, while increasing sEPSC and mEPSC frequency. The reduction of glutamatergic presynaptic transmission by 8-OH-DPAT deactivates RGCs at the neural network level and reduces the excitotoxic damage in the pathological process of chronic glaucoma.
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Affiliation(s)
- Xujiao Zhou
- Eye Institute, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), Shanghai, China
| | - Gang Li
- Eye Institute, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), Shanghai, China
| | - Shenghai Zhang
- Eye Institute, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), Shanghai, China
| | - Jihong Wu
- Eye Institute, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences (Fudan University), Shanghai, China.,Department of Ophthalmology and Vision Science, Eye and ENT Hospital, Fudan University, Shanghai, China
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14
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Carr BJ, Mihara K, Ramachandran R, Saifeddine M, Nathanson NM, Stell WK, Hollenberg MD. Myopia-Inhibiting Concentrations of Muscarinic Receptor Antagonists Block Activation of Alpha2A-Adrenoceptors In Vitro. Invest Ophthalmol Vis Sci 2019; 59:2778-2791. [PMID: 29860464 DOI: 10.1167/iovs.17-22562] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Myopia is a refractive disorder that degrades vision. It can be treated with atropine, a muscarinic acetylcholine receptor (mAChR) antagonist, but the mechanism is unknown. Atropine may block α-adrenoceptors at concentrations ≥0.1 mM, and another potent myopia-inhibiting ligand, mamba toxin-3 (MT3), binds equally well to human mAChR M4 and α1A- and α2A-adrenoceptors. We hypothesized that mAChR antagonists could inhibit myopia via α2A-adrenoceptors, rather than mAChR M4. Methods Human mAChR M4 (M4), chicken mAChR M4 (cM4), or human α2A-adrenergic receptor (hADRA2A) clones were cotransfected with CRE/promoter-luciferase (CRE-Luc; agonist-induced luminescence) and Renilla luciferase (RLuc; normalizing control) into human cells. Inhibition of normalized agonist-induced luminescence by antagonists (ATR: atropine; MT3; HIM: himbacine; PRZ: pirenzepine; TRP: tropicamide; OXY: oxyphenonium; QNB: 3-quinuclidinyl benzilate; DIC: dicyclomine; MEP: mepenzolate) was measured using the Dual-Glo Luciferase Assay System. Results Relative inhibitory potencies of mAChR antagonists at mAChR M4/cM4, from most to least potent, were QNB > OXY ≥ ATR > MEP > HIM > DIC > PRZ > TRP. MT3 was 56× less potent at cM4 than at M4. Relative potencies of mAChR antagonists at hADRA2A, from most to least potent, were MT3 > HIM > ATR > OXY > PRZ > TRP > QNB > MEP; DIC did not antagonize. Conclusions Muscarinic antagonists block hADRA2A signaling at concentrations comparable to those used to inhibit chick myopia (≥0.1 mM) in vivo. Relative potencies at hADRA2A, but not M4/cM4, correlate with reported abilities to inhibit chick form-deprivation myopia. mAChR antagonists might inhibit myopia via α2-adrenoceptors, instead of through the mAChR M4/cM4 receptor subtype.
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Affiliation(s)
- Brittany J Carr
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Koichiro Mihara
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Rithwik Ramachandran
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - Mahmoud Saifeddine
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Neil M Nathanson
- Department of Pharmacology, University of Washington, Seattle, Washington, United States
| | - William K Stell
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Morley D Hollenberg
- Inflammation Research Network-Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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15
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Troilo D, Smith EL, Nickla DL, Ashby R, Tkatchenko AV, Ostrin LA, Gawne TJ, Pardue MT, Summers JA, Kee CS, Schroedl F, Wahl S, Jones L. IMI - Report on Experimental Models of Emmetropization and Myopia. Invest Ophthalmol Vis Sci 2019; 60:M31-M88. [PMID: 30817827 PMCID: PMC6738517 DOI: 10.1167/iovs.18-25967] [Citation(s) in RCA: 215] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 10/20/2018] [Indexed: 11/24/2022] Open
Abstract
The results of many studies in a variety of species have significantly advanced our understanding of the role of visual experience and the mechanisms of postnatal eye growth, and the development of myopia. This paper surveys and reviews the major contributions that experimental studies using animal models have made to our thinking about emmetropization and development of myopia. These studies established important concepts informing our knowledge of the visual regulation of eye growth and refractive development and have transformed treatment strategies for myopia. Several major findings have come from studies of experimental animal models. These include the eye's ability to detect the sign of retinal defocus and undergo compensatory growth, the local retinal control of eye growth, regulatory changes in choroidal thickness, and the identification of components in the biochemistry of eye growth leading to the characterization of signal cascades regulating eye growth and refractive state. Several of these findings provided the proofs of concepts that form the scientific basis of new and effective clinical treatments for controlling myopia progression in humans. Experimental animal models continue to provide new insights into the cellular and molecular mechanisms of eye growth control, including the identification of potential new targets for drug development and future treatments needed to stem the increasing prevalence of myopia and the vision-threatening conditions associated with this disease.
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Affiliation(s)
- David Troilo
- SUNY College of Optometry, State University of New York, New York, New York, United States
| | - Earl L. Smith
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Debora L. Nickla
- Biomedical Sciences and Disease, New England College of Optometry, Boston, Massachusetts, United States
| | - Regan Ashby
- Health Research Institute, University of Canberra, Canberra, Australia
| | - Andrei V. Tkatchenko
- Department of Ophthalmology, Department of Pathology and Cell Biology, Columbia University, New York, New York, United States
| | - Lisa A. Ostrin
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Timothy J. Gawne
- School of Optometry, University of Alabama Birmingham, Birmingham, Alabama, United States
| | - Machelle T. Pardue
- Biomedical Engineering, Georgia Tech College of Engineering, Atlanta, Georgia, United States31
| | - Jody A. Summers
- College of Medicine, University of Oklahoma, Oklahoma City, Oklahoma, United States
| | - Chea-su Kee
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Falk Schroedl
- Departments of Ophthalmology and Anatomy, Paracelsus Medical University, Salzburg, Austria
| | - Siegfried Wahl
- Institute for Ophthalmic Research, University of Tuebingen, Zeiss Vision Science Laboratory, Tuebingen, Germany
| | - Lyndon Jones
- CORE, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada
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16
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Activation of 5-HT1A Receptors Promotes Retinal Ganglion Cell Function by Inhibiting the cAMP-PKA Pathway to Modulate Presynaptic GABA Release in Chronic Glaucoma. J Neurosci 2018; 39:1484-1504. [PMID: 30541912 DOI: 10.1523/jneurosci.1685-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 12/12/2022] Open
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) receptor agonists are neuroprotective in CNS injury models. However, the neuroprotective functional implications and synaptic mechanism of 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), a serotonin receptor (5-HT1A) agonist, in an adult male Wistar rat model of chronic glaucoma model remain unknown. We found that ocular hypertension decreased 5-HT1A receptor expression in rat retinas because the number of retinal ganglion cells (RGCs) was significantly reduced in rats with induced ocular hypertension relative to that in control retinas and 8-OH-DPAT enhanced the RGC viability. The protective effects of 8-OH-DPAT were blocked by intravitreal administration of the selective 5-HT1A antagonist WAY-100635 or the selective GABAA receptor antagonist SR95531. Using patch-clamp techniques, spontaneous and miniature GABAergic IPSCs (sIPSCs and mIPSCs, respectively) of RGCs in rat retinal slices were recorded. 8-OH-DPAT significantly increased the frequency and amplitude of GABAergic sIPSCs and mIPSCs in ON- and OFF-type RGCs. Among the signaling cascades mediated by the 5-HT1A receptor, the role of cAMP-protein kinase A (PKA) signaling was investigated. The 8-OH-DPAT-induced changes at the synaptic level were enhanced by PKA inhibition by H-89 and blocked by PKA activation with bucladesine. Furthermore, the density of phosphorylated PKA (p-PKA)/PKA was significantly increased in glaucomatous retinas and 8-OH-DPAT significantly decreased p-PKA/PKA expression, which led to the inhibition of PKA phosphorylation upon relieving neurotransmitter GABA release. These results showed that the activation of 5-HT1A receptors in retinas facilitated presynaptic GABA release functions by suppressing cAMP-PKA signaling and decreasing PKA phosphorylation, which could lead to the de-excitation of RGC circuits and suppress excitotoxic processes in glaucoma.SIGNIFICANCE STATEMENT We found that serotonin (5-HT) receptors in the retina (5-HT1A receptors) were downregulated after intraocular pressure elevation. Patch-clamp recordings demonstrated differences in the frequencies of miniature GABAergic IPSCs (mIPSCs) in ON- and OFF-type retinal ganglion cells (RGCs) and RGCs in normal and glaucomatous retinal slices. Therefore, phosphorylated protein kinase A (PKA) inhibition upon release of the neurotransmitter GABA was eliminated by 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), which led to increased levels of GABAergic mIPSCs in ON- and OFF-type RGCs, thus enhancing RGC viability and function. These protective effects were blocked by the GABAA receptor antagonist SR95531 or the 5-HT1A antagonist WAY-100635. This study identified a novel mechanism by which activation of 5-HT1A receptors protects damaged RGCs via the cAMP-PKA signaling pathway that modulates GABAergic presynaptic activity.
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17
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Abstract
The expression of serotonin (5-HT) in the retina was first reported in the sixties. The detection of vesicular monoamine transporter and serotonin receptors in several retinal cells confirm that 5-HT is playing a neuromodulatory role in this structure. Whereas signaling pathways activated by 5-HT receptor binding has been poorly investigated so far, numerous data demonstrated that 5-HT is involved in retinal physiology, retinal physiopathology and photoreceptor survival.
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18
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Wang M, Schaeffel F, Jiang B, Feldkaemper M. Effects of Light of Different Spectral Composition on Refractive Development and Retinal Dopamine in Chicks. ACTA ACUST UNITED AC 2018; 59:4413-4424. [DOI: 10.1167/iovs.18-23880] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Min Wang
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, Tuebingen, Germany
- The Second Xiangya Hospital, Central South University, Xiangya, Hunan Province, China
| | - Frank Schaeffel
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, Tuebingen, Germany
| | - Bing Jiang
- The Second Xiangya Hospital, Central South University, Xiangya, Hunan Province, China
| | - Marita Feldkaemper
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, Tuebingen, Germany
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19
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Ward AH, Siegwart JT, Frost MR, Norton TT. Intravitreally-administered dopamine D2-like (and D4), but not D1-like, receptor agonists reduce form-deprivation myopia in tree shrews. Vis Neurosci 2017; 34:E003. [PMID: 28304244 PMCID: PMC5567805 DOI: 10.1017/s0952523816000195] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We examined the effect of intravitreal injections of D1-like and D2-like dopamine receptor agonists and antagonists and D4 receptor drugs on form-deprivation myopia (FDM) in tree shrews, mammals closely related to primates. In eleven groups (n = 7 per group), we measured the amount of FDM produced by monocular form deprivation (FD) over an 11-day treatment period. The untreated fellow eye served as a control. Animals also received daily 5 µL intravitreal injections in the FD eye. The reference group received 0.85% NaCl vehicle. Four groups received a higher, or lower, dose of a D1-like receptor agonist (SKF38393) or antagonist (SCH23390). Four groups received a higher, or lower, dose of a D2-like receptor agonist (quinpirole) or antagonist (spiperone). Two groups received the D4 receptor agonist (PD168077) or antagonist (PD168568). Refractions were measured daily; axial component dimensions were measured on day 1 (before treatment) and day 12. We found that in groups receiving the D1-like receptor agonist or antagonist, the development of FDM and altered ocular component dimensions did not differ from the NaCl group. Groups receiving the D2-like receptor agonist or antagonist at the higher dose developed significantly less FDM and had shorter vitreous chambers than the NaCl group. The D4 receptor agonist, but not the antagonist, was nearly as effective as the D2-like agonist in reducing FDM. Thus, using intravitreally-administered agents, we did not find evidence supporting a role for the D1-like receptor pathway in reducing FDM in tree shrews. The reduction of FDM by the dopamine D2-like agonist supported a role for the D2-like receptor pathway in the control of FDM. The reduction of FDM by the D4 receptor agonist, but not the D4 antagonist, suggests an important role for activation of the dopamine D4 receptor in the control of axial elongation and refractive development.
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Affiliation(s)
- Alexander H. Ward
- Genetics, Genomics and Bioinformatics Theme, University of Alabama at Birmingham, Birmingham, AL 35294
| | - John T. Siegwart
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Michael R. Frost
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Thomas T. Norton
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL 35294
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20
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Li B, Luo X, Li T, Zheng C, Ji S, Ma Y, Zhang S, Zhou X. Effects of Constant Flickering Light on Refractive Status, 5-HT and 5-HT2A Receptor in Guinea Pigs. PLoS One 2016; 11:e0167902. [PMID: 27959948 PMCID: PMC5154534 DOI: 10.1371/journal.pone.0167902] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 11/22/2016] [Indexed: 11/18/2022] Open
Abstract
Purpose To investigate the effects of constant flickering light on refractive development, the role of serotonin (i.e.5-hydroxytryptamine, 5-HT)and 5-HT2A receptor in myopia induced by flickering light in guinea pigs. Methods Forty-five guinea pigs were randomly divided into three groups: control, form deprivation myopia (FDM) and flickering light induced myopia (FLM) groups(n = 15 for each group). The right eyes of the FDM group were covered with semitransparent hemispherical plastic shells serving as eye diffusers. Guinea pigs in FLM group were raised with illumination of a duty cycle of 50% at a flash frequency of 0.5Hz. The refractive status, axial length (AL), corneal radius of curvature(CRC) were measured by streak retinoscope, A-scan ultrasonography and keratometer, respectively. Ultramicroscopy images were taken by electron microscopy. The concentrations of 5-HTin the retina, vitreous body and retinal pigment epithelium (RPE) were assessed by high performance liquid chromatography, the retinal 5-HT2A receptor expression was evaluated by immunohistofluorescence and western blot. Results The refraction of FDM and FLM eyes became myopic from some time point (the 4th week and the 6th week, respectively) in the course of the experiment, which was indicated by significantly decreased refraction and longer AL when compared with the controls (p<0.05). The concentrations of 5-HT in the retina, vitreous body and RPE of FDM and FLM eyes were significantly increased in comparison with those of control eyes (both p<0.05). Similar to FDM eyes, the expression of retinal 5-HT2A receptor in FLM eyes was significantly up-regulated compared to that of control eyes (both p<0.05). Western blot analysis showed that retinal 5-HT2A receptor level elevated less in the FLM eyes than that in the FDM eyes. Moreover, the levels of norepinephrine and epinephrine in FDM and FLM groups generally decreased when compared with control groups (all p<0.05). Conclusions Constant flickering light could cause progressive myopia in guinea pigs. 5-HT and 5-HT2A receptor increased both in form deprivation myopia and flickering light induced myopia, indicating that 5-HT possibly involved in myopic development via binding to5-HT2A receptor.
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Affiliation(s)
- Bing Li
- Central Laboratory, Jinshan Hospital affiliated to Fudan University, Shanghai, China
| | - Xiumei Luo
- Department of Ophthalmology, Jinshan Hospital affiliated to Fudan University, Shanghai, China
| | - Tao Li
- Department of Ophthalmology, Jinshan Hospital affiliated to Fudan University, Shanghai, China
| | - Changyue Zheng
- Department of Ophthalmology, Jinshan Hospital affiliated to Fudan University, Shanghai, China
| | - Shunmei Ji
- Department of Ophthalmology, Jinshan Hospital affiliated to Fudan University, Shanghai, China
| | - Yuanyuan Ma
- The State Key Laboratory of Medical Neurobiology, the Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Shuangshuang Zhang
- Department of Dermatology, Jinshan Hospital affiliated to Fudan University, Shanghai, China
| | - Xiaodong Zhou
- Department of Ophthalmology, Jinshan Hospital affiliated to Fudan University, Shanghai, China
- * E-mail:
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21
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Abstract
: Human studies have provided strong evidence that exposure to time outdoors is protective against the onset of myopia. A causal factor may be that the light levels outdoors (30,000-130,000 lux) are much higher than light levels indoors (typically less than 500 lux). Studies using animal models have found that normal animals exposed to low illuminance levels (50 lux) can develop myopia. The myopia and axial elongation, produced in animals by monocular form deprivation, is reduced by light levels in the 15,000 to 25,000 range. Myopia induced with a negative-power lens seems less affected, perhaps because the lens provides a powerful target for the emmetropization mechanism. Animal studies suggest that raising the light levels may have their effect by increasing retinal dopamine activity, probably via the D2 receptor pathway, altering gene expression in the retina and reducing the signals that produce axial elongation.
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Affiliation(s)
- Thomas T Norton
- *PhD Department of Vision Sciences, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama
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22
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Trakhtenberg EF, Pita-Thomas W, Fernandez SG, Patel KH, Venugopalan P, Shechter JM, Morkin MI, Galvao J, Liu X, Dombrowski SM, Goldberg JL. Serotonin receptor 2C regulates neurite growth and is necessary for normal retinal processing of visual information. Dev Neurobiol 2016; 77:419-437. [PMID: 26999672 DOI: 10.1002/dneu.22391] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 01/25/2016] [Accepted: 03/12/2016] [Indexed: 12/21/2022]
Abstract
Serotonin (5HT) is present in a subpopulation of amacrine cells, which form synapses with retinal ganglion cells (RGCs), but little is known about the physiological role of retinal serotonergic circuitry. We found that the 5HT receptor 2C (5HTR2C) is upregulated in RGCs after birth. Amacrine cells generate 5HT and about half of RGCs respond to 5HTR2C agonism with calcium elevation. We found that there are on average 83 5HT+ amacrine cells randomly distributed across the adult mouse retina, all negative for choline acetyltransferase and 90% positive for tyrosine hydroxylase. We also investigated whether 5HTR2C and 5HTR5A affect RGC neurite growth. We found that both suppress neurite growth, and that RGCs from the 5HTR2C knockout (KO) mice grow longer neurites. Furthermore, 5HTR2C is subject to post-transcriptional editing, and we found that only the edited isoform's suppressive effect on neurite growth could be reversed by a 5HTR2C inverse agonist. Next, we investigated the physiological role of 5HTR2C in the retina, and found that 5HTR2C KO mice showed increased amplitude on pattern electroretinogram. Finally, RGC transcriptional profiling and pathways analysis suggested partial developmental compensation for 5HTR2C absence. Taken together, our findings demonstrate that 5HTR2C regulates neurite growth and RGC activity and is necessary for normal amplitude of RGC response to physiologic stimuli, and raise the hypothesis that these functions are modulated by a subset of 5HT+/ChAT-/TH+ amacrine cells as part of retinal serotonergic circuitry. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 419-437, 2017.
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Affiliation(s)
- Ephraim F Trakhtenberg
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts.,Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida
| | - Wolfgang Pita-Thomas
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida.,Department of Anatomy and Neurobiology, Washington University, St. Louis, Missouri
| | - Stephanie G Fernandez
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Karan H Patel
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Praseeda Venugopalan
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts.,Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Jesse M Shechter
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Melina I Morkin
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Joana Galvao
- Shiley Eye Center, University of California, San Diego, California
| | - Xiongfei Liu
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Susan M Dombrowski
- Genomatix Software, Ann Arbor, Michigan.,Department of Obstetrics & Gynecology, Wayne State University School of Medicine, Detroit, Michigan
| | - Jeffrey L Goldberg
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida.,Shiley Eye Center, University of California, San Diego, California.,Byers Eye Institute, Stanford University, Palo Alto, California
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Ward AH, Siegwart JT, Frost MR, Norton TT. The effect of intravitreal injection of vehicle solutions on form deprivation myopia in tree shrews. Exp Eye Res 2016; 145:289-296. [PMID: 26836248 DOI: 10.1016/j.exer.2016.01.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/14/2016] [Accepted: 01/26/2016] [Indexed: 10/22/2022]
Abstract
lntravitreal injection of substances dissolved in a vehicle solution is a common tool used to assess retinal function. We examined the effect of injection procedures (three groups) and vehicle solutions (four groups) on the development of form deprivation myopia (FDM) in juvenile tree shrews, mammals closely related to primates, starting at 24 days of visual experience (about 45 days of age). In seven groups (n = 7 per group), the myopia produced by monocular form deprivation (FD) was measured daily for 12 days during an 11-day treatment period. The FD eye was randomly selected; the contralateral eye served as an untreated control. The refractive state of both eyes was measured daily, starting just before FD began (day 1); axial component dimensions were measured on day 1 and after eleven days of treatment (day 12). Procedure groups: the myopia (treated eye - control eye refraction) in the FD group was the reference. The sham group only underwent brief daily anesthesia and opening of the conjunctiva to expose the sclera. The puncture group, in addition, had a pipette inserted daily into the vitreous. In four vehicle groups, 5 μL of vehicle was injected daily. The NaCl group received 0.85% NaCl. In the NaCl + ascorbic acid group, 1 mg/mL of ascorbic acid was added. The water group received sterile water. The water + ascorbic acid group received water with ascorbic acid (1 mg/mL). We found that the procedures associated with intravitreal injections (anesthesia, opening of the conjunctiva, and puncture of the sclera) did not significantly affect the development of FDM. However, injecting 5 μL of any of the four vehicle solutions slowed the development of FDM. NaCl had a small effect; myopia development in the last 6 days (-0.15 ± 0.08 D/day) was significantly less than in the FD group (-0.55 ± 0.06 D/day). NaCl + Ascorbic acid further slowed the development of FDM on several treatment days. H2O (-0.09 ± 0.05 D/day) and H2O + ascorbic acid (-0.08 ± 0.05 D/day) both almost completely blocked myopia development. The treated eye vitreous chamber elongation, compared with the control eye, in all groups was consistent with the amount of myopia. When FD continued (days 12-16) without injections in the water and water + ascorbic acid groups, the rate of myopia development quickly increased. Thus, it appears the vehicles affected retinal signaling rather than causing damage. The effect of water and water + ascorbic acid may be due to reduced osmolality or ionic concentration near the tip of the injection pipette. The effect of ascorbic acid, compared to NaCl alone, may be due to its reported dopaminergic activity.
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Affiliation(s)
- Alexander H Ward
- Genetics, Genomics and Bioinformatics Theme, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - John T Siegwart
- Department of Vision Sciences, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Michael R Frost
- Department of Vision Sciences, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Thomas T Norton
- Department of Vision Sciences, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Ma M, Zhang Z, Du E, Zheng W, Gu Q, Xu X, Ke B. Wnt signaling in form deprivation myopia of the mice retina. PLoS One 2014; 9:e91086. [PMID: 24755605 PMCID: PMC3995642 DOI: 10.1371/journal.pone.0091086] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 02/09/2014] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. METHODOLOGY/PRINCIPAL FINDINGS (1) One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM) was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2) Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser). Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist) or Norrin (Wnt-pathway agonist), once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist) reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. CONCLUSIONS/SIGNIFICANCE Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the development and progression of form-deprivation myopia, in a mammalian model.
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Affiliation(s)
- Mingming Ma
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Fundus Disease, Shanghai, China
| | - Zhengwei Zhang
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Fundus Disease, Shanghai, China
| | - Ergang Du
- Jinhua Eye Hospital, Jinhua, Zhejiang, China
| | - Wenjing Zheng
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Fundus Disease, Shanghai, China
| | - Qing Gu
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Fundus Disease, Shanghai, China
| | - Xun Xu
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Fundus Disease, Shanghai, China
- * E-mail: (XX); (BK)
| | - Bilian Ke
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Fundus Disease, Shanghai, China
- * E-mail: (XX); (BK)
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Smith EL, Hung LF, Arumugam B, Huang J. Negative lens-induced myopia in infant monkeys: effects of high ambient lighting. Invest Ophthalmol Vis Sci 2013; 54:2959-69. [PMID: 23557736 DOI: 10.1167/iovs.13-11713] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE To determine whether high light levels, which have a protective effect against form-deprivation myopia, also retard the development of lens-induced myopia in primates. METHODS Hyperopic defocus was imposed on 27 monkeys by securing -3 diopter (D) lenses in front of one eye. The lens-rearing procedures were initiated at 24 days of age and continued for periods ranging from 50 to 123 days. Fifteen of the treated monkeys were exposed to normal laboratory light levels (∼350 lux). For the other 12 lens-reared monkeys, auxiliary lighting increased the illuminance to 25,000 lux for 6 hours during the middle of the daily 12 hour light cycle. Refractive development, corneal power, and axial dimensions were assessed by retinoscopy, keratometry, and ultrasonography, respectively. Data were also obtained from 37 control monkeys, four of which were exposed to high ambient lighting. RESULTS in normal- and high-light-reared monkeys, hyperopic defocus accelerated vitreous chamber elongation and produced myopic shifts in refractive error. the high light regimen did not alter the degree of myopia (high light: -1.69 ± 0.84 D versus normal light: -2.08 ± 1.12 D; P = 0.40) or the rate at which the treated eyes compensated for the imposed defocus. Following lens removal, the high light monkeys recovered from the induced myopia. The recovery process was not affected by the high lighting regimen. CONCLUSIONS In contrast to the protective effects that high ambient lighting has against form-deprivation myopia, high artificial lighting did not alter the course of compensation to imposed defocus. These results indicate that the mechanisms responsible for form-deprivation myopia and lens-induced myopia are not identical.
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Affiliation(s)
- Earl L Smith
- College of Optometry, University of Houston, Houston, TX 77204-2020, USA.
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Nie HH, Huo LJ, Yang X, Gao ZY, Zeng JW, Trier K, Cui DM. Effects of 7-methylxanthine on form-deprivation myopia in pigmented rabbits. Int J Ophthalmol 2012; 5:133-7. [PMID: 22762036 DOI: 10.3980/j.issn.2222-3959.2012.02.03] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 03/31/2012] [Indexed: 11/02/2022] Open
Abstract
AIM To determine the effect of 7-methylxanthine (7-MX) on the posterior sclera of form-deprivation myopia (FDM) in pigmented rabbits. METHODS Sixteen pigmented rabbits were monocularly deprived (MD) by suturing the right eyelids after natural eye opening (ten-day old) for a period of 30 days. Two groups of pigmented rabbits were fed either 7-MX (30 mg per kg body weight; n=8) or vehicle control (saline equal volume with 7-MX; n=8). Ocular refractions, axial lengths and body weights were measured at the start and the end of the experiment 30 days later. Electron microscopy was used to measure and determine the collagen fibril diameters in the posterior pole of sclera. RESULTS In vehicle control MD pigmented rabbits, 30 days of MD produced -1.10D±0.78D of myopia and the axial length increased 0.51mm±0.09mm. In MD pigmented rabbits fed with 7-MX, 30 days of MD induced only -0.21D±0.11D of myopia and the axial length increased 0.07mm±0.10mm. There was significant change in axial length of vehicle control MD pigmented rabbits (13.11mm±0.19mm versus 12.60mm±0.06mm; P=0.03). The changes in refraction and axial length of two MD groups' contralateral eyes during the 30 days were not significantly different (2.75D±0.27D versus 2.75D±0.35D, P>0.05; 12.60mm±0.06mm versus 12.45mm±0.14mm, P>0.05). The weights of the two groups pigmented rabbits had no significant changes (187g±22.1g versus 189g±19.3g, P>0.05). The diameter of scleral collagen fibers increased in both eyes of 7-MX treated pigmented rabbits. There was significant difference in collagen fibril diameters of inner layer (111.34nm±28.30nm versus 94.80nm±27.52nm, P=0.002) and outer layer (167.92nm±55.82 nm versus 144.04 nm±47.02nm, P=0.016) in the posterior sclera between the myopic eyes of vehicle control MD group and contralateral eyes of 7-MX treated MD group. CONCLUSION 7-MX appears to prevent FDM in pigmented rabbits by remodeling the posterior sclera.
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Affiliation(s)
- Hao-Hui Nie
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, SunYat-sen University, Guangzhou 510060, Guangdong Province, China
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Yang JW, Xu YC, Sun L, Tian XD. 5-hydroxytryptamine level and 5-HT2A receptor mRNA expression in the guinea pigs eyes with spectacle lens-induced myopia. Int J Ophthalmol 2010; 3:299-303. [PMID: 22553578 DOI: 10.3980/j.issn.2222-3959.2010.04.05] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 11/18/2010] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate 5-hydroxytryptamine (5-HT) function and 5-HT receptor 2A (5-HT2A) mRNA expression in the formation of lens-induced myopia (LIM). METHODS Lens-induced myopia construction method was applied to generate myopia on guinea pig right eye (LIM eye). RESULTS LIM eyes formed significant myopia with longer axial length. 5-HT level in retina, choroids and sclera from LIM eyes was significantly higher than that in control group. 5-HT2A mRNA expression was also significantly up-regulated. CONCLUSION Refraction lens could induce myopia in guinea pig and 5-HT may play an important role in the formation of myopia by binding with 5-HT2A receptor.
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Affiliation(s)
- Ji-Wen Yang
- Department of Ophthalmology, the First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
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Qian YS, Chu RY, Hu M, Hoffman MR. Sonic hedgehog expression and its role in form-deprivation myopia in mice. Curr Eye Res 2009; 34:623-35. [PMID: 19899989 DOI: 10.1080/02713680903003492] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE To investigate whether sonic hedgehog (Shh) plays a role in postnatal eye development and the development of experimentally induced myopia. METHODS Expression of Shh, Patched-1 (Ptc-1), and Gli3 was evaluated in the eyes of 13- to 14-day-old C57B/L6 mice with form-deprivation myopia (FDM) (n = 100) and controls (n = 100) using real-time PCR and Western blot analysis. In a second experiment, 336 mice were divided into two groups: the first wore a unilateral translucent diffuser to induce myopia and the second served as a control. Both groups received four intravitreal injections of either Shh-N (Sonic hedgehog amino-terminal peptide) or cyclopamine (a specific inhibitor of the Shh pathway) every other day. Retinoscopic refraction and axial length measurements were performed on the 11th day of form deprivation. Sections of the eyes were observed using a light microscope. RESULTS Inducing myopia caused a significant increase in expression of Shh mRNA (7 days: t = 6.09, p = 0.004; 14 days: t = 3.48, p = 0.025) and protein (7 days: t = 4.06, p = 0.015; 14 days: t = 4.25, p = 0.013). Expression of both Gli3 mRNA (t = 7.61, p = 0.002) and protein (t = 2.89, p = 0.045) increased after 7 days of occlusion. Administration of Shh-N stimulated the development of myopia and axial growth in both occluded (refraction: F = 7.49, p = 0.001; axial length: F = 9.89, p < 0.001) and non-occluded eyes (refraction: F = 14.20, p < 0.001; axial length: F = 20.37, p < 0.001). Cyclopamine reduced myopic refractive error and axial elongation in occluded eyes (refraction: F = 27.91, p < 0.001; axial length: F = 15.18, p < 0.001). It also influenced non-occluded eyes, reducing axial growth and shifting the refraction toward hyperopia (refraction: F = 14.81, p < 0.001; axial length: F = 3.99, p = 0.024). No difference in retinal thickness was found between experimental and control eyes. CONCLUSIONS The Shh signaling pathway may influence both form-deprivation myopia and the postnatal growth of eyes with normal visual input.
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Affiliation(s)
- Yi-Shan Qian
- Department of Ophthalmology, Eye, Ear, Nose, Throat Hospital, Fudan University, Shanghai Medical College, Shanghai
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Troilo D, Nickla DL, Mertz JR, Summers Rada JA. Change in the synthesis rates of ocular retinoic acid and scleral glycosaminoglycan during experimentally altered eye growth in marmosets. Invest Ophthalmol Vis Sci 2006; 47:1768-77. [PMID: 16638980 PMCID: PMC1892188 DOI: 10.1167/iovs.05-0298] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The purpose of this study was to examine the possibility that all-trans-retinoic acid (RA) in the eye is a signal related to changes in scleral extracellular matrix in a primate model of postnatal eye growth. METHODS Juvenile marmosets (Callithrix jacchus) were divided into two experimental groups based on their response to monocular deprivation with diffusers: group 1, treated eyes becoming longer than fellow control eyes (n = 8), and group 2, treated eyes becoming shorter than control eyes (n = 7). Eyes were enucleated, dissected, and assayed for changes in the rates of scleral glycosaminoglycan (GAG) synthesis and ocular RA synthesis. The rate of incorporation of (35)SO4 into CPC-precipitable GAG in scleras was taken as a measure of the rate of synthesis of proteoglycans. In the same eyes the rate of RA synthesis in vivo was measured separately in the retina and the choroid/RPE (choroid with RPE attached) by HPLC. The effect of RA on the rate of scleral GAG synthesis was also examined in tissue-cultured pieces of sclera from additional marmosets. RESULTS Induced changes in vitreous chamber length in diffuser-treated eyes correlated inversely with the rate of scleral GAG synthesis (P < 0.05) and directly correlated with the rate of RA synthesis measured separately in the retina (P < 0.05) and the choroid/RPE (P < 0.05). In group 1, the rate of scleral GAG synthesis was significantly lower (P < 0.01) in the treated eyes relative to control eyes, and the rate of RA synthesis in both the retina and the choroid/RPE was significantly higher (P < 0.01). In group 2, the rates of scleral GAG synthesis and RA synthesis in either the retina or choroid/RPE were not found to change significantly in the treated eyes compared with the control eyes. RA partially reduces the rate of scleral GAG synthesis in tissue-cultured primate sclera in a dose-dependent manner after several days. CONCLUSIONS RA may play a role in the visual control of postnatal eye growth in primates, possibly by inducing changes in scleral extracellular matrix associated with increasing eye size. Decreasing growth rate below control levels may involve other mechanisms.
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Affiliation(s)
- David Troilo
- Department of Biomedical Science and Disease, The New England College of Optometry, Boston, Massachusetts 02115, USA.
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