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Chauhan MZ, Elhusseiny AM, Kishor KS, Sanvicente CT, Ali AA, Sallam AB, Bhattacharya SK, Uwaydat SH. Association of Primary Open-Angle Glaucoma with Diabetic Retinopathy among Patients with Type 1 and Type 2 Diabetes: A Large Global Database Study. Ophthalmology 2024; 131:827-835. [PMID: 38215989 DOI: 10.1016/j.ophtha.2024.01.016] [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: 08/12/2023] [Revised: 12/30/2023] [Accepted: 01/05/2024] [Indexed: 01/14/2024] Open
Abstract
PURPOSE To assess the correlation between primary open-angle glaucoma (POAG) and the risk of developing diabetic retinopathy (DR) in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). DESIGN A retrospective cohort study leveraging the global patient database of TriNetX Research Network. PARTICIPANTS The study included 44 359 patients with diabetes mellitus (DM) with POAG and 4 393 300 patients with DM without any glaucoma ≥ 18 years of age. Propensity score matching harmonized the cohorts to 39 680 patients each, covering diagnoses from January 1, 2005, to January 1, 2023. METHODS We analyzed data using specific International Classification of Diseases, 10th Revision (ICD-10) codes for DM and glaucoma. We matched the cohorts using propensity score matching, adjusting for age, sex, race/ethnicity, blood markers, relevant medical history, and ophthalmic service use. MAIN OUTCOME MEASURES The primary outcome was the first-time occurrence of DR, including nonproliferative DR (NPDR) and proliferative DR (PDR), in patients with DM with and without glaucoma at 1-, 5-, and 10-year intervals from their individual index dates. RESULTS At 10 years, patients with T1DM with POAG exhibited a heightened risk for any DR (adjusted risk ratios [RRs], 4.12; 95% confidence interval [CI], 3.05-5.57, P < 0.0001) and PDR (RR, 7.02; 95% CI, 3.62-13.61, P < 0.0001). Patients with T2DM and POAG also faced an increased 10-year risk for any DR (RR, 2.47; 95% CI, 2.28-2.68, P < 0.0001) and PDR (RR, 3.82; 95% CI, 3.09-4.70, P < 0.0001). The combined association of POAG on DR risk in those with T1DM and T2DM at 10 years was found to be significantly higher among patients with POAG (5.45%) compared with those without glaucoma (2.12%) (adjusted hazard ratio [aHR], 2.33; 95% CI, 2.14-2.53). The cumulative incidence of DR was significantly higher in the POAG group compared with nonglaucoma counterparts after a decade (log-rank P < 0.001). CONCLUSIONS Our findings underscore a substantial association between POAG and DR development in both T1DM and T2DM patients, emphasizing the need for vigilant screening and comprehensive management in glaucomatous patients with DM to mitigate the risk of DR. Future research should delve into elucidating the causal mechanisms driving these observed associations. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
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Affiliation(s)
- Muhammad Z Chauhan
- Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Abdelrahman M Elhusseiny
- Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Krishna S Kishor
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Palm Beach Gardens, Florida
| | - Carina T Sanvicente
- Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Arsalan A Ali
- Anne Burnett Marion School of Medicine, Fort Worth, Texas
| | - Ahmed B Sallam
- Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Sanjoy K Bhattacharya
- Miami Integrative Metabolomics Research Center, Bascom Palmer Eye Institute, University of Miami, Miami, Florida
| | - Sami H Uwaydat
- Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
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Zheng Z, Yu X. Insulin resistance in the retina: possible implications for certain ocular diseases. Front Endocrinol (Lausanne) 2024; 15:1415521. [PMID: 38952394 PMCID: PMC11215121 DOI: 10.3389/fendo.2024.1415521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 06/05/2024] [Indexed: 07/03/2024] Open
Abstract
Insulin resistance (IR) is becoming a worldwide medical and public health challenge as an increasing prevalence of obesity and metabolic disorders. Accumulated evidence has demonstrated a strong relationship between IR and a higher incidence of several dramatically vision-threatening retinal diseases, including diabetic retinopathy, age-related macular degeneration, and glaucoma. In this review, we provide a schematic overview of the associations between IR and certain ocular diseases and further explore the possible mechanisms. Although the exact causes explaining these associations have not been fully elucidated, underlying mechanisms of oxidative stress, chronic low-grade inflammation, endothelial dysfunction and vasoconstriction, and neurodegenerative impairments may be involved. Given that IR is a modifiable risk factor, it may be important to identify patients at a high IR level with prompt treatment, which may decrease the risk of developing certain ocular diseases. Additionally, improving IR through the activation of insulin signaling pathways could become a potential therapeutic target.
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Affiliation(s)
- Zhaoxia Zheng
- Department of Ophthalmology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
| | - Xiaobing Yu
- Department of Ophthalmology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
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3
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Pang JJ. The Variety of Mechanosensitive Ion Channels in Retinal Neurons. Int J Mol Sci 2024; 25:4877. [PMID: 38732096 PMCID: PMC11084373 DOI: 10.3390/ijms25094877] [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: 02/27/2024] [Revised: 04/16/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
Alterations in intraocular and external pressure critically involve the pathogenesis of glaucoma, traumatic retinal injury (TRI), and other retinal disorders, and retinal neurons have been reported to express multiple mechanical-sensitive channels (MSCs) in recent decades. However, the role of MSCs in visual functions and pressure-related retinal conditions has been unclear. This review will focus on the variety and functional significance of the MSCs permeable to K+, Na+, and Ca2+, primarily including the big potassium channel (BK); the two-pore domain potassium channels TRAAK and TREK; Piezo; the epithelial sodium channel (ENaC); and the transient receptor potential channels vanilloid TRPV1, TRPV2, and TRPV4 in retinal photoreceptors, bipolar cells, horizontal cells, amacrine cells, and ganglion cells. Most MSCs do not directly mediate visual signals in vertebrate retinas. On the other hand, some studies have shown that MSCs can open in physiological conditions and regulate the activities of retinal neurons. While these data reasonably predict the crossing of visual and mechanical signals, how retinal light pathways deal with endogenous and exogenous mechanical stimulation is uncertain.
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Affiliation(s)
- Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA
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4
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Ung DC, Pietrancosta N, Badillo EB, Raux B, Tapken D, Zlatanovic A, Doridant A, Pode-Shakked B, Raas-Rothschild A, Elpeleg O, Abu-Libdeh B, Hamed N, Papon MA, Marouillat S, Thépault RA, Stevanin G, Elegheert J, Letellier M, Hollmann M, Lambolez B, Tricoire L, Toutain A, Hepp R, Laumonnier F. GRID1/GluD1 homozygous variants linked to intellectual disability and spastic paraplegia impair mGlu1/5 receptor signaling and excitatory synapses. Mol Psychiatry 2024; 29:1205-1215. [PMID: 38418578 PMCID: PMC11176079 DOI: 10.1038/s41380-024-02469-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 03/01/2024]
Abstract
The ionotropic glutamate delta receptor GluD1, encoded by the GRID1 gene, is involved in synapse formation, function, and plasticity. GluD1 does not bind glutamate, but instead cerebellin and D-serine, which allow the formation of trans-synaptic bridges, and trigger transmembrane signaling. Despite wide expression in the nervous system, pathogenic GRID1 variants have not been characterized in humans so far. We report homozygous missense GRID1 variants in five individuals from two unrelated consanguineous families presenting with intellectual disability and spastic paraplegia, without (p.Thr752Met) or with (p.Arg161His) diagnosis of glaucoma, a threefold phenotypic association whose genetic bases had not been elucidated previously. Molecular modeling and electrophysiological recordings indicated that Arg161His and Thr752Met mutations alter the hinge between GluD1 cerebellin and D-serine binding domains and the function of this latter domain, respectively. Expression, trafficking, physical interaction with metabotropic glutamate receptor mGlu1, and cerebellin binding of GluD1 mutants were not conspicuously altered. Conversely, upon expression in neurons of dissociated or organotypic slice cultures, we found that both GluD1 mutants hampered metabotropic glutamate receptor mGlu1/5 signaling via Ca2+ and the ERK pathway and impaired dendrite morphology and excitatory synapse density. These results show that the clinical phenotypes are distinct entities segregating in the families as an autosomal recessive trait, and caused by pathophysiological effects of GluD1 mutants involving metabotropic glutamate receptor signaling and neuronal connectivity. Our findings unravel the importance of GluD1 receptor signaling in sensory, cognitive and motor functions of the human nervous system.
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Affiliation(s)
- Dévina C Ung
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France
| | - Nicolas Pietrancosta
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
- Laboratoire des biomolécules, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
| | | | - Brigitt Raux
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Daniel Tapken
- Department of Biochemistry I - Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780, Bochum, Germany
| | - Andjela Zlatanovic
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Adrien Doridant
- Univ. Bordeaux, CNRS, IINS, UMR 5297, F-33000, Bordeaux, France
| | - Ben Pode-Shakked
- The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
- Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, 5262000, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Annick Raas-Rothschild
- The Institute for Rare Diseases, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Bassam Abu-Libdeh
- Department of Pediatrics, Makassed Hospital and Faculty of Medicine, Al-Quds University, East Jerusalem, Jerusalem, Palestine
| | - Nasrin Hamed
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hahsomer, 5262000, Israel
| | | | | | | | - Giovanni Stevanin
- Univ. Bordeaux, INCIA, UMR 5287 CNRS EPHE, F-33000, Bordeaux, France
| | | | | | - Michael Hollmann
- Department of Biochemistry I - Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780, Bochum, Germany
| | - Bertrand Lambolez
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Ludovic Tricoire
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France
| | - Annick Toutain
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France.
- Unité fonctionnelle de Génétique Médicale, Centre Hospitalier Universitaire, 37044, Tours, France.
| | - Régine Hepp
- Sorbonne Université, INSERM, CNRS, Neuroscience Paris Seine - Institut de Biologie Paris Seine, 75005, Paris, France.
| | - Frédéric Laumonnier
- UMR 1253, iBrain, Université de Tours, Inserm, 37032, Tours, France.
- Service de Génétique, Centre Hospitalier Universitaire, 37044, Tours, France.
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Yao K, Mou Q, Lou X, Ye M, Zhao B, Hu Y, Luo J, Zhang H, Li X, Zhao Y. Microglial SIRT1 activation attenuates synapse loss in retinal inner plexiform layer via mTORC1 inhibition. J Neuroinflammation 2023; 20:202. [PMID: 37670386 PMCID: PMC10481494 DOI: 10.1186/s12974-023-02886-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/30/2023] [Indexed: 09/07/2023] Open
Abstract
BACKGROUND Optic nerve injury (ONI) is a key cause of irreversible blindness and triggers retinal ganglion cells (RGCs) change and synapse loss. Microglia is the resistant immune cell in brain and retina and has been demonstrated to be highly related with neuron and synapse injury. However, the function of Sirtuin 1 (SIRT1), a neuroprotective molecule, in mediating microglial activation, retinal synapse loss and subsequent retinal ganglion cells death in optic nerve injury model as well as the regulatory mechanism remain unclear. METHOD To this end, optic nerve crush (ONC) model was conducted to mimic optic nerve injury. Resveratrol and EX527, highly specific activator and inhibitor of SIRT1, respectively, were used to explore the function of SIRT1 in vivo and vitro. Cx3Cr1-CreERT2/RaptorF/F mice were used to delete Raptor for inhibiting mammalian target of rapamycin complex 1 (mTORC1) activity in microglia. HEK293 and BV2 cells were transfected with plasmids to explore the regulatory mechanism of SIRT1. RESULTS We discovered that microglial activation and synapse loss in retinal inner plexiform layer (IPL) occurred after optic nerve crush, with later-development retinal ganglion cells death. SIRT1 activation induced by resveratrol inhibited microglial activation and attenuated synapse loss and retinal ganglion cells injury. After injury, microglial phagocytosed synapse and SIRT1 inhibited this process to protect synapse and retinal ganglion cells. Moreover, SIRT1 exhibited neuron protective effects via activating tuberous sclerosis complex 2 (TSC2) through deacetylation, and enhancing the inhibition effect of tuberous sclerosis complex 2 on mammalian target of rapamycin complex 1 activity. CONCLUSION Our research provides novel insights into microglial SIRT1 in optic nerve injury and suggests a potential strategy for neuroprotective treatment of optic nerve injury disease.
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Affiliation(s)
- Ke Yao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qianxue Mou
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiaotong Lou
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Meng Ye
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Bowen Zhao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yuanyuan Hu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jing Luo
- Institute of Reproductive Health, Center for Reproductive Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xing Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Yin Zhao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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6
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Tribble JR, Hui F, Quintero H, El Hajji S, Bell K, Di Polo A, Williams PA. Neuroprotection in glaucoma: Mechanisms beyond intraocular pressure lowering. Mol Aspects Med 2023; 92:101193. [PMID: 37331129 DOI: 10.1016/j.mam.2023.101193] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/25/2023] [Accepted: 06/04/2023] [Indexed: 06/20/2023]
Abstract
Glaucoma is a common, complex, multifactorial neurodegenerative disease characterized by progressive dysfunction and then loss of retinal ganglion cells, the output neurons of the retina. Glaucoma is the most common cause of irreversible blindness and affects ∼80 million people worldwide with many more undiagnosed. The major risk factors for glaucoma are genetics, age, and elevated intraocular pressure. Current strategies only target intraocular pressure management and do not directly target the neurodegenerative processes occurring at the level of the retinal ganglion cell. Despite strategies to manage intraocular pressure, as many as 40% of glaucoma patients progress to blindness in at least one eye during their lifetime. As such, neuroprotective strategies that target the retinal ganglion cell and these neurodegenerative processes directly are of great therapeutic need. This review will cover the recent advances from basic biology to on-going clinical trials for neuroprotection in glaucoma covering degenerative mechanisms, metabolism, insulin signaling, mTOR, axon transport, apoptosis, autophagy, and neuroinflammation. With an increased understanding of both the basic and clinical mechanisms of the disease, we are closer than ever to a neuroprotective strategy for glaucoma.
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Affiliation(s)
- James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia; Department of Optometry & Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Heberto Quintero
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Sana El Hajji
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Katharina Bell
- NHMRC Clinical Trials Centre, University of Sydney, Australia; Eye ACP Duke-NUS, Singapore
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
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Sharif NA. Identifying new drugs and targets to treat rapidly elevated intraocular pressure for angle closure and secondary glaucomas to curb visual impairment and prevent blindness. Exp Eye Res 2023; 232:109444. [PMID: 36958427 DOI: 10.1016/j.exer.2023.109444] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/23/2023] [Accepted: 03/16/2023] [Indexed: 03/25/2023]
Abstract
A multitude of pharmacological compounds have been shown to lower and control intraocular pressure (IOP) in numerous species of animals and human subjects after topical ocular dosing or via other routes of administration. Most researchers have been interested in finding drug candidates that exhibit a relatively long duration of action from a chronic therapeutic use perspective, for example to treat ocular hypertension (OHT), primary open-angle glaucoma and even normotensive glaucoma. However, it is equally important to seek and characterize treatment modalities which offer a rapid onset of action to help provide fast relief from quickly rising IOP that occurs in certain eye diseases. These include acute angle-closure glaucoma, primary angle-closure glaucoma, uveitic and inflammatory glaucoma, medication-induced OHT, and other secondary glaucomas induced by eye injury or infection which can cause partial or complete loss of eyesight. Such fast-acting agents can delay or prevent the need for ocular surgery which is often used to lower the dangerously raised IOP. This research survey was therefore directed at identifying agents from the literature that demonstrated ocular hypotensive activity, normalizing and unifying the data, determining their onset of action and rank ordering them on the basis of rapidity of action starting within 30-60 min and lasting up to at least 3-4 h post topical ocular dosing in different animal species. This research revealed a few health authority-approved drugs and some investigational compounds that appear to meet the necessary criteria of fast onset of action coupled with significant efficacy to reduce elevated IOP (by ≥ 20%, preferably by >30%). However, translation of the novel animal-based findings to the human conditions remains to be demonstrated but represent viable targets, especially EP2-receptor agonists (e.g. omidenepag isopropyl; AL-6598; butaprost), mixed activity serotonin/dopamine receptor agonists (e.g. cabergoline), rho kinase inhibitors (e.g. AMA0076, Y39983), CACNA2D1-gene product inhibitors (e.g. pregabalin), melatonin receptor agonists, and certain K+-channel openers (e.g. nicorandil, pinacidil). Other drug candidates and targets were also identified and will be discussed.
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Affiliation(s)
- Najam A Sharif
- Institute of Ophthalmology, University College London (UCL), London, UK; Imperial College of Science and Technology, St. Mary's Campus, London, UK; Eye-ACP Duke-National University of Singapore Medical School, Singapore; Singapore Eye Research Institute (SERI), Singapore; Department of Pharmacy Sciences, Creighton University, Omaha, NE, USA; Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center, Fort Worth, Texas, USA; Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, Texas, USA; Ophthalmology Innovation Center, Santen Inc USA, Emeryville, CA, USA.
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8
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Loss of Retinogeniculate Synaptic Function in the DBA/2J Mouse Model of Glaucoma. eNeuro 2022; 9:ENEURO.0421-22.2022. [PMID: 36526366 PMCID: PMC9794376 DOI: 10.1523/eneuro.0421-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/22/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Retinal ganglion cell (RGC) axons comprise the optic nerve and carry information to the dorsolateral geniculate nucleus (dLGN), which is then relayed to the cortex for conscious vision. Glaucoma is a blinding neurodegenerative disease that commonly results from intraocular pressure (IOP)-associated injury leading to RGC axonal pathology, disruption of RGC outputs to the brain, and eventual apoptotic loss of RGC somata. The consequences of elevated IOP and glaucomatous pathology on RGC signaling to the dLGN are largely unknown yet are likely to contribute to vision loss. Here, we used anatomic and physiological approaches to study the structure and function of retinogeniculate (RG) synapses in male and female DBA/2J (D2) mice with inherited glaucoma before and after IOP elevation. D2 mice showed progressive loss of anterograde optic tract transport to the dLGN and vGlut2 labeling of RGC axon terminals while patch-clamp measurements of RG synaptic function showed that synaptic transmission was reduced in 9-month and 12-month D2 mice because of the loss of individual RGC axon inputs. TC neuron dendrites had reduced Sholl complexity at 12 months, suggestive of delayed reorganization following reduced synaptic input. There was no detectable change in RGC density in 11- to 12-month D2 retinas, quantified as the number of ganglion cell layer-residing somata immuno-positive for NeuN and immuno-negative for the amacrine marker choline acetyltransferase (ChAT). Thus, observed synaptic defects appear to precede RGC somatic loss. These findings identify glaucoma-associated and IOP-associated deficits in an important subcortical RGC projection target, shedding light on processes linking IOP to vision loss.
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9
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Garner MA, Strickland RG, Girkin CA, Gross AK. Mechanisms of retinal ganglion cell injury following acute increases in intraocular pressure. FRONTIERS IN OPHTHALMOLOGY 2022; 2:1007103. [PMID: 38983517 PMCID: PMC11182138 DOI: 10.3389/fopht.2022.1007103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/26/2022] [Indexed: 07/11/2024]
Abstract
The maintenance of intraocular pressure (IOP) is critical to preserving the pristine optics required for vision. Disturbances in IOP can directly impact the optic nerve and retina, and inner retinal injury can occur following acute and chronic IOP elevation. There are a variety of animal models that have been developed to study the effects of acute and chronic elevation of IOP on the retina, retinal ganglion cell (RGC) morphology, intracellular signaling, gene expression changes, and survival. Acute IOP models induce injury that allows for the study of RGC response to well characterized injury and potential recovery. This review will focus on the initial impact of acute IOP elevation on RGC injury and recovery as these early responses may be the best targets for potential therapeutic interventions to promote RGC survival in glaucoma.
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Affiliation(s)
- Mary Anne Garner
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ryan G. Strickland
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Christopher A. Girkin
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Alecia K. Gross
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
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10
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Evaluation of the segmented inner retinal layers in exfoliation glaucoma. Int Ophthalmol 2022; 43:1841-1848. [DOI: 10.1007/s10792-022-02583-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 11/12/2022] [Indexed: 11/24/2022]
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11
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Van Hook MJ. Influences of Glaucoma on the Structure and Function of Synapses in the Visual System. Antioxid Redox Signal 2022; 37:842-861. [PMID: 35044228 PMCID: PMC9587776 DOI: 10.1089/ars.2021.0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/31/2021] [Indexed: 11/12/2022]
Abstract
Significance: Glaucoma is an age-related neurodegenerative disorder of the visual system associated with sensitivity to intraocular pressure (IOP). It is the leading irreversible cause of vision loss worldwide, and vision loss results from damage and dysfunction of the retinal output neurons known as retinal ganglion cells (RGCs). Recent Advances: Elevated IOP and optic nerve injury triggers pruning of RGC dendrites, altered morphology of excitatory inputs from presynaptic bipolar cells, and disrupted RGC synaptic function. Less is known about RGC outputs, although evidence to date indicates that glaucoma is associated with altered mitochondrial and synaptic structure and function in RGC-projection targets in the brain. These early functional changes likely contribute to vision loss and might be a window into early diagnosis and treatment. Critical Issues: Glaucoma affects different RGC populations to varying extents and along distinct time courses. The influence of glaucoma on RGC synaptic function as well as the mechanisms underlying these effects remain to be determined. Since RGCs are an especially energetically demanding population of neurons, altered intracellular axon transport of mitochondria and mitochondrial function might contribute to RGC synaptic dysfunction in the retina and brain as well as RGC vulnerability in glaucoma. Future Directions: The mechanisms underlying differential RGC vulnerability remain to be determined. Moreover, the timing and mechanisms of RGCs synaptic dysfunction and degeneration will provide valuable insight into the disease process in glaucoma. Future work will be able to capitalize on these findings to better design diagnostic and therapeutic approaches to detect disease and prevent vision loss. Antioxid. Redox Signal. 37, 842-861.
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Affiliation(s)
- Matthew J. Van Hook
- Department of Ophthalmology & Visual Science and Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Department of Cellular & Integrative Physiology, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
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12
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Tirsi A, Wong A, Zhu D, Stoffels G, Derr P, Tello MD C. Pattern Electroretinogram Parameters and their Associations with Optical Coherence Tomography in Glaucoma Suspects. J Curr Glaucoma Pract 2022; 16:96-104. [PMID: 36128077 PMCID: PMC9452702 DOI: 10.5005/jp-journals-10078-1365] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/06/2021] [Indexed: 11/23/2022] Open
Abstract
Aim To investigate whether steady state pattern electroretinogram (ssPERG) could identify retinal ganglion cell (RGC) dysfunction, and to assess the relationship between ssPERG with optical coherence tomography (OCT) measurements in glaucoma suspects (GS). Materials and methods This was a prospective cohort study of GS, identified based on suspicious optic disk appearance and glaucoma risk factors. Complete eye exam, Standard automated perimetry, OCT, and ssPERG were performed. Magnitude (Mag), Magnitude D (MagD), and MagD/Mag ratio were subsequently used in the correlation and linear regression analyses between ssPERG parameters and the RNFL, GCL/IPL, and macular thicknesses measurements. Results Forty-nine eyes of 26 patients were included. Mag and MagD were significantly correlated with the superior, inferior, and average RNFL thicknesses (avRNFLT). All ssPERG parameters were significantly correlated with the average and minimum GCL/IPL thicknesses and the inner macular sector thicknesses. Mag and MagD significantly predicted the superior, inferior, and avRNFLT in the regression analysis. All ssPERG parameters were predictive of GCL/IPL thickness in all sectors as well as the average and minimum GCL/IPL thicknesses. All ssPERG parameters were predictive of all inner macular sector thicknesses and MagD was also predictive of some outer macular sector thicknesses as well. Conclusion ssPERG has significant correlations with and is predictive of RNFL, GCL/IPL, and macular thicknesses in glaucoma suspects. Clinical significance ssPERG may serve as a useful objective functional tool for identifying and following the progression of disease in glaucoma suspects. How to cite this article Tirsi A, Wong A, Zhu D, et al. Pattern Electroretinogram Parameters and their Associations with Optical Coherence Tomography in Glaucoma Suspects. J Curr Glaucoma Pract 2022;16(2):96-104.
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Affiliation(s)
- Andrew Tirsi
- Department of Ophthalmology, Manhattan Eye, Ear, & Throat Hospital, Northwell Health, New York, United States; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States
- Andrew Tirsi, Department of Ophthalmology, Manhattan Eye, Ear, & Throat Hospital, Northwell Health, New York, United States; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States, Phone: 1 (201) 982 4168, e-mail:
| | - Amanda Wong
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States
| | - Daniel Zhu
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States
| | - Guillaume Stoffels
- Lennox Hill Hospital/Northwell, Feinstein Institute for Medical Research, New York, United States
| | - Peter Derr
- Diopsys, Inc., Pine Brook, NJ, United States
| | - Celso Tello MD
- Department of Ophthalmology, Manhattan Eye, Ear, & Throat Hospital, Northwell Health, New York, United States; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, United States
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13
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Godini R, Fallahi H, Pocock R. The regulatory landscape of neurite development in Caenorhabditis elegans. Front Mol Neurosci 2022; 15:974208. [PMID: 36090252 PMCID: PMC9453034 DOI: 10.3389/fnmol.2022.974208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/26/2022] [Indexed: 11/18/2022] Open
Abstract
Neuronal communication requires precise connectivity of neurite projections (axons and dendrites). Developing neurites express cell-surface receptors that interpret extracellular cues to enable correct guidance toward, and connection with, target cells. Spatiotemporal regulation of neurite guidance molecule expression by transcription factors (TFs) is critical for nervous system development and function. Here, we review how neurite development is regulated by TFs in the Caenorhabditis elegans nervous system. By collecting publicly available transcriptome and ChIP-sequencing data, we reveal gene expression dynamics during neurite development, providing insight into transcriptional mechanisms governing construction of the nervous system architecture.
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Affiliation(s)
- Rasoul Godini
- Development and Stem Cells Program, Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
- *Correspondence: Rasoul Godini,
| | - Hossein Fallahi
- Department of Biology, School of Sciences, Razi University, Kermanshah, Iran
| | - Roger Pocock
- Development and Stem Cells Program, Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
- Roger Pocock,
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14
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Niu F, Han P, Zhang J, She Y, Yang L, Yu J, Zhuang M, Tang K, Shi Y, Yang B, Liu C, Peng B, Ji SJ. The m 6A reader YTHDF2 is a negative regulator for dendrite development and maintenance of retinal ganglion cells. eLife 2022; 11:75827. [PMID: 35179492 PMCID: PMC8906807 DOI: 10.7554/elife.75827] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/16/2022] [Indexed: 11/29/2022] Open
Abstract
The precise control of growth and maintenance of the retinal ganglion cell (RGC) dendrite arborization is critical for normal visual functions in mammals. However, the underlying mechanisms remain elusive. Here, we find that the N6-methyladenosine (m6A) reader YTHDF2 is highly expressed in the mouse RGCs. Conditional knockout (cKO) of Ythdf2 in the retina leads to increased RGC dendrite branching, resulting in more synapses in the inner plexiform layer. Interestingly, the Ythdf2 cKO mice show improved visual acuity compared with control mice. We further demonstrate that Ythdf2 cKO in the retina protects RGCs from dendrite degeneration caused by the experimental acute glaucoma model. We identify the m6A-modified YTHDF2 target transcripts which mediate these effects. This study reveals mechanisms by which YTHDF2 restricts RGC dendrite development and maintenance. YTHDF2 and its target mRNAs might be valuable in developing new treatment approaches for glaucomatous eyes.
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Affiliation(s)
- Fugui Niu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Peng Han
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Jian Zhang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Yuanchu She
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Lixin Yang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Jun Yu
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Mengru Zhuang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Kezhen Tang
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yuwei Shi
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Baisheng Yang
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Chunqiao Liu
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Bo Peng
- Department of Neurosurgery, Fudan University, Shanghai, China
| | - Sheng-Jian Ji
- Department of Biology, Southern University of Science and Technology, Shenzhen, China
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15
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Pericyte dysfunction and loss of interpericyte tunneling nanotubes promote neurovascular deficits in glaucoma. Proc Natl Acad Sci U S A 2022; 119:2110329119. [PMID: 35135877 PMCID: PMC8851476 DOI: 10.1073/pnas.2110329119] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2021] [Indexed: 12/14/2022] Open
Abstract
Reduced blood flow and impaired neurovascular coupling are recognized features of glaucoma, the leading cause of irreversible blindness worldwide, but the mechanisms underlying these defects are unknown. Retinal pericytes regulate microcirculatory blood flow and coordinate neurovascular coupling through interpericyte tunneling nanotubes (IP-TNTs). Using two-photon microscope live imaging of the mouse retina, we found reduced capillary diameter and impaired blood flow at pericyte locations in eyes with high intraocular pressure, the most important risk factor to develop glaucoma. We show that IP-TNTs are structurally and functionally damaged by ocular hypertension, a response that disrupted light-evoked neurovascular coupling. Pericyte-specific inhibition of excessive Ca2+ influx rescued hemodynamic responses, protected IP-TNTs and neurovascular coupling, and enhanced retinal neuronal function as well as survival in glaucomatous retinas. Our study identifies pericytes and IP-TNTs as potential therapeutic targets to counter ocular pressure-related microvascular deficits, and provides preclinical proof of concept that strategies aimed to restore intrapericyte calcium homeostasis rescue autoregulatory blood flow and prevent neuronal dysfunction.
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Vidal-Villegas B, Di Pierdomenico J, Gallego-Ortega A, Galindo-Romero C, Martínez-de-la-Casa JM, García-Feijoo J, Villegas-Pérez MP, Vidal-Sanz M. Systemic treatment with 7,8-Dihydroxiflavone activates TtkB and affords protection of two different retinal ganglion cell populations against axotomy in adult rats. Exp Eye Res 2021; 210:108694. [PMID: 34245756 DOI: 10.1016/j.exer.2021.108694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/26/2021] [Accepted: 07/01/2021] [Indexed: 12/25/2022]
Abstract
PURPOSE To analyze responses of different RGC populations to left intraorbital optic nerve transection (IONT) and intraperitoneal (i.p.) treatment with 7,8-Dihydroxyflavone (DHF), a potent selective TrkB agonist. METHODS Adult albino Sprague-Dawley rats received, following IONT, daily i.p. injections of vehicle (1%DMSO in 0.9%NaCl) or DHF. Group-1 (n = 58) assessed at 7days (d) the optimal DHF amount (1-25 mg/kg). Group-2, using freshly dissected naïve or treated retinas (n = 28), investigated if DHF treatment was associated with TrkB activation using Western-blotting at 1, 3 or 7d. Group-3 (n = 98) explored persistence of protection and was analyzed at survival intervals from 7 to 60d after IONT. Groups 2-3 received daily i.p. vehicle or DHF (5 mg/kg). Retinal wholemounts were immunolabelled for Brn3a and melanopsin to identify Brn3a+RGCs and m+RGCs, respectively. RESULTS Optimal neuroprotection was achieved with 5 mg/kg DHF and resulted in TrkB phosphorylation. The percentage of surviving Brn3a+RGCs in vehicle treated rats was 60, 28, 18, 13, 12 or 8% of the original value at 7, 10, 14, 21, 30 or 60d, respectively, while in DHF treated retinas was 94, 70, 64, 17, 10 or 9% at the same time intervals. The percentages of m+RGCs diminished by 7d-13%, and recovered by 14d-38% in vehicle-treated and to 48% in DHF-treated retinas, without further variations. CONCLUSIONS DHF neuroprotects Brn3a + RGCs and m + RGCs; its protective effects for Brn3a+RGCs are maximal at 7 days but still significant at 21d, whereas for m+RGCs neuroprotection was significant at 14d and permanent.
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Affiliation(s)
- Beatriz Vidal-Villegas
- Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain; Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca. Campus de CC de la Salud, 30120, El Palmar, Murcia, Spain
| | - Johnny Di Pierdomenico
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca. Campus de CC de la Salud, 30120, El Palmar, Murcia, Spain
| | - Alejandro Gallego-Ortega
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca. Campus de CC de la Salud, 30120, El Palmar, Murcia, Spain
| | - Caridad Galindo-Romero
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca. Campus de CC de la Salud, 30120, El Palmar, Murcia, Spain
| | - Jose M Martínez-de-la-Casa
- Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
| | - Julian García-Feijoo
- Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain
| | - María P Villegas-Pérez
- Servicio de Oftalmología, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), 28040 Madrid, Spain; Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca. Campus de CC de la Salud, 30120, El Palmar, Murcia, Spain
| | - Manuel Vidal-Sanz
- Departamento de Oftalmología, Universidad de Murcia e Instituto Murciano de Investigación Biosanitaria (IMIB) Virgen de la Arrixaca. Campus de CC de la Salud, 30120, El Palmar, Murcia, Spain.
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17
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Belforte N, Agostinone J, Alarcon-Martinez L, Villafranca-Baughman D, Dotigny F, Cueva Vargas JL, Di Polo A. AMPK hyperactivation promotes dendrite retraction, synaptic loss, and neuronal dysfunction in glaucoma. Mol Neurodegener 2021; 16:43. [PMID: 34187514 PMCID: PMC8243567 DOI: 10.1186/s13024-021-00466-z] [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: 01/18/2021] [Accepted: 06/09/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The maintenance of complex dendritic arbors and synaptic transmission are processes that require a substantial amount of energy. Bioenergetic decline is a prominent feature of chronic neurodegenerative diseases, yet the signaling mechanisms that link energy stress with neuronal dysfunction are poorly understood. Recent work has implicated energy deficits in glaucoma, and retinal ganglion cell (RGC) dendritic pathology and synapse disassembly are key features of ocular hypertension damage. RESULTS We show that adenosine monophosphate-activated protein kinase (AMPK), a conserved energy biosensor, is strongly activated in RGC from mice with ocular hypertension and patients with primary open angle glaucoma. Our data demonstrate that AMPK triggers RGC dendrite retraction and synapse elimination. We show that the harmful effect of AMPK is exerted through inhibition of the mammalian target of rapamycin complex 1 (mTORC1). Attenuation of AMPK activity restores mTORC1 function and rescues dendrites and synaptic contacts. Strikingly, AMPK depletion promotes recovery of light-evoked retinal responses, improves axonal transport, and extends RGC survival. CONCLUSIONS This study identifies AMPK as a critical nexus between bioenergetic decline and RGC dysfunction during pressure-induced stress, and highlights the importance of targeting energy homeostasis in glaucoma and other neurodegenerative diseases.
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Affiliation(s)
- Nicolas Belforte
- Department of Neuroscience, Université de Montréal, Succursale centre-ville 6128, Montréal, Québec, H3C 3J7, Canada.,Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, Québec, H2X 0A9, Canada
| | - Jessica Agostinone
- Department of Neuroscience, Université de Montréal, Succursale centre-ville 6128, Montréal, Québec, H3C 3J7, Canada.,Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, Québec, H2X 0A9, Canada
| | - Luis Alarcon-Martinez
- Department of Neuroscience, Université de Montréal, Succursale centre-ville 6128, Montréal, Québec, H3C 3J7, Canada.,Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, Québec, H2X 0A9, Canada
| | - Deborah Villafranca-Baughman
- Department of Neuroscience, Université de Montréal, Succursale centre-ville 6128, Montréal, Québec, H3C 3J7, Canada.,Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, Québec, H2X 0A9, Canada
| | - Florence Dotigny
- Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, Québec, H2X 0A9, Canada
| | - Jorge L Cueva Vargas
- Department of Neuroscience, Université de Montréal, Succursale centre-ville 6128, Montréal, Québec, H3C 3J7, Canada.,Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, Québec, H2X 0A9, Canada
| | - Adriana Di Polo
- Department of Neuroscience, Université de Montréal, Succursale centre-ville 6128, Montréal, Québec, H3C 3J7, Canada. .,Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montréal, Québec, H2X 0A9, Canada.
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18
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A Fair Assessment of Evaluation Tools for the Murine Microbead Occlusion Model of Glaucoma. Int J Mol Sci 2021; 22:ijms22115633. [PMID: 34073191 PMCID: PMC8199180 DOI: 10.3390/ijms22115633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/14/2021] [Accepted: 05/19/2021] [Indexed: 02/06/2023] Open
Abstract
Despite being one of the most studied eye diseases, clinical translation of glaucoma research is hampered, at least in part, by the lack of validated preclinical models and readouts. The most popular experimental glaucoma model is the murine microbead occlusion model, yet the observed mild phenotype, mixed success rate, and weak reproducibility urge for an expansion of available readout tools. For this purpose, we evaluated various measures that reflect early onset glaucomatous changes in the murine microbead occlusion model. Anterior chamber depth measurements and scotopic threshold response recordings were identified as an outstanding set of tools to assess the model’s success rate and to chart glaucomatous damage (or neuroprotection in future studies), respectively. Both are easy-to-measure, in vivo tools with a fast acquisition time and high translatability to the clinic and can be used, whenever judged beneficial, in combination with the more conventional measures in present-day glaucoma research (i.e., intraocular pressure measurements and post-mortem histological analyses). Furthermore, we highlighted the use of dendritic arbor analysis as an alternative histological readout for retinal ganglion cell density counts.
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19
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Al Hussein Al Awamlh S, Wareham LK, Risner ML, Calkins DJ. Insulin Signaling as a Therapeutic Target in Glaucomatous Neurodegeneration. Int J Mol Sci 2021; 22:4672. [PMID: 33925119 PMCID: PMC8124776 DOI: 10.3390/ijms22094672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 01/28/2023] Open
Abstract
Glaucoma is a multifactorial disease that is conventionally managed with treatments to lower intraocular pressure (IOP). Despite these efforts, many patients continue to lose their vision. The degeneration of retinal ganglion cells (RGCs) and their axons in the optic tract that characterizes glaucoma is similar to neurodegeneration in other age-related disorders of the central nervous system (CNS). Identifying the different molecular signaling pathways that contribute to early neuronal dysfunction can be utilized for neuroprotective strategies that prevent degeneration. The discovery of insulin and its receptor in the CNS and retina led to exploration of the role of insulin signaling in the CNS. Historically, insulin was considered a peripherally secreted hormone that regulated glucose homeostasis, with no obvious roles in the CNS. However, a growing number of pre-clinical and clinical studies have demonstrated the potential of modulating insulin signaling in the treatment of neurodegenerative diseases. This review will highlight the role that insulin signaling plays in RGC neurodegeneration. We will focus on how this pathway can be therapeutically targeted to promote RGC axon survival and preserve vision.
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Affiliation(s)
- Sara Al Hussein Al Awamlh
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (S.A.H.A.A.); (L.K.W.); (M.L.R.)
| | - Lauren K. Wareham
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (S.A.H.A.A.); (L.K.W.); (M.L.R.)
| | - Michael L. Risner
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (S.A.H.A.A.); (L.K.W.); (M.L.R.)
| | - David J. Calkins
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (S.A.H.A.A.); (L.K.W.); (M.L.R.)
- Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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20
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Calkins DJ. Adaptive responses to neurodegenerative stress in glaucoma. Prog Retin Eye Res 2021; 84:100953. [PMID: 33640464 DOI: 10.1016/j.preteyeres.2021.100953] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/08/2021] [Accepted: 02/19/2021] [Indexed: 12/12/2022]
Abstract
Glaucoma causes loss of vision through degeneration of the retinal ganglion cell (RGC) projection to the brain. The disease is characterized by sensitivity to intraocular pressure (IOP) conveyed at the optic nerve head, through which RGC axons pass unmyelinated to form the optic nerve. From this point, a pathogenic triumvirate comprising inflammatory, oxidative, and metabolic stress influence both proximal structures in the retina and distal structures in the optic projection. This review focuses on metabolic stress and how the optic projection may compensate through novel adaptive mechanisms to protect excitatory signaling to the brain. In the retina and proximal nerve head, the unmyelinated RGC axon segment is energy-inefficient, which leads to increased demand for adenosine-5'-triphosphate (ATP) at the risk of vulnerability to Ca2+-related metabolic and oxidative pressure. This vulnerability may underlie the bidirectional nature of progression. However, recent evidence highlights that the optic projection in glaucoma is not passive but rather demonstrates adaptive processes that may push back against neurodegeneration. In the retina, even as synaptic and dendritic pruning ensues, early progression involves enhanced excitability of RGCs. Enhancement involves depolarization of the resting membrane potential and increased response to light, independent of RGC morphological type. This response is axogenic, arising from increased levels and translocation of voltage-gated sodium channels (NaV) in the unmyelinated segment. During this same early period, large-scale networks of gap-junction coupled astrocytes redistribute metabolic resources to the optic projection stressed by elevated IOP to slow loss of axon function. This redistribution may reflect more local remodeling, as astrocyte processes respond to focal metabolic duress by boosting glycogen turnover in response to axonal activity in an effort to promote survival of the healthiest axons. Both enhanced excitability and metabolic redistribution are transient, indicating that the same adaptive mechanisms that apparently serve to slow progression ultimately may be too expensive for the system to sustain over longer periods.
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Affiliation(s)
- David J Calkins
- The Vanderbilt Eye Institute, Nashville, TN, USA; Vanderbilt Vision Research Center, Vanderbilt University Medical Center, 1161 21st Ave S, AA7100 Medical Center North Nashville, Tennessee, 37232, USA.
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21
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Aydın R, Barış M, Durmaz-Engin C, Al-Aswad LA, Blumberg DM, Cioffi GA, Liebmann JM, Tezel TH, Tezel G. Early localized alterations of the retinal inner plexiform layer in association with visual field worsening in glaucoma patients. PLoS One 2021; 16:e0247401. [PMID: 33630899 PMCID: PMC7906339 DOI: 10.1371/journal.pone.0247401] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/06/2021] [Indexed: 01/16/2023] Open
Abstract
Glaucoma is a chronic neurodegenerative disease of the optic nerve and a leading cause of irreversible blindness, worldwide. While the experimental research using animal models provides growing information about cellular and molecular processes, parallel analysis of the clinical presentation of glaucoma accelerates the translational progress towards improved understanding, treatment, and clinical testing of glaucoma. Optic nerve axon injury triggers early alterations of retinal ganglion cell (RGC) synapses with function deficits prior to manifest RGC loss in animal models of glaucoma. For testing the clinical relevance of experimental observations, this study analyzed the functional correlation of localized alterations in the inner plexiform layer (IPL), where RGCs establish synaptic connections with retinal bipolar and amacrine cells. Participants of the study included a retrospective cohort of 36 eyes with glaucoma and a control group of 18 non-glaucomatous subjects followed for two-years. The IPL was analyzed on consecutively collected macular SD-OCT scans, and functional correlations with corresponding 10–2 visual field scores were tested using generalized estimating equations (GEE) models. The GEE-estimated rate of decrease in IPL thickness (R = 0.36, P<0.001) and IPL density (R = 0.36, P<0.001), as opposed to unchanged or increased IPL thickness or density, was significantly associated with visual field worsening at corresponding analysis locations. Based on multivariate logistic regression analysis, this association was independent from the patients’ age, the baseline visual field scores, or the baseline thickness or alterations of retinal nerve fiber or RGC layers (P>0.05). These findings support early localized IPL alterations in correlation with progressing visual field defects in glaucomatous eyes. Considering the experimental data, glaucoma-related increase in IPL thickness/density might reflect dendritic remodeling, mitochondrial redistribution, and glial responses for synapse maintenance, but decreased IPL thickness/density might correspond to dendrite atrophy. The bridging of experimental data with clinical findings encourages further research along the translational path.
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Affiliation(s)
- Rukiye Aydın
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Mine Barış
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Ceren Durmaz-Engin
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Lama A. Al-Aswad
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Dana M. Blumberg
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - George A. Cioffi
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Jeffrey M. Liebmann
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Tongalp H. Tezel
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
| | - Gülgün Tezel
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States of America
- * E-mail:
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22
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Chan JW, Chan NCY, Sadun AA. Glaucoma as Neurodegeneration in the Brain. Eye Brain 2021; 13:21-28. [PMID: 33500674 PMCID: PMC7822087 DOI: 10.2147/eb.s293765] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/07/2021] [Indexed: 12/31/2022] Open
Abstract
Glaucoma, a group of diseases characterized by progressive optic nerve degeneration that results in irreversible blindness, can be considered a neurodegenerative disorder of both the eye and the brain. Increasing evidence from human and animal studies have shown that glaucoma shares some common neurodegenerative pathways with Alzheimer’s disease (AD) and other tauopathies, such as chronic traumatic encephalopathy (CTE) and frontotemporal dementia. This hypothesis is based on the focal adhesion pathway hypothesis and the spreading hypothesis of tau. Not only has the Apolipoprotein E (APOE) gene been shown to be associated with AD, but also with primary open angle glaucoma (POAG). This review will highlight the relevant literature in the past 20 years from PubMed that show the pathogenic overlap between POAG and AD. Neurodegenerative pathways that contribute to transsynaptic neurodegeneration in AD and other tauopathies might also be similar to those in glaucomatous neurodegeneration.
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Affiliation(s)
- Jane W Chan
- Department of Ophthalmology, Doheny Eye Institute, Pasadena, CA, USA
| | - Noel C Y Chan
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, People's Republic of China
| | - Alfredo A Sadun
- Department of Ophthalmology, Doheny Eye Institute, Pasadena, CA, USA.,Department of Ophthalmology, University of California, Los Angeles, CA, USA
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23
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Pang JJ. Roles of the ocular pressure, pressure-sensitive ion channel, and elasticity in pressure-induced retinal diseases. Neural Regen Res 2021; 16:68-72. [PMID: 32788449 PMCID: PMC7818868 DOI: 10.4103/1673-5374.286953] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The intraocular pressure inside the human eye maintains 10–21 mmHg above the atmospheric pressure. Elevation of intraocular pressure is highly correlated with the retinopathy in glaucoma, and changes in the exterior pressure during mountain hiking, air traveling, and diving may also induce vision decline and retinopathy. The pathophysiological mechanism of these pressure-induced retinal disorders has not been completely clear. Retinal neurons express pressure-sensitive channels intrinsically sensitive to pressure and membrane stretch, such as the transient receptor potential channel (TRP) family permeable to Ca2+ and Na+ and the two-pore domain K channel family. Recent data have shown that pressure excites the primate retinal bipolar cell by opening TRP vanilloid 4 to mediate transient depolarizing currents, and TRP vanilloid 4 agonists enhance the membrane excitability of primate retinal ganglion cells. The eyeball wall is constructed primarily by the sclera and cornea of low elasticity, and the flow rate of the aqueous humor and intraocular pressure both fluctuate, but the mathematical relationship between the ocular elasticity, aqueous humor volume, and intraocular pressure has not been established. This review will briefly review recent literature on the pressure-related retinal pathophysiology in glaucoma and other pressure-induced retinal disorders, the elasticity of ocular tissues, and pressure-sensitive cation channels in retinal neurons. Emerging data support the global volume and the elasticity and thickness of the sclera and cornea as variables to affect the intraocular pressure level like the volume of the aqueous humor. Recent results also suggest some potential routes for TRPs to mediate retinal ganglion cell dysfunction: TRP opening upon intraocular pressure elevation and membrane stretch, enhancing glutamate release from bipolar cells, increasing intracellular Na+, Ca2+ concentration in retinal ganglion cells and extracellular glutamate concentration, inactivating voltage-gated Na+ channels, and causing excitotoxicity and dysfunction of retinal ganglion cells. Further studies on these routes likely identify novel targets and therapeutic strategies for the treatment of pressure-induced retinal disorders.
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Affiliation(s)
- Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
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24
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Li Y, Wang Q, Chu C, Liu S. Astaxanthin protects retinal ganglion cells from acute glaucoma via the Nrf2/HO-1 pathway. J Chem Neuroanat 2020; 110:101876. [PMID: 33129943 DOI: 10.1016/j.jchemneu.2020.101876] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/06/2020] [Accepted: 10/22/2020] [Indexed: 01/19/2023]
Abstract
The death of retinal ganglion cells (RGCs) during acute glaucoma causes progressive degeneration of the retinal nerve and irreversible blindness. Astaxanthin (AST) is a type of xanthophyll carotenoids and naturally synthesized by multiple halobios. It has been reported to protect the retina from acute glaucoma due to its anti-oxidative and anti-neuroinflammatory properties. However, the mechanism underlying this process remains unclear. We designed a mouse model with acute glaucoma and AST was administered by oral gavage. Hematoxylin and eosin staining was utilized to evaluate the condition of retina and the number of ganglion cells was counted. QRT-PCR was performed to evaluate the mRNA levels of Bax and Bcl2 while Western blot assay was used to determine the protein levels of Bax, Bcl2, Nrf2 and HO-1. AST protected the retinal integrity of mice with acute glaucoma. The apoptosis of RGCs induced by ischemia and reperfusion was repressed by AST. The protective functions of AST on the retinal and ganglion cells decreased with the knock-down of Nrf2. AST promoted the activation of Nrf2 and Ho-1 in the RGCs of the model mice. AST protected the RGCs from apoptosis during acute glaucoma and alleviated the severe retinopathy symptoms through the Nrf2/Ho-1 pathway.
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Affiliation(s)
- Yan Li
- Shandong University, Jinan 250012, Shandong, China; Department of Ophthalmology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264100, Shandong, China
| | - Qiang Wang
- Department of Ophthalmology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264100, Shandong, China.
| | - Cuiying Chu
- Department of Ophthalmology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264100, Shandong, China
| | - Shu Liu
- Department of Ophthalmology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264100, Shandong, China
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25
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VanderWall KB, Lu B, Alfaro JS, Allsop AR, Carr AS, Wang S, Meyer JS. Differential susceptibility of retinal ganglion cell subtypes in acute and chronic models of injury and disease. Sci Rep 2020; 10:17359. [PMID: 33060618 PMCID: PMC7566630 DOI: 10.1038/s41598-020-71460-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 08/11/2020] [Indexed: 12/21/2022] Open
Abstract
Retinal ganglion cells (RGCs) are a heterogeneous population of neurons, comprised of numerous subtypes that work synchronously to transmit visual information to the brain. In blinding disorders such as glaucoma, RGCs are the main cell type to degenerate and lead to loss of vision. Previous studies have identified and characterized a variety of RGC subtypes in animal models, although only a handful of studies demonstrate the differential loss of these RGC subtypes in response to disease or injury. Thus, efforts of the current study utilized both chronic (bead occlusion) and acute (optic nerve crush, ONC) rat models to characterize disease response and differential loss of RGC subtypes. Bead occlusion and ONC retinas demonstrated significant RGC loss, glial reactivity and apoptosis compared to control retinas. Importantly, bead occlusion and ONC retinas resulted in differential subtype-specific loss of RGCs, with a high susceptibility for alpha- and direction selective-RGCs and preferential survival of ipRGCs. Results of this study serve as an important foundation for future experiments focused on the mechanisms resulting in the loss of RGCs in optic neuropathies, as well as the development of targeted therapeutics for RGC subtype-specific neuroprotection.
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Affiliation(s)
- Kirstin B VanderWall
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Bin Lu
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Regenerative Medicine Institute, Los Angeles, CA, 90048, USA
| | - Jorge S Alfaro
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Regenerative Medicine Institute, Los Angeles, CA, 90048, USA
| | - Anna R Allsop
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Alexa S Carr
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, 46202, USA
| | - Shaomei Wang
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Regenerative Medicine Institute, Los Angeles, CA, 90048, USA.
| | - Jason S Meyer
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Deparment of Ophthalmology, Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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26
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Belrose JL, Prasad A, Sammons MA, Gibbs KM, Szaro BG. Comparative gene expression profiling between optic nerve and spinal cord injury in Xenopus laevis reveals a core set of genes inherent in successful regeneration of vertebrate central nervous system axons. BMC Genomics 2020; 21:540. [PMID: 32758133 PMCID: PMC7430912 DOI: 10.1186/s12864-020-06954-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 07/27/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The South African claw-toed frog, Xenopus laevis, is uniquely suited for studying differences between regenerative and non-regenerative responses to CNS injury within the same organism, because some CNS neurons (e.g., retinal ganglion cells after optic nerve crush (ONC)) regenerate axons throughout life, whereas others (e.g., hindbrain neurons after spinal cord injury (SCI)) lose this capacity as tadpoles metamorphose into frogs. Tissues from these CNS regions (frog ONC eye, tadpole SCI hindbrain, frog SCI hindbrain) were used in a three-way RNA-seq study of axotomized CNS axons to identify potential core gene expression programs for successful CNS axon regeneration. RESULTS Despite tissue-specific changes in expression dominating the injury responses of each tissue, injury-induced changes in gene expression were nonetheless shared between the two axon-regenerative CNS regions that were not shared with the non-regenerative region. These included similar temporal patterns of gene expression and over 300 injury-responsive genes. Many of these genes and their associated cellular functions had previously been associated with injury responses of multiple tissues, both neural and non-neural, from different species, thereby demonstrating deep phylogenetically conserved commonalities between successful CNS axon regeneration and tissue regeneration in general. Further analyses implicated the KEGG adipocytokine signaling pathway, which links leptin with metabolic and gene regulatory pathways, and a novel gene regulatory network with genes regulating chromatin accessibility at its core, as important hubs in the larger network of injury response genes involved in successful CNS axon regeneration. CONCLUSIONS This study identifies deep, phylogenetically conserved commonalities between CNS axon regeneration and other examples of successful tissue regeneration and provides new targets for studying the molecular underpinnings of successful CNS axon regeneration, as well as a guide for distinguishing pro-regenerative injury-induced changes in gene expression from detrimental ones in mammals.
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Affiliation(s)
- Jamie L Belrose
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
- Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Aparna Prasad
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
- Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Morgan A Sammons
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA
| | - Kurt M Gibbs
- Department of Biology and Chemistry, Morehead State University, Morehead, KY, 40351, USA
| | - Ben G Szaro
- Department of Biological Sciences, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA.
- Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA.
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27
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Beykin G, Norcia AM, Srinivasan VJ, Dubra A, Goldberg JL. Discovery and clinical translation of novel glaucoma biomarkers. Prog Retin Eye Res 2020; 80:100875. [PMID: 32659431 DOI: 10.1016/j.preteyeres.2020.100875] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 06/01/2020] [Accepted: 06/04/2020] [Indexed: 12/16/2022]
Abstract
Glaucoma and other optic neuropathies are characterized by progressive dysfunction and loss of retinal ganglion cells and their axons. Given the high prevalence of glaucoma-related blindness and the availability of treatment options, improving the diagnosis and precise monitoring of progression in these conditions is paramount. Here we review recent progress in the development of novel biomarkers for glaucoma in the context of disease pathophysiology and we propose future steps for the field, including integration of exploratory biomarker outcomes into prospective therapeutic trials. We anticipate that, when validated, some of the novel glaucoma biomarkers discussed here will prove useful for clinical diagnosis and prediction of progression, as well as monitoring of clinical responses to standard and investigational therapies.
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Affiliation(s)
- Gala Beykin
- Spencer Center for Vision Research at Stanford University, 2370 Watson Ct, Palo Alto, CA, 94303, USA.
| | - Anthony M Norcia
- Department of Psychology, Stanford University, 290 Jane Stanford Way, Stanford, CA, 94305, USA.
| | - Vivek J Srinivasan
- Department of Biomedical Engineering, University of California, Davis, One Shields Ave, Davis, CA, 95616, USA; Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, 4610 X St, Sacramento, CA, 96817, USA.
| | - Alfredo Dubra
- Spencer Center for Vision Research at Stanford University, 2370 Watson Ct, Palo Alto, CA, 94303, USA.
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research at Stanford University, 2370 Watson Ct, Palo Alto, CA, 94303, USA.
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28
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VanderWall KB, Huang KC, Pan Y, Lavekar SS, Fligor CM, Allsop AR, Lentsch KA, Dang P, Zhang C, Tseng HC, Cummins TR, Meyer JS. Retinal Ganglion Cells With a Glaucoma OPTN(E50K) Mutation Exhibit Neurodegenerative Phenotypes when Derived from Three-Dimensional Retinal Organoids. Stem Cell Reports 2020; 15:52-66. [PMID: 32531194 PMCID: PMC7363877 DOI: 10.1016/j.stemcr.2020.05.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/18/2022] Open
Abstract
Retinal ganglion cells (RGCs) serve as the connection between the eye and the brain, with this connection disrupted in glaucoma. Numerous cellular mechanisms have been associated with glaucomatous neurodegeneration, and useful cellular models of glaucoma allow for the precise analysis of degenerative phenotypes. Human pluripotent stem cells (hPSCs) serve as powerful tools for studying human disease, particularly cellular mechanisms underlying neurodegeneration. Thus, efforts focused upon hPSCs with an E50K mutation in the Optineurin (OPTN) gene, a leading cause of inherited forms of glaucoma. CRISPR/Cas9 gene editing introduced the OPTN(E50K) mutation into existing lines of hPSCs, as well as generating isogenic controls from patient-derived lines. RGCs differentiated from OPTN(E50K) hPSCs exhibited numerous neurodegenerative deficits, including neurite retraction, autophagy dysfunction, apoptosis, and increased excitability. These results demonstrate the utility of OPTN(E50K) RGCs as an in vitro model of neurodegeneration, with the opportunity to develop novel therapeutic approaches for glaucoma.
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Affiliation(s)
- Kirstin B VanderWall
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Kang-Chieh Huang
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Yanling Pan
- Indiana BioMedical Gateway Program, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Sailee S Lavekar
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Clarisse M Fligor
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Anna R Allsop
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Kelly A Lentsch
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Pengtao Dang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Chi Zhang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Henry C Tseng
- Duke Eye Center and Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA
| | - Theodore R Cummins
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jason S Meyer
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Ophthalmology, Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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29
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Behtaj S, Öchsner A, Anissimov YG, Rybachuk M. Retinal Tissue Bioengineering, Materials and Methods for the Treatment of Glaucoma. Tissue Eng Regen Med 2020; 17:253-269. [PMID: 32390117 PMCID: PMC7260329 DOI: 10.1007/s13770-020-00254-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 03/17/2020] [Accepted: 03/19/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Glaucoma, a characteristic type of optic nerve degeneration in the posterior pole of the eye, is a common cause of irreversible vision loss and the second leading cause of blindness worldwide. As an optic neuropathy, glaucoma is identified by increasing degeneration of retinal ganglion cells (RGCs), with consequential vision loss. Current treatments only postpone the development of retinal degeneration, and there are as yet no treatments available for this disability. Recent studies have shown that replacing lost or damaged RGCs with healthy RGCs or RGC precursors, supported by appropriately designed bio-material scaffolds, could facilitate the development and enhancement of connections to ganglion cells and optic nerve axons. The consequence may be an improved retinal regeneration. This technique could also offer the possibility for retinal regeneration in treating other forms of optic nerve ailments through RGC replacement. METHODS In this brief review, we describe the innovations and recent developments in retinal regenerative medicine such as retinal organoids and gene therapy which are specific to glaucoma treatment and focus on the selection of appropriate bio-engineering principles, biomaterials and cell therapies that are presently employed in this growing research area. RESULTS Identification of optimal sources of cells, improving cell survival, functional integration upon transplantation, and developing techniques to deliver cells into the retinal space without provoking immune responses are the main challenges in retinal cell replacement therapies. CONCLUSION The restoration of visual function in glaucoma patients by the RGC replacement therapies requires appropriate protocols and biotechnology methods. Tissue-engineered scaffolds, the generation of retinal organoids, and gene therapy may help to overcome some of the challenges in the generation of clinically safe RGCs.
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Affiliation(s)
- Sanaz Behtaj
- School of Engineering and Built Environment, Griffith University, Engineering Drive, Southport, QLD, 4222, Australia
- Queensland Micro- and Nanotechnology Centre, Griffith University, West Creek Road, Nathan, QLD, 4111, Australia
- Department of Cell and Molecular Biology, Cell Science Research Centre, Royan Institute for Biotechnology, Isfahan, Iran
| | - Andreas Öchsner
- Faculty of Mechanical Engineering, Esslingen University of Applied Sciences, Kanalstrasse 33, 73728, Esslingen, Germany
| | - Yuri G Anissimov
- Queensland Micro- and Nanotechnology Centre, Griffith University, West Creek Road, Nathan, QLD, 4111, Australia
- School of Environment and Science, Griffith University, Parklands Drive, Southport, QLD, 4222, Australia
- Institute of Molecular Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, 119146, Russia
| | - Maksym Rybachuk
- Queensland Micro- and Nanotechnology Centre, Griffith University, West Creek Road, Nathan, QLD, 4111, Australia.
- School of Engineering and Built Environment, Griffith University, 170 Kessels Road, Nathan, QLD, 4111, Australia.
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30
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Zhang X, Tenerelli K, Wu S, Xia X, Yokota S, Sun C, Galvao J, Venugopalan P, Li C, Madaan A, Goldberg JL, Chang KC. Cell transplantation of retinal ganglion cells derived from hESCs. Restor Neurol Neurosci 2020; 38:131-140. [PMID: 31815704 DOI: 10.3233/rnn-190941] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Glaucoma, the number one cause of irreversible blindness, is characterized by the loss of retinal ganglion cells (RGCs), which do not regenerate in humans or mammals after cell death. Cell transplantation provides an opportunity to restore vision in glaucoma, or other optic neuropathies. Since transplanting primary RGCs from deceased donor tissues may not be feasible, stem cell-derived RGCs could provide a plausible alternative source of donor cells for transplant. OBJECTIVE We define a robust chemically defined protocol to differentiate human embryonic stem cells (hESCs) into RGC-like neurons. METHODS Human embryonic stem cell lines (H7-A81 and H9) and induced pluripotent stem cell (iPSC) were used for RGC differentiation. RGC immaturity was measured by calcium imaging against muscimol. Cell markers were detected by immunofluorescence staining and qRT-PCR. RGC-like cells were intravitreally injected to rat eye, and co-stained with RBPMS and human nuclei markers. All experiments were conducted at least three times independently. Data were analyzed by ANOVA with Tukey's test with P value of <0.05 considered statistically significant. RESULTS We detected retinal progenitor markers Rx and Pax6 after 15 days of differentiation, and the expression of markers for RGC-specific differentiation (Brn3a and Brn3b), maturation (synaptophysin) and neurite growth (β-III-Tubulin) after an additional 15 days. We further examined the physiologic differentiation of these hESC-derived RGC-like progeny to those differentiated in vitro from primary rodent retinal progenitor cells (RPCs) with calcium imaging, and found that both populations demonstrate the immature RGC-like response to muscimol, a GABAA receptor agonist. By one week after transplant to the adult rat eye by intravitreal injection, the human RGC-like cells successfully migrated into the ganglion cell layer. CONCLUSIONS Our protocol provides a novel, short, and cost-effective approach for RGC differentiation from hESCs, and may broaden the scope for cell replacement therapy in RGC-related optic neuropathies such as glaucoma.
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Affiliation(s)
- Xiong Zhang
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, USA
| | - Kevin Tenerelli
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, USA
| | - Suqian Wu
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
- Department of Ophthalmology & Visual Science, Eye, Ear, Nose and Throat Hospital, Fudan University, Shanghai, P.R. China
| | - Xin Xia
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
| | - Satoshi Yokota
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
| | - Catalina Sun
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, USA
| | - Joana Galvao
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, USA
| | | | - Chenyi Li
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, USA
| | - Ankush Madaan
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, USA
| | - Kun-Che Chang
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA, USA
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31
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Chauhan MZ, Valencia AK, Piqueras MC, Enriquez-Algeciras M, Bhattacharya SK. Optic Nerve Lipidomics Reveal Impaired Glucosylsphingosine Lipids Pathway in Glaucoma. Invest Ophthalmol Vis Sci 2019; 60:1789-1798. [PMID: 31022733 PMCID: PMC6485987 DOI: 10.1167/iovs.18-25802] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose To determine major differences in lipid profile between human control and glaucomatous optic nerve. To assess major enzymes in lipid pathway if aberration is revealed for a lipid class by profiling. Methods Optic nerve (ON) samples were obtained from human cadaveric donors [control (n = 11) and primary open-angle glaucoma (POAG; n = 12)]; the lipids were extracted using Bligh and Dyer methods. Control and glaucoma donors were all Caucasians age 72.3 ± 5.9 and 70.3 ± 10.5 (inclusive of both sexes), respectively. Lipids were extracted after weighing the tissue; the protein amounts in the corresponding aqueous phase of organic solvent extraction were recorded. High-resolution mass spectrometry was performed using a Q-exactive mass spectrometer coupled with an EASY-nLC 1000 liquid chromatograph instrument. Bioinformatics and statistical analysis were performed using LipidSearch v.4.1 and MetaboAnalyst 4.0/STATA 14.2. Protein amounts were determined using Bradford's method. Western blot, ELISA, and immunohistochemistry utilized established protocols and were performed for protein quantification and localization, respectively. Additional donor tissues were utilized for Western blot, ELISA, and immunohistochemistry. Results Principal component analysis (PCA) placed control and glaucomatous ONs in two distinct groups based on analysis of lipid profiles. Total lipid, total phospholipids, total ceramide, and total sphingolipids were similar (without significant difference) between control and glaucoma. However, we found a significant increase in glucosylsphingosine in glaucoma compared to control samples. We found similar levels of glucocerebrosidase (GBA), ceramide glucosyltransferase (UGCG), decreased nonlysosomal glucocerebrosidase (GBA2), and increased lysosomal and nonlysosomal acylsphingosine amidohydrolase (ASAH1 and ASAH2) levels in glaucomatous ON compared to control. Conclusions We found significant differences in glucosylsphingosine lipids, consistent with decreased GBA and GBA2 and increased ASAH1 and ASAH2 immunoreactivity in glaucoma, suggesting the potential impairment of sphingolipid enzymatic pathways in lysosomal and nonlysosomal cellular compartments.
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Affiliation(s)
- Muhammad Zain Chauhan
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Ann-Katrin Valencia
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Maria Carmen Piqueras
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Mabel Enriquez-Algeciras
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
| | - Sanjoy K Bhattacharya
- Department of Ophthalmology & Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States
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Agostinone J, Alarcon-Martinez L, Gamlin C, Yu WQ, Wong ROL, Di Polo A. Insulin signalling promotes dendrite and synapse regeneration and restores circuit function after axonal injury. Brain 2019; 141:1963-1980. [PMID: 29931057 PMCID: PMC6022605 DOI: 10.1093/brain/awy142] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/06/2018] [Indexed: 01/07/2023] Open
Abstract
Dendrite pathology and synapse disassembly are critical features of chronic neurodegenerative diseases. In spite of this, the capacity of injured neurons to regenerate dendrites has been largely ignored. Here, we show that, upon axonal injury, retinal ganglion cells undergo rapid dendritic retraction and massive synapse loss that preceded neuronal death. Human recombinant insulin, administered as eye drops or systemically after dendritic arbour shrinkage and prior to cell loss, promoted robust regeneration of dendrites and successful reconnection with presynaptic targets. Insulin-mediated regeneration of excitatory postsynaptic sites on retinal ganglion cell dendritic processes increased neuronal survival and rescued light-triggered retinal responses. Further, we show that axotomy-induced dendrite retraction triggered substantial loss of the mammalian target of rapamycin (mTOR) activity exclusively in retinal ganglion cells, and that insulin fully reversed this response. Targeted loss-of-function experiments revealed that insulin-dependent activation of mTOR complex 1 (mTORC1) is required for new dendritic branching to restore arbour complexity, while complex 2 (mTORC2) drives dendritic process extension thus re-establishing field area. Our findings demonstrate that neurons in the mammalian central nervous system have the intrinsic capacity to regenerate dendrites and synapses after injury, and provide a strong rationale for the use of insulin and/or its analogues as pro-regenerative therapeutics for intractable neurodegenerative diseases including glaucoma.
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Affiliation(s)
- Jessica Agostinone
- Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada.,University of Montreal Hospital Research Center (CR-CHUM), University of Montreal, Montreal, Quebec, Canada
| | - Luis Alarcon-Martinez
- Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada.,University of Montreal Hospital Research Center (CR-CHUM), University of Montreal, Montreal, Quebec, Canada
| | - Clare Gamlin
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington, USA
| | - Wan-Qing Yu
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington, USA
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington, USA
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada.,University of Montreal Hospital Research Center (CR-CHUM), University of Montreal, Montreal, Quebec, Canada
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Syc-Mazurek SB, Libby RT. Axon injury signaling and compartmentalized injury response in glaucoma. Prog Retin Eye Res 2019; 73:100769. [PMID: 31301400 DOI: 10.1016/j.preteyeres.2019.07.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 07/05/2019] [Accepted: 07/09/2019] [Indexed: 12/19/2022]
Abstract
Axonal degeneration is an active, highly controlled process that contributes to beneficial processes, such as developmental pruning, but also to neurodegeneration. In glaucoma, ocular hypertension leads to vision loss by killing the output neurons of the retina, the retinal ganglion cells (RGCs). Multiple processes have been proposed to contribute to and/or mediate axonal injury in glaucoma, including: neuroinflammation, loss of neurotrophic factors, dysregulation of the neurovascular unit, and disruption of the axonal cytoskeleton. While the inciting injury to RGCs in glaucoma is complex and potentially heterogeneous, axonal injury is ultimately thought to be the key insult that drives glaucomatous neurodegeneration. Glaucomatous neurodegeneration is a complex process, with multiple molecular signals contributing to RGC somal loss and axonal degeneration. Furthermore, the propagation of the axonal injury signal is complex, with injury triggering programs of degeneration in both the somal and axonal compartment. Further complicating this process is the involvement of multiple cell types that are known to participate in the process of axonal and neuronal degeneration after glaucomatous injury. Here, we review the axonal signaling that occurs after injury and the molecular signaling programs currently known to be important for somal and axonal degeneration after glaucoma-relevant axonal injuries.
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Affiliation(s)
- Stephanie B Syc-Mazurek
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA; Neuroscience Graduate Program, University of Rochester Medical Center, Rochester, NY, USA
| | - Richard T Libby
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA; Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, USA; The Center for Visual Sciences, University of Rochester, Rochester, NY, USA.
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Melanopsin +RGCs Are fully Resistant to NMDA-Induced Excitotoxicity. Int J Mol Sci 2019; 20:ijms20123012. [PMID: 31226772 PMCID: PMC6627747 DOI: 10.3390/ijms20123012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 06/11/2019] [Accepted: 06/18/2019] [Indexed: 12/13/2022] Open
Abstract
We studied short- and long-term effects of intravitreal injection of N-methyl-d-aspartate (NMDA) on melanopsin-containing (m+) and non-melanopsin-containing (Brn3a+) retinal ganglion cells (RGCs). In adult SD-rats, the left eye received a single intravitreal injection of 5µL of 100nM NMDA. At 3 and 15 months, retinal thickness was measured in vivo using Spectral Domain-Optical Coherence Tomography (SD-OCT). Ex vivo analyses were done at 3, 7, or 14 days or 15 months after damage. Whole-mounted retinas were immunolabelled for brain-specific homeobox/POU domain protein 3A (Brn3a) and melanopsin (m), the total number of Brn3a+RGCs and m+RGCs were quantified, and their topography represented. In control retinas, the mean total numbers of Brn3a+RGCs and m+RGCs were 78,903 ± 3572 and 2358 ± 144 (mean ± SD; n = 10), respectively. In the NMDA injected retinas, Brn3a+RGCs numbers diminished to 49%, 28%, 24%, and 19%, at 3, 7, 14 days, and 15 months, respectively. There was no further loss between 7 days and 15 months. The number of immunoidentified m+RGCs decreased significantly at 3 days, recovered between 3 and 7 days, and were back to normal thereafter. OCT measurements revealed a significant thinning of the left retinas at 3 and 15 months. Intravitreal injections of NMDA induced within a week a rapid loss of 72% of Brn3a+RGCs, a transient downregulation of melanopsin expression (but not m+RGC death), and a thinning of the inner retinal layers.
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Park HYL, Kim SW, Kim JH, Park CK. Increased levels of synaptic proteins involved in synaptic plasticity after chronic intraocular pressure elevation and modulation by brain-derived neurotrophic factor in a glaucoma animal model. Dis Model Mech 2019; 12:dmm.037184. [PMID: 31142572 PMCID: PMC6602315 DOI: 10.1242/dmm.037184] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 05/08/2019] [Indexed: 12/30/2022] Open
Abstract
The dendrites of retinal ganglion cells (RGCs) synapse with the axon terminals of bipolar cells in the inner plexiform layer (IPL). Changes in the RGC dendrites and synapses between the bipolar cells in the inner retinal layer may critically alter the function of RGCs in glaucoma. The present study attempted to discover changes in the synapse using brain-derived neurotrophic factor (BDNF) after glaucoma induction by chronic intraocular pressure elevation in a rat model. Immunohistochemical staining revealed that the BDNF-injected group had a significant increase in the level of synaptophysin, which is a presynaptic vesicle protein, in the innermost IPL compared with the phosphate-buffered saline (PBS)-injected group. SMI-32, which is a marker of RGCs, was colocalized with synaptophysin in RGC dendrites, and this colocalization significantly increased in the BDNF-injected group. After the induction of glaucoma, the BDNF-injected group exhibited increases in the total number of ribbon synapses, as seen using electron microscopy. Expression of calcium/calmodulin-dependent protein kinase II (CaMKII), cAMP-response element binding protein (CREB) and F-actin, which are key molecules involved in synaptic changes were upregulated after BDNF injection. These initial findings show the capability of BDNF to induce beneficial synaptic changes in glaucoma. Summary: Application of BDNF increased the expression of synaptic vesicle proteins in the inner retina via the p-Akt, CaMKII and CREB pathways, increasing F-actin in RGC dendrites.
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Affiliation(s)
- Hae-Young Lopilly Park
- Department of Ophthalmology, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Si Won Kim
- Department of Ophthalmology, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Jie Hyun Kim
- Department of Ophthalmology, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Chan Kee Park
- Department of Ophthalmology, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
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Gao F, Yang Z, Jacoby RA, Wu SM, Pang JJ. The expression and function of TRPV4 channels in primate retinal ganglion cells and bipolar cells. Cell Death Dis 2019; 10:364. [PMID: 31064977 PMCID: PMC6504919 DOI: 10.1038/s41419-019-1576-3] [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: 01/24/2018] [Accepted: 03/25/2019] [Indexed: 12/26/2022]
Abstract
The transient receptor potential vanilloid 4 (TRPV4) channel may be opened by mechanical stimuli to mediate Ca2+ and Na+ influxes, and it has been suggested to mediate glaucoma retinopathy. However, it has been mostly unclear how TRPV4 activities affect the function of primate retinal ganglion cells (RGCs). We studied RGCs and bipolar cells (BCs) in the peripheral retina of the old-world primate using whole-cell current-clamp and voltage-clamp recordings, immunomarkers and confocal microscopy. RGCs were distinguished from displaced amacrine cells (ACs) by the absence of GABA and glycine immunoreactivity and possession of an axon and a large soma in the RGC layer. Strong TRPV4 signal was concentrated in medium to large somas of RGCs, and some TRPV4 signal was found in BCs (including PKCα-positive rod BCs), as well as the end feet, soma and outer processes of Mȕller cells. TRPV4 immunoreactivity quantified by the pixel intensity histogram revealed a high-intensity component for the plexiform layers, a low-intensity component for the soma layers of ACs and Mȕller cells, and both components in the soma layers of RGCs and BCs. In large RGCs, TRPV4 agonists 4α-phorbol 12,13 didecanoate (4αPDD) and GSK1016790A reversibly enhanced the spontaneous firing and shortened the delay of voltage-gated Na+ (Nav) currents under current-clamp conditions, and under voltage-clamp conditions, 4αPDD largely reversibly increased the amplitude and frequency of spontaneous excitatory postsynaptic currents. In BCs, changes in the membrane tension induced by either applying pressure or releasing the pressure both activated a transient cation current, which reversed at ~ -10 mV and was enhanced by heating from 24 °C to 30 °C. The pressure for the half-maximal effect was ~18 mmHg. These data indicate that functional TRPV4 channels are variably expressed in primate RGCs and BCs, possibly contributing to pressure-related changes in RGCs in glaucoma.
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Affiliation(s)
- Fan Gao
- Department of Ophthalmology, Baylor College of Medicine, One Baylor Plaza, NC 205, Houston, TX, 77030, USA
| | - Zhuo Yang
- Department of Ophthalmology, Baylor College of Medicine, One Baylor Plaza, NC 205, Houston, TX, 77030, USA
| | - Roy A Jacoby
- Department of Ophthalmology, Baylor College of Medicine, One Baylor Plaza, NC 205, Houston, TX, 77030, USA
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, One Baylor Plaza, NC 205, Houston, TX, 77030, USA
| | - Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, One Baylor Plaza, NC 205, Houston, TX, 77030, USA.
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Yu S, Lin Z, Xiao Z. [Changes of membrane properties and synaptic stability of rat retinal ganglion cells during postnatal development]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2018; 38:1100-1106. [PMID: 30377110 DOI: 10.12122/j.issn.1673-4254.2018.09.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the changes in the membrane properties and synaptic stability of the rat retinal ganglion cells (RGCs) during postnatal development. METHODS Whole-cell patch-clamp technique was used to record the action potentials (AP) and miniature excitatory postsynaptic currents (mEPSC) of SD rat RGCs at postnatal days 7, 14 and 40. The active and passive membrane properties and the synaptic stability (measured by the amplitude, frequency, rise time and decay time of mEPSC) of the RGCs were analyzed using Patchmaster software. RESULTS Comparison of the RGCs in SD rats across different postnatal ages revealed significant changes in the electrophysiological characteristics of the RGCs during postnatal development. The discharge rate was significantly greater while the AP half-peak width was significantly smaller at postnatal day 15 (P15) than at P7 (P < 0.01), but were both similar between P15 and P40 (P=0.086); in terms of the passive membrane properties, the membrane time constant gradually decreased during the development. The frequency of mEPSCs increased significantly over time during postnatal development (P < 0.01), but was similar between P15 and P40 rats. CONCLUSIONS In SD rats, the membrane properties and synaptic stability of the RGCs undergo alterations following a specific pattern, which highlights a critical period where distinct changes occur in the electrophysiological characteristics of RGCs, followed by gradual stabilization over time. Such changes in the electrophysiological characteristics represent the basic characteristics of RGCs for visual signal processing, and understanding of this mechanism may provide insights into the exact role of the RGC in visual information processing.
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Affiliation(s)
- Siqi Yu
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Zhengrong Lin
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Zhongju Xiao
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
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Axogenic mechanism enhances retinal ganglion cell excitability during early progression in glaucoma. Proc Natl Acad Sci U S A 2018; 115:E2393-E2402. [PMID: 29463759 PMCID: PMC5877940 DOI: 10.1073/pnas.1714888115] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Identifying new therapies for neurodegenerative disease requires understanding how neurons respond to stress and whether this response includes adaptation to slow progression. Because neurodegeneration affects both axons and dendrites, with their synaptic contacts, adaptation could involve both compartments. We investigated this question in experimental glaucoma, the world’s leading cause of irreversible vision loss. Glaucoma attacks retinal ganglion cell neurons and their axons, which comprise the optic nerve. We found that elevations in ocular pressure, a prominent risk factor for glaucoma, caused a paradoxical increase in ganglion cell excitability, including response to light, even in cells with substantial dendritic pruning. This adaptation arose from voltage-dependent mechanisms in the axon and may help maintain signaling to the brain to preserve vision. Diseases of the brain involve early axon dysfunction that often precedes outright degeneration. Pruning of dendrites and their synapses represents a potential driver of axonopathy by reducing activity. Optic nerve degeneration in glaucoma, the world’s leading cause of irreversible blindness, involves early stress to retinal ganglion cell (RGC) axons from sensitivity to intraocular pressure (IOP). This sensitivity also influences survival of RGC dendrites and excitatory synapses in the retina. Here we tested in individual RGCs identified by type the relationship between dendritic organization and axon signaling to light following modest, short-term elevations in pressure. We found dendritic pruning occurred early, by 2 wk of elevation, and independent of whether the RGC responded to light onset (ON cells) or offset (OFF cells). Pruning was similarly independent of ON and OFF in the DBA/2J mouse, a chronic glaucoma model. Paradoxically, all RGCs, even those with significant pruning, demonstrated a transient increase in axon firing in response to the preferred light stimulus that occurred on a backdrop of generally enhanced excitability. The increased response was not through conventional presynaptic signaling, but rather depended on voltage-sensitive sodium channels that increased transiently in the axon. Pruning, axon dysfunction, and deficits in visual acuity did not progress between 2 and 4 wk of elevation. These results suggest neurodegeneration in glaucoma involves an early axogenic response that counters IOP-related stress to excitatory dendritic architecture to slow progression and maintain signaling to the brain. Thus, short-term exposure to elevated IOP may precondition the neural system to further insult.
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Reinehr S, Kuehn S, Casola C, Koch D, Stute G, Grotegut P, Dick HB, Joachim SC. HSP27 immunization reinforces AII amacrine cell and synapse damage induced by S100 in an autoimmune glaucoma model. Cell Tissue Res 2017; 371:237-249. [PMID: 29064077 DOI: 10.1007/s00441-017-2710-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 10/11/2017] [Indexed: 12/11/2022]
Abstract
Previous studies have revealed a loss of retinal ganglion cells (RGCs) and optic nerve fibers after immunization with the S100B protein. Addition of heat shock protein 27 (HSP27) also leads to a decrease of RGCs. Our present aim has been to analyze various retinal cell types after immunization with S100B or S100B + HSP27 (S100 + HSP). After 28 days, retinas were processed for immunohistology and Western blot. RGCs, immunostained for NeuN, were significantly decreased in the S100 and the S100 + HSP groups. Significantly fewer ChAT+ cells were noted in both groups, whereas parvalbumin+ cells were only affected in the S100 + HSP group. Western blot results also revealed fewer ChAT signals in both immunized groups. No changes were noted with regard to PKCα+ rod bipolar cells, whereas a significant loss of recoverin+ cone bipolar cells was observed in both groups via immunohistology and Western blot. The presynaptic marker Bassoon and the postsynaptic marker PSD95 were significantly reduced in the S100 + HSP group. Opsin+ and rhodopsin+ photoreceptors revealed no changes in either group. Thus, the inner retinal layers are affected by immunization. However, the combination of S100 and HSP27 has a stronger additive effect on the retinal synapses and AII amacrine cells.
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Affiliation(s)
- Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Christina Casola
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Dennis Koch
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Gesa Stute
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Pia Grotegut
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany.
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Affiliation(s)
- Mohammadali Almasieh
- Departments of Ophthalmology and Neurology, McGill University, Montreal H4A 3S5, Canada
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal H1T 2M4, Canada
| | - Leonard A. Levin
- Departments of Ophthalmology and Neurology, McGill University, Montreal H4A 3S5, Canada
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal H1T 2M4, Canada
- Department of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin 53706
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Kim EK, Park HYL, Park CK. Segmented inner plexiform layer thickness as a potential biomarker to evaluate open-angle glaucoma: Dendritic degeneration of retinal ganglion cell. PLoS One 2017; 12:e0182404. [PMID: 28771565 PMCID: PMC5542626 DOI: 10.1371/journal.pone.0182404] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/16/2017] [Indexed: 11/19/2022] Open
Abstract
Purpose To evaluate the changes of retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and ganglion cell-inner plexiform layer (GCIPL) thicknesses and compare structure-function relationships of 4 retinal layers using spectral-domain optical coherence tomography (SD-OCT) in macular region of glaucoma patients. Methods In cross-sectional study, a total of 85 eyes with pre-perimetric to advanced glaucoma and 26 normal controls were enrolled. The glaucomatous eyes were subdivided into three groups according to the severity of visual field defect: a preperimetric glaucoma group, an early glaucoma group, and a moderate to advanced glaucoma group. RNFL, GCL, IPL, and GCIPL thicknesses were measured at the level of the macula by the Spectralis (Heidelberg Engineering, Heidelberg, Germany) SD-OCT with automated segmentation software. For functional evaluation, corresponding mean sensitivity (MS) values were measured using 24–2 standard automated perimetry (SAP). Results RNFL, GCL, IPL, and GCIPL thicknesses were significantly different among 4 groups (P < .001). Macular structure losses were positively correlated with the MS values of the 24–2 SAP for RNFL, GCL, IPL, and GCIPL (R = 0.553, 0.636, 0.648 and 0.646, respectively, P < .001). In regression analysis, IPL and GCIPL thicknesses showed stronger association with the corresponding MS values of 24–2 SAP compared with RNFL and GCL thicknesses (R2 = 0.420, P < .001 for IPL; R2 = 0.417, P< .001 for GCIPL thickness). Conclusions Segmented IPL thickness was significantly associated with the degree of glaucoma. Segmental analysis of the inner retinal layer including the IPL in macular region may provide valuable information for evaluating glaucoma.
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Affiliation(s)
- Eun Kyoung Kim
- Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, South Korea
- Seoul St. Mary’s Hospital, Seoul, South Korea
| | - Hae-Young Lopilly Park
- Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, South Korea
- Seoul St. Mary’s Hospital, Seoul, South Korea
| | - Chan Kee Park
- Department of Ophthalmology and Visual Science, College of Medicine, The Catholic University of Korea, Seoul, South Korea
- Seoul St. Mary’s Hospital, Seoul, South Korea
- * E-mail:
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Tau Accumulation, Altered Phosphorylation, and Missorting Promote Neurodegeneration in Glaucoma. J Neurosci 2017; 36:5785-98. [PMID: 27225768 DOI: 10.1523/jneurosci.3986-15.2016] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 04/13/2016] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by the selective death of retinal ganglion cells (RGCs). Ocular hypertension is the most significant known risk factor for developing the disease, but the mechanism by which elevated pressure damages RGCs is currently unknown. The axonal-enriched microtubule-associated protein tau is a key mediator of neurotoxicity in Alzheimer's disease and other tauopathies. Using a well characterized in vivo rat glaucoma model, we show an age-related increase in endogenous retinal tau that was markedly exacerbated by ocular hypertension. Early alterations in tau phosphorylation, characterized by epitope-dependent hyperphosphorylation and hypophosphorylation, correlated with the appearance of tau oligomers in glaucomatous retinas. Our data demonstrate the mislocalization of tau in the somatodendritic compartment of RGCs subjected to high intraocular pressure. In contrast, tau was depleted from RGC axons in the optic nerve of glaucomatous eyes. Importantly, intraocular administration of short interfering RNA against tau effectively reduced retinal tau accumulation and promoted robust survival of RGC somas and axons, supporting a critical role for tau alterations in ocular hypertension-induced neuronal damage. Our study reveals that glaucoma displays signature pathological features of tauopathies, including tau accumulation, altered phosphorylation, and missorting; and identifies tau as a novel target to counter RGC neurodegeneration in glaucoma and prevalent optic neuropathies. SIGNIFICANCE STATEMENT In this study, we investigated the role of tau in retinal ganglion cell (RGC) damage in glaucoma. We demonstrate that high intraocular pressure leads to a rapid increase in endogenous retinal tau with altered phosphorylation profile and the formation of tau oligomers. Tau accumulation was primarily observed in RGC dendrites, while tau in RGC axons within the optic nerve was depleted. Attenuation of endogenous retinal tau using a targeted siRNA led to striking protection of RGC somas and axons from hypertension-induced damage. Our study identifies novel and substantial alterations of endogenous tau protein in glaucoma, including abnormal subcellular distribution, an altered phosphorylation profile, and neurotoxicity.
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Ryul Ahn H, Kim KA, Kang SW, Lee JY, Kim TJ, Jung SH. Persimmon Leaves (Diospyros kaki) Extract Protects Optic Nerve Crush-Induced Retinal Degeneration. Sci Rep 2017; 7:46449. [PMID: 28425487 PMCID: PMC5397840 DOI: 10.1038/srep46449] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 03/20/2017] [Indexed: 01/27/2023] Open
Abstract
Retinal ganglion cell (RGC) death is part of many retinal diseases. Here, we report that the ethanol extract of Diospyros kaki (EEDK) exhibits protective properties against retinal degeneration, both in vitro and in vivo. Upon exposure to cytotoxic compounds, RGC-5 cells showed approximately 40% cell viability versus the control, while pre-treatment with EEDK markedly increased cell viability in a concentration-dependent manner. Further studies revealed that cell survival induced by EEDK was associated with decreased levels of apoptotic proteins, such as poly (ADP-ribose) polymerase, p53, and cleaved caspase-3. In addition to apoptotic pathways, we demonstrated that expression levels of antioxidant-associated proteins, such as superoxide dismutase-1, glutathione S-transferase, and glutathione peroxidase-1, were positively modulated by EEDK. In a partial optic nerve crush mouse model, EEDK had similar ameliorating effects on retinal degeneration resulting from mechanical damages. Therefore, our results suggest that EEDK may have therapeutic potential against retinal degenerative disorders, such as glaucoma.
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Affiliation(s)
- Hong Ryul Ahn
- Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung 25451, Republic of Korea
| | - Kyung-A Kim
- Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung 25451, Republic of Korea.,Department of Biological Chemistry, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Suk Woo Kang
- Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung 25451, Republic of Korea
| | - Joo Young Lee
- Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung 25451, Republic of Korea
| | - Tae-Jin Kim
- Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung 25451, Republic of Korea.,Department of Biological Chemistry, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea.,Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Sang Hoon Jung
- Natural Products Research Center, Korea Institute of Science and Technology (KIST), Gangneung 25451, Republic of Korea.,Department of Biological Chemistry, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea
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