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Palanivel V, Gupta V, Chitranshi N, Tietz O, Vander Wall R, Blades R, Maha Thananthirige KP, Salkar A, Shen C, Mirzaei M, Gupta V, Graham SL, Basavarajappa D. Neuropeptide Y receptor activation preserves inner retinal integrity through PI3K/Akt signaling in a glaucoma mouse model. PNAS NEXUS 2024; 3:pgae299. [PMID: 39114576 PMCID: PMC11305140 DOI: 10.1093/pnasnexus/pgae299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 07/03/2024] [Indexed: 08/10/2024]
Abstract
Neuropeptide Y (NPY), an endogenous peptide composed of 36 amino acids, has been investigated as a potential therapeutic agent for neurodegenerative diseases due to its neuroprotective attributes. This study investigated the neuroprotective effects of NPY in a mouse model of glaucoma characterized by elevated intraocular pressure (IOP) and progressive retinal ganglion cell degeneration. Elevated IOP in mice was induced through intracameral microbead injections, accompanied by intravitreal administration of NPY peptide. The results demonstrated that NPY treatment preserved both the structural and functional integrity of the inner retina and mitigated axonal damage and degenerative changes in the optic nerve under high IOP conditions. Further, NPY treatment effectively reduced inflammatory glial cell activation, as evidenced by decreased expression of glial fibrillary acidic protein and Iba-1. Notably, endogenous NPY expression and its receptors (NPY-Y1R and NPY-Y4R) levels were negatively affected in the retina under elevated IOP conditions. NPY treatment restored these changes to a significant extent. Molecular analysis revealed that NPY mediates its protective effects through the mitogen-activated protein kinase (MAPK) and PI3K/Akt signaling pathways. These findings highlight the therapeutic potential of NPY in glaucoma treatment, underscoring its capacity to preserve retinal health, modulate receptor expression under stress, reduce neuroinflammation, and impart protection against axonal impairment.
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Affiliation(s)
- Viswanthram Palanivel
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Vivek Gupta
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Nitin Chitranshi
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Ole Tietz
- Faculty of Medicine, Health and Human Sciences, Dementia Research Centre, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Roshana Vander Wall
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Reuben Blades
- Faculty of Medicine, Health and Human Sciences, Dementia Research Centre, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Kanishka Pushpitha Maha Thananthirige
- Faculty of Medicine, Health and Human Sciences, Dementia Research Centre, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Akanksha Salkar
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Chao Shen
- Microscopy Unit, Faculty of Science and Engineering, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Mehdi Mirzaei
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
| | - Veer Gupta
- School of Medicine, Deakin University, Geelong, VIC 3216, Australia
| | - Stuart L Graham
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
- Save Sight Institute, The University of Sydney, Sydney, NSW 2000, Australia
| | - Devaraj Basavarajappa
- Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, North Ryde, Sydney, NSW 2109, Australia
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Nayak A, Deveswaran R, Swati S, Srividhya L. Agreement of tonometer for measuring intraocular pressure in Wistar rats: a systematic review. Eur J Med Res 2024; 29:332. [PMID: 38880889 PMCID: PMC11181524 DOI: 10.1186/s40001-024-01927-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 06/06/2024] [Indexed: 06/18/2024] Open
Abstract
Glaucoma is the most common cause of irreversible blindness in the world. It is associated with elevated intraocular pressure (IOP). Fluctuations in tonometer readings have implications for glaucoma research, where accurate IOP measurements are vital for evaluating disease progression and treatment efficacy. Researchers should carefully select the appropriate tonometer and consider biases associated with different tonometers. Validation against standard measurements can improve IOP measurement accuracy in rat models. In conclusion, this systematic review will emphasize on the importance of selecting the appropriate tonometer for IOP measurement in rat models, considering potential biases and their implications for glaucoma research. Accurate and consistent IOP measurement in rat models is crucial for understanding glaucoma pathophysiology and developing effective treatments. This systematic review aims to assess agreement among tonometers used for measuring IOP in Wistar rat models primarily focusing on TonoLab, TonoVet, and Tono-pen. The review was conducted using PRISMA guidelines. Two articles were included for qualitative synthesis. The studies compared manometric IOP with TonoLab, rebound tonometer, and Tono-pen XL readings. It was observed that TonoLab consistently underestimated IOP, while Tono-pen XL tended to overestimate IOP compared to manometric measurements. The study's findings will help researchers in making decisions about tonometer selection, leading to more reliable outcomes in glaucoma research using rat models. Further research, specifically RCT's (randomized controlled trial) is needed to confirm the results and enhance IOP measurement precision in rat models.
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Affiliation(s)
- Anush Nayak
- Optometry Division, Department of Allied Health Sciences, Faculty of Life and Allied Health Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, India.
| | - R Deveswaran
- Department of Pharmaceuticals, Faculty of Pharmacy, M S Ramaiah University of Applied Sciences, Bengaluru, India
| | - S Swati
- Department of Biotechnology, Faculty of Life and Allied Health Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, India
| | - L Srividhya
- Optometry Division, Department of Allied Health Sciences, Faculty of Life and Allied Health Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, India
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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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Karg MM, Lu YR, Refaian N, Cameron J, Hoffmann E, Hoppe C, Shirahama S, Shah M, Krasniqi D, Krishnan A, Shrestha M, Guo Y, Cermak JM, Walthier M, Broniowska K, Rosenzweig-Lipson S, Gregory-Ksander M, Sinclair DA, Ksander BR. Sustained Vision Recovery by OSK Gene Therapy in a Mouse Model of Glaucoma. Cell Reprogram 2023; 25:288-299. [PMID: 38060815 PMCID: PMC10739681 DOI: 10.1089/cell.2023.0074] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023] Open
Abstract
Glaucoma, a chronic neurodegenerative disease, is a leading cause of age-related blindness worldwide and characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons. Previously, we developed a novel epigenetic rejuvenation therapy, based on the expression of the three transcription factors Oct4, Sox2, and Klf4 (OSK), which safely rejuvenates RGCs without altering cell identity in glaucomatous and old mice after 1 month of treatment. In the current year-long study, mice with continuous or cyclic OSK expression induced after glaucoma-induced vision damage had occurred were tracked for efficacy, duration, and safety. Surprisingly, only 2 months of OSK fully restored impaired vision, with a restoration of vision for 11 months with prolonged expression. In RGCs, transcription from the doxycycline (DOX)-inducible Tet-On AAV system, returned to baseline 4 weeks after DOX withdrawal. Significant vision improvements remained for 1 month post switching off OSK, after which the vision benefit gradually diminished but remained better than baseline. Notably, no adverse effects on retinal structure or body weight were observed in glaucomatous mice with OSK continuously expressed for 21 months providing compelling evidence of efficacy and safety. This work highlights the tremendous therapeutic potential of rejuvenating gene therapies using OSK, not only for glaucoma but also for other ocular and systemic injuries and age-related diseases.
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Affiliation(s)
- Margarete M. Karg
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Yuancheng Ryan Lu
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
- Whitehead Institute for Biomedical Research, Department of Biology, MIT, Cambridge, Massachusetts, USA
| | - Nasrin Refaian
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - James Cameron
- Whitehead Institute for Biomedical Research, Department of Biology, MIT, Cambridge, Massachusetts, USA
| | - Emma Hoffmann
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Cindy Hoppe
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Shintaro Shirahama
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Madhura Shah
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Drenushe Krasniqi
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Anitha Krishnan
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Maleeka Shrestha
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Yinjie Guo
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | | | | | - Meredith Gregory-Ksander
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - David A. Sinclair
- Paul F. Glenn Center for Biology of Aging Research, Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Bruce R. Ksander
- Schepens Eye Research Institute of Mass Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
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Wang T, Li S, Li XM, Li C, Wang F, Jiang Q. Targeting circular RNA-Glra2 alleviates retinal neurodegeneration induced by ocular hypertension. Aging (Albany NY) 2023; 15:10705-10731. [PMID: 37819813 PMCID: PMC10599745 DOI: 10.18632/aging.205108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/08/2023] [Indexed: 10/13/2023]
Abstract
Glaucoma is a leading cause of irreversible vision loss characterized by retinal neurodegeneration. Circular RNAs (circRNAs) have emerged as the potential biomarkers and therapeutic targets for neurodegenerative diseases. However, the expression profiling of circRNAs in glaucomatous neurodegeneration has not been fully understood. In this study, we built a glaucomatous neurodegeneration model via the injection of microbeads into anterior chamber. circRNA expression profile and bioinformatics analysis revealed that compared with normal retinas, 171 circRNAs were dysregulated in the glaucomatous retinas, including 101 up-regulated circRNAs and 70 down-regulated circRNAs. Detecting the level of circular RNA-glycine receptor α2 subunit gene (cGlra2) in aqueous humor made it possible to distinguish glaucoma patients from cataract patients. Silencing of cGlra2 protected against oxidative stress- or hydrostatic pressure-induced retinal ganglion cell (RGC) injury in vitro. Moreover, silencing of cGlra2 retarded ocular hypertension-induced retinal neurodegeneration in vivo as shown by increased TUJ1 staining, reduced reactive gliosis, decreased retinal cell apoptosis, enhanced visual acuity, and improved retinal function. cGlra2 acted as a miRNA sponge to regulate RGC function through cGlra2/miR-144/BCL2L11 signaling axis. Collectively, this study provides novel insights into the underlying mechanism of retinal neurodegeneration and highlights the potential of cGlra2 as a target for the diagnosis and treatment of glaucoma.
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Affiliation(s)
- Ting Wang
- Department of Ophthalmology, The Affiliated Huaian No. 1 Hospital of Nanjing Medical University, Huai’an, Jiangsu 223300, China
| | - Shuyan Li
- Department of Ophthalmology, The Affiliated Huaian No. 1 Hospital of Nanjing Medical University, Huai’an, Jiangsu 223300, China
| | - Xiu-Miao Li
- Department of Ophthalmology and Optometry, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, Jiangsu 210000, China
| | - Chaopeng Li
- Department of Ophthalmology, The Affiliated Huaian No. 1 Hospital of Nanjing Medical University, Huai’an, Jiangsu 223300, China
| | - Fang Wang
- Department of Ophthalmology, Clinical Medical College of Shanghai 10th People’s Hospital of Nanjing Medical University, Nanjing, Shanghai 200072, China
| | - Qin Jiang
- Department of Ophthalmology and Optometry, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, Jiangsu 210000, China
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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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Shang X, Reche J, Lincke JB, Häner NU, Lever M, Böhm MR, Bormann C, Zinkernagel MS, Unterlauft JD. Stage specific glaucomatous changes of the macula recorded using spectral domain optical coherence tomography. Photodiagnosis Photodyn Ther 2023; 43:103673. [PMID: 37380114 DOI: 10.1016/j.pdpdt.2023.103673] [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: 04/03/2023] [Revised: 05/18/2023] [Accepted: 06/22/2023] [Indexed: 06/30/2023]
Abstract
BACKGROUND This study aimed to compare the thickness of different macular retinal layers in glaucomatous eyes and healthy controls, and evaluate the diagnostic performance of spectral domain optical coherence tomography (SD-OCT) parameters. METHODS In this cross-sectional comparative study, 48 glaucomatous eyes and 44 healthy controls were included. The thickness of the total retina and all retinal layers were obtained using the Early Treatment Diagnostic Retinopathy Study (ETDRS) grid. The minimal and average values of outer and inner ETDRS-rings were calculated. The diagnostic performance for detection of glaucoma was evaluated using the area under the receiver operating characteristic curve (AUC). RESULTS The thickness of the total retina, ganglion cell layer (GCL), and inner-plexiform layer (IPL) was significantly thinner in glaucomatous eyes in all sectors except the center (all p<0.05). The thickness of retinal nerve fiber layer (RNFL) was significantly thinner in the glaucoma group except in the center, nasal inner, and temporal outer sectors (all p<0.05). Layer thinning advanced with glaucoma severity. The minimal outer GCL thickness showed the highest AUC value for discrimination between glaucomatous eyes and healthy controls(0.955). The minimal outer IPL showed the highest AUC value for discriminating early-stage glaucomatous eyes from healthy controls (0.938). CONCLUSIONS Glaucomatous eyes were found to have significant thinning in the macular region. GCL and IPL showed high ability to discriminate glaucomatous and early-stage glaucomatous eyes from controls. Applying the minimal value to the ETDRS grid has the potential to provide good diagnostic abilities in glaucoma screening.
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Affiliation(s)
- Xiao Shang
- Department of Ophthalmology, Inselspital Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern 3010, Switzerland
| | - Jelena Reche
- Department of Ophthalmology, Inselspital Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern 3010, Switzerland
| | - Joel-Benjamin Lincke
- Department of Ophthalmology, Inselspital Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern 3010, Switzerland
| | - Nathanael Urs Häner
- Department of Ophthalmology, Inselspital Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern 3010, Switzerland
| | - Mael Lever
- University Eye Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Michael Rr Böhm
- University Eye Hospital Essen, Hufelandstrasse 55, Essen 45147, Germany
| | - Caroline Bormann
- University Eye Hospital Leipzig, University of Leipzig, Liebigstrasse 10, Leipzig 04105, Germany
| | - Martin S Zinkernagel
- Department of Ophthalmology, Inselspital Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern 3010, Switzerland
| | - Jan Darius Unterlauft
- Department of Ophthalmology, Inselspital Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern 3010, Switzerland.
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Agarwal R, Agarwal P, Iezhitsa I. Exploring the current use of animal models in glaucoma drug discovery: where are we in 2023? Expert Opin Drug Discov 2023; 18:1287-1300. [PMID: 37608634 DOI: 10.1080/17460441.2023.2246892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/08/2023] [Indexed: 08/24/2023]
Abstract
INTRODUCTION Animal models are widely used in glaucoma-related research. Since the elevated intraocular pressure (IOP) is a major risk factor underlying the disease pathogenesis, animal models with high IOP are commonly used. However, models are also used to represent the clinical context of glaucomatous changes developing despite a normal IOP. AREAS COVERED Herein, the authors discuss the various factors that contribute to the quality of studies using animal models based on the evaluation of studies published in 2022. The factors affecting the quality of studies using animal models, such as the animal species, age, and sex, are discussed, along with various methods and outcomes of studies involving different animal models of glaucoma. EXPERT OPINION Translating animal research data to clinical applications remains challenging. Our observations in this review clearly indicate that many studies lack scientific robustness not only in their experiment conduct but also in data analysis, interpretation, and presentation. In this context, ensuring the internal validity of animal studies is the first step in quality assurance. External validity, however, is more challenging, and steps should be taken to satisfy external validity at least to some extent.
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Affiliation(s)
- Renu Agarwal
- School of Medicine, International Medical University, Bukit Jalil, Malaysia
| | - Puneet Agarwal
- School of Medicine, International Medical University, Bukit Jalil, Malaysia
| | - Igor Iezhitsa
- School of Medicine, International Medical University, Bukit Jalil, Malaysia
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Fang CEH, Hakim MT, Siddiqui MM, Armstrong D, Shankar V. A retrospective study to assess visual field improvement following augmented trabeculectomy. Indian J Ophthalmol 2023; 71:1953-1959. [PMID: 37203064 PMCID: PMC10391496 DOI: 10.4103/ijo.ijo_2071_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Purpose To explore the visual field (VF) changes two years following augmented trabeculectomy. Methods A retrospective study of patients who underwent augmented trabeculectomy surgery with mitomycin C by a single surgeon at East Lancashire Teaching Hospitals NHS Trust over 3 years. Patients with a minimum of two years postoperative follow-up were included. Baseline characteristics, intraocular pressure (IOP), VF, number of glaucoma medications, and complications were recorded. Results In total, 206 eyes were included, 97 (47%) patients were female, and the mean age was 73.8 ± 10.3 (range 43 to 93) years. One hundred thirty-one (63.6%) eyes were pseudophakic before trabeculectomy. The patients were divided into three outcome groups according to VF outcome. Seventy-seven (37.4%) patients had stable VF, 35 (17.0%) patients showed VF improvement, and 94 (45.6%) had VF deterioration. The overall mean preoperative IOP was 22.7 ± 8.0 mmHg and postoperative IOP 10.4 ± 4.2 mmHg, with a reduction of 50.2% (P < 0.001). In total, 84.5% of postoperative patients did not require glaucoma medications. A higher number of patients with postoperative IOP ≥15 mmHg had deteriorating VF (P < 0.001). Based on preoperative MD distribution, VF improvement or stability was more achievable with patients with a preoperative VF defect up to -12 dB (n = 41, 59.4%) and in those with greater than -24 dB (n = 25, 64.1%). Conclusion Trabeculectomy continues to be an effective means of lowering IOP in patients with uncontrolled glaucoma and is important in stabilizing or improving visual fields. We recommend early trabeculectomy to prevent further VF deterioration. This may help in maintaining VF for driving status and, thus, quality of life.
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Affiliation(s)
- Clarissa E H Fang
- Ophthalmology Department, East Lancashire Hospitals NHS Trust, Burnley, United Kingdom
| | - Mohamad T Hakim
- Ophthalmology Department, East Lancashire Hospitals NHS Trust, Burnley, United Kingdom
| | - Muhammad M Siddiqui
- Ophthalmology Department, East Lancashire Hospitals NHS Trust, Burnley, United Kingdom
| | - Deborah Armstrong
- Ophthalmology Department, East Lancashire Hospitals NHS Trust, Burnley, United Kingdom
| | - Vikas Shankar
- Ophthalmology Department, East Lancashire Hospitals NHS Trust, Burnley, United Kingdom
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Zhao GL, Zhou H, Guo YH, Zhong SM, Zhou H, Li F, Lei B, Wang Z, Miao Y. Modulation of Rac1/PAK1/connexin43-mediated ATP release from astrocytes contributes to retinal ganglion cell survival in experimental glaucoma. Glia 2023; 71:1502-1521. [PMID: 36794533 DOI: 10.1002/glia.24354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/17/2023]
Abstract
Connexin43 (Cx43) is a major gap junction protein in glial cells. Mutations have been found in the gap-junction alpha 1 gene encoding Cx43 in glaucomatous human retinas, suggestive of the involvement of Cx43 in the pathogenesis of glaucoma. However, how Cx43 is involved in glaucoma is still unknown. We showed that increased intraocular pressure in a glaucoma mouse model of chronic ocular hypertension (COH) downregulated Cx43, which was mainly expressed in retinal astrocytes. Astrocytes in the optic nerve head where they gather and wrap the axons (optic nerve) of retinal ganglion cells (RGCs) were activated earlier than neurons in COH retinas and the alterations in astrocytes plasticity in the optic nerve caused a reduction in Cx43 expression. A time course showed that reductions of Cx43 expression were correlated with the activation of Rac1, a member of the Rho family. Co-immunoprecipitation assays showed that active Rac1, or the downstream signaling effector PAK1, negatively regulated Cx43 expression, Cx43 hemichannel opening and astrocyte activation. Pharmacological inhibition of Rac1 stimulated Cx43 hemichannel opening and ATP release, and astrocytes were identified to be one of the main sources of ATP. Furthermore, conditional knockout of Rac1 in astrocytes enhanced Cx43 expression and ATP release, and promoted RGC survival by upregulating the adenosine A3 receptor in RGCs. Our study provides new insight into the relationship between Cx43 and glaucoma, and suggests that regulating the interaction between astrocytes and RGCs via the Rac1/PAK1/Cx43/ATP pathway may be used as part of a therapeutic strategy for managing glaucoma.
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Affiliation(s)
- Guo-Li Zhao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Hong Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yun-Hui Guo
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Shu-Min Zhong
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Han Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Fang Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Bo Lei
- Institute of Neuroscience and Third Affiliated Hospital, Henan Provincial People's Hospital, Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Zhongfeng Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Yanying Miao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
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11
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Ramírez JM, Salobrar-García E, de Hoz R, Salazar JJ, Matamoros JA, Sánchez-Puebla L, López-Cuenca I, Fernández-Albarral JA, Ramírez AI. Laser-Induced Ocular Hypertension in a Mouse Model of Glaucoma. Methods Mol Biol 2023; 2708:49-56. [PMID: 37558959 DOI: 10.1007/978-1-0716-3409-7_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Glaucoma is a neurodegenerative disease that leads to the loss of retinal ganglion cells (RGC) and thus to blindness. There are numerous experimental models used for the study of this pathology. Among the different models, episcleral vein photocoagulation is one of the most widely used. In this model there is a transient increase in intraocular pressure that returns to normal values about 7 days after induction of ocular hypertension (OHT). In addition, typical glaucoma changes, such as loss of RGC, thinning of the optic nerve fiber layer, and glial activation, occur in this model. All these changes have been described in detail over time after OHT induction. In this chapter, we describe the detailed method of OHT induction in Swiss albino mice by diode laser photocoagulation of limbal and episcleral veins.
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Affiliation(s)
- José M Ramírez
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, School of Medicine, Complutense University of Madrid, Madrid, Spain
- Institute for Health Research, Hospital Clínico San Carlos (IdISSC), Madrid, Spain
| | - Elena Salobrar-García
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain
- Institute for Health Research, Hospital Clínico San Carlos (IdISSC), Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Rosa de Hoz
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain
- Institute for Health Research, Hospital Clínico San Carlos (IdISSC), Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Juan J Salazar
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain
- Institute for Health Research, Hospital Clínico San Carlos (IdISSC), Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - José A Matamoros
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain
| | - Lidia Sánchez-Puebla
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain
| | - Inés López-Cuenca
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - José A Fernández-Albarral
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain.
| | - Ana I Ramírez
- Ramón Castroviejo Institute for Ophthalmological Research, Complutense University of Madrid, Madrid, Spain.
- Institute for Health Research, Hospital Clínico San Carlos (IdISSC), Madrid, Spain.
- Department of Immunology, Ophthalmology and ENT, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain.
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12
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Analysis of Axonal Regrowth and Dendritic Remodeling After Optic Nerve Crush in Adult Zebrafish. Methods Mol Biol 2023; 2636:163-190. [PMID: 36881300 DOI: 10.1007/978-1-0716-3012-9_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Neurodegenerative diseases and central nervous system (CNS) injuries are frequently characterized by axonal damage, as well as dendritic pathology. In contrast to mammals, adult zebrafish show a robust regeneration capacity after CNS injury and form the ideal model organism to further unravel the underlying mechanisms for both axonal and dendritic regrowth upon CNS damage. Here, we first describe an optic nerve crush injury model in adult zebrafish, an injury paradigm that inflicts de- and regeneration of the axons of retinal ganglion cells (RGCs), but also triggers RGC dendrite disintegration and subsequent recovery in a stereotyped and timed process. Next, we outline protocols for quantifying axonal regeneration and synaptic recovery in the brain, using retro- and anterograde tracing experiments and an immunofluorescent staining for presynaptic compartments, respectively. Finally, methods to analyze RGC dendrite retraction and subsequent regrowth in the retina are delineated, using morphological measurements and immunofluorescent staining for dendritic and synaptic markers.
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13
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Pitale PM, Shen G, Sigireddi RR, Polo-Prieto M, Park YH, Gibson SE, Westenskow PD, Channa R, Frankfort BJ. Selective vulnerability of the intermediate retinal capillary plexus precedes retinal ganglion cell loss in ocular hypertension. Front Cell Neurosci 2022; 16:1073786. [PMID: 36545655 PMCID: PMC9760765 DOI: 10.3389/fncel.2022.1073786] [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: 10/18/2022] [Accepted: 11/15/2022] [Indexed: 12/08/2022] Open
Abstract
Introduction: Glaucoma, a disease of retinal ganglion cell (RGC) injury and potentially devastating vision loss, is associated with both ocular hypertension (OHT) and reduced ocular blood flow. However, the relationship between OHT and retinal capillary architecture is not well understood. In this project, we studied microvasculature damage in mice exposed to mild levels of induced OHT. Methods: Mild OHT was induced with the microbead model for 2 weeks. At this time point, some retinas were immunostained with CD31 (endothelium), Collagen IV (basement membrane), and RBPMS (RGCs) for z-stack confocal microscopy. We processed these confocal images to distinguish the three retinal capillary plexi (superficial, intermediate, and deep). We manually counted RGC density, analyzed vascular complexity, and identified topographical and spatial vascular features of the retinal capillaries using a combination of novel manual and automated workflows. Other retinas were dissociated and immunopanned to isolate RGCs and amacrine cells (ACs) for hypoxia gene array analysis. Results: RGC counts were normal but there was decreased overall retinal capillary complexity. This reduced complexity could be explained by abnormalities in the intermediate retinal capillary plexus (IRCP) that spared the other plexi. Capillary junction density, vessel length, and vascular area were all significantly reduced, and the number of acellular capillaries was dramatically increased. ACs, which share a neurovascular unit (NVU) with the IRCP, displayed a marked increase in the relative expression of many hypoxia-related genes compared to RGCs from the same preparations. Discussion: We have discovered a rapidly occurring, IRCP-specific, OHT-induced vascular phenotype that precedes RGC loss. AC/IRCP NVU dysfunction may be a mechanistic link for early vascular remodeling in glaucoma.
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Affiliation(s)
- Priyamvada M. Pitale
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Guofu Shen
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Rohini R. Sigireddi
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Maria Polo-Prieto
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Yong H. Park
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Solomon E. Gibson
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States,Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Peter D. Westenskow
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Roomasa Channa
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Benjamin J. Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States,Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States,*Correspondence: Benjamin J. Frankfort
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14
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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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15
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Lee KM, Song DY, Kim SH. Effect of Strain on Rodent Glaucoma Models: Magnetic Bead Injection Versus Hydrogel Injection Versus Circumlimbal Suture. Transl Vis Sci Technol 2022; 11:31. [PMID: 36173647 PMCID: PMC9527335 DOI: 10.1167/tvst.11.9.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To compare the inter-strain differences of three rodent glaucoma models as induced by magnetic bead injection, hydrogel injection, and circumlimbal suture. Methods In Brown Norway (BN) and Sprague Dawley (SD) rat strains, intraocular pressure (IOP) was elevated by injection of magnetic beads or hydrogel to obstruct the aqueous humor outflow or by external compression of circumlimbal suture. Maximum and average IOP values were compared according to both procedure and rat strain over 1 month postoperatively. Retinal ganglion cell (RGC) density loss was evaluated using confocal microscopic images of the flat-mounted retina obtained at postoperative days 14 and 30. Results The maximum IOPs were higher in the hydrogel injection or circumlimbal injection models than in the magnetic bead injection model (P < 0.001), whereas average IOP showed no difference between the two strains (both P ≥ 0.05). A generalized estimating equation regression model showed that the IOP increase was maintained better in the BN rats than in the SD rats (P < 0.001). Such inter-strain difference was smaller in the circumlimbal suture model. A significant decrease in RGC density was observed in all of the models for the BN rats and in the circumlimbal suture model for the SD rats at postoperative day 30. Conclusions BN rats were advantageous for the magnetic bead or hydrogel injection model, but either rat strain could be used for the circumlimbal suture model. Strains should be considered cautiously when establishing rodent glaucoma models with different IOP profiles. Translational Relevance This comparison offers the best strain for each rodent glaucoma model for assessment of glaucoma-relevant therapeutics.
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Affiliation(s)
- Kyoung Min Lee
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.,Department of Ophthalmology, Seoul National University Boramae Medical Center, Seoul, Korea
| | - Da Young Song
- Department of Ophthalmology, Seoul National University Boramae Medical Center, Seoul, Korea
| | - Seok Hwan Kim
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.,Department of Ophthalmology, Seoul National University Boramae Medical Center, Seoul, Korea
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16
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Gerberich BG, Hannon BG, Brown DM, Read AT, Ritch MD, Schrader Echeverri E, Nichols L, Potnis C, Sridhar S, Toothman MG, Schwaner SA, Winger EJ, Huang H, Gershon GS, Feola AJ, Pardue MT, Prausnitz MR, Ethier CR. Evaluation of Spatially Targeted Scleral Stiffening on Neuroprotection in a Rat Model of Glaucoma. Transl Vis Sci Technol 2022; 11:7. [PMID: 35536721 PMCID: PMC9100482 DOI: 10.1167/tvst.11.5.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/14/2022] [Indexed: 11/25/2022] Open
Abstract
Purpose Scleral stiffening may protect against glaucomatous retinal ganglion cell (RGC) loss or dysfunction associated with ocular hypertension. Here, we assess the potential neuroprotective effects of two treatments designed to stiffen either the entire posterior sclera or only the sclera adjacent to the peripapillary sclera in an experimental model of glaucoma. Methods Rat sclerae were stiffened in vivo using either genipin (crosslinking the entire posterior sclera) or a regionally selective photosensitizer, methylene blue (stiffening only the juxtaperipapillary region surrounding the optic nerve). Ocular hypertension was induced using magnetic microbeads delivered to the anterior chamber. Morphological and functional outcomes, including optic nerve axon count and appearance, retinal thickness measured by optical coherence tomography, optomotor response, and electroretinography traces, were assessed. Results Both local (juxtaperipapillary) and global (whole posterior) scleral stiffening treatments were successful at increasing scleral stiffness, but neither provided demonstrable neuroprotection in hypertensive eyes as assessed by RGC axon counts and appearance, optomotor response, or electroretinography. There was a weak indication that scleral crosslinking protected against retinal thinning as assessed by optical coherence tomography. Conclusions Scleral stiffening was not demonstrated to be neuroprotective in ocular hypertensive rats. We hypothesize that the absence of benefit may in part be due to RGC loss associated with the scleral stiffening agents themselves (mild in the case of genipin, and moderate in the case of methylene blue), negating any potential benefit of scleral stiffening. Translational Relevance The development of scleral stiffening as a neuroprotective treatment will require the identification of better tolerated stiffening protocols and further preclinical testing.
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Affiliation(s)
- Brandon G. Gerberich
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Bailey G. Hannon
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Dillon M. Brown
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - A. Thomas Read
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Matthew D. Ritch
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Elisa Schrader Echeverri
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Lauren Nichols
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Cahil Potnis
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veteran Affairs Healthcare System, Atlanta, GA, USA
| | - Sreesh Sridhar
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Maya G. Toothman
- College of Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Stephen A. Schwaner
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
- Exponent, Inc., Biomechanics Practice, Atlanta, GA, USA
| | - Erin J. Winger
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Hannah Huang
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Gabby S. Gershon
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Andrew J. Feola
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veteran Affairs Healthcare System, Atlanta, GA, USA
| | - Machelle T. Pardue
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veteran Affairs Healthcare System, Atlanta, GA, USA
| | - Mark R. Prausnitz
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - C. Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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17
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Ramamoorthy P, Alexander NL, Frankfort BJ. Abnormal perception of pattern-induced flicker colors in subjects with glaucoma. J Vis 2022; 22:5. [PMID: 35133432 PMCID: PMC8842510 DOI: 10.1167/jov.22.2.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Pattern-induced flicker colors (PIFCs) are subjective colors that can be elicited with rotation of an achromatic stimulus such as the Benham disk. The perceptive mechanisms underlying PIFCs are not well-understood, but are thought to be generated primarily by retinal cell types which may be dysfunctional in glaucoma. Using a custom computer-based system, we tested PIFC perception across several Benham disk parameters, including the rates of acceleration and deceleration, rotational direction, and image contrast in both control and glaucoma subjects. We defined the Benham perception limit (BPL) during acceleration as the rotational speed at which PIFCs were first detected (Benham perception limit for acceleration) and the BPL during deceleration as the rotational speed at which PIFCs were extinguished (Benham perception limit for deceleration). In general, we found that glaucoma subjects perceived PIFCs less frequently than control subjects. For all subjects, we found that slower rates of acceleration and deceleration resulted in a lower Benham perception limit for acceleration and a higher Benham perception limit for deceleration, suggesting that PIFCs were both more easily detected and extinguished. Finally, subjects with glaucoma required increased rotational speeds during acceleration to detect PIFCs under certain conditions. Further study is needed to determine if these findings can be used to enhance clinical detection strategies.
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Affiliation(s)
| | - Nicole L Alexander
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.,
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA.,
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18
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Ingensiep C, Schaffrath K, Walter P, Johnen S. Effects of Hydrostatic Pressure on Electrical Retinal Activity in a Multielectrode Array-Based ex vivo Glaucoma Acute Model. Front Neurosci 2022; 16:831392. [PMID: 35177963 PMCID: PMC8845467 DOI: 10.3389/fnins.2022.831392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Glaucoma is a heterogeneous eye disease causing atrophy of the optic nerve head (ONH). The optic nerve is formed by the axons of the retinal ganglion cells (RGCs) that transmit visual input to the brain. The progressive RGC loss during glaucoma leads to irreversible vision loss. An elevated intraocular pressure (IOP) is described as main risk factor in glaucoma. In this study, a multielectrode array (MEA)-based ex vivo glaucoma acute model was established and the effects of hydrostatic pressure (10, 30, 60, and 90 mmHg) on the functionality and survival of adult male and female wild-type mouse (C57BL/6) retinae were investigated. Spontaneous activity, response rate to electrical and light stimulation, and bursting behavior of RGCs was analyzed prior, during, and after pressure stress. No pressure related effects on spontaneous firing and on the response rate of the RGCs were observed. Even a high pressure level (90 mmHg for 2 h) did not disturb the RGC functionality. However, the cells’ bursting behavior significantly changed under 90 mmHg. The number of spikes in bursts doubled during pressure application and stayed on a high level after pressure stress. Addition of the amino sulfonic acid taurine (1 mM) showed a counteracting effect. OFF ganglion cells did not reveal an increase in bursts under pressure stress. Live/dead staining after pressure application showed no significant changes in RGC survival. The findings of our ex vivo model suggest that RGCs are tolerant toward high, short-time pressure stress.
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19
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Di Pierdomenico J, Henderson DCM, Giammaria S, Smith VL, Jamet AJ, Smith CA, Hooper ML, Chauhan BC. Age and intraocular pressure in murine experimental glaucoma. Prog Retin Eye Res 2021; 88:101021. [PMID: 34801667 DOI: 10.1016/j.preteyeres.2021.101021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/25/2021] [Accepted: 11/08/2021] [Indexed: 12/23/2022]
Abstract
Age and intraocular pressure (IOP) are the two most important risk factors for the development and progression of open-angle glaucoma. While IOP is commonly considered in models of experimental glaucoma (EG), most studies use juvenile or adult animals and seldom older animals which are representative of the human disease. This paper provides a concise review of how retinal ganglion cell (RGC) loss, the hallmark of glaucoma, can be evaluated in EG with a special emphasis on serial in vivo imaging, a parallel approach used in clinical practice. It appraises the suitability of EG models for the purpose of in vivo imaging and argues for the use of models that provide a sustained elevation of IOP, without compromise of the ocular media. In a study with parallel cohorts of adult (3-month-old, equivalent to 20 human years) and old (2-year-old, equivalent to 70 human years) mice, we compare the effects of elevated IOP on serial ganglion cell complex thickness and individual RGC dendritic morphology changes obtained in vivo. We also evaluate how age modulates the impact of elevated IOP on RGC somal and axonal density in histological analysis as well the density of melanopsin RGCs. We discuss the challenges of using old animals and emphasize the potential of single RGC imaging for understanding the pathobiology of RGC loss and evaluating new therapeutic avenues.
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Affiliation(s)
- Johnny Di Pierdomenico
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Delaney C M Henderson
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sara Giammaria
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Victoria L Smith
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Aliénor J Jamet
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Corey A Smith
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michele L Hooper
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Balwantray C Chauhan
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
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20
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Lucas-Ruiz F, Galindo-Romero C, Albaladejo-García V, Vidal-Sanz M, Agudo-Barriuso M. Mechanisms implicated in the contralateral effect in the central nervous system after unilateral injury: focus on the visual system. Neural Regen Res 2021; 16:2125-2131. [PMID: 33818483 PMCID: PMC8354113 DOI: 10.4103/1673-5374.310670] [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] [Received: 10/10/2020] [Revised: 11/21/2020] [Accepted: 01/11/2021] [Indexed: 12/21/2022] Open
Abstract
The retina, as part of the central nervous system is an ideal model to study the response of neurons to injury and disease and to test new treatments. During the last decade is becoming clear that unilateral lesions in bilateral areas of the central nervous system trigger an inflammatory response in the contralateral uninjured site. This effect has been better studied in the visual system where, as a rule, one retina is used as experimental and the other as control. Contralateral retinas in unilateral models of retinal injury show neuronal degeneration and glial activation. The mechanisms by which this adverse response in the central nervous system occurs are discussed in this review, focusing primarily on the visual system.
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Affiliation(s)
- Fernando Lucas-Ruiz
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIBArrixaca) Murcia, Spain
| | - Caridad Galindo-Romero
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIBArrixaca) Murcia, Spain
| | - Virginia Albaladejo-García
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIBArrixaca) Murcia, Spain
| | - Manuel Vidal-Sanz
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIBArrixaca) Murcia, Spain
| | - Marta Agudo-Barriuso
- Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIBArrixaca) Murcia, Spain
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21
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Rodrigo MJ, Martinez-Rincon T, Subias M, Mendez-Martinez S, Pablo LE, Polo V, Aragon-Navas A, Garcia-Herranz D, Feijoo JG, Osuna IB, Herrero-Vanrell R, Garcia-Martin E. Influence of Sex on Neuroretinal Degeneration: Six-Month Follow-Up in Rats With Chronic Glaucoma. Invest Ophthalmol Vis Sci 2021; 62:9. [PMID: 34643665 PMCID: PMC8525827 DOI: 10.1167/iovs.62.13.9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Purpose To evaluate differences by sex in the neuroretina of rats with chronic glaucoma over 24 weeks of follow-up, and to assess by sex the influence on neurodegeneration of different methods of inducing ocular hypertension. Methods Forty-six Long-Evans rats-18 males and 28 females-with induced chronic glaucoma were analyzed. Glaucoma was achieved via 2 models: repeatedly sclerosing the episcleral veins (9 male/14 female) or by injecting poly(lactic-co-glycolic acid) microspheres measuring 20 to 10 µm (Ms20/10) into the anterior chamber (9 male/14 female). The IOP was measured weekly by tonometer; neuroretinal function was recorded by dark/light-adapted electroretinography at baseline and weeks 12 and 24; and structure was analyzed by optical coherence tomography using the retina posterior pole, retinal nerve fiber layer and ganglion cell layer protocols at baseline and weeks 8, 12, 18, and 24. Results Males showed statistically significant (P < 0.05) higher IOP in both chronic glaucoma models, and greater differences were found in the episcleral model at earlier stages. Males with episclerally induced glaucoma showed a statistically higher increase in retinal thickness in optical coherence tomography recordings than females and also when comparing Ms20/10 at 12 weeks. Males showed a higher percentage of retinal nerve fiber layer thickness loss in both models. Ganglion cell layer thickness loss was only detected in the Ms20/10 model. Males exhibited worse dark/light-adapted functionality in chronic glaucoma models, which worsened in the episcleral sclerosis model at 12 weeks, than females. Conclusions Female rats with chronic glaucoma experienced lower IOP and structural loss and better neuroretinal functionality than males. Sex and the ocular hypertension-inducing method influenced neuroretinal degeneration.
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Affiliation(s)
- Maria J Rodrigo
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.,Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain.,National Ocular Pathology Network (OFTARED), Carlos III Health Institute, Madrid, Spain
| | - Teresa Martinez-Rincon
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.,Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Manuel Subias
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.,Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Silvia Mendez-Martinez
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.,Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Luis E Pablo
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.,Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain.,National Ocular Pathology Network (OFTARED), Carlos III Health Institute, Madrid, Spain
| | - Vicente Polo
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.,Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Alba Aragon-Navas
- Ophthalmology Innovation, Therapy and Pharmaceutical Development (InnOftal) Research Group, UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain.,Health Research Institute, San Carlos Clinical Hospital (IdISSC), Madrid, Spain
| | - David Garcia-Herranz
- Ophthalmology Innovation, Therapy and Pharmaceutical Development (InnOftal) Research Group, UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain.,Health Research Institute, San Carlos Clinical Hospital (IdISSC), Madrid, Spain
| | - Julian García Feijoo
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, Madrid, Spain.,Health Research Institute, San Carlos Clinical Hospital (IdISSC), Madrid, Spain.,Department of Ophthalmology, San Carlos Clinical Hospital, UCM, Madrid, Spain
| | - Irene Bravo Osuna
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, Madrid, Spain.,Ophthalmology Innovation, Therapy and Pharmaceutical Development (InnOftal) Research Group, UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain.,Health Research Institute, San Carlos Clinical Hospital (IdISSC), Madrid, Spain.,University Institute for Industrial Pharmacy (IUFI), School of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - Rocio Herrero-Vanrell
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, Madrid, Spain.,Ophthalmology Innovation, Therapy and Pharmaceutical Development (InnOftal) Research Group, UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain.,Health Research Institute, San Carlos Clinical Hospital (IdISSC), Madrid, Spain.,University Institute for Industrial Pharmacy (IUFI), School of Pharmacy, Complutense University of Madrid, Madrid, Spain
| | - Elena Garcia-Martin
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain.,Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain.,National Ocular Pathology Network (OFTARED), Carlos III Health Institute, Madrid, Spain.,https://orcid.org/0000-0001-6258-2489
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22
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Protective effect of Acer palmatum Thunb. leaf extract on mice with steroid-induced ocular hypertension. Mol Cell Toxicol 2021. [DOI: 10.1007/s13273-021-00173-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Mendez-Martinez S, Martínez-Rincón T, Subias M, Pablo LE, García-Herranz D, Feijoo JG, Bravo-Osuna I, Herrero-Vanrell R, Garcia-Martin E, Rodrigo MJ. Influence of Chronic Ocular Hypertension on Emmetropia: Refractive, Structural and Functional Study in Two Rat Models. J Clin Med 2021; 10:jcm10163697. [PMID: 34441992 PMCID: PMC8397123 DOI: 10.3390/jcm10163697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/29/2022] Open
Abstract
Chronic ocular hypertension (OHT) influences on refraction in youth and causes glaucoma in adulthood. However, the origin of the responsible mechanism is unclear. This study analyzes the effect of mild-moderate chronic OHT on refraction and neuroretina (structure and function) in young-adult Long-Evans rats using optical coherence tomography and electroretinography over 24 weeks. Data from 260 eyes were retrospectively analyzed in two cohorts: an ocular normotension (ONT) cohort (<20 mmHg) and an OHT cohort (>20 mmHg), in which OHT was induced either by sclerosing the episcleral veins (ES group) or by injecting microspheres into the anterior chamber. A trend toward emmetropia was found in both cohorts over time, though it was more pronounced in the OHT cohort (p < 0.001), especially in the ES group (p = 0.001) and males. IOP and refraction were negatively correlated at week 24 (p = 0.010). The OHT cohort showed early thickening in outer retinal sectors (p < 0.050) and the retinal nerve fiber layer, which later thinned. Electroretinography demonstrated early supranormal amplitudes and faster latencies that later declined. Chronic OHT accelerates emmetropia in Long–Evans rat eyes towards slowly progressive myopia, with an initial increase in structure and function that reversed over time.
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Affiliation(s)
- Silvia Mendez-Martinez
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (T.M.-R.); (M.S.); (L.E.P.); (E.G.-M.); (M.J.R.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
- Correspondence: ; Tel.: +34-9-7676-5558
| | - Teresa Martínez-Rincón
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (T.M.-R.); (M.S.); (L.E.P.); (E.G.-M.); (M.J.R.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
| | - Manuel Subias
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (T.M.-R.); (M.S.); (L.E.P.); (E.G.-M.); (M.J.R.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
| | - Luis E. Pablo
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (T.M.-R.); (M.S.); (L.E.P.); (E.G.-M.); (M.J.R.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, 28040 Madrid, Spain; (J.G.F.); (I.B.-O.); (R.H.-V.)
| | - David García-Herranz
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415 Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain;
- Health Research Institute, San Carlos Clinical Hospital (IdISSC), 28040 Madrid, Spain
- University Institute for Industrial Pharmacy (IUFI), School of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain
| | - Julian García Feijoo
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, 28040 Madrid, Spain; (J.G.F.); (I.B.-O.); (R.H.-V.)
- Department of Ophthalmology, San Carlos Clinical Hospital (IdISSC), Complutense University of Madrid, 28040 Madrid, Spain
| | - Irene Bravo-Osuna
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, 28040 Madrid, Spain; (J.G.F.); (I.B.-O.); (R.H.-V.)
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415 Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain;
- Health Research Institute, San Carlos Clinical Hospital (IdISSC), 28040 Madrid, Spain
| | - Rocío Herrero-Vanrell
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, 28040 Madrid, Spain; (J.G.F.); (I.B.-O.); (R.H.-V.)
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM 920415 Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain;
- Health Research Institute, San Carlos Clinical Hospital (IdISSC), 28040 Madrid, Spain
| | - Elena Garcia-Martin
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (T.M.-R.); (M.S.); (L.E.P.); (E.G.-M.); (M.J.R.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, 28040 Madrid, Spain; (J.G.F.); (I.B.-O.); (R.H.-V.)
| | - María J. Rodrigo
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (T.M.-R.); (M.S.); (L.E.P.); (E.G.-M.); (M.J.R.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
- National Ocular Pathology Network (OFTARED), Carlos III Health Institute, 28040 Madrid, Spain; (J.G.F.); (I.B.-O.); (R.H.-V.)
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24
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Tong Y, Wang T, Zhang X, He Y, Jiang B. Optical Coherence Tomography Evaluation of Peripapillary and Macular Structure Changes in Pre-perimetric Glaucoma, Early Perimetric Glaucoma, and Ocular Hypertension: A Systematic Review and Meta-Analysis. Front Med (Lausanne) 2021; 8:696004. [PMID: 34277670 PMCID: PMC8280320 DOI: 10.3389/fmed.2021.696004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 05/28/2021] [Indexed: 01/17/2023] Open
Abstract
Background: This study aimed to assess the differences in the average and sectoral peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell plus inner plexiform layer (mGCIPL), and macular ganglion cell complex (mGCC) thickness using optical coherence tomography (OCT) in patients with pre-perimetric glaucoma (PPG) compared to those with early perimetric glaucoma (EG) and ocular hypertension (OHT). Methods: A comprehensive literature search of the PubMed database, the Cochrane Library, and Embase was performed from inception to March 2021. The weighted mean difference (WMD) with the 95% confidence interval (CI) was pooled for continuous outcomes. Results: Twenty-three cross-sectional studies comprising 2,574 eyes (1,101 PPG eyes, 1,233 EG eyes, and 240 OHT eyes) were included in the systematic review and meta-analysis. The pooled results demonstrated that the average pRNFL (WMD = 8.22, 95% CI = 6.32–10.12, P < 0.00001), mGCIPL (WMD = 4.83, 95% CI = 3.43–6.23, P < 0.00001), and mGCC (WMD = 7.19, 95% CI = 4.52–9.85, P < 0.00001) were significantly thinner in patients with EG than in those with PPG. The sectoral thickness of pRNFL, mGCIPL, and mGCC were also significantly lower in the EG eyes. In addition, the average pRNFL and mGCC were significantly thinner in the PPG eyes than those in the OHT eyes (pRNFL: WMD = −8.57, 95% CI = −9.88 to −7.27, P < 0.00001; mGCC: WMD = −3.23, 95% CI = −6.03 to −0.44, P = 0.02). Similarly, the sectoral pRNFL and mGCC were also significantly thinner in the PPG eyes than those in the OHT eyes. Conclusion: OCT-based measurements of peripapillary and macular structural alterations can be used to distinguish PPG from EG and OHT, which can help understand the pathophysiology of glaucoma at earlier stages. Studies that employ clock hour classification methods and longitudinal studies are needed to verify our findings. Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=239798 CRD42021239798
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Affiliation(s)
- Yuxin Tong
- Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Clinical Research Center of Ophthalmic Disease, Changsha, China
| | - Tiantian Wang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
| | - Xinyu Zhang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Clinical Research Center of Ophthalmic Disease, Changsha, China
| | - Yi He
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
| | - Bing Jiang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha, China.,Hunan Clinical Research Center of Ophthalmic Disease, Changsha, China
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25
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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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26
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Pang JJ, Gao F, Wu SM. Generators of Pressure-Evoked Currents in Vertebrate Outer Retinal Neurons. Cells 2021; 10:cells10061288. [PMID: 34067375 PMCID: PMC8224636 DOI: 10.3390/cells10061288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022] Open
Abstract
(1) Background: High-tension glaucoma damages the peripheral vision dominated by rods. How mechanosensitive channels (MSCs) in the outer retina mediate pressure responses is unclear. (2) Methods: Immunocytochemistry, patch clamp, and channel fluorescence were used to study MSCs in salamander photoreceptors. (3) Results: Immunoreactivity of transient receptor potential channel vanilloid 4 (TRPV4) was revealed in the outer plexiform layer, K+ channel TRAAK in the photoreceptor outer segment (OS), and TRPV2 in some rod OS disks. Pressure on the rod inner segment evoked sustained currents of three components: (A) the inward current at <-50 mV (Ipi), sensitive to Co2+; (B) leak outward current at ≥-80 mV (Ipo), sensitive to intracellular Cs+ and ruthenium red; and (C) cation current reversed at ~10 mV (Ipc). Hypotonicity induced slow currents like Ipc. Environmental pressure and light increased the FM 1-43-identified open MSCs in the OS membrane, while pressure on the OS with internal Cs+ closed a Ca2+-dependent current reversed at ~0 mV. Rod photocurrents were thermosensitive and affected by MSC blockers. (4) Conclusions: Rods possess depolarizing (TRPV) and hyperpolarizing (K+) MSCs, which mediate mutually compensating currents between -50 mV and 10 mV, serve as an electrical cushion to minimize the impact of ocular mechanical stress.
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27
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Tao X, Sabharwal J, Wu SM, Frankfort BJ. Intraocular Pressure Elevation Compromises Retinal Ganglion Cell Light Adaptation. Invest Ophthalmol Vis Sci 2021; 61:15. [PMID: 33064129 PMCID: PMC7571289 DOI: 10.1167/iovs.61.12.15] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose Functional adaptation to ambient light is a key characteristic of retinal ganglion cells (RGCs), but little is known about how adaptation is affected by factors that are harmful to RGC health. We explored adaptation-induced changes to RGC physiology when exposed to increased intraocular pressure (IOP), a major risk factor for glaucoma. Methods Wild-type mice of both sexes were subjected to 2 weeks of IOP elevation using the bead model. Retinas were assessed using a multielectrode array to record RGC responses to checkerboard white noise stimulation under both scotopic and photopic light levels. This information was used to calculate a spike-triggered average (STA) for each RGC with which to compare between lighting levels. Results Low but not high IOP elevation resulted in several distinct RGC functional changes: (1) diminished adaptation-dependent receptive field (RF) center-surround interactions; (2) increased likelihood of a scotopic STA; and (3) increased spontaneous firing rate. Center RF size change with lighting level varied among RGCs, and both the center and surround STA peak times were consistently increased under scotopic illumination, although none of these properties were impacted by IOP level. Conclusions These findings provide novel evidence that RGCs exhibit reduced light-dependent adaptation and increased excitability when IOP is elevated to low but not high levels. These results may reveal functional changes that occur early in glaucoma, which can potentially be used to identify patients with glaucoma at earlier stages when intervention is most beneficial.
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Affiliation(s)
- Xiaofeng Tao
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States
| | - Jasdeep Sabharwal
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States
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28
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Ishikawa M, Takaseki S, Yoshitomi T, Covey DF, Zorumski CF, Izumi Y. The neurosteroid allopregnanolone protects retinal neurons by effects on autophagy and GABRs/GABA A receptors in rat glaucoma models. Autophagy 2021; 17:743-760. [PMID: 32070183 PMCID: PMC8032250 DOI: 10.1080/15548627.2020.1731270] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 01/22/2020] [Accepted: 02/14/2020] [Indexed: 12/14/2022] Open
Abstract
In an ex vivo rat glaucoma model using dissected retinas, the neurosteroid allopregnanolone (AlloP) protects retinal ganglion cells (RGCs) via GABR/GABAA receptors. To determine the involvement of macroautophagy/autophagy in neuroprotection by AlloP, we examined the effects of autophagy activators, rapamycin and torin 2, and autophagy inhibitors, bafilomycin A1 and SAR405, on retinal retinal morphology and expression of MAP1 LC3B/LC3B (microtubule-associated protein 1 light chain 3 beta) and SQSTM1 (sequestosome 1). Administration of rapamycin or torin 2 exerted partial histological neuroprotection, while combined administration of AlloP with bafilomycin A1 or SAR405 induced severe degeneration in a hyperbaric condition. Electron microscopic analyses showed that the addition of AlloP significantly increased autophagosomes and degenerative autophagic vacuoles in the retinal nerve fiber layer. Immunoblotting showed that the addition of AlloP or autophagic activators increased the lipidated form of LC3B (LC3B-II) and suppressed SQSTM1. Moreover, bafilomycin A1 increased LC3B-II and SQSTM1 protein levels in the presence of AlloP without changes in corresponding mRNAs compared to AlloP-treated retinas in a hyperbaric condition. These data indicate that AlloP likely induces a protective form of autophagy in this model. In an in vivo rat model of glaucoma, we also observed neuroprotective effects of AlloP. Injection of polystyrene microbeads into the anterior chamber increased intraocular pressure about 3-fold and induced RGC apoptosis. A single intravitreal injection of AlloP or autophagy activators prevented apoptosis and protected RGCs with autophagy activation. We conclude that AlloP may serve as a potential therapeutic agent for the treatment of glaucoma via diverse mechanisms.Abbreviations: 2HBCD: 2-Hydroxypropyl)-β-cyclodextrin; 3-MA: 3-methyladenine; AlloP: allopregnanolone; AP: autophagosome; AVd: degradative autophagic vacuoles; GCL: ganglion cell layer; INL: inner nuclear layer; IOP: intraocular pressure; IPL: inner plexiform layer; LC3B-I: cytosolic form of LC3B; LCB-II: lipidated form of LC3B; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; mPTP: mitochondrial permeability transition pore; NDS: neuronal damage score; NFL: nerve fiber layer; OH: ocular hypertension; ON: optic nerve; ONL: outer nuclear layer; OPL: outer plexiform layer; p-STR: scotopic threshold response; RGC: retinal ganglion cells; RT-PCR: real-time reverse transcription polymerase chain reaction; SQSTM1: sequestosome 1; TUNEL: TdT-mediated dUTP Nick End Labeling.
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Affiliation(s)
- Makoto Ishikawa
- Department of Ophthalmology, Akita University Graduate School of Medicine, Akita, Japan
| | - Sanae Takaseki
- Department of Ophthalmology, Akita University Graduate School of Medicine, Akita, Japan
| | - Takeshi Yoshitomi
- Department of Ophthalmology, Akita University Graduate School of Medicine, Akita, Japan
| | - Douglas F. Covey
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
| | - Charles F. Zorumski
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, USA
| | - Yukitoshi Izumi
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, MO, USA
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, MO, USA
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29
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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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30
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Van Hook MJ, Monaco C, Bierlein ER, Smith JC. Neuronal and Synaptic Plasticity in the Visual Thalamus in Mouse Models of Glaucoma. Front Cell Neurosci 2021; 14:626056. [PMID: 33584206 PMCID: PMC7873902 DOI: 10.3389/fncel.2020.626056] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/21/2020] [Indexed: 11/20/2022] Open
Abstract
Homeostatic plasticity plays important role in regulating synaptic and intrinsic neuronal function to stabilize output following perturbations to circuit activity. In glaucoma, a neurodegenerative disease of the visual system commonly associated with elevated intraocular pressure (IOP), the early disease is associated with altered synaptic inputs to retinal ganglion cells (RGCs), changes in RGC intrinsic excitability, and deficits in optic nerve transport and energy metabolism. These early functional changes can precede RGC degeneration and are likely to alter RGC outputs to their target structures in the brain and thereby trigger homeostatic changes in synaptic and neuronal properties in those brain regions. In this study, we sought to determine whether and how neuronal and synaptic function is altered in the dorsal lateral geniculate nucleus (dLGN), an important RGC projection target in the thalamus, and how functional changes related to IOP. We accomplished this using patch-clamp recordings from thalamocortical (TC) relay neurons in the dLGN in two established mouse models of glaucoma—the DBA/2J (D2) genetic mouse model and an inducible glaucoma model with intracameral microbead injections to elevate IOP. We found that the intrinsic excitability of TC neurons was enhanced in D2 mice and these functional changes were mirrored in recordings of TC neurons from microbead-injected mice. Notably, many neuronal properties were correlated with IOP in older D2 mice, when IOP rises. The frequency of miniature excitatory synaptic currents (mEPSCs) was reduced in 9-month-old D2 mice, and vGlut2 staining of RGC synaptic terminals was reduced in an IOP-dependent manner. These data suggest that glaucoma-associated changes to neuronal excitability and synaptic inputs in the dLGN might represent a combination of both stabilizing/homeostatic plasticity and pathological dysfunction.
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Affiliation(s)
- Matthew J Van Hook
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Corrine Monaco
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Obstetrics and Gynecology, Olson Center for Women's Health, University of Nebraska Medical Center, Omaha, NE, United States
| | - Elizabeth R Bierlein
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, United States
| | - Jennie C Smith
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
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31
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Tribble JR, Otmani A, Kokkali E, Lardner E, Morgan JE, Williams PA. Retinal Ganglion Cell Degeneration in a Rat Magnetic Bead Model of Ocular Hypertensive Glaucoma. Transl Vis Sci Technol 2021; 10:21. [PMID: 33510960 PMCID: PMC7804499 DOI: 10.1167/tvst.10.1.21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 12/02/2020] [Indexed: 01/22/2023] Open
Abstract
Purpose Glaucoma remains a leading cause of irreversible blindness worldwide. Animal glaucoma models replicate high intraocular pressure, a risk factor for glaucoma, to induce retinal ganglion cell (RGC) degeneration. We describe an inducible, magnetic bead model in the Brown Norway rat in which we are able to determine degeneration across multiple RGC compartments at a time point that is appropriate for investigating neurodegenerative events and potential treatment effects. Methods We induced ocular hypertension through injection of magnetic microspheres into the anterior chamber of Brown Norway rats; un-operated (naïve) rats served as controls. Intraocular pressure was recorded, and eye diameter measurements were taken before surgery and at the terminal end points. We assessed RGC degeneration and vascular changes through immunofluorescence, and axon transport to terminal brain thalami through intravitreal injection of fluorophore-conjugated cholera toxin subunit β. Results We observed clinically relevant features of disease accompanying RGC cell somal, axonal, and dendritic loss. RGC axonal dysfunction persisted along the trajectory of the cell into the terminal brain thalami, with clear disruption at the optic nerve head. We also observed vascular compromise consistent with human disease, as well as an expansion of global eye size with ocular hypertension. Conclusions The magnetic bead model in the Brown Norway rat recapitulates many clinically relevant disease features of human glaucoma, including degeneration across multiple RGC compartments. Eye expansion is likely a result of rodent scleral elasticity, and we caution that this should be considered when assessing retinal density measurements. Translational Relevance This model offers a disease-relevant platform that will allow for assessment of glaucoma-relevant therapeutics.
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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
| | - Amin Otmani
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Eirini Kokkali
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | - Emma Lardner
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK.,School of Medicine, Cardiff University, Cardiff, Wales, UK
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
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32
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Masin L, Claes M, Bergmans S, Cools L, Andries L, Davis BM, Moons L, De Groef L. A novel retinal ganglion cell quantification tool based on deep learning. Sci Rep 2021; 11:702. [PMID: 33436866 PMCID: PMC7804414 DOI: 10.1038/s41598-020-80308-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 12/15/2020] [Indexed: 02/06/2023] Open
Abstract
Glaucoma is a disease associated with the loss of retinal ganglion cells (RGCs), and remains one of the primary causes of blindness worldwide. Major research efforts are presently directed towards the understanding of disease pathogenesis and the development of new therapies, with the help of rodent models as an important preclinical research tool. The ultimate goal is reaching neuroprotection of the RGCs, which requires a tool to reliably quantify RGC survival. Hence, we demonstrate a novel deep learning pipeline that enables fully automated RGC quantification in the entire murine retina. This software, called RGCode (Retinal Ganglion Cell quantification based On DEep learning), provides a user-friendly interface that requires the input of RBPMS-immunostained flatmounts and returns the total RGC count, retinal area and density, together with output images showing the computed counts and isodensity maps. The counting model was trained on RBPMS-stained healthy and glaucomatous retinas, obtained from mice subjected to microbead-induced ocular hypertension and optic nerve crush injury paradigms. RGCode demonstrates excellent performance in RGC quantification as compared to manual counts. Furthermore, we convincingly show that RGCode has potential for wider application, by retraining the model with a minimal set of training data to count FluoroGold-traced RGCs.
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Affiliation(s)
- Luca Masin
- grid.5596.f0000 0001 0668 7884Department of Biology, Neural Circuit Development and Regeneration Research Group, KU Leuven, Leuven, Belgium
| | - Marie Claes
- grid.5596.f0000 0001 0668 7884Department of Biology, Neural Circuit Development and Regeneration Research Group, KU Leuven, Leuven, Belgium
| | - Steven Bergmans
- grid.5596.f0000 0001 0668 7884Department of Biology, Neural Circuit Development and Regeneration Research Group, KU Leuven, Leuven, Belgium
| | - Lien Cools
- grid.5596.f0000 0001 0668 7884Department of Biology, Neural Circuit Development and Regeneration Research Group, KU Leuven, Leuven, Belgium
| | - Lien Andries
- grid.5596.f0000 0001 0668 7884Department of Biology, Neural Circuit Development and Regeneration Research Group, KU Leuven, Leuven, Belgium
| | - Benjamin M. Davis
- grid.83440.3b0000000121901201Glaucoma and Retinal Neurodegenerative Disease Research Group, Institute of Ophthalmology, University College London, London, UK ,grid.496779.2Central Laser Facility, Science and Technologies Facilities Council, UK Research and Innovation, Didcot, Oxfordshire UK
| | - Lieve Moons
- grid.5596.f0000 0001 0668 7884Department of Biology, Neural Circuit Development and Regeneration Research Group, KU Leuven, Leuven, Belgium
| | - Lies De Groef
- grid.5596.f0000 0001 0668 7884Department of Biology, Neural Circuit Development and Regeneration Research Group, KU Leuven, Leuven, Belgium
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33
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Wu HJ, Kuchtey J, Kuchtey RW. Increased Susceptibility to Glaucomatous Damage in Microfibril Deficient Mice. Invest Ophthalmol Vis Sci 2021; 61:28. [PMID: 32797197 PMCID: PMC7441341 DOI: 10.1167/iovs.61.10.28] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose To test whether mice with microfibril deficiency due to the Tsk mutation of fibrillin-1 (Fbn1Tsk/+) have increased susceptibility to pressure-induced retinal ganglion cell (RGC) degeneration. Methods Intraocular pressure (IOP) elevation was induced in Fbn1Tsk/+ and wild type (wt) mice by injecting microbeads into the anterior chamber. Mice were then followed up for four months, with IOP measurements every three to six days. Retinas were stained for Brn3a to determine RGC number. Optic nerve cross-sections were stained with p-phenylene diamine to determine nerve area, axon number, and caliber and thickness of the pia mater. Results Microbead injection induced significant IOP elevation that was significantly less for Fbn1Tsk/+ mice compared with wt. The optic nerves and optic nerve axons were larger, and the elastic fiber-rich pia mater was thinner in Fbn1Tsk/+ mice. Microbead injection resulted in reduced optic nerve size, thicker pia mater, and a slight decrease in axon size. Fbn1Tsk/+ mice had significantly greater loss of RGCs and optic nerve axons compared with wt (14.8% vs. 5.8%, P = 0.002, and 17.0% vs. 7.5%, P = 0.002, respectively). Conclusions Fbn1Tsk/+mice had altered optic nerve structure as indicated by larger optic nerves, larger optic nerve axons and thinner pia mater, consistent with our previous findings. Despite lower IOP elevation, Fbn1Tsk/+mice had greater loss of RGCs and optic nerve axons, suggesting increased susceptibility to IOP-induced optic nerve degeneration in microfibril-deficient mice.
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Affiliation(s)
- Hang-Jing Wu
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - John Kuchtey
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Rachel W Kuchtey
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
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34
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Hannon BG, Feola AJ, Gerberich BG, Read AT, Prausnitz MR, Ethier CR, Pardue MT. Using retinal function to define ischemic exclusion criteria for animal models of glaucoma. Exp Eye Res 2020; 202:108354. [PMID: 33171192 DOI: 10.1016/j.exer.2020.108354] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 11/29/2022]
Abstract
Most animal models of glaucoma rely on induction of ocular hypertension (OHT), yet such models can suffer from high IOPs leading to undesirable retinal ischemia. Thus, animals with IOPs exceeding a threshold (e.g. > 60 mmHg) are often excluded from studies. However, due to the intermittent nature of IOP measurements, this approach may fail to detect ischemia. Conversely, it may also inappropriately eliminate animals with IOP spikes that do not induce ischemic damage. It is known that acute ischemia selectively impairs inner retinal function, which results in a reduced b-wave amplitude. Here, we explore the potential of using electroretinography (ERG) to detect ischemic damage in OHT eyes. 74 Brown Norway rats received a unilateral injection of magnetic microbeads to induce OHT, while contralateral eyes served as controls. IOP was measured every 2-3 days for 14 days after microbead injection. Retinal function was evaluated using dark-adapted bright flash ERG (2.1 log cd•s/m2) prior to, and at 7 and 14 days after, injection. We investigated two criteria for excluding animals: (IOP Criterion) a single IOP measurement > 60 mmHg; or (ERG Criterion) a b-wave amplitude below the 99.5% confidence interval for naïve eyes. 49 of 74 rats passed both criteria, 7 of 74 failed both, and 18 passed one criterion but not the other. We suggest that ERG testing can detect unwelcome ischemic damage in animal models of OHT. Since brief IOP spikes do not necessarily lead to ischemic retinal damage, and because extended periods of elevated IOP can be missed, such ERG-based criteria may provide more objective and robust exclusion criteria in future glaucoma studies.
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Affiliation(s)
- Bailey G Hannon
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Andrew J Feola
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veteran Affairs Healthcare System, Atlanta, GA, USA
| | - Brandon G Gerberich
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - A Thomas Read
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veteran Affairs Healthcare System, Atlanta, GA, USA
| | - Mark R Prausnitz
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - C Ross Ethier
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Machelle T Pardue
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veteran Affairs Healthcare System, Atlanta, GA, USA.
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Tao X, Sigireddi RR, Westenskow PD, Channa R, Frankfort BJ. Single transient intraocular pressure elevations cause prolonged retinal ganglion cell dysfunction and retinal capillary abnormalities in mice. Exp Eye Res 2020; 201:108296. [PMID: 33039455 DOI: 10.1016/j.exer.2020.108296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/17/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022]
Abstract
Transient intraocular pressure (IOP) elevations are likely to occur in certain forms of glaucoma and after intravitreal injections to treat various retinal diseases. However, the impact of these transient IOP elevations on the physiology of individual retinal ganglion cells (RGCs) is unknown. In this report, we explore how transient IOP elevations in mice affect RGC physiology, RGC anatomy, and retinal arteriole and capillary structure. Transient IOP elevation was induced in 12-week old wild type C57BL6J mice by injecting sodium hyaluronate into the anterior chamber. IOP was measured immediately after the injection and again 1 and 7 days later. Average peak IOP after injection was ~50 mmHg and subsequent IOPs returned to normal. RGC physiology was assessed with a multielectrode array (MEA) by calculating a spike triggered average (STA) at the same time points. RGC counts and retinal vascular structure were assessed 14 days after injection with immunohistochemistry to label RGCs and blood vessels. Transient IOP elevation caused a marked reduction of scotopic STA presence and delayed center and surround STA peak times that did not recover. Transient IOP elevation also caused a reduced photopic receptive field size and spontaneous firing rate, both of which showed some recovery with time. Transient IOP elevation also induced vascular remodeling: the number of capillary branches was decreased within the superficial and intermediate vascular plexi. RGC counts, retinal arteriole diameter, and deep capillary plexus branching were unaffected. These previously unappreciated findings suggest that transient IOP elevation may cause unrecognized and potentially long-term pathology to RGCs and associated neurovascular units which should be accounted for in clinical practice.
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Affiliation(s)
- Xiaofeng Tao
- Department of Ophthalmology, Baylor College of Medicine, United States
| | | | | | - Roomasa Channa
- Department of Ophthalmology, Baylor College of Medicine, United States
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, United States; Department of Neuroscience, Baylor College of Medicine, United States.
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36
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Zhang ML, Zhao GL, Hou Y, Zhong SM, Xu LJ, Li F, Niu WR, Yuan F, Yang XL, Wang Z, Miao Y. Rac1 conditional deletion attenuates retinal ganglion cell apoptosis by accelerating autophagic flux in a mouse model of chronic ocular hypertension. Cell Death Dis 2020; 11:734. [PMID: 32913260 PMCID: PMC7484783 DOI: 10.1038/s41419-020-02951-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/18/2020] [Accepted: 08/27/2020] [Indexed: 12/31/2022]
Abstract
Autophagy has a fundamental role in maintaining cell homeostasis. Although autophagy has been implicated in glaucomatous pathology, how it regulates retinal ganglion cell (RGC) injury is largely unknown. In the present work, we found that biphasic autophagy in RGCs occurred in a mouse model of chronic ocular hypertension (COH), accompanied by activation of Rac1, a member of the Rho family. Rac1 conditional knockout (Rac1 cKO) in RGCs attenuated RGC apoptosis, in addition to blocking the increase in the number of autophagosomes and the expression of autophagy-related proteins (Beclin1, LC3-II/I, and p62) in COH retinas. Electron micrograph and double immunostaining of LAMP1 and LC3B showed that Rac1 cKO accelerated autolysosome fusion in RGC axons of COH mice. Inhibiting the first autophagic peak with 3-methyladenine or Atg13 siRNA reduced RGC apoptosis, whereas inhibiting the second autophagic peak with 3-MA or blocking autophagic flux by chloroquine increased RGC apoptosis. Furthermore, Rac1 cKO reduced the number of autophagosomes and apoptotic RGCs induced by rapamycin injected intravitreally, which suggests that Rac1 negatively regulates mTOR activity. Moreover, Rac1 deletion decreased Bak expression and did not interfere with the interaction of Beclin1 and Bcl-2 or Bak in COH retinas. In conclusion, autophagy promotes RGC apoptosis in the early stages of glaucoma and results in autophagic cell death in later stages. Rac1 deletion alleviates RGC damage by regulating the cross talk between autophagy and apoptosis through mTOR/Beclin1-Bak. Interfering with the Rac1/mTOR signaling pathway may provide a new strategy for treating glaucoma.
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Affiliation(s)
- Meng-Lu Zhang
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Guo-Li Zhao
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Yu Hou
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Shu-Min Zhong
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Lin-Jie Xu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Fang Li
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Wei-Ran Niu
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Fei Yuan
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Xiong-Li Yang
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China
| | - Zhongfeng Wang
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China.
| | - Yanying Miao
- Department of Ophthalmology, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Zhongshan Hospital, Fudan University, 200032, Shanghai, China.
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37
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Chong RS, Busoy JMF, Tan B, Yeo SW, Lee YS, Barathi AV, Crowston JG, Schmetterer L. A Minimally Invasive Experimental Model of Acute Ocular Hypertension with Acute Angle Closure Characteristics. Transl Vis Sci Technol 2020; 9:24. [PMID: 32832230 PMCID: PMC7414621 DOI: 10.1167/tvst.9.7.24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 05/04/2020] [Indexed: 12/21/2022] Open
Abstract
Purpose To describe a minimally invasive experimental model of acute ocular hypertension (OHT) with characteristics of acute angle closure (AAC). Methods Adult C57/Bl6 mice (n = 31) were subjected to OHT in one eye using a modified circumlimbal suture technique that elevated intraocular pressure (IOP) for 30 minutes. Contralateral un-operated eyes served as controls. IOP, anterior segment optical coherence tomography, and fundus fluorescein angiography (FFA) were performed. The positive scotopic threshold response (pSTR) and a-wave and b-wave amplitudes were also evaluated. Retinal tissues were immunostained for the retinal ganglion cell (RGC) marker RBPMS and the glial marker GFAP. Results OHT eyes developed shallower anterior chambers and dilated pupils. FFA showed focal leakage in 32.2% of OHT eyes, but in none of the control eyes. pSTR was significantly reduced at week 1 in OHT eyes compared to control eyes (57.3 ± 7.2 µV vs. 106.9 ± 24.8 µV; P < 0.05), but a- and b-waves were unaffected. GFAP was upregulated in OHT eyes but not in control eyes or eyes that had been sutured without OHT. RGC density was reduced in OHT eyes after 4 weeks (3857 ± 143.8) vs. control eyes (4469 ± 176.0) (P < 0.05). Conclusions Our minimally invasive model resulted in acute OHT with characteristics of AAC in the absence of non-OHT-related neuroinflammatory changes arising from ocular injury alone. Translational Relevance This model provides a valuable approach to studying specific characteristics of a severe blinding disease in an experimental setting. Focal areas of ischemia were demonstrated, consistent with clinical studies of acute angle closure patients elsewhere, which may indicate the need for further research into how this could affect visual outcome in these patients.
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Affiliation(s)
- Rachel S Chong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Glaucoma Department, Singapore National Eye Centre, Singapore, Singapore.,Agency for Science, Technology and Research, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Joanna M F Busoy
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Sia Wey Yeo
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Ying Shi Lee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Amutha V Barathi
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jonathan G Crowston
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.,Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
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38
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Shen G, Link SS, Tao X, Frankfort BJ. Modeling a potential SANS countermeasure by experimental manipulation of the translaminar pressure difference in mice. NPJ Microgravity 2020; 6:19. [PMID: 32821777 PMCID: PMC7395713 DOI: 10.1038/s41526-020-00109-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 07/06/2020] [Indexed: 12/23/2022] Open
Abstract
The spaceflight-associated neuro-ocular syndrome (SANS), which may present after prolonged exposure to microgravity, is thought to occur due to elevated intracranial pressure (ICP). Intracranial pressure interacts with intraocular pressure (IOP) to define the translaminar pressure difference (TLPD; IOP-ICP). We combined inducible models of ICP and IOP elevation in mice to interrogate the relationships among ICP, IOP, and TLPD, and to determine if IOP elevation could mitigate the phenotypes typically caused by elevated ICP and thereby serve as a countermeasure for SANS. Ten C57BL6J mice of both genders underwent experimental elevation of ICP via infusion of artificial cerebrospinal fluid into the subarachnoid space. One eye also underwent experimental elevation of IOP using the bead injection model. Intraocular pressure and ICP were monitored for 2 weeks. Optokinetic-based contrast sensitivity was measured at baseline and after 2 weeks, and post-mortem studies of optic nerve and retina anatomy were performed. Photopic contrast sensitivity was reduced more in IOP elevated than control eyes. Scotopic contrast sensitivity was reduced similarly in IOP elevated and control eyes. However, the pattern of scotopic vision loss was not uniform in IOP elevated eyes; there was minimal loss in eyes that most closely approximated the normal TLPD. Optic nerve axon loss, increased optic nerve disorganization, and retinal ganglion cell loss all occurred similarly between IOP elevated and control eyes. Elevation of IOP in eyes with elevated ICP may counterbalance some effects on vision loss but exacerbate others, suggesting complex relationships among IOP, ICP, and TLPD.
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Affiliation(s)
- Guofu Shen
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX USA
| | - Schuyler S. Link
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX USA
| | - Xiaofeng Tao
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX USA
| | - Benjamin J. Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX USA
- Center for Space Medicine, Baylor College of Medicine, Houston, TX USA
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39
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Sladek AL, Nawy S. Ocular Hypertension Drives Remodeling of AMPA Receptors in Select Populations of Retinal Ganglion Cells. Front Synaptic Neurosci 2020; 12:30. [PMID: 32792936 PMCID: PMC7393603 DOI: 10.3389/fnsyn.2020.00030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/25/2020] [Indexed: 12/31/2022] Open
Abstract
AMPA-type glutamate receptors in the CNS are normally impermeable to Ca2+, but the aberrant expression of Ca2+-permeable AMPA receptors (CP-AMPARs) occurs in pathological conditions such as ischemia or epilepsy, or degenerative diseases such as ALS. Here, we show that select populations of retinal ganglion cells (RGCs) similarly express high levels of CP-AMPARs in a mouse model of glaucoma. CP-AMPAR expression increased dramatically in both On sustained alpha and Off transient alpha RGCs, and this increase was prevented by genomic editing of the GluA2 subunit. On sustained alpha RGCs with elevated CP-AMPAR levels displayed profound synaptic depression, which was reduced by selectively blocking CP-AMPARs, buffering Ca2+ with BAPTA, or with the CB1 antagonist AM251, suggesting that depression was mediated by a retrograde transmitter which might be triggered by the influx of Ca2+ through CP-AMPARs. Thus, glaucoma may alter the composition of AMPARs and depress excitatory synaptic input in select populations of RGCs.
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Affiliation(s)
| | - Scott Nawy
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
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Pang IH, Clark AF. Inducible rodent models of glaucoma. Prog Retin Eye Res 2020; 75:100799. [PMID: 31557521 PMCID: PMC7085984 DOI: 10.1016/j.preteyeres.2019.100799] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 11/23/2022]
Abstract
Glaucoma is one of the leading causes of vision impairment worldwide. In order to further understand the molecular pathobiology of this disease and to develop better therapies, clinically relevant animal models are necessary. In recent years, both the rat and mouse have become popular models in glaucoma research. Key reasons are: many important biological similarities shared among rodent eyes and the human eye; development of improved methods to induce glaucoma and to evaluate glaucomatous damage; availability of genetic tools in the mouse; as well as the relatively low cost of rodent studies. Commonly studied rat and mouse glaucoma models include intraocular pressure (IOP)-dependent and pressure-independent models. The pressure-dependent models address the most important risk factor of elevated IOP, whereas the pressure-independent models assess "normal tension" glaucoma and other "non-IOP" related factors associated with glaucomatous damage. The current article provides descriptions of these models, their characterizations, specific techniques to induce glaucoma, mechanisms of injury, advantages, and limitations.
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Affiliation(s)
- Iok-Hou Pang
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, USA; Department of Pharmaceutical Sciences, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Abbot F Clark
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, USA; Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA.
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Thomson BR, Grannonico M, Liu F, Liu M, Mendapara P, Xu Y, Liu X, Quaggin SE. Angiopoietin-1 Knockout Mice as a Genetic Model of Open-Angle Glaucoma. Transl Vis Sci Technol 2020; 9:16. [PMID: 32818103 PMCID: PMC7396191 DOI: 10.1167/tvst.9.4.16] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 01/06/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose A leading cause of blindness worldwide, glaucoma is often caused by elevated intraocular pressure (IOP) due to impaired aqueous humor outflow from the anterior chamber through Schlemm's canal (SC) and the trabecular meshwork. Despite the large clinical burden, glaucoma research and drug development are hindered by a limited selection of preclinical models that accurately recapitulate human disease. Here, we propose that Angpt1 conditional knockout mice may provide one such model. Angiopoietin/TEK (ANGPT/TEK) signaling is crucial for SC formation and integrity in mice and humans, and mice lacking TEK or its ligand ANGPT1 develop a hypomorphic SC insufficient for normal aqueous humor outflow. Methods We used a comprehensive histology and physiology approach to characterize the glaucoma phenotype of Angpt1 inducible knockout mice, especially focusing on retina morphology and function. Results Angpt1 deletion resulted in persistent ocular hypertension beginning in the first month after birth and leading to decreased visual acuity with age due to glaucomatous neuropathy. In the neural retina, we identified marked and specific loss of the retinal ganglion cells, whereas other retinal neurons exhibited largely normal morphology and patterning. Electroretinogram recordings demonstrated reduced scotopic threshold response, further indicating loss of retinal ganglion cell function. Conclusions These findings highlight the potential of Angpt1 conditional knockout mice as a valuable new glaucoma model. Translational Relevance Currently, few reliable, rapid-onset genetic glaucoma models are available, and Angpt1 knockout mice will provide an additional tool for studies of IOP-induced neural damage, mechanisms of disease progression, and novel treatment strategies.
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Affiliation(s)
- Benjamin R. Thomson
- Feinberg Cardiovascular and Renal Research Institute and Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Marta Grannonico
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Feng Liu
- Department of Biology, University of Virginia, Charlottesville, VA, USA
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Mingna Liu
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Parrykumar Mendapara
- Feinberg Cardiovascular and Renal Research Institute and Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Ying Xu
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Xiaorong Liu
- Department of Biology, University of Virginia, Charlottesville, VA, USA
- Department of Psychology, University of Virginia, Charlottesville, VA, USA
| | - Susan E. Quaggin
- Feinberg Cardiovascular and Renal Research Institute and Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Bhandari A, Smith JC, Zhang Y, Jensen AA, Reid L, Goeser T, Fan S, Ghate D, Van Hook MJ. Early-Stage Ocular Hypertension Alters Retinal Ganglion Cell Synaptic Transmission in the Visual Thalamus. Front Cell Neurosci 2019; 13:426. [PMID: 31607867 PMCID: PMC6761307 DOI: 10.3389/fncel.2019.00426] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/04/2019] [Indexed: 12/21/2022] Open
Abstract
Axonopathy is a hallmark of many neurodegenerative diseases including glaucoma, where elevated intraocular pressure (ocular hypertension, OHT) stresses retinal ganglion cell (RGC) axons as they exit the eye and form the optic nerve. OHT causes early changes in the optic nerve such as axon atrophy, transport inhibition, and gliosis. Importantly, many of these changes appear to occur prior to irreversible neuronal loss, making them promising points for early diagnosis of glaucoma. It is unknown whether OHT has similarly early effects on the function of RGC output to the brain. To test this possibility, we elevated eye pressure in mice by anterior chamber injection of polystyrene microbeads. Five weeks post-injection, bead-injected eyes showed a modest RGC loss in the peripheral retina, as evidenced by RBPMS antibody staining. Additionally, we observed reduced dendritic complexity and lower spontaneous spike rate of On-αRGCs, targeted for patch clamp recording and dye filling using a Opn4-Cre reporter mouse line. To determine the influence of OHT on retinal projections to the brain, we expressed Channelrhodopsin-2 (ChR2) in melanopsin-expressing RGCs by crossing the Opn4-Cre mouse line with a ChR2-reporter mouse line and recorded post-synaptic responses in thalamocortical relay neurons in the dorsal lateral geniculate nucleus (dLGN) of the thalamus evoked by stimulation with 460 nm light. The use of a Opn4-Cre reporter system allowed for expression of ChR2 in a narrow subset of RGCs responsible for image-forming vision in mice. Five weeks following OHT induction, paired pulse and high-frequency stimulus train experiments revealed that presynaptic vesicle release probability at retinogeniculate synapses was elevated. Additionally, miniature synaptic current frequency was slightly reduced in brain slices from OHT mice and proximal dendrites of post-synaptic dLGN relay neurons, assessed using a Sholl analysis, showed a reduced complexity. Strikingly, these changes occurred prior to major loss of RGCs labeled with the Opn4-Cre mouse, as indicated by immunofluorescence staining of ChR2-expressing retinal neurons. Thus, OHT leads to pre- and post-synaptic functional and structural changes at retinogeniculate synapses. Along with RGC dendritic remodeling and optic nerve transport changes, these retinogeniculate synaptic changes are among the earliest signs of glaucoma.
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Affiliation(s)
- Ashish Bhandari
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Jennie C Smith
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Yang Zhang
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States.,Creighton University School of Medicine, Omaha, NE, United States.,Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Aaron A Jensen
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Lisa Reid
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Toni Goeser
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Shan Fan
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Deepta Ghate
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
| | - Matthew J Van Hook
- Department of Ophthalmology and Visual Sciences, Stanley M. Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, United States
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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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Honda H, Anraku A, Ishida K, Enomoto N, Tomita G. Relationship between Macular Vessel Density and Focal Electroretinograms in Early Normal Tension Glaucoma. Curr Eye Res 2019; 44:753-759. [DOI: 10.1080/02713683.2019.1593464] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Hakuei Honda
- Department of Ophthalmology, Toho University Graduate School of Medicine, Tokyo, Japan
- Department of Ophthalmology, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Ayako Anraku
- Department of Ophthalmology, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Kyoko Ishida
- Department of Ophthalmology, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Nobuko Enomoto
- Department of Ophthalmology, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Goji Tomita
- Department of Ophthalmology, Toho University Ohashi Medical Center, Tokyo, Japan
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Dey A, Manthey AL, Chiu K, Do CW. Methods to Induce Chronic Ocular Hypertension: Reliable Rodent Models as a Platform for Cell Transplantation and Other Therapies. Cell Transplant 2019; 27:213-229. [PMID: 29637819 PMCID: PMC5898687 DOI: 10.1177/0963689717724793] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Glaucoma, a form of progressive optic neuropathy, is the second leading cause of blindness worldwide. Being a prominent disease affecting vision, substantial efforts are being made to better understand glaucoma pathogenesis and to develop novel treatment options including neuroprotective and neuroregenerative approaches. Cell transplantation has the potential to play a neuroprotective and/or neuroregenerative role for various ocular cell types (e.g., retinal cells, trabecular meshwork). Notably, glaucoma is often associated with elevated intraocular pressure, and over the past 2 decades, several rodent models of chronic ocular hypertension (COH) have been developed that reflect these changes in pressure. However, the underlying pathophysiology of glaucoma in these models and how they compare to the human condition remains unclear. This limitation is the primary barrier for using rodent models to develop novel therapies to manage glaucoma and glaucoma-related blindness. Here, we review the current techniques used to induce COH-related glaucoma in various rodent models, focusing on the strengths and weaknesses of the each, in order to provide a more complete understanding of how these models can be best utilized. To so do, we have separated them based on the target tissue (pre-trabecular, trabecular, and post-trabecular) in order to provide the reader with an encompassing reference describing the most appropriate rodent COH models for their research. We begin with an initial overview of the current use of these models in the evaluation of cell transplantation therapies.
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Affiliation(s)
- Ashim Dey
- 1 School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Abby L Manthey
- 2 Laboratory of Retina Brain Research, Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kin Chiu
- 2 Laboratory of Retina Brain Research, Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,3 Research Centre of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong, Hong Kong, China.,4 State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Chi-Wai Do
- 1 School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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Park YH, Snook JD, Ostrin EJ, Kim S, Chen R, Frankfort BJ. Transcriptomic profiles of retinal ganglion cells are defined by the magnitude of intraocular pressure elevation in adult mice. Sci Rep 2019; 9:2594. [PMID: 30796289 PMCID: PMC6385489 DOI: 10.1038/s41598-019-39141-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the major risk factor for glaucoma, a sight threatening disease of retinal ganglion cells (RGCs) and their axons. Despite the central importance of IOP, details of the impact of IOP elevation on RGC gene expression remain elusive. We developed a 4-step immunopanning protocol to extract adult mouse RGCs with high fidelity and used it to isolate RGCs from wild type mice exposed to 2 weeks of IOP elevation generated by the microbead model. IOP was elevated to 2 distinct levels which were defined as Mild (IOP increase >1 mmHg and <4 mmHg) and Moderate (IOP increase ≥4 mmHg). RNA sequencing was used to compare the transcriptional environment at each IOP level. Differentially expressed genes were markedly different between the 2 groups, and pathway analysis revealed frequently opposed responses between the IOP levels. These results suggest that the magnitude of IOP elevation has a critical impact on RGC transcriptional changes. Furthermore, it is possible that IOP-based set points exist within RGCs to impact the direction of transcriptional change. It is possible that this improved understanding of changes in RGC gene expression can ultimately lead to novel diagnostics and therapeutics for glaucoma.
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Affiliation(s)
- Yong H Park
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Joshua D Snook
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Edwin J Ostrin
- Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, United States
| | - Sangbae Kim
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, United States.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States. .,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, 77030, United States.
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Mouse model of ocular hypertension with retinal ganglion cell degeneration. PLoS One 2019; 14:e0208713. [PMID: 30640920 PMCID: PMC6331128 DOI: 10.1371/journal.pone.0208713] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 11/22/2018] [Indexed: 11/16/2022] Open
Abstract
Objectives Ocular hypertension is a primary risk factor for glaucoma and results in retinal ganglion cell (RGC) degeneration. Current animal models of glaucoma lack severe RGC cell death as seen in glaucoma, making assessment of physiological mediators of cell death difficult. We developed a modified mouse model of ocular hypertension whereby long-lasting elevation of intraocular pressure (IOP) is achieved, resulting in significant reproducible damage to RGCs. Results In this model, microbeads are mixed with hyaluronic acid and injected into the anterior chamber of C57BL/6J mice. The hyaluronic acid allows for a gradual release of microbeads, resulting in sustained blockage of Schlemm’s canal. IOP elevation was bimodal during the course of the model’s progression. The first peak occurred 1 hours after beads injection, with an IOP value of 44.69 ± 6.00 mmHg, and the second peak occurred 6–12 days post-induction, with an IOP value of 34.91 ± 5.21 mmHg. RGC damage was most severe in the peripheral retina, with a loss of 64.1% compared to that of untreated eyes, while the midperiphery exhibited a 32.4% loss, 4 weeks following disease induction. Conclusions These results suggest that sustained IOP elevation causes more RGC damage in the periphery than in the midperiphery of the retina. This model yields significant and reproducible RGC degeneration.
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Qin Y, Ji M, Deng T, Luo D, Zi Y, Pan L, Wang Z, Jin M. Functional and morphologic study of retinal hypoperfusion injury induced by bilateral common carotid artery occlusion in rats. Sci Rep 2019; 9:80. [PMID: 30643163 PMCID: PMC6331588 DOI: 10.1038/s41598-018-36400-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/20/2018] [Indexed: 12/20/2022] Open
Abstract
Retinal hypoperfusion injury is the pathophysiologic basis of ocular ischemic syndrome (OIS) which often leads to severe visual loss. In this study, we aimed to establish a rat model of retinal chronic hypoperfusion by bilateral common carotid artery occlusion (BCCAO) and observe changes in the retinal function and morphology. We found that model rats showed retinal arteriosclerosis, slight dilated retinal vein, small hemangiomas, hemorrhages, vascular segmental filling, and nonperfused areas after 2 weeks of BCCAO. In the model rats, the retinal circulation time was significantly prolonged by fluorescein fundus angiography (FFA), the latency of a and b waves was delayed and the amplitude was decreased significantly at each time point by electroretinogram (ERG), and the perfusion of the eyes continued to reduced. Morphologic and ultrastructural changes covered that the retinal ganglion cells (RGCs) presented obvious apoptosis and the thickness in the retinal layers were significantly thinner. Collectively, these findings suggested that BCCAO induced retinal hypoperfusion injury in the model rats, thus providing an ideal animal model for the study of OIS.
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Affiliation(s)
- Yali Qin
- Beijing University of Chinese Medicine, Beijing, 100029, China.,Department of Ophthalmology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Meiqi Ji
- Beijing University of Chinese Medicine, Beijing, 100029, China.,Department of Ophthalmology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Tingting Deng
- Clinical Medical Research Institute, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Dan Luo
- Department of Ophthalmology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Yingxin Zi
- Beijing University of Chinese Medicine, Beijing, 100029, China.,Department of Ophthalmology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Lin Pan
- Clinical Medical Research Institute, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Zhijun Wang
- Department of Ophthalmology, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Ming Jin
- Department of Ophthalmology, China-Japan Friendship Hospital, Beijing, 100029, China.
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Mild Intraocular Pressure Elevation in Mice Reveals Distinct Retinal Ganglion Cell Functional Thresholds and Pressure-Dependent Properties. J Neurosci 2019; 39:1881-1891. [PMID: 30622167 DOI: 10.1523/jneurosci.2085-18.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 01/07/2023] Open
Abstract
Elevation of intraocular pressure (IOP) causes retinal ganglion cell (RGC) dysfunction and death and is a major risk factor for glaucoma. We used a bead injection technique to increase IOP in mice of both genders by an average of ∼3 mmHg for 2 weeks. This level of IOP elevation was lower than that achieved in other studies, which allowed for the study of subtle IOP effects. We used multielectrode array recordings to determine the cellular responses of RGCs exposed to this mild degree of IOP elevation. We found that RGC photopic receptive field (RF) center size and whole-field RGC firing rates were unaffected by IOP elevation. In contrast, we found that the temporal properties of RGC photopic responses in the RF center were accelerated, particularly in ON sustained cells. We also detected a loss of antagonistic surround in several RGC subtypes. Finally, spontaneous firing rate, interspike interval variance, and contrast sensitivity were altered according to the magnitude of IOP exposure and also displayed an IOP-dependent effect. Together, these results suggest that individual RGC physiologic parameters have unique IOP-related functional thresholds that exist concurrently and change following IOP elevation according to specific patterns. Furthermore, even subtle IOP elevation can impart profound changes in RGC function, which in some cases may occur in an IOP-dependent manner. This system of overlapping functional thresholds likely underlies the complex effects of elevated IOP on the retina.SIGNIFICANCE STATEMENT Retinal ganglion cells (RGCs) are the obligate output neurons of the retina and are injured by elevated intraocular pressure (IOP) in diseases such as glaucoma. In this study, a subtle elevation of IOP in mice for 2 weeks revealed distinct IOP-related functional thresholds for specific RGC physiologic parameters and sometimes showed an IOP-dependent effect. These data suggest that overlapping IOP-related thresholds and response profiles exist simultaneously in RGCs and throughout the retina. These overlapping thresholds likely explain the range of RGC responses that occur following IOP elevation and highlight the wide capacity of neurons to respond in a diseased state.
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Enlarged Optic Nerve Axons and Reduced Visual Function in Mice with Defective Microfibrils. eNeuro 2018; 5:eN-NWR-0260-18. [PMID: 30406200 PMCID: PMC6220594 DOI: 10.1523/eneuro.0260-18.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/13/2018] [Indexed: 01/13/2023] Open
Abstract
Glaucoma is a leading cause of irreversible vision loss due to retinal ganglion cell (RGC) degeneration that develops slowly with age. Elevated intraocular pressure (IOP) is a significant risk factor, although many patients develop glaucoma with IOP in the normal range. Mutations in microfibril-associated genes cause glaucoma in animal models, suggesting the hypothesis that microfibril defects contribute to glaucoma. To test this hypothesis, we investigated IOP and functional/structural correlates of RGC degeneration in mice of either sex with abnormal microfibrils due to heterozygous Tsk mutation of the fibrilin-1 gene (Fbn1Tsk/+). Although IOP was not affected, Fbn1Tsk/+ mice developed functional deficits at advanced age consistent with glaucoma, including reduced RGC responses in electroretinogram (ERG) experiments. While RGC density in the retina was not affected, the density of RGC axons in the optic nerve was significantly reduced in Fbn1Tsk/+ mice. However, reduced axon density correlated with expanded optic nerves, resulting in similar numbers of axons in Fbn1Tsk/+ and control nerves. Axons in the optic nerves of Fbn1Tsk/+ mice were significantly enlarged and axon diameter was strongly correlated with optic nerve area, as has been reported in early pathogenesis of the DBA/2J mouse model of glaucoma. Our results suggest that microfibril abnormalities can lead to phenotypes found in early-stage glaucomatous neurodegeneration. Thinning of the elastic fiber-rich pia mater was found in Fbn1Tsk/+ mice, suggesting mechanisms allowing for optic nerve expansion and a possible biomechanical contribution to determination of axon caliber.
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