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You W, Knoops K, Boesten I, Berendschot TTJM, van Zandvoort MAMJ, Benedikter BJ, Webers CAB, Reutelingsperger CPM, Gorgels TGMF. A time window for rescuing dying retinal ganglion cells. Cell Commun Signal 2024; 22:88. [PMID: 38297331 PMCID: PMC10832163 DOI: 10.1186/s12964-023-01427-3] [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: 09/18/2023] [Accepted: 12/08/2023] [Indexed: 02/02/2024] Open
Abstract
BACKGROUND Retinal ganglion cell (RGC) degeneration and death cause vision loss in patients with glaucoma. Regulated cell death, once initiated, is generally considered to be an irreversible process. Recently, we showed that, by timely removing the cell death stimulus, stressed neuronal PC12 cells can recover from phosphatidylserine (PS) exposure, nuclear shrinkage, DNA damage, mitochondrial fragmentation, mitochondrial membrane potential loss, and retraction of neurites, all hallmarks of an activated cell death program. Whether the cell death process can be reversed in neurons of the central nervous system, like RGCs, is still unknown. Here, we studied reversibility of the activated cell death program in primary rat RGCs (prRGCs). METHODS prRGCs were exposed to ethanol (5%, vol/vol) to induce cell death. At different stages of the cell death process, ethanol was removed by washing and injured prRGCs were further cultured in fresh medium to see whether they recovered. The dynamics of single cells were monitored by high-resolution live-cell spinning disk microscopy. PS exposure, mitochondrial structure, membrane potential, and intracellular Ca2+ were revealed by annexin A5-FITC, Mito-tracker, TMRM, and Fluo 8-AM staining, respectively. The distribution of cytochrome c was investigated by immunofluorescence. The ultrastructure of mitochondria was studied by electron microscopy. RESULTS Analysis of temporal relationships between mitochondrial changes and PS exposure showed that fragmentation of the mitochondrial network and loss of mitochondrial membrane potential occurred before PS exposure. Mitochondrial changes proceeded caspase-independently, while PS exposure was caspase dependent. Interestingly, prRGCs recovered quickly from these mitochondrial changes but not from PS exposure at the plasma membrane. Correlative light and electron microscopy showed that stress-induced decrease in mitochondrial area, length and cristae number was reversible. Intracellular Ca2+ was elevated during this stage of reversible mitochondrial injury, but there was no sign of mitochondrial cytochrome c release. CONCLUSIONS Our study demonstrates that RGCs with impaired mitochondrial structure and function can fully recover if there is no mitochondrial cytochrome c release yet, and no PS is exposed at the plasma membrane. This finding indicates that there is a time window for rescuing dying or injured RGCs, by simply removing the cell death stimulus. Video Abstract.
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Affiliation(s)
- Wenting You
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
- Department of Biochemistry, CARIM School for Cardiovascular Disease, Maastricht University, Maastricht, 6229 ER, The Netherlands
- Department of Mental Health and Neuroscience, Maastricht University, Maastricht, 6229 ER, The Netherlands
| | - Kèvin Knoops
- The Microscopy CORE lab, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, 6229 ER, The Netherlands
| | - Iris Boesten
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Tos T J M Berendschot
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Marc A M J van Zandvoort
- Department of Molecular Cell Biology, CARIM School for Cardiovascular Disease, Maastricht University, Maastricht, 6229 ER, The Netherlands
- Institute of Molecular Cardiovascular Research (IMCAR), Universitätsklinikum Aachen, 52074, Aachen, Germany
| | - Birke J Benedikter
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Carroll A B Webers
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Chris P M Reutelingsperger
- Department of Biochemistry, CARIM School for Cardiovascular Disease, Maastricht University, Maastricht, 6229 ER, The Netherlands.
| | - Theo G M F Gorgels
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands.
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Liu HH, Cullen PF, Sivak JM, Gronert K, Flanagan JG. Protective Effects of Lipoxin A 4 and B 4 Signaling on the Inner Retina in a Mouse Model of Experimental Glaucoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.17.575414. [PMID: 38293224 PMCID: PMC10827219 DOI: 10.1101/2024.01.17.575414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Glaucoma is a common neurodegenerative disease characterized by progressive degeneration of retinal ganglion cells (RGCs) and the retinal nerve fiber layer (RNFL), resulting in a gradual decline of vision. A recent study by our groups indicated that the levels of lipoxins A4 (LXA4) and B4 (LXB4) in the retina and optic nerve decrease following acute injury, and that restoring their function is neuroprotective. Lipoxins are members of the specialized pro-resolving mediator (SPM) family and play key roles to mitigate and resolve chronic inflammation and tissue damage. Yet, knowledge about lipoxin neuroprotective activity remains limited. Here we investigate the in vivo efficacy of exogenous LXA4 and LXB4 administration on the inner retina in a mouse model of chronic experimental glaucoma. To investigate the contribution of LXA4 signaling we used transgenic knockout (KO) mice lacking the two mouse LXA4 receptors (Fpr2/Fpr3-/-). Functional and structural changes of inner retinal neurons were assessed longitudinally using electroretinogram (ERG) and optical coherence tomography (OCT). At the end of the experiment, retinal samples were harvested for immunohistological assessment. While both lipoxins generated protective trends, only LXB4 treatment was significant, and consistently more efficacious than LXA4 in all endpoints. Both lipoxins also appeared to dramatically reduce Müller glial reactivity following injury. In comparison, Fpr2/Fpr3 deletion significantly worsened inner retinal injury and function, consistent with an essential protective role for endogenous LXA4. Together, these results support further exploration of lipoxin signaling as a treatment for glaucomatous neurodegeneration.
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Affiliation(s)
- Hsin-Hua Liu
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
| | - Paul F. Cullen
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
| | - Jeremy M. Sivak
- Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Karsten Gronert
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
| | - John G. Flanagan
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
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Xia M, Zhang E, Yao F, Xia Z, Zhou M, Ran X, Xia X. Regional differences of the sclera in the ocular hypertensive rat model induced by circumlimbal suture. EYE AND VISION (LONDON, ENGLAND) 2023; 10:2. [PMID: 36597143 PMCID: PMC9811703 DOI: 10.1186/s40662-022-00319-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/15/2022] [Indexed: 01/05/2023]
Abstract
PURPOSE To describe the regional differences of the sclera in ocular hypertension (OHT) models with the inappropriate extension of the ocular axis. METHODS To discover the regional differences of the sclera at the early stage, OHT models were established using circumlimbal suture (CS) or sclerosant injection (SI). Axial length (AL) was measured by ultrasound and magnetic resonance imaging. The glaucoma-associated distinction was determined by intraocular pressure (IOP) and retrograde tracing of retinal ganglion cells (RGCs). The central thickness of the ganglion cell complex (GCC) was measured by optical coherence tomography. RGCs and collagen fibrils were detected using a transmission electron microscope, furthermore, anti-alpha smooth muscle actin (αSMA) was determined in the early stage after the operation. RESULTS Compared with the control group, the eyes in OHT models showed an increased IOP (P < 0.001 in the CS group, P = 0.001 in the SI group), growing AL (P = 0.026 in the CS group, P = 0.043 in the SI group), reduction of central RGCs (P < 0.001 in the CS group, P = 0.017 in the SI group), thinning central GCC (P < 0.001 in the CS group), and a distinctive expression of αSMA in the central sclera in the early 4-week stage after the operation (P = 0.002 in the CS group). Compared with the SI group, the eye in the CS group showed a significantly increased AL (7.1 ± 0.4 mm, P = 0.031), reduction of central RGCs (2121.1 ± 87.2 cells/mm2, P = 0.001), thinning central GCC (71.4 ± 0.8 pixels, P = 0.015), and a distinctive expression of αSMA (P = 0.005). Additionally, ultrastructural changes in RGCs, scleral collagen fibers, and collagen crimp were observed in the different regions. Increased collagen volume fraction in the posterior segment of the eyeball wall (30.2 ± 3.1%, P = 0.022) was observed by MASSON staining in the CS group. CONCLUSION Regional differences of the sclera in the ocular hypertensive rat model induced by CS may provide a reference for further treatment of scleral-related eye disorders.
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Affiliation(s)
- Mingfang Xia
- grid.216417.70000 0001 0379 7164Eye Center of Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.452223.00000 0004 1757 7615Hunan Key Laboratory of Ophthalmology, Changsha, 410008 Hunan China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.469519.60000 0004 1758 070XDepartment of Ophthalmology, People’s Hospital of Ningxia Hui Autonomous Region, Yinchuan, 750004 Ningxia China
| | - Endong Zhang
- grid.216417.70000 0001 0379 7164Eye Center of Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.452223.00000 0004 1757 7615Hunan Key Laboratory of Ophthalmology, Changsha, 410008 Hunan China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008 Hunan China
| | - Fei Yao
- grid.216417.70000 0001 0379 7164Eye Center of Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.452223.00000 0004 1757 7615Hunan Key Laboratory of Ophthalmology, Changsha, 410008 Hunan China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008 Hunan China
| | - Zhaohua Xia
- grid.216417.70000 0001 0379 7164Eye Center of Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.452223.00000 0004 1757 7615Hunan Key Laboratory of Ophthalmology, Changsha, 410008 Hunan China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008 Hunan China
| | - Mingmin Zhou
- grid.216417.70000 0001 0379 7164Eye Center of Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.452223.00000 0004 1757 7615Hunan Key Laboratory of Ophthalmology, Changsha, 410008 Hunan China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008 Hunan China
| | - Xufang Ran
- grid.216417.70000 0001 0379 7164Eye Center of Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.452223.00000 0004 1757 7615Hunan Key Laboratory of Ophthalmology, Changsha, 410008 Hunan China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008 Hunan China
| | - Xiaobo Xia
- grid.216417.70000 0001 0379 7164Eye Center of Xiangya Hospital, Central South University, Changsha, 410008 Hunan China ,grid.452223.00000 0004 1757 7615Hunan Key Laboratory of Ophthalmology, Changsha, 410008 Hunan China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008 Hunan China
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Sarossy M, Crowston J, Kumar D, Weymouth A, Wu Z. Prediction of glaucoma severity using parameters from the electroretinogram. Sci Rep 2021; 11:23886. [PMID: 34903831 PMCID: PMC8668922 DOI: 10.1038/s41598-021-03421-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 11/29/2021] [Indexed: 11/17/2022] Open
Abstract
Glaucoma is an optic neuropathy that results in the progressive loss of retinal ganglion cells (RGCs), which are known to exhibit functional changes prior to cell loss. The electroretinogram (ERG) is a method that enables an objective assessment of retinal function, and the photopic negative response (PhNR) has conventionally been used to provide a measure of RGC function. This study sought to examine if additional parameters from the ERG (amplitudes of the a-, b-, i-wave, as well the trough between the b- and i-wave), a multivariate adaptive regression splines (MARS; a non-linear) model and achromatic stimuli could better predict glaucoma severity in 103 eyes of 55 individuals with glaucoma. Glaucoma severity was determined using standard automated perimetry and optical coherence tomography imaging. ERGs targeting the PhNR were recorded with a chromatic (red-on-blue) and achromatic (white-on-white) stimulus with the same luminance. Linear and MARS models were fitted to predict glaucoma severity using the PhNR only or all ERG markers, derived from chromatic and achromatic stimuli. Use of all ERG markers predicted glaucoma severity significantly better than the PhNR alone (P ≤ 0.02), and the MARS performed better than linear models when using all markers (P = 0.01), but there was no significant difference between the achromatic and chromatic stimulus models. This study shows that there is more information present in the photopic ERG beyond the conventional PhNR measure in characterizing RGC function.
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Affiliation(s)
- Marc Sarossy
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia.
| | | | | | - Anne Weymouth
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Zhichao Wu
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
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Mathew DJ, Livne-Bar I, Sivak JM. An inducible rodent glaucoma model that exhibits gradual sustained increase in intraocular pressure with distinct inner retina and optic nerve inflammation. Sci Rep 2021; 11:22880. [PMID: 34819548 PMCID: PMC8613281 DOI: 10.1038/s41598-021-02057-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/09/2021] [Indexed: 01/29/2023] Open
Abstract
Glaucoma is a chronic and progressive neurodegenerative disease of the optic nerve resulting in loss of retinal ganglion cells (RGCs) and vision. The most prominent glaucoma risk factor is increased intraocular pressure (IOP), and most models focus on reproducing this aspect to study disease mechanisms and targets. Yet, current models result in IOP profiles that often do not resemble clinical glaucoma. Here we introduce a new model that results in a gradual and sustained IOP increase over time. This approach modifies a circumlimbal suture method, taking care to make the sutures 'snug' instead of tight, without inducing an initial IOP spike. This approach did not immediately affect IOPs, but generated gradual ocular hypertension (gOHT) as the sutures tighten over time, in comparison to loosely sutured control eyes (CON), resulting in an average 12.6 mmHg increase in IOP at 17 weeks (p < 0.001). Corresponding characterization revealed relevant retinal and optic nerve pathology, such as thinning of the retinal nerve fiber layer, decreased optokinetic response, RGC loss, and optic nerve head remodeling. Yet, angles remained open, with no evidence of inflammation. Corresponding biochemical profiling indicated significant increases in TGF-β2 and 3, and IL-1 family cytokines in gOHT optic nerve tissues compared to CON, with accompanying microglial reactivity, consistent with active tissue injury and repair mechanisms. Remarkably, this signature was absent from optic nerves following acute ocular hypertension (aOHT) associated with intentionally tightened sutures, although the resulting RGC loss was similar in both methods. These results suggest that the pattern of IOP change has an important impact on underlying pathophysiology.
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Affiliation(s)
- David J Mathew
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Lab Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Izhar Livne-Bar
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Lab Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Jeremy M Sivak
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada.
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada.
- Department of Lab Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
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6
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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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Garcia-Herranz D, Rodrigo MJ, Subias M, Martinez-Rincon T, Mendez-Martinez S, Bravo-Osuna I, Bonet A, Ruberte J, Garcia-Feijoo J, Pablo L, Garcia-Martin E, Herrero-Vanrell R. Novel Use of PLGA Microspheres to Create an Animal Model of Glaucoma with Progressive Neuroretinal Degeneration. Pharmaceutics 2021; 13:pharmaceutics13020237. [PMID: 33567776 PMCID: PMC7915113 DOI: 10.3390/pharmaceutics13020237] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/22/2021] [Accepted: 01/28/2021] [Indexed: 11/16/2022] Open
Abstract
Progressive degeneration of neuroretinal tissue with maintained elevated intraocular pressure (IOP) to simulate chronic glaucoma was produced by intracameral injections of poly (lactic-co-glycolic) acid (PLGA) microspheres (Ms) in rat eyes. The right eye of 39 rats received different sizes of PLGA-Ms (2 µL suspension; 10% w/v): 14 with 38–20 µm Ms (Ms38/20 model) and 25 with 20–10 µm particles (Ms20/10 model). This novel glaucoma animal model was compared to the episcleral vein sclerosis (EPI) model (25 eyes). Injections were performed at baseline, two, four and six weeks. Clinical signs, IOP, retina and optic nerve thicknesses (using in vivo optical coherence tomography; OCT), and histological studies were performed. An IOP increment was observed in all three groups, however, the values obtained from the PLGA-Ms injection resulted lower with a better preservation of the ocular surface. In fact, the injection of Ms20/10 created a gentler, more progressive, and more sustained increase in IOP. This IOP alteration was correlated with a significant decrease in most OCT parameters and in histological ganglion-cell count for the three conditions throughout the eight-week follow-up. In all cases, progressive degeneration of the retina, retinal ganglion cells and optic nerve, simulating chronic glaucoma, was detected by OCT and corroborated by histological study. Results showed an alternative glaucoma model to the well-known episcleral vein model, which was simpler to perform, more reproducible and easier to monitor in vivo.
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Affiliation(s)
- David Garcia-Herranz
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM, 28040 Madrid, Spain; (D.G.-H.); (I.B.-O.); (J.G.-F.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
| | - Maria Jesus Rodrigo
- Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, 28040 Madrid, Spain; (M.J.R.); (L.P.); (E.G.-M.)
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (M.S.); (T.M.-R.); (S.M.-M.)
- 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; (M.S.); (T.M.-R.); (S.M.-M.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
| | - Teresa Martinez-Rincon
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (M.S.); (T.M.-R.); (S.M.-M.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
| | - Silvia Mendez-Martinez
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (M.S.); (T.M.-R.); (S.M.-M.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
| | - Irene Bravo-Osuna
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM, 28040 Madrid, Spain; (D.G.-H.); (I.B.-O.); (J.G.-F.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
- Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, 28040 Madrid, Spain; (M.J.R.); (L.P.); (E.G.-M.)
- Instituto Universitario de Farmacia Industrial (IUFI), Facultad de Farmacia, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
| | - Aina Bonet
- Center for Animal Biotechnology and Gene Therapy (CBATEG), Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (A.B.); (J.R.)
- CIBER for Diabetes and Associated Metabolic Diseases (CIBERDEM), 28029 Madrid, Spain
- Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Jesus Ruberte
- Center for Animal Biotechnology and Gene Therapy (CBATEG), Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; (A.B.); (J.R.)
- CIBER for Diabetes and Associated Metabolic Diseases (CIBERDEM), 28029 Madrid, Spain
- Department of Animal Health and Anatomy, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Julian Garcia-Feijoo
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM, 28040 Madrid, Spain; (D.G.-H.); (I.B.-O.); (J.G.-F.)
- Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, 28040 Madrid, Spain; (M.J.R.); (L.P.); (E.G.-M.)
- Servicio de Oftalmología, Hospital Clínico San Carlos, 28040 Madrid, Spain
- Departamento de Inmunología, Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
| | - Luis Pablo
- Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, 28040 Madrid, Spain; (M.J.R.); (L.P.); (E.G.-M.)
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (M.S.); (T.M.-R.); (S.M.-M.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
| | - Elena Garcia-Martin
- Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, 28040 Madrid, Spain; (M.J.R.); (L.P.); (E.G.-M.)
- Department of Ophthalmology, Miguel Servet University Hospital, 50009 Zaragoza, Spain; (M.S.); (T.M.-R.); (S.M.-M.)
- Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), 50009 Zaragoza, Spain
| | - Rocío Herrero-Vanrell
- Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group, UCM, 28040 Madrid, Spain; (D.G.-H.); (I.B.-O.); (J.G.-F.)
- Departamento de Farmacia Galénica y Tecnología Alimentaria, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), IdISSC, 28040 Madrid, Spain
- Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, 28040 Madrid, Spain; (M.J.R.); (L.P.); (E.G.-M.)
- Instituto Universitario de Farmacia Industrial (IUFI), Facultad de Farmacia, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
- Correspondence: ; Tel.: +34-91-394-1739; Fax: +34-91-394-1736
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8
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Tang J, Hui F, Hadoux X, Soares B, Jamieson M, van Wijngaarden P, Coote M, Crowston JG. Short-Term Changes in the Photopic Negative Response Following Intraocular Pressure Lowering in Glaucoma. Invest Ophthalmol Vis Sci 2021; 61:16. [PMID: 32766747 PMCID: PMC7441296 DOI: 10.1167/iovs.61.10.16] [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: 01/26/2023] Open
Abstract
Purpose To evaluate the short-term changes in inner retinal function using the photopic negative response (PhNR) after intraocular pressure (IOP) reduction in glaucoma. Methods Forty-seven participants with glaucoma who were commencing a new or additional IOP-lowering therapy (treatment group) and 39 participants with stable glaucoma (control group) were recruited. IOP, visual field, retinal nerve fiber layer thickness, and electroretinograms (ERGs) were recorded at baseline and at a follow-up visit (3 ± 2 months). An optimized protocol developed for a portable ERG device was used to record the PhNR. The PhNR saturated amplitude (Vmax), Vmax ratio, semi-saturation constant (K), and slope of the Naka–Rushton function were analyzed. Results A significant percentage reduction in IOP was observed in the treatment group (28 ± 3%) compared to the control group (2 ± 3%; P < 0.0001). For PhNR Vmax, there was no significant interaction (F1,83 = 2.099, P = 0.15), but there was a significant difference between the two time points (F1,83 = 5.689, P = 0.019). Post hoc analysis showed a significant difference between baseline and 3 months in the treatment group (mean difference, 1.23 µV; 95% confidence interval [CI], 0.24–2.22) but not in the control group (0.30 µV; 95% CI, 0.78–1.38). K and slope were not significantly different in either group. Improvement beyond test–retest variability was seen in 17% of participants in the treatment group compared to 3% in the control group (P = 0.007, χ2 test). Conclusions The optimized protocol for measuring the PhNR detected short-term improvements in a proportion of participants following IOP reduction, although the majority showed no change.
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Affiliation(s)
- Jessica Tang
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Flora Hui
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Xavier Hadoux
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | | | | | - Peter van Wijngaarden
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Michael Coote
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Jonathan G Crowston
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Centre for Vision Research, Duke-NUS Medical School, Singapore, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
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9
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Wong VHY, Zhao D, Bui BV, Millar CJ, Nguyen CTO. Increased episcleral venous pressure in a mouse model of circumlimbal suture induced ocular hypertension. Exp Eye Res 2020; 202:108348. [PMID: 33166503 DOI: 10.1016/j.exer.2020.108348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE To investigate changes in aqueous humor dynamics during intraocular pressure (IOP) elevation induced by circumlimbal suture in mice. METHODS Ocular hypertension (OHT) was induced by applying a circumlimbal suture behind the limbus in male adult C57BL6/J mice. In the OHT group, the suture was left in place for an average of 8 weeks (n = 10, OHT group). In the sham control group the suture was cut at 2 days (n = 9, sham group) and in the naïve control group (n = 5) no suture was implanted. IOP was measured at baseline across 3 days, 1 h post-suture implantation, and at the chronic endpoint. Anterior segments were assessed using optical coherence tomography (OCT). Episcleral venous pressure (EVP), total outflow facility (C), uveoscleral outflow (Fu) and aqueous humor flow rate (Fin) were determined using a constant-flow infusion model. RESULTS All aqueous dynamic and chronic IOP outcome measures showed no difference between sham and naïve controls (p > 0.05) and thus these groups were combined into a single control group. IOP was elevated in OHT group compared with controls (p < 0.01). Chronic suture implantation did not change pupil size, anterior chamber depth or iridocorneal angles (p > 0.05). EVP was significantly higher in OHT eyes compared to control eyes (p < 0.01). There was no statistical difference in C, Fu and Fin between groups (p > 0.05). A significant linear correlation was found between IOP and EVP (R2 = 0.35, p = 0.001). CONCLUSIONS Circumlimbal suture implantation in mouse eyes results in chronic IOP elevation without angle closure. Chronic IOP elevation is likely to reflect higher EVP.
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Affiliation(s)
- Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Cameron J Millar
- North Texas Eye Research Institute, Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia.
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10
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Zhang Y, Fu T, Han S, Ding Y, Wang J, Zheng J, Li J. Monocular Deprivation Affects Visual Cortex Plasticity Through cPKCγ-Modulated GluR1 Phosphorylation in Mice. Invest Ophthalmol Vis Sci 2020; 61:44. [PMID: 32343785 PMCID: PMC7401946 DOI: 10.1167/iovs.61.4.44] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose To determine how visual cortex plasticity changes after monocular deprivation (MD) in mice and whether conventional protein kinase C gamma (cPKCγ) plays a role in visual cortex plasticity. Methods cPKCγ membrane translocation levels were quantified by using immunoblotting to explore the effects of MD on cPKCγ activation. Electrophysiology was used to record field excitatory postsynaptic potential (fEPSP) amplitude with the goal of observing changes in visual cortex plasticity after MD. Immunoblotting was also used to determine the phosphorylation levels of GluR1 at Ser831. Light transmission was analyzed using electroretinography to examine the effects of MD and cPKCγ on mouse retinal function. Results Membrane translocation levels of cPKCγ significantly increased in the contralateral visual cortex of MD mice compared to wild-type (WT) mice (P < 0.001). In the contralateral visual cortex, long-term potentiation (LTP) and the phosphorylation levels of GluR1 at Ser 831 were increased in cPKCγ+/+ mice after MD. Interestingly, these levels could be downregulated by cPKCγ knockout compared to cPKCγ+/++MD mice (P < 0.001). Compared to the right eyes of WT mice, the amplitudes of a-waves and b-waves declined in deprived right eyes of mice after MD (P < 0.001). There were no significant differences when comparing cPKCγ+/+ and cPKCγ−/− mice with MD. Conclusions cPKCγ participates in the plasticity of the visual cortex after MD, which is characterized by increased LTP in the contralateral visual cortex, which may be a result of cPKCγ-mediated phosphorylation of GluR1 at Ser 831.
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11
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Lakshmanan Y, Wong FSY, Zuo B, Bui BV, Chan HHL. Longitudinal outcomes of circumlimbal suture model-induced chronic ocular hypertension in Sprague-Dawley albino rats. Graefes Arch Clin Exp Ophthalmol 2020; 258:2715-2728. [PMID: 32623578 DOI: 10.1007/s00417-020-04820-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/03/2020] [Accepted: 06/26/2020] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To characterise longitudinal structural and functional changes in albino Sprague-Dawley rats following circumlimbal suture ocular hypertension (OHT) induction. METHODS Ten-week-old rats (n = 24) underwent suture implantation around the limbal region in both eyes. On the next day, the suture was removed from one eye (control eyes) and left intact in the other eye (OHT eyes) of each animal. Intraocular pressure (IOP) was monitored weekly twice for the next 15 weeks. Optical coherence tomography (OCT) and electroretinogram (ERG) were measured at baseline and weeks 4, 8, 12, and 15, and eyes were then collected for histological assessment. RESULTS Sutured eyes (n = 12) developed IOP elevation of ~ 50% in the first 2 weeks that was sustained at ~ 25% above the control eye up to week 15 (p = 0.001). Animals with insufficient IOP elevation (n = 6), corneal changes (n = 3), and attrition (n = 3) were excluded from the analysis. OHT eyes developed significant retinal nerve fibre layer (RNFL) thinning (week 4: - 19 ± 14%, p = 0.10; week 8: - 17 ± 12%, p = 0.04; week 12: - 16 ± 10%, p = 0.04, relative to baseline) and reduction in retinal ganglion cell (RGC) density (- 32 ± 26%, p = 0.02). At week 15, both inner (9 ± 7%, p = 0.01) and outer retinal layer thicknesses (6.0 ± 5%, p = 0.001) showed a mild increase in thicknesses. The positive scotopic threshold response (- 28 ± 25%, p = 0.04) and a-wave were significantly reduced at week 12 (- 35 ± 21%; p = 0.04), whereas b-wave was not significantly affected (week 12: - 18 ± 27%, p = 0.24). CONCLUSION The circumlimbal suture model produced a chronic, moderate IOP elevation in an albino strain that led to RNFL thinning and reduced RGC density along with the reductions in ganglion and photoreceptoral cell functions. There was a small thickening in both outer and inner retinal layers.
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Affiliation(s)
- Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Francisca Siu Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Bing Zuo
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Bang Viet Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Australia
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China. .,Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.
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12
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Lakshmanan Y, Wong FSY, Zuo B, So KF, Bui BV, Chan HHL. Posttreatment Intervention With Lycium Barbarum Polysaccharides is Neuroprotective in a Rat Model of Chronic Ocular Hypertension. Invest Ophthalmol Vis Sci 2020; 60:4606-4618. [PMID: 31756254 DOI: 10.1167/iovs.19-27886] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the neuroprotective effects of Lycium barbarum polysaccharides (LBP) against chronic ocular hypertension (OHT) in rats and to consider if effects differed when treatment was applied before (pretreatment) or during (posttreatment) chronic IOP elevation. Methods Sprague-Dawley rats (10-weeks old) underwent suture implantation around the limbus for 15 weeks (OHT) or 1 day (sham). Four experimental groups were studied, three OHT groups (n = 8 each) treated either with vehicle (PBS), LBP pretreatment or posttreatment, and a sham control (n = 5) received no treatment. LBP (1 mg/kg) pre- and posttreatment were commenced at 1 week before and 4 weeks after OHT induction, respectively. Treatments continued up through week 15. IOP was monitored twice weekly for 15 weeks. Optical coherence tomography and ERG were measured at baseline, week 4, 8, 12, and 15. Eyes were collected for ganglion cell layer (GCL) histologic analysis at week 15. Results Suture implantation successfully induced approximately 50% IOP elevation and the cumulative IOP was similar between the three OHT groups. When compared with vehicle control (week 4: -23 ± 5%, P = 0.03), LBP pretreatment delayed the onset of retinal nerve fiber layer (RNFL) thinning (week 4, 8: -2 ± 7%, -11 ± 3%, P > 0.05) and arrested further reduction up through week 15 (-10 ± 4%, P > 0.05). LBP posttreatment intervention showed no significant change in rate of loss (week 4, 15: -25 ± 4.1%, -28 ± 3%). However, both LBP treatments preserved the retinal ganglion cells (RGC) and retinal functions up to week 15, which were significantly reduced in vehicle control. Conclusions LBP posttreatment arrested the subsequent neuronal degeneration after treatment commencement and preserved RGC density and retinal functions in a chronic OHT model, which was comparable with pretreatment outcomes.
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Affiliation(s)
- Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Francisca Siu Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Bing Zuo
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Kwok-Fai So
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,Guangdong-Hongkong-Macau (GHM) Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Bang Viet Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Australia
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.,Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
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13
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Zhao D, Wong VHY, Nguyen CTO, Jobling AI, Fletcher EL, Vingrys AJ, Bui BV. Reversibility of Retinal Ganglion Cell Dysfunction From Chronic IOP Elevation. Invest Ophthalmol Vis Sci 2020; 60:3878-3886. [PMID: 31529082 DOI: 10.1167/iovs.19-27113] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To test the hypothesis that the capacity for retinal ganglion cells to functionally recover from chronic IOP elevation is dependent on the duration of IOP elevation. Methods IOP elevation was induced in one eye in anesthetized (isoflurane) adult C57BL6/J mice using a circumlimbal suture. Sutures were left in place for 8 and 16 weeks (n = 30 and 28). In two other groups the suture was cut after 8 and 12 weeks (n = 30 and 28), and ganglion cell function (electroretinography) and retinal structure (optical coherence tomography) were assessed 4 weeks later. Ganglion cell density was quantified by counting RBPMS (RNA-binding protein with multiple splicing)-stained cells. Results With IOP elevation (∼10 mm Hg above baseline), ganglion cell function declined to 75% ± 8% at 8 weeks and 59% ± 4% at 16 weeks relative to contralateral control eyes. The retinal nerve fiber layer was thinner at 8 (84% ± 4%) and 16 weeks (83% ± 3%), without a significant difference in total retinal thickness. Ganglion cell function recovered with IOP normalization (suture removal) at week 8 (97% ± 7%), but not at week 12 (73% ± 6%). Ganglion cell loss was found in all groups (-8% to -13%). Conclusions In the mouse circumlimbal suture model, 12 weeks of IOP elevation resulted in irreversible ganglion cell dysfunction, whereas retinal dysfunction was fully reversible after 8 weeks of IOP elevation.
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Affiliation(s)
- Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia
| | - Erica L Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
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14
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Lani R, Dias MS, Abreu CA, Araújo VG, Gonçalo T, Nascimento-Dos-Santos G, Dantas AM, Allodi S, Fiorani M, Petrs-Silva H, Linden R. A subacute model of glaucoma based on limbal plexus cautery in pigmented rats. Sci Rep 2019; 9:16286. [PMID: 31705136 PMCID: PMC6841973 DOI: 10.1038/s41598-019-52500-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/16/2019] [Indexed: 12/17/2022] Open
Abstract
Glaucoma is a neurodegenerative disorder characterized by the progressive functional impairment and degeneration of the retinal ganglion cells (RGCs) and their axons, and is the leading cause of irreversible blindness worldwide. Current management of glaucoma is based on reduction of high intraocular pressure (IOP), one of its most consistent risk factors, but the disease proceeds in almost half of the patients despite such treatments. Several experimental models of glaucoma have been developed in rodents, most of which present shortcomings such as high surgical invasiveness, slow learning curves, damage to the transparency of the optic media which prevents adequate functional assessment, and variable results. Here we describe a novel and simple method to induce ocular hypertension in pigmented rats, based on low-temperature cauterization of the whole circumference of the limbal vascular plexus, a major component of aqueous humor drainage and easily accessible for surgical procedures. This simple, low-cost and efficient method produced a reproducible subacute ocular hypertension with full clinical recovery, followed by a steady loss of retinal ganglion cells and optic axons, accompanied by functional changes detected both by electrophysiological and behavioral methods.
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Affiliation(s)
- Rafael Lani
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Mariana S Dias
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carla Andreia Abreu
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Victor G Araújo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Thais Gonçalo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Silvana Allodi
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mario Fiorani
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Hilda Petrs-Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Rafael Linden
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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15
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He Z, Zhao D, van Koeverden AK, Nguyen CT, Lim JKH, Wong VHY, Vingrys AJ, Bui BV. A Model of Glaucoma Induced by Circumlimbal Suture in Rats and Mice. J Vis Exp 2018. [PMID: 30346390 DOI: 10.3791/58287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The circumlimbal suture is a technique for inducing experimental glaucoma in rodents by chronically elevating intraocular pressure (IOP), a well-known risk factor for glaucoma. This protocol demonstrates a step-by-step guide on this technique in Long Evans rats and C57BL/6 mice. Under general anesthesia, a "purse-string" suture is applied on the conjunctiva, around the equator and behind the limbus of the eye. The fellow eye serves as an untreated control. Over the duration of our study, which was a period of 8 weeks for rats and 12 weeks for mice, IOP remained elevated, as measured regularly by rebound tonometry in conscious animals without topical anesthesia. In both species, the sutured eyes showed electroretinogram features consistent with preferential inner retinal dysfunction. Optical coherence tomography showed selective thinning of the retinal nerve fiber layer. Histology of the rat retina in cross-section found reduced cell density in the ganglion cell layer, but no change in other cellular layers. Staining of flat-mounted mouse retinae with a ganglion cell specific marker (RBPMS) confirmed ganglion cell loss. The circumlimbal suture is a simple, minimally invasive and cost-effective way to induce ocular hypertension that leads to ganglion cell injury in both rats and mice.
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Affiliation(s)
- Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne
| | | | | | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne;
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16
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Fry LE, Fahy E, Chrysostomou V, Hui F, Tang J, van Wijngaarden P, Petrou S, Crowston JG. The coma in glaucoma: Retinal ganglion cell dysfunction and recovery. Prog Retin Eye Res 2018; 65:77-92. [DOI: 10.1016/j.preteyeres.2018.04.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/18/2018] [Accepted: 04/03/2018] [Indexed: 01/07/2023]
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17
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Shen G, Link S, Kumar S, Nusbaum DM, Tse DY, Fu Y, Wu SM, Frankfort BJ. Characterization of Retinal Ganglion Cell and Optic Nerve Phenotypes Caused by Sustained Intracranial Pressure Elevation in Mice. Sci Rep 2018; 8:2856. [PMID: 29434244 PMCID: PMC5809383 DOI: 10.1038/s41598-018-21254-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/31/2018] [Indexed: 12/16/2022] Open
Abstract
Elevated intracranial pressure (ICP) can result in multiple neurologic sequelae including vision loss. Inducible models of ICP elevation are lacking in model organisms, which limits our understanding of the mechanism by which increased ICP impacts the visual system. We adapted a mouse model for the sustained elevation of ICP and tested the hypothesis that elevated ICP impacts the optic nerve and retinal ganglion cells (RGCs). ICP was elevated and maintained for 2 weeks, and resulted in multiple anatomic changes that are consistent with human disease including papilledema, loss of physiologic cupping, and engorgement of the optic nerve head. Elevated ICP caused a loss of RGC somas in the retina and RGC axons within the optic nerve, as well as a reduction in both RGC electrical function and contrast sensitivity. Elevated ICP also caused increased hypoxia-inducible factor (HIF)-1 alpha expression in the ganglion cell layer. These experiments confirm that sustained ICP elevation can be achieved in mice and causes phenotypes that preferentially impact RGCs and are similar to those seen in human disease. With this model, it is possible to model human diseases of elevated ICP such as Idiopathic Intracranial Hypertension and Spaceflight Associated Neuro-ocular Syndrome.
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Affiliation(s)
- Guofu Shen
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Schuyler Link
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Sandeep Kumar
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Derek M Nusbaum
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Dennis Y Tse
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong
| | - Yingbin Fu
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, 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.
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18
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Liu HH, Zhang L, Shi M, Chen L, Flanagan JG. Comparison of laser and circumlimbal suture induced elevation of intraocular pressure in albino CD-1 mice. PLoS One 2017; 12:e0189094. [PMID: 29190824 PMCID: PMC5708743 DOI: 10.1371/journal.pone.0189094] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/18/2017] [Indexed: 12/23/2022] Open
Abstract
Animal models of ocular hypertension are important tools for glaucoma studies. Both acute transient models and chronic models of ocular hypertension may be useful to investigate specific aspects of neurodegeneration. In this study, we compare the intraocular pressure (IOP) and inner retinal changes induced by 1) laser photocoagulation of both episcleral veins and limbal vessels and 2) circumlimbal suture in CD-1 mice. The suture group is divided into 3 subgroups depending on the level of the immediate IOP spike (acute > 55 mmHg or chronic < 55 mmHg) and time period of monitoring (7 or 28 days). The laser group is followed for 7 days. IOP data show that it peaks at 5 hours and returns to normal level within 7 days in the laser group. In all suture groups, IOP spikes initially and decreases gradually, but it remains significantly elevated at 7 days. In 7 days, the acute suture model generates rapid loss of retinal nerve fiber layer (RNFL) and retinal ganglion cells (RGCs) when compared to the gradual loss by the chronic suture model, possibly due to retinal ischemia and reperfusion within the first few hours after treatment. The laser model falls between the acute suture and chronic suture models resulting in less RNFL and RGC loss than the acute suture model but significantly more loss than the chronic suture model. These results suggest that when using suture models of IOP elevation, it is critical to take the initial IOP spike into consideration and to choose between the acute and chronic models depending on respective research purposes.
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Affiliation(s)
- Hsin-Hua Liu
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
- * E-mail:
| | - Liwei Zhang
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - Meng Shi
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - Lu Chen
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - John G. Flanagan
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
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Livne-Bar I, Wei J, Liu HH, Alqawlaq S, Won GJ, Tuccitto A, Gronert K, Flanagan JG, Sivak JM. Astrocyte-derived lipoxins A4 and B4 promote neuroprotection from acute and chronic injury. J Clin Invest 2017; 127:4403-4414. [PMID: 29106385 DOI: 10.1172/jci77398] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022] Open
Abstract
Astrocytes perform critical non-cell autonomous roles following CNS injury that involve either neurotoxic or neuroprotective effects. Yet the nature of potential prosurvival cues has remained unclear. In the current study, we utilized the close interaction between astrocytes and retinal ganglion cells (RGCs) in the eye to characterize a secreted neuroprotective signal present in retinal astrocyte conditioned medium (ACM). Rather than a conventional peptide neurotrophic factor, we identified a prominent lipid component of the neuroprotective signal through metabolomics screening. The lipoxins LXA4 and LXB4 are small lipid mediators that act locally to dampen inflammation, but they have not been linked directly to neuronal actions. Here, we determined that LXA4 and LXB4 are synthesized in the inner retina, but their levels are reduced following injury. Injection of either lipoxin was sufficient for neuroprotection following acute injury, while inhibition of key lipoxin pathway components exacerbated injury-induced damage. Although LXA4 signaling has been extensively investigated, LXB4, the less studied lipoxin, emerged to be more potent in protection. Moreover, LXB4 neuroprotection was different from that of established LXA4 signaling, and therapeutic LXB4 treatment was efficacious in a chronic model of the common neurodegenerative disease glaucoma. Together, these results identify a potential paracrine mechanism that coordinates neuronal homeostasis and inflammation in the CNS.
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Affiliation(s)
- Izhar Livne-Bar
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Wei
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - Hsin-Hua Liu
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - Samih Alqawlaq
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Gah-Jone Won
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Alessandra Tuccitto
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - John G Flanagan
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - Jeremy M Sivak
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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Turner AJ, Vander Wall R, Gupta V, Klistorner A, Graham SL. DBA/2J mouse model for experimental glaucoma: pitfalls and problems. Clin Exp Ophthalmol 2017; 45:911-922. [PMID: 28516453 DOI: 10.1111/ceo.12992] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/04/2017] [Accepted: 05/11/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND The DBA/2J mouse has been described as a model for congenital experimental glaucoma. It develops anterior segment anomalies with synechiae and pigment dispersion leading to raised intraocular pressure and glaucomatous damage. However, there are serious practical considerations when using this model in longitudinal studies. METHODS We followed 118 mice from 12-48 weeks of age in a pharmaceutical trial. Here we report on the findings in control animals (n = 37). Intraocular pressure was measured weekly, electrophysiology and optical coherence tomography every 6 weeks. A subset also had invasive intraocular pressure measurements performed prior to euthanasia. RESULTS Although intraocular pressure eventually rose by 9 months in most animals, tonometry was complicated by corneal calcification in the majority of animals rendering intraocular pressure measurement unreliable. Invasive intraocular pressure did not correlate with non-invasive measures. Loss of scotopic threshold response and thinning of inner retinal layers on optical coherence tomography was observed over time, suggesting glaucomatous damage, but this occurred in some animals without raised intraocular pressure. Poor pupil dilation significantly affected electrophysiology, optical coherence tomography and fundus imaging; 22% of animals developed major systemic complications leading to high dropout rate. CONCLUSIONS The DBA/2J experimental glaucoma model shows variability in expression, and its pathological changes cause major difficulties in assessing disease progression. From our experience, the model presents significant challenges for drug studies in glaucoma, as there are many confounding factors: difficulty with accurate intraocular pressure measurement, in vivo imaging, and electrophysiology recording and a high dropout rate. In addition, there may be an underlying neurodegenerative process independent of intraocular pressure.
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Affiliation(s)
- Anita J Turner
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Roshana Vander Wall
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Vivek Gupta
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Alex Klistorner
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Stuart L Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
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Zhao D, Nguyen CTO, Wong VHY, Lim JKH, He Z, Jobling AI, Fletcher EL, Chinnery HR, Vingrys AJ, Bui BV. Characterization of the Circumlimbal Suture Model of Chronic IOP Elevation in Mice and Assessment of Changes in Gene Expression of Stretch Sensitive Channels. Front Neurosci 2017; 11:41. [PMID: 28239332 PMCID: PMC5301305 DOI: 10.3389/fnins.2017.00041] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 01/19/2017] [Indexed: 12/30/2022] Open
Abstract
To consider whether a circumlimbal suture can be used to chronically elevate intraocular pressure (IOP) in mice and to assess its effect on retinal structure, function and gene expression of stretch sensitive channels. Anesthetized adult C57BL6/J mice had a circumlimbal suture (10/0) applied around the equator of one eye. In treated eyes (n = 23) the suture was left in place for 12 weeks whilst in sham control eyes the suture was removed at day two (n = 17). Contralateral eyes served as untreated controls. IOP was measured after surgery and once a week thereafter. After 12 weeks, electroretinography (ERG) was performed to assess photoreceptor, bipolar cell and retinal ganglion cell (RGC) function. Retinal structure was evaluated using optical coherence tomography. Retinae were processed for counts of ganglion cell density or for quantitative RT-PCR to quantify purinergic (P2x7, Adora3, Entpd1) or stretch sensitive channel (Panx1, Trpv4) gene expression. Immediately after suture application, IOP spiked to 33 ± 3 mmHg. After 1 day, IOP had recovered to 27 ± 3 mmHg. Between weeks 2 and 12, IOP remained elevated above baseline (control 14 ± 1 mmHg, ocular hypertensive 19 ± 1 mmHg). Suture removal at day 2 (Sham) restored IOP to baseline levels, where it remained through to week 12. ERG analysis showed that 12 weeks of IOP elevation reduced photoreceptor (−15 ± 4%), bipolar cell (−15 ± 4%) and ganglion cell responses (−19 ± 6%) compared to sham controls and respective contralateral eyes (untreated). The retinal nerve fiber layer was thinned in the presence of normal total retinal thickness. Ganglion cell density was reduced across all quadrants (superior −12 ± 5%; temporal, −7% ± 2%; inferior −9 ± 4%; nasal −8 ± 5%). Quantitative RT-PCR revealed a significant increase in Entpd1 gene expression (+11 ± 4%), whilst other genes were not significantly altered (P2x7, Adora3, Trpv4, Panx1). Our results show that circumlimbal ligation produces mild chronic ocular hypertension and retinal dysfunction in mice. Consistent with a sustained change to purinergic signaling we found an up-regulation of Entpd1.
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Affiliation(s)
- Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, University of Melbourne Parkville, VIC, Australia
| | - Erica L Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne Parkville, VIC, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
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