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Su CC, Liu C, Adi V, Chan KC, Tseng HC. Age-related effects of optineurin deficiency in the mouse eye. Vision Res 2024; 224:108463. [PMID: 39208752 DOI: 10.1016/j.visres.2024.108463] [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: 06/01/2024] [Revised: 07/30/2024] [Accepted: 07/30/2024] [Indexed: 09/04/2024]
Abstract
Optineurin (OPTN) is a gene associated with familial normal tension glaucoma (NTG). While NTG involves intraocular pressure (IOP)-independent neurodegeneration of the visual pathway that progresses with age, how OPTN dysfunction leads to NTG remains unclear. Here, we generated an OPTN knockout mouse (Optn-/-) model to test the hypothesis that a loss-of-function mechanism induces structural and functional eye deterioration with aging. Eye anatomy, visual function, IOP, retinal histology, and retinal ganglion cell survival were compared to littermate wild-type (WT) control mice. Consistent with OPTN's role in NTG, loss of OPTN did not increase IOP or alter gross eye anatomy in young (2-3 months) or aged (12 months) mice. When retinal layers were quantitated, young Optn-/- mice had thinner retina in the peripheral regions than young WT mice, primarily due to thinner ganglion cell-inner plexiform layers. Despite this, visual function in Optn-/- mice was not severely impaired, even with aging. We also assessed relative abundance of retinal cell subtypes, including amacrine cells, bipolar cells, cone photoreceptors, microglia, and astrocytes. While many of these cellular subtypes were unaffected by Optn deletion, more dopaminergic amacrine cells were observed in aged Optn-/- mice. Taken together, our findings showed that complete loss of Optn resulted in mild retinal changes and less visual function impairment, supporting the possibility that OPTN-associated glaucoma does not result from a loss-of-function disease mechanism. Further research using these Optn mice will elucidate detailed molecular pathways involved in NTG and identify clinical or environmental risk factors that can be targeted for glaucoma treatment.
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Affiliation(s)
- Chien-Chia Su
- Duke Eye Center, Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA; Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Crystal Liu
- Departments of Ophthalmology and Radiology, Neuroscience Institute, and Tech4Health Institute, New York University Grossman School of Medicine, New York, NY 10017, USA
| | - Vishnu Adi
- Departments of Ophthalmology and Radiology, Neuroscience Institute, and Tech4Health Institute, New York University Grossman School of Medicine, New York, NY 10017, USA
| | - Kevin C Chan
- Departments of Ophthalmology and Radiology, Neuroscience Institute, and Tech4Health Institute, New York University Grossman School of Medicine, New York, NY 10017, USA; Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY 11201, USA
| | - Henry C Tseng
- Duke Eye Center, Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA.
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Kim D, Fang R, Zhang P, Sun C, Li G, Montgomery C, John SWM, Stamer WD, Zhang HF, Ethier CR. In vivo quantification of anterior and posterior chamber volumes in mice: implications for aqueous humor dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.24.604989. [PMID: 39091756 PMCID: PMC11291131 DOI: 10.1101/2024.07.24.604989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Purpose Aqueous humor inflow rate, a key parameter influencing aqueous humor dynamics, is typically measured by fluorophotometery. Analyzing fluorophotometric data depends, inter alia, on the volume of aqueous humor in the anterior, but not the posterior, chamber. Previous fluorophotometric studies of aqueous inflow rate in mice have assumed the ratio of anterior:posterior volumes in mice to be similar to those in humans. Our goal was to measure anterior and posterior chamber volumes in mice to facilitate better estimates of aqueous inflow rates. Methods We used standard near-infrared optical coherence tomography (OCT) and robotic visible-light OCT (vis-OCT) to visualize, reconstruct and quantify the volumes of the anterior and posterior chambers of the mouse eye in vivo. We used histology and micro-CT scans to validate relevant landmarks from ex vivo tissues to facilitate in vivo measurement. Results Posterior chamber volume is 1.1 times the anterior chamber volume in BALB/cAnNCrl mice, i.e. the anterior chamber constitutes about 47% of the total aqueous humor volume, which is very dissimilar to the situation in humans. Anterior chamber volumes in 2-month-old BALB/cAnNCrl and 7-month-old C57BL6/J mice were 1.55 ± 0.36 μL (n=10) and 2.41 ± 0.29 μL (n=8), respectively. This implies that previous studies likely over-estimated aqueous inflow rate by approximately two-fold. Conclusions It is necessary to reassess previously reported estimates of aqueous inflow rates, and thus aqueous humor dynamics in the mouse. For example, we now estimate that only 0-15% of aqueous humor drains via the pressure-independent (unconventional) route, similar to that seen in humans and monkeys.
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Affiliation(s)
- Daniel Kim
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | - Raymond Fang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | - Pengpeng Zhang
- Department of Mechanical Engineering, Northwestern University, Evanston, IL
| | - Cheng Sun
- Department of Mechanical Engineering, Northwestern University, Evanston, IL
| | - Guorong Li
- Department of Ophthalmology, Duke University, Durham, NC
| | - Christa Montgomery
- Department of Ophthalmology, Columbia University Irving Medical Center, and Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | - Simon W M John
- Department of Ophthalmology, Columbia University Irving Medical Center, and Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | | | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL
| | - C Ross Ethier
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
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3
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Fu H, Siggs OM, Knight LS, Staffieri SE, Ruddle JB, Birsner AE, Collantes ER, Craig JE, Wiggs JL, D’Amato RJ. Thrombospondin 1 missense alleles induce extracellular matrix protein aggregation and TM dysfunction in congenital glaucoma. J Clin Invest 2022; 132:e156967. [PMID: 36453543 PMCID: PMC9711877 DOI: 10.1172/jci156967] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 10/11/2022] [Indexed: 12/03/2022] Open
Abstract
Glaucoma is a highly heritable disease that is a leading cause of blindness worldwide. Here, we identified heterozygous thrombospondin 1 (THBS1) missense alleles altering p.Arg1034, a highly evolutionarily conserved amino acid, in 3 unrelated and ethnically diverse families affected by congenital glaucoma, a severe form of glaucoma affecting children. Thbs1R1034C-mutant mice had elevated intraocular pressure (IOP), reduced ocular fluid outflow, and retinal ganglion cell loss. Histology revealed an abundant, abnormal extracellular accumulation of THBS1 with abnormal morphology of juxtacanalicular trabecular meshwork (TM), an ocular tissue critical for aqueous fluid outflow. Functional characterization showed that the THBS1 missense alleles found in affected individuals destabilized the THBS1 C-terminus, causing protein misfolding and extracellular aggregation. Analysis using a range of amino acid substitutions at position R1034 showed that the extent of aggregation was correlated with the change in protein-folding free energy caused by variations in amino acid structure. Extracellular matrix (ECM) proteins, especially fibronectin, which bind to THBS1, also accumulated within THBS1 deposits. These results show that missense variants altering THBS1 p.Arg1034 can cause elevated IOP through a mechanism involving impaired TM fluid outflow in association with accumulation of aggregated THBS1 in the ECM of juxtacanalicular meshwork with altered morphology.
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Affiliation(s)
- Haojie Fu
- Vascular Biology Program, Department of Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Owen M. Siggs
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
- Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Lachlan S.W. Knight
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Sandra E. Staffieri
- Centre for Eye Research Australia (CERA), Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Department of Ophthalmology, University of Melbourne, Department of Surgery, Parkville, Victoria, Australia
- Department of Ophthalmology, Royal Children’s Hospital, Parkville, Victoria, Australia
| | - Jonathan B. Ruddle
- Department of Ophthalmology, Royal Children’s Hospital, Parkville, Victoria, Australia
| | - Amy E. Birsner
- Vascular Biology Program, Department of Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
| | | | - Jamie E. Craig
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Janey L. Wiggs
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Massachusetts Eye and Ear, Boston, Massachusetts, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
| | - Robert J. D’Amato
- Vascular Biology Program, Department of Surgery, Boston Children’s Hospital, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
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Lysyl oxidase-like 1 deficiency alters ultrastructural and biomechanical properties of the peripapillary sclera in mice. Matrix Biol Plus 2022; 16:100120. [PMID: 36060791 PMCID: PMC9436796 DOI: 10.1016/j.mbplus.2022.100120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 08/17/2022] [Indexed: 11/30/2022] Open
Abstract
Lysyl oxidate-like 1 knockout (Loxl1-/-) mice have decreased vision without elevated intraocular pressure. Loxl1-/- mice exhibit biometric changes of the anterior segment of the eye. Loxl1-/- mice have altered elastin and collagen structure in peripapillary sclera. Structural alternations of peripapillary sclera correlate with its increased stiffness in Loxl1-/- mice.
Lysyl oxidase-like 1 encoded by the LOXL1 gene is a member of the lysyl oxidase family of enzymes that are important in the maintenance of extracellular matrix (ECM)-rich tissue. LOXL1 is important for proper elastic fiber formation and mice lacking LOXL1 (Loxl1−/−) exhibit systemic elastic fiber disorders, such as pelvic organ prolapse, a phenotype associated with exfoliation syndrome (XFS) in humans. Patients with XFS have a significant risk of developing exfoliation glaucoma (XFG), a severe form of glaucoma, which is a neurodegenerative condition leading to irreversible blindness if not detected and treated in a timely fashion. Although Loxl1−/− mice have been used extensively to investigate mechanisms of pelvic organ prolapse, studies of eyes in those mice are limited and some showed inconsistent ocular phenotypes. In this study we demonstrate that Loxl1−/− mice have significant anterior segment biometric abnormalities which recapitulate some human XFS features. We then focused on the peripapillary sclera (PPS), a critical structure for maintaining optic nerve health. We discovered quantitative and qualitive changes in ultrastructure of PPS, such as reduced elastic fibers, enlarged collagen fibrils, and transformed collagen lamella organization detected by transmission electron microscopy (TEM). Importantly, these changes corelate with altered tissue biomechanics detected by Atomic Force Microscopy (AFM) of PPS in mice. Together, our results support a crucial role for LOXL1 in ocular tissue structure and biomechanics, and Loxl1−/− mice could be a valuable resource for understanding the role of scleral tissue biomechanics in ocular disease.
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Binter M, Lüdtke P, Langer F, Schigiel T, Framme C, Heider M, Tode J. Changes in Intraocular Pressure following Narcosis With Medetomidine, Midazolam, and Fentanyl in Association With Initial Intraocular Pressure in Mice. Curr Eye Res 2022; 47:1553-1558. [PMID: 35943353 DOI: 10.1080/02713683.2022.2101667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/30/2022] [Accepted: 07/06/2022] [Indexed: 01/27/2023]
Abstract
PURPOSE This article describes the development of decreased intraocular pressure (IOP) under general anesthesia with medetomidine, midazolam, and fentanyl in mice with normal and elevated IOP. METHODS IOP was measured using the iCare Tonolab rebound tonometer. Twelve 3-4 months-old male and female C57BL/6J mice were randomized to a control group with physiological IOP and a high IOP group with experimentally induced ocular hypertension using tarsal injections of dexamethasone-21-acetate. For anesthesia, medetomidine and midazolam were used, subgroups additionally received fentanyl. IOP was measured every 2.5 min for 30 min. RESULTS Control group differed with 14.89 mmHg (SEM: 0.58) significantly (p = 0.0002) from the high IOP group with initial 20.44 mmHg (SEM: 0.75). All groups showed a significant (p < 0.05) decrease in IOP under general anesthesia. There was no significant difference in IOP development and decrease between the group additionally receiving fentanyl and the group without fentanyl. The decrease in IOP was highly dependent on the initial value, with the high IOP group showing a greater decrease. After 10 min, no significant difference in IOP could be detected between the high IOP and control group. CONCLUSIONS In mice, general anesthesia with medetomidine and midazolam leads to a declining IOP over time. Adding fentanyl to the anesthesia did not alter these effects. The decline is time-dependent and IOP-dependent.
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Affiliation(s)
- Maximilian Binter
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
| | - Philipp Lüdtke
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
| | - Fridolin Langer
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
| | - Thomas Schigiel
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
| | - Carsten Framme
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
| | - Miriam Heider
- Institute for Laboratory Animal Science, Hannover Medical School, Hannover, Germany
| | - Jan Tode
- Department of Ophthalmology, Hannover Medical School, Hannover, Germany
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6
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Madekurozwa M, Reina-Torres E, Overby DR, van Batenburg-Sherwood J. Measurement of postmortem outflow facility using iPerfusion. Exp Eye Res 2022; 220:109103. [PMID: 35525299 DOI: 10.1016/j.exer.2022.109103] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/24/2022] [Accepted: 04/28/2022] [Indexed: 11/04/2022]
Abstract
The key risk factor for glaucoma is elevation of intraocular pressure (IOP) and alleviating it is the only effective therapeutic approach to inhibit further vision loss. IOP is regulated by the flow of aqueous humour across resistive tissues, and a reduction in outflow facility C, is responsible for the IOP elevation in glaucoma. Measurement of C is therefore important when investigating the pathophysiology of glaucoma and testing candidate treatments for lowering IOP. Due to similar anatomy and response to pharmacological treatments, mouse eyes are a common model of human aqueous humour dynamics. The ex vivo preparation, in which an enucleated mouse eye is mounted in a temperature controlled bath and cannulated, has been well characterised and is widely used. The postmortem in situ model, in which the eyes are perfused within the cadaver, has received relatively little attention. In this study, we investigate the postmortem in situ model using the iPerfusion system, with a particular focus on i) the presence or absence of pressure-independent flow, ii) the effect of evaporation on measured flow rates and iii) the magnitude and pressure dependence of outflow facility and how these properties are affected by postmortem changes. Measurements immediately after cannulation and following multi-pressure facility measurement demonstrated negligible pressure-independent flow in postmortem eyes, in contrast to assumptions made in previous studies. Using a humidity chamber, we investigated whether the humidity of the surrounding air would influence measured flow rates. We found that at room levels of humidity, evaporation of saline droplets on the eye resulted in artefactual flow rates with a magnitude comparable to outflow, which were eliminated by a high relative humidity (>85%) environment. Average postmortem outflow facility was ∼4 nl/min/mmHg, similar to values observed ex vivo, irrespective of whether a postmortem delay was introduced prior to cannulation. The intra-animal variability of measured outflow facility values was also reduced relative to previous ex vivo data. The pressure-dependence of outflow facility was reduced in the postmortem relative to ex vivo model, and practically eliminated when eyes were cannulated >40 min after euthanisation. Overall, our results indicate that the moderately increased technical complexity associated with postmortem perfusion provides reduced variability and reduced pressure-dependence in outflow facility, when experimental conditions are properly controlled.
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Affiliation(s)
| | | | - Darryl R Overby
- Dept. of Bioengineering, Imperial College London, London, SW7 2AZ, UK.
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7
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McDowell CM, Kizhatil K, Elliott MH, Overby DR, van Batenburg-Sherwood J, Millar JC, Kuehn MH, Zode G, Acott TS, Anderson MG, Bhattacharya SK, Bertrand JA, Borras T, Bovenkamp DE, Cheng L, Danias J, De Ieso ML, Du Y, Faralli JA, Fuchshofer R, Ganapathy PS, Gong H, Herberg S, Hernandez H, Humphries P, John SWM, Kaufman PL, Keller KE, Kelley MJ, Kelly RA, Krizaj D, Kumar A, Leonard BC, Lieberman RL, Liton P, Liu Y, Liu KC, Lopez NN, Mao W, Mavlyutov T, McDonnell F, McLellan GJ, Mzyk P, Nartey A, Pasquale LR, Patel GC, Pattabiraman PP, Peters DM, Raghunathan V, Rao PV, Rayana N, Raychaudhuri U, Reina-Torres E, Ren R, Rhee D, Chowdhury UR, Samples JR, Samples EG, Sharif N, Schuman JS, Sheffield VC, Stevenson CH, Soundararajan A, Subramanian P, Sugali CK, Sun Y, Toris CB, Torrejon KY, Vahabikashi A, Vranka JA, Wang T, Willoughby CE, Xin C, Yun H, Zhang HF, Fautsch MP, Tamm ER, Clark AF, Ethier CR, Stamer WD. Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms. Invest Ophthalmol Vis Sci 2022; 63:12. [PMID: 35129590 PMCID: PMC8842499 DOI: 10.1167/iovs.63.2.12] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/08/2021] [Indexed: 01/07/2023] Open
Abstract
Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.
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Affiliation(s)
- Colleen M. McDowell
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | | | - Michael H. Elliott
- University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Darryl R. Overby
- Department of Bioengineering, Imperial College London, United Kingdom
| | | | - J. Cameron Millar
- Department of Pharmacology & Neuroscience, and North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Markus H. Kuehn
- Department of Ophthalmology and Visual Sciences and Institute for Vision Research, The University of Iowa; Center for the Prevention and Treatment of Visual Loss, Veterans Affairs Medical Center, Iowa City, Iowa, United States
| | - Gulab Zode
- Department of Pharmacology & Neuroscience, and North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Ted S. Acott
- Ophthalmology and Biochemistry and Molecular Biology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Michael G. Anderson
- Department of Molecular Physiology and Biophysics and Department of Ophthalmology and Visual Sciences, The University of Iowa; Center for the Prevention and Treatment of Visual Loss, Veterans Affairs Medical Center, Iowa City, Iowa, United States
| | | | - Jacques A. Bertrand
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Terete Borras
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | | | - Lin Cheng
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - John Danias
- SUNY Downstate Health Sciences University, Brooklyn, New York, United States
| | - Michael Lucio De Ieso
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, North Carolina, United States
| | - Yiqin Du
- Department of Ophthalmology, University of Pittsburgh, Pennsylvania, United States
| | - Jennifer A. Faralli
- Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Rudolf Fuchshofer
- Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany
| | - Preethi S. Ganapathy
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, United States
| | - Haiyan Gong
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Samuel Herberg
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, United States
| | | | - Peter Humphries
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Simon W. M. John
- Department of Ophthalmology, Columbia University, New York, New York, United States
| | - Paul L. Kaufman
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Kate E. Keller
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Mary J. Kelley
- Department of Ophthalmology and Department of Integrative Biosciences, Oregon Health & Science University, Portland, Oregon, United States
| | - Ruth A. Kelly
- Ocular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - David Krizaj
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah, United States
| | - Ajay Kumar
- Department of Ophthalmology, University of Pittsburgh, Pennsylvania, United States
| | - Brian C. Leonard
- Department of Surgical and Radiological Sciences, University of California, Davis, Davis, California, United States
| | - Raquel L. Lieberman
- Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Paloma Liton
- Department of Ophthalmology and Department of Pathology, Duke University, Durham, North Carolina, United States
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
| | - Katy C. Liu
- Duke Eye Center, Duke Health, Durham, North Carolina, United States
| | - Navita N. Lopez
- Department of Neurobiology, University of Utah, Salt Lake City, Utah, United States
| | - Weiming Mao
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Timur Mavlyutov
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Fiona McDonnell
- Duke Eye Center, Duke Health, Durham, North Carolina, United States
| | - Gillian J. McLellan
- Department of Surgical Sciences and Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Philip Mzyk
- Department of Ophthalmology and Visual Sciences, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | - Andrews Nartey
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Louis R. Pasquale
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Gaurang C. Patel
- Ophthalmology Research, Regeneron Pharmaceuticals, Tarreytown, New York, United States
| | | | - Donna M. Peters
- Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, Madison, Wisconsin, United States
| | | | - Ponugoti Vasantha Rao
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, United States
| | - Naga Rayana
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Urmimala Raychaudhuri
- Department of Neurobiology, University of California, Irvine, Irvine, California, United States
| | - Ester Reina-Torres
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Ruiyi Ren
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
| | - Douglas Rhee
- Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Uttio Roy Chowdhury
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - John R. Samples
- Washington State University, Floyd Elson College of Medicine, Spokane, Washington, United States
| | | | - Najam Sharif
- Santen Inc., Emeryville, California, United States
| | - Joel S. Schuman
- Department of Ophthalmology and Department of Physiology and Neuroscience, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, New York, United States; Departments of Biomedical Engineering and Electrical and Computer Engineering, New York University Tandon School of Engineering, Brooklyn, New York, United States; Center for Neural Science, College of Arts and Science, New York University, New York, New York, United States
| | - Val C. Sheffield
- Department of Pediatrics and Department of Ophthalmology and Visual Sciences, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
| | - Cooper H. Stevenson
- Department of Pharmacology & Neuroscience, and North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Avinash Soundararajan
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | | | - Chenna Kesavulu Sugali
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Yang Sun
- Veterans Affairs Palo Alto Health Care System, Stanford University, Palo Alto, California, United States
| | - Carol B. Toris
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States; Department of Ophthalmology and Vision Sciences, The Ohio State University, Columbus, Ohio, United States
| | | | - Amir Vahabikashi
- Cell and Developmental Biology Department, Northwestern University, Chicago, Illinois, United States
| | - Janice A. Vranka
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Ting Wang
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, United States
| | - Colin E. Willoughby
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland, United Kingdom
| | - Chen Xin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Hongmin Yun
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Hao F. Zhang
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois, United States
| | - Michael P. Fautsch
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois, United States
| | | | - Abbot F. Clark
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - C. Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology; Emory University School of Medicine, Emory University, Atlanta, Georgia, United States
| | - W. Daniel Stamer
- Duke Ophthalmology, Duke University, Durham, North Carolina, United States
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8
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Toris CB, Gagrani M, Ghate D. Current methods and new approaches to assess aqueous humor dynamics. EXPERT REVIEW OF OPHTHALMOLOGY 2021. [DOI: 10.1080/17469899.2021.1902308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Carol B. Toris
- Dept. Of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA
- Dept. Of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH USA
| | - Meghal Gagrani
- Dept. Of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA
| | - Deepta Ghate
- Dept. Of Ophthalmology and Visual Science, University of Nebraska Medical Center, Omaha, NE, USA
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Secreted protein acidic and rich in cysteine (SPARC) knockout mice have greater outflow facility. PLoS One 2020; 15:e0241294. [PMID: 33147244 PMCID: PMC7641442 DOI: 10.1371/journal.pone.0241294] [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] [Received: 04/01/2020] [Accepted: 10/12/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that regulates intraocular pressure (IOP) by altering extracellular matrix (ECM) homeostasis within the trabecular meshwork (TM). We hypothesized that the lower IOP previously observed in SPARC -/- mice is due to a greater outflow facility. Methods Mouse outflow facility (Clive) was determined by multiple flow rate infusion, and episcleral venous pressure (Pe) was estimated by manometry. The animals were then euthanized, eliminating aqueous formation rate (Fin) and Pe. The C value was determined again (Cdead) while Fin was reduced to zero. Additional mice were euthanized for immunohistochemistry to analyze ECM components of the TM. Results The Clive and Cdead of SPARC -/- mice were 0.014 ± 0.002 μL/min/mmHg and 0.015 ± 0.002 μL/min/mmHg, respectively (p = 0.376, N/S). Compared to the Clive = 0.010 ± 0.002 μL/min/mmHg and Cdead = 0.011 ± 0.002 μL/min/mmHg in the WT mice (p = 0.548, N/S), the Clive and Cdead values for the SPARC -/- mice were higher. Pe values were estimated to be 8.0 ± 0.2 mmHg and 8.3 ± 0.7 mmHg in SPARC -/- and WT mice, respectively (p = 0.304, N/S). Uveoscleral outflow (Fu) was 0.019 ± 0.007 μL/min and 0.022 ± 0.006 μL/min for SPARC -/- and WT mice, respectively (p = 0.561, N/S). Fin was 0.114 ± 0.002 μL/min and 0.120 ± 0.016 μL/min for SPARC -/- and WT mice (p = 0.591, N/S). Immunohistochemistry demonstrated decreases of collagen types IV and VI, fibronectin, laminin, PAI-1, and tenascin-C within the TM of SPARC -/- mice (p < 0.05). Conclusions The lower IOP of SPARC -/- mice is due to greater aqueous humor outflow facility through the conventional pathway. Corresponding changes in several matricellular proteins and ECM structural components were noted in the TM of SPARC -/- mice.
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10
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Fiedorowicz M, Wełniak-Kamińska M, Świątkiewicz M, Orzeł J, Chorągiewicz T, Toro MD, Rejdak R, Bogorodzki P, Grieb P. Changes of Ocular Dimensions as a Marker of Disease Progression in a Murine Model of Pigmentary Glaucoma. Front Pharmacol 2020; 11:573238. [PMID: 33013417 PMCID: PMC7500411 DOI: 10.3389/fphar.2020.573238] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 08/17/2020] [Indexed: 12/11/2022] Open
Abstract
Purpose The elevation of intraocular pressure (IOP), a major risk factor in glaucoma, is an important parameter tracked in experimental models of this disease. However, IOP measurement in laboratory rodents is challenging and may not correlate with some key pathological events that occur in the development of glaucoma. The aims of this study were to quantify changes in ocular morphology in DBA/2J mice that develop spontaneous, age-dependent, pigmentary glaucoma and to check the possible correlation of these parameters with IOP. Method Eye morphology was evaluated with MRI in DBA/2J, DBA/2J-Gpnmb+/SjJ, and C57BL/6J female mice ages 3, 6, 9, 12, and 15 months. The animals were anesthetized with isoflurane. A planar receive-only surface coil (inner diameter = 10 mm) was placed over each animal’s left eye and the image was acquired with a 7T small animal-dedicated magnetic resonance tomograph and T2-weighted TurboRARE sequence. Ocular dimensions were manually quantitated using OsiriX software. IOP was measured with rebound tonometry. Results In the control animals, no age-related changes in the ocular morphology were noted. Since 6 months of age, the anterior chamber deepening and elongation of the eyeballs of DBA/2J mice was detectable. We found a significant, positive correlation between IOP and axial length, anterior chamber area, or anterior chamber width in C57BL/6J mice but not in DBA/2J mice. However, after excluding the measurements performed in the oldest DBA/2J mice (i.e. analyzing only the animals ages 3 to 12 months), we demonstrated a significant positive correlation between IOP and anterior chamber width. Conclusion High-resolution magnetic resonance imaging of the eye area in mice enables reproducible and consistent measures of key dimensions of the eyeball. We observed age-dependent alterations in the eye morphology of DBA/2J mice that mostly affected the anterior chamber. We also demonstrated a correlation between some of the ocular dimensions and the IOP of C57Bl/6J mice and DBA/2J mice with moderately advanced glaucomatous pathology.
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Affiliation(s)
- Michał Fiedorowicz
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,Small Animal Magnetic Resonance Imaging Laboratory, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Marlena Wełniak-Kamińska
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,Small Animal Magnetic Resonance Imaging Laboratory, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Maciej Świątkiewicz
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,Small Animal Magnetic Resonance Imaging Laboratory, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Jarosław Orzeł
- Small Animal Magnetic Resonance Imaging Laboratory, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - Tomasz Chorągiewicz
- Department of General Ophthalmology, Medical University of Lublin, Lublin, Poland
| | - Mario Damiano Toro
- Department of General Ophthalmology, Medical University of Lublin, Lublin, Poland.,Faculty of Medical Sciences, Collegium Medicum, Cardinal Stefan Wyszyński University, Warsaw, Poland
| | - Robert Rejdak
- Department of General Ophthalmology, Medical University of Lublin, Lublin, Poland
| | - Piotr Bogorodzki
- Small Animal Magnetic Resonance Imaging Laboratory, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - Paweł Grieb
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
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11
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Jasien JV, Girkin CA, Downs JC. Effect of Anesthesia on Intraocular Pressure Measured With Continuous Wireless Telemetry in Nonhuman Primates. Invest Ophthalmol Vis Sci 2019; 60:3830-3834. [PMID: 31529079 PMCID: PMC6750888 DOI: 10.1167/iovs.19-27758] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/09/2019] [Indexed: 12/28/2022] Open
Abstract
Purpose To compare the effects of both injectable anesthesia (ketamine/dexmedetomidine versus ketamine/xylazine) and inhalant anesthesia (isoflurane) on IOP using continuous, bilateral IOP telemetry in nonhuman primates (NHP). Methods Bilateral IOP was recorded continuously using a proven implantable telemetry system in five different sessions at least 2 weeks apart in four male rhesus macaques under two conditions: ketamine (3 mg/kg) with dexmedetomidine (50 μg/kg) or ketamine with xylazine (0.5 mg/kg) for induction, both followed by isoflurane for maintenance. IOP transducers were calibrated via anterior chamber manometry. Bilateral IOP was averaged over 2 minutes after injectable anesthetic induction and again after isoflurane inhalant had stabilized the anesthetic plane, then compared to baseline IOP measurements acquired immediately prior to anesthesia (both before and after initial human contact). Results When compared to pre-contact baseline measurements, ketamine/dexmedetomidine injectable anesthesia lowers IOP by 1.5 mm Hg on average (P < 0.05), but IOP did not change with ketamine/xylazine anesthesia. IOP returned to baseline levels shortly after isoflurane gas anesthesia was initiated. However, injectable anesthesia lowered IOP by an average of 5.4 mm Hg when compared to that measured after initial human contact (P < 0.01). Conclusions Anesthetic effects on IOP are generally small when compared to precontact baseline but much larger when compared to IOP measures taken after human contact, indicating that IOP is temporarily elevated due to acute stress (similar to a "white coat effect") and then decreased with anesthetic relaxation. Anesthetic induction with ketamine/xylazine and maintenance with isoflurane gas should be used when IOP is measured postanesthesia.
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Affiliation(s)
- Jessica V. Jasien
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Christopher A. Girkin
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - J. Crawford Downs
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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12
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Fiedorowicz M, Orzel J, Kossowski B, Welniak-Kaminska M, Choragiewicz T, Swiatkiewicz M, Rejdak R, Bogorodzki P, Grieb P. Anterograde Transport in Axons of the Retinal Ganglion Cells and its Relationship to the Intraocular Pressure during Aging in Mice with Hereditary Pigmentary Glaucoma. Curr Eye Res 2017; 43:539-546. [PMID: 29283693 DOI: 10.1080/02713683.2017.1416147] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To establish a relationship between impairment of the anterograde axonal transport (AAT) in the axons of the retinal ganglion cells and the intraocular pressure (IOP) during aging in mice with hereditary glaucoma. METHODS Quantitative in vivo approach based on manganese enhanced magnetic resonance imaging was developed in order to evaluate AAT in 3-, 6-, and 14-month old DBA/2J mice that develop age-dependent pigmentary glaucoma or age-matched C57Bl/6 mice that do not develop any retinal disease. Unilateral intravitreous administration of MnCl2 solution was followed 24 h later by MRI performed to obtain spin-lattice relaxation times (T1) for regions of interest encompassing the superior colliculi (SC) and the lateral geniculate nuclei (LGN). From the MRI scans, the estimates of Mn2+ concentrations in SC and LGN contralateral to the injection site, hence the efficiency of AAT in ON, were obtained. IOP and eye morphology was also monitored. RESULTS In C57Bl/6 mice, AAT to SC was decreasing with age, 30% decrease was noted between 3 and 14 months. The decrease in axonal transport to LGN was less pronounced in this strain. In 3-month-old DBA/2J mice, axonal transport to SC was 30% lower than in 3-month-old C57Bl/6 mice but no significant decrease was noted in 6-month-old animals. However, a decrease of over 95% in axonal transport both to SC and LGN was noted in 14-month-old DBA/2J mice. DBA/2J mice exhibited a sharp increase in IOP at 6 months, which reversed at 14 months but displayed age-dependent elongation of the eyeball and deepening of the anterior chamber. CONCLUSION Failure of AAT to SC of DBA/2J mice during development of pigmentary glaucoma does not follow closely changes in IOP and eye morphology. The relationship between IOP and AAT in optic nerve and tract is complex and may reflect preconditioning mechanism.
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Affiliation(s)
- Michal Fiedorowicz
- a Mossakowski Medical Research Centre , Polish Academy of Sciences , Warsaw , Poland
| | - Jaroslaw Orzel
- a Mossakowski Medical Research Centre , Polish Academy of Sciences , Warsaw , Poland.,b Faculty of Electronics and Information Technology , Warsaw University of Technology , Warsaw , Poland
| | - Bartosz Kossowski
- a Mossakowski Medical Research Centre , Polish Academy of Sciences , Warsaw , Poland.,b Faculty of Electronics and Information Technology , Warsaw University of Technology , Warsaw , Poland.,c Nencki Institute of Experimental Biology , Polish Academy of Sciences , Warsaw , Poland
| | | | | | - Maciej Swiatkiewicz
- a Mossakowski Medical Research Centre , Polish Academy of Sciences , Warsaw , Poland
| | - Robert Rejdak
- a Mossakowski Medical Research Centre , Polish Academy of Sciences , Warsaw , Poland.,d 1st Eye Hospital, Medical University of Lublin , Lublin , Poland
| | - Piotr Bogorodzki
- a Mossakowski Medical Research Centre , Polish Academy of Sciences , Warsaw , Poland.,b Faculty of Electronics and Information Technology , Warsaw University of Technology , Warsaw , Poland
| | - Pawel Grieb
- a Mossakowski Medical Research Centre , Polish Academy of Sciences , Warsaw , Poland
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13
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Lopez NN, Patel GC, Raychaudhuri U, Aryal S, Phan TN, Clark AF, Millar JC. Anterior chamber perfusion versus posterior chamber perfusion does not influence measurement of aqueous outflow facility in living mice by constant flow infusion. Exp Eye Res 2017; 164:95-108. [PMID: 28822760 DOI: 10.1016/j.exer.2017.08.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 07/13/2017] [Accepted: 08/14/2017] [Indexed: 11/25/2022]
Abstract
Mice are now routinely utilized in studies of aqueous humor outflow dynamics. In particular, conventional aqueous outflow facility (C) is routinely measured via perfusion of the aqueous chamber by a number of laboratories. However, in mouse eyes perfused ex-vivo, values for C are variable depending upon whether the perfusate is introduced into the posterior chamber (PC) versus the anterior chamber (AC). Perfusion via the AC leads to posterior bowing of the iris, and traction on the iris root/scleral spur, which may increase C. Perfusion via the PC does not yield this effect. But the equivalent situation in living mice has not been investigated. We sought to determine whether AC versus PC perfusion of the living mouse eye may lead to different values for C. All experiments were conducted in C57BL/6J mice (all ♀) between the ages of 20 and 30 weeks. Mice were divided into groups of 3-4 animals each. In all groups, both eyes were perfused. C was measured in groups 1 and 2 by constant flow infusion (from a 50 μL microsyringe) via needle placement in the AC, and in the PC, respectively. To investigate the effect of ciliary muscle (CM) tone on C, groups 3 and 4 were perfused live via the AC or PC with tropicamide (muscarinic receptor antagonist) added to the perfusate at a concentration of 100 μM. To investigate immediate effect of euthanasia, groups 5 and 6 were perfused 15-30 min after death via the AC or PC. To investigate the effect of CM tone on C immediately following euthanasia, groups 7 and 8 were perfused 15-30 min after death via the AC or PC with tropicamide added to the perfusate at a concentration of 100 μM. C in Groups 1 (AC perfusion) and 2 (PC perfusion) was computed to be 19.5 ± 0.8 versus 21.0 ± 2.1 nL/min/mmHg, respectively (mean ± SEM, p > 0.4, not significantly different). In live animals in which tropicamide was present in the perfusate, C in Group 3 (AC perfusion) was significantly greater than C in Group 4 (PC perfusion) (22.0 ± 4.0 versus 14.0 ± 2.0 nL/min/mmHg, respectively, p = 0.0021). In animals immediately following death, C in groups 5 (AC perfusion) and 6 (PC perfusion) was computed to be 21.2 ± 2.0 versus 22.8 ± 1.4 nL/min/mmHg, respectively (mean ± SEM, p = 0.1196, not significantly different). In dead animals in which tropicamide was present in the perfusate, C in group 7 (AC perfusion) was greater than C in group 8 (PC perfusion) (20.6 ± 1.4 versus 14.2 ± 2.6 nL/min/mmHg, respectively, p < 0.0001). C in eyes in situ in living mice or euthanized animals within 15-30 min post mortem is not significantly different when measured via AC perfusion or PC perfusion. In eyes of live or freshly euthanized mice, C is greater when measured via AC versus PC perfusion when tropicamide (a mydriatic and cycloplegic agent) is present in the perfusate.
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Affiliation(s)
- Navita N Lopez
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Gaurang C Patel
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Urmimala Raychaudhuri
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Subhash Aryal
- Department of Biostatistics and Epidemiology, University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Tien N Phan
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Abbot F Clark
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - J Cameron Millar
- North Texas Eye Research Institute (NTERI), University of North Texas Health Science Center (UNTHSC), 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA.
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14
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Şimşek T, Altınışık U, Erşan İ, Şahin H, Altınışık B, Erbaş M, Pala Ç. Prevention of intraocular pressure elevation with oleuropein rich diet in rabbits, during the general anaesthesia. SPRINGERPLUS 2016; 5:952. [PMID: 27386396 PMCID: PMC4929104 DOI: 10.1186/s40064-016-2402-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/24/2016] [Indexed: 11/10/2022]
Abstract
Background Oleuropein is known to have anti-oxidant and anti-inflammatory effects. An important aim of anesthetic management in ocular surgery is to keep the intraocular pressure under control. Studies have researched a variety of prophylactic materials used to prevent increases in intraocular pressure. We aimed to research the effects of oleuropein on intraocular pressure (IOP) during general anaesthesia. Methods Fourteen New Zealand rabbits were randomly divided into two groups of seven. The rabbits in Group O were given olive leaf extract (OLE) equivalent to a daily dose of 20 mg/kg oleuropein for 15 days. HPLC method used for oleuropein standardization. For anaesthesia induction 1 mg/kg rocuronium was given and after muscle relaxation all animals had a V-gel Rabbit inserted. Anesthetic maintenance was provided by 1 MAC isoflurane. Twenty minutes after rabbits were given 10 mg/kg ketamine, basal IOP values were measured. After the V-gel rabbit was inserted, in the 5th, 10th, 20th, 25th and 30th minutes measurements were repeated. Results IOP data variation of OLE group was compared with control group and the measured levels were lower in Group O during the anaesthesia. IOP was 33.8 ± 4 mmHg in Group C and 24.1 ± 8 mmHg in Group O in 25th minute and the difference between the two groups was statistically significant at this time. Conclusion We observed that consumption of prophylactic OLE had a reducing effect on IOP in the period before waking in anaesthesia. We believe it is necessary to investigate the effects of OLE on IOP in broad participation patient groups.
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Affiliation(s)
- Tuncer Şimşek
- Department of Anesthesiology and Reanimation, Medical Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Uğur Altınışık
- Department of Anesthesiology and Reanimation, Medical Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - İsmail Erşan
- Department of Ophthalmology, Medical Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Hasan Şahin
- Department of Anesthesiology and Reanimation, Medical Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Betül Altınışık
- Department of Anesthesiology and Reanimation, Medical Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Mesut Erbaş
- Department of Anesthesiology and Reanimation, Medical Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Çiğdem Pala
- Department of Food Engineering, Engineering Faculty of Çanakkale Onsekiz Mart University, Çanakkale, Turkey
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15
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Transplantation of iPSC-derived TM cells rescues glaucoma phenotypes in vivo. Proc Natl Acad Sci U S A 2016; 113:E3492-500. [PMID: 27274060 DOI: 10.1073/pnas.1604153113] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Glaucoma is a common cause of vision loss or blindness and reduction of intraocular pressure (IOP) has been proven beneficial in a large fraction of glaucoma patients. The IOP is maintained by the trabecular meshwork (TM) and the elevation of IOP in open-angle glaucoma is associated with dysfunction and loss of the postmitotic cells residing within this tissue. To determine if IOP control can be maintained by replacing lost TM cells, we transplanted TM-like cells derived from induced pluripotent stem cells into the anterior chamber of a transgenic mouse model of glaucoma. Transplantation led to significantly reduced IOP and improved aqueous humor outflow facility, which was sustained for at least 9 wk. The ability to maintain normal IOP engendered survival of retinal ganglion cells, whose loss is ultimately the cause for reduced vision in glaucoma. In vivo and in vitro analyses demonstrated higher TM cellularity in treated mice compared with littermate controls and indicated that this increase is primarily because of a proliferative response of endogenous TM cells. Thus, our study provides in vivo demonstration that regeneration of the glaucomatous TM is possible and points toward novel approaches in the treatment of this disease.
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16
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Boussommier-Calleja A, Li G, Wilson A, Ziskind T, Scinteie OE, Ashpole NE, Sherwood JM, Farsiu S, Challa P, Gonzalez P, Downs JC, Ethier CR, Stamer WD, Overby DR. Physical Factors Affecting Outflow Facility Measurements in Mice. Invest Ophthalmol Vis Sci 2016; 56:8331-9. [PMID: 26720486 DOI: 10.1167/iovs.15-17106] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Mice are commonly used to study conventional outflow physiology. This study examined how physical factors (hydration, temperature, and anterior chamber [AC] deepening) influence ocular perfusion measurements in mice. METHODS Outflow facility (C) and pressure-independent outflow (Fu) were assessed by multilevel constant pressure perfusion of enucleated eyes from C57BL/6 mice. To examine the effect of hydration, seven eyes were perfused at room temperature, either immersed to the limbus in saline and covered with wet tissue paper or exposed to room air. Temperature effects were examined in 12 eyes immersed in saline at 20 °C or 35 °C. Anterior chamber deepening was examined in 10 eyes with the cannula tip placed in the anterior versus posterior chamber (PC). Posterior bowing of the iris (AC deepening) was visualized by three-dimensional histology in perfusion-fixed C57BL/6 eyes and by spectral-domain optical coherence tomography in living CD1 mice. RESULTS Exposure to room air did not significantly affect C, but led to a nonzero Fu that was significantly reduced upon immersion in saline. Increasing temperature from 20 °C to 35 °C increased C by 2.5-fold, more than could be explained by viscosity changes alone (1.4-fold). Perfusion via the AC, but not the PC, led to posterior iris bowing and increased outflow. CONCLUSIONS Insufficient hydration contributes to the appearance of pressure-independent outflow in enucleated mouse eyes. Despite the large lens, AC deepening may artifactually increase outflow in mice. Temperature-dependent metabolic processes appear to influence conventional outflow regulation. Physical factors should be carefully controlled in any outflow studies involving mice.
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Affiliation(s)
| | - Guorong Li
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Amanda Wilson
- Department of Bioengineering Imperial College London, London, United Kingdom
| | - Tal Ziskind
- Department of Bioengineering Imperial College London, London, United Kingdom
| | - Oana Elena Scinteie
- Department of Bioengineering Imperial College London, London, United Kingdom
| | - Nicole E Ashpole
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Joseph M Sherwood
- Department of Bioengineering Imperial College London, London, United Kingdom
| | - Sina Farsiu
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Pratap Challa
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Pedro Gonzalez
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - J Crawford Downs
- Department of Ophthalmology, The University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, United States
| | - C Ross Ethier
- Department of Bioengineering Imperial College London, London, United Kingdom 4Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Darryl R Overby
- Department of Bioengineering Imperial College London, London, United Kingdom
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17
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Abstract
Elevated intraocular pressure (IOP) is the predominant risk factor for glaucoma, and reducing IOP is the only successful strategy to prevent further glaucomatous vision loss. IOP is determined by the balance between the rates of aqueous humour secretion and outflow, and a pathological reduction in the hydraulic conductance of outflow, known as outflow facility, is responsible for IOP elevation in glaucoma. Mouse models are often used to investigate the mechanisms controlling outflow facility, but the diminutive size of the mouse eye makes measurement of outflow technically challenging. In this study, we present a new approach to measure and analyse outflow facility using iPerfusion™, which incorporates an actuated pressure reservoir, thermal flow sensor, differential pressure measurement and an automated computerised interface. In enucleated eyes from C57BL/6J mice, the flow-pressure relationship is highly non-linear and is well represented by an empirical power law model that describes the pressure dependence of outflow facility. At zero pressure, the measured flow is indistinguishable from zero, confirming the absence of any significant pressure independent flow in enucleated eyes. Comparison with the commonly used 2-parameter linear outflow model reveals that inappropriate application of a linear fit to a non-linear flow-pressure relationship introduces considerable errors in the estimation of outflow facility and leads to the false impression of pressure-independent outflow. Data from a population of enucleated eyes from C57BL/6J mice show that outflow facility is best described by a lognormal distribution, with 6-fold variability between individuals, but with relatively tight correlation of facility between fellow eyes. iPerfusion represents a platform technology to accurately and robustly characterise the flow-pressure relationship in enucleated mouse eyes for the purpose of glaucoma research and with minor modifications, may be applied in vivo to mice, as well as to eyes from other species or different biofluidic systems.
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18
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Ko MK, Kim EK, Gonzalez JM, Tan JC. Dose- and time-dependent effects of actomyosin inhibition on live mouse outflow resistance and aqueous drainage tissues. Sci Rep 2016; 6:21492. [PMID: 26884319 PMCID: PMC4756686 DOI: 10.1038/srep21492] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 01/26/2016] [Indexed: 11/13/2022] Open
Abstract
Actomyosin contractility modulates outflow resistance of the aqueous drainage tissues and intraocular pressure, a key pathogenic factor of glaucoma. We established methodology to reliably analyze the effect of latrunculin-B (Lat-B)-induced actin depolymerization on outflow physiology in live mice. A voltage-controlled microperfusion system for delivering drugs and simultaneously analyzing outflow resistance was tested in live C57BL/6 mice. Flow rate and perfusion pressure were reproducible within a coefficient of variation of 2%. Outflow facility for phosphate-buffered saline (0.0027 ± 0.00036 μL/min/mmHg; mean ± SD) and 0.02% ethanol perfusions (Lat-B vehicle; 0.0023 ± 0.0005 μL/min/mmHg) were similar and stable over 2 hours (p > 0.1 for change), indicating absence of a ‘washout’ artifact seen in larger mammals. Outflow resistance changed in graded fashion, decreasing dose- and time-dependently over 2 hours for Lat-B doses of 2.5 μM (p = 0.29), 5 μM (p = 0.039) and 10 μM (p = 0.001). Resulting outflow resistance was about 10 times lower with 10 μM Lat-B than vehicle control. The filamentous actin network was decreased and structurally altered in the ciliary muscle (46 ± 5.6%) and trabecular meshwork (37 ± 8.3%) of treated eyes relative to vehicle controls (p < 0.005; 5 μM Lat-B). Mouse actomyosin contractile mechanisms are important to modulating aqueous outflow resistance, mirroring mechanisms in primates. We describe approaches to reliably probe these mechanisms in vivo.
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Affiliation(s)
- MinHee K Ko
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Eun Kyoung Kim
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Jose M Gonzalez
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - James C Tan
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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19
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Huang J, Camras LJ, Yuan F. Mechanical analysis of rat trabecular meshwork. SOFT MATTER 2015; 11:2857-2865. [PMID: 25710888 DOI: 10.1039/c4sm01949k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Stiffness of trabecular meshwork (TM) may play an important role in regulating outflow resistance in healthy and glaucomatous eyes. However, the current techniques for stiffness measurement can only be applied to TM dissected from human donor or large animal eyes. It is a challenge to measure TM stiffness in mouse/rat eyes because of their smaller sizes and the delicate nature of TM dissection. To this end, a new technique was developed to determine the stiffness of rat TM using atomic force microscopy (AFM). In the study, rat eyes were enucleated immediately after death and perfused with a tracer (Evans blue) for 40 min. Then, the anterior segment was dissected and flat-mounted on a Petri dish with TM facing upwards. An AFM probe with a gold-coated colloid tip was used to sequentially indent the corneal, TM, and uveoscleral tissues. Assuming these tissues to be neo-Hookean materials, the indentation data were analyzed with a newly developed mathematical model to calculate the apparent initial Young's moduli (E0)(app). The geometric mean & SE of (E0)(app) were 162 Pa & 1.2 (n = 13) for TM and 6189 Pa & 1.4 (n = 11) for cornea; and the difference was statistically significant (p < 0.01). The technique established in this study allows the use of rat eye as a potential model for investigation of TM stiffness and its influences on outflow resistance. Future studies may also utilize this technique to evaluate mechanisms of TM stiffness change caused by aging, outflow dysfunction, pathogenesis of glaucoma, and drug treatment.
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Affiliation(s)
- Jianyong Huang
- Department of Biomedical Engineering, Duke University, 136 Hudson Hall, Durham, NC 27708, USA.
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Yun H, Lathrop KL, Yang E, Sun M, Kagemann L, Fu V, Stolz DB, Schuman JS, Du Y. A laser-induced mouse model with long-term intraocular pressure elevation. PLoS One 2014; 9:e107446. [PMID: 25216052 PMCID: PMC4162591 DOI: 10.1371/journal.pone.0107446] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 08/10/2014] [Indexed: 12/13/2022] Open
Abstract
Purpose To develop and characterize a mouse model with intraocular pressure (IOP) elevation after laser photocoagulation on the trabecular meshwork (TM), which may serve as a model to investigate the potential of stem cell-based therapies for glaucoma. Methods IOP was measured in 281 adult C57BL/6 mice to determine normal IOP range. IOP elevation was induced unilaterally in 50 adult mice, by targeting the TM through the limbus with a 532-nm diode laser. IOP was measured up to 24 weeks post-treatment. The optic nerve damage was detected by electroretinography and assessed by semiautomatic counting of optic nerve axons. Effects of laser treatment on the TM were evaluated by histology, immunofluorescence staining, optical coherence tomography (OCT) and transmission electron microscopy (TEM). Results The average IOP of C57BL/6 mice was 14.5±2.6 mmHg (Mean ±SD). After laser treatment, IOP averaged above 20 mmHg throughout the follow-up period of 24 weeks. At 24 weeks, 57% of treated eyes had elevated IOP with the mean IOP of 22.5±2.5 mmHg (Mean ±SED). The difference of average axon count (59.0%) between laser treated and untreated eyes was statistically significant. Photopic negative response (PhNR) by electroretinography was significantly decreased. CD45+ inflammatory cells invaded the TM within 1 week. The expression of SPARC was increased in the TM from 1 to 12 weeks. Histology showed the anterior chamber angle open after laser treatment. OCT indicated that most of the eyes with laser treatment had no synechia in the anterior chamber angles. TEM demonstrated disorganized and compacted extracellular matrix in the TM. Conclusions An experimental murine ocular hypertension model with an open angle and optic nerve axon loss was produced with laser photocoagulation, which could be used to investigate stem cell-based therapies for restoration of the outflow pathway integrity for ocular hypertension or glaucoma.
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Affiliation(s)
- Hongmin Yun
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Kira L. Lathrop
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Enzhi Yang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Ming Sun
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Larry Kagemann
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Valeria Fu
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Donna B. Stolz
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Joel S. Schuman
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Yiqin Du
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Overby DR, Bertrand J, Tektas OY, Boussommier-Calleja A, Schicht M, Ethier CR, Woodward DF, Stamer WD, Lütjen-Drecoll E. Ultrastructural changes associated with dexamethasone-induced ocular hypertension in mice. Invest Ophthalmol Vis Sci 2014; 55:4922-33. [PMID: 25028360 DOI: 10.1167/iovs.14-14429] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PURPOSE To determine whether dexamethasone (DEX)-induced ocular hypertension (OHT) in mice mimics the hallmarks of steroid-induced glaucoma (SIG) in humans, including reduced conventional outflow facility (C), increased extracellular matrix (ECM), and myofibroblasts within the outflow pathway. METHODS Osmotic mini-pumps were implanted subcutaneously into C57BL/6J mice for systemic delivery of DEX (3-4 mg/kg/d, n = 31 mice) or vehicle (n = 28). IOP was measured weekly by rebound tonometry. After 3 to 4 weeks, mice were euthanized and eyes enucleated for ex vivo perfusion to measure C, for electron microscopy to examine the trabecular meshwork (TM) and Schlemm's canal (SC), or for immunohistochemistry to examine type IV collagen and α-smooth muscle actin. The length of basement membrane material (BMM) was measured along the anterior-posterior extent of SC by electron microscopy. Ultrastructural changes in BMM of DEX-treated mice were compared against archived human SIG specimens. RESULTS Dexamethasone increased IOP by 2.6 ± 1.6 mm Hg (mean ± SD) over 3 to 4 weeks and decreased C by 52% ± 17% versus controls. Intraocular pressure elevation correlated with decreased C. Dexamethasone treatment led to increased fibrillar material in the TM, plaque-like sheath material surrounding elastic fibers, and myofibroblasts along SC outer wall. The length of BMM underlying SC was significantly increased in mice with DEX and in humans with SIG, and in mice decreased C correlated with increased BMM. CONCLUSIONS Dexamethasone-induced OHT in mice mimics hallmarks of human SIG within 4 weeks of DEX treatment. The correlation between reduced C and newly formed ECM motivates further study using DEX-treated mice to investigate the pathogenesis of conventional outflow obstruction in glaucoma.
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Affiliation(s)
- Darryl R Overby
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Jacques Bertrand
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Ozan-Yüksel Tektas
- Department of Anatomy II, University of Erlangen-Nürnberg, Erlangen, Germany
| | | | - Martin Schicht
- Department of Anatomy II, University of Erlangen-Nürnberg, Erlangen, Germany
| | - C Ross Ethier
- Department of Bioengineering, Imperial College London, London, United Kingdom Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - David F Woodward
- Department of Biological Sciences, Allergan, Inc., Irvine, California, United States
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Elke Lütjen-Drecoll
- Department of Anatomy II, University of Erlangen-Nürnberg, Erlangen, Germany
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Overby DR, Bertrand J, Schicht M, Paulsen F, Stamer WD, Lütjen-Drecoll E. The structure of the trabecular meshwork, its connections to the ciliary muscle, and the effect of pilocarpine on outflow facility in mice. Invest Ophthalmol Vis Sci 2014; 55:3727-36. [PMID: 24833737 DOI: 10.1167/iovs.13-13699] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the connections between the ciliary muscle (CM), trabecular meshwork (TM), and Schlemm's canal (SC) and their innervations that allows CM contraction (by pilocarpine) to influence conventional outflow in mice. METHODS Sequential sections and whole mounts of murine corneoscleral angles were stained for elastin, α-smooth muscle actin (αSMA), vesicular acetylcholine transporter (VAChT), neuronal nitric oxide synthase (nNOS), vasoactive intestinal peptide (VIP), and tyrosine hydroxylase (TH). Elastic (EL) fibers between the CM, TM, and SC were examined in ultrathin, sequential sections from different planes. The effect of pilocarpine (100 μM) on conventional outflow facility was measured by perfusion of enucleated mouse eyes. RESULTS The mouse TM contains a three-dimensional (3D) net of EL fibers connecting the inner wall of SC to the cornea anteriorly, the ciliary body (CB) internally and the choroid and CM posteriorly. The CM bifurcates near the posterior TM, extending outer tendons to the juxtacanalicular tissue and inner wall of SC and internal connections to the lamellated TM and CB. Ciliary muscle and lamellated TM cells stain with αSMA and are innervated by VAChT-containing nerve fibers, without TH, VIP, or nNOS. Pilocarpine doubled outflow facility. CONCLUSIONS Mouse eyes resemble primate eyes not only by their well developed SC and TM, but also by their 3D EL net tethering together the TM and SC inner wall and by the tendinous insertion of the CM into this net. The increase in outflow facility following cholinergic stimulation in mice, as in primates, supports using mice for studies of aqueous humor dynamics and glaucoma.
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Affiliation(s)
- Darryl R Overby
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Jacques Bertrand
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Martin Schicht
- Department of Anatomy II, University of Erlangen-Nürnberg, Germany
| | | | - W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
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Boussommier-Calleja A, Overby DR. The influence of genetic background on conventional outflow facility in mice. Invest Ophthalmol Vis Sci 2013; 54:8251-8. [PMID: 24235015 DOI: 10.1167/iovs.13-13025] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Intraocular pressure (IOP) varies between genetically distinct strains of mice. The purpose was to test the hypothesis that strain-dependent differences in IOP are attributable to differences in conventional outflow facility (C). METHODS The IOP was measured by rebound tonometry in conscious or anesthetized BALB/cJ, C57BL/6J, and CBA/J mice (N = 6-10 per strain). Conventional outflow facility was measured by ex vivo perfusion of enucleated eyes (N = 9-10 per strain). RESULTS Conscious IOP varied between strains, being highest in CBA/J (14.5 ± 0.9 mm Hg, mean ± SD), intermediate in C57BL/6J (12.3 ± 1.0 mm Hg), and lowest in BALB/cJ (10.6 ± 1.8 mm Hg) mice. Anesthesia reduced IOP and eliminated any detectable differences between strains. Conventional outflow facility also varied between strains, but, in contrast to IOP, C was lowest in CBA/J (0.0113 ± 0.0031 μL/min/mm Hg) and highest in BALB/cJ (0.0164 ± 0.0059 μL/min/mm Hg). Like IOP, C was intermediate in C57BL/6J (0.0147 ± 0.0029 μL/min/mm Hg). There was a strong correlation between conscious IOP and outflow resistance (1/C) from individual eyes across all three strains, revealing that 70% of the variation in IOP was attributable to variation in outflow resistance. CONCLUSIONS Differences in IOP among three genetically distinct murine strains are attributable largely to differences in conventional outflow facility. These results motivate further studies using mice to identify the morphologic and genetic factors that underlie IOP regulation within the conventional outflow pathway.
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Qiu Y, Yang H, Lei B. Effects of Three Commonly Used Anesthetics on Intraocular Pressure in Mouse. Curr Eye Res 2013; 39:365-9. [DOI: 10.3109/02713683.2013.845224] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Li G, Gonzalez P, Camras LJ, Navarro I, Qiu J, Challa P, Stamer WD. Optimizing gene transfer to conventional outflow cells in living mouse eyes. Exp Eye Res 2013; 109:8-16. [PMID: 23337742 DOI: 10.1016/j.exer.2013.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 12/22/2012] [Accepted: 01/07/2013] [Indexed: 10/27/2022]
Abstract
The mouse eye has physiological and genetic advantages to study conventional outflow function. However, its small size and shallow anterior chamber presents technical challenges to efficient intracameral delivery of genetic material to conventional outflow cells. The goal of this study was to optimize methods to overcome this technical hurdle, without damaging ocular structures or compromising outflow function. Gene targeting was monitored by immunofluorescence microscopy after transduction of adenovirus encoding green fluorescent protein driven by a CMV promoter. Guided by a micromanipulator and stereomicroscope, virus was delivered intracamerally to anesthetized mice by bolus injection using a 33 gauge needle attached to Hamilton syringe or infusion with glass micropipette connected to syringe pump. The total number of particles introduced remained constant, while volume of injected virus solution (3-10 μl) was varied for each method and time of infusion (3-40 min) tested. Outflow facility and intraocular pressure were monitored invasively using established techniques. Unlike bolus injections or slow infusions, introduction of virus intracamerally during rapid infusions (3 min) at any volume tested preferentially targeted trabecular meshwork and Schlemm's canal cells, with minimal transduction of neighboring cells. While infusions resulted in transient intraocular pressure spikes (commensurate with volume infused, Δ40-70 mmHg), eyes typically recovered within 60 min. Transduced eyes displayed normal outflow facility and tissue morphology 3-6 days after infusions. Taken together, fast infusion of virus solution in small volumes intracamerally is a novel and effective method to selectively deliver agents to conventional outflow cells in living mice.
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Affiliation(s)
- G Li
- Department of Ophthalmology, Duke University School of Medicine, Box 3802, Durham, NC 27710, USA
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Wu J, Li G, Luna C, Spasojevic I, Epstein DL, Gonzalez P. Endogenous production of extracellular adenosine by trabecular meshwork cells: potential role in outflow regulation. Invest Ophthalmol Vis Sci 2012; 53:7142-8. [PMID: 22997289 DOI: 10.1167/iovs.12-9968] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate the mechanisms for endogenous production of extracellular adenosine in trabecular meshwork (TM) cells and evaluate its physiological relevance to the regulation of aqueous humor outflow facility. METHODS Extra-cellular levels of adenosine monophosphate (AMP) and adenosine in porcine trabecular meshwork (PTM) cells treated with adenosine triphosphate (ATP), AMP, cAMP or forskolin with or without specific inhibitors of phosphodiesterases (IBMX) and CD73 (AMPCP) were determined by high-pressure liquid chromatography fluorometry. Extracellular adenosine was also evaluated in cell cultures subjected to cyclic mechanical stress (CMS) (20% stretching; 1 Hz) and after disruption of lipid rafts with methyl-β-cyclodextrin. Expression of CD39 and CD73 in porcine TM cells and tissue were examined by Q-PCR and Western blot. The effect of inhibition of CD73 on outflow facility was evaluated in perfused living mouse eyes. RESULTS PTM cells generated extracellular adenosine from extracellular ATP and AMP but not from extracellular cAMP. Increased intracellular cAMP mediated by forskolin led to a significant increase in extracellular adenosine production that was not prevented by IBMX. Inhibition of CD73 resulted, in all cases, in a significant decrease in extracellular adenosine. CMS induced a significant activation of extracellular adenosine production. Inhibition of CD73 activity with AMPCP in living mouse eyes resulted in a significant decrease in outflow facility. CONCLUSIONS These results support the concept that the extracellular adenosine pathway might play an important role in the homeostatic regulation of outflow resistance in the TM, and suggest a novel mechanism by which pathologic alteration of the TM, such as increased tissue rigidity, could lead to abnormal elevation of IOP in glaucoma.
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Affiliation(s)
- Jing Wu
- Department of Ophthalmology, Duke University, Durham, North Carolina, USA
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Boussommier-Calleja A, Bertrand J, Woodward DF, Ethier CR, Stamer WD, Overby DR. Pharmacologic manipulation of conventional outflow facility in ex vivo mouse eyes. Invest Ophthalmol Vis Sci 2012; 53:5838-45. [PMID: 22807298 DOI: 10.1167/iovs.12-9923] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Mouse models are useful for glaucoma research, but it is unclear whether intraocular pressure (IOP) regulation in mice operates through mechanisms similar to those in humans. Our goal was to determine whether pharmacologic compounds that affect conventional outflow facility in human eyes exert similar effects in C57BL/6 mice. METHODS A computerized perfusion system was used to measure conventional outflow facility in enucleated mouse eyes ex vivo. Paired eyes were perfused sequentially, either immediately after enucleation or after 3 hours storage at 4°C. Three groups of experiments examined sphingosine 1-phosphate (S1P), S1P with antagonists to S1P(1) and S1P(2) receptors, and the prostanoid EP(4) receptor agonist 3,7-dithia PGE(1). We also examined whether a 24-hour postmortem delay affected the response to 3,7-dithia prostaglandin E(1) (PGE(1)). RESULTS S1P decreased facility by 39%, and was blocked almost completely by an S1P(2), but not S1P(1), receptor antagonist. The S1P(2) receptor antagonist alone increased facility nearly 2-fold. 3,7-dithia PGE(1) increased facility by 106% within 3 hours postmortem. By 24 hours postmortem, the facility increase caused by 3,7-dithia PGE(1) was reduced 3-fold, yet remained statistically detectable. CONCLUSIONS C57BL/6 mice showed opposing effects of S1P(2) and EP(4) receptor activation on conventional outflow facility, as observed in human eyes. Pharmacologic effects on facility were detectable up to 24 hours postmortem in enucleated mouse eyes. Mice are suitable models to examine the pharmacology of S1P and EP(4) receptor stimulation on IOP regulation as occurs within the conventional outflow pathway of human eyes, and are promising for studying other aspects of aqueous outflow dynamics.
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Ding C, Wang P, Tian N. Effect of general anesthetics on IOP in elevated IOP mouse model. Exp Eye Res 2011; 92:512-20. [PMID: 21457709 PMCID: PMC3116023 DOI: 10.1016/j.exer.2011.03.016] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 03/21/2011] [Accepted: 03/21/2011] [Indexed: 12/23/2022]
Abstract
Elevated intraocular pressure (IOP) is the best recognized risk factor for the pathogenesis of glaucoma and the extent of retinal ganglion cell (RGC) degeneration in glaucoma is closely correlated with the extent of IOP elevation. Therefore, accurately and reliably measuring IOP is critical in investigating the mechanism of pressure-induced RGC damage in glaucoma. However, IOP is measured under general anesthesia in most studies using mouse models and many anesthetics affect the IOP measurements in both human and animals. In the present study, we used a noninvasive approach to measure the IOP of mice with normal and elevated IOP. The approach used mice that were awake and mice that were under general anesthesia. Our results demonstrate that not only the behavioral training enables IOP measurement from conscious mice without using a restrainer, it also significantly improves the consistency and reliability of the IOP measurement. In addition, we provide a direct comparison between awake and anesthetized IOP measurements as a function of time after the induction of general anesthesia with several commonly used anesthetic agents. We found that all tested general anesthetics significantly altered the IOP measurements both in normal eyes and in those with elevated IOP. Therefore, we conclude that behavioral training of mice can provide an approach to measure awake IOP that does not require general anesthesia and thus produces reliable and consistent results.
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Affiliation(s)
- Chun Ding
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Hunan, China
- Department of Ophthalmology and Visual Science, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Ping Wang
- Department of Ophthalmology and Visual Science, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Ning Tian
- Department of Ophthalmology and Visual Science, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
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