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Becker S, L'Ecuyer Z, Jones BW, Zouache MA, McDonnell FS, Vinberg F. Modeling complex age-related eye disease. Prog Retin Eye Res 2024; 100:101247. [PMID: 38365085 DOI: 10.1016/j.preteyeres.2024.101247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/18/2024]
Abstract
Modeling complex eye diseases like age-related macular degeneration (AMD) and glaucoma poses significant challenges, since these conditions depend highly on age-related changes that occur over several decades, with many contributing factors remaining unknown. Although both diseases exhibit a relatively high heritability of >50%, a large proportion of individuals carrying AMD- or glaucoma-associated genetic risk variants will never develop these diseases. Furthermore, several environmental and lifestyle factors contribute to and modulate the pathogenesis and progression of AMD and glaucoma. Several strategies replicate the impact of genetic risk variants, pathobiological pathways and environmental and lifestyle factors in AMD and glaucoma in mice and other species. In this review we will primarily discuss the most commonly available mouse models, which have and will likely continue to improve our understanding of the pathobiology of age-related eye diseases. Uncertainties persist whether small animal models can truly recapitulate disease progression and vision loss in patients, raising doubts regarding their usefulness when testing novel gene or drug therapies. We will elaborate on concerns that relate to shorter lifespan, body size and allometries, lack of macula and a true lamina cribrosa, as well as absence and sequence disparities of certain genes and differences in their chromosomal location in mice. Since biological, rather than chronological, age likely predisposes an organism for both glaucoma and AMD, more rapidly aging organisms like small rodents may open up possibilities that will make research of these diseases more timely and financially feasible. On the other hand, due to the above-mentioned anatomical and physiological features, as well as pharmacokinetic and -dynamic differences small animal models are not ideal to study the natural progression of vision loss or the efficacy and safety of novel therapies. In this context, we will also discuss the advantages and pitfalls of alternative models that include larger species, such as non-human primates and rabbits, patient-derived retinal organoids, and human organ donor eyes.
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Affiliation(s)
- Silke Becker
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Zia L'Ecuyer
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Bryan W Jones
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Moussa A Zouache
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Fiona S McDonnell
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Frans Vinberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA.
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Patil SV, Kaipa BR, Ranshing S, Sundaresan Y, Millar JC, Nagarajan B, Kiehlbauch C, Zhang Q, Jain A, Searby CC, Scheetz TE, Clark AF, Sheffield VC, Zode GS. Lentiviral mediated delivery of CRISPR/Cas9 reduces intraocular pressure in a mouse model of myocilin glaucoma. Sci Rep 2024; 14:6958. [PMID: 38521856 PMCID: PMC10960846 DOI: 10.1038/s41598-024-57286-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/16/2024] [Indexed: 03/25/2024] Open
Abstract
Mutations in myocilin (MYOC) are the leading known genetic cause of primary open-angle glaucoma, responsible for about 4% of all cases. Mutations in MYOC cause a gain-of-function phenotype in which mutant myocilin accumulates in the endoplasmic reticulum (ER) leading to ER stress and trabecular meshwork (TM) cell death. Therefore, knocking out myocilin at the genome level is an ideal strategy to permanently cure the disease. We have previously utilized CRISPR/Cas9 genome editing successfully to target MYOC using adenovirus 5 (Ad5). However, Ad5 is not a suitable vector for clinical use. Here, we sought to determine the efficacy of adeno-associated viruses (AAVs) and lentiviruses (LVs) to target the TM. First, we examined the TM tropism of single-stranded (ss) and self-complimentary (sc) AAV serotypes as well as LV expressing GFP via intravitreal (IVT) and intracameral (IC) injections. We observed that LV_GFP expression was more specific to the TM injected via the IVT route. IC injections of Trp-mutant scAAV2 showed a prominent expression of GFP in the TM. However, robust GFP expression was also observed in the ciliary body and retina. We next constructed lentiviral particles expressing Cas9 and guide RNA (gRNA) targeting MYOC (crMYOC) and transduction of TM cells stably expressing mutant myocilin with LV_crMYOC significantly reduced myocilin accumulation and its associated chronic ER stress. A single IVT injection of LV_crMYOC in Tg-MYOCY437H mice decreased myocilin accumulation in TM and reduced elevated IOP significantly. Together, our data indicates, LV_crMYOC targets MYOC gene editing in TM and rescues a mouse model of myocilin-associated glaucoma.
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Affiliation(s)
- Shruti V Patil
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Balasankara Reddy Kaipa
- Department of Ophthalmology and Center for Translational Vision Research, University of California, 829 Health Sciences Rd, Irvine, CA, 92617, USA
| | - Sujata Ranshing
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Yogapriya Sundaresan
- Department of Ophthalmology and Center for Translational Vision Research, University of California, 829 Health Sciences Rd, Irvine, CA, 92617, USA
| | - J Cameron Millar
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Bhavani Nagarajan
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Charles Kiehlbauch
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Qihong Zhang
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
| | - Ankur Jain
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
| | - Charles C Searby
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
| | - Todd E Scheetz
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, 52242, USA
| | - Abbot F Clark
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Val C Sheffield
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, 52242, USA
| | - Gulab S Zode
- Department of Ophthalmology and Center for Translational Vision Research, University of California, 829 Health Sciences Rd, Irvine, CA, 92617, USA.
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Faralli JA, Filla MS, Yang YF, Sun YY, Johns K, Keller KE, Peters DM. Digital spatial profiling of segmental outflow regions in trabecular meshwork reveals a role for ADAM15. PLoS One 2024; 19:e0298802. [PMID: 38394161 PMCID: PMC10889904 DOI: 10.1371/journal.pone.0298802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
In this study we used a spatial transcriptomics approach to identify genes specifically associated with either high or low outflow regions in the trabecular meshwork (TM) that could potentially affect aqueous humor outflow in vivo. High and low outflow regions were identified and isolated from organ cultured human anterior segments perfused with fluorescently-labeled 200 nm FluoSpheres. The NanoString GeoMx Digital Spatial Profiler (DSP) platform was then used to identified genes in the paraffin embedded tissue sections from within those regions. These transcriptome analyses revealed that 16 genes were statistically upregulated in high outflow regions and 57 genes were statistically downregulated in high outflow regions when compared to low outflow regions. Gene ontology enrichment analysis indicated that the top three biological categories of these differentially expressed genes were ECM/cell adhesion, signal transduction, and transcription. The ECM/cell adhesion genes that showed the largest differential expression (Log2FC ±1.5) were ADAM15, BGN, LDB3, and CRKL. ADAM15, which is a metalloproteinase that can bind integrins, was upregulated in high outflow regions, while the proteoglycan BGN and two genes associated with integrin signaling (LDB3, and CRKL) were downregulated. Immunolabeling studies supported the differential expression of ADAM15 and showed that it was specifically upregulated in high outflow regions along the inner wall of Schlemm's canal and in the juxtacanalicular (JCT) region of the TM. In addition to these genes, the studies showed that genes for decorin, a small leucine-rich proteoglycan, and the α8 integrin subunit were enriched in high outflow regions. These studies identify several novel genes that could be involved in segmental outflow, thus demonstrating that digital spatial profiling could be a useful approach for understanding segmental flow through the TM. Furthermore, this study suggests that changes in the expression of genes involved in regulating the activity and/or organization of the ECM and integrins in the TM are likely to be key players in segmental outflow.
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Affiliation(s)
- Jennifer A. Faralli
- Departments of Pathology & Laboratory Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Mark S. Filla
- Departments of Pathology & Laboratory Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Yong-Feng Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Ying Ying Sun
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Kassidy Johns
- Departments of Pathology & Laboratory Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Kate E. Keller
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Donna M. Peters
- Departments of Pathology & Laboratory Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
- Ophthalmology & Visual Sciences, University of Wisconsin, Madison, Wisconsin, United States of America
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Shimizu S, Honjo M, Liu M, Aihara M. An Autotaxin-Induced Ocular Hypertension Mouse Model Reflecting Physiological Aqueous Biomarker. Invest Ophthalmol Vis Sci 2024; 65:32. [PMID: 38386333 PMCID: PMC10896239 DOI: 10.1167/iovs.65.2.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024] Open
Abstract
Purpose Animal models of ocular hypertension (OH) have been developed to understand the pathogenesis of glaucoma and facilitate drug discovery. However, many of these models are fraught with issues, including severe intraocular inflammation and technical challenges. Lysophosphatidic acid (LPA) is implicated in trabecular meshwork fibrosis and increased resistance of aqueous outflow, factors that contribute to high intraocular pressure (IOP) in human open-angle glaucoma. We aimed to elevate IOP by increasing expression of the LPA-producing enzyme autotaxin (ATX) in mouse eyes. Methods Tamoxifen-inducible ATX transgenic mice were developed. Tamoxifen was administered to six- to eight-week-old mice via eye drops to achieve ATX overexpression in the eye. IOP and retinal thickness were measured over time, and retinal flat-mount were evaluated to count retinal ganglion cells (RGCs) loss after three months. Results Persistent elevation of ATX expression in mouse eyes was confirmed through immunohistochemistry and LysoPLD activity measurement. ATX Tg mice exhibited significantly increased IOP for nearly two months following tamoxifen treatment, with no anterior segment changes or inflammation. Immunohistochemical analysis revealed enhanced expression of extracellular matrix near the angle after two weeks and three months of ATX induction. This correlated with reduced outflow facility, indicating that sustained ATX overexpression induces angle fibrosis, elevating IOP. Although inner retinal layer thickness remained stable, peripheral retina showed a notable reduction in RGC cell count. Conclusions These findings confirm the successful creation of an open-angle OH mouse model, in which ATX expression in the eye prompts fibrosis near the angle and maintains elevated IOP over extended periods.
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Affiliation(s)
- Shota Shimizu
- Department of Ophthalmology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
- Senju Laboratory of Ocular Science, Senju Pharmaceutical Co., Ltd., Kobe, Hyogo, Japan
| | - Megumi Honjo
- Department of Ophthalmology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| | - Mengxuan Liu
- Department of Ophthalmology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| | - Makoto Aihara
- Department of Ophthalmology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
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Yan X, Wu S, Liu Q, Cheng Y, Teng Y, Ren T, Zhang J, Wang N. Serine to proline mutation at position 341 of MYOC impairs trabecular meshwork function by causing autophagy deregulation. Cell Death Discov 2024; 10:21. [PMID: 38212635 PMCID: PMC10784477 DOI: 10.1038/s41420-024-01801-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 12/24/2023] [Accepted: 01/04/2024] [Indexed: 01/13/2024] Open
Abstract
Glaucoma is a highly heritable disease, and myocilin was the first identified causal and most common pathogenic gene in glaucoma. Serine-to-proline mutation at position 341 of myocilin (MYOCS341P) is associated with severe glaucoma phenotypes in a five-generation primary open-angle glaucoma family. However, the underlying mechanisms are underexplored. Herein, we established the MYOCS341P transgenic mouse model and characterized the glaucoma phenotypes. Further, we systematically explored the functional differences between wild-type and MYOCS341P through immunoprecipitation, mass spectrometry, and RNA-seq analyses. We found that MYOCS341P transgenic mice exhibit glaucoma phenotypes, characterized by reduced aqueous humor outflow, elevated intraocular pressure, decreased trabecular meshwork (TM) cell number, narrowed Schlemm's canal, retinal ganglion cell loss, and visual impairment. Mechanistically, the secretion of dysfunctional MYOCS341P accumulated in the endoplasmic reticulum (ER), inducing ER stress and dysregulation of autophagy, thereby promoting TM cell death. We describe an effective transgenic model for mechanistic studies and the screening of therapeutic targets. Our data generated from high-throughput analyses help elucidate the mechanism underlying mutant MYOC-related glaucoma.
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Affiliation(s)
- Xuejing Yan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Qian Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Ying Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Yufei Teng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Tianmin Ren
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Jingxue Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
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Chrysostomou V, Bell KC, Ng SW, Suresh S, Karthik G, Millet M, Chung Y, Crowston JG. A new model of axon degeneration in the mouse optic nerve using repeat intraocular pressure challenge. Exp Eye Res 2024; 238:109722. [PMID: 37952724 DOI: 10.1016/j.exer.2023.109722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/29/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
We characterize a new experimental model for inducing retinal ganglion cell (RGC) dysfunction and degeneration in mice. C57BL/6J mice were subjected to two acute periods of intraocular pressure (IOP) elevation (50 mmHg for 30 min) by cannulation of the anterior chamber. We used full-field electroretinography and visual evoked potentials (VEPs) to measure subsequent changes in retina and optic nerve function, and histochemical techniques to assess RGC survival and optic nerve structure. In 12 month old mice, a single IOP challenge caused loss and subsequent recovery of RGC function over the following 28 days with minimal cell death and no observed axonal damage. A second identical IOP challenge resulted in persistent RGC dysfunction and significant (36%) loss of RGC somas. This was accompanied by a 16.7% delay in the latency and a 27.6% decrease in the amplitude of the VEP. Severe axonal damage was seen histologically with enlargement of axons, myelin disruption, reduced axon density, and the presence of glial scarring. In contrast, younger 3 month old mice when exposed to a single or repeat IOP challenge showed quicker RGC functional recovery after a single challenge and full functional recovery after a repeat challenge with no detectable optic nerve dysfunction. These data demonstrate a highly reproducible and minimally invasive method for inducing RGC degeneration and axonal damage in mice. Resilience of the optic nerve to damage is highly dependent on animal age. The time-defined nature of functional versus structural loss seen in this model stands to facilitate investigation of neuroglial responses in the retina after IOP injury and the associated evaluation of neuroprotective treatment strategies. Further, the model may be used to investigate the impact of aging and the cellular switch between neurorecovery and neurodegeneration.
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Affiliation(s)
- Vicki Chrysostomou
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore.
| | - Katharina C Bell
- Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore; EYE-ACP, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Save Sight Institute, Charles Perkins Centre, University of Sydney, Australia
| | - Sze Woei Ng
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore
| | - Samyuktha Suresh
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore
| | - Gayathri Karthik
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore
| | - Marion Millet
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore
| | - Yingying Chung
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore
| | - Jonathan G Crowston
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore; Save Sight Institute, Charles Perkins Centre, University of Sydney, Australia
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Binter M, Langer F, Hu X, Lindziute M, Framme C, Tode J, Fuchs H. A simple dissection method for the isolation of mouse trabecular meshwork cells. PLoS One 2023; 18:e0296124. [PMID: 38128042 PMCID: PMC10734917 DOI: 10.1371/journal.pone.0296124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 11/17/2023] [Indexed: 12/23/2023] Open
Abstract
PURPOSE The outflow pathway, especially trabecular meshwork (TM), plays an essential role in glaucoma, and the availability of TM cells is crucial for in vitro research. So far, the isolation of TM cells from mice has been anything but manageable due to the small size of the eye. Direct isolation using a stereomicroscope and forceps requires a high grade of dexterity. Indirect isolation is based on the phagocytic properties of TM cells and involves injecting magnetic microspheres into the anterior chamber of live mice followed by isolation. Therefore, a simpler, less expensive, and nonexperimental strategy for isolating mouse TM cells would be desirable. METHODS After enucleation, the eyes were cut in half anterior-to-posteriorly. The lens and posterior segment were removed. Iris and the attached ciliary body were gently pulled backward and disconnected from the remaining tissue to expose the TM. By incising through the cornea anteriorly and posteriorly of the TM, the cornea/TM stripe could be isolated. The cornea/TM stripe was cultured with the pigmented side down in a 6-well. The outgrowing pigmented cells were analyzed by immunocytochemistry and mRNA expression for previously described TM cell markers. The phagocytic properties of the cells were additionally confirmed using fluorescent microspheres. RESULTS Pigmented phagocytic cells were the first to grow out of the cornea/TM strips after approximately 4-7 days. Cells were positive for Collagen IV, Fibronectin1, Vimentin, and Actin alpha 2 and could phagocytize fluorescent microbeads. Cross-linked actin networks were visible after 9 days of exposure to TGFB2 (transforming growth factor-beta 2). Additionally, treatment with 500 nM Dexamethasone for one week increased myocilin expression, as previously reported for TM cells. In addition, we proved that this method can also be used in albino mice, which lack pigmentation of the trabecular meshwork. CONCLUSIONS The isolated cells show phagocytic properties and specific expression of markers reported in TM cells. Therefore, our dissection-based method is inexpensive and reproducible for isolating TM cells in mice.
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Affiliation(s)
- Maximilian Binter
- Institute of Ophthalmology, Hannover Medical School, University Eye Hospital, Hannover, Germany
| | - Fridolin Langer
- Institute of Ophthalmology, Hannover Medical School, University Eye Hospital, Hannover, Germany
| | - Xiaonan Hu
- Institute of Ophthalmology, Hannover Medical School, University Eye Hospital, Hannover, Germany
| | - Migle Lindziute
- Institute of Ophthalmology, Hannover Medical School, University Eye Hospital, Hannover, Germany
| | - Carsten Framme
- Institute of Ophthalmology, Hannover Medical School, University Eye Hospital, Hannover, Germany
| | - Jan Tode
- Institute of Ophthalmology, Hannover Medical School, University Eye Hospital, Hannover, Germany
| | - Heiko Fuchs
- Institute of Ophthalmology, Hannover Medical School, University Eye Hospital, Hannover, Germany
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Patil SV, Kaipa BR, Ranshing S, Sundaresan Y, Millar JC, Nagarajan B, Kiehlbauch C, Zhang Q, Jain A, Searby CC, Scheetz TE, Clark AF, Sheffield VC, Zode GS. Lentiviral mediated delivery of CRISPR/Cas9 reduces intraocular pressure in a mouse model of myocilin glaucoma. RESEARCH SQUARE 2023:rs.3.rs-3740880. [PMID: 38196579 PMCID: PMC10775399 DOI: 10.21203/rs.3.rs-3740880/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Mutations in myocilin (MYOC) are the leading known genetic cause of primary open-angle glaucoma, responsible for about 4% of all cases. Mutations in MYOC cause a gain-of-function phenotype in which mutant myocilin accumulates in the endoplasmic reticulum (ER) leading to ER stress and trabecular meshwork (TM) cell death. Therefore, knocking out myocilin at the genome level is an ideal strategy to permanently cure the disease. We have previously utilized CRISPR/Cas9 genome editing successfully to target MYOC using adenovirus 5 (Ad5). However, Ad5 is not a suitable vector for clinical use. Here, we sought to determine the efficacy of adeno-associated viruses (AAVs) and lentiviruses (LVs) to target the TM. First, we examined the TM tropism of single-stranded (ss) and self-complimentary (sc) AAV serotypes as well as LV expressing GFP via intravitreal (IVT) and intracameral (IC) injections. We observed that LV_GFP expression was more specific to the TM injected via the IVT route. IC injections of Trp-mutant scAAV2 showed a prominent expression of GFP in the TM. However, robust GFP expression was also observed in the ciliary body and retina. We next constructed lentiviral particles expressing Cas9 and guide RNA (gRNA) targeting MYOC (crMYOC) and transduction of TM cells stably expressing mutant myocilin with LV_crMYOC significantly reduced myocilin accumulation and its associated chronic ER stress. A single IVT injection of LV_crMYOC in Tg-MYOCY437H mice decreased myocilin accumulation in TM and reduced elevated IOP significantly. Together, our data indicates, LV_crMYOC targets MYOC gene editing in TM and rescues a mouse model of myocilin-associated glaucoma.
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Affiliation(s)
- Shruti V Patil
- University of North Texas Health Science Center at Fort Worth
| | | | - Sujata Ranshing
- University of North Texas Health Science Center at Fort Worth
| | | | | | | | | | | | | | | | | | - Abbot F Clark
- University of North Texas Health Science Center at Fort Worth
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9
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Agarwal R, Iezhitsa I. Genetic rodent models of glaucoma in representing disease phenotype and insights into the pathogenesis. Mol Aspects Med 2023; 94:101228. [PMID: 38016252 DOI: 10.1016/j.mam.2023.101228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/31/2023] [Accepted: 11/11/2023] [Indexed: 11/30/2023]
Abstract
Genetic rodent models are widely used in glaucoma related research. With vast amount of information revealed by human studies about genetic correlations with glaucoma, use of these models is relevant and required. In this review, we discuss the glaucoma endophenotypes and importance of their representation in an experimental animal model. Mice and rats are the most popular animal species used as genetic models due to ease of genetic manipulations in these animal species as well as the availability of their genomic information. With technological advances, induction of glaucoma related genetic mutations commonly observed in human is possible to achieve in rodents in a desirable manner. This approach helps to study the pathobiology of the disease process with the background of genetic abnormalities, reveals potential therapeutic targets and gives an opportunity to test newer therapeutic options. Various genetic manipulation leading to appearance of human relevant endophenotypes in rodents indicate their relevance in glaucoma pathology and the utility of these rodent models for exploring various aspects of the disease related to targeted mutation. The molecular pathways involved in the pathophysiology of glaucoma leading to elevated intraocular pressure and the disease hallmark, apoptosis of retinal ganglion cells and optic nerve degeneration, have been extensively explored in genetic rodent models. In this review, we discuss the consequences of various genetic manipulations based on the primary site of pathology in the anterior or the posterior segment. We discuss how these genetic manipulations produce features in rodents that can be considered a close representation of disease phenotype in human. We also highlight several molecular mechanisms revealed by using genetic rodent models of glaucoma including those involved in increased aqueous outflow resistance, loss of retinal ganglion cells and optic neuropathy. Lastly, we discuss the limitations of the use of genetic rodent models in glaucoma related research.
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Affiliation(s)
- Renu Agarwal
- School of Medicine, International Medical University, Malaysia.
| | - Igor Iezhitsa
- School of Medicine, International Medical University, Malaysia
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10
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Buffault J, Brignole-Baudouin F, Labbé A, Baudouin C. An Overview of Current Glaucomatous Trabecular Meshwork Models. Curr Eye Res 2023; 48:1089-1099. [PMID: 37661784 DOI: 10.1080/02713683.2023.2253378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/26/2023] [Accepted: 08/25/2023] [Indexed: 09/05/2023]
Abstract
PURPOSE To provide an overview of the existing alternative models for studying trabecular meshwork (TM). METHODS Literature review. RESULTS The TM is a complex tissue that regulates aqueous humor outflow from the eye. Dysfunction of the TM is a major contributor to the pathogenesis of open-angle glaucoma, a leading cause of irreversible blindness worldwide. The TM is a porous structure composed of trabecular meshwork cells (TMC) within a multi-layered extracellular matrix (ECM). Although dysregulation of the outflow throughout the TM represents the first step in the disease process, the underlying mechanisms of TM degeneration associate cell loss and accumulation of ECM, but remain incompletely understood, and drugs targeting the TM are limited. Therefore, experimental models of glaucomatous trabeculopathy are necessary for preclinical screening, to advance research on this disease's pathophysiology, and to develop new therapeutic strategies targeting the TM. Traditional animal models have been used extensively, albeit with inherent limitations, including ethical concerns and limited translatability to humans. Consequently, there has been an increasing focus on developing alternative in vitro models to study the TM. Recent advancements in three-dimensional cell culture and tissue engineering are still in their early stages and do not yet fully reflect the complexity of the outflow pathway. However, they have shown promise in reducing reliance on animal experimentation in certain aspects of glaucoma research. CONCLUSION This review provides an overview of the existing alternative models for studying TM and their potential for advancing research on the pathophysiology of open-angle glaucoma and developing new therapeutic strategies.
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Affiliation(s)
- Juliette Buffault
- Department of Ophthalmology III, Quinze-Vingts National Ophthalmology Hospital, IHU Foresight, Paris, France
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, IHU Foresight, Paris, France
- Department of Ophthalmology, Ambroise Paré Hospital, APHP, Université de Versailles Saint-Quentin-en-Yvelines, Boulogne-Billancourt, France
| | - Françoise Brignole-Baudouin
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, IHU Foresight, Paris, France
- Department of Biology, Quinze-Vingts National Ophthalmology Hospital, IHU Foresight, Paris, France
| | - Antoine Labbé
- Department of Ophthalmology III, Quinze-Vingts National Ophthalmology Hospital, IHU Foresight, Paris, France
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, IHU Foresight, Paris, France
- Department of Ophthalmology, Ambroise Paré Hospital, APHP, Université de Versailles Saint-Quentin-en-Yvelines, Boulogne-Billancourt, France
| | - Christophe Baudouin
- Department of Ophthalmology III, Quinze-Vingts National Ophthalmology Hospital, IHU Foresight, Paris, France
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, IHU Foresight, Paris, France
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11
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Lo J, Mehta K, Dhillon A, Huang YK, Luo Z, Nam MH, Al Diri I, Chang KC. Therapeutic strategies for glaucoma and optic neuropathies. Mol Aspects Med 2023; 94:101219. [PMID: 37839232 PMCID: PMC10841486 DOI: 10.1016/j.mam.2023.101219] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/02/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023]
Abstract
Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.
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Affiliation(s)
- Jung Lo
- Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan
| | - Kamakshi Mehta
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA
| | - Armaan Dhillon
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Yu-Kai Huang
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, 80708, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan
| | - Ziming Luo
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, 94304, USA
| | - Mi-Hyun Nam
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA.
| | - Issam Al Diri
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - Kun-Che Chang
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Neurobiology, Center of Neuroscience, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
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12
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Mimura M, Akagi T, Kohmoto R, Fujita Y, Sato Y, Ikeda T. Measurement of vitreous humor pressure in vivo using an optic fiber pressure sensor. Sci Rep 2023; 13:18233. [PMID: 37880357 PMCID: PMC10600124 DOI: 10.1038/s41598-023-45616-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 10/21/2023] [Indexed: 10/27/2023] Open
Abstract
We conducted a study to assess the pressure difference between the aqueous and vitreous humors in rabbit eyes using a direct intraocular pressure (IOP) measurement method. A micro-optic-fiber pressure sensor was utilized for this purpose. Preliminary experiments with enucleated porcine eyes confirmed the sensor's accuracy in measuring both aqueous and vitreous humor pressure. The main study involved six healthy albino rabbits, where the sensor measured the pressure in the anterior chamber (aIOP) and posterior vitreous-cavity (pIOP). These measurements were compared to aIOP values obtained through rebound tonometry. Additionally, pre- and postoperative pressure comparisons were made after performing a vitrectomy. Results revealed a significant disparity between aqueous and vitreous humor pressures. Prior to vitrectomy, pIOP was 22.8 mmHg, over twice as high as aIOP (11.0 mmHg), but decreased to a similar level following the procedure. Comparison between the sensor measurements and rebound tonometry showed agreement in aIOP values. In conclusion, our study demonstrates that vitreous humor pressure is consistently higher than aqueous humor pressure, reaching the upper limit of normal IOP. Furthermore, vitrectomy effectively reduces pIOP, aligning it with aIOP. These findings contribute valuable insights into intraocular pressure dynamics and have implications for clinical interventions targeting ocular pressure regulation.
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Affiliation(s)
- Masashi Mimura
- Department of Ophthalmology, Osaka Medical College, Takatsuki-City, Osaka, Japan.
- Department of Ophthalmology, Hyogo Medical University, 1-1, Mukogawa-Cho, Nishinomiya-Shi, Hyogo , 663-8501, Japan.
- Department of Ophthalmology, Toho University Sakura Medical Center, Sakura-City, Chiba, Japan.
| | - Tadamichi Akagi
- Division of Ophthalmology and Visual Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Ryosuke Kohmoto
- Department of Ophthalmology, Osaka Medical College, Takatsuki-City, Osaka, Japan
| | - Yasushi Fujita
- Department of Ophthalmology, Osaka Medical College, Takatsuki-City, Osaka, Japan
| | - Yohei Sato
- Department of Ophthalmology, Osaka Medical College, Takatsuki-City, Osaka, Japan
| | - Tsunehiko Ikeda
- Department of Ophthalmology, Osaka Medical College, Takatsuki-City, Osaka, Japan
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13
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Scuteri D, Pocobelli G, Sakurada Y, Russo R, Tonin P, Nicotera P, Bagetta G, Corasaniti MT, Nucci C. Effect of genotype on individual response to the pharmacological treatment of glaucoma: a systematic review and meta-analysis. Biol Direct 2023; 18:66. [PMID: 37833756 PMCID: PMC10576330 DOI: 10.1186/s13062-023-00423-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023] Open
Abstract
The social impact of glaucoma is worth of note: primary open-angle glaucoma (POAG) is one of the leading causes of irreversible blindness worldwide, affecting some 68.56 million people with overall prevalence of 2.4%. Since one of the main risk factors for the development of POAG is the increase of intraocular pressure (IOP) causing retinal ganglion cells death, the medical treatment of POAG consists in the use of drugs endowed with neuroprotective effect and able to reduce IOP. These drugs include beta-blockers, prostaglandin analogues, carbonic anhydrase inhibitors, alpha or cholinergic agonists and rho kinase inhibitors. However, not all the patients respond to the same extent to the therapy in terms of efficacy and safety. Genetics and genome wide association studies have highlighted the occurrence of mutations and polymorphisms influencing the predisposition to develop POAG and its phenotype, as well as affecting the response to pharmacological treatment. The present systematic review and meta-analysis aims at identifying genetic variants and at verifying whether these can influence the responsiveness of patients to therapy for efficacy and safety. It follows the most updated Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 recommendations. The literature search was conducted consulting the most relevant scientific databases, i.e. PubMed/MEDLINE, Scopus, Web of Science and Public Health Genomics and Precision Health Knowledge Base up to June 14th, 2023. The search retrieved 1026 total records, among which eight met the eligibility criteria for inclusion in the analysis. The results demonstrated that the most investigated pharmacogenetic associations concern latanoprost and timolol, and that efficacy was studied more in depth than safety. Moreover, the heterogeneity of design and paucity of studies prompt further investigation in randomized clinical trials. In fact, adequately powered and designed pharmacogenetic association studies are needed to provide body of evidence with good certainty for a more appropriate use of medical therapy in POAG.PROSPERO registration: CRD42023434867.
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Affiliation(s)
- Damiana Scuteri
- Pharmacotechnology Documentation and Transfer Unit, Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
- Regional Center for Serious Brain Injuries, S. Anna Institute, 88900 Crotone, Italy
| | - Giulio Pocobelli
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Yoichi Sakurada
- Department of Ophthalmology, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi 409-3821 Japan
| | - Rossella Russo
- Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
| | - Paolo Tonin
- Regional Center for Serious Brain Injuries, S. Anna Institute, 88900 Crotone, Italy
| | - Pierluigi Nicotera
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Giacinto Bagetta
- Pharmacotechnology Documentation and Transfer Unit, Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
| | | | - Carlo Nucci
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
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14
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Saccuzzo EG, Youngblood HA, Lieberman RL. Myocilin misfolding and glaucoma: A 20-year update. Prog Retin Eye Res 2023:101188. [PMID: 37217093 DOI: 10.1016/j.preteyeres.2023.101188] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 05/24/2023]
Abstract
Mutations in the gene MYOC account for approximately 5% of cases of primary open angle glaucoma (POAG). MYOC encodes for the protein myocilin, a multimeric secreted glycoprotein composed of N-terminal coil-coil (CC) and leucine zipper (LZ) domains that are connected via a disordered linker to a 30 kDa olfactomedin (OLF) domain. More than 90% of glaucoma-causing mutations are localized to the OLF domain. While myocilin is expressed in numerous tissues, mutant myocilin is only associated with disease in the anterior segment of the eye, in the trabecular meshwork. The prevailing pathogenic mechanism involves a gain of toxic function whereby mutant myocilin aggregates intracellularly instead of being secreted, which causes cell stress and an early timeline for TM cell death, elevated intraocular pressure, and subsequent glaucomatous neurodegeneration. In this review, we focus on the work our lab has conducted over the past ∼15 years to enhance our molecular understanding of myocilin-associated glaucoma, which includes details of the molecular structure and the nature of the aggregates formed by mutant myocilin. We conclude by discussing open questions, such as predicting phenotype from genotype alone, the elusive native function of myocilin, and translational directions enabled by our work.
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Affiliation(s)
- Emily G Saccuzzo
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA
| | - Hannah A Youngblood
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA
| | - Raquel L Lieberman
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA.
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15
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Zhu W, Zhang X, Wu S, Wang N, Kuehn MH. iPSCs-Based Therapy for Trabecular Meshwork. Handb Exp Pharmacol 2023; 281:277-300. [PMID: 37495850 DOI: 10.1007/164_2023_671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
The trabecular meshwork (TM) of the eye serves as an essential tissue in controlling aqueous humor (AH) outflow and intraocular pressure (IOP) homeostasis. However, dysfunctional TM cells and/or decreased TM cellularity is become a critical pathogenic cause for primary open-angle glaucoma (POAG). Consequently, it is particularly valuable to investigate TM characteristics, which, in turn, facilitates the development of new treatments for POAG. Since 2006, the advancement in induced pluripotent stem cells (iPSCs) provides a new tool to (1) model the TM in vitro and (2) regenerate degenerative TM in POAG. In this context, we first summarize the current approaches to induce the differentiation of TM-like cells from iPSCs and compare iPSC-derived TM models to the conventional in vitro TM models. The efficacy of iPSC-derived TM cells for TM regeneration in POAG models is also discussed. Through these approaches, iPSCs are becoming essential tools in glaucoma modeling and for developing personalized treatments for TM regeneration.
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Affiliation(s)
- Wei Zhu
- Department of Pharmacology, School of Pharmacy, Qingdao University, Qingdao, China.
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University & Capital Medical University, Beijing, China.
| | - Xiaoyan Zhang
- Department of Pharmacology, School of Pharmacy, Qingdao University, Qingdao, China
| | - Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital Eye Center, Capital Medical University, Beijing, China
| | - Ningli Wang
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University & Capital Medical University, Beijing, China
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital Eye Center, Capital Medical University, Beijing, China
| | - Markus H Kuehn
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
- Center for the Prevention and Treatment of Visual Loss, Iowa City Veterans Affairs Medical Center, Iowa City, IA, USA
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16
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Burdon KP, Graham P, Hadler J, Hulleman JD, Pasutto F, Boese EA, Craig JE, Fingert JH, Hewitt AW, Siggs OM, Whisenhunt K, Young TL, Mackey DA, Dubowsky A, Souzeau E. Specifications of the ACMG/AMP variant curation guidelines for myocilin: Recommendations from the clingen glaucoma expert panel. Hum Mutat 2022; 43:2170-2186. [PMID: 36217948 PMCID: PMC9771967 DOI: 10.1002/humu.24482] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/02/2022] [Accepted: 10/06/2022] [Indexed: 01/25/2023]
Abstract
The standardization of variant curation criteria is essential for accurate interpretation of genetic results and clinical care of patients. The variant curation guidelines developed by the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) in 2015 are widely used but are not gene specific. To address this issue, the Clinical Genome Resource (ClinGen) Variant Curation Expert Panels (VCEP) have been tasked with developing gene-specific variant curation guidelines. The Glaucoma VCEP was created to develop rule specifications for genes associated with primary glaucoma, including myocilin (MYOC), the most common cause of Mendelian glaucoma. Of the 28 ACMG/AMP criteria, the Glaucoma VCEP adapted 15 rules to MYOC and determined 13 rules not applicable. Key specifications included determining minor allele frequency thresholds, developing an approach to counting probands and segregations, and reviewing functional assays. The rules were piloted on 81 variants and led to a change in classification in 40% of those that were classified in ClinVar, with functional evidence influencing the classification of 18 variants. The standardized variant curation guidelines for MYOC provide a framework for the consistent application of the rules between laboratories, to improve MYOC genetic testing in the management of glaucoma.
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Affiliation(s)
- Kathryn P. Burdon
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Patricia Graham
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Centre for Ophthalmology and Vision Sciences, Lions Eye Institute, University of Western Australia, Perth, WA, Australia
| | - Johanna Hadler
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA, Australia
- SA Pathology, Adelaide, SA, Australia
| | - John D. Hulleman
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Francesca Pasutto
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Erin A. Boese
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Jamie E. Craig
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA, Australia
| | - John H. Fingert
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Alex W. Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Owen M. Siggs
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA, Australia
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Kristina Whisenhunt
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Terri L. Young
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - David A. Mackey
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
- Centre for Ophthalmology and Vision Sciences, Lions Eye Institute, University of Western Australia, Perth, WA, Australia
| | | | - Emmanuelle Souzeau
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Adelaide, SA, Australia
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17
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Human Pro370Leu Mutant Myocilin Induces the Phenotype of Open-Angle Glaucoma in Transgenic Mice. Cell Mol Neurobiol 2022:10.1007/s10571-022-01280-x. [PMID: 36069958 DOI: 10.1007/s10571-022-01280-x] [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: 04/20/2022] [Accepted: 08/30/2022] [Indexed: 11/03/2022]
Abstract
To investigate the characteristics of mutation myocilin proteins and glaucoma pathological phenotype in transgenic mice with full-length human Pro370Leu mutant myocilin gene (Tg-MYOCP370L). Tg-MYOCP370L mice were established using the CRISPR/Cas9 system. Long-term intraocular pressure (IOP) was measured, myocilin protein expressions in anterior chamber angle, retina, optic nerve tissues and aqueous humor were detected by western blot. RBPMS, myocilin, Iba-1 and GFAP expression were visualized by immunofluorescence. H&E staining was applied to assess the ocular angle and retinal morphology. Aqueous humor dynamics were visualized by Gadolinium magnetic resonance imaging (Gd-MRI). TUNEL assay was used to evaluate the specific cell apoptosis in trabecular meshwork and retina. Optomotor and electroretinography tests were employed to evaluate the visual function in Tg-MYOCP370L and wild-type (WT) mice. Homozygous myocilin mutation at position 503 (C > T) was identified by PCR and sequencing in Tg-MYOCP370L mice. Myocilin protein expression was overexpressed in eye tissues of Tg-MYOCP370L mice with reduced myocilin secretion in aqueous humor. H&E staining showed normal histological morphology of anterior chamber angle whereas decreased thickness and nuclei in ganglion cell layer were found (P < 0.05). Gd signals were significantly increased in the anterior chamber of Tg-MYOCP370L compared with WT eyes (P < 0.05). IOP was elevated in Tg-MYOCP370L mice starting at 5 months of age, with significant RGC loss (P < 0.05). Upregulation of caspase-3 and caspase-9 expressions and increased TUNEL-positive cells were found in eyes of Tg-MYOCP370L mice. Excessive activation of retinal glial cells and impaired visual function were detected in Tg-MYOCP370L mice. Tg-MYOCP370L mice can induce the phenotype of open-angle glaucoma, featured as IOP elevation, activated retinal glial cells, loss of RGCs and impaired visual function. These pathologic changes may arise from the abnormal mutant myocilin protein accumulation in the trabecular meshwork and injured aqueous humor drainage. Therefore, Tg-MYOCP370L mice model can serve as an effective animal model for glaucoma research, especially for glaucoma-associated myocilin mutation studies.
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18
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Transgenic Overexpression of Myocilin Leads to Variable Ocular Anterior Segment and Retinal Alterations Associated with Extracellular Matrix Abnormalities in Adult Zebrafish. Int J Mol Sci 2022; 23:ijms23179989. [PMID: 36077382 PMCID: PMC9456529 DOI: 10.3390/ijms23179989] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/18/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Myocilin is an enigmatic glaucoma-associated glycoprotein whose biological role remains incompletely understood. To gain novel insight into its normal function, we used transposon-mediated transgenesis to generate the first zebrafish line stably overexpressing myocilin [Tg(actb1:myoc-2A-mCherry)]. qPCR showed an approximately four-fold increased myocilin expression in transgenic zebrafish embryos (144 hpf). Adult (13 months old) transgenic animals displayed variable and age-dependent ocular anterior segment alterations. Almost 60% of two-year-old male, but not female, transgenic zebrafish developed enlarged eyes with severe asymmetrical and variable abnormalities in the anterior segment, characterized by corneal limbus hypertrophy, and thickening of the cornea, iris, annular ligament and lens capsule. The most severe phenotype presented small or absent ocular anterior chamber and pupils, due to iris overgrowth along with dysplastic retinal growth and optic nerve hypertrophy. Immunohistochemistry revealed increased presence of myocilin in most altered ocular tissues of adult transgenic animals, as well as signs of retinal gliosis and expanded ganglion cells and nerve fibers. The preliminary results indicate that these cells contributed to retinal dysplasia. Visual impairment was demonstrated in all old male transgenic zebrafish. Transcriptomic analysis of the abnormal transgenic eyes identified disrupted expression of genes involved in lens, muscular and extracellular matrix activities, among other processes. In summary, the developed transgenic zebrafish provides a new tool to investigate this puzzling protein and provides evidence for the role of zebrafish myocilin in ocular anterior segment and retinal biology, through the influence of extracellular matrix organization and cellular proliferation.
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Hamada K, Shinozaki Y, Namekata K, Matsumoto M, Ohno N, Segawa T, Kashiwagi K, Harada T, Koizumi S. Loss of P2Y 1 receptors triggers glaucoma-like pathology in mice. Br J Pharmacol 2021; 178:4552-4571. [PMID: 34309010 DOI: 10.1111/bph.15637] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/22/2021] [Accepted: 07/16/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Glaucoma, the leading cause of blindness, damages the retinal ganglion cells. Elevated intraocular pressure (IOP) is a high-risk factor for glaucoma, so topical hypotensive drugs are usually used for treatment. Because not all patients do not respond adequately to current treatments, there is a need to identify a new molecular target to reduce IOP. Here, we have assessed the role of P2Y1 receptors in mediating elevated IOP. EXPERIMENTAL APPROACH P2Y1 receptor agonist was instilled into the eyes of mice, and the IOP changes were measured by a rebound-type tonometer. Expression of P2Y1 receptors was estimated by immunohistochemistry. Ocular function was measured by a multifocal electroretinogram. KEY RESULTS A single dose of the P2Y1 receptor agonist transiently reduced IOP and such effects were absent in P2Y1 receptor-deficient (P2Y1 KO) mice. P2Y1 receptors were functionally expressed in the ciliary body, trabecular meshwork and Schlemm's canal. Activation of P2Y1 receptors negatively regulated aquaporin 4 (AQP4) function but up-regulated endothelial NOS (eNOS). P2Y1 KO mice showed chronic ocular hypertension regardless of age. P2Y1 KO mice at 3 months old showed no damage to retinal ganglion cells, whereas 12-month-old mice showed a significant loss of these cells and impairment of ocular functions. Damage to retinal ganglion cells was attenuated by chronic administration of an IOP-reducing agent. CONCLUSION AND IMPLICATIONS Activation of P2Y1 receptors reduced IOP via dual pathways including AQP4 and eNOS. Loss of P2Y1 receptors resulted in glaucomatous optic neuropathy, suggesting that P2Y1 receptors might provide an effective target in the treatment of glaucoma.
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Affiliation(s)
- Kentaro Hamada
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Mami Matsumoto
- Division of Ultrastructural Research, National Institute of Physiological Sciences, Aichi, Japan
| | - Nobuhiko Ohno
- Division of Ultrastructural Research, National Institute of Physiological Sciences, Aichi, Japan.,Department of Anatomy, Jichi Medical University, Tochigi, Japan
| | - Takahiro Segawa
- Center for Life Science Research, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Kenji Kashiwagi
- Department of Ophthalmology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
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Scelsi HF, Barlow BM, Saccuzzo EG, Lieberman RL. Common and rare myocilin variants: Predicting glaucoma pathogenicity based on genetics, clinical, and laboratory misfolding data. Hum Mutat 2021; 42:903-946. [PMID: 34082484 DOI: 10.1002/humu.24238] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 05/07/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022]
Abstract
Rare variants of the olfactomedin domain of myocilin are considered causative for inherited, early-onset open-angle glaucoma, with a misfolding toxic gain-of-function pathogenic mechanism detailed by 20 years of laboratory research. Myocilin variants are documented in the scientific literature and identified through large-scale genetic sequencing projects such as those curated in the Genome Aggregation Database (gnomAD). In the absence of key clinical and laboratory information, however, the pathogenicity of any given variant is not clear, because glaucoma is a heterogeneous and prevalent age-onset disease, and common variants are likely benign. In this review, we reevaluate the likelihood of pathogenicity for the ~100 nonsynonymous missense, insertion-deletion, and premature termination of myocilin olfactomedin variants documented in the literature. We integrate available clinical, laboratory cellular, biochemical and biophysical data, the olfactomedin domain structure, and population genetics data from gnomAD. Of the variants inspected, ~50% can be binned based on a preponderance of data, leaving many of uncertain pathogenicity that motivate additional studies. Ultimately, the approach of combining metrics from different disciplines will likely resolve outstanding complexities regarding the role of this misfolding-prone protein within the context of a multifactorial and prevalent ocular disease, and pave the way for new precision medicine therapeutics.
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Affiliation(s)
- Hailee F Scelsi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Brett M Barlow
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Emily G Saccuzzo
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Raquel L Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
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21
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Yoneshige A, Hagiyama M, Takashima Y, Ueno S, Inoue T, Kimura R, Koriyama Y, Ito A. Elevated Hydrostatic Pressure Causes Retinal Degeneration Through Upregulating Lipocalin-2. Front Cell Dev Biol 2021; 9:664327. [PMID: 34136483 PMCID: PMC8201777 DOI: 10.3389/fcell.2021.664327] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/10/2021] [Indexed: 12/13/2022] Open
Abstract
Elevation of intraocular pressure is a major risk factor for glaucoma development, which causes the loss of retinal ganglion cells (RGCs). Lipocalin 2 (Lcn2) is upregulated in glaucomatous retinae; however, whether Lcn2 is directly involved in glaucoma is debated. In this study, retinal explant cultures were subjected to increased water pressure using a two-chamber culture device, and Lcn2 protein levels were examined by immunoblotting. In situ TdT-mediated dUTP nick and labeling (TUNEL) and glial fibrillary acidic protein (GFAP) immunohistochemical assays were performed to assess apoptosis and gliosis, respectively. The neurotoxicity of Lcn2 in the retinal explant culture was determined with exogenous administration of recombinant Lcn2. The Lcn2 protein levels, percentage of TUNEL-positive cells, and GFAP-positive area were significantly higher in retinae cultured under 50 cm H2O pressure loads compared to those cultured under 20 cm H2O. We found that Lcn2 exhibited neurotoxicity in retinae at dose of 1 μg/ml. The negative effects of increased hydrostatic pressure were attenuated by the iron chelator deferoxamine. This is the first report demonstrating the direct upregulation of Lcn2 by elevating hydrostatic pressure. Modulating Lcn2 and iron levels may be a promising therapeutic approach for retinal degeneration.
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Affiliation(s)
- Azusa Yoneshige
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Man Hagiyama
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Yasutoshi Takashima
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Satoru Ueno
- Department of Ophthalmology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Takao Inoue
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Ryuichiro Kimura
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Yoshiki Koriyama
- Graduate School and Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan
| | - Akihiko Ito
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
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22
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Lieberman RL, Ma MT. Molecular Insights into Myocilin and Its Glaucoma-Causing Misfolded Olfactomedin Domain Variants. Acc Chem Res 2021; 54:2205-2215. [PMID: 33847483 DOI: 10.1021/acs.accounts.1c00060] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Numerous human disorders arise due to the inability of a particular protein to adopt its correct three-dimensional structure in the context of the cell, leading to aggregation. A new addition to the list of such protein conformational disorders is the inherited subtype of glaucoma. Different and rare coding mutations in myocilin, found in families throughout the world, are causal for early onset ocular hypertension, a key glaucoma risk factor. Myocilin is expressed at high levels in the trabecular meshwork (TM) extracellular matrix. The TM is the anatomical region of the eye that regulates intraocular pressure, and its dysfunction is associated with most forms of glaucoma. Disease variants, distributed across the 30 kDa olfactomedin domain (mOLF), cause myocilin to be sequestered intracellularly instead of being secreted to the TM extracellular matrix. The working hypothesis is that the intracellular aggregates cause a toxic gain of function: TM cell death is thought to lead to TM matrix dysfunction, hastening elevated intraocular pressure and subsequent vision loss.Our lab has provided molecular underpinnings for myocilin structure and misfolding, placing myocilin-associated glaucoma within the context of amyloid diseases like Alzheimer and diabetes. We have dissected complexities of the modular wild-type (WT) myocilin structure and associated misfolded states. Our data support the model that full-length WT myocilin adopts a Y-shaped dimer-of-dimers conferred by two different coiled-coil regions, generating new hypotheses regarding its mysterious function. The mOLF β-propellers are paired at each tip of the Y. Disease-associated variants aggregate because mOLFs are less stable, leading to facile aggregation under physiological conditions (37 °C, pH 7.2). Mutant myocilin aggregates exhibit numerous characteristics of amyloid in vitro and in cells, and aggregation proceeds from a partially folded state accessed preferentially by disease variants at physiological conditions. Interestingly, destabilization is not a universal consequence of mutation. We identified counterintuitive, stabilizing point variants that adopt a non-native structure and do not aggregate; however, these variants have not been identified in glaucoma patients. An ongoing effort is predicting the consequence of any given mutation. This effort is relevant to interpreting data from large-scale sequencing projects where clinical and family history data are not available. Finally, our work suggests avenues to develop disease-modifying precision medicines for myocilin-associated glaucoma.
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Affiliation(s)
- Raquel L. Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, Georgia 30332-0400, United States
| | - Minh Thu Ma
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, Georgia 30332-0400, United States
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23
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Snider EJ, Hardie BA, Li Y, Gao K, Splaine F, Kim RK, Vannatta RT, Read AT, Ethier CR. A Porcine Organ-Culture Glaucoma Model Mimicking Trabecular Meshwork Damage Using Oxidative Stress. Invest Ophthalmol Vis Sci 2021; 62:18. [PMID: 33704361 PMCID: PMC7960799 DOI: 10.1167/iovs.62.3.18] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose Re-cellularization of the trabecular meshwork (TM) using stem cells is a potential novel treatment for ocular hypertension associated with glaucoma. To assess the therapeutic efficacy of this approach, improved in vivo and ex vivo models of TM pathophysiology are needed. Here, we investigate whether oxidative stress, induced by hydrogen peroxide (H2O2), can model glaucomatous ocular hypertension in the readily available porcine anterior segment organ culture model. Methods The impact of H2O2 on TM cell viability and function was first evaluated in vitro using primary porcine TM cells. Oxidative stress was then induced by H2O2 infusion into perfused porcine anterior segments. Trabecular meshwork function was assessed by tracking matrix metalloproteinase (MMP) activity and the ability of the preparation to maintain intraocular pressure (IOP) homeostasis after a flow challenge (doubled fluid infusion rate). Finally, the TM was evaluated histologically. Results H2O2 treatment resulted in a titratable reduction in cellularity across multiple primary TM cell donor strains. In organ culture preparations, H2O2-treated eyes showed impaired IOP homeostasis (i.e., IOPs stabilized at higher levels after a flow challenge vs. control eyes). This result was consistent with reduced MMP activity and TM cellularity; however, damage to the TM microstructure was not histologically evident in anterior segments receiving H2O2. Conclusions Titrated H2O2 infusion resulted in TM cellular dysfunction without destruction of TM structure. Thus, this porcine organ culture model offers a useful platform for assessing trabecular meshwork therapies to treat ocular hypertension associated with glaucoma.
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Affiliation(s)
- Eric J Snider
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - Becky A Hardie
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - Yinglin Li
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - Kristin Gao
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - Fiona Splaine
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - R Kijoon Kim
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - R Taylor Vannatta
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - A Thomas Read
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
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24
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Kasetti RB, Maddineni P, Kiehlbauch C, Patil S, Searby CC, Levine B, Sheffield VC, Zode GS. Autophagy stimulation reduces ocular hypertension in a murine glaucoma model via autophagic degradation of mutant myocilin. JCI Insight 2021; 6:143359. [PMID: 33539326 PMCID: PMC8021112 DOI: 10.1172/jci.insight.143359] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/28/2021] [Indexed: 02/06/2023] Open
Abstract
Elevation of intraocular pressure (IOP) due to trabecular meshwork (TM) damage is associated with primary open-angle glaucoma (POAG). Myocilin mutations resulting in elevated IOP are the most common genetic causes of POAG. We have previously shown that mutant myocilin accumulates in the ER and induces chronic ER stress, leading to TM damage and IOP elevation. However, it is not understood how chronic ER stress leads to TM dysfunction and loss. Here, we report that mutant myocilin activated autophagy but was functionally impaired in cultured human TM cells and in a mouse model of myocilin-associated POAG (Tg-MYOCY437H). Genetic and pharmacological inhibition of autophagy worsened mutant myocilin accumulation and exacerbated IOP elevation in Tg-MYOCY437H mice. Remarkably, impaired autophagy was associated with chronic ER stress-induced transcriptional factor CHOP. Deletion of CHOP corrected impaired autophagy, enhanced recognition and degradation of mutant myocilin by autophagy, and reduced glaucoma in Tg-MYOCY437H mice. Stimulating autophagic flux via tat-beclin 1 peptide or torin 2 promoted autophagic degradation of mutant myocilin and reduced elevated IOP in Tg-MYOCY437H mice. Our study provides an alternate treatment strategy for myocilin-associated POAG by correcting impaired autophagy in the TM.
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Affiliation(s)
- Ramesh B. Kasetti
- Department of Pharmacology and Neuroscience and the North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - Prabhavathi Maddineni
- Department of Pharmacology and Neuroscience and the North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - Charles Kiehlbauch
- Department of Pharmacology and Neuroscience and the North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - Shruti Patil
- Department of Pharmacology and Neuroscience and the North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
| | - Charles C. Searby
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Beth Levine
- Center for Autophagy Research, Department of Internal Medicine
- Howard Hughes Medical Institute, and
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Val C. Sheffield
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Gulab S. Zode
- Department of Pharmacology and Neuroscience and the North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, USA
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25
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Wiemann S, Reinhard J, Reinehr S, Cibir Z, Joachim SC, Faissner A. Loss of the Extracellular Matrix Molecule Tenascin-C Leads to Absence of Reactive Gliosis and Promotes Anti-inflammatory Cytokine Expression in an Autoimmune Glaucoma Mouse Model. Front Immunol 2020; 11:566279. [PMID: 33162981 PMCID: PMC7581917 DOI: 10.3389/fimmu.2020.566279] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/26/2020] [Indexed: 01/13/2023] Open
Abstract
Previous studies demonstrated that retinal damage correlates with a massive remodeling of extracellular matrix (ECM) molecules and reactive gliosis. However, the functional significance of the ECM in retinal neurodegeneration is still unknown. In the present study, we used an intraocular pressure (IOP) independent experimental autoimmune glaucoma (EAG) mouse model to examine the role of the ECM glycoprotein tenascin-C (Tnc). Wild type (WT ONA) and Tnc knockout (KO ONA) mice were immunized with an optic nerve antigen (ONA) homogenate and control groups (CO) obtained sodium chloride (WT CO, KO CO). IOP was measured weekly and electroretinographies were recorded at the end of the study. Ten weeks after immunization, we analyzed retinal ganglion cells (RGCs), glial cells, and the expression of different cytokines in retina and optic nerve tissue in all four groups. IOP and retinal function were comparable in all groups. Although RGC loss was less severe in KO ONA, WT as well as KO mice displayed a significant cell loss after immunization. Compared to KO ONA, less βIII-tubulin+ axons, and downregulated oligodendrocyte markers were noted in WT ONA optic nerves. In retina and optic nerve, we found an enhanced GFAP+ staining area of astrocytes in immunized WT. A significantly higher number of retinal Iba1+ microglia was found in WT ONA, while a lower number of Iba1+ cells was observed in KO ONA. Furthermore, an increased expression of the glial markers Gfap, Iba1, Nos2, and Cd68 was detected in retinal and optic nerve tissue of WT ONA, whereas comparable levels were observed in KO ONA. In addition, pro-inflammatory Tnfa expression was upregulated in WT ONA, but downregulated in KO ONA. Vice versa, a significantly increased anti-inflammatory Tgfb1 expression was measured in KO ONA animals. We conclude that Tnc plays an important role in glial and inflammatory response during retinal neurodegeneration. Our results provide evidence that Tnc is involved in glaucomatous damage by regulating retinal glial activation and cytokine release. Thus, this transgenic EAG mouse model for the first time offers the possibility to investigate IOP-independent glaucomatous damage in direct relation to ECM remodeling.
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Affiliation(s)
- Susanne Wiemann
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr University Bochum, Bochum, Germany
| | - Zülal Cibir
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr University Bochum, Bochum, Germany
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
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26
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Tundo GR, Sbardella D, Santoro AM, Coletta A, Oddone F, Grasso G, Milardi D, Lacal PM, Marini S, Purrello R, Graziani G, Coletta M. The proteasome as a druggable target with multiple therapeutic potentialities: Cutting and non-cutting edges. Pharmacol Ther 2020; 213:107579. [PMID: 32442437 PMCID: PMC7236745 DOI: 10.1016/j.pharmthera.2020.107579] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 01/10/2023]
Abstract
Ubiquitin Proteasome System (UPS) is an adaptable and finely tuned system that sustains proteostasis network under a large variety of physiopathological conditions. Its dysregulation is often associated with the onset and progression of human diseases; hence, UPS modulation has emerged as a promising new avenue for the development of treatments of several relevant pathologies, such as cancer and neurodegeneration. The clinical interest in proteasome inhibition has considerably increased after the FDA approval in 2003 of bortezomib for relapsed/refractory multiple myeloma, which is now used in the front-line setting. Thereafter, two other proteasome inhibitors (carfilzomib and ixazomib), designed to overcome resistance to bortezomib, have been approved for treatment-experienced patients, and a variety of novel inhibitors are currently under preclinical and clinical investigation not only for haematological malignancies but also for solid tumours. However, since UPS collapse leads to toxic misfolded proteins accumulation, proteasome is attracting even more interest as a target for the care of neurodegenerative diseases, which are sustained by UPS impairment. Thus, conceptually, proteasome activation represents an innovative and largely unexplored target for drug development. According to a multidisciplinary approach, spanning from chemistry, biochemistry, molecular biology to pharmacology, this review will summarize the most recent available literature regarding different aspects of proteasome biology, focusing on structure, function and regulation of proteasome in physiological and pathological processes, mostly cancer and neurodegenerative diseases, connecting biochemical features and clinical studies of proteasome targeting drugs.
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Affiliation(s)
- G R Tundo
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy.
| | | | - A M Santoro
- CNR, Institute of Crystallography, Catania, Italy
| | - A Coletta
- Department of Chemistry, University of Aarhus, Aarhus, Denmark
| | - F Oddone
- IRCCS-Fondazione Bietti, Rome, Italy
| | - G Grasso
- Department of Chemical Sciences, University of Catania, Catania, Italy
| | - D Milardi
- CNR, Institute of Crystallography, Catania, Italy
| | - P M Lacal
- Laboratory of Molecular Oncology, IDI-IRCCS, Rome, Italy
| | - S Marini
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - R Purrello
- Department of Chemical Sciences, University of Catania, Catania, Italy
| | - G Graziani
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
| | - M Coletta
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy.
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27
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Gindina S, Hu Y, Barron AO, Qureshi Z, Danias J. Tissue plasminogen activator attenuates outflow facility reduction in mouse model of juvenile open angle glaucoma. Exp Eye Res 2020; 199:108179. [PMID: 32739292 DOI: 10.1016/j.exer.2020.108179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/19/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022]
Abstract
Tissue plasminogen activator (tPA) has been shown to prevent steroid-induced reduction in aqueous humor outflow facility via an upregulation in matrix metalloproteinase (Mmp) expression. The purpose of this study was to determine whether tPA can rescue outflow facility reduction in the Tg-MYOCY437H mouse model, which replicates human juvenile open angle glaucoma. Outflow facility was measured in Tg-MYOCY437H mice following: periocular steroid exposure and intraocular protein treatment with enzymatically active or enzymatically inactive tPA. Effects of tPA on outflow facility were compared to those of animals treated with topical sodium phenylbutarate (PBA), a modulator of endoplasmic reticulum stress. Gene expression of fibrinolytic pathway components (Plat, Plau, and Pai-1) and matrix metalloproteinases (Mmp-2, -9, and -13) was determined in angle ring tissues containing the trabecular meshwork. Tg-MYOCY437H mice did not display further outflow facility reduction following steroid exposure. Enzymatically active and enzymatically inactive tPA were equally effective in attenuating outflow facility reduction in Tg-MYOCY437H mice and caused enhanced expression of matrix metalloproteinases (Mmp-9 and Mmp-13). tPA was equally effective to topical PBA treatment in ameliorating outflow facility reduction in Tg-MYOCY437H mice. Both treatments were associated with an upregulation in Mmp-9 expression while tPA also upregulated Mmp-13 expression. tPA increases the expression of matrix metalloproteinases and may cause extracellular matrix remodeling at the trabecular meshwork, which results in reversal of outflow facility reduction in Tg-MYOCY437H mice.
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Affiliation(s)
- Sofya Gindina
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA; Department of Ophthalmology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA.
| | - Yan Hu
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA; Department of Ophthalmology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Arturo O Barron
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA; Department of Ophthalmology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Zain Qureshi
- Department of Ophthalmology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - John Danias
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA; Department of Ophthalmology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
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28
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Schnichels S, Paquet-Durand F, Löscher M, Tsai T, Hurst J, Joachim SC, Klettner A. Retina in a dish: Cell cultures, retinal explants and animal models for common diseases of the retina. Prog Retin Eye Res 2020; 81:100880. [PMID: 32721458 DOI: 10.1016/j.preteyeres.2020.100880] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 12/11/2022]
Abstract
For many retinal diseases, including age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy (DR), the exact pathogenesis is still unclear. Moreover, the currently available therapeutic options are often unsatisfactory. Research designed to remedy this situation heavily relies on experimental animals. However, animal models often do not faithfully reproduce human disease and, currently, there is strong pressure from society to reduce animal research. Overall, this creates a need for improved disease models to understand pathologies and develop treatment options that, at the same time, require fewer or no experimental animals. Here, we review recent advances in the field of in vitro and ex vivo models for AMD, glaucoma, and DR. We highlight the difficulties associated with studies on complex diseases, in which both the initial trigger and the ensuing pathomechanisms are unclear, and then delineate which model systems are optimal for disease modelling. To this end, we present a variety of model systems, ranging from primary cell cultures, over organotypic cultures and whole eye cultures, to animal models. Specific advantages and disadvantages of such models are discussed, with a special focus on their relevance to putative in vivo disease mechanisms. In many cases, a replacement of in vivo research will mean that several different in vitro models are used in conjunction, for instance to analyze and validate causative molecular pathways. Finally, we argue that the analytical decomposition into appropriate cell and tissue model systems will allow making significant progress in our understanding of complex retinal diseases and may furthermore advance the treatment testing.
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Affiliation(s)
- Sven Schnichels
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Germany.
| | - François Paquet-Durand
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Germany
| | - Marina Löscher
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Germany
| | - Teresa Tsai
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Germany
| | - José Hurst
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Germany
| | - Alexa Klettner
- Department of Ophthalmology, University Medical Center, University of Kiel, Kiel, Germany
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29
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The Genetic and Endoplasmic Reticulum-Mediated Molecular Mechanisms of Primary Open-Angle Glaucoma. Int J Mol Sci 2020; 21:ijms21114171. [PMID: 32545285 PMCID: PMC7312987 DOI: 10.3390/ijms21114171] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 12/14/2022] Open
Abstract
Glaucoma is a heterogenous, chronic, progressive group of eye diseases, which results in irreversible loss of vision. There are several types of glaucoma, whereas the primary open-angle glaucoma (POAG) constitutes the most common type of glaucoma, accounting for three-quarters of all glaucoma cases. The pathological mechanisms leading to POAG pathogenesis are multifactorial and still poorly understood, but it is commonly known that significantly elevated intraocular pressure (IOP) plays a crucial role in POAG pathogenesis. Besides, genetic predisposition and aggregation of abrogated proteins within the endoplasmic reticulum (ER) lumen and subsequent activation of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent unfolded protein response (UPR) signaling pathway may also constitute important factors for POAG pathogenesis at the molecular level. Glaucoma is commonly known as a ‘silent thief of sight’, as it remains asymptomatic until later stages, and thus its diagnosis is frequently delayed. Thereby, detailed knowledge about the glaucoma pathophysiology is necessary to develop both biochemical and genetic tests to improve its early diagnosis as well as develop a novel, ground-breaking treatment strategy, as currently used medical therapies against glaucoma are limited and may evoke numerous adverse side-effects in patients.
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30
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Yemanyi F, Vranka J, Raghunathan V. Generating cell-derived matrices from human trabecular meshwork cell cultures for mechanistic studies. Methods Cell Biol 2020; 156:271-307. [PMID: 32222223 DOI: 10.1016/bs.mcb.2019.10.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ocular hypertension has been attributed to increased resistance to aqueous outflow often as a result of changes in trabecular meshwork (TM) extracellular matrix (ECM) using in vivo animal models (for example, by genetic manipulation) and ex vivo anterior segment perfusion organ cultures. These are, however, complex and difficult in dissecting molecular mechanisms and interactions. In vitro approaches to mimic the underlying substrate exist by manipulating either ECM topography, mechanics, or chemistry. These models best investigate the role of individual ECM protein(s) and/or substrate property, and thus do not recapitulate the multifactorial extracellular microenvironment; hence, mitigating its physiological relevance for mechanistic studies. Cell-derived matrices (CDMs), however, are capable of presenting a 3D-microenvironment rich in topography, chemistry, and whose mechanics can be tuned to better represent the network of native ECM constituents in vivo. Critically, the composition of CDMs may also be fine-tuned by addition of small molecules or relevant bioactive factors to mimic homeostasis or pathology. Here, we first provide a streamlined protocol for generating CDMs from TM cell cultures from normal or glaucomatous donor tissues. Second, we document how TM cells can be pharmacologically manipulated to obtain glucocorticoid-induced CDMs and how generated pristine CDMs can be manipulated with reagents like genipin. Finally, we summarize how CDMs may be used in mechanistic studies and discuss their probable application in future TM regenerative studies.
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Affiliation(s)
- Felix Yemanyi
- Department of Basic Sciences, University of Houston, Houston, TX, United States
| | - Janice Vranka
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, United States
| | - VijayKrishna Raghunathan
- Department of Basic Sciences, University of Houston, Houston, TX, United States; The Ocular Surface Institute, College of Optometry, University of Houston, Houston, TX, United States; Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX, United States.
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31
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Effect of ocular hypertension on the pattern of retinal ganglion cell subtype loss in a mouse model of early-onset glaucoma. Exp Eye Res 2019; 185:107703. [PMID: 31211954 PMCID: PMC7430001 DOI: 10.1016/j.exer.2019.107703] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/06/2019] [Accepted: 06/15/2019] [Indexed: 12/16/2022]
Abstract
Glaucoma is a neurodegenerative disease with elevated intraocular pressure as one of the major risk factors. Glaucoma leads to irreversible loss of vision and its progression involves optic nerve head cupping, axonal degeneration, retinal ganglion cell (RGC) loss, and visual field defects. Despite its high global prevalence, glaucoma still remains a major neurodegenerative disease. Introduction of mouse models of experimental glaucoma has become integral to glaucoma research due to well-studied genetics as well as ease of manipulations. Many established inherent and inducible mouse models of glaucoma are used to study the molecular and physiological progression of the disease. One such model of spontaneous mutation is the nee model, which is caused by mutation of the Sh3pxd2b gene. In both humans and mice, mutations disrupting function of the SH3PXD2B adaptor protein cause a developmental syndrome including secondary congenital glaucoma. The purpose of this study was to characterize the early onset nee glaucoma phenotype on the C57BL/6J background and to evaluate the pattern of RGC loss and axonal degeneration in specific RGC subtypes. We found that the B6.Sh3pxd2bnee mutant animals exhibit glaucoma phenotypes of elevated intraocular pressure, RGC loss and axonal degeneration. Moreover, the non-image forming RGCs survived longer than the On-Off direction selective RGCs (DSGC), and the axonal death in these RGCs was independent of their respective RGC subtype. In conclusion, through this study we characterized an experimental model of early onset glaucoma on a C57BL/6J background exhibiting key glaucoma phenotypes. In addition, we describe that RGC death has subtype-specific sensitivities and follows a specific pattern of cell death under glaucomatous conditions.
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32
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Lee SH, Sim KS, Kim CY, Park TK. Transduction Pattern of AAVs in the Trabecular Meshwork and Anterior-Segment Structures in a Rat Model of Ocular Hypertension. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 14:197-205. [PMID: 31406700 PMCID: PMC6685643 DOI: 10.1016/j.omtm.2019.06.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/27/2019] [Indexed: 12/19/2022]
Abstract
Adeno-associated viruses (AAVs) are the vector of choice for gene therapy in the eye, and self-complementary AAVs (scAAVs), which do not require second-strand DNA synthesis, can be transduced into cells of the trabecular meshwork (TM). The scAAV transduction patterns in the anterior segment of normotensive eyes have been investigated previously, but those in ocular hypertensive (OHT) eyes have not. We assessed the transduction efficiencies of AAV serotypes 2, 5, and 8 in the anterior-segment structures of the eyes of Sprague-Dawley rats with OHT by circumlimbal suturing, followed 3 days later by intracameral injection of scAAV serotype 2 (scAAV2), scAAV5, or scAAV8 packaged with EGFP. The transduction of scAAV2 and scAAV5 in the TM of OHT rats was markedly enhanced after 1 month, and transduction of scAAV5 was more efficient than that of scAAV2; transduction of scAAV8 into the TM did not occur. The transduction of scAAV2, scAAV5, and scAAV8 was enhanced in the ciliary body, iris, and corneal endothelium of the OHT eyes for 3 months. The expression levels of receptors for scAAV2 and scAAV5 were significantly increased in the OHT compared with control eyes. The results demonstrated that scAAV2 and scAAV5 target the ciliary body and TM in OHT eyes, and that the OHT-related changes in anterior-segment structures enhance scAAV transduction.
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Affiliation(s)
- Si Hyung Lee
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Cheonan 31151, Republic of Korea.,Department of Ophthalmology, Soonchunhyang University Hospital Bucheon, Bucheon 14584, Republic of Korea
| | - Kyeong Sun Sim
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Cheonan 31151, Republic of Korea.,Department of Ophthalmology, Soonchunhyang University Hospital Bucheon, Bucheon 14584, Republic of Korea
| | - Chan Yun Kim
- Institute of Vision Research, Department of Ophthalmology, Severance Hospital, Yonsei University, College of Medicine, Seoul 03722, Korea
| | - Tae Kwann Park
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Cheonan 31151, Republic of Korea.,Department of Ophthalmology, Soonchunhyang University Hospital Bucheon, Bucheon 14584, Republic of Korea
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33
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Evangelho K, Mastronardi CA, de-la-Torre A. Experimental Models of Glaucoma: A Powerful Translational Tool for the Future Development of New Therapies for Glaucoma in Humans-A Review of the Literature. MEDICINA (KAUNAS, LITHUANIA) 2019; 55:E280. [PMID: 31212881 PMCID: PMC6630440 DOI: 10.3390/medicina55060280] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 06/04/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022]
Abstract
Glaucoma is a common complex disease that leads to irreversible blindness worldwide. Even though preclinical studies showed that lowering intraocular pressure (IOP) could prevent retinal ganglion cells loss, clinical evidence suggests that lessening IOP does not prevent glaucoma progression in all patients. Glaucoma is also becoming more prevalent in the elderly population, showing that age is a recognized major risk factor. Indeed, recent findings suggest that age-related tissue alterations contribute to the development of glaucoma and have encouraged exploration for new treatment approaches. In this review, we provide information on the most frequently used experimental models of glaucoma and describe their advantages and limitations. Additionally, we describe diverse animal models of glaucoma that can be potentially used in translational medicine and aid an efficient shift to the clinic. Experimental animal models have helped to understand the mechanisms of formation and evacuation of aqueous humor, and the maintenance of homeostasis of intra-ocular pressure. However, the transfer of pre-clinical results obtained from animal studies into clinical trials may be difficult since the type of study does not only depend on the type of therapy to be performed, but also on a series of factors observed both in the experimental period and the period of transfer to clinical application. Conclusions: Knowing the exact characteristics of each glaucoma experimental model could help to diminish inconveniences related to the process of the translation of results into clinical application in humans.
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Affiliation(s)
- Karine Evangelho
- Doctorado en Ciencias Biomédicas y Biológicas, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá,11121, Colombia.
| | - Claudio A Mastronardi
- Neuroscience Research Group (NeurUROS), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, 11121, Colombia.
| | - Alejandra de-la-Torre
- Neuroscience Research Group (NeurUROS), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, 11121, Colombia.
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34
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Reinhard J, Wiemann S, Joachim SC, Palmhof M, Woestmann J, Denecke B, Wang Y, Downey GP, Faissner A. Heterozygous Meg2 Ablation Causes Intraocular Pressure Elevation and Progressive Glaucomatous Neurodegeneration. Mol Neurobiol 2019; 56:4322-4345. [PMID: 30315478 DOI: 10.1007/s12035-018-1376-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 09/28/2018] [Indexed: 02/07/2023]
Abstract
Glaucomatous neurodegeneration represents one of the major causes of irreversible blindness worldwide. Yet, the detailed molecular mechanisms that initiate optic nerve damage and retinal ganglion cell (RGC) loss are not fully understood. Members of the protein tyrosine phosphatase (PTP) superfamily are key players in numerous neurodegenerative diseases. In order to investigate the potential functional relevance of the PTP megakaryocyte 2 (Meg2) in retinal neurodegeneration, we analyzed Meg2 knockout (KO) and heterozygous (HET)-synonym protein-tyrosine phosphatase non-receptor type 9 (Ptpn9)-mice. Interestingly, via global microarray and quantitative real-time PCR (RT-qPCR) analyses of Meg2 KO and HET retinae, we observed a dysregulation of several candidate genes that are highly associated with retinal degeneration and intraocular pressure (IOP) elevation, the main risk factor for glaucoma. Subsequent IOP measurements in Meg2 HET mice verified progressive age-dependent IOP elevation. Ultrastructural analyses and immunohistochemistry showed severe optic nerve degeneration accompanied by a dramatic loss of RGCs. Additionally, HET mice displayed reactive micro-/macrogliosis and early activation of the classical complement cascade with pronounced deposition of the membrane attack complex (MAC) in the retina and optic nerve. When treated with latanoprost, significant IOP lowering prevented RGC loss and microglial invasion in HET mice. Finally, electroretinogram (ERG) recordings revealed reduced a- and b-wave amplitudes, indicating impaired retinal functionality in Meg2 HET mice. Collectively, our findings indicate that the heterozygous loss of Meg2 in mice is sufficient to cause IOP elevation and glaucomatous neurodegeneration. Thus, Meg2 HET mice may serve as a novel animal model to study the pathomechanism involved in the onset and progression of glaucoma.
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Affiliation(s)
- Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology, NDEF 05/594, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany
| | - Susanne Wiemann
- Department of Cell Morphology and Molecular Neurobiology, NDEF 05/594, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Marina Palmhof
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Julia Woestmann
- Department of Cell Morphology and Molecular Neurobiology, NDEF 05/594, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany
| | - Bernd Denecke
- Interdisciplinary Centre for Clinical Research, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Yingchun Wang
- Division of Respirology, Department of Medicine, University of Toronto and Toronto General Hospital Research Institute of the University Health Network, 610 University Avenue, Toronto, ON, M5S 1A8, Canada
| | - Gregory P Downey
- Division of Pulmonary Sciences and Critical Care Medicine, Departments of Medicine and Immunology and Microbiology, University of Colorado, Aurora, CO, 80045, USA
- Division of Pulmonary, Critical Care and Sleep Medicine, Departments of Medicine, Pediatrics and Biomedical Research, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206, USA
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, NDEF 05/594, Faculty of Biology and Biotechnology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
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35
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Patterson-Orazem AC, Hill SE, Wang Y, Dominic IM, Hall CK, Lieberman RL. Differential Misfolding Properties of Glaucoma-Associated Olfactomedin Domains from Humans and Mice. Biochemistry 2019; 58:1718-1727. [PMID: 30802039 DOI: 10.1021/acs.biochem.8b01309] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mutations in myocilin, predominantly within its olfactomedin (OLF) domain, are causative for the heritable form of open angle glaucoma in humans. Surprisingly, mice expressing Tyr423His mutant myocilin, corresponding to a severe glaucoma-causing mutation (Tyr437His) in human subjects, exhibit a weak, if any, glaucoma phenotype. To address possible protein-level discrepancies between mouse and human OLFs, which might lead to this outcome, biophysical properties of mouse OLF were characterized for comparison with those of human OLF. The 1.55 Å resolution crystal structure of mouse OLF reveals an asymmetric 5-bladed β-propeller that is nearly indistinguishable from previous structures of human OLF. Wild-type and selected mutant mouse OLFs mirror thermal stabilities of their human OLF counterparts, including characteristic stabilization in the presence of calcium. Mouse OLF forms thioflavin T-positive aggregates with a similar end-point morphology as human OLF, but amyloid aggregation kinetic rates of mouse OLF are faster than human OLF. Simulations and experiments support the interpretation that kinetics of mouse OLF are faster because of a decreased charge repulsion arising from more neutral surface electrostatics. Taken together, phenotypic differences observed in mouse and human studies of mutant myocilin could be a function of aggregation kinetics rates, which would alter the lifetime of putatively toxic protofibrillar intermediates.
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Affiliation(s)
- Athéna C Patterson-Orazem
- School of Chemistry & Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States
| | - Shannon E Hill
- School of Chemistry & Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States
| | - Yiming Wang
- Department of Chemical & Biomolecular Engineering , North Carolina State University , Raleigh , North Carolina 27695-7905 , United States
| | - Iramofu M Dominic
- School of Chemistry & Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States
| | - Carol K Hall
- Department of Chemical & Biomolecular Engineering , North Carolina State University , Raleigh , North Carolina 27695-7905 , United States
| | - Raquel L Lieberman
- School of Chemistry & Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States
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36
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Dey A, Manthey AL, Chiu K, Do CW. Methods to Induce Chronic Ocular Hypertension: Reliable Rodent Models as a Platform for Cell Transplantation and Other Therapies. Cell Transplant 2019; 27:213-229. [PMID: 29637819 PMCID: PMC5898687 DOI: 10.1177/0963689717724793] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Glaucoma, a form of progressive optic neuropathy, is the second leading cause of blindness worldwide. Being a prominent disease affecting vision, substantial efforts are being made to better understand glaucoma pathogenesis and to develop novel treatment options including neuroprotective and neuroregenerative approaches. Cell transplantation has the potential to play a neuroprotective and/or neuroregenerative role for various ocular cell types (e.g., retinal cells, trabecular meshwork). Notably, glaucoma is often associated with elevated intraocular pressure, and over the past 2 decades, several rodent models of chronic ocular hypertension (COH) have been developed that reflect these changes in pressure. However, the underlying pathophysiology of glaucoma in these models and how they compare to the human condition remains unclear. This limitation is the primary barrier for using rodent models to develop novel therapies to manage glaucoma and glaucoma-related blindness. Here, we review the current techniques used to induce COH-related glaucoma in various rodent models, focusing on the strengths and weaknesses of the each, in order to provide a more complete understanding of how these models can be best utilized. To so do, we have separated them based on the target tissue (pre-trabecular, trabecular, and post-trabecular) in order to provide the reader with an encompassing reference describing the most appropriate rodent COH models for their research. We begin with an initial overview of the current use of these models in the evaluation of cell transplantation therapies.
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Affiliation(s)
- Ashim Dey
- 1 School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Abby L Manthey
- 2 Laboratory of Retina Brain Research, Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Kin Chiu
- 2 Laboratory of Retina Brain Research, Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,3 Research Centre of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong, Hong Kong, China.,4 State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Chi-Wai Do
- 1 School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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37
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Lynch JM, Dolman AJ, Guo C, Dolan K, Xiang C, Reda S, Li B, Prasanna G. Mutant myocilin impacts sarcomere ultrastructure in mouse gastrocnemius muscle. PLoS One 2018; 13:e0206801. [PMID: 30395621 PMCID: PMC6218065 DOI: 10.1371/journal.pone.0206801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 10/19/2018] [Indexed: 11/19/2022] Open
Abstract
Myocilin (MYOC) is the gene with mutations most common in glaucoma. In the eye, MYOC is in trabecular meshwork, ciliary body, and retina. Other tissues with high MYOC transcript levels are skeletal muscle and heart. To date, the function of wild-type MYOC remains unknown and how mutant MYOC causes high intraocular pressure and glaucoma is ambiguous. By investigating mutant MYOC in a non-ocular tissue we hoped to obtain novel insight into mutant MYOC pathology. For this study, we utilized a transgenic mouse expressing human mutant MYOC Y437H protein and we examined its skeletal (gastrocnemius) muscle phenotype. Electron micrographs showed that sarcomeres in the skeletal muscle of mutant CMV-MYOC-Y437H mice had multiple M-bands. Western blots of soluble muscle lysates from transgenics indicated a decrease in two M-band proteins, myomesin 1 (MYOM1) and muscle creatine kinase (CKM). Immunoprecipitation identified CKM as a MYOC binding partner. Our results suggest that binding of mutant MYOC to CKM is changing sarcomere ultrastructure and this may adversely impact muscle function. We speculate that a person carrying the mutant MYOC mutation will likely have a glaucoma phenotype and may also have undiagnosed muscle ailments or vice versa, both of which will have to be monitored and treated.
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MESH Headings
- Animals
- Cytoskeletal Proteins/genetics
- Cytoskeletal Proteins/metabolism
- Disease Models, Animal
- Eye Proteins/genetics
- Eye Proteins/metabolism
- Female
- Gene Expression
- Glaucoma, Open-Angle/genetics
- Glaucoma, Open-Angle/metabolism
- Glaucoma, Open-Angle/pathology
- Glycoproteins/genetics
- Glycoproteins/metabolism
- Humans
- Intraocular Pressure/genetics
- Male
- Mice
- Mice, Mutant Strains
- Mice, Transgenic
- Microscopy, Electron, Transmission
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/ultrastructure
- Mutant Proteins/genetics
- Mutant Proteins/metabolism
- Mutation
- Myocardium/metabolism
- Phenotype
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sarcomeres/genetics
- Sarcomeres/metabolism
- Sarcomeres/ultrastructure
- Trabecular Meshwork/metabolism
- Trabecular Meshwork/ultrastructure
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Affiliation(s)
- Jeffrey M. Lynch
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
- * E-mail:
| | - Andrew J. Dolman
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
| | - Chenying Guo
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
| | - Katie Dolan
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
| | - Chuanxi Xiang
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
| | - Samir Reda
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
| | - Bing Li
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
| | - Ganesh Prasanna
- Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, MA, United States of America
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38
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Lynch JM, Li B, Katoli P, Xiang C, Leehy B, Rangaswamy N, Saenz-Vash V, Wang YK, Lei H, Nicholson TB, Meredith E, Rice DS, Prasanna G, Chen A. Binding of a glaucoma-associated myocilin variant to the αB-crystallin chaperone impedes protein clearance in trabecular meshwork cells. J Biol Chem 2018; 293:20137-20156. [PMID: 30389787 DOI: 10.1074/jbc.ra118.004325] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/19/2018] [Indexed: 01/09/2023] Open
Abstract
Myocilin (MYOC) was discovered more than 20 years ago and is the gene whose mutations are most commonly observed in individuals with glaucoma. Despite extensive research efforts, the function of WT MYOC has remained elusive, and how mutant MYOC is linked to glaucoma is unclear. Mutant MYOC is believed to be misfolded within the endoplasmic reticulum, and under normal physiological conditions misfolded MYOC should be retro-translocated to the cytoplasm for degradation. To better understand mutant MYOC pathology, we CRISPR-engineered a rat to have a MYOC Y435H substitution that is the equivalent of the pathological human MYOC Y437H mutation. Using this engineered animal model, we discovered that the chaperone αB-crystallin (CRYAB) is a MYOC-binding partner and that co-expression of these two proteins increases protein aggregates. Our results suggest that the misfolded mutant MYOC aggregates with cytoplasmic CRYAB and thereby compromises protein clearance mechanisms in trabecular meshwork cells, and this process represents the primary mode of mutant MYOC pathology. We propose a model by which mutant MYOC causes glaucoma, and we propose that therapeutic treatment of patients having a MYOC mutation may focus on disrupting the MYOC-CRYAB complexes.
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Affiliation(s)
- Jeffrey M Lynch
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139.
| | - Bing Li
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Parvaneh Katoli
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Chuanxi Xiang
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Barrett Leehy
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Nalini Rangaswamy
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Veronica Saenz-Vash
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Y Karen Wang
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Hong Lei
- Laboratory Animal Services, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Thomas B Nicholson
- Chemical Biology and Therapeutics, and Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Erik Meredith
- Global Developmental Chemistry, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Dennis S Rice
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Ganesh Prasanna
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Amy Chen
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
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39
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Affiliation(s)
- Timothy E. Yap
- Imperial College Healthcare NHS Trust (ICHNT), The Western Eye Hospital, London, UK
- The Imperial College Ophthalmic Research Group (ICORG), Imperial College London, London, UK
| | - Eduardo M. Normando
- Imperial College Healthcare NHS Trust (ICHNT), The Western Eye Hospital, London, UK
- The Imperial College Ophthalmic Research Group (ICORG), Imperial College London, London, UK
| | - Maria Francesca Cordeiro
- Imperial College Healthcare NHS Trust (ICHNT), The Western Eye Hospital, London, UK
- The Imperial College Ophthalmic Research Group (ICORG), Imperial College London, London, UK
- Department of Visual Neuroscience, Glaucoma and Retinal Neurodegeneration Group, UCL Institute of Ophthalmology, London, UK
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40
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Raghunathan VK, Benoit J, Kasetti R, Zode G, Salemi M, Phinney BS, Keller KE, Staverosky JA, Murphy CJ, Acott T, Vranka J. Glaucomatous cell derived matrices differentially modulate non-glaucomatous trabecular meshwork cellular behavior. Acta Biomater 2018. [PMID: 29524673 DOI: 10.1016/j.actbio.2018.02.037] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Ocular hypertension is a causal risk-factor to developing glaucoma. This is associated with stiffening of the trabecular meshwork (TM), the primary site of resistance to aqueous-humor-outflow. The mechanisms underlying this stiffening or how pathologic extracellular matrix (ECM) affects cell function are poorly understood. It is recognized that mechanotransduction systems allow cells to sense and translate the intrinsic biophysical properties of ECM into intracellular signals to control gene transcription, protein expression, and cell behavior. Using an anterior segment perfusion model, we document that there are significantly more low flow regions that are much stiffer, and fewer high flow regions that are less stiff in glaucomatous TM (GTM) when compared to non-glaucomatous TMs (NTM). GTM tissue also has fewer cells overall when compared with NTM tissue. In order to study the role of pathologic ECM in glaucoma disease progression, we conducted studies using cell derived matrices (CDM). First, we characterized the mechanics, composition and organization of fibronectin in ECM deposited by GTM and NTM cells treated with glucocorticosteroids. Then, we determined that these GTM-derived ECM are able to induce stiffening of normal NTM cells, and alter their gene/protein expression to resemble that of a glaucomatous phenotype. Further, we demonstrate that GTM-derived ECM causes endoplasmic reticular stress in NTM. They also became resistant to being reorganized by these NTM cells. These phenomena were exacerbated by ECMs obtained from steroid treated glaucoma model groups. Collectively, our data demonstrates that CDMs represent a novel tool for the study of bidirectional interactions between TM cells and their immediate microenvironment. STATEMENT OF SIGNIFICANCE Extracellular matrix (ECM) changes are prevalent in a number of diseases. The precise mechanisms by which changes in the ECM contribute to disease progression is unclear, primarily due to absence of appropriate models. Here, using glaucoma as a disease model, we document changes in cell derived matrix (CDM) and tissue mechanics that contribute to the pathology. Subsequently, we determine the effect that ECMs from diseased and healthy individuals have on healthy cell behaviors. Data emanating from this study demonstrate that CDMs are a potent tool for the study of cell-ECM interactions.
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41
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Raghunathan V, Eaton JS, Christian BJ, Morgan JT, Ver Hoeve JN, Yang CYC, Gong H, Rasmussen CA, Miller PE, Russell P, Nork TM, Murphy CJ. Biomechanical, ultrastructural, and electrophysiological characterization of the non-human primate experimental glaucoma model. Sci Rep 2017; 7:14329. [PMID: 29085025 PMCID: PMC5662689 DOI: 10.1038/s41598-017-14720-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/13/2017] [Indexed: 11/08/2022] Open
Abstract
Laser-induced experimental glaucoma (ExGl) in non-human primates (NHPs) is a common animal model for ocular drug development. While many features of human hypertensive glaucoma are replicated in this model, structural and functional changes in the unlasered portions of trabecular meshwork (TM) of laser-treated primate eyes are understudied. We studied NHPs with ExGl of several years duration. As expected, ExGl eyes exhibited selective reductions of the retinal nerve fiber layer that correlate with electrophysiologic measures documenting a link between morphologic and elctrophysiologic endpoints. Softening of unlasered TM in ExGl eyes compared to untreated controls was observed. The degree of TM softening was consistent, regardless of pre-mortem clinical findings including severity of IOP elevation, retinal nerve fiber layer thinning, or electrodiagnostic findings. Importantly, this softening is contrary to TM stiffening reported in glaucomatous human eyes. Furthermore, microscopic analysis of unlasered TM from eyes with ExGl demonstrated TM thinning with collapse of Schlemm's canal; and proteomic analysis confirmed downregulation of metabolic and structural proteins. These data demonstrate unexpected and compensatory changes involving the TM in the NHP model of ExGl. The data suggest that compensatory mechanisms exist in normal animals and respond to elevated IOP through softening of the meshwork to increase outflow.
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Affiliation(s)
- VijayKrishna Raghunathan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California - Davis, Davis, California, 95616, United States of America
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America
- The Ocular Surface Institute, Department of Basic Sciences, College of Optometry, University of Houston, Houston, Texas, 77204, United States of America
| | - J Seth Eaton
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California - Davis, Davis, California, 95616, United States of America
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America
| | - Brian J Christian
- Covance Laboratories, Inc., Madison, Wisconsin, 53704, United States of America
| | - Joshua T Morgan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California - Davis, Davis, California, 95616, United States of America
| | - James N Ver Hoeve
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, Wisconsin, 53792, United States of America
| | - Chen-Yuan Charlie Yang
- Department of Anatomy and Neurobiology, School of Medicine, Boston University, Boston, Massachusetts, 02118, United States of America
- Department of Ophthalmology, School of Medicine, Boston University, Boston, Massachusetts, 02118, United States of America
| | - Haiyan Gong
- Department of Anatomy and Neurobiology, School of Medicine, Boston University, Boston, Massachusetts, 02118, United States of America
- Department of Ophthalmology, School of Medicine, Boston University, Boston, Massachusetts, 02118, United States of America
| | - Carol A Rasmussen
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, Wisconsin, 53792, United States of America
| | - Paul E Miller
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin - Madison, Madison, Wisconsin, 53706, United States of America
| | - Paul Russell
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California - Davis, Davis, California, 95616, United States of America
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America
| | - T Michael Nork
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America.
- Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, Wisconsin, 53792, United States of America.
| | - Christopher J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California - Davis, Davis, California, 95616, United States of America.
- Ocular Services On Demand (OSOD), Madison, Wisconsin, 53719, United States of America.
- Department of Ophthalmology & Vision Science, School of Medicine, University of California - Davis, Sacramento, California, 95817, United States of America.
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Joe MK, Lieberman RL, Nakaya N, Tomarev SI. Myocilin Regulates Metalloprotease 2 Activity Through Interaction With TIMP3. Invest Ophthalmol Vis Sci 2017; 58:5308-5318. [PMID: 29049729 PMCID: PMC5644706 DOI: 10.1167/iovs.16-20336] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose To elucidate functions of wild-type myocilin, a secreted glycoprotein associated with glaucoma. Methods Lysates of mouse eyes were used for immunoprecipitation with affinity-purified antibodies against mouse myocilin. Shotgun proteomic analysis was used for the identification of proteins interacting with myocilin. Colocalization of myocilin and tissue inhibitor of metalloproteinases 3 (TIMP3) in different eye structures was investigated by a multiplex fluorescent in situ hybridization and immunofluorescent labeling with subsequent confocal microscopy. Matrix metalloproteinase 2 (MMP2) activity assay was used to test effects of myocilin on TIMP3 inhibitory action. Results TIMP3 was identified by a shotgun proteomic analysis as a protein that was coimmunoprecipitated with myocilin from eye lysates of wild-type and transgenic mice expressing elevated levels of mouse myocilin but not from lysates of transgenic mice expressing mutated mouse myocilin. Interaction of myocilin and TIMP3 was confirmed by coimmunoprecipitation of myocilin and TIMP3 from HEK293 cells transiently transfected with cDNAs encoding these proteins. The olfactomedin domain of myocilin is essential for interaction with TIMP3. In the eye, the main sites of myocilin and TIMP3 colocalization are the trabecular meshwork, sclera, and choroid. Using purified proteins, it has been shown that myocilin markedly enhanced the inhibitory activity of TIMP3 toward MMP2. Conclusions Myocilin may serve as a modulator of TIMP3 activity via interactions with the myocilin olfactomedin domain. Our data imply that in the case of MYOCILIN null or some glaucoma-causing mutations, inhibitory activity of TIMP3 toward MMP2 might be reduced, mimicking deleterious mutations in the TIMP3 gene.
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Affiliation(s)
- Myung Kuk Joe
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Raquel L Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Naoki Nakaya
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Stanislav I Tomarev
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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Barzago MM, Kurosaki M, Fratelli M, Bolis M, Giudice C, Nordio L, Cerri E, Domenici L, Terao M, Garattini E. Generation of a new mouse model of glaucoma characterized by reduced expression of the AP-2β and AP-2δ proteins. Sci Rep 2017; 7:11140. [PMID: 28894266 PMCID: PMC5593953 DOI: 10.1038/s41598-017-11752-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/30/2017] [Indexed: 12/20/2022] Open
Abstract
We generated 6 transgenic lines with insertion of an expression plasmid for the R883/M xanthine dehydrogenase (XDH) mutant protein. Approximately 20% of the animals deriving from one of the transgenic lines show ocular abnormalities and an increase in intra-ocular pressure which are consistent with glaucoma. The observed pathologic phenotype is not due to expression of the transgene, but rather the consequence of the transgene insertion site, which has been defined by genome sequencing. The insertion site maps to chromosome 1qA3 in close proximity to the loci encoding AP-2β and AP-2δ, two proteins expressed in the eye. The insertion leads to a reduction in AP-2β and AP-2δ levels. Down-regulation of AP-2β expression is likely to be responsible for the pathologic phenotype, as conditional deletion of the Tfap2b gene in the neural crest has recently been shown to cause defective development of the eye anterior segment and early-onset glaucoma. In these conditional knock-out and our transgenic mice, the morphological/histological features of the glaucomatous pathology are surprisingly similar. Our transgenic mouse represents a model of angle-closure glaucoma and a useful tool for the study of the pathogenesis and the development of innovative therapeutic strategies.
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Affiliation(s)
- Maria Monica Barzago
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Mami Kurosaki
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Maddalena Fratelli
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Marco Bolis
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Chiara Giudice
- DIVET, Faculty of Veterinary Medicine, University of Milan, Italy, Via Celoria 10, 20113, Milano, Italy
| | - Laura Nordio
- DIVET, Faculty of Veterinary Medicine, University of Milan, Italy, Via Celoria 10, 20113, Milano, Italy
| | - Elisa Cerri
- Consiglio Nazionale delle Ricerche (CNR), Neuroscience Institute, Pisa, Italy
| | - Luciano Domenici
- Consiglio Nazionale delle Ricerche (CNR), Neuroscience Institute, Pisa, Italy
- Department of Applied Clinical Sciences and Biotechnology (DISCAB), University of L'Aquila, L'Aquila, Italy
| | - Mineko Terao
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy.
| | - Enrico Garattini
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy.
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De Groef L, Andries L, Siwakoti A, Geeraerts E, Bollaerts I, Noterdaeme L, Etienne I, Papageorgiou AP, Stalmans I, Billen J, West-Mays JA, Moons L. Aberrant Collagen Composition of the Trabecular Meshwork Results in Reduced Aqueous Humor Drainage and Elevated IOP in MMP-9 Null Mice. Invest Ophthalmol Vis Sci 2017; 57:5984-5995. [PMID: 27820954 PMCID: PMC5102567 DOI: 10.1167/iovs.16-19734] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Homeostatic turnover of the trabecular meshwork extracellular matrix (ECM) is essential to regulate aqueous humor outflow and to maintain intraocular pressure homeostasis. In this study, we evaluated aqueous humor turnover, intraocular pressure, and trabecular meshwork organization in MMP-9 null mice. Methods Intraocular pressure and aqueous humor turnover were measured in MMP-9 null versus wild-type mice. Morphology of the anterior segment of the eye, with special attention to the structural organization of the trabecular meshwork, was investigated by means of optical coherence tomography, light microscopy, and transmission electron microscopy. Furthermore, using quantitative real-time polymerase chain reaction and immunostainings, we evaluated the ECM composition of the trabecular meshwork. Finally, the integrity and function of the retina and optic nerve were assessed, via optical coherence tomography, histologic techniques, and optomotor testing. Results MMP-9 null mice displayed early-onset ocular hypertension and reduced aqueous humor turnover. While transmission electron microscopic analysis did not reveal any abnormalities in the cellular organization of the trabecular meshwork, detailed investigation of collagen expression indicated that there is an aberrant trabecular meshwork ECM composition in MMP-9 null mice. Notably, at the age of 13 months, no glaucomatous neurodegeneration was seen in MMP-9 null mice. Conclusions Our observations corroborate MMP-9 as an important remodeler of the collagenous composition of the trabecular meshwork and provide evidence for a causal link between MMP-9 deficiency, trabecular meshwork ultrastructure, and ocular hypertension.
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Affiliation(s)
- Lies De Groef
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium 2Laboratory of Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Lien Andries
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Anuja Siwakoti
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Hamilton, Ontario, Canada
| | - Emiel Geeraerts
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Ilse Bollaerts
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lut Noterdaeme
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | | | - Anna-Pia Papageorgiou
- Centre for Molecular and Vascular Biology (CMVB), Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium 6Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands
| | - Ingeborg Stalmans
- Laboratory of Ophthalmology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Johan Billen
- Laboratory of Socioecology and Social Evolution, Ecology, Evolution and Biodiversity Conservation Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Judith A West-Mays
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Hamilton, Ontario, Canada
| | - Lieve Moons
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
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Liu Y, Allingham RR. Major review: Molecular genetics of primary open-angle glaucoma. Exp Eye Res 2017; 160:62-84. [PMID: 28499933 DOI: 10.1016/j.exer.2017.05.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/29/2017] [Accepted: 05/07/2017] [Indexed: 12/13/2022]
Abstract
Glaucoma is a leading cause of irreversible blindness worldwide. Primary open-angle glaucoma (POAG), the most common type, is a complex inherited disorder that is characterized by progressive retinal ganglion cell death, optic nerve head excavation, and visual field loss. The discovery of a large, and growing, number of genetic and chromosomal loci has been shown to contribute to POAG risk, which carry implications for disease pathogenesis. Differential gene expression analyses in glaucoma-affected tissues as well as animal models of POAG are enhancing our mechanistic understanding in this common, blinding disorder. In this review we summarize recent developments in POAG genetics and molecular genetics research.
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Affiliation(s)
- Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States; Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, GA, United States
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States; Duke - National University of Singapore (Duke-NUS), Singapore.
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Patel GC, Phan TN, Maddineni P, Kasetti RB, Millar JC, Clark AF, Zode GS. Dexamethasone-Induced Ocular Hypertension in Mice: Effects of Myocilin and Route of Administration. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:713-723. [PMID: 28167045 DOI: 10.1016/j.ajpath.2016.12.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 12/05/2016] [Accepted: 12/08/2016] [Indexed: 11/24/2022]
Abstract
Glucocorticoid (GC)-induced ocular hypertension (OHT) is a serious adverse effect of prolonged GC therapy that can lead to iatrogenic glaucoma and permanent vision loss. An appropriate mouse model can help us understand precise molecular mechanisms and etiology of GC-induced OHT. We therefore developed a novel, simple, and reproducible mouse model of GC-induced OHT. GC-induced myocilin expression in the trabecular meshwork (TM) has been suggested to play an important role in GC-induced OHT. We further determined whether myocilin contributes to GC-OHT. C57BL/6J mice received weekly periocular conjunctival fornix injections of a dexamethasone-21-acetate (DEX-Ac) formulation. Intraocular pressure (IOP) elevation was relatively rapid and significant, and correlated with reduced conventional outflow facility. Nighttime IOPs were higher in ocular hypertensive eyes compared to daytime IOPs. DEX-Ac treatment led to increased expression of fibronectin, collagen I, and α-smooth muscle actin in the TM in mouse eyes. No changes in body weight indicated no systemic toxicity associated with DEX-Ac treatment. Wild-type mice showed increased myocilin expression in the TM on DEX-Ac treatment. Both wild-type and Myoc-/- mice had equivalent and significantly elevated IOP with DEX-Ac treatment every week. In conclusion, our mouse model mimics many aspects of GC-induced OHT in humans, and we further demonstrate that myocilin does not play a major role in DEX-induced OHT in mice.
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Affiliation(s)
- Gaurang C Patel
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Tien N Phan
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Prabhavathi Maddineni
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Ramesh B Kasetti
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - J Cameron Millar
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Abbot F Clark
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas.
| | - Gulab S Zode
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas.
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Fini ME, Schwartz SG, Gao X, Jeong S, Patel N, Itakura T, Price MO, Price FW, Varma R, Stamer WD. Steroid-induced ocular hypertension/glaucoma: Focus on pharmacogenomics and implications for precision medicine. Prog Retin Eye Res 2017; 56:58-83. [PMID: 27666015 PMCID: PMC5237612 DOI: 10.1016/j.preteyeres.2016.09.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 09/17/2016] [Accepted: 09/19/2016] [Indexed: 02/06/2023]
Abstract
Elevation of intraocular pressure (IOP) due to therapeutic use of glucocorticoids is called steroid-induced ocular hypertension (SIOH); this can lead to steroid-induced glaucoma (SIG). Glucocorticoids initiate signaling cascades ultimately affecting expression of hundreds of genes; this provides the potential for a highly personalized pharmacological response. Studies attempting to define genetic risk factors were undertaken early in the history of glucocorticoid use, however scientific tools available at that time were limited and progress stalled. In contrast, significant advances were made over the ensuing years in defining disease pathophysiology. As the genomics age emerged, it appeared the time was right to renew investigation into genetics. Pharmacogenomics is an unbiased discovery approach, not requiring an underlying hypothesis, and provides a way to pinpoint clinically significant genes and pathways that could not have been discovered any other way. Results of the first genome-wide association study to identify polymorphisms associated with SIOH, and follow-up on two novel genes linked to the disorder, GPR158 and HCG22, is discussed in the second half of the article. However, knowledge of genetic variants determining response to steroids in the eye also has value in its own right as a predictive and diagnostic tool. This article concludes with a discussion of how the Precision Medicine Initiative®, announced by U.S. President Obama in his 2015 State of the Union address, is beginning to touch the practice of ophthalmology. It is argued that SIOH/SIG may provide one of the next opportunities for effective application of precision medicine.
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Affiliation(s)
- M Elizabeth Fini
- USC Institute for Genetic Medicine and Department of Cell & Neurobiology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Stephen G Schwartz
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 3880 Tamiami Trail North, Naples, FL, 34103, USA.
| | - Xiaoyi Gao
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1905 W Taylor St., Suite 235, Chicago, IL, 60612, USA.
| | - Shinwu Jeong
- USC Institute for Genetic Medicine, USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Nitin Patel
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Marianne O Price
- Cornea Research Foundation of America, 9002 North Meridian Street, Indianapolis, IN, 46260, USA.
| | - Francis W Price
- Price Vision Group, 9002 North Meridian Street, Indianapolis, IN, 46260, USA.
| | - Rohit Varma
- Office of the Dean, USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 1975 Zonal Ave., KAM 500, Los Angeles, CA, 90089, USA.
| | - W Daniel Stamer
- Department of Ophthalmology and Department of Biomedical Engineering, Duke University, AERI Room 4008, 2351 Erwin Rd, Durham, NC, 27705, USA.
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Chen L, Gage PJ. Heterozygous Pitx2 Null Mice Accurately Recapitulate the Ocular Features of Axenfeld-Rieger Syndrome and Congenital Glaucoma. Invest Ophthalmol Vis Sci 2016; 57:5023-5030. [PMID: 27654429 PMCID: PMC5040192 DOI: 10.1167/iovs.16-19700] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose The purpose of this analysis was to assess the utility of Pitx2+/- mice as a model for the ocular features of Axenfeld-Rieger Syndrome and for congenital glaucoma. Methods Eyes of Pitx2+/- and wild-type littermates were examined clinically using optical coherence tomography (OCT) and fundus photography. Intraocular pressures were measured using a TonoLab rebound tonometer. Eyes were examined histologically to assess PITX2 expression, structural integrity, and optic nerve and ganglion cell content. Results PITX2 is present postnatally in the corneal endothelium and stroma, iris stroma, trabecular meshwork, and Schlemm's canal. Reduced central corneal thickness, iris defects, and iridicorneal adhesions are all prevalent in Pitx2+/- eyes. Although optic nerve heads appear normal at postnatal day 7, IOP is elevated and optic nerve head cupping is fully penetrant in Pitx2+/- eyes by 3 weeks of age. Neurodegeneration is present in a significant percentage of optic nerves from Pitx2+/- mice by 3 weeks of age, and is fully penetrant by 2 months of age. Pitx2+/- eyes show significant reductions in specifically ganglion cell density in all four quadrants by 2 months of age. Conclusions Pitx2+/- mice model the major ocular features of Axenfeld-Rieger Syndrome and will be an important resource for understanding the molecular mechanisms leading to anterior segment dysgenesis and a high prevalence of glaucoma in this disease. In addition, these mice may provide an efficient new model for assessing the molecular events in glaucoma more generally, and for developing and testing new treatment paradigms for this disease.
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Affiliation(s)
- Lisheng Chen
- Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Philip J Gage
- Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States 2Department of Cell & Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States
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Chen L, Zhao Y, Zhang H. Comparative Anatomy of the Trabecular Meshwork, the Optic Nerve Head and the Inner Retina in Rodent and Primate Models Used for Glaucoma Research. Vision (Basel) 2016; 1:vision1010004. [PMID: 31740629 PMCID: PMC6848998 DOI: 10.3390/vision1010004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/26/2016] [Accepted: 07/08/2016] [Indexed: 12/13/2022] Open
Abstract
Glaucoma is a heterogeneous group of ocular disorders with a multi-faceted etiology. Although numerous studies on glaucoma using different animal models have been published, it is unwise to simply generalize the results of one model to all glaucomatous situations because of the differences in the anatomy and morphology of animal eyes in comparison with humans’. In this review, we highlight the differences in the trabecular meshwork (TM) tissue, lamina cribrosa (LC) region, optic nerve head (ONH) and the inner layer of the retina in mice, rats and monkeys. In comparison with humans, non-human primates show TM, retina and ONH that are anatomically almost identical. The rat model shows many similarities in the aqueous outflow pathway compared to humans. The mouse ONH lacks collagenous LC, and this finding is observed across different mouse strains. The tissue structure of the ONH in rodents is similar to that in humans, although the blood supply shows differences. The number of cells in the ganglion layer depends on the rodent strain. Despite some differences from humans, rodents are a good choice for studying different types of glaucoma, and the modeling method should be selected based on the experimental needs and the hypothesis being tested.
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Affiliation(s)
| | | | - Hong Zhang
- Correspondence: ; Tel.: +86-139-7167-9079; Fax: +86-027-8366-3688
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50
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Martino VB, Sabljic T, Deschamps P, Green RM, Akula M, Peacock E, Ball A, Williams T, West-Mays JA. Conditional deletion of AP-2β in mouse cranial neural crest results in anterior segment dysgenesis and early-onset glaucoma. Dis Model Mech 2016; 9:849-61. [PMID: 27483349 PMCID: PMC5007979 DOI: 10.1242/dmm.025262] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 06/21/2016] [Indexed: 12/11/2022] Open
Abstract
Anterior segment dysgenesis (ASD) encompasses a group of developmental disorders in which a closed angle phenotype in the anterior chamber of the eye can occur and 50% of patients develop glaucoma. Many ASDs are thought to involve an inappropriate patterning and migration of the periocular mesenchyme (POM), which is derived from cranial neural crest cells (NCCs) and mesoderm. Although, the mechanism of this disruption is not well understood, a number of transcriptional regulatory molecules have previously been implicated in ASDs. Here, we investigate the function of the transcription factor AP-2β, encoded by Tfap2b, which is expressed in NCCs and their derivatives. Wnt1-Cre-mediated conditional deletion of Tfap2b in NCCs resulted in post-natal ocular defects typified by opacity. Histological data revealed that the conditional AP-2β NCC knockout (KO) mutants exhibited dysgenesis of multiple structures in the anterior segment of the eye including defects in the corneal endothelium, corneal stroma, ciliary body and disruption in the iridocorneal angle with adherence of the iris to the cornea. We further show that this phenotype leads to a significant increase in intraocular pressure and a subsequent loss of retinal ganglion cells and optic nerve degeneration, features indicative of glaucoma. Overall, our findings demonstrate that AP-2β is required in the POM for normal development of the anterior segment of the eye and that the AP-2β NCC KO mice might serve as a new and exciting model of ASD and glaucoma that is fully penetrant and with early post-natal onset. Summary: Tissue-specific deletion of transcription factor AP-2β in the neural-crest-derived periocular mesenchyme generates a novel model of anterior segment dysgenesis and early onset glaucoma in mice.
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Affiliation(s)
- Vanessa B Martino
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Room 4N65, 1200 Main St. West, Hamilton, Ontario, Canada L8N 3Z5
| | - Thomas Sabljic
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Room 4N65, 1200 Main St. West, Hamilton, Ontario, Canada L8N 3Z5
| | - Paula Deschamps
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Room 4N65, 1200 Main St. West, Hamilton, Ontario, Canada L8N 3Z5
| | - Rebecca M Green
- Department of Craniofacial Biology, University of Colorado Denver, Anschutz Medical Campus, Mailstop 8120, RC-1 South Building, 11th Floor, Room 111, 12801 East 17th Ave. P.O., Aurora, CO 80045, USA Department of Cell and Developmental Biology, University of Colorado Denver, Anschutz Medical Campus, Mailstop 8120, RC-1 South Building, 11th Floor, Room 111, 12801 East 17th Ave. P.O., Aurora, CO 80045, USA
| | - Monica Akula
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Room 4N65, 1200 Main St. West, Hamilton, Ontario, Canada L8N 3Z5
| | - Erica Peacock
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Room 4N65, 1200 Main St. West, Hamilton, Ontario, Canada L8N 3Z5
| | - Alexander Ball
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Room 4N65, 1200 Main St. West, Hamilton, Ontario, Canada L8N 3Z5
| | - Trevor Williams
- Department of Craniofacial Biology, University of Colorado Denver, Anschutz Medical Campus, Mailstop 8120, RC-1 South Building, 11th Floor, Room 111, 12801 East 17th Ave. P.O., Aurora, CO 80045, USA Department of Cell and Developmental Biology, University of Colorado Denver, Anschutz Medical Campus, Mailstop 8120, RC-1 South Building, 11th Floor, Room 111, 12801 East 17th Ave. P.O., Aurora, CO 80045, USA
| | - Judith A West-Mays
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Room 4N65, 1200 Main St. West, Hamilton, Ontario, Canada L8N 3Z5
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