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Yadav M, Kumar M, Dhull CS, Sachdeva S, Bhardwaj A, Yadav A, Panghal V, Sharma P, Kumari A, Yadav R, Singh M, Kumar R, Deora A, Rathi M, Kaur P, Tanwar M. Identification and structural analysis of pathogenic variants in MYOC and CYP1B1 genes in Indian JOAG patients. Jpn J Ophthalmol 2025; 69:469-481. [PMID: 39998747 DOI: 10.1007/s10384-025-01173-8] [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: 08/22/2024] [Accepted: 12/14/2024] [Indexed: 02/27/2025]
Abstract
PURPOSE Juvenile onset open-angle glaucoma (JOAG) manifests in individuals under the age of 40, resulting in elevated intraocular pressure and significant optic nerve damage. To broaden the spectrum of mutations associated with JOAG and to determine their specific structural implications, we examined Myocilin and Cytochrome P450 1B1 gene in a cohort of 111 unrelated North Indian patients diagnosed with JOAG. STUDY DESIGN A clinical and experimental study. METHODS PCR-DNA sequencing screened the coding exons and intron-exon junctions of the MYOC and CYP1B1 genes in 111 unrelated JOAG patients and 100 controls. Identified sequence variations were searched in the ClinVar database, HGMD, and dbSNP. Six different online available algorithms including rare exome variant ensemble learner (REVEL), Sorting Intolerant From Tolerant (SIFT), Mutation Taster, SNAP2, IMutant2.0, and MutPred2 were used for the pathogenicity prediction of missense variations. The Structural consequences of detected possible pathogenic variations were predicted by using PyMol, Chimera and MD simulation of these changes. RESULTS Potentially-pathogenic variations were observed in thirty patients (27.02%) within the MYOC and CYP1B1 genes, encompassing both novel and previously documented variants. Structural predictions of novel potentially-pathogenic mutations indicate altered stability and flexibility. CONCLUSION Analysis reveals a higher prevalence of CYP1B1 gene variants (22.5%) relative to MYOC gene variants (4.5%), suggesting that CYP1B1 is the predominant gene implicated in JOAG among Indian patients. Our findings enhance the understanding of mutation spectra and frequencies of MYOC and CYP1B1gene in JOAG among the North Indian population. Structural predictions of novel pathogenic mutations could enhance the understanding of JOAG pathogenesis and support subsequent functional analysis.
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Affiliation(s)
- Manoj Yadav
- Department of Genetics, Maharshi Dayanand University, Rohtak, HR, 124001, India
| | - Mukesh Kumar
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Chand Singh Dhull
- Regional Institute of Ophthalmology, Pt. B.D. Sharma, University of Health Sciences, Rohtak, Haryana, 124001, India
| | - Sumit Sachdeva
- Regional Institute of Ophthalmology, Pt. B.D. Sharma, University of Health Sciences, Rohtak, Haryana, 124001, India
| | - Aarti Bhardwaj
- Department of Genetics, Maharshi Dayanand University, Rohtak, HR, 124001, India
| | - Anshu Yadav
- Department of Genetics, Maharshi Dayanand University, Rohtak, HR, 124001, India
| | - Vishal Panghal
- Department of Genetics, Maharshi Dayanand University, Rohtak, HR, 124001, India
| | - Pradeep Sharma
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Ankit Kumari
- Department of Biotechnology, Maharshi Dayanand University, Rohtak, HR, 124001, India
| | - Ritu Yadav
- Department of Genetics, Maharshi Dayanand University, Rohtak, HR, 124001, India
| | - Mayank Singh
- Department of Medical Oncology, Dr. B. R. A.-Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Rakesh Kumar
- School of Biotechnology, Shri Mata Vaishno Devi University, Katra, J&K, 182320, India
| | - Anupama Deora
- Department of Genetics, Maharshi Dayanand University, Rohtak, HR, 124001, India
| | - Manisha Rathi
- Regional Institute of Ophthalmology, Pt. B.D. Sharma, University of Health Sciences, Rohtak, Haryana, 124001, India
| | - Punit Kaur
- Department of Biophysics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Mukesh Tanwar
- Department of Genetics, Maharshi Dayanand University, Rohtak, HR, 124001, India.
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
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Scelsi HF, Close EGS, Huard DJE, Dunn E, Bogdanović N, Mudiyanselage SHW, Grant A, Stagg SM, Schmidt‐Krey I, Van Horn WD, Lieberman RL. Detection of non-native species formed during fibrillization of the myocilin olfactomedin domain. Protein Sci 2025; 34:e70063. [PMID: 40095382 PMCID: PMC11912428 DOI: 10.1002/pro.70063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2024] [Revised: 01/10/2025] [Accepted: 01/31/2025] [Indexed: 03/19/2025]
Abstract
Glaucoma is a group of neurodegenerative diseases that together are the leading cause of irreversible blindness worldwide. Myocilin-associated glaucoma is an inherited form of this disease, caused by intracellular aggregation of misfolded mutant myocilin. In vitro, the myocilin C-terminal olfactomedin domain (OLF), the relevant domain for glaucoma pathogenesis, can be driven to form amyloid-like fibrils under mild conditions. Here we characterize a species present during in vitro fibrillization. Purified OLF was subjected to fibrillization at concentrations required for downstream electron microscopy imaging and NMR spectroscopy. Additional biophysical techniques, including analytical ultracentrifugation and X-ray crystallography, were employed to further characterize the multicomponent mixture. Negative stain transmission electron microscopy (TEM) shows a non-native species reminiscent of known prefibrillar oligomers from other amyloid systems, NMR indicates a minor population of partially misfolded species is present in solution, and cryo-EM imaging shows two-dimensional protein arrays. The predominant soluble species remaining in solution after the fibril reaction is natively folded, as evidenced by X-ray crystallography. In summary, after incubating OLF under fibrillization-promoting conditions, there is a heterogeneous mixture consisting of soluble folded protein, mature amyloid-like fibrils, and partially misfolded intermediate species that at present belie additional molecular detail. The characterization of OLF fibrillar species illustrates the challenges associated with developing a comprehensive understanding of the fibrillization process for large, non-model amyloidogenic proteins.
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Affiliation(s)
- Hailee F. Scelsi
- School of Chemistry and BiochemistryGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Emily G. S. Close
- School of Chemistry and BiochemistryGeorgia Institute of TechnologyAtlantaGeorgiaUSA
- Pacific Northwest National LaboratoryRichlandWashingtonUSA
| | - Dustin J. E. Huard
- School of Chemistry and BiochemistryGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Elijah Dunn
- School of Chemistry and BiochemistryGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Nebojša Bogdanović
- Institute of Molecular BiophysicsFlorida State UniversityTallahasseeFloridaUSA
| | - Sonali H. W. Mudiyanselage
- Biodesign Center for Personalized DiagnosticsArizona State UniversityTempeArizonaUSA
- School of Molecular SciencesArizona State UniversityTempeArizonaUSA
| | - Arshay Grant
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Scott M. Stagg
- Institute of Molecular BiophysicsFlorida State UniversityTallahasseeFloridaUSA
- Department of Biological SciencesFlorida State UniversityTallahasseeFloridaUSA
| | | | - Wade D. Van Horn
- Biodesign Center for Personalized DiagnosticsArizona State UniversityTempeArizonaUSA
- School of Molecular SciencesArizona State UniversityTempeArizonaUSA
| | - Raquel L. Lieberman
- School of Chemistry and BiochemistryGeorgia Institute of TechnologyAtlantaGeorgiaUSA
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Hill KR, Scelsi HF, Youngblood HA, Faralli JA, Itakura T, Fini ME, Peters DM, Lieberman RL. Structural basis for anomalous cellular trafficking behavior of glaucoma-associated A427T mutant myocilin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.02.26.640437. [PMID: 40060664 PMCID: PMC11888440 DOI: 10.1101/2025.02.26.640437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/15/2025]
Abstract
Familial mutations in myocilin cause vision loss in glaucoma due to misfolding and a toxic gain of function in a senescent cell type in the anterior eye. Here we characterize the cellular behavior and structure of the myocilin (myocilin A427T) mutant, of uncertain pathogenicity. Our characterization of A427T demonstrates that even mutations that minimally perturb myocilin structure and stability can present challenges for protein quality control clearance pathways. Namely, when expressed in an inducible immortalized trabecular meshwork cell line, inhibition of the proteasome reroutes wild-type myocilin, but not myocilin A427T, from endoplasmic reticulum associated degradation to lysosomal degradation. Yet, the crystal structure of the A427T myocilin olfactomedin domain shows modest perturbations largely confined to the mutation site. The previously unappreciated range of mutant myocilin behavior correlating with variable stability and structure provides a rationale for why it is challenging to predict causal pathogenicity of a given myocilin mutation, even in the presence of clinical data for members of an affected family. Comprehending the continuum of mutant myocilin behavior in the laboratory supports emerging efforts to use genetics to assess glaucoma risk in the clinic. In addition, the study supports a therapeutic strategy aimed at enhancing autophagic clearance of mutant myocilin.
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Affiliation(s)
- Kamisha R Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA
| | - Hailee F Scelsi
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA
| | - Hannah A Youngblood
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA
| | - Jennifer A Faralli
- Department of Pathology & Laboratory Medicine, University of Wisconsin, Madison, WI
| | - Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA
| | - M Elizabeth Fini
- New England Eye Center, Tufts Medical Center; Department of Ophthalmology, School of Medicine and Tufts Graduate School of Biomedical Sciences, Tufts University, Boston, MA
| | - Donna M Peters
- Department of Pathology & Laboratory Medicine, University of Wisconsin, Madison, WI
| | - Raquel L Lieberman
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA
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Kaipa BR, Kasetti R, Sundaresan Y, Li L, Yacoub S, Millar JC, Cho W, Skowronska-Krawczyk D, Maddineni P, Palczewski K, Zode GS. Impaired axonal transport contributes to neurodegeneration in a Cre-inducible mouse model of myocilin-associated glaucoma. JCI Insight 2025; 10:e188710. [PMID: 39836483 PMCID: PMC11949003 DOI: 10.1172/jci.insight.188710] [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: 01/23/2025] Open
Abstract
Elevation of intraocular pressure (IOP) due to trabecular meshwork (TM) dysfunction, leading to neurodegeneration, is the pathological hallmark of primary open-angle glaucoma (POAG). Impaired axonal transport is an early and critical feature of glaucomatous neurodegeneration. However, a robust mouse model that accurately replicates these human POAG features has been lacking. We report the development and characterization of a new Cre-inducible mouse model expressing a DsRed-tagged Y437H mutant of human myocilin (Tg.CreMYOCY437H). A single intravitreal injection of HAd5-Cre induced selective MYOC expression in the TM, causing TM dysfunction, reducing the outflow facility, and progressively elevating IOP in Tg.CreMYOCY437H mice. Sustained IOP elevation resulted in significant loss of retinal ganglion cells (RGCs) and progressive axonal degeneration in Cre-induced Tg.CreMYOCY437H mice. Notably, impaired anterograde axonal transport was observed at the optic nerve head before RGC degeneration, independent of age, indicating that impaired axonal transport contributes to RGC degeneration in Tg.CreMYOCY437H mice. In contrast, axonal transport remained intact in ocular hypertensive mice injected with microbeads, despite significant RGC loss. Our findings indicate that Cre-inducible Tg.CreMYOCY437H mice replicate all glaucoma phenotypes, providing an ideal model for studying early events of TM dysfunction and neuronal loss in POAG.
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Affiliation(s)
- Balasankara Reddy Kaipa
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, and
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, California, USA
| | - Ramesh Kasetti
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Texas, USA
| | - Yogapriya Sundaresan
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, and
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, California, USA
| | - Linya Li
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, and
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, California, USA
| | - Sam Yacoub
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Texas, USA
| | - J. Cameron Millar
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Texas, USA
| | - William Cho
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, and
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, California, USA
| | - Dorota Skowronska-Krawczyk
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, and
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, California, USA
| | - Prabhavathi Maddineni
- Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, Missouri, USA
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, and
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, California, USA
- Department of Chemistry and
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, USA
| | - Gulab S. Zode
- Gavin Herbert Eye Institute-Center for Translational Vision Research, Department of Ophthalmology, and
- Department of Physiology and Biophysics, University of California Irvine School of Medicine, Irvine, California, USA
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5
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Ma MT, Qerqez AN, Hill KR, Azouz LR, Youngblood HA, Hill SE, Ku Y, Peters DM, Maynard JA, Lieberman RL. Antibody-mediated clearance of an ER-resident aggregate that causes glaucoma. PNAS NEXUS 2025; 4:pgae556. [PMID: 39726989 PMCID: PMC11670252 DOI: 10.1093/pnasnexus/pgae556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Accepted: 12/05/2024] [Indexed: 12/28/2024]
Abstract
Recombinant antibodies are a promising class of therapeutics to treat protein misfolding associated with neurodegenerative diseases, and several antibodies that inhibit aggregation are approved or in clinical trials to treat Alzheimer's disease. Here, we developed antibodies targeting the aggregation-prone β-propeller olfactomedin (OLF) domain of myocilin, variants of which comprise the strongest genetic link to glaucoma and cause early onset vision loss for several million individuals worldwide. Mutant myocilin aggregates intracellularly in the endoplasmic reticulum (ER). Subsequent ER stress causes cytotoxicity that hastens dysregulation of intraocular pressure, the primary risk factor for most forms of glaucoma. Our antibody discovery campaign yielded two recombinant antibodies: anti-OLF1 recognizes a linear epitope, while anti-OLF2 is selective for natively folded OLF and inhibits aggregation in vitro. By binding OLF, these antibodies engage autophagy/lysosomal degradation to promote degradation of two pathogenic mutant myocilins. This work demonstrates the potential for therapeutic antibodies to disrupt ER-localized protein aggregates by altering the fate of folding intermediates. This approach could be translated as a precision medicine to treat myocilin-associated glaucoma with in situ antibody expression. More generally, the study supports the approach of enhancing lysosomal degradation to treat proteostasis decline in glaucoma and other diseases.
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Affiliation(s)
- Minh Thu Ma
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332, USA
| | - Ahlam N Qerqez
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Kamisha R Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332, USA
| | - Laura R Azouz
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Hannah A Youngblood
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332, USA
| | - Shannon E Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332, USA
| | - Yemo Ku
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332, USA
| | - Donna M Peters
- Department of Pathology & Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
- Department of Ophthalmology & Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712, USA
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Raquel L Lieberman
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, GA 30332, USA
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6
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Henderson J, O'Callaghan J, Campbell M. Gene therapy for glaucoma: Targeting key mechanisms. Vision Res 2024; 225:108502. [PMID: 39423611 PMCID: PMC11579448 DOI: 10.1016/j.visres.2024.108502] [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: 07/31/2024] [Revised: 10/04/2024] [Accepted: 10/04/2024] [Indexed: 10/21/2024]
Abstract
Glaucoma is a group of optic neuropathies characterised by progressive retinal ganglion cell (RGC) degeneration and is the leading cause of irreversible blindness worldwide. Current treatments for glaucoma focus on reducing intraocular pressure (IOP) with topical medications. However, many patients do not achieve sufficient IOP reductions with such treatments. Patient compliance to dosing schedules also poses a significant challenge, further limiting their effectiveness. While surgical options exist for resistant cases, these are invasive and carry risks of complications. Thus, there is a critical need for better strategies to prevent irreversible vision loss in glaucoma. Gene therapy holds significant promise in this regard, offering potential long-term solutions by targeting the disease's underlying causes at a molecular level. Gene therapy strategies for glaucoma primarily target the two key hallmarks of the disease: elevated IOP and RGC death. This review explores key mechanisms underlying these hallmarks and discusses the current state of gene therapies targeting them. In terms of IOP reduction, this review covers strategies aimed at enhancing extracellular matrix turnover in the conventional outflow pathway, targeting fibrosis, regulating aqueous humor production, and targeting myocilin for gene-specific therapy. Neuroprotective strategies explored include targeting neurotrophic factors and their receptors, reducing oxidative stress and mitochondrial dysfunction, and preventing Wallerian degeneration. This review also briefly highlights key research priorities for advancing gene therapies for glaucoma through the clinical pipeline, such as refining delivery vectors and improving transgene regulation. Addressing these priorities will be essential for translating advancements from preclinical models into effective clinical therapies for glaucoma.
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Affiliation(s)
- Jeff Henderson
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | | | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
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Zolotareva K, Dotsenko PA, Podkolodnyy N, Ivanov R, Makarova AL, Chadaeva I, Bogomolov A, Demenkov PS, Ivanisenko V, Oshchepkov D, Ponomarenko M. Candidate SNP Markers Significantly Altering the Affinity of the TATA-Binding Protein for the Promoters of Human Genes Associated with Primary Open-Angle Glaucoma. Int J Mol Sci 2024; 25:12802. [PMID: 39684516 DOI: 10.3390/ijms252312802] [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: 09/30/2024] [Revised: 11/20/2024] [Accepted: 11/25/2024] [Indexed: 12/18/2024] Open
Abstract
Primary open-angle glaucoma (POAG) is the most common form of glaucoma. This condition leads to optic nerve degeneration and eventually to blindness. Tobacco smoking, alcohol consumption, fast-food diets, obesity, heavy weight lifting, high-intensity physical exercises, and many other bad habits are lifestyle-related risk factors for POAG. By contrast, moderate-intensity aerobic exercise and the Mediterranean diet can alleviate POAG. In this work, we for the first time estimated the phylostratigraphic age indices (PAIs) of all 153 POAG-related human genes in the NCBI Gene Database. This allowed us to separate them into two groups: POAG-related genes that appeared before and after the phylum Chordata, that is, ophthalmologically speaking, before and after the camera-type eye evolved. Next, in the POAG-related genes' promoters, we in silico predicted all 3835 candidate SNP markers that significantly change the TATA-binding protein (TBP) affinity for these promoters and, through this molecular mechanism, the expression levels of these genes. Finally, we verified our results against five independent web services-PANTHER, DAVID, STRING, MetaScape, and GeneMANIA-as well as the ClinVar database. It was concluded that POAG is likely to be a symptom of the human self-domestication syndrome, a downside of being civilized.
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Affiliation(s)
- Karina Zolotareva
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
| | - Polina A Dotsenko
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Nikolay Podkolodnyy
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
- Institute of Computational Mathematics and Mathematical Geophysics, SB RAS, Novosibirsk 630090, Russia
| | - Roman Ivanov
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
| | - Aelita-Luiza Makarova
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
| | - Irina Chadaeva
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
| | - Anton Bogomolov
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Pavel S Demenkov
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
| | - Vladimir Ivanisenko
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Dmitry Oshchepkov
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| | - Mikhail Ponomarenko
- Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences (ICG SB RAS), Novosibirsk 630090, Russia
- Kurchatov Genome Center at the ICG SB RAS, Novosibirsk 630090, Russia
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Kaipa BR, Kasetti R, Sundaresan Y, Li L, Yacoub S, Millar C, Cho W, Skowronska-Krawczyk D, Maddineni P, Palczewski K, Zode G. Impaired axonal transport at the optic nerve head contributes to neurodegeneration in a novel Cre-inducible mouse model of myocilin glaucoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.18.613712. [PMID: 39345520 PMCID: PMC11429981 DOI: 10.1101/2024.09.18.613712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Elevation of intraocular pressure (IOP) due to trabecular meshwork (TM) dysfunction, leading to neurodegeneration, is the pathological hallmark of primary open-angle glaucoma (POAG). Impaired axonal transport is an early and critical feature of glaucomatous neurodegeneration. However, a robust mouse model that replicates these human POAG features accurately has been lacking. We report the development and characterization of a novel Cre-inducible mouse model expressing a DsRed-tagged Y437H mutant of human myocilin (Tg.CreMYOCY437H). A single intravitreal injection of HAd5-Cre induced selective MYOC expression in the TM, causing TM dysfunction, reducing outflow facility, and progressively elevating IOP in Tg.CreMYOCY437H mice. Sustained IOP elevation resulted in significant retinal ganglion cell (RGC) loss and progressive axonal degeneration in Cre-induced Tg.CreMYOCY437H mice. Notably, impaired anterograde axonal transport was observed at the optic nerve head before RGC degeneration, independent of age, indicating that impaired axonal transport contributes to RGC degeneration in Tg.CreMYOCY437H mice. In contrast, axonal transport remained intact in ocular hypertensive mice injected with microbeads, despite significant RGC loss. Our findings indicate that Cre-inducible Tg.CreMYOCY437H mice replicate all glaucoma phenotypes, providing an ideal model for studying early events of TM dysfunction and neuronal loss in POAG.
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9
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Maxwell G, Souzeau E. Childhood glaucoma: Implications for genetic counselling. Clin Genet 2024; 106:545-563. [PMID: 39206700 DOI: 10.1111/cge.14603] [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: 05/09/2024] [Revised: 07/17/2024] [Accepted: 07/23/2024] [Indexed: 09/04/2024]
Abstract
Childhood glaucoma is a heterogeneous group of ocular disorders defined by an age of onset from birth to 18 years. These vision-threatening disorders require early diagnosis, timely treatment, and lifelong management to maintain vision and minimise irreversible blindness. The genetics of childhood glaucoma is complex with both phenotypic and genetic heterogeneity. The purpose of this review is to summarise the different types of childhood glaucoma and their genetic architecture to aid in the genetic counselling process with patients and their families. We provide an overview of associated syndromes and discuss implications for genetic counselling, including genetic testing strategies, cascade genetic testing, and reproductive options.
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Affiliation(s)
- Giorgina Maxwell
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, Flinders University, Adelaide, South Australia, Australia
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10
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Tundo GR, Cavaterra D, Pandino I, Zingale GA, Giammaria S, Boccaccini A, Michelessi M, Roberti G, Tanga L, Carnevale C, Figus M, Grasso G, Coletta M, Bocedi A, Oddone F, Sbardella D. The Delayed Turnover of Proteasome Processing of Myocilin upon Dexamethasone Stimulation Introduces the Profiling of Trabecular Meshwork Cells' Ubiquitylome. Int J Mol Sci 2024; 25:10017. [PMID: 39337505 PMCID: PMC11432723 DOI: 10.3390/ijms251810017] [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: 08/01/2024] [Revised: 09/11/2024] [Accepted: 09/13/2024] [Indexed: 09/30/2024] Open
Abstract
Glaucoma is chronic optic neuropathy whose pathogenesis has been associated with the altered metabolism of Trabecular Meshwork Cells, which is a cell type involved in the synthesis and remodeling of the trabecular meshwork, the main drainage pathway of the aqueous humor. Starting from previous findings supporting altered ubiquitin signaling, in this study, we investigated the ubiquitin-mediated turnover of myocilin (MYOC/TIGR gene), which is a glycoprotein with a recognized role in glaucoma pathogenesis, in a human Trabecular Meshwork strain cultivated in vitro in the presence of dexamethasone. This is a validated experimental model of steroid-induced glaucoma, and myocilin upregulation by glucocorticoids is a phenotypic marker of Trabecular Meshwork strains. Western blotting and native-gel electrophoresis first uncovered that, in the presence of dexamethasone, myocilin turnover by proteasome particles was slower than in the absence of the drug. Thereafter, co-immunoprecipitation, RT-PCR and gene-silencing studies identified STUB1/CHIP as a candidate E3-ligase of myocilin. In this regard, dexamethasone treatment was found to downregulate STUB1/CHIP levels by likely promoting its proteasome-mediated turnover. Hence, to strengthen the working hypothesis about global alterations of ubiquitin-signaling, the first profiling of TMCs ubiquitylome, in the presence and absence of dexamethasone, was here undertaken by diGLY proteomics. Application of this workflow effectively highlighted a robust dysregulation of key pathways (e.g., phospholipid signaling, β-catenin, cell cycle regulation) in dexamethasone-treated Trabecular Meshwork Cells, providing an ubiquitin-centered perspective around the effect of glucocorticoids on metabolism and glaucoma pathogenesis.
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Affiliation(s)
- Grazia Raffaella Tundo
- Department of Clinical Sciences and Translational Medicine, University of Tor Vergata, 00133 Rome, Italy
| | - Dario Cavaterra
- Department of Chemical Sciences and Technologies, University of Tor Vergata, 00133 Rome, Italy (A.B.)
| | - Irene Pandino
- IRCCS-Fondazione Bietti, 00168 Rome, Italy (G.R.); (M.C.)
| | | | - Sara Giammaria
- IRCCS-Fondazione Bietti, 00168 Rome, Italy (G.R.); (M.C.)
| | | | | | - Gloria Roberti
- IRCCS-Fondazione Bietti, 00168 Rome, Italy (G.R.); (M.C.)
| | - Lucia Tanga
- IRCCS-Fondazione Bietti, 00168 Rome, Italy (G.R.); (M.C.)
| | | | - Michele Figus
- Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa, 56124 Pisa, Italy;
| | - Giuseppe Grasso
- Department of Chemical Sciences, University of Catania, 95125 Catania, Italy;
| | | | - Alessio Bocedi
- Department of Chemical Sciences and Technologies, University of Tor Vergata, 00133 Rome, Italy (A.B.)
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11
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Saccuzzo EG, Robang AS, Gao Y, Chen B, Lieberman RL, Paravastu AK. Evidence for S 331-G-S-L within the amyloid core of myocilin olfactomedin domain fibrils based on low-resolution 3D solid-state NMR spectra. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.09.606901. [PMID: 39149386 PMCID: PMC11326258 DOI: 10.1101/2024.08.09.606901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Myocilin-associated glaucoma is a protein-conformational disorder associated with formation of a toxic amyloid-like aggregate. Numerous destabilizing single point variants, distributed across the myocilin olfactomedin β-propeller (OLF, myocilin residues 245-504, 30 kDa) are associated with accelerated disease progression. In vitro, wild type (WT) OLF can be promoted to form thioflavin T (ThT)-positive fibrils under mildly destabilizing (37°C, pH 7.2) conditions. Consistent with the notion that only a small number of residues within a protein are responsible for amyloid formation, 3D 13C-13C solid-state NMR spectra show that OLF fibrils are likely to be composed of only about one third of the overall sequence. Here, we probe the residue composition of fibrils formed de novo from purified full-length OLF. We were able to make sequential assignments consistent with the sequence S331-G-S-L334. This sequence appears once within a previously identified amyloid-prone region (P1, G326AVVYSGSLYFQ) internal to OLF. Since nearly half of the pairs of adjacent residues (di-peptides) in OLF occur only once in the primary structure and almost all the 3-residue sequences (tri-peptides) are unique, remarkably few sequential assignments are necessary to uniquely identify specific regions of the amyloid core. This assignment approach could be applied to other systems to expand our molecular comprehension of how folded proteins undergo fibrillization.
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Affiliation(s)
- Emily G Saccuzzo
- School of Chemistry & Biochemistry and Georgia Institute of Technology, Atlanta, GA
- Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA
| | - Alicia S Robang
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Yuan Gao
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Bo Chen
- Department of Physics, University of Central Florida, Orlando, FL
| | - Raquel L Lieberman
- School of Chemistry & Biochemistry and Georgia Institute of Technology, Atlanta, GA
- Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA
| | - Anant K Paravastu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA
- Parker H. Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA
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12
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Kolovos A, Hassall MM, Siggs OM, Souzeau E, Craig JE. Polygenic Risk Scores Driving Clinical Change in Glaucoma. Annu Rev Genomics Hum Genet 2024; 25:287-308. [PMID: 38599222 DOI: 10.1146/annurev-genom-121222-105817] [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] [Indexed: 04/12/2024]
Abstract
Glaucoma is a clinically heterogeneous disease and the world's leading cause of irreversible blindness. Therapeutic intervention can prevent blindness but relies on early diagnosis, and current clinical risk factors are limited in their ability to predict who will develop sight-threatening glaucoma. The high heritability of glaucoma makes it an ideal substrate for genetic risk prediction, with the bulk of risk being polygenic in nature. Here, we summarize the foundations of glaucoma genetic risk, the development of polygenic risk prediction instruments, and emerging opportunities for genetic risk stratification. Although challenges remain, genetic risk stratification will significantly improve glaucoma screening and management.
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Affiliation(s)
- Antonia Kolovos
- Department of Ophthalmology, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia; , , ,
| | - Mark M Hassall
- Department of Ophthalmology, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia; , , ,
| | - Owen M Siggs
- Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia;
- Department of Ophthalmology, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia; , , ,
| | - Emmanuelle Souzeau
- Department of Ophthalmology, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia; , , ,
| | - Jamie E Craig
- Department of Ophthalmology, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia; , , ,
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13
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Greatbatch CJ, Lu Q, Hung S, Barnett AJ, Wing K, Liang H, Han X, Zhou T, Siggs OM, Mackey DA, Cook AL, Senabouth A, Liu GS, Craig JE, MacGregor S, Powell JE, Hewitt AW. High throughput functional profiling of genes at intraocular pressure loci reveals distinct networks for glaucoma. Hum Mol Genet 2024; 33:739-751. [PMID: 38272457 PMCID: PMC11031357 DOI: 10.1093/hmg/ddae003] [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: 10/15/2023] [Revised: 12/18/2023] [Accepted: 04/06/2024] [Indexed: 01/27/2024] Open
Abstract
INTRODUCTION Primary open angle glaucoma (POAG) is a leading cause of blindness globally. Characterized by progressive retinal ganglion cell degeneration, the precise pathogenesis remains unknown. Genome-wide association studies (GWAS) have uncovered many genetic variants associated with elevated intraocular pressure (IOP), one of the key risk factors for POAG. We aimed to identify genetic and morphological variation that can be attributed to trabecular meshwork cell (TMC) dysfunction and raised IOP in POAG. METHODS 62 genes across 55 loci were knocked-out in a primary human TMC line. Each knockout group, including five non-targeting control groups, underwent single-cell RNA-sequencing (scRNA-seq) for differentially-expressed gene (DEG) analysis. Multiplexed fluorescence coupled with CellProfiler image analysis allowed for single-cell morphological profiling. RESULTS Many gene knockouts invoked DEGs relating to matrix metalloproteinases and interferon-induced proteins. We have prioritized genes at four loci of interest to identify gene knockouts that may contribute to the pathogenesis of POAG, including ANGPTL2, LMX1B, CAV1, and KREMEN1. Three genetic networks of gene knockouts with similar transcriptomic profiles were identified, suggesting a synergistic function in trabecular meshwork cell physiology. TEK knockout caused significant upregulation of nuclear granularity on morphological analysis, while knockout of TRIOBP, TMCO1 and PLEKHA7 increased granularity and intensity of actin and the cell-membrane. CONCLUSION High-throughput analysis of cellular structure and function through multiplex fluorescent single-cell analysis and scRNA-seq assays enabled the direct study of genetic perturbations at the single-cell resolution. This work provides a framework for investigating the role of genes in the pathogenesis of glaucoma and heterogenous diseases with a strong genetic basis.
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Affiliation(s)
- Connor J Greatbatch
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Qinyi Lu
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Sandy Hung
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St, East Melbourne 3002, Australia
| | - Alexander J Barnett
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Kristof Wing
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Helena Liang
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St, East Melbourne 3002, Australia
| | - Xikun Han
- QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, Brisbane 4006, Australia
| | - Tiger Zhou
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, 1 Flinders Dr, Bedford Park, South Australia 5042, Australia
| | - Owen M Siggs
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, Sydney, NSW 2010, Australia
- School of Clinical Medicine, Faculty of Medicine and Health, Short Street, St George Hospital KOGARAH UNSW, Sydney 2217, Australia
| | - David A Mackey
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, Tasmania 7000, Australia
- Lions Eye Institute, Centre for Vision Sciences, University of Western Australia, 2 Verdun Street Nedlands WA 6009, Australia
| | - Anthony L Cook
- Wicking Dementia Research and Education Centre, University of Tasmania, 17 Liverpool Street, Hobart, TAS 7000, Australia
| | - Anne Senabouth
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, Sydney, NSW 2010, Australia
| | - Guei-Sheung Liu
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Jamie E Craig
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, 1 Flinders Dr, Bedford Park, South Australia 5042, Australia
| | - Stuart MacGregor
- QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, Brisbane 4006, Australia
| | - Joseph E Powell
- Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, Sydney, NSW 2010, Australia
- UNSW Cellular Genomics Futures Institute, University of New South Wales, 384 Victoria St, Darlinghurst, Sydney, NSW 2010, Australia
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool Street, Hobart, Tasmania 7000, Australia
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne St, East Melbourne 3002, Australia
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14
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Saccuzzo EG, Mebrat MD, Scelsi HF, Kim M, Ma MT, Su X, Hill SE, Rheaume E, Li R, Torres MP, Gumbart JC, Van Horn WD, Lieberman RL. Competition between inside-out unfolding and pathogenic aggregation in an amyloid-forming β-propeller. Nat Commun 2024; 15:155. [PMID: 38168102 PMCID: PMC10762032 DOI: 10.1038/s41467-023-44479-2] [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: 02/14/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024] Open
Abstract
Studies of folded-to-misfolded transitions using model protein systems reveal a range of unfolding needed for exposure of amyloid-prone regions for subsequent fibrillization. Here, we probe the relationship between unfolding and aggregation for glaucoma-associated myocilin. Mutations within the olfactomedin domain of myocilin (OLF) cause a gain-of-function, namely cytotoxic intracellular aggregation, which hastens disease progression. Aggregation by wild-type OLF (OLFWT) competes with its chemical unfolding, but only below the threshold where OLF loses tertiary structure. Representative moderate (OLFD380A) and severe (OLFI499F) disease variants aggregate differently, with rates comparable to OLFWT in initial stages of unfolding, and variants adopt distinct partially folded structures seen along the OLFWT urea-unfolding pathway. Whether initiated with mutation or chemical perturbation, unfolding propagates outward to the propeller surface. In sum, for this large protein prone to amyloid formation, the requirement for a conformational change to promote amyloid fibrillization leads to direct competition between unfolding and aggregation.
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Affiliation(s)
- Emily G Saccuzzo
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, USA
| | - Mubark D Mebrat
- Biodesign Center for Personalized Diagnostics, Arizona State University, Tempe, USA
- School of Molecular Sciences, Arizona State University, Tempe, USA
| | - Hailee F Scelsi
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, USA
| | - Minjoo Kim
- Biodesign Center for Personalized Diagnostics, Arizona State University, Tempe, USA
- School of Molecular Sciences, Arizona State University, Tempe, USA
| | - Minh Thu Ma
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, USA
| | - Xinya Su
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, USA
| | - Shannon E Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, USA
| | - Elisa Rheaume
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, USA
| | - Renhao Li
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta and Department of Pediatrics, Emory University School of Medicine, Atlanta, USA
| | - Matthew P Torres
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, USA
| | - James C Gumbart
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, USA
- School of Physics, Georgia Institute of Technology, Atlanta, USA
| | - Wade D Van Horn
- Biodesign Center for Personalized Diagnostics, Arizona State University, Tempe, USA.
- School of Molecular Sciences, Arizona State University, Tempe, USA.
| | - Raquel L Lieberman
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, USA.
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15
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Shiga Y, Hashimoto K, Fujita K, Maekawa S, Sato K, Kubo S, Kawase K, Tokumo K, Kiuchi Y, Mori S, Nakamura M, Iwata T, Nishiguchi KM, Nakazawa T. Identification of OPTN p.(Asn51Thr): A novel pathogenic variant in primary open-angle glaucoma. GENETICS IN MEDICINE OPEN 2023; 2:100839. [PMID: 39669598 PMCID: PMC11613796 DOI: 10.1016/j.gimo.2023.100839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 12/14/2024]
Abstract
Purpose Pathogenic variants in TBK1, MYOC, and OPTN are associated with primary open-angle glaucoma (POAG) with severe visual field defects. This study aims to understand further POAG-related pathogenic variant(s) based on a cohort of East Asian populations that have not been well-characterized. Methods We conducted a comprehensive screening of TBK1, MYOC, and OPTN variants in 174 POAG Japanese patients, followed by 8380 population-specific genome sequencing data references, segregation analysis, and functional protein assays to determine pathogenic variants. Results Despite the small sample size, 4 variants were novel, 2 of which p.(Cys5Trp) and p.(Thr293Met) were in the MYOC gene, and 2 p.(Asn51Thr), and p.(Gln142His) were in the OPTN. Notably, the OPTN p.(Asn51Thr) missense variant adjacent to the p.(Glu50Lys) variant, a well-known POAG pathogenic variant, was segregated from all proband's family members with POAG. Moreover, in silico and in vitro analyses revealed that the OPTN p.(Asn51Thr) protein increased binding instability, interactions of the OPTN-TBK1 complex, and enhanced protein insolubility, likewise the p.(Glu50Lys) protein. Conclusion Our findings may provide further genetic insights into rare variants of POAG and support the clear conclusion that OPTN p.(Asn51Thr) is a novel likely pathogenic variant.
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Affiliation(s)
- Yukihiro Shiga
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Neuroscience Division, Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
- Department of Neuroscience, Université de Montréal, Montréal, Québec, Canada
| | - Kazuki Hashimoto
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Kosuke Fujita
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Shigeto Maekawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Kota Sato
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Shintaroh Kubo
- Department of Anatomy and Cell Biology, McGill University, Montréal, Québec, Canada
- Department of Biological Science, Grad. Sch. of Sci, The University of Tokyo, Tokyo, Japan
| | - Kazuhide Kawase
- Yasuma Eye Clinic, Nagoya, Aichi, Japan
- Department of Ophthalmology Protective Care for Sensory Disorders, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Kana Tokumo
- Department of Ophthalmology and Visual Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Science, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Sotaro Mori
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Makoto Nakamura
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Koji M. Nishiguchi
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Toru Nakazawa
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Department of Advanced Ophthalmic Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- Department of Ophthalmic Imaging and Information Analytics, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
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16
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Saccuzzo EG, Youngblood HA, Lieberman RL. Myocilin misfolding and glaucoma: A 20-year update. Prog Retin Eye Res 2023; 95:101188. [PMID: 37217093 PMCID: PMC10330797 DOI: 10.1016/j.preteyeres.2023.101188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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 coiled-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 glaucoma-associated retinal degeneration. 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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17
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Scelsi HF, Hill KR, Barlow BM, Martin MD, Lieberman RL. Quantitative differentiation of benign and misfolded glaucoma-causing myocilin variants on the basis of protein thermal stability. Dis Model Mech 2023; 16:dmm049816. [PMID: 36579626 PMCID: PMC9844228 DOI: 10.1242/dmm.049816] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/28/2022] [Indexed: 12/30/2022] Open
Abstract
Accurate predictions of the pathogenicity of mutations associated with genetic diseases are key to the success of precision medicine. Inherited missense mutations in the myocilin (MYOC) gene, within its olfactomedin (OLF) domain, constitute the strongest genetic link to primary open-angle glaucoma via a toxic gain of function, and thus MYOC is an attractive precision-medicine target. However, not all mutations in MYOC cause glaucoma, and common variants are expected to be neutral polymorphisms. The Genome Aggregation Database (gnomAD) lists ∼100 missense variants documented within OLF, all of which are relatively rare (allele frequency <0.001%) and nearly all are of unknown pathogenicity. To distinguish disease-causing OLF variants from benign OLF variants, we first characterized the most prevalent population-based variants using a suite of cellular and biophysical assays, and identified two variants with features of aggregation-prone familial disease variants. Next, we considered all available biochemical and clinical data to demonstrate that pathogenic and benign variants can be differentiated statistically based on a single metric: the thermal stability of OLF. Our results motivate genotyping MYOC in patients for clinical monitoring of this widespread, painless and irreversible ocular disease.
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Affiliation(s)
- Hailee F. Scelsi
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA 30332-0400, USA
| | - Kamisha R. Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA 30332-0400, USA
| | - Brett M. Barlow
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA 30332-0400, USA
| | - Mackenzie D. Martin
- 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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18
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Adhikari B, Osmond MJ, Pantcheva MB, Krebs MD. Glycosaminoglycans Influence Extracellular Matrix of Human Trabecular Meshwork Cells Cultured on 3D Scaffolds. ACS Biomater Sci Eng 2022; 8:5221-5232. [PMID: 36384278 DOI: 10.1021/acsbiomaterials.2c00457] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Glaucoma is a multifactorial progressive optic neuropathy characterized by the loss of retinal ganglion cells leading to irreversible blindness. It is the leading cause of global irreversible blindness and is currently affecting over 70 million people. Elevated intraocular pressure (IOP) is considered the only modifiable risk factor and is a target of numerous treatment modalities. Researchers have assigned this elevation of IOP to accumulation of extracellular matrix (ECM) components in the aqueous humor (AH) outflow pathway. The major drainage structure for AH outflow is the trabecular meshwork (TM). The ECM of the TM is important in regulating IOP in both normal and glaucomatous eyes. In this work, we have studied the role of exogeneous glycosaminoglycans (GAGs), glucocorticoids, and culture conditions on the expression of the ECM gene and proteins by human TM (hTM) cells cultured on biomaterial scaffolds. Gene and protein expression levels of elastin, laminin, and matrix metalloproteinase-2 (MMP-2) were evaluated using quantitative PCR and immunohistochemistry. Pressure gradient changes in cell-laden scaffolds in perfusion cultures were also monitored. Our findings show that GAGs and dexamethasone play an influencing role in hTM ECM turnover at both transcriptional and translational levels by altering expression levels of elastin, laminin, and MMP-2. Understanding the role of exogeneous factors on hTM cell behavior is helpful in gaining insights on glaucoma pathogenesis and ultimately pivotal in development of novel therapeutics against the disease.
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Affiliation(s)
- Bikram Adhikari
- Quantitative Biosciences and Bioengineering, Colorado School of Mines, 1500 Illinois St., Golden, Colorado 80401, United States
| | - Matthew J Osmond
- Chemical and Biological Engineering, Colorado School of Mines, 1500 Illinois St., Golden, Colorado 80401, United States
| | - Mina B Pantcheva
- Ophthalmology, University of Colorado School of Medicine, 1675 Aurora Ct., Aurora, Colorado 80045, United States
| | - Melissa D Krebs
- Quantitative Biosciences and Bioengineering, Colorado School of Mines, 1500 Illinois St., Golden, Colorado 80401, United States.,Chemical and Biological Engineering, Colorado School of Mines, 1500 Illinois St., Golden, Colorado 80401, United States
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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: 1.7] [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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20
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El Helwe H, Samuel S, Gupta S, Neeson C, Chachanidze M, Solá-Del Valle DA. Case Report: Reversal and subsequent return of optic disc cupping in a myocilin (MYOC) gene-associated severe Juvenile Open-Angle Glaucoma (JOAG) patient. F1000Res 2022; 11:1361. [PMID: 38868171 PMCID: PMC11167334 DOI: 10.12688/f1000research.127871.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/11/2022] [Indexed: 06/14/2024] Open
Abstract
To our knowledge, this case report describes the first instance of reversal of glaucomatous optic nerve cupping in a young adult with a rare form of juvenile open-angle glaucoma (JOAG) associated with a novel variant of the myocilin gene (MYOC). This 25-year-old woman with severe-stage MYOC-associated JOAG presented with blurry vision and intermittent pain in her left eye. She had a strong family history of glaucoma in multiple first-degree relatives with an identified novel variant of MYOC. Examination revealed intraocular pressures (IOPs) of 10 mmHg OD and 46 mmHg OS, with cup-to-disc ratios of 0.90 and 0.80. The patient experienced substantial reversal of optic disc cupping OS following dramatic IOP reduction with trabeculectomy, and subsequently experienced a return of cupping after an IOP spike 15 months postoperatively. The reversal of cupping did not correspond to any changes in the patient's visual field. After an initial decrease in retinal nerve fiber layer (RNFL) thickness, RNFL remained stable for over 2 years after trabeculectomy as seen on Optical Coherence Tomography (OCT). This case suggests reversal of cupping can occur well into adulthood in a MYOC-associated JOAG patient, and it demonstrates the potential bidirectionality of this phenomenon. Moreover, it suggests that these structural changes may not correspond to any functional changes in visual fields or RNFL thickness.
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Affiliation(s)
- Hani El Helwe
- Glaucoma Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114, USA
- Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Sandy Samuel
- Glaucoma Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114, USA
- Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Sanchay Gupta
- Glaucoma Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114, USA
- Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Cameron Neeson
- Glaucoma Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114, USA
| | - Marika Chachanidze
- Glaucoma Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114, USA
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21
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CRISPR-Cas9 Technology for the Creation of Biological Avatars Capable of Modeling and Treating Pathologies: From Discovery to the Latest Improvements. Cells 2022; 11:cells11223615. [PMID: 36429042 PMCID: PMC9688409 DOI: 10.3390/cells11223615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/10/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022] Open
Abstract
This is a spectacular moment for genetics to evolve in genome editing, which encompasses the precise alteration of the cellular DNA sequences within various species. One of the most fascinating genome-editing technologies currently available is Clustered Regularly Interspaced Palindromic Repeats (CRISPR) and its associated protein 9 (CRISPR-Cas9), which have integrated deeply into the research field within a short period due to its effectiveness. It became a standard tool utilized in a broad spectrum of biological and therapeutic applications. Furthermore, reliable disease models are required to improve the quality of healthcare. CRISPR-Cas9 has the potential to diversify our knowledge in genetics by generating cellular models, which can mimic various human diseases to better understand the disease consequences and develop new treatments. Precision in genome editing offered by CRISPR-Cas9 is now paving the way for gene therapy to expand in clinical trials to treat several genetic diseases in a wide range of species. This review article will discuss genome-editing tools: CRISPR-Cas9, Zinc Finger Nucleases (ZFNs), and Transcription Activator-Like Effector Nucleases (TALENs). It will also encompass the importance of CRISPR-Cas9 technology in generating cellular disease models for novel therapeutics, its applications in gene therapy, and challenges with novel strategies to enhance its specificity.
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22
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Askari S, Azizi F, Javadpour P, Karimi N, Ghasemi R. Endoplasmic reticulum stress as an underlying factor in leading causes of blindness and potential therapeutic effects of 4-phenylbutyric acid: from bench to bedside. EXPERT REVIEW OF OPHTHALMOLOGY 2022. [DOI: 10.1080/17469899.2022.2145945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Sahar Askari
- Neuroscience Research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Azizi
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Pegah Javadpour
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nasser Karimi
- Eye and Skull Base Research Centers, The Five Senses Institute, Iran University of Medical Sciences, Tehran, Iran5Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rasoul Ghasemi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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23
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Sharma R, Kumari A, Kundu B, Grover A. Amyloid fibrillation of the glaucoma associated myocilin protein is inhibited by epicatechin gallate (ECG). RSC Adv 2022; 12:29469-29481. [PMID: 36320765 PMCID: PMC9562371 DOI: 10.1039/d2ra05061g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 09/18/2022] [Indexed: 11/05/2022] Open
Abstract
Inherited glaucoma is a recent addition to the inventory of diseases arising due to protein misfolding. Mutations in the olfactomedin (OLF) domain of myocilin are the most common genetic cause behind this disease. Disease associated variants of m-OLF are predisposed to misfold and aggregate in the trabecular meshwork (TM) tissue of the eye. In recent years, the nature of these aggregates was revealed to exhibit the hallmarks of amyloids. Amyloid aggregates are highly stable structures that are formed, often with toxic consequences in a number of debilitating diseases. In spite of its clinical relevance the amyloidogenic nature of m-OLF has not been studied adequately. Here we have studied the amyloid fibrillation of m-OLF and report ECG as an inhibitor against it. Using biophysical and biochemical assays, coupled with advanced microscopic evaluations we show that ECG binds and stabilizes native m-OLF and thus prevents its aggregation into amyloid fibrils. Furthermore, we have used REMD simulations to delineate the stabilizing effects of ECG on the structure of m-OLF. Collectively, we report ECG as a molecular scaffold for designing and testing of novel inhibitors against m-OLF amyloid fibrillation.
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Affiliation(s)
- Ritika Sharma
- School of Biotechnology, Jawaharlal Nehru UniversityNew Delhi-110067India+91-8130738032
| | - Anchala Kumari
- Indian Council of Medical Research, International Health DivisionNew Delhi-110029India
| | - Bishwajit Kundu
- Kusuma School of Biological Sciences, Indian Institute of Technology DelhiHauz KhasNew DelhiIndia – 110016
| | - Abhinav Grover
- School of Biotechnology, Jawaharlal Nehru UniversityNew Delhi-110067India+91-8130738032
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24
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Saccuzzo EG, Martin MD, Hill KR, Ma MT, Ku Y, Lieberman RL. Calcium dysregulation potentiates wild-type myocilin misfolding: implications for glaucoma pathogenesis. J Biol Inorg Chem 2022; 27:553-564. [PMID: 35831671 PMCID: PMC10085244 DOI: 10.1007/s00775-022-01946-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/02/2022] [Indexed: 10/17/2022]
Abstract
Myocilin is secreted from trabecular meshwork cells to an eponymous extracellular matrix that is critical for maintaining intraocular pressure. Missense mutations found in the myocilin olfactomedin domain (OLF) lead to intracellular myocilin misfolding and are causative for the heritable form of early-onset glaucoma. The OLF domain contains a unique internal, hetero-dinuclear calcium site. Here, we tested the hypothesis that calcium dysregulation causes wild-type (WT) myocilin misfolding reminiscent of that observed for disease variants. Using two cellular models expressing WT myocilin, we show that the Ca2+ ATPase channel blocker thapsigargin inhibits WT myocilin secretion. Intracellular WT myocilin is at least partly insoluble and aggregated in the endoplasmic reticulum (ER), and stains positively with an amyloid dye. By comparing the effect of thapsigargin on WT myocilin to that on a de novo secretion-competent Ca2+-free variant D478S, we discern that non-secretion of WT myocilin is due initially to calcium dysregulation, and is potentiated further by resultant ER stress. In E. coli, depletion of calcium leads to recombinant expression of misfolded isolated WT OLF but the D478S variant is still produced as a folded monomer. Treatment of cells expressing a double mutant composed of D478S and either disease variants P370L or Y437H with thapsigargin promotes its misfolding and aggregation, demonstrating the limits of D478S to correct secretion defects. Taken together, the heterodinuclear calcium site is a liability for proper folding of myocilin. Our study suggests a molecular mechanism by which WT myocilin misfolding may contribute broadly to glaucoma-associated ER stress. This study explores the effect of calcium depletion on myocilin olfactomedin domain folding.
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Affiliation(s)
- Emily G Saccuzzo
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA
| | - Mackenzie D Martin
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA
| | - Kamisha R Hill
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA
| | - Minh Thu Ma
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA
| | - Yemo Ku
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA
| | - Raquel L Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr. NW, Atlanta, GA, 30332-0400, USA.
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25
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Wilson MR, Satapathy S, Jeong S, Fini ME. Clusterin, other extracellular chaperones, and eye disease. Prog Retin Eye Res 2022; 89:101032. [PMID: 34896599 PMCID: PMC9184305 DOI: 10.1016/j.preteyeres.2021.101032] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 11/30/2021] [Accepted: 11/30/2021] [Indexed: 12/15/2022]
Abstract
Proteostasis refers to all the processes that maintain the correct expression level, location, folding and turnover of proteins, essential to organismal survival. Both inside cells and in body fluids, molecular chaperones play key roles in maintaining proteostasis. In this article, we focus on clusterin, the first-recognized extracellular mammalian chaperone, and its role in diseases of the eye. Clusterin binds to and inhibits the aggregation of proteins that are misfolded due to mutations or stresses, clears these aggregating proteins from extracellular spaces, and facilitates their degradation. Clusterin exhibits three main homeostatic activities: proteostasis, cytoprotection, and anti-inflammation. The so-called "protein misfolding diseases" are caused by aggregation of misfolded proteins that accumulate pathologically as deposits in tissues; we discuss several such diseases that occur in the eye. Clusterin is typically found in these deposits, which is interpreted to mean that its capacity as a molecular chaperone to maintain proteostasis is overwhelmed in the disease state. Nevertheless, the role of clusterin in diseases involving such deposits needs to be better defined before therapeutic approaches can be entertained. A more straightforward case can be made for therapeutic use of clusterin based on its proteostatic role as a proteinase inhibitor, as well as its cytoprotective and anti-inflammatory properties. It is likely that clusterin works together in this way with other extracellular chaperones to protect the eye from disease, and we discuss several examples. We end this article by predicting future steps that may lead to development of clusterin as a biological drug.
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Affiliation(s)
- Mark R Wilson
- Molecular Horizons and the School of Chemistry and Molecular Bioscience, University of Wollongong; Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, New South Wales, 2522, Australia.
| | - Sandeep Satapathy
- Molecular Horizons and the School of Chemistry and Molecular Bioscience, University of Wollongong; Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, New South Wales, 2522, Australia.
| | - Shinwu Jeong
- USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 1333 San Pablo Street., Los Angeles, CA, 90033, USA.
| | - M Elizabeth Fini
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine; Program in Pharmacology & Drug Development, Graduate School of Biomedical Sciences, Tufts University, 800 Washington St, Boston, MA, 02111, USA.
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26
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Combined Therapy Using Human Corneal Stromal Stem Cells and Quiescent Keratocytes to Prevent Corneal Scarring after Injury. Int J Mol Sci 2022; 23:ijms23136980. [PMID: 35805991 PMCID: PMC9267074 DOI: 10.3390/ijms23136980] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/18/2022] [Accepted: 06/21/2022] [Indexed: 02/04/2023] Open
Abstract
Corneal blindness due to scarring is conventionally treated by corneal transplantation, but the shortage of donor materials has been a major issue affecting the global success of treatment. Pre-clinical and clinical studies have shown that cell-based therapies using either corneal stromal stem cells (CSSC) or corneal stromal keratocytes (CSK) suppress corneal scarring at lower levels. Further treatments or strategies are required to improve the treatment efficacy. This study examined a combined cell-based treatment using CSSC and CSK in a mouse model of anterior stromal injury. We hypothesize that the immuno-regulatory nature of CSSC is effective to control tissue inflammation and delay the onset of fibrosis, and a subsequent intrastromal CSK treatment deposited collagens and stromal specific proteoglycans to recover a native stromal matrix. Using optimized cell doses, our results showed that the effect of CSSC treatment for suppressing corneal opacities was augmented by an additional intrastromal CSK injection, resulting in better corneal clarity. These in vivo effects were substantiated by a further downregulated expression of stromal fibrosis genes and the restoration of stromal fibrillar organization and regularity. Hence, a combined treatment of CSSC and CSK could achieve a higher clinical efficacy and restore corneal transparency, when compared to a single CSSC treatment.
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27
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Collantes ERA, Delfin MS, Fan B, Torregosa JMR, Siguan-Bell C, de Guzman Florcruz NV, Martinez JMD, Masna-Hidalgo BJ, Guzman VPT, Anotado-Flores JF, Levina FD, Hernandez SRC, Collantes AA, Sibulo MC, Rong S, Wiggs JL. EFEMP1 rare variants cause familial juvenile-onset open-angle glaucoma. Hum Mutat 2022; 43:240-252. [PMID: 34923728 PMCID: PMC8972201 DOI: 10.1002/humu.24320] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 12/02/2021] [Accepted: 12/15/2021] [Indexed: 02/03/2023]
Abstract
Juvenile open-angle glaucoma (JOAG) is a severe type of glaucoma with onset before age 40 and dominant inheritance. Using exome sequencing we identified 3 independent families from the Philippines with novel EFEMP1 variants (c.238A>T, p.Asn80Tyr; c.1480T>C, p.Ter494Glnext*29; and c.1429C>T, p.Arg477Cys) co-segregating with disease. Affected variant carriers (N = 34) exhibited severe disease with average age of onset of 16 years and with 76% developing blindness. To investigate functional effects, we transfected COS7 cells with vectors expressing the three novel EFEMP1 variants and showed that all three variants found in JOAG patients caused significant intracellular protein aggregation and retention compared to wild type and also compared to EFEMP1 variants associated with other ocular phenotypes including an early-onset form of macular degeneration, Malattia Leventinese/Doyne's Honeycomb retinal dystrophy. These results suggest that rare EFEMP1 coding variants can cause JOAG through a mechanism involving protein aggregation and retention, and that the extent of intracellular retention correlates with disease phenotype. This is the first report of EFEMP1 variants causing JOAG, expanding the EFEMP1 disease spectrum. Our results suggest that EFEMP1 mutations appear to be a relatively common cause of JOAG in Filipino families, an ethnically diverse population.
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Affiliation(s)
- Edward Ryan A. Collantes
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
- Department of Ophthalmology, Manila Doctors Hospital, Manila, Philippines
| | - Manuel S. Delfin
- Department of Ophthalmology, Manila Doctors Hospital, Manila, Philippines
| | - Baojian Fan
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
| | - Justine May R. Torregosa
- Department of Ophthalmology, Cebu Institute of Medicine, Cebu Velez General Hospital, Cebu City, Philippines
| | - Christine Siguan-Bell
- Department of Ophthalmology, Cebu Institute of Medicine, Cebu Velez General Hospital, Cebu City, Philippines
| | - Nilo Vincent de Guzman Florcruz
- Department of Ophthalmology and Visual Sciences, University of the Philippines-Philippine General Hospital, Manila, Philippines
- Glaucoma Service, Department of Ophthalmology, East Avenue Medical Center, Quezon City, Philippines
| | - Jose Maria D. Martinez
- Glaucoma Service, Department of Ophthalmology, East Avenue Medical Center, Quezon City, Philippines
| | | | | | | | - Faye D. Levina
- Department of Ophthalmology, Jose R. Reyes Memorial Medical Center, Manila, Philippines
| | | | | | | | - Shisong Rong
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
| | - Janey L. Wiggs
- Harvard Medical School Department of Ophthalmology, Massachusetts Eye and Ear, Boston, USA
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28
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Riau AK, Boey KPY, Binte M Yusoff NZ, Goh TW, Yam GHF, Tang KF, Phua CSH, Chen HJ, Chiew YF, Liu YC, Mehta JS. Experiment-Based Validation of Corneal Lenticule Banking in a Health Authority-Licensed Facility. Tissue Eng Part A 2021; 28:69-83. [PMID: 34128385 DOI: 10.1089/ten.tea.2021.0042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
With the expected rise in patients undergoing refractive lenticule extraction worldwide, the number of discarded corneal stromal lenticules will increase. Therefore, establishing a lenticule bank to collect, catalog, process, cryopreserve, and distribute the lenticules (for future therapeutic needs) could be advantageous. In this study, we validated the safety of lenticule banking that involved the collection of human lenticules from our eye clinic, transportation of the lenticules to a Singapore Ministry of Health-licensed lenticule bank, processing, and cryopreservation of the lenticules, which, after 3 months or, a longer term, 12 months, were retrieved and transported to our laboratory for implantation in rabbit corneas. The lenticule collection was approved by the SingHealth Centralised Institutional Review Board (CIRB). Both short-term and long-term cryopreserved lenticules, although not as transparent as fresh lenticules due to an altered collagen fibrillar packing, did not show any sign of rejection and cytotoxicity, and did not induce haze or neovascularization for 16 weeks even when antibiotic and steroidal administration were withdrawn after 8 weeks. The lenticular transparency progressively improved and was mostly clear after 4 weeks, the same period when we observed the stabilization of corneal hydration. We showed that the equalization of the collagen fibrillar packing of the lenticules with that of the host corneal stroma contributed to the lenticular haze clearance. Most importantly, no active wound healing and inflammatory reactions were seen after 16 weeks. Our study suggests that long-term lenticule banking is a feasible approach for the storage of stromal lenticules after refractive surgery.
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Affiliation(s)
- Andri K Riau
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Kenny P Y Boey
- Group Laboratory Operations, Cordlife Group Limited, Singapore, Singapore
| | | | - Tze-Wei Goh
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Gary H F Yam
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kin F Tang
- Group Laboratory Operations, Cordlife Group Limited, Singapore, Singapore.,Singapore Laboratory, Cordlife Group Limited, Singapore, Singapore
| | | | - Hui-Jun Chen
- Singapore Laboratory, Cordlife Group Limited, Singapore, Singapore
| | - Yoke F Chiew
- Singapore Laboratory, Cordlife Group Limited, Singapore, Singapore
| | - Yu-Chi Liu
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore.,Corneal and External Eye Disease Department, Singapore National Eye Centre, Singapore, Singapore
| | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore.,Corneal and External Eye Disease Department, Singapore National Eye Centre, Singapore, Singapore
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29
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Sharma R, Grover A. Myocilin-associated Glaucoma: A Historical Perspective and Recent Research Progress. Mol Vis 2021; 27:480-493. [PMID: 34497454 PMCID: PMC8403517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/18/2021] [Indexed: 10/29/2022] Open
Abstract
Glaucoma a debilitating disease, is globally the second most common kind of permanent blindness. Primary open-angle glaucoma (POAG) is its most prevalent form and is often linked with alterations in the myocilin gene (MYOC). MYOC encodes the myocilin protein, which is expressed throughout the body, but primarily in trabecular meshwork (TM) tissue in the eyes. TM is principally involved in regulating intraocular pressure (IOP), and elevated IOP is the main risk factor associated with glaucoma. The myocilin protein's function remains unknown; however, mutations compromise its folding and processing inside TM cells, contributing to the glaucoma phenotype. While glaucoma is a complex disease with various molecules and factors as contributing causes, the role played by myocilin has been the most widely studied. The current review describes the present understanding of myocilin and its association with glaucoma and aims to shift the focus toward developing targeted therapies for treating glaucoma patients with variations in MYOC.
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30
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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: 2.8] [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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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: 13] [Impact Index Per Article: 3.3] [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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Rozpędek-Kamińska W, Galita G, Siwecka N, Carroll SL, Diehl JA, Kucharska E, Pytel D, Majsterek I. The Potential Role of Small-Molecule PERK Inhibitor LDN-0060609 in Primary Open-Angle Glaucoma Treatment. Int J Mol Sci 2021; 22:ijms22094494. [PMID: 33925820 PMCID: PMC8123501 DOI: 10.3390/ijms22094494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 04/23/2021] [Accepted: 04/24/2021] [Indexed: 01/13/2023] Open
Abstract
Primary open-angle glaucoma (POAG) constitutes the most common type of glaucoma. Emerging evidence suggests that Endoplasmic Reticulum (ER) stress and the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-mediated Unfolded Protein Response (UPR) signaling pathway play a key role in POAG pathogenesis. Thus, the main aim of the study was to evaluate the effectiveness of the PERK inhibitor LDN-0060609 in cellular model of glaucoma using primary human trabecular meshwork (HTM) cells. To evaluate the level of the ER stress marker proteins, Western blotting and TaqMan gene expression assay were used. The cytotoxicity was measured by XTT, LDH assays and Giemsa staining, whereas genotoxicity via comet assay. Changes in cell morphology were assessed by phase-contrast microscopy. Analysis of apoptosis was performed by caspase-3 assay and flow cytometry (FC), whereas cell cycle progression by FC. The results obtained have demonstrated that LDN-0060609 triggered a significant decrease of ER stress marker proteins within HTM cells with induced ER stress conditions. Moreover, LDN-0060609 effectively increased viability, reduced DNA damage, increased proliferation, restored normal morphology, reduced apoptosis and restored normal cell cycle distribution of HTM cells with induced ER stress conditions. Thereby, PERK inhibitors, such as LDN-0060609, may provide an innovative, ground-breaking treatment strategy against POAG.
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Affiliation(s)
- Wioletta Rozpędek-Kamińska
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
| | - Grzegorz Galita
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
| | - Natalia Siwecka
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
| | - Steven L. Carroll
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA;
| | - John Alan Diehl
- Hollings Cancer Center, Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA;
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ewa Kucharska
- Department of Gerontology, Geriatrics and Social Work, Jesuit University Ignatianum, 31-501 Krakow, Poland;
| | - Dariusz Pytel
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
- Hollings Cancer Center, Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA;
- Correspondence: (D.P.); (I.M.); Tel.: +48-42-272-53-00 (D.P. & I.M.)
| | - Ireneusz Majsterek
- Department of Clinical Chemistry and Biochemistry, Medical University of Lodz, 90-419 Lodz, Poland; (W.R.-K.); (G.G.); (N.S.)
- Correspondence: (D.P.); (I.M.); Tel.: +48-42-272-53-00 (D.P. & I.M.)
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Gao Y, Saccuzzo EG, Hill SE, Huard DJE, Robang AS, Lieberman RL, Paravastu AK. Structural Arrangement within a Peptide Fibril Derived from the Glaucoma-Associated Myocilin Olfactomedin Domain. J Phys Chem B 2021; 125:2886-2897. [PMID: 33683890 DOI: 10.1021/acs.jpcb.0c11460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Myocilin-associated glaucoma is a new addition to the list of diseases linked to protein misfolding and amyloid formation. Single point variants of the ∼257-residue myocilin olfactomedin domain (mOLF) lead to mutant myocilin aggregation. Here, we analyze the 12-residue peptide P1 (GAVVYSGSLYFQ), corresponding to residues 326-337 of mOLF, previously shown to form amyloid fibrils in vitro and in silico. We applied solid-state NMR structural measurements to test the hypothesis that P1 fibrils adopt one of three predicted structures. Our data are consistent with a U-shaped fibril arrangement for P1, one that is related to the U-shape predicted previously in silico. Our data are also consistent with an antiparallel fibril arrangement, likely driven by terminal electrostatics. Our proposed structural model is reminiscent of fibrils formed by the Aβ(1-40) Iowa mutant peptide, but with a different arrangement of molecular turn regions. Taken together, our results strengthen the connection between mOLF fibrils and the broader amylome and contribute to our understanding of the fundamental molecular interactions governing fibril architecture and stability.
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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: 34] [Impact Index Per Article: 8.5] [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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Cring MR, Sheffield VC. Gene therapy and gene correction: targets, progress, and challenges for treating human diseases. Gene Ther 2020; 29:3-12. [PMID: 33037407 DOI: 10.1038/s41434-020-00197-8] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/24/2020] [Accepted: 09/21/2020] [Indexed: 12/28/2022]
Abstract
The field of gene therapy has made significant strides over the last several decades toward the treatment of previously untreatable genetic disease. Gene therapy techniques have been aimed at mitigating disease features of recessive and dominant disorders, as well as several cancers and other diseases. While there have been numerous disease targets of gene therapy trials, only four therapies have reached FDA and/or EMA approval for clinical use. Gene correction using CRISPR-Cas9 is an extension of gene therapy that has received considerable attention in recent years and boasts many possible uses beyond classical gene therapy approaches. While there is significant therapeutic potential using gene therapy and gene correction strategies, a number of hurdles remain to be overcome before they become more common in clinical use, particularly with regards to safety and efficacy. As research progresses in this exciting field, it is likely that these therapies will become first-line treatments and will have tremendous positive impacts on the lives of patients with genetic disorders.
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Affiliation(s)
- Matthew R Cring
- Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa, Iowa City, IA, USA.,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
| | - Val C Sheffield
- Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa, Iowa City, IA, USA. .,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA.
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36
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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: 71] [Impact Index Per Article: 14.2] [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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Buffault J, Labbé A, Hamard P, Brignole-Baudouin F, Baudouin C. [The trabecular meshwork: Structure, function and clinical implications. A review of the littérature (French translation of the article)]. J Fr Ophtalmol 2020; 43:779-793. [PMID: 32807552 DOI: 10.1016/j.jfo.2020.04.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 11/26/2022]
Abstract
Glaucoma is a blinding optic neuropathy, the main risk factor for which is increased intraocular pressure (IOP). The trabecular meshwork, located within the iridocorneal angle, is the main pathway for drainage of aqueous humor (AH) out of the eye, and its dysfunction is responsible for the IOP elevation. The trabecular meshwork is a complex, fenestrated, three-dimensional structure composed of trabecular meshwork cells (TMC) interdigitated into a multilayered organization within the extracellular matrix (ECM). The purpose of this literature review is to provide an overview of current understanding of the trabecular meshwork and its pathophysiology in glaucoma. Thus, we will present the main anatomical and cellular bases for the regulation of aqueous humor outflow resistance, the pathophysiological mechanisms involved in trabecular dysfunction in the various types of glaucoma, as well as current and future therapeutic strategies targeting the trabecular meshwork.
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Affiliation(s)
- J Buffault
- Service d'ophtalmologie, centre hospitalier national d'ophtalmologie des Quinze-Vingts, IHU FOReSIGHT, 28, rue de Charenton, 75012 Paris, France.
| | - A Labbé
- Service d'ophtalmologie, centre hospitalier national d'ophtalmologie des Quinze-Vingts, IHU FOReSIGHT, 28, rue de Charenton, 75012 Paris, France; Service d'ophtalmologie, hôpital Ambroise-Paré, AP-HP, 9, avenue Charles-de-Gaulle, 92100 Boulogne-Billancourt, France; Inserm, CNRS, institut de la vision, Sorbonne université, 17, rue Moreau, 75012 Paris, France
| | - P Hamard
- Service d'ophtalmologie, centre hospitalier national d'ophtalmologie des Quinze-Vingts, IHU FOReSIGHT, 28, rue de Charenton, 75012 Paris, France
| | - F Brignole-Baudouin
- Inserm, CNRS, institut de la vision, Sorbonne université, 17, rue Moreau, 75012 Paris, France; Service de biologie médicale, centre hospitalier national d'ophtalmologie des Quinze-Vingts, IHU FOReSIGHT, 28, rue de Charenton, 75012 Paris, France
| | - C Baudouin
- Service d'ophtalmologie, centre hospitalier national d'ophtalmologie des Quinze-Vingts, IHU FOReSIGHT, 28, rue de Charenton, 75012 Paris, France; Service d'ophtalmologie, hôpital Ambroise-Paré, AP-HP, 9, avenue Charles-de-Gaulle, 92100 Boulogne-Billancourt, France; Inserm, CNRS, institut de la vision, Sorbonne université, 17, rue Moreau, 75012 Paris, France
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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: 6] [Impact Index Per Article: 1.2] [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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Yan X, Wu S, Liu Q, Li Y, Zhu W, Zhang J. Accumulation of Asn450Tyr mutant myocilin in ER promotes apoptosis of human trabecular meshwork cells. Mol Vis 2020; 26:563-573. [PMID: 32818018 PMCID: PMC7406863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 07/27/2020] [Indexed: 11/30/2022] Open
Abstract
PURPOSE In a previous study, we identified the Asn450Tyr mutant myocilin gene (Myoc-N450Y) in the pedigree of families with juvenile open angle glaucoma (JOAG), but whether N450Y is a pathogenic mutation remained to be determined. The present study aimed at exploring the role of Myoc-N450Y in primary human trabecular meshwork (HTM) cells. METHODS Primary HTM cells were infected with lentivirus with wild-type myocilin (Myoc-WT) or Myoc-N450Y. Primary HTM cells overexpressing Myoc-WT or Myoc-N450Y was treated with sodium 4-phenylbutyrate (4-PBA) or not. The secretion and intracellular distribution of Myoc were analyzed with western blotting and immunofluorescence. Expression of endoplasmic reticulum (ER) stress-related proteins was detected with quantitative real-time PCR (qRT-PCR) and western blotting. Cell viability, apoptosis, and expression of the related proteins were examined with Cell Counting Kit-8 (CCK-8), flow cytometry analysis, and western blotting, respectively. RESULTS We found that non-secretion of Myoc-N450Y induced ER stress by colocalization with the ER marker calreticulin (CALR), and upregulating the expression of ER stress markers in primary HTM cells. Moreover, overexpression of Myoc-N450Y inhibited the viability and induced apoptosis of primary HTM cells, and inhibition of PI3K/AKT signaling was induced by ER stress. Reduction in ER stress with 4-PBA decreased the level of ER stress markers, promoted secretion, and prevented accumulation of myocilin in the Myoc-N450Y group. Apoptosis was rescued, and inhibition of PI3K/AKT signaling was reversed, after PBA treatment in primary HTM cells with Myoc-N450Y overexpression. CONCLUSIONS The study results suggest that Myoc-N450Y promotes apoptosis of primary HTM cells via the ER stress-induced apoptosis pathway, in which the PI3K/AKT signaling pathway plays a crucial role.
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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, China
| | - Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Qian Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Yang Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Wei Zhu
- Department of Pharmacology, Qingdao University School of Pharmacy, Qingdao, China
| | - Jingxue Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
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40
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The trabecular meshwork: Structure, function and clinical implications. A review of the literature. J Fr Ophtalmol 2020; 43:e217-e230. [PMID: 32561029 DOI: 10.1016/j.jfo.2020.05.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/25/2020] [Accepted: 05/27/2020] [Indexed: 02/06/2023]
Abstract
Glaucoma is a blinding optic neuropathy, the main risk factor for which is increased intraocular pressure (IOP). The trabecular meshwork, located within the iridocorneal angle, is the main pathway for drainage of aqueous humor (AH) out of the eye, and its dysfunction is responsible for the IOP elevation. The trabecular meshwork is a complex, fenestrated, three-dimensional structure composed of trabecular meshwork cells (TMC) interdigitated into a multilayered organization within the extracellular matrix (ECM). The purpose of this literature review is to provide an overview of current understanding of the trabecular meshwork and its pathophysiology in glaucoma. Thus, we will present the main anatomical and cellular bases for the regulation of aqueous humor outflow resistance, the pathophysiological mechanisms involved in trabecular dysfunction in the various types of glaucoma, as well as current and future therapeutic strategies targeting the trabecular meshwork.
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41
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Judge SM, Deyhle MR, Neyroud D, Nosacka RL, D'Lugos AC, Cameron ME, Vohra RS, Smuder AJ, Roberts BM, Callaway CS, Underwood PW, Chrzanowski SM, Batra A, Murphy ME, Heaven JD, Walter GA, Trevino JG, Judge AR. MEF2c-Dependent Downregulation of Myocilin Mediates Cancer-Induced Muscle Wasting and Associates with Cachexia in Patients with Cancer. Cancer Res 2020; 80:1861-1874. [PMID: 32132110 DOI: 10.1158/0008-5472.can-19-1558] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 11/27/2019] [Accepted: 02/24/2020] [Indexed: 12/27/2022]
Abstract
Skeletal muscle wasting is a devastating consequence of cancer that contributes to increased complications and poor survival, but is not well understood at the molecular level. Herein, we investigated the role of Myocilin (Myoc), a skeletal muscle hypertrophy-promoting protein that we showed is downregulated in multiple mouse models of cancer cachexia. Loss of Myoc alone was sufficient to induce phenotypes identified in mouse models of cancer cachexia, including muscle fiber atrophy, sarcolemmal fragility, and impaired muscle regeneration. By 18 months of age, mice deficient in Myoc showed significant skeletal muscle remodeling, characterized by increased fat and collagen deposition compared with wild-type mice, thus also supporting Myoc as a regulator of muscle quality. In cancer cachexia models, maintaining skeletal muscle expression of Myoc significantly attenuated muscle loss, while mice lacking Myoc showed enhanced muscle wasting. Furthermore, we identified the myocyte enhancer factor 2 C (MEF2C) transcription factor as a key upstream activator of Myoc whose gain of function significantly deterred cancer-induced muscle wasting and dysfunction in a preclinical model of pancreatic ductal adenocarcinoma (PDAC). Finally, compared with noncancer control patients, MYOC was significantly reduced in skeletal muscle of patients with PDAC defined as cachectic and correlated with MEF2c. These data therefore identify disruptions in MEF2c-dependent transcription of Myoc as a novel mechanism of cancer-associated muscle wasting that is similarly disrupted in muscle of patients with cachectic cancer. SIGNIFICANCE: This work identifies a novel transcriptional mechanism that mediates skeletal muscle wasting in murine models of cancer cachexia that is disrupted in skeletal muscle of patients with cancer exhibiting cachexia.
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Affiliation(s)
- Sarah M Judge
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida.
| | - Michael R Deyhle
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Daria Neyroud
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Rachel L Nosacka
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Andrew C D'Lugos
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Miles E Cameron
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida.,Department of Surgery, University of Florida Health Science Center, Gainesville, Florida
| | - Ravneet S Vohra
- Department of Physiology, College of Medicine, University of Florida Health Science Center, Gainesville, Florida
| | - Ashley J Smuder
- Department of Health and Human Performance, University of Florida, Gainesville, Florida
| | - Brandon M Roberts
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Chandler S Callaway
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Patrick W Underwood
- Department of Surgery, University of Florida Health Science Center, Gainesville, Florida
| | - Stephen M Chrzanowski
- Department of Physiology, College of Medicine, University of Florida Health Science Center, Gainesville, Florida
| | - Abhinandan Batra
- Department of Physiology, College of Medicine, University of Florida Health Science Center, Gainesville, Florida
| | - Meghan E Murphy
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Jonathan D Heaven
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida
| | - Glenn A Walter
- Department of Physiology, College of Medicine, University of Florida Health Science Center, Gainesville, Florida
| | - Jose G Trevino
- Department of Surgery, University of Florida Health Science Center, Gainesville, Florida
| | - Andrew R Judge
- Department of Physical Therapy, University of Florida Health Science Center, Gainesville, Florida.
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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: 18] [Impact Index Per Article: 3.6] [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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43
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Li H, Yang Y, Hong W, Huang M, Wu M, Zhao X. Applications of genome editing technology in the targeted therapy of human diseases: mechanisms, advances and prospects. Signal Transduct Target Ther 2020; 5:1. [PMID: 32296011 PMCID: PMC6946647 DOI: 10.1038/s41392-019-0089-y] [Citation(s) in RCA: 1063] [Impact Index Per Article: 212.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 09/21/2019] [Accepted: 09/21/2019] [Indexed: 02/06/2023] Open
Abstract
Based on engineered or bacterial nucleases, the development of genome editing technologies has opened up the possibility of directly targeting and modifying genomic sequences in almost all eukaryotic cells. Genome editing has extended our ability to elucidate the contribution of genetics to disease by promoting the creation of more accurate cellular and animal models of pathological processes and has begun to show extraordinary potential in a variety of fields, ranging from basic research to applied biotechnology and biomedical research. Recent progress in developing programmable nucleases, such as zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeat (CRISPR)-Cas-associated nucleases, has greatly expedited the progress of gene editing from concept to clinical practice. Here, we review recent advances of the three major genome editing technologies (ZFNs, TALENs, and CRISPR/Cas9) and discuss the applications of their derivative reagents as gene editing tools in various human diseases and potential future therapies, focusing on eukaryotic cells and animal models. Finally, we provide an overview of the clinical trials applying genome editing platforms for disease treatment and some of the challenges in the implementation of this technology.
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Affiliation(s)
- Hongyi Li
- Department of Gynecology and Obstetrics, Development and Related Disease of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second Hospital, Sichuan University, Chengdu, 610041, P. R. China
| | - Yang Yang
- Department of Gynecology and Obstetrics, Development and Related Disease of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second Hospital, Sichuan University, Chengdu, 610041, P. R. China
| | - Weiqi Hong
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P. R. China
| | - Mengyuan Huang
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Chengdu, Sichuan, 610041, P. R. China
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58203, USA.
| | - Xia Zhao
- Department of Gynecology and Obstetrics, Development and Related Disease of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second Hospital, Sichuan University, Chengdu, 610041, P. R. China.
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44
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Different Grp94 components interact transiently with the myocilin olfactomedin domain in vitro to enhance or retard its amyloid aggregation. Sci Rep 2019; 9:12769. [PMID: 31484937 PMCID: PMC6726633 DOI: 10.1038/s41598-019-48751-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 08/07/2019] [Indexed: 01/04/2023] Open
Abstract
The inherited form of open angle glaucoma arises due to a toxic gain-of-function intracellular misfolding event involving a mutated myocilin olfactomedin domain (OLF). Mutant myocilin is recognized by the endoplasmic reticulum (ER)-resident heat shock protein 90 paralog, glucose regulated protein 94 (Grp94), but their co-aggregation precludes mutant myocilin clearance by ER-associated degradation. When the Grp94-mutant myocilin interaction is abrogated by inhibitors or siRNA, mutant myocilin is efficiently degraded. Here we dissected Grp94 into component domains (N, NM, MC) to better understand the molecular factors governing its interaction with OLF. We show that the Grp94 N-terminal nucleotide-binding N domain is responsible for accelerating OLF aggregation in vitro. Upon inhibiting the isolated N domain pharmacologically or removing the Pre-N terminal 57 residues from full-length Grp94, OLF aggregation rates revert to those seen for OLF alone, but only pharmacological inhibition rescues co-aggregation. The Grp94-OLF interaction is below the detection limit of fluorescence polarization measurements, but chemical crosslinking paired with mass spectrometry analyses traps a reproducible interaction between OLF and the Grp94 N domain, as well as between OLF and the Grp94 M domain. The emerging molecular-level picture of quinary interactions between Grp94 and myocilin points to a role for the far N-terminal sequence of the Grp94 N domain and a cleft in the M domain. Our work further supports drug discovery efforts to inhibit these interactions as a strategy to treat myocilin-associated glaucoma.
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45
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Patterson-Orazem AC, Lieberman RL. Antibodies Used to Detect Glaucoma-Associated Myocilin: More or Less Than Meets the Eye? Invest Ophthalmol Vis Sci 2019; 60:2034-2037. [PMID: 31067323 PMCID: PMC6890424 DOI: 10.1167/iovs.19-26843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Antibodies are key reagents used in vision research, indeed across biomedical research, but they often do not reveal the whole story about a sample. It is important for researchers to be aware of aspects of antibodies that may affect or limit data interpretation. Federal agencies now require funded grants to demonstrate how they will authenticate reagents used. There is also a push for recombinant antibodies, enabled by phage display technology awarded the 2018 Nobel Prize in Chemistry, which allow for thorough validation and a fixed DNA sequence. Here, we discuss how issues surrounding antibodies are pertinent to detecting myocilin, a protein found in trabecular meshwork and associated with a portion of hereditary glaucoma. Confirmation of myocilin expression in tissues and cell culture has been adopted as validation standard in trabecular meshwork research; thus, a discussion of antibody characteristics and fidelity is critical. Further, based on our basic structural understanding of myocilin architecture and its biophysical aggregation properties, we provide a wish list for the characteristics of next-generation antibody reagents for vision researchers. In the long term, well-characterized antibodies targeting myocilin will enable new insights into its function and involvement in glaucoma pathogenesis.
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Affiliation(s)
- Athéna C Patterson-Orazem
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Raquel L Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
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46
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Wang KJ, Da Wang J, Chen DD, Wang MY, Yun B, Zhu SQ. Characterization of a p.R76H mutation in Cx50 identified in a Chinese family with congenital nuclear cataract. J Formos Med Assoc 2019; 119:144-149. [PMID: 30928190 DOI: 10.1016/j.jfma.2019.02.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 09/02/2018] [Accepted: 02/25/2019] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND/PURPOSE A three-generation Chinese family with autosomal dominant congenital nuclear cataract was recruited. This study aimed to identify the disease-causing gene for nuclear cataract with functional dissections of the identified mutant. METHODS Detailed clinical data and family history were recorded. Candidate gene sequencing was performed to identify the disease-causing mutation. Recombinant connexin50 (Cx50) wild type and mutant constructs were synthesized. Triton X-100 solubility and subcellular localization of the recombinant Cx50 proteins were analyzed in HeLa cells. Apoptosis was assayed as the percentage of fragmented nuclei in transfected cells. RESULTS All affected individuals in the family displayed clear phenotypes of dense nuclear cataracts. A c.227 G > A variation was found in the coding region of Cx50, which arginine residue at position 76 was substituted by histidine (p.R76H). This mutation was co-segregated with the disease in the family, and was not observed in 110 unrelated Chinese controls. No statistically significant differences were found in the Triton X-100 solubility and apoptosis rate between wild type and mutant Cx50 in HeLa cells. However, Cx50 mutant was unable to form gap junctional plaques between adjacent cells as the wild type proteins did. CONCLUSION This study identified a novel cataract phenotype caused by the p.R76H mutation in Cx50, providing evidence of further phenotypic heterogeneity associated with this mutation. Functional analysis showed that the mutation affected the formation of gap junction channels and led to opacity in the lens.
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Affiliation(s)
- Kai Jie Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology &Visual Sciences Key Lab, Beijing, 100730, China
| | - Jin Da Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology &Visual Sciences Key Lab, Beijing, 100730, China
| | - Dou Dou Chen
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology &Visual Sciences Key Lab, Beijing, 100730, China
| | - Ming Yang Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology &Visual Sciences Key Lab, Beijing, 100730, China
| | - Bo Yun
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology &Visual Sciences Key Lab, Beijing, 100730, China
| | - Si Quan Zhu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology &Visual Sciences Key Lab, Beijing, 100730, China.
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47
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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: 1.0] [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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48
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O'Gorman L, Cree AJ, Ward D, Griffiths HL, Sood R, Denniston AK, Self JE, Ennis S, Lotery AJ, Gibson J. Comprehensive sequencing of the myocilin gene in a selected cohort of severe primary open-angle glaucoma patients. Sci Rep 2019; 9:3100. [PMID: 30816137 PMCID: PMC6395666 DOI: 10.1038/s41598-019-38760-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 01/07/2019] [Indexed: 11/16/2022] Open
Abstract
Primary open-angle glaucoma (POAG) is the most common form of glaucoma, prevalent in approximately 1–2% of Caucasians in the UK over the age of 40. It is characterised by an open anterior chamber angle, raised intraocular pressure (IOP) and optic nerve damage leading to loss of sight. The myocilin gene (MYOC) is the most common glaucoma-causing gene, accounting for ~2% of British POAG cases. 358 patients were selected for next generation sequencing (NGS) with the following selection criteria: Caucasian ethnicity, intraocular pressure (IOP) 21–40 mm Hg, cup:disc ratio ≥0.6 and visual field mean deviation ≤−3. The entire MYOC gene (17,321 bp) was captured including the promoter, introns, UTRs and coding exons. We identify 12 exonic variants (one stop-gain, five missense and six synonymous variants), two promoter variants, 133 intronic variants, two 3′ UTR variants and 23 intergenic variants. Four known or predicted pathogenic exonic variants (p.R126W, p.K216K, p.Q368* and p.T419A) were identified across 11 patients, which accounts for 3.07% of this POAG cohort. This is the first time that the entire region of MYOC has been sequenced and variants reported for a cohort of POAG patients.
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Affiliation(s)
- Luke O'Gorman
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Angela J Cree
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Daniel Ward
- Molecular Genetics Wessex Regional Genetics Laboratory, Salisbury NHS Foundation Trust, Salisbury, UK
| | - Helen L Griffiths
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Roshan Sood
- Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, UK
| | - Alastair K Denniston
- Department of Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Jay E Self
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.,Eye Unit, University Hospital Southampton, Southampton, UK
| | - Sarah Ennis
- Human Genetics & Genomic Medicine, Faculty of Medicine, University of Southampton, Southampton, UK.
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.,Eye Unit, University Hospital Southampton, Southampton, UK
| | - Jane Gibson
- Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, UK
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49
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Arcalis E, Ibl V, Hilscher J, Rademacher T, Avesani L, Morandini F, Bortesi L, Pezzotti M, Vitale A, Pum D, De Meyer T, Depicker A, Stoger E. Russell-Like Bodies in Plant Seeds Share Common Features With Prolamin Bodies and Occur Upon Recombinant Protein Production. FRONTIERS IN PLANT SCIENCE 2019; 10:777. [PMID: 31316529 PMCID: PMC6611407 DOI: 10.3389/fpls.2019.00777] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/28/2019] [Indexed: 05/06/2023]
Abstract
Although many recombinant proteins have been produced in seeds at high yields without adverse effects on the plant, endoplasmic reticulum (ER) stress and aberrant localization of endogenous or recombinant proteins have also been reported. The production of murine interleukin-10 (mIL-10) in Arabidopsis thaliana seeds resulted in the de novo formation of ER-derived structures containing a large fraction of the recombinant protein in an insoluble form. These bodies containing mIL-10 were morphologically similar to Russell bodies found in mammalian cells. We confirmed that the compartment containing mIL-10 was enclosed by ER membranes, and 3D electron microscopy revealed that these structures have a spheroidal shape. Another feature shared with Russell bodies is the continued viability of the cells that generate these organelles. To investigate similarities in the formation of Russell-like bodies and the plant-specific protein bodies formed by prolamins in cereal seeds, we crossed plants containing ectopic ER-derived prolamin protein bodies with a line accumulating mIL-10 in Russell-like bodies. This resulted in seeds containing only one population of protein bodies in which mIL-10 inclusions formed a central core surrounded by the prolamin-containing matrix, suggesting that both types of protein aggregates are together removed from the secretory pathway by a common mechanism. We propose that, like mammalian cells, plant cells are able to form Russell-like bodies as a self-protection mechanism, when they are overloaded with a partially transport-incompetent protein, and we discuss the resulting challenges for recombinant protein production.
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Affiliation(s)
- Elsa Arcalis
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Verena Ibl
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Julia Hilscher
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Thomas Rademacher
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Aachen, Germany
| | - Linda Avesani
- Department of Biotechnology, University of Verona, Verona, Italy
| | | | - Luisa Bortesi
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Mario Pezzotti
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Alessandro Vitale
- Institute of Agricultural Biology and Biotechnology, CNR, Milan, Italy
| | - Dietmar Pum
- Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Thomas De Meyer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Ann Depicker
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- VIB Center for Plant Systems Biology, Ghent, Belgium
| | - Eva Stoger
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
- *Correspondence: Eva Stoger, ;
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50
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Wang H, Li M, Zhang Z, Xue H, Chen X, Ji Y. Physiological function of myocilin and its role in the pathogenesis of glaucoma in the trabecular meshwork (Review). Int J Mol Med 2018; 43:671-681. [PMID: 30483726 PMCID: PMC6317685 DOI: 10.3892/ijmm.2018.3992] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 11/16/2018] [Indexed: 12/26/2022] Open
Abstract
Myocilin is highly expressed in the trabecular meshwork (TM), which plays an important role in the regulation of intraocular pressure (IOP). Myocilin abnormalities may cause dysfunction of the TM, potentially leading to increased IOP. High IOP is a well‑known primary risk factor for glaucoma. Myocilin mutations are common among glaucoma patients, and they are implicated in juvenile‑onset open‑angle glaucoma (JOAG) and adult‑onset primary open‑angle glaucoma (POAG). Aggregation of aberrant mutant myocilins is closely associated with glaucoma pathogenesis. The aim of the present review was to discuss the recent findings regarding the major physiological functions of myocilin, such as intra‑ and extracellular proteolytic processes. We also aimed to discuss the risk factors associated with myocilin and the development of glaucoma, such as misfolded/mutant myocilin, imbalance of myocilin and extracellular proteins, and instability of mutant myocilin associated with temperature. Finally, we further outlined certain issues that are yet to be resolved, which may represent the basis for future studies on the role of myocilin in glaucoma.
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Affiliation(s)
- Hongwei Wang
- Department of Ophthalmology, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Mingzhe Li
- Department of Ophthalmology, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 201399, P.R. China
| | - Zhenzhen Zhang
- Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, P.R. China
| | - Haifeng Xue
- Public Health School, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Xing Chen
- Department of Science and Education, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Yong Ji
- Department of General Surgery, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
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