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Wu HJ, Krystofiak E, Kuchtey J, Kuchtey RW. Enhanced Optic Nerve Expansion and Altered Ultrastructure of Elastic Fibers Induced by Lysyl Oxidase Inhibition in a Mouse Model of Marfan Syndrome. THE AMERICAN JOURNAL OF PATHOLOGY 2024:S0002-9440(24)00115-9. [PMID: 38548269 DOI: 10.1016/j.ajpath.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 02/27/2024] [Accepted: 03/11/2024] [Indexed: 04/09/2024]
Abstract
Two major constituents of exfoliation material, fibrillin-1 and lysyl oxidase-like 1 (encoded by FBN1 and LOXL1), are implicated in exfoliation glaucoma, yet their individual contributions to ocular phenotype are minor. To test the hypothesis that a combination of FBN1 mutation and LOXL1 deficiency exacerbates ocular phenotypes, the pan-LOX inhibitor β-aminopropionitrile (BAPN) was used to treat adult wild-type (WT) and Fbn1C1041G/+ mice for 8 weeks and their eyes were examined. Although intraocular pressure did not change and exfoliation material was not detected in the eyes, BAPN treatment worsened optic nerve and axon expansion in Fbn1C1041G/+ mice, an early sign of axonal damage in rodent models of glaucoma. Disruption of elastic fibers was detected only in Fbn1C1041G/+ mice, which increased with BAPN treatment, as shown by histologic and immunohistochemical staining of the optic nerve pia mater. Transmission electron microscopy showed that Fbn1C1041G/+ mice had fewer microfibrils, smaller elastin cores, and a lower density of elastic fibers compared with WT mice in control groups. BAPN treatment led to elastin core expansion in both WT and Fbn1C1041G/+ mice, but an increase in the density of elastic fiber was confined to Fbn1C1041G/+ mice. LOX inhibition had a stronger effect on optic nerve and elastic fiber parameters in the context of Fbn1 mutation, indicating the Marfan mouse model with LOX inhibition warrants further investigation for exfoliation glaucoma pathogenesis.
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Affiliation(s)
- Hang-Jing Wu
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Evan Krystofiak
- Cell Imaging Shared Resource, Vanderbilt University, Nashville, Tennessee
| | - John Kuchtey
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rachel W Kuchtey
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
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NikhalaShree S, George RJ, Shantha B, Vijaya L, Sulochana KN, Coral K. Copper, Lysyl Oxidase Activity, and Collagen in Aqueous Humour of Primary Glaucoma: An Association with Clinical Parameters. Ophthalmic Res 2023; 66:949-957. [PMID: 37253350 DOI: 10.1159/000531247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 05/05/2023] [Indexed: 06/01/2023]
Abstract
INTRODUCTION To measure copper (Cu), lysyl oxidase (LOX) activity, and collagen levels in aqueous humour (AH) of primary glaucoma patients and correlate with clinical parameters. METHODS 120 patients with 40 each of primary open angle glaucoma (POAG), primary angle closure glaucoma (PACG), and cataract controls were recruited in this case-control study. AH samples were collected during the trabeculectomy and cataract surgeries. Cu levels were measured using an atomic absorption spectrophotometer. LOX unit activity was determined by Amplex Red assay and collagen concentration by Sirius red assay. RESULTS Significantly higher levels of Cu expressed as median (IQR) µmol/L were observed in POAG (p = 0.008) and PACG (p = 0.005) compared to controls. The LOX activity was increased in POAG and PACG (p = 0.04) compared to controls represented as median (IQR) µmol/min. The collagen levels given as median (IQR) mg/ml showed an insignificant increase in POAG and PACG compared to controls (p = 0.78). The LOX unit activity was correlated with visual field index (VFI), which showed a significant increase with the progression of the diseases (p < 0.05), whereas Cu levels were negatively correlated with LOX activity in AH. Cu and LOX activity showed weak correlation with YAG peripheral iridotomy (YAGPI), duration of anti-glaucoma medications, and highest preoperative intraocular pressure. CONCLUSION Elevated Cu and LOX activity was observed in both POAG and PACG groups compared to controls. LOX activity showed notable increase with VFI as the severity of the disease. Although Cu levels are increased in glaucoma, it's insufficient to significantly increase the activity of LOX.
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Affiliation(s)
- Sampath NikhalaShree
- R.S. Mehta Jain Department of Biochemistry and Cell Biology, KBIRVO, Vision Research Foundation, Sankara Nethralaya, Chennai, India
- School of Chemical and Biotechnology, SASTRA Deemed-to-be University, Thanjavur, India
| | - Ronnie Jacob George
- Smt Jadhavbai Nathmal Singhvee Glaucoma Services, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | - Balekudaru Shantha
- Smt Jadhavbai Nathmal Singhvee Glaucoma Services, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | - Lingam Vijaya
- Smt Jadhavbai Nathmal Singhvee Glaucoma Services, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | | | - Karunakaran Coral
- R.S. Mehta Jain Department of Biochemistry and Cell Biology, KBIRVO, Vision Research Foundation, Sankara Nethralaya, Chennai, India
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3
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Reichheld SE, Muiznieks LD, Huynh Q, Wang N, Ing C, Miao M, Sitarz EE, Pomès R, Sharpe S, Keeley FW. The evolutionary background and functional consequences of the rs2071307 polymorphism in human tropoelastin. Biopolymers 2020; 112:e23414. [PMID: 33351193 DOI: 10.1002/bip.23414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 01/01/2023]
Abstract
Elastin is a major polymeric protein of the extracellular matrix, providing critical properties of extensibility and elastic recoil. The rs2071307 genomic polymorphism, resulting in the substitution of a serine for a glycine residue in a VPG motif in tropoelastin, has an unusually high minor allele frequency in humans. A consequence of such allelic heterozygosity would be the presence of a heterogeneous elastin polymer in up to 50% of the population, a situation which appears to be unique to Homo sapiens. VPG motifs are extremely common in hydrophobic domains of tropoelastins and are the sites of transient β-turns that are essential for maintaining the conformational flexibility required for its function as an entropic elastomer. Earlier data demonstrated that single amino acid substitutions in tropoelastin can have functional consequences for polymeric elastin, particularly when present in mixed polymers. Here, using NMR and molecular dynamics approaches, we show the rs2071307 polymorphism reduces local propensity for β-turn formation, with a consequent increase in polypeptide hydration and an expansion of the conformational ensemble manifested as an increased hydrodynamic radius, radius of gyration and asphericity. Furthermore, this substitution affects functional properties of polymeric elastin, particularly in heterogeneous polymers mimicking allelic heterozygosity. We discuss whether such effects, together with the unusually high minor allele frequency of the polymorphism, could imply some some evolutionary advantage for the heterozygous state.
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Affiliation(s)
- Sean E Reichheld
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA
| | - Lisa D Muiznieks
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA.,Elvesys Microfluidics Innovation Center, 172 rue de Charonne, 75011, Paris, France
| | - Quang Huynh
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA
| | - Nick Wang
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA.,135 W 52nd St. Apt 20A, 10019-7691, New York, New York, USA
| | - Christopher Ing
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA.,ProteinQure, Suite 304, 119 Spadina Avenue, M5V2L1, Toronto, Ontario, Canada
| | - Ming Miao
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA
| | - Eva E Sitarz
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA
| | - Régis Pomès
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Simon Sharpe
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Fred W Keeley
- Molecular Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, USA.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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Abstract
PURPOSE/AIM We aimed to characterize the connective tissue microanatomy, elastin abundance, and fiber orientation in the human optic nerve sheath, also known as the optic nerve dura mater, for correlation with its biomechanical properties. MATERIALS AND METHODS Seven whole human orbits aged 4-93 years, and five isolated human optic nerve sheaths aged 26-75 years were formalin fixed, paraffin embedded, coronally sectioned, stained by Masson trichrome and van Gieson's elastin methods, and analyzed quantitatively for elastin fiber abundance and orientation. Elastin area fraction was defined as area stained for elastin divided by total area. RESULTS While unilaminar in children, the adult ON sheath exhibited distinct inner and outer layers. Collagen was denser and more compact in the inner layer. Elastin area fraction was significantly greater at 6.0 ± 0.4% (standard error of mean) in the inner than outer layer at 3.6 ± 0.4% (P < 10-5). Elastin fibers had three predominant orientations: longitudinal, diagonal, and circumferential. Of circumferential fibers, 63 ± 4.7% were in the inner and 37 ± 4.7% in the outer layer (P < 10-4). Longitudinal and diagonal fibers were uniformly distributed in both layers. Elastin density and sheath thickness increased significantly with age (P < .01). CONCLUSIONS The adult human optic nerve sheath is bilaminar, with each layer containing elastin fibers oriented in multiple directions consistent with isotropic properties. Differences in laminar elastin density and orientation may reflect greater tensile loading in the inner than in the outer layer.
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Affiliation(s)
- Alan Le
- Department of Bioengineering, University of California , Los Angeles, California, USA.,Department of Ophthalmology and Stein Eye Institute, University of California , Los Angeles, California, USA
| | - Andrew Shin
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital , Boston, Massachusetts, USA
| | - Joseph Park
- Department of Bioengineering, University of California , Los Angeles, California, USA.,Department of Ophthalmology and Stein Eye Institute, University of California , Los Angeles, California, USA
| | - Vadims Poukens
- Department of Ophthalmology and Stein Eye Institute, University of California , Los Angeles, California, USA
| | - Joseph L Demer
- Department of Ophthalmology and Stein Eye Institute, University of California , Los Angeles, California, USA.,Department of Neurology, University of California , Los Angeles, California, USA.,Neuroscience, University of California , Los Angeles, California, USA.,Bioengineering Interdepartmental Programs, University of California , Los Angeles, California, USA.,David Geffen Medical School, University of California , Los Angeles, California, USA
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Sequence variants of human tropoelastin affecting assembly, structural characteristics and functional properties of polymeric elastin in health and disease. Matrix Biol 2019; 84:68-80. [DOI: 10.1016/j.matbio.2019.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/23/2019] [Accepted: 06/25/2019] [Indexed: 12/19/2022]
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Schmelzer CEH, Heinz A, Troilo H, Lockhart-Cairns MP, Jowitt TA, Marchand MF, Bidault L, Bignon M, Hedtke T, Barret A, McConnell JC, Sherratt MJ, Germain S, Hulmes DJS, Baldock C, Muller L. Lysyl oxidase-like 2 (LOXL2)-mediated cross-linking of tropoelastin. FASEB J 2019; 33:5468-5481. [PMID: 30676771 PMCID: PMC6629125 DOI: 10.1096/fj.201801860rr] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lysyl oxidases (LOXs) play a central role in extracellular matrix remodeling during development and tumor growth and fibrosis through cross-linking of collagens and elastin. We have limited knowledge of the structure and substrate specificity of these secreted enzymes. LOXs share a conserved C-terminal catalytic domain but differ in their N-terminal region, which is composed of 4 repeats of scavenger receptor cysteine-rich (SRCR) domains in LOX-like (LOXL) 2. We investigated by X-ray scattering and electron microscopy the low-resolution structure of the full-length enzyme and the structure of a shorter form lacking the catalytic domain. Our data demonstrate that LOXL2 has a rod-like structure with a stalk composed of the SRCR domains and the catalytic domain at its tip. We detected direct interaction between LOXL2 and tropoelastin (TE) and also LOXL2-mediated deamination of TE. Using proteomics, we identified several allysines together with cross-linked TE peptides. The elastin-like material generated was resistant to trypsin proteolysis and displayed mechanical properties similar to mature elastin. Finally, we detected the codistribution of LOXL2 and elastin in the vascular wall. Altogether, these data suggest that LOXL2 could participate in elastogenesis in vivo and could be used as a means of cross-linking TE in vitro for biomimetic and cell-compatible tissue engineering purposes.-Schmelzer, C. E. H., Heinz, A., Troilo, H., Lockhart-Cairns, M.-P., Jowitt, T. A., Marchand, M. F., Bidault, L., Bignon, M., Hedtke, T., Barret, A., McConnell, J. C., Sherratt, M. J., Germain, S., Hulmes, D. J. S., Baldock, C., Muller, L. Lysyl oxidase-like 2 (LOXL2)-mediated cross-linking of tropoelastin.
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Affiliation(s)
- Christian E H Schmelzer
- Fraunhofer Institute for Microstructure of Materials and Systems (IMWS), Halle (Saale), Germany.,Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Andrea Heinz
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.,Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark
| | - Helen Troilo
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom.,Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Michael P Lockhart-Cairns
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom.,Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Thomas A Jowitt
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom.,Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Marion F Marchand
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France.,Collège Doctoral, Sorbonne Université, Paris, France
| | - Laurent Bidault
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
| | - Marine Bignon
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
| | - Tobias Hedtke
- Fraunhofer Institute for Microstructure of Materials and Systems (IMWS), Halle (Saale), Germany.,Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Alain Barret
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
| | - James C McConnell
- Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Michael J Sherratt
- Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Stéphane Germain
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
| | - David J S Hulmes
- UMR 5305, Centre National de la Recherche Scientifique (CNRS), Laboratoire de Biologie Tissulaire et Ingénierie Thérapeutique (LBTI), Université de Lyon, Lyon, France
| | - Clair Baldock
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom.,Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Laurent Muller
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
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7
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Single nucleotide polymorphisms and domain/splice variants modulate assembly and elastomeric properties of human elastin. Implications for tissue specificity and durability of elastic tissue. Biopolymers 2017; 107. [DOI: 10.1002/bip.23007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/23/2016] [Accepted: 12/03/2016] [Indexed: 12/13/2022]
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Quigley HA. The contribution of the sclera and lamina cribrosa to the pathogenesis of glaucoma: Diagnostic and treatment implications. PROGRESS IN BRAIN RESEARCH 2015; 220:59-86. [PMID: 26497785 DOI: 10.1016/bs.pbr.2015.04.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glaucoma, the second most common cause of world blindness, results from loss of retinal ganglion cells (RGC). RGC die as a consequence of injury to their axons, as they pass through the transition between the environment within the eye and that of the retrobulbar optic nerve, as they course to central visual centers. At the optic nerve head (ONH), axonal transport becomes abnormal, at least in part due to the effect of strain induced by intraocular pressure (IOP) on the sclera and ONH. Animal glaucoma models provide the ability to study how alterations in ocular connective tissues affect this pathological process. New therapeutic interventions are being investigated to mitigate glaucoma blindness by modifying the remodeling of ocular tissues in glaucoma. Some genetically altered mice are resistant to glaucoma damage, while treatment of the sclera with cross-linking agents makes experimental mouse glaucoma damage worse. Inhibition of transforming growth factor β activity is strikingly protective. Treatments that alter the response of ocular connective tissues to IOP may be effective in protecting those with glaucoma from vision loss.
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Affiliation(s)
- Harry A Quigley
- Glaucoma Center of Excellence, Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Quigley HA, Cone FE. Development of diagnostic and treatment strategies for glaucoma through understanding and modification of scleral and lamina cribrosa connective tissue. Cell Tissue Res 2013; 353:231-44. [PMID: 23535950 PMCID: PMC3716834 DOI: 10.1007/s00441-013-1603-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 02/28/2013] [Indexed: 12/13/2022]
Abstract
Considerable evidence indicates that the state of ocular connective tissues and their response in glaucomatous disease affect the degree of glaucoma damage. Both experimental and clinical data suggest that improved diagnostic and prognostic information can be derived from the assessment of the mechanical responsiveness of the sclera and lamina cribrosa to intraocular pressure (IOP). Controlled mutagenesis of the sclera has produced a mouse strain that is relatively resistant to increased IOP. Alteration of the baseline scleral state can be accomplished through either increased cross-linking of fibrillar components or their reduction. The sclera is a dynamic structure, altering its structure and behavior in response to IOP change. The biochemical pathways that control these responses are fertile areas for new glaucoma treatments.
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Affiliation(s)
- Harry A Quigley
- Glaucoma Center of Excellence, Wilmer Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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10
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Nguyen C, Cone FE, Nguyen TD, Coudrillier B, Pease ME, Steinhart MR, Oglesby EN, Jefferys JL, Quigley HA. Studies of scleral biomechanical behavior related to susceptibility for retinal ganglion cell loss in experimental mouse glaucoma. Invest Ophthalmol Vis Sci 2013; 54:1767-80. [PMID: 23404116 DOI: 10.1167/iovs.12-10952] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To study anatomical changes and mechanical behavior of the sclera in mice with experimental glaucoma by comparing CD1 to B6 mice. METHODS Chronic experimental glaucoma for 6 weeks was produced in 2- to 4-month-old CD1 (43 eyes) and B6 mice (42 eyes) using polystyrene bead injection into the anterior chamber with 126 control CD1 and 128 control B6 eyes. Intraocular pressure (IOP) measurements were made with the TonoLab at baseline and after bead injection. Axial length and scleral thickness were measured after sacrifice in the CD1 and B6 animals and compared to length data from 78 eyes of DBA/2J mice. Inflation testing of posterior sclera was conducted, and circumferential and meridional strain components were determined from the displacement response. RESULTS Experimental glaucoma led to increases in axial length and width by comparison to fellow eyes (6% in CD1 and 10% in B6; all P < 0.03). While the peripapillary sclera became thinner in both mouse types with glaucoma, the remainder of the sclera uniformly thinned in CD1, but thickened in B6. Peripapillary sclera in CD1 controls had significantly greater temporal meridional strain than B6 and had differences in the ratios of meridional to effective circumferential strain from B6 mice. In both CD1 and B6 mice, exposure to chronic IOP elevation resulted in stiffer pressure-strain responses for both the effective circumferential and meridional strains (multivariable regression model, P = 0.01-0.03). CONCLUSIONS Longer eyes, greater scleral strain in some directions at baseline, and generalized scleral thinning after glaucoma were characteristic of CD1 mice that have greater tendency to retinal ganglion cell damage than B6 mice. Increased scleral stiffness after glaucoma exposure in mice mimics findings in monkey and human glaucoma eyes.
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Affiliation(s)
- Cathy Nguyen
- Glaucoma Center of Excellence, Wilmer Eye Institute at Johns Hopkins University, Baltimore, Maryland, USA
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11
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The genetics of pigment dispersion syndrome and pigmentary glaucoma. Surv Ophthalmol 2012; 58:164-75. [PMID: 23218808 DOI: 10.1016/j.survophthal.2012.08.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 08/04/2012] [Accepted: 08/07/2012] [Indexed: 11/21/2022]
Abstract
We review the inheritance patterns and recent genetic advances in the study of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). Both conditions may result from combinations of mutations in more than one gene or from common variants in many genes, each contributing small effects. We discuss the currently known genetic loci that may be related with PDS/PG in humans, the role of animal models in expanding our understanding of the genetic basis of PDS, the genetic factors underlying the risk for conversion from PDS to PG and the relationship between genetic and environmental--as well as anatomical--risk factors.
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12
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Uitto J, Li Q, Urban Z. The complexity of elastic fibre biogenesis in the skin--a perspective to the clinical heterogeneity of cutis laxa. Exp Dermatol 2012; 22:88-92. [PMID: 23088642 DOI: 10.1111/exd.12025] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2012] [Indexed: 11/28/2022]
Abstract
Elastic fibres are critical connective tissue components providing elasticity and resilience to skin and other tissues. These fibres are composed of elastin and a number of elastin-associated microfibrillar proteins that assemble in a complex fibre network in a multi-step process. Multiple cellular processes, including mitochondrial function, specific molecules in the secretory pathways and temporally and spatially ordered production of elastic fibre components, are required for the biogenesis of functional elastic fibres. Abnormalities in these processes can lead to loss of functional elastic fibres manifesting phenotypically as a skin disease. The paradigm of elastic fibre diseases affecting the skin is cutis laxa, a clinically and genetically heterogeneous group of disorders characterized by loose and sagging skin, frequently associated with extracutaneous manifestations in the lungs and the arterial blood vessels. The complexity of cutis laxa is emphasized by the fact that as many as 10 distinct genes can harbour mutations in this and related disorders. Understanding of the pathomechanistic pathways involved in perturbed elastic fibre assembly in cutis laxa provides information potentially helpful for the development of molecular strategies towards treatment of these, currently intractable, diseases.
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Affiliation(s)
- Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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13
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Schlötzer-Schrehardt U, Hammer CM, Krysta AW, Hofmann-Rummelt C, Pasutto F, Sasaki T, Kruse FE, Zenkel M. LOXL1 deficiency in the lamina cribrosa as candidate susceptibility factor for a pseudoexfoliation-specific risk of glaucoma. Ophthalmology 2012; 119:1832-43. [PMID: 22633114 DOI: 10.1016/j.ophtha.2012.03.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 03/07/2012] [Accepted: 03/07/2012] [Indexed: 01/25/2023] Open
Abstract
PURPOSE To test the hypothesis that a primary disturbance in lysyl oxidase-like 1 (LOXL1) and elastin metabolism in the lamina cribrosa of eyes with pseudoexfoliation syndrome constitutes an independent risk factor for glaucoma development and progression. DESIGN Observational, consecutive case series. PARTICIPANTS Posterior segment tissues obtained from 37 donors with early and late stages of pseudoexfoliation syndrome without glaucoma, 37 normal age-matched control subjects, 5 eyes with pseudoexfoliation-associated open-angle glaucoma, and 5 eyes with primary open-angle glaucoma (POAG). METHODS Protein and mRNA expression of major elastic fiber components (elastin, fibrillin-1, fibulin-4), collagens (types I, III, and IV), and lysyl oxidase crosslinking enzymes (LOX, LOXL1, LOXL2) were assessed in situ by quantitative real-time polymerase chain reaction, (immuno)histochemistry, and light and electron microscopy. Lysyl oxidase-dependent elastin fiber assembly was assessed by primary optic nerve head astrocytes in vitro. MAIN OUTCOME MEASURES Expression levels of elastic proteins, collagens, and lysyl oxidases in the lamina cribrosa. RESULTS Lysyl oxidase-like 1 proved to be the major lysyl oxidase isoform in the normal lamina cribrosa in association with a complex elastic fiber network. Compared with normal and POAG specimens, lamina cribrosa tissues obtained from early and late stages of pseudoexfoliation syndrome without and with glaucoma consistently revealed a significant coordinated downregulation of LOXL1 and elastic fiber constituents on mRNA and protein level. In contrast, expression levels of collagens and other lysyl oxidase isoforms were not affected. Dysregulated expression of LOXL1 and elastic proteins was associated with pronounced (ultra)structural alterations of the elastic fiber network in the laminar beams of pseudoexfoliation syndrome eyes. Inhibition of LOXL1 interfered with elastic fiber assembly by optic nerve head astrocytes in vitro. CONCLUSIONS The findings provide evidence for a pseudoexfoliation-specific elastinopathy of the lamina cribrosa resulting from a primary disturbance in LOXL1 regulation and elastic fiber homeostasis, possibly rendering pseudoexfoliation syndrome eyes more vulnerable to pressure-induced optic nerve damage and glaucoma development and progression.
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14
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Tribute to Rosario Hernandez. Exp Eye Res 2011; 93:116-9. [DOI: 10.1016/j.exer.2011.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 05/09/2011] [Accepted: 05/10/2011] [Indexed: 11/22/2022]
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Lack of association of polymorphisms in elastin with pseudoexfoliation syndrome and glaucoma. J Glaucoma 2010; 19:432-6. [PMID: 20051886 DOI: 10.1097/ijg.0b013e3181c4b0fe] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the elastin gene (ELN) as a secondary risk factor for pseudoexfoliation syndrome (PXFS) and the associated glaucoma pseudoexfoliation glaucoma (PXFG). METHODS One hundred seventy-eight unrelated patients with PXFS, including 132 patients with PXFG, and 113 unrelated controls were recruited from the Massachusetts Eye and Ear Infirmary. All the patients and controls were white of European ancestry. Three tag SNPs (rs2071307, rs3823879, and rs3757587) that capture the majority of alleles in ELN were genotyped. Single-SNP association was analyzed using Fisher exact test. Haplotype analysis and the set-based test were used to assess the association for the whole gene. Interaction analysis was done between the ELN SNP rs2071307 and LOXL1 SNP rs2165241 using logistic regression. Multiple comparisons were corrected using the Bonferroni method. RESULTS All 3 ELN tag SNPs were not significantly associated with PXFS and PXFG (P>0.20). The minor allele frequencies in PXFS, PXFG, and controls were 40.7%, 39.8%, and 45.6%, respectively for rs2071307, 6.7%, 6.3%, and 5.4% for rs3823879, and 14.8%, 16.2%, and 13.6% for rs3757587. Haplotype analysis and the set-based test did not find significant association of ELN with PXFS (P=0.94 and 0.99, respectively). No significant interaction effects on PXFS were identified between the ELN and LOXL1 SNPs (P=0.55). CONCLUSIONS Our results suggest that common polymorphisms of ELN are not associated with PXFS and PXFG in white populations. Further studies are required to identify secondary genetic factors that contribute to PXFS.
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Abstract
Glaucoma, a leading cause of blindness worldwide, is characterized by progressive optic nerve damage, usually associated with intraocular pressure. Although the clinical progression of the disease is well defined, the molecular events responsible for glaucoma are currently poorly understood and current therapeutic strategies are not curative. This review summarizes the human genetics and genomic approaches that have shed light on the complex inheritance of glaucoma genes and the potential for gene-based and cellular therapies that this research makes possible.
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Affiliation(s)
- Bao Jian Fan
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
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Lysyl oxidase-like 1 gene polymorphisms in German patients with normal tension glaucoma, pigmentary glaucoma and exfoliation glaucoma. J Glaucoma 2010; 19:136-41. [PMID: 19373106 DOI: 10.1097/ijg.0b013e31819f9330] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the association between lysyl-oxidase-like 1 (LOXL1) gene polymorphisms and exfoliation glaucoma, pigmentary glaucoma and normal tension glaucoma in a case-control cohort of German patients. METHODS Six single nucleotide polymorphisms in a 22 kb genomic region encompassing the LOXL1 gene plus an additional "outlier" single nucleotide polymorphism located approximately 1.1 Mb upstream of LOXL1 were genotyped in 128 exfoliation glaucoma patients, 88 pigmentary glaucoma patients, 273 normal tension glaucoma patients, and 280 healthy control subjects either with TaqMan allelic discrimination assays or by direct sequencing, and a genetic association study was performed. RESULTS For the exfoliation glaucoma cases, case-control allelic association for 6 single nucleotide polymorphisms were highly significant. In contrast, there were no genotypic differences between pigmentary glaucoma cases, normal tension glaucoma cases and controls. However, an association between rs1048661 genotype and age at disease onset was suggested for pigmentary glaucoma patients. CONCLUSIONS Our study reveals that in the German population the LOXL1 genetic predisposition is limited to exfoliation glaucoma and does not include normal tension glaucoma. In addition, our study implicates that LOXL1 polymorphisms are not likely to have a major influence on the pathophysiology of pigmentary glaucoma. However, 1 nonsynonymous polymorphism may serve as a predictor of age at disease onset in pigmentary glaucoma.
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Miao H, Crabb AW, Hernandez MR, Lukas TJ. Modulation of factors affecting optic nerve head astrocyte migration. Invest Ophthalmol Vis Sci 2010; 51:4096-103. [PMID: 20375339 DOI: 10.1167/iovs.10-5177] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
PURPOSE The authors investigated the role of myosin light chain kinase (MYLK) and transforming growth factor beta (TGFbeta) receptor pathways in optic nerve head (ONH) astrocyte migration. They further investigated how the expression of these genes is altered by elevated hydrostatic pressure (HP). METHODS PCR was used to determine the isoforms of MYLK expressed in ONH astrocytes. siRNAs against MYLK (all isoforms) and TGFbeta receptor 2 (TGFBR2) were prepared and tested for effects on the migration of cultured ONH astrocytes. Finally, the effects of elevated HP (24-96 hours) on the expression of MYLK isoforms and selected TGFbeta pathway components were measured. RESULTS Multiple isoforms of MYLK are present in ONH astrocytes from Caucasian (CA) and African American (AA) donors. Both populations express the short form (MYLK-130) and the long form (MYLK-210) of MYLK and a splicing variant within MYLK-210. MYLK-directed siRNA decreased MYLK expression and cell migration compared with control siRNA. siRNA directed against TGFbeta receptor 2 also decreased cell migration compared with control and decreased extracellular matrix genes regulated by TGFbeta signaling. Elevated HP increased the expression of MYLK-130 and MYLK-210 in both populations of astrocytes. However, TGFbeta2 was uniquely upregulated by exposure to elevated HP in CA compared with AA astrocytes. CONCLUSIONS Differential expression of TGFbeta pathway genes and MYLK isoforms observed in populations of glaucomatous astrocytes applies to the elevated HP model system. MYLK may be a new target for intervention in glaucoma to alter reactive astrocyte migration in the ONH.
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Affiliation(s)
- Haixi Miao
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
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Gelman S, Cone FE, Pease ME, Nguyen TD, Myers K, Quigley HA. The presence and distribution of elastin in the posterior and retrobulbar regions of the mouse eye. Exp Eye Res 2009; 90:210-5. [PMID: 19853602 DOI: 10.1016/j.exer.2009.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 09/14/2009] [Accepted: 10/13/2009] [Indexed: 01/30/2023]
Abstract
The Presence and distribution of elastin in the posterior and retrobulbar regions of the mouse eye was investigated. Mice of two strains (C57/BL6 and DBA/2J) were studied at 2 months and 8-12 months of age. Light, confocal, and transmission electron microscopy were used to identify elastin, using immunohistochemical techniques and ultrastructural evaluation. Elastin was found in the following ocular structures: conjunctiva, muscle tendons, sclera, choroid, and meninges. The elastin in the sclera was most dense in a ring surrounding the peripapillary optic nerve head, with its presence in the inner sclera declining with greater distance from the nerve head. Elastin fibers were oriented in the sclera along what would be expected to be the principal stress directions generated from the intraocular pressure, though actual biomechanical measurements have not yet been made in the mouse sclera. Elastin comprises a portion of the mouse sclera and its distribution in the peripapillary area is similar to that in human eyes.
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Affiliation(s)
- Scott Gelman
- Glaucoma Research Laboratory, Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Abstract
Glaucomatous vision loss results from the progressive degeneration of optic nerve axons and the death of retinal ganglion cells. This process is accompanied by dramatic alterations in the functional properties and distribution of glial cells in both the retina and the optic nerve head in a reaction commonly referred to as glial activation. The recent availability of rodent and cell culture glaucoma models has substantially contributed to our knowledge of glial activation under glaucomatous conditions. Conclusions drawn from these studies have led to the refinement of existing hypotheses and the generation of new ones. Because these hypotheses encompass both protective and injurious roles for glia, the impact of specific aspects of glial activation are current topics of intensive research, speculation, and debate in the field. With these unresolved issues in mind, this review will summarize recent progress in our understanding of the process of glial activation in the glaucomatous optic nerve head and retina.
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Schlötzer-Schrehardt U, Pasutto F, Sommer P, Hornstra I, Kruse FE, Naumann GOH, Reis A, Zenkel M. Genotype-correlated expression of lysyl oxidase-like 1 in ocular tissues of patients with pseudoexfoliation syndrome/glaucoma and normal patients. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 173:1724-35. [PMID: 18974306 DOI: 10.2353/ajpath.2008.080535] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pseudoexfoliation (PEX) syndrome is a generalized disease of the extracellular matrix and the most common identifiable cause of open-angle glaucoma. Two single nucleotide polymorphisms in the lysyl oxidase-like 1 (LOXL1) gene (rs1048661 and rs3825942) have been recently identified as strong genetic risk factors for both PEX syndrome and PEX glaucoma. Here we investigated the expression and localization of LOXL1, LOXL2, and lysyl oxidase (LOX) in tissues of PEX syndrome/glaucoma patients and controls in correlation with their individual single nucleotide polymorphism genotypes and stages of disease. LOXL1 ocular expression was reduced by approximately 20% per risk allele of rs1048661, whereas risk alleles of rs3825942, which were highly overrepresented in PEX cases, did not affect LOXL1 expression levels. Irrespective of the individual genotype, LOXL1 expression was significantly increased in early PEX stages but was decreased in advanced stages both with and without glaucoma compared with controls, whereas LOX and LOXL2 showed no differences between groups. LOXL1 was also found to be a major component of fibrillar PEX aggregates in both intra- and extraocular locations and to co-localize with various elastic fiber components. These findings provide evidence for LOXL1 involvement in the initial stages of abnormal fibrogenesis in PEX tissues. Alterations of LOXL1 activation, processing, and/or substrate specificity may contribute to the abnormal aggregation of elastic fiber components into characteristic PEX fibrils.
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Schlötzer-Schrehardt U. Molecular pathology of pseudoexfoliation syndrome/glaucoma--new insights from LOXL1 gene associations. Exp Eye Res 2008; 88:776-85. [PMID: 18809397 DOI: 10.1016/j.exer.2008.08.012] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 08/15/2008] [Accepted: 08/19/2008] [Indexed: 02/08/2023]
Abstract
Pseudoexfoliation (PEX) syndrome is a generalized disease of the extracellular matrix and a major cause of severe open-angle glaucoma. Single nucleotide polymorphisms (SNPs) in exon 1 of the lysyl oxidase-like 1 (LOXL1) gene have been recently identified as strong genetic risk factors for both PEX syndrome and PEX glaucoma. LOXL1 is a pivotal cross-linking enzyme in extracellular matrix metabolism and seems to be specifically required for elastic fiber formation and stabilization. This review outlines our current understanding of the role of LOXL1 in the pathophysiology of PEX syndrome and PEX glaucoma. The available data suggest that LOXL1 is differentially regulated dependent on the phase of progression of the fibrotic process. While increased levels of LOXL1 participate in the formation of abnormal PEX fiber aggregates in the initial phase of fibrogenesis, inadequate tissue levels may promote elastotic processes in advanced stages of the disease. Although the functional significance of LOXL1 in the specific PEX-associated matrix process still has to be determined, elucidation of the underlying molecular pathogenesis has been evolving, and might eventually open new approaches for specific treatment strategies in the future.
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Miao H, Chen L, Riordan SM, Li W, Juarez S, Crabb AM, Lukas TJ, Du P, Lin SM, Wise A, Agapova OA, Yang P, Gu CC, Hernandez MR. Gene expression and functional studies of the optic nerve head astrocyte transcriptome from normal African Americans and Caucasian Americans donors. PLoS One 2008; 3:e2847. [PMID: 18716680 PMCID: PMC2518525 DOI: 10.1371/journal.pone.0002847] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 07/07/2008] [Indexed: 11/19/2022] Open
Abstract
Purpose To determine whether optic nerve head (ONH) astrocytes, a key cellular component of glaucomatous neuropathy, exhibit differential gene expression in primary cultures of astrocytes from normal African American (AA) donors compared to astrocytes from normal Caucasian American (CA) donors. Methods We used oligonucleotide Affymetrix microarray (HG U133A & HG U133A 2.0 chips) to compare gene expression levels in cultured ONH astrocytes from twelve CA and twelve AA normal age matched donor eyes. Chips were normalized with Robust Microarray Analysis (RMA) in R using Bioconductor. Significant differential gene expression levels were detected using mixed effects modeling and Statistical Analysis of Microarray (SAM). Functional analysis and Gene Ontology were used to classify differentially expressed genes. Differential gene expression was validated by quantitative real time RT-PCR. Protein levels were detected by Western blots and ELISA. Cell adhesion and migration assays tested physiological responses. Glutathione (GSH) assay detected levels of intracellular GSH. Results Multiple analyses selected 87 genes differentially expressed between normal AA and CA (P<0.01). The most relevant genes expressed in AA were categorized by function, including: signal transduction, response to stress, ECM genes, migration and cell adhesion. Conclusions These data show that normal astrocytes from AA and CA normal donors display distinct expression profiles that impact astrocyte functions in the ONH. Our data suggests that differences in gene expression in ONH astrocytes may be specific to the development and/or progression of glaucoma in AA.
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Affiliation(s)
- Haixi Miao
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Lin Chen
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Sean M. Riordan
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Wenjun Li
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Santiago Juarez
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Andrea M. Crabb
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Thomas J. Lukas
- Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Pan Du
- Robert H, Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Simon M. Lin
- Robert H, Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Alexandria Wise
- Department of Biology, City College of New York, New York, New York, United States of America
| | - Olga A. Agapova
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Ping Yang
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Charles C. Gu
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - M. Rosario Hernandez
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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Pober BR, Johnson M, Urban Z. Mechanisms and treatment of cardiovascular disease in Williams-Beuren syndrome. J Clin Invest 2008; 118:1606-15. [PMID: 18452001 DOI: 10.1172/jci35309] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Williams-Beuren syndrome (WBS) is a microdeletion disorder caused by heterozygous loss of approximately 1.5-Mb pairs of DNA from chromosome 7. Patients with WBS have a characteristic constellation of medical and cognitive findings, with a hallmark feature of generalized arteriopathy presenting as stenoses of elastic arteries and hypertension. Human and mouse studies establish that defects in the elastin gene, leading to elastin haploinsufficiency, underlie the arteriopathy. In this review we describe potential links between elastin expression and arteriopathy, possible explanations for disease variability, and current treatment options and their limitations, and we propose several new directions for the development of nonsurgical preventative therapies based on insights from elastin biology.
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Affiliation(s)
- Barbara R Pober
- Department of Pediatrics, MassGeneral Hospital for Children, Simches Research Building, Rm. 222, 185 Cambridge St., Boston, Massachusetts 02114, USA.
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Sappington RM, Calkins DJ. Contribution of TRPV1 to microglia-derived IL-6 and NFkappaB translocation with elevated hydrostatic pressure. Invest Ophthalmol Vis Sci 2008; 49:3004-17. [PMID: 18362111 DOI: 10.1167/iovs.07-1355] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
PURPOSE The authors investigated the contributions of the transient receptor potential vanilloid-1 receptor (TRPV1) and Ca(2+) to microglial IL-6 and nuclear factor kappa B (NFkappaB) translocation with elevated hydrostatic pressure. METHODS The authors first examined IL-6 colocalization with the microglia marker Iba-1 in the DBA/2 mouse model of glaucoma to establish relevance. They isolated microglia from rat retina and maintained them at ambient or elevated (+70 mm Hg) hydrostatic pressure in vitro and used ELISA and immunocytochemistry to measure changes in the IL-6 concentration and NFkappaB translocation induced by the Ca(2+) chelator EGTA, the broad-spectrum Ca(2+) channel inhibitor ruthenium red, and the TRPV1 antagonist iodo-resiniferatoxin (I-RTX). They applied the Ca(2+) dye Fluo-4 AM to measure changes in intracellular Ca(2+) at elevated pressure induced by I-RTX and confirmed TRPV1 expression in microglia using PCR and immunocytochemistry. RESULTS In DBA/2 retina, elevated intraocular pressure increased microglial IL-6 in the ganglion cell layer. Elevated hydrostatic pressure (24 hours) increased microglial IL-6 release, cytosolic NFkappaB, and NFkappaB translocation in vitro. These effects were reduced substantially by EGTA and ruthenium red. Antagonism of TRPV1 in microglia partially inhibited pressure-induced increases in IL-6 release and NFkappaB translocation. Brief elevated pressure (1 hour) induced a significant increase in microglial intracellular Ca(2+) that was partially attenuated by TRPV1 antagonism. CONCLUSIONS Elevated pressure induces an influx of extracellular Ca(2+) in retinal microglia that precedes the activation of NFkappaB and the subsequent production and release of IL-6 and is at least partially dependent on the activation of TRPV1 and other ruthenium red-sensitive channels.
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Affiliation(s)
- Rebecca M Sappington
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0654, USA
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Traboulsi EI, Sarfarazi M. The use of microarray technology in deciphering the cause of genetic eye diseases: LOXL1 and exfoliation syndrome. Am J Ophthalmol 2008; 145:391-3. [PMID: 18282488 DOI: 10.1016/j.ajo.2007.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2007] [Revised: 11/28/2007] [Accepted: 12/01/2007] [Indexed: 11/16/2022]
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Hernandez MR, Miao H, Lukas T. Astrocytes in glaucomatous optic neuropathy. PROGRESS IN BRAIN RESEARCH 2008; 173:353-73. [DOI: 10.1016/s0079-6123(08)01125-4] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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