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Kapuganti RS, Sahoo L, Mohanty PP, Hayat B, Parija S, Alone DP. Role of clusterin gene 3'-UTR polymorphisms and promoter hypomethylation in the pathogenesis of pseudoexfoliation syndrome and pseudoexfoliation glaucoma. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194980. [PMID: 37652361 DOI: 10.1016/j.bbagrm.2023.194980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/16/2023] [Accepted: 08/21/2023] [Indexed: 09/02/2023]
Abstract
Pseudoexfoliation (PEX) is a multifactorial age-related disease characterized by the deposition of extracellular fibrillar aggregates in the anterior ocular tissues. This study aims to identify the genetic and epigenetic contribution of clusterin (CLU) in PEX pathology. CLU is a molecular chaperone upregulated in PEX and genetically associated with the disease. Sequencing of a 2.9 kb region encompassing the previously associated rs2279590 in 250 control and 313 PEX [(207 pseudoexfoliation syndrome (PEXS) and 106 pseudoexfoliation glaucoma (PEXG)] individuals identified three single nucleotide polymorphisms (SNPs), rs9331942, rs9331949 and rs9331950, in the 3'-UTR of CLU of which rs9331942 and rs9331949 were found to be significantly associated with PEXS and PEXG as risk factors. Following in silico analysis, in vitro luciferase reporter assays in human embryonic kidney cells revealed that risk alleles at rs9331942 and rs9331949 bind to miR-223 and miR-1283, respectively, suggesting differential regulation of clusterin in the presence of risk alleles at the SNPs. Further, through bisulfite sequencing, we also identified that CLU promoter is hypomethylated in DNA from blood and lens capsules of PEX patients compared to controls that correlated with decreased expression of DNA methyltransferase 1 (DNMT1). Promoter demethylation of CLU using DNMT inhibitor, 5'-aza-dC, in human lens epithelial cells increased CLU expression. Chromatin immunoprecipitation assays showed that the demethylated CLU promoter provides increased access to the transcription factor, Sp1, which might lead to enhanced expression of CLU. In conclusion, this study highlights the different molecular mechanisms of clusterin regulation in pseudoexfoliation pathology.
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Affiliation(s)
- Ramani Shyam Kapuganti
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | - Lipsa Sahoo
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | | | - Bushra Hayat
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | - Sucheta Parija
- All India Institute of Medical Sciences, Bhubaneswar, Sijua, Patrapada, Bhubaneswar, Odisha, 751019, India
| | - Debasmita Pankaj Alone
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India.
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2
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Gross C, Guérin LP, Socol BG, Germain L, Guérin SL. The Ins and Outs of Clusterin: Its Role in Cancer, Eye Diseases and Wound Healing. Int J Mol Sci 2023; 24:13182. [PMID: 37685987 PMCID: PMC10488069 DOI: 10.3390/ijms241713182] [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: 06/30/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Clusterin (CLU) is a glycoprotein originally discovered in 1983 in ram testis fluid. Rapidly observed in other tissues, it was initially given various names based on its function in different tissues. In 1992, it was finally named CLU by consensus. Nearly omnipresent in human tissues, CLU is strongly expressed at fluid-tissue interfaces, including in the eye and in particular the cornea. Recent research has identified different forms of CLU, with the most prominent being a 75-80 kDa heterodimeric protein that is secreted. Another truncated version of CLU (55 kDa) is localized to the nucleus and exerts pro-apoptotic activities. CLU has been reported to be involved in various physiological processes such as sperm maturation, lipid transportation, complement inhibition and chaperone activity. CLU was also reported to exert important functions in tissue remodeling, cell-cell adhesion, cell-substratum interaction, cytoprotection, apoptotic cell death, cell proliferation and migration. Hence, this protein is sparking interest in tissue wound healing. Moreover, CLU gene expression is finely regulated by cytokines, growth factors and stress-inducing agents, leading to abnormally elevated levels of CLU in many states of cellular disturbance, including cancer and neurodegenerative conditions. In the eye, CLU expression has been reported as being severely increased in several pathologies, such as age-related macular degeneration and Fuch's corneal dystrophy, while it is depleted in others, such as pathologic keratinization. Nevertheless, the precise role of CLU in the development of ocular pathologies has yet to be deciphered. The question of whether CLU expression is influenced by these disorders or contributes to them remains open. In this article, we review the actual knowledge about CLU at both the protein and gene expression level in wound healing, and explore the possibility that CLU is a key factor in cancer and eye diseases. Understanding the expression and regulation of CLU could lead to the development of novel therapeutics for promoting wound healing.
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Affiliation(s)
- Christelle Gross
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
- Centre de Recherche du CHU de Québec, Axe Médecine Régénératrice, Québec City, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
| | | | - Bianca G. Socol
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
| | - Lucie Germain
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
- Centre de Recherche du CHU de Québec, Axe Médecine Régénératrice, Québec City, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Sylvain L. Guérin
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
- Centre de Recherche du CHU de Québec, Axe Médecine Régénératrice, Québec City, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
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3
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Murenu E, Gerhardt MJ, Biel M, Michalakis S. More than meets the eye: The role of microglia in healthy and diseased retina. Front Immunol 2022; 13:1006897. [PMID: 36524119 PMCID: PMC9745050 DOI: 10.3389/fimmu.2022.1006897] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 11/11/2022] [Indexed: 11/30/2022] Open
Abstract
Microglia are the main resident immune cells of the nervous system and as such they are involved in multiple roles ranging from tissue homeostasis to response to insults and circuit refinement. While most knowledge about microglia comes from brain studies, some mechanisms have been confirmed for microglia cells in the retina, the light-sensing compartment of the eye responsible for initial processing of visual information. However, several key pieces of this puzzle are still unaccounted for, as the characterization of retinal microglia has long been hindered by the reduced population size within the retina as well as the previous lack of technologies enabling single-cell analyses. Accumulating evidence indicates that the same cell type may harbor a high degree of transcriptional, morphological and functional differences depending on its location within the central nervous system. Thus, studying the roles and signatures adopted specifically by microglia in the retina has become increasingly important. Here, we review the current understanding of retinal microglia cells in physiology and in disease, with particular emphasis on newly discovered mechanisms and future research directions.
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Affiliation(s)
- Elisa Murenu
- Department of Ophthalmology, Klinikum der Ludwig-Maximilians-Universität München, Munich, Germany,*Correspondence: Elisa Murenu, ; ; Stylianos Michalakis,
| | | | - Martin Biel
- Department of Pharmacy, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Department of Ophthalmology, Klinikum der Ludwig-Maximilians-Universität München, Munich, Germany,*Correspondence: Elisa Murenu, ; ; Stylianos Michalakis,
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Mastronikolis S, Pagkalou M, Plotas P, Kagkelaris K, Georgakopoulos C. Emerging roles of oxidative stress in the pathogenesis of pseudoexfoliation syndrome (Review). Exp Ther Med 2022; 24:602. [PMID: 35949329 PMCID: PMC9353531 DOI: 10.3892/etm.2022.11539] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/06/2022] [Indexed: 11/25/2022] Open
Abstract
Pseudoexfoliation syndrome (PEXS) is a systemic disease caused by defects in the extracellular matrix (ECM) remodelling process leading to the chronic deposition of extracellular, fibrillary, white flaky pseudoexfoliation material (PEXM) throughout the body. Specifically, PEXM deposits on the lens capsule cause open-angle glaucoma, cataracts and blindness in patients with PEXS. Several gene single nucleotide polymorphisms are linked to the development of PEXS in humans, including lysyl oxidase-like 1 gene, clusterin and fibulin-5. The exact reason for the PEXM generation and its resulting pathogenesis is not well understood. However, defective ECM remodelling and oxidative stress (OS) have been hypothesized as significant events leading to the PEXM. Specifically, the link between OS and PEXS has been well studied, although the investigation is still ongoing. The present review explored recent advances in various aspects of PEXS and the involvement of OS in the eye for PEXS development.
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Affiliation(s)
| | - Marina Pagkalou
- Department of Chemistry, University of Crete, 70013 Heraklion, Greece
| | - Panagiotis Plotas
- Laboratory of Primary Health Care, School of Health Rehabilitation Sciences, University of Patras, 26334 Patras, Greece
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Soundararajan A, Wang T, Ghag SA, Kang MH, Pattabiraman PP. Novel insight into the role of clusterin on intraocular pressure regulation by modifying actin polymerization and extracellular matrix remodeling in the trabecular meshwork. J Cell Physiol 2022; 237:3012-3029. [PMID: 35567755 PMCID: PMC9283260 DOI: 10.1002/jcp.30769] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 04/03/2022] [Accepted: 04/20/2022] [Indexed: 11/09/2022]
Abstract
This study provides comprehensive mechanistic evidence for the role of clusterin, a stress-response secretory chaperone protein, in the modulation of intraocular pressure (IOP) by regulating the trabecular meshwork (TM) actin cytoskeleton and the extracellular matrix (ECM). The pathological stressors on TM known to elevate IOP significantly lowered clusterin protein levels indicating stress-related clusterin function loss. Small interfering RNA-mediated clusterin loss in human TM cells in vitro induced actin polymerization and stabilization via protein kinase D1, serine/threonine-protein kinase N2 (PRK2), and LIM kinase 1 (LIMK1), and the recruitment and activation of adhesome proteins including paxillin, vinculin, and integrin αV and β5. A complete loss of clusterin as seen in clusterin knockout mice (Clu-/- ) led to significant IOP elevation at postnatal Day 70. Contrarily, constitutive clusterin expression using adenovirus (AdCLU) in HTM cells resulted in the loss of actin polymerization via decreased PRK2, and LIMK1 and negative regulation of integrin αV and β5. Furthermore, we found that AdCLU treatment in HTM cells significantly decreased the ECM protein expression and distribution by significantly increasing matrix metalloprotease 2 (MMP2) activity and lowering the levels of pro-fibrotic proteins such as transforming growth factor-β2 (TGFβ2), thrombospondin-1 (TSP-1), and plasminogen activator inhibitor-1 (PAI-1). Finally, we found that HTM cells supplemented with recombinant human clusterin attenuated the pro-fibrotic effects of TGFβ2. For the first time this study demonstrates the importance of clusterin in the regulation of TM actin cytoskeleton - ECM interactions and the maintenance of IOP, thus making clusterin an interesting target to reverse elevated IOP.
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Affiliation(s)
- Avinash Soundararajan
- Department of Ophthalmology, Glick Eye InstituteIndiana University School of MedicineIndianapolisIndianaUSA
| | - Ting Wang
- Department of Ophthalmology, Glick Eye InstituteIndiana University School of MedicineIndianapolisIndianaUSA
- Stark Neuroscience Research InstituteIndiana University Purdue University IndianapolisIndianapolisIndianaUSA
| | - Sachin A. Ghag
- Department of Ophthalmology, Glick Eye InstituteIndiana University School of MedicineIndianapolisIndianaUSA
| | - Min H. Kang
- Department of Ophthalmology and Visual Sciences, University Hospitals Eye InstituteCase Western Reserve University School of MedicineClevelandOhioUSA
| | - Padmanabhan P. Pattabiraman
- Department of Ophthalmology, Glick Eye InstituteIndiana University School of MedicineIndianapolisIndianaUSA
- Stark Neuroscience Research InstituteIndiana University Purdue University IndianapolisIndianapolisIndianaUSA
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6
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Chakraborty M, Rao A. Alternate Causes for Pathogenesis of Exfoliation Glaucoma, a Multifactorial Elastotic Disorder: A Literature Review. Curr Issues Mol Biol 2022; 44:1191-1202. [PMID: 35723301 PMCID: PMC8946964 DOI: 10.3390/cimb44030078] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 12/27/2022] Open
Abstract
Exfoliation glaucoma (XFG) is the most recognizable form of secondary open-angle glaucoma associated with a high risk of blindness. This disease is characterized by white flaky granular deposits in the anterior chamber that leads to the elevation of intraocular pressure (IOP) and subsequent glaucomatous optic nerve damage. Conventionally, XFG is known to respond poorly to medical therapy, and surgical intervention is the only management option in most cases. Various genetic and nongenetic factors are known to be linked to the development of XFG. Despite decades of research on the genetic factors in exfoliation syndrome (XFS) by study groups and global consortia involving different ethnic populations, the pathogenesis of XFS and the mechanism of onset of glaucoma still remains an unsolved mystery. The key lies in understanding how the function of a gene (or set of genes) is altered by environmental triggers, along with other molecular events that underlie the key disease attributes, namely, oxidative stress and the disruption of the blood–aqueous barrier (BAB). It remains a challenge to evolve a theory encompassing all factions of molecular events occurring independently or parallelly that determine the disease manifestation (phenotype) or the stage of the disease in the eye (or in any tissue) in exfoliation. Our enhanced understanding of the underlying molecular pathophysiology of XFG, beyond the known genes or polymorphisms involved in the disease, will lead to improved diagnosis and management and the ability to recognize how the environment influences these key events that lead to the disease phenotype or disease progression. This review summarizes the recent observations and discoveries of four key factors that may hold the answers to the non-lysyl oxidase-like 1 (LOXL1) mechanisms behind XFG pathogenesis, namely, the epigenetic factor miRNA, disordered autophagy along with the potential involvement of mitochondrial mutations, and a compromised aqueous–blood barrier.
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Affiliation(s)
- Munmun Chakraborty
- Hyderabad Eye Research Foundation (HERF), L.V. Prasad Eye Institute, Bhubaneswar 751024, Odisha, India;
- School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Aparna Rao
- Hyderabad Eye Research Foundation (HERF), L.V. Prasad Eye Institute, Bhubaneswar 751024, Odisha, India;
- School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
- Correspondence:
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7
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Mastronikolis S, Pagkalou M, Baroutas G, Kyriakopoulou K, Makri ΟE, Georgakopoulos CD. Pseudoexfoliation syndrome: The critical role of the extracellular matrix in pathogenesis and treatment. IUBMB Life 2022; 74:995-1002. [PMID: 35201654 DOI: 10.1002/iub.2606] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/30/2022] [Accepted: 02/07/2022] [Indexed: 11/11/2022]
Abstract
Pseudoexfoliation syndrome (PEXS) is an age-related condition manifesting mainly in ocular tissues. PEXS is manifested through excess aggregation of fibrillary extracellular material at the anterior part of the eye that consists of a plethora of biomolecules, such as different proteoglycans (PGs) and glycosaminoglycans. PEXS is often linked to increased intraocular pressure, and can also lead to pseudoexfoliation glaucoma with very poor prognosis. Various stimuli are known to affect PEXS, including oxidation stress (OS), UV radiation and osmotic pressure. OS, is prominently involved on the progression of the syndrome as it promotes fibrogenesis, possibly via the induction of transforming growth factor-β (TGF-β) and other biomolecular effectors. In addition, PEXS initiation is tightly connected with the dysregulation of extracellular matrix (ECM) homeostasis since aberrant expression of ECM molecules is linked to both the accumulation and low degradation of pseudoexfoliation material. This article aims at uncovering the crucial role of various ECM effectors such as lysyl oxidase-like proteins, matrix metalloproteinases, and TGF-β1, as well as the biochemical pathways involved in the development and the progression of the PEXS.
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Affiliation(s)
- Stylianos Mastronikolis
- Department of Ophthalmology, Medical School, University of Patras, Rion, Achaia, Greece.,Neurosurgery Department, James Cook University Hospital, Middlesbrough, UK
| | - Marina Pagkalou
- Department of Chemistry, University of Crete, Voutes, Heraklion, Greece
| | - Giorgos Baroutas
- Biochemistry Biochemical Analysis & Matrix Pathobiology Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, Patras, Greece
| | - Konstantina Kyriakopoulou
- Biochemistry Biochemical Analysis & Matrix Pathobiology Research Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, Patras, Greece
| | - Οlga E Makri
- Department of Ophthalmology, Medical School, University of Patras, Rion, Achaia, Greece
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8
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Proteome alterations in the aqueous humor reflect structural and functional phenotypes in patients with advanced normal-tension glaucoma. Sci Rep 2022; 12:1221. [PMID: 35075201 PMCID: PMC8786875 DOI: 10.1038/s41598-022-05273-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 12/23/2021] [Indexed: 12/28/2022] Open
Abstract
Previous reports have shown possible association between altered protein levels in aqueous humor (AH) and normal-tension glaucoma (NTG), but the underlying pathogenetic mechanism as well as specific molecular biomarkers for NTG remains still elusive. Here, we aimed to identify novel biomarkers for advanced NTG by analyzing the proteome of patient-derived AH and their correlation with various functional and structural parameters from the visual field test (VF), optical coherence tomography (OCT), and OCT angiography (OCTA). We determined differentially expressed proteins (DEPs) of the AH of patients with advanced NTG (n = 20) using label-free quantitative (LFQ) proteomics with pooled samples and data-independent acquisition (DIA) analysis with individual samples, and the roles of AH DEPs in biological pathways were evaluated using bioinformatics. We identified 603 proteins in the AH of patients with advanced NTG, and 61 of them were selected as DEPs via global proteome LFQ profiling. Individual DIA analyses identified a total of 12 DEPs as biomarker candidates, seven of which were upregulated, and five were downregulated. Gene ontology enrichment analysis revealed that those DEPs were mainly involved in the immune response. Moreover, IGFBP2, ENO1, C7, B2M, AMBP, DSP, and DCD showed a significant correlation with the mean deviation of VF and with peripapillary and macular parameters from OCT and OCTA. The present study provides possible molecular biomarkers for the diagnosis of advanced NTG.
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9
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Upregulated NOTCH Signaling in the Lens of Patients with Pseudoexfoliation Syndrome Compared to Pseudoexfoliation Glaucoma Suggests Protective Role. J Glaucoma 2022; 31:e1-e9. [DOI: 10.1097/ijg.0000000000001975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 12/03/2021] [Indexed: 11/26/2022]
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10
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Li J, Du L, He JN, Chu KO, Guo CL, Wong MOM, Pang CP, Chu WK. Anti-inflammatory Effects of GTE in Eye Diseases. Front Nutr 2021; 8:753955. [PMID: 34966770 PMCID: PMC8711650 DOI: 10.3389/fnut.2021.753955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 11/22/2021] [Indexed: 12/14/2022] Open
Abstract
Ocular inflammation is a common complication of various eye diseases with wide consequences from irritations to potentially sight-threatening complications. Green tea is a popular beverage throughout the world. One of the proven health benefits of consuming green tea extract (GTE) is anti-inflammation. Catechins are the biologically active constituents of GTE. In in vitro and in vivo studies, GTE and catechins present inhibition of inflammatory responses in the development of ocular inflammation including infectious, non-infectious or autoimmune, and oxidative-induced complications. Research on the ocular inflammation in animal models has made significant progress in the past decades and several key disease mechanisms have been identified. Here we review the experimental investigations on the effects of GTE and catechins on various ocular inflammation related diseases including glaucoma, age-related macular degeneration, uveitis and ocular surface inflammation. We also review the pharmacokinetics of GTE constituents and safety of green tea consumption. We discuss the insights and perspectives of these experimental results, which would be useful for future development of novel therapeutics in human.
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Affiliation(s)
- Jian Li
- Department of Ophthalmology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Lin Du
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Jing Na He
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Kai On Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Cosmos Liutao Guo
- Bachelor of Medicine and Bachelor of Surgery Programme, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Mandy Oi Man Wong
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China.,Hong Kong Eye Hospital, Hong Kong, Hong Kong SAR, China
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Wai Kit Chu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
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11
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Reinehr S, Doerner JD, Mueller-Buehl AM, Koch D, Fuchshofer R, Dick HB, Joachim SC. Cytokine and Complement Response in the Glaucomatous βB1-CTGF Mouse Model. Front Cell Neurosci 2021; 15:718087. [PMID: 34867198 PMCID: PMC8637215 DOI: 10.3389/fncel.2021.718087] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 10/22/2021] [Indexed: 11/13/2022] Open
Abstract
Glaucoma is a complex neurodegenerative disease leading to a loss of retinal ganglion cells (RGCs) and optic nerve axons. An activation of the complement system seems to contribute to cell loss in this disease. Hence, we investigated a possible initiation of the complement system and the cytokine response in the βB1-CTGF glaucoma model. In these mice, intraocular pressure is elevated, which is the main glaucoma risk factor in patients, and RGC loss occurs at 15 weeks of age. Therefore, quantitative real-time PCR and immunohistological experiments were performed in 5-, 10-, and 15-week-old βB1-CTGF animals and their corresponding wildtypes (WT) to analyze the expression of several complement system factors. We could show that mRNA levels of the terminal complement pathway components C3 and C5 (Hc) were upregulated at 10 weeks. In accordance, more C3+ and membrane attack complex+ cells were observed in transgenic retinae. Further, the C5a receptor anaphylatoxin receptor (C5ar) and the complement component C5a receptor 1 (C5ar1; CD88) mRNA levels were upregulated in 10- and 15-week-old βB1-CTGF mice. Interestingly, all three activation routes of the complement system were elevated in βB1-CTGF mice at some age. Especially C1q, as a marker of the classical pathway, was significantly increased at all investigated ages. Furthermore, mRNA expression levels of interferon-γ (Infg) were upregulated at 5 weeks, while Cxcl1 and Cxcl2 mRNA levels were upregulated at 10 and 15 weeks. The mRNA levels of the chemokines Cxcl10 were increased at all ages in βB1-CTGF mice. These results lead to the assumption that in these transgenic mice, a complement activation mainly through the classical pathway as well as a cytokine response plays a major role in cell death.
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Affiliation(s)
- Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Johanna D. Doerner
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Ana M. Mueller-Buehl
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Dennis Koch
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Rudolf Fuchshofer
- Institute of Human Anatomy and Embryology, University Regensburg, Regensburg, Germany
| | - H. Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
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12
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Rostagno A, Calero M, Holton JL, Revesz T, Lashley T, Ghiso J. Association of clusterin with the BRI2-derived amyloid molecules ABri and ADan. Neurobiol Dis 2021; 158:105452. [PMID: 34298087 PMCID: PMC8440498 DOI: 10.1016/j.nbd.2021.105452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 06/30/2021] [Accepted: 07/18/2021] [Indexed: 10/20/2022] Open
Abstract
Familial British and Danish dementias (FBD and FDD) share striking neuropathological similarities with Alzheimer's disease (AD), including intraneuronal neurofibrillary tangles as well as parenchymal and vascular amyloid deposits. Multiple amyloid associated proteins with still controversial role in amyloidogenesis colocalize with the structurally different amyloid peptides ABri in FBD, ADan in FDD, and Aβ in AD. Genetic variants and plasma levels of one of these associated proteins, clusterin, have been identified as risk factors for AD. Clusterin is known to bind soluble Aβ in biological fluids, facilitate its brain clearance, and prevent its aggregation. The current work identifies clusterin as the major ABri- and ADan-binding protein and provides insight into the biochemical mechanisms leading to the association of clusterin with ABri and ADan deposits. Mirroring findings in AD, the studies corroborate clusterin co-localization with cerebral parenchymal and vascular amyloid deposits in both disorders. Ligand affinity chromatography with downstream Western blot and amino acid sequence analyses unequivocally identified clusterin as the major ABri- and ADan-binding plasma protein. ELISA highlighted a specific saturable binding of clusterin to ABri and ADan with low nanomolar Kd values within the same range as those previously demonstrated for the clusterin-Aβ interaction. Consistent with its chaperone activity, thioflavin T binding assays clearly showed a modulatory effect of clusterin on ABri and ADan aggregation/fibrillization properties. Our findings, together with the known multifunctional activity of clusterin and its modulatory activity on the complex cellular pathways leading to oxidative stress, mitochondrial dysfunction, and the induction of cell death mechanisms - all known pathogenic features of these protein folding disorders - suggests the likelihood of a more complex role and a translational potential for the apolipoprotein in the amelioration/prevention of these pathogenic mechanisms.
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Affiliation(s)
- Agueda Rostagno
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Miguel Calero
- Instituto de Salud Carlos III, 28029 Madrid, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; Alzheimer's Center Reina Sofia Foundation - CIEN Foundation, 28031 Madrid, Spain
| | - Janice L Holton
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Tamas Revesz
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK; Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Tammaryn Lashley
- The Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK; Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA; Department of Psychiatry, New York University School of Medicine, New York, NY 10016, USA.
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Cueto AFV, Álvarez L, García M, Álvarez-Barrios A, Artime E, Cueto LFV, Coca-Prados M, González-Iglesias H. Candidate Glaucoma Biomarkers: From Proteins to Metabolites, and the Pitfalls to Clinical Applications. BIOLOGY 2021; 10:763. [PMID: 34439995 PMCID: PMC8389649 DOI: 10.3390/biology10080763] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/05/2021] [Accepted: 08/08/2021] [Indexed: 12/17/2022]
Abstract
Glaucoma is an insidious group of eye diseases causing degeneration of the optic nerve, progressive loss of vision, and irreversible blindness. The number of people affected by glaucoma is estimated at 80 million in 2021, with 3.5% prevalence in people aged 40-80. The main biomarker and risk factor for the onset and progression of glaucoma is the elevation of intraocular pressure. However, when glaucoma is diagnosed, the level of retinal ganglion cell death usually amounts to 30-40%; hence, the urgent need for its early diagnosis. Molecular biomarkers of glaucoma, from proteins to metabolites, may be helpful as indicators of pathogenic processes observed during the disease's onset. The discovery of human glaucoma biomarkers is hampered by major limitations, including whether medications are influencing the expression of molecules in bodily fluids, or whether tests to validate glaucoma biomarker candidates should include human subjects with different types and stages of the disease, as well as patients with other ocular and neurodegenerative diseases. Moreover, the proper selection of the biofluid or tissue, as well as the analytical platform, should be mandatory. In this review, we have summarized current knowledge concerning proteomics- and metabolomics-based glaucoma biomarkers, with specificity to human eye tissue and fluid, as well the analytical approach and the main results obtained. The complex data published to date, which include at least 458 different molecules altered in human glaucoma, merit a new, integrative approach allowing for future diagnostic tests based on the absolute quantification of local and/or systemic biomarkers of glaucoma.
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Affiliation(s)
- Andrés Fernández-Vega Cueto
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain; (A.F.-V.C.); (M.G.)
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (L.Á.); (A.Á.-B.); (E.A.)
| | - Lydia Álvarez
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (L.Á.); (A.Á.-B.); (E.A.)
| | - Montserrat García
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain; (A.F.-V.C.); (M.G.)
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (L.Á.); (A.Á.-B.); (E.A.)
| | - Ana Álvarez-Barrios
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (L.Á.); (A.Á.-B.); (E.A.)
| | - Enol Artime
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (L.Á.); (A.Á.-B.); (E.A.)
| | - Luis Fernández-Vega Cueto
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain; (A.F.-V.C.); (M.G.)
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (L.Á.); (A.Á.-B.); (E.A.)
| | - Miguel Coca-Prados
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT 06510, USA;
| | - Héctor González-Iglesias
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain; (A.F.-V.C.); (M.G.)
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (L.Á.); (A.Á.-B.); (E.A.)
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Immune Responses in the Glaucomatous Retina: Regulation and Dynamics. Cells 2021; 10:cells10081973. [PMID: 34440742 PMCID: PMC8391899 DOI: 10.3390/cells10081973] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 12/27/2022] Open
Abstract
Glaucoma is a multifactorial disease resulting in progressive vision loss due to retinal ganglion cell (RGC) dysfunction and death. Early events in the pathobiology of the disease include oxidative, metabolic, or mechanical stress that acts upon RGC, causing these to rapidly release danger signals, including extracellular ATP, resulting in micro- and macroglial activation and neuroinflammation. Danger signaling also leads to the formation of inflammasomes in the retina that enable maturation of proinflammatory cytokines such IL-1β and IL-18. Chronic neuroinflammation can have directly damaging effects on RGC, but it also creates a proinflammatory environment and compromises the immune privilege of the retina. In particular, continuous synthesis of proinflammatory mediators such as TNFα, IL-1β, and anaphylatoxins weakens the blood–retina barrier and recruits or activates T-cells. Recent data have demonstrated that adaptive immune responses strongly exacerbate RGC loss in animal models of the disease as T-cells appear to target heat shock proteins displayed on the surface of stressed RGC to cause their apoptotic death. It is possible that dysregulation of these immune responses contributes to the continued loss of RGC in some patients.
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Yavrum F, Elgin U, Kocer ZA, Fidanci V, Sen E. Evaluation of aqueous humor and serum clusterin levels in patients with glaucoma. BMC Ophthalmol 2021; 21:25. [PMID: 33422048 PMCID: PMC7796574 DOI: 10.1186/s12886-020-01781-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/21/2020] [Indexed: 12/03/2022] Open
Abstract
Background To compare the aqueous humor (AH) and the serum clusterin levels of patients with pseudoexfoliation syndrome (PEX), pseudoexfoliation glaucoma (PEXG), and primary open-angle glaucoma (POAG) with each other and with an age- and sex-matched control group. Methods This prospective, cross-sectionalstudy evaluated 92 eyes from 92 adult cases of uncomplicated phacoemulsification and posterior chamber intraocular lens (IOL) implantation. The cases were divided into PEX, PEXG, POAG, and control groups. Serum samples were taken from the antecubital vein just before the surgery, and the AH samples were aspirated at the beginning of the surgery. Kruskal-Wallis H, One-way ANOVA, Mann-Whitney U with Bonferroni correction and Chi-Square tests were used for statistical analysis. Results The serum clusterin levels were the highest in the PEXG group, but no statistically significant differences were observed between the groups (p=0.633). The mean AH clusterin levels were 286.79±29.64 μg/mL in the PEXG group, 263.92±31.70 μg/mL in the PEX group, 272.59±49.71 μg/mL in the POAG group, and 193.50±62.38 μg/mL in the control group (p< 0.001). This came out to be 1.48 times increase for the PEXG group, 1.36 for the PEX group, and 1.41 for the POAG group when compared with the control subjects. Conclusions A higher level of clusterin in the anterior chamber was found to be associated with PEX and PEXG. In addition, a high level of anterior chamber clusterin in POAG, which is a new finding, showed that this molecule might be important not only in pseudoexfoliation, but also other types of glaucoma like POAG.
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Affiliation(s)
| | - Ufuk Elgin
- University of Health Sciences, Ulucanlar Eye Research Hospital, Ankara, Turkey
| | - Zeynep Adiyaman Kocer
- University of Health Sciences, Ankara Research and Training Hospital, Ankara, Turkey
| | - Vildan Fidanci
- University of Health Sciences, Ankara Research and Training Hospital, Ankara, Turkey
| | - Emine Sen
- University of Health Sciences, Ulucanlar Eye Research Hospital, Ankara, Turkey
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Barnum SR, Bubeck D, Schein TN. Soluble Membrane Attack Complex: Biochemistry and Immunobiology. Front Immunol 2020; 11:585108. [PMID: 33240274 PMCID: PMC7683570 DOI: 10.3389/fimmu.2020.585108] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
The soluble membrane attack complex (sMAC, a.k.a., sC5b-9 or TCC) is generated on activation of complement and contains the complement proteins C5b, C6, C7, C8, C9 together with the regulatory proteins clusterin and/or vitronectin. sMAC is a member of the MACPF/cholesterol-dependent-cytolysin superfamily of pore-forming molecules that insert into lipid bilayers and disrupt cellular integrity and function. sMAC is a unique complement activation macromolecule as it is comprised of several different subunits. To date no complement-mediated function has been identified for sMAC. sMAC is present in blood and other body fluids under homeostatic conditions and there is abundant evidence documenting changes in sMAC levels during infection, autoimmune disease and trauma. Despite decades of scientific interest in sMAC, the mechanisms regulating its formation in healthy individuals and its biological functions in both health and disease remain poorly understood. Here, we review the structural differences between sMAC and its membrane counterpart, MAC, and examine sMAC immunobiology with respect to its presence in body fluids in health and disease. Finally, we discuss the diagnostic potential of sMAC for diagnostic and prognostic applications and potential utility as a companion diagnostic.
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Affiliation(s)
| | - Doryen Bubeck
- Department of Life Sciences, Imperial College London, London, United Kingdom
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Simsek M, Kocer AM, Cevik S, Sen E, Elgin U. Evaluation of the optic nerve head vessel density in the patients with asymmetric pseudoexfoliative glaucoma: an OCT angiography study. Graefes Arch Clin Exp Ophthalmol 2020; 258:1493-1501. [PMID: 32300958 DOI: 10.1007/s00417-020-04668-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 03/22/2020] [Accepted: 03/27/2020] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To evaluate vascular microcirculation changes of the optic nerve head (ONH) in the patients with asymmetric pseudoexfoliative glaucoma (XFG) using optical coherence tomography angiography (OCTA) and to compare vessel density (VD) results with healthy individuals. METHODS This prospective study enrolled 120 eyes in total. The eyes were divided into 3 groups: 40 glaucomatous and 40 non-glaucomatous fellow eyes without clinically pseudoexfoliation material (XFM) of patients with asymmetric XFG, and 40 healthy eyes as controls. The optic disc region was evaluated with OCTA (Optovue, Inc., Fremont, CA). VD was assessed as the ratio of the area formed by the vessels in 3 different regions: (1) inside disc; (2) in the peripapillary area defined as a 1-mm wide elliptical annulus around the disc; and (3) in the whole image defined as a 4-mm wide papillary region. RESULTS There were significant decreases in VD values of all regions in XFG eyes compared to fellow and control eyes (p < 0.05 for all comparisons). The mean VD values of peripapillary area and whole image were lower in the non-glaucomatous fellow eyes compared with control eyes (p = 0.011 and p = 0.015, respectively). The receiver operating characteristic analysis for differentiating fellow eyes from healthy eyes had highest area under the curve and sensitivity at 90% specificity for superior-hemi (0.811, 65.2%), followed by ppVD (0.775, 61.8%) and whole image (0.743, 55.9%). CONCLUSIONS OCTA as a novel imaging may be a valuable structural test in diagnosis and follow-up of glaucoma.
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Affiliation(s)
- Mert Simsek
- Department of Ophthalmology, Ulucanlar Eye Education and Research Hospital, University of Health Sciences, Kale Mahallesi, Ulucanlar Caddesi, No:59, 06250, Altındağ/Ankara, Turkey.
| | - Ali Mert Kocer
- Department of Ophthalmology, Ulucanlar Eye Education and Research Hospital, University of Health Sciences, Kale Mahallesi, Ulucanlar Caddesi, No:59, 06250, Altındağ/Ankara, Turkey
| | - Seda Cevik
- Department of Ophthalmology, Ulucanlar Eye Education and Research Hospital, University of Health Sciences, Kale Mahallesi, Ulucanlar Caddesi, No:59, 06250, Altındağ/Ankara, Turkey
| | - Emine Sen
- Department of Ophthalmology, Ulucanlar Eye Education and Research Hospital, University of Health Sciences, Kale Mahallesi, Ulucanlar Caddesi, No:59, 06250, Altındağ/Ankara, Turkey
| | - Ufuk Elgin
- Department of Ophthalmology, Ulucanlar Eye Education and Research Hospital, University of Health Sciences, Kale Mahallesi, Ulucanlar Caddesi, No:59, 06250, Altındağ/Ankara, Turkey
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Ghaffari Sharaf M, Damji KF, Unsworth LD. Recent advances in risk factors associated with ocular exfoliation syndrome. Acta Ophthalmol 2020; 98:113-120. [PMID: 31736276 DOI: 10.1111/aos.14298] [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: 04/05/2019] [Accepted: 10/13/2019] [Indexed: 12/12/2022]
Abstract
Exfoliation syndrome is generally considered a progressive age-related systemic disorder of the extracellular matrix, which is clinically characterized through the observation of flaky white aggregates on ocular tissues. Exfoliation syndrome is directly linked to exfoliative glaucoma in elderly patients, where it is known as the most common identifiable cause of open-angle glaucoma. Despite the identification of various risk factors associated with exfoliation syndrome, the exact pathogenesis of this syndrome has not been fully elucidated. There is a growing number of genome-wide association studies in different populations around the world to identify genetic factors underlying exfoliation syndrome. Besides variants in LOXL1 and CACNA1A genes, new loci have been recently identified which are believed to be associated with exfoliation syndrome. Among different genetic factors, functional variants might help to better understand mechanisms underlying this systemic disorder. Besides genetic factors, epigenetic regulation of different gene expression patterns has been thought to play a role in its pathogenesis. Other factors have been also considered to be involved in the development of exfoliation syndrome at cellular organelles level where mitochondrial impairment and autophagy dysfunction have been suggested in relation to exfoliation syndrome. This review addresses the most recent findings on genetic factors as well as cellular and molecular mechanisms involved in both the development and progression of exfoliation syndrome.
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Affiliation(s)
- Mehdi Ghaffari Sharaf
- Department of Chemical and Materials Engineering University of Alberta Edmonton Alberta Canada
| | - Karim F. Damji
- Department of Ophthalmology and Visual Sciences University of Alberta Edmonton Alberta Canada
| | - Larry D. Unsworth
- Department of Chemical and Materials Engineering University of Alberta Edmonton Alberta Canada
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Li S, Li D, Shao M, Cao W, Sun X. Decreased Serum Levels of Complement C3 Reflect Complement System Dysregulation in Patients With Primary Open-angle Glaucoma: Results From a Pilot Study. J Glaucoma 2019; 27:761-768. [PMID: 30036292 DOI: 10.1097/ijg.0000000000001014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE To evaluate the serum complement component (C)3 concentration in patients with primary open-angle glaucoma (POAG) and to investigate the association between C3 levels and POAG severity. MATERIALS AND METHODS This study enrolled 190 consecutive POAG patients and 204 normal control subjects. A detailed eye and systematic examination, including intraocular pressure, gonioscopy, fundus photography, A-scan ultrasound, visual field testing, electrocardiograms, x-rays, liver function, renal function, infectious disease, etc., and measurement of serum C3 concentration by immunoturbidimetry, was performed. The subgroups were classified according to age (17 to 29, 30 to 49, 50 to 69, 70+ y), sex, and visual field: mild (MD≤6 dB), moderate (6 dB<MD≤12 dB), and severe (MD>12 dB) glaucoma. RESULTS The serum C3 level of the POAG (95.63±17.71 mg/dL) was ∼20.93% lower than that of the control group (115.65±22.19 mg/dL) (P<0.001). A similar result was observed when serum levels of C3 were compared between the POAG and control groups with respect to age and sex. The mean serum C3 level was lowest in the severe POAG group (85.18±19.62 mg/dL), followed by the moderate POAG group (96.62±12.63 mg/dL) and the mild POAG group (110.44±14.89 mg/dL) (P<0.001). Multiple logistic regression analyses revealed a significant correlation between the C3 levels and the vertical cup-disc ratio (B=-0.373, P=0.026), C3 levels and MD (B=-0.546, P=0.001). Logistic regression analyses revealed that serum C3 levels were associated (odds ratio=0.939, 95% CI=0.901-0.979, P=0.003) with severity of POAG. CONCLUSIONS The POAG patients had decreased C3 levels, which were further negatively associated with POAG severity, suggesting the involvement of C3 in the pathomechanisms of POAG.
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Affiliation(s)
- Shengjie Li
- Departments of Clinical Laboratory.,Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University
| | - Danhui Li
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Medical School, Xi'an Jiaotong University, Xi'an, Shanxi, China
| | | | - Wenjun Cao
- Departments of Clinical Laboratory.,Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University
| | - Xinghuai Sun
- Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University.,Key Laboratory of Myopia, Ministry of Health, Fudan University.,Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai
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Abstract
In this review, we present an update on biomarkers (both clinical and laboratory) on the basis of recent peer-reviewed publications relating to pseudoexfoliation syndrome and pseudoexfoliation glaucoma.
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Abstract
Exfoliation syndrome (XFS) is a common age-related matrix process resulting from excessive production and disordered assembly of elastic microfibrillar components into highly cross-linked fibrillary aggregates throughout the anterior eye segment and various organ systems. The underlying molecular pathophysiology involves a complex interplay of profibrotic protagonists including growth factors, proteolytic enzymes and inhibitors, proinflammatory cytokines, chaperones, and dysregulated stress response pathways including insufficient autophagy. Interaction between individual genetic predisposition and stress factors is a plausible theory explaining the development of XFS in the aging individual. Genome-wide association studies have identified robust genetic associations with LOXL1, CACNA1A, and 5 additional genes including POMP and TMEM136, which provide new biological insights into the pathology of XFS and highlight a role for abnormal matrix cross-linking processes, Ca channel deficiency, blood-aqueous barrier dysfunction, and abnormal ubiquitin-proteasome signaling in XFS pathophysiology. However, the exact pathophysiological mechanisms, the functional role of genetic risk variants, and gene-environment interactions still remain to be characterized.
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Comparative Quantitative Analysis of Porcine Optic Nerve Head and Retina Subproteomes. Int J Mol Sci 2019; 20:ijms20174229. [PMID: 31470587 PMCID: PMC6747248 DOI: 10.3390/ijms20174229] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/16/2019] [Accepted: 08/27/2019] [Indexed: 11/17/2022] Open
Abstract
Optic nerve head (ONH) and retina (RET) are the main sites of damage in neurodegenerative optic neuropathies including glaucoma. Up to date, little is known about the molecular interplay between these two adjoining ocular components in terms of proteomics. To close this gap, we investigated ONH and RET protein extracts derived from porcine eyes (n = 12) (Sus scrofa domestica Linnaeus 1758) using semi-quantitative mass spectrometry (MS)-based proteomics comprising bottom-up LC–ESI MS/MS and targeted SPE-MALDI-TOF MS analysis. In summary, more than 1600 proteins could be identified from the ONH/RET tissue complex. Moreover, ONH and RET displayed tissue-specific characteristics regarding their qualitative and semi-quantitative protein compositions. Gene ontology (GO)-based functional and protein–protein interaction analyses supported a close functional connection between the metabolic-related RET and the structural-associated ONH subproteomes, which could be affected under disease conditions. Inferred from the MS findings, stress-associated proteins including clusterin, ceruloplasmin, and endoplasmin can be proposed as extracellular mediators of the ONH/ RET proteome interface. In conclusion, ONH and RET show obvious proteomic differences reflecting characteristic functional features which have to be considered for future protein biomarker profiling studies.
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Hayat B, Padhy B, Mohanty PP, Alone DP. Altered unfolded protein response and proteasome impairment in pseudoexfoliation pathogenesis. Exp Eye Res 2019; 181:197-207. [DOI: 10.1016/j.exer.2019.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/03/2019] [Accepted: 02/04/2019] [Indexed: 02/02/2023]
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The Association of Oxidative Stress Status with Open-Angle Glaucoma and Exfoliation Glaucoma: A Systematic Review and Meta-Analysis. J Ophthalmol 2019; 2019:1803619. [PMID: 30766729 PMCID: PMC6350588 DOI: 10.1155/2019/1803619] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 12/31/2018] [Indexed: 12/15/2022] Open
Abstract
Purpose To systematically evaluate the associations between oxidative stress status and different types of glaucoma. Design Systematic review and meta-analysis. Methods We searched PubMed, EMBASE, and the Web of Science for randomized controlled trials written in the English language between January 1, 1990, and November 30, 2016. A random effects model was used to estimate oxidative stress status along with weighted mean differences and 95% confidence intervals (CIs). A funnel plot analysis and Egger's test were performed to assess potential publication bias. Main outcome measures Oxidative stress status was abnormal and different in patients with OAG (open-angle glaucoma) and EXG (exfoliation glaucoma). Results Blood TAS (total antioxidant status) was lower in the OAG group than in the control group, with a mean difference of 0.580 mmol/L (p < 0.0001, 95% CI = −0.668 to −0.492). The aqueous humor SOD (superoxide dismutase), GPX (glutathione peroxidase), and CAT (catalase) levels were higher in the OAG group than in the control group, with mean differences of 17.989 U/mL (p < 0.0001, 95% CI = 14.579–21.298), 12.441 U/mL (p < 0.0001, 95% CI = 10.423–14.459), and 1.229 fmol/mL (p=0.042, 95% CI = 0.043–2.414), respectively. Blood TAS was lower in the EXG group than in the control group, with a mean difference of 0.262 mmol/L (p < 0.0001, 95% CI = −0.393 to −0.132). However, there were no differences in blood TOS and aqueous humor TOS between the EXG group and the control group. Conclusions This meta-analysis indicates that OAG patients had a lower TAS in the blood and higher levels of SOD, GPX, and CAT in the aqueous humor, while EXG patients only had a decreased TAS in the blood.
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Wiggs JL, Kang JH, Fan B, Levkovitch-Verbin H, Pasquale LR. A Role for Clusterin in Exfoliation Syndrome and Exfoliation Glaucoma? J Glaucoma 2018; 27 Suppl 1:S61-S66. [PMID: 29965900 PMCID: PMC8035929 DOI: 10.1097/ijg.0000000000000916] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The multifunctional protein clusterin (CLU) is a secreted glycoprotein ubiquitously expressed throughout the body, including in the eye. Its primary function is to act as an extracellular molecular chaperone, preventing the precipitation and aggregation of misfolded extracellular proteins. Clusterin is commonly identified at fluid-tissue interfaces, and has been identified in most body fluids. It is a component of exfoliation material, and CLU mRNA is reduced in eyes with exfoliation syndrome compared with controls. SNPs located in the CLU genomic region have been associated with Alzheimer disease (AD) at the genome-wide level and several CLU SNPs located in an apparent regulatory region have been nominally associated with XFS/XFG in Caucasians with European ancestry and in south Indians. Interestingly, clusterin associates with altered elastic fibers in human photoaged skin and prevents UV-induced elastin aggregation in vitro. In light of the known geographic risk factors for XFS/XFG, which could include UV light, investigations of CLU-geographic interactions could be of interest. Future studies investigating rare CLU variation and other complex interactions including gene-gene interactions in XFS/XFG cases and controls may also be fruitful. Although CLU has been considered as a therapeutic target in AD, cancer and dry eye, a role for clusterin in XFS/XFG needs to be better defined before therapeutic approaches involving CLU can be entertained.
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Affiliation(s)
- Janey L. Wiggs
- Department of Ophthalmology, Mass Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Jae Hee Kang
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - BaoJian Fan
- Department of Ophthalmology, Mass Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Hani Levkovitch-Verbin
- Goldschleger Eye Institute, Tel Hashomer, Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Louis R. Pasquale
- Department of Ophthalmology, Mass Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
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Bernstein AM, Ritch R, Wolosin JM. Exfoliation Syndrome: A Disease of Autophagy and LOXL1 Proteopathy. J Glaucoma 2018; 27 Suppl 1:S44-S53. [PMID: 29547474 PMCID: PMC6028293 DOI: 10.1097/ijg.0000000000000919] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Exfoliation syndrome (XFS) is an age-related disease involving the deposition of aggregated fibrillar material (exfoliation material) at extracellular matrices in tissues that synthesize elastic fibers. Its main morbidity is in the eye, where exfoliation material accumulations form on the surface of the ciliary body, iris, and lens. Exfoliation glaucoma (XFG) occurs in a high proportion of persons with XFS and can be a rapidly progressing disease. Worldwide, XFG accounts for about 25% of open-angle glaucoma cases. XFS and XFG show a sharp age-dependence, similarly to the many age-related diseases classified as aggregopathies. Progress in understanding the cellular bases for XFS/XFG has been slowed by a lack of experimental models. Working with primary human tenon fibroblasts (TF) derived from trabeculectomies of XFG patients and age-matched primary open-glaucoma controls, we found that TF from XFG cells display many of the functional features observed in cells from other protein aggregate diseases, such as Parkinson, Alzheimer, Huntington, and age-related macular degeneration. We have documented defects in lysosomal positioning, microtubule organization, autophagy processing rate, and mitochondrial health. In regard to failure of lysosomal and autophagosome positioning in XFG cells, we have found that XFG TF are unable to establish the transnuclear microtubule organizing center that is required for efficient centripetal vesicular locomotion along microtubules. In regard to potential sources of the autophagy malfunction, we have directed our attention to a potential role of the lysyl oxidase-like 1 protein (LOXL1), the elastic fiber catalyst that displays variant-dependent association with risk for XFG. Our experiments show that (a) in XFG cells, a substantial fraction of LOXL1 is processed for degradation by the autophagic system; (b) most of the LOXL1 N-terminus domain exists in a highly disordered state, a condition known to greatly increase the frequency of polypeptide misfolding; (c) that maximum misfolding occurs at amino acid position 153, the location of the high risk variant G153D; and (d) that replacement of glycine (G) by aspartate (D) there results in a substantial decrease in disorder within the 20 amino acid surrounding domain. Finally, we show that clusterin, a protein that can be induced by the presence of intracellular, or extracellular aggregates, is uniformly overexpressed in XFG TF. The implications of our results for a theory relating XFG to cellular aggregopathy are discussed.
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Affiliation(s)
- Audrey M Bernstein
- Department of Ophthalmology, Eye and Vision Research Institute Icahn School of Medicine at Mount Sinai
- Department of Ophthalmology, Center for Vision Research, SUNY Upstate Medical University, Syracuse, NY
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary of Mount Sinai, New York
| | - Jose M Wolosin
- Department of Ophthalmology, Eye and Vision Research Institute Icahn School of Medicine at Mount Sinai
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Adav SS, Wei J, Terence Y, Ang BCH, Yip LWL, Sze SK. Proteomic Analysis of Aqueous Humor from Primary Open Angle Glaucoma Patients on Drug Treatment Revealed Altered Complement Activation Cascade. J Proteome Res 2018; 17:2499-2510. [DOI: 10.1021/acs.jproteome.8b00244] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sunil S. Adav
- School of Biological Sciences, Nanyang Technological University, Singapore 639798
| | - Jin Wei
- School of Biological Sciences, Nanyang Technological University, Singapore 639798
- Renmin Hospital of Wuhan University, Wuhan, Hubei 430072, PR China
| | - Yap Terence
- School of Biological Sciences, Nanyang Technological University, Singapore 639798
| | - Bryan C. H. Ang
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore 308433
| | - Leonard W. L. Yip
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore 308433
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, Singapore 639798
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Ţălu Ş, Sueiras VM, Moy VT, Ziebarth NM. Micromorphology analysis of the anterior human lens capsule. Mol Vis 2018; 24:902-912. [PMID: 30713427 PMCID: PMC6334982 DOI: pmid/30713427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/31/2018] [Indexed: 02/07/2023] Open
Abstract
PURPOSE This study aimed to quantify the three-dimensional micromorphology of the surface of the human lens capsule as a function of age. METHODS Imaging experiments were conducted on whole human lenses received from eight human cadavers (donor age range: 30-88 years). Imaging was performed with an atomic force microscope (AFM) in contact mode in fluid. The porosity and surface roughness were quantified from the height images obtained. A novel approach, based on stereometric and fractal analysis of three-dimensional surfaces developed for use in conjunction with AFM data, was also used to analyze the surface microtexture as a function of age. RESULTS The AFM images obtained depict a highly ordered fibrous structure at the surface of the lens capsule, although the overall structure visually changes with age. Porosity and roughness were quantified for each image and analyzed as a function of donor age. The interfibrillar spacing revealed an increasing trend with age, although this result was not significant (p = 0.110). The root mean square (RMS) deviation and average deviation significantly decreased with increasing age (p<0.001 for both). The fractal analysis provided quantitative values for 29 amplitude, hybrid, functional, and spatial parameters. All the hybrid parameters decreased with age, although not significantly. Of the functional parameters, the surface bearing index increased significantly with age (p = 0.017) and the summit height exhibited a decreasing trend with age (p = 0.298). Of the spatial parameters, the dominant radial wavelength trend moved toward an increase with age (p = 0.103) and the cross-hatch angle tended toward a decrease with age (p = 0.213). CONCLUSIONS Significant changes in the three-dimensional surface microtexture of the human lens capsule were found with age, although more experiments on a larger dataset are needed to conclude this with certainty. The analyzed AFM images demonstrate a fractal nature of the surface, which is not considered in classical surface statistical parameters. The surface fractal dimension may be useful in ophthalmology for quantifying human lens architectural changes associated with different disease states to further our understanding of disease evolution.
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Affiliation(s)
- Ştefan Ţălu
- The Technical University of Cluj-Napoca, The Directorate of Research, Development and Innovation Management (DMCDI), Cluj-Napoca, Romania
| | - Vivian M Sueiras
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL
| | - Vincent T Moy
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL
| | - Noël M Ziebarth
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL
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31
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Mirzaei M, Gupta VB, Chick JM, Greco TM, Wu Y, Chitranshi N, Wall RV, Hone E, Deng L, Dheer Y, Abbasi M, Rezaeian M, Braidy N, You Y, Salekdeh GH, Haynes PA, Molloy MP, Martins R, Cristea IM, Gygi SP, Graham SL, Gupta VK. Age-related neurodegenerative disease associated pathways identified in retinal and vitreous proteome from human glaucoma eyes. Sci Rep 2017; 7:12685. [PMID: 28978942 PMCID: PMC5627288 DOI: 10.1038/s41598-017-12858-7] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 09/14/2017] [Indexed: 12/05/2022] Open
Abstract
Glaucoma is a chronic disease that shares many similarities with other neurodegenerative disorders of the central nervous system. This study was designed to evaluate the association between glaucoma and other neurodegenerative disorders by investigating glaucoma-associated protein changes in the retina and vitreous humour. The multiplexed Tandem Mass Tag based proteomics (TMT-MS3) was carried out on retinal tissue and vitreous humour fluid collected from glaucoma patients and age-matched controls followed by functional pathway and protein network interaction analysis. About 5000 proteins were quantified from retinal tissue and vitreous fluid of glaucoma and control eyes. Of the differentially regulated proteins, 122 were found linked with pathophysiology of Alzheimer’s disease (AD). Pathway analyses of differentially regulated proteins indicate defects in mitochondrial oxidative phosphorylation machinery. The classical complement pathway associated proteins were activated in the glaucoma samples suggesting an innate inflammatory response. The majority of common differentially regulated proteins in both tissues were members of functional protein networks associated brain changes in AD and other chronic degenerative conditions. Identification of previously reported and novel pathways in glaucoma that overlap with other CNS neurodegenerative disorders promises to provide renewed understanding of the aetiology and pathogenesis of age related neurodegenerative diseases.
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Affiliation(s)
- Mehdi Mirzaei
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia. .,Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia. .,Australian Proteome Analysis Facility, Macquarie University, Sydney, NSW, Australia.
| | - Veer B Gupta
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Joel M Chick
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Todd M Greco
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Yunqi Wu
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Nitin Chitranshi
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Roshana Vander Wall
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Eugene Hone
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Liting Deng
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Yogita Dheer
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Mojdeh Abbasi
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Mahdie Rezaeian
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia
| | - Yuyi You
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Save Sight Institute, Sydney University, Sydney, NSW, Australia
| | - Ghasem Hosseini Salekdeh
- Department of Molecular Systems Biology, Cell Science Research Center, Royan, Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Paul A Haynes
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Mark P Molloy
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia.,Australian Proteome Analysis Facility, Macquarie University, Sydney, NSW, Australia
| | - Ralph Martins
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ileana M Cristea
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
| | - Stuart L Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Save Sight Institute, Sydney University, Sydney, NSW, Australia
| | - Vivek K Gupta
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
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Williams PA, Braine CE, Foxworth NE, Cochran KE, John SWM. GlyCAM1 negatively regulates monocyte entry into the optic nerve head and contributes to radiation-based protection in glaucoma. J Neuroinflammation 2017; 14:93. [PMID: 28446179 PMCID: PMC5406973 DOI: 10.1186/s12974-017-0868-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/18/2017] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND We previously reported a profound long-term neuroprotection subsequent to a single radiation-therapy in the DBA/2J mouse model of glaucoma. This neuroprotection prevents entry of monocyte-like immune cells into the optic nerve head during glaucoma. Gene expression studies in radiation-treated mice implicated Glycam1 in this protection. Glycam1 encodes a proteoglycan ligand for L-selectin and is an excellent candidate to modulate immune cell entry into the eye. Here, we experimentally test the hypothesis that radiation-induced over-expression of Glycam1 is a key component of the neuroprotection. METHODS We generated a null allele of Glycam1 on a DBA/2J background. Gene and protein expression of Glycam1, monocyte entry into the optic nerve head, retinal ganglion cell death, and axon loss in the optic nerve were assessed. RESULTS Radiation therapy potently inhibits monocyte entry into the optic nerve head and prevents retinal ganglion cell death and axon loss. DBA/2J mice carrying a null allele of Glycam1 show increased monocyte entry and increased retinal ganglion cell death and axon loss following radiation therapy, but the majority of optic nerves were still protected by radiation therapy. CONCLUSIONS Although GlyCAM1 is an L-selectin ligand, its roles in immunity are not yet fully defined. The current study demonstrates a partial role for GlyCAM1 in radiation-mediated protection. Furthermore, our results clearly show that GlyCAM1 levels modulate immune cell entry from the vasculature into neural tissues. As Glycam1 deficiency has a more profound effect on cell entry than on neurodegeneration, further experiments are needed to precisely define the role of monocyte entry in DBA/2J glaucoma. Nevertheless, GlyCAM1's function as a negative regulator of extravasation may lead to novel therapeutic strategies for an array of common conditions involving inflammation.
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Affiliation(s)
| | | | | | | | - Simon W. M. John
- The Jackson Laboratory, Bar Harbor, ME USA
- Department of Ophthalmology, Tufts University of Medicine, Boston, MA USA
- The Howard Hughes Medical Institute, Bar Harbor, ME USA
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Williams PA, Marsh-Armstrong N, Howell GR. Neuroinflammation in glaucoma: A new opportunity. Exp Eye Res 2017; 157:20-27. [PMID: 28242160 PMCID: PMC5497582 DOI: 10.1016/j.exer.2017.02.014] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 02/16/2017] [Accepted: 02/23/2017] [Indexed: 10/20/2022]
Abstract
Mounting evidence suggests neuroinflammation is a key process in glaucoma, yet the precise roles are not known. Understanding these complex processes, which may also be a key in other common neurodegenerations such as Alzheimer's disease, will lead to targeted therapeutics for a disease that affects as many as 80 million people worldwide. Here, we define neuroinflammation as any immune-relevant response by a variety of cell types including astrocytes, microglia, and peripherally derived cells occurring in the optic nerve head and/or retina. In this review article, we first discuss clinical evidence for neuroinflammation in glaucoma and define neuroinflammation in glaucoma. We then review the inflammatory pathways that have been associated with glaucoma. Finally, we set out key research directions that we believe will greatly advance our understanding of the role of neuroinflammation in glaucoma. This review arose from a discussion of neuroinflammation in glaucoma at the 2015 meeting of The Lasker/IRRF Initiative for Innovation in Vision Science. This manuscript sets out to summarize one of these sessions; "Inflammation and Glaucomatous Neurodegeneration", as well as to review the current state of the literature surrounding neuroinflammation in glaucoma.
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Affiliation(s)
| | - Nick Marsh-Armstrong
- The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, USA; Graduate Program of Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, USA.
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Aboobakar IF, Johnson WM, Stamer WD, Hauser MA, Allingham RR. Major review: Exfoliation syndrome; advances in disease genetics, molecular biology, and epidemiology. Exp Eye Res 2016; 154:88-103. [PMID: 27845061 DOI: 10.1016/j.exer.2016.11.011] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/06/2016] [Accepted: 11/10/2016] [Indexed: 12/20/2022]
Abstract
Exfoliation syndrome (XFS) is a common age-related disorder that leads to deposition of extracellular fibrillar material throughout the body. The most recognized disease manifestation is exfoliation glaucoma (XFG), which is a common cause of blindness worldwide. Recent developments in XFS genetics, cell biology and epidemiology have greatly improved our understanding of the etiology of this complex inherited disease. This review summarizes current knowledge of XFS pathogenesis, identifies gaps in knowledge, and discusses areas for future research.
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Affiliation(s)
- Inas F Aboobakar
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - William M Johnson
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - Michael A Hauser
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA.
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Pasquale LR, Borrás T, Fingert JH, Wiggs JL, Ritch R. Exfoliation syndrome: assembling the puzzle pieces. Acta Ophthalmol 2016; 94:e505-12. [PMID: 26648185 DOI: 10.1111/aos.12918] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 09/25/2015] [Indexed: 12/15/2022]
Abstract
PURPOSE To summarize various topics and the cutting edge approaches to refine XFS pathogenesis that were discussed at the 21st annual Glaucoma Foundation Think Tank meeting in New York City, Sept. 19-20, 2014. METHODS The highlights of three categories of talks on cutting edge research in the field were summarized. RESULTS Exfoliation syndrome (XFS) is a systemic disorder with a substantial ocular burden, including high rates of cataract, cataract surgery complications, glaucoma and retinal vein occlusion. New information about XFS is akin to puzzle pieces that do not quite join together to reveal a clear picture regarding how exfoliation material (XFM) forms. CONCLUSION Meeting participants concluded that it is unclear how the mild homocysteinemia seen in XFS might contribute to the disarrayed extracellular aggregates characteristic of this syndrome. Lysyl oxidase-like 1 (LOXL1) variants are unequivocally genetic risk factors for XFS but exactly how these variants contribute to the assembly of exfoliation material (XFM) remains unclear. Variants in a new genomic region, CACNA1A associated with XFS, may alter calcium concentrations at the cell surface and facilitate XFM formation but much more work is needed before we can place this new finding in proper context. It is hoped that various animal model and ex vivo systems will emerge that will allow for proper assembly of the puzzle pieces into a coherent picture of XFS pathogenesis. A clear understanding of XFS pathogenesis may lead to 'upstream solutions' to reduce the ocular morbidity produced by XFS.
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Affiliation(s)
- Louis R. Pasquale
- Department of Ophthalmology; Mass Eye & Ear Infirmary; Harvard Medical School; Boston Massachusetts USA
- Department of Medicine; Harvard Medical School; Brigham and Women's Hospital; Boston Massachusetts USA
| | - Terete Borrás
- Department of Ophthalmology; University of North Carolina; Chapel Hill North Carolina USA
| | - John H. Fingert
- Department of Ophthalmology and Visual Sciences; University of Iowa; Iowa City Iowa USA
| | - Janey L. Wiggs
- Department of Ophthalmology; Mass Eye & Ear Infirmary; Harvard Medical School; Boston Massachusetts USA
| | - Robert Ritch
- Einhorn Clinical Research Center; New York Eye and Ear Infirmary of Mount Sinai; New York City New York USA
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Fini ME, Bauskar A, Jeong S, Wilson MR. Clusterin in the eye: An old dog with new tricks at the ocular surface. Exp Eye Res 2016; 147:57-71. [PMID: 27131907 DOI: 10.1016/j.exer.2016.04.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/22/2016] [Accepted: 04/23/2016] [Indexed: 12/30/2022]
Abstract
The multifunctional protein clusterin (CLU) was first described in 1983 as a secreted glycoprotein present in ram rete testis fluid that enhanced aggregation ('clustering') of a variety of cells in vitro. It was also independently discovered in a number of other systems. By the early 1990s, CLU was known under many names and its expression had been demonstrated throughout the body, including in the eye. Its homeostatic activities in proteostasis, cytoprotection, and anti-inflammation have been well documented, however its roles in health and disease are still not well understood. CLU is prominent at fluid-tissue interfaces, and in 1996 it was demonstrated to be the most highly expressed transcript in the human cornea, the protein product being localized to the apical layers of the mucosal epithelia of the cornea and conjunctiva. CLU protein is also present in human tears. Using a preclinical mouse model for desiccating stress that mimics human dry eye disease, the authors recently demonstrated that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration in the tears. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to LGALS3 (galectin-3), a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. CLU depletion from the ocular surface epithelia is seen in a variety of inflammatory conditions in humans and mice that lead to squamous metaplasia and a keratinized epithelium. This suggests that CLU might have a specific role in maintaining mucosal epithelial differentiation, an idea that can now be tested using the mouse model for desiccating stress. Most excitingly, the new findings suggest that CLU could serve as a novel biotherapeutic for dry eye disease.
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Affiliation(s)
- M Elizabeth Fini
- USC Institute for Genetic Medicine and Departments of Cell & Neurobiology and Ophthalmology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA 90089-9037, USA.
| | - Aditi Bauskar
- USC Institute for Genetic Medicine and Graduate Program in Medical Biology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA 90089-9037, USA.
| | - Shinwu Jeong
- USC Institute for Genetic Medicine and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA 90089-9037, USA.
| | - Mark R Wilson
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales, 2522 Australia.
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Williams PA, Tribble JR, Pepper KW, Cross SD, Morgan BP, Morgan JE, John SWM, Howell GR. Inhibition of the classical pathway of the complement cascade prevents early dendritic and synaptic degeneration in glaucoma. Mol Neurodegener 2016; 11:26. [PMID: 27048300 PMCID: PMC4822272 DOI: 10.1186/s13024-016-0091-6] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 12/13/2022] Open
Abstract
Background Glaucoma is a complex, multifactorial disease characterised by the loss of retinal ganglion cells and their axons leading to a decrease in visual function. The earliest events that damage retinal ganglion cells in glaucoma are currently unknown. Retinal ganglion cell death appears to be compartmentalised, with soma, dendrite and axon changes potentially occurring through different mechanisms. There is mounting evidence from other neurodegenerative diseases suggesting that neuronal dendrites undergo a prolonged period of atrophy, including the pruning of synapses, prior to cell loss. In addition, recent evidence has shown the role of the complement cascade in synaptic pruning in glaucoma and other diseases. Results Using a genetic (DBA/2J mouse) and an inducible (rat microbead) model of glaucoma we first demonstrate that there is loss of retinal ganglion cell synapses and dendrites at time points that precede axon or soma loss. We next determine the role of complement component 1 (C1) in early synaptic loss and dendritic atrophy during glaucoma. Using a genetic knockout of C1qa (D2.C1qa-/- mouse) or pharmacological inhibition of C1 (in the rat bead model) we show that inhibition of C1 is sufficient to preserve dendritic and synaptic architecture. Conclusions This study further supports assessing the potential for complement-modulating therapeutics for the prevention of retinal ganglion cell degeneration in glaucoma.
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Affiliation(s)
| | - James R Tribble
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | | | - Stephen D Cross
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - B Paul Morgan
- Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Simon W M John
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Department of Ophthalmology, Tufts University of Medicine, Boston, MA, 02111, USA. .,The Howard Hughes Medical Institute, Bar Harbor, ME, 04609, USA.
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA, USA.
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38
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Fan BJ, Pasquale LR, Kang JH, Levkovitch-Verbin H, Haines JL, Wiggs JL. Association of clusterin (CLU) variants and exfoliation syndrome: An analysis in two Caucasian studies and a meta-analysis. Exp Eye Res 2015; 139:115-22. [PMID: 26272660 DOI: 10.1016/j.exer.2015.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 11/18/2022]
Abstract
Exfoliation syndrome (XFS) is an important risk factor for glaucoma (XFG) worldwide. LOXL1 variants are highly associated with XFS in most populations; however, the high frequency of risk alleles in normal individuals and the reversal of risk alleles in different ethnic populations suggest that other factors contribute to XFS pathogenesis. Clusterin (CLU) is an extracellular matrix chaperone that prevents protein aggregation and is highly expressed in ocular tissues affected by XFS. Studies examining common CLU variants for association with XFS have been inconsistent. The purpose of this study was to evaluate CLU variants for association with XFS in two independent datasets from the United States (222 cases and 344 controls) and Israel (92 cases and 102 controls). Seven tag SNPs that captured >95% of alleles at r(2) greater than 0.8 across the CLU genomic region were genotyped using TaqMan assays. Genotypes for an additional SNP, rs2279590, were imputed using phased haplotypes of HapMap reference CEU samples. Of the 8 CLU SNPs selected for the study, none were significantly associated with XFS in either case-control group (age and sex adjusted P > 0.14 and 0.36, respectively, in the US and Israeli datasets), or when they were meta-analyzed together (age and sex adjusted P > 0.13). Haplotype analysis using all 8 SNPs or only the promoter region SNPs also did not show significant associations of CLU with XFS in the combined US and Israeli dataset (P > 0.28). Meta-analysis of the data from this study and previous studies in Caucasian populations (1184 cases and 978 controls) resulted in statistically significant association of rs2279590 with XFS (summary OR = 1.18, 95% CI: 1.03-1.33, P = 0.01). Significant association between rs2279590 and XFS was also found in Indian populations (summary OR = 0.76, 95% CI: 0.61-0.96; P = 0.02); however, significant heterogeneity between the Caucasian and Indian populations possibly due to reversal of the risk allele precluded an overall meta-analysis for rs2279590 (Q = 0.001, I(2) = 91%). No significant association was identified for rs3087554 in either Caucasian populations (summary OR = 0.90, 95% CI: 0.77-1.05, P = 0.17) or Indian populations (summary OR = 0.89, 95% CI: 0.72-1.10, P = 0.28), or in both populations combined (1705 cases and 3713 controls; summary OR = 0.90, 95% CI: 0.79-1.01, P = 0.08). Significant heterogeneity precluded the addition of the Japanese data to the meta-analysis for rs3087554 (Q = 0.006, I(2) = 87%). Our results suggest that common CLU variants may contribute to modest XFS risk but even larger datasets are required to confirm these findings.
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Affiliation(s)
- Bao J Fan
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Louis R Pasquale
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA; Channing Division of Network Medicine, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA
| | - Jae H Kang
- Channing Division of Network Medicine, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA
| | - Hani Levkovitch-Verbin
- Goldschleger Eye Institute, Chaim Sheba Medical Center, Tel Aviv University, Tel Hashomer, Israel
| | - Jonathan L Haines
- Department of Epidemiology & Biostatistics, Case Western Reserve University, Cleveland, OH, USA
| | - Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA.
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Update on pseudoexfoliation syndrome pathogenesis and associations with intraocular pressure, glaucoma and systemic diseases. Curr Opin Ophthalmol 2015; 26:82-9. [PMID: 25594764 DOI: 10.1097/icu.0000000000000132] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW Pseudoexfoliation (PEX) syndrome is a common age-related disorder affecting intraocular and extraocular tissues. This review focuses on recent publications related with the pathogenesis and associations of PEX syndrome with intraocular pressure (IOP), glaucoma and systemic diseases. RECENT FINDINGS In PEX tissues, expression of lysyl oxidase-like 1 (LOXL1) was found to be markedly dysregulated. This may adversely affect elastin metabolism and lead to elastotic alteration in tissues such as lamina cribrosa. There is increasing evidence that cellular stress conditions and low-grade chronic inflammatory processes are involved in the pathogenesis of PEX. Although there is an increased risk for glaucoma development in patients with PEX and ocular hypertension as compared with non-PEX patients with ocular hypertension, LOXL1 single nucleotide polymorphisms were not associated with intraocular pressure (IOP) differences. Lack of association of PEX with all-cause mortality or dementia has been reported recently. The association with vascular diseases is not consistent among different studies. SUMMARY Despite the high prevalence of the LOXL1 variants in the general population, a much lower proportion of the population develops PEX, suggesting that in addition to LOXL1, other genetic, epigenetic and environmental factors may contribute to the development of PEX. Also, LOXL1 cannot help to identify those with PEX at increased risk for glaucoma development. Increased risk for glaucoma development in PEX patients who present with increased IOP may be related to other factors beyond IOP, contributing to increased vulnerability of the optic nerve to glaucoma development in the presence of PEX.
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Ţălu Ş, Stach S, Sueiras V, Ziebarth NM. Fractal analysis of AFM images of the surface of Bowman's membrane of the human cornea. Ann Biomed Eng 2015; 43:906-16. [PMID: 25266935 DOI: 10.1007/s10439-014-1140-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 09/23/2014] [Indexed: 02/07/2023]
Abstract
The objective of this study is to further investigate the ultrastructural details of the surface of Bowman's membrane of the human cornea, using atomic force microscopy (AFM) images. One representative image acquired of Bowman's membrane of a human cornea was investigated. The three-dimensional (3-D) surface of the sample was imaged using AFM in contact mode, while the sample was completely submerged in optisol solution. Height and deflection images were acquired at multiple scan lengths using the MFP-3D AFM system software (Asylum Research, Santa Barbara, CA), based in IGOR Pro (WaveMetrics, Lake Oswego, OR). A novel approach, based on computational algorithms for fractal analysis of surfaces applied for AFM data, was utilized to analyze the surface structure. The surfaces revealed a fractal structure at the nanometer scale. The fractal dimension, D, provided quantitative values that characterize the scale properties of surface geometry. Detailed characterization of the surface topography was obtained using statistical parameters, in accordance with ISO 25178-2: 2012. Results obtained by fractal analysis confirm the relationship between the value of the fractal dimension and the statistical surface roughness parameters. The surface structure of Bowman's membrane of the human cornea is complex. The analyzed AFM images confirm a fractal nature of the surface, which is not taken into account by classical surface statistical parameters. Surface fractal dimension could be useful in ophthalmology to quantify corneal architectural changes associated with different disease states to further our understanding of disease evolution.
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Affiliation(s)
- Ştefan Ţălu
- Discipline of Descriptive Geometry and Engineering Graphics, Department of AET, Faculty of Mechanical Engineering, Technical University of Cluj-Napoca, 103-105 B-dul Muncii St., 400641, Cluj-Napoca, Cluj, Romania,
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Lens capsule structure assessed with atomic force microscopy. Mol Vis 2015; 21:316-23. [PMID: 25814829 PMCID: PMC4360172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 03/12/2015] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To image the ultrastructure of the anterior lens capsule at the nanoscale level using atomic force microscopy (AFM). METHODS Experiments were performed on anterior lens capsules maintained in their in situ location surrounding the lens from six human cadavers (donor age range: 44-88 years), four cynomolgus monkeys (Macaca fascicularis age range: 4.83-8.92 years), and seven pigs (<6 months). Hydration of all samples was maintained using Dulbecco's Modified Eagle Medium (DMEM). Whole lenses were removed from the eye and placed anterior side up in agarose gel before gel hardening where only the posterior half of the lens was contained within the gel. After the gel hardened, the Petri dish was filled with DMEM until the point where the intact lens was fully submerged. AFM was used to image the anterior lens surface in contact mode. An integrated analysis program was used to calculate the interfibrillar spacing, fiber diameter, and surface roughness of the samples. RESULTS The AFM images depict a highly ordered fibrous structure at the surface of the lens capsule in all three species. The interfibrillar spacing for the porcine, cynomolgus monkey, and human lens capsules was 0.68±0.25, 1.80±0.39, and 1.08±0.25 μm, respectively. In the primate, interfibrillar spacing significantly decreased linearly as a function of age. The fiber diameters ranged from 50 to 950 nm. Comparison of the root mean square (RMS) and average deviation demonstrate that the surface of the porcine lens capsule is the smoothest, and that the human and cynomolgus monkey capsules are significantly rougher. CONCLUSIONS AFM was successful in providing high-resolution images of the nanostructure of the lens capsule samples. Species-dependent differences were observed in the overall structure and surface roughness.
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Medical Management of Exfoliative Glaucoma. Clin Ophthalmol 2014; 54:57-70. [DOI: 10.1097/iio.0000000000000043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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