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Niazi S, Moshirfar M, Alizadeh F, Doroodgar F, Baradaran-Rafii A, Filutowski O, Niazi F, Ambrósio R. Association of 2 Lysyl Oxidase Gene Single Nucleotide Polymorphisms with Keratoconus: A Nationwide Registration Study. OPHTHALMOLOGY SCIENCE 2022; 3:100247. [PMID: 36748061 PMCID: PMC9898806 DOI: 10.1016/j.xops.2022.100247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/31/2022] [Accepted: 11/03/2022] [Indexed: 11/10/2022]
Abstract
Purpose Keratoconus (KC) is the most common primary ectatic corneal disease, characterized by progressive thinning of the cornea, affecting its shape and structure and leading to visual loss. Lysyl oxidase is an important component of the extracellular matrix and contributes to the homeostasis of corneal stromal extracellular matrix via enzymatic reaction. This nationwide registration study aims to examine the association of KC with 2 known single nucleotide polymorphisms, rs2956540 and rs10519694, in a population of Iranian descent. Design Case-control. Participants One hundred seventy-eight subjects with KC and 180 clinically healthy subjects participated in the study. Methods Genomic DNA was extracted from peripheral blood samples, and their genotypes were determined using tetra-primer amplification refractory mutation system-polymerase chain reaction. Main Outcome Measures Allele frequency for rs2956540 and rs10519694. Results Genotype frequency was significantly different between cases and controls for rs2956540 (P value = 0.019). The rs2956540 C allele carriers were significantly more frequent among KC cases than healthy controls (P valuechi-square = 0.015, P valueFisher exact = 0.017). There was a significant difference in genotype frequency between groups for rs10519694 (P value = 0.001). T allele carriers were significantly more frequent among KC patients (P valuechi-square = 0.002, P valueFisher exact = 0.001). Sex stratification revealed no significant differences in genotype frequency between males and females in cases and controls. Fitting the general linear model showed that rs10519694 could be considered a predictor for the development of KC (P value = 0.001); however, this was not observed for rs2956540 (P value = 0.323). Conclusions rs2956540 and rs10519694 are associated with KC in a population of Iranian descent. rs10519694 could potentially be used for KC risk prediction.
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Affiliation(s)
- Sana Niazi
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Majid Moshirfar
- John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Fatemeh Alizadeh
- Department of Genomic Psychiatry and Behavioral Genomics (DGPBG), Roozbeh Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Farideh Doroodgar
- Translational Ophthalmology Research Center, Tehran University of Medical Sciences, Tehran, Iran,Negah Specialty Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran,Correspondence: Farideh Doroodgar, MD; Address: Negah Specialty Ophthalmic Hospital and Research Center, No 3., Ketabi St., Shariati Ave., Tehran, Iran; Postal Code: 1544914599
| | - Alireza Baradaran-Rafii
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran,Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Oliver Filutowski
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Feizollah Niazi
- Clinical Research Development Center, Shahid Modarres Educational hospital, Shahid Behesht University of Medical Sciences, Tehran, Iran
| | - Renato Ambrósio
- Department of Ophthalmology, Federal University the State of Rio de Janeiro (UNIRIO), São Paulo, Brazil,Department of Ophthalmology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil,Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil,Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil,BrAIN: Brazilian Artificial Intelligence Networking in Medicine, Rio de Janeiro & Maceió, Brazil
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Hao XD, Gao H, Xu WH, Shan C, Liu Y, Zhou ZX, Wang K, Li PF. Systematically Displaying the Pathogenesis of Keratoconus via Multi-Level Related Gene Enrichment-Based Review. Front Med (Lausanne) 2022; 8:770138. [PMID: 35141241 PMCID: PMC8818795 DOI: 10.3389/fmed.2021.770138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/31/2021] [Indexed: 01/20/2023] Open
Abstract
Keratoconus (KC) is an etiologically heterogeneous corneal ectatic disorder. To systematically display the pathogenesis of keratoconus (KC), this study reviewed all the reported genes involved in KC, and performed an enrichment analysis of genes identified at the genome, transcription, and protein levels respectively. Combined analysis of multi-level results revealed their shared genes, gene ontology (GO), and pathway terms, to explore the possible pathogenesis of KC. After an initial search, 80 candidate genes, 2,933 transcriptional differential genes, and 947 differential proteins were collected. The candidate genes were significantly enriched in extracellular matrix (ECM) related terms, Wnt signaling pathway and cytokine activities. The enriched GO/pathway terms of transcription and protein levels highlight the importance of ECM, cell adhesion, and inflammatory once again. Combined analysis of multi-levels identified 13 genes, 43 GOs, and 12 pathways. The pathogenic relationships among these overlapping factors maybe as follows. The gene mutations/variants caused insufficient protein dosage or abnormal function, together with environmental stimulation, leading to the related functions and pathways changes in the corneal cells. These included response to the glucocorticoid and reactive oxygen species; regulation of various signaling (P13K-AKT, MAPK and NF-kappaB), apoptosis and aging; upregulation of cytokines and collagen-related enzymes; and downregulation of collagen and other ECM-related proteins. These undoubtedly lead to a reduction of extracellular components and induction of cell apoptosis, resulting in the loosening and thinning of corneal tissue structure. This study, in addition to providing information about the genes involved, also provides an integrated insight into the gene-based etiology and pathogenesis of KC.
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Affiliation(s)
- Xiao-Dan Hao
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- *Correspondence: Xiao-Dan Hao
| | - Hua Gao
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China
- Shandong Eye Hospital, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China
| | - Wen-Hua Xu
- Department of Inspection, The Medical Faculty of Qingdao University, Qingdao, China
| | - Chan Shan
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Ying Liu
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Zhi-Xia Zhou
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Kun Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- Kun Wang
| | - Pei-Feng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
- Pei-Feng Li
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Lin Q, Zheng L, Shen Z. A novel variant in TGFBI causes keratoconus in a two-generation Chinese family. Ophthalmic Genet 2021; 43:159-163. [PMID: 34895010 DOI: 10.1080/13816810.2021.2015788] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND This study aims to investigate the genetic abnormalities in a two-generation Chinese family affected by keratoconus (KC). A two-generation Chinese family affected by KC was studied. MATERIALS AND METHODS A total of 118 unrelated healthy individuals without KC were recruited as controls. The family history, clinical data, and peripheral blood leukocytes were collected from all subjects. Whole exome sequencing was performed using the genomic DNA of the proband (II.2) and the other two affected family members (I.1 and II.3). Afterwards, polymerase chain reaction was performed for the other enrolled subjects to verify the variants identified in family members with KC. The PolyPhen2, SIFT, PROVEIN and Mutation Taster software programs were applied to analyze the functional consequences of the variants. RESULTS A single nucleotide polymorphism (VARIANT) (c.1406 G > A [rs759370852]) in the transforming growth factor beta-induced (TGFBI) gene was identified in all affected family members, which resulted in a p.R469H amino acid change. This variant was not detected in the controls. The variant c.1406 G > A in TGFBI was predicted as probably damaging with software programs. CONCLUSION A novel variant c.1406 G > A in TGFBI has been identified, and probably contributes to the pathogenesis of KC.
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Affiliation(s)
- Qinghong Lin
- Refractive Surgery Department, Hefei Bright Eye Hospital, Hefei, Anhui Province, China
| | - Lin Zheng
- Refractive Surgery Department, Hefei Bright Eye Hospital, Hefei, Anhui Province, China
| | - Zhengwei Shen
- Refractive Surgery Department, Hefei Bright Eye Hospital, Hefei, Anhui Province, China
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Ates KM, Estes AJ, Liu Y. Potential underlying genetic associations between keratoconus and diabetes mellitus. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2021; 1:100005. [PMID: 34746916 PMCID: PMC8570550 DOI: 10.1016/j.aopr.2021.100005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/18/2021] [Accepted: 08/29/2021] [Indexed: 12/14/2022]
Abstract
Background Keratoconus (KC) is the most common ectatic corneal disease, characterized by significantly localized thinning of the corneal stroma. Genetic, environmental, hormonal, and metabolic factors contribute to the pathogenesis of KC. Additionally, multiple comorbidities, such as diabetes mellitus, may affect the risk of KC. Main Body Patients with diabetes mellitus (DM) have been reported to have lower risk of developing KC by way of increased endogenous collagen crosslinking in response to chronic hyperglycemia. However, this remains a debated topic as other studies have suggested either a positive association or no association between DM and KC. To gain further insight into the underlying genetic components of these two diseases, we reviewed candidate genes associated with KC and central corneal thickness in the literature. We then explored how these genes may be regulated similarly or differentially under hyperglycemic conditions and the role they play in the systemic complications associated with DM. Conclusion Our comprehensive review of potential genetic factors underlying KC and DM provides a direction for future studies to further determine the genetic etiology of KC and how it is influenced by systemic diseases such as diabetes.
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Affiliation(s)
- Kristin M. Ates
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Amy J. Estes
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
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Veerappa AM. Cascade of interactions between candidate genes reveals convergent mechanisms in keratoconus disease pathogenesis. Ophthalmic Genet 2021; 42:114-131. [PMID: 33554698 DOI: 10.1080/13816810.2020.1868013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Keratoconus is a progressive thinning, steepening and distortion of the cornea which can lead to loss of vision if left untreated. Keratoconus has a complex multifactorial etiology, with genetic and environmental components contributing to the disease pathophysiology. Studies have observed high concordance between monozygotic twins, discordance between dizygotic twins, and high familial segregation indicating the presence of a very strong genetic component in the pathogenesis of keratoconus. The use of genome-wide linkage studies on families and twins, genome-wide association studies (GWAS) on case-controls, next-generation sequencing (NGS)-based genomic screens on both familial and non-familial cohorts have led to the identification of keratoconus candidate genes with much greater success and increased resproducibility of genetic findings. This review focuses on candidate genes identified till date and attempts to understand their role in biological processes underlying keratoconus pathogenesis. In addition, using these genes I propose molecular pathways that could contribute to keratoconus pathogenesis. The pathways identified the presence of direct cross-talk between known candidate genes of keratoconus and remarkably, 28 known candidate genes have a direct relationship among themselves that involves direct protein-protein binding, regulatory activities such as activation and inhibition, chaperone, transcriptional activation/co-activation, and enzyme catalysis. This review attempts to describe these relationships and cross-talks in the context of keratoconus pathogenesis.
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Affiliation(s)
- Avinash M Veerappa
- Department of Ophthalmology, NYU Langone Medical Center, New York, New York, USA
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Xu X, Zhang X, Cui Y, Yang H, Ping X, Wu J, Yu X, Jin X, Huang X, Shentu X. Three novel variants identified within ECM-related genes in Chinese Han keratoconus patients. Sci Rep 2020; 10:5844. [PMID: 32246022 PMCID: PMC7125089 DOI: 10.1038/s41598-020-62572-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 03/04/2020] [Indexed: 12/24/2022] Open
Abstract
As the primary indication for corneal transplantation, the pathogenesis of keratoconus remains elusive. Aiming to identify whether any mutation from extracellular-matrix (ECM)-related genes contributes to the patients with sporadic cases of keratoconus (KC) from Chinese Han population, one hundred and fifty-three participants in total were enrolled in our study, including fifty-three KC patients and one hundred healthy controls. Mutational analysis of three ECM-related genes (LOX, COL5A1 and TIMP3) with next-generation sequencing and Sanger sequencing was performed. To further confirm the function of three ECM-related genes in the pathogenesis of keratoconus, we performed Real-time Quantitative PCR in vitro. Results showed that three new sequence variants (c.95 G > A in LOX, c.1372 C > T in COL5A1 and c.476 C > T in TIMP3) were identified in aforementioned ECM-related genes in KC patients without being detected among the healthy controls. According to the results of QPCR, we found that the expression levels of LOX and TIMP3 were decreased in the KC patients, while COL5A1 showed no significant difference of expression. This is the first time to screen so many ECM-related genes in Chinese keratoconus patients using next-generation sequencing. We find numerous underlying causal variants, enlarging lots of mutation spectrums and thus providing new sites for other investigators to replicate and for further research.
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Affiliation(s)
- Xiayan Xu
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Xin Zhang
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Yilei Cui
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Hao Yang
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Xiyuan Ping
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Jing Wu
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Xiaoning Yu
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Xiuming Jin
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Xiaodan Huang
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China
| | - Xingchao Shentu
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, Zhejiang, China.
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Tahiri Joutei Hassani R, Querques G, Liang H, Souied E, Baudouin C. Occurence of bilateral keratoconus and basal laminar drusen: A chance association or a true relationship? J Fr Ophtalmol 2019; 42:e479-e481. [PMID: 31272700 DOI: 10.1016/j.jfo.2019.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 01/27/2019] [Accepted: 02/08/2019] [Indexed: 10/26/2022]
Affiliation(s)
- R Tahiri Joutei Hassani
- Department of Ambulatory Surgery, Granville Hospital, Granville, 50400, France; Ophthalmology Practice "Le Visiologiste", Granville, 50400, France.
| | - G Querques
- Department of Ophthalmology, Creteil Eye Clinic, University Paris-Est-Creteil, Creteil, 94000, France
| | - H Liang
- Department of Ophthalmology III, Quinze-Vingts National Ophthalmology Hospital, Paris, 75012, France; Center of Clinical Investigations 503, Quinze-Vingts National Ophthalmology Hospital, Paris, 75012, France
| | - E Souied
- Department of Ophthalmology, Creteil Eye Clinic, University Paris-Est-Creteil, Creteil, 94000, France
| | - C Baudouin
- Department of Ophthalmology III, Quinze-Vingts National Ophthalmology Hospital, Paris, 75012, France; Center of Clinical Investigations 503, Quinze-Vingts National Ophthalmology Hospital, Paris, 75012, France; Ambroise-Paré Hospital, Versailles St Quentin en Yvelines University, AP-HP, Boulogne-Billancourt, 92100, France; Inserm UMRS 968, Vision Institute, University Pierre-et-Marie-Curie, Paris, 75012, France
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Araki-Sasaki K, Osakabe Y, Fujita K, Miyata K, Hirano K. Collagen fiber changes related to keratoconus with secondary corneal amyloidosis. Int Med Case Rep J 2018; 11:193-199. [PMID: 30214321 PMCID: PMC6121752 DOI: 10.2147/imcrj.s162655] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We describe the histological changes in the collagen fibers of a 50-year-old male who presented keratoconus with secondary corneal amyloidosis. Corneal tissue from the patient was obtained following a penetrating keratoplasty and was subjected to histochemical analysis using Masson’s trichrome staining, Congo red staining, anti-lactoferrin antibody, and anti-transforming growth factor-beta-induced protein (TGFBIp) antibody. A Congo red-positive region was detected in the anterior half of the stroma in the center and inferior cornea. Although hemotoxylin and eosin staining revealed irregularity in the Congo red-positive region, other parts of the stroma did not show any abnormalities. Positive staining both by anti-TGFBIp and anti-lactoferrin antibodies was observed in the Congo red-positive region. Interestingly, all the layers of the corneal stroma, including the peripheral region, were positively stained by anti-TFGBIp antibody, even in the Congo red-negative area. Masson’s trichrome staining also showed irregular staining throughout the corneal stroma, even outside of the Congo red-positive region. Additionally, Bowman’s layer, which consists of collagen type IV, was damaged. TGFBIp was strongly expressed and Masson’s trichrome staining was reduced throughout the entire keratoconic stroma. The constant qualitative changes in keratoconic collagen fibers, along with the observed abnormality in the Bowman’s membrane, might point to the pathogenesis of secondary corneal amyloidosis in keratoconus.
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Affiliation(s)
- Kaoru Araki-Sasaki
- Department of Ophthalmology, Japan Community Health Care Organization, Hoshigaoka Medical Center, Hirakata, Japan,
| | - Yasuhiro Osakabe
- Department of Molecular Pathology, Tokyo Medical University, Tokyo, Japan
| | - Koji Fujita
- Department of Molecular Pathology, Tokyo Medical University, Tokyo, Japan
| | - Kazunori Miyata
- Department of Ophthalmology, Miyata Eye Hospital, Miyakonojo, Japan
| | - Koji Hirano
- Department of Ophthalmology, Ban Buntane Hotokukai Hospital, Fujita Health University, Nagoya, Japan
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State of the Art and Beyond: Anterior Segment Diagnostics Genetic Diagnostics in Corneal Disease. Int Ophthalmol Clin 2017; 57:13-26. [PMID: 28590278 DOI: 10.1097/iio.0000000000000178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bykhovskaya Y, Margines B, Rabinowitz YS. Genetics in Keratoconus: where are we? EYE AND VISION 2016; 3:16. [PMID: 27350955 PMCID: PMC4922054 DOI: 10.1186/s40662-016-0047-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/03/2016] [Indexed: 01/06/2023]
Abstract
Keratoconus (KC) is a non-inflammatory thinning and protrusion of the cornea in which the cornea assumes a conical shape. Complex etiology of this condition at present remains an enigma. Although environmental factors have been involved in KC pathogenesis, strong underlining genetic susceptibility has been proven. The lack of consistent findings among early genetic studies suggested a heterogeneity and complex nature of the genetic contribution to the development of KC. Recently, genome-wide linkage studies (GWLS) and genome-wide association studies (GWAS) were undertaken. Next-generation sequencing (NGS)-based genomic screens are also currently being carried out. Application of these recently developed comprehensive genetic tools led to a much greater success and increased reproducibility of genetic findings in KC. Involvement of the LOX gene identified through GWLS has been confirmed in multiple cohorts of KC patients around the world. KC susceptibility region located at the 2q21.3 chromosomal region near the RAB3GAP1 gene identified through GWAS was independently replicated. Rare variants in the ZNF469 gene (mutated in corneal dystrophy Brittle Cornea Syndrome) and in the TGFBI gene (mutated in multiple corneal epithelial–stromal TGFBI dystrophies) have been repeatedly identified in familial and sporadic KC patients of different ethnicities. Additional comprehensive strategies using quantitative endophenotypes have been successfully employed to bring further understanding to the genetics of KC. Additional genetic determinants including the COL5A1 gene have been identified in the GWAS of KC-related trait central corneal thickness. These recent discoveries confirmed the importance of the endophenotype approach for studying complex genetic diseases such as KC and showed that different connective tissue disorders may have the same genetic determinants.
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Affiliation(s)
- Yelena Bykhovskaya
- Regenerative Medicine Institute and Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, USA ; Cornea Genetic Eye Institute, 50 N. La Cienega Blvd. Suite #340, Beverly Hills, CA 90211 USA
| | - Benjamin Margines
- Cornea Genetic Eye Institute, 50 N. La Cienega Blvd. Suite #340, Beverly Hills, CA 90211 USA
| | - Yaron S Rabinowitz
- Regenerative Medicine Institute and Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, USA ; Cornea Genetic Eye Institute, 50 N. La Cienega Blvd. Suite #340, Beverly Hills, CA 90211 USA ; The Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, USA
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Bykhovskaya Y, Gromova A, Makarenkova HP, Rabinowitz YS. Abnormal regulation of extracellular matrix and adhesion molecules in corneas of patients with keratoconus. ACTA ACUST UNITED AC 2016; 5:63-70. [PMID: 28989906 DOI: 10.5005/jp-journals-10025-1123] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIM To identify changes in the expression of genes coding for extracellular matrix (ECM) proteins in patients with non-inflammatory corneal disorder keratoconus (KC), patients with corneal scarring, and normal controls. MATERIALS AND METHODS Total RNA extracted from corneal tissue of 13 KC patients, 2 patients with corneal scaring and 4 normal controls was analyzed using Human Extracellular Matrix & Adhesion Molecules Profiler PCR Array. Statistically significant changes in gene expression were identified using the Data Analysis software. RESULTS Comparison of KC and control corneas with thresholds of 1.5 or greater fold change and a p-value of 0.05 or lower, revealed 21 differentially expressed genes, 16 genes were downregulated and 5 were upregulated. Among transcripts downregulated in KC patients we identified THBS1, ADAMTS1, SPP1, several collagens and integrins. We found TGFBI (BIGH3) gene was the most significantly upregulated transcript. CONCLUSION Development of keratoconus results in deregulation of gene expression of extracellular matrix and adhesion molecules. CLINICAL SIGNIFICANCE Downregulation of collagens and upregulation of TGFBI repeatedly identified in KC patients may be used as clinical markers of the disease.
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Affiliation(s)
- Yelena Bykhovskaya
- Regenerative Medicine Institute and Department of Surgery, Cedars-Sinai, USA.,Cornea Genetic Eye Institute, USA
| | - Anastasia Gromova
- Department of Cell and Molecular Biology, The Scripps Research Institute, USA
| | - Helen P Makarenkova
- Department of Cell and Molecular Biology, The Scripps Research Institute, USA
| | - Yaron S Rabinowitz
- Regenerative Medicine Institute and Department of Surgery, Cedars-Sinai, USA.,Cornea Genetic Eye Institute, USA.,The Jules Stein Eye Institute, University of California Los Angeles, USA
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Saleh S, Brownstein S, Manusow JS, Jastrzebski A, Lam K, Sassani JW, Mintsioulis G, Gilberg SM. Secondary corneal amyloidosis after perforating corneal trauma: A series of 5 cases and review of the literature. Surv Ophthalmol 2015; 60:590-5. [PMID: 26253297 DOI: 10.1016/j.survophthal.2015.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/25/2015] [Accepted: 07/17/2015] [Indexed: 10/23/2022]
Abstract
We retrospectively reviewed the clinical and surgical histories of 5 patients with traumatic secondary corneal amyloidosis, a relatively rare sequela of nonsurgical and surgical perforating corneal trauma. Four had history of nonsurgical trauma, and 1 had surgical trauma to the cornea. Three specimens were obtained by penetrating keratoplasties and 2 by excision of the cornea during evisceration of the ocular contents. All the corneal specimens showed full-thickness scars of a prior perforating wound with congophilic amyloid deposits that exhibited apple-green birefringence under polarized light and dichroism. All cases had variable degrees of predominantly chronic nongranulomatous inflammation. Ultrastructural examination in 1 patient disclosed 8-nm diameter fibrils in disarray, consistent with amyloid. Amyloid P immunostaining was positive in all 3 patients tested for this protein.
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Affiliation(s)
- Solin Saleh
- Department of Ophthalmology, The Ottawa Hospital, Ottawa, Ontario, Canada; Department of Pathology, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Seymour Brownstein
- Department of Ophthalmology, The Ottawa Hospital, Ottawa, Ontario, Canada; Department of Pathology, The Ottawa Hospital, Ottawa, Ontario, Canada.
| | - Joshua S Manusow
- Department of Ophthalmology, The Ottawa Hospital, Ottawa, Ontario, Canada; Department of Pathology, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - André Jastrzebski
- Department of Ophthalmology, The Ottawa Hospital, Ottawa, Ontario, Canada; Department of Pathology, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Kay Lam
- Department of Ophthalmology, The Ottawa Hospital, Ottawa, Ontario, Canada; Department of Pathology, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Joseph W Sassani
- Department of Ophthalmology, Milton S. Hershey Medical Centre, Pennsylvania State University, Hershey, Pennsylvania, USA; Department of Pathology, Milton S. Hershey Medical Centre, Pennsylvania State University, Hershey, Pennsylvania, USA
| | - George Mintsioulis
- Department of Ophthalmology, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Steven M Gilberg
- Department of Ophthalmology, The Ottawa Hospital, Ottawa, Ontario, Canada
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Priyadarsini S, McKay TB, Sarker-Nag A, Karamichos D. Keratoconus in vitro and the key players of the TGF-β pathway. Mol Vis 2015; 21:577-88. [PMID: 26015770 PMCID: PMC4443584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/20/2015] [Indexed: 11/04/2022] Open
Abstract
PURPOSE Keratoconus (KC) is a corneal thinning disease of unknown etiology whose pathophysiology is correlated with the presence of a thin corneal stroma and altered extracellular matrix (ECM). Transforming growth factor-β (TGF-β) signaling is a key regulator of ECM secretion and assembly in multiple tissues, including the anterior segment of the eye, and it has been linked to KC. We have previously shown that human keratoconus cells (HKCs) have a myofibroblast phenotype and altered ECM assembly compared to normal human corneal fibroblasts (HCFs). Moreover, TGF-β3 treatment promotes assembly of a more normal stromal ECM and modulates the fibrotic phenotype in HKCs. Herein, we identify alterations in TGF-β signaling that contribute to the observed fibrotic phenotype in HKCs. METHODS HCFs and HKCs were stimulated with TGF-β1, TGF-β2, or TGF-β3 isoforms (0.1 ng/mL) in the presence of a stable vitamin C derivative (0.5 mM) for 4 weeks. All samples were examined using RT-PCR and western blotting to quantify changes in the expressions of key TGF-β signaling molecules between HCFs and HKCs. RESULTS We found a significant downregulation in the SMAD6 and SMAD7 expressions by HKCs when compared to HCFs (p≤0.05). Moreover, stimulation of HKCs with any of the three TGF-β isoforms did not significantly alter the expressions of SMAD6 or SMAD7. HCFs also showed an upregulation in TGF-βRI, TGF-βRII, and TGF-βRIII following TGF-β3 treatment, whereas HKCs showed a significant two-fold downregulation. CONCLUSIONS Overall, our data shows the decreased expressions of the regulatory SMADs SMAD6 and SMAD7 by HKCs contribute to the pathological ECM structure observed in KC, and TGF-β3 may attenuate this mechanism by downregulating the expression of the key profibrotic receptor, TGF-βRII. Our study suggests a significant role of altered regulation of TGF-β signaling in KC progression and that it may enable novel therapeutic developments targeting TGF-β receptor regulation.
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Affiliation(s)
- Shrestha Priyadarsini
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Tina B. McKay
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Akhee Sarker-Nag
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Dimitrios Karamichos
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
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McKay TB, Lyon D, Sarker-Nag A, Priyadarsini S, Asara JM, Karamichos D. Quercetin attenuates lactate production and extracellular matrix secretion in keratoconus. Sci Rep 2015; 5:9003. [PMID: 25758533 PMCID: PMC4355637 DOI: 10.1038/srep09003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 02/16/2015] [Indexed: 11/20/2022] Open
Abstract
Keratoconus(KC) is an ecstatic corneal disease leading to corneal-thinning and the formation of a cone-like cornea. Elevated lactate levels, increased oxidative stress, and myofibroblast formation have all been previously reported. In the current study, we assess the role of Quercetin on collagen secretion and myofibroblast formation in KC in vitro. Human corneal fibroblasts(HCFs) and human keratoconus cells(HKCs) were treated with a stable Vitamin C derivative and cultured for 4 weeks, stimulating formation of a self-assembled extracellular matrix. All samples were analyzed using Western blots and targeted tandem mass spectrometry. Our data showed that Quercetin significantly down regulates myofibroblast differentiation and fibrotic markers, such as α-smooth muscle actin (α-SMA) and Collagen III (Col III), in both HCFs and HKCs. Collagen III secretion was reduced 80% in both HCFs and HKCs following Quercetin treatment. Furthermore, Quercetin reduced lactate production by HKCs to normal HCF levels. Quercetin down regulated TGF-βR2 and TGF-β2 expression in HKCs suggesting a significant link to the TGF-β pathway. These results assert that Quercetin is a key regulator of fibrotic markers and ECM assembly by modulating cellular metabolism and TGF-β signaling. Our study suggests that Quercetin is a potential therapeutic for treatment of corneal dystrophies, such as KC.
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Affiliation(s)
- T. B. McKay
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - D. Lyon
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - A. Sarker-Nag
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - S. Priyadarsini
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - J. M. Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - D. Karamichos
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Araki-Sasaki K, Osakabe Y, Fukuoka H, Ideta R, Hirano K. Findings of secondary corneal amyloidosis with ultrahigh-resolution optical coherence tomography. Clin Ophthalmol 2014; 8:2115-9. [PMID: 25342882 PMCID: PMC4206355 DOI: 10.2147/opth.s70759] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose To describe observations by ultrahigh-resolution optical coherence tomography (OCT) in a secondary corneal amyloidosis (SCA) patient with histological analysis of excised tissue. A unique finding under OCT of her fellow eye is also described. Case A 39-year-old female had suffered from trichiasis in both of her eyes for more than 30 years. Slit-lamp examination showed a milky-white soft mass on her left cornea and a linear opacity on the fellow cornea at the cilia-attached region. OCT demonstrated the presence of a mass region within a thin epithelial layer and no destruction of Bowman’s layer in her left cornea. In the fellow cornea, which exhibited a linear opacity, a high-density spot in Bowman’s layer was observed at the cilia-attached region covered by the epithelial layer, with normal thickness. Histological examination of the excised cornea showed that the mass was positive with both Congo red and antilactoferrin antibody. Conclusion SCA, amyloid gradually accumulates above Bowman’s layer, occupying the epithelial layer, with no destruction of Bowman’s layer until the advanced stage. A high-density spot in Bowman’s layer might be the first stage of SCA.
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Affiliation(s)
- Kaoru Araki-Sasaki
- Department of Ophthalmology, Japan Community Health Care Organization, Hoshigaoka Medical Center, Hirakata, Japan
| | - Yasuhiro Osakabe
- Department of Molecular Pathology, Tokyo Medical University, Tokyo, Japan
| | - Hideki Fukuoka
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | | | - Koji Hirano
- Department of Ophthalmology, Ban Buntane Hotokukai Hospital, School of Medicine, Fujita Health University, Nagoya, Japan
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Biochemical properties and aggregation propensity of transforming growth factor-induced protein (TGFBIp) and the amyloid forming mutants. Ocul Surf 2014; 13:9-25. [PMID: 25557343 DOI: 10.1016/j.jtos.2014.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 04/01/2014] [Accepted: 04/08/2014] [Indexed: 02/07/2023]
Abstract
TGFBI-associated corneal dystrophies are characterized by accumulation of insoluble deposits of the mutant protein transforming growth factor β-induced protein (TGFBIp) in the cornea. Depending on the nature of mutation, the lesions appear as granular (non-amyloid) or lattice lines (amyloid) in the Bowman's layer or in the stroma. This review article emphasizes the structural biology aspects of TGFBIp. We discuss the tinctorial properties and ultrastructure of deposits observed in granular and lattice corneal dystrophic mutants with amyloid and non-amyloid forms of other human protein deposition diseases and review the biochemical and putative functional role of the protein. Using bioinformatics tools, we identify intrinsic aggregation propensity and discuss the possible protective role of gatekeepers close to the "aggregation-prone" regions of native TGFBIp. We describe the relative aggregation rates of lattice corneal dystrophy (LCD) and granular corneal dystrophy (GCD2) mutants using the three-parameter model, which is based on intrinsic properties of polypeptide chains. The predictive power of this model is compared with two other algorithms. We conclude that the model is able to predict the aggregation rate of mutants which do not alter overall net charge of the protein. The need to understand the mechanism of corneal dystrophies from the structural biology viewpoint is emphasized.
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Patel DA, Harocopos GJ, Chang SH, Vora SC, Lubniewski AJ, Huang AJ. Novel CHST6 gene mutations in 2 unrelated cases of macular corneal dystrophy. Cornea 2011; 30:664-9. [PMID: 21242781 PMCID: PMC3092828 DOI: 10.1097/ico.0b013e3182012888] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate the possible mutations in the carbohydrate sulfotransferase 6 (CHST6) gene of 2 unrelated cases of macular corneal dystrophy (MCD) and to report atypical stromal deposits in one of them. METHODS Corneal tissues were stained with antisulfated keratan sulfate (KS), antitransforming growth factor beta 1-induced protein (TGFBIp), thioflavin-T, alcian blue, and Masson trichrome. Sequencing was performed to identify potential mutations in the CHST6 gene and the fourth and twelfth exons of the TGFBI gene. RESULTS Alcian blue staining revealed the presence of multiple subepithelial and intrastromal mucopolysaccharide deposits, confirming the diagnosis of MCD in both cases. Immunofluorescence staining in case 1 revealed the presence of sulfated KS only in the keratocytes and select endothelial cells, consistent with MCD type IA. Preferential expression of sulfated KS was observed in keratocytes and extracellular stromal matrix in case 2, consistent with MCD type II. Atypical subepithelial and superficial stromal deposits were observed in case 1, which stained positively with alcian blue, eosin, Masson trichrome, and thioflavin-T indicating the presence of hyaline and amyloid materials. CHST6 gene sequencing revealed 2 heterozygous mutations in case 1 (a p.Arg211Gln and a novel mutation of p.Arg177Gly) and a novel homozygous mutation of p.Pro186Arg in case 2. No mutations were found in exons 4 or 12 of the TGFBI gene in case 1. CONCLUSIONS Secondary hyalinosis and amyloidosis occur in a case of MCD type IA with a novel p.Arg177Gly mutation in CHST6. A novel p.Pro186Arg mutation in CHST6 is associated with MCD type II in an African American.
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Affiliation(s)
- Dhara A. Patel
- Departments of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
| | - George J. Harocopos
- Departments of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
- Departments of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - Shu-Hong Chang
- Departments of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
| | - Smita C. Vora
- Departments of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
| | - Anthony J. Lubniewski
- Departments of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
| | - Andrew J.W. Huang
- Departments of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO
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Conformational diseases: looking into the eyes. Brain Res Bull 2010; 81:12-24. [PMID: 19808079 DOI: 10.1016/j.brainresbull.2009.09.015] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 09/11/2009] [Accepted: 09/29/2009] [Indexed: 01/09/2023]
Abstract
Conformational diseases, a general term comprising more than 40 disorders are caused by the accumulation of unfolded or misfolded proteins. Improper protein folding (misfolding) as well as accrual of unfolded proteins can lead to the formation of disordered (amorphous) or ordered (amyloid fibril) aggregates. The gradual accumulation of protein aggregates and the acceleration of their formation by stress explain the characteristic late or episodic onset of the diseases. The best studied in this group are neurodegenerative diseases and amyloidosis accompanied by the deposition of a specific aggregation-prone proteins or protein fragments and formation of insoluble fibrils. Amyloidogenic protein accumulation often occurs in the brain tissues, e.g. in Alzheimer's disease with the deposition of amyloid-beta and Tau, in scrapie and bovine spongiform encephalopathy with the accumulation of prion protein, in Parkinson's disease with the deposition of alpha-synuclein. Other examples of amyloid proteins are transthyretin, immunoglobulin light chain, gelsolin, etc. In addition to the brain, the accumulation of unfolded or misfolded proteins leading to pathology takes place in a wide variety of organs and tissues, including different parts of the eye. The best studied ocular conformational diseases are cataract in the lens and retinitis pigmentosa in the retina, but accumulation of misfolded proteins also occurs in other parts of the eye causing various disorders. Furthermore, ocular manifestation of systemic amyloidosis often causes the deposition of amyloidogenic proteins in different ocular tissues. Here we present the data regarding naturally unfolded and misfolded proteins in eye tissues, their structure-function relationships, and molecular mechanisms underlying their involvement in diseases. We also summarize the etiology of ocular conformational diseases and discuss approaches to their treatment.
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