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Volatier T, Cursiefen C, Notara M. Current Advances in Corneal Stromal Stem Cell Biology and Therapeutic Applications. Cells 2024; 13:163. [PMID: 38247854 PMCID: PMC10814767 DOI: 10.3390/cells13020163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/08/2024] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
Corneal stromal stem cells (CSSCs) are of particular interest in regenerative ophthalmology, offering a new therapeutic target for corneal injuries and diseases. This review provides a comprehensive examination of CSSCs, exploring their anatomy, functions, and role in maintaining corneal integrity. Molecular markers, wound healing mechanisms, and potential therapeutic applications are discussed. Global corneal blindness, especially in more resource-limited regions, underscores the need for innovative solutions. Challenges posed by corneal defects, emphasizing the urgent need for advanced therapeutic interventions, are discussed. The review places a spotlight on exosome therapy as a potential therapy. CSSC-derived exosomes exhibit significant potential for modulating inflammation, promoting tissue repair, and addressing corneal transparency. Additionally, the rejuvenation potential of CSSCs through epigenetic reprogramming adds to the evolving regenerative landscape. The imperative for clinical trials and human studies to seamlessly integrate these strategies into practice is emphasized. This points towards a future where CSSC-based therapies, particularly leveraging exosomes, play a central role in diversifying ophthalmic regenerative medicine.
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Affiliation(s)
- Thomas Volatier
- Department of Ophthalmology, Faculty of Medicine, University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
| | - Claus Cursiefen
- Department of Ophthalmology, Faculty of Medicine, University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Cologne Excellence Cluster for Cellular Stress Responses Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
| | - Maria Notara
- Department of Ophthalmology, Faculty of Medicine, University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine, University Hospital Cologne, University of Cologne, 50931 Cologne, Germany
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Al-Qahtani BS, Alkatan HM, Khandekar R, Al-Salem A, Al-Swailem SA. Clinical features and histopathological analysis of corneal myxoma. Sci Rep 2022; 12:11207. [PMID: 35778593 PMCID: PMC9249855 DOI: 10.1038/s41598-022-15475-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/24/2022] [Indexed: 11/09/2022] Open
Abstract
To describe the presentation, histopathological characteristics, and management outcomes for corneal myxoma. This one-armed cohort study evaluated histologically confirmed consecutive cases of corneal myxoma. Data were evaluated on demographics, clinical presentation, management, histopathological and immunohistochemical features, and outcomes; visual acuity and corneal clarity. The study sample was comprised of 10 eyes (10 patients). The median age at presentation was 10.5 years. Five eyes had high intraocular pressure, four eyes had decreased distance visual acuity and one eye became discolored. Surgical management included penetrating keratoplasty (8 eyes), phototherapeutic keratectomy (1 eye), and evisceration because of a blind painful eye (1 eye). Postoperative best-corrected distance vision ranged from 20/20 to 20/60 (1 eye), < 20/60 to 20/200 (2 eyes), < 20/200 to 20/400 (1 eye), < 20/200 to light perception (4 eyes) and no light perception (1 eye). The histopathology of these lesions showed typical subepithelial proliferating spindle-shaped cells of mesenchymal origin within a myxoid stroma rich in glycosaminoglycan. The median duration of follow-up was 5 years. Recurrence was observed in an eye that underwent local excision. Corneal myxoma is a rare lesion that is presumably isolated, secondary, and reactive in nature. Surgically management yields reasonably favorable outcomes.
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Affiliation(s)
- Bader S Al-Qahtani
- Research Department, King Khaled Eye Specialist Hospital, PO Box 7191, Riyadh, 11462, Saudi Arabia.,Ophthalmolmology Department, King Faisal Specialist Hospital, Riyadh, Saudi Arabia
| | - Hind M Alkatan
- Ophthalmology Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia.,King Saud University Medical City, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Rajiv Khandekar
- Research Department, King Khaled Eye Specialist Hospital, PO Box 7191, Riyadh, 11462, Saudi Arabia
| | - Ahmed Al-Salem
- Research Department, King Khaled Eye Specialist Hospital, PO Box 7191, Riyadh, 11462, Saudi Arabia
| | - Samar A Al-Swailem
- Research Department, King Khaled Eye Specialist Hospital, PO Box 7191, Riyadh, 11462, Saudi Arabia.
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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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Thomson BR, Liu P, Onay T, Du J, Tompson SW, Misener S, Purohit RR, Young TL, Jin J, Quaggin SE. Cellular crosstalk regulates the aqueous humor outflow pathway and provides new targets for glaucoma therapies. Nat Commun 2021; 12:6072. [PMID: 34663817 PMCID: PMC8523664 DOI: 10.1038/s41467-021-26346-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 09/30/2021] [Indexed: 11/09/2022] Open
Abstract
Primary congenital glaucoma (PCG) is a severe disease characterized by developmental defects in the trabecular meshwork (TM) and Schlemm's canal (SC), comprising the conventional aqueous humor outflow pathway of the eye. Recently, heterozygous loss of function variants in TEK and ANGPT1 or compound variants in TEK/SVEP1 were identified in children with PCG. Moreover, common variants in ANGPT1and SVEP1 have been identified as risk alleles for primary open angle glaucoma (POAG) in GWAS studies. Here, we show tissue-specific deletion of Angpt1 or Svep1 from the TM causes PCG in mice with severe defects in the adjacent SC. Single-cell transcriptomic analysis of normal and glaucomatous Angpt1 deficient eyes allowed us to identify distinct TM and SC cell populations and discover additional TM-SC signaling pathways. Furthermore, confirming the importance of angiopoietin signaling in SC, delivery of a recombinant ANGPT1-mimetic promotes developmental SC expansion in healthy and Angpt1 deficient eyes, blunts intraocular pressure (IOP) elevation and RGC loss in a mouse model of PCG and lowers IOP in healthy adult mice. Our data highlight the central role of ANGPT1-TEK signaling and TM-SC crosstalk in IOP homeostasis and provide new candidates for SC-targeted glaucoma therapy.
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Affiliation(s)
- Benjamin R Thomson
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- The Feinberg Cardiovascular and Renal Research Institute, Chicago, IL, USA
| | - Pan Liu
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- The Feinberg Cardiovascular and Renal Research Institute, Chicago, IL, USA
| | - Tuncer Onay
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Jing Du
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- The Feinberg Cardiovascular and Renal Research Institute, Chicago, IL, USA
| | - Stuart W Tompson
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Sol Misener
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- The Feinberg Cardiovascular and Renal Research Institute, Chicago, IL, USA
| | - Raj R Purohit
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- The Feinberg Cardiovascular and Renal Research Institute, Chicago, IL, USA
| | - Terri L Young
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Jing Jin
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
- The Feinberg Cardiovascular and Renal Research Institute, Chicago, IL, USA
| | - Susan E Quaggin
- Division of Nephrology and Hypertension, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
- The Feinberg Cardiovascular and Renal Research Institute, Chicago, IL, USA.
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Alvarado-Villacorta R, Torres Zavala NM, Marroquín Loayza L, Rodríguez-Reyes AA. Conjunctival myxoma: A systematic review of a rare tumor. Surv Ophthalmol 2021; 67:729-740. [PMID: 34461119 DOI: 10.1016/j.survophthal.2021.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 12/14/2022]
Abstract
Conjunctival myxoma is an uncommon benign tumor that may develop as a localized disease or as part of the Carney complex, in which case it can cause significant morbidity and mortality. Conjunctival myxomas can mimic other pure or mixed tumors and are often overlooked in clinical practice. Histopathological studies are essential for diagnosis; however, controversy regarding their pathological and immunohistochemical features makes the diagnostic process more difficult. Because of the importance of correctly classifying these conjunctival tumors, as well as recognizing when a systematic screening is required owing to the possible association with life-threatening diseases, we comprehensively evaluate the literature on this rare entity based on a systematic approach.
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Affiliation(s)
- Rosa Alvarado-Villacorta
- Cornea and Refractive Surgery Department, Asociación para Evitar la Ceguera en México IAP., Mexico City, Mexico; Faculty of Medicine, Universidad Nacional Autónoma de México, Mexico City, Mexico; Latin American Network for Research in Eye Diseases-LANRED, Mexico City, Mexico.
| | | | - Lelia Marroquín Loayza
- Ocular Pathology Laboratory "Dr. José Antonio Avendaño Valdez," Instituto Nacional de Oftalmología "Dr. Francisco Contreras Campos," Lima, Peru
| | - Abelardo A Rodríguez-Reyes
- Faculty of Medicine, Universidad Nacional Autónoma de México, Mexico City, Mexico; Ophthalmic Pathology Service, Asociación para Evitar la Ceguera en México, I.A.P., Mexico City, Mexico
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6
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Fukuda K. Corneal fibroblasts: Function and markers. Exp Eye Res 2020; 200:108229. [PMID: 32919991 DOI: 10.1016/j.exer.2020.108229] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023]
Abstract
Corneal stromal keratocytes contribute to the maintenance of corneal transparency and shape by synthesizing and degrading extracellular matrix. They are quiescent in the healthy cornea, but they become activated in response to insults from the external environment that breach the corneal epithelium, with such activation being associated with phenotypic transformation into fibroblasts. Corneal fibroblasts (activated keratocytes) act as sentinel cells to sense various external stimuli-including damage-associated molecular patterns derived from injured cells, pathogen-associated molecular patterns of infectious microorganisms, and inflammatory mediators such as cytokines-under pathological conditions such as trauma, infection, and allergy. The expression of various chemokines and adhesion molecules by corneal fibroblasts determines the selective recruitment and activation of inflammatory cells in a manner dependent on the type of insult. In infectious keratitis, the interaction of corneal fibroblasts with various components of microbes and with cytokines derived from infiltrated inflammatory cells results in excessive degradation of stromal collagen and consequent corneal ulceration. Corneal fibroblasts distinguish between type 1 and type 2 inflammation through recognition of corresponding cytokines, with their activation by type 2 cytokines contributing to the pathogenesis of corneal lesions in severe ocular allergic diseases. Pharmacological targeting of corneal fibroblast function is thus a potential novel therapeutic approach to prevention of excessive corneal stromal inflammation, damage, and scarring.
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Affiliation(s)
- Ken Fukuda
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Oko-cho, Nankoku City, Kochi, 783-8505, Japan.
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Espana EM, Birk DE. Composition, structure and function of the corneal stroma. Exp Eye Res 2020; 198:108137. [PMID: 32663498 PMCID: PMC7508887 DOI: 10.1016/j.exer.2020.108137] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
No other tissue in the body depends more on the composition and organization of the extracellular matrix (ECM) for normal structure and function than the corneal stroma. The precise arrangement and orientation of collagen fibrils, lamellae and keratocytes that occurs during development and is needed in adults to maintain stromal function is dependent on the regulated interaction of multiple ECM components that contribute to attain the unique properties of the cornea: transparency, shape, mechanical strength, and avascularity. This review summarizes the contribution of different ECM components, their structure, regulation and function in modulating the properties of the corneal stroma. Fibril forming collagens (I, III, V), fibril associated collagens with interrupted triple helices (XII and XIV), network forming collagens (IV, VI and VIII) as well as small leucine-rich proteoglycans (SLRP) expressed in the stroma: decorin, biglycan, lumican, keratocan, and fibromodulin are some of the ECM components reviewed in this manuscript. There are spatial and temporal differences in the expression of these ECM components, as well as interactions among them that contribute to stromal function. Unique regions within the stroma like Bowman's layer and Descemet's layer are discussed. To define the complexity of corneal stroma composition and structure as well as the relationship to function is a daunting task. Our knowledge is expanding, and we expect that this review provides a comprehensive overview of current knowledge, definition of gaps and suggests future research directions.
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Affiliation(s)
- Edgar M Espana
- Department of Molecular Pharmacology and Physiology, USA; Cornea, External Disease and Refractive Surgery, Department of Ophthalmology, University of South Florida, Morsani College of Medicine, Tampa, FL, USA
| | - David E Birk
- Department of Molecular Pharmacology and Physiology, USA.
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Yam GHF, Riau AK, Funderburgh ML, Mehta JS, Jhanji V. Keratocyte biology. Exp Eye Res 2020; 196:108062. [PMID: 32442558 DOI: 10.1016/j.exer.2020.108062] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 12/12/2022]
Abstract
The study of corneal stromal keratocytes is motivated by its strong association with corneal health and visual function. They play a dominant role in the maintenance of corneal homeostasis and transparency through the production of collagens, proteoglycans and corneal crystallins. Trauma-induced apoptosis of keratocytes and replacement by fibroblasts and myofibroblasts disrupt the stromal matrix organization, resulting in corneal haze formation and vision loss. It is, therefore, important to understand the biology and behaviours of keratocytes and the associated stromal cell types (like fibroblasts, myofibroblasts, stromal stem cells) in wound healing, corneal pathologies (including keratoconus, keratitis, endothelial disorders) as well as different ophthalmic situations (such as collagen crosslinking/photodynamic treatment, keratoplasty and refractive surgery, and topical medications). The recent development of ex vivo propagation of keratocytes and stromal stem cells, and their translational applications, either via stromal injection or incorporated in bioscaffold, have been shown to restore the corneal transparency and regenerate native stromal tissue in animal models of corneal haze and other disorders.
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Affiliation(s)
- Gary H F Yam
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Andri K Riau
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore
| | | | - Jodhbir S Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA
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Histological Corneal Alterations in Keratoconus After Crosslinking—Expansion of Findings. Cornea 2019; 39:333-341. [DOI: 10.1097/ico.0000000000002144] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fernández-Pérez J, Ahearne M. Influence of Biochemical Cues in Human Corneal Stromal Cell Phenotype. Curr Eye Res 2018; 44:135-146. [PMID: 30335528 DOI: 10.1080/02713683.2018.1536216] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE To identify biochemical cues that could promote a keratocyte-like phenotype in human corneal stromal cells that had become fibroblastic when expanded in serum-supplemented media while also examining the effect on cell proliferation and migration. METHODS Proliferation was assessed by PrestoBlue™, morphology was monitored by phase contrast microscopy, phenotype was analyzed by real-time polymerase chain reaction (qPCR), immunochemistry and flow cytometry, and migration was studied with a scratch assay. RESULTS Ascorbic Acid (AA), Retinoic Acid (RA), Insulin-Transferrin-Selenium (ITS), Insulin-like Growth Factor 1 (IGF-1) and 3-isobutyl-1-methylxanthine (IBMX) promoted a dendritic morphology, increased the expression of keratocyte markers, such as keratocan, aldehyde dehydrogenase 3 family member A1 (ALDH3A1) and CD34, and prevented myofibroblast differentiation, while in some cases increasing proliferation. Transforming Growth Factor beta 1 (TGF-β1) and 3 (TGF-β3) promoted the differentiation toward myofibroblasts, with increased expression of α-SMA. Fibroblast Growth Factor 2 (FGF-2) supported a fibroblastic phenotype while Platelet-Derived Growth Factor Homodimer B (PDGF-BB) induced a pro-migratory fibroblastic phenotype. A combination of all the pro-keratocyte factors was also compared to the serum-free only, which significantly increased CD34 and keratocan expression. CONCLUSIONS Partially recovery towards a quiescent keratocyte-like phenotype was achieved by the removal of serum and the addition of AA, IGF-1, RA, ITS and IBMX to a basal medium. These findings can be used to develop cell-based corneal therapies and to study corneal diseases in vitro.
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Affiliation(s)
- Julia Fernández-Pérez
- a Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin , University of Dublin , Dublin , Ireland.,b Trinity Centre for Bioengineering, Trinity Biomedical Science Institute, Trinity College Dublin , University of Dublin , Dublin , Ireland
| | - Mark Ahearne
- a Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin , University of Dublin , Dublin , Ireland.,b Trinity Centre for Bioengineering, Trinity Biomedical Science Institute, Trinity College Dublin , University of Dublin , Dublin , Ireland
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Balestrazzi A, Martone G, Traversi C, Haka G, Toti P, Caporossi A. Keratoconus Associated with Corneal Macular Dystrophy: In vivo Confocal Microscopic Evaluation. Eur J Ophthalmol 2018; 16:745-50. [PMID: 17061228 DOI: 10.1177/112067210601600514] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose The authors present a case, studied through in vivo confocal microscopy, of concomitant keratoconus and macular corneal dystrophy (MCD). Methods A 29-year-old man underwent a penetrating keratoplasty in the right eye in May 2005. Confocal microscopy was performed to examine the cornea of the right eye. Results A diagnosis of concomitant keratoconus and MCD was suspected, due to the simultaneous findings of corneal ectasia and stromal opacities. Conclusions In this case, using in vivo confocal microscopy, morphologic changes were detected in many corneal layers and compared with the histopathologic findings. The morphologic alterations were found mainly in the area of the cornea apex.
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Affiliation(s)
- A Balestrazzi
- Department of Ophthalmology and Neurosurgery, University of Siena, Siena, Italy.
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Molecular and Histopathological Changes Associated with Keratoconus. BIOMED RESEARCH INTERNATIONAL 2017; 2017:7803029. [PMID: 28251158 PMCID: PMC5303843 DOI: 10.1155/2017/7803029] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 12/16/2016] [Accepted: 01/04/2017] [Indexed: 12/13/2022]
Abstract
Keratoconus (KC) is a corneal thinning disorder that leads to loss of visual acuity through ectasia, opacity, and irregular astigmatism. It is one of the leading indicators for corneal transplantation in the Western countries. KC usually starts at puberty and progresses until the third or fourth decade; however its progression differs among patients. In the keratoconic cornea, all layers except the endothelium have been shown to have histopathological structural changes. Despite numerous studies in the last several decades, the mechanisms of KC development and progression remain unclear. Both genetic and environmental factors may contribute to the pathogenesis of KC. Many previous articles have reviewed the genetic aspects of KC, but in this review we summarize the histopathological features of different layers of cornea and discuss the differentially expressed proteins in the KC-affected cornea. This summary will help emphasize the major molecular defects in KC and identify additional research areas related to KC, potentially opening up possibilities for novel methods of KC prevention and therapeutic intervention.
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Crosslinking and corneal cryotherapy in acanthamoeba keratitis -- a histological study. Graefes Arch Clin Exp Ophthalmol 2016; 254:149-53. [PMID: 26483144 DOI: 10.1007/s00417-015-3189-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 09/17/2015] [Accepted: 09/30/2015] [Indexed: 10/22/2022] Open
Abstract
PURPOSE Acanthamoeba keratitis is rare, but difficult to treat. Penetrating keratoplasty is performed in therapy-resistant cases. Nevertheless, subsequent recurrences occur in 40 % of the cases. In addition to triple-topical therapy (polyhexamid, propamidinisoethionat, neomycin), treatment alternatives are corneal cryotherapy and/or crosslinking (CXL). The aim of our present histological study was to analyze the persistence of acanthamoebatrophozoites and cysts, the persistence of bacteria, and activation of keratocytes in corneas of acanthamoeba keratitis patients following corneal cryotherapy and/or CXL. PATIENTS AND METHODS We analyzed histologically corneal buttons (from penetrating keratoplasties) of nine patients with acanthamoeba keratitis, following corneal cryotherapy (two patients) or a combination of crosslinking and corneal cryotherapy (seven patients), using haematoxilin–eosin, periodic acid Schiff (PAS), Gram and alpha-smooth muscle actin (alpha-SMA) stainings. RESULTS Acanthamoeba trophozoites persisted in three corneas after cryotherapy and CXL. Cysts persisted in one of two corneas following corneal cryotherapy and in six of seven corneas after a combination of CXL and cryotherapy. One cornea showed positive Gram staining, but there were no alpha-SMA positive keratocytes in any of the corneas. CONCLUSIONS Crosslinking and corneal cryotherapy have only limited impact on killing of acanthamoeba trophozoites, cysts, or bacteria. Corneal cryotherapy and CXL did not stimulate myofibroblastic transformation of keratocytes.
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Abstract
Corneal endothelial cells (CECs) are terminally differentiated cells, specialized in regulating corneal hydration and transparency. They are highly polarized flat cells that separate the cornea from the aqueous humor. Their apical surface, in contact with aqueous humor is hexagonal, whereas their basal surface is irregular. We characterized the structure of human CECs in 3D using confocal microscopy of immunostained whole corneas in which cells and their interrelationships remain intact. Hexagonality of the apical surface was maintained by the interaction between tight junctions and a submembraneous network of actomyosin, braced like a drum. Lateral membranes, which support enzymatic pumps, presented complex expansions resembling interdigitated foot processes at the basal surface. Using computer-aided design and drafting software, we obtained a first simplified 3D model of CECs. By comparing their expression with those in epithelial, stromal and trabecular corneal cells, we selected 9 structural or functional proteins for which 3D patterns were specific to CECs. This first 3D map aids our understanding of the morphologic and functional specificity of CECs and could be used as a reference for characterizing future cell therapy products destined to treat endothelial dysfunctions.
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Wisse RP, Kuiper JJ, Gans R, Imhof S, Radstake TR, Van der Lelij A. Cytokine Expression in Keratoconus and its Corneal Microenvironment: A Systematic Review. Ocul Surf 2015; 13:272-83. [DOI: 10.1016/j.jtos.2015.04.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/11/2015] [Accepted: 04/01/2015] [Indexed: 12/26/2022]
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Foster JW, Gouveia RM, Connon CJ. Low-glucose enhances keratocyte-characteristic phenotype from corneal stromal cells in serum-free conditions. Sci Rep 2015; 5:10839. [PMID: 26039975 PMCID: PMC4650697 DOI: 10.1038/srep10839] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 04/17/2015] [Indexed: 11/24/2022] Open
Abstract
The avascular cornea is a uniquely-isolated organ, with its stroma constituting a nutrient-poor environment. Consequently, the availability of metabolites such as glucose to corneal stromal cells is considerably reduced compared with other tissues, or indeed with media commonly used to culture these cells in vitro. However, the role of glucose in the behaviour of human corneal keratocytes has been overlooked. As such, we sought to investigate the effects of low-glucose formulations on the phenotype of human corneal stromal cells. Cells cultured in low-glucose were able to survive for extended periods when compared to high-glucose, serum-free conditions. Furthermore, low-glucose enhanced their reversal to a keratocyte-characteristic phenotype. Specifically, cells within low-glucose medium assumed dendritic morphologies, with bean-shaped condensed nuclei, absence of alpha-smooth muscle actin or stress fibres, and a corresponding reduction in migratory and contractile activities when compared with high-glucose, serum-free conditions. Moreover, cells within low-glucose uniquely recovered the ability to express a robust keratocyte-characteristic marker, CD34, while still expressing elevated levels of other representative phenotypic markers such as keratocan, lumican, ALDH1A1, and ALDH3A1. These results indicate that low-glucose enhances keratocyte-characteristic phenotype above and beyond established media formulations and thus has important implications for corneal biology in health and disease.
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Affiliation(s)
| | - Ricardo M. Gouveia
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Che J. Connon
- Institute of Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
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Kumar P, Satyam A, Fan X, Rochev Y, Rodriguez BJ, Gorelov A, Joshi L, Raghunath M, Pandit A, Zeugolis DI. Accelerated Development of Supramolecular Corneal Stromal-Like Assemblies from Corneal Fibroblasts in the Presence of Macromolecular Crowders. Tissue Eng Part C Methods 2015; 21:660-70. [PMID: 25535812 DOI: 10.1089/ten.tec.2014.0387] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Tissue engineering by self-assembly uses the cells' secretome as a regeneration template and biological factory of trophic factors. Despite the several advantages that have been witnessed in preclinical and clinical settings, the major obstacle for wide acceptance of this technology remains the tardy extracellular matrix formation. In this study, we assessed the influence of macromolecular crowding (MMC)/excluding volume effect, a biophysical phenomenon that accelerates thermodynamic activities and biological processes by several orders of magnitude, in human corneal fibroblast (HCF) culture. Our data indicate that the addition of negatively charged galactose derivative (carrageenan) in HCF culture, even at 0.5% serum, increases by 12-fold tissue-specific matrix deposition, while maintaining physiological cell morphology and protein/gene expression. Gene analysis indicates that a glucose derivative (dextran sulfate) may drive corneal fibroblasts toward a myofibroblast lineage. Collectively, these results indicate that MMC may be suitable not only for clinical translation and commercialization of tissue engineering by self-assembly therapies, but also for the development of in vitro pathophysiology models.
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Affiliation(s)
- Pramod Kumar
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Abhigyan Satyam
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Xingliang Fan
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Yury Rochev
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Brian J Rodriguez
- 2 Conway Institute of Biomolecular & Biomedical Research, University College Dublin , Dublin, Ireland
| | - Alexander Gorelov
- 3 School of Chemistry & Chemical Biology, University College Dublin , Dublin, Ireland
| | - Lokesh Joshi
- 4 Alimentary Glycoscience Research Cluster, NUI Galway , Galway, Ireland
| | - Michael Raghunath
- 5 Department of Bioengineering, Faculty of Engineering, National University of Singapore , Singapore, Singapore .,6 Tissue Engineering Programme, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore , Singapore, Singapore
| | - Abhay Pandit
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Dimitrios I Zeugolis
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
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18
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Järventausta PJ, Tervo TMT, Kivelä T, Holopainen JM. Peripheral hypertrophic subepithelial corneal degeneration - clinical and histopathological features. Acta Ophthalmol 2014; 92:774-82. [PMID: 24655442 DOI: 10.1111/aos.12394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 02/15/2014] [Indexed: 12/22/2022]
Abstract
PURPOSE To refine the diagnostic criteria for peripheral hypertrophic subepithelial corneal degeneration (PHSD) and characterize its clinical phenotype, histopathology and immunohistochemical features. METHODS Diagnostic criteria were refined on the basis of literature data. Fourteen patients (13 women and one man; median age 52 years, range 33-66) were identified based on these criteria. Keratectomy specimens were evaluated via routine and immunohistochemical stainings. The main outcome measures were symptoms, clinical phenotype, immunological status and histopathologic results. RESULTS We defined the diagnostic criteria of typical PHSD as elevated circumferential and perilimbal subepithelial fibrosis with focal superficial corneal neovascularization, which were supported by female sex (93%), bilaterality (86%), the centre being in the upper quadrants (81%) and irregular astigmatism of two dioptres or more. The typical symptoms were reduced vision (86%) and the symptoms of ocular surface disease (64%). Light microscopy showed fibrosis with abundant collagen deposition but no inflammation in all patients. An immunohistochemical analysis of nine patients showed uniform staining for vimentin in three distinct types of fibroblasts in variable proportions: keratocyte-like cells that were positive for CD34, myofibroblasts that were positive for smooth muscle actin (SMA) and fibroblasts that were negative for CD34 and SMA. Small numbers of CD68-positive macrophages were also found. CONCLUSIONS Peripheral hypertrophic subepithelial degeneration is characteristic of middle-aged women, in whom it is typically a bilateral idiopathic degeneration of the cornea associated with ocular surface disease and reduced vision. The fibrotic lesions probably undergo remodelling, inducing changes in corneal contour. A smouldering low-grade inflammation favouring low TGF-β1 concentrations is postulated as the primary pathological process leading to PHSD.
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Affiliation(s)
| | | | - Tero Kivelä
- Helsinki University Eye Hospital; Helsinki Finland
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19
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Lee SH, Kim KW, Kim MK, Chun YS, Kim JC. Evaluation of stem cell components in retrocorneal membranes. J Korean Med Sci 2014; 29:846-51. [PMID: 24932088 PMCID: PMC4055820 DOI: 10.3346/jkms.2014.29.6.846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/10/2014] [Indexed: 12/30/2022] Open
Abstract
The purpose of this study was to elucidate the origin and cellular composition of retrocorneal membranes (RCMs) associated with chemical burns using immunohistochemical staining for primitive cell markers. Six cases of RCMs were collected during penetrating keratoplasty. We examined RCMs with hematoxylin and eosin (H&E), periodic acid-Schiff (PAS) staining and immunohistochemical analysis using monoclonal antibodies against hematopoietic stem cells (CD34, CD133, c-kit), mesenchymal stem cells (beta-1-integrin, TGF-β, vimentin, hSTRO-1), fibroblasts (FGF-β, α-smooth muscle actin), and corneal endothelial cells (type IV collagen, CD133, VEGF, VEGFR1). Histologic analysis of RCMs revealed an organized assembly of spindle-shaped cells, pigment-laden cells, and thin collagenous matrix structures. RCMs were positive for markers of mesenchymal stem cells including beta-1-integrin, TGF-β, vimentin, and hSTRO-1. Fibroblast markers were also positive, including FGF-β and α-smooth muscle actin (SMA). In contrast, immunohistochemical staining was negative for hematopoietic stem cell markers including CD34, CD133 and c-kit as well as corneal endothelial cell markers such as type IV collagen, CD133 except VEGF and VEGFR1. Pigment-laden cells did not stain with any antibodies. The results of this study suggest that RCMs consist of a thin collagen matrix and fibroblast-like cells and may be a possible neogenetic structure produced from a lineage of bone marrow-derived mesenchymal stem cells.
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Affiliation(s)
- Seok Hyun Lee
- Department of Ophthalmology, Chung-Ang University Hospital, College of Medicine, Seoul, Korea
| | - Kyoung Woo Kim
- Department of Ophthalmology, Chung-Ang University Hospital, College of Medicine, Seoul, Korea
| | - Mi Kyung Kim
- Department of Pathology, Chung-Ang University Hospital, College of Medicine, Seoul, Korea
| | - Yeoun Sook Chun
- Department of Ophthalmology, Chung-Ang University Hospital, College of Medicine, Seoul, Korea
| | - Jae Chan Kim
- Department of Ophthalmology, Chung-Ang University Hospital, College of Medicine, Seoul, Korea
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20
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Abstract
The cornea is a tough transparent tissue admitting and focusing light in the eye. More than 90% of the cornea is stroma, a highly organized, transparent connective tissue maintained by keratocytes, quiescent mesenchymal cells of neural crest origin. A small population of cells in the mammalian stroma displays properties of mesenchymal stem cells, including clonal growth, multipotent differentiation, and expression of an array of stem cell-specific markers. Unlike keratocytes, the corneal stromal stem cells (CSSCs) undergo extensive expansion in vitro without loss of the ability to adopt a keratocyte phenotype. Several lines of evidence suggest CSSCs to be of neural crest lineage and not from bone marrow. CSSCs are localized in the anterior peripheral (limbal) stroma near to stem cells of the corneal epithelium. CSSCs may function to support potency of the epithelial stem cells in their unique limbal niche. On the other hand, little information is available documenting a role for CSSCs in vivo in stromal wound healing or regeneration. In vitro CSSCs reproduce the highly organized connective tissue of the stroma, demonstrating a potential use of these cells in tissue bioengineering. Direct introduction of CSSCs into the corneal stroma generated transparent tissue in a mouse model of corneal opacity. Human CSSCs injected into mice corneas did not elicit immune rejection over an extended period of time. The CSSCs therefore appear offer an opportunity to develop cell- and tissue-based therapies for irreversible corneal blindness, conditions affecting more than 10 million individuals worldwide.
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Affiliation(s)
- Niveditha Pinnamaneni
- Department of Ophthalmology, UPMC Eye Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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21
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Bray LJ, Heazlewood CF, Atkinson K, Hutmacher DW, Harkin DG. Evaluation of methods for cultivating limbal mesenchymal stromal cells. Cytotherapy 2012; 14:936-47. [PMID: 22587591 DOI: 10.3109/14653249.2012.684379] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND AIMS Mesenchymal stromal cells (MSC) with similar properties to bone marrow-derived mesenchymal stromal cells (BM-MSC) have recently been grown from the limbus of the human cornea. We have evaluated methods for culturing human limbal MSC (L-MSC). METHODS Four basic strategies were compared: serum-supplemented medium (10% fetal bovine serum; FBS), standard serum-free medium supplemented with B-27, epidermal growth factor and fibroblast growth factor 2, or one of two commercial serum-free media, defined keratinocyte serum-free medium (Invitrogen) and MesenCult-XF® (Stem Cell Technologies). The resulting cultures were examined using photography, flow cytometry (for CD34, CD45, CD73, CD90, CD105, CD141 and CD271), immunocytochemistry (alpha-smooth muscle actin; α-sma), differentiation assays (osteogenesis, adipogenesis and chrondrogenesis) and co-culture experiments with human limbal epithelial (HLE) cells. RESULTS While all techniques supported the establishment of cultures to varying degrees, sustained growth and serial propagation were only achieved in 10% FBS medium or MesenCult-XF medium. Cultures established in 10% FBS medium were 70-80% CD34(-) CD45(-) CD90 (+) CD73 (+) CD105 (+) , approximately 25% α-sma (+) and displayed multipotency. Cultures established in MesenCult-XF were > 95% CD34(-) CD45(-) CD90 (+) CD73 (+) CD105 (+) , 40% CD141 (+) , rarely expressed α-sma, and displayed multipotency. L-MSC supported growth of HLE cells, with the largest epithelial islands being observed in the presence of MesenCult-XF-grown L-MSC. All HLE cultures supported by L-MSC widely expressed the progenitor cell marker ∆Np63, along with the corneal differentiation marker cytokeratin 3. CONCLUSIONS MesenCult-XF is a superior culture system for L-MSC, but further studies are required to explore the significance of CD141 expression in these cells.
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Affiliation(s)
- Laura J Bray
- Queensland Eye Institute, South Brisbane, Queensland, Australia.
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22
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Hippert C, Ibanes S, Serratrice N, Court F, Malecaze F, Kremer EJ, Kalatzis V. Corneal transduction by intra-stromal injection of AAV vectors in vivo in the mouse and ex vivo in human explants. PLoS One 2012; 7:e35318. [PMID: 22523585 PMCID: PMC3327666 DOI: 10.1371/journal.pone.0035318] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 03/14/2012] [Indexed: 12/13/2022] Open
Abstract
The cornea is a transparent, avascular tissue that acts as the major refractive surface of the eye. Corneal transparency, assured by the inner stroma, is vital for this role. Disruption in stromal transparency can occur in some inherited or acquired diseases. As a consequence, light entering the eye is blocked or distorted, leading to decreased visual acuity. Possible treatment for restoring transparency could be via viral-based gene therapy. The stroma is particularly amenable to this strategy due to its immunoprivileged nature and low turnover rate. We assayed the potential of AAV vectors to transduce keratocytes following intra-stromal injection in vivo in the mouse cornea and ex vivo in human explants. In murine and human corneas, we transduced the entire stroma using a single injection, preferentially targeted keratocytes and achieved long-term gene transfer (up to 17 months in vivo in mice). Of the serotypes tested, AAV2/8 was the most promising for gene transfer in both mouse and man. Furthermore, transgene expression could be transiently increased following aggression to the cornea.
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Affiliation(s)
- Claire Hippert
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Universités Montpellier I & II, Montpellier, France
| | - Sandy Ibanes
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Universités Montpellier I & II, Montpellier, France
| | - Nicolas Serratrice
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Universités Montpellier I & II, Montpellier, France
| | - Franck Court
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Universités Montpellier I & II, Montpellier, France
| | - François Malecaze
- Inserm U563, Toulouse, France
- Département d'Ophtalmologie, Hôpital Purpan, Toulouse, France
| | - Eric J. Kremer
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Universités Montpellier I & II, Montpellier, France
| | - Vasiliki Kalatzis
- Institut de Génétique Moléculaire de Montpellier, CNRS, Montpellier, France
- Universités Montpellier I & II, Montpellier, France
- * E-mail:
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23
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Belliveau MJ, Liao WN, Brownstein S, Manusow JS, Jordan DR, Gilberg S, Mintsioulis G. Myxomatous corneal degeneration: a clinicopathological study of six cases and a review of the literature. Surv Ophthalmol 2012; 57:264-71. [PMID: 22370508 DOI: 10.1016/j.survophthal.2011.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 09/16/2011] [Accepted: 09/20/2011] [Indexed: 11/18/2022]
Abstract
Thirteen cases with myxomatous changes of the corneal stroma have been reported to date. We report six additional cases with clinical, histopathological, and immunohistochemical data. The clinical appearance is most often a gelatinous, whitish elevation with insidious onset. Histopathologically, there are inconspicuous spindle- and stellate-shaped cells in a loose, myxoid matrix. The typical location is in the anterior cornea beneath the epithelium, with varying degrees of extension into the stroma. Vimentin and smooth-muscle actin immunohistochemical stains are characteristically positive, and staining occasionally may be seen with muscle-specific actin, whereas CD34 staining usually is negative. In most cases, myxomatous changes are a degenerative process involving transformation of stromal keratocytes into cells with prominent secretory activity and myofibroblastic differentiation. Most occur in corneas with a history of ocular disease or trauma that disrupts Bowman's layer. We suggest labelling lesions with these features as "myxomatous corneal degeneration." So-called "primary corneal myxomas" also exist where there is no significant history. It remains unclear whether the myxomatous changes in such lesions are neoplastic or degenerative. Myxomatous corneal changes are likely under-recognized and under-diagnosed.
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Affiliation(s)
- Michel J Belliveau
- Department of Ophthalmology, University of Ottawa Eye Institute and The Ottawa Hospital, Ottawa, Ontario, Canada
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24
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Harkin DG, George KA, Madden PW, Schwab IR, Hutmacher DW, Chirila TV. Silk fibroin in ocular tissue reconstruction. Biomaterials 2011; 32:2445-58. [DOI: 10.1016/j.biomaterials.2010.12.041] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 12/27/2010] [Indexed: 12/28/2022]
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25
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Moon BG, Kim JH, Lee JE, Kim MJ, Kim JY, Tchah H. Long-term Clinical Outcomes of Femtosecond LASER-Assisted Descemet's Stripping Endothelial Keratoplasty. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2011. [DOI: 10.3341/jkos.2011.52.6.679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Byung Gil Moon
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jae Hyung Kim
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Joo Eun Lee
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Myoung Joon Kim
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jae Yong Kim
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Hungwon Tchah
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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26
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Bardet E, Touboul D, Kerautret J, Léger F, Binder PS, Colin J. Interface fluid syndrome after bioptics. J Refract Surg 2010; 27:383-6. [PMID: 21162473 DOI: 10.3928/1081597x-20101111-01] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Accepted: 10/19/2010] [Indexed: 11/20/2022]
Abstract
PURPOSE To report an unusual case of interface fluid syndrome after refractive surgery. METHODS A 37-year-old man with high myopia underwent a planned bioptics procedure including creation of a corneal flap using a mechanical microkeratome and concurrent anterior chamber phakic intraocular lens implantation; excimer laser ablation was not performed at this time. RESULTS Postoperatively, the patient developed corneal edema and was referred to our department. Interface fluid syndrome was confirmed using optical coherence tomography; the mechanism was due to endothelial cell pump dysfunction. CONCLUSIONS This is the first report to document interface fluid syndrome following a planned bioptics procedure.
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Affiliation(s)
- Emilie Bardet
- Department of Ophthalmology and Pathology, University Hospital of Bordeaux, Bordeaux, France.
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27
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Use of magnetically oriented orthogonal collagen scaffolds for hemi-corneal reconstruction and regeneration. Biomaterials 2010; 31:8313-22. [PMID: 20708260 DOI: 10.1016/j.biomaterials.2010.07.066] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 07/16/2010] [Indexed: 11/22/2022]
Abstract
We recently showed that the highly organized architecture of the corneal stroma could be reproduced using scaffolds consisting of orthogonally aligned multilayers of collagen fibrils prepared using a high magnetic field. Here we show that such scaffolds permit the reconstruction in vitro of human hemi-corneas (stroma + epithelium), using primary human keratocytes and limbal stem cell derived human keratinocytes. On the surface of these hemi-corneas, a well-differentiated epithelium was formed, as determined both histologically and ultrastructurally and by the expression of characteristic markers. Within the stroma, the keratocytes aligned with the directions of the fibrils in the scaffold and synthesized a new extracellular matrix with typical collagen markers and small, uniform diameter fibrils. Finally, in vivo experiments using a rabbit model showed that these orthogonally oriented multi-layer scaffolds could be used to repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization.
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28
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Effects of riboflavin/UVA corneal cross-linking on keratocytes and collagen fibres in human cornea. Clin Exp Ophthalmol 2010; 38:49-56. [PMID: 20447101 DOI: 10.1111/j.1442-9071.2010.02207.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the effects of corneal cross-linking on keratocytes and collagen fibres in human corneas. METHODS Fifteen corneal buttons were examined. Ten were from patients with keratoconus submitted to penetrating keratoplasty and five of them were treated with cross-linking 6 months before penetrating keratoplasty. Five normal corneal buttons from healthy donors were used as controls. All samples were prepared for TUNEL assay and Western blot analysis for the detection of keratocyte apoptosis and immunohistochemical analysis for the morphological evaluation of keratocytes and collagen fibre diameter. RESULTS Normal corneas exhibited no TUNEL-positive keratocytes and keratoconic and cross-linked corneas showed moderate apoptotic cells mainly in the anterior part of the stroma. This apoptotic trend was confirmed by the cleavage of poly (ADP-ribose) polymerase assessed using Western blot. The Ki-67 staining showed a significant increase in the keratocyte proliferation in cross-linked corneas compared with normal and keratoconus. In cross-linked corneas CD34-positive keratocytes were regularly distributed throughout the whole corneal stroma as in the control, and keratoconus was associated with patchy loss of immunoreactivity. The immunohistochemical analysis of collagen type I showed a significant increase in fibre diameter of cross-linked corneas compared with control and keratoconus. CONCLUSION Corneal cross-linking leads to keratocyte damage; after 6 months a repopulation by proliferating cells, a distribution of CD34-positive keratocytes as in control and an increase in collagen fibre diameter were observed. These modifications are the morphological correlate of the process leading to an increase in biomechanical stability.
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29
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Said DG, Nubile M, Alomar T, Hopkinson A, Gray T, Lowe J, Dua HS. Histologic Features of Transplanted Amniotic Membrane: Implications for Corneal Wound Healing. Ophthalmology 2009; 116:1287-95. [PMID: 19447498 DOI: 10.1016/j.ophtha.2009.01.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Revised: 12/19/2008] [Accepted: 01/23/2009] [Indexed: 11/18/2022] Open
Affiliation(s)
- Dalia G Said
- Division of Ophthalmology, University of Nottingham, University Hospital, Queens Medical Centre, Nottingham, England
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30
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Expression and function of fibroblast growth factor-inducible 14 in human corneal myofibroblasts. Exp Eye Res 2009; 89:256-62. [PMID: 19344712 DOI: 10.1016/j.exer.2009.03.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 02/24/2009] [Accepted: 03/24/2009] [Indexed: 11/23/2022]
Abstract
The interaction of fibroblast growth factor-inducible 14 (Fn14) and, its ligand tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is known to be important in wound healing of tissues. However, to our knowledge, expression and function of Fn14 in corneal myofibroblasts, which have a crucial role in wound healing of corneal stroma, has not been investigated. In this study, we investigated the expression and function of Fn14 in corneal myofibroblasts. Expression of Fn14 protein was assessed by flow cytometry. Corneal myofibroblasts showed strong expression of Fn14 protein, while keratocytes did not. TGF-beta(1) promoted the differentiation of keratocytes into corneal myofibroblasts, and induced Fn14 expression. These data reveal that keratocytes phenotype determines the level of Fn14 expression. ELISA was used to detect chemokines and matrix metalloproteinases in the supernatant of corneal myofibroblasts cultured with or without stimulation by TWEAK and/or TGF-beta(1). TWEAK increased the production of IL-8, MCP-1, and RANTES by corneal myofibroblasts via Fn14. TGF-beta(1) augmented the TWEAK-induced production of these chemokines. TWEAK also increased the production of MMP-1 and -3 by corneal myofibroblasts via Fn14, while TGF-beta(1) inhibited this effect of TWEAK on MMP production. TWEAK-induced phosphorylation of NF-kappaB and MAP kinase in corneal myofibroblasts. Furthermore, TWEAK partially inhibited the differentiation of keratocytes into corneal myofibroblasts promoted by TGF-beta(1). These data suggest that the Fn14/TWEAK system may have several roles in wound healing by corneal myofibroblasts. In the future, modulation of the TWEAK/Fn14 system may become a novel approach for control corneal wound healing.
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Abstract
Primary corneal myxoma is extremely rare. It has only been reported on 2 previous occasions. Secondary corneal myxomas are more common, arising from corneal diseases such as infective keratitis, keratoconus, and bullous keratopathy. Myxomas occur commonly in other soft tissues such as the heart, paranasal sinuses, and muscles but can rarely present in periocular structures including the conjunctiva, orbit, and eyelid. Ours is only the third case of primary corneal myxoma reported in the literature and illustrates several unusual features. These include an inferonasal location between the corneal epithelium and Bowman layer and with no relationship to the corneal stroma, rapid tumor growth over a 3-month period, and no previous ocular trauma or conjunctival pathology. The histology of this lesion has an important part to play in the management of this condition as it determines the cellular origin, establishes a benign or malignant state, and helps with treatment and prognosis. One reported case of primary corneal myxoma recurred within 2 months after local resection. This was treated with bandage soft contact lens, and no recurrence had been reported since. Our case is now 12 months post op and has had no recurrence.
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32
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Thill M, Schlagner K, Altenähr S, Ergün S, Faragher RGA, Kilic N, Bednarz J, Vohwinkel G, Rogiers X, Hossfeld DK, Richard G, Gehling UM. A novel population of repair cells identified in the stroma of the human cornea. Stem Cells Dev 2008; 16:733-45. [PMID: 17999595 DOI: 10.1089/scd.2006.0084] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The transmembrane protein CD133 is expressed on somatic stem cells of various adult human tissues. To investigate whether human corneal stroma also contains CD133-expressing cells and to analyze their functional features, stromal cells were isolated by collagenase digestion, immunophenotyped, and transferred to different culture systems to determine their stem cell properties as well as their differentiation potentials. For comparison, the embryonic keratocyte cell line EK1.Br, the dermal stromal cell line NHDF, and stromal cells of diseased corneas were studied. On average, 5.3% of the normal stromal cells expressed the stem cell marker CD133 and 3.6% co-expressed CD34. Expression of CD133 but not CD34 was also demonstrated for EK1.Br cells, whereas NHDF cells were negative for both markers. Further analysis of CD133(+) normal corneal cells revealed that a significant proportion displayed a monocytic phenotype with co-expression of CD45 and CD14. In diseased corneas, up to 26.8% of the stromal cells showed expression of CD133, and virtually all CD133(+) cells co-expressed CD14 but not CD45. Moreover, using a standard clonogenic assay, normal stromal cells had the capacity to form colonies of the macrophage lineage. These colonies could be further differentiated into lumican-expressing keratocytes. Our data suggest that the human corneal stroma harbors CD133(+) monocytic progenitor cells, which possess the potential to differentiate into the fibrocytic lineage. Thus, CD133(+) /CD45(+) /CD14(+) cells might represent stromal repair cells that differentiate into keratocytes via a CD133(+)/CD45()/CD14(+) intermediate stage. The findings from our study may shed new light on regenerative processes of the human corneal stroma.
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Affiliation(s)
- Michelle Thill
- Department of Ophthalmology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
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Chen L, Ebihara N, Fujiki K, Murakami A. Expression and Distribution of Junctional Adhesion Molecule-1 in the Human Cornea. Jpn J Ophthalmol 2007; 51:405-11. [DOI: 10.1007/s10384-007-0479-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 07/30/2007] [Indexed: 11/24/2022]
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Coassin M, Zhang C, Green WR, Aquavella JV, Akpek EK. Histopathologic and immunologic aspects of alphacor artificial corneal failure. Am J Ophthalmol 2007; 144:699-704. [PMID: 17964323 DOI: 10.1016/j.ajo.2007.07.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2007] [Revised: 07/17/2007] [Accepted: 07/20/2007] [Indexed: 11/15/2022]
Abstract
PURPOSE To describe the histopathologic and immunologic characteristics of late artificial corneal failure in a small series of patients who underwent AlphaCor implantation and to elucidate the mechanisms involved. DESIGN Clinicopathologic case series. METHODS Three patients were diagnosed with corneal melting during the late postoperative period and required the removal of the devices. The explanted devices embedded within the corneal tissues were examined by light microscopy, electron microscopy, and immunohistochemical studies. RESULTS Light microscopic examination of the specimens disclosed adequate biointegration with no foreign body response. Immunofluorescence studies of the skirt exhibited expression of inflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha), and some interferon gamma (IFN-gamma). The keratocytes stained positively for Thy-1 and smooth muscle actin but negatively for CD34. CONCLUSIONS Although these findings confirm the occurrence of biointegration, myofibroblastic differentiation of the ingrowing keratocytes is a prominent feature.
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Affiliation(s)
- Marco Coassin
- Wilmer Institute, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA
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Tseng SCG, Espana EM, Kawakita T, Di Pascuale MA, Li W, He H, Liu TS, Cho TH, Gao YY, Yeh LK, Liu CY. How does amniotic membrane work? Ocul Surf 2007; 2:177-87. [PMID: 17216089 DOI: 10.1016/s1542-0124(12)70059-9] [Citation(s) in RCA: 226] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Transplantation of amniotic membrane as a temporary or permanent graft promotes epithelial wound healing and exerts potent anti-inflammatory and anti-scarring effects on the ocular surface. These actions depend on the killing of allogeneic amniotic cells and preservation of the cytokine-containing matrix during the preparation of the amniotic membrane. This review describes how these actions inherently operate in utero and how amniotic membrane transplantation aims to recreate such a fetal environment to exert these actions by insulating the surgical site from the host environment. These actions also render the amniotic membrane a unique niche capable of expanding both epithelial and mesenchymal progenitor cells ex vivo, while maintaining their normal cell phenotypes. As a result, the amniotic membrane becomes an ideal substrate for engineering different types of ocular surface tissues for transplantation. Further studies investigating the exact molecular mechanism by which the amniotic membrane works will undoubtedly unravel additional applications in reconstruction and engineering of both ocular and nonocular tissues in the burgeoning field of regenerative medicine.
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Samimi S, Leger F, Touboul D, Colin J. Histopathological findings after intracorneal ring segment implantation in keratoconic human corneas. J Cataract Refract Surg 2007; 33:247-53. [PMID: 17276265 DOI: 10.1016/j.jcrs.2006.08.059] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Accepted: 08/25/2006] [Indexed: 11/23/2022]
Abstract
PURPOSE To evaluate histopathological changes induced in keratoconic corneas after implantation of Intacs intracorneal ring segments (Addition Technology, Inc.). SETTING Departments of Ophthalmology and Pathology, Hospital Pellegrin, Bordeaux, France. METHODS This retrospective study included 8 keratoconic, contact-lens-intolerant eyes of 8 patients who had penetrating keratoplasty (PKP) after removal of Intacs inserts because of a poor refractive outcome or insert extrusion. Light microscopy was performed on all specimens after conventional staining. Immunohistochemistry was performed to identify cell types located next to the tunnel using AE1/AE3 cytokeratins, CD34, vimentin, collagen IV, and alpha-smooth muscle actin monoclonal antibodies. RESULTS Conventional histology showed hypoplasia of the epithelium immediately surrounding the channel. There was no evidence of an inflammatory response or foreign-body granuloma. Keratocyte density was decreased above and below the tunnel, and collagen IV synthesis was seen in the scar area. All samples stained negatively with alpha-smooth muscle actin, indicating that myofibroblasts were not present. These changes were no longer visible when PKP was performed more than 6 months after Intacs explantation. CONCLUSIONS Intacs induced keratocyte apoptosis, probably through a switch to a collagenous synthetic phenotype. Although histological changes seem to be entirely reversible after implant removal, longer follow-up is necessary to determine whether they accelerate corneal thinning and keratoconus progression via apoptosis and release of metalloprotease.
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Affiliation(s)
- Sépideh Samimi
- Ophthalmology and Pathology Departments, Hospital Pellegrin, Bordeaux, France
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Acosta AC, Espana EM, Stoiber J, Lamar PD, Marangon F, Alfonso E, Parel JM. Corneal stroma regeneration in felines after supradescemetic keratoprosthesis implantation. Cornea 2006; 25:830-8. [PMID: 17068461 DOI: 10.1097/01.ico.0000220769.19402.86] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To show corneal regeneration in 3 cats that underwent lamellar keratectomy (90%) depth during supradescemetic keratoprosthetic implantation. METHODS Three 2-year-old cats that underwent spontaneous keratoprosthesis extrusion between 15 and 150 days after implanting a supradescemetic prosthesis into their right eyes were studied. Corneal structures and stroma thickness were evaluated by slit-lamp photographs, pachymetry, and confocal microscopy. Regenerated corneal epithelial cells, stroma matrix, and keratocyte morphology were studied with histology and transmission electron microscopy. Epithelial and stromal cell immunocharacterization was performed. RESULTS Corneas progressively regained normal thickness and improved clarity within 40 to 60 days. Slit-lamp photographs and pachymetry showed gains in stromal thickness until 600 microm or more. In vivo confocal microscopy showed the restoration of normal epithelium and stroma in all cats. Corneal nerves were seen in the regenerated stroma of 2 cats. Immunostaining showed absent alpha-smooth muscle actin (SMA) expression and a keratin K3-expressing epithelium. Electron microscopy showed regeneration of normal epithelium with a well-formed basement membrane, organized corneal lamellae, and the presence of normal keratocytes. CONCLUSION Felines are capable of regenerating corneal structures including epithelium and reinnervated stroma matrix after deep lamellar keratectomy. The use of feline models in corneal keratoprosthesis is therefore questionable.
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Affiliation(s)
- Ana C Acosta
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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Perrella G, Brusini P, Spelat R, Hossain P, Hopkinson A, Dua HS. Expression of haematopoietic stem cell markers, CD133 and CD34 on human corneal keratocytes. Br J Ophthalmol 2006; 91:94-9. [PMID: 16956910 PMCID: PMC1857557 DOI: 10.1136/bjo.2006.097352] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To study the expression of CD133 and CD34 antigens on cultured human keratocytes over time. METHODS Primary cultures of human corneal stromal cells were established from explants derived from cadaver eye donors. The cultures were sorted for CD133+ and CD34+ cells using magnetic beads. Both the primary cultures and secondary passages of sorted cells were further analysed by flow cytometry and western blot analysis for expression of the same antigens over time. RESULTS Four different cell populations-namely, CD133+, CD133-, CD34+ and CD34-, were identified in the culture samples. Two further specific subgroups were identified by flow cytometry: CD133+/CD34- cells and CD133+/CD34+ cells. Expression of CD133 declines more than CD34 with time in cell cultures. Although most cells lost expression of these markers, small populations retained staining up to 5 weeks in culture. CONCLUSION Human keratocytes express the haematopoietic stem cell markers CD133 and CD34. This expression decreases with time in culture, with most but not all cells losing expression. On the basis of these markers, the corneal stroma shows a heterogeneous population of cells. Expression or down regulation of expression of these molecules could represent different stages of activation of these cells.
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Affiliation(s)
- G Perrella
- Department of Experimental and Clinical Pathology and Medicine, University of Udine. Ple SM Misericordia, Udine 33100, Italy.
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Kawakita T, Espana EM, He H, Smiddy R, Parel JM, Liu CY, Tseng SCG. Preservation and expansion of the primate keratocyte phenotype by downregulating TGF-beta signaling in a low-calcium, serum-free medium. Invest Ophthalmol Vis Sci 2006; 47:1918-27. [PMID: 16638999 PMCID: PMC1569676 DOI: 10.1167/iovs.05-1040] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE To demonstrate whether the original keratocyte phenotype is maintained with proliferative activity by suppressing TGF-beta signaling in rhesus monkey keratocytes expanded in a serum-free and low-[Ca2+] medium. METHODS Rhesus monkey keratocytes were isolated from central corneal buttons by collagenase digestion for 16 hours, seeded on plastic in Dulbecco's modified Eagle's medium (DMEM) containing insulin-transferrin-sodium selenite (ITS) supplement (DMEM/ITS) or 10% fetal bovine serum (DMEM/10% FBS), or in a defined keratinocyte serum-free medium (KSFM). After confluence, cells in KSFM were continuously subcultured at a 1-to-3 split. Cellular proliferation was analyzed by immunostaining for Ki67 and the MTT assay. The cellular phenotype was determined by immunostaining for aldehyde dehydrogenase (ALDH), keratocan, and CD34 and by the expression of keratocan promoter-driven enhanced cyan fluorescent protein (ECFP). The stability of the keratocyte phenotype was examined by switching KSFM to DMEM/ITS and DMEM/10% FBS. TGF-beta signaling was monitored by measuring the promoter activity of TGF-beta1, -beta2, and -beta RII after transient adenoviral transfection, and cytolocalization of Smad2 and Smad4. RESULTS In KSFM, monkey keratocytes proliferated while maintaining the expression of keratocan, CD34, and ALDH proteins and keratocan promoter-driven ECFP for at least 15 passages. The nuclear accumulation of Smad2 and Smad4 and the promoter activities of TGF-beta1 and -beta RII were significantly downregulated in KSFM compared with DMEM/10% FBS. In KSFM, an increase of [Ca2+] to 1.8 mM and addition of 10% FBS synergistically downregulated the keratocan promoter activity, facilitated Smad2 and Smad4 nuclear translocation, and upregulated TGF-beta1 and -beta RII promoter activities. CONCLUSIONS The normal monkey keratocyte phenotype can be maintained in a low-calcium, serum-free medium by downregulating Smad-mediated TGF-beta signaling.
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Affiliation(s)
- Tetsuya Kawakita
- From TissueTech, Inc., Ocular Surface Center, Miami, Florida; and the
| | - Edgar M. Espana
- From TissueTech, Inc., Ocular Surface Center, Miami, Florida; and the
| | - Hua He
- From TissueTech, Inc., Ocular Surface Center, Miami, Florida; and the
| | - Robert Smiddy
- From TissueTech, Inc., Ocular Surface Center, Miami, Florida; and the
| | - Jean-Marie Parel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida
| | - Chia-Yang Liu
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida
| | - Scheffer C. G. Tseng
- From TissueTech, Inc., Ocular Surface Center, Miami, Florida; and the
- Corresponding author: Scheffer C. G. Tseng, Ocular Surface Center, 7000 SW 97 Avenue, Suite 213, Miami, FL 33176;
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Sosnová M, Bradl M, Forrester JV. CD34+ corneal stromal cells are bone marrow-derived and express hemopoietic stem cell markers. Stem Cells 2006; 23:507-15. [PMID: 15790772 DOI: 10.1634/stemcells.2004-0291] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Previous studies have suggested that corneal stromal keratocytes express the CD34 antigen. We wished to investigate CD34 antigen expression in normal mouse cornea using dual- and triple-staining techniques. Whole-mount preparations of mouse and rat corneas were examined with confocal microscopy using single, dual, or triple immunostaining to study their morphology, phenotype, and distribution. Single-cell suspensions from normal mouse corneas were also prepared and analyzed by flow cytometry. After short-term culture of corneal stromal explants, nonadherent cells were harvested and cytospins were prepared and stained for different markers. Combined staining for F-actin and leukocyte differentiation markers clearly showed that the corneal stroma contains a population of CD45(+) resident bone marrow-derived cells, whereas most cells were CD45-F-actin(+) keratocytes. A significant proportion (two thirds) of CD45(+) cells in the normal corneal stroma expressed CD34(+), whereas no CD45(-) cells (i.e., keratocytes) coexpressed CD34. In addition, CD34(+) cells were CD11c(-) and CD11b(+). Fewer than 10% of the CD34(+) cells also coexpressed Sca-1(+), but no CD34(+) cells coexpressed major histocompatibility complex (MHC) class II(+). In contrast, the remaining population of CD45(+)CD34(-) cells in the corneal stroma expressed CD11b, MHC class II(+) but not CD11c and were found mostly in the anterior and peripheral part of stroma. These cells are in intimate contact with corneal keratocytes, which stained only for F-actin and were negative for all leukocyte markers. Very few CD45(+) cells expressed the B220 marker, suggesting a plasmacytoid dendritic cell phenotype. Flow cytometry analyses confirmed the morphometric data showing that 68% of CD45(+) cells coexpress CD34 and CD11b, whereas 22% are CD11b(+)CD34(-).We conclude that the normal mouse cornea contains two populations of bone marrow-derived leukocytes, both of which are distinct from stromal keratocytes. The larger population resembles CD34(+) hemopoietic stem cells, whereas the smaller population are CD34(-)CD11b(+) MHC class II(+) macrophages. A very small percentage comprises plasmacytoid dendritic cells.
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Affiliation(s)
- Magdaléna Sosnová
- Department of Ophthalmology, University of Aberdeen, Aberdeen AB25 5ZD, Scotland, United Kingdom
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Vascotto SG, Griffith M. Localization of candidate stem and progenitor cell markers within the human cornea, limbus, and bulbar conjunctiva in vivo and in cell culture. ACTA ACUST UNITED AC 2006; 288:921-31. [PMID: 16779811 DOI: 10.1002/ar.a.20346] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Corneal diseases are some of the most prevalent causes of blindness worldwide. While the most common treatment for corneal blindness is the transplantation of cadaver corneas, expanded limbal stem cells are finding recent application. Unknown, however, is the identity of the actual repopulating stem cell fraction utilized in both treatments and the critical factors governing successful engraftment and repopulation. In order to localize potential stem cell populations in vivo, we have immunohistochemically mapped a battery of candidate stem and progenitor cell markers including c-Kit and other growth factor receptors, nuclear markers including DeltaNp63, as well as adhesion factors across the cornea and distal sclera. Cell populations that differentially and specifically stained for some of these markers include the basal and superficial limbal/conjunctival epithelium and scattered cells within the substantia propria of the bulbar conjunctiva. We have also determined that the culture of differentiated cornea epithelial cells as dissociated and explant cultures induces the expression of several markers previously characterized as candidate limbal stem cell markers. This study provides a foundation to explore candidate corneal stem cell populations. As well, we show that expression of traditional stem cell markers may not be reliable indicator of stem cell content during limbal stem cell expansion in vitro and could contribute to the variable success rates of corneal stem cell transplantation.
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Abstract
PURPOSE To present the clinical and histopathological characteristics of a corneal myxoma. METHODS A 36-year-old, white woman presented with blurred vision and a whitish opacity on the left cornea. Clinical examination revealed a whitish, non-tender, 5 x 9 mm superficial tumour on the cornea. The tumour was excised and examined microscopically. RESULTS The tumour was composed of spindle-shaped cells in a myxomatous ground substance. Immunohistochemically, the tumour cells were positive for vimentin, muscle-specific antigen and smooth muscle antigen. The tumour was classified as a myxoma of the cornea. The origin of the tumour is discussed. CONCLUSION This is the second reported case of a corneal myxoma without prior corneal disease.
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Tosi GM, Traversi C, Schuerfeld K, Mittica V, Massaro-Giordano M, Tilanus MAD, Caporossi A, Toti P. Amniotic membrane graft: Histopathological findings in five cases. J Cell Physiol 2004; 202:852-7. [PMID: 15481059 DOI: 10.1002/jcp.20180] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Amniotic membrane transplantation (AMT) is an effective treatment for ocular surface reconstruction; however, the mechanisms through which amniotic membrane (AM) exerts its effects as well as its fate after transplantation have not been entirely elucidated and have been investigated only in part. We evaluate the integration of AM in the host cornea in five patients who underwent AMT as the result of Bowen's disease, band keratopathy, radio- or cryotherapy-induced keratopathy, chemical burn or post-herpetic deep corneal ulcer with descemetocele. Due to persistent opacification in four cases and a progressing tumor in one case, penetrating keratoplasty (PK) and enucleation were performed as early as 2 months and up to 20 months after AMT. The corneas were analyzed histopathologically. To evaluate AM remnants, corneas were stained with periodic acid Schiff's reaction (PAS), Alcian blue, and Gomory and Masson trichrome; immunostaining including collagens III and IV antibodies was also performed. None of the corneas showed remnants of AM. In all cases, we observed discontinuity of Bowman's membrane. In three cases, the corneal epithelium was completely restored, ranging from three to six cell layers. In the other two cases, we detected an intense inflammatory reaction with rich neovascularization; the epithelial surface of the central cornea was completely restored, while at the periphery of the cornea goblet mucus-producing cells were present. Although clinically useful in all cases, restoration of a stable corneal epithelium through AMT is limited by the extent and severity of limbal stem cell deficiency (LSCD). The lack of histologically documented AM remnants in our cases seems to explain the efficacy of AMT more through its biological properties than through its mechanical properties.
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Affiliation(s)
- Gian Marco Tosi
- Department of Ophthalmology and Neurosurgery, University of Siena, Siena, Italy
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