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Verma S, Lin X, Coulson-Thomas VJ. The Potential Reversible Transition between Stem Cells and Transient-Amplifying Cells: The Limbal Epithelial Stem Cell Perspective. Cells 2024; 13:748. [PMID: 38727284 PMCID: PMC11083486 DOI: 10.3390/cells13090748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/18/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Stem cells (SCs) undergo asymmetric division, producing transit-amplifying cells (TACs) with increased proliferative potential that move into tissues and ultimately differentiate into a specialized cell type. Thus, TACs represent an intermediary state between stem cells and differentiated cells. In the cornea, a population of stem cells resides in the limbal region, named the limbal epithelial stem cells (LESCs). As LESCs proliferate, they generate TACs that move centripetally into the cornea and differentiate into corneal epithelial cells. Upon limbal injury, research suggests a population of progenitor-like cells that exists within the cornea can move centrifugally into the limbus, where they dedifferentiate into LESCs. Herein, we summarize recent advances made in understanding the mechanism that governs the differentiation of LESCs into TACs, and thereafter, into corneal epithelial cells. We also outline the evidence in support of the existence of progenitor-like cells in the cornea and whether TACs could represent a population of cells with progenitor-like capabilities within the cornea. Furthermore, to gain further insights into the dynamics of TACs in the cornea, we outline the most recent findings in other organ systems that support the hypothesis that TACs can dedifferentiate into SCs.
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Affiliation(s)
- Sudhir Verma
- College of Optometry, University of Houston, 4901 Calhoun Road, Houston, TX 77204, USA;
- Deen Dayal Upadhyaya College, University of Delhi, Delhi 110078, India
| | - Xiao Lin
- College of Optometry, University of Houston, 4901 Calhoun Road, Houston, TX 77204, USA;
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2
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Xiao Y, McGhee CNJ, Zhang J. Adult stem cells in the eye: Identification, characterisation, and therapeutic application in ocular regeneration - A review. Clin Exp Ophthalmol 2024; 52:148-166. [PMID: 38214071 DOI: 10.1111/ceo.14309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 09/25/2023] [Indexed: 01/13/2024]
Abstract
Adult stem cells, present in various parts of the human body, are undifferentiated cells that can proliferate and differentiate to replace dying cells within tissues. Stem cells have specifically been identified in the cornea, trabecular meshwork, crystalline lens, iris, ciliary body, retina, choroid, sclera, conjunctiva, eyelid, lacrimal gland, and orbital fat. The identification of ocular stem cells broadens the potential therapeutic strategies for untreatable eye diseases. Currently, stem cell transplantation for corneal and conjunctival diseases remains the most common stem cell-based therapy in ocular clinical management. Lens epithelial stem cells have been applied in the treatment of paediatric cataracts. Several early-phase clinical trials for corneal and retinal regeneration using ocular stem cells are also underway. Extensive preclinical studies using ocular stem cells have been conducted, showing encouraging outcomes. Ocular stem cells currently demonstrate great promise in potential treatments of eye diseases. In this review, we focus on the identification, characterisation, and therapeutic application of adult stem cells in the eye.
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Affiliation(s)
- Yuting Xiao
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Charles N J McGhee
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Jie Zhang
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
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3
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Zhang W, Lan X, Zhu J, Zhang C, Huang Y, Mo K, Tan J, Guo H, Huang H, Li M, Ouyang H, Wang L. Healing Ability of Central Corneal Epithelium in Rabbit Ocular Surface Injury Models. Transl Vis Sci Technol 2022; 11:28. [PMID: 35771535 PMCID: PMC9251814 DOI: 10.1167/tvst.11.6.28] [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] [Indexed: 11/29/2022] Open
Abstract
Purpose Wound healing of the corneal epithelium mainly involves two types of cells: limbal stem/progenitor cells (LSCs) and differentiated central corneal epithelial cells (CECs). The healing ability of CECs is still debatable, and its correlated transcriptomic alterations during wound healing are yet to be elucidated. This study aimed to determine the healing ability and mechanisms underlying the actions of CECs using rabbit ocular surface injury models. Methods A central corneal ring-like residual epithelium model was used to investigate the healing ability of CECs. Uninjured and injury-stimulated LSCs and CECs were collected for transcriptomic analysis. The analysis results were verified by quantitative reverse transcriptase polymerase chain reaction, immunofluorescence staining, and two types of rabbit corneal injury models. Results During wound healing, the upregulated genes in LSCs were mostly enriched in the mitotic cell cycle–related processes, but those in CECs were mostly enriched in cell adhesion and migration. CECs could repair the epithelial defects successfully at one-time injuries. However, after repetitive injuries, the CECs repaired notably slower and failed to completely heal the defect, but the LSCs repaired even faster than the one-time injury. Conclusions Our results indicated rabbit CECs repair the epithelial defect mainly depending on migration and its proliferative ability is limited, and LSCs are the main source of regenerative epithelial cells. Translational Relevance This study provides information on gene expression in the corneal epithelium during wound healing, indicating that regulation of the cell cycle, cell adhesion, and migration may be the basis for future treatment strategies for corneal wound healing.
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Affiliation(s)
- Wang Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Xihong Lan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Jin Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Canwei Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Ying Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Kunlun Mo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Jieying Tan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Huizhen Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Huaxing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Mingsen Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Hong Ouyang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Li Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
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4
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Biswas S, Shafiquzzaman M, Yu G, Li P, Yu Q, Zhao P, Li B, Li J. Notch1 signaling in keratocytes maintains corneal transparency by suppressing VEGF expression. Stem Cell Reports 2022; 17:1442-1457. [PMID: 35623350 PMCID: PMC9214072 DOI: 10.1016/j.stemcr.2022.04.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 11/29/2022] Open
Abstract
The cornea fends off chemicals, dirt, and infectious particles and provides most of the eye's focusing power. Corneal transparency is of paramount importance to normal vision, yet how it is established and maintained remains unclear. Here, we ablated Notch1 in keratocytes using Twist2-Cre mice and found that Twist2-Cre; Notch1f/f mice developed stroma expansion and neovascularization, followed by hyperproliferation and metaplasia of corneal epithelial progenitor cells and plaque formation at central cornea, leading to loss of transparency. Development of these phenotypes does not involve bacteria-caused inflammation; instead, Notch1 deletion upregulates Vegfa and Vegfc via Hif1α in keratocytes. Vascular endothelial growth factor (VEGF) receptor inhibitor axitinib prevented development of these anomalies in Twist2-Cre; Notch1f/f mice, suggesting that VEGFs secreted by keratocytes promote not only neovascularization but also proliferation and metaplasia of epithelial progenitor cells at central cornea. This study uncovers a Notch1-Hif1α-VEGF pathway in keratocytes that maintains corneal transparency and represents a potential target for treatment of related corneal disorders.
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Affiliation(s)
- Soma Biswas
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Md Shafiquzzaman
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China; School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Guo Yu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ping Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qian Yu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Peiquan Zhao
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Baojie Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China; Institute of Traditional Chinese Medicine and Stem Cell Research, School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jing Li
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Efficient Isolation and Functional Characterization of Niche Cells from Human Corneal Limbus. Int J Mol Sci 2022; 23:ijms23052750. [PMID: 35269891 PMCID: PMC8911296 DOI: 10.3390/ijms23052750] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 02/23/2022] [Accepted: 02/28/2022] [Indexed: 12/13/2022] Open
Abstract
The fate decision of limbal epithelial progenitor cells (LEPC) at the human corneal limbus is determined by the surrounding microenvironment with limbal niche cells (LNC) as one of its essential components. Research on freshly isolated LNC which mainly include limbal mesenchymal stromal cells (LMSC) and limbal melanocytes (LM) has been hampered by a lack of efficient protocols to isolate and purify these cells. We devised a protocol for rapid retrieval of pure LMSC, LM and LEPC populations by collagenase digestion of limbal tissue and subsequent fluorescence-activated cell sorting (FACS) using antibodies against CD90 and CD117. The sorted cells were characterized by immunophenotyping and functional assays. The effects of LMSC and LM on LEPC were studied in 3D co-cultures and LEPC differentiation status was assessed by immunohistochemistry. Enzymatic digestion and flow sorting yielded pure populations of LMSC (CD117−CD90+), LM (CD117+CD90−), and LEPC (CD117−CD90−). The LMSC exhibited self-renewal capacity (55.0 ± 4.6 population doublings), expressed mesenchymal stem cell markers (CD73, CD90, CD105, and CD44), and transdifferentiated to adipocytes, osteocytes, or chondrocytes. The LM exhibited self-renewal capacity and sustained melanin production. The sorted LEPC expressed epithelial progenitor markers (CK14, CK19, and CK15) and showed a colony-forming ability. Co-cultivation of LMSC and LM with LEPC resulted in a 4–5-layered stratified epithelium and supported the preservation of a LEPC phenotype, as reflected by increased p63+ and Ki67+ cells and decreased CK12+ cells compared with LEPC monocultures. A highly efficient isolation of pure LM, LMSC, and LEPC populations from a single preparation may allow for direct transcriptomic and proteomic profiling as well as functional studies on native unpassaged LNC, which can be considered as proper equivalents of LNC in vivo. The developed biomimetic 3D co-culture method could provide an experimental model for investigating the functional role of LNC in the limbal stem cell niche.
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Van Meenen J, Ní Dhubhghaill S, Van den Bogerd B, Koppen C. An Overview of Advanced In Vitro Corneal Models: Implications for Pharmacological Testing. TISSUE ENGINEERING PART B-REVIEWS 2021; 28:506-516. [PMID: 33878935 DOI: 10.1089/ten.teb.2021.0031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cornea is an important barrier to consider when developing ophthalmic formulations, but proper modeling of this multilayered tissue remains a challenge. This is due to the varying properties associated with each layer in addition to the dynamics of the tear film. Hence, the most representative models to date rely on animals. Animal models, however, differ from humans in several aspects and are subject to ethical limitations. Consequently, in vitro approaches are being developed to address these issues. This review focuses on the barrier properties of the cornea and evaluates the most advanced three-dimensional cultures of human corneal equivalents in literature. Their application potential is subsequently assessed and discussed in the context of preclinical testing along with our perspective toward the future. Impact statement Most ocular drugs are applied topically, with the transcorneal pathway as the main administration route. Animal corneas are currently the only advanced models available, contributing to the drug attrition rate. Anatomical and physiological interspecies differences might account for a poor translatability of preclinical results to clinical trials, urging researchers to devise better corneal equivalents. This review elaborates on the emerging generation of three-dimensional in vitro models, which comprises spheroids, organoids, and organs-on-chips, which can serve as a stepping stone for advancements in this field.
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Affiliation(s)
- Joris Van Meenen
- Antwerp Research Group for Ocular Science, Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Sorcha Ní Dhubhghaill
- Antwerp Research Group for Ocular Science, Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium.,Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
| | - Bert Van den Bogerd
- Antwerp Research Group for Ocular Science, Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Carina Koppen
- Antwerp Research Group for Ocular Science, Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium.,Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
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7
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Yu Q, Biswas S, Ma G, Zhao P, Li B, Li J. Canonical NF-κB signaling maintains corneal epithelial integrity and prevents corneal aging via retinoic acid. eLife 2021; 10:e67315. [PMID: 34085926 PMCID: PMC8192125 DOI: 10.7554/elife.67315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 06/04/2021] [Indexed: 12/12/2022] Open
Abstract
Disorders of the transparent cornea affect millions of people worldwide. However, how to maintain and/or regenerate this organ remains unclear. Here, we show that Rela (encoding a canonical NF-κB subunit) ablation in K14+ corneal epithelial stem cells not only disrupts corneal regeneration but also results in age-dependent epithelial deterioration, which triggers aberrant wound-healing processes including stromal remodeling, neovascularization, epithelial metaplasia, and plaque formation at the central cornea. These anomalies are largely recapitulated in normal mice that age naturally. Mechanistically, Rela deletion suppresses expression of Aldh1a1, an enzyme required for retinoic acid synthesis from vitamin A. Retinoic acid administration blocks development of ocular anomalies in Krt14-Cre; Relaf/f mice and naturally aged mice. Moreover, epithelial metaplasia and plaque formation are preventable by inhibition of angiogenesis. This study thus uncovers the major mechanisms governing corneal maintenance, regeneration, and aging and identifies the NF-κB-retinoic acid pathway as a therapeutic target for corneal disorders.
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MESH Headings
- Age Factors
- Aldehyde Dehydrogenase 1 Family/genetics
- Aldehyde Dehydrogenase 1 Family/metabolism
- Animals
- Burns, Chemical/drug therapy
- Burns, Chemical/etiology
- Burns, Chemical/metabolism
- Burns, Chemical/pathology
- Cell Differentiation/drug effects
- Cell Proliferation/drug effects
- Cells, Cultured
- Cellular Senescence/drug effects
- Corneal Neovascularization/metabolism
- Corneal Neovascularization/pathology
- Corneal Neovascularization/prevention & control
- Corneal Stroma/drug effects
- Corneal Stroma/metabolism
- Corneal Stroma/pathology
- Disease Models, Animal
- Epithelium, Corneal/drug effects
- Epithelium, Corneal/metabolism
- Epithelium, Corneal/pathology
- Eye Burns/chemically induced
- Eye Burns/drug therapy
- Eye Burns/metabolism
- Eye Burns/pathology
- Mice, Knockout
- Regeneration/drug effects
- Retinal Dehydrogenase/genetics
- Retinal Dehydrogenase/metabolism
- Signal Transduction
- Stem Cells/drug effects
- Stem Cells/metabolism
- Stem Cells/pathology
- Transcription Factor RelA/genetics
- Transcription Factor RelA/metabolism
- Tretinoin/pharmacology
- Mice
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Affiliation(s)
- Qian Yu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong UniversityShanghaiChina
| | - Soma Biswas
- Department of Ophthalmology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Gang Ma
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong UniversityShanghaiChina
| | - Peiquan Zhao
- Department of Ophthalmology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Baojie Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong UniversityShanghaiChina
- Institute of Traditional Chinese Medicine and Stem Cell Research, School of Basic Medicine, Chengdu University of Traditional Chinese MedicineChengduChina
| | - Jing Li
- Department of Ophthalmology, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
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8
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Adil MT, Henry JJ. Understanding cornea epithelial stem cells and stem cell deficiency: Lessons learned using vertebrate model systems. Genesis 2021; 59:e23411. [PMID: 33576188 DOI: 10.1002/dvg.23411] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 12/13/2022]
Abstract
Animal models have contributed greatly to our understanding of human diseases. Here, we focus on cornea epithelial stem cell (CESC) deficiency (commonly called limbal stem cell deficiency, LSCD). Corneal development, homeostasis and wound healing are supported by specific stem cells, that include the CESCs. Damage to or loss of these cells results in blindness and other debilitating ocular conditions. Here we describe the contributions from several vertebrate models toward understanding CESCs and LSCD treatments. These include both mammalian models, as well as two aquatic models, Zebrafish and the amphibian, Xenopus. Pioneering developments have been made using stem cell transplants to restore normal vision in patients with LSCD, but questions still remain about the basic biology of CESCs, including their precise cell lineages and behavior in the cornea. We describe various cell lineage tracing studies to follow their patterns of division, and the fates of their progeny during development, homeostasis, and wound healing. In addition, we present some preliminary results using the Xenopus model system. Ultimately, a more thorough understanding of these cornea cells will advance our knowledge of stem cell biology and lead to better cornea disease therapeutics.
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Affiliation(s)
- Mohd Tayyab Adil
- Department of Cell & Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jonathan J Henry
- Department of Cell & Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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9
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Differences in sphere-forming cells from keratoconic and normal corneal tissue: Implications for keratoconus pathogenesis. Exp Eye Res 2020; 202:108301. [PMID: 33086037 DOI: 10.1016/j.exer.2020.108301] [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: 04/24/2020] [Revised: 09/15/2020] [Accepted: 10/12/2020] [Indexed: 11/23/2022]
Abstract
Keratoconus is primarily an anterior corneal disorder of unclear aetiology. Stem cells may play a role in the perpetuation of keratoconus, although this has yet to be definitively established. Sphere-forming cells from normal human donor corneas have previously been shown to be a heterogenous mix of epithelial, stromal, stem and progenitor cell components which have potential for treatment of corneal dystrophies. Our work set out to isolate and characterise sphere-forming cells from human keratoconic tissue. Keratoconic donor corneas were successfully used to culture sphere-forming cells in vitro. Time lapse imaging of these spheres on a collagen surface over 8 days revealed keratoconic spheres lack the ability to maintain a central core and have diminished ability to repopulate the surface. Immunocytochemistry showed positive labelling for the stem cell marker 'Adenosine triphosphate-binding cassette sub-family B member 5 (ABCB5)' indicating stem cell retention and the myofibroblast marker alpha smooth muscle actin indicating wound repair while droplet digital Polymerase Chain Reaction confirmed an increase in expression of stem and stromal cell markers in keratoconic spheres compared to spheres cultured from normal donors at day 7 post-placement. Keratoconic sphere-forming cells showed a diminished repopulation ability, a faster wound healing response and lack of central core retention. These results suggest stem cells in keratoconus may be in an elevated state of wound repair and unable to respond appropriately to further injury in corneal maintenance. Sphere forming cell populations in keratoconus appear to be different to those isolated from normal corneas and this may be an important consideration in unearthing keratoconus aetiology.
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Peripheral (not central) corneal epithelia contribute to the closure of an annular debridement injury. Proc Natl Acad Sci U S A 2019; 116:26633-26643. [PMID: 31843909 PMCID: PMC6936562 DOI: 10.1073/pnas.1912260116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
The well-accepted proposition that central corneal epithelia have limited self-renewal and therefore poor regenerative capacity has recently been challenged. However, methods for real-time monitoring to identify which cells take part in this process are scant. In this study, we visualized and quantified the contribution of central versus peripheral/limbal epithelia during annular wound healing by intravital imaging, through an organ culture system, and via computational modeling. Our results verify the contribution of K14+ limbal-derived stem cells and their early progeny in playing a vital role in this process, while central corneal epithelia contribute minimally to wound closure. Corneal epithelia have limited self-renewal and therefore reparative capacity. They are continuously replaced by transient amplifying cells which spawn from stem cells and migrate from the periphery. Because this view has recently been challenged, our goal was to resolve the conflict by giving mice annular injuries in different locations within the corneolimbal epithelium, then spatiotemporally fate-mapping cell behavior during healing. Under these conditions, elevated proliferation was observed in the periphery but not the center, and wounds predominantly resolved by centripetally migrating limbal epithelia. After wound closure, the central corneal epithelium was completely replaced by K14+ limbal-derived clones, an observation supported by high-resolution fluorescence imaging of genetically marked cells in organ-cultured corneas and via computational modeling. These results solidify the essential role of K14+ limbal epithelial stem cells for wound healing and refute the notion that stem cells exist within the central cornea and that their progeny have the capacity to migrate centrifugally.
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11
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Utheim OA, Pasovic L, Raeder S, Eidet JR, Fostad IG, Sehic A, Roald B, de la Paz MF, Lyberg T, Dartt DA, Utheim TP. Effects of explant size on epithelial outgrowth, thickness, stratification, ultrastructure and phenotype of cultured limbal epithelial cells. PLoS One 2019; 14:e0212524. [PMID: 30861002 PMCID: PMC6413940 DOI: 10.1371/journal.pone.0212524] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/04/2019] [Indexed: 01/16/2023] Open
Abstract
Purpose Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency. Limbal cells can be harvested from either a healthy part of the patient’s eye or the eye of a donor. Small explants are less likely to inflict injury to the donor site. We investigated the effects of limbal explant size on multiple characteristics known to be important for transplant function. Methods Human limbal epithelial cells were expanded from large versus small explants (3 versus 1 mm of the corneal circumference) for 3 weeks and characterized by light microscopy, immunohistochemistry, and transmission electron microscopy. Epithelial thickness, stratification, outgrowth, ultrastructure and phenotype were assessed. Results Epithelial thickness and stratification were similar between the groups. Outgrowth size correlated positively with explant size (r = 0.37; P = 0.01), whereas fold growth correlated negatively with explant size (r = –0.55; P < 0.0001). Percentage of cells expressing the limbal epithelial cell marker K19 was higher in cells derived from large explants (99.1±1.2%) compared to cells derived from small explants (93.2±13.6%, P = 0.024). The percentage of cells expressing ABCG2, integrin β1, p63, and p63α that are markers suggestive of an immature phenotype; Keratin 3, Connexin 43, and E-Cadherin that are markers of differentiation; and Ki67 and PCNA that indicate cell proliferation were equal in both groups. Desmosome and hemidesmosome densities were equal between the groups. Conclusion For donor- and culture conditions used in the present study, large explants are preferable to small in terms of outgrowth area. As regards limbal epithelial cell thickness, stratification, mechanical strength, and the attainment of a predominantly immature phenotype, both large and small explants are sufficient.
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Affiliation(s)
- O. A. Utheim
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Norwegian Dry Eye Clinic, Oslo, Norway
- * E-mail:
| | - L. Pasovic
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - S. Raeder
- Norwegian Dry Eye Clinic, Oslo, Norway
| | - J. R. Eidet
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - I. G. Fostad
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - A. Sehic
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
- Department of Maxillofacial surgery, Oslo University Hospital, Oslo, Norway
| | - B. Roald
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - M. F. de la Paz
- Institut Universitari Barraquer, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - T. Lyberg
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - D. A. Dartt
- Schepens Eye Research Institute/Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States of America
| | - T. P. Utheim
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
- Norwegian Dry Eye Clinic, Oslo, Norway
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
- Department of Maxillofacial surgery, Oslo University Hospital, Oslo, Norway
- Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
- Department of Ophthalmology, Stavanger University Hospital, Stavanger, Norway
- Department of Clinical Medicine, Faculty of Medicine, University of Bergen, Bergen, Norway
- Department of Ophthalmology, Soerlandet Hospital Arendal, Arendal, Norway
- Department of Ophthalmology, Drammen Hospital, Vestre Viken Hospital Trust, Drammen, Norway
- National Centre for Optics, Vision and Eye Care, Faculty of Health and Social Sciences, University of Southeast Norway, Kongsberg, Norway
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Zhang Y, Hu Y, Li X, Shi X, Xu F, Jia H. Observation of corneal transplantation in peripheral corneal disease postoperatively. Exp Ther Med 2018; 15:5384-5388. [PMID: 29904417 DOI: 10.3892/etm.2018.6100] [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: 10/11/2017] [Accepted: 03/19/2018] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to investigate the role of the limbal stem cells in corneal epithelial homeostasis in patients with peripheral corneal disease who received corneal transplantation surgery. This retrospective study enrolled 85 patients (85 eyes) with peripheral corneal lesion who underwent corneal transplantation at Department of Ophthalmology in First Hospital of Jilin University, Jilin, China. All patients during each follow-up period were examined for best corrected visual acuity, corneal reconstruction (assessed by slit-lamp biomicroscopy), anterior segment optical coherence tomography, and confocal microscopy. Patients were followed up for 3.5±2.4 years. All patients had improved postoperative best corrected visual acuity. Neither vascularization nor conjunctivalization of the graft occurred. Scanning of the graft was covered by normal corneal epithelium as confirmed on the laser scanning in vivo confocal microscopy. No evidence of normal limbal was detected in any of the operation eyes. The limbal stem cells may not play a critical role during normal corneal epithelial turnover in patients with peripheral corneal disease following corneal transplantation surgery.
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Affiliation(s)
- Yibing Zhang
- Department of Ophthalmology, First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yuan Hu
- Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Xiaodong Li
- Department of Ophthalmology, Baicheng Central Hospital, Baicheng, Jilin 137000, P.R. China
| | - Xiaoru Shi
- Department of Ophthalmology, First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Feihong Xu
- Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Hui Jia
- Department of Ophthalmology, First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
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13
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Zhang C, Du L, Pang K, Wu X. Differentiation of human embryonic stem cells into corneal epithelial progenitor cells under defined conditions. PLoS One 2017; 12:e0183303. [PMID: 28813511 PMCID: PMC5557585 DOI: 10.1371/journal.pone.0183303] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 08/02/2017] [Indexed: 12/13/2022] Open
Abstract
The development of cell-based therapies using stem cells represents a significant breakthrough in the treatment of limbal stem cell deficiency (LSCD). The aim of this study was to develop a novel protocol to differentiate human embryonic stem cells (hESCs) into corneal epithelial progenitor cells (CEPCs), with similar features to primary cultured human limbal stem cells (LSCs), using a medium composed of DMEM/F12 and defined keratinocyte serum-free medium (KSFM) (1:1) under different carbon dioxide (CO2) levels in culture. The differentiated cells exhibited a similar morphology to limbal stem cells under 5%, 7%, and 9% CO2 and expressed the LSC markers ABCG-2 and p63; however, CK14 was only expressed in the cells cultured under 7% and 9% CO2. Quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis indicated that the ABCG2, p63, and CK14 levels in the 7% CO2 and 9% CO2 groups were higher than those in the 5% CO2 group and in undifferentiated hESCs (p<0.05). The highest expression of ABCG2 and p63 was exhibited in the cells cultured under 7% CO2 at day 6 of differentiation. Western blotting indicated that the ABCG2 and p63 levels were higher at day 6 than the other time points in the 7% CO2 and 9% CO2 groups. The highest protein expression of ABCG2 and p63 was identified in the 7% CO2 group. The neural cell-specific marker tubulin β3 and the epidermal marker K1/10 were also detected in the differentiated cells via immunofluorescent staining; thus, cell sorting was performed via fluorescence-activated cell sorting (FACS), and ABCG2-positive cells were isolated as CEPCs. The sorted cells formed three to four layers of epithelioid cells by airlifting culture and expressed ABCG2, p63, CK14, and CK3. In conclusion, the novel induction system conditioned by 7% CO2 in this study may be an effective and feasible method for CEPC differentiation.
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Affiliation(s)
- Canwei Zhang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong, PR China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital of Shandong University, Jinan, Shandong, PR China
| | - Liqun Du
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong, PR China
| | - Kunpeng Pang
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong, PR China
| | - Xinyi Wu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, Shandong, PR China
- * E-mail:
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Age-related differences in corneal epithelial thickness measurements with anterior segment optical coherence tomography. Jpn J Ophthalmol 2016; 60:357-64. [PMID: 27324656 DOI: 10.1007/s10384-016-0457-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/26/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE To measure corneal epithelial thickness (CET) in healthy adults and to investigate its variation with age by use of anterior segment optical coherence tomography (OCT). METHODS A total of 210 healthy individuals were enrolled and divided into four, almost equally sized groups on the basis of age: 18-29 years (group 1), 30-44 years (group 2), 45-59 years (group 3), and 60-80 years (group 4). The CET and total corneal thickness in the central area (diameter 6.0 mm) of each patient were obtained by Fourier-domain OCT, and the regional thickness and topographic variability were compared among the age groups. In addition, the correlations between the CET and age, gender, and refractive status were analyzed using partial correlation tests and multiple regression analysis. RESULTS The CET of the central segment (diameter 2 mm) in groups 1, 2, 3, and 4 were 53.74 ± 3.82, 54.48 ± 3.33, 53.89 ± 3.73, and 53.30 ± 3.36 µm, respectively, demonstrating no significant change with age (P = 0.416). In most of the paracentral and all of the midperipheral zones (annuli 2-5 and 5-6 mm from the center, respectively), the CET differed significantly among the four groups. Correlation analysis suggested that the CET is greater in men than in women and that the CET of both the paracentral and the midperipheral zones is inversely correlated with age. Topographic variability was also inversely correlated with age. CONCLUSIONS The CET became thinner with age in the paracentral and midperipheral zones, while the central CET seems to remain constant. Gender differences should be considered in the assessment of CET.
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Tomasello L, Musso R, Cillino G, Pitrone M, Pizzolanti G, Coppola A, Arancio W, Di Cara G, Pucci-Minafra I, Cillino S, Giordano C. Donor age and long-term culture do not negatively influence the stem potential of limbal fibroblast-like stem cells. Stem Cell Res Ther 2016; 7:83. [PMID: 27296060 PMCID: PMC4906894 DOI: 10.1186/s13287-016-0342-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 01/14/2016] [Accepted: 05/16/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND In regenerative medicine the maintenance of stem cell properties is of crucial importance. Ageing is considered a cause of reduced stemness capability. The limbus is a stem niche of easy access and harbors two stem cell populations: epithelial stem cells and fibroblast-like stem cells. Our aim was to investigate whether donor age and/or long-term culture have any influence on stem cell marker expression and the profiles in the fibroblast-like stem cell population. METHODS Fibroblast-like stem cells were isolated and digested from 25 limbus samples of normal human corneo-scleral rings and long-term cultures were obtained. SSEA4 expression and sphere-forming capability were evaluated; cytofluorimetric assay was performed to detect the immunophenotypes HLA-DR, CD45, and CD34 and the principle stem cell markers ABCG2, OCT3/4, and NANOG. Molecular expression of the principal mesenchymal stem cell genes was investigated by real-time PCR. Two-dimensional gel electrophoresis and mass spectrometric sequencing were performed and a stable proteomic profile was identified. The proteins detected were explored by gene ontology and STRING analysis. The data were reported as means ± SD, compared by Student's unpaired t test and considering p < 0.05 as statistically significant. RESULTS The isolated cells did not display any hematopoietic surface marker (CD34 and CD45) and HLA-DR and they maintained these features in long-term culture. The expression of the stemness genes and the multilineage differentiation under in-vitro culture conditions proved to be well maintained. Proteomic analysis revealed a fibroblast-like stem cell profile of 164 proteins with higher expression levels. Eighty of these showed stable expression levels and were involved in maintenance of "the stem gene profile"; 84 were differentially expressed and were involved in structural activity. CONCLUSIONS The fibroblast-like limbal stem cells confirmed that they are a robust source of adult stem cells and that they have good plasticity, good proliferative capability, and long-term maintenance of stem cell properties, independently of donor age and long-term culture conditions. Our findings confirm that limbal fibroblast-like stem cells are highly promising for application in regenerative medicine and that in-vitro culture steps do not influence their stem cell properties. Moreover, the proteomic data enrich our knowledge of fibroblast-like stem cells.
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Affiliation(s)
- Laura Tomasello
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | - Rosa Musso
- Centro di Oncobiologia Sperimentale (COBS), Palermo, Italy
| | - Giovanni Cillino
- Department of Ophthalmology, University of Palermo, Palermo, Italy
| | - Maria Pitrone
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | - Giuseppe Pizzolanti
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
- ATeN (Advanced Technologies Network Center), University of Palermo, Palermo, Italy
| | - Antonina Coppola
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | - Walter Arancio
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | | | | | | | - Carla Giordano
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy.
- ATeN (Advanced Technologies Network Center), University of Palermo, Palermo, Italy.
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16
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Hashemi H, Asgari S, Emamian MH, Mehravaran S, Fotouhi A. Five year changes in central and peripheral corneal thickness: The Shahroud Eye Cohort Study. Cont Lens Anterior Eye 2016; 39:331-5. [PMID: 27302856 DOI: 10.1016/j.clae.2016.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 04/28/2016] [Accepted: 05/27/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE To determine five year changes in corneal thickness from the apex to the 8mm periphery and related factors through a longitudinal population-based study of middle-aged Iranians. METHODS In the first phase, 4670 of the 5190 participants, and in the second phase, 4666 of the 4737 participants were examined with the Pentacam. In this report, analysis was done on right eye data of 2509 people who had no diabetes, pterygium, or history of eye surgery, and their image quality was displayed as "ok". Thickness changes in different parts of the cornea and their relation with age, gender, refractive error, and intraocular pressure (IOP) were assessed using repeated measures analysis of covariance. RESULTS Corneal thickness reduced by 1.5±11.7μm in the apex, 2.6±11.7μm in the thinnest point, and 5.3±12.2, 7.7±14.3, and 11.4±18.6μm in peripheral rings of 2, 3, and 4mm radius, respectively (all p<0.001 with and without adjusting for baseline thickness). Of the studied thickness variables, only changes in the 4mm ring significantly related with age (p<0.001) and gender (p<0.001); there was less change in older age and in men. Thickness changes were not related to refractive error or IOP (all p>0.05). CONCLUSION Corneal thickness decreased with age in this sample of 40-64year olds. There was significantly greater thinning in the periphery compared to the corneal center even after controlling for baseline thickness. Results of this longitudinal study can be helpful in understanding age-related changes in the cornea and the eye.
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Affiliation(s)
- Hassan Hashemi
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Soheila Asgari
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | | | - Shiva Mehravaran
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Akbar Fotouhi
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, P.O. Box 14155-6446, Tehran, Iran.
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17
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Veréb Z, Póliska S, Albert R, Olstad OK, Boratkó A, Csortos C, Moe MC, Facskó A, Petrovski G. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing. Sci Rep 2016; 6:26227. [PMID: 27195722 PMCID: PMC4872602 DOI: 10.1038/srep26227] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 04/25/2016] [Indexed: 12/13/2022] Open
Abstract
Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases.
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Affiliation(s)
- Zoltán Veréb
- Stem Cells and Eye Research Laboratory, Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Szilárd Póliska
- Center for Clinical Genomics and Personalized Medicine, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Réka Albert
- Stem Cells and Eye Research Laboratory, Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Ole Kristoffer Olstad
- Department of Medical Biochemistry, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Anita Boratkó
- Department of Medical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Csilla Csortos
- Department of Medical Chemistry, University of Debrecen, Debrecen, Hungary
| | - Morten C Moe
- Centre of Eye Research, Department of Ophthalmology, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Andrea Facskó
- Stem Cells and Eye Research Laboratory, Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Goran Petrovski
- Stem Cells and Eye Research Laboratory, Department of Ophthalmology, Faculty of Medicine, University of Szeged, Szeged, Hungary.,Centre of Eye Research, Department of Ophthalmology, Oslo University Hospital, University of Oslo, Oslo, Norway
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18
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Zhang Y, Sun H, Liu Y, Chen S, Cai S, Zhu Y, Guo P. The Limbal Epithelial Progenitors in the Limbal Niche Environment. Int J Med Sci 2016; 13:835-840. [PMID: 27877075 PMCID: PMC5118754 DOI: 10.7150/ijms.16563] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/01/2016] [Indexed: 02/06/2023] Open
Abstract
Limbal epithelial progenitors are stem cells located in limbal palisades of vogt. In this review, we present the audience with recent evidence that limbal epithelial progenitors may be a powerful stem cell resource for the cure of human corneal stem cell deficiency. Further understanding of their mechanism may shed lights to the future successful application of stem cell therapy not only to the eye tissue, but also to the other tissues in the human body.
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Affiliation(s)
- Yuan Zhang
- Research and Development Department, TissueTech, Inc., 7000 SW 97th Avenue, Suite 212, Miami, FL 33173, USA
| | - Hong Sun
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Yongsong Liu
- Department of Ophthalmology, Yan' An Hospital of Kunming City, Kunming, 650051, China
| | - Shuangling Chen
- Research and Development Department, TissueTech, Inc., 7000 SW 97th Avenue, Suite 212, Miami, FL 33173, USA
| | - Subo Cai
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yingting Zhu
- Research and Development Department, TissueTech, Inc., 7000 SW 97th Avenue, Suite 212, Miami, FL 33173, USA
| | - Ping Guo
- Shenzhen Eye Hospital, School of Optometry & Ophthalmology of Shenzhen University, Shenzhen Key Laboratory of Department of Ophthalmology, Shenzhen, 518000, China
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Dorà NJ, Hill RE, Collinson JM, West JD. Lineage tracing in the adult mouse corneal epithelium supports the limbal epithelial stem cell hypothesis with intermittent periods of stem cell quiescence. Stem Cell Res 2015; 15:665-677. [PMID: 26554513 PMCID: PMC4686565 DOI: 10.1016/j.scr.2015.10.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/26/2015] [Accepted: 10/26/2015] [Indexed: 12/24/2022] Open
Abstract
The limbal epithelial stem cell (LESC) hypothesis proposes that LESCs in the corneal limbus maintain the corneal epithelium both during normal homeostasis and wound repair. The alternative corneal epithelial stem cell (CESC) hypothesis proposes that LESCs are only involved in wound repair and CESCs in the corneal epithelium itself maintain the corneal epithelium during normal homeostasis. We used tamoxifen-inducible, CreER-loxP lineage tracing to distinguish between these hypotheses. Clones of labelled cells were induced in adult CAGG-CreER;R26R-LacZ reporter mice and their distributions analysed after different chase periods. Short-lived clones, derived from labelled transient amplifying cells, were shed during the chase period and long-lived clones, derived from stem cells, expanded. At 6 weeks, labelled clones appeared at the periphery, extended centripetally as radial stripes and a few reached the centre by 14 weeks. Stripe numbers depended on the age of tamoxifen treatment. Stripes varied in length, some were discontinuous, few reached the centre and almost half had one end at the limbus. Similar stripes extended across the cornea in CAGG-CreER;R26R-mT/mG reporter mice. The distributions of labelled clones are inconsistent with the CESC hypothesis and support the LESC hypothesis if LESCs cycle between phases of activity and quiescence, each lasting several weeks.
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Affiliation(s)
- Natalie J Dorà
- Centre for Integrative Physiology, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Robert E Hill
- Medical and Developmental Genetics Section, MRC Human Genetics Unit, MRC IGMM, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, UK
| | - J Martin Collinson
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - John D West
- Centre for Integrative Physiology, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
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20
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Di Girolamo N, Bobba S, Raviraj V, Delic NC, Slapetova I, Nicovich PR, Halliday GM, Wakefield D, Whan R, Lyons JG. Tracing the fate of limbal epithelial progenitor cells in the murine cornea. Stem Cells 2015; 33:157-69. [PMID: 24966117 DOI: 10.1002/stem.1769] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 05/24/2014] [Indexed: 12/15/2022]
Abstract
Stem cell (SC) division, deployment, and differentiation are processes that contribute to corneal epithelial renewal. Until now studying the destiny of these cells in a living mammal has not been possible. However, the advent of inducible multicolor genetic tagging and powerful imaging technologies has rendered this achievable in the translucent and readily accessible murine cornea. K14CreER(T2)-Confetti mice that harbor two copies of the Brainbow 2.1 cassette, yielding up to 10 colors from the stochastic recombination of fluorescent proteins, were used to monitor K-14(+) progenitor cell dynamics within the corneal epithelium in live animals. Multicolored columns of cells emerged from the basal limbal epithelium as they expanded and migrated linearly at a rate of 10.8 µm/day toward the central cornea. Moreover, the permanent expression of fluorophores, passed on from progenitor to progeny, assisted in discriminating individual clones as spectrally distinct streaks containing more than 1,000 cells within the illuminated area. The centripetal clonal expansion is suggestive that a single progenitor cell is responsible for maintaining a narrow corridor of corneal epithelial cells. Our data are in agreement with the limbus as the repository for SC as opposed to SC being distributed throughout the central cornea. This is the first report describing stem/progenitor cell fate determination in the murine cornea using multicolor genetic tracing. This model represents a powerful new resource to monitor SC kinetics and fate choice under homeostatic conditions, and may assist in assessing clonal evolution during corneal development, aging, wound-healing, disease, and following transplantation.
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Affiliation(s)
- N Di Girolamo
- School of Medical Sciences, University of New South Wales, Sydney, Australia
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21
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Nakamura T, Inatomi T, Sotozono C, Koizumi N, Kinoshita S. Ocular surface reconstruction using stem cell and tissue engineering. Prog Retin Eye Res 2015; 51:187-207. [PMID: 26187034 DOI: 10.1016/j.preteyeres.2015.07.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 07/08/2015] [Accepted: 07/08/2015] [Indexed: 12/22/2022]
Abstract
Most human sensory information is gained through eyesight, and integrity of the ocular surface, including cornea and conjunctiva, is known to be indispensable for good vision. It is believed that severe damage to corneal epithelial stem cells results in devastating ocular surface disease, and many researchers and scientists have tried to reconstruct the ocular surface using medical and surgical approaches. Ocular surface reconstruction via regenerative therapy is a newly developed medical field that promises to be the next generation of therapeutic modalities, based on the use of tissue-specific stem cells to generate biological substitutes and improve tissue functions. The accomplishment of these objectives depends on three key factors: stem cells, which have highly proliferative capacities and longevities; the substrates determining the environmental niche; and growth factors that support them appropriately. This manuscript describes the diligent development of ocular surface reconstruction using tissue engineering techniques, both past and present, and discusses and validates their future use for regenerative therapy in this field.
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Affiliation(s)
- Takahiro Nakamura
- Department of Frontier Medical Sciences and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
| | - Tsutomu Inatomi
- Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Chie Sotozono
- Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Noriko Koizumi
- Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Shigeru Kinoshita
- Department of Frontier Medical Sciences and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
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22
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Hertsenberg AJ, Funderburgh JL. Stem Cells in the Cornea. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:25-41. [PMID: 26310147 DOI: 10.1016/bs.pmbts.2015.04.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cornea is the tough, transparent tissue through which light first enters the eye and functions as a barrier to debris and infection as well as two-thirds of the refractive power of the eye. Corneal damage that is not promptly treated will often lead to scarring and vision impairment. Due to the limited options currently available to treat corneal scars, the identification and isolation of stem cells in the cornea has received much attention, as they may have potential for autologous, cell-based approaches to the treatment of damaged corneal tissue.
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Affiliation(s)
- Andrew J Hertsenberg
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - James L Funderburgh
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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23
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Zhang ZH, Liu HY, Liu K, Xu X. Comparison of Explant and Enzyme Digestion Methods for Ex Vivo Isolation of Limbal Epithelial Progenitor Cells. Curr Eye Res 2015; 41:318-25. [PMID: 25860821 DOI: 10.3109/02713683.2015.1014566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To compare the effectiveness of two isolation systems for stemness, proliferation and mesenchymal contamination of ex vivo cultured limbal epithelial cells (LECs). METHODS Whole explant and dispase digestion methods were used to isolate LECs. For whole explant isolation, one limbal explant was cultivated up to four consecutive times (through LEC1 to LEC4). The performance of LECs isolated with both systems was evaluated according to the following parameters: immunofluorescent staining for adenosine 5'-triphosphate-binding cassette member 2 (ABCG2), p63, cytokeratin 3 (K3), Ki67, and vimentin, and flow cytometry analysis for ABCG2, Ki67 and vimentin. RESULTS Twelve LEC cultures were established using whole explant isolation, and nine LEC cultures were established using dispase digestion isolation. In immunofluorescent staining analysis, the ABCG2, p63 and Ki67 expressions were higher in LECs isolated with dispase compared to any LECs isolated with explant. Only the differences in ABCG2 and Ki67 were statistically significant. Further, LEC4 isolated with explant had the highest percentage of cells positive for vimentin, and LEC1 had the highest percentage of cells positive for K3. However, no significant differences were detected. In flow cytometry analysis, the expressions of ABCG2 and Ki67 were statistically higher for LECs isolated with dispase compared to any LECs isolated with explant. CONCLUSION Dispase digestion isolation technique was significantly superior to explant isolation techniques in terms of progenitor and proliferative cell contents.
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Affiliation(s)
- Zhi-Hua Zhang
- a Department of Ophthalmology , Shanghai First People's Hospital Affiliated to Shanghai Jiaotong University , Shanghai , China
| | - Hai-Yun Liu
- a Department of Ophthalmology , Shanghai First People's Hospital Affiliated to Shanghai Jiaotong University , Shanghai , China
| | - Kun Liu
- a Department of Ophthalmology , Shanghai First People's Hospital Affiliated to Shanghai Jiaotong University , Shanghai , China
| | - Xun Xu
- a Department of Ophthalmology , Shanghai First People's Hospital Affiliated to Shanghai Jiaotong University , Shanghai , China
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West JD, Dorà NJ, Collinson JM. Evaluating alternative stem cell hypotheses for adult corneal epithelial maintenance. World J Stem Cells 2015; 7:281-99. [PMID: 25815115 PMCID: PMC4369487 DOI: 10.4252/wjsc.v7.i2.281] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/26/2014] [Accepted: 10/14/2014] [Indexed: 02/07/2023] Open
Abstract
In this review we evaluate evidence for three different hypotheses that explain how the corneal epithelium is maintained. The limbal epithelial stem cell (LESC) hypothesis is most widely accepted. This proposes that stem cells in the basal layer of the limbal epithelium, at the periphery of the cornea, maintain themselves and also produce transient (or transit) amplifying cells (TACs). TACs then move centripetally to the centre of the cornea in the basal layer of the corneal epithelium and also replenish cells in the overlying suprabasal layers. The LESCs maintain the corneal epithelium during normal homeostasis and become more active to repair significant wounds. Second, the corneal epithelial stem cell (CESC) hypothesis postulates that, during normal homeostasis, stem cells distributed throughout the basal corneal epithelium, maintain the tissue. According to this hypothesis, LESCs are present in the limbus but are only active during wound healing. We also consider a third possibility, that the corneal epithelium is maintained during normal homeostasis by proliferation of basal corneal epithelial cells without any input from stem cells. After reviewing the published evidence, we conclude that the LESC and CESC hypotheses are consistent with more of the evidence than the third hypothesis, so we do not consider this further. The LESC and CESC hypotheses each have difficulty accounting for one main type of evidence so we evaluate the two key lines of evidence that discriminate between them. Finally, we discuss how lineage-tracing experiments have begun to resolve the debate in favour of the LESC hypothesis. Nevertheless, it also seems likely that some basal corneal epithelial cells can act as long-term progenitors if limbal stem cell function is compromised. Thus, this aspect of the CESC hypothesis may have a lasting impact on our understanding of corneal epithelial maintenance, even if it is eventually shown that stem cells are restricted to the limbus as proposed by the LESC hypothesis.
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Affiliation(s)
- John D West
- John D West, Natalie J Dorà, Genes and Development Group, Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
| | - Natalie J Dorà
- John D West, Natalie J Dorà, Genes and Development Group, Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
| | - J Martin Collinson
- John D West, Natalie J Dorà, Genes and Development Group, Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, University of Edinburgh, EH8 9XD Edinburgh, United Kingdom
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Li H, Dai Y, Shu J, Yu R, Guo Y, Chen J. Spheroid cultures promote the stemness of corneal stromal cells. Tissue Cell 2015; 47:39-48. [DOI: 10.1016/j.tice.2014.10.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 10/31/2014] [Accepted: 10/31/2014] [Indexed: 12/13/2022]
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26
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Yoon JJ, Ismail S, Sherwin T. Limbal stem cells: Central concepts of corneal epithelial homeostasis. World J Stem Cells 2014; 6:391-403. [PMID: 25258661 PMCID: PMC4172668 DOI: 10.4252/wjsc.v6.i4.391] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 08/20/2014] [Accepted: 09/01/2014] [Indexed: 02/06/2023] Open
Abstract
A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent studies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal surface
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27
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Dhouailly D, Pearton DJ, Michon F. The vertebrate corneal epithelium: From early specification to constant renewal. Dev Dyn 2014; 243:1226-41. [DOI: 10.1002/dvdy.24179] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 08/06/2014] [Accepted: 08/09/2014] [Indexed: 12/30/2022] Open
Affiliation(s)
- Danielle Dhouailly
- University Joseph Fourier; AGIM FRE CNRS 3405 Site Santé Centre Jean Roget La Tronche France
| | - David J. Pearton
- Oceanographic Research Institute; Marine Parade Durban South Africa
| | - Frederic Michon
- Institute of Biotechnology; Developmental Biology Program; University of Helsinki; Helsinki Finland
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28
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Joe AW, Yeung SN. Concise review: identifying limbal stem cells: classical concepts and new challenges. Stem Cells Transl Med 2013; 3:318-22. [PMID: 24327757 DOI: 10.5966/sctm.2013-0137] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The presence of a clear cornea is required for vision, and corneal epithelial cells play a key role. There is a long held view, supported by decades of study, that corneal epithelial stem cells reside at the limbus to regulate homeostatic cell turnover and wound healing. However, the identification of specific markers that allow the isolation and characterization of limbal stem cells remains elusive. Here, we review the classical concepts of limbal stem cell identity and highlight the current state of the field.
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Affiliation(s)
- Aaron W Joe
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Yoon JJ, Wang EF, Ismail S, McGhee JJ, Sherwin T. Sphere-forming cells from peripheral cornea demonstrate polarity and directed cell migration. Cell Biol Int 2013; 37:949-60. [PMID: 23619932 DOI: 10.1002/cbin.10119] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 04/10/2013] [Indexed: 12/13/2022]
Abstract
Sphere-forming cells from peripheral cornea represent a potential source of progenitor cells for treatment of corneal degenerative diseases. Control of cellular repopulation on transplantable substrates is important to prevent uncontrolled growth in unfavourable directions. The coordination of cellular outgrowth may be in response to environmental cues and/or cellular signals from other spheres. To investigate this, cell migration patterns were observed following placement of spheres on an adhesive surface. Human peripheral corneal cells were maintained using a sphere-forming assay and their behaviour on collagen substrate recorded by time-lapse imaging. Immunocytochemistry and proliferation assays were used to detect protein expression and cell division. Proliferation assays showed that spheres formed by a combination of cell division and aggregation. Cell division continued within spheres for up to 4 months and was up-regulated when exposed to differentiation medium and collagen substrate. The spheres expressed both epithelial and stromal cell markers. When exposed to collagen; (1) 25% of the spheres showed spontaneous polarised outgrowth. (2) One sphere initially showed polarised outgrowth followed by collective migration with discrete morphological changes to form leading and trailing compartments. (3) A sphere which did not show polarised outgrowth was also capable of collective migration using cell protrusion and retraction. (4) Active recruitment of cells into spheres was observed. (5) Placement of spheres in close proximity led to production of a cell exclusion area adjacent to spheres. Thus peripheral corneal cell spheres are dynamic entities capable of developing polarity and modifying migration in response to their environment.
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Affiliation(s)
- Jinny Jung Yoon
- Faculty of Medical and Health Sciences, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Private Bag 92019, Auckland, 1020, New Zealand
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Forrester JV, Steptoe RJ, Klaska IP, Martin-Granados C, Dua HS, Degli-Esposti MA, Wikstrom ME. Cell-based therapies for ocular inflammation. Prog Retin Eye Res 2013; 35:82-101. [PMID: 23542232 DOI: 10.1016/j.preteyeres.2013.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 01/31/2013] [Accepted: 02/01/2013] [Indexed: 12/13/2022]
Abstract
Since the plasticity and the potential for re-programming cells has become widely accepted, there has been great interest in cell-based therapies. These are being applied to a range of diseases, not least ocular diseases, where it is assumed that there is a reduced risk of immune rejection although this may be more perceived than real. There are two broad classes of cell-based therapies: those aimed at restoring structure and function of specific tissues and cells; and those directed towards restoring immunological homeostasis by controlling the damaging effects of inflammatory disease. Stem cells of all types represent the first group and prototypically have been used with the aim of regenerating failing cells. In contrast, immune cells have been suggested as potential modulators of inflammation. However, there is functional overlap in these two applications, with some types of stem cells, such as mesenchymal stem cells, demonstrating a potent immunomodulatory effect. This review summarises recent information on cell based therapies for ocular disease, with special emphasis on ocular inflammatory disease, and explores current uses, potential and limitations.
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Affiliation(s)
- John V Forrester
- Immunology Program, Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, Australia.
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Abstract
The transplantation of cultured limbal epithelial cells (LEC) has since its first application in 1997 emerged as a promising technique for treating limbal stem cell deficiency. The culture methods hitherto used vary with respect to preparation of the harvested tissue, choice of culture medium, culture time, culture substrates, and supplementary techniques. In this chapter, we describe a procedure for establishing human LEC cultures using a feeder-free explant culture technique with human amniotic membrane (AM) as the culture substrate.
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Kaltschmidt B, Kaltschmidt C, Widera D. Adult craniofacial stem cells: sources and relation to the neural crest. Stem Cell Rev Rep 2012; 8:658-71. [PMID: 22170630 DOI: 10.1007/s12015-011-9340-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
During the process of development, neural crest cells migrate out from their niche between the newly formed ectoderm and the neural tube. Thereafter, they give rise not only to ectodermal cell types, but also to mesodermal cell types. Cell types with neural crest ancestry consequently comprise a number of specialized varieties, such as ectodermal neurons, melanocytes and Schwann cells, as well as mesodermal osteoblasts, adipocytes and smooth muscle cells. Numerous recent studies suggest that stem cells with a neural crest origin persist into adulthood, especially within the mammalian craniofacial compartment. This review discusses the sources of adult neural crest-derived stem cells (NCSCs) derived from the cranium, as well as their differentiation potential and expression of key stem cell markers. Furthermore, the expression of marker genes associated with embryonic stem cells and the issue of multi- versus pluripotency of adult NCSCs is reviewed. Stringent tests are proposed, which, if performed, are anticipated to clarify the issue of adult NCSC potency. Finally, current pre-clinical and clinical data are discussed in light of the clinical impact of adult NCSCs.
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Affiliation(s)
- Barbara Kaltschmidt
- Molecular Neurobiology, University of Bielefeld, Universitätsstr. 25, 33501 Bielefeld, Germany
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Crawford AZ, McGhee CNJ. Management of limbal stem cell deficiency in severe ocular chemical burns. Clin Exp Ophthalmol 2012; 40:227-9. [PMID: 22490111 DOI: 10.1111/j.1442-9071.2012.02775.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Mort RL, Douvaras P, Morley SD, Dorà N, Hill RE, Collinson JM, West JD. Stem cells and corneal epithelial maintenance: insights from the mouse and other animal models. Results Probl Cell Differ 2012; 55:357-94. [PMID: 22918816 PMCID: PMC3471528 DOI: 10.1007/978-3-642-30406-4_19] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Maintenance of the corneal epithelium is essential for vision and is a dynamic process incorporating constant cell production, movement and loss. Although cell-based therapies involving the transplantation of putative stem cells are well advanced for the treatment of human corneal defects, the scientific understanding of these interventions is poor. No definitive marker that discriminates stem cells that maintain the corneal epithelium from the surrounding tissue has been discovered and the identity of these elusive cells is, therefore, hotly debated. The key elements of corneal epithelial maintenance have long been recognised but it is still not known how this dynamic balance is co-ordinated during normal homeostasis to ensure the corneal epithelium is maintained at a uniform thickness. Most indirect experimental evidence supports the limbal epithelial stem cell (LESC) hypothesis, which proposes that the adult corneal epithelium is maintained by stem cells located in the limbus at the corneal periphery. However, this has been challenged recently by the corneal epithelial stem cell (CESC) hypothesis, which proposes that during normal homeostasis the mouse corneal epithelium is maintained by stem cells located throughout the basal corneal epithelium with LESCs only contributing during wound healing. In this chapter we review experimental studies, mostly based on animal work, that provide insights into how stem cells maintain the normal corneal epithelium and consider the merits of the alternative LESC and CESC hypotheses. Finally, we highlight some recent research on other stem cell systems and consider how this could influence future research directions for identifying the stem cells that maintain the corneal epithelium.
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