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Rice G, Farrelly O, Huang S, Kuri P, Curtis E, Ohman L, Li N, Lengner C, Lee V, Rompolas P. Sox9 marks limbal stem cells and is required for asymmetric cell fate switch in the corneal epithelium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.08.588195. [PMID: 38645161 PMCID: PMC11030424 DOI: 10.1101/2024.04.08.588195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Adult tissues with high cellular turnover require a balance between stem cell renewal and differentiation, yet the mechanisms underlying this equilibrium are unclear. The cornea exhibits a polarized lateral flow of progenitors from the peripheral stem cell niche to the center; attributed to differences in cellular fate. To identify genes that are critical for regulating the asymmetric fates of limbal stem cells and their transient amplified progeny in the central cornea, we utilized an in vivo cell cycle reporter to isolate proliferating basal cells across the anterior ocular surface epithelium and performed single-cell transcriptional analysis. This strategy greatly increased the resolution and revealed distinct basal cell identities with unique expression profiles of structural genes and transcription factors. We focused on Sox9; a transcription factor implicated in stem cell regulation across various organs. Sox9 was found to be differentially expressed between limbal stem cells and their progeny in the central corneal. Lineage tracing analysis confirmed that Sox9 marks long-lived limbal stem cells and conditional deletion led to abnormal differentiation and squamous metaplasia in the central cornea. These data suggest a requirement for Sox9 for the switch to asymmetric fate and commitment toward differentiation, as transient cells exit the limbal niche. By inhibiting terminal differentiation of corneal progenitors and forcing them into perpetual symmetric divisions, we replicated the Sox9 loss-of-function phenotype. Our findings reveal an essential role for Sox9 for the spatial regulation of asymmetric fate in the corneal epithelium that is required to sustain tissue homeostasis.
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Wu J, Chen N, Grau E, Johnson L, Liu Y, Li C, Scott PA, Kim C, Sun D, Kaplan HJ, Shao H. Short chain fatty acids inhibit corneal inflammatory responses to TLR ligands via the ocular G-protein coupled receptor 43. Ocul Surf 2024; 32:48-57. [PMID: 38224777 PMCID: PMC11056309 DOI: 10.1016/j.jtos.2024.01.005] [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: 09/09/2023] [Revised: 11/22/2023] [Accepted: 01/12/2024] [Indexed: 01/17/2024]
Abstract
PURPOSE Short chain fatty acids (SCFAs) produced by gut microbiota are known to play primary roles in gut homeostasis by immunomodulation partially through G-protein coupled receptors (GPR) 43. Using mouse models of TLR ligand induced keratitis, we investigated whether SCFAs and GPR43 play any regulatory roles in the pathogenesis of inflammatory responses in the eye. METHODS Both human and mouse eyes were labeled with a specific antibody for GPR43 and imaged by a laser scanning confocal microscope. Corneal cups from naïve C57BL/6J (B6) and GPR43 knockout (KO) mice were stimulated with TLR ligands in the presence or absence of sodium butyrate overnight and then processed for RT-PCR assay for expression of GPR43 and cytokines. Keratitis was induced by Poly I:C in wild type (WT) B6, GPR43KO and chimeric mice and the disease severity was evaluated by the corneal fluorescein staining test, and infiltrating cell staining and calculating in corneal whole mount. RESULTS GPR43 is expressed in both human and mouse eyes and the expression is bidirectionally regulated by TLR ligands and butyrate. Butyrate significantly inhibited inflammation caused by several TLR ligands such as Poly I:C, Flagellin, and CpG-ODN (TLR-3, 5 and 9 agonists, respectively) in WT, but not GPR43KO, mice. Butyrate inhibition of TLR-induced keratitis is mediated by the GPR43 expressed in tissue but not hematopoietic, cells. CONCLUSIONS This is the first report to demonstrate of the protective effect of SCFAs on microbial keratitis, and the dynamic expression and anti-inflammatory function of GPR43 in the eye. SCFAs can modulate inflammation and immunity in the eye through GPR43.
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Affiliation(s)
- Jun Wu
- Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Nu Chen
- Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Elizabeth Grau
- Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Luke Johnson
- Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Yongqing Liu
- Department of Medicine-oncology, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Chi Li
- Department of Medicine-oncology, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Patrick A Scott
- Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville, School of Medicine, Louisville, KY, USA
| | - Chang Kim
- Department of Pathology, Mary H. Weiser Food Allergy Center, 4025 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI, USA
| | - Deming Sun
- Doheny Eye Institute & Department Ophthalmology, David Geffen School of Medicine/UCLA, Los Angeles, CA, USA
| | - Henry J Kaplan
- Department of Ophthalmology and Biochemistry & Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri, USA
| | - Hui Shao
- Department of Ophthalmology and Visual Sciences, Kentucky Lions Eye Center, University of Louisville, School of Medicine, Louisville, KY, USA.
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Quagliata M, Papini AM, Rovero P. Therapeutic applications of thymosin peptides: a patent landscape 2018-present. Expert Opin Ther Pat 2023; 33:865-873. [PMID: 38131310 DOI: 10.1080/13543776.2023.2298833] [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: 10/23/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
INTRODUCTION Thymosins are small proteins found mainly in the thymus. They are involved in several biological processes, including immunoregulation, angiogenesis, and anti-inflammatory activity. Due to these multiple activities, thymosins are widely used as therapeutics. In fact, these peptides have shown interesting results in the treatment of eye disorders, anticancer therapy, and dysregulated immune disorders. AREA COVERED We analyzed the thymosins therapeutic patent landscape describing the most significant patents published after 2018 and originally written in English, classified according to the different type of functions and diseases. We searched 'Thymosin' on Patentscope and Espacenet. EXPERT OPINION Thymalfasin (Zadaxin) is the only FDA-approved thymosine-based drug used to treat chronic hepatitis B and C and as a chemotherapy inducer. This outcome demonstrates how thymosins can be exploited as therapeutics, especially in immunological and anti-cancer therapies. However, the development of modified thymosins could expand their therapeutic interest and application in different diseases. In fact, by chemical modifications, it is possible to increase proteolytic stability in the biological environment, enhance cell permeability, and stabilize the secondary structure of the peptide. Finally, the development of shorter sequences could reduce the cost and production time of these thymosin-based drugs.
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Affiliation(s)
- Michael Quagliata
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry "Ugo Schiff", University of Florence, Sesto Fiorentino, Italy
| | - Anna Maria Papini
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of Chemistry "Ugo Schiff", University of Florence, Sesto Fiorentino, Italy
| | - Paolo Rovero
- Interdepartmental Research Unit of Peptide and Protein Chemistry and Biology, Department of NeuroFarBa, University of Florence, Sesto Fiorentino, Italy
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Lin S, Cai M, Zhang L, Mao Y, Wu H, Liu X, Li Y, Liang M, Cheng X, Yu F, He H, Zong R, Wu H, Liu Z, Ou S, Li W. Limbal Stem Cell Dysfunction Induced by Severe Dry Eye via Activation of the p38 MAPK Signaling Pathway. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1863-1878. [PMID: 37634709 DOI: 10.1016/j.ajpath.2023.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 08/04/2023] [Accepted: 08/11/2023] [Indexed: 08/29/2023]
Abstract
Severe dry eye (SDE) can cause grievous damage to the ocular surface and result in vision impairment and even blindness. To investigate the fate of limbal stem cells in SDE and the underlying mechanism, the current study established an SDE rat model by removing the extraorbital and infraorbital lacrimal glands and maintaining them in a low-humidity environment. One month after the surgery, aqueous tear secretion was reduced dramatically, blood vessels invaded into the central cornea, and inflammatory cells infiltrated into the limbal stroma. The expressions of keratin 12 and paired box gene 6 were down-regulated dramatically, while those of keratin 10, small proline-rich protein 1b, and mucin 5AC were up-regulated in the corneal epithelium of the SDE rats. Cell proliferation in the limbal epithelium was up-regulated, while the stem/progenitor marker adenosine 5'-triphosphate-binding cassette member 2 and the limbal epithelial colony-forming efficiency were decreased in the SDE condition. Furthermore, the p38 mitogen-activated protein kinase signaling pathway was activated in the limbal corneal epithelium of SDE rats. The abnormal differentiation and stemness loss in the corneal epithelium could be reversed upon treatment with a p38 inhibitor in a SDE in vivo model and in vitro hyperosmolar corneal epithelial culture conditions. These data suggest that SDE can lead to limbal stem cell dysfunction, and p38 mitogen-activated protein kinase signaling pathway activation plays an essential role in this process.
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Affiliation(s)
- Sijie Lin
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Minqing Cai
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Lingyu Zhang
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Yi Mao
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Han Wu
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Xiaodong Liu
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Yixuan Li
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Minghui Liang
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Xinxuan Cheng
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Fei Yu
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Hui He
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Rongrong Zong
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China
| | - Huping Wu
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China; Fujian Provincial Key Laboratory of Corneal & Ocular Surface Diseases, Xiamen, China
| | - Zuguo Liu
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China; Fujian Provincial Key Laboratory of Corneal & Ocular Surface Diseases, Xiamen, China; Xiang'an Hospital, Xiamen University, Xiamen, China
| | - Shangkun Ou
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China; Fujian Provincial Key Laboratory of Corneal & Ocular Surface Diseases, Xiamen, China.
| | - Wei Li
- Eye Institute of Xiamen University and affiliated Xiamen Eye Center, School of Medicine, Xiamen, China; Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, China; Fujian Provincial Key Laboratory of Corneal & Ocular Surface Diseases, Xiamen, China; Xiang'an Hospital, Xiamen University, Xiamen, China.
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Moshirfar M, Masud M, Harvey DH, Payne C, Bruce E, Ronquillo YC, Hoopes PC. The Multifold Etiologies of Limbal Stem Cell Deficiency: A Comprehensive Review on the Etiologies and Additional Treatment Options for Limbal Stem Cell Deficiency. J Clin Med 2023; 12:4418. [PMID: 37445454 DOI: 10.3390/jcm12134418] [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: 04/22/2023] [Revised: 06/16/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Given the various ocular manifestations of limbal stem cell insufficiency, an awareness of the genetic, acquired, and immunological causes and associated additional treatments of limbal stem cell deficiency (LSCD) is essential for providers. We performed a comprehensive review of the literature on the various etiologies and specific therapies for LSCD. The resources utilized in this review included Medline (PubMed), Embase, and Google Scholar. All English-language articles and case reports published from November 1986 through to October 2022 were reviewed in this study. There were collectively 99 articles on these topics. No other exclusion criteria were applied. Depending on the etiology, ocular manifestations of limbal stem cell deficiency range from dry eye syndrome and redness to more severe outcomes, including corneal ulceration, ocular surface failure, and vision loss. Identifying the source of damage for LSCD is critical in the treatment process, given that therapy may extend beyond the scope of the standard protocol, including artificial tears, refractive surgery, and allogeneic stem cell transplants. This comprehensive review of the literature demonstrates the various genetic, acquired, and immunological causes of LSCD and the spectrum of supplemental therapies available.
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Affiliation(s)
- Majid Moshirfar
- Hoopes Vision Research Center, Hoopes Vision, Draper, UT 84020, USA
- John A. Moran Eye Center, School of Medicine, University of Utah, Salt Lake City, UT 84132, USA
- Utah Lions Eye Bank, Murray, UT 84107, USA
| | - Maliha Masud
- School of Medicine, University of Nevada Reno, Reno, NV 89557, USA
| | - Devon Hori Harvey
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Carter Payne
- Hoopes Vision Research Center, Hoopes Vision, Draper, UT 84020, USA
| | - Elayna Bruce
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | | | - Philip C Hoopes
- Hoopes Vision Research Center, Hoopes Vision, Draper, UT 84020, USA
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Di Girolamo N, Park M. Cell identity changes in ocular surface Epithelia. Prog Retin Eye Res 2022:101148. [DOI: 10.1016/j.preteyeres.2022.101148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/13/2022] [Accepted: 11/09/2022] [Indexed: 11/21/2022]
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Park M, Zhang R, Pandzic E, Sun M, Coulson-Thomas VJ, Di Girolamo N. Plasticity of ocular surface epithelia: Using a murine model of limbal stem cell deficiency to delineate metaplasia and transdifferentiation. Stem Cell Reports 2022; 17:2451-2466. [DOI: 10.1016/j.stemcr.2022.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 11/06/2022] Open
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Sunny SS, Lachova J, Dupacova N, Kozmik Z. Multiple roles of Pax6 in postnatal cornea development. Dev Biol 2022; 491:1-12. [PMID: 36049534 DOI: 10.1016/j.ydbio.2022.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 08/20/2022] [Accepted: 08/23/2022] [Indexed: 11/19/2022]
Abstract
Mammalian corneal development is a multistep process, including formation of the corneal epithelium (CE), endothelium and stroma during embryogenesis, followed by postnatal stratification of the epithelial layers and continuous renewal of the epithelium to replace the outermost corneal cells. Here, we employed the Cre-loxP system to conditionally deplete Pax6 proteins in two domains of ocular cells, i.e., the ocular surface epithelium (cornea, limbus and conjunctiva) (OSE) or postnatal CE via K14-cre or Aldh3-cre, respectively. Earlier and broader inactivation of Pax6 in the OSE resulted in thickened OSE with CE and limbal cells adopting the conjunctival keratin expression pattern. More restricted depletion of Pax6 in postnatal CE resulted in an abnormal cornea marked by reduced epithelial thickness despite increased epithelial cell proliferation. Immunofluorescence studies revealed loss of intermediate filament Cytokeratin 12 and diffused expression of adherens junction components, together with reduced tight junction protein, Zonula occludens-1. Furthermore, the expression of Cytokeratin 14, a basal cell marker in apical layers, indicates impaired differentiation of CE cells. Collectively, our data demonstrate that Pax6 is essential for maintaining proper differentiation and strong intercellular adhesion in postnatal CE cells, whereas limbal Pax6 is required to prevent the outgrowth of conjunctival cells to the cornea.
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Affiliation(s)
- Sweetu Susan Sunny
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, Praha 4, 142 20, Czech Republic
| | - Jitka Lachova
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, Praha 4, 142 20, Czech Republic
| | - Naoko Dupacova
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, Praha 4, 142 20, Czech Republic
| | - Zbynek Kozmik
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, Praha 4, 142 20, Czech Republic.
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Lasagni Vitar R, Triani F, Barbariga M, Fonteyne P, Rama P, Ferrari G. Substance P/neurokinin-1 receptor pathway blockade ameliorates limbal stem cell deficiency by modulating mTOR pathway and preventing cell senescence. Stem Cell Reports 2022; 17:849-863. [PMID: 35334220 PMCID: PMC9023781 DOI: 10.1016/j.stemcr.2022.02.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 11/01/2022] Open
Abstract
Severe ocular surface diseases can lead to limbal stem cell deficiency (LSCD), which is accompanied by defective healing. We aimed to evaluate the role of the substance P (SP)/neurokinin-1 receptor (NK1R) pathway in corneal epithelium wound healing in a pre-clinical model of LSCD. SP ablation or NK1R blockade significantly increased epithelial wound healing (p < 0.001) and corneal transparency (p < 0.001), compared with wild type (WT). In addition, a reduced number of infiltrating goblet and conjunctival cells (p < 0.05) and increased number of epithelial stem cells (p < 0.01), which also expressed NK1R, was observed. The mammalian target of rapamycin (mTOR) pathway was significantly inhibited (p < 0.05) and expression of γH2AX was significantly reduced (p < 0.05) after SP ablation. These results suggest that excessive expression of SP is associated with LSCD and results in accelerated senescence and exhaustion of residual stem cells. Topical treatment with NK1R antagonist ameliorates clinical signs associated with LSCD and could be used as an adjuvant treatment in LSCD.
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Affiliation(s)
- Romina Lasagni Vitar
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Francesca Triani
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Marco Barbariga
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Philippe Fonteyne
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Paolo Rama
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Giulio Ferrari
- Cornea and Ocular Surface Disease Unit, Eye Repair Lab, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy.
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Evaluating the clinical translational relevance of animal models for limbal stem cell deficiency: A systematic review. Ocul Surf 2021; 23:169-183. [PMID: 34583088 DOI: 10.1016/j.jtos.2021.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE Animal models are pivotal for elucidating pathophysiological mechanisms and evaluating novel therapies. This systematic review identified studies that developed or adapted animal models of limbal stem cell deficiency (LSCD), assessed their reporting quality, summarized their key characteristics, and established their clinical translational relevance to human disease. METHODS The protocol was prospectively registered (PROSPERO CRD42020203937). Searches were conducted in PubMed, Ovid EMBASE and Web of Science in August 2020. Two authors screened citations, extracted data, assessed the reporting quality of eligible studies using the ARRIVE guidelines, and judged the clinical translational relevance of each model using a custom matrix. RESULTS 105 studies were included. Rabbits were the most common animal species. Overall, 97% of studies recapitulated LSCD to a clinical etiology, however 62% did not provide sufficient methodological detail to enable independent reproduction of the model. Adverse events and/or exclusion of animals were infrequently (20%) reported. Approximately one-quarter of studies did not produce the intended severity of LSCD; 34% provided insufficient information to assess the fidelity of disease induction. Adjunctive diagnostic confirmation of LSCD induction was performed in 13% of studies. CONCLUSIONS This is the first systematic review to assess the reporting quality and clinical translational relevance of animal models of LSCD. Models of LSCD have evolved over time, resulting in variable reporting of the characteristics of animals, experimental procedures and adverse events. In most studies, validation of LSCD was made using clinical tests; newer adjunctive techniques would enhance diagnostic validation. As most studies sought to evaluate novel therapies for LSCD, animal models should ideally recapitulate all features of the condition that develop in patients.
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Latta L, Figueiredo FC, Ashery-Padan R, Collinson JM, Daniels J, Ferrari S, Szentmáry N, Solá S, Shalom-Feuerstein R, Lako M, Xapelli S, Aberdam D, Lagali N. Pathophysiology of aniridia-associated keratopathy: Developmental aspects and unanswered questions. Ocul Surf 2021; 22:245-266. [PMID: 34520870 DOI: 10.1016/j.jtos.2021.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 07/19/2021] [Accepted: 09/08/2021] [Indexed: 12/13/2022]
Abstract
Aniridia, a rare congenital disease, is often characterized by a progressive, pronounced limbal insufficiency and ocular surface pathology termed aniridia-associated keratopathy (AAK). Due to the characteristics of AAK and its bilateral nature, clinical management is challenging and complicated by the multiple coexisting ocular and systemic morbidities in aniridia. Although it is primarily assumed that AAK originates from a congenital limbal stem cell deficiency, in recent years AAK and its pathogenesis has been questioned in the light of new evidence and a refined understanding of ocular development and the biology of limbal stem cells (LSCs) and their niche. Here, by consolidating and comparing the latest clinical and preclinical evidence, we discuss key unanswered questions regarding ocular developmental aspects crucial to AAK. We also highlight hypotheses on the potential role of LSCs and the ocular surface microenvironment in AAK. The insights thus gained lead to a greater appreciation for the role of developmental and cellular processes in the emergence of AAK. They also highlight areas for future research to enable a deeper understanding of aniridia, and thereby the potential to develop new treatments for this rare but blinding ocular surface disease.
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Affiliation(s)
- L Latta
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany; Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.
| | - F C Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom
| | - R Ashery-Padan
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - J M Collinson
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, United Kingdom
| | - J Daniels
- Cells for Sight, UCL Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - S Ferrari
- The Veneto Eye Bank Foundation, Venice, Italy
| | - N Szentmáry
- Dr. Rolf. M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - S Solá
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - R Shalom-Feuerstein
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel
| | - M Lako
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - S Xapelli
- Instituto Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - D Aberdam
- Centre de Recherche des Cordeliers, INSERM U1138, Team 17, France; Université de Paris, 75006, Paris, France.
| | - N Lagali
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway.
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Corneal Epithelial Stem Cells-Physiology, Pathophysiology and Therapeutic Options. Cells 2021; 10:cells10092302. [PMID: 34571952 PMCID: PMC8465583 DOI: 10.3390/cells10092302] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 12/12/2022] Open
Abstract
In the human cornea, regeneration of the epithelium is regulated by the stem cell reservoir of the limbus, which is the marginal region of the cornea representing the anatomical and functional border between the corneal and conjunctival epithelium. In support of this concept, extensive limbal damage, e.g., by chemical or thermal injury, inflammation, or surgery, may induce limbal stem cell deficiency (LSCD) leading to vascularization and opacification of the cornea and eventually vision loss. These acquired forms of limbal stem cell deficiency may occur uni- or bilaterally, which is important for the choice of treatment. Moreover, a variety of inherited diseases, such as congenital aniridia or dyskeratosis congenita, are characterized by LSCD typically occurring bilaterally. Several techniques of autologous and allogenic stem cell transplantation have been established. The limbus can be restored by transplantation of whole limbal grafts, small limbal biopsies or by ex vivo-expanded limbal cells. In this review, the physiology of the corneal epithelium, the pathophysiology of LSCD, and the therapeutic options will be presented.
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Yokoo S, Yamagami S. Goblet Cell Differentiation Potential in Human Corneal Limbal Epithelial Progenitor Cells In Vitro. Invest Ophthalmol Vis Sci 2021; 61:27. [PMID: 33112944 PMCID: PMC7594597 DOI: 10.1167/iovs.61.12.27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The existence of goblet cells has been regarded as a critical differential point to distinguish conjunctival epithelium from corneal epithelium in vivo. We tested differentiation potential of single progenitor cells from corneal limbal epithelium with growth factors in vitro. Methods Dissociated single cells from corneal limbal epithelium were cultured in the serum- and feeder cell–free medium containing B27 and various growth factors using nontissue culture dishes. Specific marker expression was examined in the colonies stimulated with growth factors. Differentiation of some mucosal epithelia was tested. Results Adherent single cells from dissociated single cells in corneal limbal epithelium did not proliferate in the serum- and feeder cell–free medium containing B27 only and formed corneal epithelium with B27 plus epidermal growth factor, while they gave rise to goblet cell with periodic acid Schiff–positive mucin and cytokeratin-3 and-12 expressing corneal epithelium with fibroblast growth factor (FGF)2 stimulation. Colonies stimulated with FGF2 expressed goblet cell specific MUC5AC and cytokeratin-7 mRNA and protein. FGF receptor 1 was a functional receptor for the differentiation to goblet cells and corneal epithelium. Conclusions Single corneal limbal progenitor cells give rise to goblet cells and corneal epithelium by FGF2 stimulation via FGF receptor 1 in vitro.
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Affiliation(s)
- Seiichi Yokoo
- Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.,Department of Ophthalmology, Kyoto Prefectural University of Medicine, Japan
| | - Satoru Yamagami
- Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.,Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan
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14
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Conjunctival Implantation Cyst in the Orbicularis Oculi Muscle: Review of a Possible Origin From Displaced Stem Cells With a Differential Diagnosis. Ophthalmic Plast Reconstr Surg 2021; 37:1-11. [PMID: 32304506 DOI: 10.1097/iop.0000000000001631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To document a unique case of a corneal/conjunctival epithelial inclusion cyst located in the orbicularis oculi muscle with a comprehensive review of variant conjunctival cysts and simulating conditions. METHODS Clinicopathologic case report with detailed histopathologic and immunohistochemical evaluation for cytokeratins combined with a tabulation of mimicking lesions and relevant literature citations. RESULTS A 59-year-old man experienced severe blunt left periorbital trauma that resulted in a limbal partial-thickness corneal wound with an associated epithelial abrasion and a full-thickness eyelid laceration extending from the superior fornix to the margin. Several months after surgical repair of the eyelid a cyst appeared in the superior pretarsal skin. Histopathologic and immunohistochemical investigations supplied data suggesting that the cyst had a high probability of a corneoscleral limbal stem cell origin. Distinctive features of the lesion are contrasted with those of allied or simulating cysts. CONCLUSIONS Stem cells are now believed to be located at the corneoscleral limbus, in the inferior fornix, in the medial canthal region, and at the eyelid margin where transitions from conjunctival epithelium to epidermal epithelium occur. Due to their replicative, hardy and robust nature, stem cells displaced to alien environments are most likely to survive and produce cysts. The cyst's corneal-type cytologic characteristics, the absence of goblet cells, and the expression of a broad spectrum of cytokeratin biomarkers in the current case give support to the proposal that limbal stem cells in the region of the corneal laceration were displaced to the eyelid orbicularis muscle and were responsible for this most extraordinary cyst. Comparison with other epithelial cystic linings lends further evidence for this conclusion.
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15
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Azmi MF, Abd Ghafar N, Che Hamzah J, Chua KH, Ng SL. The role of Gelam honey in accelerating reepithelialization of ex vivo corneal abrasion model. J Food Biochem 2021; 45:e13645. [PMID: 33569805 DOI: 10.1111/jfbc.13645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/26/2022]
Abstract
This study aimed to investigate the role of Gelam honey (GH) in accelerating reepithelialization of corneal abrasion. Corneal epithelial cells (CEC) isolated from New Zealand white rabbit corneas, were cultured and circular-shaped wounds were created onto them, representing the corneal abrasion model. These wounds were treated with basal (BM) and cornea media (CM) supplemented with GH. The percentage of wound closure was measured on day 0, 3, and 5. Expressions of cytokeratin 3 (CK3), cluster of differentiation 44 (CD 44), and connexin 43 (Cx43) were analyzed via qRT-PCR and immunocytochemistry. The results showed CEC cultured in GH-enriched media reepithelialized faster compared to control. Corneal abrasion treated with CM supplemented with GH closed completely on day 5. CK3, CD44, and Cx43 expressions correspond to the stages of reepithelialization. In conclusion, GH promotes the healing of the ex vivo corneal abrasion model. Further explorations of its potential as adjuvant therapy in treating corneal injuries are needed. PRACTICAL APPLICATIONS: Honey has been reported to have many medicinal properties including antibacterial, anti-inflammatory, and the ability to promote skin wound healing. However, the effects of honey on corneal wound healing have not been fully elucidated. In the present study, we aimed to determine the effects of Gelam honey (GH), well-known local honey obtained from the beehive of Gelam trees (Melaleuca spp.), on the ex vivo corneal abrasion model via cell migration study and analysis of genes and proteins during corneal epithelial wound healing. GH has proven to have accelerated effects on the corneal epithelial cell migration during the closure of the ex vivo corneal abrasion wound model. The expressions of the genes and proteins of the corneal epithelial wound healing markers were in accordance with the stages of healing. Therefore, GH has the potential to be developed as adjuvant therapy in the form of GH-based eye drop in treating corneal injuries.
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Affiliation(s)
- Muhammad Fairuz Azmi
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia, Wilayah Persekutuan Kuala Lumpur, Malaysia.,Department of Anatomy, Faculty of Medicine, Universiti Teknologi MARA, Jalan Hospital, Sungai Buloh, Malaysia
| | - Norzana Abd Ghafar
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Jemaima Che Hamzah
- Department of Ophthalmology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Kien Hui Chua
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Sook Luan Ng
- Craniofacial Diagnostic and Bioscience Centre, Faculty of Dentistry, Universiti Kebangsaan Malaysia, Cawangan Kampus Kuala Lumpur, Kuala Lumpur, Malaysia
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16
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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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17
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Puri S, Sun M, Mutoji KN, Gesteira TF, Coulson-Thomas VJ. Epithelial Cell Migration and Proliferation Patterns During Initial Wound Closure in Normal Mice and an Experimental Model of Limbal Stem Cell Deficiency. Invest Ophthalmol Vis Sci 2021; 61:27. [PMID: 32790859 PMCID: PMC7441334 DOI: 10.1167/iovs.61.10.27] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Purpose Establishing the dynamics of corneal wound healing is of vital importance to better understand corneal inflammation, pathology, and corneal regeneration. Numerous studies have made great strides in investigating multiple aspects of corneal wound healing; however, some aspects remain to be elucidated. This study worked toward establishing (1) if epithelial limbal stem cells (LSCs) are necessary for healing all corneal wounds, (2) the mechanism by which epithelial cells migrate toward the wound, and (3) if centrifugal epithelial cell movement exists. Methods To establish different aspects of corneal epithelial wound healing we subjected mice lacking hyaluronan synthase 2 (previously shown to lack LSCs) and wild-type mice to different corneal debridement injury models. Results Our data show that both LSCs and corneal epithelial cells contribute toward closure of corneal wounds. In wild-type mice, removal of the limbal rim delayed closure of 1.5-mm wounds, and not of 0.75-mm wounds, indicating that smaller wounds do not rely on LSCs as do larger wounds. In mice shown to lack LSCs, removal of the limbal rim did not affect wound healing, irrespective of the wound size. Finally, transient amplifying cells and central epithelial cells move toward a central corneal wound in a centripetal manner, whereas central epithelial cells may move in a centrifugal manner to resurface peripheral corneal wounds. Conclusions Our findings show the dimensions of the corneal wound dictate involvement of LSCs. Our data suggest that divergent findings by different groups on the dynamics of wound healing can be in part owing to differences in the wounding models used.
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Affiliation(s)
- Sudan Puri
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Mingxia Sun
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Kazadi N Mutoji
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Tarsis F Gesteira
- College of Optometry, University of Houston, Houston, Texas, United States
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18
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Kao WWY. Keratin expression by corneal and limbal stem cells during development. Exp Eye Res 2020; 200:108206. [PMID: 32882212 DOI: 10.1016/j.exer.2020.108206] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/15/2022]
Abstract
Keratins are the forming units of intermediate filaments (IF) that provide mechanical support, and formation of desmosomes between cells and hemi desmosomes with basement membranes for epithelium integrity. Keratin IF are polymers of obligate heterodimer consisting one type I keratin and one type II keratin molecules. There are 54 functional keratin genes in human genome, which are classified into three major groups, i.e., epithelial keratins, hair follicle cell-specific epithelial keratins and hair keratins. Their expression is cell type-specific and developmentally regulated. Corneal epithelium expresses a subgroup of keratins similar to those of epidermal epithelium. Limbal basal stem cells express K5/K14, and K8/K18 and K8/K19 IF suggesting that there probably are two populations of limbal stem cells (LSCs). In human, LSCs at limbal basal layer can directly stratify and differentiate to limbal suprabasal cells that express K3/K12 IF, or centripetally migrate then differentiate to corneal basal transient amplifying cells (TAC) that co-express both K3/K12 and K5/K14 prior to moving upward and assuming suprabasal cells phenotype of only K3/K12 expression that signifies corneal type epithelium differentiation. In rodent, the differentiated cornea epithelial cells express K5/K12 in lieu of K3/K12, because K3 allele exists as a pseudogene and does not encode a functional K3 protein. The basal corneal cells of new-born mice originate from surface ectoderm during embryonic development slowly commit to differentiation of becoming TAC co-expressing K5/K12 and K5/K14 IF. However, the centripetal migration may still occur at a slower rate in young mice, which is accelerated during wound healing. In this review, we will discuss and compare the cornea-specific keratins expression patterns between corneal and epidermal epithelial cells during mouse development, and between human and mouse during development and homeostasis in adult, and pathology caused by a mutation of keratins.
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Affiliation(s)
- Winston W-Y Kao
- Departments of Ophthalmology, University of Cincinnati, Cincinnati, OH, 45267-0838, USA.
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19
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Lee SC, Hyon JY, Jeon HS. Contact Lens Induced Limbal Stem Cell Deficiency: Clinical Features in Korean Patients. KOREAN JOURNAL OF OPHTHALMOLOGY 2020; 33:500-505. [PMID: 31833246 PMCID: PMC6911783 DOI: 10.3341/kjo.2019.0095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 08/22/2019] [Indexed: 12/15/2022] Open
Abstract
Purpose To describe the clinical features of Korean patients with contact lens-induced limbal stem cell deficiency (CL-LSCD). Methods Medical records of 22 patients who were diagnosed with CL-LSCD between 2014 and 2019 were reviewed retrospectively. Outcome measures included demographics, clinical presentation, treatment, clinical course, and pattern of contact lens (CL) wear. Results Forty-two eyes of 22 patients were found to have typical changes associated with CL-LSCD. Twenty (91%) patients were women and mean age was 36 ± 12 years. All patients had myopia with mean spherical equivalent of −7.52 ± 3.2 diopter. Twenty (91%) patients had bilateral disease and the location of limbal involvement was diffuse in 20 eyes (47.6%) and partial in 22 eyes (52.4%, superior in 20 eyes and inferior in 2 eyes). Fourteen (63.6%) patients complained of decreased visual acuity. Average period of CL wear was 14 ± 9 years. Four patients used cosmetic colored CLs and four patients had a history of overnight CL wear. All 12 patients who completed follow-up (28 ± 42 weeks) showed improvement in visual acuity and ocular surface condition after cessation of CL wear and medical treatment. Of them, five (42%) patients showed full recovery while seven (58%) showed partial recovery. Conclusions If a patient with a history of CL wear for an extended period of time presents with decreased visual acuity, practitioners should perform detailed examinations with suspicion of CL-LSCD, including fluorescein staining. CL-LSCD is usually reversible and close follow-up with conservative treatment is recommended as the initial treatment option.
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Affiliation(s)
- Seung Chan Lee
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
| | - Joon Young Hyon
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.,Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hyun Sun Jeon
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.,Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea.
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20
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Swamynathan SK, Wells A. Conjunctival goblet cells: Ocular surface functions, disorders that affect them, and the potential for their regeneration. Ocul Surf 2020; 18:19-26. [PMID: 31734511 PMCID: PMC7004882 DOI: 10.1016/j.jtos.2019.11.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/15/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023]
Abstract
Conjunctival goblet cells (CGCs) are specialized cells that produce and secrete soluble mucins to the tear film that bathes the ocular surface. CGC numbers and functions are affected in various ocular surface diseases including dry eye disease with diverse etiologies. In this review we will (i) summarize the important functions of CGCs in ocular surface health, (ii) describe the ocular surface diseases that affect CGC numbers and function, (iii) provide an update on recent research outcomes that elucidate CGC differentiation, gene expression and functions, and (iv) present evidence in support of the prediction that restoring CGC numbers and/or functions is a viable strategy for alleviating ocular surface disorders that impact the CGCs.
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Affiliation(s)
- Shivalingappa K Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Fox Center for Vision Restoration, University of Pittsburgh, Pittsburgh, PA, USA; Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Alan Wells
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA; Pittsburgh Veterans Affairs Medical Center, Pittsburgh, PA, USA.
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21
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He J, Pham TL, Kakazu AH, Bazan HEP. Remodeling of Substance P Sensory Nerves and Transient Receptor Potential Melastatin 8 (TRPM8) Cold Receptors After Corneal Experimental Surgery. Invest Ophthalmol Vis Sci 2019; 60:2449-2460. [PMID: 31157834 PMCID: PMC6545819 DOI: 10.1167/iovs.18-26384] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose To investigate changes in corneal nerves positive to substance P (SP) and transient receptor potential melastatin 8 (TRPM8) and gene expression in the trigeminal ganglia (TG) following corneal surgery to unveil peripheral nerve mechanism of induced dry eye-like pain (DELP). Methods Surgery was performed on mice by removing the central epithelial and anterior stromal nerves. Mice were euthanized at different times up to 15 weeks. Immunostaining was performed with TRPM8, SP, or protein gene product 9.5 (PGP9.5) antibodies, and epithelial nerve densities were calculated. The origin of TRPM8- and SP-TG neurons were analyzed by retrograde tracing. Gene expression in TG was studied by real-time PCR analysis. Results SP-positive epithelial corneal nerves were more abundant than TRPM8 and were expressed in different TG neurons. After injury, epithelial nerve regeneration occurs in two distinct stages. An early regeneration of the remaining epithelial bundles reached the highest density on day 3 and then rapidly degraded. From day 5, the epithelial nerves originated from the underlying stromal nerves were still lower than normal levels by week 15. The SP- and TRPM8-positive nerve fibers followed the same pattern as the total nerves. TRPM8-positive terminals increased slowly and reached only half of normal values by 3 months. Corneal sensitivity gradually increased and reached normal values on day 12. Corneal injury also induced significant changes in TG gene expression, decreasing trpm8 and tac1 genes. Conclusions Abnormal SP expression, low amounts of TRPM8 terminals, and hypersensitive nerve response occur long after the injury and changes in gene expression in the TG suggest a contribution to the pathogenesis of corneal surgery-induced DELP.
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Affiliation(s)
- Jiucheng He
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States.,Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Thang Luong Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Azucena H Kakazu
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
| | - Haydee E P Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States.,Department of Ophthalmology, School of Medicine, Louisiana State University Health New Orleans, New Orleans, Louisiana, United States
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22
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Park M, Mazalo J, Di Girolamo N. Insulin-like growth factor binding protein-7: A marker of conjunctivalization in an animal model of limbal stem cell deficiency. Ocul Surf 2019; 17:447-457. [PMID: 31125784 DOI: 10.1016/j.jtos.2019.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/15/2019] [Accepted: 05/20/2019] [Indexed: 01/13/2023]
Abstract
PURPOSE Limbal stem cell deficiency (LSCD) is characterized by the loss of limbal epithelial stem cells, resulting in a pathological process termed 'conjunctivalization' which compromises corneal transparency, leading to blindness. Current diagnosis for LSCD is limited because reliable conjunctiva-specific biomarkers are lacking. This study sought to address this shortcoming through the serendipitous discovery of insulin-like growth factor binding protein (IGFBP)-7. METHODS IGFBP-7 expression was determined in normal (n=83) and conjunctivalized (n=52) mouse corneas with experimentally-induced LSCD, and in cadaveric normal human corneas (n=7) and human pterygia (n=15); a disease characterized by the invasion of a conjunctivalized, fibrovascular pannus. Clinical assessments including slit-lamp microscopy, fluorescein staining and impression cytology, and biochemical, molecular and immunological assays were also conducted. RESULTS Mass spectrometry of conditioned media from mouse limbal explant-derived cells revealed the presence of IGFBP-7. This factor was expressed in normal limbal and conjunctival epithelium and conjunctivalized corneas from mice with LSCD, and in human pterygium epithelium but not in normal mouse or human corneal epithelium. Four weeks after inducing LSCD, IGFBP-7 staining was increased by 2.9-fold in mouse corneas compared to steady-state, and by 1.6-fold in impression cytology specimens derived from the same mice. Notably, IGFBP-7 was detected approximately 2-weeks earlier than Muc5AC. CONCLUSIONS This study provides novel insights into the specificity of IGFBP-7 for the mammalian conjunctival epithelium in health and disease. A point-of-care test for IGFBP-7 could be developed to assist clinicians in early diagnosis, and in monitoring disease progression, severity and therapeutic outcomes in patients with LSCD.
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Affiliation(s)
- Mijeong Park
- Mechanisms of Disease and Translational Research, School of Medical Sciences, Faculty of Medicine, University of NSW, Sydney, NSW, 2052, Australia
| | - Jessica Mazalo
- Mechanisms of Disease and Translational Research, School of Medical Sciences, Faculty of Medicine, University of NSW, Sydney, NSW, 2052, Australia
| | - Nick Di Girolamo
- Mechanisms of Disease and Translational Research, School of Medical Sciences, Faculty of Medicine, University of NSW, Sydney, NSW, 2052, Australia.
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23
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Chen Y, Yin YW, Zhao Y, Wu XY, Young K, Song WT, Xia XB, Wen D. Differentiation of human embryonic stem cells derived mesenchymal stem cells into corneal epithelial cells after being seeded on decellularized SMILE-derived lenticules. Int J Ophthalmol 2019; 12:717-724. [PMID: 31131228 DOI: 10.18240/ijo.2019.05.04] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 03/27/2019] [Indexed: 12/14/2022] Open
Abstract
AIM To evaluate the feasibility of mesenchymal stem cells (MSCs) to differentiate into corneal epithelial cells after being seeded on the decellularized small incision lenticule extraction (SMILE)-derived lenticules. METHODS The fresh lenticules procured from patients undergoing SMILE for the correction of myopia were decellularized. The MSCs were subsequently cultivated on those denuded lenticules. The MSCs without lenticules were used as a control. The proliferation activity of the MSCs after seeding 24h was quantitatively determined with the Cell Counting Kit-8 (CCK-8) assay. Immunofluorescence staining and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to assess the marker expression in differentiated MSCs. RESULTS The data showed that both fresh and decellularized lenticules could significantly promote the proliferation of MSCs, compared to that in control (P=0.02 for fresh lenticules, P=0.001 for decellularize ones, respectively). The MSCs seeded on both lenticules were positive for cytokeratin 3 (CK3) staining. The expression of CK3 increased 5-fold in MSCs seeded on fresh lenticules and 18-fold on decellularized ones, compared to that in control. There was a significant difference in the expression of CK3 in MSCs seeded on fresh and decellularized lenticules (P<0.001). The expression of CK8 and CK18 was similar in pure MSCs and MSCs seeded on fresh lenticules (P>0.05), while the expression of these markers was decreased in MSCs seeded on decellularized ones. CONCLUSION These results suggest that the decellularized lenticules might be more suitable for MSCs to differentiate into corneal epithelial cells, which offers the prospect of a novel therapeutic modality of SMILE-derived lenticules in regenerative corneal engineering.
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Affiliation(s)
- Yao Chen
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Ye-Wei Yin
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Yang Zhao
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Xiao-Ying Wu
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Kelly Young
- Department of Veterans Affairs, Miami VA Healthcare System, Miami, Florida 33125, USA
| | - Wei-Tao Song
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Xiao-Bo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Dan Wen
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
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24
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Kethiri AR, Raju E, Bokara KK, Mishra DK, Basu S, Rao CM, Sangwan VS, Singh V. Inflammation, vascularization and goblet cell differences in LSCD: Validating animal models of corneal alkali burns. Exp Eye Res 2019; 185:107665. [PMID: 31095932 DOI: 10.1016/j.exer.2019.05.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 05/06/2019] [Accepted: 05/09/2019] [Indexed: 12/15/2022]
Abstract
Limbal stem cell deficiency (LSCD) is one of the serious cause of visual impairment and blindness with loss of corneal clarity and vascularization. Factors such as ocular burns (acids, lime, thermal), genetic disorders or infections results in the loss of limbal stem cells leading to LSCD. Reliable animal models of LSCD are useful for understanding the pathophysiology and developing novel therapeutic approaches. The purpose of the present study was to validate small and large animal models of LSCD by immunohistochemcal, clinical and histopathological comparison with human. The animal models of LSCD were created by topical administration of sodium hydroxide on the ocular surface of C57BL/6 mice (m, n = 12) and New Zealand white rabbits (r, n = 12) as per the standard existing protocol. Human corneal specimens (h, n = 12) were obtained from tissue bank who had chemical burn-induced LSCD. All samples were either paraffin embedded or frozen in cryogenic medium and the sections were processed for Hematoxylin-Eosin and Periodic Acid-Schiff staining to analyse the morphology and histopathological features of the corneal surface such as vascularization, inflammation, presence of goblet cells, epithelial hyperplasia and keratinization. Immunofluorescence was performed to distinguish between corneal (CK3+), conjunctival (CK19+) and epidermal (CK10+) epithelial phenotype. Histological analysis of corneal specimens from the three groups showed the presence of goblet cells (h:83%, m:50%, r:50%, p = 0.014), epithelial hypertrophy (h:92%, m:50%, r:66.6%, p = 0.04), epithelial hyperplasia (h:50%, m:17%, r:17%, p = 0.18), intra epithelial edema (h:42%, m:33%, r:100%, p = 0.02), stromal inflammation (h:100%, m:67%, r:67%, p = 0.01) and stromal vascularization (h:100%, m:50%, r:67%), in varying proportions. Immunostaining showed presence of total LSCD (CK19 + and/or CK10+, CK3-) in 92% of human and 50% of animal specimens. While partial LSCD (CK19 + and/or CK10+, CK3+) was seen in 8% of human and 50% of animal specimens. Our study shows the significant differences in the extent of vascularization, inflammation, epithelial thickness and goblet cell formation in mice and rabbit models of LSCD when compared to post-chemical burn LSCD in human corneas. In both mice and rabbit models complete LSCD developed in only 50% of cases and this important fact needs to be considered when working with animal models of LSCD.
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Affiliation(s)
- Abhinav Reddy Kethiri
- SSR-Stem Cell Biology Laboratory, Center for Regenerative Ophthalmology, L V Prasad Eye Institute, Hyderabad, India; (b).Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Enoch Raju
- SSR-Stem Cell Biology Laboratory, Center for Regenerative Ophthalmology, L V Prasad Eye Institute, Hyderabad, India
| | - Kiran Kumar Bokara
- CSIR-Center for Cellular and Molecular Biology, Medical Biotechnology Complex, Uppal Road, Hyderabad, India
| | - Dilip Kumar Mishra
- Ophthalmic Pathology Laboratory, L.V. Prasad Eye Institute, Hyderabad, India
| | - Sayan Basu
- SSR-Stem Cell Biology Laboratory, Center for Regenerative Ophthalmology, L V Prasad Eye Institute, Hyderabad, India; Tej Kohli Cornea Institute, L.V. Prasad Eye Institute, Hyderabad, India
| | - Ch Mohan Rao
- CSIR-Center for Cellular and Molecular Biology, Medical Biotechnology Complex, Uppal Road, Hyderabad, India
| | - Virender Singh Sangwan
- SSR-Stem Cell Biology Laboratory, Center for Regenerative Ophthalmology, L V Prasad Eye Institute, Hyderabad, India; Tej Kohli Cornea Institute, L.V. Prasad Eye Institute, Hyderabad, India
| | - Vivek Singh
- SSR-Stem Cell Biology Laboratory, Center for Regenerative Ophthalmology, L V Prasad Eye Institute, Hyderabad, India; Tej Kohli Cornea Institute, L.V. Prasad Eye Institute, Hyderabad, India.
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Li YJ, Luo LJ, Harroun SG, Wei SC, Unnikrishnan B, Chang HT, Huang YF, Lai JY, Huang CC. Synergistically dual-functional nano eye-drops for simultaneous anti-inflammatory and anti-oxidative treatment of dry eye disease. NANOSCALE 2019; 11:5580-5594. [PMID: 30860532 DOI: 10.1039/c9nr00376b] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have developed a rapid and straightforward topical treatment method for dry eye disease (DED) using poly(catechin) capped-gold nanoparticles (Au@Poly-CH NPs) carrying amfenac [AF; a nonsteroidal anti-inflammatory drug (NSAID)] through effective attenuation of ocular surface tissue damage in dry eyes. A dual-targeted strategy based on ocular therapeutics was adopted to simultaneously block the cyclooxygenase enzymes-induced inflammation and reactive oxygen species (ROS)-induced oxidative stress, the primary two causes of DED. The self-assembled core-shell Au@Poly-CH NPs synthesized via a simple reaction between tetrachloroaurate(iii) and catechin possess a poly(catechin) shell (∼20 nm) on the surface of each Au NP (∼60 nm). The anti-oxidant and anti-inflammatory properties of AF/Au@Poly-CH NPs were evaluated by DCFH-DA and prostaglandin E2/VEGF assays, respectively. Our results demonstrate that Au@Poly-CH NPs not only act as an anti-oxidant to suppress ROS-mediated processes, but also serve as a drug carrier of AF for a synergistic effect on anti-inflammation. In vivo biocompatibility studies show good tolerability of AF/Au@Poly-CH NPs for potential use in the treatment of ocular surface pathologies. The dual-targeted therapeutic effects of AF/Au@Poly-CH NPs lead to rapid recovery from DED in a rabbit model. Au@Poly-CH NPs loaded with NSAIDs is a promising multifunctional nanocomposite for treating various inflammation- and oxidative stress-related diseases.
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Affiliation(s)
- Yu-Jia Li
- Graduate Institute of Biomedical Engineering, Chang Gung University, Taoyuan, 33302, Taiwan.
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26
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Pietraszkiewicz A, Hampton C, Caplash S, Lei L, Capetanaki Y, Tadvalkar G, Pal-Ghosh S, Stepp MA, Bargagna-Mohan P, Mohan R. Desmin deficiency is not sufficient to prevent corneal fibrosis. Exp Eye Res 2019; 180:155-163. [PMID: 30590024 PMCID: PMC6389382 DOI: 10.1016/j.exer.2018.12.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/08/2018] [Accepted: 12/22/2018] [Indexed: 12/16/2022]
Abstract
The type III intermediate filament (IF) proteins vimentin and desmin are sequentially overexpressed in stromal myofibroblasts over the period when fibrosis sets in after corneal injury. Prior findings have revealed vimentin-deficient mice are significantly protected from corneal fibrosis after alkali injury, which has implicated this IF protein as an important regulator of corneal fibrosis. It has remained as yet unproven whether desmin contributes in any significant manner to corneal fibrosis. Here we have employed desmin-deficient (Des KO) mice in the corneal alkali injury model and show that injured Des KO mice develop fibrosis and show similar levels of corneal opacity at 14 days post-injury as wild type (WT) mice and retain this phenotype even at 30d post injury. Des KO corneas from injured mice show upregulation of vimentin and alpha-smooth muscle actin expression to equivalent levels as WT corneas, illuminating that desmin deficiency does not interfere with myofibrobast differentiation. Employing the small molecule withaferin A (WFA), an inhibitor of vimentin, we show that WFA treatment causes the decrease in steady state levels of vimentin and serine 38 phosphorylated vimentin, the latter a biomarker associated with corneal fibrosis, and improved corneal clarity through blockade of myofibroblast differentiation. To investigate further the mechanism of fibrosis in desmin deficiency, we examined keratin 8 expression in the epithelium, and found reduced levels of this cytokeratin in injured Des KO corneas compared to WT corneas. This finding also corroborates the decrease of cell proliferation in injured Des KO corneas compared to that in WT corneas. The fibrotic phenotype of Des KO corneas also features abundant vascularization, further exemplifying the magnitude of corneal pathology. Together, these findings illuminate that desmin does not contribute significantly to corneal fibrosis in this injury model.
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Affiliation(s)
| | - Christopher Hampton
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA
| | - Sonny Caplash
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA
| | - Ling Lei
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA
| | - Yassemi Capetanaki
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Gauri Tadvalkar
- Department of Ophthalmology, George Washington University, Washington, DC, USA
| | - Sonali Pal-Ghosh
- Department of Ophthalmology, George Washington University, Washington, DC, USA
| | - Mary Ann Stepp
- Department of Ophthalmology, George Washington University, Washington, DC, USA
| | - Paola Bargagna-Mohan
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA
| | - Royce Mohan
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT, USA.
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27
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Park M, Richardson A, Pandzic E, Lobo EP, Whan R, Watson SL, Lyons JG, Wakefield D, Di Girolamo N. Visualizing the Contribution of Keratin-14 + Limbal Epithelial Precursors in Corneal Wound Healing. Stem Cell Reports 2018; 12:14-28. [PMID: 30554917 PMCID: PMC6335450 DOI: 10.1016/j.stemcr.2018.11.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 12/16/2022] Open
Abstract
It is thought that corneal epithelial injuries resolve by leading-edge cells “sliding” or “rolling” into the wound bed. Here, we challenge this notion and show by real-time imaging that corneal wounds initially heal by “basal cell migration.” The K14CreERT2-Confetti multi-colored reporter mouse was employed to spatially and temporally fate-map cellular behavior during corneal wound healing. Keratin-14+ basal epithelia are forced into the wound bed by increased population pressure gradient from the limbus to the wound edge. As the defect resolves, centripetally migrating epithelia decelerate and replication in the periphery is reduced. With time, keratin-14+-derived clones diminish in number concomitant with their expansion, indicative that clonal evolution aligns with neutral drifting. These findings have important implications for the involvement of stem cells in acute tissue regeneration, in key sensory tissues such as the cornea. Basal limbal epithelial cell proliferation is increased following a corneal injury Corneal epithelial wounds initially heal by K14+ basal cell migration STICS accurately measures clonal dynamics during wound closure Computational modeling confirms the pivotal role of LESCs in wound repair
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Affiliation(s)
- Mijeong Park
- Mechanisms of Disease and Translational Research, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Alexander Richardson
- Mechanisms of Disease and Translational Research, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Elvis Pandzic
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Erwin P Lobo
- School of Mathematics and Statistics, Faculty of Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Renee Whan
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | | | - J Guy Lyons
- Discipline of Dermatology, Bosch Institute, Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia; Immune Imaging, Centenary Institute, Sydney, NSW 2006, Australia; Cancer Services, Royal Prince Alfred Hospital, Sydney, NSW 2006, Australia
| | - Denis Wakefield
- Mechanisms of Disease and Translational Research, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nick Di Girolamo
- Mechanisms of Disease and Translational Research, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia.
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Wang Y, Mahesh P, Wang Y, Novo SG, Shihan MH, Hayward-Piatkovskyi B, Duncan MK. Spatiotemporal dynamics of canonical Wnt signaling during embryonic eye development and posterior capsular opacification (PCO). Exp Eye Res 2018; 175:148-158. [PMID: 29932883 DOI: 10.1016/j.exer.2018.06.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 06/14/2018] [Accepted: 06/18/2018] [Indexed: 02/07/2023]
Abstract
The appropriate spatial and temporal regulation of canonical Wnt signaling is vital for eye development. However, the literature often conflicts on the distribution of canonical Wnt signaling in the eye. Here, using a sensitive mouse transgenic reporter line, we report a detailed re-evaluation of the spatiotemporal dynamics of canonical Wnt signaling in the developing eye. Canonical Wnt activity was dynamic in the optic vesicle and later in the retina, while it was absent from the ectodermal precursors of the lens and corneal epithelium. However, later in corneal development, canonical Wnt reporter activity was detected in corneal stroma and endothelium precursors as they form from the neural crest, although this was lost around birth. Interestingly, while no canonical Wnt signaling was detected in the corneal limbus or basal cells at any developmental stage, it was robust in adult corneal wing and squamous epithelial cells. While canonical Wnt reporter activity was also absent from the postnatal lens, upon lens injury intended to model cataract surgery, it upregulated within 12 h in remnant lens epithelial cells, and co-localized with alpha smooth muscle actin in fibrotic lens epithelial cells from 48 h post-surgery onward. This pattern correlated with downregulation of the inhibitor of canonical Wnt signaling, Dkk3. These data demonstrate that canonical Wnt signaling is dynamic within the developing eye and upregulates in lens epithelial cells in response to lens injury. As canonical Wnt signaling can collaborate with TGFβ to drive fibrosis in other systems, these data offer the first evidence in a lens-injury model that canonical Wnt may synergize with TGFβ signaling to drive fibrotic posterior capsular opacification (PCO).
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Affiliation(s)
- Yichen Wang
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Priyha Mahesh
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Yan Wang
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Samuel G Novo
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Mahbubul H Shihan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | | | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States.
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30
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Sartaj R, Zhang C, Wan P, Pasha Z, Guaiquil V, Liu A, Liu J, Luo Y, Fuchs E, Rosenblatt MI. Characterization of slow cycling corneal limbal epithelial cells identifies putative stem cell markers. Sci Rep 2017. [PMID: 28630424 PMCID: PMC5476663 DOI: 10.1038/s41598-017-04006-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In order to identify reliable markers of corneal epithelial stem cells, we employed an inducible transgenic “pulse-chase” murine model (K5Tta × TRE-H2BGFP) to localize, purify, and characterize slow cycling cells in the cornea. The retention of GFP labeling in slowly dividing cells allowed for localization of these cells to the corneal limbus and their subsequent purification by FACS. Transcriptome analysis from slow cycling cells identified differentially expressed genes when comparing to GFP- faster-dividing cells. RNA-Seq data from corneal epithelium were compared to epidermal hair follicle stem cell RNA-Seq to identify genes representing common putative stem cell markers or determinants, which included Sox9, Fzd7, Actn1, Anxa3 and Krt17. Overlapping retention of GFP and immunohistochemical expression of Krt15, ΔNp63, Sox9, Actn1, Fzd7 and Krt17 were observed in our transgenic model. Our analysis presents an array of novel genes as putative corneal stem cell markers.
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Affiliation(s)
- R Sartaj
- University of Illinois, Chicago, USA
| | - C Zhang
- Weill Cornell Medical College, New York, USA
| | - P Wan
- Weill Cornell Medical College, New York, USA
| | - Z Pasha
- University of Illinois, Chicago, USA
| | | | - A Liu
- Weill Cornell Medical College, New York, USA
| | - J Liu
- Weill Cornell Medical College, New York, USA
| | - Y Luo
- University of Illinois, Chicago, USA
| | - E Fuchs
- The Rockefeller University, New York, USA
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31
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Afsharkhamseh N, Ghahari E, Eslani M, Djalilian AR. A Simple Mechanical Procedure to Create Limbal Stem Cell Deficiency in Mouse. J Vis Exp 2016. [PMID: 27911382 DOI: 10.3791/54658] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Limbal stem cell deficiency (LSCD) is a state of malfunction or loss of limbal epithelial stem cells, after which the corneal epithelium is replaced with conjunctiva. Patients suffer from recurrent corneal defects, pain, inflammation, and loss of vision. Previously, a murine model of LSCD was described and compared to two other models. The goal was to produce a consistent mouse model of LSCD that both mimics the phenotype in humans and lasts long enough to make it possible to study the disease pathophysiology and to evaluate new treatments. Here, the technique is described in more detail. A motorized tool with a rotating burr has been designed to remove the rust rings from the corneal surface or to smooth the pterygium bed in patients. It is a suitable device to create the desired LSCD model. It is a readily available, easy-to-use tool with a fine tip that makes it appropriate for working on small eyes, as in mice. Its application prevents unnecessary trauma to the eye and it does not result in unwanted injuries, as often is the case with chemical injury models. As opposed to a blunt scraper, it removes the epithelium with the basement membrane. In this protocol, the limbal area was abraded two times, and then the whole corneal epithelium was shaved from limbus to limbus. To avoid stroma injury, care was taken not to brush the corneal surface once the epithelium was already removed.
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Affiliation(s)
- Neda Afsharkhamseh
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago
| | - Elham Ghahari
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago
| | - Medi Eslani
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago
| | - Ali R Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago;
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32
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Rossen J, Amram A, Milani B, Park D, Harthan J, Joslin C, McMahon T, Djalilian A. Contact Lens-induced Limbal Stem Cell Deficiency. Ocul Surf 2016; 14:419-434. [PMID: 27480488 PMCID: PMC5065783 DOI: 10.1016/j.jtos.2016.06.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/28/2016] [Accepted: 06/30/2016] [Indexed: 12/15/2022]
Abstract
Limbal stem cell deficiency (LSCD) is a pathologic condition caused by the dysfunction and/or destruction of stem cell precursors of the corneal epithelium, typified clinically by corneal conjunctivalization. The purpose of this review is to critically discuss a less well-known cause of limbal stem cell disease: contact lens (CL) wear. A literature search was conducted to include original articles containing patients with CL-induced LSCD. This review describes epidemiology, diagnostic strategies, pathogenesis, differential diagnosis, and treatment modalities for this condition.
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Affiliation(s)
- Jennifer Rossen
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Alec Amram
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Behrad Milani
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Dongwook Park
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Jennifer Harthan
- Illinois College of Optometry, Illinois Eye Institute, Chicago, IL, USA
| | - Charlotte Joslin
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Timothy McMahon
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Ali Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA.
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Douvaras P, Dorà NJ, Mort RL, Lodge EJ, Hill RE, West JD. Abnormal corneal epithelial maintenance in mice heterozygous for the micropinna microphthalmia mutation Mp. Exp Eye Res 2016; 149:26-39. [PMID: 27235794 PMCID: PMC4974241 DOI: 10.1016/j.exer.2016.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/26/2016] [Accepted: 05/23/2016] [Indexed: 01/06/2023]
Abstract
We investigated the corneal morphology of adult Mp/+ mice, which are heterozygous for the micropinna microphthalmia mutation, and identified several abnormalities, which implied that corneal epithelial maintenance was abnormal. The Mp/+ corneal epithelium was thin, loosely packed and contained goblet cells in older mice. Evidence also suggested that the barrier function was compromised. However, there was no major effect on corneal epithelial cell turnover and mosaic patterns of radial stripes indicated that radial cell movement was normal. Limbal blood vessels formed an abnormally wide limbal vasculature ring, K19-positive cells were distributed more widely than normal and K12 was weakly expressed in the peripheral cornea. This raises the possibilities that the limbal-corneal boundary was poorly defined or the limbus was wider than normal. BrdU label-retaining cell numbers and quantitative clonal analysis suggested that limbal epithelial stem cell numbers were not depleted and might be higher than normal. However, as corneal epithelial homeostasis was abnormal, it is possible that Mp/+ stem cell function was impaired. It has been shown recently that the Mp mutation involves a chromosome 18 inversion that disrupts the Fbn2 and Isoc1 genes and produces an abnormal, truncated fibrillin-2MP protein. This abnormal protein accumulates in the endoplasmic reticulum (ER) of cells that normally express Fbn2 and causes ER stress. It was also shown that Fbn2 is expressed in the corneal stroma but not the corneal epithelium, suggesting that the presence of truncated fibrillin-2MP protein in the corneal stroma disrupts corneal epithelial homeostasis in Mp/+ mice. Heterozygous mutant Mp/+ mice have small, abnormal eyes. The corneal epithelium is thin, loosely packed and has goblet cells. Corneal epithelial cell turnover and radial cell movement appear normal. The cornea-limbal border is poorly defined and the limbus appears wider than normal. Indirect tests suggest stem cells are not depleted and numbers might be increased.
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Affiliation(s)
- Panagiotis Douvaras
- Genes and Development Group, Centre for Integrative Physiology, Clinical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Natalie J Dorà
- Genes and Development Group, Centre for Integrative Physiology, Biomedical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Richard L Mort
- Genes and Development Group, Centre for Integrative Physiology, Clinical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Emily J Lodge
- Genes and Development Group, Centre for Integrative Physiology, Clinical Sciences, 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
| | - John D West
- Genes and Development Group, Centre for Integrative Physiology, Clinical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.
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Chang JH, Putra I, Huang YH, Chang M, Han K, Zhong W, Gao X, Wang S, Dugas-Ford J, Nguyen T, Hong YK, Azar DT. Limited versus total epithelial debridement ocular surface injury: Live fluorescence imaging of hemangiogenesis and lymphangiogenesis in Prox1-GFP/Flk1::Myr-mCherry mice. Biochim Biophys Acta Gen Subj 2016; 1860:2148-56. [PMID: 27233452 DOI: 10.1016/j.bbagen.2016.05.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/04/2016] [Accepted: 05/20/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND Immunohistochemical staining experiments have shown that both hemangiogenesis and lymphangiogenesis occur following severe corneal and conjunctival injury and that the neovascularization of the cornea often has severe visual consequences. To better understand how hemangiogenesis and lymphangiogenesis are induced by different degrees of ocular injury, we investigated patterns of injury-induced corneal neovascularization in live Prox1-GFP/Flk1::myr-mCherry mice, in which blood and lymphatic vessels can be imaged simultaneously in vivo. METHODS The eyes of Prox1-GFP/Flk1::myr-mCherry mice were injured according to four models based on epithelial debridement of the: A) central cornea (a 1.5-mm-diameter circle of tissue over the corneal apex), B) total cornea, C) bulbar conjunctiva, and D) cornea+bulbar conjunctiva. Corneal blood and lymphatic vessels were imaged on days 0, 3, 7, and 10 post-injury, and the percentages of the cornea containing blood and lymphatic vessels were calculated. RESULTS Neither central corneal nor bulbar conjunctival debridement resulted in significant vessel growth in the mouse cornea, whereas total corneal and corneal+bulbar conjunctival debridement did. On day 10 in the central cornea, total cornea, bulbar conjunctiva, and corneal+bulbar conjunctival epithelial debridement models, the percentage of the corneal surface that was occupied by blood vessels (hemangiogenesis) was 1.9±0.8%, 7.14±2.4%, 2.29±1%, and 15.05±2.14%, respectively, and the percentage of the corneal surface that was occupied by lymphatic vessels (lymphangiogenesis) was 2.45±1.51%, 4.85±0.95%, 2.95±1.27%, and 4.15±3.85%, respectively. CONCLUSIONS Substantial corneal debridement was required to induce corneal neovascularization in the mouse cornea, and the corneal epithelium may therefore be partially responsible for maintaining corneal avascularity. GENERAL SIGNIFICANCE Our study demonstrates that GFP/Flk1::myr-mCherry mice are a useful model for studying coordinated hemangiogenic and lymphangiogenic responses.
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Affiliation(s)
- Jin-Hong Chang
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.
| | - Ilham Putra
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Yu-Hui Huang
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Michael Chang
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Kyuyeon Han
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Wei Zhong
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Xinbo Gao
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Shuangyong Wang
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Jennifer Dugas-Ford
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Tara Nguyen
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Young-Kwon Hong
- Department of Surgery, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Dimitri T Azar
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.
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35
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Ma H, Qi C, Cheng C, Yang Z, Cao H, Yang Z, Tong J, Yao X, Lei Z. AIE-Active Tetraphenylethylene Cross-Linked N-Isopropylacrylamide Polymer: A Long-Term Fluorescent Cellular Tracker. ACS APPLIED MATERIALS & INTERFACES 2016; 8:8341-8348. [PMID: 26966832 DOI: 10.1021/acsami.5b11091] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
There is a great demand to understand cell transplantation, migration, division, fusion, and lysis. Correspondingly, illuminant object-labeled bioprobes have been employed as long-term cellular tracers, which could provide valuable insights into detecting these biological processes. In this work, we designed and synthesized a fluorescent polymer, which was comprised of hydrophilic N-isopropylacrylamide polymers as matrix and a hydrophobic tetraphenylethene (TPE) unit as AIE-active cross-linkers (DDBV). It was found that when the feed molar ratio of N-isopropylacrylamides to cross-linkers was 22:1, the produced polymers demonstrated the desirable LCST at 37.5 °C. And also, the temperature sensitivity of polymers could induce phase transfer within a narrow window (32-38 °C). Meanwhile, phase transfer was able to lead the florescent response. And thus, we concluded that two responses occur when one stimulus is input. Therefore, the new cross-linker of DDBV rendered a new performance from PNIPAm and a new chance to create new materials. Moreover, the resulted polymers demonstrated very good biocompatibility with living A549 human lung adenocarcinoma cells and L929 mouse fibroblast cells, respectively. Both of these cells retained very active viabilities in the concentration range of 7.8-125 μL/mg of polymers. Notably, P[(NIPAm)22-(DDBV)1] (P6) could be readily internalized by living cells with a noninvasive manner. The cellular staining by the fluorescent polymer is so indelible that it enables cell tracing for at least 10 passages.
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Affiliation(s)
- Hengchang Ma
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Chunxuan Qi
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Chao Cheng
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Zengming Yang
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Haiying Cao
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Zhiwang Yang
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Jinhui Tong
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Xiaoqiang Yao
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
| | - Ziqiang Lei
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University , Lanzhou, Gansu 730070, China
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Pajoohesh‐Ganji A, Pal‐Ghosh S, Tadvalkar G, Stepp MA. K14 + compound niches are present on the mouse cornea early after birth and expand after debridement wounds. Dev Dyn 2015; 245:132-43. [PMID: 26515029 PMCID: PMC4715603 DOI: 10.1002/dvdy.24365] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/22/2015] [Accepted: 10/23/2015] [Indexed: 12/31/2022] Open
Abstract
Background: We previously identified compound niches (CNs) at the limbal:corneal border of the mouse cornea that contain corneal epithelial progenitor cells, express Keratin 8 (K8), and goblet cell mucin Muc5AC. During re‐epithelialization after 2.5 mm epithelial debridement wounds, CNs migrate onto the cornea and expand in number mimicking conjunctivalization. When CNs form during development and whether they express corneal epithelial progenitor cell enriched K14 was not known. Results: To provide insight into corneal epithelial homeostasis, we quantify changes in expression of simple (K8, K18, K19) and stratified squamous epithelial keratins (K5, K12, K14, and K15) during postnatal development and in response to 2.5 mm wounds using quantitative polymerase chain reaction (Q‐PCR), confocal imaging and immunoblots. K14 + CNs are present 7 days after birth. By 21 days, when the eyelids are open, K8, K19, and Muc5AC are also expressed in CNs. By 28 days after wounding, the corneal epithelium shows enhanced mRNA and protein expression for K14 and retains mRNA and protein for corneal epithelial specific K12. Conclusions: The keratin phenotype observed in corneal epithelial cells before eyelid opening is similar to that seen during wound healing. Data show K14 + corneal epithelial progenitor cells expand in number after 2.5 mm wounds. Developmental Dynamics 245:132–143, 2016. © 2015 The Authors. Developmental Dynamics published by Wiley Periodicals, Inc. The first report of three-dimensional imaging of palatal muscles during development in humans. Detailed development of the levator veli palatini (LVP). Implications for the relationship between the innervation of the LVP and velopharyngeal dysfunction after palatoplasty.
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Affiliation(s)
- Ahdeah Pajoohesh‐Ganji
- Department of Anatomy and Regenerative BiologyThe George Washington University Medical SchoolWashingtonDC
| | - Sonali Pal‐Ghosh
- Department of Anatomy and Regenerative BiologyThe George Washington University Medical SchoolWashingtonDC
| | - Gauri Tadvalkar
- Department of Anatomy and Regenerative BiologyThe George Washington University Medical SchoolWashingtonDC
| | - Mary Ann Stepp
- Department of Anatomy and Regenerative BiologyThe George Washington University Medical SchoolWashingtonDC
- Department of OphthalmologyThe George Washington University Medical SchoolWashingtonDC
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Afsharkhamseh N, Movahedan A, Gidfar S, Huvard M, Wasielewski L, Milani BY, Eslani M, Djalilian AR. Stability of limbal stem cell deficiency after mechanical and thermal injuries in mice. Exp Eye Res 2015; 145:88-92. [PMID: 26607808 DOI: 10.1016/j.exer.2015.11.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 12/15/2022]
Abstract
We studied the reproducibility and stability of limbal stem cell deficiency (LSCD) in mice following controlled injuries to the corneal and limbal epithelia. In one method, corneal and limbal epithelia were entirely removed with a 0.5 mm metal burr. In the other, limbus to limbus epithelial removal with the burr was followed by thermal injury to the limbus. These two methods were compared with a previously published one. Unwounded corneas were used as control. The corneas were examined monthly for three months by slit lamp with fluorescein staining. Immunofluorescence staining for cytokeratin 12 and 8 on corneal wholemount and cross sections were performed to determine the phenotype of the epithelium. Mechanical shaving of the epithelium, with or without thermal injury, resulted in a reproducible state of LSCD marked by superficial neovascularization, reduce of keratin 12 expression and presence of goblet cells on the cornea. The phenotype was stable in 100% of the eyes up to at least three months. Thermal injury produced a more severe phenotype with more significant stromal opacification. These corneal injury models may be useful for studying the mechanisms leading to limbal stem cell deficiency.
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Affiliation(s)
- Neda Afsharkhamseh
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
| | - Asadolah Movahedan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
| | - Sanaz Gidfar
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
| | - Michael Huvard
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
| | - Lisa Wasielewski
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
| | - Behrad Y Milani
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
| | - Medi Eslani
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA
| | - Ali R Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, USA.
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Moving epithelia: Tracking the fate of mammalian limbal epithelial stem cells. Prog Retin Eye Res 2015; 48:203-25. [DOI: 10.1016/j.preteyeres.2015.04.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 04/10/2015] [Accepted: 04/16/2015] [Indexed: 12/13/2022]
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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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McCauley HA, Liu CY, Attia AC, Wikenheiser-Brokamp KA, Zhang Y, Whitsett JA, Guasch G. TGFβ signaling inhibits goblet cell differentiation via SPDEF in conjunctival epithelium. Development 2014; 141:4628-39. [PMID: 25377551 DOI: 10.1242/dev.117804] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The ocular surface epithelia, including the stratified but non-keratinized corneal, limbal and conjunctival epithelium, in concert with the epidermal keratinized eyelid epithelium, function together to maintain eye health and vision. Abnormalities in cellular proliferation or differentiation in any of these surface epithelia are central in the pathogenesis of many ocular surface disorders. Goblet cells are important secretory cell components of various epithelia, including the conjunctiva; however, mechanisms that regulate goblet cell differentiation in the conjunctiva are not well understood. Herein, we report that conditional deletion of transforming growth factor β receptor II (Tgfbr2) in keratin 14-positive stratified epithelia causes ocular surface epithelial hyperplasia and conjunctival goblet cell expansion that invaginates into the subconjunctival stroma in the mouse eye. We found that, in the absence of an external phenotype, the ocular surface epithelium develops properly, but young mice displayed conjunctival goblet cell expansion, demonstrating that TGFβ signaling is required for normal restriction of goblet cells within the conjunctiva. We observed increased expression of SAM-pointed domain containing ETS transcription factor (SPDEF) in stratified conjunctival epithelial cells in Tgfbr2 cKO mice, suggesting that TGFβ restricted goblet cell differentiation directly by repressing Spdef transcription. Gain of function of Spdef in keratin 14-positive epithelia resulted in the ectopic formation of goblet cells in the eyelid and peripheral cornea in adult mice. We found that Smad3 bound two distinct sites on the Spdef promoter and that treatment of keratin 14-positive cells with TGFβ inhibited SPDEF activation, thereby identifying a novel mechanistic role for TGFβ in regulating goblet cell differentiation.
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Affiliation(s)
- Heather A McCauley
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnett Avenue, Cincinnati, OH 45229, USA
| | - Chia-Yang Liu
- Department of Ophthalmology, Edith J. Crawley Vision Research Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Aria C Attia
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnett Avenue, Cincinnati, OH 45229, USA
| | - Kathryn A Wikenheiser-Brokamp
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnett Avenue, Cincinnati, OH 45229, USA Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center and University of Cincinnati, 3333 Burnett Avenue, Cincinnati, OH 45229, USA
| | - Yujin Zhang
- Department of Ophthalmology, Edith J. Crawley Vision Research Center, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jeffrey A Whitsett
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnett Avenue, Cincinnati, OH 45229, USA
| | - Géraldine Guasch
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnett Avenue, Cincinnati, OH 45229, USA
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Manthey AL, Terrell AM, Wang Y, Taube JR, Yallowitz AR, Duncan MK. The Zeb proteins δEF1 and Sip1 may have distinct functions in lens cells following cataract surgery. Invest Ophthalmol Vis Sci 2014; 55:5445-55. [PMID: 25082886 DOI: 10.1167/iovs.14-14845] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Posterior capsular opacification (PCO), the most prevalent side effect of cataract surgery, occurs when residual lens epithelial cells (LECs) undergo fiber cell differentiation or epithelial-to-mesenchymal transition (EMT). Here, we used a murine cataract surgery model to investigate the role of the Zeb proteins, Smad interacting protein 1 (Sip1) and δ-crystallin enhancer-binding factor 1 (δEF1), during PCO. METHODS Extracapsular extraction of lens fiber cells was performed on wild-type and Sip1 knockout mice. Protein expression patterns were assessed at multiple time points after surgery using confocal immunofluorescence. βB1-Crystallin mRNA levels were measured using quantitative RT-PCR. We used Transfac searches to identify δEF1 binding sites in the βB1-crystallin promoter and transfection analysis to test the ability of δEF1 to regulate βB1-crystallin expression. RESULTS δEF1, which, in other systems, can activate fibrotic genes (e.g., α-smooth muscle actin) and repress epithelial genes, upregulates by 48 hours after fiber cell removal. In culture, δEF1 repressed βB1-crystallin promoter activity, suggesting that it may also turn off lens gene expression following surgery, contributing to "fibrotic PCO" development. Sip1 also upregulates in LECs by 48 hours, but analysis of Sip1 knockout lenses demonstrated that Sip1 does not play a major role in EMT or fiber cell differentiation after surgery. However, Sip1 knockout LECs do express the ectodermal marker keratin 8, suggesting that Sip1 may limit the reprogramming of residual LECs to an embryonic state. CONCLUSIONS Zeb transcription factors likely play important, but distinct roles in PCO development after cataract surgery.
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Affiliation(s)
- Abby L Manthey
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Anne M Terrell
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Yan Wang
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Jennifer R Taube
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Alisha R Yallowitz
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
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Medically reversible limbal stem cell disease: clinical features and management strategies. Ophthalmology 2014; 121:2053-8. [PMID: 24908203 DOI: 10.1016/j.ophtha.2014.04.025] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 02/18/2014] [Accepted: 04/21/2014] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To describe the clinical features and management strategies in patients whose limbal stem cell (LSC) disease reversed with medical therapy. DESIGN Retrospective case series. PARTICIPANTS Twenty-two eyes of 15 patients seen at 3 tertiary referral centers between 2007 and 2011 with 3 months or more of follow-up. METHODS Medical records of patients with medically reversible LSC disease were reviewed. Demographic data, causes, location and duration of disease, and medical inventions were analyzed. MAIN OUTCOME MEASURES Primary outcomes assessed included resolution of signs of LSC disease and improvement in visual acuity. RESULTS Causes of the LSC disease included contact lens wear only (13 eyes), contact lens wear in the setting of ocular rosacea (3 eyes), benzalkonium chloride toxicity (2 eyes), and idiopathic (4 eyes). Ophthalmologic findings included loss of limbal architecture, a whorl-like epitheliopathy, or an opaque epithelium arising from the limbus with late fluorescein staining. The superior limbus was the most common site of involvement (95%). The corneal epithelial phenotype returned to normal with only conservative measures, including lubrication and discontinuing contact lens wear in 4 patients (4 eyes), whereas in 11 patients (18 eyes), additional interventions were required after at least 3 months of conservative therapy. Medical interventions included topical corticosteroids, topical cyclosporine, topical vitamin A, oral doxycycline, punctal occlusion, or a combination thereof. All eyes achieved a stable ocular surface over a mean follow-up of 15 months (range, 4-60 months). Visual acuity improved from a mean of 20/42 to 20/26 (P < 0.0184). CONCLUSIONS Disturbances to the LSC function, niche, or both may be reversible with medical therapy. These cases, which represent a subset of patients with LSC deficiency, may be considered to have LSC niche dysfunction.
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Stepp MA, Zieske JD, Trinkaus-Randall V, Kyne BM, Pal-Ghosh S, Tadvalkar G, Pajoohesh-Ganji A. Wounding the cornea to learn how it heals. Exp Eye Res 2014; 121:178-93. [PMID: 24607489 DOI: 10.1016/j.exer.2014.02.007] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 02/07/2014] [Accepted: 02/10/2014] [Indexed: 12/12/2022]
Abstract
Corneal wound healing studies have a long history and rich literature that describes the data obtained over the past 70 years using many different species of animals and methods of injury. These studies have lead to reduced suffering and provided clues to treatments that are now helping patients live more productive lives. In spite of the progress made, further research is required since blindness and reduced quality of life due to corneal scarring still happens. The purpose of this review is to summarize what is known about different types of wound and animal models used to study corneal wound healing. The subject of corneal wound healing is broad and includes chemical and mechanical wound models. This review focuses on mechanical injury models involving debridement and keratectomy wounds to reflect the authors' expertise.
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Affiliation(s)
- Mary Ann Stepp
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA; Department of Ophthalmology, The George Washington University Medical Center, Washington, DC 20037, USA.
| | - James D Zieske
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114-2500, USA
| | - Vickery Trinkaus-Randall
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA 02118, USA; Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Briana M Kyne
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Sonali Pal-Ghosh
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Gauri Tadvalkar
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
| | - Ahdeah Pajoohesh-Ganji
- Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA
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Figus M, Nardi M, Piaggi P, Sartini M, Guidi G, Martini L, Lazzeri S. Bimatoprost 0.01% vs bimatoprost 0.03%: a 12-month prospective trial of clinical and in vivo confocal microscopy in glaucoma patients. Eye (Lond) 2014; 28:422-9. [PMID: 24434659 DOI: 10.1038/eye.2013.304] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 11/19/2013] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To evaluate the safety of two commercially available formulations of bimatoprost eye drops: 0.03 and 0.01% ophthalmic solutions. METHODS This was a randomized, prospective, parallel-group, open-label, cohort study. A total of 60 glaucoma patients (60 eyes) under bimatoprost 0.03% monotherapy since at least 1 year were enrolled. Selected patients were randomized to receive a single drop of bimatoprost 0.01% (n=30) or bimatoprost 0.03% (n=30) ophthalmic solutions for 12 months. Statistical analysis was performed using paired t-test and repeated measures ANOVA test. RESULTS Global clinical score (the sum of pruritus, stinging/burning, blurred vision, sticky eye sensation, eye dryness sensation, and foreign body sensation) significantly decreased in the bimatoprost 0.01% group from baseline 4.7 ± 3.8 to 2.9 ± 2.3 (P < 0.001) and 2.5 ± 2.0 (P < 0.001) at 6-month and 12-month follow-ups, respectively. Comparison between groups showed differences at both follow-up visits (P = 0.003 and P < 0.001, respectively). In vivo confocal microscopy revealed a significant increase in goblet cell density in the bimatoprost 0.01% group compared with the bimatoprost 0.03% group (P<0.001 at both follow-up visits). All functional parameters and conjunctival hyperemia improved in the bimatoprost 0.01% group at each follow-up visit (P < 0.05) and in comparison with bimatoprost 0.03% (P < 0.05). CONCLUSION The results of this trial suggest that bimatoprost 0.01% eye drops seem to decrease the ocular discomfort with respect to bimatoprost 0.03% eye drops.
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Affiliation(s)
- M Figus
- Ophthalmology Unit, Department of Surgical, Medical and Molecular Pathology, and Critical Area, University of Pisa, Pisa, Italy
| | - M Nardi
- Ophthalmology Unit, Department of Surgical, Medical and Molecular Pathology, and Critical Area, University of Pisa, Pisa, Italy
| | - P Piaggi
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - M Sartini
- Ophthalmology Unit, Department of Surgical, Medical and Molecular Pathology, and Critical Area, University of Pisa, Pisa, Italy
| | - G Guidi
- Ophthalmology Unit, Department of Surgical, Medical and Molecular Pathology, and Critical Area, University of Pisa, Pisa, Italy
| | - L Martini
- Ophthalmology Unit, Department of Surgical, Medical and Molecular Pathology, and Critical Area, University of Pisa, Pisa, Italy
| | - S Lazzeri
- Ophthalmology Unit, Department of Surgical, Medical and Molecular Pathology, and Critical Area, University of Pisa, Pisa, Italy
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Manthey AL, Lachke SA, FitzGerald PG, Mason RW, Scheiblin DA, McDonald JH, Duncan MK. Loss of Sip1 leads to migration defects and retention of ectodermal markers during lens development. Mech Dev 2013; 131:86-110. [PMID: 24161570 DOI: 10.1016/j.mod.2013.09.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 09/04/2013] [Accepted: 09/11/2013] [Indexed: 12/17/2022]
Abstract
SIP1 encodes a DNA-binding transcription factor that regulates multiple developmental processes, as highlighted by the pleiotropic defects observed in Mowat-Wilson syndrome, which results from mutations in this gene. Further, in adults, dysregulated SIP1 expression has been implicated in both cancer and fibrotic diseases, where it functionally links TGFβ signaling to the loss of epithelial cell characteristics and gene expression. In the ocular lens, an epithelial tissue important for vision, Sip1 is co-expressed with epithelial markers, such as E-cadherin, and is required for the complete separation of the lens vesicle from the head ectoderm during early ocular morphogenesis. However, the function of Sip1 after early lens morphogenesis is still unknown. Here, we conditionally deleted Sip1 from the developing mouse lens shortly after lens vesicle closure, leading to defects in coordinated fiber cell tip migration, defective suture formation, and cataract. Interestingly, RNA-Sequencing analysis on Sip1 knockout lenses identified 190 differentially expressed genes, all of which are distinct from previously described Sip1 target genes. Furthermore, 34% of the genes with increased expression in the Sip1 knockout lenses are normally downregulated as the lens transitions from the lens vesicle to early lens, while 49% of the genes with decreased expression in the Sip1 knockout lenses are normally upregulated during early lens development. Overall, these data imply that Sip1 plays a major role in reprogramming the lens vesicle away from a surface ectoderm cell fate towards that necessary for the development of a transparent lens and demonstrate that Sip1 regulates distinctly different sets of genes in different cellular contexts.
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Affiliation(s)
- Abby L Manthey
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA; Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19716, USA
| | - Paul G FitzGerald
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA 95616, USA
| | - Robert W Mason
- Department of Biomedical Research, Alfred I duPont Hospital for Children, Wilmington, DE 19803, USA
| | - David A Scheiblin
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - John H McDonald
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
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Douvaras P, Mort RL, Edwards D, Ramaesh K, Dhillon B, Morley SD, Hill RE, West JD. Increased corneal epithelial turnover contributes to abnormal homeostasis in the Pax6(+/-) mouse model of aniridia. PLoS One 2013; 8:e71117. [PMID: 23967157 PMCID: PMC3742784 DOI: 10.1371/journal.pone.0071117] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 06/24/2013] [Indexed: 01/09/2023] Open
Abstract
We aimed to test previous predictions that limbal epithelial stem cells (LESCs) are quantitatively deficient or qualitatively defective in Pax6+/− mice and decline with age in wild-type (WT) mice. Consistent with previous studies, corneal epithelial stripe patterns coarsened with age in WT mosaics. Mosaic patterns were also coarser in Pax6+/− mosaics than WT at 15 weeks but not at 3 weeks, which excludes a developmental explanation and strengthens the prediction that Pax6+/− mice have a LESC-deficiency. To investigate how Pax6 genotype and age affected corneal homeostasis, we compared corneal epithelial cell turnover and label-retaining cells (LRCs; putative LESCs) in Pax6+/− and WT mice at 15 and 30 weeks. Limbal BrdU-LRC numbers were not reduced in the older WT mice, so this analysis failed to support the predicted age-related decline in slow-cycling LESC numbers in WT corneas. Similarly, limbal BrdU-LRC numbers were not reduced in Pax6+/− heterozygotes but BrdU-LRCs were also present in Pax6+/− corneas. It seems likely that Pax6+/− LRCs are not exclusively stem cells and some may be terminally differentiated CD31-positive blood vessel cells, which invade the Pax6+/− cornea. It was not, therefore, possible to use this approach to test the prediction that Pax6+/− corneas had fewer LESCs than WT. However, short-term BrdU labelling showed that basal to suprabasal movement (leading to cell loss) occurred more rapidly in Pax6+/− than WT mice. This implies that epithelial cell loss is higher in Pax6+/− mice. If increased corneal epithelial cell loss exceeds the cell production capacity it could cause corneal homeostasis to become unstable, resulting in progressive corneal deterioration. Although it remains unclear whether Pax6+/− mice have LESC-deficiency, we suggest that features of corneal deterioration, that are often taken as evidence of LESC-deficiency, might occur in the absence of stem cell deficiency if corneal homeostasis is destabilised by excessive cell loss.
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Affiliation(s)
- Panagiotis Douvaras
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Richard L. Mort
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Dominic Edwards
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Kanna Ramaesh
- Tennent Institute of Ophthalmology, Gartnaval General Hospital, Glasgow, United Kingdom
| | - Baljean Dhillon
- School of Clinical Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Steven D. Morley
- Division of Health Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Robert E. Hill
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - John D. West
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Chi C, Trinkaus-Randall V. New insights in wound response and repair of epithelium. J Cell Physiol 2013; 228:925-9. [PMID: 23129239 DOI: 10.1002/jcp.24268] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 10/18/2012] [Indexed: 01/26/2023]
Abstract
Epithelial wounds usually heal relatively quickly, but repair may be impaired by environmental stressors, such as hypoxic or diabetic states, rendering patients vulnerable to a number of corneal pathologies. Though this response appears simple, at first, years of research have uncovered the complicated biochemical pathways coordinating the wound healing response. Here, we investigate signaling cascades and individual proteins involved in the corneal epithelium's self-repair. We will explore how an epithelial cell migrates across the wound bed and attaches itself to its new post-injury surroundings, including its neighboring cells and the basement membrane, through focal adhesions and hemidesmosomes. We will also discuss how the cell coordinates this motion physiologically, through calcium signaling and protein phosphorylation, focusing on the communication through purinergic, glutamatergic, and growth factor receptors. Many of these aspects reflect and can be extended to similar epithelial surfaces, and can be used to facilitate wound healing in patients with various underlying pathologies. The collective library of laboratory and clinical research done around the world has demonstrated how important precise regulation of these processes is in order for the injured corneal epithelium to properly heal.
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Affiliation(s)
- Cheryl Chi
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA
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Osei-Bempong C, Figueiredo FC, Lako M. The limbal epithelium of the eye - A review of limbal stem cell biology, disease and treatment. Bioessays 2012; 35:211-9. [DOI: 10.1002/bies.201200086] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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