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Ma R, Li Y, Dong X, Zhang Y, Chen X, Zhang Y, Zou H, Wang Y. PAX6/CXCL14 regulatory axis promotes the repair of corneal injury by enhancing corneal epithelial cell proliferation. J Transl Med 2024; 22:458. [PMID: 38750454 PMCID: PMC11094923 DOI: 10.1186/s12967-024-05270-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 05/02/2024] [Indexed: 05/19/2024] Open
Abstract
BACKGROUND Corneal injuries, often leading to severe vision loss or blindness, have traditionally been treated with the belief that limbal stem cells (LSCs) are essential for repair and homeostasis, while central corneal epithelial cells (CCECs) were thought incapable of such repair. However, our research reveals that CCECs can fully heal and maintain the homeostasis of injured corneas in rats, even without LSCs. We discovered that CXCL14, under PAX6's influence, significantly boosts the stemness, proliferation, and migration of CCECs, facilitating corneal wound healing and homeostasis. This finding introduces CXCL14 as a promising new drug target for corneal injury treatment. METHODS To investigate the PAX6/CXCL14 regulatory axis's role in CCECs wound healing, we cultured human corneal epithelial cell lines with either increased or decreased expression of PAX6 and CXCL14 using adenovirus transfection in vitro. Techniques such as coimmunoprecipitation, chromatin immunoprecipitation, immunofluorescence staining, western blot, real-time PCR, cell colony formation, and cell cycle analysis were employed to validate the axis's function. In vivo, a rat corneal epithelial injury model was developed to further confirm the PAX6/CXCL14 axis's mechanism in repairing corneal damage and maintaining corneal homeostasis, as well as to assess the potential of CXCL14 protein as a therapeutic agent for corneal injuries. RESULTS Our study reveals that CCECs naturally express high levels of CXCL14, which is significantly upregulated by PAX6 following corneal damage. We identified SDC1 as CXCL14's receptor, whose engagement activates the NF-κB pathway to stimulate corneal repair by enhancing the stemness, proliferative, and migratory capacities of CCECs. Moreover, our research underscores CXCL14's therapeutic promise for corneal injuries, showing that recombinant CXCL14 effectively accelerates corneal healing in rat models. CONCLUSION CCECs play a critical and independent role in the repair of corneal injuries and the maintenance of corneal homeostasis, distinct from that of LSCs. The PAX6/CXCL14 regulatory axis is pivotal in this process. Additionally, our research demonstrates that the important function of CXCL14 in corneal repair endows it with the potential to be developed into a novel therapeutic agent for treating corneal injuries.
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Affiliation(s)
- Ruijue Ma
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Nankai University Affiliated Eye Hospital, Tianjin, 300020, China
| | - Yingxi Li
- Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, 300070, China
| | - Xiaoli Dong
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Nankai University Affiliated Eye Hospital, Tianjin, 300020, China
| | - Yiming Zhang
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS8 1UD, UK
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, 300070, China
| | - Xiaosu Chen
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Yue Zhang
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Nankai University Affiliated Eye Hospital, Tianjin, 300020, China
| | - Haohan Zou
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Nankai University Affiliated Eye Hospital, Tianjin, 300020, China
| | - Yan Wang
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Nankai University Affiliated Eye Hospital, Tianjin, 300020, China.
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Duncan MK, Daruich A, Valleix S, Bremond-Gignac D. Reduction of lens size in PAX6-related aniridia. Exp Eye Res 2024; 238:109746. [PMID: 38056551 PMCID: PMC10843565 DOI: 10.1016/j.exer.2023.109746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/08/2023]
Abstract
Heterozygous mutation of PAX6 in humans leads to congenital aniridia (OMIM 106210) which is typified by congenital iris and foveal defects, and later onset glaucoma, aniridic keratopathy, and cataract. Mice heterozygous for Pax6 mutations phenocopy many aspects of aniridia including the iris defects, keratopathy and cataract, although Pax6 mutant mice have small lenses, a phenotype which is not typically reported in human aniridia, perhaps due to difficulties in measuring lens diameter during typical ophthalmic examinations as the lens periphery is shielded by the iris. In order to overcome this, records of patients diagnosed with congenital aniridia between April 2015 and May 2021 at the Necker-Enfants Malades Hospital, and genetically confirmed with a disease-causing PAX6 variant, were retrospectively reviewed for those with normal axial length whose iris defects allowed visualization of the lens margins and corneal diameter to allow calculation of a lens/corneal diameter ratio. This value was compared with values obtained from a cohort of patients with Sjödell grade IV oculocutaneous albinism type 1 (OCA1; OMIM 203100) which allowed visualization of the lens periphery via iris transillumination. This analysis revealed that patients with congenital aniridia had a significantly lower lens/corneal ratio when compared to those with albinism, suggesting that humans haploinsufficient for PAX6, like mice, rats, frogs, and zebrafish, exhibit reductions in lens size.
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Affiliation(s)
- Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.
| | - Alejandra Daruich
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
| | - Sophie Valleix
- INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France; Service de Médecine Génomique des Maladies de Système et d'Organe, APHP Centre, Paris, Université de Paris Cité, Fédération de Génétique et de Médecine Génomique, Hôpital Cochin, 27 rue du Fbg St-Jacques, 75679, Paris, Cedex 14, France
| | - Dominique Bremond-Gignac
- Ophthalmology Department, Necker-Enfants Malades University Hospital, AP-HP, Paris Cité University, Paris, France; INSERM, UMRS1138, Team 17, From Physiopathology of Ocular Diseases to Clinical Development, Sorbonne Paris Cité University, Centre de Recherche des Cordeliers, Paris, France
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Mirjalili Mohanna SZ, Korecki AJ, Simpson EM. rAAV-PHP.B escapes the mouse eye and causes lethality whereas rAAV9 can transduce aniridic corneal limbal stem cells without lethality. Gene Ther 2023; 30:670-684. [PMID: 37072572 PMCID: PMC10506911 DOI: 10.1038/s41434-023-00400-6] [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: 01/06/2023] [Revised: 03/28/2023] [Accepted: 04/05/2023] [Indexed: 04/20/2023]
Abstract
Recently safety concerns have been raised in connection with high doses of recombinant adeno-associated viruses (rAAV). Therefore, we undertook a series of experiments to test viral capsid (rAAV9 and rAAV-PHP.B), dose, and route of administration (intrastromal, intravitreal, and intravenous) focused on aniridia, a congenital blindness that currently has no cure. The success of gene therapy for aniridia may depend on the presence of functional limbal stem cells (LSCs) in the damaged aniridic corneas and whether rAAV can transduce them. Both these concerns were unknown, and thus were also addressed by our studies. For the first time, we report ataxia and lethality after intravitreal or intrastromal rAAV-PHP.B virus injections. We demonstrated virus escape from the eye and transduction of non-ocular tissues by rAAV9 and rAAV-PHP.B capsids. We have also shown that intrastromal and intravitreal delivery of rAAV9 can transduce functional LSCs, as well as all four PAX6-expressing retinal cell types in aniridic eye, respectively. Overall, lack of adverse events and successful transduction of LSCs and retinal cells makes it clear that rAAV9 is the capsid of choice for future aniridia gene therapy. Our finding of rAAV lethality after intraocular injections will be impactful for other researchers developing rAAV-based gene therapies.
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Affiliation(s)
- Seyedeh Zeinab Mirjalili Mohanna
- Centre for Molecular Medicine and Therapeutics at British Columbia Children's Hospital, The University of British Columbia, Vancouver, BC, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada
| | - Andrea J Korecki
- Centre for Molecular Medicine and Therapeutics at British Columbia Children's Hospital, The University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth M Simpson
- Centre for Molecular Medicine and Therapeutics at British Columbia Children's Hospital, The University of British Columbia, Vancouver, BC, Canada.
- Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada.
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4
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Swamynathan SK, Swamynathan S. Corneal epithelial development and homeostasis. Differentiation 2023; 132:4-14. [PMID: 36870804 PMCID: PMC10363238 DOI: 10.1016/j.diff.2023.02.002] [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: 10/26/2022] [Revised: 01/27/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023]
Abstract
The corneal epithelium (CE), the most anterior cellular structure of the eye, is a self-renewing stratified squamous tissue that protects the rest of the eye from external elements. Each cell in this exquisite three-dimensional structure needs to have proper polarity and positional awareness for the CE to serve as a transparent, refractive, and protective tissue. Recent studies have begun to elucidate the molecular and cellular events involved in the embryonic development, post-natal maturation, and homeostasis of the CE, and how they are regulated by a well-coordinated network of transcription factors. This review summarizes the status of related knowledge and aims to provide insight into the pathophysiology of disorders caused by disruption of CE development, and/or homeostasis.
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Affiliation(s)
| | - Sudha Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
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5
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Abdolkarimi D, Cunha DL, Lahne1 M, Moosajee M. PAX6 disease models for aniridia. Indian J Ophthalmol 2022; 70:4119-4129. [PMID: 36453299 PMCID: PMC9940591 DOI: 10.4103/ijo.ijo_316_22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/01/2022] [Accepted: 08/10/2022] [Indexed: 12/12/2022] Open
Abstract
Aniridia is a pan-ocular genetic developmental eye disorder characterized by complete or partial iris and foveal hypoplasia, for which there is no treatment currently. Progressive sight loss can arise from cataracts, glaucoma, and aniridia-related keratopathy, which can be managed conservatively or through surgical intervention. The vast majority of patients harbor heterozygous mutations involving the PAX6 gene, which is considered the master transcription factor of early eye development. Over the past decades, several disease models have been investigated to gain a better understanding of the molecular pathophysiology, including several mouse and zebrafish strains and, more recently, human-induced pluripotent stem cells (hiPSCs) derived from aniridia patients. The latter provides a more faithful cellular system to study early human eye development. This review outlines the main aniridia-related animal and cellular models used to study aniridia and highlights the key discoveries that are bringing us closer to a therapy for patients.
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Affiliation(s)
| | - Dulce Lima Cunha
- UCL Institute of Ophthalmology, London, UK
- Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, Netherlands
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- The Francis Crick Institute, London, UK
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Maiti G, Monteiro de Barros MR, Hu N, Dolgalev I, Roshan M, Foster JW, Tsirigos A, Wahlin KJ, Chakravarti S. Single cell RNA-seq of human cornea organoids identifies cell fates of a developing immature cornea. PNAS NEXUS 2022; 1:pgac246. [PMID: 36712326 PMCID: PMC9802453 DOI: 10.1093/pnasnexus/pgac246] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 10/26/2022] [Indexed: 11/27/2022]
Abstract
The cornea is a protective and refractive barrier in the eye crucial for vision. Understanding the human cornea in health, disease, and cell-based treatments can be greatly advanced with cornea organoids developed in culture from induced pluripotent stem cells. While a limited number of studies have investigated the single-cell transcriptomic composition of the human cornea, its organoids have not been examined similarly. Here, we elucidated the transcriptomic cell fate map of 4-month-old human cornea organoids and human donor corneas. The organoids harbor cell clusters that resemble cells of the corneal epithelium, stroma, and endothelium, with subpopulations that capture signatures of early developmental states. Unlike the adult cornea where the largest cell population is stromal, the organoids contain large proportions of epithelial and endothelial-like cells. These corneal organoids offer a 3D model to study corneal diseases and integrated responses of different cell types.
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Affiliation(s)
- George Maiti
- Department of Ophthalmology, NYU Grossman School of Medicine, Science Building, Fifth Floor 435 E 30th, New York, NY 10016, USA
| | - Maithê Rocha Monteiro de Barros
- Department of Ophthalmology, NYU Grossman School of Medicine, Science Building, Fifth Floor 435 E 30th, New York, NY 10016, USA
| | - Nan Hu
- Department of Ophthalmology, NYU Grossman School of Medicine, Science Building, Fifth Floor 435 E 30th, New York, NY 10016, USA
| | - Igor Dolgalev
- Applied Bioinformatics Laboratories, NYU Grossman School of Medicine, Science Building, Eighth Floor, 435 E 30th, New York, NY 10016, USA
| | - Mona Roshan
- University of California San Diego, ACTRI Building Rm Lower level 3E419, 9452 Medical Center Drive, La Jolla, CA 92037, USA
| | - James W Foster
- Wilmer Eye Institute, Johns Hopkins school of Medicine, Smith M037, 400 Broadway, Baltimore, MD 21287, USA
| | - Aristotelis Tsirigos
- Applied Bioinformatics Laboratories, NYU Grossman School of Medicine, Science Building, Eighth Floor, 435 E 30th, New York, NY 10016, USA,Department of Pathology, NYU Grossman School of Medicine, Science Building, Fifth Floor 435 E 30th, New York, NY 10016, USA
| | - Karl J Wahlin
- University of California San Diego, ACTRI Building Rm Lower level 3E419, 9452 Medical Center Drive, La Jolla, CA 92037, USA
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Wang S, Jaggi U, Ghiasi H. Knockout of signal peptide peptidase in the eye reduces HSV-1 replication and eye disease in ocularly infected mice. PLoS Pathog 2022; 18:e1010898. [PMID: 36215312 PMCID: PMC9584536 DOI: 10.1371/journal.ppat.1010898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 10/20/2022] [Accepted: 09/26/2022] [Indexed: 11/26/2022] Open
Abstract
We previously reported that knocking out signal peptide peptidase (SPP), a glycoprotein K (gK) binding partner, in mouse peripheral sensory neurons reduced latency-reactivation in infected mice without affecting primary virus replication or eye disease. Since virus replication in the eye plays an essential role in eye disease, we generated a conditional knockout mouse lacking SPP expression in the eye by crossing Pax6 (paired box 6)-Cre mice that have intact Pax6 expression with SPPflox/flox mice. Significantly less SPP protein expression was detected in the eyes of Pax6-SPP-/- mice than in WT control mice. HSV-1 replication in the eyes of Pax6-SPP-/- mice was significantly lower than in WT control mice. Levels of gB, gK, and ICP0 transcripts in corneas, but not trigeminal ganglia (TG), of Pax6-SPP-/- infected mice were also significantly lower than in WT mice. Corneal scarring and angiogenesis were significantly lower in Pax6-SPP-/- mice than in WT control mice, while corneal sensitivity was significantly higher in Pax6-SPP-/- mice compared with WT control mice. During acute viral infection, absence of SPP in the eye did not affect CD4 expression but did affect CD8α and IFNγ expression in the eye. However, in the absence of SPP, latency-reactivation was similar in Pax6-SPP-/- and WT control groups. Overall, our results showed that deleting SPP expression in the eyes reduced primary virus replication in the eyes, reduced CD8α and IFNγ mRNA expression, reduced eye disease and reduced angiogenesis but did not alter corneal sensitivity or latency reactivation to HSV-1 infection. Thus, blocking gK binding to SPP in the eye may have therapeutic potential by reducing both virus replication in the eye and eye disease associated with virus replication.
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Affiliation(s)
- Shaohui Wang
- Center for Neurobiology & Vaccine Development, Ophthalmology Research, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Ujjaldeep Jaggi
- Center for Neurobiology & Vaccine Development, Ophthalmology Research, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Homayon Ghiasi
- Center for Neurobiology & Vaccine Development, Ophthalmology Research, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
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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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Ochi S, Manabe S, Kikkawa T, Osumi N. Thirty Years' History since the Discovery of Pax6: From Central Nervous System Development to Neurodevelopmental Disorders. Int J Mol Sci 2022; 23:6115. [PMID: 35682795 PMCID: PMC9181425 DOI: 10.3390/ijms23116115] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/19/2022] [Accepted: 05/27/2022] [Indexed: 12/23/2022] Open
Abstract
Pax6 is a sequence-specific DNA binding transcription factor that positively and negatively regulates transcription and is expressed in multiple cell types in the developing and adult central nervous system (CNS). As indicated by the morphological and functional abnormalities in spontaneous Pax6 mutant rodents, Pax6 plays pivotal roles in various biological processes in the CNS. At the initial stage of CNS development, Pax6 is responsible for brain patterning along the anteroposterior and dorsoventral axes of the telencephalon. Regarding the anteroposterior axis, Pax6 is expressed inversely to Emx2 and Coup-TF1, and Pax6 mutant mice exhibit a rostral shift, resulting in an alteration of the size of certain cortical areas. Pax6 and its downstream genes play important roles in balancing the proliferation and differentiation of neural stem cells. The Pax6 gene was originally identified in mice and humans 30 years ago via genetic analyses of the eye phenotypes. The human PAX6 gene was discovered in patients who suffer from WAGR syndrome (i.e., Wilms tumor, aniridia, genital ridge defects, mental retardation). Mutations of the human PAX6 gene have also been reported to be associated with autism spectrum disorder (ASD) and intellectual disability. Rodents that lack the Pax6 gene exhibit diverse neural phenotypes, which might lead to a better understanding of human pathology and neurodevelopmental disorders. This review describes the expression and function of Pax6 during brain development, and their implications for neuropathology.
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Affiliation(s)
| | | | | | - Noriko Osumi
- Department of Developmental Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; (S.O.); (S.M.); (T.K.)
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Sasamoto Y, Lee CAA, Yoshihara M, Martin G, Ksander BR, Frank MH, Frank NY. High expression of SARS-CoV2 viral entry-related proteins in human limbal stem cells. Ocul Surf 2022; 23:197-200. [PMID: 34653711 PMCID: PMC8511872 DOI: 10.1016/j.jtos.2021.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/24/2021] [Accepted: 10/07/2021] [Indexed: 12/25/2022]
Abstract
PURPOSE Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). While the ocular surface is considered one of the major SARS-CoV2 transmission routes, the specific cellular tropism of SARS-CoV2 is not fully understood. In the current study, we evaluated the expression and regulation of two SARS-CoV2 viral entry proteins, TMPRSS2 and ACE2, in human ocular epithelial cells and stem cells. METHODS TMPRSS2 and ACE2 expression in ABCB5-positive limbal stem cells (LSCs) were assessed by RNAseq, flow cytometry and immunohistochemistry. PAX6, TMPRSS2, and ACE2 mRNA expression values were obtained from the GSE135455 and DRA002960 RNA-seq datasets. siRNA-mediated PAX6 knockdown (KD) was performed in limbal and conjunctival epithelial cells. TMPRSS2 and ACE2 expression in the PAX6 KD cells was analyzed by qRT-PCR and Western blot. RESULTS We found that ABCB5-positive LSCs express high levels of TMPRSS2 and ACE2 compared to ABCB5-negative limbal epithelial cells. Mechanistically, gene knockout and overexpression models revealed that the eye transcription factor PAX6 negatively regulates TMPRSS2 expression. Therefore, low levels of PAX6 in ABCB5-positive LSCs promote TMPRSS2 expression, and high levels of TMPRSS2 and ACE2 expression by LSCs indicate enhanced susceptibility to SARS-CoV2 infection in this stem cell population. CONCLUSIONS Our study points to a need for COVID-19 testing of LSCs derived from donor corneas before transplantation to patients with limbal stem cell deficiency. Furthermore, our findings suggest that expandable human ABCB5+ LSC cultures might represent a relevant novel model system for studying cellular SARS-CoV2 viral entry mechanisms and evaluating related targeting strategies.
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Affiliation(s)
- Yuzuru Sasamoto
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; Transplant Research Program, Boston Children's Hospital, Boston, MA, United States
| | - Catherine A A Lee
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; Transplant Research Program, Boston Children's Hospital, Boston, MA, United States
| | - Masahito Yoshihara
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Gabrielle Martin
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; Transplant Research Program, Boston Children's Hospital, Boston, MA, United States
| | - Bruce R Ksander
- Massachusetts Eye & Ear Infirmary, Schepens Eye Research Institute, Boston, MA, United States
| | - Markus H Frank
- Transplant Research Program, Boston Children's Hospital, Boston, MA, United States; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA; Harvard Skin Disease Research Center, Department of Dermatology, Brigham and Women's Hospital, Boston, MA, USA; School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia
| | - Natasha Y Frank
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, United States; Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA; Department of Medicine, VA Boston Healthcare System, Boston, MA, United States.
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11
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Decreased FABP5 and DSG1 protein expression following PAX6 knockdown of differentiated human limbal epithelial cells. Exp Eye Res 2021; 215:108904. [PMID: 34954205 DOI: 10.1016/j.exer.2021.108904] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 11/22/2022]
Abstract
PAX6 haploinsufficiency related aniridia is characterized by disorder of limbal epithelial cells (LECs) and aniridia related keratopathy. In the limbal epithelial cells of aniridia patients, deregulated retinoic acid (RA) signaling components were identified. We aimed to visualize differentiation marker and RA signaling component expression in LECs, combining a differentiation triggering growth condition with a small interfering RNA (siRNA) based aniridia cell model (PAX6 knock down). Primary LECs were isolated from corneoscleral rims of healthy donors and cultured in serum free low Ca2+ medium (KSFM) and in KSFM supplemented with 0.9 mmol/L Ca2+. In addition, LECs were treated with siRNA against PAX6. DSG1, PAX6, KRT12, KRT 3, ADH7, RDH10, ALDH1A1, ALDH3A1, STRA6, CYP1B1, RBP1, CRABP2, FABP5, PPARG, VEGFA and ELOVL7 expression was determined using qPCR and western blot. DSG1, FABP5, ADH7, ALDH1A1, RBP1, CRABP2 and PAX6 mRNA and FABP5 protein expression increased (p ≤ 0.03), PPARG, CYP1B1 mRNA expression decreased (p ≤ 0.0003) and DSG1 protein expression was only visible after Ca2+ supplementation. After PAX6 knock down and Ca2+ supplementation, ADH7 and ALDH1A1 mRNA and DSG1 and FABP5 protein expression decreased (p ≤ 0.04), compared to Ca2+ supplementation alone. Using our cell model, with Ca2+ supplementation and PAX6 knockdown with siRNA treatment against PAX6, we provide evidence that haploinsufficiency of the master regulatory gene PAX6 contributes to differentiation defect in the corneal epithelium through alterations of RA signalling. Upon PAX6 knockdown, DSG1 differentiation marker and FABP5 RA signaling component mRNA expression decreases. A similar effect becomes apparent at protein level though differentiation triggering Ca2+ supplementation in the siRNA-based aniridia cell model. Expression data from this cell model and from our siRNA aniridia cell model strongly indicate that FABP5 expression is PAX6 dependent. These new findings may lead to a better understanding of differentiation processes in LECs and are able to explain the insufficient cell function in AAK.
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Latta L, Knebel I, Bleil C, Stachon T, Katiyar P, Zussy C, Fries FN, Käsmann-Kellner B, Seitz B, Szentmáry N. Similarities in DSG1 and KRT3 Downregulation through Retinoic Acid Treatment and PAX6 Knockdown Related Expression Profiles: Does PAX6 Affect RA Signaling in Limbal Epithelial Cells? Biomolecules 2021; 11:1651. [PMID: 34827649 PMCID: PMC8615883 DOI: 10.3390/biom11111651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/11/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
Congenital PAX6-aniridia is a rare panocular disease resulting from limbal stem cell deficiency. In PAX6-aniridia, the downregulation of the retinol-metabolizing enzymes ADH7 (All-trans-retinol dehydrogenase 7) and ALDH1A1/A3 (Retinal dehydrogenase 1, Aldehyde dehydrogenase family 1 member A3) have been described in limbal epithelial cells (LECs) and conjunctival epithelial cells. The aim of this study was to identify the role of retinol derivates in the differentiation of human LEC and its potential impact on aniridia-associated keratopathy development. Human LEC were isolated from healthy donor corneas and were cultured with retinol, retinoic acid, or pan-retinoic acid receptor antagonist (AGN 193109) acting on RARα, β, γ (NR1B1, NR1B2 NR1B3) or were cultured with pan-retinoid X receptor antagonist (UVI 3003) acting on RXR α, β, γ (retinoid X receptor, NR2B1, NR2B2, BR2B3). Using qPCR, differentiation marker and retinoid-/fatty acid metabolism-related mRNA expression was analysed. DSG1 (Desmoglein 1), KRT3 (Keratin 3), and SPINK7 (Serine Peptidase Inhibitor Kazal Type 7) mRNA expression was downregulated when retinoid derivates were used. AGN 193109 treatment led to the upregulation of ADH7, KRT3, and DSG1 mRNA expression and to the downregulation of KRT12 (Keratin 12) and KRT19 (Keratin 19) mRNA expression. Retinol and all-trans retinoic acid affect some transcripts of corneal LEC in a similar way to what has been observed in the LEC of PAX6-aniridia patients with the altered expression of differentiation markers. An elevated concentration of retinol derivatives in LEC or an altered response to retinoids may contribute to this pattern. These initial findings help to explain ocular surface epithelia differentiation disorders in PAX6-aniridia and should be investigated in patient cells or in cell models in the future in more detail.
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Affiliation(s)
- Lorenz Latta
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg, Germany; (L.L.); (I.K.); (C.B.); (T.S.); (P.K.); (C.Z.)
| | - Igor Knebel
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg, Germany; (L.L.); (I.K.); (C.B.); (T.S.); (P.K.); (C.Z.)
| | - Constanze Bleil
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg, Germany; (L.L.); (I.K.); (C.B.); (T.S.); (P.K.); (C.Z.)
| | - Tanja Stachon
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg, Germany; (L.L.); (I.K.); (C.B.); (T.S.); (P.K.); (C.Z.)
| | - Priya Katiyar
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg, Germany; (L.L.); (I.K.); (C.B.); (T.S.); (P.K.); (C.Z.)
- Department of Ophthalmology, Saarland University Medical Center, 66421 Homburg, Germany; (F.N.F.); (B.K.-K.); (B.S.)
| | - Claire Zussy
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg, Germany; (L.L.); (I.K.); (C.B.); (T.S.); (P.K.); (C.Z.)
| | - Fabian Norbert Fries
- Department of Ophthalmology, Saarland University Medical Center, 66421 Homburg, Germany; (F.N.F.); (B.K.-K.); (B.S.)
| | - Barbara Käsmann-Kellner
- Department of Ophthalmology, Saarland University Medical Center, 66421 Homburg, Germany; (F.N.F.); (B.K.-K.); (B.S.)
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, 66421 Homburg, Germany; (F.N.F.); (B.K.-K.); (B.S.)
| | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg, Germany; (L.L.); (I.K.); (C.B.); (T.S.); (P.K.); (C.Z.)
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13
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Álvarez de Toledo Elizalde J, López García S, Benítez Del Castillo JM, Durán de la Colina J, Gris Castejón O, Celis Sánchez J, Herreras Cantalapiedra JM. Aniridia and the ocular surface: Medical and surgical problems and solutions. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2021; 96 Suppl 1:15-37. [PMID: 34836585 DOI: 10.1016/j.oftale.2021.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/12/2021] [Indexed: 06/13/2023]
Abstract
Congenital aniridia is a multisystemic genetic disease due to a mutation in PAX6 gene which severely affects the development and functionality of the human eyes. In patients affected by the mutation, aside from the absence or defects of iris tissue formation, abnormalities in position or opacities of the crystalline lens, macular hypoplasia, ocular surface disease is the main cause of visual loss and the deterioration of the quality of life of most patients. Limbal stem cell deficiency combined with tear film instability and secondary dry eye cause aniridic keratopathy which, in advanced stages, ends up in corneal opacification. In this paper, the actual knowledge about congenital aniridia keratopathy physiopathology and medical and surgical treatment options and their efficacy are discussed. Indications and results of topical treatments with artificial tears and blood-derivatives in its initial stages, and different surgical techniques as limbal stem cell transplantation, keratoplasty and keratoprostheses are reviewed. Finally, recent advances and results in regenerative medicine techniques with ex vivo stem cell cultivation or other types of cultivated cells are presented.
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Affiliation(s)
| | - S López García
- Hospital Universitario Severo Ochoa, Leganés, Madrid, Spain
| | - J M Benítez Del Castillo
- Cátedra de Oftalmología, Hospital Clínico San Carlos, Universidad Complutense, Clínica Rementería, Madrid, Spain
| | - J Durán de la Colina
- Cátedra de Oftalmología, Universidad del País Vasco, Instituto Clínico-Quirúrgico de Oftalmología, Bilbao, Spain
| | - O Gris Castejón
- Departamento de Córnea y Superficie Ocular, Instituto de Microcirugía Ocular de Barcelona (IMO), Barcelona, Spain
| | - J Celis Sánchez
- Unidad de Córnea y Superficie ocular, Hospital La Mancha-Centro, Alcázar de San Juan, Spain
| | - J M Herreras Cantalapiedra
- Instituto Universitario de Oftalmobiología Aplicada (IOBA) de la Universidad de Valladolid, Servicio de Oftalmología del Hospital Clínico Universitario de Valladolid, Valladolid, Spain
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14
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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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Abdul-Al M, Kyeremeh GK, Saeinasab M, Heidari Keshel S, Sefat F. Stem Cell Niche Microenvironment: Review. Bioengineering (Basel) 2021; 8:bioengineering8080108. [PMID: 34436111 PMCID: PMC8389324 DOI: 10.3390/bioengineering8080108] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 12/13/2022] Open
Abstract
The cornea comprises a pool of self-regenerating epithelial cells that are crucial to preserving clarity and visibility. Limbal epithelial stem cells (LESCs), which live in a specialized stem cell niche (SCN), are crucial for the survival of the human corneal epithelium. They live at the bottom of the limbal crypts, in a physically enclosed microenvironment with a number of neighboring niche cells. Scientists also simplified features of these diverse microenvironments for more analysis in situ by designing and recreating features of different SCNs. Recent methods for regenerating the corneal epithelium after serious trauma, including burns and allergic assaults, focus mainly on regenerating the LESCs. Mesenchymal stem cells, which can transform into self-renewing and skeletal tissues, hold immense interest for tissue engineering and innovative medicinal exploration. This review summarizes all types of LESCs, identity and location of the human epithelial stem cells (HESCs), reconstruction of LSCN and artificial stem cells for self-renewal.
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Affiliation(s)
- Mohamed Abdul-Al
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD71DP, UK; (M.A.-A.); (G.K.K.)
| | - George Kumi Kyeremeh
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD71DP, UK; (M.A.-A.); (G.K.K.)
| | - Morvarid Saeinasab
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad 91779 48974, Iran;
| | - Saeed Heidari Keshel
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran 19839 69411, Iran;
| | - Farshid Sefat
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD71DP, UK; (M.A.-A.); (G.K.K.)
- Interdisciplinary Research Centre in Polymer Science & Technology (Polymer IRC), University of Bradford, Bradford BD71DP, UK
- Correspondence:
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16
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Fattah IOA, Madani GA, El-Din WAN. Topical onion juice mitigates the morphological alterations of the cornea in the aged male rats. Anat Cell Biol 2021; 54:375-386. [PMID: 34253691 PMCID: PMC8493016 DOI: 10.5115/acb.21.077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 12/05/2022] Open
Abstract
Aging is associated with structural and functional changes of the cornea. Fresh onion juice contains phenolic compounds and flavonoids that may provide an anti-aging effect. The aim of this study was to assess the ability of the onion juice to ameliorate these aging changes. Rats were grouped as adult and aged groups. Rats of both groups received eye drops of diluted onion juice in their right eyes every 8 hours for 12 weeks, while the left ones were served as control eyes. The corneas of both eyes underwent histopathological, immunohistochemical and morphometric assessments, in addition to measuring their intraocular pressure (IOP). The aged group exhibited a significantly elevated IOP, decreased tear secretion, degenerated corneal epithelium and endothelium, surface erosions and stromal edema with irregular collagen fibers. Administration of onion juice led to lowering of IOP, significant increase in tearing, restoration of most of epithelial, endothelial and stromal integrity, and increased epithelial, keratocystic and endothelial cell densities. Immunohistochemically, the epithelium and endothelium revealed positive immune reactions for both epidermal growth factor receptor (EGFR) and paired box protein-6 (PAX6) in the control and onion-treated corneas of the adult group, while these immune reactions were negative in the untreated aged ones. Onion drops in aged corneas showed a positive immune reaction for EFGR and PAX6 involving the epithelial and endothelial layers. In conclusion, topical onion juice improves corneal aging changes through its direct effect, and indirectly through lowering IOP and enhancing tear secretion.
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Affiliation(s)
- Islam Omar Abdel Fattah
- Department of Human Anatomy and Embryology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Gisma Ahmed Madani
- Department of Anatomy, Faculty of Medicine, The National University, Khartoum, Sudan
| | - Wael Amin Nasr El-Din
- Department of Human Anatomy and Embryology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.,Department of Anatomy, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain
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17
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Dysfunction of the limbal epithelial stem cell niche in aniridia-associated keratopathy. Ocul Surf 2021; 21:160-173. [PMID: 34102310 DOI: 10.1016/j.jtos.2021.06.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/22/2021] [Accepted: 06/01/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE Abnormalities in the limbal niche microenvironment have been suggested to be causally involved in aniridia-associated keratopathy (AAK), but histological analyses on the limbal structure and composition in AAK are lacking. Here, we investigated morphologic and molecular alterations of the limbal epithelial stem cell niche in human congenital aniridia. METHODS The blind, buphthalmic and painful left eye of a 16-year old girl with congenital aniridia and juvenile glaucoma had to be enucleated because of uncontrolled intraocular pressure. The diagnosis of AAK was based on classical clinical features and partial limbal stem cell deficiency in the superior half. Genetic analysis identified a large heterozygous PAX6 gene deletion encompassing exons 11-15 as well as exon 9 of the neighboring ELP4 gene. Three limbal biopsies were taken from the superior, nasal and temporal regions to isolate and cultivate limbal epithelial progenitor cells and subject them to mRNA expression analyses. The globe was vertically bisected and processed for light and transmission electron microscopy and immunohistochemistry. RESULTS Comparative analysis of the superior and inferior limbal zones showed a gradual degradation of palisade structures associated with the transition from a hyperplastic to an attenuated corneal epithelium, inflammatory cell infiltrations and basement membrane irregularities. The clinically unaffected inferior part revealed no distinct stem cell clusters in the preserved palisade region, but a uniform population of hyperproliferative, undifferentiated progenitor cells in the basal/suprabasal layers of limbal and corneal epithelia, which gave rise to maldifferentiated epithelial cells exhibiting a conjunctival/epidermal phenotype and nuclear-to-cytoplasmic translocation of Pax6. The structure of the limbal niche was fundamentally perturbed, showing marked alterations in extracellular matrix composition, dislocation of atypical melanocytes lacking melanosomes and melanin, aberrant Wnt/β-catenin and retinoic acid signaling, and massive immune cell infiltration. CONCLUSIONS Considering the limitations of a single Case study, the findings suggest that ocular surface alterations in AAK are caused by a primary dysfunction and gradual breakdown of the limbal stem cell niche through Pax6-related effects on both melanogenesis and epithelial differentiation.
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18
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Pujari R, Deshmukh R, Sheth C, Rajan MS. Maternal finger-prick allogenic blood for persistent corneal epithelial defects. BMJ Case Rep 2021; 14:14/4/e241138. [PMID: 33837031 PMCID: PMC8042995 DOI: 10.1136/bcr-2020-241138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
This is a case of a 17-year-old patient with aniridia-related keratopathy and persistent epithelial defect (PED) treated successfully using maternal finger-prick blood (FPB). Maternal allogenic FPB treatment was initiated to the patient who was non-compliant with the use of autologous FPB. The PED was successfully managed with maternal FPB treatment with rapid and complete closure of the epithelial defect. Additionally, there was immediate and sustained symptomatic improvement to pain and recovery of vision in the only seeing eye. There was no immunological reaction to allogenic blood. Maternal finger-prick allogenic blood could serve as a potential alternative to serum eye drops or autologous FPB in the management of refractory PED, particularly in reference to the paediatric or the vulnerable age group. Further studies are required to confirm the role of allogenic blood in the treatment of PED.
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Affiliation(s)
- Rathin Pujari
- Department of Ophthalmology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Rashmi Deshmukh
- Department of Ophthalmology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Chirag Sheth
- Department of Ophthalmology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Madhavan S Rajan
- Department of Ophthalmology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.,Vision and Eye Research Institute, Anglia Ruskin University, Chelmsford, Essex, UK
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19
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Landsend ECS, Lagali N, Utheim TP. Congenital aniridia - A comprehensive review of clinical features and therapeutic approaches. Surv Ophthalmol 2021; 66:1031-1050. [PMID: 33675823 DOI: 10.1016/j.survophthal.2021.02.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 02/16/2021] [Accepted: 02/23/2021] [Indexed: 12/13/2022]
Abstract
Congenital aniridia is a rare genetic eye disorder with total or partial absence of the iris from birth. In most cases the genetic origin of aniridia is a mutation in the PAX6 gene, leading to involvement of most eye structures. Hypoplasia of the fovea is usually present and is associated with reduced visual acuity and nystagmus. Aniridia-associated keratopathy, glaucoma, and cataract are serious and progressive complications that can further reduce visual function. Treatment of the ocular complications of aniridia is challenging and has a high risk of side effects. New approaches such as stem cell therapy may, however, offer better prognoses. We describe the various ocular manifestations of aniridia, with a special focus on conditions that commonly require treatment. We also review the growing literature reporting systemic manifestations of the disease.
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Affiliation(s)
| | - Neil Lagali
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Tor P Utheim
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway; Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
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20
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Tiwari A, Swamynathan S, Campbell G, Jhanji V, Swamynathan SK. BMP6 Regulates Corneal Epithelial Cell Stratification by Coordinating Their Proliferation and Differentiation and Is Upregulated in Pterygium. Invest Ophthalmol Vis Sci 2021; 61:46. [PMID: 32845956 PMCID: PMC7452852 DOI: 10.1167/iovs.61.10.46] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose Proper balance between cell proliferation and differentiation is essential for corneal epithelial (CE) stratification and homeostasis. Although bone morphogenetic protein-6 (BMP6) is known to be expressed in the CE for over 25 years, its function in this tissue remains unknown. Here, we test the hypothesis that BMP6 promotes CE cell stratification and homeostasis by regulating their proliferation and differentiation. Methods We employed postnatal day-12 (PN-12), PN-14, PN-20, and PN-90 mouse eyes; human corneal limbal epithelial (HCLE) cells; and ocular surface fibrovascular disease pterygium tissues to evaluate the role of BMP6 in CE proliferation, differentiation, and pathology by RT-qPCR, immunoblots, and/or immunofluorescent staining. Cell proliferation was quantified by immunostaining for Ki67. Results Coincident with the mouse CE stratification between PN-12 and PN-20, BMP6 was significantly upregulated and the BMP6 antagonist Noggin downregulated. Mature CE retained high BMP6 and low Noggin expression at PN-90. BMP6 and its receptors BMPR1A and BMPR2 were upregulated during in vitro stratification of HCLE cells. Consistent with its anti-proliferative role, exogenous BMP6 suppressed HCLE cell proliferation, downregulated cyclin-D1 and cyclin-D2, and upregulated cell-cycle inhibitors Krüppel-like factor 4 (KLF4) and p21. BMP6 also upregulated the desmosomal cadherins desmoplakin and desmoglein in HCLE cells, consistent with its pro-differentiation role. Human pterygium displayed significant upregulation of BMP6 coupled with downregulation of Noggin and cell-cycle suppressors KLF4 and p21. Conclusions BMP6 coordinates CE stratification and homeostasis by regulating their proliferation and differentiation. BMP6 is significantly upregulated in human pterygium concurrent with downregulation of Noggin, KLF4, and p21.
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Affiliation(s)
- Anil Tiwari
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Sudha Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Gregory Campbell
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Shivalingappa K Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
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21
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Rabiee B, Anwar KN, Shen X, Putra I, Liu M, Jung R, Afsharkhamseh N, Rosenblatt MI, Fishman GA, Liu X, Ghassemi M, Djalilian AR. Gene dosage manipulation alleviates manifestations of hereditary PAX6 haploinsufficiency in mice. Sci Transl Med 2020; 12:eaaz4894. [PMID: 33298563 DOI: 10.1126/scitranslmed.aaz4894] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 04/16/2020] [Accepted: 09/04/2020] [Indexed: 12/15/2022]
Abstract
In autosomal dominant conditions with haploinsufficiency, a single functional allele cannot maintain sufficient dosage for normal function. We hypothesized that pharmacologic induction of the wild-type allele could lead to gene dosage compensation and mitigation of the disease manifestations. The paired box 6 (PAX6) gene is crucial in tissue development and maintenance particularly in eye, brain, and pancreas. Aniridia is a panocular condition with impaired eye development and limited vision due to PAX6 haploinsufficiency. To test our hypothesis, we performed a chemical screen and found mitogen-activated protein kinase kinase (MEK) inhibitors to induce PAX6 expression in normal and mutant corneal cells. Treatment of newborn Pax6-deficient mice (Pax6Sey-Neu/+ ) with topical or systemic MEK inhibitor PD0325901 led to increased corneal PAX6 expression, improved corneal morphology, reduced corneal opacity, and enhanced ocular function. These results suggest that induction of the wild-type allele by drug repurposing is a potential therapeutic strategy for haploinsufficiencies, which is not limited to specific mutations.
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Affiliation(s)
- Behnam Rabiee
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Khandaker N Anwar
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Xiang Shen
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Ilham Putra
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Mingna Liu
- Departments of Biology and Psychology, University of Virginia, Charlottesville, VA 22903, USA
| | - Rebecca Jung
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Neda Afsharkhamseh
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Mark I Rosenblatt
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Gerald A Fishman
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, IL 60608, USA
| | - Xiaorong Liu
- Departments of Biology and Psychology, University of Virginia, Charlottesville, VA 22903, USA
| | - Mahmood Ghassemi
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Ali R Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA.
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Morphometric analysis of the lens in human aniridia and mouse Small eye. Exp Eye Res 2020; 203:108371. [PMID: 33248069 DOI: 10.1016/j.exer.2020.108371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/17/2020] [Accepted: 11/22/2020] [Indexed: 12/16/2022]
Abstract
Congenital aniridia is caused by heterozygous mutations in the PAX6 gene. In this disease, congenital iris and foveal hypoplasia is associated with juvenile onset cataract, glaucoma, and corneal keratopathy. In rodents, Pax6 mutations result in a congenital reduction in ocular size that is not typically described in human aniridia. Here, the ocular morphometry of aniridia patients is compared with the lens phenotype of Pax6+/tm1/Pgr mice to reveal whether there are species differences in Pax6 regulation of lens development and homeostasis. Ultrasound biometry (UBM) revealed that eleven percent of aniridia patients exhibited mild microphthalmia while the anterior chamber depth of aniridic eyes was significantly reduced from 6 months of age onward. Although aniridic lens thickness was normal from birth, it was significantly decreased in aniridic lenses older than 30. Notably, 86% of aniridic lenses exhibited cataractous changes in this cohort. In addition, a significant proportion of aniridia patients develop lens subluxation as they age associated with reduced lens diameter as measured by anterior segment optical coherence tomography (AS-OCT). Analysis of young adult Pax6+/tm1/Pgr mouse lenses by micro-computed tomography (microCT), bright field and dark field imaging revealed that they are reduced in size but did not exhibit overt cataracts at this age. Overall, this study reveals that congenital microphthalmia as assessed by axial length, or microphakia, as assessed by lens thickness, are not typical in human aniridia, although these are primary manifestations of Pax6 mutations in mice, suggesting that PAX6 regulates some aspects of lens development differently between these species.
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23
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Latta L, Ludwig N, Krammes L, Stachon T, Fries FN, Mukwaya A, Szentmáry N, Seitz B, Wowra B, Kahraman M, Keller A, Meese E, Lagali N, Käsmann-Kellner B. Abnormal neovascular and proliferative conjunctival phenotype in limbal stem cell deficiency is associated with altered microRNA and gene expression modulated by PAX6 mutational status in congenital aniridia. Ocul Surf 2020; 19:115-127. [PMID: 32422284 DOI: 10.1016/j.jtos.2020.04.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 03/09/2020] [Accepted: 04/26/2020] [Indexed: 12/18/2022]
Abstract
PURPOSE To evaluate conjunctival cell microRNA (miRNAs) and mRNA expression in relation to observed phenotype of progressive limbal stem cell deficiency in a cohort of subjects with congenital aniridia with known genetic status. METHODS Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and miRNA and mRNA analyses were performed using microarrays. Results were related to severity of keratopathy and genetic cause of aniridia. RESULTS Of 2549 miRNAs, 21 were differentially expressed in aniridia relative to controls (fold change ≤ -1.5 or ≥ +1.5). Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold in severely vascularized corneas. At the mRNA level, 539 transcripts were differentially expressed (fold change ≤ -2 or ≥ +2), among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all being components of the AP-1 transcription factor complex. Pathway analysis revealed enrichment of PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several miRNAs and transcripts regulating retinoic acid metabolism, expression levels correlated with keratopathy severity and genetic status. CONCLUSION Strong dysregulation of key factors at the miRNA and mRNA level suggests that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, and these changes are expressed in a PAX6 mutation-dependent manner. Additionally, retinoic acid metabolism is disrupted in severe, but not mild forms of the limbal stem cell deficiency in aniridia.
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Affiliation(s)
- L Latta
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.
| | - N Ludwig
- Department of Human Genetics, Saarland University, Homburg, Saar, Germany; Center for Human and Molecular Biology, Saarland University, Homburg, Saar, Germany
| | - L Krammes
- Department of Human Genetics, Saarland University, Homburg, Saar, Germany
| | - T Stachon
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - F N Fries
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - A Mukwaya
- Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, Linköping, Sweden
| | - N Szentmáry
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany; Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - B Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - B Wowra
- Chair and Clinical Department of Ophthalmology, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia in Katowice, Poland
| | - M Kahraman
- Chair for Clinical Bioinformatics, Saarland University, Saarbruecken, Germany
| | - A Keller
- Chair for Clinical Bioinformatics, Saarland University, Saarbruecken, Germany
| | - E Meese
- Department of Human Genetics, Saarland University, Homburg, Saar, Germany
| | - N Lagali
- Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, Linköping, Sweden; Department of Ophthalmology, Sørlandet Hospital Arendal, Arendal, Norway.
| | - B Käsmann-Kellner
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
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Keratin 12 mRNA expression could serve as an early corneal marker for limbal explant cultures. Cytotechnology 2020; 72:239-245. [PMID: 32016711 PMCID: PMC7192984 DOI: 10.1007/s10616-020-00373-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 01/23/2020] [Indexed: 10/31/2022] Open
Abstract
This investigation aimed to identify early corneal marker and conjunctival epithelial differentiation through transcriptional analysis of limbal explant cultures and study early differentiation patterns of known corneal and conjunctival differentiation markers. 2 mm punch biopsies of limbal region were obtained from 6 donors of the Lions Cornea Bank Saar-Lorloux/Trier-Westpfalz. Limbal explants were dissected into corneal and conjunctival biopsy sections. Biopsies were placed with epithelial side down into 12 Wells. As soon as the outgrowing cells had reached confluence, they were harvested. mRNA expression of corneal differentiation markers KRT12, KRT3, DSG1, PAX6, ADH7 and ALDH1A1, conjunctival markers KRT19, KRT13 and stem cell marker ABCG2 were measured via qPCR. KRT12 and PAX6 protein expressions were evaluated using Western Blot. Results suggested that KRT12 mRNA expression was significantly higher in outgrowing cells from the corneal side of the biopsies as in those from the conjunctival side (p = 0.0043). There was no significant difference in mRNA expression of other analyzed markers comparing with marker expression of outgrown cells from both limbal biopsies (p > 0.13). KRT12 and PAX6 Western Blot analysis showed no difference in cells harvested from both sides. In conclusion, KRT12 mRNA might be a marker to measure corneal origin of cells from limbal biopsies with unknown composition of corneal and conjunctival progenitor cells. KRT3, DSG1, PAX6, ADH7, ALDH1A1, KRT19, KRT13 and ABCG2 mRNA as well as KRT12 and PAX6 protein expression could not contribute to differentiate corneal from conjunctival cell identity from limbal biopsies.
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25
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Yazdanpanah G, Bohm KJ, Hassan OM, Karas FI, Elhusseiny AM, Nonpassopon M, Niparugs M, Tu EY, Sugar J, Rosenblatt MI, Cortina MS, Djalilian AR. Management of Congenital Aniridia-Associated Keratopathy: Long-Term Outcomes from a Tertiary Referral Center. Am J Ophthalmol 2020; 210:8-18. [PMID: 31730836 DOI: 10.1016/j.ajo.2019.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/30/2019] [Accepted: 11/04/2019] [Indexed: 11/17/2022]
Abstract
PURPOSE To report the outcomes of medical and surgical management for congenital aniridia-associated keratopathy (AAK) over a long-term follow-up period. DESIGN Retrospective, comparative case series. METHODS Medical records of patients diagnosed with congenital aniridia were retrospectively reviewed. Age, sex, ethnicity, follow-up time, AAK stage, noncorneal abnormalities, ocular surgeries, and complications were recorded. The visual acuity equivalent (VAE), approximate Early Treatment Diabetic Retinopathy Study (appETDRS) letter score, was calculated using recorded Snellen visual acuities. RESULTS A total of 92 eyes of 47 patients (31 females) with mean age of 48.0 ± 18.0 years and mean follow-up of 78.6 ± 42.2 months were included. At the initial visit, 12 eyes (13%) were classified as Stage I AAK, 33 eyes (35.9%) were Stage II, 25 eyes (27.2%) were Stage III, 17 eyes (18.5%) were Stage IV, and 5 eyes (5.4%) were Stage V. Limbal stem cell transplantation (LSCT) and Boston keratoprosthesis (KPro) were frequently performed in eyes with Stages III-V. These advanced corneal surgeries significantly improved the median (95% confidence interval [CI]) of calculated appETDRS scores from 2 (0-20) to 26 (15-41) (Snellen values, 20/20,000 to 20/300; P = 0.0004). Patients with earlier Stages (I-II) of AAK were managed medically and had stable visual acuity through their final visits (appETDRS score of 26 [20-35] to 35 [26-35]; Snellen, 20/300 to 20/200; P > 0.05). The appETDRS VAE was significantly improved from 20 (0-35) to 30 (20-55), Snellen, 20/400 to 20/250, following LSCT (P = 0.021) and from 2 (0-20) to 2 (0-41) after KPro; Snellen, 20/20,000 VAE but with improved 95% CI after follow-up (P = 0.019). CONCLUSIONS With proper characterization and staging of AAK, individualized medical and advanced surgical interventions preserves and improves visual acuity.
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Affiliation(s)
- Ghasem Yazdanpanah
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Kelley J Bohm
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Omar M Hassan
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Faris I Karas
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Abdelrahman M Elhusseiny
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Manachai Nonpassopon
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Muanploy Niparugs
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Elmer Y Tu
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Joel Sugar
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Mark I Rosenblatt
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Maria S Cortina
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA.
| | - Ali R Djalilian
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois, USA.
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Rubelowski AK, Latta L, Katiyar P, Stachon T, Käsmann-Kellner B, Seitz B, Szentmáry N. HCE-T cell line lacks cornea-specific differentiation markers compared to primary limbal epithelial cells and differentiated corneal epithelium. Graefes Arch Clin Exp Ophthalmol 2020; 258:565-575. [PMID: 31927639 DOI: 10.1007/s00417-019-04563-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 11/25/2019] [Accepted: 12/09/2019] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Human corneal epithelial cell-transformed (HCE-T) cell line is used as a widely accepted barrier model for pharmacological investigations in the context of eye application. The differentiation of (limbal) corneal epithelial into mature corneal epithelium coincides with the expression of established differentiation markers. If these differentiation mechanisms are disturbed, it will lead to ocular surface disease. In this study, we want to compare the expression of differentiation markers in the HCE-T cell line to differentiated primary epithelial cells (pCECs) and primary limbal epithelial cell (LEC) culture. This is necessary in order to decide whether HCE-T cells could be a tool to study the differentiation process and its regulatory networks in corneal epithelium. METHODS Primary limbal epithelial cells (LECs) for cell culture and primary corneal epithelial cells (pCECs) as differentiated tissue samples were obtained from the limbus or central cornea region of corneal donors. HCE-T cell line was purchased from RIKEN Institute RCB-2280.Expression levels of conjunctival- and corneal-specific keratin and adhesion markers (KRT3, KRT12, KRT13, KRT19, DSG1), stem cell and differentiation markers (PAX6, ABCG2, ADH7, TP63, ALDH1A1), and additional (unvalidated) putative differentiation and stem cell markers (CTSV, SPINK7, DKK1) were analyzed with qPCR. Additionally, KRT3, KRT12, DSG1, and PAX6 protein levels were analyzed with Western blot. RESULTS KRT3, KRT12, DSG1, PAX6, ADH7, and ALDH1A1 mRNA expressions were higher in LECs and magnitudes higher in pCECs compared to HCE-T cells. KRT3, KRT12, PAX6, ALDH1A1, ADH7, TP63, and CTSV mRNAs have shown increasing mRNA expression from HCE-T < HCE-T cultured in keratinocyte serum-free medium (KSFM) < LEC < to pCEC.KRT3 and KRT12 protein expressions were only slightly increased in LEC compared to HCE-T samples, and the strongest signals were seen in pCEC samples. DSG1 protein expression was only detected in pCECs. PAX6 protein expression was hardly detected in HCE-T cells, and no difference could be seen between LECs and pCECs. CONCLUSIONS The HCE-T cell line is even less differentiated than LECs regarding the investigated markers and therefore might also lack the ability to express differentiation markers at protein level. Hence, this cell line is not suitable to study corneal differentiation processes. Primary LECs in the way cultured here are not an ideal system compared to differentiated epithelium in organ culture but should be preferred to HCE-T cells if corneal differentiation markers are investigated. Other cell models or differentiation protocols should be developed in the future to gain new tools for research on ocular surface diseases.
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Affiliation(s)
- Anna-Klara Rubelowski
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Lorenz Latta
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.
| | - Priya Katiyar
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Tanja Stachon
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | | | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Nóra Szentmáry
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.,Department of Ophthalmology, Semmelweis University, Budapest, Hungary
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27
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Sonam S, Srnak JA, Perry KJ, Henry JJ. Molecular markers for corneal epithelial cells in larval vs. adult Xenopus frogs. Exp Eye Res 2019; 184:107-125. [PMID: 30981716 DOI: 10.1016/j.exer.2019.04.010] [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: 03/11/2019] [Accepted: 04/08/2019] [Indexed: 12/14/2022]
Abstract
Corneal Epithelial Stem Cells (CESCs) and their proliferative progeny, the Transit Amplifying Cells (TACs), are responsible for maintaining the integrity and transparency of the cornea. These stem cells (SCs) are widely used in corneal transplants and ocular surface reconstruction. Molecular markers are essential to identify, isolate and enrich for these cells, yet no definitive CESC marker has been established. An extensive literature survey shows variability in the expression of putative CESC markers among vertebrates; being attributed to species-specific variations, or other differences in developmental stages of these animals, approaches used in these studies and marker specificity. Here, we expanded the search for CESC markers using the amphibian model Xenopus laevis. In previous studies we found that long-term label retaining cells (suggestive of CESCs and TACs) are present throughout the larval basal corneal epithelium. In adult frogs, these cells become concentrated in the peripheral cornea (limbal region). Here, we used immunofluorescence to characterize the expression of nine proteins in the corneas of both Xenopus larvae and adults (post-metamorphic). We found that localization of some markers change between larval and adult stages. Markers such as p63, Keratin 19, and β1-integrin are restricted to basal corneal epithelial cells of the larvae. After metamorphosis their expression is found in basal and intermediate layer cells of the adult frog corneal epithelium. Another protein, Pax6 was expressed in the larval corneas, but surprisingly it was not detected in the adult corneal epithelium. For the first time we report that Tcf7l2 can be used as a marker to differentiate cornea vs. skin in frogs. Tcf7l2 is present only in the frog skin, which differs from reports indicating that the protein is expressed in the human cornea. Furthermore, we identified the transition between the inner, and the outer surface of the adult frog eyelid as a key boundary in terms of marker expression. Although these markers are useful to identify different regions and cellular layers of the frog corneal epithelium, none is unique to CESCs or TACs. Our results confirm that there is no single conserved CESC marker in vertebrates. This molecular characterization of the Xenopus cornea facilitates its use as a vertebrate model to understand the functions of key proteins in corneal homeostasis and wound repair.
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Affiliation(s)
- Surabhi Sonam
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Jennifer A Srnak
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Kimberly J Perry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Jonathan J Henry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA.
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Expression of retinoic acid signaling components ADH7 and ALDH1A1 is reduced in aniridia limbal epithelial cells and a siRNA primary cell based aniridia model. Exp Eye Res 2019; 179:8-17. [DOI: 10.1016/j.exer.2018.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/29/2018] [Accepted: 10/03/2018] [Indexed: 01/31/2023]
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Abstract
This chapter provides an overview of the early developmental origins of six ocular tissues: the cornea, lens, ciliary body, iris, neural retina, and retina pigment epithelium. Many of these tissue types are concurrently specified and undergo a complex set of morphogenetic movements that facilitate their structural interconnection. Within the context of vertebrate eye organogenesis, we also discuss the genetic hierarchies of transcription factors and signaling pathways that regulate growth, patterning, cell type specification and differentiation.
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Affiliation(s)
- Joel B Miesfeld
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, Davis, CA, United States
| | - Nadean L Brown
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, Davis, CA, United States.
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Vicente A, Byström B, Pedrosa Domellöf F. Altered Signaling Pathways in Aniridia-Related Keratopathy. ACTA ACUST UNITED AC 2018; 59:5531-5541. [DOI: 10.1167/iovs.18-25175] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- André Vicente
- Department of Clinical Science, Ophthalmology, Umeå University, Umeå, Sweden
| | - Berit Byström
- Department of Clinical Science, Ophthalmology, Umeå University, Umeå, Sweden
| | - Fátima Pedrosa Domellöf
- Department of Clinical Science, Ophthalmology, Umeå University, Umeå, Sweden
- Department of Integrative Medical Biology, Section for Anatomy, Umeå University, Umeå, Sweden
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31
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Dorà NJ, Manuel M, Kleinjan DJ, Price DJ, Collinson JM, Hill RE, West JD. A conditional Pax6 depletion study with no morphological effect on the adult mouse corneal epithelium. BMC Res Notes 2018; 11:705. [PMID: 30290846 PMCID: PMC6173925 DOI: 10.1186/s13104-018-3812-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 09/30/2018] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE The corneas of heterozygous Pax6+/- mice develop abnormally and deteriorate further after birth but it is not known whether the postnatal deterioration is predetermined by abnormal development. Our objective was to identify whether depletion of Pax6 in adult mice caused any corneal abnormalities, similar to those in Pax6+/- mice, where Pax6 levels are low throughout development and adulthood. We used two tamoxifen-inducible, Cre-loxP experimental strategies to deplete Pax6 either ubiquitously or in a restricted range of cell types. RESULTS In a preliminary study, ubiquitous depletion of Pax6 by tamoxifen treatment of E9.5 CAG-CreERTg/-;Pax6fl/fl embryos affected eye development. Tamoxifen treatment of 12-week old, adult CAG-CreERTg/-;Pax6fl/+ and CAG-CreERTg/-;Pax6fl/fl mice resulted in weak and/or patchy Pax6 immunostaining in the corneal epithelium but caused no corneal abnormalities. GFP staining in tamoxifen-treated CAG-CreERTg/-;RCE:loxP reporter mice was also patchy. We attribute patchy Pax6 staining to mosaic deletion of the Pax6fl allele, probably caused by mosaic CAG-CreERTg expression. In a parallel study, we treated adult Krt19-CreERTg/-;Pax6fl/+ mice with tamoxifen to try to deplete Pax6 in limbal epithelial stem cells (LESCs) which replenish the corneal epithelium. However, Pax6 staining remained strong after a 12-week chase period so the Krt19-CreERTg/- transgene may have failed to target LESCs.
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Affiliation(s)
- Natalie J. Dorà
- Centre for Integrative Physiology, Biomedical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD UK
- Present Address: Biology Teaching Organisation, University of Edinburgh, Ashworth Laboratories, Charlotte Auerbach Road, King’s Buildings, Edinburgh, EH9 3FL UK
| | - Martine Manuel
- Centre for Discovery Brain Sciences, Biomedical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD UK
| | - Dirk-Jan Kleinjan
- Medical and Developmental Genetics Section, MRC Human Genetics Unit, MRC IGMM, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU UK
- Present Address: Centre for Mammalian Synthetic Biology, University of Edinburgh, Roger Land Building, Alexander Crum Brown Road, King’s Buildings, Edinburgh, EH9 3FF UK
| | - David J. Price
- Centre for Discovery Brain Sciences, Biomedical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD UK
| | - J. Martin Collinson
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD 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
- Centre for Integrative Physiology, Clinical Sciences, University of Edinburgh Medical School, Hugh Robson Building, George Square, Edinburgh, EH8 9XD UK
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Abstract
Paired box protein 6 (PAX6) is a master regulator of the eye development. Over the last past two decades, our understanding of eye development, especially the molecular function of PAX6, has focused on transcriptional control of the Pax6 expression. However, other regulatory mechanisms for gene expression, including alternative splicing (AS), have been understudied in the eye development. Recent findings suggest that two PAX6 isoforms generated by AS of Pax6 pre-mRNA may play previously underappreciated role(s) during eye development, especially, the corneal development.
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Affiliation(s)
- Jung Woo Park
- Faculty of Health Sciences, University of Macau , Macau, China
| | - Juan Yang
- Faculty of Health Sciences, University of Macau , Macau, China
| | - Ren-He Xu
- Faculty of Health Sciences, University of Macau , Macau, China
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33
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Wang S, Kobeissi A, Dong Y, Kaplan N, Yang W, He C, Zeng K, Peng H. MicroRNAs-103/107 Regulate Autophagy in the Epidermis. J Invest Dermatol 2018; 138:1481-1490. [PMID: 29452119 DOI: 10.1016/j.jid.2018.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 02/03/2018] [Accepted: 02/05/2018] [Indexed: 12/23/2022]
Abstract
We have shown that microRNAs-103 and -107 (miRs-103/107) positively regulate end-stage autophagy by ensuring dynamin activity in cultured keratinocytes. Most work in end-stage autophagy has been conducted using in vitro model systems. In vivo regulation of end-stage autophagy in epidermis remains unknown. Here, we used antagomirs to subcutaneously knock down miR-107 in the skin; conversely, we delivered miR-107 mimic subcutaneously via in vivo transfection to increase this miR. We found that antagomir-107 treatment in epidermis: (i) depleted endogenous miR-107; (ii) increased GFP-LC3 puncta in epidermal basal layers of GFP-LC3 transgenic mice, indicative of an accumulation of autophagosomes; (iii) inhibited LC3 turnover and increased p62, suggesting an inhibition of autophagy flux; and (iv) increased phosphorylated dynamin (p-dynamin, an inactive form), a key enzyme in end-stage autophagy. Conversely, miR-107 mimic treatment in mouse epidermis: decreased GFP-LC3 puncta in basal layer, as well as p62 protein levels; and diminished p-dynamin, indicative of activation of this enzyme. In human epidermal keratinocytes, antagos-103/107 cause the formation of large vacuoles and an increase in p-dynamin, which can be rescued by inhibition of protein kinase C pathway. Collectively, these results suggest that the miR-103/107 family has a critical role in regulating end-stage autophagy in mouse epidermis via PLD1/2-protein kinase C-dynamin pathway.
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Affiliation(s)
- Sijia Wang
- Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China; Department of Dermatology, Northwestern University, Chicago, Illinois, USA
| | - Aya Kobeissi
- Department of Dermatology, Northwestern University, Chicago, Illinois, USA
| | - Ying Dong
- Department of Dermatology, Northwestern University, Chicago, Illinois, USA; Department of Ophthalmology, the First Affiliated Hospital, Chinese PLA General Hospital, Beijing, China
| | - Nihal Kaplan
- Department of Dermatology, Northwestern University, Chicago, Illinois, USA
| | - Wending Yang
- Department of Dermatology, Northwestern University, Chicago, Illinois, USA
| | - Congcong He
- Cell and Molecular Biology, Northwestern University, Chicago, Illinois, USA
| | - Kang Zeng
- Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.
| | - Han Peng
- Department of Dermatology, Northwestern University, Chicago, Illinois, USA.
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Sun J, Liu WH, Deng FM, Luo YH, Wen K, Zhang H, Liu HR, Wu J, Su BY, Liu YL. Differentiation of rat adipose-derived mesenchymal stem cells into corneal-like epithelial cells driven by PAX6. Exp Ther Med 2018; 15:1424-1432. [PMID: 29434727 PMCID: PMC5774412 DOI: 10.3892/etm.2017.5576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 09/06/2017] [Indexed: 12/15/2022] Open
Abstract
Corneal integrity, transparency and vision acuity are maintained by corneal epithelial cells (CECs), which are continuously renewed by corneal limbal stem cells (LSCs). Deficiency of CECs and/or LSCs is associated with numerous ocular diseases. Paired box (PAX)6 is an eye development-associated transcription factor that is necessary for cell fate determination and differentiation of LSCs and CECs. In the present study, the PAX6 gene was introduced into adipose-derived rat mesenchymal stem cells (ADMSCs) to investigate whether PAX6-transfected cells were able to transdifferentiate into corneal-like epithelial cells and to further verify whether the cells were suitable as a cell source for corneal transplantation. The ADMSCs were isolated from the bilateral inguinal region of healthy Sprague Dawley rats. The characteristics of ADMSCs were identified using flow cytometric analysis. After subculture, ADMSCs underwent transfection with recombinant plasmid containing either PAX6-enhanced green fluorescent protein (EGFP) complementary (c)DNA or EGFP cDNA (blank plasmid group), followed by selection with G418 and determination of the transfection efficiency. Subsequently, the morphology of the ADMSCs and the expression profiles of corneal-specific markers CK3/12 and epithelial-specific adhesion protein were determined. E-cadherin was detected using immunofluorescence staining and western blot analysis at 21 days following transfection. An MTT cell proliferation and a colony formation assay were performed to assess the proliferative activity and clonogenicity of PAX6-transfected ADMSCs. Finally, the PAX6-expressing ADMSCs were transplanted onto the cornea of a rabbits with limbal stem cell deficiency (LSCD). At 21 days after transfection, the ADMSCs with PAX6 transfection exhibited a characteristic flagstone-like appearance with assembled corneal-like epithelial cells, and concomitant prominent expression of the corneal-specific markers cytokeratin 3/12 and E-cadherin. Furthermore, the proliferation and colony formation ability of PAX6-overexpressing ADMSCs was significantly retarded. The transplantation experiment indicated that PAX6-reprogramed ADMSCs attached to and replenished the damaged cornea via formation of stratified corneal epithelium. Taken together, these results suggested that conversion of ADMSCs into corneal-like epithelium may be driven by PAX6 transfection, which makes ADMSCs a promising cell candidate for the treatment of LSCD.
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Affiliation(s)
- Jing Sun
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Chongqing 400038, P.R. China
- Department of Regeneration Key Lab of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Wei-Hua Liu
- Department of Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Feng-Mei Deng
- Department of Regeneration Key Lab of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Yong-Hui Luo
- Department of Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Ke Wen
- Department of Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Hong Zhang
- Department of Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Hai-Rong Liu
- Department of Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Jiang Wu
- Department of Biomedical Engineering, West China Center of Medical Sciences, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Bing-Yin Su
- Department of Regeneration Key Lab of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
| | - Yi-Lun Liu
- Department of Surgery, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China
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Hu W, Zhang Y, Tighe S, Zhu YT, Li GG. A New Isolation Method of Human Lacrimal Canaliculus Epithelial Stem Cells by Maintaining Close Association with Their Niche Cells. Int J Med Sci 2018; 15:1260-1267. [PMID: 30275751 PMCID: PMC6158657 DOI: 10.7150/ijms.27705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 06/30/2018] [Indexed: 02/06/2023] Open
Abstract
Purpose: To investigate whether lacrimal canaliculus epithelial stem cells (LCESC) could be isolated and expanded in vitro. Methods: The lacrimal canaliculus epithelium of 6 patients with limbal stem cell deficiency (LSCD) caused by alkali burn or Stevens Johnson Syndrome were examined by lacrimal endoscope. Cadaveric eyelids were fixed and prepared for cross section and stained with HE and antibodies against PCK, Vim, p63α, SCF and c-Kit. Canaliculus tissue was separated under an operating microscope using a lacrimal probe as an indicator and digested with collagenase A. The clusters of epithelial cells with closely associated stroma were further digested with Trypsin/EDTA to obtain single cells for culture on Matrigel-coated plastic plates in MESCM media. The expression of SCF, c-Kit and p63α was determined by immunostaining. The colony-forming efficiency on 3T3 feeder layers was also measured by calculating the percentage of the clone number divided by the total number cells seeded. Results: The epithelial layers of five out of six inferior lacrimal canaliculi and all the six superior lacrimal canaliculi were visually normal in appearance. Five to fifteen layers of the epithelium in the human lacrimal canaliculi were present with a small, tightly compacted basal layer of cells expressing PCK, p63α, SCF and c-Kit. LCESC were isolated by collagenase A and obtained clonal growth in MESCM. The colony-forming efficiency of LCESC holoclones on a 3T3 feeder layer was 3.2%, compared to 1.9% for those of limbal stem cells (LSC). Conclusions: Herein, we first report that LCESCs can be isolated and have stem cell characteristics, similar to those of LSCs. Such a discovery raises a promising substrate resource of stem cells for LSC reconstruction in LSCD patients.
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Affiliation(s)
- Weikun Hu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PRC. 430030
| | - Yuan Zhang
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL, USA. 33173
| | - Sean Tighe
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL, USA. 33173
| | - Ying-Tieng Zhu
- Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL, USA. 33173
| | - Gui-Gang Li
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PRC. 430030.,Tissue Tech, Inc., Ocular Surface Center, and Ocular Surface Research & Education Foundation, Miami, FL, USA. 33173
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Latta L, Viestenz A, Stachon T, Colanesi S, Szentmáry N, Seitz B, Käsmann-Kellner B. Human aniridia limbal epithelial cells lack expression of keratins K3 and K12. Exp Eye Res 2017; 167:100-109. [PMID: 29162348 DOI: 10.1016/j.exer.2017.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/13/2017] [Accepted: 11/17/2017] [Indexed: 01/12/2023]
Abstract
Aniridia is a rare disease of the eye that affects the iris, lens and the cornea. In about 90% of the cases, patients showed a loss of PAX6 function. Patients with aniridia often develop aniridia-related keratopathy (ARK), due to limbal stem cell insufficiency. The aim of this study was to determine the differentiation status of limbal epithelial cells (LECs) in patients with ARK. Epithelial cells were isolated from the limbus region of two patients with aniridia and cultured in KSFM medium supplemented with EGF and BPE. Normal cells were obtained from limbus region of cadaveric control patients. Cells were analyzed with RT-PCR, qPCR and Western blot to evaluate expression of the developmental transcription factor, PAX6, potential stem cell markers, ΔNp63α and ABCG2, and corneal differentiation markers, keratin 12 (K12) and K3. Conjunctival differentiation markers, keratin 13 (K13) and K19 were also investigated. Cells were immunostained to evaluate K3, PAX6, and p63α protein expression. Protein coding sequence of PAX6 from patient LEC-cDNA was cloned and sequenced. RT-PCR showed that K3 and K12 transcripts were absent from patient cells, but present in healthy control preparations. Transcription levels of PAX6, ABCG2, and p63α of aniridia patients show no differences compared to normal control cells. Western blot showed reduced PAX6, protein levels in aniridia-LECs compared to control-LECs. Immunostaining also showed reduced PAX6 and K3 expression in aniridia-LECs compared to control-LECs. One aniridia patient showed a loss of stop codon in half of the cloned transcripts. In the second aniridia patient mRNA degradation through nonsense mediated decay seems to be very likely since we could not identify the mutation c.174C > T (Refseq. NM_000280), or misspliced transcripts in cDNA. We identified decreased PAX6 protein levels in aniridia patients in addition to decreased K12 mRNA levels compared to control cells. This result indicates an altered differentiation of limbal epithelial cells of aniridia patients. Further studies are necessary to evaluate the mechanism of differentiation of limbal epithelial cells in aniridia.
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Affiliation(s)
- Lorenz Latta
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany.
| | - Arne Viestenz
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Tanja Stachon
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Sarah Colanesi
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Nóra Szentmáry
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany; Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
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Rönkkö S, Vellonen KS, Järvinen K, Toropainen E, Urtti A. Human corneal cell culture models for drug toxicity studies. Drug Deliv Transl Res 2017; 6:660-675. [PMID: 27613190 PMCID: PMC5097077 DOI: 10.1007/s13346-016-0330-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In vivo toxicity and absorption studies of topical ocular drugs are problematic, because these studies involve invasive tissue sampling and toxic effects in animal models. Therefore, different human corneal models ranging from simple monolayer cultures to three-dimensional models have been developed for toxicological prediction with in vitro models. Each system has its own set of advantages and disadvantages. Use of non-corneal cells, inadequate characterization of gene-expression profiles, and accumulation of genomic aberrations in human corneal models are typical drawbacks that decrease their reliability and predictive power. In the future, further improvements are needed for verifying comparable expression profiles and cellular properties of human corneal models with their in vivo counterparts. A rapidly expanding stem cell technology combined with tissue engineering may give future opportunities to develop new tools in drug toxicity studies. One approach may be the production of artificial miniature corneas. In addition, there is also a need to use large-scale profiling approaches such as genomics, transcriptomics, proteomics, and metabolomics for understanding of the ocular toxicity.
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Affiliation(s)
- Seppo Rönkkö
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Kati-Sisko Vellonen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Kristiina Järvinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Elisa Toropainen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland
| | - Arto Urtti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O.Box 1627, 70211, Kuopio, Finland. .,Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland.
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38
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PAX6 regulates human corneal epithelium cell identity. Exp Eye Res 2017; 154:30-38. [DOI: 10.1016/j.exer.2016.11.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 07/21/2016] [Accepted: 11/02/2016] [Indexed: 01/06/2023]
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39
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Analysis of compound heterozygotes reveals that the mouse floxed Pax6 (tm1Ued) allele produces abnormal eye phenotypes. Transgenic Res 2016; 25:679-92. [PMID: 27240603 PMCID: PMC5023747 DOI: 10.1007/s11248-016-9962-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/13/2016] [Indexed: 01/27/2023]
Abstract
Analysis of abnormal phenotypes produced by different types of mutations has been crucial for our understanding of gene function. Some floxed alleles that retain a neomycin-resistance selection cassette (neo cassette) are not equivalent to wild-type alleles and provide useful experimental resources. Pax6 is an important developmental gene and the aim of this study was to determine whether the floxed Pax6tm1Ued (Pax6fl) allele, which has a retained neo cassette, produced any abnormal eye phenotypes that would imply that it differs from the wild-type allele. Homozygous Pax6fl/fl and heterozygous Pax6fl/+ mice had no overt qualitative eye abnormalities but morphometric analysis showed that Pax6fl/fl corneas tended be thicker and smaller in diameter. To aid identification of weak effects, we produced compound heterozygotes with the Pax6Sey-Neu (Pax6−) null allele. Pax6fl/− compound heterozygotes had more severe eye abnormalities than Pax6+/− heterozygotes, implying that Pax6fl differs from the wild-type Pax6+ allele. Immunohistochemistry showed that the Pax6fl/− corneal epithelium was positive for keratin 19 and negative for keratin 12, indicating that it was abnormally differentiated. This Pax6fl allele provides a useful addition to the existing Pax6 allelic series and this study demonstrates the utility of using compound heterozygotes with null alleles to unmask cryptic effects of floxed alleles.
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40
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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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Samant M, Chauhan BK, Lathrop KL, Nischal KK. Congenital aniridia: etiology, manifestations and management. EXPERT REVIEW OF OPHTHALMOLOGY 2016; 11:135-144. [PMID: 30100922 DOI: 10.1586/17469899.2016.1152182] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Congenital aniridia manifests as total or partial absence of the iris caused most commonly by mutations in PAX6, FOXC1, PITX2, and CYP1B1. Recently two new genes, FOXD3 and TRIM44, have also been implicated in isolated studies. We discuss the genotype-phenotype correlations for the main implicated genes. Classic aniridia is a panocular condition, which includes aniridia, cataract, corneal pannus, foveal, and optic nerve hypoplasia associated with mutations in the PAX6 gene. Classical aniridia is due to PAX6 mutations, while other genes contribute to aniridia-like phenotypes. We review the challenges involved in the management of aniridia, and discuss various surgical interventions. The clinical importance of defining the genotype in cases of congenital aniridia has become acutely apparent with the advent of possible therapies for classical aniridia, which are discussed.
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Affiliation(s)
- Monica Samant
- Children's Eye Center of UPMC, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Bharesh K Chauhan
- Children's Eye Center of UPMC, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | - Kira L Lathrop
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.,Department of Engineering. University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania 15213, USA
| | - Ken K Nischal
- Children's Eye Center of UPMC, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
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PAX6 Isoforms, along with Reprogramming Factors, Differentially Regulate the Induction of Cornea-specific Genes. Sci Rep 2016; 6:20807. [PMID: 26899008 PMCID: PMC4761963 DOI: 10.1038/srep20807] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 01/08/2016] [Indexed: 01/06/2023] Open
Abstract
PAX6 is the key transcription factor involved in eye development in humans, but the differential functions of the two PAX6 isoforms, isoform-a and isoform-b, are largely unknown. To reveal their function in the corneal epithelium, PAX6 isoforms, along with reprogramming factors, were transduced into human non-ocular epithelial cells. Herein, we show that the two PAX6 isoforms differentially and cooperatively regulate the expression of genes specific to the structure and functions of the corneal epithelium, particularly keratin 3 (KRT3) and keratin 12 (KRT12). PAX6 isoform-a induced KRT3 expression by targeting its upstream region. KLF4 enhanced this induction. A combination of PAX6 isoform-b, KLF4, and OCT4 induced KRT12 expression. These new findings will contribute to furthering the understanding of the molecular basis of the corneal epithelium specific phenotype.
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Zhang Y, Sun H, Liu Y, Chen S, Cai S, Zhu Y, Guo P. The Limbal Epithelial Progenitors in the Limbal Niche Environment. Int J Med Sci 2016; 13:835-840. [PMID: 27877075 PMCID: PMC5118754 DOI: 10.7150/ijms.16563] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/01/2016] [Indexed: 02/06/2023] Open
Abstract
Limbal epithelial progenitors are stem cells located in limbal palisades of vogt. In this review, we present the audience with recent evidence that limbal epithelial progenitors may be a powerful stem cell resource for the cure of human corneal stem cell deficiency. Further understanding of their mechanism may shed lights to the future successful application of stem cell therapy not only to the eye tissue, but also to the other tissues in the human body.
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Affiliation(s)
- Yuan Zhang
- Research and Development Department, TissueTech, Inc., 7000 SW 97th Avenue, Suite 212, Miami, FL 33173, USA
| | - Hong Sun
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Yongsong Liu
- Department of Ophthalmology, Yan' An Hospital of Kunming City, Kunming, 650051, China
| | - Shuangling Chen
- Research and Development Department, TissueTech, Inc., 7000 SW 97th Avenue, Suite 212, Miami, FL 33173, USA
| | - Subo Cai
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yingting Zhu
- Research and Development Department, TissueTech, Inc., 7000 SW 97th Avenue, Suite 212, Miami, FL 33173, USA
| | - Ping Guo
- Shenzhen Eye Hospital, School of Optometry & Ophthalmology of Shenzhen University, Shenzhen Key Laboratory of Department of Ophthalmology, Shenzhen, 518000, China
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44
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Ihnatko R, Eden U, Fagerholm P, Lagali N. Congenital Aniridia and the Ocular Surface. Ocul Surf 2015; 14:196-206. [PMID: 26738798 DOI: 10.1016/j.jtos.2015.10.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/26/2015] [Accepted: 10/15/2015] [Indexed: 12/15/2022]
Abstract
Aniridia is a congenital pan-ocular disorder caused by haplo-insufficiency of Pax6, a crucial gene for proper development of the eye. Aniridia affects a range of eye structures, including the cornea, iris, anterior chamber angle, lens, and fovea. The ocular surface, in particular, can be severely affected by a progressive pathology termed aniridia-associated keratopathy (AAK), markedly contributing to impaired vision. The purpose of this review is to provide an update of the current knowledge of the genetic, clinical, micro-morphological, and molecular aspects of AAK. We draw upon material presented in the literature and from our own observations in large aniridia cohorts. We summarize signs and symptoms of AAK, describe current options for management, and discuss the latest research findings that may lead to better diagnosis and new treatment or prevention strategies for this debilitating ocular surface condition.
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Affiliation(s)
- Robert Ihnatko
- Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Ulla Eden
- Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Per Fagerholm
- Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Neil Lagali
- Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
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45
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Delp EE, Swamynathan S, Kao WW, Swamynathan SK. Spatiotemporally Regulated Ablation of Klf4 in Adult Mouse Corneal Epithelial Cells Results in Altered Epithelial Cell Identity and Disrupted Homeostasis. Invest Ophthalmol Vis Sci 2015; 56:3549-58. [PMID: 26047041 DOI: 10.1167/iovs.15-16463] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE In previous studies, conditional disruption of Klf4 in the developing mouse ocular surface from embryonic day 10 resulted in corneal epithelial fragility, stromal edema, and loss of conjunctival goblet cells, revealing the importance of Klf4 in ocular surface maturation. Here, we use spatiotemporally regulated ablation of Klf4 to investigate its functions in maintenance of adult corneal epithelial homeostasis. METHODS Expression of Cre was induced in ternary transgenic (Klf4(LoxP/LoxP)/Krt12(rtTA/rtTA)/Tet-O-Cre) mouse corneal epithelium by doxycycline administered through intraperitoneal injections and drinking water, to generate corneal epithelium-specific deletion of Klf4 (Klf4(Δ/ΔCE)). Corneal epithelial barrier function was tested by fluorescein staining. Expression of selected Klf4-target genes was determined by quantitative PCR (QPCR), immunoblotting, and immunofluorescent staining. RESULTS Klf4 was efficiently ablated within 5 days of doxycycline administration in adult Klf4(Δ/ΔCE) corneal epithelium. The Klf4(Δ/ΔCE) corneal epithelial barrier function was disrupted, and the basal cells were swollen and rounded after 15 days of doxycycline treatment. Increased numbers of cell layers and Ki67-positive proliferating cells suggested deregulated Klf4(Δ/ΔCE) corneal epithelial homeostasis. Expression of tight junction proteins ZO-1 and occludin, desmosomal Dsg and Dsp, basement membrane laminin-332, and corneal epithelial-specific keratin-12 was decreased, while that of matrix metalloproteinase Mmp9 and noncorneal keratin-17 increased, suggesting altered Klf4(Δ/ΔCE) corneal epithelial cell identity. CONCLUSIONS Ablation of Klf4 in the adult mouse corneas resulted in the absence of characteristic corneal epithelial cell differentiation, disrupted barrier function, and squamous metaplasia, revealing that Klf4 is essential for maintenance of the adult corneal epithelial cell identity and homeostasis.
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Affiliation(s)
- Emili E Delp
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Sudha Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Winston W Kao
- Department of Ophthalmology, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States
| | - Shivalingappa K Swamynathan
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States 3McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 4Department of Cell Biology, U
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46
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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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Reis LM, Semina EV. Conserved genetic pathways associated with microphthalmia, anophthalmia, and coloboma. ACTA ACUST UNITED AC 2015; 105:96-113. [PMID: 26046913 DOI: 10.1002/bdrc.21097] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/13/2015] [Indexed: 12/19/2022]
Abstract
The human eye is a complex organ whose development requires extraordinary coordination of developmental processes. The conservation of ocular developmental steps in vertebrates suggests possible common genetic mechanisms. Genetic diseases involving the eye represent a leading cause of blindness in children and adults. During the last decades, there has been an exponential increase in genetic studies of ocular disorders. In this review, we summarize current success in identification of genes responsible for microphthalmia, anophthalmia, and coloboma (MAC) phenotypes, which are associated with early defects in embryonic eye development. Studies in animal models for the orthologous genes identified overlapping phenotypes for most factors, confirming the conservation of their function in vertebrate development. These animal models allow for further investigation of the mechanisms of MAC, integration of various identified genes into common developmental pathways and finally, provide an avenue for the development and testing of therapeutic interventions.
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Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Cell Biology Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
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Zhang J, Upadhya D, Lu L, Reneker LW. Fibroblast growth factor receptor 2 (FGFR2) is required for corneal epithelial cell proliferation and differentiation during embryonic development. PLoS One 2015; 10:e0117089. [PMID: 25615698 PMCID: PMC4304804 DOI: 10.1371/journal.pone.0117089] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 12/19/2014] [Indexed: 11/19/2022] Open
Abstract
Fibroblast growth factors (FGFs) play important roles in many aspects of embryonic development. During eye development, the lens and corneal epithelium are derived from the same surface ectodermal tissue. FGF receptor (FGFR)-signaling is essential for lens cell differentiation and survival, but its role in corneal development has not been fully investigated. In this study, we examined the corneal defects in Fgfr2 conditional knockout mice in which Cre expression is activated at lens induction stage by Pax6 P0 promoter. The cornea in LeCre, Fgfr2loxP/loxP mice (referred as Fgfr2CKO) was analyzed to assess changes in cell proliferation, differentiation and survival. We found that Fgfr2CKO cornea was much thinner in epithelial and stromal layer when compared to WT cornea. At embryonic day 12.5–13.5 (E12.5–13.5) shortly after the lens vesicle detaches from the overlying surface ectoderm, cell proliferation (judged by labeling indices of Ki-67, BrdU and phospho-histone H3) was significantly reduced in corneal epithelium in Fgfr2CKO mice. At later stage, cell differentiation markers for corneal epithelium and underlying stromal mesenchyme, keratin-12 and keratocan respectively, were not expressed in Fgfr2CKO cornea. Furthermore, Pax6, a transcription factor essential for eye development, was not present in the Fgfr2CKO mutant corneal epithelial at E16.5 but was expressed normally at E12.5, suggesting that FGFR2-signaling is required for maintaining Pax6 expression in this tissue. Interestingly, the role of FGFR2 in corneal epithelial development is independent of ERK1/2-signaling. In contrast to the lens, FGFR2 is not required for cell survival in cornea. This study demonstrates for the first time that FGFR2 plays an essential role in controlling cell proliferation and differentiation, and maintaining Pax6 levels in corneal epithelium via ERK-independent pathways during embryonic development.
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Affiliation(s)
- Jinglin Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China
| | - Dinesh Upadhya
- Dept. of Ophthalmology, Mason Eye Institute, University of Missouri, Columbia, Missouri, United States of America
| | - Lin Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China
| | - Lixing W. Reneker
- Dept. of Ophthalmology, Mason Eye Institute, University of Missouri, Columbia, Missouri, United States of America
- * E-mail:
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49
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Science and Art of Cell-Based Ocular Surface Regeneration. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 319:45-106. [DOI: 10.1016/bs.ircmb.2015.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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50
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Dorà NJ, Collinson JM, Hill RE, West JD. Hemizygous Le-Cre transgenic mice have severe eye abnormalities on some genetic backgrounds in the absence of LoxP sites. PLoS One 2014; 9:e109193. [PMID: 25272013 PMCID: PMC4182886 DOI: 10.1371/journal.pone.0109193] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 08/29/2014] [Indexed: 11/18/2022] Open
Abstract
Eye phenotypes were investigated in Le-CreTg/−; Pax6fl/+ mice, which were expected to show tissue-specific reduction of Pax6 in surface ectoderm derivatives. To provide a better comparison with our previous studies of Pax6+/− eye phenotypes, hemizygous Le-CreTg/− and heterozygous Pax6fl/+mice were crossed onto the CBA/Ca genetic background. After the Le-Cre transgene had been backcrossed to CBA/Ca for seven generations, significant eye abnormalities occurred in some hemizygous Le-CreTg/−; Pax6+/+ controls (without a floxed Pax6fl allele) as well as experimental Le-CreTg/−; Pax6fl/+ mice. However, no abnormalities were seen in Le-Cre−/−; Pax6fl/+ or Le-Cre−/−; Pax6+/+ controls (without the Le-Cre transgene). The severity and frequency of the eye abnormalities in Le-CreTg/−; Pax6+/+ control mice diminished after backcrossing Le-CreTg/− mice to the original FVB/N strain for two generations, showing that the effect was reversible. This genetic background effect suggests that the eye abnormalities are a consequence of an interaction between the Le-Cre transgene and alleles of unknown modifier genes present in certain genetic backgrounds. The abnormalities were also ameliorated by introducing additional Pax6 gene copies on a CBA/Ca background, suggesting involvement of Pax6 depletion in Le-CreTg/−; Pax6+/+ mice rather than direct action of Cre recombinase on cryptic pseudo-loxP sites. One possibility is that expression of Cre recombinase from the Pax6-Le regulatory sequences in the Le-Cre transgene depletes cofactors required for endogenous Pax6 gene expression. Our observation that eye abnormalities can occur in hemizygous Le-CreTg/−; Pax6+/+ mice, in the absence of a floxed allele, demonstrates the importance of including all the relevant genetic controls in Cre-loxP experiments.
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Affiliation(s)
- Natalie J. Dorà
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - J. Martin Collinson
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, 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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