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Torrents S, Grau-Vorster M, Vives J. Illustrative Potency Assay Examples from Approved Therapies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1420:139-149. [PMID: 37258788 DOI: 10.1007/978-3-031-30040-0_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Advanced therapy medicinal products (ATMP) encompass a new type of drugs resulting from the manipulation of genes, cells, and tissues to generate innovative medicinal entities with tailored pharmaceutical activity. Definition of suitable potency tests for product release are challenging in this context, in which the active ingredient is composed of living cells and the mechanism of action often is poorly understood. In this chapter, we present and discuss actual potency assays used for the release of representative commercial ATMP from each category of products (namely, KYMRIAH® (tisagenlecleucel), Holoclar® (limbal epithelial stem cells), and PROCHYMAL®/RYONCIL™ (remestemcel-L)). We also examine concerns related to the biological relevance of selected potency assays and challenges ahead for harmonization and broader implementation in compliance with current quality standards and regulatory guidelines.
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Affiliation(s)
- Sílvia Torrents
- Banc de Sang i Teixits, Edifici Dr. Frederic Duran i Jordà, Barcelona, Spain
- Transfusion Medicine group, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marta Grau-Vorster
- Banc de Sang i Teixits, Edifici Dr. Frederic Duran i Jordà, Barcelona, Spain
- Transfusion Medicine group, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Joaquim Vives
- Banc de Sang i Teixits, Edifici Dr. Frederic Duran i Jordà, Barcelona, Spain.
- Musculoskeletal Tissue Engineering Group, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
- Departament de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.
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Chen YY, Sun YC, Tsai CY, Chu HS, Wu JH, Chang HW, Chen WL. Spectral-domain optical coherence tomography for evaluating palisades of Vogt in ocular surface disorders with limbal involvement. Sci Rep 2021; 11:12502. [PMID: 34127762 PMCID: PMC8203687 DOI: 10.1038/s41598-021-91999-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 05/17/2021] [Indexed: 12/03/2022] Open
Abstract
Spectral-domain optical coherence tomography (SD-OCT) has been used to observe the morphology of the palisades of Vogt (POV) with satisfactory resolutions. In this study, we used SD-OCT to examine the microstructure of the POV in ocular surface disorders with limbal involvement. We detect subclinical limbal pathologies based on five parameters, including (1) decreased epithelial thickness, (2) loss of the sharp stromal tip, (3) loss of the smooth epithelial-stromal interface, (4) dilated stromal vessels, and (5) decreased POV density. Eighteen eyes of 10 patients with advancing wavelike epitheliopathy (AWE) and 15 eyes of 9 patients with phlyctenular keratitis/ocular rosacea were recruited. SD-OCT could detect abnormal changes in the POV in 100% of the lesion sites. In presumed-healthy areas of the diseased eyes diagnosed by slit-lamp biomicroscopy, SD-OCT detected abnormal changes in the POV in 100% of the eyes in both groups. In patients with unilateral disease, abnormal changes in the POV were detected by SD-OCT in 50% and 100% of presumed-healthy eyes diagnosed by slit-lamp biomicroscopy in the AWE group and phlyctenular keratitis/ocular rosacea group, respectively. SD-OCT is powerful in detecting POV changes in ocular surface disorders and can provide useful information that cannot be provided by slit-lamp biomicroscopy.
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Affiliation(s)
- Ying-Yi Chen
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan
| | - Yi-Chen Sun
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan.,Department of Ophthalmology, Taipei Tzu Chi Hospital, The Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan
| | - Chia-Ying Tsai
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Ophthalmology, Fu-Jen Catholic University, New Taipei City, Taiwan.,School of Medicine, College of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Hsiao-Sang Chu
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Advanced Ocular Surface and Corneal Nerve Research Center, National Taiwan University Hospital, Taipei, Taiwan
| | - Jo-Hsuan Wu
- Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, CA, USA
| | - Huai-Wen Chang
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan
| | - Wei-Li Chen
- Department of Ophthalmology, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan. .,Advanced Ocular Surface and Corneal Nerve Research Center, National Taiwan University Hospital, Taipei, Taiwan. .,Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan.
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Gore A, Kadar T, Dachir S, Horwitz V. Therapeutic measures for sulfur mustard-induced ocular injury. Toxicol Lett 2021; 340:58-66. [PMID: 33440228 DOI: 10.1016/j.toxlet.2021.01.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 02/07/2023]
Abstract
The use of sulfur mustard (SM) in global terrorism is still a relevant threat to both civilian population and military personnel. Casualties exposed to SM may present mild, moderate or severe acute ocular lesions followed by a complete ocular resolution, chronic lesions or re-emerged ocular pathologies after a latent period. Current treatment for SM-induced ocular injury is based mainly on the clinical manifestation at the different stages of the injury and includes pharmaceutical and surgical interventions. These therapeutic measures are beneficial but not sufficient, and the ocular injury remains a continuous challenge for medical professionals. This review focuses on treatment experience carried out in humans and studied in animal models, for both SM-induced ocular acute injury and late pathology. In general, therapeutic measures are based on clinical features of the ocular injury or on the involvement of specific factors during the ocular injury that point out towards potential treatments. Anti-inflammatory treatments and limbal stem cell transplantation techniques were developed based on the clinical manifestation of the ocular injury. Optional therapies for impaired corneal innervation and endothelium are suggested for future research. Additionally, studies on potential treatments with anti-matrix metalloproteinase (MMP), anti-vascular endothelial growth factor (VEGF) and anti-IL-6 agents are discussed. Consequently, future studies may reveal the potential of additional pharmacological and biological treatments or advanced cellular and molecular biology methods to serve as novel therapeutic measures and techniques for this complicated ocular injury.
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Affiliation(s)
- Ariel Gore
- Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100, Israel.
| | - Tamar Kadar
- Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100, Israel
| | - Shlomit Dachir
- Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100, Israel
| | - Vered Horwitz
- Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100, Israel.
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Bevacizumab Induces Upregulation of Keratin 3 and VEGFA in Human Limbal Epithelial Cells in Vitro. J Clin Med 2019; 8:jcm8111925. [PMID: 31717500 PMCID: PMC6912829 DOI: 10.3390/jcm8111925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/14/2019] [Accepted: 11/07/2019] [Indexed: 02/06/2023] Open
Abstract
Topical application of vascular endothelial growth factor A (VEGFA) inhibitors including Bevacizumab is used for antiangiogenic therapy at the ocular surface. While clinical studies have suggested that this approach is well-tolerated, the effect of the drug on limbal epithelial stem cells has not been studied. In this study, the effect of Bevacizumab on phenotype and functionality of putative limbal epithelial stem cells (SC) was investigated. The effect of Bevacizumab on human limbal epithelial cells was assessed in terms of metabolic activity and scratch wound closure. The different treatment groups featured no difference in proliferation and colony forming efficiency (CFE) of limbal epithelial cells or their putative SC marker expression. A significant delay in scratch closure of all the Bevacizumab-treated groups was detected at 4 h. RNA and protein quantification indicated a dose-responsive increase of keratin 3. VEGFA RNA expression also increased while VEGFC and D as well as VEGFR1, 2 and 3 were unchanged. This study highlights previously unknown effects of Bevacizumab on cultured putative limbal epithelial SC: a dose-related increase of keratin 3, an increase in VEGFA as well as a delay in scratch wound closure. These in vitro data should be considered when using Bevacizumab in the context of limbal epithelial SC transplantation.
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Tomasello L, Coppola A, Pitrone M, Failla V, Cillino S, Pizzolanti G, Giordano C. PFN1 and integrin-β1/mTOR axis involvement in cornea differentiation of fibroblast limbal stem cells. J Cell Mol Med 2019; 23:7210-7221. [PMID: 31513338 PMCID: PMC6815913 DOI: 10.1111/jcmm.14438] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/26/2019] [Accepted: 05/15/2019] [Indexed: 12/14/2022] Open
Abstract
Ex vivo limbal stem cell transplantation is the main therapeutic approach to address a complete and functional re-epithelialization in corneal blindness, the second most common eye disorder. Although important key points were defined, the molecular mechanisms involved in the epithelial phenotype determination are unclear. Our previous studies have demonstrated the pluripotency and immune-modulatory of fibroblast limbal stem cells (f-LSCs), isolated from the corneal limbus. We defined a proteomic profile especially enriched in wound healing and cytoskeleton-remodelling proteins, including Profilin-1 (PFN1). In this study we postulate that pfn-1 knock down promotes epithelial lineage by inhibiting the integrin-β1(CD29)/mTOR pathway and subsequent NANOG down-expression. We showed that it is possible modulate pfn1 expression levels by treating f-LSCs with Resveratrol (RSV), a natural compound: pfn1 decline is accompanied with up-regulation of the specific differentiation epithelial genes pax6 (paired-box 6), sox17 (sex determining region Y-box 17) and ΔNp63-α (p63 splice variant), consistent with drop-down of the principle stem gene levels. These results contribute to understand the molecular biology of corneal epithelium development and suggest that pfn1 is a potential molecular target for the treatment of corneal blindness based on epithelial cell dysfunction.
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Affiliation(s)
- Laura Tomasello
- Laboratory of Regenerative Medicine "Aldo Galluzzo", Section of Endocrinology, Diabetology and Metabolism, Department of Promozione della Salute, Materno-Infantile, di Medicina Interna e Specialistica di Eccellenza "G. D'Alessandro" (ProMISE), University of Palermo, Palermo, Italy
| | - Antonina Coppola
- Laboratory of Regenerative Medicine "Aldo Galluzzo", Section of Endocrinology, Diabetology and Metabolism, Department of Promozione della Salute, Materno-Infantile, di Medicina Interna e Specialistica di Eccellenza "G. D'Alessandro" (ProMISE), University of Palermo, Palermo, Italy
| | - Maria Pitrone
- Laboratory of Regenerative Medicine "Aldo Galluzzo", Section of Endocrinology, Diabetology and Metabolism, Department of Promozione della Salute, Materno-Infantile, di Medicina Interna e Specialistica di Eccellenza "G. D'Alessandro" (ProMISE), University of Palermo, Palermo, Italy
| | - Valentina Failla
- Department of Ophthalmology, University of Palermo, Palermo, Italy
| | | | - Giuseppe Pizzolanti
- Laboratory of Regenerative Medicine "Aldo Galluzzo", Section of Endocrinology, Diabetology and Metabolism, Department of Promozione della Salute, Materno-Infantile, di Medicina Interna e Specialistica di Eccellenza "G. D'Alessandro" (ProMISE), University of Palermo, Palermo, Italy
| | - Carla Giordano
- Laboratory of Regenerative Medicine "Aldo Galluzzo", Section of Endocrinology, Diabetology and Metabolism, Department of Promozione della Salute, Materno-Infantile, di Medicina Interna e Specialistica di Eccellenza "G. D'Alessandro" (ProMISE), University of Palermo, Palermo, Italy
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Hos D, Matthaei M, Bock F, Maruyama K, Notara M, Clahsen T, Hou Y, Le VNH, Salabarria AC, Horstmann J, Bachmann BO, Cursiefen C. Immune reactions after modern lamellar (DALK, DSAEK, DMEK) versus conventional penetrating corneal transplantation. Prog Retin Eye Res 2019; 73:100768. [PMID: 31279005 DOI: 10.1016/j.preteyeres.2019.07.001] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 07/01/2019] [Accepted: 07/02/2019] [Indexed: 12/12/2022]
Abstract
In the past decade, novel lamellar keratoplasty techniques such as Deep Anterior Lamellar Keratoplasty (DALK) for anterior keratoplasty and Descemet stripping automated endothelial keratoplasty (DSAEK)/Descemet membrane endothelial keratoplasty (DMEK) for posterior keratoplasty have been developed. DALK eliminates the possibility of endothelial allograft rejection, which is the main reason for graft failure after penetrating keratoplasty (PK). Compared to PK, the risk of endothelial graft rejection is significantly reduced after DSAEK/DMEK. Thus, with modern lamellar techniques, the clinical problem of endothelial graft rejection seems to be nearly solved in the low-risk situation. However, even with lamellar grafts there are epithelial, subepithelial and stromal immune reactions in DALK and endothelial immune reactions in DSAEK/DMEK, and not all keratoplasties can be performed in a lamellar fashion. Therefore, endothelial graft rejection in PK is still highly relevant, especially in the "high-risk" setting, where the cornea's (lymph)angiogenic and immune privilege is lost due to severe inflammation and pathological neovascularization. For these eyes, currently available treatment options are still unsatisfactory. In this review, we will describe currently used keratoplasty techniques, namely PK, DALK, DSAEK, and DMEK. We will summarize their indications, provide surgical descriptions, and comment on their complications and outcomes. Furthermore, we will give an overview on corneal transplant immunology. A specific focus will be placed on endothelial graft rejection and we will report on its incidence, clinical presentation, and current/future treatment and prevention options. Finally, we will speculate how the field of keratoplasty and prevention of corneal allograft rejection will develop in the future.
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Affiliation(s)
- Deniz Hos
- Department of Ophthalmology, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Mario Matthaei
- Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Felix Bock
- Department of Ophthalmology, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Kazuichi Maruyama
- Department of Innovative Visual Science, Graduate School of Medicine, Osaka University, Japan
| | - Maria Notara
- Department of Ophthalmology, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Thomas Clahsen
- Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Yanhong Hou
- Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Viet Nhat Hung Le
- Department of Ophthalmology, University of Cologne, Cologne, Germany; Department of Ophthalmology, Hue College of Medicine and Pharmacy, Hue University, Viet Nam
| | | | - Jens Horstmann
- Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Bjoern O Bachmann
- Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Claus Cursiefen
- Department of Ophthalmology, University of Cologne, Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
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8
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Tomasello L, Musso R, Cillino G, Pitrone M, Pizzolanti G, Coppola A, Arancio W, Di Cara G, Pucci-Minafra I, Cillino S, Giordano C. Donor age and long-term culture do not negatively influence the stem potential of limbal fibroblast-like stem cells. Stem Cell Res Ther 2016; 7:83. [PMID: 27296060 PMCID: PMC4906894 DOI: 10.1186/s13287-016-0342-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 01/14/2016] [Accepted: 05/16/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND In regenerative medicine the maintenance of stem cell properties is of crucial importance. Ageing is considered a cause of reduced stemness capability. The limbus is a stem niche of easy access and harbors two stem cell populations: epithelial stem cells and fibroblast-like stem cells. Our aim was to investigate whether donor age and/or long-term culture have any influence on stem cell marker expression and the profiles in the fibroblast-like stem cell population. METHODS Fibroblast-like stem cells were isolated and digested from 25 limbus samples of normal human corneo-scleral rings and long-term cultures were obtained. SSEA4 expression and sphere-forming capability were evaluated; cytofluorimetric assay was performed to detect the immunophenotypes HLA-DR, CD45, and CD34 and the principle stem cell markers ABCG2, OCT3/4, and NANOG. Molecular expression of the principal mesenchymal stem cell genes was investigated by real-time PCR. Two-dimensional gel electrophoresis and mass spectrometric sequencing were performed and a stable proteomic profile was identified. The proteins detected were explored by gene ontology and STRING analysis. The data were reported as means ± SD, compared by Student's unpaired t test and considering p < 0.05 as statistically significant. RESULTS The isolated cells did not display any hematopoietic surface marker (CD34 and CD45) and HLA-DR and they maintained these features in long-term culture. The expression of the stemness genes and the multilineage differentiation under in-vitro culture conditions proved to be well maintained. Proteomic analysis revealed a fibroblast-like stem cell profile of 164 proteins with higher expression levels. Eighty of these showed stable expression levels and were involved in maintenance of "the stem gene profile"; 84 were differentially expressed and were involved in structural activity. CONCLUSIONS The fibroblast-like limbal stem cells confirmed that they are a robust source of adult stem cells and that they have good plasticity, good proliferative capability, and long-term maintenance of stem cell properties, independently of donor age and long-term culture conditions. Our findings confirm that limbal fibroblast-like stem cells are highly promising for application in regenerative medicine and that in-vitro culture steps do not influence their stem cell properties. Moreover, the proteomic data enrich our knowledge of fibroblast-like stem cells.
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Affiliation(s)
- Laura Tomasello
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | - Rosa Musso
- Centro di Oncobiologia Sperimentale (COBS), Palermo, Italy
| | - Giovanni Cillino
- Department of Ophthalmology, University of Palermo, Palermo, Italy
| | - Maria Pitrone
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | - Giuseppe Pizzolanti
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
- ATeN (Advanced Technologies Network Center), University of Palermo, Palermo, Italy
| | - Antonina Coppola
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | - Walter Arancio
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy
| | | | | | | | - Carla Giordano
- Laboratory of Regenerative Medicine, Section of Endocrinology, Diabetology and Metabolism, Di.Bi.M.I.S., University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy.
- ATeN (Advanced Technologies Network Center), University of Palermo, Palermo, Italy.
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Short-term uvb-irradiation leads to putative limbal stem cell damage and niche cell-mediated upregulation of macrophage recruiting cytokines. Stem Cell Res 2015; 15:643-654. [DOI: 10.1016/j.scr.2015.10.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/16/2015] [Indexed: 01/17/2023] Open
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Chan EH, Chen L, Rao JY, Yu F, Deng SX. Limbal Basal Cell Density Decreases in Limbal Stem Cell Deficiency. Am J Ophthalmol 2015; 160:678-84.e4. [PMID: 26149968 DOI: 10.1016/j.ajo.2015.06.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 06/26/2015] [Accepted: 06/27/2015] [Indexed: 12/13/2022]
Abstract
PURPOSE To investigate changes in limbal basal epithelial cell density in eyes with limbal stem cell deficiency (LSCD) using in vivo confocal laser scanning microscopy. DESIGN Retrospective observational comparative study. METHODS A total of 43 eyes of 30 patients diagnosed with LSCD were included in the study. Ten eyes from normal subjects were included as control. Confocal imaging of the central cornea, and the superior, nasal, inferior and temporal limbus were collected using the Heidelberg Retina Tomograph III Rostock Corneal Module. Basal cell density in all locations was measured by 2 independent observers. RESULTS The mean basal cell density of the normal group was 9264 ± 598 cells/mm(2) in the cornea and 7120 ± 362 cells/mm(2) in the limbus. In the LSCD group, the mean basal cell density in the cornea decreased 31.0% (6389 ± 1820 cells/mm(2), P < .001) and in the limbus decreased 23.6% (5440 ± 1123 cells/mm(2), P < .001) compared to that in the control. There was a trend of basal cell density decline in more advanced stages of LSCD. The basal cell density declined in the unaffected regions at a similar degree as that in the affected region in sectoral LSCD (P > .05). The basal cell diameter increased by 24.6% in the cornea (14.7 μm) and by 15.7% in the limbus (15.5 μm) compared to the control. CONCLUSIONS Basal cell density in both central cornea and limbus decreases in LSCD. Limbal stem cells (LSCs) are affected globally and basal cell density could be used as a parameter to measure LSC function at the early stages of the disease process.
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Huang M, Wang B, Wan P, Liang X, Wang X, Liu Y, Zhou Q, Wang Z. Roles of limbal microvascular net and limbal stroma in regulating maintenance of limbal epithelial stem cells. Cell Tissue Res 2014; 359:547-563. [PMID: 25398719 DOI: 10.1007/s00441-014-2032-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 10/14/2014] [Indexed: 02/06/2023]
Abstract
Knowledge of the microenvironment (niche) of stem cells is helpful for stem-cell-based regenerative medicine. In the eye, limbal epithelial stem cells (corneal epithelial stem cells) provide the self-renewal capacity of the corneal epithelium and are essential for maintaining corneal transparency and vision. Limbal epithelial stem cell deficiency results in significant visual deterioration. Successful treatment of this type of blinding disease requires studies of the limbal epithelial stem cells and their microenvironment. We investigate the function of the limbal microvascular net and the limbal stroma in the maintenace of the limbal epithelial stem cell niche in vivo and examine the regulation of limbal epithelial stem cell survival, proliferation and differentiation in vivo. We assess the temporal and spatial changes in the expression patterns of the following markers during a six-month follow-up of various rabbit limbal autograft transplantation models: vascular endothelial cell marker CD31, corneal epithelium differentiation marker K3, limbal epithelial stem-cell-associated markers P63 and ABCG2 and proliferating cell nuclear marker Ki67. Our results suggest that limbal epithelial stem cells cannot maintain their stemness or proliferation without the support of the limbal microvascular net microenvironment. Thus, both the limbal microvascular net and the limbal stroma play important roles as components of the limbal epithelial stem cell niche maintaining limbal epithelial stem cell survival and proliferation and the avoidance of differentiation. The limbal stroma constitutes the structural basis of the limbal epithelial stem cell niche and the limbal microvascular net is a requirement for this niche. These new insights should aid the eventual construction of tissue-engineered cornea for corneal blind patients in the future.
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Affiliation(s)
- Minghai Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xian Lie Nan Road, Guangzhou, 510060, People's Republic of China.,Nanning Aier Eye Hospital, Nanning, 530015, People's Republic of China
| | - Bowen Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xian Lie Nan Road, Guangzhou, 510060, People's Republic of China
| | - Pengxia Wan
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, People's Republic of China
| | - Xuanwei Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xian Lie Nan Road, Guangzhou, 510060, People's Republic of China
| | - Xiaoran Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xian Lie Nan Road, Guangzhou, 510060, People's Republic of China
| | - Ying Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xian Lie Nan Road, Guangzhou, 510060, People's Republic of China
| | - Qiang Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xian Lie Nan Road, Guangzhou, 510060, People's Republic of China
| | - Zhichong Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xian Lie Nan Road, Guangzhou, 510060, People's Republic of China.
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Ksander BR, Kolovou PE, Wilson BJ, Saab KR, Guo Q, Ma J, McGuire SP, Gregory MS, Vincent WJB, Perez VL, Cruz-Guilloty F, Kao WWY, Call MK, Tucker BA, Zhan Q, Murphy GF, Lathrop KL, Alt C, Mortensen LJ, Lin CP, Zieske JD, Frank MH, Frank NY. ABCB5 is a limbal stem cell gene required for corneal development and repair. Nature 2014; 511:353-7. [PMID: 25030174 DOI: 10.1038/nature13426] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/30/2014] [Indexed: 12/20/2022]
Abstract
Corneal epithelial homeostasis and regeneration are sustained by limbal stem cells (LSCs), and LSC deficiency is a major cause of blindness worldwide. Transplantation is often the only therapeutic option available to patients with LSC deficiency. However, while transplant success depends foremost on LSC frequency within grafts, a gene allowing for prospective LSC enrichment has not been identified so far. Here we show that ATP-binding cassette, sub-family B, member 5 (ABCB5) marks LSCs and is required for LSC maintenance, corneal development and repair. Furthermore, we demonstrate that prospectively isolated human or murine ABCB5-positive LSCs possess the exclusive capacity to fully restore the cornea upon grafting to LSC-deficient mice in xenogeneic or syngeneic transplantation models. ABCB5 is preferentially expressed on label-retaining LSCs in mice and p63α-positive LSCs in humans. Consistent with these findings, ABCB5-positive LSC frequency is reduced in LSC-deficient patients. Abcb5 loss of function in Abcb5 knockout mice causes depletion of quiescent LSCs due to enhanced proliferation and apoptosis, and results in defective corneal differentiation and wound healing. Our results from gene knockout studies, LSC tracing and transplantation models, as well as phenotypic and functional analyses of human biopsy specimens, provide converging lines of evidence that ABCB5 identifies mammalian LSCs. Identification and prospective isolation of molecularly defined LSCs with essential functions in corneal development and repair has important implications for the treatment of corneal disease, particularly corneal blindness due to LSC deficiency.
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Affiliation(s)
- Bruce R Ksander
- 1] Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Harvard Medical School, Boston, Massachusetts 02114, USA [2]
| | - Paraskevi E Kolovou
- 1] Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Harvard Medical School, Boston, Massachusetts 02114, USA [2]
| | - Brian J Wilson
- 1] Transplant Research Program, Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Department of Dermatology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA [3] Department of Medicine, VA Boston Healthcare System, Boston, Massachusetts 02130, USA
| | - Karim R Saab
- 1] Transplant Research Program, Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Department of Dermatology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Qin Guo
- 1] Department of Medicine, VA Boston Healthcare System, Boston, Massachusetts 02130, USA [2] Transplant Research Program, Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts 02115, USA [3] Department of Dermatology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Jie Ma
- 1] Transplant Research Program, Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Department of Dermatology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Sean P McGuire
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Meredith S Gregory
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - William J B Vincent
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Victor L Perez
- Bascom Palmer Eye Institute and the Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Fernando Cruz-Guilloty
- Bascom Palmer Eye Institute and the Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Winston W Y Kao
- Department of Ophthalmology, University of Cincinnati Medical Center, Cincinnati, Ohio 45229, USA
| | - Mindy K Call
- Department of Ophthalmology, University of Cincinnati Medical Center, Cincinnati, Ohio 45229, USA
| | - Budd A Tucker
- Stephen A Wynn Institute for Vision Research, Carver College of Medicine, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa 52242, USA
| | - Qian Zhan
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - George F Murphy
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Kira L Lathrop
- Department of Ophthalmology, University of Pittsburgh School of Medicine & Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania 15213, USA
| | - Clemens Alt
- Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Luke J Mortensen
- Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Charles P Lin
- Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - James D Zieske
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Markus H Frank
- 1] Transplant Research Program, Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts 02115, USA [2] Department of Dermatology, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA [3] Harvard Stem Cell Institute, Harvard Medical School, Boston, Massachusetts 02138, USA [4]
| | - Natasha Y Frank
- 1] Department of Medicine, VA Boston Healthcare System, Boston, Massachusetts 02130, USA [2] Transplant Research Program, Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts 02115, USA [3] Harvard Stem Cell Institute, Harvard Medical School, Boston, Massachusetts 02138, USA [4] Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA [5]
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13
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Cultivation and characterization of limbal epithelial stem cells on contact lenses with a feeder layer: toward the treatment of limbal stem cell deficiency. Cornea 2014; 33:65-71. [PMID: 24162749 DOI: 10.1097/ico.0000000000000002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Limbal epithelial sheets are used to promote corneal surface reconstruction after the detection of limbal epithelial stem cell deficiency. The aim of this study was to evaluate a novel combination of limbal stem cells (LSCs) maintained on contact lenses (CLs) in the presence of a 3T3 feeder cell layer regarding preservation of stem cell phenotype and the potential use for future in vivo transplantation. METHODS Limbal epithelial cells were isolated from rabbit cornea and cultured with 3T3 cells on CLs. The preservation of LSC phenotype was determined using p63α and ABCG2 immunostaining, whereas epithelial differentiation was evaluated using CK3 and CK19. The colony-forming assay was used to determine the percentage of LSCs in cultures. Finally, CLs seeded with PKH26-labeled LSCs were transferred to rabbit eyes after performing a surgical keratectomy, and the transition and phenotype of labeled cells on the corneal surface were evaluated in whole-mount corneas. RESULTS Proliferation of individual limbal cells was observed on CLs with a 3T3 feeder cell layer, showing holoclone formation and retention of viable stem or progenitor cell phenotype. Finally, a higher transition of cultivated cells after a dual sequential CL transplantation to the ocular surface was observed, showing the preservation of the LSC phenotype in the corneal surface. CONCLUSIONS Limbal cells cultivated on a CL carrier overlaying a 3T3 feeder layer are mitotically active and retain the LSC phenotype. This novel technique of using CLs as a carrier offers an easily manipulable and nonimmunogenic method for transferring LSCs for ocular surface reconstruction in patients with limbal epithelial stem cell deficiency.
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14
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Yin JQ, Liu WQ, Liu C, Zhang YH, Hua JL, Liu WS, Dou ZY, Lei AM. Reconstruction of damaged corneal epithelium using Venus-labeled limbal epithelial stem cells and tracking of surviving donor cells. Exp Eye Res 2013; 115:246-54. [DOI: 10.1016/j.exer.2013.07.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/17/2013] [Accepted: 07/23/2013] [Indexed: 10/26/2022]
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15
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Bath C. Human corneal epithelial subpopulations: oxygen dependent ex vivo expansion and transcriptional profiling. Acta Ophthalmol 2013; 91 Thesis 4:1-34. [PMID: 23732018 DOI: 10.1111/aos.12157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Corneal epithelium is being regenerated throughout life by limbal epithelial stem cells (LESCs) believed to be located in histologically defined stem cell niches in corneal limbus. Defective or dysfunctional LESCs result in limbal stem cell deficiency (LSCD) causing pain and decreased visual acuity. Since the first successful treatment of LSCD by transplantation of ex vivo expanded LESCs in 1997, many attempts have been carried out to optimize culture conditions to improve the outcome of surgery. To date, progress in this field of bioengineering is substantially hindered by both the lack of specific biomarkers of LESCs and the lack of a precise molecular characterization of in situ epithelial subpopulations. The aim of this dissertation was to optimize culture systems with regard to the environmental oxygen concentration for selective ex vivo expansion of LESCs and to analyse in situ subpopulations in human corneal epithelium using a combination of laser capture microdissection and RNA sequencing for global transcriptomic profiling. We compared dissociation cultures, using either expansion on γ-irradiated NIH/3T3 feeder cells in serum-rich medium or expansion directly on plastic in serum-free EpiLife medium, using a range of physiologically relevant oxygen concentrations (2%, 5%, 10%, 15% and 20%). Using immunocytochemistry and advanced fluorescence microscopy, cells were characterized regarding growth, cell cycle distribution, colony-forming efficiency (CFE), phenotypes and cytomorphometry. Limbal epithelial cells expanded in 2% O2 exhibited slow growth, low fraction of cells in S/G2 , high CFE, high expression of stem cell markers ABCG2 and p63α, and low fraction of differentiation marker CK3 resembling a LESC phenotype. The effect of hypoxia to maintain LESCs in culture was not dependent on the system used for propagation (Bath et al. 2013a). Laser capture microdissection was used to isolate cellular subpopulations in situ from the spatially defined differentiation pathway in human corneal epithelium according to an optimized protocol for maintenance of expression profiles. Isolated total RNA from basal limbal crypts (BLCs), superficial limbal crypts (SLCs), paracentral/central cornea and limbal stroma was amplified and converted to fragmented cDNA libraries for use in deep paired-end next-generation sequencing. Global transcriptional profiling was carried out using bioinformatics. The location of primitive cells in BLCs, migratory and activated cells in SLCs and differentiated cells in paracentral/central cornea was evident from mapping of significantly upregulated genes in each compartment to the gene ontology (GO). Interestingly, many GO terms in BLCs were also involved in neurogenic processes, whereas many GO terms in SLCs were related to vasculature. Mapping upregulated genes in BLCs to pathway annotations in Kyoto Encyclopedia of Genes and Genomes described many active pathways as signalling and cancer-associated pathways. We supply extensive information on possible novel biomarkers, reveal insight into both active pathways and novel regulators of LESCs such as Lrig1 and SOX9 and provide an immense amount of data for future exploration (Bath et al. 2013b). Selective ex vivo expansion of LESCs in hypoxia and the comprehensive molecular characterization of corneal epithelial subpopulations in situ are expected to be beneficial for the future treatment of LSCD by cultured limbal epithelial transplantation.
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Affiliation(s)
- Chris Bath
- Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
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16
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Notara M, Hernandez D, Mason C, Daniels JT. Characterization of the phenotype and functionality of corneal epithelial cells derived from mouse embryonic stem cells. Regen Med 2012; 7:167-78. [PMID: 22397607 DOI: 10.2217/rme.11.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIMS To investigate the optimum conditions for the differentiation of a mouse embryonic stem cell line towards corneal epithelial cell fate. MATERIALS & METHODS The effect of conditioned media from both metabolically active (to produce lineage A) and growth-arrested limbal fibroblasts (lineage G) were compared with basal media (lineage N) in terms of morphology and marker expression, assessed by immunocytochemistry and reverse transcription PCR. Cultures were transplanted into a porcine ex vivo model to investigate their ability for wound healing and cornea repair. RESULTS Lineage N exhibited cobblestone morphology and expressed CK12 and p63α, while OCT4 and SSEA1 were downregulated. Post-transplantation, these cells were able to multilayer and heal after wounding while maintaining marker expression. CONCLUSION Lineages with corneal epithelial-like characteristics, which are derived from embryonic stem cells, have potential for use in the study of corneal wound healing and therapy.
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Affiliation(s)
- Maria Notara
- Department of Ocular Biology & Therapeutics, UCL Institute of Ophthalmology, London, UK.
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17
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Kadar T, Horwitz V, Sahar R, Cohen M, Cohen L, Gez R, Tveria L, Gutman H, Buch H, Fishbine E, Brandeis R, Dachir S, Amir A. Delayed Loss of Corneal Epithelial Stem Cells in a Chemical Injury Model Associated with Limbal Stem Cell Deficiency in Rabbits. Curr Eye Res 2011; 36:1098-107. [DOI: 10.3109/02713683.2011.609305] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Tamar Kadar
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Vered Horwitz
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Rita Sahar
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Maayan Cohen
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Liat Cohen
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Rellie Gez
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Liat Tveria
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Hila Gutman
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Hillel Buch
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Eliezer Fishbine
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Rachel Brandeis
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Shlomit Dachir
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
| | - Adina Amir
- Department of Pharmacology, Israel Institute for Biological Research,
Ness Ziona, Israel
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18
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Abstract
BACKGROUND Limbal stem cell deficiency (LSCD) results from damage to or destruction of corneal stem cells. METHODS A retrospective review of clinical records of a patient with LSCD describes the use of scleral lenses in disease management. RESULTS A patient presented with a one-year history of clinically diagnosed LSCD, which was worsening despite aggressive topical and systemic medical therapy. The condition resolved rapidly with initiation of scleral lens wear. The integrity of the ocular surface was maintained for 18 months even after the cessation of lens wear. CONCLUSION Scleral lenses might allow some patients with LSCD to delay or avoid more aggressive surgical intervention.
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Affiliation(s)
- Muriel M Schornack
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota 55905, USA.
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19
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Notara M, Schrader S, Daniels JT. The porcine limbal epithelial stem cell niche as a new model for the study of transplanted tissue-engineered human limbal epithelial cells. Tissue Eng Part A 2011; 17:741-50. [PMID: 20929285 DOI: 10.1089/ten.tea.2010.0343] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Transparency of the human cornea is dependent upon the integrity of its epithelium and hence a population of limbal epithelial stem cells (LESCs). We have previously shown that LESCs reside in limbal epithelial crypts at the periphery of the human cornea. In this study the anatomy and functionality of the porcine limbus was evaluated for the first time as a novel model of the human limbus. Scanning electron microscopy, confocal microscopy, and histology revealed common structures in the porcine and human limbus in terms of the location and topography of palisades of Vogt and limbal epithelial crypts. Epithelial cells harvested from crypt regions achieved higher colony forming efficiency than cultures established from the noncrypt regions and central cornea. Also, expression of the putative SC markers p63α and integrin β1 brightness was higher in the basal layer of the crypt regions, as shown by immunocytochemistry. De-epithelialized porcine corneas were used as an in vitro organ culture model to study the fate of transplanted human epithelium cultured from the limbus. Multilayered epithelium was observed after ∼1 week. Subsequently, wounds were inflicted on the central corneal epithelium. The wounded tissue healed within 5-7 days, and multilayering of the central corneal epithelium was re-established. The transplanted epithelia were repeatedly wounded at least four times and the wounds healed by 1 week. Putative SC marker expression of the transplanted epithelia was confirmed using immunohistochemistry. These results demonstrate that the porcine limbus shares features with the human limbus and as such provides a suitable model for the study of cultured limbal epithelial cell transplantation. These data have significant clinical value as this model can provide information on LESC fate post-transplantation and their ability to respond to injury, which is not possible to study in patients.
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Affiliation(s)
- Maria Notara
- Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom.
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20
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Vergallo C, Fonseca T, Pizzi G, Dini L. Lycopersicon esculentum lectin is a marker of transient amplifying cells in in vitro cultures of isolated limbal stem cells. Tissue Cell 2010; 42:259-65. [PMID: 20542531 DOI: 10.1016/j.tice.2010.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 05/03/2010] [Accepted: 05/07/2010] [Indexed: 11/19/2022]
Abstract
The maintenance of a healthy corneal epithelium under both normal and wound healing conditions is achieved by a population of stem cells (SCs) located in the basal epithelium at the corneoscleral limbus. In the light of the development of strategies for reconstruction of the ocular surface in patients with limbal stem cell deficiency, a major challenge in corneal SCs biology remains the ability to identify stem cells in situ and in vitro. To date, not so much markers exist for the identification of different phenotypes. CESCs (corneal epithelial stem cells) isolated from limbal biopsies were maintained in primary culture for 14 days and stained with Hoechst and a panel of FITC-conjugated lectins. All lectins, with the exception of Lycopersicon esculentum, labelled CESCs irrespective of the degree of differentiation. Lycopersicon esculentum, that binds N-acetylglucosamine oligomers, labelled intensely only the surface of TACs (single corneal epithelial stem cells better than colonial cells). These results suggest that Lycopersicon esculentum lectin is a useful and easy-to-use marker for the in vitro identification of TACs (transient amplifying cells) in cultures of isolated CESCs.
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Affiliation(s)
- C Vergallo
- Department of Biological and Environmental Science and Technology, University of the Salento, Via per Monteroni, 73100 Lecce, Italy
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21
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New technologies in limbal epithelial stem cell transplantation. Curr Opin Biotechnol 2009; 20:593-7. [PMID: 19833502 DOI: 10.1016/j.copbio.2009.09.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 09/16/2009] [Indexed: 02/07/2023]
Abstract
Destruction of the limbal epithelial stem cell (LESC) population in the cornea can lead to disorders that result in chronic inflammation, pain and impaired vision. Amniotic membrane (AM) is commonly used as a substrate for LESC transplantation for ocular surface repair but it is not an ideal substrate and so attempts have been made to find a more suitable alternative. The possible substitutes reviewed here include modified AM, cell carriers such as contact lenses or gauze as well as natural substrates fibrin and silk fibroin and many collagen-based scaffolds. Although there are a number of interesting systems in development, the search for an appropriate alternative continues.
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Affiliation(s)
- Chris Mason
- Advanced Centre for Biochemical Engineering, University College London, Roberts Building, Torrington Place, London, WC1E 7JE, UK
| | - Elisa Manzotti
- Future Medicine Ltd, Unitec House, 2 Albert Place, Finchley Central, London, N3 1QB, UK
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23
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Abstract
Topical and systemic administration of drugs to the eye is highly inefficient and there is a need for controlled, sustained release, particularly for conditions that affect the posterior segment. Various nonimplantable and implantable drug delivery devices have been developed. Colloidal carriers may allow targeted drug delivery and afford protection to substances that are sensitive to degradation, particularly RNA/DNA-based treatments. Gene therapy and cell transplantation are also starting to emerge as alternatives to conventional pharmacological treatment. There is the potential to use existing ocular devices to deliver drugs. In order to exploit this opportunity, modifications to drugs and devices, along with clarification of the appropriate drug dose, must be undertaken. This review will describe some of the treatment options for ocular disease and barriers to drug delivery, discuss the design of existing drug delivery systems and highlight some of the research into combining drug delivery with existing ocular medical devices.
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Affiliation(s)
- Victoria R Kearns
- Clinical Engineering and Ophthalmology, School of Clinical Sciences, University of Liverpool, Daulby Street, Liverpool, L69 3GA, UK
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Takács L, Tóth E, Berta A, Vereb G. Stem cells of the adult cornea: from cytometric markers to therapeutic applications. Cytometry A 2009; 75:54-66. [PMID: 19051301 DOI: 10.1002/cyto.a.20671] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cornea is a major protective shield of the interior of the eye and represents two thirds of its refractive power. It is made up of three tissue layers that have different developmental origins: the outer, epithelial layer develops from the ectoderm overlying the lens vesicle, whereas the stroma and the endothelium have mesenchymal origin. In the adult organism, the outermost corneal epithelium is the most exposed to environmental damage, and its constant renewal is assured by the epithelial stem cells that reside in the limbus, the circular border of the cornea. Cell turnover in the stromal layer is very slow and the endothelial cells probably do not reproduce in the adult organism. However, recent experimental evidence indicates that stem cells may be found in these layers. Damage to any of the corneal layers leads to loss of transparency and low vision. Corneal limbal stem cell deficiency results in severe ocular surface disease and its treatment by transplantating ex vivo expanded limbal epithelial cells is becoming widely accepted today. Stromal and endothelial stem cells are potential tools of tissue engineering and regenerative therapies of corneal ulcers and endothelial cell loss. In the past few years, intensive research has focused on corneal stem cells aiming to improve the outcomes of the current corneal stem cell transplantation techniques. This review summarizes the current state of knowledge on corneal epithelial, stromal and endothelial stem cells. Special emphasis is placed on the molecular markers that may help to identify these cells, and the recently revealed mechanisms that could maintain their "stemness" or drive their differentiation. The techniques for isolating and culturing/expanding these cells are also described.
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Affiliation(s)
- Lili Takács
- Department of Ophthalmology, Medical and Health Science Center, University of Debrecen, Hungary
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25
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Regenerating cochlear hair cells: quo vadis stem cell. Cell Tissue Res 2008; 333:373-9. [PMID: 18575894 DOI: 10.1007/s00441-008-0639-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 05/07/2008] [Accepted: 05/08/2008] [Indexed: 12/30/2022]
Abstract
Many elderly people worldwide lose the neurosensory part of their ear and turn deaf. Cochlear implants to restore some hearing after neurosensory hearing loss are, at present, the only therapy for these people. In contrast to this therapy, replacement of hair cells via stem cell therapies holds the promise for a cure. We review here current insights into embryonic, adult, and inducible stem cells that might provide cells for seeding the cochlea with the hope of new hair cell formation. We propose a two-step approach using a first set of transcription factors to enhance the generation of inducible pluripotent stem (iPS) cells and a second set of factors to initiate the differentiation of hair cells. Recent evidence regarding ear development and stem cell research strongly suggest that microRNAs will be an important new regulatory factor in both iPS cell formation and differentiation to reprogram cells into hair cells. In addition, we highlight currently insurmountable obstacles to the successful transformation of stem cells into hair cell precursors and their injection into the cochlear canal to replace lost hair cells.
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26
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Bibliography. Current world literature. Corneal and external disorders. Curr Opin Ophthalmol 2008; 19:363-6. [PMID: 18545022 DOI: 10.1097/icu.0b013e328308161d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Benitah SA. Epidermal stem cells in skin homeostasis and cutaneous carcinomas. Clin Transl Oncol 2008; 9:760-6. [PMID: 18158979 DOI: 10.1007/s12094-007-0137-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Skin and squamous epithelia regulate water and heat homeostasis and constitute our first barrier of protection against pathogens. Cells from the outermost layer of the skin, the cornified envelope (stratum corneum), are constantly being shed, imposing a constant demand for replenishment to maintain homeostasis. Hair follicles and sebaceous glands provide protective hair growth and skin sebum, and continuously undergo cycles of growth and regression. The outstanding ability of the epidermis, hair follicles and sebaceous glands to self-renew relies on a population of adult stem cells that are maintained throughout our life span. In this review we will provide an overview of our current knowledge about epidermal stem cells, and some of the molecular mechanisms that identify them and dictate their behaviour. We will also summarise our view on the possible link between adult epidermal stem cells and cancer stem cells within skin and squamous neoplasias. The potential of epidermal stem cells in regenerative medicine and for designing targeted antitumoral therapies will be discussed.
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Affiliation(s)
- S Aznar Benitah
- Epithelial Homeostasis and Cancer Laboratory, Department of Differentiation and Cancer, Center for Genomic Regulation (CRG-PRBB), Barcelona, Spain.
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