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Trujillo Cubillo L, Gurdal M, Zeugolis DI. Corneal fibrosis: From in vitro models to current and upcoming drug and gene medicines. Adv Drug Deliv Rev 2024; 209:115317. [PMID: 38642593 DOI: 10.1016/j.addr.2024.115317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 02/29/2024] [Accepted: 04/18/2024] [Indexed: 04/22/2024]
Abstract
Fibrotic diseases are characterised by myofibroblast differentiation, uncontrolled pathological extracellular matrix accumulation, tissue contraction, scar formation and, ultimately tissue / organ dysfunction. The cornea, the transparent tissue located on the anterior chamber of the eye, is extremely susceptible to fibrotic diseases, which cause loss of corneal transparency and are often associated with blindness. Although topical corticosteroids and antimetabolites are extensively used in the management of corneal fibrosis, they are associated with glaucoma, cataract formation, corneoscleral melting and infection, imposing the need of far more effective therapies. Herein, we summarise and discuss shortfalls and recent advances in in vitro models (e.g. transforming growth factor-β (TGF-β) / ascorbic acid / interleukin (IL) induced) and drug (e.g. TGF-β inhibitors, epigenetic modulators) and gene (e.g. gene editing, gene silencing) therapeutic strategies in the corneal fibrosis context. Emerging therapeutical agents (e.g. neutralising antibodies, ligand traps, receptor kinase inhibitors, antisense oligonucleotides) that have shown promise in clinical setting but have not yet assessed in corneal fibrosis context are also discussed.
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Affiliation(s)
- Laura Trujillo Cubillo
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular & Biomedical Research and School of Mechanical & Materials Engineering, University College Dublin (UCD), Dublin, Ireland
| | - Mehmet Gurdal
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular & Biomedical Research and School of Mechanical & Materials Engineering, University College Dublin (UCD), Dublin, Ireland
| | - Dimitrios I Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular & Biomedical Research and School of Mechanical & Materials Engineering, University College Dublin (UCD), Dublin, Ireland.
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2
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Frese L, Darwiche SE, Gunning ME, Hoerstrup SP, von Rechenberg B, Giovanoli P, Calcagni M. Optimizing large-scale autologous human keratinocyte sheets for major burns-Toward an animal-free production and a more accessible clinical application. Health Sci Rep 2022; 5:e449. [PMID: 35028432 PMCID: PMC8738975 DOI: 10.1002/hsr2.449] [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: 02/11/2021] [Revised: 10/18/2021] [Accepted: 10/25/2021] [Indexed: 11/17/2022] Open
Abstract
Background and Aims Autologous keratinocyte sheets constitute an important component of the burn wound treatment toolbox available to a surgeon and can be considered a life‐saving procedure for patients with severe burns over 50% of their total body surface area. Large‐scale keratinocyte sheet cultivation still fundamentally relies on the use of animal components such as inactivated murine 3T3 fibroblasts as feeders, animal‐derived enzymes such as trypsin, as well as media components such as fetal bovine serum (FBS). This study was therefore aimed to optimize autologous keratinocyte sheets by comparing various alternatives to critical components in their production. Methods Human skin samples were retrieved from remnant operative tissues. Cell isolation efficiency and viability were investigated by comparing the efficacy of porcine‐derived trypsin and animal‐free enzymes (Accutase and TrypLESelect). The subsequent expansion of the cells and the keratinocyte sheet formation was analyzed, comparing various cell culture substrates (inactivated murine 3T3 fibroblasts, inactivated human fibroblasts, Collagen I or plain tissue culture plastic), as well as media containing serum or chemically defined animal‐free media. Results The cell isolation step showed clear cell yield advantages when using porcine‐derived trypsin, compared to animal‐free alternatives. The keratinocyte sheets produced using animal‐free serum were similar to those produced using 3T3 feeder layer and FBS‐containing medium, particularly in mechanical integrity as all grafts were liftable. In addition, sheets grown on collagen in an animal‐free medium showed indications of advantages in homogeneity, speed, reduced variability, and differentiation status compared to the other growth conditions investigated. Most importantly, the procedure was compatible with the up‐scaling requirements of major burn wound treatments. Conclusion This study demonstrated that animal‐free components could be used successfully to reduce the risk profile of large‐scale autologous keratinocyte sheet production, and thereby increase clinical accessibility.
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Affiliation(s)
- Laura Frese
- Institute for Regenerative Medicine (IREM) University of Zurich Zurich Switzerland.,Center for Applied Biotechnology and Molecular Medicine (CABMM) University of Zurich Zurich Switzerland.,La Colline Sion Switzerland
| | - Salim Elias Darwiche
- Center for Applied Biotechnology and Molecular Medicine (CABMM) University of Zurich Zurich Switzerland.,Musculoskeletal Research Unit (MSRU), Vetsuisse Faculty University of Zurich Zurich Switzerland
| | - Myrna Elisabeth Gunning
- Department of Plastic and Reconstructive Surgery University Hospital Zurich Zurich Switzerland
| | - Simon Philipp Hoerstrup
- Institute for Regenerative Medicine (IREM) University of Zurich Zurich Switzerland.,Center for Applied Biotechnology and Molecular Medicine (CABMM) University of Zurich Zurich Switzerland
| | - Brigitte von Rechenberg
- Center for Applied Biotechnology and Molecular Medicine (CABMM) University of Zurich Zurich Switzerland.,Musculoskeletal Research Unit (MSRU), Vetsuisse Faculty University of Zurich Zurich Switzerland
| | - Pietro Giovanoli
- Department of Plastic and Reconstructive Surgery University Hospital Zurich Zurich Switzerland
| | - Maurizio Calcagni
- Center for Applied Biotechnology and Molecular Medicine (CABMM) University of Zurich Zurich Switzerland.,Department of Plastic and Reconstructive Surgery University Hospital Zurich Zurich Switzerland
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Shetty R, Kumar NR, Subramani M, Krishna L, Murugeswari P, Matalia H, Khamar P, Dadachanji ZV, Mohan RR, Ghosh A, Das D. Safety and efficacy of combination of suberoylamilide hydroxyamic acid and mitomycin C in reducing pro-fibrotic changes in human corneal epithelial cells. Sci Rep 2021; 11:4392. [PMID: 33623133 PMCID: PMC7902619 DOI: 10.1038/s41598-021-83881-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 02/01/2021] [Indexed: 12/14/2022] Open
Abstract
Corneal haze post refractive surgery is prevented by mitomycin c (MMC) treatment though it can lead to corneal endothelial damage, persistent epithelial defects and necrosis of cells. Suberanilohydroxamic acid (SAHA) however has been proposed to prevent corneal haze without any adverse effects. For clinical application we have investigated the short and long term outcome of cells exposed to SAHA. Human donor cornea, cultured limbal epithelial cells, corneal rims and lenticules were incubated with SAHA and MMC. The cells/tissue was then analyzed by RT-qPCR, immunofluorescence and western blot for markers of apoptosis and fibrosis. The results reveal that short term exposure of SAHA and SAHA + MMC reduced apoptosis levels and increased αSMA expression compared to those treated with MMC. Epithelial cells derived from cultured corneal rim that were incubated with the MMC, SAHA or MMC + SAHA revealed enhanced apoptosis, reduced levels of CK3/CK12, ∆NP63 and COL4A compared to other treatments. In SAHA treated lenticules TGFβ induced fibrosis was reduced. The results imply that MMC treatment for corneal haze has both short term and long term adverse effects on cells and the cellular properties. However, a combinatorial treatment of SAHA + MMC prevents expression of corneal fibrotic markers without causing any adverse effect on cellular properties.
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Affiliation(s)
- Rohit Shetty
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Nimisha Rajiv Kumar
- GROW Laboratory, Narayana Nethralaya Post Graduate Institute of Ophthalmology, Narayana Nethralaya Foundation, Narayana Nethralaya, Narayana Health City, Bommasandra, , Bangalore, Karnataka, 560 099, India
| | - Murali Subramani
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Lekshmi Krishna
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Ponnalagu Murugeswari
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Himanshu Matalia
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Pooja Khamar
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Zelda V Dadachanji
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Rajiv R Mohan
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, 65211, USA. .,Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, 65212, USA. .,Harry S Truman Veterans' Memorial Hospital, Columbia, MO, 65201, USA.
| | - Arkasubhra Ghosh
- GROW Laboratory, Narayana Nethralaya Post Graduate Institute of Ophthalmology, Narayana Nethralaya Foundation, Narayana Nethralaya, Narayana Health City, Bommasandra, , Bangalore, Karnataka, 560 099, India.
| | - Debashish Das
- Stem Cell Research Lab, GROW Laboratory, Narayana Nethralaya Foundation, Narayana Nethralaya, Bangalore, Karnataka, India.
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Applicability of flow cytometry γH2AX assay in population studies: suitability of fresh and frozen whole blood samples. Arch Toxicol 2021; 95:1843-1851. [PMID: 33624155 DOI: 10.1007/s00204-021-03009-z] [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] [Received: 10/27/2020] [Accepted: 02/16/2021] [Indexed: 10/22/2022]
Abstract
Phosphorylation of H2AX histone (γH2AX) represents an early event in the DNA damage response against double-strand breaks (DSB); hence, its measurement provides a surrogate biomarker of DSB. Recently, we reported initial steps in the standardization of γH2AX assay in peripheral blood leukocytes (PBL), addressing the possibility of using cryopreserved samples, and the need of phytohaemagglutinin (PHA) stimulation prior analysis (Toxicol Sci 2015, 144:406-13). Validating the use of whole blood samples as cell specimen for this assay would be particularly useful for human population studies. Hence, in the current study we determined for the first time the feasibility of whole blood samples, both fresh and frozen, to be used in the γH2AX assay, evaluated by flow cytometry, and the convenience of PHA stimulation. Freshly collected and cryopreserved whole blood samples were treated with bleomycin (BLM), actinomycin-D (Act-D) and mitomycin C (MMC); half of the samples were previously incubated with PHA. Results were compared with those from PBL. Negative responses in MMC treatments were probably due to the quiescence of unstimulated cells, or to the short treatment time in PHA stimulated cells. Fresh whole blood samples exhibited a more intense response to BLM and Act-D treatments in stimulated cells, probably due to DSB indirectly produced from other less relevant types of DNA damage. Results obtained in frozen whole blood samples indicate that PHA stimulation is not advisable. In conclusion, this study demonstrates that whole blood samples can be used to assess DSB-related genotoxicity by the flow cytometry γH2AX assay.
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Signaling interplay between PARP1 and ROS regulates stress-induced cell death and developmental changes in Dictyostelium discoideum. Exp Cell Res 2020; 397:112364. [DOI: 10.1016/j.yexcr.2020.112364] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 11/03/2020] [Accepted: 11/07/2020] [Indexed: 12/22/2022]
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Carlos de Oliveira R, Wilson SE. Biological effects of mitomycin C on late corneal haze stromal fibrosis following PRK. Exp Eye Res 2020; 200:108218. [PMID: 32905844 DOI: 10.1016/j.exer.2020.108218] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/25/2020] [Accepted: 08/30/2020] [Indexed: 12/12/2022]
Abstract
This review details the current understanding of the mechanism of action and corneal effects of mitomycin C (MMC) for prophylactic prevention of stromal fibrosis after photorefractive keratectomy (PRK), and includes discussion of available information on dosage and exposure time recommended for MMC during PRK. MMC is an alkylating agent, with DNA-crosslinking activity, that inhibits DNA replication and cellular proliferation. It acts as a pro-drug and requires reduction in the tissue to be converted to an active agent capable of DNA alkylation. Although MMC augments the early keratocyte apoptosis wave in the anterior corneal stroma, its most important effect responsible for inhibition of fibrosis in surface ablation procedures such as PRK is via the inhibition of mitosis of myofibroblast precursor cells during the first few weeks after PRK. MMC use is especially useful when treating eyes with higher levels of myopia (≥approximately 6 D), which have shown higher risk of developing fibrosis (also clinically termed late haze). Studies have supported the use of MMC at a concentration of 0.02%, rather than lower doses (such as 0.01% or 0.002%), for optimal reduction of fibrosis after PRK. Exposure times for 0.02% MMC longer than 40 s may be beneficial for moderate to high myopia (≥6D), but shorter exposures times appear to be equally effective for lower levels of myopia. Although MMC treatment may also be beneficial in preventing fibrosis after PRK treatments for hyperopia and astigmatism, more studies are needed. Thus, despite the clinical use of MMC after PRK for nearly twenty years-with limited evidence of harmful effects in the cornea-many decades of experience will be needed to exclude late long-term effects that could be noted after MMC treatment.
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Affiliation(s)
| | - Steven E Wilson
- The Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.
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In Vitro Antigenotoxic, Antihelminthic and Antioxidant Potentials Based on the Extracted Metabolites from Lichen, Candelariella vitellina. Pharmaceutics 2020; 12:pharmaceutics12050477. [PMID: 32456266 PMCID: PMC7285106 DOI: 10.3390/pharmaceutics12050477] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/17/2020] [Accepted: 05/20/2020] [Indexed: 01/22/2023] Open
Abstract
Lichens have recently received great attention due to their pharmacological potentials. The antigenotoxic potential of C. vitellina extract (25 and 50 µg/mL) was assessed in normal human peripheral blood lymphocytes (HPBL) against Mitomycin C (MMC) co-treatments. Flow cytometric analyses of cell cycle distribution, as well as apoptosis (Annexin V/PI), revealed that the extract had significantly (p ≤ 0.05) ameliorated the MMC toxicity by reducing the apoptotic cells and normalized the cell cycle phases. C. vitellina exhibited antigenotoxicity by ameliorating the diminished mitotic index and DNA single-strand breaks caused by MMC. Herein, the hydromethanolic extract (80%) of Candelariella vitellina (Japan) lichen, exhibited very low cytotoxicity towards normal human peripheral lymphocytes (HPBL) with IC50 >1000 µg/mL. In order to explore the antihelminthic effect, Echinococcus granulosus protoscoleces were used in vitro. Eosin staining revealed significant (p ≤ 0.05) dose and time-dependent scolicidal effects of the extract confirmed by degenerative alterations as observed by electron scan microscopy. Furthermore, primary and secondary metabolites were investigated using GC-MS and qualitative HPLC, revealing the presence of sugars, alcohols, different phenolic acids and light flavonoids. Significant antioxidant capacities were also demonstrated by DPPH radical-scavenging assay. In conclusion, the promising antigenotoxic, antihelminthic and antioxidant potentials of C. vitellina extract encourage further studies to evaluate its possible therapeutic potency.
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A Critical Overview of the Biological Effects of Mitomycin C Application on the Cornea Following Refractive Surgery. Adv Ther 2019; 36:786-797. [PMID: 30859502 PMCID: PMC6824355 DOI: 10.1007/s12325-019-00905-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Indexed: 01/14/2023]
Abstract
During the last 2 decades, modifying the shape of the cornea by means of laser photoablation has emerged as a successful and popular treatment option for refractive errors. Corneal surface ablation techniques such as photorefractive keratectomy (PRK) and laser-assisted subepithelial keratomileusis (LASEK) offer good refractive results while having a minimal impact on corneal biomechanical stability. Past limitations of these techniques included the long-term regression of refractive outcome and a vigorous healing response that reduced corneal clarity in some patients (giving rise to what is clinically described as “haze”). Mitomycin C (MMC) was introduced as a healing modulator and applied on the corneal surface after refractive surgery to address these drawbacks. This article critically reviews the available evidence on the biological effects, safety, and clinical benefits of the off-label use of MMC in corneal refractive surgery.
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A Review of Mitomycin Use in Ophthalmic Surgery: Clarification of Safety Standards for Patients and Hospital Personnel. CURRENT OPHTHALMOLOGY REPORTS 2016. [DOI: 10.1007/s40135-016-0111-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kadam AA, Jubin T, Mir HA, Begum R. Potential role of Apoptosis Inducing Factor in evolutionarily significant eukaryote, Dictyostelium discoideum survival. Biochim Biophys Acta Gen Subj 2016; 1861:2942-2955. [PMID: 27663234 DOI: 10.1016/j.bbagen.2016.09.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 08/27/2016] [Accepted: 09/16/2016] [Indexed: 11/25/2022]
Abstract
Apoptosis Inducing Factor (AIF), a phylogenetically conserved mitochondrial inter-membrane space flavoprotein has an important role in caspase independent cell death. Nevertheless, AIF is also essential for cell survival. It is required for mitochondrial organization and energy metabolism. Upon apoptotic stimulation, AIF induces DNA fragmentation after its mitochondrio-nuclear translocation. Although it executes critical cellular functions in a coordinated manner, the exact mechanism still remains obscure. The present study aims to understand AIF's role in cell survival, growth and development by its down-regulation in an interesting unicellular eukaryote, D. discoideum which exhibits multicellularity upon starvation. Constitutive AIF down-regulated (dR) cells exhibited slower growth and delayed developmental morphogenesis. Also, constitutive AIF dR cells manifested high intracellular ROS, oxidative DNA damage and calcium levels with lower ATP content. Interestingly, constitutive AIF dR cells showed amelioration in cell growth upon antioxidant treatment, strengthening its role as ROS regulator. Under oxidative stress, AIF dR cells showed early mitochondrial membrane depolarization followed by AIF translocation from mitochondria to nucleus and exhibited necrotic cell death as compared to paraptoptic cell death of control cells. Thus, the results of this study provide an exemplar where AIF is involved in growth and development by regulating ROS levels and maintaining mitochondrial function in D. discoideum, an evolutionarily significant model organism exhibiting caspase independent apoptosis.
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Affiliation(s)
- Ashlesha A Kadam
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India
| | - Tina Jubin
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India
| | - Hina A Mir
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India
| | - Rasheedunnisa Begum
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, 390 002, Gujarat, India.
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Matsui Y, Sunatani Y, Hayashi N, Okino K, Okushi Y, Mukai K, Adachi H, Yamaya H, Iwabuchi K, Yokoyama H. DNA double-strand breaks induced intractable glomerular fibrosis in renal allografts. Clin Exp Nephrol 2015; 20:479-88. [PMID: 26440363 DOI: 10.1007/s10157-015-1174-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/24/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUNDS The relationship between DNA damage and glomerular fibrosis in renal allografts remains unclear. METHODS We examined renal allograft specimens from 35 patients in which DNA double-strand breaks (DSBs) and glomerular fibrosis were detected by phospho-histone H2A.X (γ-H2AX) expression and collagen (COL) types III, IV, and VI accumulation. We also examined the in vitro relationship between DNA damage and COL accumulation by mitomycin C (MMc)-induced DNA damage in human glomerular endothelial cells (HRGEc). RESULTS The γ-H2AX and COL type VI, which mainly accumulated in the subendothelial and mesangial regions, were positively correlated with the duration of the post-renal transplant (RT) period. In multiple regression analysis, the duration of the post-RT period and cg in the Banff '07 classification were identified as a significant predictor of COL type VI accumulation and γ-H2AX expression in the glomerular capillaries. In addition, the γ-H2AX-positive area was also identified as a predictor of glomerular accumulation of COL type VI. COL type VI was detected in the cytoplasm of the HRGEc, which was secreted into the supernatant after MMc stimulation with γ-H2AX expression. The number of γ-H2AX (-)/COL type VI (+) cells was inversely associated with the number of γ-H2AX (+)/COL type VI (-) cells during 24-h MMc treatment. CONCLUSIONS Our findings suggest that the long-term RT induces DSBs and HRGEc-secreted COL type VI accumulation in the glomerular capillaries, which might progress to intractable glomerular fibrosis.
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Affiliation(s)
- Yuki Matsui
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan
| | - Yumi Sunatani
- Department of Biochemistry I, School of Medicine, Kanazawa Medical University, Ishikawa, Japan
| | - Norifumi Hayashi
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan
| | - Kazuaki Okino
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan
| | - Yuki Okushi
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan
| | - Kiyotaka Mukai
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan
| | - Hiroki Adachi
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan
| | - Hideki Yamaya
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan
| | - Kuniyoshi Iwabuchi
- Department of Biochemistry I, School of Medicine, Kanazawa Medical University, Ishikawa, Japan
| | - Hitoshi Yokoyama
- Department of Nephrology, School of Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa, 920-0293, Japan.
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Chang IY, Kim JN, Kim SO, Han M, Huh JS, Maeng YH, Yoon SP. Morphological effects of mitomycin C on urothelial responses to experimentally-induced urethral stricture in rats. Int J Urol 2015; 22:702-9. [PMID: 25871346 DOI: 10.1111/iju.12780] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/12/2015] [Accepted: 03/08/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To analyze the urothelial responses to mitomycin C treatment after urethral injury in rats, as the urothelium might play a role in the pathogenesis of urethral stricture. METHODS Male Sprague-Dawley rats were divided into four groups (n = 5/group): negative control, positive control without further treatment, experimental control treated with sodium hyaluronate and sodium carboxymethylcellulose, and experimental treated with mitomycin C after internal urethrotomy. RESULTS Compared with negative controls, positive controls showed a significant increase in cell proliferation and DNA damage accompanied by a considerable decrease in DNA repair in the urothelium, which resulted in urethral stricture. Experimental controls showed a significant increase in cell proliferation, DNA damage and DNA repair compared with negative controls. The mitomycin C-treated group showed a significant decrease in cell proliferation and DNA damage, but a considerable increase in DNA repair compared with the positive and experimental control groups. DNA damage was immediately increased after urethral injury, but DNA repair and cell proliferation showed belated and upregulated expression after mitomycin C treatment. CONCLUSIONS Mitomycin C could induce healthy re-epithelialization without severe damage in the urothelium. This finding might support the possibility of using mitomycin C as an adjuvant therapy for urethral strictures, and it might also suggest a urothelial role in the process of urethral stricture after urethral injury.
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Affiliation(s)
- In Youb Chang
- Department of Anatomy, College of Medicine, Chosun University
| | - Jin Nam Kim
- Department of Internal Medicine, Seoulpaik Hospital, Inje University College of Medicine, Seoul
| | - Sun-Ouck Kim
- Department of Urology, Chonnam National University Medical School, Gwangju
| | - Misook Han
- Department of Nursing, School of Natural Science, Songwon University, Gwangju
| | - Jung-Sik Huh
- Department of Urology, School of Medicine, Jeju National University
| | - Young Hee Maeng
- Department of Pathology, School of Medicine, Jeju National University
| | - Sang Pil Yoon
- Department of Anatomy, School of Medicine, Jeju National University, Jeju, Korea
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Rojas E, Lorenzo Y, Haug K, Nicolaissen B, Valverde M. Epithelial cells as alternative human biomatrices for comet assay. Front Genet 2014; 5:386. [PMID: 25506353 PMCID: PMC4246922 DOI: 10.3389/fgene.2014.00386] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/22/2014] [Indexed: 01/01/2023] Open
Abstract
The comet assay is a valuable experimental tool aimed at mapping DNA damage in human cells in vivo for environmental and occupational monitoring, as well as for therapeutic purposes, such as storage prior to transplant, during tissue engineering, and in experimental ex vivo assays. Furthermore, due to its great versatility, the comet assay allows to explore the use of alternative cell types to assess DNA damage, such as epithelial cells. Epithelial cells, as specialized components of many organs, have the potential to serve as biomatrices that can be used to evaluate genotoxicity and may also serve as early effect biomarkers. Furthermore, 80% of solid cancers are of epithelial origin, which points to the importance of studying DNA damage in these tissues. Indeed, studies including comet assay in epithelial cells have either clear clinical applications (lens and corneal epithelial cells) or examine genotoxicity within human biomonitoring and in vitro studies. We here review improvements in determining DNA damage using the comet assay by employing lens, corneal, tear duct, buccal, and nasal epithelial cells. For some of these tissues invasive sampling procedures are needed. Desquamated epithelial cells must be obtained and dissociated prior to examination using the comet assay, and such procedures may induce varying amounts of DNA damage. Buccal epithelial cells require lysis enriched with proteinase K to obtain free nucleosomes. Over a 30 year period, the comet assay in epithelial cells has been little employed, however its use indicates that it could be an extraordinary tool not only for risk assessment, but also for diagnosis, prognosis of treatments and diseases.
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Affiliation(s)
- Emilio Rojas
- Depto. Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México México, México
| | - Yolanda Lorenzo
- Department of Ophthalmology, Center for Eye Research, Oslo University Hospital, Ullevål, University of Oslo Oslo, Norway
| | - Kristiane Haug
- Department of Ophthalmology, Center for Eye Research, Oslo University Hospital, Ullevål, University of Oslo Oslo, Norway
| | - Bjørn Nicolaissen
- Department of Ophthalmology, Center for Eye Research, Oslo University Hospital, Ullevål, University of Oslo Oslo, Norway
| | - Mahara Valverde
- Depto. Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México México, México
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Li NYK, Chen F, Dikkers FG, Thibeault SL. Dose-dependent effect of mitomycin C on human vocal fold fibroblasts. Head Neck 2014; 36:401-10. [PMID: 23765508 PMCID: PMC4113207 DOI: 10.1002/hed.23310] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2013] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND The purpose of this study was to evaluate in vitro cytotoxicity and antifibrotic effects of mitomycin C on normal and scarred human vocal fold fibroblasts. METHODS Fibroblasts were subjected to mitomycin C treatment at 0.2, 0.5, or 1 mg/mL, or serum control. Cytotoxicity, immunocytochemistry, and Western blot for collagen I/III were performed at days 0, 1, 3, and 5. RESULTS Significant decreases in live cells were measured for mitomycin C-treated cells on days 3 and 5 for all doses. Extracellular staining of collagen I/III was observed in mitomycin C-treated cells across all doses and times. Extracellular staining suggests apoptosis with necrosis, compromising the integrity of cell membranes and release of cytosolic proteins into the extracellular environment. Western blot indicates inhibition of collagen at all doses except 0.2 mg/mL at day 1. CONCLUSION A total of 0.2 mg/mL mitomycin C may provide initial and transient stimulation of collagen for necessary repair to damaged tissue without the long-term risk of fibrosis.
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Affiliation(s)
- Nicole Y. K. Li
- Department of Hearing and Speech Sciences, University of Maryland–College Park, College Park, Maryland
| | - Fei Chen
- Department of Speech and Hearing Sciences, University of Hong Kong, Hong Kong
| | - Frederik G. Dikkers
- Department of Otorhinolaryngology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Susan L. Thibeault
- Division of Otolaryngology–Head and Neck Surgery, Department of Surgery, University of Wisconsin–Madison, Madison, Wisconsin
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Roh DS, Du Y, Gabriele ML, Robinson AR, Niedernhofer LJ, Funderburgh JL. Age-related dystrophic changes in corneal endothelium from DNA repair-deficient mice. Aging Cell 2013; 12:1122-31. [PMID: 23927039 DOI: 10.1111/acel.12143] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2013] [Indexed: 12/13/2022] Open
Abstract
The corneal endothelium (CE) is a single layer of cells lining the posterior face of the cornea providing metabolic functions essential for maintenance of corneal transparency. Adult CE cells lack regenerative potential, and the number of CE cells decreases throughout life. To determine whether endogenous DNA damage contributes to the age-related spontaneous loss of CE, we characterized CE in Ercc1(-/Δ) mice, which have impaired capacity to repair DNA damage and age prematurely. Eyes from 4.5- to 6-month-old Ercc1(-/Δ) mice, age-matched wild-type (WT) littermates, and old WT mice (24- to 34-month-old) were compared by spectral domain optical coherence tomography and corneal confocal microscopy. Histopathological changes in CE were further identified in paraffin tissue sections, whole-mount immunostaining, and scanning electron and transmission electron microscopy. The CE of old WT mice displayed polymorphism and polymegathism, polyploidy, decreased cell density, increased cell size, increases in Descemet's thickness, and the presence of posterior projections originating from the CE toward the anterior chamber, similar to changes documented for aging human corneas. Similar changes were observed in young adult Ercc1(-/Δ) mice CE, demonstrating spontaneous premature aging of the CE of these DNA repair-deficient mice. CD45(+) immune cells were associated with the posterior surface of CE from Ercc1(-/Δ) mice and the tissue expressed increased IL-1α, Cxcl2, and TNFα, pro-inflammatory proteins associated with senescence-associated secretory phenotype. These data provide strong experimental evidence that DNA damage can promote aging of the CE and that Ercc1(-/Δ) mice offer a rapid and accurate model to study CE pathogenesis and therapy.
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Affiliation(s)
- Danny S. Roh
- Department of Ophthalmology; University of Pittsburgh School of Medicine; 203 Lothrop St. Pittsburgh PA 15213 USA
| | - Yiqin Du
- Department of Ophthalmology; University of Pittsburgh School of Medicine; 203 Lothrop St. Pittsburgh PA 15213 USA
| | - Michelle L. Gabriele
- Department of Ophthalmology; University of Pittsburgh School of Medicine; 203 Lothrop St. Pittsburgh PA 15213 USA
| | - Andria R. Robinson
- Department of Human Genetics; University of Pittsburgh School of Public Health; 130 DeSoto Street Pittsburgh PA 15261 USA
- University of Pittsburgh Cancer Institute; Hillman Cancer Center; 5117 Centre Ave, 2.6 Pittsburgh PA 15213 USA
| | - Laura J. Niedernhofer
- University of Pittsburgh Cancer Institute; Hillman Cancer Center; 5117 Centre Ave, 2.6 Pittsburgh PA 15213 USA
- Department of Microbiology and Molecular Genetics; University of Pittsburgh School of Medicine; 523 Bridgeside Point II 450 Technology Drive Pittsburgh PA 15219 USA
| | - James L. Funderburgh
- Department of Ophthalmology; University of Pittsburgh School of Medicine; 203 Lothrop St. Pittsburgh PA 15213 USA
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Jester JV, Nien CJ, Vasiliou V, Brown DJ. Quiescent keratocytes fail to repair MMC induced DNA damage leading to the long-term inhibition of myofibroblast differentiation and wound healing. Mol Vis 2012; 18:1828-39. [PMID: 22815636 PMCID: PMC3398499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 07/01/2012] [Indexed: 11/16/2022] Open
Abstract
PURPOSE The purpose of this study was to determine the acute and long-term effects of mitomycin C (MMC) on quiescent rabbit corneal keratocytes regarding cell proliferation, myofibroblast differentiation and DNA repair. METHODS Quiescent keratocytes cultured in serum-free media were exposed to various concentrations of MMC and then treated with transforming growth factor-β (TGFβ). DNA damage was evaluated in both cultured keratocytes and live rabbit eyes following treatment with MMC. The long-term ability of quiescent keratocytes to repair MMC induced damage in vivo was evaluated in rabbits treated with MMC 2 months before 100 μm deep lamellar keratectomy (LK) injury. RESULTS MMC significantly blocked TGFβ-induced cell proliferation and myofibroblast differentiation in cultured quiescent keratocytes and altered the transcriptional regulation of macrophage chemotactic protein-1 (MCP-1) and alpha smooth muscle actin (αSMA). MMC also induced phosphorylation of the nuclear histone marker of DNA damage, γH2AX (a member of the H2A histone family), without induction of cell cycle entry or immediate DNA repair measured by Comet assay. In live rabbits, 0.2 mg/ml MMC significantly induced γH2AX nuclear immunostaining (p<0.05) throughout the cornea and corneas receiving 0.2 mg/ml MMC treatment 2 months before LK injury showed complete absence of any corneal scarring. CONCLUSIONS MMC induces DNA damage to quiescent corneal keratocytes, which remains unrepaired, resulting in abnormal cell replication and gene transcription that leads to long-term effects on corneal repair. Overall these findings suggest that there may be long-term and perhaps permanent consequences to the application of MMC as an anti-fibrotic therapy.
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Affiliation(s)
- James V. Jester
- The Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Chyong Jy Nien
- The Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Vasilis Vasiliou
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO
| | - Donald J. Brown
- The Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
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17
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Abstract
PURPOSE To provide an overview of the safety and efficacy of mitomycin C (MMC) as adjuvant therapy after refractive surgery procedures. METHODS Literature review. RESULTS Over the past 10 years, MMC has been used by refractive surgeons to prophylactically decrease haze after surface ablation procedures and therapeutically in the treatment of preexisting haze. Development of MMC treatments has had a significant role in the revival of surface ablation techniques. We reviewed the literature regarding mechanism of action of MMC, its role in modulating wound healing after refractive surgery, and its safety and efficacy as adjuvant therapy applied after primary photorefractive keratectomy surgery or after photorefractive keratectomy re-treatment after laser in situ keratomileusis and other corneal surgeries and disorders. The drug is a potent mitotic inhibitor that effectively blocks keratocyte activation, proliferation, and myofibroblast differentiation. Many studies have suggested that MMC is safe and effective in doses used by anterior surface surgeons, although there continue to be concerns regarding long-term safety. After initial depletion of anterior keratocytes, keratocyte density seems to return to normal 6 to 12 months after the use of MMC when corneas are examined with the confocal microscope. Most clinical studies found no difference between preoperative and postoperative corneal endothelial cell densities when MMC 0.02% was applied during refractive surgery, with exposure time of 2 minutes or less. CONCLUSIONS After more than 10 years of use, MMC has been found to be effective when used for prevention and treatment of corneal haze. Questions remain regarding optimal treatment parameters and long-term safety.
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18
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Paz MM, Pritsos CA. The Molecular Toxicology of Mitomycin C. ADVANCES IN MOLECULAR TOXICOLOGY VOLUME 6 2012. [DOI: 10.1016/b978-0-444-59389-4.00007-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Abstract
PURPOSE To evaluate the long-term corneal safety of topical mitomycin C (MMC) used during photorefractive keratectomy to prevent haze formation in highly myopic eyes. METHODS Twenty-eight patients with bilateral high myopia underwent photorefractive keratectomy. One eye was randomly assigned to intraoperative 0.02% MMC and the fellow eye to conventional treatment. Each eye was checked at baseline and at 5 years after surgery using in vivo corneal confocal microscopy. RESULTS At baseline, the endothelial cell density was 2970 ± 295 cells per square millimeter in the MMC-treated eyes and 2839 ± 323 cells per square millimeter in the control eyes. At 5 years, it was 2803 ± 307 and 2780 ± 264 cells per square millimeter, respectively (P = 0.27). The number of corneal nerve fibers was 3.9 ± 1.6 in the MMC-treated eyes and 4.4 ± 1.3 in the control eyes. At 5 years, it was 3.0 ± 1.6 and 2.7 ± 1.3, respectively (P = 0.15). The density of corneal nerves was 9600 ± 2915 μm/mm(2) in the MMC-treated eyes and 11,352 ± 3898 μm/mm(2) in the control eyes. At 5 years, the density was higher in the MMC-treated eyes (6790 ± 2447 μm/mm(2)) than in the control eyes (6024 ± 2977 μm/mm(2)) (P = 0.003). The number of nerve beadings at baseline was 12.9 ± 1.7/100 μm in the MMC-treated eyes and 12.3 ± 2.0/100 μm in the control eyes. At 5 years, it was 9.9 ± 2.6/100 and 9.4 ± 2.9/100 μm, respectively (P = 1.00). At 5 years, corneal nerve branching and tortuosity were similar in the 2 groups (P = 0.88 and 0.54, respectively). Epithelium thickness remained statistically unchanged (P = 0.69). CONCLUSIONS Intraoperative use of topical 0.02% MMC compared with standard treatment does not induce significant long-term corneal changes, as assessed by in vivo corneal confocal microscopy.
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Roh DS, Funderburgh JL. Rapid changes in connexin-43 in response to genotoxic stress stabilize cell-cell communication in corneal endothelium. Invest Ophthalmol Vis Sci 2011; 52:5174-82. [PMID: 21666237 DOI: 10.1167/iovs.11-7272] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To determine how corneal endothelial (CE) cells respond to acute genotoxic stress through changes in connexin-43 (Cx43) and gap junction intercellular communication (GJIC). METHODS Cultured bovine CE cells were exposed to mitomycin C or other DNA-damaging agents. Changes in the levels, stability, binding partners, and trafficking of Cx43 were assessed by Western blot analysis and immunostaining. Live-cell imaging of a Cx43-green fluorescent protein (GFP) fusion protein was used to evaluate internalization of cell surface Cx43. Dye transfer and fluorescent recovery after photobleaching (FRAP) assessed GJIC. RESULTS After genotoxic stress, Cx43 accumulated in large gap junction plaques, had reduced zonula occludens-1 binding, and displayed increased stability. Live-cell imaging of Cx43-GFP plaques in stressed CE cells revealed reduced gap junction internalization and degradation compared to control cells. Mitomycin C enhanced transport of Cx43 from the endoplasmic reticulum to the cell surface and formation of gap junction plaques. Mitomycin C treatment also protected GJIC from disruption after cytokine treatment. DISCUSSION These results show a novel CE cell response to genotoxic stress mediated by marked and rapid changes in Cx43 and GJIC. This stabilization of cell-cell communication may be an important early adaptation to acute stressors encountered by CE.
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Affiliation(s)
- Danny S Roh
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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21
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Corwin WL, Baust JM, Baust JG, Van Buskirk RG. The unfolded protein response in human corneal endothelial cells following hypothermic storage: implications of a novel stress pathway. Cryobiology 2011; 63:46-55. [PMID: 21549109 DOI: 10.1016/j.cryobiol.2011.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 04/15/2011] [Accepted: 04/20/2011] [Indexed: 01/22/2023]
Abstract
Human corneal endothelial cells (HCEC) have become increasingly important for a range of eye disease treatment therapies. Accordingly, a more detailed understanding of the processing and preservation associated stresses experienced by corneal cells might contribute to improved therapeutic outcomes. To this end, the unfolded protein response (UPR) pathway was investigated as a potential mediator of corneal cell death in response to hypothermic storage. Once preservation-induced failure had begun in HCECs stored at 4°C, it was noted that necrosis accounted for the majority of cell death but with significant apoptotic involvement, peaking at several hours post-storage (4-8h). Western blot analysis demonstrated changes associated with apoptotic activation (caspase 9, caspase 3, and PARP cleavage). Further, the activation of the UPR pathway was observed through increased and sustained levels of ER folding and chaperone proteins (Bip, PDI, and ERO1-Lα) in samples experiencing significant cell death. Modulation of the UPR pathway using the specific inhibitor, salubrinal, resulted in a 2-fold increase in cell survival in samples experiencing profound cold-induced failure. Furthermore, this increased cell survival was associated with increased membrane integrity, cell attachment, and decreased necrotic cell death populations. Conversely, addition of the UPR inducer, tunicamycin, during cold exposure resulted in a significant decrease in HCEC survival during the recovery period. These data implicate for the first time that this novel cell stress pathway may be activated in HCEC as a result of the complex stresses associated with hypothermic exposure. The data suggest that the targeted control of the UPR pathway during both processing and preservation protocols may improve cell survival and function of HCEC thus improving the clinical utility of these cells as well as whole human corneas.
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Affiliation(s)
- William L Corwin
- Institute of Biomedical Technology, Binghamton University, NY 13902, USA
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de Benito-Llopis L, Teus MA. Efficacy of surface ablation retreatments using mitomycin C. Am J Ophthalmol 2010; 150:376-380.e2. [PMID: 20570239 DOI: 10.1016/j.ajo.2010.03.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2009] [Revised: 03/20/2010] [Accepted: 03/24/2010] [Indexed: 10/19/2022]
Abstract
PURPOSE To evaluate the visual and refractive results and the incidence of complications after laser subepithelial keratectomy (LASEK) enhancement using mitomycin C (MMC) after a previous LASEK procedure with MMC. DESIGN Retrospective, noncomparative, interventional case series. METHODS Setting was Vissum Santa Hortensia, Madrid, Spain. We performed a retrospective study of LASEK-treated eyes that received intraoperative MMC for 30 seconds and that needed an enhancement procedure. LASEK retreatment with MMC 0.02%, applied for 60 seconds, was performed 3 to 6 months after the initial surgery. We measured the visual and refractive results 3 months after the enhancement and the incidence of complications. RESULTS Eighty-two eyes were included in the study. The preoperative data were best spectacle-corrected visual acuity (BSCVA) 1.08 +/- 0.19, sphere -4.68 +/- 2.8 diopters (D), and cylinder -1.30 +/- 1.20 D. Three to 6 months postoperatively, before enhancement, the uncorrected VA (UCVA) was 0.59 +/- 0.2; the BSCVA, 0.976 +/- 0.2; the residual sphere, +0.17 +/- 0.7 D, and the cylinder, -0.39 +/- 0.5 D. Three months after retreatment, the UCVA was 0.93 +/- 0.1; the BSCVA, 0.977 +/- 0.1; the residual sphere, 0.09 +/- 0.3 D; and the residual cylinder, -0.2 +/- 0.3 D. The safety index after retreatment was 1.01 +/- 0.1, and the efficacy index was 0.96 +/- 0.1. No haze, no delay in epithelial healing, and no case of endothelial decompensation were detected. CONCLUSION Surface ablation retreatment using MMC seems to be effective to correct residual refractive errors after an initial surgery with MMC.
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23
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Li N, Sarojini H, An J, Wang E. Prosaposin in the secretome of marrow stroma-derived neural progenitor cells protects neural cells from apoptotic death. J Neurochem 2009; 112:1527-38. [PMID: 20050969 DOI: 10.1111/j.1471-4159.2009.06565.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Functionally, adult stem cells not only participate in replication and differentiation to various cell lineages, but also may be involved in rescuing cells from apoptosis. Identifying functional factors secreted by stem cells, as well as their target cells, may advance our understanding of stem cells' multifaceted physiologic functions. Here, we report that mouse bone marrow stromal cell-derived neuroprogenitor cells (mMSC-NPC) provide a protective function by secreting a key factor, prosaposin (PSAP), capable of rescuing mature neurons from apoptotic death. This factor is identified as the lead protein in the secretome of mMSC-NPC cultures by tandem mass spectroscopic profiling, and further validated by western blotting and immunocytochemistry. The secretome of MSC-NPC reduces toxin-induced cell death in cultures of rat pheochromocytoma neuronal cells, human ReNcell CX neurons, and rat cortical primary neurons; removal of PSAP by immunodepletion annuls this protective effect. This neuronal protection against toxin treatment was validated further by the recombinant PSAP peptide. Interestingly, the secretome of neuronal culture does not possess such a self-protective action. We suggest that upon injury, a subgroup of MSCs differentiates into neural/neuronal progenitor cells, and remains in this intermediate stem cell-like stage, defending injured neighboring mature neurons from apoptosis by secreting PSAP.
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Affiliation(s)
- Na Li
- Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Gheens Center on Aging, Louisville, Kentucky 40202, USA
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Patel SV, Bourne WM. Corneal endothelial cell loss 9 years after excimer laser keratorefractive surgery. ACTA ACUST UNITED AC 2009; 127:1423-7. [PMID: 19901206 DOI: 10.1001/archophthalmol.2009.192] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To determine the long-term changes in the corneal endothelium after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). METHODS Twenty-nine eyes (16 patients) received myopic LASIK or PRK, with intended correction to emmetropia. Central endothelial photographs were taken before and 9 years after surgery and were analyzed by the same masked investigator after appropriate calibration for magnification. Comparisons were made by using generalized estimating equation models to account for any correlation between fellow eyes of the same patient. The annual exponential rate of cell loss was compared with cell loss during a 10-year period in 42 normal (unoperated) corneas of 42 subjects. RESULTS Endothelial cell density 9 years after LASIK and PRK had decreased by 5.3% from preoperative density (P < .001), whereas coefficient of variation of cell area (P = .24) and percentage of hexagonal cells (P = .19) did not change. The mean annual rate of cell loss after refractive surgery (0.6% [standard deviation, 0.8%]) was not different from that in normal corneas (0.6% [0.5%], P = .88; minimum detectable difference = 0.5%; alpha = .05; beta = .20). CONCLUSIONS Laser in situ keratomileusis and PRK had no long-term effect on the corneal endothelium. Corneas that have undergone LASIK or PRK can be considered for use as donors for posterior lamellar keratoplasty procedures.
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Affiliation(s)
- Sanjay V Patel
- Department of Ophthalmology, Mayo Clinic, Rochester, MN 55905, USA.
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Roh DS, Funderburgh JL. Impact on the corneal endothelium of mitomycin C during photorefractive keratectomy. J Refract Surg 2009; 25:894-7. [PMID: 19835330 DOI: 10.3928/1081597x-20090617-10] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Accepted: 05/05/2009] [Indexed: 11/20/2022]
Abstract
PURPOSE This brief review examines both basic science and clinical studies to evaluate the potential impact on the health of the corneal endothelium of mitomycin C (MMC) usage during photorefractive keratectomy (PRK). METHODS The mechanism of action and consequences of MMC are reviewed within the context of in vitro, animal, and clinical studies and a hypothesis of how this vital cell layer responds to MMC at both the cellular and clinical levels is formed. RESULTS Seven basic science studies were reviewed demonstrating significant MMC toxicity to corneal endothelial cells. Of the five clinical studies reviewed, three demonstrated no effect on corneal endothelial density, whereas two studies found significant cell loss after MMC usage. CONCLUSIONS Although all of the basic science studies reviewed highlight the toxicity of MMC on the corneal endothelium, current clinical studies are less conclusive. Given the corneal penetration of MMC and the fragile nature of the corneal endothelium, additional follow-up studies are needed to determine the long-term impact of MMC usage during PRK on the corneal endothelium.
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Affiliation(s)
- Danny S Roh
- Department of Ophthalmology, UPMC Eye and Ear Institute, University of Pittsburgh School of Medicine, PA, USA
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Abstract
Mitomycin C has played a deciding role in the current revival of excimer laser surface ablation techniques. We review the literature regarding mechanism of action of mitomycin C, histological effects on the cornea, and indications, dose, exposure time, and toxicity of mitomycin C in corneal refractive surgery. Mitomycin C is an alkylating agent with cytotoxic and antiproliferative effects that reduces the myofibroblast repopulation after laser surface ablation and, therefore, reduces the risk of postoperative corneal haze. It is used prophylactically to avoid haze after primary surface ablation and therapeutically to treat pre-existing haze. There is no definite evidence that establishes an exact diopter limit or ablation depth at which to apply prophylactic mitomycin C. It is usually applied at a concentration of 0.2mg/ml (0.02%) for 12 to 120 seconds over the ablated stroma, although some studies suggest that lower concentrations (0.01%, 0.002%) could also be effective in preventing haze when treating low to moderate myopia. This dose of mitomycin C has not been associated with any clinically relevant epithelial corneal toxicity. Its effect on the endothelium is more controversial: two studies report a decrease in endothelial cell density, but the majority of reports suggest that the endothelium is not altered. Regarding mitomycin C's effect on keratocyte population, although animal studies report keratocyte depletion after its use, longer follow-up suggested that the initial keratocyte depletion does not persist over time.
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