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Cheng KKW, Fingerhut L, Duncan S, Prajna NV, Rossi AG, Mills B. In vitro and ex vivo models of microbial keratitis: Present and future. Prog Retin Eye Res 2024; 102:101287. [PMID: 39004166 DOI: 10.1016/j.preteyeres.2024.101287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 07/16/2024]
Abstract
Microbial keratitis (MK) is an infection of the cornea, caused by bacteria, fungi, parasites, or viruses. MK leads to significant morbidity, being the fifth leading cause of blindness worldwide. There is an urgent requirement to better understand pathogenesis in order to develop novel diagnostic and therapeutic approaches to improve patient outcomes. Many in vitro, ex vivo and in vivo MK models have been developed and implemented to meet this aim. Here, we present current in vitro and ex vivo MK model systems, examining their varied design, outputs, reporting standards, and strengths and limitations. Major limitations include their relative simplicity and the perceived inability to study the immune response in these MK models, an aspect widely accepted to play a significant role in MK pathogenesis. Consequently, there remains a dependence on in vivo models to study this aspect of MK. However, looking to the future, we draw from the broader field of corneal disease modelling, which utilises, for example, three-dimensional co-culture models and dynamic environments observed in bioreactors and organ-on-a-chip scenarios. These remain unexplored in MK research, but incorporation of these approaches will offer further advances in the field of MK corneal modelling, in particular with the focus of incorporation of immune components which we anticipate will better recapitulate pathogenesis and yield novel findings, therefore contributing to the enhancement of MK outcomes.
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Affiliation(s)
- Kelvin Kah Wai Cheng
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Leonie Fingerhut
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Sheelagh Duncan
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - N Venkatesh Prajna
- Department of Cornea and Refractive Surgery Services, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - Adriano G Rossi
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom
| | - Bethany Mills
- Centre for Inflammation Research, Institute of Regeneration and Repair, University of Edinburgh, United Kingdom.
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Dias Rates ER, Almeida CD, de Paula Fiod Costa E, Jansen de Mello Farias R, Santos-Oliveira R, Rebelo Alencar LM. Evaluation of biophysical alterations in the epithelial and endothelial layer of patients with Bullous Keratopathy. Exp Eye Res 2024; 240:109791. [PMID: 38253307 DOI: 10.1016/j.exer.2024.109791] [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: 08/04/2023] [Revised: 11/07/2023] [Accepted: 01/13/2024] [Indexed: 01/24/2024]
Abstract
The cornea is a fundamental ocular tissue for the sense of sight. Thanks to it, the refraction of two-thirds of light manages to participate in the visual process and protect against mechanical damage. Because it is transparent, avascular, and innervated, the cornea comprises five main layers: Epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. Each layer plays a key role in the functionality and maintenance of ocular tissue, providing unique ultrastructural and biomechanical properties. Bullous Keratopathy (BK) is an endothelial dysfunction that leads to corneal edema, loss of visual acuity, epithelial blisters, and severe pain, among other symptoms. The corneal layers are subject to changes in their biophysical properties promoted by Keratopathy. In this context, the Atomic Force Microscopy (AFM) technique in air was used to investigate the anterior epithelial surface and the posterior endothelial surface, healthy and with BK, using a triangular silicone tip with a nominal spring constant of 0.4 N/m. Six human corneas (n = 6) samples were used for each analyzed group. Roughness data, calculated by third-order polynomial adjustment, adhesion, and Young's modulus, were obtained to serve as a comparison and identification of morphological and biomechanical changes possibly associated with the pathology, such as craters and in the epithelial layer and exposure of a fibrotic layer due to loss of the endothelial cell wall. Endothelial cell membrane area and volume data were calculated, obtaining a relevant comparison between the control and patient. Such results may provide new data on the physical properties of the ocular tissue to understand the physiology of the cornea when it has pathology.
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Affiliation(s)
- Erick Rafael Dias Rates
- Federal University of Maranhão, Department of Physics, Laboratory of Biophysics and Nanosystems, Campus Bacanga, São Luís, Maranhão, 65080-805, Brazil
| | - Charles Duarte Almeida
- Federal University of Maranhão, Department of Physics, Laboratory of Biophysics and Nanosystems, Campus Bacanga, São Luís, Maranhão, 65080-805, Brazil
| | - Elaine de Paula Fiod Costa
- Federal University of Maranhão, HU-UFMA - Hospital Universitário, R. Barão de Itapari, 227 - Centro, São Luís, MA, 65020-070, Brazil
| | | | - Ralph Santos-Oliveira
- Rio de Janeiro State University, Laboratory of Nanoradiopharmaceuticals and Radiopharmacy, Rio de Janeiro, Rio de Janeiro, 23070200, Brazil; Brazilian Nuclear Energy Commission, Nuclear Engineering Institute, Rio de Janeiro, Rio de Janeiro, 21941906, Brazil
| | - Luciana M Rebelo Alencar
- Federal University of Maranhão, Department of Physics, Laboratory of Biophysics and Nanosystems, Campus Bacanga, São Luís, Maranhão, 65080-805, Brazil.
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Chai N, Stachon T, Berger T, Li Z, Seitz B, Langenbucher A, Szentmáry N. Short-Term Effect of Rose Bengal Photodynamic Therapy (RB-PDT) on Collagen I, Collagen V, NF-κB, LOX, TGF-β and IL-6 Expression of Human Corneal Fibroblasts, In Vitro. Curr Eye Res 2024; 49:150-157. [PMID: 37921272 DOI: 10.1080/02713683.2023.2276057] [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: 07/31/2023] [Accepted: 10/24/2023] [Indexed: 11/04/2023]
Abstract
PURPOSE To investigate collagen I, collagen V, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), lysyl oxidase (LOX), transforming growth factor β1 (TGF-β1) and interleukin-6 (IL-6) expression in healthy and keratoconus human corneal fibroblasts (HCFs and KC-HCFs), 24 h after Rose Bengal photodynamic therapy (RB-PDT). METHODS HCFs were isolated from healthy human corneal donors (n = 5) and KC-HCFs from elective penetrating keratoplasties (n = 5). Both cell cultures underwent RB-PDT (0.001% RB concentration, 0.17 J/cm2 fluence) and 24 h later collagen I, collagen V, NF-κB, LOX, TGF-β1 and IL-6 mRNA and protein expression have been determined using qPCR and Western blot, IL-6 concentration in the cell culture supernatant by ELISA. RESULTS TGF-β1 mRNA expression was significantly lower (p = 0.02) and IL-6 mRNA expression was significantly higher in RB-PDT treated HCFs (p = 0.01), than in HCF controls. COL1A1, COL5A1 and TGF-β1 mRNA expression was significantly lower (p = 0.04; p = 0.02 and p = 0.003) and IL-6 mRNA expression was significantly higher (p = 0.02) in treated KC-HCFs, than in KC-HCF controls. TGF-β1 protein expression in treated HCFs was significantly higher than in HCF controls (p = 0.04). IL-6 protein concentration in the HCF and KC-HCF culture supernatant after RB-PDT was significantly higher than in controls (p = 0.02; p = 0.01). No other analyzed mRNA and protein expression differed significantly between the RB-PDT treated and untreated groups. CONCLUSIONS Our study demonstrates that RB-PDT reduces collagen I, collagen V and TGF-β1 mRNA expression, while increasing IL-6 mRNA and protein expression in KC-HCFs. In HCFs, RB-PDT increases TGF-β1 and IL-6 protein level after 24 h.
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Affiliation(s)
- Ning Chai
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - Tanja Stachon
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - Tim Berger
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Zhen Li
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | | | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
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Tang Y, Du E, Wang G, Qin F, Meng Z, Dai L, Wang Y, Ren S. A negative feedback loop centered on SMAD3 expression in transforming growth factor β1-induced corneal myofibroblast differentiation. Exp Eye Res 2023; 236:109654. [PMID: 37734427 DOI: 10.1016/j.exer.2023.109654] [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: 06/08/2023] [Revised: 09/10/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023]
Abstract
SMAD3 downregulation is documented in transforming growth factor β1 (TGF-β1)-induced corneal fibroblasts differentiation to myofibroblasts ("fibroTOmyoDiff") or corneal wound healing. However, the exact regulatory mechanism of TGF-β1/SMAD3 pathway in this context remains unclear. Here, we investigated the role and related mechanism of SMAD3 down-regulation in TGF-β1-induced human corneal fibroTOmyoDiff. By detecting expression changes of SMAD family during this process, we demonstrated that SMAD3 protein expression was dramatically decreased in the process and the decrease occurred mainly in SMAD3 gene transcription. Furthermore, SMAD3 overexpression using lentivirus infection and knockdown using sgRNA lentivirus infection or siRNAs revealed that SMAD3 overexpression enhanced TGF-β1-induced corneal fibroTOmyoDiff and vice versa. In addition, specific siRNAs and inhibitors targeting particular signaling pathway were used to figure out the intracellular signaling pathway regulating SMAD3, and the result showed that the decease of SMAD3 induced by TGF-β1 stimulation in human corneal fibroblasts (HCFs) was strikingly prevented by SMAD4 knockdown or p38 signaling inhibitor SB203580 treatment. Collectively, these results demonstrate that, in TGF-β1 induced corneal fibroTOmyoDiff, down-regulation of SMAD3 expression regulated by SMAD4 and p38 signaling pathways forms a negative feedback loop of TGFβ signaling to avoid excessive activation of the signaling, which suggest that SMAD3 may be a key target for corneal fibrosis treatment.
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Affiliation(s)
- Yunlan Tang
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
| | - Enming Du
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
| | - Gang Wang
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
| | - Fangyuan Qin
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
| | - Zhihong Meng
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
| | - Lijuan Dai
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
| | - Yiqiang Wang
- Wisdom Lake Academy of Pharmacy, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China.
| | - Shengwei Ren
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, 450003, China.
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Petroll WM, Miron-Mendoza M, Sunkara Y, Ikebe HR, Sripathi NR, Hassaniardekani H. The impact of UV cross-linking on corneal stromal cell migration, differentiation and patterning. Exp Eye Res 2023; 233:109523. [PMID: 37271309 PMCID: PMC10825899 DOI: 10.1016/j.exer.2023.109523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 05/09/2023] [Accepted: 06/01/2023] [Indexed: 06/06/2023]
Abstract
Previous studies have demonstrated that UV cross-linking (CXL) increases stromal stiffness and produces alterations in extracellular matrix (ECM) microstructure. In order to investigate how CXL impacts both keratocyte differentiation and patterning within the stroma, and fibroblast migration and myofibroblast differentiation on top of the stroma, we combined CXL with superficial phototherapeutic keratectomy (PTK) in a rabbit model. Twenty-six rabbits underwent a 6 mm diameter, 70 μm deep phototherapeutic keratectomy (PTK) with an excimer laser to remove the epithelium and anterior basement membrane. In 14 rabbits, standard CXL was performed in the same eye immediately after PTK. Contralateral eyes served as controls. In vivo confocal microscopy through focusing (CMTF) was used to analyze corneal epithelial and stromal thickness, as well as stromal keratocyte activation and corneal haze. CMTF scans were collected pre-operatively, and from 7 to 120 days after the procedure. A subset of rabbits was sacrificed at each time point, and corneas were fixed and labeled in situ for multiphoton fluorescence microscopy and second harmonic generation imaging. In vivo and in situ imaging demonstrated that haze after PTK was primarily derived from a layer of myofibroblasts that formed on top of the native stroma. Over time, this fibrotic layer was remodeled into more transparent stromal lamellae, and quiescent cells replaced myofibroblasts. Migrating cells within the native stroma underneath the photoablated area were elongated, co-aligned with collagen, and lacked stress fibers. In contrast, following PTK + CXL, haze was derived primarily from highly reflective necrotic "ghost cells" in the anterior stroma, and fibrosis on top of the photoablated stroma was not observed at any time point evaluated. Cells formed clusters as they migrated into the cross-linked stromal tissue and expressed stress fibers; some cells at the edge of the CXL area also expressed α-SM actin, suggesting myofibroblast transformation. Stromal thickness increased significantly between 21 and 90 days after PTK + CXL (P < 0.001) and was over 35 μm higher than baseline at Day 90 (P < 0.05). Overall, these data suggest that cross-linking inhibits interlamellar cell movement, and that these changes lead to a disruption of normal keratocyte patterning and increased activation during stromal repopulation. Interestingly, CXL also prevents PTK-induced fibrosis on top of the stroma, and results in long term increases in stromal thickness in the rabbit model.
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Affiliation(s)
- W Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA; Department of Biomedical Engineering, UT Southwestern Medical Center, Dallas, TX, USA.
| | | | - Yukta Sunkara
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Hikaru R Ikebe
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Nishith R Sripathi
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
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Kumar R, Sinha NR, Mohan RR. Corneal gene therapy: Structural and mechanistic understanding. Ocul Surf 2023; 29:279-297. [PMID: 37244594 DOI: 10.1016/j.jtos.2023.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Cornea, a dome-shaped and transparent front part of the eye, affords 2/3rd refraction and barrier functions. Globally, corneal diseases are the leading cause of vision impairment. Loss of corneal function including opacification involve the complex crosstalk and perturbation between a variety of cytokines, chemokines and growth factors generated by corneal keratocytes, epithelial cells, lacrimal tissues, nerves, and immune cells. Conventional small-molecule drugs can treat mild-to-moderate traumatic corneal pathology but requires frequent application and often fails to treat severe pathologies. The corneal transplant surgery is a standard of care to restore vision in patients. However, declining availability and rising demand of donor corneas are major concerns to maintain ophthalmic care. Thus, the development of efficient and safe nonsurgical methods to cure corneal disorders and restore vision in vivo is highly desired. Gene-based therapy has huge potential to cure corneal blindness. To achieve a nonimmunogenic, safe and sustained therapeutic response, the selection of a relevant genes, gene editing methods and suitable delivery vectors are vital. This article describes corneal structural and functional features, mechanistic understanding of gene therapy vectors, gene editing methods, gene delivery tools, and status of gene therapy for treating corneal disorders, diseases, and genetic dystrophies.
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Affiliation(s)
- Rajnish Kumar
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow campus, UP, 226028, India
| | - Nishant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA
| | - Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
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Meng N, Wu J, Chen J, Luo Y, Xu L, Li X. Basement membrane regeneration and TGF-β1 expression in rabbits with corneal perforating injury. Mol Vis 2023; 29:58-67. [PMID: 37287643 PMCID: PMC10243679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 05/18/2023] [Indexed: 06/09/2023] Open
Abstract
Purpose To evaluate the relationship between basement membrane (BM) regeneration and the spatiotemporal expression of TGF-β1 during wound healing in rabbits with corneal perforating injury. Methods Forty-two rabbits were randomly allocated into 7 experimental groups, with 6 rabbits per group at each time point. The central cornea of the left eye was injured with 2.0 mm trephine to establish the perforating injury model. Six rabbits that received no treatment were used as controls. The cornea was evaluated at 3 days, 1-3 weeks, and 1-3 months after injury with a slit lamp for haze levels. Real-time quantitative polymerase chain reaction (qRT-PCR) was performed to quantify the relative expression of TGF-β1 and α-SMA mRNA. Immunofluorescence (IF) was used to assess TGF-β1 and alpha-smooth actin (α-SMA) expression and localization. BM regeneration was assessed using transmission electron microscopy (TEM). Results After injury, dense haze appeared at 1 month and then gradually faded. The relative expression of TGF-β1 mRNA peaked at 1 week and then decreased until 2 months. The relative α-SMA mRNA expression reached its peak at 1 week, then reached a small peak again at 1 month. IF results showed that TGF-β1 was initially detected in the fibrin clot at 3 days and then in the entire repairing stroma at 1 week. TGF-β1 localization gradually diminished from the anterior region to the posterior region at 2 weeks to 1 month, and it was nearly absent at 2 months. The myofibroblast marker α-SMA was observed in the entire healing stroma at 2 weeks. Localization of α-SMA gradually disappeared from the anterior region at 3 weeks to 1 month, remaining only in the posterior region at 2 months and disappearing at 3 months. Defective epithelial basement membrane (EBM) was first detected at 3 weeks after injury, then gradually repaired, and was nearly regenerated at 3 months. A thin and uneven Descemet's membrane (DM) was initially detected at 2 months after injury, then gradually regenerated to some extent, but remained abnormal at 3 months. Conclusions In the rabbit corneal perforating injury model, EBM regeneration was observed earlier than DM. At 3 months, complete EBM regeneration was observed, while the regenerated DM was still defective. TGF-β1 was distributed throughout the entire wound area in the early stages and then decreased from the anterior to the posterior region. α-SMA exhibited a similar temporospatial expression to TGF-β1. EBM regeneration may play a key role in low expression of TGF-β1 and α-SMA in the anterior stroma. Meanwhile, incomplete DM regeneration may contribute to the sustained expression of TGF-β1 and α-SMA in the posterior stroma.
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Affiliation(s)
- Na Meng
- Department of Ophthalmology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jinling Wu
- Department of Ophthalmology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jingjing Chen
- Department of Ophthalmology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Yuqing Luo
- Department of Ophthalmology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Luxing Xu
- Department of Ophthalmology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Xia Li
- Department of Ophthalmology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
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Ong HS, Riau AK, Yam GHF, Yusoff NZBM, Han EJY, Goh TW, Lai RC, Lim SK, Mehta JS. Mesenchymal Stem Cell Exosomes as Immunomodulatory Therapy for Corneal Scarring. Int J Mol Sci 2023; 24:7456. [PMID: 37108619 PMCID: PMC10144287 DOI: 10.3390/ijms24087456] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Corneal scarring is a leading cause of worldwide blindness. Human mesenchymal stem cells (MSC) have been reported to promote corneal wound healing through secreted exosomes. This study investigated the wound healing and immunomodulatory effects of MSC-derived exosomes (MSC-exo) in corneal injury through an established rat model of corneal scarring. After induction of corneal scarring by irregular phototherapeutic keratectomy (irrPTK), MSC exosome preparations (MSC-exo) or PBS vehicle as controls were applied to the injured rat corneas for five days. The animals were assessed for corneal clarity using a validated slit-lamp haze grading score. Stromal haze intensity was quantified using in-vivo confocal microscopy imaging. Corneal vascularization, fibrosis, variations in macrophage phenotypes, and inflammatory cytokines were evaluated using immunohistochemistry techniques and enzyme-linked immunosorbent assays (ELISA) of the excised corneas. Compared to the PBS control group, MSC-exo treatment group had faster epithelial wound closure (0.041), lower corneal haze score (p = 0.002), and reduced haze intensity (p = 0.004) throughout the follow-up period. Attenuation of corneal vascularisation based on CD31 and LYVE-1 staining and reduced fibrosis as measured by fibronectin and collagen 3A1 staining was also observed in the MSC-exo group. MSC-exo treated corneas also displayed a regenerative immune phenotype characterized by a higher infiltration of CD163+, CD206+ M2 macrophages over CD80+, CD86+ M1 macrophages (p = 0.023), reduced levels of pro-inflammatory IL-1β, IL-8, and TNF-α, and increased levels of anti-inflammatory IL-10. In conclusion, topical MSC-exo could alleviate corneal insults by promoting wound closure and reducing scar development, possibly through anti-angiogenesis and immunomodulation towards a regenerative and anti-inflammatory phenotype.
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Affiliation(s)
- Hon Shing Ong
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 168751, Singapore
| | - Andri K. Riau
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Gary Hin-Fai Yam
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | | | - Evelina J. Y. Han
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
| | - Tze-Wei Goh
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
| | - Ruenn Chai Lai
- Institute of Medical Biology & Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138648, Singapore
| | - Sai Kiang Lim
- Institute of Medical Biology & Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138648, Singapore
| | - Jodhbir S. Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 168751, Singapore
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
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Rozo V, Quan M, Aung T, Kang J, Thomasy SM, Leonard BC. Andrographolide Inhibits Corneal Fibroblast to Myofibroblast Differentiation In Vitro. Biomolecules 2022; 12:biom12101447. [PMID: 36291655 PMCID: PMC9599903 DOI: 10.3390/biom12101447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/30/2022] [Accepted: 10/05/2022] [Indexed: 11/16/2022] Open
Abstract
Corneal opacification due to fibrosis is a leading cause of blindness worldwide. Fibrosis occurs from many causes including trauma, photorefractive surgery, microbial keratitis (infection of the cornea), and chemical burns, yet there is a paucity of therapeutics to prevent or treat corneal fibrosis. This study aimed to determine if andrographolide, a labdane diterpenoid found in Andrographis paniculate, has anti-fibrotic properties. Furthermore, we evaluated if andrographolide could prevent the differentiation of fibroblasts to myofibroblasts in vitro, given that the transforming growth factor beta-1(TGF-β1) stimulated persistence of myofibroblasts in the cornea is a primary component of fibrosis. We demonstrated that andrographolide inhibited the upregulation of alpha smooth muscle actin (αSMA) mRNA and protein in rabbit corneal fibroblasts (RCFs), thus, demonstrating a reduction in the transdifferentiation of myofibroblasts. Immunofluorescent staining of TGF-β1-stimulated RCFs confirmed a dose-dependent decrease in αSMA expression when treated with andrographolide. Additionally, andrographolide was well tolerated in vivo and had no impact on corneal epithelialization in a rat debridement model. These data support future studies investigating the use of andrographolide as an anti-fibrotic in corneal wound healing.
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Affiliation(s)
- Vanessa Rozo
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Melinda Quan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Theint Aung
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Jennifer Kang
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Sara M. Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, CA 95616, USA
| | - Brian C. Leonard
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
- Correspondence:
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BMP3 inhibits TGFβ2-mediated myofibroblast differentiation during wound healing of the embryonic cornea. NPJ Regen Med 2022; 7:36. [PMID: 35879352 PMCID: PMC9314337 DOI: 10.1038/s41536-022-00232-9] [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: 12/02/2021] [Accepted: 07/06/2022] [Indexed: 11/29/2022] Open
Abstract
Often acute damage to the cornea initiates drastic tissue remodeling, resulting in fibrotic scarring that disrupts light transmission and precedes vision impairment. Very little is known about the factors that can mitigate fibrosis and promote scar-free cornea wound healing. We previously described transient myofibroblast differentiation during non-fibrotic repair in an embryonic cornea injury model. Here, we sought to elucidate the mechanistic regulation of myofibroblast differentiation during embryonic cornea wound healing. We found that alpha-smooth muscle actin (αSMA)-positive myofibroblasts are superficial and their presence inversely correlates with wound closure. Expression of TGFβ2 and nuclear localization of pSMAD2 were elevated during myofibroblast induction. BMP3 and BMP7 were localized in the corneal epithelium and corresponded with pSMAD1/5/8 activation and absence of myofibroblasts in the healing stroma. In vitro analyses with corneal fibroblasts revealed that BMP3 inhibits the persistence of TGFβ2-induced myofibroblasts by promoting disassembly of focal adhesions and αSMA fibers. This was confirmed by the expression of vinculin and pFAK. Together, these data highlight a mechanism to inhibit myofibroblast persistence during cornea wound repair.
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Nissen EJ, Saeger M, Nölle B, Roider J. Clinicopathological Correlation of Microbial Keratitis and Ahead: Is There a Corneal Sepsis? Klin Monbl Augenheilkd 2022; 239:857-866. [PMID: 35858596 DOI: 10.1055/a-1811-7171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Microbial, infectious keratitis is a relevant indication for penetrating keratoplasty. The requirement for transplantation results in histopathological examination of the entire thickness of the cornea. Although the clinical diagnosis is not always possible to confirm, pathology can support diagnostic evidence of clinical presentation and pathogenesis. This is achieved with multiple methods from cytology, histochemistry, immunohistology, molecular pathology and in rare cases electron microscopy. These allow tissue-based detection of previous and parallel diseases and the responsible pathogens. The failure of satisfactory clinicopathological correlation raises the question whether a suspected pathogen was not ultimately responsible for destroyed corneal tissue. The pathogenesis of keratitis requiring transplantation is not yet completely understood, also on the experimental level. The development of such a keratitis can lead to a clinical symptomatology which can be described as "threatening organ dysfunction", a term used in sepsis research. Considering recent literature, possible correlations between sepsis and microbial keratitis and their relation to histopathology are discussed.
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Affiliation(s)
- Ebba J Nissen
- Klinik für Ophthalmologie, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Deutschland
| | - Mark Saeger
- Klinik für Ophthalmologie, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Deutschland
| | - Bernhard Nölle
- Klinik für Ophthalmologie, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Deutschland
| | - Johann Roider
- Klinik für Ophthalmologie, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Deutschland
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12
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Extracellular Vesicles in Corneal Fibrosis/Scarring. Int J Mol Sci 2022; 23:ijms23115921. [PMID: 35682600 PMCID: PMC9180085 DOI: 10.3390/ijms23115921] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022] Open
Abstract
Communication between cells and the microenvironment is a complex, yet crucial, element in the development and progression of varied physiological and pathological processes. Accumulating evidence in different disease models highlights roles of extracellular vesicles (EVs), either in modulating cell signaling paracrine mechanism(s) or harnessing their therapeutic moiety. Of interest, the human cornea functions as a refractive and transparent barrier that protects the intraocular elements from the external environment. Corneal trauma at the ocular surface may lead to diminished corneal clarity and detrimental effects on visual acuity. The aberrant activation of corneal stromal cells, which leads to myofibroblast differentiation and a disorganized extracellular matrix is a central biological process that may result in corneal fibrosis/scarring. In recent years, understanding the pathological and therapeutic EV mechanism(s) of action in the context of corneal biology has been a topic of increasing interest. In this review, we describe the clinical relevance of corneal fibrosis/scarring and how corneal stromal cells contribute to wound repair and their generation of the stromal haze. Furthermore, we will delve into EV characterization, their subtypes, and the pathological and therapeutic roles they play in corneal scarring/fibrosis.
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13
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Topical losartan inhibits corneal scarring fibrosis and collagen type IV deposition after Descemet's membrane-endothelial excision in rabbits. Exp Eye Res 2022; 216:108940. [DOI: 10.1016/j.exer.2022.108940] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/20/2021] [Accepted: 01/07/2022] [Indexed: 12/20/2022]
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14
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Wilson SE. Defective perlecan-associated basement membrane regeneration and altered modulation of transforming growth factor beta in corneal fibrosis. Cell Mol Life Sci 2022; 79:144. [PMID: 35188596 PMCID: PMC8972081 DOI: 10.1007/s00018-022-04184-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/14/2022] [Accepted: 02/01/2022] [Indexed: 02/06/2023]
Abstract
In the cornea, the epithelial basement membrane (EBM) and corneal endothelial Descemet's basement membrane (DBM) critically regulate the localization, availability and, therefore, the functions of transforming growth factor (TGF)β1, TGFβ2, and platelet-derived growth factors (PDGF) that modulate myofibroblast development. Defective regeneration of the EBM, and notably diminished perlecan incorporation, occurs via several mechanisms and results in excessive and prolonged penetration of pro-fibrotic growth factors into the stroma. These growth factors drive mature myofibroblast development from both corneal fibroblasts and bone marrow-derived fibrocytes, and then the persistence of these myofibroblasts and the disordered collagens and other matrix materials they produce to generate stromal scarring fibrosis. Corneal stromal fibrosis often resolves completely if the inciting factor is removed and the BM regenerates. Similar defects in BM regeneration are likely associated with the development of fibrosis in other organs where perlecan has a critical role in the modulation of signaling by TGFβ1 and TGFβ2. Other BM components, such as collagen type IV and collagen type XIII, are also critical regulators of TGF beta (and other growth factors) in the cornea and other organs. After injury, BM components are dynamically secreted and assembled through the cooperation of neighboring cells-for example, the epithelial cells and keratocytes for the corneal EBM and corneal endothelial cells and keratocytes for the corneal DBM. One of the most critical functions of these reassembled BMs in all organs is to modulate the pro-fibrotic effects of TGFβs, PDGFs and other growth factors between tissues that comprise the organ.
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Affiliation(s)
- Steven E Wilson
- Cole Eye Institute, I-32, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH, USA.
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Nuwormegbe S, Park NY, Kim SW. Lobeglitazone attenuates fibrosis in corneal fibroblasts by interrupting TGF-beta-mediated Smad signaling. Graefes Arch Clin Exp Ophthalmol 2021; 260:149-162. [PMID: 34468828 DOI: 10.1007/s00417-021-05370-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/30/2021] [Accepted: 08/06/2021] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Transforming growth factor beta 1 (TGF-β1) is an important cytokine released after ocular surface injury to promote wound healing. However, its persistence at the injury site triggers a fibrotic response that leads to corneal scarring and opacity. Thiazolidinediones (TZDs) are synthetic peroxisome proliferator-activated receptor gamma (PPAR-γ) ligands used to regulate glucose and lipid metabolism in the management of type 2 diabetes. Studies have also showed TZDs have antifibrotic effect. In this study, we investigated the antifibrotic effect of the TZD lobeglitazone on TGF-β1-induced fibrosis in corneal fibroblasts. METHODS Human primary corneal fibroblasts were cultivated and treated with TGF-β1 (5 ng/mL) to induce fibrosis, with or without pre-treatments with different concentrations of lobeglitazone. Myofibroblast differentiation and extracellular matrix (ECM) protein expression was evaluated by western blotting, immunofluorescence, real-time PCR, and collagen gel contraction assay. The effect of lobeglitazone on TGF-β1-induced reactive oxygen species (ROS) generation was evaluated by DCFDA-cellular ROS detection assay kit. Signaling proteins were evaluated by western blotting to determine the mechanism underlying the antifibrotic effect. RESULTS Our results showed lobeglitazone attenuated TGF-β1-induced ECM synthesis and myofibroblast differentiation of corneal fibroblasts. This antifibrotic effect appeared to be independent of PPAR signaling and rather due to the inhibition of the TGF-β1-induced Smad signaling. Lobeglitazone also blocked TGF-β1-induced ROS generation and nicotinamide adenine dinucleotide phosphate oxidase (Nox) 4 transcription. CONCLUSION These findings indicate that lobeglitazone may be a promising therapeutic agent for corneal scarring. KEY MESSAGES.
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Affiliation(s)
- Selikem Nuwormegbe
- Department of Global Medical Science, Wonju College of Medicine, Yonsei University, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea
| | - Na-Young Park
- Department of Ophthalmology, Wonju College of Medicine, Yonsei University, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea
| | - Sun Woong Kim
- Department of Ophthalmology, Wonju College of Medicine, Yonsei University, Wonju, Ilsan-ro, Gangwon-do, 26426, Republic of Korea.
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Jhanji V, Billig I, Yam GHF. Cell-Free Biological Approach for Corneal Stromal Wound Healing. Front Pharmacol 2021; 12:671405. [PMID: 34122095 PMCID: PMC8193853 DOI: 10.3389/fphar.2021.671405] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/17/2021] [Indexed: 12/13/2022] Open
Abstract
Corneal opacification is the fourth most common cause of blindness globally behind cataracts, glaucoma, and age-related macular degeneration. The standard treatment of serious corneal scarring is corneal transplantation. Though it is effective for restoring vision, the treatment outcome is not optimal, due to limitations such as long-term graft survival, lifelong use of immunosuppressants, and a loss of corneal strength. Regulation of corneal stromal wound healing, along with inhibition or downregulation of corneal scarring is a promising approach to prevent corneal opacification. Pharmacological approaches have been suggested, however these are fraught with side effects. Tissue healing is an intricate process that involves cell death, proliferation, differentiation, and remodeling of the extracellular matrix. Current research on stromal wound healing is focused on corneal characteristics such as the immune response, angiogenesis, and cell signaling. Indeed, promising new technologies with the potential to modulate wound healing are under development. In this review, we provide an overview of cell-free strategies and some approaches under development that have the potential to control stromal fibrosis and scarring, especially in the context of early intervention.
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Affiliation(s)
- Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Isabelle Billig
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Gary Hin-Fai Yam
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States
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17
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Wilson SE. Interleukin-1 and Transforming Growth Factor Beta: Commonly Opposing, but Sometimes Supporting, Master Regulators of the Corneal Wound Healing Response to Injury. Invest Ophthalmol Vis Sci 2021; 62:8. [PMID: 33825855 PMCID: PMC8039470 DOI: 10.1167/iovs.62.4.8] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Purpose Interleukin (IL)-1α/IL-1β and transforming growth factor (TGF)β1/TGFβ2 have both been promoted as “master regulators” of the corneal wound healing response due to the large number of processes each regulates after injury or infection. The purpose of this review is to highlight the interactions between these systems in regulating corneal wound healing. Methods We conducted a systematic review of the literature. Results Both regulator pairs bind to receptors expressed on keratocytes, corneal fibroblasts, and myofibroblasts, as well as bone marrow-derived cells that include fibrocytes. IL-1α and IL-1β modulate healing functions, such as keratocyte apoptosis, chemokine production by corneal fibroblasts, hepatocyte growth factor (HGF), and keratinocyte growth factor (KGF) production by keratocytes and corneal fibroblasts, expression of metalloproteinases and collagenases by corneal fibroblasts, and myofibroblast apoptosis. TGFβ1 and TGFβ2 stimulate the development of myofibroblasts from keratocyte and fibrocyte progenitor cells, and adequate stromal levels are requisite for the persistence of myofibroblasts. Conversely, TGFβ3, although it functions via the same TGF beta I and II receptors, may, at least in some circumstances, play a more antifibrotic role—although it also upregulates the expression of many profibrotic genes. Conclusions The overall effects of these two growth factor-cytokine-receptor systems in controlling the corneal wound healing response must be coordinated during the wound healing response to injury or infection. The activities of both systems must be downregulated in coordinated fashion to terminate the response to injury and eliminate fibrosis. Translational Relevance A better standing of the IL-1 and TGFβ systems will likely lead to better approaches to control the excessive healing response to infections and injuries leading to scarring corneal fibrosis.
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Affiliation(s)
- Steven E Wilson
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, United States
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18
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Wei W, Sun XY, Shen D, Wang XR, Ji YQ, Zhang CN. Comparison of healing patterns of different side-cut angulations after FS-LASIK. Int J Ophthalmol 2021; 14:430-435. [PMID: 33747821 DOI: 10.18240/ijo.2021.03.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 06/05/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate and evaluate healing patterns around flaps made with different side-cut angulations after femtosecond laser in situ keratomileusis (FS-LASIK). METHODS Thirty-four patients (68 eyes) received a 90° side-cut (n=34) or a 120° side-cut flaps (n=34) made with a femtosecond laser. One day, 1wk, 1 and 3mo postoperatively, side-cut scar was evaluated under slit-lamp photography according to a new grading system (Grade 0=transparent scar, 1=faint healing opacity, and 2=evident healing opacity). In vivo corneal confocal microscopy and anterior segment optical coherence tomography (AS-OCT) were used to observe wound-healing patterns around flap margin in the two groups. Sirius Scheimpflug Analyzer was also used to analyze higher order aberrations 3mo after surgery. RESULTS There were no significant differences in flap wound-healing patterns at each follow up between the two groups (P>0.05). Three months after surgery, the flap edge scar classified as Grade 0 had excellent apposition and rapid nerve regeneration. At 3 mm and 5 mm pupil diameters, there were significant differences in trefoil aberrations between the two groups (P<0.05), but no statistically significant differences were found in total higher order aberrations (HOAs), spherical aberrations or coma in any of the pupil size conditions (P>0.05). CONCLUSION Flap edge scars classified as Grade 0 have excellent apposition and rapid nerve regeneration, and 120° side-cut angle flaps induce less trefoil aberrations after FS-LASIK.
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Affiliation(s)
- Wei Wei
- Xi'an No.1 Hospital; Shaanxi Institute of Ophthalmology; Shaanxi Key Laboratory of Ophthalmology; Clinical Research Center for Ophthalmology Diseases of Shaanxi Province, First Affiliated Hospital of Northwestern University, Xi'an 710002, Shaanxi Province, China
| | - Xi-Yu Sun
- Xi'an No.1 Hospital; Shaanxi Institute of Ophthalmology; Shaanxi Key Laboratory of Ophthalmology; Clinical Research Center for Ophthalmology Diseases of Shaanxi Province, First Affiliated Hospital of Northwestern University, Xi'an 710002, Shaanxi Province, China
| | - Di Shen
- Xi'an No.1 Hospital; Shaanxi Institute of Ophthalmology; Shaanxi Key Laboratory of Ophthalmology; Clinical Research Center for Ophthalmology Diseases of Shaanxi Province, First Affiliated Hospital of Northwestern University, Xi'an 710002, Shaanxi Province, China
| | - Xiao-Rui Wang
- Xi'an No.1 Hospital; Shaanxi Institute of Ophthalmology; Shaanxi Key Laboratory of Ophthalmology; Clinical Research Center for Ophthalmology Diseases of Shaanxi Province, First Affiliated Hospital of Northwestern University, Xi'an 710002, Shaanxi Province, China
| | - Yu-Qiang Ji
- Xi'an No.1 Hospital; Shaanxi Institute of Ophthalmology; Shaanxi Key Laboratory of Ophthalmology; Clinical Research Center for Ophthalmology Diseases of Shaanxi Province, First Affiliated Hospital of Northwestern University, Xi'an 710002, Shaanxi Province, China
| | - Chang-Ning Zhang
- Xi'an No.1 Hospital; Shaanxi Institute of Ophthalmology; Shaanxi Key Laboratory of Ophthalmology; Clinical Research Center for Ophthalmology Diseases of Shaanxi Province, First Affiliated Hospital of Northwestern University, Xi'an 710002, Shaanxi Province, China
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19
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Wilson SE. Corneal myofibroblasts and fibrosis. Exp Eye Res 2020; 201:108272. [PMID: 33010289 DOI: 10.1016/j.exer.2020.108272] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 09/18/2020] [Accepted: 09/20/2020] [Indexed: 12/16/2022]
Abstract
Myofibroblasts are alpha-smooth muscle actin (SMA)+ cells that have a critical role in the corneal stromal response to infections, injuries, and surgeries, and which produce corneal scarring fibrosis when they develop in excess. These contractile and opaque cells-produce large amounts of disordered extracellular matrix (ECM)-and develop from keratocyte-derived corneal fibroblasts or bone marrow-derived fibrocytes, and possibly other cell types, in response to TGFβ1, TGFβ2 and PDGF from the epithelium, tears, endothelium, and other stromal cells. Recent proteomic analyses have revealed that the myofibroblasts that develop from different progenitors aren't interchangeable, but have major differences in protein expression and functions. Absence or defective regeneration of the epithelial basement membrane (EBM) and/or Descemet's basement membrane (DBM) results in development and persistence of myofibroblasts in the corneal stroma. The functions of myofibroblasts in the cornea include production of volume-additive ECM, tissue contraction, production of various growth factors, cytokines and chemokines that regulate stromal cells, including other myofibroblasts, production of collagenases and metalloproteinases involved in tissue remodeling, and the expression of toll-like receptors that likely have critical roles in the clearance of bacteria and viruses causing corneal infections.
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20
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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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21
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McKay TB, Schlötzer-Schrehardt U, Pal-Ghosh S, Stepp MA. Integrin: Basement membrane adhesion by corneal epithelial and endothelial cells. Exp Eye Res 2020; 198:108138. [PMID: 32712184 DOI: 10.1016/j.exer.2020.108138] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 12/11/2022]
Abstract
Integrins mediate adhesion of cells to substrates and maintain tissue integrity by facilitating mechanotransduction between cells, the extracellular matrix, and gene expression in the nucleus. Changes in integrin expression in corneal epithelial cells and corneal endothelial cells impacts their adhesion to the epithelial basement membrane (EpBM) and Descemet's membrane, respectively. Integrins also play roles in assembly of basement membranes by both activating TGFβ1 and other growth factors. Over the past two decades, this knowledge has been translated into methods to grow corneal epithelial and endothelial cells in vitro for transplantation in the clinic thereby transforming clinical practice and quality of life for patients. Current knowledge on the expression and function of the integrins that mediate adhesion to the basement membrane expressed by corneal epithelial and endothelial cells in health and disease is summarized. This is the first review to discuss similarities and differences in the integrins expressed by both cell types.
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Affiliation(s)
- Tina B McKay
- Department of Ophthalmology, Schepens Eye Research Institute / Mass Eye and Ear, 20 Staniford Street, Boston, MA, 02114, USA
| | - Ursula Schlötzer-Schrehardt
- Department of Ophthalmology, Universitätsklinikum Erlangen and Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington, DC, 20052, USA
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington, DC, 20052, USA; Department of Ophthalmology, The George Washington School of Medicine and Health Sciences, Washington, DC, 20052, USA.
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22
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de Oliveira RC, Wilson SE. Descemet's membrane development, structure, function and regeneration. Exp Eye Res 2020; 197:108090. [PMID: 32522478 DOI: 10.1016/j.exer.2020.108090] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 02/07/2023]
Abstract
Basement membranes are layers of extracellular matrix which anchor the epithelium or endothelium to connective tissues in most organs. Descemet's membrane- which is the basement membrane for the corneal endothelium- is a dense, thick, relatively transparent and cell-free matrix that separates the posterior corneal stroma from the underlying endothelium. It was historically named Descemet's membrane after Jean Descemet, a French physician, but it is also known as the posterior limiting elastic lamina, lamina elastica posterior, and membrane of Demours. Normal Descemet's membrane ultrastructure in humans has been shown to consist of an interfacial matrix that attaches to the overlying corneal stroma, an anterior banded layer and a posterior non-banded layer-upon which corneal endothelial cells attach. These layers have been shown to have unique composition and morphology, and to contribute to corneal homeostasis and clarity, participate in the control of corneal hydration and to modulate TGF-β-induced posterior corneal fibrosis. Pathophysiological alterations of Descemet's membrane are noted in ocular diseases such as Fuchs' dystrophy, bullous keratopathy, keratoconus, primary congenital glaucoma (Haab's striae), as well as in systemic conditions. Unrepaired extensive damage to Descemet's membrane results in severe corneal opacity and vision loss due to stromal fibrosis, which may require penetrating keratoplasty to restore corneal transparency. The purpose of this article is to highlight the current understanding of Descemet's membrane structure, function and potential for regeneration.
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Bâră RI, Voinea LM, Vrapciu AD, Rusu MC. Adding myofibroblasts to the lacrimal pump. Acta Histochem 2020; 122:151536. [PMID: 32156483 DOI: 10.1016/j.acthis.2020.151536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 01/03/2023]
Abstract
The lacrimal sac (LS) empties in the nasolacrimal duct to drain the tears in the inferior nasal meatus. Different studies indicated the role of the lacrimal pump in the lacrimal drainage. Although controversial, the lacrimal pump mechanism is an extrinsic one, either active, or passive. An intrinsic contractile potential of the LS was not documented previously. We thus aimed a retrospective immunohistochemical study to test the alpha-smooth muscle actin (α-SMA) and h-caldesmon expression in the LS wall. We used archived paraffin-embedded samples of LS from ten adult patients. The α-SMA + phenotype was detected in basal epithelial cells, in subepithelial ribbons of stromal cells, in vascular smooth muscle cells, as well as in pericytes. H-caldesmon was exclusively expressed in pericytes, vascular smooth muscle cells and myoepithelial cells of the subepithelial glands. The most striking feature we found in all samples was a consistent stromal network of α-SMA+/h-caldesmon- myofibroblasts. This finding supports an intrinsic scaffold useful for the lacrimal pump.
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Affiliation(s)
- Raluca Iustina Bâră
- Department of Ophtalmology, Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania; Department of Ophtalmology, Bucharest University Emergency Hospital, Bucharest, Romania.
| | - Liliana Mary Voinea
- Department of Ophtalmology, Bucharest University Emergency Hospital, Bucharest, Romania; Department of Ophthalmology, Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
| | - Alexandra Diana Vrapciu
- Division of Anatomy, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
| | - Mugurel Constantin Rusu
- Division of Anatomy, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, 8 Eroilor Sanitari Blvd., RO-050474, Bucharest, Romania.
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