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Poole K, Iyer KS, Schmidtke DW, Petroll WM, Varner VD. Corneal keratocytes, fibroblasts, and myofibroblasts exhibit distinct transcriptional profiles in vitro. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582620. [PMID: 38464034 PMCID: PMC10925317 DOI: 10.1101/2024.02.28.582620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Purpose After stromal injury to the cornea, the release of growth factors and pro-inflammatory cytokines promotes the activation of quiescent keratocytes into a migratory fibroblast and/or fibrotic myofibroblast phenotype. Persistence of the myofibroblast phenotype can lead to corneal fibrosis and scarring, which are leading causes of blindness worldwide. This study aims to establish comprehensive transcriptional profiles for cultured corneal keratocytes, fibroblasts, and myofibroblasts to gain insights into the mechanisms through which these phenotypic changes occur. Methods Primary rabbit corneal keratocytes were cultured in either defined serum-free media (SF), fetal bovine serum (FBS) containing media, or in the presence of TGF-β1 to induce keratocyte, fibroblast, or myofibroblast phenotypes, respectively. Bulk RNA sequencing followed by bioinformatic analyses was performed to identify significant differentially expressed genes (DEGs) and enriched biological pathways for each phenotype. Results Genes commonly associated with keratocytes, fibroblasts, or myofibroblasts showed high relative expression in SF, FBS, or TGF-β1 culture conditions, respectively. Differential expression and functional analyses revealed novel DEGs for each cell type, as well as enriched pathways indicative of differences in proliferation, apoptosis, extracellular matrix (ECM) synthesis, cell-ECM interactions, cytokine signaling, and cell mechanics. Conclusions Overall, these data demonstrate distinct transcriptional differences among cultured corneal keratocytes, fibroblasts, and myofibroblasts. We have identified genes and signaling pathways that may play important roles in keratocyte differentiation, including many related to mechanotransduction and ECM biology. Our findings have revealed novel molecular markers for each cell type, as well as possible targets for modulating cell behavior and promoting physiological corneal wound healing.
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Erkoc-Biradli FZ, Erenay B, Ozgun A, Öztatlı H, Işık F, Ateş U, Rasier R, Garipcan B. Mesenchymal stem cells derived-exosomes enhanced amniotic membrane extract promotes corneal keratocyte proliferation. Biotechnol Prog 2024; 40:e3465. [PMID: 38602120 DOI: 10.1002/btpr.3465] [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: 08/23/2023] [Revised: 03/20/2024] [Accepted: 03/26/2024] [Indexed: 04/12/2024]
Abstract
Amniotic membrane extract (AME) and Wharton's jelly mesenchymal stem cells derived-exosomes (WJ-MSC-Exos) are promising therapeutic solutions explored for their potential in tissue engineering and regenerative medicine, particularly in skin and corneal wound healing applications. AME is an extract form of human amniotic membrane and known to contain a plethora of cytokines and growth factors, making it a highly attractive option for topical applications. Similarly, WJ-MSC-Exos have garnered significant interest for their wound healing properties. Although WJ-MSC-Exos and AME have been used separately for wound healing research, their combined synergistic effects have not been studied extensively. In this study, we evaluated the effects of both AME and WJ-MSC-Exos, individually and together, on the proliferation of corneal keratocytes as well as their ability to promote in vitro cell migration, wound healing, and their impact on cellular morphology. Our findings indicated that the presence of both exosomes (3 × 105 Exo/mL) and AME (50 μg/mL) synergistically enhance the proliferation of corneal keratocytes. Combined use of these solutions (3 × 105 Exo/mL + 50 μg/mL) increased cell proliferation compared to only 50 μg/mL AME treatment on day 3 (**** p < 0.0001). This mixture treatment (3 × 105 Exo/mL + 50 μg/mL) increased wound closure rate compared to isolated WJ-MSC-Exo treatment (3 × 105 Exo/mL) (*p < 0.05). Overall, corneal keratocytes treated with AME and WJ-MSC-Exo (3 × 105 Exo/mL + 50 μg/mL) mixture resulted in enhanced proliferation and wound healing tendency. Utilization of combined use of AME and WJ-MSC-Exo can pave the way for a promising foundation for corneal repair research.
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Affiliation(s)
- Fatma Zehra Erkoc-Biradli
- Biomimetics and Bioinspired Biomaterials Research Laboratory, Institute of Biomedical Engineering, Bogaziçi University, Istanbul, Turkey
| | - Berkay Erenay
- Biomimetics and Bioinspired Biomaterials Research Laboratory, Institute of Biomedical Engineering, Bogaziçi University, Istanbul, Turkey
| | - Alp Ozgun
- Ottawa Hospital Research Institute, Ottawa, Canada
| | - Hayriye Öztatlı
- Biomimetics and Bioinspired Biomaterials Research Laboratory, Institute of Biomedical Engineering, Bogaziçi University, Istanbul, Turkey
| | - Ferda Işık
- Stembio Cord Blood Cell & Tissue Center, Kocaeli, Turkey
| | - Utku Ateş
- Stembio Cord Blood Cell & Tissue Center, Kocaeli, Turkey
| | - Rıfat Rasier
- Department of Ophthalmology, İstinye University, Istanbul, Turkey
| | - Bora Garipcan
- Biomimetics and Bioinspired Biomaterials Research Laboratory, Institute of Biomedical Engineering, Bogaziçi University, Istanbul, Turkey
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Iyer KS, Maruri DP, Schmidtke DW, Petroll WM, Varner VD. Treatment with both TGF-β1 and PDGF-BB disrupts the stiffness-dependent myofibroblast differentiation of corneal keratocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582803. [PMID: 38496568 PMCID: PMC10942298 DOI: 10.1101/2024.02.29.582803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
During corneal wound healing, stromal keratocytes transform into a repair phenotype that is driven by the release of cytokines, like transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor-BB (PDGF-BB). Previous work has shown that TGF-β1 promotes the myofibroblast differentiation of corneal keratocytes in a manner that depends on PDGF signaling. In addition, changes in mechanical properties are known to regulate the TGF-β1-mediated differentiation of cultured keratocytes. While PDGF signaling acts synergistically with TGF-β1 during myofibroblast differentiation, how treatment with multiple growth factors affects stiffness-dependent differences in keratocyte behavior is unknown. Here, we treated primary corneal keratocytes with PDGF-BB and TGF-β1 and cultured them on polyacrylamide (PA) substrata of different stiffnesses. In the presence of TGF-β1 alone, the cells underwent stiffness-dependent myofibroblast differentiation. On stiff substrata, the cells developed robust stress fibers, exhibited high levels of ⍺-SMA staining, formed large focal adhesions (FAs), and exerted elevated contractile forces, whereas cells in a compliant microenvironment showed low levels of ⍺-SMA immunofluorescence, formed smaller focal adhesions, and exerted decreased contractile forces. When the cultured keratocytes were treated simultaneously with PDGF-BB however, increased levels of ⍺-SMA staining and stress fiber formation were observed on compliant substrata, even though the cells did not exhibit elevated contractility or focal adhesion size. Pharmacological inhibition of PDGF signaling disrupted the myofibroblast differentiation of cells cultured on substrata of all stiffnesses. These results indicate that treatment with PDGF-BB can decouple molecular markers of myofibroblast differentiation from the elevated contractile phenotype otherwise associated with these cells, suggesting that crosstalk in the mechanotransductive signaling pathways downstream of TGF-β1 and PDGF-BB can regulate the stiffness-dependent differentiation of cultured keratocytes. Statement of Significance In vitro experiments have shown that changes in ECM stiffness can regulate the differentiation of myofibroblasts. Typically, these assays involve the use of individual growth factors, but it is unclear how stiffness-dependent differences in cell behavior are affected by multiple cytokines. Here, we used primary corneal keratocytes to show that treatment with both TGF-β1 and PDGF-BB disrupts the dependency of myofibroblast differentiation on substratum stiffness. In the presence of both growth factors, keratocytes on soft substrates exhibited elevated ⍺-SMA immunofluorescence without a corresponding increase in contractility or focal adhesion formation. This result suggests that molecular markers of myofibroblast differentiation can be dissociated from the elevated contractile behavior associated with the myofibroblast phenotype, suggesting potential crosstalk in mechanotransductive signaling pathways downstream of TGF-β1 and PDGF-BB.
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Thomasy SM, Leonard BC, Greiner MA, Skeie JM, Raghunathan VK. Squishy matters - Corneal mechanobiology in health and disease. Prog Retin Eye Res 2024; 99:101234. [PMID: 38176611 PMCID: PMC11193890 DOI: 10.1016/j.preteyeres.2023.101234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/06/2024]
Abstract
The cornea, as a dynamic and responsive tissue, constantly interacts with mechanical forces in order to maintain its structural integrity, barrier function, transparency and refractive power. Cells within the cornea sense and respond to various mechanical forces that fundamentally regulate their morphology and fate in development, homeostasis and pathophysiology. Corneal cells also dynamically regulate their extracellular matrix (ECM) with ensuing cell-ECM crosstalk as the matrix serves as a dynamic signaling reservoir providing biophysical and biochemical cues to corneal cells. Here we provide an overview of mechanotransduction signaling pathways then delve into the recent advances in corneal mechanobiology, focusing on the interplay between mechanical forces and responses of the corneal epithelial, stromal, and endothelial cells. We also identify species-specific differences in corneal biomechanics and mechanotransduction to facilitate identification of optimal animal models to study corneal wound healing, disease, and novel therapeutic interventions. Finally, we identify key knowledge gaps and therapeutic opportunities in corneal mechanobiology that are pressing for the research community to address especially pertinent within the domains of limbal stem cell deficiency, keratoconus and Fuchs' endothelial corneal dystrophy. By furthering our understanding corneal mechanobiology, we can contextualize discoveries regarding corneal diseases as well as innovative treatments for them.
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Affiliation(s)
- Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California - Davis, Davis, CA, United States; Department of Ophthalmology & Vision Science, School of Medicine, University of California - Davis, Davis, CA, United States; California National Primate Research Center, Davis, CA, United States.
| | - Brian C Leonard
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California - Davis, Davis, CA, United States; Department of Ophthalmology & Vision Science, School of Medicine, University of California - Davis, Davis, CA, United States
| | - Mark A Greiner
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, United States; Iowa Lions Eye Bank, Coralville, IA, United States
| | - Jessica M Skeie
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, United States; Iowa Lions Eye Bank, Coralville, IA, United States
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Cappitti A, Palmieri F, Garella R, Tani A, Chellini F, Salzano De Luna M, Parmeggiani C, Squecco R, Martella D, Sassoli C. Development of accessible platforms to promote myofibroblast differentiation by playing on hydrogel scaffold composition. BIOMATERIALS ADVANCES 2023; 155:213674. [PMID: 37922662 DOI: 10.1016/j.bioadv.2023.213674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 10/19/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023]
Abstract
Mechanomimetic materials are particularly attractive for modeling in vitro fibroblast to myofibroblast (Myof) transition, a key process in the physiological repair of damaged tissue, and recognized as the core cellular mechanism of pathological fibrosis in different organs. In vivo, mechanical stimuli from the extracellular matrix (ECM) are crucial, together with cell-cell contacts and the pro-fibrotic transforming growth factor (TGF)-β1, in promoting fibroblast differentiation. Here, we explore the impact of hydrogels made by polyacrylamide with different composition on fibroblast behavior. By appropriate modulation of the hydrogel composition (e.g. adjusting the crosslinker content), we produce and fully characterize three kinds of scaffolds with different Young modulus (E). We observe that soft hydrogels (E < 1 kPa) induced fibroblast differentiation better than stiffer ones, also in the absence of TGF-β1. This study provides a readily accessible biomaterial platform to promote Myof generation. The easy approach used and the commercial availability of the monomers make these hydrogels suitable to a wide range of biomedical applications combined with high reproducibility and simple preparation protocols.
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Affiliation(s)
- Alice Cappitti
- Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy
| | - Francesco Palmieri
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, 50134 Florence, Italy
| | - Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, 50134 Florence, Italy
| | - Alessia Tani
- Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, Imaging Platform, University of Florence, 50134 Florence, Italy
| | - Flaminia Chellini
- Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, Imaging Platform, University of Florence, 50134 Florence, Italy
| | - Martina Salzano De Luna
- Department of chemical, materials and industrial production engineering, University of Naples Federico II, 80125 Napoli, Italy
| | - Camilla Parmeggiani
- Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy; European Laboratory for Non-Linear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, 50134 Florence, Italy.
| | - Daniele Martella
- Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy; European Laboratory for Non-Linear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy; Istituto Nazionale di Ricerca Metrologica (INRiM), 10135 Torino, Italy.
| | - Chiara Sassoli
- Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, Imaging Platform, University of Florence, 50134 Florence, Italy
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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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Zhang R, Li B, Li H. Extracellular-Matrix Mechanics Regulate the Ocular Physiological and Pathological Activities. J Ophthalmol 2023; 2023:7626920. [PMID: 37521908 PMCID: PMC10386902 DOI: 10.1155/2023/7626920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/06/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023] Open
Abstract
The extracellular matrix (ECM) is a noncellular structure that plays an indispensable role in a series of cell life activities. Accumulating studies have demonstrated that ECM stiffness, a type of mechanical forces, exerts a pivotal influence on regulating organogenesis, tissue homeostasis, and the occurrence and development of miscellaneous diseases. Nevertheless, the role of ECM stiffness in ophthalmology is rarely discussed. In this review, we focus on describing the important role of ECM stiffness and its composition in multiple ocular structures (including cornea, retina, optic nerve, trabecular reticulum, and vitreous) from a new perspective. The abnormal changes in ECM can trigger physiological and pathological activities of the eye, suggesting that compared with different biochemical factors, the transmission and transduction of force signals triggered by mechanical cues such as ECM stiffness are also universal in different ocular cells. We expect that targeting ECM as a therapeutic approach or designing advanced ECM-based technologies will have a broader application prospect in ophthalmology.
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Affiliation(s)
- Ran Zhang
- Department of Ophthalmology & Optometry, North Sichuan Medical College, Nanchong 637000, Sichuan, China
- Department of Ophthalmology, Central Hospital of Suining City, Suining 629000, Sichuan, China
| | - Bo Li
- Department of Ophthalmology, Central Hospital of Suining City, Suining 629000, Sichuan, China
| | - Heng Li
- Department of Ophthalmology & Optometry, North Sichuan Medical College, Nanchong 637000, Sichuan, China
- Department of Ophthalmology, Central Hospital of Suining City, Suining 629000, Sichuan, China
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Pot SA, Lin Z, Shiu J, Benn MC, Vogel V. Growth factors and mechano-regulated reciprocal crosstalk with extracellular matrix tune the keratocyte-fibroblast/myofibroblast transition. Sci Rep 2023; 13:11350. [PMID: 37443325 PMCID: PMC10345140 DOI: 10.1038/s41598-023-37776-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Improper healing of the cornea after injury, infections or surgery can lead to corneal scar formation, which is associated with the transition of resident corneal keratocytes into activated fibroblasts and myofibroblasts (K-F/M). Myofibroblasts can create an extracellular matrix (ECM) niche in which fibrosis is promoted and perpetuated, resulting in progressive tissue opacification and vision loss. As a reversion back to quiescent keratocytes is essential to restore corneal transparency after injury, we characterized how growth factors with demonstrated profibrotic effects (PDGF, FGF, FBS, TGFβ1) induce the K-F/M transition, and whether their withdrawal can revert it. Indeed, the upregulated expression of αSMA and the associated changes in cytoskeletal architecture correlated with increases in cell contractility, fibronectin (Fn) and collagen matrix density and Fn fiber strain, as revealed by 2D cell culture, nanopillar cellular force mapping and a FRET-labeled Fn tension probe. Substrate mechanosensing drove a more complete K-F/M transition reversal following growth factor withdrawal on nanopillar arrays than on planar glass substrates. Using decellularized ECM scaffolds, we demonstrated that the K-F/M transition was inhibited in keratocytes reseeded onto myofibroblast-assembled, and/or collagen-1-rich ECM. This supports the presence of a myofibroblast-derived ECM niche that contains cues favoring tissue homeostasis rather than fibrosis.
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Affiliation(s)
- Simon A Pot
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
- Ophthalmology Section, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
| | - Zhe Lin
- Ruisi (Fujian) Biomedical Engineering Research Center Co Ltd, 26-1 Wulongjiang Road, Fuzhou, 350100, People's Republic of China
| | - Jauye Shiu
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland
- Graduate Institute of Biomedical Sciences, China Medical University, No. 91, Xueshi Rd, North District, Taichung City, Taiwan
| | - Mario C Benn
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland
| | - Viola Vogel
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
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Shiju TM, Sampaio LP, Hilgert GSL, Wilson SE. Corneal epithelial basement membrane assembly is mediated by epithelial cells in coordination with corneal fibroblasts during wound healing. Mol Vis 2023; 29:68-86. [PMID: 37287640 PMCID: PMC10243680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 05/18/2023] [Indexed: 06/09/2023] Open
Abstract
Purpose To understand which cell types, either alone or in combination, contribute to the assembly of the epithelial basement membrane (BM) during corneal wound healing. Methods A 3D corneal organotypic model and an in situ rabbit photorefractive keratectomy (PRK) model were used in this study. The 3D corneal organotypic model was established by culturing the rabbit corneal epithelial cells with either corneal fibroblasts or myofibroblasts embedded in collagen type I for 18 days. Corneal fibroblasts were isolated from fresh rabbit corneas, and the myofibroblasts were derived either directly from bone marrow or differentiated from corneal fibroblasts. Immunocytochemistry for alpha-smooth muscle actin (SMA), vimentin, desmin, and vinculin markers confirmed well-differentiated myofibroblasts. Immunohistochemistry was performed in cryofixed sections for BM markers, including laminin alpha-5, laminin beta-3, perlecan, nidogen-1, and collagen type IV. Specimens were also examined with transmission electron microscopy (TEM). Corneas were collected from rabbits after -3 diopter (D) PRK at different time points after surgery, with four corneas at each time point in each group. Cryofixed corneal sections were stained for vimentin, alpha-SMA, and nidogen-1. Results The formation of an epithelial BM with expression of laminin alpha-5, laminin beta-3, perlecan, nidogen-1, and collagen IV was observed at the interface between the corneal epithelial cells and corneal fibroblasts. TEM images further confirmed the presence of epithelial BM in organotypic cultures of epithelial cells and corneal fibroblasts. No epithelial BM was observed in cultures of corneal epithelial cells and myofibroblasts (cornea or bone marrow derived), corneal epithelial cells alone, or corneal fibroblasts alone. In rabbit corneas after -3D PRK, a strong association was observed between the regenerating epithelial BM and the presence of corneal fibroblasts at the site of epithelial BM generation. Conclusions The corneal epithelial BM assembly is mediated by epithelial cells in coordination with corneal fibroblasts during wound healing.
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Bhattacharya S, Mukherjee A, Pisano S, Dimri S, Knaane E, Altshuler A, Nasser W, Dey S, Shi L, Mizrahi I, Blum N, Jokel O, Amitai-Lange A, Kaganovsky A, Mimouni M, Socea S, Midlij M, Tiosano B, Hasson P, Feral C, Wolfenson H, Shalom-Feuerstein R. The biophysical property of the limbal niche maintains stemness through YAP. Cell Death Differ 2023:10.1038/s41418-023-01156-7. [PMID: 37095157 DOI: 10.1038/s41418-023-01156-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 04/26/2023] Open
Abstract
The cell fate decisions of stem cells (SCs) largely depend on signals from their microenvironment (niche). However, very little is known about how biochemical niche cues control cell behavior in vivo. To address this question, we focused on the corneal epithelial SC model in which the SC niche, known as the limbus, is spatially segregated from the differentiation compartment. We report that the unique biomechanical property of the limbus supports the nuclear localization and function of Yes-associated protein (YAP), a putative mediator of the mechanotransduction pathway. Perturbation of tissue stiffness or YAP activity affects SC function as well as tissue integrity under homeostasis and significantly inhibited the regeneration of the SC population following SC depletion. In vitro experiments revealed that substrates with the rigidity of the corneal differentiation compartment inhibit nuclear YAP localization and induce differentiation, a mechanism that is mediated by the TGFβ-SMAD2/3 pathway. Taken together, these results indicate that SC sense biomechanical niche signals and that manipulation of mechano-sensory machinery or its downstream biochemical output may bear fruits in SC expansion for regenerative therapy.
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Affiliation(s)
- Swarnabh Bhattacharya
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel.
- Department of Medical Oncology and Center for Functional Cancer Epigenetics, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
- Departments of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
| | - Abhishek Mukherjee
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Sabrina Pisano
- Université Côte d'Azur, INSERM, CNRS, IRCAN, 06107, Nice, France
| | - Shalini Dimri
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Eman Knaane
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Anna Altshuler
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Waseem Nasser
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Sunanda Dey
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Lidan Shi
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Ido Mizrahi
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Noam Blum
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Ophir Jokel
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Aya Amitai-Lange
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Anna Kaganovsky
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Michael Mimouni
- Department of Ophthalmology, Rambam Health Care Campus, 31096, Haifa, Israel
| | - Sergiu Socea
- Department of Ophthalmology, Rambam Health Care Campus, 31096, Haifa, Israel
| | - Mohamad Midlij
- Department of Ophthalmology, Hilel Yafe Medical Center, Hadera, Israel
| | - Beatrice Tiosano
- Department of Ophthalmology, Hilel Yafe Medical Center, Hadera, Israel
| | - Peleg Hasson
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel
| | - Chloe Feral
- Université Côte d'Azur, INSERM, CNRS, IRCAN, 06107, Nice, France
| | - Haguy Wolfenson
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel.
| | - Ruby Shalom-Feuerstein
- Department of Genetics & Developmental Biology, The Rappaport Faculty of Medicine & Research Institute, Technion Integrated Cancer Center, Technion - Israel Institute of Technology, 31096, Haifa, Israel.
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11
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Tischenko K, Brill-Karniely Y, Steinberg E, Segev-Yekutiel H, Benny O. Surface physical cues mediate the uptake of foreign particles by cancer cells. APL Bioeng 2023; 7:016113. [PMID: 36960390 PMCID: PMC10030191 DOI: 10.1063/5.0138245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/02/2023] [Indexed: 03/22/2023] Open
Abstract
Cancer phenotypes are often associated with changes in the mechanical states of cells and their microenvironments. Numerous studies have established correlations between cancer cell malignancy and cell deformability at the single-cell level. The mechanical deformation of cells is required for the internalization of large colloidal particles. Compared to normal epithelial cells, cancer cells show higher capacities to distort their shapes during the engulfment of external particles, thus performing phagocytic-like processes more efficiently. This link between cell deformability and particle uptake suggests that the cell's adherence state may affect this particle uptake, as cells become stiffer when plated on a more rigid substrate and vice versa. Based on this, we hypothesized that cancer cells of the same origin, which are subjected to external mechanical cues through attachment to surfaces with varying rigidities, may express different capacities to uptake foreign particles. The effects of substrate rigidity on cancer cell uptake of inert particles (0.8 and 2.4 μm) were examined using surfaces with physiologically relevant rigidities (from 0.5 to 64 kPa). Our data demonstrate a wave-like ("meandering") dependence of cell uptake on the rigidity of the culture substrate explained by a superposition of opposing physical and biological effects. The uptake patterns were inversely correlated with the expression of phosphorylated paxillin, indicating that the initial passive particle absorbance is the primary limiting step toward complete uptake. Overall, our findings may provide a foundation for mechanical rationalization of particle uptake design.
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Affiliation(s)
- Katerina Tischenko
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001 Israel
| | - Yifat Brill-Karniely
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001 Israel
| | - Eliana Steinberg
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001 Israel
| | - Hadas Segev-Yekutiel
- The Core Research Facility, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001 Israel
| | - Ofra Benny
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001 Israel
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12
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Chen J, Mo Q, Long Q, Sheng R, Chen Z, Luo Y, Liu C, Backman LJ, Zhang Y, Zhang W. Hydroxycamptothecin and Substratum Stiffness Synergistically Regulate Fibrosis of Human Corneal Fibroblasts. ACS Biomater Sci Eng 2023; 9:959-967. [PMID: 36705297 DOI: 10.1021/acsbiomaterials.2c01302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Corneal fibrosis is a common outcome of inappropriate repair associated with trauma or ocular infection. Altered biomechanical properties with increased corneal stiffness is a feature of fibrosis that cause corneal opacities, resulting in severe visual impairment and even blindness. The present study aims to determine the effect of hydroxycamptothecin (HCPT) and matrix stiffness on transforming growth factor-β1 (TGF-β1)-induced fibrotic processes in human corneal fibroblasts (HTK cells). HTK cells were cultured on substrates with different stiffnesses ("soft", ∼261 kPa; "stiff", ∼2.5 × 103 kPa) and on tissue culture plastic (TCP, ∼106 kPa) and simultaneously treated with or without 1 μg/mL HCPT and 10 ng/mL TGF-β1. We found that HCPT induced decreased cell viability and antiproliferative effects on HTK cells. TGF-β1-induced expression of fibrosis-related genes (FN1, ACTA2) was reduced if the cells were simultaneously treated with HCPT. Substrate stiffness did not affect the expression of fibrosis-related genes. The TGF-β1 induced expression of FN1 on both soft and stiff substrates was reduced if cells were simultaneously treated with HCPT. However, this trend was not seen for ACTA2, i.e., the TGF-β1 induced expression of ACTA2 was not reduced by simultaneous treatment of HCPT in either soft or stiff substrate. Instead, HCPT treatment in the presence of TGF-β1 resulted in increased gene expression of keratocyte phenotype makers (LUM, KERA, AQP1, CHTS6) on both substrate stiffnesses. In addition, the protein expression of keratocyte phenotype makers LUM and ALDH3 was increased in HTK cells simultaneously treated with TGF-β1 and HCPT on stiff substrate as compared to control, i.e., without HCPT. In conclusion, we found that HCPT can reduce TGF-β1-induced fibrosis and promote the keratocyte phenotype in a substrate stiffness dependent manner. Thus, HCPT stimulation might be an approach to stimulate keratocytes in the appropriate healing stage to avoid or reverse fibrosis and achieve more optimal corneal wound healing.
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Affiliation(s)
- Jialin Chen
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China.,Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210096, China.,China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou 310058, China
| | - Qingyun Mo
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Qiuzi Long
- Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China.,Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Renwang Sheng
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Zhixuan Chen
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Yifan Luo
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Chuanquan Liu
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Ludvig J Backman
- Department of Integrative Medical Biology, Anatomy, Umeå University, Umeå SE-901 87, Sweden.,Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå SE-901 87, Sweden
| | - Yanan Zhang
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China
| | - Wei Zhang
- School of Medicine, Southeast University, Nanjing 210009, China.,Center for Stem Cell and Regenerative Medicine, Southeast University, Nanjing 210009, China.,Jiangsu Key Laboratory for Biomaterials and Devices, Southeast University, Nanjing 210096, China.,China Orthopedic Regenerative Medicine Group (CORMed), Hangzhou 310058, China
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13
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Lin X, Mekonnen T, Verma S, Zevallos-Delgado C, Singh M, Aglyamov SR, Gesteira TF, Larin KV, Coulson-Thomas VJ. Hyaluronan Modulates the Biomechanical Properties of the Cornea. Invest Ophthalmol Vis Sci 2022; 63:6. [PMID: 36478198 PMCID: PMC9733656 DOI: 10.1167/iovs.63.13.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Purpose Hyaluronan (HA) is a major constituent of the extracellular matrix (ECM) that has high viscosity and is essential for maintaining tissue hydration. In the cornea, HA is enriched in the limbal region and is a key component of the limbal epithelial stem cell niche. HA is upregulated after injury participating in the formation of the provisional matrix, and has a key role in regulating the wound healing process. This study investigated whether changes in the distribution of HA before and after injury affects the biomechanical properties of the cornea in vivo. Methods Corneas of wild-type (wt) mice and mice lacking enzymes involved in the biosynthesis of HA were analyzed before, immediately after, and 7 and 14 days after a corneal alkali burn (AB). The corneas were evaluated using both a ring light and fluorescein stain by in vivo confocal microscopy, optical coherence elastography (OCE), and immunostaining of corneal whole mounts. Results Our results show that wt mice and mice lacking HA synthase (Has)1 and 3 present an increase in corneal stiffness 7 and 14 days after AB without a significant increase in HA expression and absence of scarring at 14 days after AB. In contrast, mice lacking Has2 present a significant decrease in corneal stiffness, with a significant increase in HA expression and scarring at 14 days after AB. Conclusions Our findings show that the mechanical properties of the cornea are significantly modulated by changes in HA distribution following alkali burn.
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Affiliation(s)
- Xiao Lin
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Taye Mekonnen
- Department of Biomedical Engineering, University of Houston, Houston, Texas, United States
| | - Sudhir Verma
- College of Optometry, University of Houston, Houston, Texas, United States,Department of Zoology, Deen Dayal Upadhyaya College, University of Delhi, Delhi, India
| | | | - Manmohan Singh
- Department of Biomedical Engineering, University of Houston, Houston, Texas, United States
| | - Salavat R. Aglyamov
- Department of Mechanical Engineering, University of Houston, Houston, Texas, United States
| | - Tarsis F. Gesteira
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Kirill V. Larin
- Department of Biomedical Engineering, University of Houston, Houston, Texas, United States
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14
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Yang S, Zhang J, Tan Y, Wang Y. Unraveling the mechanobiology of cornea: From bench side to the clinic. Front Bioeng Biotechnol 2022; 10:953590. [PMID: 36263359 PMCID: PMC9573972 DOI: 10.3389/fbioe.2022.953590] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 09/06/2022] [Indexed: 11/18/2022] Open
Abstract
The cornea is a transparent, dome-shaped structure on the front part of the eye that serves as a major optic element and a protector from the external environment. Recent evidence shows aberrant alterations of the corneal mechano-environment in development and progression of various corneal diseases. It is, thus, critical to understand how corneal cells sense and respond to mechanical signals in physiological and pathological conditions. In this review, we summarize the corneal mechano-environment and discuss the impact of these mechanical cues on cellular functions from the bench side (in a laboratory research setting). From a clinical perspective, we comprehensively review the mechanical changes of corneal tissue in several cornea-related diseases, including keratoconus, myopia, and keratectasia, following refractive surgery. The findings from the bench side and clinic underscore the involvement of mechanical cues in corneal disorders, which may open a new avenue for development of novel therapeutic strategies by targeting corneal mechanics.
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Affiliation(s)
- Shu Yang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
- Department of Ophthalmology, The First People’s Hospital of Huzhou, Huzhou, Zhejiang, China
| | - Jing Zhang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
- School of Optometry, Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Youhua Tan
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
- *Correspondence: Youhua Tan, ; Yan Wang,
| | - Yan Wang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
- *Correspondence: Youhua Tan, ; Yan Wang,
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15
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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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16
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Xu J, Chen P, Luan X, Yuan X, Wei S, Li Y, Guo C, Wu X, Di G. The NLRP3 Activation in Infiltrating Macrophages Contributes to Corneal Fibrosis by Inducing TGF-β1 Expression in the Corneal Epithelium. Invest Ophthalmol Vis Sci 2022; 63:15. [PMID: 35838447 PMCID: PMC9296889 DOI: 10.1167/iovs.63.8.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose To explore the effect and mechanism of NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasomes on corneal fibrosis. Methods The wild-type, NLRP3 knockout (KO), and myeloid cell-specific NLRP3 KO (NLRP3 Lyz-KO) C57 mice were used to establish a corneal scarring model. NLRP3 inhibitor, IL-1β neutralizing antibody, and an IL-1R antagonist were used to investigate the role of NLRP3 and IL-1β in corneal fibrosis. The expression of the NLRP3 signaling pathway related proteins, alpha-smooth muscle actin, TGF-β was determined by quantitative real-time polymerase chain reaction, Western blotting, and immunofluorescence staining. Flow cytometry was used to detect the infiltration of macrophages during corneal fibrosis. Results The components of the NLRP3 inflammasomes were elevated and activated during corneal scarring. Additionally, genetic or chemical-mediated blocking of NLRP3 as well as IL-1β significantly alleviated corneal fibrosis. Moreover, neutrophil (CD45+Ly6G+) and macrophage (CD45+ F4/80+) accumulation increased in the cornea during the progression of corneal fibrosis. Intriguingly, the increased concentrations of NLRP3 and IL-1β were prominently colocalized with the infiltrating F4/80+ macrophages. Expectedly, NLRP3 Lyz-KO mice exhibited a marked decrease in their corneal fibrosis symptoms. Mechanistically, the activation of IL-1β or macrophage NLRP3 stimulated the expression of TGF-β1 in the corneal epithelial cells, whereas an NLRP3 deficiency decreased its expression in the corneal epithelium. Conclusions These observations revealed that the NLRP3 inflammasome activation in infiltrating macrophages contributes to corneal fibrosis by regulating corneal epithelial TGF-β1 expression. Targeting the NLRP3 inflammasome might be a promising strategy for the treatment of corneal scarring.
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Affiliation(s)
- Jing Xu
- School of Basic Medicine, Medical College, Qingdao University, Qingdao, China
| | - Peng Chen
- School of Basic Medicine, Medical College, Qingdao University, Qingdao, China
| | - Xiaoyu Luan
- School of Basic Medicine, Medical College, Qingdao University, Qingdao, China
| | - Xinying Yuan
- School of Basic Medicine, Medical College, Qingdao University, Qingdao, China
| | - Susu Wei
- School of Basic Medicine, Medical College, Qingdao University, Qingdao, China
| | - Yaxin Li
- School of Basic Medicine, Medical College, Qingdao University, Qingdao, China
| | - Chuanlong Guo
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Xianggen Wu
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Guohu Di
- School of Basic Medicine, Medical College, Qingdao University, Qingdao, China
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17
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Iyer KS, Maruri DP, Peak KE, Schmidtke DW, Petroll WM, Varner VD. ECM stiffness modulates the proliferation but not the motility of primary corneal keratocytes in response to PDGF-BB. Exp Eye Res 2022; 220:109112. [PMID: 35595094 PMCID: PMC10163834 DOI: 10.1016/j.exer.2022.109112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/25/2022] [Accepted: 05/11/2022] [Indexed: 11/04/2022]
Abstract
During corneal wound healing, keratocytes present within the corneal stroma become activated into a repair phenotype upon the release of growth factors, such as transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor-BB (PDGF-BB). The process of injury and repair can lead to changes in the mechanical properties of the tissue, and previous work has shown that the TGF-β1-mediated myofibroblast differentiation of corneal keratocytes depends on substratum stiffness. It is still unclear, however, if changes in stiffness can modulate keratocyte behavior in response to other growth factors, such as PDGF-BB. Here, we used a polyacrylamide (PA) gel system to determine whether changes in stiffness influence the proliferation and motility of primary corneal keratocytes treated with PDGF-BB. In the presence of PDGF-BB, cells on stiffer substrata exhibited a more elongated morphology and had higher rates of proliferation than cells in a more compliant microenvironment. Using a freeze-injury to assay cell motility, however, we did not observe any stiffness-dependent differences in the migration of keratocytes treated with PDGF-BB. Taken together, these data highlight the importance of biophysical cues during corneal wound healing and suggest that keratocytes respond differently to changes in ECM stiffness in the presence of different growth factors.
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Affiliation(s)
- Krithika S Iyer
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Daniel P Maruri
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Kara E Peak
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - David W Schmidtke
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA; Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - W Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Victor D Varner
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA; Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
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18
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Maruri DP, Iyer KS, Schmidtke DW, Petroll WM, Varner VD. Signaling Downstream of Focal Adhesions Regulates Stiffness-Dependent Differences in the TGF- β1-Mediated Myofibroblast Differentiation of Corneal Keratocytes. Front Cell Dev Biol 2022; 10:886759. [PMID: 35693927 PMCID: PMC9177138 DOI: 10.3389/fcell.2022.886759] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/06/2022] [Indexed: 12/05/2022] Open
Abstract
Following injury and refractive surgery, corneal wound healing can initiate a protracted fibrotic response that interferes with ocular function. This fibrosis is related, in part, to the myofibroblast differentiation of corneal keratocytes in response to transforming growth factor beta 1 (TGF-β1). Previous studies have shown that changes in the mechanical properties of the extracellular matrix (ECM) can regulate this process, but the mechanotransductive pathways that govern stiffness-dependent changes in keratocyte differentiation remain unclear. Here, we used a polyacrylamide (PA) gel system to investigate how mechanosensing via focal adhesions (FAs) regulates the stiffness-dependent myofibroblast differentiation of primary corneal keratocytes treated with TGF-β1. Soft (1 kPa) and stiff (10 kPa) PA substrata were fabricated on glass coverslips, plated with corneal keratocytes, and cultured in defined serum free media with or without exogenous TGF-β1. In some experiments, an inhibitor of focal adhesion kinase (FAK) activation was also added to the media. Cells were fixed and stained for F-actin, as well as markers for myofibroblast differentiation (α-SMA), actomyosin contractility phosphorylated myosin light chain (pMLC), focal adhesions (vinculin), or Smad activity (pSmad3). We also used traction force microscopy (TFM) to quantify cellular traction stresses. Treatment with TGF-β1 elicited stiffness-dependent differences in the number, size, and subcellular distribution of FAs, but not in the nuclear localization of pSmad3. On stiff substrata, cells exhibited large FAs distributed throughout the entire cell body, while on soft gels, the FAs were smaller, fewer in number, and localized primarily to the distal tips of thin cellular extensions. Larger and increased numbers of FAs correlated with elevated traction stresses, increased levels of α-SMA immunofluorescence, and more prominent and broadly distributed pMLC staining. Inhibition of FAK disrupted stiffness-dependent differences in keratocyte contractility, FA patterning, and myofibroblast differentiation in the presence of TGF-β1. Taken together, these data suggest that signaling downstream of FAs has important implications for the stiffness-dependent myofibroblast differentiation of corneal keratocytes.
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Affiliation(s)
- Daniel P. Maruri
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, United States
| | - Krithika S. Iyer
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, United States
| | - David W. Schmidtke
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, United States,Department of Surgery, UT Southwestern Medical Center, Dallas, TX, United States
| | - W. Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, United States
| | - Victor D. Varner
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, United States,Department of Surgery, UT Southwestern Medical Center, Dallas, TX, United States,*Correspondence: Victor D. Varner,
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19
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Yang C, Pan J, Luo X, Li J, Jiang Z. Hypoxia-induced mesenchymal stem cells inhibit corneal fibroblast proliferation by regulating the WWP2/Notch1 axis. Regen Med 2022; 17:375-388. [PMID: 35545948 DOI: 10.2217/rme-2021-0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: This study aimed to explore the role of hypoxic mesenchymal stem cells (MSCs) in corneal alkali burns and the underlying mechanism. Materials & methods: Rat corneal fibroblasts were incubated with IL-6, followed by treatment with hypoxic MSC supernatant. A rat corneal alkali burn model was implemented and processed with hypoxic MSCs. The associated factors were detected by corresponding methods. Results: Hypoxic MSCs reduced the Notch1 level and the proliferation of rat corneal fibroblasts. Hypoxic MSCs or WWP2 overexpression in MSCs enhanced ubiquitination of Notch1. WWP2 interacted with Notch1, and WWP2 silencing reversed the effects of the hypoxic MSCs. Hypoxic MSC treatment in vivo decreased the corneal neovascularization scores and opacity scores. Conclusion: Hypoxic MSCs inhibited inflammation and alleviated corneal injury in alkali burns via the WWP2/Notch1 axis.
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Affiliation(s)
- Chongmeng Yang
- Department of Ophthalmology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, China
| | - Jian Pan
- Department of Ophthalmology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, China
| | - Xu Luo
- Burn & Wound Healing Centre, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China.,Wound Repair Department, The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, 324000, China
| | - Jianmin Li
- Department of Pathology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, China
| | - Zipei Jiang
- Department of Ophthalmology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, China
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20
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Amin S, Jalilian E, Katz E, Frank C, Yazdanpanah G, Guaiquil VH, Rosenblatt MI, Djalilian AR. The Limbal Niche and Regenerative Strategies. Vision (Basel) 2021; 5:vision5040043. [PMID: 34698278 PMCID: PMC8544688 DOI: 10.3390/vision5040043] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/27/2021] [Accepted: 09/16/2021] [Indexed: 12/17/2022] Open
Abstract
The protective function and transparency provided by the corneal epithelium are dependent on and maintained by the regenerative capacity of limbal epithelial stem cells (LESCs). These LESCs are supported by the limbal niche, a specialized microenvironment consisting of cellular and non-cellular components. Disruption of the limbal niche, primarily from injuries or inflammatory processes, can negatively impact the regenerative ability of LESCs. Limbal stem cell deficiency (LSCD) directly hampers the regenerative ability of the corneal epithelium and allows the conjunctival epithelium to invade the cornea, which results in severe visual impairment. Treatment involves restoring the LESC population and functionality; however, few clinically practiced therapies currently exist. This review outlines the current understanding of the limbal niche, its pathology and the emerging approaches targeted at restoring the limbal niche. Most emerging approaches are in developmental phases but show promise for treating LSCD and accelerating corneal regeneration. Specifically, we examine cell-based therapies, bio-active extracellular matrices and soluble factor therapies in considerable depth.
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Affiliation(s)
- Sohil Amin
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
| | - Elmira Jalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
| | - Eitan Katz
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
| | - Charlie Frank
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
| | - Ghasem Yazdanpanah
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
- Richard and Loan Hill Department of Bioengineering, University of Illinois Chicago, Chicago, IL 60612, USA
| | - Victor H. Guaiquil
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
| | - Mark I. Rosenblatt
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
| | - Ali R. Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA; (S.A.); (E.J.); (E.K.); (C.F.); (G.Y.); (V.H.G.); (M.I.R.)
- Correspondence:
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21
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Guo Y, Mei F, Huang Y, Ma S, Wei Y, Zhang X, Xu M, He Y, Heng BC, Chen L, Deng X. Matrix stiffness modulates tip cell formation through the p-PXN-Rac1-YAP signaling axis. Bioact Mater 2021; 7:364-376. [PMID: 34466738 PMCID: PMC8379356 DOI: 10.1016/j.bioactmat.2021.05.033] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/05/2021] [Accepted: 05/19/2021] [Indexed: 01/01/2023] Open
Abstract
Endothelial tip cell outgrowth of blood-vessel sprouts marks the initiation of angiogenesis which is critical in physiological and pathophysiological procedures. However, how mechanical characteristics of extracellular matrix (ECM) modulates tip cell formation has been largely neglected. In this study, we found enhanced CD31 expression in the stiffening outer layer of hepatocellular carcinoma than in surrounding soft tissues. Stiffened matrix promoted sprouting from endothelial cell (EC) spheroids and upregulated expressions of tip cell-enriched genes in vitro. Moreover, tip cells showed increased cellular stiffness, more actin cytoskeleton organization and enhanced YAP nuclear transfer than stalk and phalanx ECs. We further uncovered that substrate stiffness regulates FAK and Paxillin phosphorylation in focal adhesion of ECs promoting Rac1 transition from inactive to active state. YAP is subsequently activated and translocated into nucleus, leading to increased tip cell specification. p-Paxillin can also loosen the intercellular connection which also facilitates tip cell specification. Collectively our present study shows that matrix stiffness modulates tip cell formation through p-PXN-Rac1-YAP signaling axis, shedding light on the role of mechanotransduction in tip cell formation. This is of special significance in biomaterial design and treatment of some pathological situations. Mechanotransduction is implicated in angiogenesis and tip cell formation. Tip cells showed different mechanical properties from stalk and phalanx ECs. Paxillin, Rac1 and YAP might be novel treatment targets for some diseases. Material stiffness affects tip cell specification.
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Affiliation(s)
- Yaru Guo
- Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Feng Mei
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Ying Huang
- Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Siqin Ma
- Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Yan Wei
- Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Xuehui Zhang
- Department of Dental Materials, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, 100081, PR China
- Beijing Laboratory of Biomedical Materials, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
| | - Mingming Xu
- Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Ying He
- Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Boon Chin Heng
- Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
| | - Lili Chen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
- Corresponding author. Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Xuliang Deng
- Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China
- Department of Dental Materials, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, 100081, PR China
- Beijing Laboratory of Biomedical Materials, Peking University School and Hospital of Stomatology, Beijing, 100081, PR China
- Corresponding author. Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, 100081, China.
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22
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Xin Y, Kang BS, Zheng YP, Shan SW, Kee CS, Tan Y. Biophysical properties of corneal cells reflect high myopia progression. Biophys J 2021; 120:3498-3507. [PMID: 34022236 DOI: 10.1016/j.bpj.2021.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 04/07/2021] [Accepted: 05/17/2021] [Indexed: 01/07/2023] Open
Abstract
Myopia is a common ocular disorder with significant alterations in the anterior ocular structure, including the cornea. The cell biophysical phenotype has been proposed to reflect the state of various diseases. However, the biophysical properties of corneal cells have not been characterized during myopia progression and their relationship with myopia remains unknown. This study characterizes the biophysical properties of corneal cells in normal, myopic, and recovered conditions, using two classical myopia models. Surprisingly, myopic corneal cells considerably reduce F-actin and microtubule content and cellular stiffness and generate elevated traction force compared with control cells. When myopia is restored to the healthy state, these biophysical properties are partially or fully restored to the levels of control cells. Furthermore, the level of chromatin condensation is significantly increased in the nucleus of myopic corneal cells and reduced to a level similar to healthy cells after recovery. These findings demonstrate that the reversible biophysical alterations of corneal cells reflect myopia progression, facilitating the study of the role of corneal cell biophysics in myopia.
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Affiliation(s)
- Ying Xin
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China; Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Byung Soo Kang
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Yong-Ping Zheng
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Sze Wan Shan
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Chea-Su Kee
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China.
| | - Youhua Tan
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China; Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
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