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Ko JA, Komatsu K, Minamoto A, Kondo S, Okumichi H, Hirooka K, Kiuchi Y. Effects of Ripasudil, a Rho-Kinase Inhibitor, on Scar Formation in a Mouse Model of Filtration Surgery. Curr Eye Res 2023; 48:826-835. [PMID: 37216470 DOI: 10.1080/02713683.2023.2217367] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 05/24/2023]
Abstract
PURPOSE Glaucoma is a leading cause of blindness worldwide. Characteristic changes occur in the optic nerve and visual field of patients with glaucoma; optic nerve damage can be mitigated by lowering intraocular pressure. Treatment modalities include drugs and lasers; filtration surgery is necessary for patients with insufficient intraocular pressure reduction. Scar formation often contributes to glaucoma filtration surgery failure by increasing fibroblast proliferation and activation. Here, we examined the effects of ripasudil, a Rho-associated protein kinase (ROCK) inhibitor, on postoperative scar formation in human Tenon's fibroblasts. METHODS Collagen gel contraction assays were used to compare contractility activity among ripasudil and other anti-glaucoma drugs. The effect of Ripasudil in combination with other anti-glaucoma drugs and transforming growth factor-β (TGF-β), latanoprost and timolol-induce contractions were also tested in this study. Immunofluorescence and Western blotting were used to study the expression of factors relating scarring formation. RESULTS Ripasudil inhibited contraction in collagen gel assay and reduced α-smooth muscle actin (SMA) and vimentin (scar formation-related factors) expression, which was inversely promoted by latanoprost, timolol or TGF-β. Ripasudil also inhibited contraction on TGF-β, latanoprost and timolol-induced contraction. Furthermore, we investigated the effects of ripasudil on postoperative scarring in a mouse model; ripasudil suppressed postoperative scar formation by altering the expression of α-SMA and vimentin. CONCLUSIONS These results suggest that ripasudil, ROCK inhibitor may inhibit excessive fibrosis after glaucoma filtering surgery vis inhibition the transdifferentiation of tenon fibroblast into myofibroblast and may have a potential effect as anti-scarring for glaucoma filtration surgery.
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Affiliation(s)
- Ji-Ae Ko
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Kaori Komatsu
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Akira Minamoto
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Satomi Kondo
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Hideaki Okumichi
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Kazuyuki Hirooka
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
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Ibrahim DG, Ko JA, Iwata W, Okumichi H, Kiuchi Y. An in vitro study of scarring formation mediated by human Tenon fibroblasts: Effect of Y-27632, a Rho kinase inhibitor. Cell Biochem Funct 2019; 37:113-124. [PMID: 30773659 PMCID: PMC6646872 DOI: 10.1002/cbf.3382] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 01/03/2019] [Accepted: 01/24/2019] [Indexed: 01/18/2023]
Abstract
Scar formation is the most common cause for failure of glaucoma filtration surgery because of increased fibroblast proliferation and activation. We have now examined the effect of Y‐27632, a Rho‐associated protein kinase (ROCK) inhibitor, on postsurgical scarring formation in human Tenon fibroblasts (HTFs). Collagen gel contraction assay was used to compare contractility activity of Y‐27632 with several antiglaucoma drugs. Immunofluorescence and western blotting were used to examine expression of scar formation–related factors. We found that Y‐27632 inhibited collagen gel contraction, as well as α‐smooth muscle actin and vimentin expression; these were promoted by treatment with latanoprost, timolol, or transforming growth factor (TGF)–β. To investigate the effect of Y‐27632 in postsurgical scarring, we mimicked TGF‐β secretion by stimulating HTFs with TGF‐β prior to Y‐27632 treatment. HTFs cultured in the presence of TGF‐β significantly increased gel contraction. In contrast, when HTFs were treated with 10μM Y‐27632, contraction was significantly inhibited. Furthermore, Y‐27632 reduced TGF‐β–induced phosphorylation of mitogen‐activated protein kinase signalling. These results suggest that ROCK inhibitors may inhibit fibrosis by inhibiting transdifferentiation of Tenon fibroblasts into myofibroblasts and by inhibiting TGF‐β signalling after surgery through mitogen‐activated protein kinase pathway suppression. These results implicate that ROCK inhibitors may improve outcomes after filtering surgery with a potential antiscarring effect, while latanoprost and timolol may induce fibrosis. Significance of the study Scar formation is the primary cause of failure after glaucoma filtration surgery. A ROCK inhibitor, Y‐27632, has been introduced as a novel potential antiglaucoma treatment to reduce intraocular pressure. The aim of our study was to elucidate the effect of Y‐27632 on scarring formation after glaucoma filtration surgery, in direct comparison with other antiglaucoma drugs. Our findings thus suggested that Y‐27632 may inhibit fibrosis and improve outcome after glaucoma filtration surgery through inhibition of transdifferentiation of Tenon fibroblasts into myofibroblasts, and the TGF‐β and MAPK signalling after surgery, while latanoprost and timolol may induce fibrosis.
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Affiliation(s)
- Diah Gemala Ibrahim
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan.,Department of Ophthalmology, Hasanuddin University, Makassar, Indonesia
| | - Ji-Ae Ko
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Wakana Iwata
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Hideaki Okumichi
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
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Dang Y, Waxman S, Wang C, Loewen RT, Sun M, Loewen NA. A porcine ex vivo model of pigmentary glaucoma. Sci Rep 2018; 8:5468. [PMID: 29615741 PMCID: PMC5882895 DOI: 10.1038/s41598-018-23861-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 03/16/2018] [Indexed: 11/11/2022] Open
Abstract
Pigment dispersion can lead to pigmentary glaucoma, a poorly understood condition of younger myopic eyes with fluctuating high intraocular pressure. It has been difficult to investigate its pathogenesis without a model similar to human eyes in size and behavior. Here we present a porcine ex vivo model that recreates several features of pigmentary glaucoma, including intraocular hypertension, accumulation of pigment in the trabecular meshwork, and declining phagocytosis. We found that trabecular meshwork cells regulate outflow, form actin stress fibers, and have a decreased phagocytic activity. Gene expression microarrays and a pathway analysis of TM monolayers as well as ex vivo anterior segment perfusion cultures indicated that RhoA plays a central role in regulating the cytoskeleton, motility, and phagocytosis in the trabecular meshwork, providing new insights and targets to investigate in pigmentary glaucoma.
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Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Susannah Waxman
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Chao Wang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
| | - Ralitsa T Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Ming Sun
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America
| | - Nils A Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, United States of America.
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Wang K, Johnstone MA, Xin C, Song S, Padilla S, Vranka JA, Acott TS, Zhou K, Schwaner SA, Wang RK, Sulchek T, Ethier CR. Estimating Human Trabecular Meshwork Stiffness by Numerical Modeling and Advanced OCT Imaging. Invest Ophthalmol Vis Sci 2017; 58:4809-4817. [PMID: 28973327 PMCID: PMC5624775 DOI: 10.1167/iovs.17-22175] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Purpose The purpose of this study was to estimate human trabecular meshwork (hTM) stiffness, thought to be elevated in glaucoma, using a novel indirect approach, and to compare results with direct en face atomic force microscopy (AFM) measurements. Methods Postmortem human eyes were perfused to measure outflow facility and identify high- and low-flow regions (HF, LF) by tracer. Optical coherence tomography (OCT) images were obtained as Schlemm's canal luminal pressure was directly manipulated. TM stiffness was deduced by an inverse finite element modeling (FEM) approach. A series of AFM forcemaps was acquired along a line traversing the anterior angle on a radially cut flat-mount corneoscleral wedge with TM facing upward. Results The elastic modulus of normal hTM estimated by inverse FEM was 70 ± 20 kPa (mean ± SD), whereas glaucomatous hTM was slightly stiffer (98 ± 19 kPa). This trend was consistent with TM stiffnesses measured by AFM: normal hTM stiffness = 1.37 ± 0.56 kPa, which was lower than glaucomatous hTM stiffness (2.75 ± 1.19 kPa). None of these differences were statistically significant. TM in HF wedges was softer than that in LF wedges for both normal and glaucomatous eyes based on the inverse FEM approach but not by AFM. Outflow facility was significantly correlated with TM stiffness estimated by FEM in six human eyes (P = 0.018). Conclusions TM stiffness is higher, but only modestly so, in glaucomatous patients. Outflow facility in both normal and glaucomatous human eyes appears to associate with TM stiffness. This evidence motivates further studies to investigate factors underlying TM biomechanical property regulation.
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Affiliation(s)
- Ke Wang
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, Georgia, United States
| | - Murray A Johnstone
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Chen Xin
- Department of Bioengineering, University of Washington, Seattle, Washington, United States
| | - Shaozhen Song
- Department of Bioengineering, University of Washington, Seattle, Washington, United States
| | - Steven Padilla
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Janice A Vranka
- Department of Ophthalmology, Casey Eye Institute, Portland, Oregon, United States
| | - Ted S Acott
- Department of Ophthalmology, Casey Eye Institute, Portland, Oregon, United States
| | - Kai Zhou
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, Georgia, United States
| | - Stephen A Schwaner
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, Georgia, United States
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, United States
| | - Todd Sulchek
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - C Ross Ethier
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, Georgia, United States.,George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
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Trabecular meshwork stiffness in glaucoma. Exp Eye Res 2016; 158:3-12. [PMID: 27448987 DOI: 10.1016/j.exer.2016.07.011] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/15/2016] [Accepted: 07/18/2016] [Indexed: 12/26/2022]
Abstract
Alterations in stiffness of the trabecular meshwork (TM) may play an important role in primary open-angle glaucoma (POAG), the second leading cause of blindness. Specifically, certain data suggest an association between elevated intraocular pressure (IOP) and increased TM stiffness; however, the underlying link between TM stiffness and IOP remains unclear and requires further study. We here first review the literature on TM stiffness measurements, encompassing various species and based on a number of measurement techniques, including direct approaches such as atomic force microscopy (AFM) and uniaxial tension tests, and indirect methods based on a beam deflection model. We also briefly review the effects of several factors that affect TM stiffness, including lysophospholipids, rho-kinase inhibitors, cytoskeletal disrupting agents, dexamethasone (DEX), transforming growth factor-β2 (TGF-β2), nitric oxide (NO) and cellular senescence. We then describe a method we have developed for determining TM stiffness measurement in mice using a cryosection/AFM-based approach, and present preliminary data on TM stiffness in C57BL/6J and CBA/J mouse strains. Finally, we investigate the relationship between TM stiffness and outflow facility between these two strains. The method we have developed shows promise for further direct measurements of mouse TM stiffness, which may be of value in understanding mechanistic relations between outflow facility and TM biomechanical properties.
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