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You Y, Bai C, Wang W, Zhan T, Hu X, Hao F, Xia M, Liu Y, Ma T, Liu Y, Zheng C, Pu T, Zhang Y, Lu Y, Ding N, Li J, Yin Y, Chen Y, Wang L, Zhou J, Niu L, Xiu Y, Lu Y, Jia T, Liu X, Zhang C. Comparative proteomics in captive giant pandas to identify proteins involved in age-related cataract formation. Sci Rep 2023; 13:12722. [PMID: 37543644 PMCID: PMC10404263 DOI: 10.1038/s41598-023-40003-0] [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: 02/28/2023] [Accepted: 08/03/2023] [Indexed: 08/07/2023] Open
Abstract
Approximately 20% of aged captive giant pandas (Ailuropoda melanoleuca) have cataracts that impair their quality of life. To identify potential biomarkers of cataract formation, we carried out a quantitative proteomics analysis of 10 giant pandas to find proteins differing in abundance between healthy and cataract-bearing animals. We identified almost 150 proteins exceeding our threshold for differential abundance, most of which were associated with GO categories related to extracellular localization. The most significant differential abundance was associated with components of the proteasome and other proteins with a role in proteolysis or its regulation, most of which were depleted in pandas with cataracts. Other modulated proteins included components of the extracellular matrix or cytoskeleton, as well as associated signaling proteins and regulators, but we did not find any differentially expressed transcription factors. These results indicate that the formation of cataracts involves a complex post-transcriptional network of signaling inside and outside lens cells to drive stress responses as a means to address the accumulation of protein aggregates triggered by oxidative damage. The modulated proteins also indicate that it should be possible to predict the onset of cataracts in captive pandas by taking blood samples and testing them for the presence or absence of specific protein markers.
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Affiliation(s)
- Yuyan You
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China.
| | - Chao Bai
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China
| | - Wei Wang
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China
| | - Tongtong Zhan
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China
| | - Xin Hu
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China
| | | | | | - Yan Liu
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China
| | - Tao Ma
- Beijing Zoo, Beijing, China
| | | | | | | | | | | | | | | | | | - Yucun Chen
- Strait (Fuzhou) Giant Panda Research and Exchange Centers, Fuzhou, China
| | | | | | | | - Yunfang Xiu
- Strait (Fuzhou) Giant Panda Research and Exchange Centers, Fuzhou, China
| | - Yan Lu
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China.
| | | | | | - Chenglin Zhang
- Beijing Key Laboratory of Captive Wildlife Technologies, Beijing Zoo, Beijing, China.
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2
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Wishart TFL, Lovicu FJ. Heparan sulfate proteoglycans (HSPGs) of the ocular lens. Prog Retin Eye Res 2023; 93:101118. [PMID: 36068128 DOI: 10.1016/j.preteyeres.2022.101118] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022]
Abstract
Heparan sulfate proteoglycans (HSPGs) reside in most cells; on their surface, in the pericellular milieu and/or extracellular matrix. In the eye, HSPGs can orchestrate the activity of key signalling molecules found in the ocular environment that promote its development and homeostasis. To date, our understanding of the specific roles played by individual HSPG family members, and the heterogeneity of their associated sulfated HS chains, is in its infancy. The crystalline lens is a relatively simple and well characterised ocular tissue that provides an ideal stage to showcase and model the expression and unique roles of individual HSPGs. Individual HSPG core proteins are differentially localised to eye tissues in a temporal and spatial developmental- and cell-type specific manner, and their loss or functional disruption results in unique phenotypic outcomes for the lens, and other ocular tissues. More recent work has found that different HS sulfation enzymes are also presented in a cell- and tissue-specific manner, and that disruption of these different sulfation patterns affects specific HS-protein interactions. Not surprisingly, these sulfated HS chains have also been reported to be required for lens and eye development, with dysregulation of HS chain structure and function leading to pathogenesis and eye-related phenotypes. In the lens, HSPGs undergo significant and specific changes in expression and function that can drive pathology, or in some cases, promote tissue repair. As master signalling regulators, HSPGs may one day serve as valuable biomarkers, and even as putative targets for the development of novel therapeutics, not only for the eye but for many other systemic pathologies.
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Affiliation(s)
- Tayler F L Wishart
- Molecular and Cellular Biomedicine, School of Medical Sciences, The University of Sydney, NSW, Australia.
| | - Frank J Lovicu
- Molecular and Cellular Biomedicine, School of Medical Sciences, The University of Sydney, NSW, Australia; Save Sight Institute, The University of Sydney, NSW, Australia.
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3
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Ma B, Ni N, Shao W, Xu J, Ji J, Luo M. Bit1 is involved in regulation between integrin and TGFβ signaling in lens epithelial cells. Cell Cycle 2022; 21:2283-2297. [PMID: 35737738 PMCID: PMC9586669 DOI: 10.1080/15384101.2022.2092818] [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: 07/28/2021] [Revised: 04/03/2022] [Accepted: 06/16/2022] [Indexed: 11/03/2022] Open
Abstract
Bit1, as an integrin-specific effector, is specifically expressed in lens epithelial cells (LECs) and may be essential to maintain the normal function of LECs. The present study investigated the function of Bit1 and its regulatory mechanism in LECs. Knockdown of Bit1 was mediated by a lentivirus with a specific short-hairpin RNA against Bit1 in SRA01/04 cells. Cell proliferation ability was measured by CCK-8 assay. Cell migration was examined by transwell and wound-healing assays. The effect of Bit1 knockdown on genome-wide expression patterns was studied via a GeneChip® PrimeView™ Human Gene Expression Array. Based on the ingenuity pathway analysis (IPA), Bit1's regulation of target pathways and genes was verified by real-time qPCR and Western blotting. Bit1 knockdown inhibited proliferation, migration, and regulated cell cycle and apoptosis of LECs. Microarray gene expression analysis and IPA assays revealed that integrin and TGFβ signaling pathways were remarkably impacted by Bit1 expression. FAK, PAK2, ITGA5, and ITGB1 were identified as core node molecules under the control of Bit1. Bit1 participates in integrin and TGFβ signaling via regulating downstream FAK and PAK2 and subsequently affecting EMT-related gene expression including ITGA5, ITGB1, and αSMA. In conclusion, Bit1 plays as an important role in the regulation between integrin and TGFβ signaling, which affects cell survival, migration, and EMT of LECs.
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Affiliation(s)
- Bo Ma
- Department of Ophthalmology, Shanghai Ninth People’s Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ni Ni
- Department of Ophthalmology, Shanghai Ninth People’s Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wanyu Shao
- Department of Ophthalmology, Shanghai Ninth People’s Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jingying Xu
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Jiali Ji
- Department of Ophthalmology, Shanghai Ninth People’s Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min Luo
- Department of Ophthalmology, Shanghai Ninth People’s Hospital Affiliated Shanghai Jiao Tong University School of Medicine, Shanghai, China
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4
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Taiyab A, West-Mays J. Lens Fibrosis: Understanding the Dynamics of Cell Adhesion Signaling in Lens Epithelial-Mesenchymal Transition. Front Cell Dev Biol 2022; 10:886053. [PMID: 35656546 PMCID: PMC9152183 DOI: 10.3389/fcell.2022.886053] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/11/2022] [Indexed: 12/13/2022] Open
Abstract
Injury to the ocular lens perturbs cell-cell and cell-capsule/basement membrane interactions leading to a myriad of interconnected signaling events. These events include cell-adhesion and growth factor-mediated signaling pathways that can ultimately result in the induction and progression of epithelial-mesenchymal transition (EMT) of lens epithelial cells and fibrosis. Since the lens is avascular, consisting of a single layer of epithelial cells on its anterior surface and encased in a matrix rich capsule, it is one of the most simple and desired systems to investigate injury-induced signaling pathways that contribute to EMT and fibrosis. In this review, we will discuss the role of key cell-adhesion and mechanotransduction related signaling pathways that regulate EMT and fibrosis in the lens.
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5
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Gheyas R, Ortega-Alvarez R, Chauss D, Kantorow M, Menko AS. Suppression of PI3K signaling is linked to autophagy activation and the spatiotemporal induction of the lens organelle free zone. Exp Cell Res 2022; 412:113043. [PMID: 35101390 PMCID: PMC8859841 DOI: 10.1016/j.yexcr.2022.113043] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/03/2022] [Accepted: 01/18/2022] [Indexed: 12/12/2022]
Abstract
The terminal steps of lens cell differentiation require elimination of all organelles to create a central Organelle Free Zone (OFZ) that is required for lens function of focusing images on the retina. Previous studies show that the spatiotemporal elimination of these organelles during development is autophagy-dependent. We now show that the inhibition of PI3K signaling in lens organ culture results in the premature induction of autophagy within 24 h, including a significant increase in LAMP1+ lysosomes, and the removal of lens organelles from the center of the lens. Specific inhibition of just the PI3K/Akt signaling axis was directly linked to the elimination of mitochondria and ER, while pan-PI3K inhibitors that block all PI3K downstream signaling removed all organelles, including nuclei. Therefore, blocking the PI3K/Akt pathway was alone insufficient to remove nuclei. RNAseq analysis revealed increased mRNA levels of the endogenous inhibitor of PI3K activation, PIK3IP1, in differentiating lens fiber cells preceding the induction of OFZ formation. Co-immunoprecipitation confirmed that PIK3IP1 associates with multiple PI3K p110 isoforms just prior to formation of the OFZ, providing a likely endogenous mechanism for blocking all PI3K signaling and activating the autophagy pathway required to form the OFZ during lens development.
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Affiliation(s)
- Rifah Gheyas
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ramon Ortega-Alvarez
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Daniel Chauss
- Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Marc Kantorow
- Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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6
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Shihan MH, Novo SG, Wang Y, Sheppard D, Atakilit A, Arnold TD, Rossi NM, Faranda AP, Duncan MK. αVβ8 integrin targeting to prevent posterior capsular opacification. JCI Insight 2021; 6:145715. [PMID: 34554928 PMCID: PMC8663568 DOI: 10.1172/jci.insight.145715] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 09/22/2021] [Indexed: 12/18/2022] Open
Abstract
Fibrotic posterior capsular opacification (PCO), a major complication of cataract surgery, is driven by transforming growth factor–β (TGF-β). Previously, αV integrins were found to be critical for the onset of TGF-β–mediated PCO in vivo; however, the functional heterodimer was unknown. Here, β8 integrin–conditional knockout (β8ITG-cKO) lens epithelial cells (LCs) attenuated their fibrotic responses, while both β5 and β6 integrin–null LCs underwent fibrotic changes similar to WT at 5 days post cataract surgery (PCS). RNA-Seq revealed that β8ITG-cKO LCs attenuated their upregulation of integrins and their ligands, as well as known targets of TGF-β–induced signaling, at 24 hours PCS. Treatment of β8ITG-cKO eyes with active TGF-β1 at the time of surgery rescued the fibrotic response. Treatment of WT mice with an anti-αVβ8 integrin function blocking antibody at the time of surgery ameliorated both canonical TGF-β signaling and LC fibrotic response PCS, and treatment at 5 days PCS, after surgically induced fibrotic responses were established, largely reversed this fibrotic response. These data suggest that αVβ8 integrin is a major regulator of TGF-β activation by LCs PCS and that therapeutics targeting αVβ8 integrin could be effective for fibrotic PCO prevention and treatment.
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Affiliation(s)
- Mahbubul H Shihan
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Samuel G Novo
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Yan Wang
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | | | | | - Thomas D Arnold
- Department of Pediatrics, University of California, San Francisco, San Francisco, California, USA
| | - Nicole M Rossi
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Adam P Faranda
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
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7
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Wishart TFL, Lovicu FJ. An Atlas of Heparan Sulfate Proteoglycans in the Postnatal Rat Lens. Invest Ophthalmol Vis Sci 2021; 62:5. [PMID: 34730792 PMCID: PMC8572486 DOI: 10.1167/iovs.62.14.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose The arrangement of lens cells is regulated by ocular growth factors. Although the effects of these inductive molecules on lens cell behavior (proliferation, survival, and fiber differentiation) are well-characterized, the precise mechanisms underlying the regulation of growth factor-mediated signaling in lens remains elusive. Increasing evidence highlights the importance of heparan sulfate proteoglycans (HSPGs) for the signaling regulation of growth factors; however, the identity of the different lens HSPGs and the specific roles they play in lens biology are still unknown. Methods Semiquantitative real-time (RT)‐PCR and immunolabeling were used to characterize the spatial distribution of all known HSPG core proteins and their associated glycosaminoglycans (heparan and chondroitin sulfate) in the postnatal rat lens. Fibroblast growth factor (FGF)-2-treated lens epithelial explants, cultured in the presence of Surfen (an inhibitor of heparan sulfate [HS]-growth factor binding interactions) were used to investigate the requirement for HS in FGF-2-induced proliferation, fiber differentiation, and ERK1/2-signaling. Results The lens expresses all HSPGs. These HSPGs are differentially localized to distinct functional regions of the lens. In vitro, inhibition of HS-sulfation with Surfen blocked FGF-2-mediated ERK1/2-signaling associated with lens epithelial cell proliferation and fiber differentiation, highlighting that these cellular processes are dependent on HS. Conclusions These findings support a requirement for HSPGs in FGF-2 driven lens cell proliferation and fiber differentiation. The identification of specific HSPG core proteins in key functional lens regions, and the divergent expression patterns of closely related HSPGs, suggests that different HSPGs may differentially regulate growth factor signaling networks leading to specific biological events involved in lens growth and maintenance.
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Affiliation(s)
- Tayler F L Wishart
- School of Medical Sciences, The University of Sydney, New South Wales, Australia
| | - Frank J Lovicu
- School of Medical Sciences, The University of Sydney, New South Wales, Australia.,Save Sight Institute, The University of Sydney, New South Wales, Australia
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8
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Physiological Functions of Thiol Peroxidases (Gpx1 and Prdx2) during Xenopus laevis Embryonic Development. Antioxidants (Basel) 2021; 10:antiox10101636. [PMID: 34679770 PMCID: PMC8533462 DOI: 10.3390/antiox10101636] [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: 09/29/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 11/18/2022] Open
Abstract
Glutathione peroxidase 1 (Gpx1) and peroxiredoxin 2 (Prdx2) belong to the thiol peroxidase family of antioxidants, and have been studied for their antioxidant functions and roles in cancers. However, the physiological significance of Gpx1 and Prdx2 during vertebrate embryogenesis are lacking. Currently, we investigated the functional roles of Gpx1 and Prdx2 during vertebrate embryogenesis using Xenopus laevis as a vertebrate model. Our investigations revealed the zygotic nature of gpx1 having its localization in the eye region of developing embryos, whereas prdx2 exhibited a maternal nature and were localized in embryonic ventral blood islands. Furthermore, the gpx1-morphants exhibited malformed eyes with incompletely detached lenses. However, the depletion of prdx2 has not established its involvement with embryogenesis. A molecular analysis of gpx1-depleted embryos revealed the perturbed expression of a cryba1-lens-specific marker and also exhibited reactive oxygen species (ROS) accumulation in the eye regions of gpx1-morphants. Additionally, transcriptomics analysis of gpx1-knockout embryos demonstrated the involvement of Wnt, cadherin, and integrin signaling pathways in the development of malformed eyes. Conclusively, our findings indicate the association of gpx1 with a complex network of embryonic developmental pathways and ROS responses, but detailed investigation is a prerequisite in order to pinpoint the mechanistic details of these interactions.
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9
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Mrugacz M, Bryl A, Falkowski M, Zorena K. Integrins: An Important Link between Angiogenesis, Inflammation and Eye Diseases. Cells 2021; 10:1703. [PMID: 34359873 PMCID: PMC8305893 DOI: 10.3390/cells10071703] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 12/25/2022] Open
Abstract
Integrins belong to a group of cell adhesion molecules (CAMs) which is a large group of membrane-bound proteins. They are responsible for cell attachment to the extracellular matrix (ECM) and signal transduction from the ECM to the cells. Integrins take part in many other biological activities, such as extravasation, cell-to-cell adhesion, migration, cytokine activation and release, and act as receptors for some viruses, including severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). They play a pivotal role in cell proliferation, migration, apoptosis, tissue repair and are involved in the processes that are crucial to infection, inflammation and angiogenesis. Integrins have an important part in normal development and tissue homeostasis, and also in the development of pathological processes in the eye. This review presents the available evidence from human and animal research into integrin structure, classification, function and their role in inflammation, infection and angiogenesis in ocular diseases. Integrin receptors and ligands are clinically interesting and may be promising as new therapeutic targets in the treatment of some eye disorders.
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Affiliation(s)
- Małgorzata Mrugacz
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, 15-089 Bialystok, Poland;
| | - Anna Bryl
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, 15-089 Bialystok, Poland;
| | | | - Katarzyna Zorena
- Department of Immunobiology and Environmental Microbiology, Medical University of Gdansk, 80-211 Gdansk, Poland;
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10
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Liu J, Riquelme MA, Li Z, Li Y, Tong Y, Quan Y, Pei C, Gu S, Jiang JX. Mechanosensitive collaboration between integrins and connexins allows nutrient and antioxidant transport into the lens. J Cell Biol 2021; 219:211530. [PMID: 33180092 PMCID: PMC7668387 DOI: 10.1083/jcb.202002154] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 09/01/2020] [Accepted: 09/28/2020] [Indexed: 01/08/2023] Open
Abstract
The delivery of glucose and antioxidants is vital to maintain homeostasis and lens transparency. Here, we report a new mechanism whereby mechanically activated connexin (Cx) hemichannels serve as a transport portal for delivering glucose and glutathione (GSH). Integrin α6β1 in outer cortical lens fiber activated by fluid flow shear stress (FFSS) induced opening of hemichannels. Inhibition of α6 activation prevented hemichannel opening as well as glucose and GSH uptake. The activation of integrin β1, a heterodimeric partner of α6 in the absence of FFSS, increased Cx50 hemichannel opening. Hemichannel activation by FFSS depended on the interaction of integrin α6 and Cx50 C-terminal domain. Moreover, hemichannels in nuclear fiber were unresponsive owing to Cx50 truncation. Taken together, these results show that mechanically activated α6β1 integrin in outer cortical lens fibers leads to opening of hemichannels, which transport glucose and GSH into cortical lens fibers. This study unveils a new transport mechanism that maintains metabolic and antioxidative function of the lens.
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Affiliation(s)
- Jie Liu
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX.,The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Manuel A Riquelme
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX
| | - Zhen Li
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX
| | - Yuting Li
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX
| | - Yuxin Tong
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX
| | - Yumeng Quan
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX.,The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Cheng Pei
- The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Sumin Gu
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX
| | - Jean X Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX
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Abstract
Clear vision is dependent on features that protect the anatomical integrity of the eye (cornea and sclera) and those that contribute to internal ocular homeostasis by conferring hemangiogenic (avascular tissues and antiangiogenic factors), lymphangiogenic (lack of draining lymphatics), and immunologic (tight junctions that form blood-ocular barriers, immunosuppressive cells, and modulators) privileges. The later examples are necessary components that enable the eye to maintain an immunosuppressive environment that responds to foreign invaders in a deviated manner, minimizing destructive inflammation that would impair vision. These conditions allowed for the observations made by Medawar, in 1948, of delayed rejection of allogenic tissue grafts in the anterior chamber of mouse eye and permit the sequestration of foreign invaders (eg, Toxoplasma gondii) within the retina of healthy individuals. Yet successful development of intraocular drugs (biologics and delivery devices) has been stymied by adverse ocular pathology, much of which is driven by immune pathways. The eye can be intolerant of foreign protein irrespective of delivery route, and endogenous ocular cells have remarkable plasticity when recruited to preserve visual function. This article provides a review of current understanding of ocular immunology and the potential role of immune mechanisms in pathology observed with intraocular drug delivery.
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Affiliation(s)
| | | | - Sharmila Masli
- 12259Boston University School of Medicine, Boston, MA, USA
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12
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Wormstone IM, Wormstone YM, Smith AJO, Eldred JA. Posterior capsule opacification: What's in the bag? Prog Retin Eye Res 2020; 82:100905. [PMID: 32977000 DOI: 10.1016/j.preteyeres.2020.100905] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 12/18/2022]
Abstract
Cataract, a clouding of the lens, is the most common cause of blindness in the world. It has a marked impact on the wellbeing and productivity of individuals and has a major economic impact on healthcare providers. The only means of treating cataract is by surgical intervention. A modern cataract operation generates a capsular bag, which comprises a proportion of the anterior capsule and the entire posterior capsule. The bag remains in situ, partitions the aqueous and vitreous humours, and in the majority of cases, houses an intraocular lens (IOL). The production of a capsular bag following surgery permits a free passage of light along the visual axis through the transparent intraocular lens and thin acellular posterior capsule. Lens epithelial cells, however, remain attached to the anterior capsule, and in response to surgical trauma initiate a wound-healing response that ultimately leads to light scatter and a reduction in visual quality known as posterior capsule opacification (PCO). There are two commonly-described forms of PCO: fibrotic and regenerative. Fibrotic PCO follows classically defined fibrotic processes, namely hyperproliferation, matrix contraction, matrix deposition and epithelial cell trans-differentiation to a myofibroblast phenotype. Regenerative PCO is defined by lens fibre cell differentiation events that give rise to Soemmerring's ring and Elschnig's pearls and becomes evident at a later stage than the fibrotic form. Both fibrotic and regenerative forms of PCO contribute to a reduction in visual quality in patients. This review will highlight the wealth of tools available for PCO research, provide insight into our current knowledge of PCO and discuss putative management of PCO from IOL design to pharmacological interventions.
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Affiliation(s)
- I M Wormstone
- School of Biological Sciences, University of East Anglia, Norwich, UK.
| | - Y M Wormstone
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - A J O Smith
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - J A Eldred
- School of Biological Sciences, University of East Anglia, Norwich, UK
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13
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LncRNA KCNQ1OT1 knockdown inhibits viability, migration and epithelial-mesenchymal transition in human lens epithelial cells via miR-26a-5p/ITGAV/TGF-beta/Smad3 axis. Exp Eye Res 2020; 200:108251. [PMID: 32950535 DOI: 10.1016/j.exer.2020.108251] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Long noncoding RNA potassium voltage-gated channel subfamily Q member 1 opposite strand/antisense transcript 1 (KCNQ1OT1) takes part in diabetic cataract progression. This research aims to analyze the function and mechanism of KCNQ1OT1 on viability, migration and epithelial-mesenchymal transition (EMT) in lens epithelial cells. METHODS 20 diabetic cataract posterior lens capsule tissues and normal samples were collected. Lens epithelial cells (SRA01/04) were stimulated via high glucose (HG). The levels of KCNQ1OT1, miR-26a-5p, integrin αV (ITGAV), TGF-β, Smad3 and phosphorylated (p)-Smad3 were measured via quantitative real-time polymerase chain reaction or Western blot. Cell viability, migration and EMT were analyzed via MTT, wound healing, transwell and Western blot assays. The target relationship between miR-26a-5p and KCNQ1OT1 or ITGAV was determined via luciferase reporter assay. RESULTS KCNQ1OT1 was up-regulated and miR-26a-5p level was reduced in diabetic cataract tissues and HG-treated SRA01/04 cells. Silence of KCNQ1OT1 or miR-26a-5p up-regulation repressed cell viability, migration and EMT in SRA01/04 cells stimulated via HG. KCNQ1OT1 could target miR-26a-5p and controlled cell viability, migration and EMT via regulating miR-26a-5p. ITGAV was targeted via miR-26a-5p and positively regulated via KCNQ1OT1. ITGAV overexpression promoted cell viability, migration and EMT in HG-treated SRA01/04 cells, which were mitigated by KCNQ1OT1 silence. KCNQ1OT1 knockdown mitigated HG-induced the activation of TGF-β/Smad3 signaling by regulating miR-26a-5p. CONCLUSION KCNQ1OT1 knockdown represses cell viability, migration and EMT through miR-26a-5p/ITGAV/TGF-β/Smad3 axis in SRA01/04 cells under HG condition, providing a new target for the treatment of diabetic cataract.
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14
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Shihan MH, Kanwar M, Wang Y, Jackson EE, Faranda AP, Duncan MK. Fibronectin has multifunctional roles in posterior capsular opacification (PCO). Matrix Biol 2020; 90:79-108. [PMID: 32173580 DOI: 10.1016/j.matbio.2020.02.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 02/10/2020] [Accepted: 02/25/2020] [Indexed: 12/26/2022]
Abstract
Fibrotic posterior capsular opacification (PCO), one of the major complications of cataract surgery, occurs when lens epithelial cells (LCs) left behind post cataract surgery (PCS) undergo epithelial to mesenchymal transition, migrate into the optical axis and produce opaque scar tissue. LCs left behind PCS robustly produce fibronectin, although its roles in fibrotic PCO are not known. In order to determine the function of fibronectin in PCO pathogenesis, we created mice lacking the fibronectin gene (FN conditional knock out -FNcKO) from the lens. While animals from this line have normal lenses, upon lens fiber cell removal which models cataract surgery, FNcKO LCs exhibit a greatly attenuated fibrotic response from 3 days PCS onward as assessed by a reduction in surgery-induced cell proliferation, and fibrotic extracellular matrix (ECM) production and deposition. This is correlated with less upregulation of Transforming Growth Factor β (TGFβ) and integrin signaling in FNcKO LCs PCS concomitant with sustained Bone Morphogenetic Protein (BMP) signaling and elevation of the epithelial cell marker E cadherin. Although the initial fibrotic response of FNcKO LCs was qualitatively normal at 48 h PCS as measured by the upregulation of fibrotic marker protein αSMA, RNA sequencing revealed that the fibrotic response was already quantitatively attenuated at this time, as measured by the upregulation of mRNAs encoding molecules that control, and are controlled by, TGFβ signaling, including many known markers of fibrosis. Most notably, gremlin-1, a known regulator of TGFβ superfamily signaling, was upregulated sharply in WT LCs PCS, while this response was attenuated in FNcKO LCs. As exogenous administration of either active TGFβ1 or gremlin-1 to FNcKO lens capsular bags rescued the attenuated fibrotic response of fibronectin null LCs PCS including the loss of SMAD2/3 phosphorylation, this suggests that fibronectin plays multifunctional roles in fibrotic PCO development.
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Affiliation(s)
- Mahbubul H Shihan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Mallika Kanwar
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Yan Wang
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Erin E Jackson
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Adam P Faranda
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
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15
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Dewi CU, O'Connor MD. Use of Human Pluripotent Stem Cells to Define Initiating Molecular Mechanisms of Cataract for Anti-Cataract Drug Discovery. Cells 2019; 8:E1269. [PMID: 31627438 PMCID: PMC6830331 DOI: 10.3390/cells8101269] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/08/2019] [Accepted: 10/15/2019] [Indexed: 01/09/2023] Open
Abstract
Cataract is a leading cause of blindness worldwide. Currently, restoration of vision in cataract patients requires surgical removal of the cataract. Due to the large and increasing number of cataract patients, the annual cost of surgical cataract treatment amounts to billions of dollars. Limited access to functional human lens tissue during the early stages of cataract formation has hampered efforts to develop effective anti-cataract drugs. The ability of human pluripotent stem (PS) cells to make large numbers of normal or diseased human cell types raises the possibility that human PS cells may provide a new avenue for defining the molecular mechanisms responsible for different types of human cataract. Towards this end, methods have been established to differentiate human PS cells into both lens cells and transparent, light-focusing human micro-lenses. Sensitive and quantitative assays to measure light transmittance and focusing ability of human PS cell-derived micro-lenses have also been developed. This review will, therefore, examine how human PS cell-derived lens cells and micro-lenses might provide a new avenue for development of much-needed drugs to treat human cataract.
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Affiliation(s)
- Chitra Umala Dewi
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.
| | - Michael D O'Connor
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.
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16
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Wernecke L, Keckeis S, Reichhart N, Strauß O, Salchow DJ. Epithelial-Mesenchymal Transdifferentiation in Pediatric Lens Epithelial Cells. Invest Ophthalmol Vis Sci 2019; 59:5785-5794. [PMID: 30521667 DOI: 10.1167/iovs.18-23789] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Posterior capsule opacification (PCO) is a complication after cataract surgery, particularly in children. Epithelial-mesenchymal transition (EMT) of lens epithelial cells, mediated by transforming growth factor beta (TGFβ), contributes to PCO. However, its pathogenesis in children is poorly understood. We correlated cell growth in culture with patient characteristics, studied gene expression of pediatric lens epithelial cells (pLEC), and examined the effects of TGFβ-2 on these cells in vitro. Methods Clinical characteristics of children with cataracts correlated with growth behavior of pLEC in vitro. mRNA expression of epithelial (αB-crystallin, connexin-43) and mesenchymal (αV-integrin, α-smooth muscle actin, collagen-Iα2, fibronectin-1) markers was quantified in pLEC and in cell line HLE-B3 in the presence and absence of TGFβ-2. Results Fifty-four anterior lens capsules from 40 children aged 1 to 180 months were obtained. Cell outgrowth occurred in 44% of the capsules from patients ≤ 12 months and in 33% of capsules from children aged 13 to 60 months, but in only 6% of capsules from children over 60 months. TGFβ-2 significantly upregulated expression of αB-crystallin (HLE-B3), αV-integrin (HLE-B3), collagen-Iα2, and fibronectin-1 (in pLEC and HLE-B3 cells). Conclusions Patient characteristics correlated with growth behavior of pLEC in vitro, paralleling a higher clinical incidence of PCO in younger children. Gene expression profiles of pLEC and HLE-B3 suggest that upregulation of αV-integrin, collagen-Iα2, and fibronectin-1 are involved in EMT.
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Affiliation(s)
- Laura Wernecke
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Ophthalmology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Susanne Keckeis
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Nadine Reichhart
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Olaf Strauß
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Daniel J Salchow
- Department of Ophthalmology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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17
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Zhao Y, Wilmarth PA, Cheng C, Limi S, Fowler VM, Zheng D, David LL, Cvekl A. Proteome-transcriptome analysis and proteome remodeling in mouse lens epithelium and fibers. Exp Eye Res 2019; 179:32-46. [PMID: 30359574 PMCID: PMC6360118 DOI: 10.1016/j.exer.2018.10.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 08/31/2018] [Accepted: 10/20/2018] [Indexed: 12/21/2022]
Abstract
Epithelial cells and differentiated fiber cells represent distinct compartments in the ocular lens. While previous studies have revealed proteins that are preferentially expressed in epithelial vs. fiber cells, a comprehensive proteomics library comparing the molecular compositions of epithelial vs. fiber cells is essential for understanding lens formation, function, disease and regenerative potential, and for efficient differentiation of pluripotent stem cells for modeling of lens development and pathology in vitro. To compare protein compositions between the lens epithelium and fibers, we employed tandem mass spectrometry (2D-LC/MS) analysis of microdissected mouse P0.5 lenses. Functional classifications of the top 525 identified proteins into gene ontology categories by molecular processes and subcellular localizations, were adapted for the lens. Expression levels of both epithelial and fiber proteomes were compared with whole lens proteome and mRNA levels using E14.5, E16.5, E18.5, and P0.5 RNA-Seq data sets. During this developmental time window, multiple complex biosynthetic and catabolic processes generate the molecular and structural foundation for lens transparency. As expected, crystallins showed a high correlation between their mRNA and protein levels. Comprehensive data analysis confirmed and/or predicted roles for transcription factors (TFs), RNA-binding proteins (e.g. Carhsp1), translational apparatus including ribosomal heterogeneity and initiation factors, microtubules, cytoskeletal [e.g. non-muscle myosin IIA heavy chain (Myh9) and βB2-spectrin (Sptbn2)] and membrane proteins in lens formation and maturation. Our data highlighted many proteins with unknown functions in the lens that were preferentially enriched in epithelium or fibers, setting the stage for future studies to further dissect the roles of these proteins in fiber cell differentiation vs. epithelial cell maintenance. In conclusion, the present proteomic datasets represent the first mouse lens epithelium and fiber cell proteomes, establish comparative analyses of protein and RNA-Seq data, and characterize the major proteome remodeling required to form the mature lens fiber cells.
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Affiliation(s)
- Yilin Zhao
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Phillip A Wilmarth
- Department of Biochemistry & Molecular Biology, Oregon Health Sciences University, 3181 Southwest Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Catherine Cheng
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Saima Limi
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Velia M Fowler
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Deyou Zheng
- Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Neurology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Department of Neurosurgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, China
| | - Larry L David
- Department of Biochemistry & Molecular Biology, Oregon Health Sciences University, 3181 Southwest Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Ales Cvekl
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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18
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VanSlyke JK, Boswell BA, Musil LS. Fibronectin regulates growth factor signaling and cell differentiation in primary lens cells. J Cell Sci 2018; 131:jcs.217240. [PMID: 30404825 DOI: 10.1242/jcs.217240] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 09/23/2018] [Indexed: 12/30/2022] Open
Abstract
Lens epithelial cells are bound to the lens extracellular matrix capsule, of which laminin is a major component. After cataract surgery, surviving lens epithelial cells are exposed to increased levels of fibronectin, and so we addressed whether fibronectin influences lens cell fate, using DCDML cells as a serum-free primary lens epithelial cell culture system. We found that culturing DCDMLs with plasma-derived fibronectin upregulated canonical TGFβ signaling relative to cells plated on laminin. Fibronectin-exposed cultures also showed increased TGFβ signaling-dependent differentiation into the two cell types responsible for posterior capsule opacification after cataract surgery, namely myofibroblasts and lens fiber cells. Increased TGFβ activity could be identified in the conditioned medium recovered from cells grown on fibronectin. Other experiments showed that plating DCDMLs on fibronectin overcomes the need for BMP in fibroblast growth factor (FGF)-induced lens fiber cell differentiation, a requirement that is restored when endogenous TGFβ signaling is inhibited. These results demonstrate how the TGFβ-fibronectin axis can profoundly affect lens cell fate. This axis represents a novel target for prevention of late-onset posterior capsule opacification, a common but currently intractable complication of cataract surgery.
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Affiliation(s)
- Judy K VanSlyke
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Bruce A Boswell
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Linda S Musil
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA
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19
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Liu J, Xu D, Li J, Gao N, Liao C, Jing R, Wu B, Ma B, Shao Y, Pei C. The role of focal adhesion kinase in transforming growth factor-β2 induced migration of human lens epithelial cells. Int J Mol Med 2018; 42:3591-3601. [PMID: 30280182 DOI: 10.3892/ijmm.2018.3912] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 09/19/2018] [Indexed: 11/05/2022] Open
Abstract
The migration of lens epithelial cells towards the posterior capsule is a key event in the development of posterior capsule opacification (PCO). Accumulating evidence has described crosstalk between growth factors and adhesive signaling pathways in wound healing and cell migration. The aim of the present study was to elucidate an aberrant transforming growth factor (TGF)‑β2 signaling pathway that regulated the migration of lens epithelial cells in the pathological context of PCO. The expression of fibronectin, focal adhesion kinase (FAK) and phosphorylated (p)‑FAK in HLE‑B3 cells following TGF‑β2 treatment was determined by western blot analysis and the expression of integrin α5β1 was detected by flow cytometry. Cell migration capacity was measured by wound healing and Transwell assays in the presence of 1,2,4,5‑tetraaminobenzene tetrahydrochloride, a selective FAK inhibitor, fibronectin small interfering RNA interference, arginylglycylaspartic acid peptides or α5β1‑integrin neutralizing antibodies. The 1,2,4,5‑tetraaminobenzene tetrahydrochloride was administered daily to 16 rabbits following cataract surgery. Fibronectin and TGF‑β expression were increased in the PCO group, demonstrated by immunofluorescence assays. PCO grading was conducted by slit‑lamp biomicroscopy and evaluation of posterior capsule opacification software. It was observed that TGF‑β2 promoted HLE‑B3 cell migration and upregulated fibronectin expression, which was followed by an increased phosphorylation of FAK. In addition, TGF‑β2 treatment and fibronectin surface coating significantly increased cell migration and FAK activation, which was inhibited by disrupting fibronectin‑integrin α5β1 interaction with the arginylglycylaspartic acid peptide, α5β1‑integrin neutralizing antibody or fibronectin depletion. Finally, suppression of FAK signaling by its inhibitor significantly decreased cell migration in vitro and attenuated PCO development in vivo. In summary, TGF‑β2 was indicated to promote the migration of lens epithelial cells through the TGF‑β2/fibronectin/integrin/FAK axis. Inhibition of FAK activity decreased TGF‑β2‑mediated cell migration in vitro and improved the symptoms of PCO in a rabbit model.
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Affiliation(s)
- Jie Liu
- Department of Ophthalmology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Dan Xu
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biological Science and Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Jingming Li
- Department of Ophthalmology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Ning Gao
- Department of Ophthalmology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Chongbing Liao
- Center for Translational Medicine, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Ruihua Jing
- Department of Ophthalmology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Bogang Wu
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Bo Ma
- Department of Ophthalmology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Yongping Shao
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biological Science and Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, P.R. China
| | - Cheng Pei
- Department of Ophthalmology, First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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20
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Mostafavi-Pour Z, Ashrafi MR, Talaei-Khozani T. Down regulation of ITGA4 and ITGA5 genes after formation of 3D spherules by human Wharton's jelly stem cells (hWJSCs). Mol Biol Rep 2018; 45:245-252. [PMID: 29411210 DOI: 10.1007/s11033-018-4157-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 01/30/2018] [Indexed: 12/27/2022]
Abstract
Human Wharton's jelly mesenchymal stem cells (hWJSCs) are multipotent stem cells that could be aggregated into 3D spherules. ITGA4 and ITGA5 genes encode α4 and α5 subunits of integrins, respectively. In this study, we analyzed expression levels of ITGA4 and ITGA5 gene mRNAs in undifferentiated and 3D spherules forming hWJSCs in order to determine their expression pattern for possible future treatment of cancer cells in a co-culture fashion. For the purpose of obtaining hWJSCs, umbilical cords were collected from patients with caesarian section at full term delivery. The cells were then characterized according to cell surface markers using flow cytometry. Furthermore pluripotency of the obtained cells was verified. Subsequently the cells were aggregated in 3D spherules using hanging drop cultures. Expression levels of ITGA4 and ITGA5 gene mRNAs were determined by RT-PCR and Real time PCR, both in the initial undifferentiated cells and those aggregated in the spherules. The obtained hWJSCs demonstrated pluripotency, differentiating to adipogenic and osteogenic cells. They also expressed mesenchymal stem cell surface markers. Following the aggregation of these cells and formation of 3D spherules, mRNA expression levels of both genes were significantly reduced (P < 0.05) compared with the initial undifferentiated state. The results of this study demonstrated that aggregation of hWJSCs into spherules alters their expression of ITGA4 and ITGA5. The implications of such an alteration would require further research.
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Affiliation(s)
- Zohreh Mostafavi-Pour
- Recombinant Protein Laboratory, School of Advance Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran. .,Biochemistry Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Mohammad Reza Ashrafi
- Biochemistry Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Biochemistry, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Tahereh Talaei-Khozani
- Department of Anatomy, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Tissue Engineering Lab, Anatomy Department, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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21
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Murphy P, Kabir MH, Srivastava T, Mason ME, Dewi CU, Lim S, Yang A, Djordjevic D, Killingsworth MC, Ho JWK, Harman DG, O'Connor MD. Light-focusing human micro-lenses generated from pluripotent stem cells model lens development and drug-induced cataract in vitro. Development 2018; 145:dev.155838. [PMID: 29217756 PMCID: PMC5825866 DOI: 10.1242/dev.155838] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 11/15/2017] [Indexed: 12/14/2022]
Abstract
Cataracts cause vision loss and blindness by impairing the ability of the ocular lens to focus light onto the retina. Various cataract risk factors have been identified, including drug treatments, age, smoking and diabetes. However, the molecular events responsible for these different forms of cataract are ill-defined, and the advent of modern cataract surgery in the 1960s virtually eliminated access to human lenses for research. Here, we demonstrate large-scale production of light-focusing human micro-lenses from spheroidal masses of human lens epithelial cells purified from differentiating pluripotent stem cells. The purified lens cells and micro-lenses display similar morphology, cellular arrangement, mRNA expression and protein expression to human lens cells and lenses. Exposing the micro-lenses to the emergent cystic fibrosis drug Vx-770 reduces micro-lens transparency and focusing ability. These human micro-lenses provide a powerful and large-scale platform for defining molecular disease mechanisms caused by cataract risk factors, for anti-cataract drug screening and for clinically relevant toxicity assays.
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Affiliation(s)
- Patricia Murphy
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Md Humayun Kabir
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia.,Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Tarini Srivastava
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Michele E Mason
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Chitra U Dewi
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Seakcheng Lim
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Andrian Yang
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - Djordje Djordjevic
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - Murray C Killingsworth
- Electron Microscopy Laboratory, NSW Health Pathology and Correlative Microscopy Facility, Ingham Institute, Liverpool, NSW 2170, Australia
| | - Joshua W K Ho
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.,St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - David G Harman
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia.,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Michael D O'Connor
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia .,Medical Sciences Research Group, Western Sydney University, Campbelltown, NSW 2560, Australia
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22
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Wang D, Wang E, Liu K, Xia CH, Li S, Gong X. Roles of TGFβ and FGF signals during growth and differentiation of mouse lens epithelial cell in vitro. Sci Rep 2017; 7:7274. [PMID: 28779082 PMCID: PMC5544739 DOI: 10.1038/s41598-017-07619-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/29/2017] [Indexed: 11/29/2022] Open
Abstract
Transforming growth factor β (TGFβ) and fibroblast growth factor (FGF) signaling pathways play important roles in the proliferation and differentiation of lens epithelial cells (LECs) during development. Low dosage bFGF promotes cell proliferation while high dosage induces differentiation. TGFβ signaling regulates LEC proliferation and differentiation as well, but also promotes epithelial-mesenchymal transitions that lead to cataracts. Thus far, it has been difficult to recapitulate the features of germinative LECs in vitro. Here, we have established a LEC culture protocol that uses SB431542 (SB) compound to inhibit TGFβ/Smad activation, and found that SB treatment promoted mouse LEC proliferation, maintained LECs’ morphology and distinct markers including N-cadherin, c-Maf, Prox1, and αA-, αB-, and β-crystallins. In contrast, low-dosage bFGF was unable to sustain those markers and, combined with SB, altered LECs’ morphology and β-crystallin expression. We further found that Matrigel substrate coatings greatly increased cell proliferation and uniquely affected β-crystallin expression. Cultured LECs retained the ability to differentiate into γ-crystallin-positive lentoids by high-dosage bFGF treatment. Thus, a suppression of TGFβ/Smad signaling in vitro is critical to maintaining characteristic features of mouse LECs, especially expression of the key transcription factors c-Maf and Prox1.
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Affiliation(s)
- Dong Wang
- School of Optometry and Vision Science Program, University of California Berkeley, California, 94720, USA.,Department of Bioengineering, University of California, Berkeley, California, 94720, USA.,Department of Bioengineering, University of California, Los Angeles, California, 90095, USA
| | - Eddie Wang
- School of Optometry and Vision Science Program, University of California Berkeley, California, 94720, USA
| | - Kelsey Liu
- School of Optometry and Vision Science Program, University of California Berkeley, California, 94720, USA
| | - Chun-Hong Xia
- School of Optometry and Vision Science Program, University of California Berkeley, California, 94720, USA
| | - Song Li
- Department of Bioengineering, University of California, Berkeley, California, 94720, USA.,Department of Bioengineering, University of California, Los Angeles, California, 90095, USA.,Department of Medicine, University of California, Los Angeles, California, 90095, USA
| | - Xiaohua Gong
- School of Optometry and Vision Science Program, University of California Berkeley, California, 94720, USA.
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23
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Liu J, Yan XL, Zheng XL, Mei L, Wang S, Han J, Yan H. Electric field exposure promotes epithelial‑mesenchymal transition in human lens epithelial cells via integrin β1‑FAK signaling. Mol Med Rep 2017; 16:4008-4014. [PMID: 28765922 PMCID: PMC5646981 DOI: 10.3892/mmr.2017.7086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 05/17/2017] [Indexed: 01/14/2023] Open
Abstract
Electric field (EF) exposure can affect the elongation, migration, orientation, and division of cells. The present study tested the hypothesis that EF may also affect epithelial-mesenchymal transition (EMT) in lens epithelial cells and that this effect may be an important inducer in the pathological process of posterior capsule opacification (PCO). Human lens epithelial (HLE)-B3 cells were exposed to an EF. Experiments were performed in the presence or absence of an anti-integrin β1 blocking antibody or a small molecule inhibitor targeting focal adhesion kinase (FAK). Cell morphology changes were observed by microscopy. The expression levels of integrin β1, FAK, phosphorylated (p)FAK and of EMT markers, E-cadherin and Vimentin, were examined by immunofluorescence, reverse transcription-quantitative polymerase chain reaction and western blotting. Following exposure to EF, HLE-B3 cells appeared elongated and resembled more fibroblast-like cells. Expression of E-cadherin was decreased, while expression of Vimentin was increased in HLE-B3 cells exposed to EF, compared with control cells. In addition, the mRNA expression levels of integrin β1 were increased, and the protein expression levels of integrin β1 and pFAK were increased in HLE-B3 cells exposed to EF, compared with control cells. Blocking of integrin β1 suppressed the EMT-related morphological changes of HLE-B3 cells and reduced the activation of FAK following EF exposure. However, blocking of pFAK did not affect the EMT status of HLE-B3 cells induced by EF. In conclusion, the present study demonstrated that EF exposure induced EMT in HLE-B3 cells and that this effect may partially be mediated by the activation of integrin β1-FAK signaling. The present results may provide a new mechanistic approach to prevent the development of PCO.
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Affiliation(s)
- Jun Liu
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Xiao-Long Yan
- Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Xiao-Liang Zheng
- Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Lin Mei
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Song Wang
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Jing Han
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Hong Yan
- Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
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Qin Y, Zhu Y, Luo F, Chen C, Chen X, Wu M. Killing two birds with one stone: dual blockade of integrin and FGF signaling through targeting syndecan-4 in postoperative capsular opacification. Cell Death Dis 2017; 8:e2920. [PMID: 28703800 PMCID: PMC5550862 DOI: 10.1038/cddis.2017.315] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/03/2017] [Accepted: 06/05/2017] [Indexed: 12/12/2022]
Abstract
The most common complication after cataract surgery is postoperative capsular opacification, which includes anterior capsular opacification (ACO) and posterior capsular opacification (PCO). Increased adhesion of lens epithelial cells (LECs) to the intraocular lens material surface promotes ACO formation, whereas proliferation and migration of LECs to the posterior capsule lead to the development of PCO. Cell adhesion is mainly mediated by the binding of integrin to extracellular matrix proteins, while cell proliferation and migration are regulated by fibroblast growth factor (FGF). Syndecan-4 (SDC-4) is a co-receptor for both integrin and FGF signaling pathways. Therefore, SDC-4 may be an ideal therapeutic target for the prevention and treatment of postoperative capsular opacification. However, how SDC-4 contributes to FGF-mediated proliferation, migration, and integrin-mediated adhesion of LECs is unclear. Here, we found that downregulation of SDC-4 inhibited FGF signaling through the blockade of ERK1/2 and PI3K/Akt/mTOR activation, thus suppressing cell proliferation and migration. In addition, downregulation of SDC-4 suppressed integrin-mediated cell adhesion through inhibiting focal adhesion kinase (FAK) phosphorylation. Moreover, SDC-4 knockout mice exhibited normal lens morphology, but had significantly reduced capsular opacification after injury. Finally, SDC-4 expression level was increased in the anterior capsule LECs of age-related cataract patients. Taken together, we for the first time characterized the key regulatory role of SDC-4 in FGF and integrin signaling in human LECs, and provided the basis for future pharmacological interventions of capsular opacification.
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Affiliation(s)
- Yingyan Qin
- State key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Yi Zhu
- State key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.,Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Furong Luo
- State key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Chuan Chen
- State key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.,Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Xiaoyun Chen
- State key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Mingxing Wu
- State key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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25
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Shirai K, Tanaka SI, Lovicu FJ, Saika S. The murine lens: A model to investigate in vivo epithelial-mesenchymal transition. Dev Dyn 2017; 247:340-345. [PMID: 28480986 PMCID: PMC5836960 DOI: 10.1002/dvdy.24518] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/09/2017] [Accepted: 04/24/2017] [Indexed: 12/21/2022] Open
Abstract
Epithelial–mesenchymal transition (EMT) produces myofibroblasts that contribute to the formation of fibrotic tissue with an impairment of tissue homeostasis and functionality. The crystalline lens of the eye is a unique transparent and isolated tissue. The lens vesicle becomes isolated from the surface ectoderm, its cells are all contained as they line the inner surface of the lens capsule. Clinically the formation of fibrotic tissue by the lens epithelial cells causes a type of cataract or opacification and contraction of the lens capsule postcataract surgery. Production of EMT in the intact animal lens by using specific gene transfer to the lens or experimental lens injury has been shown to be a powerful tool to investigate EMT processes. It is not easy to uncover whether the origin of the myofibroblast is epithelial cell‐derived or from other cell lineages in fibrotic tissues. However, myofibroblasts that appear in the crystalline lens pathology are totally derived from the lens epithelial cells for the reasons mentioned above. Here, we report on different animal models of lens EMT, using either transgenic approaches or injury to study the biological aspects of EMT. Developmental Dynamics 247:340–345, 2018. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists Lens, Epithelial‐mesenchymal transition, mice.
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Affiliation(s)
- Kumi Shirai
- Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan
| | - Sai-Ichi Tanaka
- Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan
| | - Frank J Lovicu
- Save Sight Institute and Discipline of Anatomy and Histology, Bosch Institute, School of Medical Sciences, The University of Sydney, NSW, Australia
| | - Shizuya Saika
- Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan
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26
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Boswell BA, Korol A, West-Mays JA, Musil LS. Dual function of TGFβ in lens epithelial cell fate: implications for secondary cataract. Mol Biol Cell 2017; 28:907-921. [PMID: 28209733 PMCID: PMC5385940 DOI: 10.1091/mbc.e16-12-0865] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 12/29/2022] Open
Abstract
The most common vision-disrupting complication of cataract surgery is posterior capsule opacification (PCO; secondary cataract). PCO is caused by residual lens cells undergoing one of two very different cell fates: either transdifferentiating into myofibroblasts or maturing into lens fiber cells. Although TGFβ has been strongly implicated in lens cell fibrosis, the factors responsible for the latter process have not been identified. We show here for the first time that TGFβ can induce purified primary lens epithelial cells within the same culture to undergo differentiation into either lens fiber cells or myofibroblasts. Marker analysis confirmed that the two cell phenotypes were mutually exclusive. Blocking the p38 kinase pathway, either with direct inhibitors of the p38 MAP kinase or a small-molecule therapeutic that also inhibits the activation of p38, prevented TGFβ from inducing epithelial-myofibroblast transition and cell migration but did not prevent fiber cell differentiation. Rapamycin had the converse effect, linking MTOR signaling to induction of fiber cell differentiation by TGFβ. In addition to providing novel potential therapeutic strategies for PCO, our findings extend the so-called TGFβ paradox, in which TGFβ can induce two disparate cell fates, to a new epithelial disease state.
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Affiliation(s)
- Bruce A Boswell
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR 97239
| | - Anna Korol
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Hamilton, ON L8N 3Z5, Canada
| | - Judith A West-Mays
- Department of Pathology and Molecular Medicine, McMaster University Health Science Centre, Hamilton, ON L8N 3Z5, Canada
| | - Linda S Musil
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR 97239
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27
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Nibourg LM, Gelens E, Nibourg SAF, de Jong MR, Kuijer R, van Kooten TG, Koopmans SA. Effects of peptide ratios in nanofibre-based hydrogels for the prevention of capsular opacification. Acta Ophthalmol 2016; 94:721-729. [PMID: 27062370 DOI: 10.1111/aos.13047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
Abstract
PURPOSE To moderate the capsular opacification (CO) response after lens surgery, an experimental study was performed in which nanofibre-based hydrogels (nanogels) with different ratios of attached peptides were applied to provide extracellular matrix-related cues for lens epithelial cells (LECs) in a porcine eye model. METHODS The lens content was removed, and the capsules were refilled with nanogel. Lenses were divided into two groups, the first group (n = 34) was refilled with nanogels containing different ratios of two laminin-derived peptides (IKVAV + YIGSR), and the latter group (n = 26) was refilled with nanogel combinations of a fibronectin-derived and a type IV collagen-derived peptide (RGDS + DGEA). Two lenses were refilled with culture medium to investigate the effect of the medium on LECs. After refilling, lenses were extracted and cultured for 3 weeks. Lens epithelial cells (LECs) were assessed for morphology and alpha-smooth muscle actin (αSMA) expression using confocal laser scanning microscopy. RESULTS Differences were seen in cell morphology between lenses refilled with nanogels with IKVAV + YIGSR and RGDS + DGEA peptides. In nanogels with IKVAV + YIGSR peptides, differences in LEC morphology were largest when ratios between the peptides were unequal, whereas LEC responses from the RGDS + DGEA refilled groups showed variation in LEC morphology dependent on the total quantity of mixed-in peptides. The culture medium did not induce proliferation or transformation of LECs. CONCLUSIONS Ratios and concentrations of cell adhesion-mediating peptides both can direct the LEC response, depending on the adhesion molecules of origin, by influencing LEC proliferation and transformation. Nanogels with incorporated peptides may be tuned towards CO prevention.
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Affiliation(s)
- Lisanne M. Nibourg
- Department of Ophthalmology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
- Laboratory for Experimental Ophthalmology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
- W.J. Kolff Institute; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
| | | | - Simone A. F. Nibourg
- Department of Ophthalmology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
- Laboratory for Experimental Ophthalmology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
| | | | - Roel Kuijer
- W.J. Kolff Institute; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
- Department of Biomedical Engineering; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
| | - Theo G. van Kooten
- W.J. Kolff Institute; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
- Department of Biomedical Engineering; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
| | - Steven A. Koopmans
- Department of Ophthalmology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
- W.J. Kolff Institute; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
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28
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Pathania M, Wang Y, Simirskii VN, Duncan MK. β1-integrin controls cell fate specification in early lens development. Differentiation 2016; 92:133-147. [PMID: 27596755 PMCID: PMC5159248 DOI: 10.1016/j.diff.2016.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/05/2016] [Accepted: 08/09/2016] [Indexed: 02/03/2023]
Abstract
Integrins are heterodimeric cell surface molecules that mediate cell-extracellular matrix (ECM) adhesion, ECM assembly, and regulation of both ECM and growth factor induced signaling. However, the developmental context of these diverse functions is not clear. Loss of β1-integrin from the lens vesicle (mouse E10.5) results in abnormal exit of anterior lens epithelial cells (LECs) from the cell cycle and their aberrant elongation toward the presumptive cornea by E12.5. These cells lose expression of LEC markers and initiate expression of the Maf (also known as c-Maf) and Prox1 transcription factors as well as other lens fiber cell markers. β1-integrin null LECs also upregulate the ERK, AKT and Smad1/5/8 phosphorylation indicative of BMP and FGF signaling. By E14.5, β1-integrin null lenses have undergone a complete conversion of all lens epithelial cells into fiber cells. These data suggest that shortly after lens vesicle closure, β1-integrin blocks inappropriate differentiation of the lens epithelium into fibers, potentially by inhibiting BMP and/or FGF receptor activation. Thus, β1-integrin has an important role in fine-tuning the response of the early lens to the gradient of growth factors that regulate lens fiber cell differentiation.
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Affiliation(s)
- Mallika Pathania
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Yan Wang
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Vladimir N Simirskii
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
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Impaired ADAMTS9 secretion: A potential mechanism for eye defects in Peters Plus Syndrome. Sci Rep 2016; 6:33974. [PMID: 27687499 PMCID: PMC5043182 DOI: 10.1038/srep33974] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/06/2016] [Indexed: 01/15/2023] Open
Abstract
Peters Plus syndrome (PPS), a congenital disorder of glycosylation, results from recessive mutations affecting the glucosyltransferase B3GLCT, leading to congenital corneal opacity and diverse extra-ocular manifestations. Together with the fucosyltransferase POFUT2, B3GLCT adds Glucoseβ1-3Fucose disaccharide to a consensus sequence in thrombospondin type 1 repeats (TSRs) of several proteins. Which of these target proteins is functionally compromised in PPS is unknown. We report here that haploinsufficiency of murine Adamts9, encoding a secreted metalloproteinase with 15 TSRs, leads to congenital corneal opacity and Peters anomaly (persistent lens-cornea adhesion), which is a hallmark of PPS. Mass spectrometry of recombinant ADAMTS9 showed that 9 of 12 TSRs with the O-fucosylation consensus sequence carried the Glucoseβ1-3Fucose disaccharide and B3GLCT knockdown reduced ADAMTS9 secretion in HEK293F cells. Together, the genetic and biochemical findings imply a dosage-dependent role for ADAMTS9 in ocular morphogenesis. Reduced secretion of ADAMTS9 in the absence of B3GLCT is proposed as a mechanism of Peters anomaly in PPS. The functional link between ADAMTS9 and B3GLCT established here also provides credence to their recently reported association with age-related macular degeneration.
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30
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Cvekl A, Callaerts P. PAX6: 25th anniversary and more to learn. Exp Eye Res 2016; 156:10-21. [PMID: 27126352 DOI: 10.1016/j.exer.2016.04.017] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/12/2016] [Accepted: 04/22/2016] [Indexed: 01/29/2023]
Abstract
The DNA-binding transcription factor PAX6 was cloned 25 years ago by multiple teams pursuing identification of human and mouse eye disease causing genes, cloning vertebrate homologues of pattern-forming regulatory genes identified in Drosophila, or abundant eye-specific transcripts. Since its discovery in 1991, genetic, cellular, molecular and evolutionary studies on Pax6 mushroomed in the mid 1990s leading to the transformative thinking regarding the genetic program orchestrating both early and late stages of eye morphogenesis as well as the origin and evolution of diverse visual systems. Since Pax6 is also expressed outside of the eye, namely in the central nervous system and pancreas, a number of important insights into the development and function of these organs have been amassed. In most recent years, genome-wide technologies utilizing massively parallel DNA sequencing have begun to provide unbiased insights into the regulatory hierarchies of specification, determination and differentiation of ocular cells and neurogenesis in general. This review is focused on major advancements in studies on mammalian eye development driven by studies of Pax6 genes in model organisms and future challenges to harness the technology-driven opportunities to reconstruct, step-by-step, the transition from naïve ectoderm, neuroepithelium and periocular mesenchyme/neural crest cells into the three-dimensional architecture of the eye.
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Affiliation(s)
- Ales Cvekl
- The Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA; The Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
| | - Patrick Callaerts
- Laboratory of Behavioral and Developmental Genetics, K.U. Leuven, VIB, 3000, Leuven, Belgium.
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31
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Zheng YP, Zhang SB, Wang F, Liu H, Zhang W, Song B, Liu ZY, Xiong L, Fan YZ, Liao DY. Effects of lentiviral RNA interference-mediated downregulation of integrin-linked kinase on biological behaviors of human lens epithelial cells. Int J Ophthalmol 2016; 9:21-8. [PMID: 26949605 DOI: 10.18240/ijo.2016.01.04] [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: 01/08/2015] [Accepted: 06/09/2015] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate the effects of lentivirus (LV) mediated integrin-linked kinase (ILK) RNA interference (RNAi) on biological behaviors of human lens epithelial cells (LECs). METHODS Human cataract LECs and immortalized human LEC line, human lens epithelial (HLE) B-3 cells were transfected by lentiviral vector expressing ILK-specific short hairpin RNA (shRNA) and then stimulated by transforming growth factor-β (TGF-β), the silencing of ILK gene and protein was identified by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot methods; biological behaviors including cell cycle and apoptosis, cell morphology, α-smooth muscle actin (SMA) stress fiber formation and cell migration were examined. RESULTS Remarkable decreases of ILK protein expression were detected in LECs carrying lentiviral ILK-shRNA vector; flow cytometry revealed arresting of cell cycle progression through the G1/S transition and higher apoptosis rate in ILK-RNAi-LV transfected cells. Less α-SMA stress fiber formation and migration was observed in ILK-RNAi-LV transfected LECs. CONCLUSION The present study demonstrated that ILK was an important regulator for LECs proliferation and migration. LV mediated ILK RNAi is an effective way to decrease ILK-regulated cell growth by arresting cell cycle progression and increasing cell apoptosis, as well as, to prevent cell migration by inhibiting TGF-β induced α-SMA stress fiber formation. Thus, LV mediated ILK RNAi might be useful to prevent posterior capsular opacification.
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Affiliation(s)
- Yu-Ping Zheng
- Department of Ophthalmology, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Shao-Bo Zhang
- Department of Ophthalmology, Tangdu Hospital, the Fourth Military Medical University, Xi'an 710038, Shaanxi Province, China
| | - Feng Wang
- Department of Ophthalmology, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Hui Liu
- Department of Otolaryngology, Shaanxi Provincial People's Hospital, Xi'an 710068, Shaanxi Province, China
| | - Wen Zhang
- Department of Otolaryngology, Shaanxi Provincial People's Hospital, Xi'an 710068, Shaanxi Province, China
| | - Bin Song
- Department of Otolaryngology, Shaanxi Provincial People's Hospital, Xi'an 710068, Shaanxi Province, China
| | - Zi-Yao Liu
- Department of Ophthalmology, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Lei Xiong
- Department of Ophthalmology, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Ya-Zhi Fan
- Department of Ophthalmology, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Ding-Ying Liao
- Department of Ophthalmology, the Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
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Zhang Y, Fan J, Ho JWK, Hu T, Kneeland SC, Fan X, Xi Q, Sellarole MA, de Vries WN, Lu W, Lachke SA, Lang RA, John SWM, Maas RL. Crim1 regulates integrin signaling in murine lens development. Development 2015; 143:356-66. [PMID: 26681494 PMCID: PMC4725338 DOI: 10.1242/dev.125591] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 12/07/2015] [Indexed: 12/19/2022]
Abstract
The developing lens is a powerful system for investigating the molecular basis of inductive tissue interactions and for studying cataract, the leading cause of blindness. The formation of tightly controlled cell-cell adhesions and cell-matrix junctions between lens epithelial (LE) cells, between lens fiber (LF) cells, and between these two cell populations enables the vertebrate lens to adopt a highly ordered structure and acquire optical transparency. Adhesion molecules are thought to maintain this ordered structure, but little is known about their identity or interactions. Cysteine-rich motor neuron 1 (Crim1), a type I transmembrane protein, is strongly expressed in the developing lens and its mutation causes ocular disease in both mice and humans. How Crim1 regulates lens morphogenesis is not understood. We identified a novel ENU-induced hypomorphic allele of Crim1, Crim1glcr11, which in the homozygous state causes cataract and microphthalmia. Using this and two other mutant alleles, Crim1null and Crim1cko, we show that the lens defects in Crim1 mouse mutants originate from defective LE cell polarity, proliferation and cell adhesion. Crim1 adhesive function is likely to be required for interactions both between LE cells and between LE and LF cells. We show that Crim1 acts in LE cells, where it colocalizes with and regulates the levels of active β1 integrin and of phosphorylated FAK and ERK. The RGD and transmembrane motifs of Crim1 are required for regulating FAK phosphorylation. These results identify an important function for Crim1 in the regulation of integrin- and FAK-mediated LE cell adhesion during lens development. Summary: Crim1, a type I transmembrane protein, acts in lens epithelial cells where it colocalizes with and regulates the levels of active β1 integrin to control cell adhesion during mouse lens morphogenesis.
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Affiliation(s)
- Ying Zhang
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jieqing Fan
- Department of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Joshua W K Ho
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA Center for Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA Victor Chang Cardiac Research Institute, and The University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Tommy Hu
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Stephen C Kneeland
- Howard Hughes Medical Institute and The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
| | - Xueping Fan
- Renal Section, Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Qiongchao Xi
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Michael A Sellarole
- Victor Chang Cardiac Research Institute, and The University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Wilhelmine N de Vries
- Victor Chang Cardiac Research Institute, and The University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Weining Lu
- Renal Section, Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Salil A Lachke
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Richard A Lang
- Department of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Simon W M John
- Victor Chang Cardiac Research Institute, and The University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Richard L Maas
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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Lin F, Chen Y, Liang H, Tan S. Echistatin prevents posterior capsule opacification in diabetic rabbit model via integrin linked kinase signaling pathway. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:14294-14304. [PMID: 26823745 PMCID: PMC4713531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 10/21/2015] [Indexed: 06/05/2023]
Abstract
PURPOSE To investigate the effect of disintegrin echistatin on integrin linked kinase (ILK) and subsequent PI3-K/Akt and ERK1/2 signaling pathways in the posterior capsule opacification (PCO) model of diabetic rabbit. METHODS 56 rabbits were injected alloxan to model diabetic. Then they accepted lens extraction surgery and randomly and intraoperatively injected distilled water (control group; n = 28) or 10.0 mg·L(-1) echistatin (echistatin-treated group; n = 28) into the anterior chamber. Each group was subdivided into ten days group (n = 14) and six weeks group (n = 14) respectively. The PCO severity was evaluated with a slit lamp microscope and light microscope for 10 days and 6 weeks postoperatively. The levels of ILK in the posterior capsule were determined by Q-PCR, Western blotting and Immunohistochemistry. Akt and ERK1/2 phosphorylation were analyzed by Western blotting. RESULTS 10 days and 6 weeks after surgery, the grades of PCO in the echistatin-treated group were lower than the control group. The lens epithelial cells (LECs) in the posterior capsule of echistatin-treated eyes had decreased degrees of proliferation and migration than the control group. And no significant side effects appeared after treated with echistatin. Echistatin could significantly reduce the expression of ILK in terms of both mRNA and protein levels. The phosphorylation levels of Akt and ERK1/2 were decreased in the echistatin-treated group compared with the control group. CONCLUSIONS Echistatin could inhibit postoperative PCO occurrence and development in diabetic rabbit eyes, which may be related to down-regulation the expression of ILK and inhibition the PI3-K/Akt and ERK1/2 pathways.
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Affiliation(s)
- Fengbin Lin
- Department of Ophthalmology, First Affiliated Hospital of Guangxi Medical University Nanning 530021, Guangxi, China
| | - Yingying Chen
- Department of Ophthalmology, First Affiliated Hospital of Guangxi Medical University Nanning 530021, Guangxi, China
| | - Hao Liang
- Department of Ophthalmology, First Affiliated Hospital of Guangxi Medical University Nanning 530021, Guangxi, China
| | - Shaojian Tan
- Department of Ophthalmology, First Affiliated Hospital of Guangxi Medical University Nanning 530021, Guangxi, China
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34
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Nibourg LM, Gelens E, de Jong MR, Kuijer R, van Kooten TG, Koopmans SA. Nanofiber-based hydrogels with extracellular matrix-based synthetic peptides for the prevention of capsular opacification. Exp Eye Res 2015; 143:60-7. [PMID: 26474493 DOI: 10.1016/j.exer.2015.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/23/2015] [Accepted: 10/02/2015] [Indexed: 11/29/2022]
Abstract
Nanofiber-based hydrogels (nanogels) with different, covalently bound peptides were used as an extracellular environment for lens epithelial cells (LECs) in order to modulate the capsular opacification (CO) response after lens surgery in a porcine eye model. Lenses were divided into 15 groups (n = 4 per group), the lens content was removed and the empty capsules were refilled with nanogel without peptides and nanogels with 13 combinations of 5 different peptides: two laminin-derived, two fibronectin-derived, and one collagen IV-derived peptide representing cell adhesion motifs. A control group of 4 lenses was refilled with hyaluronan. After refilling, lenses were extracted from the porcine eye and cultured for three weeks. LECs were assessed for morphology and alpha smooth muscle actin (αSMA) expression using confocal laser scanning microscopy. Compared to hyaluronan controls, lenses filled with nanogel had less CO formation, indicated by a lower αSMA expression (P = 0.004). Microscopy showed differences in morphological cell response within the nanogel refilled groups. αSMA expression in these groups was highest in lenses refilled with nanogel without peptides (9.54 ± 11.29%). Overall, LEC transformation is reduced by the presence of nanogels and the response is improved even further by incorporation of extracellular matrix peptides representing adhesion motifs. Thus, nanomaterials targeting biological pathways, in our case interactions with integrin signaling, are a promising avenue toward reduction of CO. Further research is needed to optimize nanogel-peptide combinations that fully prevent CO.
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Affiliation(s)
- Lisanne M Nibourg
- University of Groningen, University Medical Center Groningen, Dept. of Ophthalmology, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Laboratory for Experimental Ophthalmology, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
| | - Edith Gelens
- Nano Fiber Matrices B.V., Zernikepark 6-8, 9747 AN Groningen, The Netherlands
| | - Menno R de Jong
- Nano Fiber Matrices B.V., Zernikepark 6-8, 9747 AN Groningen, The Netherlands
| | - Roel Kuijer
- University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Dept. of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Theo G van Kooten
- University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Dept. of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Steven A Koopmans
- University of Groningen, University Medical Center Groningen, Dept. of Ophthalmology, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
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SIPA1L3 identified by linkage analysis and whole-exome sequencing as a novel gene for autosomal recessive congenital cataract. Eur J Hum Genet 2015; 23:1627-33. [PMID: 25804400 DOI: 10.1038/ejhg.2015.46] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/25/2022] Open
Abstract
Congenital cataract (CC) is one of the most important causes for blindness or visual impairment in infancy. A substantial proportion of isolated CCs has monogenic causes. The disease is genetically heterogeneous, and all Mendelian modes of inheritance have been reported. We mapped a locus for isolated CC on 19p13.1-q13.2 in a distantly consanguineous German family with two sisters affected by dense white cataracts. Whole-exome sequencing identified a homozygous nonsense variant c.4489C>T (p.(R1497*)) in SIPA1L3 (signal-induced proliferation-associated 1 like 3) in both affected children. SIPA1L3 encodes a GTPase-activating protein (GAP), which interacts with small GTPases of the Rap family via its Rap-GAP-domain. The suggested role of Rap GTPases in cell growth, differentiation and organization of the cytoskeleton in the human lens, and lens-enriched expression of the murine ortholog gene Sipa1l3 in embryonic mice indicates that this gene is crucial for early lens development. Our results provide evidence that sequence variants in human SIPA1L3 cause autosomal recessive isolated CC and give new insight into the molecular pathogenesis underlying human cataracts.
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36
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Prevention of posterior capsular opacification. Exp Eye Res 2015; 136:100-15. [PMID: 25783492 DOI: 10.1016/j.exer.2015.03.011] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 02/04/2015] [Accepted: 03/13/2015] [Indexed: 01/22/2023]
Abstract
Posterior capsular opacification (PCO) is a common complication of cataract surgery. The development of PCO is due to a combination of the processes of proliferation, migration, and transdifferentiation of residual lens epithelial cells (LECs) on the lens capsule. In the past decades, various forms of PCO prevention have been examined, including adjustments of techniques and intraocular lens materials, pharmacological treatments, and prevention by interfering with biological processes in LECs. The only method so far that seems effective is the implantation of an intraocular lens with sharp edged optics to mechanically prevent PCO formation. In this review, current knowledge of the prevention of PCO will be described. We illustrate the biological pathways underlying PCO formation and the various approaches to interfere with the biological processes to prevent PCO. In this type of prevention, the use of nanotechnological advances can play a role.
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37
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Lens Development and Crystallin Gene Expression. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:129-67. [DOI: 10.1016/bs.pmbts.2015.05.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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38
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Basu S, Rajakaruna S, Reyes B, Van Bockstaele E, Menko AS. Suppression of MAPK/JNK-MTORC1 signaling leads to premature loss of organelles and nuclei by autophagy during terminal differentiation of lens fiber cells. Autophagy 2014; 10:1193-211. [PMID: 24813396 PMCID: PMC4203547 DOI: 10.4161/auto.28768] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although autophagic pathways are essential to developmental processes, many questions still remain regarding the initiation signals that regulate autophagy in the context of differentiation. To address these questions we studied the ocular lens, as the programmed elimination of nuclei and organelles occurs in a precisely regulated spatiotemporal manner to form the organelle-free zone (OFZ), a characteristic essential for vision acuity. Here, we report our discovery that inactivation of MAPK/JNK induces autophagy for formation of the OFZ through its regulation of MTORC1, where MAPK/JNK signaling is required for both MTOR activation and RPTOR/RAPTOR phosphorylation. Autophagy pathway proteins including ULK1, BECN1/Beclin 1, and MAP1LC3B2/LC3B-II were upregulated in the presence of inhibitors to either MAPK/JNK or MTOR, inducing autophagic loss of organelles to form the OFZ. These results reveal that MAPK/JNK is a positive regulator of MTORC1 signaling and its developmentally regulated inactivation provides an inducing signal for the coordinated autophagic removal of nuclei and organelles required for lens function.
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Affiliation(s)
- Subhasree Basu
- Department of Pathology, Anatomy and Cell Biology; Thomas Jefferson University; Philadelphia, PA USA
| | - Suren Rajakaruna
- Department of Pathology, Anatomy and Cell Biology; Thomas Jefferson University; Philadelphia, PA USA
| | - Beverly Reyes
- Department of Neuroscience; Farber Institute for Neuroscience; Thomas Jefferson University; Philadelphia, PA USA
| | - Elisabeth Van Bockstaele
- Department of Neuroscience; Farber Institute for Neuroscience; Thomas Jefferson University; Philadelphia, PA USA
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology; Thomas Jefferson University; Philadelphia, PA USA
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39
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Mochizuki T, Masai I. The lens equator: a platform for molecular machinery that regulates the switch from cell proliferation to differentiation in the vertebrate lens. Dev Growth Differ 2014; 56:387-401. [PMID: 24720470 DOI: 10.1111/dgd.12128] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 02/20/2014] [Accepted: 02/21/2014] [Indexed: 01/17/2023]
Abstract
The vertebrate lens is a transparent, spheroidal tissue, located in the anterior region of the eye that focuses visual images on the retina. During development, surface ectoderm associated with the neural retina invaginates to form the lens vesicle. Cells in the posterior half of the lens vesicle differentiate into primary lens fiber cells, which form the lens fiber core, while cells in the anterior half maintain a proliferative state as a monolayer lens epithelium. After formation of the primary fiber core, lens epithelial cells start to differentiate into lens fiber cells at the interface between the lens epithelium and the primary lens fiber core, which is called the equator. Differentiating lens fiber cells elongate and cover the old lens fiber core, resulting in growth of the lens during development. Thus, lens fiber differentiation is spatially regulated and the equator functions as a platform that regulates the switch from cell proliferation to cell differentiation. Since the 1970s, the mechanism underlying lens fiber cell differentiation has been intensively studied, and several regulatory factors that regulate lens fiber cell differentiation have been identified. In this review, we focus on the lens equator, where these regulatory factors crosstalk and cooperate to regulate lens fiber differentiation. Normally, lens epithelial cells must pass through the equator to start lens fiber differentiation. However, there are reports that when the lens epithelium structure is collapsed, lens fiber cell differentiation occurs without passing the equator. We also discuss a possible mechanism that represses lens fiber cell differentiation in lens epithelium.
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Affiliation(s)
- Toshiaki Mochizuki
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa, 904-0495, Japan
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40
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Scheiblin DA, Gao J, Caplan JL, Simirskii VN, Czymmek KJ, Mathias RT, Duncan MK. Beta-1 integrin is important for the structural maintenance and homeostasis of differentiating fiber cells. Int J Biochem Cell Biol 2014; 50:132-45. [PMID: 24607497 DOI: 10.1016/j.biocel.2014.02.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Revised: 02/04/2014] [Accepted: 02/21/2014] [Indexed: 11/19/2022]
Abstract
β1-Integrin is a heterodimeric transmembrane protein that has roles in both cell-extra-cellular matrix and cell-cell interactions. Conditional deletion of β1-integrin from all lens cells during embryonic development results in profound lens defects, however, it is less clear whether this reflects functions in the lens epithelium alone or whether this protein plays a role in lens fibers. Thus, a conditional approach was used to delete β1-integrin solely from the lens fiber cells. This deletion resulted in two distinct phenotypes with some lenses exhibiting cataracts while others were clear, albeit with refractive defects. Analysis of "clear" conditional knockout lenses revealed that they had profound defects in fiber cell morphology associated with the loss of the F-actin network. Physiological measurements found that the lens fiber cells had a twofold increase in gap junctional coupling, perhaps due to differential localization of connexins 46 and 50, as well as increased water permeability. This would presumably facilitate transport of ions and nutrients through the lens, and may partially explain how lenses with profound structural abnormalities can maintain transparency. In summary, β1-integrin plays a role in maintaining the cellular morphology and homeostasis of the lens fiber cells.
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Affiliation(s)
- David A Scheiblin
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Junyuan Gao
- Department of Physiology and Biophysics, State University of New York at Stony Brook, Stony Brook, New York, NY 11794-8661, United States
| | - Jeffrey L Caplan
- Delaware Biotechnology Institute, University of Delaware, Newark, DE 19716, United States
| | - Vladimir N Simirskii
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Kirk J Czymmek
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Richard T Mathias
- Department of Physiology and Biophysics, State University of New York at Stony Brook, Stony Brook, New York, NY 11794-8661, United States
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States.
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41
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Mamuya FA, Wang Y, Roop VH, Scheiblin DA, Zajac JC, Duncan MK. The roles of αV integrins in lens EMT and posterior capsular opacification. J Cell Mol Med 2014; 18:656-70. [PMID: 24495224 PMCID: PMC4000117 DOI: 10.1111/jcmm.12213] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 11/18/2013] [Indexed: 12/23/2022] Open
Abstract
Posterior capsular opacification (PCO) is the major complication arising after cataract treatment. PCO occurs when the lens epithelial cells remaining following surgery (LCs) undergo a wound healing response producing a mixture of α-smooth muscle actin (α-SMA)-expressing myofibroblasts and lens fibre cells, which impair vision. Prior investigations have proposed that integrins play a central role in PCO and we found that, in a mouse fibre cell removal model of cataract surgery, expression of αV integrin and its interacting β-subunits β1, β5, β6, β8 are up-regulated concomitant with α-SMA in LCs following surgery. To test the hypothesis that αV integrins are functionally important in PCO pathogenesis, we created mice lacking the αV integrin subunit in all lens cells. Adult lenses lacking αV integrins are transparent and show no apparent morphological abnormalities when compared with control lenses. However, following surgical fibre cell removal, the LCs in control eyes increased cell proliferation, and up-regulated the expression of α-SMA, β1-integrin, fibronectin, tenascin-C and transforming growth factor beta (TGF-β)-induced protein within 48 hrs, while LCs lacking αV integrins exhibited much less cell proliferation and little to no up-regulation of any of the fibrotic markers tested. This effect appears to result from the known roles of αV integrins in latent TGF-β activation as αV integrin null lenses do not exhibit detectable SMAD-3 phosphorylation after surgery, while this occurs robustly in control lenses, consistent with the known roles for TGF-β in fibrotic PCO. These data suggest that therapeutics antagonizing αV integrin function could be used to prevent fibrotic PCO following cataract surgery.
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Affiliation(s)
- Fahmy A Mamuya
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
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42
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Teo ZL, McQueen-Miscamble L, Turner K, Martinez G, Madakashira B, Dedhar S, Robinson ML, de Iongh RU. Integrin linked kinase (ILK) is required for lens epithelial cell survival, proliferation and differentiation. Exp Eye Res 2014; 121:130-42. [PMID: 24472646 DOI: 10.1016/j.exer.2014.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/10/2014] [Accepted: 01/14/2014] [Indexed: 01/11/2023]
Abstract
While the role of growth factors in lens development has been investigated extensively, the role of extracellular matrix signalling is less well understood. The developing lens expresses predominantly laminin-binding integrins (such as α3β1, α6β1), which are cooperatively required in the lens epithelium during development. We investigated the role of ILK, a downstream mediator of integrin signalling in mice conditionally null for Ilk. Mutant lenses showed epithelial thinning at E17.5 with reduced proliferation and epithelial cell number and aberrant fibre differentiation. There was complete loss of the central epithelium from postnatal day (P) 2 due to cell death followed by fibre cell degeneration and death by P10 as well as rupture of the lens capsule between P10 and P21. At E17.5 there was significant inhibition (∼50%) of epithelial cell cycle progression, as shown by BrdU incorporation, cyclin D1/D2 and phospho-histone H3 immunostaining. The epithelial marker, E-cadherin, was decreased progressively from E17.5 to P2, in the central epithelium, but there was no significant change in Pax6 expression. Analyses of ERK and Akt phosphorylation indicated marked depression of MAPK and PI3K-Akt signalling, which correlated with decreased phosphorylation of FRS2α and Shp2, indicating altered activation of FGF receptors. At later postnatal stages there was reduced or delayed expression of fibre cell markers (β-crystallin and p57(kip2)). Loss of Ilk also affected deposition of extracellular matrix, with marked retention of collagen IV within differentiating fibre cells. By quantitative RT-PCR array there was significantly decreased expression of 19 genes associated with focal adhesions, actin filament stability and MAPK and PI3K/Akt signalling. Overall, these data indicate that ILK is required for complete activation of signalling cascades downstream of the FGF receptor in lens epithelium and fibre cells during development and thus is involved in epithelial proliferation, survival and subsequent fibre differentiation.
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Affiliation(s)
- Zhi Ling Teo
- Ocular Development Laboratory, Anatomy and Neuroscience, University of Melbourne, Victoria 3010, Australia
| | - Lachlan McQueen-Miscamble
- Ocular Development Laboratory, Anatomy and Neuroscience, University of Melbourne, Victoria 3010, Australia
| | - Kirsty Turner
- Ocular Development Laboratory, Anatomy and Neuroscience, University of Melbourne, Victoria 3010, Australia
| | - Gemma Martinez
- Ocular Development Laboratory, Anatomy and Neuroscience, University of Melbourne, Victoria 3010, Australia
| | | | - Shoukat Dedhar
- British Columbia Cancer Research Centre, Vancouver, B.C., Canada
| | | | - Robb U de Iongh
- Ocular Development Laboratory, Anatomy and Neuroscience, University of Melbourne, Victoria 3010, Australia.
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43
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Lens extrusion from Laminin alpha 1 mutant zebrafish. ScientificWorldJournal 2014; 2014:524929. [PMID: 24526906 PMCID: PMC3914655 DOI: 10.1155/2014/524929] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 11/26/2013] [Indexed: 01/07/2023] Open
Abstract
We report analysis of the ocular lens phenotype of the recessive, larval lethal zebrafish mutant, lama1a69/a69. Previous work revealed that this mutant has a shortened body axis and eye defects including a defective hyaloid vasculature, focal corneal dysplasia, and loss of the crystalline lens. While these studies highlight the importance of laminin α1 in lens development, a detailed analysis of the lens defects seen in these mutants was not reported. In the present study, we analyze the lenticular anomalies seen in the lama1a69/a69 mutants and show that the lens defects result from the anterior extrusion of lens material from the eye secondary to structural defects in the lens capsule and developing corneal epithelium associated with basement membrane loss. Our analysis provides further insights into the role of the lens capsule and corneal basement membrane in the structural integrity of the developing eye.
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44
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Shimada A, Miyata Y, Kosano H. Type I collagen accelerates the spreading of lens epithelial cells through the expression and activation of matrix metalloproteinases. Curr Eye Res 2014; 39:460-71. [PMID: 24400880 DOI: 10.3109/02713683.2013.853194] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Matrix metalloproteinases (MMPs) are involved in posterior capsule opacification (PCO), but the mechanisms that promote MMP expression are yet to be determined. In this study, we investigated whether type I collagen, which is only detected in aged or cataractous lens capsules, affects the expression and activation of MMPs in primary-cultured chicken lens epithelial cells (LECs). MATERIALS AND METHODS Chicken LECs were isolated from chicken embryos and cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum (FBS) on type I collagen-coated dishes. The activity of secreted MMPs was examined using gelatin zymography, and cell spreading was determined as the average area of randomly distributed cells. For some experiments, LECs were cultured in the presence of the broad-spectrum MMP inhibitor, GM6001. LECs cultured on uncoated dishes were used as controls. To examine the involvement of MMP in cell migration, a wound-healing assay was performed in the presence of the MMP inhibitor. RESULTS Chicken LECs constitutively express the pro-form of MMP-2. When LECs were cultured on type I collagen-coated dishes, they expressed the active form of MMP-2 and the pro-form of MMP-9. This expression and activation by type I collagen was also observed in the human LEC line SRA-01/04, but not the human Müller glial cell line, MIO-M1. Type I collagen enhanced cell spreading, which was suppressed by the MMP inhibitor. Type I collagen also accelerated α-smooth muscle actin expression. In addition, LEC migration was inhibited by the MMP inhibitor in a dose-dependent manner in the wound-healing assay. CONCLUSION Type I collagen promotes the expression and activation of MMPs in a LEC-specific manner. These results suggest that type I collagen may play a role in PCO development.
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Affiliation(s)
- Arata Shimada
- Faculty of Pharmaceutical Science, Teikyo University , Itabashi-ku, Tokyo , Japan
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45
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Simirskii VN, Duncan MK, Paltsev MA, Suchkov SV. β1 integrin as the integrating component in cell-cell cooperation for maintenance of lens transparency. DOKL BIOCHEM BIOPHYS 2014; 453:297-9. [PMID: 24385100 DOI: 10.1134/s1607672913060069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Indexed: 02/03/2023]
Affiliation(s)
- V N Simirskii
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119991, Russia
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46
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Basu S, Rajakaruna S, De Arcangelis A, Zhang L, Georges-Labouesse E, Menko AS. α6 integrin transactivates insulin-like growth factor receptor-1 (IGF-1R) to regulate caspase-3-mediated lens epithelial cell differentiation initiation. J Biol Chem 2013; 289:3842-55. [PMID: 24381169 DOI: 10.1074/jbc.m113.515254] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The canonical mitochondrial death pathway was first discovered for its role in signaling apoptosis. It has since been found to have a requisite function in differentiation initiation in many cell types including the lens through low level activation of the caspase-3 protease. The ability of this pathway to function as a molecular switch in lens differentiation depends on the concurrent induction of survival molecules in the Bcl-2 and IAP families, induced downstream of an IGF-1R/NFκB coordinate survival signal, to regulate caspase-3 activity. Here we investigated whether α6 integrin signals upstream to this IGF-1R-mediated survival-linked differentiation signal. Our findings show that IGF-1R is recruited to and activated specifically in α6 integrin receptor signaling complexes in the lens equatorial region, where lens epithelial cells initiate their differentiation program. In studies with both α6 integrin knock-out mice lenses and primary lens cell cultures following α6 integrin siRNA knockdown, we show that IGF-1R activation is dependent on α6 integrin and that this transactivation requires Src kinase activity. In addition, without α6 integrin, activation and expression of NFκB was diminished, and expression of Bcl-2 and IAP family members were down-regulated, resulting in high levels of caspase-3 activation. As a result, a number of hallmarks of lens differentiation failed to be induced; including nuclear translocation of Prox1 in the differentiation initiation zone and apoptosis was promoted. We conclude that α6 integrin is an essential upstream regulator of the IGF-1R survival pathway that regulates the activity level of caspase-3 for it to signal differentiation initiation of lens epithelial cells.
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Affiliation(s)
- Subhasree Basu
- From the Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 and
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47
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McHugh KJ, Saint-Geniez M, Tao SL. Topographical control of ocular cell types for tissue engineering. J Biomed Mater Res B Appl Biomater 2013; 101:1571-84. [PMID: 23744715 PMCID: PMC4090092 DOI: 10.1002/jbm.b.32968] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 03/19/2013] [Accepted: 04/21/2013] [Indexed: 02/06/2023]
Abstract
Visual impairment affects over 285 million people worldwide and has a major impact on an individual's quality of life. Tissue engineering has the potential to increase the quality of life for many of these patients by preventing vision loss or restoring vision using cell-based therapies. However, these strategies will require an understanding of the microenvironmental factors that influence cell behavior. The eye is a well-organized organ whose structural complexity is essential for proper function. Interactions between ocular cells and their highly ordered extracellular matrix are necessary for maintaining key tissue properties including corneal transparency and retinal lamination. Therefore, it is not surprising that culturing these cells in vitro on traditional flat substrates result in irregular morphology. Instead, topographically patterned biomaterials better mimic native extracellular matrix and have been shown to elicit in vivo-like morphology and gene expression which is essential for tissue engineering. Herein we review multiple methods for producing well-controlled topography and discuss optimal biomaterial scaffold design for cells of the cornea, retina, and lens.
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Affiliation(s)
- Kevin J. McHugh
- The Charles Stark Draper Laboratory, Cambridge, MA
- Schepens Eye Research Institute, Boston, MA
- Department of Biomedical Engineering, Boston University, Boston, MA
| | - Magali Saint-Geniez
- Schepens Eye Research Institute, Boston, MA
- Department of Ophthalmology, Harvard Medical School, Boston, MA
| | - Sarah L. Tao
- The Charles Stark Draper Laboratory, Cambridge, MA
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48
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Hayes JM, Hartsock A, Clark BS, Napier HRL, Link BA, Gross JM. Integrin α5/fibronectin1 and focal adhesion kinase are required for lens fiber morphogenesis in zebrafish. Mol Biol Cell 2012; 23:4725-38. [PMID: 23097490 PMCID: PMC3521681 DOI: 10.1091/mbc.e12-09-0672] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 10/16/2012] [Indexed: 11/16/2022] Open
Abstract
Lens fiber formation and morphogenesis requires a precise orchestration of cell- extracellular matrix (ECM) and cell-cell adhesive changes in order for a lens epithelial cell to adopt a lens fiber fate, morphology, and migratory ability. The cell-ECM interactions that mediate these processes are largely unknown, and here we demonstrate that fibronectin1 (Fn1), an ECM component, and integrin α5, its cellular binding partner, are required in the zebrafish lens for fiber morphogenesis. Mutations compromising either of these proteins lead to cataracts, characterized by defects in fiber adhesion, elongation, and packing. Loss of integrin α5/Fn1 does not affect the fate or viability of lens epithelial cells, nor does it affect the expression of differentiation markers expressed in lens fibers, although nucleus degradation is compromised. Analysis of the intracellular mediators of integrin α5/Fn1 activity focal adhesion kinase (FAK) and integrin-linked kinase (ILK) reveals that FAK, but not ILK, is also required for lens fiber morphogenesis. These results support a model in which lens fiber cells use integrin α5 to migrate along a Fn-containing substrate on the apical side of the lens epithelium and on the posterior lens capsule, likely activating an intracellular signaling cascade mediated by FAK in order to orchestrate the cytoskeletal changes in lens fibers that facilitate elongation, migration, and compaction.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Embryo, Nonmammalian/embryology
- Embryo, Nonmammalian/metabolism
- Fibronectins/genetics
- Fibronectins/metabolism
- Focal Adhesion Kinase 1/genetics
- Focal Adhesion Kinase 1/metabolism
- Gene Expression Regulation, Developmental
- Gene Knockdown Techniques
- Immunohistochemistry
- In Situ Hybridization
- Integrin alpha5/genetics
- Integrin alpha5/metabolism
- Lens, Crystalline/embryology
- Lens, Crystalline/metabolism
- Lens, Crystalline/ultrastructure
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Microscopy, Confocal
- Microscopy, Electron
- Models, Genetic
- Morphogenesis/genetics
- Mutation
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
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Affiliation(s)
- Julie M. Hayes
- Section of Molecular Cell and Developmental Biology and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78722
| | - Andrea Hartsock
- Section of Molecular Cell and Developmental Biology and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78722
| | - Brian S. Clark
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226-0509
| | - Hugh R. L. Napier
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226-0509
| | - Brian A. Link
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226-0509
| | - Jeffrey M. Gross
- Section of Molecular Cell and Developmental Biology and Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78722
- Institute for Neuroscience, University of Texas at Austin, Austin, TX 78722
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49
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Cammas L, Wolfe J, Choi SY, Dedhar S, Beggs HE. Integrin-linked kinase deletion in the developing lens leads to capsule rupture, impaired fiber migration and non-apoptotic epithelial cell death. Invest Ophthalmol Vis Sci 2012; 53:3067-81. [PMID: 22491404 DOI: 10.1167/iovs.11-9128] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
PURPOSE The lens is a powerful model system to study integrin-mediated cell-matrix interaction in an in vivo context, as it is surrounded by a true basement membrane, the lens capsule. To characterize better the function of integrin-linked kinase (ILK), we examined the phenotypic consequences of its deletion in the developing mouse lens. METHODS ILK was deleted from the embryonic lens either at the time of placode invagination using the Le-Cre line or after initial lens formation using the Nestin-Cre line. RESULTS Early deletion of ILK leads to defects in extracellular matrix deposition that result in lens capsule rupture at the lens vesicle stage (E13.5). If ILK was deleted at a later time-point after initial establishment of the lens capsule, rupture was prevented. Instead, ILK deletion resulted in secondary fiber migration defects and, most notably, in cell death of the anterior epithelium (E18.5-P0). Remarkably, dying cells did not stain positively for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) or activated-caspase 3, suggesting that they were dying from a non-apoptotic mechanism. Moreover, cross to a Bax(fl/fl)/Bak⁻/⁻ mouse line that is resistant to most forms of apoptosis failed to promote cell survival in the ILK-deleted lens epithelium. Electron microscopy revealed the presence of numerous membranous vacuoles containing degrading cellular material. CONCLUSIONS. Our study reveals a role for ILK in extracellular matrix organization, fiber migration, and cell survival. Furthermore, to our knowledge we show for the first time that ILK disruption results in non-apoptotic cell death in vivo.
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Affiliation(s)
- Laura Cammas
- Department of Ophthalmology, University of California, San Francisco, CA, USA
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50
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Basu S, Rajakaruna S, Menko AS. Insulin-like growth factor receptor-1 and nuclear factor κB are crucial survival signals that regulate caspase-3-mediated lens epithelial cell differentiation initiation. J Biol Chem 2012; 287:8384-97. [PMID: 22275359 DOI: 10.1074/jbc.m112.341586] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
It is now known that the function of the caspase family of proteases is not restricted to effectors of programmed cell death. For example, there is a significant non-apoptotic role for caspase-3 in cell differentiation. Our own studies in the developing lens show that caspase-3 is activated downstream of the canonical mitochondrial death pathway to act as a molecular switch in signaling lens cell differentiation. Importantly, for this function, caspase-3 is activated at levels far below those that induce apoptosis. We now have provided evidence that regulation of caspase-3 for its role in differentiation induction is dependent on the insulin-like growth factor-1 receptor (IGF-1R) survival-signaling pathway. IGF-1R executed this regulation of caspase-3 by controlling the expression of molecules in the Bcl-2 and inhibitor of apoptosis protein (IAP) families. This effect of IGF-1R was mediated through NFκB, demonstrated here to function as a crucial downstream effector of IGF-1R. Inhibition of expression or activation of NFκB blocked expression of survival proteins in the Bcl-2 and IAP families and removed controls on the activation state of caspase-3. The high level of caspase-3 activation that resulted from inhibiting this IGF-1R/NFκB signaling pathway redirected cell fate from differentiation toward apoptosis. These results provided the first evidence that the IGF-1R/NFκB cell survival signal is a crucial regulator of the level of caspase-3 activation for its non-apoptotic function in signaling cell differentiation.
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Affiliation(s)
- Subhasree Basu
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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