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VanSlyke JK, Boswell BA, Musil LS. TGFβ overcomes FGF-induced transinhibition of EGFR in lens cells to enable fibrotic secondary cataract. Mol Biol Cell 2024; 35:ar75. [PMID: 38598298 DOI: 10.1091/mbc.e24-01-0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024] Open
Abstract
To cause vision-disrupting fibrotic secondary cataract (PCO), lens epithelial cells that survive cataract surgery must migrate to the posterior of the lens capsule and differentiate into myofibroblasts. During this process, the cells become exposed to the FGF that diffuses out of the vitreous body. In normal development, such relatively high levels of FGF induce lens epithelial cells to differentiate into lens fiber cells. It has been a mystery as to how lens cells could instead undergo a mutually exclusive cell fate, namely epithelial to myofibroblast transition, in the FGF-rich environment of the posterior capsule. We and others have reported that the ability of TGFβ to induce lens cell fibrosis requires the activity of endogenous ErbBs. We show here that lens fiber-promoting levels of FGF induce desensitization of ErbB1 (EGFR) that involves its phosphorylation on threonine 669 mediated by both ERK and p38 activity. Transinhibition of ErbB1 by FGF is overcome by a time-dependent increase in ErbB1 levels induced by TGFβ, the activation of which is increased after cataract surgery. Our studies provide a rationale for why TGFβ upregulates ErbB1 in lens cells and further support the receptor as a therapeutic target for PCO.
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Affiliation(s)
- Judy K VanSlyke
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239
| | - Bruce A Boswell
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239
| | - Linda S Musil
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239
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VanSlyke JK, Boswell BA, Musil LS. Tonic ErbB signaling underlies TGFβ-induced activation of ERK and is required for lens cell epithelial to myofibroblast transition. Mol Biol Cell 2024; 35:ar35. [PMID: 38170570 PMCID: PMC10916858 DOI: 10.1091/mbc.e23-07-0294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/01/2023] [Accepted: 12/20/2023] [Indexed: 01/05/2024] Open
Abstract
Fibrosis is a major, but incompletely understood, component of many diseases. The most common vision-disrupting complication of cataract surgery involves differentiation of residual lens cells into myofibroblasts. In serum-free primary cultures of lens epithelial cells (DCDMLs), inhibitors of either ERK or of ErbB signaling prevent TGFβ from upregulating both early (fibronectin) and late (αSMA) markers of myofibroblast differentiation. TGFβ stimulates ERK in DCDMLs within 1.5 h. Kinase inhibitors of ErbBs, but not of several other growth factor receptors in lens cells, reduce phospho ERK to below basal levels in the absence or presence of TGFβ. This effect is attributable to constitutive ErbB activity playing a major role in regulating the basal levels pERK. Additional studies support a model in which TGFβ-generated reactive oxygen species serve to indirectly amplify ERK signaling downstream of tonically active ErbBs to mediate myofibroblast differentiation. ERK activity is in turn essential for expression of ErbB1 and ErbB2, major inducers of ERK signaling. By mechanistically linking TGFβ, ErbB, and ERK signaling to myofibroblast differentiation, our data elucidate a new role for ErbBs in fibrosis and reveal a novel mode by which TGFβ directs lens cell fate.
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Affiliation(s)
- Judy K. VanSlyke
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239
| | - Bruce A. Boswell
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239
| | - Linda S. Musil
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239
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Jing RH, Hu CH, Qi TT, Ma B. Role of reactive oxygen species in epithelial-mesenchymal transition and apoptosis of human lens epithelial cells. Int J Ophthalmol 2023; 16:1935-1941. [PMID: 38111943 PMCID: PMC10700083 DOI: 10.18240/ijo.2023.12.04] [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: 11/21/2022] [Accepted: 08/15/2023] [Indexed: 12/20/2023] Open
Abstract
AIM To investigate the role of reactive oxygen species (ROS) in epithelial-mesenchymal transition (EMT) and apoptosis of human lens epithelial cells (HLECs). METHODS Flow cytometry was used to assess ROS production after transforming growth factor β2 (TGF-β2) induction. Apoptosis of HLECs after H2O2 and TGF-β2 interference with or without ROS scavenger N-acetylcysteine (NAC) were assessed by flow cytometry. The corresponding protein expression levels of the EMT marker α-smooth muscle actin (α-SMA), the extracellular matrix (ECM), marker fibronectin (Fn), and apoptosis-associated proteins were detected by using Western blotting in the presence of an ROS scavenger (NAC). Wound-healing and Transwell assays were used to assess the migration capability of HLECs. RESULTS TGF-β2 stimulates ROS production within 8h in HLECs. Additionally, TGF-β2 induced HLECs cell apoptosis, EMT/ECM synthesis protein markers expression, and pro-apoptotic proteins production; nonetheless, NAC treatment prevented these responses. Similarly, TGF-β2 promoted HLECs cell migration, whereas NAC inhibited cell migration. We further determined that although ROS initiated apoptosis, it only induced the accumulation of the EMT marker α-SMA protein, but not COL-1 or Fn. CONCLUSION ROS contribute to TGF-β2-induced EMT/ECM synthesis and cell apoptosis of HLECs; however, ROS alone are not sufficient for EMT/ECM synthesis.
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Affiliation(s)
- Rui-Hua Jing
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Cong-Hui Hu
- Department of Ophthalmology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China
| | - Tian-Tian Qi
- Department of Ophthalmology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China
| | - Bo Ma
- Department of Ophthalmology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China
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Li Y, Acosta FM, Jiang JX. Gap Junctions or Hemichannel-Dependent and Independent Roles of Connexins in Fibrosis, Epithelial-Mesenchymal Transitions, and Wound Healing. Biomolecules 2023; 13:1796. [PMID: 38136665 PMCID: PMC10742173 DOI: 10.3390/biom13121796] [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: 11/07/2023] [Revised: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Fibrosis initially appears as a normal response to damage, where activated fibroblasts produce large amounts of the extracellular matrix (ECM) during the wound healing process to assist in the repair of injured tissue. However, the excessive accumulation of the ECM, unresolved by remodeling mechanisms, leads to organ dysfunction. Connexins, a family of transmembrane channel proteins, are widely recognized for their major roles in fibrosis, the epithelial-mesenchymal transition (EMT), and wound healing. Efforts have been made in recent years to identify novel mediators and targets for this regulation. Connexins form gap junctions and hemichannels, mediating communications between neighboring cells and inside and outside of cells, respectively. Recent evidence suggests that connexins, beyond forming channels, possess channel-independent functions in fibrosis, the EMT, and wound healing. One crucial channel-independent function is their role as the primary functional component for cell adhesion. Other channel-independent functions of connexins involve their roles in mitochondria and exosomes. This review summarizes the latest advances in the channel-dependent and independent roles of connexins in fibrosis, the EMT, and wound healing, with a particular focus on eye diseases, emphasizing their potential as novel, promising therapeutic targets.
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Affiliation(s)
- Yuting Li
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
- Department of Pathology, Basic Medical School, Ningxia Medical University, Yinchuan 750004, China
| | - Francisca M. Acosta
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
| | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; (Y.L.); (F.M.A.)
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Brennan L, Disatham J, Menko AS, Kantorow M. Multiomic analysis implicates FOXO4 in genetic regulation of chick lens fiber cell differentiation. Dev Biol 2023; 504:25-37. [PMID: 37722500 PMCID: PMC10843493 DOI: 10.1016/j.ydbio.2023.09.005] [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: 05/15/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/20/2023]
Abstract
A classic model for identification of novel differentiation mechanisms and pathways is the eye lens that consists of a monolayer of quiescent epithelial cells that are the progenitors of a core of mature fully differentiated fiber cells. The differentiation of lens epithelial cells into fiber cells follows a coordinated program involving cell cycle exit, expression of key structural proteins and the hallmark elimination of organelles to achieve transparency. Although multiple mechanisms and pathways have been identified to play key roles in lens differentiation, the entirety of mechanisms governing lens differentiation remain to be discovered. A previous study established that specific chromatin accessibility changes were directly associated with the expression of essential lens fiber cell genes, suggesting that the activity of transcription factors needed for expression of these genes could be regulated through binding access to the identified chromatin regions. Sequence analysis of the identified chromatin accessible regions revealed enhanced representation of the binding sequence for the transcription factor FOXO4 suggesting a direct role for FOXO4 in expression of these genes. FOXO4 is known to regulate a variety of cellular processes including cellular response to metabolic and oxidative stress, cell cycle withdrawal, and homeostasis, suggesting a previously unidentified role for FOXO4 in the regulation of lens cell differentiation. To further evaluate the role of FOXO4 we employed a multiomics approach to analyze the relationship between genome-wide FOXO4 binding, the differentiation-specific expression of key genes, and chromatin accessibility. To better identify active promoters and enhancers we also examined histone modification through analysis of H3K27ac. Specific methods included CUT&RUN (FOXO4 binding and H3K27ac modification), RNA-seq (differentiation state specific gene expression), and ATAC-seq (chromatin accessibility). CUT&RUN identified 20,966 FOXO4 binding sites and 33,921 H3K27ac marked regions across the lens fiber cell genome. RNA-seq identified 956 genes with significantly greater expression levels in fiber cells compared to epithelial cells (log2FC > 0.7, q < 0.05) and 2548 genes with significantly lower expression levels (log2FC < -0.7, q < 0.05). Integrated analysis identified 1727 differentiation-state specific genes that were nearest neighbors to at least one FOXO4 binding site, including genes encoding lens gap junctions (GJA1, GJA3), lens structural proteins (BFSP1, CRYBB1, ASL1), and genes required for lens transparency (HSF4, NRCAM). Multiomics analysis comparing the identified FOXO4 binding sites in published ATAC-seq data revealed that chromatin accessibility was associated with FOXO4-dependent gene expression during lens differentiation. The results provide evidence for an important requirement for FOXO4 in the regulated expression of key genes required for lens differentiation and link epigenetic regulation of chromatin accessibility and H3K27ac histone modification with the function of FOXO4 in controlling lens gene expression during lens fiber cell differentiation.
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Affiliation(s)
- Lisa Brennan
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Joshua Disatham
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - A Sue Menko
- Department of Pathology and Genomic Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Marc Kantorow
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
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Chhunchha B, Kumar R, Kubo E, Thakur P, Singh DP. Prdx6 Regulates Nlrp3 Inflammasome Activation-Driven Inflammatory Response in Lens Epithelial Cells. Int J Mol Sci 2023; 24:16276. [PMID: 38003466 PMCID: PMC10671722 DOI: 10.3390/ijms242216276] [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: 10/15/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
The continuum of antioxidant response dysregulation in aging/oxidative stress-driven Nlrp3 inflammasome activation-mediated inflammatory response is associated with age-related diseases. Peroxiredoxin (Prdx) 6 is a key antioxidant that provides cytoprotection by regulating redox homeostasis. Herein, using lens epithelial cells (LECs) derived from the targeted inactivation of Prdx6 gene and aging lenses, we present molecular evidence that Prdx6-deficiency causes oxidative-driven Nlrp3 inflammasome activation, resulting in pyroptosis in aging/redox active cells wherein Prdx6 availability offsets the inflammatory process. We observed that Prdx6-/- and aging LECs harboring accumulated reactive oxygen species (ROS) showed augmented activation of Nlrp3 and bioactive inflammatory components, like Caspase-1, IL-1β, ASC and Gasdermin-D. Similar to lipopolysaccharide treatment, oxidative exposure led to further ROS amplification with increased activation of the Nlrp3 inflammasome pathway. Mechanistically, we found that oxidative stress enhanced Kruppel-like factor 9 (Klf9) expression in aging/Prdx6-/- mLECs, leading to a Klf9-dependent increase in Nlrp3 transcription, while the elimination of ROS by the delivery of Prdx6 or by silencing Klf9 prevented the inflammatory response. Altogether, our data identify the biological significance of Prdx6 as an intrinsic checkpoint for regulating the cellular health of aging or redox active LECs and provide opportunities to develop antioxidant-based therapeutic(s) to prevent oxidative/aging-related diseases linked to aberrant Nlrp3 inflammasome activation.
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Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Rakesh Kumar
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Kahoku 9200293, Ishikawa, Japan;
| | - Priyanka Thakur
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
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FGF-2 Differentially Regulates Lens Epithelial Cell Behaviour during TGF-β-Induced EMT. Cells 2023; 12:cells12060827. [PMID: 36980168 PMCID: PMC10046997 DOI: 10.3390/cells12060827] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/02/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
Fibroblast growth factor (FGF) and transforming growth factor-beta (TGF-β) can regulate and/or dysregulate lens epithelial cell (LEC) behaviour, including proliferation, fibre differentiation, and epithelial–mesenchymal transition (EMT). Earlier studies have investigated the crosstalk between FGF and TGF-β in dictating lens cell fate, that appears to be dose dependent. Here, we tested the hypothesis that a fibre-differentiating dose of FGF differentially regulates the behaviour of lens epithelial cells undergoing TGF-β-induced EMT. Postnatal 21-day-old rat lens epithelial explants were treated with a fibre-differentiating dose of FGF-2 (200 ng/mL) and/or TGF-β2 (50 pg/mL) over a 7-day culture period. We compared central LECs (CLECs) and peripheral LECs (PLECs) using immunolabelling for changes in markers for EMT (α-SMA), lens fibre differentiation (β-crystallin), epithelial cell adhesion (β-catenin), and the cytoskeleton (alpha-tropomyosin), as well as Smad2/3- and MAPK/ERK1/2-signalling. Lens epithelial explants cotreated with FGF-2 and TGF-β2 exhibited a differential response, with CLECs undergoing EMT while PLECs favoured more of a lens fibre differentiation response, compared to the TGF-β-only-treated explants where all cells in the explants underwent EMT. The CLECs cotreated with FGF and TGF-β immunolabelled for α-SMA, with minimal β-crystallin, whereas the PLECs demonstrated strong β-crystallin reactivity and little α-SMA. Interestingly, compared to the TGF-β-only-treated explants, α-SMA was significantly decreased in the CLECs cotreated with FGF/TGF-β. Smad-dependent and independent signalling was increased in the FGF-2/TGF-β2 co-treated CLECs, that had a heightened number of cells with nuclear localisation of Smad2/3 compared to the PLECs, that in contrast had more pronounced ERK1/2-signalling over Smad2/3 activation. The current study has confirmed that FGF-2 is influential in differentially regulating the behaviour of LECs during TGF-β-induced EMT, leading to a heterogenous cell population, typical of that observed in the development of post-surgical, posterior capsular opacification (PCO). This highlights the cooperative relationship between FGF and TGF-β leading to lens pathology, providing a different perspective when considering preventative measures for controlling PCO.
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Upreti A, Padula SL, Tangeman JA, Wagner BD, O’Connell MJ, Jaquish TJ, Palko RK, Mantz CJ, Anand D, Lovicu FJ, Lachke SA, Robinson ML. Lens Epithelial Explants Treated with Vitreous Humor Undergo Alterations in Chromatin Landscape with Concurrent Activation of Genes Associated with Fiber Cell Differentiation and Innate Immune Response. Cells 2023; 12:501. [PMID: 36766843 PMCID: PMC9914805 DOI: 10.3390/cells12030501] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/31/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Lens epithelial explants are comprised of lens epithelial cells cultured in vitro on their native basement membrane, the lens capsule. Biologists have used lens epithelial explants to study many different cellular processes including lens fiber cell differentiation. In these studies, fiber differentiation is typically measured by cellular elongation and the expression of a few proteins characteristically expressed by lens fiber cells in situ. Chromatin and RNA was collected from lens epithelial explants cultured in either un-supplemented media or media containing 50% bovine vitreous humor for one or five days. Chromatin for ATAC-sequencing and RNA for RNA-sequencing was prepared from explants to assess regions of accessible chromatin and to quantitatively measure gene expression, respectively. Vitreous humor increased chromatin accessibility in promoter regions of genes associated with fiber differentiation and, surprisingly, an immune response, and this was associated with increased transcript levels for these genes. In contrast, vitreous had little effect on the accessibility of the genes highly expressed in the lens epithelium despite dramatic reductions in their mRNA transcripts. An unbiased analysis of differentially accessible regions revealed an enrichment of cis-regulatory motifs for RUNX, SOX and TEAD transcription factors that may drive differential gene expression in response to vitreous.
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Affiliation(s)
- Anil Upreti
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Stephanie L. Padula
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Jared A. Tangeman
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Brad D. Wagner
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | | | - Tycho J. Jaquish
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Raye K. Palko
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Courtney J. Mantz
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Frank J. Lovicu
- Molecular and Cellular Biomedicine, School of Medical Sciences, and Save Sight Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Salil A. Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19716, USA
| | - Michael L. Robinson
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
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Li J, Yu J, Huang W, Sang F, Li J, Ren Y, Huang H, Wang M, Li K, Zhang J, Li H, Cui X, Zhang J, Hu M, Yuan F, Guo W, Zhang F, Mu H, Hu Y. Extracellular HSP90 promotes differentiation of lens epithelial cells to fiber cells by activating LRP1-YAP-PROX1 axis. FASEB J 2023; 37:e22783. [PMID: 36705056 DOI: 10.1096/fj.202201187rr] [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: 07/29/2022] [Revised: 12/20/2022] [Accepted: 01/09/2023] [Indexed: 01/28/2023]
Abstract
Capsular residual lens epithelial cells (CRLEC) undergo differentiation to fiber cells for lens regeneration or tansdifferentiation to myofibroblasts leading to posterior capsular opacification (PCO) after cataract surgery. The underlying regulatory mechanism remains unclear. Using human lens epithelial cell lines and the ex vivo cultured rat lens capsular bag model, we found that the lens epithelial cells secrete HSP90α extracellularly (eHSP90) through an autophagy-associated pathway. Administration of recombinant GST-HSP90α protein or its M-domain induces the elongation of rat CRLEC cells with concomitant upregulation of the crucial fiber cell transcriptional factor PROX1and its downstream targets, β- and γ-crystallins and structure proteins. This regulation is abolished by PROX1 siRNA. GST-HSP90α upregulates PROX1 by binding to LRP1 and activating LRP1-AKT mediated YAP degradation. The upregulation of GST-HSP90α on PROX1 expression and CRLEC cell elongation is inhibited by LRP1 and AKT inhibitors, but activated by YAP-1 inhibitor (VP). These data demonstrated that the capsular residue epithelial cells upregulate and secrete eHSP90α, which in turn drive the differentiation of lens epithelial cell to fiber cells. The recombinant HSP90α protein is a potential novel differentiation regulator during lens regeneration.
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Affiliation(s)
- Jing Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China.,Kaifeng Key Lab for Cataract and Myopia, Institute of Eye Disease, Kaifeng Central Hospital, Kaifeng, China
| | - Jingjing Yu
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Weikang Huang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Fan Sang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Junmin Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Yanzhu Ren
- Kaifeng Key Lab for Cataract and Myopia, Institute of Eye Disease, Kaifeng Central Hospital, Kaifeng, China
| | - Huili Huang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Mingli Wang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Kejia Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Jun Zhang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Hui Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Xiukun Cui
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Jing Zhang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Mengyue Hu
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Fengling Yuan
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Weikai Guo
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China
| | - Fengyan Zhang
- Department of ophthalmology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hongmei Mu
- Kaifeng Key Lab for Cataract and Myopia, Institute of Eye Disease, Kaifeng Central Hospital, Kaifeng, China
| | - Yanzhong Hu
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital of Henan University, Henan University, Kaifeng, China.,Kaifeng Key Lab for Cataract and Myopia, Institute of Eye Disease, Kaifeng Central Hospital, Kaifeng, China.,Department of ophthalmology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Zhao G, Pan AY, Feng Y, Rasko JE, Bailey CG, Lovicu FJ. Sprouty and Spred temporally regulate ERK1/2-signaling to suppress TGFβ-induced lens EMT. Exp Eye Res 2022; 219:109070. [DOI: 10.1016/j.exer.2022.109070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/22/2022] [Accepted: 04/04/2022] [Indexed: 11/04/2022]
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FILIP1L-mediated cell apoptosis, epithelial-mesenchymal transition and extracellular matrix synthesis aggravate posterior capsular opacification. Life Sci 2021; 286:120061. [PMID: 34666037 DOI: 10.1016/j.lfs.2021.120061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/23/2022]
Abstract
AIMS The epithelial-mesenchymal transition (EMT), extracellular matrix (ECM) synthesis and cell migration of residual lens cells constitute the canonical mechanisms of posterior capsular opacification (PCO). Recently, myofibroblast cell apoptosis is also observed in the rabbit PCO model. However, whether cell apoptosis is a key factor affecting PCO and regulates EMT/ECM synthesis/cell migration remains obscure. MAIN METHODS Flow cytometry was utilized to assess cell cycle and apoptosis. EMT marker α-smooth muscle actin (α-SMA), ECM markers fibronectin (Fn), type 1 collagen (COL-1) and apoptosis-associated proteins in the presence or absence of EMT/ECM inhibitor (LY2109761), apoptosis inhibitor (ZVAD) or apoptosis activator (BTSA1) were detected by Western blotting. Downstream effector genes in apoptosis-induced lens epithelial cell lines (LECs) were analyzed by RNA-seq. Gene silencing and overexpression in LECs were performed to validate the role of effector genes. We measured cell migration capability using Wound healing and Transwell assays. KEY FINDINGS We found that TGF-β2 induced cell apoptosis. ZVAD inhibited α-SMA expression in the ex vivo capsule model and decreased the expression of both EMT and ECM markers in TGF-β2-treated LECs. RNA-seq revealed that FILIP1L was significantly decreased in apoptosis-activated cells. We further validated that the knockdown of FILIP1L could enhance EMT and ECM synthesis and promote cell migration and that FILIP1L overexpression could reverse these effects. Apoptosis might contribute to TGF-β2-induced EMT and ECM synthesis during PCO, and these contributions are mediated by FILIP1L. SIGNIFICANCE Our findings uncover the role of apoptosis in PCO development and provide new drug targets.
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Basta MD, Paulson H, Walker JL. The local wound environment is a key determinant of the outcome of TGFβ signaling on the fibrotic response of CD44 + leader cells in an ex vivo post-cataract-surgery model. Exp Eye Res 2021; 213:108829. [PMID: 34774488 DOI: 10.1016/j.exer.2021.108829] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/22/2021] [Accepted: 11/03/2021] [Indexed: 01/17/2023]
Abstract
The cytokine transforming growth factor beta (TGFβ) has a role in regulating the normal and pathological response to wound healing, yet how it shifts from a pro-repair to a pro-fibrotic function within the wound environment is still unclear. Using a clinically relevant ex vivo post-cataract surgery model that mimics the lens fibrotic disease posterior capsule opacification (PCO), we investigated the influence of two distinct wound environments on shaping the TGFβ-mediated injury response of CD44+ vimentin-rich leader cells. The substantial fibrotic response of this cell population occurred within a rigid wound environment under the control of endogenous TGFβ. However, TGFβ was dispensable for the role of leader cells in wound healing on the endogenous basement membrane wound environment, where repair occurs in the absence of a major fibrotic outcome. A difference between leader cell function in these distinct environments was their cell surface expression of the latent TGFβ activator, αvβ3 integrin. This receptor is exclusively found on this CD44+ cell population when they localize to the leading edge of the rigid wound environment. Providing exogenous TGFβ to bypass any differences in the ability of the leader cells to sustain activation of TGFβ in different environments revealed their inherent ability to induce pro-fibrotic reactions on the basement membrane wound environment. Furthermore, exposure of the leader cells in the rigid wound environment to TGFβ led to an accelerated fibrotic response including the earlier appearance of pro-collagen + cells, alpha smooth muscle actin (αSMA)+ myofibroblasts, and increased fibrotic matrix production. Collectively, these findings show the influence of the local wound environment on the extent and severity of TGFβ-induced fibrotic responses. These findings have important implications for understanding the development of the lens fibrotic disease PCO in response to cataract surgery wounding.
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Affiliation(s)
- Morgan D Basta
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Heather Paulson
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Janice L Walker
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA; Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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13
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Immune responses to injury and their links to eye disease. Transl Res 2021; 236:52-71. [PMID: 34051364 PMCID: PMC8380715 DOI: 10.1016/j.trsl.2021.05.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/12/2021] [Accepted: 05/24/2021] [Indexed: 12/31/2022]
Abstract
The eye is regarded as an immune privileged site. Since the presence of a vasculature would impair vision, the vasculature of the eye is located outside of the central light path. As a result, many regions of the eye evolved mechanisms to deliver immune cells to sites of dysgenesis, injury, or in response to the many age-related pathologies. While the purpose of these immune responses is reparative or protective, cytokines released by immune cells compromise visual acuity by inducing inflammation and fibrosis. The response to traumatic or pathological injury is distinct in different regions of the eye. Age-related diseases impact both the anterior and posterior segment and lead to reduced quality of life and blindness. Here we focus attention on the role that inflammation and fibrosis play in the progression of age-related pathologies of the cornea and the lens as well as in glaucoma, the formation of epiretinal membranes, and in proliferative vitreoretinopathy.
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Key Words
- 2ryERM
- A T-helper cell that expresses high levels of IL-17 which can suppress T-regulatory cell function
- A cytokine expressed early during inflammation that attracts neutrophils
- A cytokine expressed early during inflammation that attracts neutrophils, sometimes referred to as monocyte chemoattractant protein-1 (MCP-1))
- A mouse model that lacks functional T and B cells and used to study the immune response
- A pigmented mouse strain used for research and known to mount a primarily Th1 response to infection
- A protein encoded by the ADGRE1 gene that, in mice, is expressed primarily on macrophages
- A strain of pigmented mice used in glaucoma research
- ACAID
- APCs
- ASC
- An albino mouse strain used for research and known to mount a primarily Th2 response to infection
- Antigen Presenting Cells, this class includes dendritic cells and monocytes
- BALB/c
- BM
- C57BL6
- CCL2
- CD45
- CNS
- CXCL1
- Central Nervous System
- Cluster of differentiation 45 antigen
- DAMPs
- DBA/2J
- EBM
- ECM
- EMT
- ERM
- Epithelial Basement Membrane
- F4/80
- FGF2
- HA =hyaluronic acid
- HSK
- HSP
- HSPGs
- HSV
- ICN
- IL-20
- IL6
- ILM
- IOP
- Inner (or internal) limiting membrane
- Interleukin 6
- Interleukin-20
- MAGP1
- MHC-II
- Major histocompatibility complex type II, a class of MHC proteins typically found only on APCs
- Microfibril-associated glycoprotein 1
- N-cad
- N-cadherin
- NEI
- NK
- National Eye Institute
- Natural killer T cells
- PCO
- PDGF
- PDR
- PVD
- PVR
- Platelet derived growth factor
- Posterior capsular opacification
- RGC
- RPE
- RRD
- Rag1-/-
- Retinal ganglion cells
- Retinal pigment epithelial cells
- SMAD
- Sons of Mothers Against Decapentaplegic, SMADs are a class of molecules that mediate TGF and bone morphogenetic protein signaling
- T-helper cell 1 response, proinflammatory adaptive response involving interferon gamma and associated with autoimmunity
- T-helper cell 2 response involving IgE and interleukins 4,5, and 13, also induces the anti-inflammatory interleukin 10 family cytokines
- T-regulatory cell
- TG
- TGF1
- TM
- TNF
- Th1
- Th17
- Th2
- Transforming growth factor 1
- Treg
- Tumor necrosis factor a cytokine produced during inflammation
- VEGF
- Vascular endothelial growth factor
- WHO
- World Health Organization
- anterior chamber immune deviation
- anterior subcapsular cataracts
- basement membrane
- damage-associated molecular patterns
- epiretinal membrane
- epiretinal membrane secondary to disease pathology
- epithelial-mesenchymal transition
- extracellular matrix
- fibroblast growth factor 2, also referred to as basic FGF
- heat shock protein
- heparan sulfate proteoglycans
- herpes simplex virus
- herpes stromal keratitis
- iERM
- idiopathic epiretinal membrane
- intraepithelial corneal nerves
- intraocular pressure
- mTOR
- mechanistic target of rapamycin, a protein kinase encoded by the MTOR genes that regulates a variety of signal transduction events including cell growth, autophagy and actin cytoskeleton
- posterior vitreous detachment
- proliferative diabetic retinopathy
- proliferative vitreoretinopathy
- rhegmatogenous (rupture, tear) retinal detachment
- trabecular meshwork
- trigeminal ganglion
- αSMA
- α−Smooth muscle actin, a class of actin expressed in mesenchymal cells
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14
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Patel SD, Aryal S, Mennetti LP, Parreno J. Whole mount staining of lenses for visualization of lens epithelial cell proteins. MethodsX 2021; 8:101376. [PMID: 34430272 PMCID: PMC8374519 DOI: 10.1016/j.mex.2021.101376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/26/2021] [Indexed: 11/17/2022] Open
Abstract
Whole mount imaging of the lens allows for high spatial resolution visualization of lens epithelial structures by using small molecule fluorescent probes. However, the visualization of specific proteins in lens epithelial cells within whole lenses remains a challenge as the capsule that surrounds the lens does not allow penetration of antibodies. Here we describe a whole mount imaging method that allows us to overcome this challenge by digesting the lens capsules of paraformaldehyde fixed lenses using collagenase. This method enables the penetration of antibodies for effective visualization of proteins in the epithelium of whole lenses.A limitation to lens whole mount imaging is the ability to visualize specific proteins as the collagen capsule surrounding the lens impedes the penetration of antibodies This protocol helps overcome this limitation by a light collagenase digestion of the capsule of fixed lenses prior to immunostaining This method allows for the imaging of specific proteins in the epithelium of the whole lens tissue
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Affiliation(s)
- Shaili D Patel
- Department of Biological Sciences, University of Delaware USA
| | - Sandeep Aryal
- Department of Biological Sciences, University of Delaware USA
| | | | - Justin Parreno
- Department of Biological Sciences, University of Delaware USA
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15
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Rankenberg J, Rakete S, Wagner BD, Patnaik JL, Henning C, Lynch A, Glomb MA, Nagaraj RH. Advanced glycation end products in human diabetic lens capsules. Exp Eye Res 2021; 210:108704. [PMID: 34302851 DOI: 10.1016/j.exer.2021.108704] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022]
Abstract
Advanced glycation end products (AGEs) accumulate with age in human lens capsules. AGEs in lens capsules potentiate the transforming growth factor beta-2-mediated mesenchymal transition of lens epithelial cells, which suggests that they play a role in posterior capsule opacification after cataract surgery. We measured AGEs by liquid chromatography-mass spectrometry in capsulorhexis specimens obtained during cataract surgery from nondiabetic and diabetic patients with and without established retinopathy. Our data showed that the levels of most AGEs (12 out of 13 measured) were unaltered in diabetic patients and diabetic patients with retinopathy compared to nondiabetic patients. There was one exception: glucosepane, which was significantly higher in diabetic patients, both with (6.85 pmol/μmol OH-proline) and without retinopathy (8.32 pmol/μmol OH-proline), than in nondiabetic patients (4.01 pmol/μmol OH-proline). Our study provides an explanation for the similar incidence of posterior capsule opacification between nondiabetic and diabetic cataract patients observed in several studies.
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Affiliation(s)
- Johanna Rankenberg
- Sue-Anschutz Eye Center, Department of Ophthalmology, School of Medicine, Aurora, CO, USA
| | - Stefan Rakete
- Sue-Anschutz Eye Center, Department of Ophthalmology, School of Medicine, Aurora, CO, USA; Present Address: Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital LMU, Munich, Germany
| | - Brandie D Wagner
- Sue-Anschutz Eye Center, Department of Ophthalmology, School of Medicine, Aurora, CO, USA; Colorado School of Public Health, Aurora, CO, USA
| | - Jennifer L Patnaik
- Sue-Anschutz Eye Center, Department of Ophthalmology, School of Medicine, Aurora, CO, USA
| | - Christian Henning
- Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/ Saale, Germany
| | - Anne Lynch
- Sue-Anschutz Eye Center, Department of Ophthalmology, School of Medicine, Aurora, CO, USA
| | - Marcus A Glomb
- Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/ Saale, Germany
| | - Ram H Nagaraj
- Sue-Anschutz Eye Center, Department of Ophthalmology, School of Medicine, Aurora, CO, USA; School of Pharmacy, University of Colorado, Aurora, CO, USA.
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16
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Disatham J, Brennan L, Chauss D, Kantorow J, Afzali B, Kantorow M. A functional map of genomic HIF1α-DNA complexes in the eye lens revealed through multiomics analysis. BMC Genomics 2021; 22:497. [PMID: 34215186 PMCID: PMC8254356 DOI: 10.1186/s12864-021-07795-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/09/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND During eye lens development the embryonic vasculature regresses leaving the lens without a direct oxygen source. Both embryonically and throughout adult life, the lens contains a decreasing oxygen gradient from the surface to the core that parallels the natural differentiation of immature surface epithelial cells into mature core transparent fiber cells. These properties of the lens suggest a potential role for hypoxia and the master regulator of the hypoxic response, hypoxia-inducible transcription factor 1 (HIF1), in the regulation of genes required for lens fiber cell differentiation, structure and transparency. Here, we employed a multiomics approach combining CUT&RUN, RNA-seq and ATACseq analysis to establish the genomic complement of lens HIF1α binding sites, genes activated or repressed by HIF1α and the chromatin states of HIF1α-regulated genes. RESULTS CUT&RUN analysis revealed 8375 HIF1α-DNA binding complexes in the chick lens genome. One thousand one hundred ninety HIF1α-DNA binding complexes were significantly clustered within chromatin accessible regions (χ2 test p < 1 × 10- 55) identified by ATACseq. Formation of the identified HIF1α-DNA complexes paralleled the activation or repression of 526 genes, 116 of which contained HIF1α binding sites within 10kB of the transcription start sites. Some of the identified HIF1α genes have previously established lens functions while others have novel functions never before examined in the lens. GO and pathway analysis of these genes implicate HIF1α in the control of a wide-variety of cellular pathways potentially critical for lens fiber cell formation, structure and function including glycolysis, cell cycle regulation, chromatin remodeling, Notch and Wnt signaling, differentiation, development, and transparency. CONCLUSIONS These data establish the first functional map of genomic HIF1α-DNA complexes in the eye lens. They identify HIF1α as an important regulator of a wide-variety of genes previously shown to be critical for lens formation and function and they reveal a requirement for HIF1α in the regulation of a wide-variety of genes not yet examined for lens function. They support a requirement for HIF1α in lens fiber cell formation, structure and function and they provide a basis for understanding the potential roles and requirements for HIF1α in the development, structure and function of more complex tissues.
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Affiliation(s)
- Joshua Disatham
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd., Boca Raton, FL 33431 USA
| | - Lisa Brennan
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd., Boca Raton, FL 33431 USA
| | - Daniel Chauss
- Immunoregulation Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD 20892 USA
| | | | - Behdad Afzali
- Immunoregulation Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD 20892 USA
| | - Marc Kantorow
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd., Boca Raton, FL 33431 USA
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17
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Shibata S, Shibata N, Ohtsuka S, Yoshitomi Y, Kiyokawa E, Yonekura H, Singh DP, Sasaki H, Kubo E. Role of Decorin in Posterior Capsule Opacification and Eye Lens Development. Cells 2021; 10:863. [PMID: 33918979 PMCID: PMC8070370 DOI: 10.3390/cells10040863] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 12/20/2022] Open
Abstract
Decorin (DCN) is involved in a variety of physiological and pathological processes. Epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) has been proposed as a major cause for the development of posterior capsule opacification (PCO) after cataract surgery. We investigated the plausible target gene(s) that suppress PCO. The expression of Dcn was significantly upregulated in rat PCO tissues compared to that observed in the control using a microarray-based approach. LECs treated with fibroblast growth factor (FGF) 2 displayed an enhanced level of DCN expression, while LECs treated with transforming growth factor (TGF)β-2 showed a decrease in DCN expression. The expression of tropomyosin 1 (Tpm1), a marker of lens EMT increased after the addition of TGFβ-2 in human LEC; however, upregulation of Tpm1 mRNA or protein expression was reduced in human LECs overexpressing human DCN (hDCN). No phenotypic changes were observed in the lenses of 8- and 48-week-old transgenic mice for lens-specific hDCN (hDCN-Tg). Injury-induced EMT of the mouse lens, and the expression patterns of α smooth muscle actin, were attenuated in hDCN-Tg mice lenses. Overexpression of DCN inhibited the TGFβ-2-induced upregulation of Tpm1 and EMT observed during wound healing of the lens, but it did not affect mouse lens morphology until 48 weeks of age. Our findings demonstrate that DCN plays a significant role in regulating EMT formation of LECs and PCO, and suggest that for therapeutic intervention, maintenance of physiological expression of DCN is essential to attenuate EMT progression and PCO formation.
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Affiliation(s)
- Shinsuke Shibata
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 9200293, Japan; (S.S.); (N.S.); (H.S.)
| | - Naoko Shibata
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 9200293, Japan; (S.S.); (N.S.); (H.S.)
| | - Satoshi Ohtsuka
- Medical Research Institute, Kanazawa Medical University, Ishikawa 9200293, Japan;
- Laboratory for Experimental Animals, Kyoto Prefectural University of Medicine, Kyoto 6028566, Japan
| | - Yasuo Yoshitomi
- Department of Biochemistry, Kanazawa Medical University, Ishikawa 9200293, Japan; (Y.Y.); (H.Y.)
| | - Etsuko Kiyokawa
- Department of Oncogenic Pathology, Kanazawa Medical University, Ishikawa 9200293, Japan;
| | - Hideto Yonekura
- Department of Biochemistry, Kanazawa Medical University, Ishikawa 9200293, Japan; (Y.Y.); (H.Y.)
| | - Dhirendra P. Singh
- Department of Ophthalmology, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Hiroshi Sasaki
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 9200293, Japan; (S.S.); (N.S.); (H.S.)
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa 9200293, Japan; (S.S.); (N.S.); (H.S.)
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18
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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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19
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Long-term myofibroblast persistence in the capsular bag contributes to the late spontaneous in-the-bag intraocular lens dislocation. Sci Rep 2020; 10:20532. [PMID: 33239706 PMCID: PMC7689492 DOI: 10.1038/s41598-020-77207-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 10/28/2020] [Indexed: 12/15/2022] Open
Abstract
Late spontaneous in-the-bag intraocular lens (IOL) dislocation is a complication presenting 6 months or later after cataract surgery. We aimed to characterize the cells in the lens capsules (LCs) of 18 patients with spontaneous late in-the-bag IOL dislocation. Patients' average age was 82.6 ± 1.5 years (range 72-98), and most of them had pseudoexfoliation syndrome (PEX). Cells from the LCs were positive for myofibroblast (αSMA), proliferation (Ki-67, PCNA), early lens development/lens progenitor (SOX2, PAX6), chemokine receptor (CXCR4), and transmembrane (N-cadherin) markers, while negative for epithelial (E-cadherin) marker. Moreover, the cells produced abundant fibronectin, type I and type V collagen in the nearby extracellular matrix (ECM). During ex vivo cultivation of dislocated IOL-LCs in toto, the cells proliferated and likely migrated onto the IOL's anterior side. EdU proliferation assay confirmed the proliferation potential of the myofibroblasts (MFBs) in dislocated IOL-LCs. Primary cultured lens epithelial cells/MFBs isolated from the LC of dislocated IOLs could induce collagen matrix contraction and continuously proliferated, migrated, and induced ECM remodeling. Taken together, this indicates that long-lived MFBs of dislocated IOLs might contribute to the pathogenic mechanisms in late in-the-bag IOL dislocation.
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20
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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: 77] [Impact Index Per Article: 19.3] [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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21
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Richardson RB, Ainsbury EA, Prescott CR, Lovicu FJ. Etiology of posterior subcapsular cataracts based on a review of risk factors including aging, diabetes, and ionizing radiation. Int J Radiat Biol 2020; 96:1339-1361. [DOI: 10.1080/09553002.2020.1812759] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Richard B. Richardson
- Radiobiology and Health Branch, Canadian Nuclear Laboratories (CNL), Chalk River, Canada
- McGill University’s Medical Physics Unit, Cedars Cancer Centre, Montreal, Canada
| | - Elizabeth A. Ainsbury
- Public Health England’s Centre for Chemical, Radiological and Environmental Hazards, Oxford, UK
| | | | - Frank J. Lovicu
- School of Medical Sciences, The University of Sydney, Sydney, Australia
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22
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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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23
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Hu S, Liu H, Hu Z, Li L, Yang Y. Follistatin-like 1: A dual regulator that promotes cardiomyocyte proliferation and fibrosis. J Cell Physiol 2020; 235:5893-5902. [PMID: 32017077 DOI: 10.1002/jcp.29588] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 01/13/2020] [Indexed: 12/14/2022]
Abstract
Follistatin-like 1 (FSTL1) is a key factor in maintaining cardiac growth and development. It can be activated by exercise training and has a dual role in promoting cardiomyocyte proliferation and fibrosis, but its underlying mechanism is not fully understood. To elucidate the dual mechanism and target of FSTL1 regulating of cardiomyocyte proliferation and myocardial fibrosis, and the mechanism by which exercise-regulated FSTL1 improves cardiovascular disease, we explored the signal transduction pathway of FSTL1 promoting cardiomyocyte proliferation and fibrosis, and compared the effects of different modes of exercise on the dual role of FSTL1. We believe that the dual role of promoting cardiomyocyte proliferation and fibrosis may be related to the ratio of cardiomyocyte and myocardial interstitial cell proliferation, different stages of the disease, different degrees of fibrosis, immune repair process, and transforming growth factor-β activation. Compared with long-term excessive endurance exercise, moderate resistance exercise can activate cardiomyocyte proliferation pathway through FSTL1, which is one of the effective ways to prevent cardiovascular disease.
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Affiliation(s)
- Siyuan Hu
- Graduate School, Wuhan Sports University, Wuhan, China.,School of Sports Art, Hunan University of Chinese Medicine, Changsha, China
| | - Hua Liu
- College of Health Science, Wuhan Sports University, Wuhan, China
| | - Zhixi Hu
- Institute of Chinese Medicine Diagnosis, Hunan University of Chinese Medicine, Changsha, China
| | - Lin Li
- Institute of Chinese Medicine Diagnosis, Hunan University of Chinese Medicine, Changsha, China
| | - Yi Yang
- College of Health Science, Wuhan Sports University, Wuhan, China
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24
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Li J, Xue W, Wang X, Huang W, Wang XX, Li H, Cui X, Li M, Mu H, Ren Y, Zhang F, Hu Y. HSP90 as a novel therapeutic target for posterior capsule opacification. Exp Eye Res 2019; 189:107821. [DOI: 10.1016/j.exer.2019.107821] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 09/17/2019] [Accepted: 09/28/2019] [Indexed: 12/21/2022]
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25
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Taler K, Weiss O, Rotem-Bamberger S, Rubinstein AM, Seritrakul P, Gross JM, Inbal A. Lysyl hydroxylase 3 is required for normal lens capsule formation and maintenance of lens epithelium integrity and fate. Dev Biol 2019; 458:177-188. [PMID: 31669351 DOI: 10.1016/j.ydbio.2019.10.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/03/2019] [Accepted: 10/20/2019] [Indexed: 02/06/2023]
Abstract
Lens abnormalities are a major cause of reduced vision and blindness. One mechanism that can lead to reduced lens transparency, i.e. cataract, is abnormal behavior of lens epithelial cells (LECs), the precursors of the transparent lens fiber cells. Here we describe a zebrafish mutation causing the embryonic lens epithelium to generate cellular masses comprising partially differentiated lens fiber cells. We identify the mutant gene as plod3, which encodes for Lysyl hydroxylase 3 (Lh3), an enzyme essential for modification of collagens, including Collagen IV, a main component of the lens capsule. We show that plod3-deficient lenses have abnormal lens epithelium from an early developmental stage, as well as abnormal lens capsules. Subsequently, upregulation of TGFβ signaling takes place, which drives the formation of lens epithelial cellular masses. We identify a similar phenotype in Collagen IVα5-deficient embryos, suggesting a key role for the defective lens capsule in the pathogenesis. We propose that plod3 and col4a5 mutant zebrafish can serve as useful models for better understanding the biology of LECs during embryonic development and in formation of lens epithelium-derived cataract.
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Affiliation(s)
- Kineret Taler
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Omri Weiss
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Shahar Rotem-Bamberger
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ariel M Rubinstein
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Pawat Seritrakul
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jeffrey M Gross
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Adi Inbal
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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26
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Ma B, Jing R, Liu J, Qi T, Pei C. Gremlin is a potential target for posterior capsular opacification. Cell Cycle 2019; 18:1714-1726. [PMID: 31234714 DOI: 10.1080/15384101.2019.1632125] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Objective: The present study was conducted to determine the role of gremlin during the development of posterior capsular opacification (PCO) via in vitro and in vivo experiments. Methods: The activation, roles and relationships of the BMPs/Smad1/5, MAPK, FAK and AKT signaling pathways in human lens epithelial cells (HLECs) after gremlin induction were detected by western blotting and real-time PCR. Wound-healing, transwell, capsular bag models and rat PCO models assays were used to test the effects of gremlin on HLECs' migration, proliferation, EMT-specific protein α-smooth muscle actin(α-SMA)and development of PCO in rats. Results: Our data showed that knockdown of the gremlin inhibited the development of PCO and reduced expression of α-SMA in rats. While gremlin did not alter the migration of HLECs, it increased the expression of p-ERK and p-AKT. Knockout of Smad2 or Smad3 inhibited the expression of p-ERK and p-AKT proteins induced by gremlin. Gremlin also reduced BMP4-induced expression of the p-Smad1/5 protein. Finally, knockout of Smad1/5 increased gremlin-induced expression of α-SMA, fibronectin and type I collagen (COL-1) in HLECs. Conclusion: These results suggested that gremlin contributed to the development of PCO by promoting LEC proliferation, activation of TGF-β/Smad, ERK and AKT signaling and inhibition of BMPs/Smad1/5 signaling. Furthermore, inhibiting gremlin effectively impaired both PCO development in rats and EMT in the lens capsule. Thus, our data suggest that gremlin might be a potential target for PCO.
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Affiliation(s)
- Bo Ma
- a Department of Ophthalmology , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , Shaanxi , China
| | - Ruihua Jing
- a Department of Ophthalmology , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , Shaanxi , China
| | - Jie Liu
- a Department of Ophthalmology , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , Shaanxi , China
| | - Tiantian Qi
- a Department of Ophthalmology , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , Shaanxi , China
| | - Cheng Pei
- a Department of Ophthalmology , The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an , Shaanxi , China
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27
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Jiang J, Shihan MH, Wang Y, Duncan MK. Lens Epithelial Cells Initiate an Inflammatory Response Following Cataract Surgery. Invest Ophthalmol Vis Sci 2019; 59:4986-4997. [PMID: 30326070 PMCID: PMC6188467 DOI: 10.1167/iovs.18-25067] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose Lens epithelial cell (LEC) conversion to myofibroblast is responsible for fibrotic cataract surgery complications including posterior capsular opacification. While transforming growth factor beta (TGFβ) signaling is important, the mechanisms by which the TGFβ pathway is activated post cataract surgery (PCS) are not well understood. Methods RNA-seq was performed on LECs obtained from a mouse cataract surgery model at the time of surgery and 24 hours later. Bioinformatic analysis was performed with iPathwayGuide. Expression dynamics were determined by immunofluorescence. Results The LEC transcriptome is massively altered by 24 hours PCS. The differentially expressed genes included those important for lens biology, and fibrotic markers. However, the most dramatic changes were in the expression of genes regulating the innate immune response, with the top three altered genes exhibiting greater than 1000-fold upregulation. Immunolocalization revealed that CXCL1, S100a9, CSF3, COX-2, CCL2, LCN2, and HMOX1 protein levels upregulate in LECs between 1 hour and 6 hours PCS and peak at 24 hours PCS, while their levels sharply attenuate by 3 days PCS. This massive upregulation of known inflammatory mediators precedes the infiltration of neutrophils into the eye at 18 hours PCS, the upregulation of canonical TGFβ signaling at 48 hours PCS, and the infiltration of macrophages at 3 days PCS. Conclusions These data demonstrate that LECs produce proinflammatory cytokines immediately following lens injury that could drive postsurgical flare, and suggest that inflammation may be a major player in the onset of lens-associated fibrotic disease PCS.
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Affiliation(s)
- Jian Jiang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Mahbubul H Shihan
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Yan Wang
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States
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28
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Aldose reductase inhibition enhances lens regeneration in mice. Chem Biol Interact 2019; 307:58-62. [PMID: 31026421 DOI: 10.1016/j.cbi.2019.04.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 03/23/2019] [Accepted: 04/16/2019] [Indexed: 01/05/2023]
Abstract
After cataract surgery, epithelial cells lining the anterior lens capsule can transition to one of two divergent pathways, including fibrosis which leads to posterior capsular opacification (PCO), or lens fiber cell differentiation which leads to regeneration of lens material. We previously showed that the PCO response can be suppressed with aldose reductase (AR) inhibitors. In this present study we show that AR inhibition, both genetic and pharmacologic with Sorbinil, can augment the process of lens regeneration. Extracapsular lens extraction (ECLE) was carried out in C57BL/6 (WT), AR overexpression (AR-Tg), and AR knockout (ARKO) mice, and in some cases in mice treated with the AR inhibitor sorbinil. Whole eyes were harvested approximately 8 weeks after ECLE and evaluated by histological analysis and immunostaining for the fiber cell marker γ-crystallin. All eyes examined for lens regeneration were paraffin embedded for serial sectioning to produce three-dimensional reconstructed models of lens morphology and size. We observed that AR-null mice respond to ECLE by regenerating a lens-like structure with a circular shape and array of cell nuclei reminiscent of the lens bow region typical of the native mammalian lens. Although WT and AR-Tg eyes also produced some regenerated lens material after ECLE, their structures were consistently smaller than ARKO regenerated lenses. WT mice treated with sorbinil showed higher levels of lens regeneration after ECLE compared to WT mice, as assessed by size and three-dimensional morphology. Altogether, this study adds evidence for a critical role for AR in the response of lens epithelial cells to cataract extraction and lens regeneration.
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29
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Menko AS, Walker JL, Stepp MA. Fibrosis: Shared Lessons From the Lens and Cornea. Anat Rec (Hoboken) 2019; 303:1689-1702. [PMID: 30768772 PMCID: PMC6697240 DOI: 10.1002/ar.24088] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/23/2018] [Accepted: 09/04/2018] [Indexed: 12/13/2022]
Abstract
Regenerative repair in response to wounding involves cell proliferation and migration. This is followed by the reestablishment of cell structure and organization and a dynamic process of remodeling and restoration of the injured cells' extracellular matrix microenvironment and the integration of the newly synthesized matrix into the surrounding tissue. Fibrosis in the lungs, liver, and heart can lead to loss of life and in the eye to loss of vision. Learning to control fibrosis and restore normal tissue function after injury repair remains a goal of research in this area. Here we use knowledge gained using the lens and the cornea to provide insight into how fibrosis develops and clues to how it can be controlled. The lens and cornea are less complex than other tissues that develop life‐threatening fibrosis, but they are well characterized and research using them as model systems to study fibrosis is leading toward an improved understanding of fibrosis. Here we summarize the current state of the literature and how it is leading to promising new treatments. Anat Rec, 2019. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.
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Affiliation(s)
- A Sue Menko
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Janice L Walker
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, George Washington University, Washington, District of Columbia
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30
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Zukin LM, Pedler MG, Groman-Lupa S, Pantcheva M, Ammar DA, Petrash JM. Aldose Reductase Inhibition Prevents Development of Posterior Capsular Opacification in an In Vivo Model of Cataract Surgery. Invest Ophthalmol Vis Sci 2019; 59:3591-3598. [PMID: 30025084 PMCID: PMC6049986 DOI: 10.1167/iovs.18-23935] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose Cataract surgery is a procedure by which the lens fiber cell mass is removed from its capsular bag and replaced with a synthetic intraocular lens. Postoperatively, remnant lens epithelial cells can undergo an aberrant wound healing response characterized by an epithelial-to-mesenchymal transition (EMT), leading to posterior capsular opacification (PCO). Aldose reductase (AR) inhibition has been shown to decrease EMT markers in cell culture models. In this study, we aim to demonstrate that AR inhibition can attenuate induction of EMT markers in an in vivo model of cataract surgery. Methods A modified extracapsular lens extraction (ECLE) was performed on C57BL/6 wildtype, AR overexpression (AR-Tg), and AR knockout mice. Immunofluorescent staining for the myofibroblast marker α-smooth muscle actin (α-SMA), epithelial marker E-cadherin, and lens fiber cell markers αA-crystallin and Aquaporin 0 was used to characterize postoperative PCO. Quantitative reverse transcription PCR (qRT-PCR) was employed to quantify postoperative changes in α-SMA, vimentin, fibronectin, and E-cadherin. In a separate experiment, the AR inhibitor Sorbinil was applied postoperatively and qRT-PCR was used to assess changes in EMT markers. Results Genetic AR knockout reduced ECLE-induced upregulation of α-SMA and downregulation of E-cadherin. These immunofluorescent changes were mirrored quantitatively in changes in mRNA levels. Similarly, Sorbinil blocked characteristic postoperative EMT changes in AR-Tg mice. Interestingly, genetic AR knockout did not prevent postoperative induction of the lens fiber cell markers αA-crystallin and Aquaporin 0. Conclusions AR inhibition prevents the postoperative changes in EMT markers characteristic of PCO yet preserves the postoperative induction of lens fiber cell markers.
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Affiliation(s)
- Leonid M Zukin
- Department of Ophthalmology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States
| | - Michelle G Pedler
- Department of Ophthalmology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States
| | - Sergio Groman-Lupa
- Department of Ophthalmology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States.,Asociación para Evitar la Ceguera en México, Mexico City, Mexico
| | - Mina Pantcheva
- Department of Ophthalmology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States
| | - David A Ammar
- Department of Ophthalmology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States
| | - J Mark Petrash
- Department of Ophthalmology, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States.,Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States
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31
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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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32
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Musavi Shenas MH, Eghbal-Fard S, Mehrisofiani V, Abd Yazdani N, Rahbar Farzam O, Marofi F, Yousefi M. MicroRNAs and signaling networks involved in epithelial-mesenchymal transition. J Cell Physiol 2018; 234:5775-5785. [PMID: 30417364 DOI: 10.1002/jcp.27489] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 09/06/2018] [Indexed: 12/17/2022]
Abstract
Epithelial-mesenchymal transition (EMT) is a phenomenon in which epithelial cells lose their cell-to-cell connection and are detached from the base membrane. EMT is fundamental for many biological processes such as embryonic development and neurogenesis. It also plays a significant role in cancer progression and metastasis. EMT regulation occurs through a sophisticated network of transcription regulations that include many signaling pathways. The exact mechanism of cancer gene regulation has not been understood yet. However, it is interesting to study the role of microRNAs and epigenetics mechanism in the cancer development. In this review, the transcription regulation of EMT and the analysis of possible overlap between microRNAs and their targets which are involved in the cancer development are scrutinized.
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Affiliation(s)
| | - Shadi Eghbal-Fard
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Vahid Mehrisofiani
- Aging Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nima Abd Yazdani
- Aging Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Omid Rahbar Farzam
- Aging Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Faroogh Marofi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehdi Yousefi
- Aging Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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33
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Mochizuki T, Kojima Y, Nishiwaki Y, Harakuni T, Masai I. Endocytic trafficking factor VPS45 is essential for spatial regulation of lens fiber differentiation in zebrafish. Development 2018; 145:145/20/dev170282. [PMID: 30322969 PMCID: PMC6215396 DOI: 10.1242/dev.170282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/10/2018] [Indexed: 01/20/2023]
Abstract
In vertebrate lens, lens epithelial cells cover the anterior half of the lens fiber core. Lens epithelial cells proliferate, move posteriorly and start to differentiate into lens fiber cells at the lens equator. Although FGF signaling promotes this equatorial commencement of lens fiber differentiation, the underlying mechanism is not fully understood. Here, we show that lens epithelial cells abnormally enter lens fiber differentiation without passing through the equator in zebrafish vps45 mutants. VPS45 belongs to the Sec1/Munc18-like protein family and promotes endosome trafficking, which differentially modulates signal transduction. Ectopic lens fiber differentiation in vps45 mutants does not depend on FGF, but is mediated through activation of TGFβ signaling and inhibition of canonical Wnt signaling. Thus, VPS45 normally suppresses lens fiber differentiation in the anterior region of lens epithelium by modulating TGFβ and canonical Wnt signaling pathways. These data indicate a novel role of endosome trafficking to ensure equator-dependent commencement of lens fiber differentiation. Summary: The endocytic regulator VPS45 suppresses FGF-independent lens fiber differentiation and ensures the spatial pattern of lens development.
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Affiliation(s)
- Toshiaki Mochizuki
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha 1919-1, Onna, Okinawa 098-0945, Japan
| | - Yutaka Kojima
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha 1919-1, Onna, Okinawa 098-0945, Japan
| | - Yuko Nishiwaki
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha 1919-1, Onna, Okinawa 098-0945, Japan
| | - Tetsuya Harakuni
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha 1919-1, Onna, Okinawa 098-0945, Japan
| | - Ichiro Masai
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Tancha 1919-1, Onna, Okinawa 098-0945, Japan
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ERK1/2-mediated EGFR-signaling is required for TGFβ-induced lens epithelial-mesenchymal transition. Exp Eye Res 2018; 178:108-121. [PMID: 30290164 DOI: 10.1016/j.exer.2018.09.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/30/2018] [Accepted: 09/28/2018] [Indexed: 02/02/2023]
Abstract
Epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) plays a critical role in the pathogenesis of fibrotic cataract. Transforming growth factor-beta (TGFβ) is a potent inducer of this fibrotic process in lens. Recent studies in cancer progression have shown that in addition to activating the canonical Smad signaling pathway, TGFβ can also transactivate the epidermal growth factor receptor (EGFR) to enhance invasive cell migration. The present study aims to elucidate the involvement of EGFR-signaling in TGFβ-induced EMT in LECs. Treatment with TGFβ2 induced transdifferentiation of LECs into myofibroblastic cells, typical of an EMT. TGFβ2 induced the phosphorylation of the EGFR and upregulation of Egfr and Hb-egf gene expression. Pharmacologic inhibition of EGFR-signaling using PD153035 inhibited TGFβ-induced EMT, including the upregulation of mesenchymal markers and downregulation of epithelial markers. Crosstalk between TGFβ2-induced EGFR and ERK1/2 was evident, with both pathways impacting on Smad2/3-signaling. Our finding that TGFβ2 transactivates downstream EGFR-signaling reveals a previously unknown mechanism in the pathogenesis of cataract. Understanding the complex interplay between divergent canonical and non-canonical signaling pathways, as well as downstream target genes involved in TGFβ-induced EMT, will enable the development of more effective targeted therapies in the pharmacological treatment of cataract.
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Zhao Y, Zheng D, Cvekl A. A comprehensive spatial-temporal transcriptomic analysis of differentiating nascent mouse lens epithelial and fiber cells. Exp Eye Res 2018; 175:56-72. [PMID: 29883638 PMCID: PMC6167154 DOI: 10.1016/j.exer.2018.06.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/01/2018] [Accepted: 06/03/2018] [Indexed: 02/07/2023]
Abstract
Elucidation of both the molecular composition and organization of the ocular lens is a prerequisite to understand its development, function, pathology, regenerative capacity, as well as to model lens development and disease using in vitro differentiation of pluripotent stem cells. Lens is comprised of the anterior lens epithelium and posterior lens fibers, which form the bulk of the lens. Lens fibers differentiate from lens epithelial cells through cell cycle exit-coupled differentiation that includes cellular elongation, accumulation of crystallins, cytoskeleton and membrane remodeling, and degradation of organelles within the central region of the lens. Here, we profiled spatiotemporal expression dynamics of both mRNAs and non-coding RNAs from microdissected mouse nascent lens epithelium and lens fibers at four developmental time points (embryonic [E] day 14.5, E16.5, E18.5, and P0.5) by RNA-seq. During this critical time window, multiple complex biosynthetic and catabolic processes generate the molecular and structural foundation for lens transparency. Throughout this developmental window, 3544 and 3518 genes show consistently and significantly greater expression in the nascent lens epithelium and fibers, respectively. Comprehensive data analysis confirmed major roles of FGF-MAPK, Wnt/β-catenin, PI3K/AKT, TGF-β, and BMP signaling pathways and revealed significant novel contributions of mTOR, EIF2, EIF4, and p70S6K signaling in lens formation. Unbiased motif analysis within promoter regions of these genes with consistent expression changes between epithelium and fiber cells revealed an enrichment for both established (e.g. E2Fs, Etv5, Hsf4, c-Maf, MafG, MafK, N-Myc, and Pax6) transcription factors and a number of novel regulators of lens formation, such as Arntl2, Dmrta2, Stat5a, Stat5b, and Tulp3. In conclusion, the present RNA-seq data serves as a comprehensive reference resource for deciphering molecular principles of normal mammalian lens differentiation, mapping a full spectrum of signaling pathways and DNA-binding transcription factors operating in both lens compartments, and predicting novel pathways required to establish lens transparency.
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Affiliation(s)
- Yilin Zhao
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Deyou Zheng
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Neurosurgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
| | - Ales Cvekl
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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36
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Sükösd AK, Rapp J, Feller D, Sétáló G, Gáspár B, Pongrácz JE, Ábrahám H, Biró Z. Cell death and survival following manual and femtosecond laser-assisted capsulotomy in age-related cataract. Int J Ophthalmol 2018; 11:1440-1446. [PMID: 30225215 PMCID: PMC6133884 DOI: 10.18240/ijo.2018.09.02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 07/12/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To study molecular and morphological changes in lens epithelial cells following femtosecond laser-assisted and manually performed continuous curvilinear capsulotomy (CCC) in order to get information about these methods regarding their potential role in the induction of development of secondary cataract. METHODS Anterior lens capsules (ALC) were removed from 40 patients with age-related cataract by manual CCC and by femtosecond laser-assisted capsulotomy (FLAC). Samples removed by manual CCC were assorted in group 1, FLAC samples were classified in group 2. Morphology of lens epithelial cells was examined with light and electron microscopes. Following capsulotomy, expressions of p53, Bcl-2 and cyclin D1 genes were analyzed with reverse transcriptase polymerase chain reaction. Immunohistochemistry was used to detect the pro-apoptotic p53 in the epithelial cells. RESULTS Light and electron microscopic examination showed that ALC of group 1 contained more degenerating cells following manual CCC than after FLAC. The expression level of p53 was higher after manual than laser-assisted surgery. Immunocytochemistry indicated significantly higher number of cells containing p53 protein in the manual CCC group than following FLAC. Bcl-2 and cyclin D1 gene expression levels were slightly lower following manual CCC than after FLAC, but the difference was not significant. CONCLUSION Manually removed ALC shows slightly, but not significantly larger damage due to the mechanical stretching and pulling of the capsule than those removed using FLAC.
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Affiliation(s)
- Andrea Krisztina Sükösd
- Department of Ophthalmology, the University of Pécs Medical School and Clinical Centre, Pécs 7623, Hungary
| | - Judit Rapp
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, the University of Pécs, Pécs 7624, Hungary
- János Szentágothai Research Centre of the University of Pécs, Pécs 7624, Hungary
| | - Diána Feller
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, the University of Pécs, Pécs 7624, Hungary
- János Szentágothai Research Centre of the University of Pécs, Pécs 7624, Hungary
| | - György Sétáló
- János Szentágothai Research Centre of the University of Pécs, Pécs 7624, Hungary
- Department of Medical Biology and Central Electron Microscopic Laboratory, the University of Pécs Medical School, Pécs 7624, Hungary
| | | | - Judit E. Pongrácz
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, the University of Pécs, Pécs 7624, Hungary
- János Szentágothai Research Centre of the University of Pécs, Pécs 7624, Hungary
| | - Hajnalka Ábrahám
- Department of Medical Biology and Central Electron Microscopic Laboratory, the University of Pécs Medical School, Pécs 7624, Hungary
| | - Zsolt Biró
- Department of Ophthalmology, the University of Pécs Medical School and Clinical Centre, Pécs 7623, Hungary
- Optimum Laser Centre, Budapest 1124, Hungary
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Matrix-bound AGEs enhance TGFβ2-mediated mesenchymal transition of lens epithelial cells via the noncanonical pathway: implications for secondary cataract formation. Biochem J 2018; 475:1427-1440. [PMID: 29588342 DOI: 10.1042/bcj20170856] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 03/19/2018] [Accepted: 03/27/2018] [Indexed: 12/28/2022]
Abstract
Advanced glycation end products (AGEs) are post-translational modifications formed from the reaction of reactive carbonyl compounds with amino groups in proteins. Our laboratory has previously shown that AGEs in extracellular matrix (ECM) proteins promote TGFβ2 (transforming growth factor-beta 2)-mediated epithelial-to-mesenchymal transition (EMT) of lens epithelial cells (LECs), which could play a role in fibrosis associated with posterior capsule opacification. We have also shown that αB-crystallin plays an important role in TGFβ2-mediated EMT of LECs. Here, we investigated the signaling mechanisms by which ECM-AGEs enhance TGFβ2-mediated EMT in LECs. We found that in LECs cultured on AGE-modified basement protein extract (AGE-BME), TGFβ2 treatment up-regulated the mesenchymal markers α-SMA (α-smooth muscle actin) and αB-crystallin and down-regulated the epithelial marker E-cadherin more than LECs cultured on unmodified BME and treated with TGFβ2. Using a Multiplex Assay, we found that AGE-BME significantly up-regulated the noncanonical pathway by promoting phosphorylation of ERK (extracellular signal-regulated kinases), AKT, and p38 MAPK (mitogen-activated protein kinases) during TGFβ2-mediated EMT. This EMT response was strongly suppressed by inhibition of AKT and p38 MAPK phosphorylation. The AKT inhibitor LY294002 also suppressed TGFβ2-induced up-regulation of nuclear Snail and reduced phosphorylation of GSK3β. Inhibition of Snail expression suppressed TGFβ2-mediated α-SMA expression. αB-Crystallin was up-regulated in an AKT-dependent manner during AGE-BME/TGFβ2-mediated EMT in LECs. The absence of αB-crystallin in LECs suppressed TGFβ2-induced GSK3β phosphorylation, resulting in lower Snail levels. Taken together, these results show that ECM-AGEs enhance the TGFβ2-mediated EMT response through activation of the AKT/Snail pathway, in which αB-crystallin plays an important role as a linker between the TGFβ2 and AGE-mediated signaling pathways.
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Wojciechowski MC, Shu DY, Lovicu FJ. ERK1/2-Dependent Gene Expression Contributing to TGFβ-Induced Lens EMT. Curr Eye Res 2018; 43:986-997. [PMID: 29652528 DOI: 10.1080/02713683.2018.1464193] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE This study aims to highlight some of the genes that are differentially regulated by ERK1/2 signaling in TGFβ-induced EMT in lens, and their potential contribution to this pathological process. MATERIALS AND METHODS Rat lens epithelial explants were cultured with or without TGFβ over a 3-day-culture period to induce EMT, in the presence or absence of UO126 (ERK1/2 signaling inhibitor), both prior to TGFβ-treatment, or 24 or 48 hours after TGFβ treatment. Smad2/3-nuclear immunolabeling was used to indicate active TGFβ signaling, and quantitative RT-PCR was used to analyze changes in the different treatment groups in expression of the following representative genes: TGFβ signaling (Smad7, Smurf1, and Rnf111), epithelial markers (Pax6, Cdh1, Zeb1, and Zeb2), cell survival/death regulators (Bcl2, Bax, and Bad) and lens mesenchymal markers (Mmp9, Fn1, and Col1a1), over the 3 days of culture. RESULTS ERK1/2 was found to regulate the expression of Smurf1, Smad7, Rnf11, Cdh1, Pax6, Zeb1, Bcl2, Bax, and Bad genes in lens cells. TGFβ signaling was evident by nuclear localization of Smad2/3 and this was effectively blocked by pre-treatment with UO126, but not by post-treatment with this ERK1/2 signaling inhibitor. TGFβ induced the expression of its signaling partners (Smad7, Smurf1, and Rnf111), as well as lens mesenchymal genes (Mmp9, Fn1, and Col1a1), consistent with its role in inducing an EMT. These TGFβ-responsive signaling genes, as well as the mesenchymal markers, were all positively regulated by ERK1/2-activity. The expression levels of the lens epithelial genes we examined, and genes that were associated with cell death/survival, were not directly impacted by TGFβ. CONCLUSIONS TGFβ-mediated ERK1/2 signaling positively modulates the expression of mesenchymal genes in lens epithelial explants undergoing EMT, in addition to regulating TGFβ-mediated regulatory genes. Independent of TGFβ, ERK1/2 activity can also regulate the expression of endogenous lens epithelial genes, highlighting its potential key role in regulation of both normal and pathological lens cellular processes.
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Affiliation(s)
| | - Daisy Y Shu
- a Discipline of Anatomy and Histology , Bosch Institute, University of Sydney , Sydney , Australia.,b Save Sight Institute , University of Sydney , Sydney , Australia
| | - Frank J Lovicu
- a Discipline of Anatomy and Histology , Bosch Institute, University of Sydney , Sydney , Australia.,b Save Sight Institute , University of Sydney , Sydney , Australia
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Cvekl A, Zhang X. Signaling and Gene Regulatory Networks in Mammalian Lens Development. Trends Genet 2017; 33:677-702. [PMID: 28867048 DOI: 10.1016/j.tig.2017.08.001] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/27/2017] [Accepted: 08/01/2017] [Indexed: 11/16/2022]
Abstract
Ocular lens development represents an advantageous system in which to study regulatory mechanisms governing cell fate decisions, extracellular signaling, cell and tissue organization, and the underlying gene regulatory networks. Spatiotemporally regulated domains of BMP, FGF, and other signaling molecules in late gastrula-early neurula stage embryos generate the border region between the neural plate and non-neural ectoderm from which multiple cell types, including lens progenitor cells, emerge and undergo initial tissue formation. Extracellular signaling and DNA-binding transcription factors govern lens and optic cup morphogenesis. Pax6, c-Maf, Hsf4, Prox1, Sox1, and a few additional factors regulate the expression of the lens structural proteins, the crystallins. Extensive crosstalk between a diverse array of signaling pathways controls the complexity and order of lens morphogenetic processes and lens transparency.
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Affiliation(s)
- Ales Cvekl
- Departments of Genetics and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Xin Zhang
- Departments of Ophthalmology, Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA.
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