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Ashok A, Chaudhary S, Kritikos AE, Kang MH, McDonald D, Rhee DJ, Singh N. TGFβ2-Hepcidin Feed-Forward Loop in the Trabecular Meshwork Implicates Iron in Glaucomatous Pathology. Invest Ophthalmol Vis Sci 2020; 61:24. [PMID: 32182331 PMCID: PMC7401420 DOI: 10.1167/iovs.61.3.24] [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] [Indexed: 02/07/2023] Open
Abstract
Purpose Elevated levels of transforming-growth-factor (TGF)-β2 in the trabecular meshwork (TM) and aqueous humor are associated with primary open-angle glaucoma (POAG). The underlying mechanism includes alteration of extracellular matrix homeostasis through Smad-dependent and independent signaling. Smad4, an essential co-Smad, upregulates hepcidin, the master regulator of iron homeostasis. Here, we explored whether TGF-β2 upregulates hepcidin, implicating iron in the pathogenesis of POAG. Methods Primary human TM cells and human and bovine ex vivo anterior segment organ cultures were exposed to bioactive TGF-β2, hepcidin, heparin (a hepcidin antagonist), or N-acetyl carnosine (an antioxidant), and the change in the expression of hepcidin, ferroportin, ferritin, and TGF-β2 was evaluated by semiquantitative RT-PCR, Western blotting, and immunohistochemistry. Increase in reactive oxygen species (ROS) was quantified with dihydroethidium, an ROS-sensitive dye. Results Primary human TM cells and bovine TM tissue synthesize hepcidin locally, which is upregulated by bioactive TGF-β2. Hepcidin downregulates ferroportin, its downstream target, increasing ferritin and iron-catalyzed ROS. This causes reciprocal upregulation of TGF-β2 at the transcriptional and translational levels. Heparin downregulates hepcidin, and reduces TGF-β2-mediated increase in ferritin and ROS. Notably, both heparin and N-acetyl carnosine reduce TGF-β2-mediated reciprocal upregulation of TGF-β2. Conclusions The above observations suggest that TGF-β2 and hepcidin form a self-sustained feed-forward loop through iron-catalyzed ROS. This loop is partially disrupted by a hepcidin antagonist and an anti-oxidant, implicating iron and ROS in TGF-β2-mediated POAG. We propose that modification of currently available hepcidin antagonists for ocular use may prove beneficial for the therapeutic management of TGF-β2-associated POAG.
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Roberts AL, Mavlyutov TA, Perlmutter TE, Curry SM, Harris SL, Chauhan AK, McDowell CM. Fibronectin extra domain A (FN-EDA) elevates intraocular pressure through Toll-like receptor 4 signaling. Sci Rep 2020; 10:9815. [PMID: 32555351 PMCID: PMC7299944 DOI: 10.1038/s41598-020-66756-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 05/27/2020] [Indexed: 02/08/2023] Open
Abstract
Elevated intraocular pressure (IOP) is a major risk factor for the development and progression of primary open angle glaucoma and is due to trabecular meshwork (TM) damage, which leads to impaired aqueous humor outflow. Here, we explore a novel molecular mechanism involved in glaucomatous TM damage. We investigated the role of an endogenous Toll-like receptor 4 (TLR4) ligand, fibronectin-EDA (FN-EDA), in TGFβ2-induced ocular hypertension in mice. We utilized transgenic mouse strains that either constitutively express only FN containing the EDA isoform or contain an EDA-null allele and express only FN lacking EDA, with or without a mutation in Tlr4, in our inducible mouse model of ocular hypertension by injection of Ad5.TGFβ2. IOP was measured over time and eyes accessed by immunohistochemistry for total FN and FN-EDA expression. Constitutively active EDA caused elevated IOP starting at 14 weeks of age. Ad5.TGFβ2 induced ocular hypertension in wildtype C57BL/6J mice and further amplified the IOP in constitutively active EDA mice. TLR4 null and EDA null mice blocked Ad5.TGFβ-induced ocular hypertension. Total FN and FN-EDA isoform expression increased in response to Ad5.TGFβ2. These data suggest that both TLR4 and FN-EDA contribute to TGFβ2 induced ocular hypertension.
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Affiliation(s)
- Amanda L Roberts
- North Texas Eye Research Institute, Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Timur A Mavlyutov
- Department of Ophthalmology and Visual Sciences, McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Tanisha E Perlmutter
- Department of Ophthalmology and Visual Sciences, McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Stacy M Curry
- North Texas Eye Research Institute, Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Sherri L Harris
- North Texas Eye Research Institute, Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Anil K Chauhan
- Department of Internal Medicine, University of Iowa, Iowa City, IA, United States
| | - Colleen M McDowell
- Department of Ophthalmology and Visual Sciences, McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States.
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53
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Cai J, Perkumas K, Stamer WD, Liu Y. An In Vitro Bovine Cellular Model for Human Schlemm's Canal Endothelial Cells and Their Response to TGFβ Treatment. Transl Vis Sci Technol 2020; 9:32. [PMID: 32832237 PMCID: PMC7414733 DOI: 10.1167/tvst.9.7.32] [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: 03/23/2020] [Accepted: 05/17/2020] [Indexed: 12/12/2022] Open
Abstract
Purpose Due to the limited availability of primary human Schlemm's canal (SC) endothelial cells, we aimed to develop an in vitro cellular model using the angular aqueous plexus (AAP) cells from bovine eyes. Methods We harvested a mixture of cells from the trabecular meshwork region including AAP loops from multiple donors, followed by puromycin treatment and immunostaining of Von Willebrand factor and vascular endothelial (VE)-cadherin to confirm identity. Previously identified differentially expressed genes in glaucomatous SC cells were examined in non-glaucomatous SC cells (n = 3) under 0% or 15% equibiaxial strain for 24 hours using droplet digital polymerase chain reaction (ddPCR) and analyzed using the Ingenuity Pathway Analysis (IPA) software application to identify upstream regulators. To compare the cellular responses to candidate regulators of these mechanoresponsive genes, AAP and human SC cells (n = 3) were treated with 5 or 10 ng/mL transforming growth factor beta-2 (TGFβ2) for 24 or 48 hours, followed with expression profiling using real-time PCR or ddPCR. Results We found that the isolated AAP cells displayed uniform cobblestone-like morphology and positive expression of two endothelial markers. In stretched SC cells, nine glaucoma-related genes were upregulated, and IPA implicated TGFβ as a potential upstream regulator. The effects of TGFβ2 treatment were similar for both AAP and SC cells in a dose- and time-dependent manner, activating TGFBR1 and SMAD2, inhibiting BMP4, and altering expression of three glaucoma-related genes (DCN,EZR, and CYP1B1). Conclusions Bovine AAP cells may serve as an alternative cellular model of human SC cells. Translational Relevance These AAP cells may be used to study the functional pathways related to the outflow facility.
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Affiliation(s)
- Jingwen Cai
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
| | | | - W. Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, NC, USA
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, USA
- James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, USA
- Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, GA, USA
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54
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Yang Y, Abdulatef ASWA, Zhang L, Jiang H, Zeng Z, Li H, Xia X. Cross-talk between MYOC p. Y437H mutation and TGF-β2 in the pathology of glaucoma. Int J Med Sci 2020; 17:1062-1070. [PMID: 32410836 PMCID: PMC7211149 DOI: 10.7150/ijms.43614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 04/13/2020] [Indexed: 12/13/2022] Open
Abstract
Objective: To identify the interaction between the MYOC Y437H mutation and TGF-β2 in a family with primary open-angle glaucoma (POAG). Methods: The MYOC Y437H mutation was identified in a family with POAG; the family was a fourth-generation family with 27 members, of which 6 members were affected. Analysis focused on the secreted myocilin protein and TGF-β2 found in the aqueous humor. Samples were taken both from normal controls and MYOC mutant carriers and cross-talk between MYOC Y437H and TGF-β2 were evaluated in the trabecular meshwork (TM) cells. Results: Aqueous humor secreted myocilin protein levels were reduced while TGF-β2 levels were increased in patients with the MYOC (c.1309T>C) mutation. This inverse relationship indicated that elevated TGF-β2 may be an important pathogenic mechanism in the progression of myocilin-related POAG. In TM cells expressing the MYOC Y437H mutant, exogenous TGF-β2 also significantly increased myocilin expression as well as the endoplasmic reticulum (ER) stress markers GRP94 and CHOP. This increase in TGF-β2 was also associated with increased cell death in cells carrying the MYOC Y437H mutation. Conclusion: These data collectively suggest that the mutual interaction between glaucomatous MYOC mutation and TGF-β2 contributed to the cell death of TM cells. This relationship also provides a new, therapeutic targets for the treatment of glaucoma.
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Affiliation(s)
- Yang Yang
- Eye center of Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.,Department of Ophthalmology, the First People's Hospital of Yueyang, Yueyang, 414000, Hunan Province, China
| | | | - LuSi Zhang
- The School of Life Sciences, Central South University, Changsha 410078, Hunan Province, China
| | - Haibo Jiang
- Eye center of Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Zhou Zeng
- Eye center of Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
| | - Haibo Li
- Eye center of Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.,Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410008, Hunan Province, China
| | - Xiaobo Xia
- Eye center of Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.,Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410008, Hunan Province, China
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55
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Zhao Z, Lin CY, Cheng K. siRNA- and miRNA-based therapeutics for liver fibrosis. Transl Res 2019; 214:17-29. [PMID: 31476281 PMCID: PMC6848786 DOI: 10.1016/j.trsl.2019.07.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/08/2019] [Accepted: 07/18/2019] [Indexed: 02/07/2023]
Abstract
Liver fibrosis is a wound-healing process induced by chronic liver injuries, such as nonalcoholic steatohepatitis, hepatitis, alcohol abuse, and metal poisoning. The accumulation of excessive extracellular matrix (ECM) in the liver is a key characteristic of liver fibrosis. Activated hepatic stellate cells (HSCs) are the major producers of ECM and therefore play irreplaceably important roles during the progression of liver fibrosis. Liver fibrogenesis is highly correlated with the activation of HSCs, which is regulated by numerous profibrotic cytokines. Using RNA interference to downregulate these cytokines in activated HSCs is a promising strategy to reverse liver fibrosis. Meanwhile, microRNAs (miRNAs) have also been exploited for the treatment of liver fibrosis. This review focuses on the current siRNA- and miRNA-based liver fibrosis treatment strategies by targeting activated HSCs in the liver.
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Affiliation(s)
- Zhen Zhao
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, Missouri
| | - Chien-Yu Lin
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, Missouri
| | - Kun Cheng
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, Missouri.
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56
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Nettesheim A, Shim MS, Hirt J, Liton PB. Transcriptome analysis reveals autophagy as regulator of TGFβ/Smad-induced fibrogenesis in trabecular meshwork cells. Sci Rep 2019; 9:16092. [PMID: 31695131 PMCID: PMC6834604 DOI: 10.1038/s41598-019-52627-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/18/2019] [Indexed: 01/29/2023] Open
Abstract
The trabecular meshwork (TM) is a specialized ocular tissue, which is responsible, together with the Schlemm’s canal (SC), for maintaining appropriate levels of intraocular pressure. Dysfunction of these tissues leads to ocular hypertension and increases the risk for developing glaucoma. Previous work by our laboratory revealed dysregulated autophagy in aging and in glaucomatous TM cells. In order to gain more insight in the role of autophagy in the TM pathophysiology, we have conducted transcriptome and functional network analyses of TM primary cells with silenced expression of the autophagy genes Atg5 and Atg7. Atg5/7-deficient TM cells showed changes in transcript levels of several fibrotic genes, including TGFβ2, BAMBI, and SMA. Furthermore, genetic and pharmacological inhibition of autophagy was associated with a parallel reduction in TGFβ-induced fibrosis, caused by a BAMBI-mediated reduced activation of Smad2/3 signaling in autophagy-deficient cells. At the same time, TGFβ treatment led to Smad2/3-dependent dysregulation of autophagy in TM cells, characterized by increased LC3-II levels and autophagic vacuoles content. Together, our results indicate a cross-talk between autophagy and TGFβ signaling in TM cells.
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Affiliation(s)
| | - Myoung Sup Shim
- Duke University, Department of Ophthalmology, Durham, NC, USA
| | - Josh Hirt
- Duke University, Department of Ophthalmology, Durham, NC, USA
| | - Paloma B Liton
- Duke University, Department of Ophthalmology, Durham, NC, USA.
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57
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Moazzeni H, Mirrahimi M, Moghadam A, Banaei-Esfahani A, Yazdani S, Elahi E. Identification of genes involved in glaucoma pathogenesis using combined network analysis and empirical studies. Hum Mol Genet 2019; 28:3637-3663. [PMID: 31518395 DOI: 10.1093/hmg/ddz222] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/30/2019] [Accepted: 09/04/2019] [Indexed: 12/25/2022] Open
Abstract
Glaucoma is a leading cause of blindness. We aimed in this study to identify genes that may make subtle and cumulative contributions to glaucoma pathogenesis. To this end, we identified molecular interactions and pathways that include transcription factors (TFs) FOXC1, PITX2, PAX6 and NFKB1 and various microRNAs including miR-204 known to have relevance to trabecular meshwork (TM) functions and/or glaucoma. TM tissue is involved in glaucoma pathogenesis. In-house microarray transcriptome results and data sources were used to identify target genes of the regulatory molecules. Bioinformatics analyses were done to filter TM and glaucoma relevant genes. These were submitted to network-creating softwares to define interactions, pathways and a network that would include the genes. The network was stringently scrutinized and minimized, then expanded by addition of microarray data and data on TF and microRNA-binding sites. Selected features of the network were confirmed by empirical studies such as dual luciferase assays, real-time PCR and western blot experiments and apoptosis assays. MYOC, WDR36, LTPBP2, RHOA, CYP1B1, OPA1, SPARC, MEIS2, PLEKHG5, RGS5, BBS5, ALDH1A1, NOMO2, CXCL6, FMNL2, ADAMTS5, CLOCK and DKK1 were among the genes included in the final network. Pathways identified included those that affect ECM properties, IOP, ciliary body functions, retinal ganglion cell viability, apoptosis, focal adhesion and oxidative stress response. The identification of many genes potentially involved in glaucoma pathology is consistent with its being a complex disease. The inclusion of several known glaucoma-related genes validates the approach used.
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Affiliation(s)
- Hamidreza Moazzeni
- School of Biology, College of Science, University of Tehran, Tehran, Iran
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mehraban Mirrahimi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Abolfazl Moghadam
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Amir Banaei-Esfahani
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran
| | - Shahin Yazdani
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
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58
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Shen W, Huang B, He Y, Shi L, Yang J. Long non‐coding RNA RP11‐820 promotes extracellular matrix production via regulating miR‐3178/MYOD1 in human trabecular meshwork cells. FEBS J 2019; 287:978-990. [PMID: 31495061 DOI: 10.1111/febs.15058] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 05/09/2019] [Accepted: 09/03/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Wencui Shen
- Tianjin Eye Hospital & Eye Institute Tianjin Key Lab of Ophthalmology and Visual Science NanKai University Tianjin China
| | - Bingqing Huang
- Department of Pathology Institute of Hematology and Blood Diseases Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Tianjin China
| | - Ye He
- Tianjin Medical University Eye Hospital China
| | - Liukun Shi
- Tianjin Eye Hospital & Eye Institute Tianjin Key Lab of Ophthalmology and Visual Science NanKai University Tianjin China
| | - Jin Yang
- Tianjin Eye Hospital & Eye Institute Tianjin Key Lab of Ophthalmology and Visual Science NanKai University Tianjin China
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59
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Funke S, Beutgen VM, Bechter L, Schmelter C, Zurawski V, Perumal N, Pfeiffer N, Grus FH. An In-Depth View of the Porcine Trabecular Meshwork Proteome. Int J Mol Sci 2019; 20:E2526. [PMID: 31121981 PMCID: PMC6566244 DOI: 10.3390/ijms20102526] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 02/07/2023] Open
Abstract
The house swine (Sus scrofa domestica Linnaeus 1758) is an important model organism regarding the study of neurodegenerative diseases, especially ocular neuropathies such as glaucoma. This is due to the high comparability of the porcine and human eye regarding anatomy and molecular features. In the pathogenesis of glaucoma, the trabecular meshwork (TM) forms a key ocular component in terms of intraocular pressure (IOP) elevation. Thereby, functional TM abnormalities are correlated with distinct proteomic alterations. However, a detailed analysis of the TM proteome has not been realized so far. Since the porcine eye has high potential as a model system to study ocular diseases such as glaucoma, the present study focuses on the in-depth analysis of the porcine TM proteome. By use of a bottom-up (BU) mass spectrometric (MS) platform utilizing electrospray ionization liquid chromatography tandem MS (LC-ESI-MS/MS) considering database-dependent and peptide de novo sequencing, more than 3000 TM proteins were documented with high confidence (FDR < 1%). A distinct number of proteins with neuronal association were revealed. To the best to our knowledge, many of these protein species have not been reported for TM tissue before such as reelin, centlein and high abundant neuroblast differentiation-associated protein AHNAK (AHNAK). Thereby, AHNAK might play a superordinate role in the TM regarding proposed tissue involvement in barrier function. Also, a high number of secretory proteins could be identified. The generated TM proteomic landscape underlines a multifunctional character of the TM beyond representing a simple drainage system. Finally, the protein catalogue of the porcine TM provides an in-depth view of the TM molecular landscape and will serve as an important reference map in terms of glaucoma research utilizing porcine animal models, porcine TM tissues and/or cultured TM cells.
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Affiliation(s)
- Sebastian Funke
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
| | - Vanessa M Beutgen
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
| | - Lea Bechter
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
| | - Carsten Schmelter
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
| | - Vanessa Zurawski
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
| | - Natarajan Perumal
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
| | - Norbert Pfeiffer
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
| | - Franz H Grus
- Experimental and Translational Ophthalmology, Department of Ophthalmology, University Medical Center, 55101 Mainz, Germany.
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60
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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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61
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Belmares R, Raychaudhuri U, Maansson S, Clark AF. Histological investigation of human glaucomatous eyes: Extracellular fibrotic changes and galectin 3 expression in the trabecular meshwork and optic nerve head. Clin Anat 2018; 31:1031-1049. [PMID: 30117188 DOI: 10.1002/ca.23263] [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: 07/03/2018] [Revised: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 11/09/2022]
Abstract
Glaucoma is a leading cause of irreversible vision loss and is associated with fibrotic changes in two ocular tissues-the optic nerve head (ONH) and trabecular meshwork (TM). We investigated the differences in extracellular matrix components (ECM) including collagen, elastin, transforming growth factor beta-2, type-II receptor (TGFβRII) and Galectin3 (Gal3) in the glaucomatous human eyes to quantify fibrotic changes in ONH and TM. Glaucomatous and control human donor eyes were prepared for chemical and immunological staining to quantify ECM protein expression in the TM and ONH. Chemical staining included: Trichrome (collagen), Vernhoeff-Van Giesen (elastin) and Sirius Red (collagen). Immunohistochemistry was used to determine levels of Gal3 and TGFβ2RII. Quantitative analyses were performed using Image J software. Student's t-test was used to compare groups and Pearson's test was used to determine correlations P-values of 0.05 (or less) were considered statistically significant. Deposition of ECM proteins was elevated in glaucomatous tissues. There was increased collagen (P = 0.0469), Gal3 (P < 0.0001) and TGFβ2RII (P = 0.0005) in the TM of glaucomatous eyes. Likewise, collagen (P = 0.0517) and Galectin3 (P = 0.041) were increased in the ONH glaucomatous eyes. There was a correlation of TGFβRII with Gal3 in the TM (P < 0.0001) and optic nerve (P = 0.0003). The TM and ONH of glaucomatous eyes showed increased expression of ECM proteins supporting a fibrotic pathology. Galectin3 and TGFβ-2R II showed a positive correlation in TM and optic nerve supporting co-localization and suggesting their potential role in the glaucoma fibrotic process. Clin. Anat. 31:1031-1049, 2018. © 2018 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.
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Affiliation(s)
- Ricardo Belmares
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas.,Center for Anatomical Sciences, University of North Texas Health Science Center, Fort Worth, Texas
| | - Urmimala Raychaudhuri
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Sandra Maansson
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Abbot F Clark
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas.,Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas
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62
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Suri F, Yazdani S, Elahi E. LTBP2 knockdown and oxidative stress affect glaucoma features including TGFβ pathways, ECM genes expression and apoptosis in trabecular meshwork cells. Gene 2018; 673:70-81. [PMID: 29908281 DOI: 10.1016/j.gene.2018.06.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/09/2018] [Accepted: 06/12/2018] [Indexed: 01/02/2023]
Abstract
Glaucoma is the leading cause of irreversible blindness worldwide. Although the etiology of glaucoma is incompletely understood, it is known that the extracellular matrix (ECM) of the trabecular meshwork, oxidative stress, TGFβ signaling pathways, and apoptosis are important components of glaucoma pathogenesis. These components appear to be interrelated, but knowledge on their interactions remains incomplete. Relevant to this gap in knowledge, LTBP2, glaucoma causing gene, may also be related to the mentioned components of glaucoma pathogenesis because of its putative roles in TGFβ signaling and ECM functions. This background prompted us to further query interactions among some molecules and pathways thought to be important in glaucoma etiology, with emphasis on oxidative stress and LTBP2. To this end, effects of LTBP2 siRNA knockdown, oxidative stress induction, TGFβ2 and gremlin exposures on canonical TGFβ and BMP signaling pathways, expression of ECM related genes, and apoptosis were assayed in primary human trabecular meshwork cell cultures. We found that oxidative stress induction and LTBP2 knockdown both affected all the processes queried, and that their affects paralleled one another. We suggest that effects of both oxidative stress and LTBP2 knockdown on the ECM and apoptosis may be mediated by TGFβ and BMP signaling pathway activation.
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Affiliation(s)
- Fatemeh Suri
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; School of Biology, University College of Science, University of Tehran, Tehran, Iran
| | - Shahin Yazdani
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elahe Elahi
- School of Biology, University College of Science, University of Tehran, Tehran, Iran; Department of Biotechnology, University College of Science, University of Tehran, Tehran, Iran.
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Hernandez H, Millar JC, Curry SM, Clark AF, McDowell CM. BMP and Activin Membrane Bound Inhibitor Regulates the Extracellular Matrix in the Trabecular Meshwork. Invest Ophthalmol Vis Sci 2018; 59:2154-2166. [PMID: 29801150 PMCID: PMC5915111 DOI: 10.1167/iovs.17-23282] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 03/22/2018] [Indexed: 01/18/2023] Open
Abstract
Purpose The trabecular meshwork (TM) has an important role in the regulation of aqueous humor outflow and IOP. Regulation of the extracellular matrix (ECM) by TGFβ2 has been studied extensively. Bone morphogenetic protein (BMP) and activin membrane-bound inhibitor (BAMBI) has been shown to inhibit or modulate TGFβ2 signaling. We investigate the role of TGFβ2 and BAMBI in the regulation of TM ECM and ocular hypertension. Methods Mouse TM (MTM) cells were isolated from B6;129S1-Bambitm1Jian/J flox mice, characterized for TGFβ2 and dexamethasone (DEX)-induced expression of fibronectin, collagen-1, collagen-4, laminin, α-smooth muscle actin, cross-linked actin networks (CLANs) formation, and DEX-induced myocilin (MYOC) expression. MTM cells were transduced with Ad5.GFP to identify transduction efficiency. MTM cells and mouse eyes were transduced with Ad5.Null, Ad5.Cre, Ad5.TGFβ2, or Ad5.TGFβ2 + Ad5.Cre to evaluate the effect on ECM production, IOP, and outflow facility. Results MTM cells express TM markers and respond to DEX and TGFβ2. Ad5.GFP at 100 MOI had the highest transduction efficiency. Bambi knockdown by Ad5.Cre and Ad5.TGFβ2 increased fibronectin, collagen-1, and collagen-4 in TM cells in culture and tissue. Ad5.Cre, Ad5.TGFβ2, and Ad5.TGFβ2 + Ad5.Cre each significantly induced ocular hypertension and lowered aqueous humor outflow facility in transduced eyes. Conclusions We show for the first time to our knowledge that knockdown of Bambi alters ECM expression in cultured cells and mouse TM, reduces outflow facility, and causes ocular hypertension. These data provide a novel insight into the development of glaucomatous TM damage and identify BAMBI as an important regulator of TM ECM and ocular hypertension.
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Affiliation(s)
- Humberto Hernandez
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - J. Cameron Millar
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Stacy M. Curry
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Abbot F. Clark
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Colleen M. McDowell
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
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Tapella L, Cerruti M, Biocotino I, Stevano A, Rocchio F, Canonico PL, Grilli M, Genazzani AA, Lim D. TGF-β2 and TGF-β3 from cultured β-amyloid-treated or 3xTg-AD-derived astrocytes may mediate astrocyte-neuron communication. Eur J Neurosci 2018; 47:211-221. [DOI: 10.1111/ejn.13819] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 12/16/2017] [Accepted: 12/18/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Laura Tapella
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Matteo Cerruti
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Isabella Biocotino
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Alessio Stevano
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Francesca Rocchio
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Pier Luigi Canonico
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Mariagrazia Grilli
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Armando A. Genazzani
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
| | - Dmitry Lim
- Department of Pharmaceutical Sciences; Università degli Studi del Piemonte Orientale “Amedeo Avogadro”; 28100 Novara Italy
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Sasaki R, Devhare P, Ray RB, Ray R. Hepatitis C virus-induced tumor-initiating cancer stem-like cells activate stromal fibroblasts in a xenograft tumor model. Hepatology 2017; 66:1766-1778. [PMID: 28664988 PMCID: PMC5696059 DOI: 10.1002/hep.29346] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 06/02/2017] [Accepted: 06/26/2017] [Indexed: 12/20/2022]
Abstract
UNLABELLED Hepatitis C virus (HCV) often causes persistent infection and is an increasingly important factor in the etiology of fibrosis/cirrhosis and hepatocellular carcinoma, although the mechanisms for the disease processes remain unclear. We have shown previously that HCV infection generates an epithelial-mesenchymal transition state and tumor-initiating cancer stem-like cells in human hepatocytes. In this study, we investigated whether HCV-induced tumor-initiating cancer stem-like cells when implanted into mice activate stromal fibroblasts. A number of fibroblast activation markers, including matrix metalloproteinase 2, were significantly increased at the mRNA or protein level in the xenograft tumors, suggesting the presence of tumor-associated fibroblasts. Fibroblast activation markers of murine origin were specifically increased in tumor, suggesting that fibroblasts migrate to form stroma. Next, we demonstrated that conditioned medium from HCV-infected human hepatocytes activates fibrosis-related markers in hepatic stellate cells. We further observed that these HCV-infected hepatocytes express transforming growth factor beta, which activates stromal fibroblast markers. Subsequent analysis suggested that anti-transforming growth factor beta neutralizing antibody, when incubated with conditioned medium from HCV-infected hepatocytes, inhibits fibrosis marker activation in primary human hepatic stellate cells. CONCLUSION HCV-infected hepatocytes induce local fibroblast activation by secretion of transforming growth factor beta, and a preneoplastic or tumor state of the hepatocytes influences the network for the tumor-associated fibroblast environment. (Hepatology 2017;66:1766-1778).
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Affiliation(s)
- Reina Sasaki
- Department of Pathology, Saint Louis University, Missouri, USA,Department of Internal Medicine, Saint Louis University, Missouri, USA
| | - Pradip Devhare
- Department of Pathology, Saint Louis University, Missouri, USA
| | - Ratna B. Ray
- Department of Pathology, Saint Louis University, Missouri, USA
| | - Ranjit Ray
- Department of Internal Medicine, Saint Louis University, Missouri, USA,Department of Molecular Microbiology & Immunology, Saint Louis University, Missouri, USA
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66
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Pfeiffer N, Voykov B, Renieri G, Bell K, Richter P, Weigel M, Thieme H, Wilhelm B, Lorenz K, Feindor M, Wosikowski K, Janicot M, Päckert D, Römmich R, Mala C, Fettes P, Leo E. First-in-human phase I study of ISTH0036, an antisense oligonucleotide selectively targeting transforming growth factor beta 2 (TGF-β2), in subjects with open-angle glaucoma undergoing glaucoma filtration surgery. PLoS One 2017; 12:e0188899. [PMID: 29190672 PMCID: PMC5708654 DOI: 10.1371/journal.pone.0188899] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 11/10/2017] [Indexed: 12/12/2022] Open
Abstract
Purpose To evaluate the safety and tolerability of intravitreal ISTH0036, an antisense oligonucleotide selectively targeting transforming growth factor beta 2 (TGF-β2), in patients with primary open angle glaucoma (POAG) undergoing trabeculectomy (TE; glaucoma filtration surgery). Methods In this prospective phase I trial glaucoma patients scheduled for TE with mitomycin C (MMC) received a single intravitreal injection of ISTH0036 at the end of surgery in escalating total doses of 6.75 μg, 22.5 μg, 67.5 μg or 225 μg, resulting in calculated intraocular ISTH0036 concentrations in the vitreous humor of approximately 0.3 μM, 1 μM, 3 μM or 10 μM after injection, respectively. Outcomes assessed included: type and frequency of adverse events (AEs), intraocular pressure (IOP), numbers of interventions post trabeculectomy, bleb survival, visual acuity, visual field, electroretinogram (ERG), slit lamp biomicroscopy and optic disc assessment. Results In total, 12 patients were treated in the 4 dose groups. Main ocular AEs observed were corneal erosion, corneal epithelium defect, or too high or too low IOP, among others. No AE was reported to be related to ISTH0036. All other safety-related analyses did not reveal any toxicities of concern, either. The mean medicated preoperative IOP at decision time-point for surgery was 27.3 mmHg +/- 12.6 mmHg (SD). Mean IOP (±SD) for dose levels 1, 2, 3, and 4 were at Day 43 9.8 mmHg ± 1.0 mmHg, 11.3 mmHg ± 6.7 mmHg, 5.5 mmHg ± 3.0 mmHg and 7.5 mmHg ± 2.3 mmHg SD; and at Day 85 9.7 mmHg ± 3.3 mmHg, 14.2 mmHg ± 6.5 mmHg, 5.8 mmHg ± 1.8 mmHg and 7.8 mmHg ± 0.6 mmHg, respectively. In contrast to IOP values for dose levels 1 and 2, IOP values for dose levels 3 and 4 persistently remained below 10 mmHg throughout the observation period. Conclusion This first-in-human trial demonstrates that intravitreal injection of ISTH0036 at the end of TE is safe. Regarding IOP control, single-dose ISTH0036 administration of 67.5 μg or 225 μg at the time of TE resulted in IOP values persistently < 10 mmHg over the three month postoperative observation period.
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Affiliation(s)
- Norbert Pfeiffer
- Dpt. of Ophthalmology, University Medical Center Mainz, Mainz, Germany
- * E-mail:
| | - Bogomil Voykov
- Dpt. of Ophthalmology, University Hospital Tuebingen, Tuebingen, Germany
| | - Giulia Renieri
- Dpt. of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Katharina Bell
- Dpt. of Ophthalmology, University Medical Center Mainz, Mainz, Germany
| | - Paul Richter
- Dpt. of Ophthalmology, University Hospital Tuebingen, Tuebingen, Germany
| | - Melanie Weigel
- Dpt. of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Hagen Thieme
- Dpt. of Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Barbara Wilhelm
- STZ Eyetrial, University Hospital Tuebingen, Tuebingen, Germany
| | - Katrin Lorenz
- Dpt. of Ophthalmology, University Medical Center Mainz, Mainz, Germany
- SynteractHCR Deutschland GmbH, Munich, Germany
| | | | | | | | | | | | | | | | - Eugen Leo
- Isarna Therapeutics GmbH, Munich, Germany
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Keller KE, Bradley JM, Sun YY, Yang YF, Acott TS. Tunneling Nanotubes are Novel Cellular Structures That Communicate Signals Between Trabecular Meshwork Cells. Invest Ophthalmol Vis Sci 2017; 58:5298-5307. [PMID: 29049733 PMCID: PMC5656416 DOI: 10.1167/iovs.17-22732] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Purpose The actin cytoskeleton of trabecular meshwork (TM) cells plays a role in regulating aqueous humor outflow. Many studies have investigated stress fibers, but F-actin also assembles into other supramolecular structures including filopodia. Recently, specialized filopodia called tunneling nanotubes (TNTs) have been described, which communicate molecular signals and organelles directly between cells. Here, we investigate TNT formation by TM cells. Methods Human TM cells were labeled separately with the fluorescent dyes, DiO and DiD, or with mitochondrial dye. Fixed or live TM cells were imaged using confocal microscopy. Image analysis software was used to track fluorescent vesicles and count the number and length of filopodia. The number of fluorescently labeled vesicles transferred between cells was counted in response to specific inhibitors of the actin cytoskeleton. Human TM tissue was stained with phalloidin. Results Live-cell confocal imaging of cultured TM cells showed transfer of fluorescently labeled vesicles and mitochondria via TNTs. In TM tissue, a long (160 μm) actin-rich cell process bridged an intertrabecular space and did not adhere to the substratum. Treatment of TM cells with CK-666, an Arp2/3 inhibitor, significantly decreased the number and length of filopodia, decreased transfer of fluorescently labeled vesicles and induced thick stress fibers compared to vehicle control. Conversely, inhibiting stress fibers using Y27632 increased transfer of vesicles and induced long cell processes. Conclusions Identification of TNTs provides a means by which TM cells can directly communicate with each other over long distances. This may be particularly important to overcome limitations of diffusion-based signaling in the aqueous humor fluid environment.
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Affiliation(s)
- Kate E Keller
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - John M Bradley
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Ying Ying Sun
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Yong-Feng Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Ted S Acott
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
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Walton KL, Johnson KE, Harrison CA. Targeting TGF-β Mediated SMAD Signaling for the Prevention of Fibrosis. Front Pharmacol 2017; 8:461. [PMID: 28769795 PMCID: PMC5509761 DOI: 10.3389/fphar.2017.00461] [Citation(s) in RCA: 384] [Impact Index Per Article: 54.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/27/2017] [Indexed: 01/18/2023] Open
Abstract
Fibrosis occurs when there is an imbalance in extracellular matrix (ECM) deposition and degradation. Excessive ECM deposition results in scarring and thickening of the affected tissue, and interferes with tissue and organ homeostasis – mimicking an exaggerated “wound healing” response. Many transforming growth factor-β (TGF-β) ligands are potent drivers of ECM deposition, and additionally, have a natural affinity for the ECM, creating a concentrated pool of pro-fibrotic factors at the site of injury. Consequently, TGF-β ligands are upregulated in many human fibrotic conditions and, as such, are attractive targets for fibrosis therapy. Here, we will discuss the contribution of TGF-β proteins in the pathogenesis of fibrosis, and promising anti-fibrotic approaches that target TGF-β ligands.
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Affiliation(s)
- Kelly L Walton
- Growth Factor Therapeutics Laboratory, Department of Physiology, Monash University, ClaytonVIC, Australia
| | - Katharine E Johnson
- Growth Factor Therapeutics Laboratory, Department of Physiology, Monash University, ClaytonVIC, Australia
| | - Craig A Harrison
- Growth Factor Therapeutics Laboratory, Department of Physiology, Monash University, ClaytonVIC, Australia
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Mody AA, Wordinger RJ, Clark AF. Role of ID Proteins in BMP4 Inhibition of Profibrotic Effects of TGF-β2 in Human TM Cells. Invest Ophthalmol Vis Sci 2017; 58:849-859. [PMID: 28159972 PMCID: PMC5295782 DOI: 10.1167/iovs.16-20472] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose Increased expression of TGF-β2 in primary open-angle glaucoma (POAG) aqueous humor (AH) and trabecular meshwork (TM) causes deposition of extracellular matrix (ECM) in the TM and elevated IOP. Bone morphogenetic proteins (BMPs) regulate TGF-β2–induced ECM production. The underlying mechanism for BMP4 inhibition of TGF-β2–induced fibrosis remains undetermined. Bone morphogenic protein 4 induces inhibitor of DNA binding proteins (ID1, ID3), which suppress transcription factor activities to regulate gene expression. Our study will determine whether ID1and ID3 proteins are downstream targets of BMP4, which attenuates TGF-β2 induction of ECM proteins in TM cells. Methods Primary human TM cells were treated with BMP4, and ID1 and ID3 mRNA, and protein expression was determined by quantitative PCR (Q-PCR) and Western immunoblotting. Intracellular ID1 and ID3 protein localization was studied by immunocytochemistry. Transformed human TM cells (GTM3 cells) were transfected with ID1 or ID3 expression vectors to determine their potential inhibitory effects on TGF-β2–induced fibronectin and plasminogen activator inhibitor-I (PAI-1) protein expression. Results Basal expression of ID1-3 was detected in primary human TM cells. Bone morphogenic protein 4 significantly induced early expression of ID1 and ID3 mRNA (P < 0.05) and protein in primary TM cells, and a BMP receptor inhibitor blocked this induction. Overexpression of ID1 and ID3 significantly inhibited TGF-β2–induced expression of fibronectin and PAI-1 in TM cells (P < 0.01). Conclusions Bone morphogenic protein 4 induced ID1 and ID3 expression suppresses TGF-β2 profibrotic activity in human TM cells. In the future, targeting specific regulators may control the TGF-β2 profibrotic effects on the TM, leading to disease modifying IOP lowering therapies.
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Affiliation(s)
- Avani A Mody
- North Texas Eye Research Institute, University North Texas Health Science Center, Fort Worth, Texas, United States
| | - Robert J Wordinger
- North Texas Eye Research Institute, University North Texas Health Science Center, Fort Worth, Texas, United States
| | - Abbot F Clark
- North Texas Eye Research Institute, University North Texas Health Science Center, Fort Worth, Texas, United States
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70
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Muralidharan AR, Maddala R, Skiba NP, Rao PV. Growth Differentiation Factor-15-Induced Contractile Activity and Extracellular Matrix Production in Human Trabecular Meshwork Cells. Invest Ophthalmol Vis Sci 2017; 57:6482-6495. [PMID: 27918822 PMCID: PMC5152563 DOI: 10.1167/iovs.16-20671] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose To determine the role and regulation of growth differentiation factor-15 (GDF-15), a TGF-β-related cytokine in human trabecular meshwork (TM) cells in the context of aqueous humor (AH) outflow and IOP. Methods Regulation of expression by external cues, and the distribution and secretion of GDF-15 by human TM primary cell cultures, and the effects of recombinant (r) GDF-15 on TM cell contractile characteristics, actin cytoskeleton, cell adhesion, extracellular matrix (ECM), α-smooth muscle actin (αSMA), SMAD signaling, and gene expression were determined by immunoblot, immunofluorescence, mass spectrometry, cDNA microarray, and real-time quantitative PCR (RT-qPCR) analyses. Results Growth differentiation factor-15, a common constituent of ECM derived from the human TM cells, was confirmed to be distributed throughout the conventional aqueous humor outflow pathway of the human eye. Growth differentiation factor-15 protein levels were significantly increased in human TM cells in response to TGF-β2, dexamethasone, endothelin-1, lysophosphatidic acid, TNF-α, IL-1β treatment, and by cyclic mechanical stretch. Stimulation of human TM cells with rGDF-15 caused a significant increase in the formation of actin stress fibers and focal adhesions, myosin light chain phosphorylation, SMAD signaling, gene expression, and the levels of αSMA and ECM proteins. Conclusions The results of this study, including a robust induction of GDF-15 expression by several external factors known to elevate IOP, and rGDF-15-induced increase in contractility, cell adhesion, and the levels of ECM proteins and αSMA in TM cells, collectively suggest a potential role for GDF-15 in homeostasis and dysregulation of AH outflow and IOP in normal and glaucomatous eyes, respectively.
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Affiliation(s)
| | - Rupalatha Maddala
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, United States
| | - Nikolai P Skiba
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, United States
| | - Ponugoti Vasantha Rao
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina, United States 2Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, United States
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Bermudez JY, Webber HC, Patel GC, Liu X, Cheng YQ, Clark AF, Mao W. HDAC Inhibitor-Mediated Epigenetic Regulation of Glaucoma-Associated TGFβ2 in the Trabecular Meshwork. Invest Ophthalmol Vis Sci 2017; 57:3698-707. [PMID: 27403998 PMCID: PMC4973502 DOI: 10.1167/iovs16-19446] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Purpose Elevated intraocular pressure (IOP) in primary open-angle glaucoma (POAG) results from glaucomatous damage to the trabecular meshwork (TM). The glaucoma-associated factor TGFβ2 is increased in aqueous humor and TM of POAG patients. We hypothesize that histone acetylation has a role in dysregulated TGFβ2 expression. Methods Protein acetylation was compared between nonglaucomatous TM (NTM) and glaucomatous TM (GTM) cells using Western immunoblotting (WB). Nonglaucomatous TM cells were treated with 10 nM thailandepsin-A (TDP-A), a potent histone deacetylase inhibitor for 4 days. Total and nuclear proteins, RNA, and nuclear protein-DNA complexes were harvested for WB, quantitative PCR (qPCR), and chromatin immunoprecipitation (ChIP) assays, respectively. Paired bovine eyes were perfused with TDP-A versus DMSO, or TDP-A versus TDP-A plus the TGFβ pathway inhibitor LY364947 for 5 to 9 days. Intraocular pressure, TM, and perfusate proteins were compared. Results We found increased acetylated histone 3 and total protein acetylation in the GTM cells and TDP-A treated NTM cells. Chromatin immunoprecipitation assays showed that TDP-A induced histone hyperacetylation associated with the TGFβ2 promoter. This change of acetylation significantly increased TGFβ2 mRNA and protein expression in NTM cells. In perfusion-cultured bovine eyes, TDP-A increased TGFβ2 in the perfusate as well as elevated IOP. Histologic and immunofluorescent analyses showed increased extracellular matrix and cytoskeletal proteins in the TM of TDP-A treated bovine eyes. Cotreatment with the TGFβ pathway inhibitor LY364947 blocked TDP-A–induced ocular hypertension. Conclusions Our results suggest that histone acetylation has an important role in increased expression of the glaucoma-associated factor TGFβ2. Histone hyperacetylation may be the initiator of glaucomatous damage to the TM.
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Affiliation(s)
- Jaclyn Y Bermudez
- North Texas Eye Research Institute University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Hannah C Webber
- North Texas Eye Research Institute University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Gaurang C Patel
- North Texas Eye Research Institute University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Xiangyang Liu
- UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Yi-Qiang Cheng
- UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Abbot F Clark
- North Texas Eye Research Institute University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Weiming Mao
- North Texas Eye Research Institute University of North Texas Health Science Center, Fort Worth, Texas, United States
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Cheng J, Liang J, Qi J. Role of nuclear factor (erythroid-derived 2)-like 2 in the age-resistant properties of the glaucoma trabecular meshwork. Exp Ther Med 2017; 14:791-796. [PMID: 28673001 DOI: 10.3892/etm.2017.4543] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/26/2017] [Indexed: 12/21/2022] Open
Abstract
Glaucoma is a major cause of irreversible blindness. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) regulates the expression of numerous antioxidants within cells and is therefore a focus of current ophthalmic research. To determine the roles of Nrf2 in mediating the glaucoma trabecular meshwork (GTM), the present study evaluated the levels of Nrf2 expression in GTM and human trabecular meshwork (HTM) cells by reverse-transcription-quantitative polymerase chain reaction and western blot analysis. It was principally observed that Nrf2 expression was downregulated in GTM cells. In addition, to determine the influence of Nrf2 on the apoptosis and proliferation of GTM and HTM cells, transfection assays and western blotting were performed to evaluate the expression of apoptosis-related proteins. The results of the current study indicated that Nrf2 may promote viability and reduce apoptosis in GTM and HTM cells. Collectively, these data suggest that Nrf2 may be a novel therapeutic target to treat glaucoma.
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Affiliation(s)
- Jintao Cheng
- Department of Ophthalmology, Yishui Central Hospital, Linyi, Shandong 276400, P.R. China
| | - Jiamei Liang
- Department of Ophthalmology, Yishui Central Hospital, Linyi, Shandong 276400, P.R. China
| | - Jinze Qi
- Department of Ophthalmology, Yishui Central Hospital, Linyi, Shandong 276400, P.R. China
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Zhavoronkov A, Izumchenko E, Kanherkar RR, Teka M, Cantor C, Manaye K, Sidransky D, West MD, Makarev E, Csoka AB. Pro-fibrotic pathway activation in trabecular meshwork and lamina cribrosa is the main driving force of glaucoma. Cell Cycle 2017; 15:1643-52. [PMID: 27229292 PMCID: PMC4934076 DOI: 10.1080/15384101.2016.1170261] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
While primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide, it still does not have a clear mechanism that can explain all clinical cases of the disease. Elevated IOP is associated with increased accumulation of extracellular matrix (ECM) proteins in the trabecular meshwork (TM) that prevents normal outflow of aqueous humor (AH) and has damaging effects on the fine mesh-like lamina cribrosa (LC) through which the optic nerve fibers pass. Applying a pathway analysis algorithm, we discovered that an elevated level of TGFβ observed in glaucoma-affected tissues could lead to pro-fibrotic pathway activation in TM and in LC. In turn, activated pro-fibrotic pathways lead to ECM remodeling in TM and LC, making TM less efficient in AH drainage and making LC more susceptible to damage from elevated IOP via ECM transformation in LC. We propose pathway targets for potential therapeutic interventions to delay or avoid fibrosis initiation in TM and LC tissues.
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Affiliation(s)
- Alex Zhavoronkov
- a Insilico Medicine, Inc., ETC, Johns Hopkins University , Baltimore , MD , USA.,b The Biogerontology Research Foundation , London , UK
| | - Evgeny Izumchenko
- e Johns Hopkins University , Department of Otolaryngology-Head and Neck Surgery
| | - Riya R Kanherkar
- c Vision Genomics, LLC , Washington, DC , USA.,d Epigenetics Laboratory, Howard University , Washington, DC , USA
| | - Mahder Teka
- c Vision Genomics, LLC , Washington, DC , USA
| | - Charles Cantor
- f Boston University , Boston , MA , USA.,g Retrotope, Inc ; Los Altos Hills , CA , USA
| | - Kebreten Manaye
- d Epigenetics Laboratory, Howard University , Washington, DC , USA
| | | | | | - Eugene Makarev
- a Insilico Medicine, Inc., ETC, Johns Hopkins University , Baltimore , MD , USA
| | - Antonei Benjamin Csoka
- c Vision Genomics, LLC , Washington, DC , USA.,d Epigenetics Laboratory, Howard University , Washington, DC , USA
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Ban N, Siegfried CJ, Lin JB, Shui YB, Sein J, Pita-Thomas W, Sene A, Santeford A, Gordon M, Lamb R, Dong Z, Kelly SC, Cavalli V, Yoshino J, Apte RS. GDF15 is elevated in mice following retinal ganglion cell death and in glaucoma patients. JCI Insight 2017; 2:91455. [PMID: 28469085 DOI: 10.1172/jci.insight.91455] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 04/04/2017] [Indexed: 10/19/2022] Open
Abstract
Glaucoma is the second leading cause of blindness worldwide. Physicians often use surrogate endpoints to monitor the progression of glaucomatous neurodegeneration. These approaches are limited in their ability to quantify disease severity and progression due to inherent subjectivity, unreliability, and limitations of normative databases. Therefore, there is a critical need to identify specific molecular markers that predict or measure glaucomatous neurodegeneration. Here, we demonstrate that growth differentiation factor 15 (GDF15) is associated with retinal ganglion cell death. Gdf15 expression in the retina is specifically increased after acute injury to retinal ganglion cell axons and in a murine chronic glaucoma model. We also demonstrate that the ganglion cell layer may be one of the sources of secreted GDF15 and that GDF15 diffuses to and can be detected in aqueous humor (AH). In validating these findings in human patients with glaucoma, we find not only that GDF15 is increased in AH of patients with primary open angle glaucoma (POAG), but also that elevated GDF15 levels are significantly associated with worse functional outcomes in glaucoma patients, as measured by visual field testing. Thus, GDF15 maybe a reliable metric of glaucomatous neurodegeneration, although further prospective validation studies will be necessary to determine if GDF15 can be used in clinical practice.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Rajendra S Apte
- Departments of Ophthalmology.,Medicine, and.,Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, USA
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Abstract
The immune system plays important role in protecting the organism by recognizing non-self molecules from pathogen such as bacteria, parasitic worms, and viruses. When the balance of the host defense system is disturbed, immunodeficiency, autoimmunity, and inflammation occur. Nucleic acid aptamers are short single-stranded DNA (ssDNA) or RNA ligands that interact with complementary molecules with high specificity and affinity. Aptamers that target the molecules involved in immune system to modulate their function have great potential to be explored as new diagnostic and therapeutic agents for immune disorders. This review summarizes recent advances in the development of aptamers targeting immune system. The selection of aptamers with superior chemical and biological characteristics will facilitate their application in the diagnosis and treatment of immune disorders.
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76
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Karaśkiewicz J, Penkala K, Mularczyk M, Lubiński W. Evaluation of retinal ganglion cell function after intraocular pressure reduction measured by pattern electroretinogram in patients with primary open-angle glaucoma. Doc Ophthalmol 2017; 134:89-97. [PMID: 28176172 PMCID: PMC5364261 DOI: 10.1007/s10633-017-9575-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 01/23/2017] [Indexed: 11/26/2022]
Abstract
BACKGROUND To evaluate retinal ganglion cell (RGC) function after intraocular pressure (IOP) reduction measured by pattern electroretinogram (PERG) in patients with newly diagnosed, non-treated preperimetric and early stages of primary open-angle glaucoma (POAG). METHODS Twenty-four eyes from 24 patients with POAG: 11 eyes with preperimetric glaucoma and 13 eyes with early glaucoma received Ganfort ® (bimatoprost + timolol) once a day for a period of 1 month. Before and after the treatment, following measurements were analyzed: IOP, mean ocular perfusion pressure (MOPP), peak time of P50 and amplitude of P50 and N95 waves in PERG (ISCEV standard 2012). Correlations between PERG P50 and N95 waves, IOP and MOPP were calculated. RESULTS After therapy, IOP significantly decreased in all eyes, on average 31%. Significant increase in MOPP in all eyes on average 14% was detected. PERG amplitude of P50 and N95 waves increased in 75 and 79% eyes, respectively, on average P50 by 28% and N95 by 38%. There were no significant interactions between the change of PERG parameters in time and stage of glaucoma. CONCLUSIONS Significant IOP-lowering therapy can improve RGC function measured by PERG, in patients with preperimetric and early stages of POAG.
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Affiliation(s)
- Joanna Karaśkiewicz
- Department of Ophthalmology, Pomeranian Medical University, Powstańców Wielkopolskich 72 Str., Szczecin, Poland
| | - Krzysztof Penkala
- Department of Systems, Signals and Electronics Engineering, Faculty of Electrical Engineering, West Pomeranian University of Technology, Szczecin, Poland
| | - Maciej Mularczyk
- Department of General and Clinical Anatomy, Pomeranian Medical University, Szczecin, Poland
| | - Wojciech Lubiński
- Department of Ophthalmology, Pomeranian Medical University, Powstańców Wielkopolskich 72 Str., Szczecin, Poland.
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77
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Fini ME, Schwartz SG, Gao X, Jeong S, Patel N, Itakura T, Price MO, Price FW, Varma R, Stamer WD. Steroid-induced ocular hypertension/glaucoma: Focus on pharmacogenomics and implications for precision medicine. Prog Retin Eye Res 2017; 56:58-83. [PMID: 27666015 PMCID: PMC5237612 DOI: 10.1016/j.preteyeres.2016.09.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 09/17/2016] [Accepted: 09/19/2016] [Indexed: 02/06/2023]
Abstract
Elevation of intraocular pressure (IOP) due to therapeutic use of glucocorticoids is called steroid-induced ocular hypertension (SIOH); this can lead to steroid-induced glaucoma (SIG). Glucocorticoids initiate signaling cascades ultimately affecting expression of hundreds of genes; this provides the potential for a highly personalized pharmacological response. Studies attempting to define genetic risk factors were undertaken early in the history of glucocorticoid use, however scientific tools available at that time were limited and progress stalled. In contrast, significant advances were made over the ensuing years in defining disease pathophysiology. As the genomics age emerged, it appeared the time was right to renew investigation into genetics. Pharmacogenomics is an unbiased discovery approach, not requiring an underlying hypothesis, and provides a way to pinpoint clinically significant genes and pathways that could not have been discovered any other way. Results of the first genome-wide association study to identify polymorphisms associated with SIOH, and follow-up on two novel genes linked to the disorder, GPR158 and HCG22, is discussed in the second half of the article. However, knowledge of genetic variants determining response to steroids in the eye also has value in its own right as a predictive and diagnostic tool. This article concludes with a discussion of how the Precision Medicine Initiative®, announced by U.S. President Obama in his 2015 State of the Union address, is beginning to touch the practice of ophthalmology. It is argued that SIOH/SIG may provide one of the next opportunities for effective application of precision medicine.
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Affiliation(s)
- M Elizabeth Fini
- USC Institute for Genetic Medicine and Department of Cell & Neurobiology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Stephen G Schwartz
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 3880 Tamiami Trail North, Naples, FL, 34103, USA.
| | - Xiaoyi Gao
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1905 W Taylor St., Suite 235, Chicago, IL, 60612, USA.
| | - Shinwu Jeong
- USC Institute for Genetic Medicine, USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Nitin Patel
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA, 90089, USA.
| | - Marianne O Price
- Cornea Research Foundation of America, 9002 North Meridian Street, Indianapolis, IN, 46260, USA.
| | - Francis W Price
- Price Vision Group, 9002 North Meridian Street, Indianapolis, IN, 46260, USA.
| | - Rohit Varma
- Office of the Dean, USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 1975 Zonal Ave., KAM 500, Los Angeles, CA, 90089, USA.
| | - W Daniel Stamer
- Department of Ophthalmology and Department of Biomedical Engineering, Duke University, AERI Room 4008, 2351 Erwin Rd, Durham, NC, 27705, USA.
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78
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Application of multiplex immunoassay technology to investigations of ocular disease. Expert Rev Mol Med 2016; 18:e15. [PMID: 27577534 DOI: 10.1017/erm.2016.15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Eye-derived fluids, including tears, aqueous humour and vitreous humour often contain molecular signatures of ocular disease states. These signatures can be composed of cytokines, chemokines, growth factors, proteases and soluble receptors. However, the small quantities (<10 µl) of these fluids severely limit the detection of these proteins by traditional enzyme-linked immunosorbent assay or Western blot. To maximise the amount of information generated from the analysis of these specimens, many researchers have employed multiplex immunoassay technologies for profiling the expression or modification of multiple proteins from minute sample volumes.
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Paula JS, O'Brien C, Stamer WD. Life under pressure: The role of ocular cribriform cells in preventing glaucoma. Exp Eye Res 2016; 151:150-9. [PMID: 27567558 DOI: 10.1016/j.exer.2016.08.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 08/22/2016] [Accepted: 08/23/2016] [Indexed: 02/08/2023]
Abstract
Primary open-angle glaucoma is a multifactorial blinding disease often impacting the two pressure-sensitive regions of the eye: the conventional outflow pathway and the optic nerve head (ONH). The connective tissues that span these two openings in the globe are the trabecular meshwork of the conventional outflow pathway and the lamina cribrosa of the ONH. Resident cribiform cells of these two regions are responsible for actively remodeling and maintaining their connective tissues. In glaucoma, aberrant maintenance of the juxtacanalicular tissues (JCT) of the conventional outflow pathway results in ocular hypertension and pathological remodeling of the lamina cribrosa results in ONH cupping, damaging retinal ganglion cell axons. Interestingly, cells cultured from the lamina cribrosa and the JCT of the trabecular meshwork have similarities regarding gene expression, protein production, plus cellular responses to growth factors and mechanical stimuli. This review compares and contrasts the current knowledge of these two cell types, whose health is critical for protecting the eye from glaucomatous changes. In response to pressure gradients across their respective cribiform tissues, the goal is to better understand and differentiate healthy from pathological behavior of these two cell types.
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Affiliation(s)
- Jayter S Paula
- Department of Ophthalmology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil; Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Colm O'Brien
- Ophthalmology, UCD School of Medicine, Mater Hospital, Dublin, Ireland
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA.
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80
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Liu Y, Bailey JC, Helwa I, Dismuke WM, Cai J, Drewry M, Brilliant MH, Budenz DL, Christen WG, Chasman DI, Fingert JH, Gaasterland D, Gaasterland T, Gordon MO, Igo RP, Kang JH, Kass MA, Kraft P, Lee RK, Lichter P, Moroi SE, Realini A, Richards JE, Ritch R, Schuman JS, Scott WK, Singh K, Sit AJ, Song YE, Vollrath D, Weinreb R, Medeiros F, Wollstein G, Zack DJ, Zhang K, Pericak-Vance MA, Gonzalez P, Stamer WD, Kuchtey J, Kuchtey RW, Allingham RR, Hauser MA, Pasquale LR, Haines JL, Wiggs JL. A Common Variant in MIR182 Is Associated With Primary Open-Angle Glaucoma in the NEIGHBORHOOD Consortium. Invest Ophthalmol Vis Sci 2016; 57:4528-4535. [PMID: 27537254 PMCID: PMC4991020 DOI: 10.1167/iovs.16-19688] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/21/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Noncoding microRNAs (miRNAs) have been implicated in the pathogenesis of glaucoma. We aimed to identify common variants in miRNA coding genes (MIR) associated with primary open-angle glaucoma (POAG). METHODS Using the NEIGHBORHOOD data set (3853 cases/33,480 controls with European ancestry), we first assessed the relation between 85 variants in 76 MIR genes and overall POAG. Subtype-specific analyses were performed in high-tension glaucoma (HTG) and normal-tension glaucoma subsets. Second, we examined the expression of miR-182, which was associated with POAG, in postmortem human ocular tissues (ciliary body, cornea, retina, and trabecular meshwork [TM]), using miRNA sequencing (miRNA-Seq) and droplet digital PCR (ddPCR). Third, miR-182 expression was also examined in human aqueous humor (AH) by using miRNA-Seq. Fourth, exosomes secreted from primary human TM cells were examined for miR-182 expression by using miRNA-Seq. Fifth, using ddPCR we compared miR-182 expression in AH between five HTG cases and five controls. RESULTS Only rs76481776 in MIR182 gene was associated with POAG after adjustment for multiple comparisons (odds ratio [OR] = 1.23, 95% confidence interval [CI]: 1.11-1.42, P = 0.0002). Subtype analysis indicated that the association was primarily in the HTG subset (OR = 1.26, 95% CI: 1.08-1.47, P = 0.004). The risk allele T has been associated with elevated miR-182 expression in vitro. Data from ddPCR and miRNA-Seq confirmed miR-182 expression in all examined ocular tissues and TM-derived exosomes. Interestingly, miR-182 expression in AH was 2-fold higher in HTG patients than nonglaucoma controls (P = 0.03) without controlling for medication treatment. CONCLUSIONS Our integrative study is the first to associate rs76481776 with POAG via elevated miR-182 expression.
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Affiliation(s)
- Yutao Liu
- Department of Cellular Biology and Anatomy Augusta University, Augusta, Georgia, United States
- James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
- Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, Georgia, United States
| | - Jessica Cooke Bailey
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States
| | - Inas Helwa
- Department of Cellular Biology and Anatomy Augusta University, Augusta, Georgia, United States
| | - W. Michael Dismuke
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Jingwen Cai
- Department of Cellular Biology and Anatomy Augusta University, Augusta, Georgia, United States
| | - Michelle Drewry
- Department of Cellular Biology and Anatomy Augusta University, Augusta, Georgia, United States
| | - Murray H. Brilliant
- Center for Human Genetics, Marshfield Clinic Research Foundation, Marshfield, Wisconsin, United States
| | - Donald L. Budenz
- Department of Ophthalmology, University of North Carolina, Chapel Hill, North Carolina, United States
| | - William G. Christen
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
| | - Daniel I. Chasman
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
| | - John H. Fingert
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
| | | | - Terry Gaasterland
- Scripps Genome Center, University of California at San Diego, San Diego, California, United States
| | - Mae O. Gordon
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Robert P. Igo
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jae H. Kang
- Channing Division of Network Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
| | - Michael A. Kass
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Peter Kraft
- School of Public Health, Harvard University, Boston, Massachusetts, United States
| | - Richard K. Lee
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Paul Lichter
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Sayoko E. Moroi
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Anthony Realini
- Department of Ophthalmology, West Virginia University Eye Institute, Morgantown, West Virginia, United States
| | - Julia E. Richards
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
| | - Joel S. Schuman
- Department of Ophthalmology, UPMC Eye Center, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - William K. Scott
- Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Kuldev Singh
- Department of Ophthalmology, Stanford University, Palo Alto, California, United States
| | - Arthur J. Sit
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Yeunjoo E. Song
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States
| | - Douglas Vollrath
- Department of Ophthalmology, Stanford University, Palo Alto, California, United States
| | - Robert Weinreb
- Department of Ophthalmology and Hamilton Glaucoma Center, University of California, San Diego, California, United States
| | - Felipe Medeiros
- Department of Ophthalmology and Hamilton Glaucoma Center, University of California, San Diego, California, United States
| | - Gadi Wollstein
- Department of Ophthalmology, UPMC Eye Center, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Donald J. Zack
- Wilmer Eye Institute, Johns Hopkins University Hospital, Baltimore, Maryland, United States
| | - Kang Zhang
- Department of Ophthalmology and Hamilton Glaucoma Center, University of California, San Diego, California, United States
| | - Margaret A. Pericak-Vance
- Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Pedro Gonzalez
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - W. Daniel Stamer
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - John Kuchtey
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Rachel W. Kuchtey
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - R. Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Michael A. Hauser
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States
| | - Louis R. Pasquale
- Channing Division of Network Medicine, Brigham and Women's Hospital, Boston, Massachusetts, United States
- Department of Ophthalmology, Mass Eye & Ear, Boston, Massachusetts, United States
| | - Jonathan L. Haines
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, Ohio, United States
| | - Janey L. Wiggs
- Department of Ophthalmology, Mass Eye & Ear, Boston, Massachusetts, United States
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81
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The role of integrins in glaucoma. Exp Eye Res 2016; 158:124-136. [PMID: 27185161 DOI: 10.1016/j.exer.2016.05.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 05/06/2016] [Accepted: 05/10/2016] [Indexed: 01/04/2023]
Abstract
Integrins are a family of heterodimeric transmembrane receptors that mediate adhesion to the extracellular matrix (ECM). In addition to their role as adhesion receptors, integrins can act as ''bidirectional signal transducers'' that coordinate a large number of cellular activities in response to the extracellular environment and intracellular signaling events. This bidirectional signaling helps maintain tissue homeostasis. Dysregulated bidirectional signaling, however, could trigger the propagation of feedback loops that can lead to the establishment of a disease state such as glaucoma. Here we discuss the role of integrins and bidirectional signaling as they relate to the glaucomatous phenotype with special emphasis on the αvβ3 integrin. We present evidence that this particular integrin may have a significant impact on the pathogenesis of glaucoma.
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82
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Kuehn MH, Lipsett KA, Menotti-Raymond M, Whitmore SS, Scheetz TE, David VA, O'Brien SJ, Zhao Z, Jens JK, Snella EM, Ellinwood NM, McLellan GJ. A Mutation in LTBP2 Causes Congenital Glaucoma in Domestic Cats (Felis catus). PLoS One 2016; 11:e0154412. [PMID: 27149523 PMCID: PMC4858209 DOI: 10.1371/journal.pone.0154412] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 03/31/2016] [Indexed: 01/18/2023] Open
Abstract
The glaucomas are a group of diseases characterized by optic nerve damage that together represent a leading cause of blindness in the human population and in domestic animals. Here we report a mutation in LTBP2 that causes primary congenital glaucoma (PCG) in domestic cats. We identified a spontaneous form of PCG in cats and established a breeding colony segregating for PCG consistent with fully penetrant, autosomal recessive inheritance of the trait. Elevated intraocular pressure, globe enlargement and elongated ciliary processes were consistently observed in all affected cats by 8 weeks of age. Varying degrees of optic nerve damage resulted by 6 months of age. Although subtle lens zonular instability was a common feature in this cohort, pronounced ectopia lentis was identified in less than 10% of cats examined. Thus, glaucoma in this pedigree is attributed to histologically confirmed arrest in the early post-natal development of the aqueous humor outflow pathways in the anterior segment of the eyes of affected animals. Using a candidate gene approach, significant linkage was established on cat chromosome B3 (LOD 18.38, θ = 0.00) using tightly linked short tandem repeat (STR) loci to the candidate gene, LTBP2. A 4 base-pair insertion was identified in exon 8 of LTBP2 in affected individuals that generates a frame shift that completely alters the downstream open reading frame and eliminates functional domains. Thus, we describe the first spontaneous and highly penetrant non-rodent model of PCG identifying a valuable animal model for primary glaucoma that closely resembles the human disease, providing valuable insights into mechanisms underlying the disease and a valuable animal model for testing therapies.
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Affiliation(s)
- Markus H. Kuehn
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Koren A. Lipsett
- Laboratory of Genomic Diversity, National Cancer Institute, Frederick, Maryland, United States of America
- Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Marilyn Menotti-Raymond
- Laboratory of Genomic Diversity, National Cancer Institute, Frederick, Maryland, United States of America
| | - S. Scott Whitmore
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Todd E. Scheetz
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Victor A. David
- Laboratory of Genomic Diversity, National Cancer Institute, Frederick, Maryland, United States of America
- Basic Research Laboratory, National Cancer Institute, Frederick, Maryland, United States of America
| | - Stephen J. O'Brien
- Laboratory of Genomic Diversity, National Cancer Institute, Frederick, Maryland, United States of America
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia
- Oceanographic Center, Nova Southeastern University, Fort Lauderdale, Florida, United States of America
| | - Zhongyuan Zhao
- Department of Chemistry, Gettysburg College, Gettysburg, Pennsylvania, United States of America
| | - Jackie K. Jens
- Department of Animal Science, Iowa State University, Ames, Iowa, United States of America
| | - Elizabeth M. Snella
- Department of Animal Science, Iowa State University, Ames, Iowa, United States of America
| | - N. Matthew Ellinwood
- Department of Animal Science, Iowa State University, Ames, Iowa, United States of America
- Department of Veterinary Clinical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Gillian J. McLellan
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Surgical Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- McPherson Eye Research Institute, Madison, Wisconsin, United States of America
- * E-mail:
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83
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Dang Y, Loewen R, Parikh HA, Roy P, Loewen NA. Gene transfer to the outflow tract. Exp Eye Res 2016; 158:73-84. [PMID: 27131906 DOI: 10.1016/j.exer.2016.04.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/22/2016] [Accepted: 04/25/2016] [Indexed: 12/24/2022]
Abstract
Elevated intraocular pressure is the primary cause of open angle glaucoma. Outflow resistance exists within the trabecular meshwork but also at the level of Schlemm's canal and further downstream within the outflow system. Viral vectors allow to take advantage of naturally evolved, highly efficient mechanisms of gene transfer, a process that is termed transduction. They can be produced at biosafety level 2 in the lab using protocols that have evolved considerably over the last 15-20 years. Applied by an intracameral bolus, vectors follow conventional as well as uveoscleral outflow pathways. They may affect other structures in the anterior chamber depending on their transduction kinetics which can vary among species when using the same vector. Not all vectors can express long-term, a desirable feature to address the chronicity of glaucoma. Vectors that integrate into the genome of the target cell can achieve transgene function for the life of the transduced cell but are mutagenic by definition. The most prominent long-term expressing vector systems are based on lentiviruses that are derived from HIV, FIV, or EIAV. Safety considerations make non-primate lentiviral vector systems easier to work with as they are not derived from human pathogens. Non-integrating vectors are subject to degradation and attritional dilution during cell division. Lentiviral vectors have to integrate in order to express while adeno-associated viral vectors (AAV) often persist as intracellular concatemers but may also integrate. Adeno- and herpes viral vectors do not integrate and earlier generation systems might be relatively immunogenic. Nonviral methods of gene transfer are termed transfection with few restrictions of transgene size and type but often a much less efficient gene transfer that is also short-lived. Traditional gene transfer delivers exons while some vectors (lentiviral, herpes and adenoviral) allow transfer of entire genes that include introns. Recent insights have highlighted the role of non-coding RNA, most prominently, siRNA, miRNA and lncRNA. SiRNA is highly specific, miRNA is less specific, while lncRNA uses highly complex mechanisms that involve secondary structures and intergenic, intronic, overlapping, antisense, and bidirectional location. Several promising preclinical studies have targeted the RhoA or the prostaglandin pathway or modified the extracellular matrix. TGF-β and glaucoma myocilin mutants have been transduced to elevate the intraocular pressure in glaucoma models. Cell based therapies have started to show first promise. Past approaches have focused on the trabecular meshwork and the inner wall of Schlemm's canal while new strategies are concerned with modification of outflow tract elements that are downstream of the trabecular meshwork.
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Affiliation(s)
- Yalong Dang
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Ralitsa Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Hardik A Parikh
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, USA; New Jersey Medical School, Rutgers State University of New Jersey, Newark, NJ 07103, USA
| | - Pritha Roy
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Nils A Loewen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, USA.
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84
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The exit strategy: Pharmacological modulation of extracellular matrix production and deposition for better aqueous humor drainage. Eur J Pharmacol 2016; 787:32-42. [PMID: 27112663 DOI: 10.1016/j.ejphar.2016.04.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/20/2016] [Accepted: 04/22/2016] [Indexed: 01/28/2023]
Abstract
Primary open angle glaucoma (POAG) is an optic neuropathy and an irreversible blinding disease. The etiology of glaucoma is not known but numerous risk factors are associated with this disease including aging, elevated intraocular pressure (IOP), race, myopia, family history and use of steroids. In POAG, the resistance to the aqueous humor drainage is increased leading to elevated IOP. Lowering the resistance and ultimately the IOP has been the only way to slow disease progression and prevent vision loss. The primary drainage pathway comprising of the trabecular meshwork (TM) is made up of relatively large porous beams surrounded by extracellular matrix (ECM). Its juxtacanalicular tissue (JCT) or the cribriform meshwork is made up of cells embedded in dense ECM. The JCT is considered to offer the major resistance to the aqueous humor outflow. This layer is adjacent to the endothelial cells forming Schlemm's canal, which provides approximately 10% of the outflow resistance. The ECM in the TM and the JCT undergoes continual remodeling to maintain normal resistance to aqueous humor outflow. It is believed that the TM is a major contributor of ECM proteins and evidence points towards increased ECM deposition in the outflow pathway in POAG. It is not clear how and from where the ECM components emerge to hinder the normal aqueous humor drainage. This review focuses on the involvement of the ECM in ocular hypertension and glaucoma and the mechanisms by which various ocular hypotensive drugs, both current and emerging, target ECM production, remodeling, and deposition.
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85
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Sun G, Chen J, Yang S, Parker TMN, Goodman GMP, Hasama JM, Zhao J. Therapeutic effects of OP-1 on metal wear particle induced osteoblasts injury in vitro. Int J Clin Exp Med 2015; 8:22175-22182. [PMID: 26885192 PMCID: PMC4729978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
Aseptic lossening is a main reason for the revision of total joint arthroplasty. Metal-wear particles induced deregulation of bone resorption or formation has been considered as the major process of aseptic lossening. Osteogenic protein-1 (OP-1) can be used to improve bone formation. However, such effect is not clearly understood after the metal-wear particles injury. Here, we investigated the molecular mechanisms by which OP-1 regulates the activity of bone formation and anti-inflammatory after injury. Results showed that OP-1 increased cell viability and bone formation ability of impaired osteoblast cells at 72 hours after being injured by cobalt particles. Pathway analyses revealed that both mRNA and protein levels of Smad1 and Smad5 were significantly increased upon the treatment of OP-1 in the cell injury model. Similarly, runt-related transcription factor 2 (Runx2) was also significantly upregulated in the OP-1 treated cells. Moreover, treatment with OP-1 inhibited the secretion of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and IL-18 in cobalt impaired cells. Collectively, these results suggest that OP-1 could inhibit cobalt particles induced cell injury by activating Smad1, Smad5, and Runx2, and such procedure is accompanied by anti-inflammatory reaction.
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Affiliation(s)
- Guojing Sun
- Department of Orthopedics, Jinling HospitalNanjing 210002, Jiangsu, China
| | - Jianmin Chen
- Department of Orthopedics, The 81st Hospital of PLANanjing 210002, Jiangsu, China
| | - Shufeng Yang
- Department of Orthopedics, The 81st Hospital of PLANanjing 210002, Jiangsu, China
| | | | - Gary MP Goodman
- DLPartner Immunotherapeutic Research LabMD 20742, United States
| | - Jack M Hasama
- DLPartner Immunotherapeutic Research LabMD 20742, United States
| | - Jianning Zhao
- Department of Orthopedics, Jinling HospitalNanjing 210002, Jiangsu, China
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86
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Cai J, Perkumas KM, Qin X, Hauser MA, Stamer WD, Liu Y. Expression Profiling of Human Schlemm's Canal Endothelial Cells From Eyes With and Without Glaucoma. Invest Ophthalmol Vis Sci 2015; 56:6747-53. [PMID: 26567786 PMCID: PMC4614909 DOI: 10.1167/iovs.15-17720] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 09/12/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Ocular hypertension is a major risk factor for glaucoma and the inner wall of Schlemm's canal (SC) endothelia participates in the regulation of aqueous humor outflow resistance. This study aimed to identify differentially expressed genes in primary cultures of SC cells from glaucoma patients. METHODS This study examined SC samples from three glaucoma cases and four controls. Schlemm's canal cells were isolated from eight different postmortem human eyes. Total RNA was extracted, labeled, and hybridized to Illumina HumanWG-6 BeadChips containing probes for approximately 47,000 human transcripts. After extracting the data using Illumina GenomeStudio software, the data were normalized and analyzed using the R package limma in Bioconductor. Using Protein ANalysis THrough Evolutionary Relationships (PANTHER) software, gene ontology analysis of highly expressed genes was executed in controls and glaucoma groups separately. Pathway analysis was performed with differentially expressed genes using WebGestalt (WEB-based GEne SeT AnaLysis Toolkit). Selected genes were validated using droplet digital PCR (ddPCR). RESULTS Gene ontology analysis indicated similar functional categories in cases and controls. Differential analysis identified a total of 113 genes with at least 2-fold expression changes in cases. Pathway analysis indicated significant enrichment of genes in cell adhesion, heparin binding, glycosaminoglycan binding, filopodium, and extracellular matrix remodeling. Eighteen selected genes with differential expression were successfully validated using ddPCR. CONCLUSIONS This study represents the first genome-wide expression study of human primary SC cells from glaucoma patients and provides a potential list of targets regulating SC cell stiffness and pore formation, eventually the outflow resistance in glaucoma individuals.
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Affiliation(s)
- Jingwen Cai
- Department of Cellular Biology and Anatomy, Georgia Regents University, Augusta, Georgia, United States
| | - Kristin M. Perkumas
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
| | - Xuejun Qin
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States
- Department of Medicine, Duke University, Durham, North Carolina, United States
| | - Michael A. Hauser
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States
- Department of Medicine, Duke University, Durham, North Carolina, United States
| | - W. Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, North Carolina, United States
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Georgia Regents University, Augusta, Georgia, United States
- James & Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, Georgia, United States
- Center for Biotechnology and Genomic Medicine, Georgia Regents University, Augusta, Georgia, United States
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87
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Genes, pathways, and animal models in primary open-angle glaucoma. Eye (Lond) 2015; 29:1285-98. [PMID: 26315706 DOI: 10.1038/eye.2015.160] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 07/27/2015] [Indexed: 02/08/2023] Open
Abstract
Glaucoma is an optic neuropathy characterized by loss of retinal ganglion cells (RGCs) and consequently visual field loss. It is a complex and heterogeneous disease in which both environmental and genetic factors play a role. With the advent of genome-wide association studies (GWASs), the number of loci associated with primary open-angle glaucoma (POAG) have increased greatly. There has also been major progress in understanding the genes determining the vertical cup-disc ratio (VCDR), disc area (DA), cup area (CA), intraocular pressure (IOP), and central corneal thickness (CCT). In this review, we will update and summarize the genetic loci associated so far with POAG, VCDR, DA, CA, IOP, and CCT. We will describe the pathways revealed and supported by genetic association studies, integrating current knowledge from human and experimental data. Finally, we will discuss approaches for functional genomics and clinical translation.
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Wiggs JL. Glaucoma Genes and Mechanisms. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:315-42. [PMID: 26310163 DOI: 10.1016/bs.pmbts.2015.04.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genetic studies have yielded important genes contributing to both early-onset and adult-onset forms of glaucoma. The proteins encoded by the current collection of glaucoma genes participate in a broad range of cellular processes and biological systems. Approximately half the glaucoma-related genes function in the extracellular matrix, however proteins involved in cytokine signaling, lipid metabolism, membrane biology, regulation of cell division, autophagy, and ocular development also contribute to the disease pathogenesis. While the function of these proteins in health and disease are not completely understood, recent studies are providing insight into underlying disease mechanisms, a critical step toward the development of gene-based therapies. In this review, genes known to cause early-onset glaucoma or contribute to adult-onset glaucoma are organized according to the cell processes or biological systems that are impacted by the function of the disease-related protein product.
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Affiliation(s)
- Janey L Wiggs
- Harvard Medical School, and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.
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Morgan JT, Raghunathan VK, Chang YR, Murphy CJ, Russell P. The intrinsic stiffness of human trabecular meshwork cells increases with senescence. Oncotarget 2015; 6:15362-74. [PMID: 25915531 PMCID: PMC4558157 DOI: 10.18632/oncotarget.3798] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 03/20/2015] [Indexed: 12/26/2022] Open
Abstract
Dysfunction of the human trabecular meshwork (HTM) plays a central role in the age-associated disease glaucoma, a leading cause of irreversible blindness. The etiology remains poorly understood but cellular senescence, increased stiffness of the tissue, and the expression of Wnt antagonists such as secreted frizzled related protein-1 (SFRP1) have been implicated. However, it is not known if senescence is causally linked to either stiffness or SFRP1 expression. In this study, we utilized in vitro HTM senescence to determine the effect on cellular stiffening and SFRP1 expression. Stiffness of cultured cells was measured using atomic force microscopy and the morphology of the cytoskeleton was determined using immunofluorescent analysis. SFRP1 expression was measured using qPCR and immunofluorescent analysis. Senescent cell stiffness increased 1.88±0.14 or 2.57±0.14 fold in the presence or absence of serum, respectively. This was accompanied by increased vimentin expression, stress fiber formation, and SFRP1 expression. In aggregate, these data demonstrate that senescence may be a causal factor in HTM stiffening and elevated SFRP1 expression, and contribute towards disease progression. These findings provide insight into the etiology of glaucoma and, more broadly, suggest a causal link between senescence and altered tissue biomechanics in aging-associated diseases.
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Affiliation(s)
- Joshua T. Morgan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Vijay Krishna Raghunathan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Yow-Ren Chang
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Christopher J. Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
- Department of Ophthalmology &; Vision Science, School of Medicine, University of California, Davis, CA, USA
| | - Paul Russell
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
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Vranka JA, Kelley MJ, Acott TS, Keller KE. Extracellular matrix in the trabecular meshwork: intraocular pressure regulation and dysregulation in glaucoma. Exp Eye Res 2015; 133:112-25. [PMID: 25819459 DOI: 10.1016/j.exer.2014.07.014] [Citation(s) in RCA: 264] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/14/2014] [Accepted: 07/16/2014] [Indexed: 12/30/2022]
Abstract
The trabecular meshwork (TM) is located in the anterior segment of the eye and is responsible for regulating the outflow of aqueous humor. Increased resistance to aqueous outflow causes intraocular pressure to increase, which is the primary risk factor for glaucoma. TM cells reside on a series of fenestrated beams and sheets through which the aqueous humor flows to exit the anterior chamber via Schlemm's canal. The outer trabecular cells are phagocytic and are thought to function as a pre-filter. However, most of the outflow resistance is thought to be from the extracellular matrix (ECM) of the juxtacanalicular region, the deepest portion of the TM, and from the inner wall basement membrane of Schlemm's canal. It is becoming increasingly evident that the extracellular milieu is important in maintaining the integrity of the TM. In glaucoma, not only have ultrastructural changes been observed in the ECM of the TM, and a significant number of mutations in ECM genes been noted, but the stiffness of glaucomatous TM appears to be greater than that of normal tissue. Additionally, TGFβ2 has been found to be elevated in the aqueous humor of glaucoma patients and is assumed to be involved in ECM changes deep with the juxtacanalicular region of the TM. This review summarizes the current literature on trabecular ECM as well as the development and function of the TM. Animal models and organ culture models targeting specific ECM molecules to investigate the mechanisms of glaucoma are described. Finally, the growing number of mutations that have been identified in ECM genes and genes that modulate ECM in humans with glaucoma are documented.
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Affiliation(s)
- Janice A Vranka
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Mary J Kelley
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ted S Acott
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kate E Keller
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA.
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91
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Jeong S, Patel N, Edlund CK, Hartiala J, Hazelett DJ, Itakura T, Wu PC, Avery RL, Davis JL, Flynn HW, Lalwani G, Puliafito CA, Wafapoor H, Hijikata M, Keicho N, Gao X, Argüeso P, Allayee H, Coetzee GA, Pletcher MT, Conti DV, Schwartz SG, Eaton AM, Fini ME. Identification of a Novel Mucin Gene HCG22 Associated With Steroid-Induced Ocular Hypertension. Invest Ophthalmol Vis Sci 2015; 56:2737-48. [PMID: 25813999 PMCID: PMC4416661 DOI: 10.1167/iovs.14-14803] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 12/04/2014] [Indexed: 12/24/2022] Open
Abstract
PURPOSE The pathophysiology of ocular hypertension (OH) leading to primary open-angle glaucoma shares many features with a secondary form of OH caused by treatment with glucocorticoids, but also exhibits distinct differences. In this study, a pharmacogenomics approach was taken to discover candidate genes for this disorder. METHODS A genome-wide association study was performed, followed by an independent candidate gene study, using a cohort enrolled from patients treated with off-label intravitreal triamcinolone, and handling change in IOP as a quantitative trait. RESULTS An intergenic quantitative trait locus (QTL) was identified at chromosome 6p21.33 near the 5' end of HCG22 that attained the accepted statistical threshold for genome-level significance. The HCG22 transcript, encoding a novel mucin protein, was expressed in trabecular meshwork cells, and expression was stimulated by IL-1, and inhibited by triamcinolone acetate and TGF-β. Bioinformatic analysis defined the QTL as an approximately 4 kilobase (kb) linkage disequilibrium block containing 10 common single nucleotide polymorphisms (SNPs). Four of these SNPs were identified in the National Center for Biotechnology Information (NCBI) GTEx eQTL browser as modifiers of HCG22 expression. Most are predicted to disrupt or improve motifs for transcription factor binding, the most relevant being disruption of the glucocorticoid receptor binding motif. A second QTL was identified within the predicted signal peptide of the HCG22 encoded protein that could affect its secretion. Translation, O-glycosylation, and secretion of the predicted HCG22 protein was verified in cultured trabecular meshwork cells. CONCLUSIONS Identification of two independent QTLs that could affect expression of the HCG22 mucin gene product via two different mechanisms (transcription or secretion) is highly suggestive of a role in steroid-induced OH.
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Affiliation(s)
- Shinwu Jeong
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 2USC Eye Institute/Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California
| | - Nitin Patel
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Christopher K Edlund
- Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Jaana Hartiala
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Dennis J Hazelett
- USC/Norris Comprehensive Cancer Center, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Pei-Chang Wu
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 5Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Robert L Avery
- California Retina Consultants, Santa Barbara, California, United States
| | - Janet L Davis
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Harry W Flynn
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Geeta Lalwani
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Carmen A Puliafito
- USC Eye Institute/Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 7Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Med
| | | | - Minako Hijikata
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Naoto Keicho
- Department of Pathophysiology and Host Defense, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - Xiaoyi Gao
- Department of Ophthalmology and Visual Sciences, University of Illinois, Chicago, Illinois, United States
| | - Pablo Argüeso
- The Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Hooman Allayee
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 3Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angele
| | - Gerhard A Coetzee
- Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 4USC/Norris Comprehensive Cancer Center, Keck School of Medicine of USC, University of Southern California, Los An
| | - Mathew T Pletcher
- Department of Molecular Therapeutics, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, United States
| | - David V Conti
- Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States
| | - Stephen G Schwartz
- Bascom Palmer Eye Institute and Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, United States
| | | | - M Elizabeth Fini
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States 2USC Eye Institute/Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California
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92
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Doucette LP, Rasnitsyn A, Seifi M, Walter MA. The interactions of genes, age, and environment in glaucoma pathogenesis. Surv Ophthalmol 2015; 60:310-26. [PMID: 25907525 DOI: 10.1016/j.survophthal.2015.01.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 12/30/2022]
Abstract
Glaucoma, a progressive degenerative condition that results in the death of retinal ganglion cells, is one of the leading causes of blindness, affecting millions worldwide. The mechanisms underlying glaucoma are not well understood, although years of studies have shown that the largest risk factors are elevated intraocular pressure, age, and genetics. Eleven genes and multiple loci have been identified as contributing factors. These genes act by a number of mechanisms, including mechanical stress, ischemic/oxidative stress, and neurodegeneration. We summarize the recent advances in the understanding of glaucoma and propose a unified hypothesis for glaucoma pathogenesis. Glaucoma does not result from a single pathological mechanism, but rather a combination of pathways that are influenced by genes, age, and environment. In particular, we hypothesize that, in the presence of genetic risk factors, exposure to environment stresses results in an earlier age of onset for glaucoma. This hypothesis is based upon the overlap of the molecular pathways in which glaucoma genes are involved. Because of the interactions between these processes, it is likely that there are common therapies that may be effective for different subtypes of glaucoma.
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Affiliation(s)
- Lance P Doucette
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Alexandra Rasnitsyn
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Morteza Seifi
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada
| | - Michael A Walter
- Faculty of Medicine and Dentistry, Department of Medical Genetics, Edmonton, Alberta T6G 2H7, Canada.
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93
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Stamer WD, Braakman ST, Zhou EH, Ethier CR, Fredberg JJ, Overby DR, Johnson M. Biomechanics of Schlemm's canal endothelium and intraocular pressure reduction. Prog Retin Eye Res 2015; 44:86-98. [PMID: 25223880 PMCID: PMC4268318 DOI: 10.1016/j.preteyeres.2014.08.002] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/25/2014] [Accepted: 08/26/2014] [Indexed: 12/29/2022]
Abstract
Ocular hypertension in glaucoma develops due to age-related cellular dysfunction in the conventional outflow tract, resulting in increased resistance to aqueous humor outflow. Two cell types, trabecular meshwork (TM) and Schlemm's canal (SC) endothelia, interact in the juxtacanalicular tissue (JCT) region of the conventional outflow tract to regulate outflow resistance. Unlike endothelial cells lining the systemic vasculature, endothelial cells lining the inner wall of SC support a transcellular pressure gradient in the basal to apical direction, thus acting to push the cells off their basal lamina. The resulting biomechanical strain in SC cells is quite large and is likely to be an important determinant of endothelial barrier function, outflow resistance and intraocular pressure. This review summarizes recent work demonstrating how biomechanical properties of SC cells impact glaucoma. SC cells are highly contractile, and such contraction greatly increases cell stiffness. Elevated cell stiffness in glaucoma may reduce the strain experienced by SC cells, decrease the propensity of SC cells to form pores, and thus impair the egress of aqueous humor from the eye. Furthermore, SC cells are sensitive to the stiffness of their local mechanical microenvironment, altering their own cell stiffness and modulating gene expression in response. Significantly, glaucomatous SC cells appear to be hyper-responsive to substrate stiffness. Thus, evidence suggests that targeting the material properties of SC cells will have therapeutic benefits for lowering intraocular pressure in glaucoma.
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Affiliation(s)
- W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, NC 27710, USA; Department of Biomedical Engineering, Duke University, Durham, NC, 27710, USA.
| | - Sietse T Braakman
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Enhua H Zhou
- Department of Ophthalmology, Novartis Institutes of BioMedical Research, Cambridge, MA 02139, USA
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; Department of Biomedical Engineering, Emory University, Atlanta, GA 30322, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30322, USA
| | - Jeffrey J Fredberg
- Program in Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, MA 02115, USA; Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA
| | - Darryl R Overby
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Mark Johnson
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, US; Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA; Department of Ophthalmology Engineering, Northwestern University, Chicago, IL, USA
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94
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Li G, Farsiu S, Qiu J, Dixon A, Song C, McKinnon SJ, Yuan F, Gonzalez P, Stamer WD. Disease progression in iridocorneal angle tissues of BMP2-induced ocular hypertensive mice with optical coherence tomography. Mol Vis 2014; 20:1695-709. [PMID: 25558173 PMCID: PMC4279588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 12/18/2014] [Indexed: 11/16/2022] Open
Abstract
PURPOSE The goal of the present study was to test for the first time whether glaucomatous-like disease progression in a mouse can be assessed morphologically and functionally with spectral domain optical coherence tomography (SD-OCT). METHODS We monitored progressive changes in conventional outflow tissues of living mice overexpressing human bone morphogenetic protein 2 (BMP2), a model for glaucoma. Intraocular pressure (IOP) and outflow tissue morphology/Young's modulus were followed in mice for 36 days with rebound tonometry and SD-OCT, respectively. Results were compared to standard histological methods. Outflow facility was calculated from flow measurements with direct cannulation of anterior chambers subjected to three sequential pressure steps. RESULTS Overexpression of BMP2 significantly elevated IOP in a biphasic manner over time compared to mice that overexpressed green fluorescent protein in outflow cells and naïve controls. SD-OCT revealed changes in outflow tissues overexpressing BMP2 that corresponded with the timing of the IOP phases and decreased outflow facility. In the first phase, the angle was open, but the trabecular meshwork and the cornea were thickened. OCT detected increased trabecular meshwork stiffness after provocative IOP challenges of the BMP2 eyes, which corresponded to increased collagen deposition with transmission electron microscopy. In contrast, the angle was closed in the second phase. IOP elevation over 36 days due to BMP2 overexpression resulted in significant retinal ganglion cell and axon loss. CONCLUSIONS Although not a feasible open-angle glaucoma model, the BMP2 mice were useful for demonstrating the utility of SD-OCT in following disease progression and differentiating between two forms of ocular pathology over time that resulted in ocular hypertension.
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Affiliation(s)
- Guorong Li
- Department of Ophthalmology, Duke University, Durham, NC
| | - Sina Farsiu
- Department of Ophthalmology, Duke University, Durham, NC,Department of Biomedical Engineering, Duke University, Durham, NC
| | - Jianming Qiu
- Department of Ophthalmology, Duke University, Durham, NC
| | - Angela Dixon
- Department of Ophthalmology, Duke University, Durham, NC
| | - Chunwei Song
- School of Astronautics, Harbin Institute of Technology, Harbin, China
| | - Stuart J. McKinnon
- Department of Ophthalmology, Duke University, Durham, NC,Department of Neurobiology, Duke University, Durham, NC
| | - Fan Yuan
- Department of Biomedical Engineering, Duke University, Durham, NC
| | - Pedro Gonzalez
- Department of Ophthalmology, Duke University, Durham, NC
| | - W. Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, NC,Department of Biomedical Engineering, Duke University, Durham, NC
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95
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Kaposi's sarcoma-associated herpesvirus downregulates transforming growth factor β2 to promote enhanced stability of capillary-like tube formation. J Virol 2014; 88:14301-9. [PMID: 25275137 DOI: 10.1128/jvi.01696-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
UNLABELLED Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS), the most common tumor of AIDS patients worldwide. A key characteristic of KS tumors is extremely high levels of vascular slits and extravasated red blood cells, making neoangiogenesis a key component of the tumor. The main KS tumor cell is the spindle cell, a cell of endothelial origin that maintains KSHV predominantly in the latent state. In cultured endothelial cells, latent KSHV infection induces angiogenic phenotypes, including longer-term stabilization of capillary-like tube formation in Matrigel, a basement membrane matrix. The present studies show that KSHV infection of endothelial cells strongly downregulates transforming growth factor β2 (TGF-β2). This downregulation allows the stabilization of capillary-like tube formation during latent infection, as the addition of exogenous TGF-β2 inhibits the KSHV-induced stability of these structures. While two KSHV microRNAs are sufficient to downregulate TGF-β2 in endothelial cells, they are not required during KSHV infection. However, activation of the gp130 cell surface receptor is both necessary and sufficient for downregulation of TGF-β2 in KSHV-infected cells. IMPORTANCE Kaposi's sarcoma is a highly vascularized, endothelial cell-based tumor supporting large amounts of angiogenesis. There is evidence that KSHV, the etiologic agent of KS, induces aberrant angiogenesis. For example, KSHV induces stabilization of capillary-like tube formation in cultured endothelial cells. A clearer understanding of how KSHV regulates angiogenesis could provide potential therapeutic targets for KS. We found that KSHV downregulates TGF-β2, a cytokine related to TGF-β1 that is known to inhibit angiogenesis. The downregulation of this inhibitor promotes the stability of capillary-like tube formation insofar as adding back TGF-β2 to infected cells blocks KSHV-induced long-term tubule stability. Therefore, KSHV downregulation of TGF-β2 may increase aberrant vascularization in KS tumors through increased capillary formation and thereby aid in KS tumor promotion.
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Abu-Hassan DW, Acott TS, Kelley MJ. The Trabecular Meshwork: A Basic Review of Form and Function. ACTA ACUST UNITED AC 2014; 2. [PMID: 25356439 DOI: 10.13188/2334-2838.1000017] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Diala W Abu-Hassan
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, Oregon, USA
| | - Ted S Acott
- Department of Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, USA
| | - Mary J Kelley
- Department of Biochemistry & Physiology, University of Jordan, Amman, Jordan
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