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Wilson MR, Satapathy S, Jeong S, Fini ME. Clusterin, other extracellular chaperones, and eye disease. Prog Retin Eye Res 2021; 89:101032. [PMID: 34896599 DOI: 10.1016/j.preteyeres.2021.101032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 11/30/2021] [Accepted: 11/30/2021] [Indexed: 12/15/2022]
Abstract
Proteostasis refers to all the processes that maintain the correct expression level, location, folding and turnover of proteins, essential to organismal survival. Both inside cells and in body fluids, molecular chaperones play key roles in maintaining proteostasis. In this article, we focus on clusterin, the first-recognized extracellular mammalian chaperone, and its role in diseases of the eye. Clusterin binds to and inhibits the aggregation of proteins that are misfolded due to mutations or stresses, clears these aggregating proteins from extracellular spaces, and facilitates their degradation. Clusterin exhibits three main homeostatic activities: proteostasis, cytoprotection, and anti-inflammation. The so-called "protein misfolding diseases" are caused by aggregation of misfolded proteins that accumulate pathologically as deposits in tissues; we discuss several such diseases that occur in the eye. Clusterin is typically found in these deposits, which is interpreted to mean that its capacity as a molecular chaperone to maintain proteostasis is overwhelmed in the disease state. Nevertheless, the role of clusterin in diseases involving such deposits needs to be better defined before therapeutic approaches can be entertained. A more straightforward case can be made for therapeutic use of clusterin based on its proteostatic role as a proteinase inhibitor, as well as its cytoprotective and anti-inflammatory properties. It is likely that clusterin works together in this way with other extracellular chaperones to protect the eye from disease, and we discuss several examples. We end this article by predicting future steps that may lead to development of clusterin as a biological drug.
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Affiliation(s)
- Mark R Wilson
- Molecular Horizons and the School of Chemistry and Molecular Bioscience, University of Wollongong; Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, New South Wales, 2522, Australia.
| | - Sandeep Satapathy
- Molecular Horizons and the School of Chemistry and Molecular Bioscience, University of Wollongong; Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, New South Wales, 2522, Australia.
| | - Shinwu Jeong
- USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 1333 San Pablo Street., Los Angeles, CA, 90033, USA.
| | - M Elizabeth Fini
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine; Program in Pharmacology & Drug Development, Graduate School of Biomedical Sciences, Tufts University, 800 Washington St, Boston, MA, 02111, USA.
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2
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Skugor A, Kjos NP, Sundaram AYM, Mydland LT, Ånestad R, Tauson AH, Øverland M. Effects of long-term feeding of rapeseed meal on skeletal muscle transcriptome, production efficiency and meat quality traits in Norwegian Landrace growing-finishing pigs. PLoS One 2019; 14:e0220441. [PMID: 31390356 PMCID: PMC6685631 DOI: 10.1371/journal.pone.0220441] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 07/16/2019] [Indexed: 12/30/2022] Open
Abstract
This study was performed to investigate the effects of dietary inclusion of 20% rapeseed meal (RSM) as an alternative to soybean meal (SBM) in a three-month feeding experiment with growing finishing pigs. Dietary alteration affected growth performance, several carcass traits and transcriptional responses in the skeletal muscle, but did not affect measured meat quality traits. In general, pigs fed the RSM test diet exhibited reduced growth performance compared to pigs on SBM control diet. Significant transcriptional changes in the skeletal muscle of growing pigs fed RSM diet were likely the consequence of an increased amount of fiber and higher polyunsaturated fatty acids, and presence of bioactive phytochemicals, such as glucosinolates. RNAseq pipeline using Tophat2-Cuffdiff identified 57 upregulated and 63 downregulated genes in RSM compared to SBM pigs. Significantly enriched among downregulated pathways was p53-mediated signalling involved in cellular proliferation, while activation of negative growth regulators (IER5, KLF10, BTG2, KLF11, RETREG1, PRUNE2) in RSM fed pigs provided further evidence for reduced proliferation and increased cellular death, in accordance with the observed reduction in performance traits. Upregulation of well-known metabolic controllers (PDK4, UCP3, ESRRG and ESRRB), involved in energy homeostasis (glucose and lipid metabolism, and mitochondrial function), suggested less available energy and nutrients in RSM pigs. Furthermore, several genes supported more pronounced proteolysis (ABTB1, OTUD1, PADI2, SPP1) and reduced protein synthesis (THBS1, HSF4, AP1S2) in RSM muscle tissue. In parallel, higher levels of NR4A3, PDK4 and FGF21, and a drop in adropin, ELOVL6 and CIDEC/FSP27 indicated increased lipolysis and fatty acid oxidation, reflective of lower dressing percentage. Finally, pigs exposed to RSM showed greater expression level of genes responsive to oxidative stress, indicated by upregulation of GPX1, GPX2, and TXNIP.
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Affiliation(s)
- Adrijana Skugor
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Aas, Norway
| | - Nils Petter Kjos
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Aas, Norway
| | | | - Liv Torunn Mydland
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Aas, Norway
| | - Ragnhild Ånestad
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Aas, Norway
| | - Anne-Helene Tauson
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Aas, Norway
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Margareth Øverland
- Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Aas, Norway
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3
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Patterson-Orazem AC, Lieberman RL. Antibodies Used to Detect Glaucoma-Associated Myocilin: More or Less Than Meets the Eye? Invest Ophthalmol Vis Sci 2019; 60:2034-2037. [PMID: 31067323 PMCID: PMC6890424 DOI: 10.1167/iovs.19-26843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Antibodies are key reagents used in vision research, indeed across biomedical research, but they often do not reveal the whole story about a sample. It is important for researchers to be aware of aspects of antibodies that may affect or limit data interpretation. Federal agencies now require funded grants to demonstrate how they will authenticate reagents used. There is also a push for recombinant antibodies, enabled by phage display technology awarded the 2018 Nobel Prize in Chemistry, which allow for thorough validation and a fixed DNA sequence. Here, we discuss how issues surrounding antibodies are pertinent to detecting myocilin, a protein found in trabecular meshwork and associated with a portion of hereditary glaucoma. Confirmation of myocilin expression in tissues and cell culture has been adopted as validation standard in trabecular meshwork research; thus, a discussion of antibody characteristics and fidelity is critical. Further, based on our basic structural understanding of myocilin architecture and its biophysical aggregation properties, we provide a wish list for the characteristics of next-generation antibody reagents for vision researchers. In the long term, well-characterized antibodies targeting myocilin will enable new insights into its function and involvement in glaucoma pathogenesis.
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Affiliation(s)
- Athéna C Patterson-Orazem
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Raquel L Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
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4
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Patterson-Orazem AC, Hill SE, Fautsch MP, Lieberman RL. Epitope mapping of commercial antibodies that detect myocilin. Exp Eye Res 2018; 173:109-112. [PMID: 29752947 DOI: 10.1016/j.exer.2018.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/17/2018] [Accepted: 05/05/2018] [Indexed: 01/26/2023]
Abstract
The presence of myocilin is often used in the process of validating trabecular meshwork (TM) cells and eye tissues, but the antibody reagents used for detection are poorly characterized. Indeed, for over a century, researchers have been using antibodies to track proteins of interest in a variety of biological contexts, but many antibodies remain ill-defined at the molecular level and in their target epitope. Such issues have prompted efforts from major funding agencies to validate reagents and combat reproducibility issues across biomedical sciences. Here we characterize the epitopes recognized by four commercial myocilin antibodies, aided by structurally and biochemically characterized myocilin fragments. All four antibodies recognize enriched myocilin secreted from human TM cell media. The detection of myocilin fragments by ELISA and Western blot reveal a variety of epitopes across the myocilin polypeptide chain. A more precise understanding of myocilin antibody targets, including conformational specificity, should aid the community in standardizing protocols across laboratories and in turn, lead to a better understanding of eye physiology and disease.
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Affiliation(s)
- Athéna C Patterson-Orazem
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, United States
| | - Shannon E Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, United States
| | - Michael P Fautsch
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, 55905, United States
| | - Raquel L Lieberman
- School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, United States.
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5
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Keller KE, Bhattacharya SK, Borrás T, Brunner TM, Chansangpetch S, Clark AF, Dismuke WM, Du Y, Elliott MH, Ethier CR, Faralli JA, Freddo TF, Fuchshofer R, Giovingo M, Gong H, Gonzalez P, Huang A, Johnstone MA, Kaufman PL, Kelley MJ, Knepper PA, Kopczynski CC, Kuchtey JG, Kuchtey RW, Kuehn MH, Lieberman RL, Lin SC, Liton P, Liu Y, Lütjen-Drecoll E, Mao W, Masis-Solano M, McDonnell F, McDowell CM, Overby DR, Pattabiraman PP, Raghunathan VK, Rao PV, Rhee DJ, Chowdhury UR, Russell P, Samples JR, Schwartz D, Stubbs EB, Tamm ER, Tan JC, Toris CB, Torrejon KY, Vranka JA, Wirtz MK, Yorio T, Zhang J, Zode GS, Fautsch MP, Peters DM, Acott TS, Stamer WD. Consensus recommendations for trabecular meshwork cell isolation, characterization and culture. Exp Eye Res 2018; 171:164-173. [PMID: 29526795 PMCID: PMC6042513 DOI: 10.1016/j.exer.2018.03.001] [Citation(s) in RCA: 205] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/30/2022]
Abstract
Cultured trabecular meshwork (TM) cells are a valuable model system to study the cellular mechanisms involved in the regulation of conventional outflow resistance and thus intraocular pressure; and their dysfunction resulting in ocular hypertension. In this review, we describe the standard procedures used for the isolation of TM cells from several animal species including humans, and the methods used to validate their identity. Having a set of standard practices for TM cells will increase the scientific rigor when used as a model, and enable other researchers to replicate and build upon previous findings.
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Affiliation(s)
| | | | | | | | | | - Abbott F Clark
- University of North Texas Health Sciences Center, United States
| | | | - Yiqin Du
- University of Pittsburgh, United States
| | | | | | | | - Thomas F Freddo
- Massachusetts College of Pharmacy and Health Sciences, United States
| | | | | | | | | | - Alex Huang
- University of California, Los Angeles, United States
| | | | | | | | | | | | | | | | | | | | - Shan C Lin
- University of California, San Francisco, United States
| | | | | | | | - Weiming Mao
- University of North Texas Health Sciences Center, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - James C Tan
- University of Southern California, United States
| | | | | | | | - Mary K Wirtz
- Oregon Health and Science University, United States
| | - Thomas Yorio
- University of North Texas Health Sciences Center, United States
| | - Jie Zhang
- University of California, Los Angeles, United States
| | - Gulab S Zode
- University of North Texas Health Sciences Center, United States
| | - Michael P Fautsch
- Department of Ophthalmology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States.
| | - Donna M Peters
- Department of Pathology & Laboratory Medicine, University of Wisconsin, 1300 University Ave, Madison, WI 53706, United States.
| | - Ted S Acott
- Department of Ophthalmology, Department of Biochemistry & Molecular Biology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, United States.
| | - W Daniel Stamer
- Department of Ophthalmology, Duke University, DUMC 3802, Durham, NC 27705, United States.
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6
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Kasetti RB, Phan TN, Millar JC, Zode GS. Expression of Mutant Myocilin Induces Abnormal Intracellular Accumulation of Selected Extracellular Matrix Proteins in the Trabecular Meshwork. Invest Ophthalmol Vis Sci 2017; 57:6058-6069. [PMID: 27820874 PMCID: PMC5102566 DOI: 10.1167/iovs.16-19610] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Abnormal accumulation of extracellular matrix (ECM) in the trabecular meshwork (TM) is associated with decreased aqueous humor outflow facility and IOP elevation in POAG. Previously, we have developed a transgenic mouse model of POAG (Tg-MYOCY437H) by expressing human mutant myocilin (MYOC), a known genetic cause of POAG. The purpose of this study is to examine whether expression of mutant myocilin leads to reduced outflow facility and abnormal ECM accumulation in Tg-MYOCY437H mice and in cultured human TM cells. Methods Conscious IOP was measured at various ages of Tg-MYOCY437H mice using a rebound tonometer. Outflow facility was measured in 10-month-old Tg-MYOCY437H mice. Selected ECM proteins were examined in human TM-3 cells stably expressing mutant myocilin and primary human TM cells (n = 4) as well as in the TM of Tg-MYOCY437H mice by real-time PCR, Western blotting, and immunostaining. Furthermore, TM cells expressing WT or mutant myocilin were treated with 5 mM sodium 4-phenylbutyrate (PBA), and ECM proteins were examined by Western blot and immunostaining. Results Starting from 3 months of age, Tg-MYOCY437H mice exhibited significant IOP elevation compared with wild-type (WT) littermates. Outflow facility was significantly reduced in Tg-MYOCY437H mice (0.0195 μl/min/mm Hg in Tg-MYOCY437H vs. 0.0332 μl/min/mm Hg in WT littermates). Increased accumulation of fibronectin, elastin, and collagen type IV and I was observed in the TM of Tg-MYOCY437H mice compared with WT littermates. Furthermore, increased ECM proteins were also associated with induction of endoplasmic reticulum (ER) stress markers, GRP78 and CHOP in the TM of Tg-MYOCY437H mice. Human TM-3 cells stably expressing DsRed-tagged Y437H mutant MYOC exhibited inhibition of myocilin secretion and its intracellular accumulation compared with TM cells expressing WT MYOC. Expression of mutant MYOC in TM-3 cells or human primary TM cells induced ER stress and also increased intracellular protein levels of fibronectin, elastin, laminin, and collagen IV and I. In addition, TM-3 cells expressing mutant myocilin exhibited reduced active forms of matrix metalloproteinase (MMP)-2 and MMP-9 in conditioned medium compared with TM-3 cells expressing WT myocilin. Interestingly, both intracellularly accumulated fibronectin and collagen I colocalized with mutant myocilin and also with ER marker KDEL further suggesting intracellular accumulation of these proteins in the ER of TM cells. Furthermore, reduction of ER stress via PBA decreased selected ECM proteins in primary TM cells. Conclusions These studies demonstrate that mutant myocilin induces abnormal ECM accumulation in the ER of TM cells, which may be responsible for reduced outflow facility and IOP elevation in myocilin-associated glaucoma.
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Affiliation(s)
- Ramesh B Kasetti
- North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Texas, United States
| | - Tien N Phan
- North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Texas, United States
| | - J Cameron Millar
- North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Texas, United States
| | - Gulab S Zode
- North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Texas, United States
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Liu Y, Zhang P, Pan J, D'Souza MA, Dufresne CP, Semba RD, Qian J, Edward DP. Anatomical differences of the protein profile in the rabbit sclera during growth. Exp Eye Res 2017; 154:53-63. [DOI: 10.1016/j.exer.2016.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 10/07/2016] [Accepted: 11/01/2016] [Indexed: 10/20/2022]
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Itakura T, Peters DM, Fini ME. Glaucomatous MYOC mutations activate the IL-1/NF-κB inflammatory stress response and the glaucoma marker SELE in trabecular meshwork cells. Mol Vis 2015; 21:1071-84. [PMID: 26396484 PMCID: PMC4575906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 09/15/2015] [Indexed: 11/14/2022] Open
Abstract
PURPOSE Activation of the IL-1/NF-κB inflammatory stress pathway and induction of SELE expression in the trabecular meshwork (TBM) is a marker for high-tension glaucomas of diverse etiology. Pathway activation stimulates aqueous outflow and protects against oxidative stress, but may be damaging in the long-term. MYOC mutations have been causally linked to high-tension forms of primary open angle glaucoma (POAG). This study investigated a possible link between MYOC mutations and activation of the IL-1/NF-κB pathway and expression of SELE. METHODS We constructed MYOC expression vectors with mutations at sites that cause POAG. Mutations (Q368X, Y437H, A427T) were selected to represent proteins with differing POAG-causing potency (Q368X > Y437H > A427T) and intracellular retention behavior (Q368X and Y437H retained, A427T released). The constructs were made in two different kinds of vectors; one a plasmid designed for transient transfection (pCMV6), and one a doxycycline-inducible lentiviral vector (pSLIK) for stable cell transduction. The immortalized human trabecular meshwork line TM-1 was used for all expression studies. Expression of IL1A mRNA was determined by reverse transcription (RT)-PCR, as well as a set of five other genes associated with signaling pathways linked to glaucoma: IL1B and IL6 (NF-κB pathway), TGFB2 and ACTA2 (TGF-β pathway) and FOXO1 (E2F1 apoptotic pathway). An ELISA was used to quantify IL1A protein released into culture media. To quantify intracellular NF-κB activity, we transiently transfected stably transduced cell lines with a luciferase expression vector under control of the IL8 promoter (containing an NF-κB response element). RESULTS Transiently expressed wild-type MYOC was released into cell culture media, whereas mutant MYOCs Q368X and Y437H remained within cells. Both mutant MYOCs activated the IL-1/ NF-κB pathway, significantly stimulating expression of IL1A and IL1B. However Y437H, which causes a severe glaucoma phenotype, was less effective than Q368X, which causes a moderate glaucoma phenotype. In addition, the retained mutants stimulated expression of stress response genes ACTA2 and FOXO1. Unexpectedly, wild-type MYOC significantly decreased expression of IL6 and TGFB2, to approximately half of the control levels, and expression of IL1B and ACTA2 was also slightly decreased. Induction of MYOC mutants Q368X and Y437H in stably transduced cell lines significantly stimulated the level of IL1A protein released into culture media. Once again however, the effect of the severe MYOC mutant Y437H was less than the effect of the moderate MYOC mutant Q368X. In contrast, induced expression of the intracellularly retained mutant MYOC A427T or wild-type MYOC did not change the amount of IL1A protein in culture media. Induction of Y437H MYOC plus IL1A treatment increased NF-κB activity by 25% over IL1A alone. In contrast, induction of Q368X or A427T plus IL1A treatment did not significantly affect NF-κB activity over IL1A alone. However, wild-type MYOC expression inhibited IL1A-stimulated NF-κB activity. We also observed that endogenous MYOC expression was induced by IL1A in TM-1 cells and primary TBM cell cultures. SELE was co-expressed with MYOC in the primary cell lines. CONCLUSIONS These results indicate that POAG-causing MYOC mutants activate the IL-1/NF-κB pathway, with activation levels correlated with intracellular retention of the protein, but not POAG-causing potency. Unexpectedly, it was also discovered that wild-type MYOC inhibits activation of the IL-1/NF-κB pathway, and that activation of the IL-1/NF-κB pathway stimulates expression of MYOC. This is the first evidence that glaucoma-causing MYOC mutants can activate the inflammatory response and that wild-type MYOC has anti-inflammatory activity.
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Affiliation(s)
- Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA
| | - Donna M. Peters
- Departments of Pathology & Laboratory Medicine and Ophthalmology & Visual Sciences, University of Wisconsin, Madison, WI
| | - M. Elizabeth Fini
- USC Institute for Genetic Medicine, USC Eye Institute, and Departments of Cell & Neurobiology and Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA
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Wu Y, Chen W, Guo M, He Q, Hu Y. Effects of transforming growth factor-β2 on myocilin expression and secretion in human primary cultured trabecular meshwork cells. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2014; 7:4827-4836. [PMID: 25197353 PMCID: PMC4152043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/23/2014] [Indexed: 06/03/2023]
Abstract
High intraocular pressure (IOP) is a risk factor for primary open-angle glaucoma (POAG). The trabecular meshwork (TM), a reticular tissue in the outflow passage of the aqueous humor (AH), is a major contributor to intraocular outflow resistance. High levels of myocilin (MYOC), which is expressed in the TM, are associated with high IOP. Furthermore, transforming growth factor-β2 (TGF-β2) concentrations in human AH are significantly elevated in POAG patients. This study was designed to investigate the effects of TGF-β2 on MYOC expression and secretion in human primary cultured TM cells. Primary cultured human TM cells were treated with 0 (control group), 1, 10, and 100 ng/mL TGF-β2 for 12, 24, or 48 h. MYOC mRNA and protein expressions in TM cells and protein secretion in conditioned media were analyzed by semi-quantitative RT-PCR, Western blotting, and enzyme-linked immunosorbent assays (ELISA), respectively. TM cells treated with 1, 10, and, 100 ng/mL TGF-β2 for 48 h showed higher MYOC mRNA and protein expressions than those in the control group (0 ng/mL TGF-β2) (all P < 0.05). Treatment with TGF-β2 for 48 h also induced MYOC secretion in conditioned media in a dose-dependent manner (0 ng/mL: 7.107±1.163 pg/ml; 1 ng/mL: 7.879±1.894 pg/ml; 10 ng/mL: 8.063±1.181 pg/ml; 100 ng/mL: 8.902±0.699 pg/ml; all P < 0.05). In Conclusion, TGF-β2 induced MYOC expression and secretion in human primary cultured TM cells. Further investigations are required to confirm the involvement of these two factors in POAG pathogenesis.
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Affiliation(s)
- Yuyu Wu
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University Quanzhou, China
| | - Wanzhu Chen
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University Quanzhou, China
| | - Maosheng Guo
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University Quanzhou, China
| | - Qin He
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University Quanzhou, China
| | - Yan Hu
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University Quanzhou, China
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10
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Orwig SD, Chi PV, Du Y, Hill SE, Cavitt MA, Suntharalingam A, Turnage KC, Dickey CA, France S, Fu H, Lieberman RL. Ligands for glaucoma-associated myocilin discovered by a generic binding assay. ACS Chem Biol 2014; 9:517-25. [PMID: 24279319 DOI: 10.1021/cb4007776] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mutations in the olfactomedin domain of myocilin (myoc-OLF) are the strongest link to inherited primary open angle glaucoma. In this recently identified protein misfolding disorder, aggregation-prone disease variants of myocilin hasten glaucoma-associated elevation of intraocular pressure, leading to vision loss. Despite its well-documented pathogenic role, myocilin remains a domain of unknown structure or function. Here we report the first small-molecule ligands that bind to the native state of myoc-OLF. To discover these molecules, we designed a general label-free, mix-and-measure, high throughput chemical assay for restabilization (CARS), which is likely readily adaptable to discover ligands for other proteins. Of the 14 hit molecules identified from screening myoc-OLF against the Sigma-Aldrich Library of Pharmacologically Active Compounds using CARS, surface plasmon resonance binding studies reveal three are stoichiometric ligand scaffolds with low micromolar affinity. Two compounds, GW5074 and apigenin, inhibit myoc-OLF amyloid formation in vitro. Structure-activity relationship-based soluble derivatives reduce aggregation in vitro as well as enhance secretion of full-length mutant myocilin in a cell culture model. Our compounds set the stage for a new chemical probe approach to clarify the biological function of wild-type myocilin and represent lead therapeutic compounds for diminishing intracellular sequestration of toxic mutant myocilin.
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Affiliation(s)
- Susan D. Orwig
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
| | - Pamela V. Chi
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
| | - Yuhong Du
- Department
of Pharmacology, Emory University School of Medicine, 1510 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Shannon E. Hill
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
| | - Marchello A. Cavitt
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
| | - Amrithaa Suntharalingam
- Department
of Molecular Medicine and Byrd Alzheimer’s Research Institute, University of South Florida, 4001 E. Fletcher Ave. Tampa, Florida 33613, United States
| | - Katherine C. Turnage
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
| | - Chad A. Dickey
- Department
of Molecular Medicine and Byrd Alzheimer’s Research Institute, University of South Florida, 4001 E. Fletcher Ave. Tampa, Florida 33613, United States
| | - Stefan France
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
| | - Haian Fu
- Department
of Pharmacology, Emory University School of Medicine, 1510 Clifton
Road, Atlanta, Georgia 30322, United States
| | - Raquel L. Lieberman
- School of Chemistry & Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive NW, Atlanta, Georgia 30332-0400, United States
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