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Wu X, Liang J, Liu J, Huang Y, Zhang L, Liu X, Guo J, Zhang M, Chen Y, Wang J. Silibinin attenuates TGF-β2-induced fibrogenic changes in human trabecular meshwork cells by targeting JAK2/STAT3 and PI3K/AKT signaling pathways. Exp Eye Res 2024; 244:109939. [PMID: 38789021 DOI: 10.1016/j.exer.2024.109939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/13/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024]
Abstract
Transforming growth factor-β2 (TGF-β2) induced fibrogenic changes in human trabecular meshwork (HTM) cells have been implicated in trabecular meshwork (TM) damage and intraocular pressure (IOP) elevation in primary open-angle glaucoma (POAG) patients. Silibinin (SIL) exhibited anti-fibrotic properties in various organs and tissues. This study aimed to assess the effects of SIL on the TGF-β2-treated HTM cells and to elucidate the underlying mechanisms. Our study found that SIL effectively inhibited HTM cell proliferation, attenuated TGF-β2-induced cell migration, and mitigated TGF-β2-induced reorganization of both actin and vimentin filaments. Moreover, SIL suppressed the expressions of fibronectin (FN), collagen type I alpha 1 chain (COL1A1), and alpha-smooth muscle actin (α-SMA) in the TGF-β2-treated HTM cells. RNA sequencing indicated that SIL interfered with the phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB, also known as AKT) signaling pathway, extracellular matrix (ECM)-receptor interaction, and focal adhesion in the TGF-β2-treated HTM cells. Western blotting demonstrated SIL inhibited the activation of Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) and the downstream PI3K/AKT signaling pathways induced by TGF-β2, potentially contributing to its inhibitory effects on ECM protein production in the TGF-β2-treated HTM cells. Our study demonstrated the ability of SIL to inhibit TGF-β2-induced fibrogenic changes in HTM cells. SIL could be a potential IOP-lowering agent by reducing the fibrotic changes in the TM tissue of POAG patients, which warrants further investigation through additional animal and clinical studies.
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Affiliation(s)
- Xueping Wu
- Jinzhou Medical University, Jinzhou, Liaoning, 121001, China; Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China
| | - Jia Liang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China
| | - Jinfeng Liu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China
| | - Yijia Huang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China
| | - Liyun Zhang
- Department of Ophthalmology, General Hospital of Central Theater Command, Wuhan 430070, P.R. China
| | - Xin Liu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China
| | - Junhong Guo
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China
| | - Min Zhang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China
| | - Yudong Chen
- The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong, 523700, China.
| | - Jiantao Wang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, 518040, China.
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Short and long-term effect of dexamethasone on the transcriptome profile of primary human trabecular meshwork cells in vitro. Sci Rep 2022; 12:8299. [PMID: 35585182 PMCID: PMC9117214 DOI: 10.1038/s41598-022-12443-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/06/2022] [Indexed: 12/13/2022] Open
Abstract
In the quest of identifying newer molecular targets for the management of glucocorticoid-induced ocular hypertension (GC-OHT) and glaucoma (GCG), several microarray studies have attempted to investigate the genome-wide transcriptome profiling of primary human trabecular meshwork (TM) cells in response to dexamethasone (DEX). However, no studies are reported so far to demonstrate the temporal changes in the expression of genes in the cultured human TM cells in response to DEX treatment. Therefore, in the present study, the time-dependent changes in the genome-wide expression of genes in primary human TM cells after short (16 hours: 16 h) and long exposure (7 days: 7 d) of DEX was investigated using RNA sequencing. There were 199 (118 up-regulated; 81 down-regulated) and 525 (119 up-regulated; 406 down-regulated) DEGs in 16 h and 7 d treatment groups respectively. The unique genes identified in 16 h and 7 d treatment groups were 152 and 478 respectively. This study found a distinct gene signature and pathways between two treatment regimes. Longer exposure of DEX treatment showed a dys-regulation of Wnt and Rap1 signaling and so highlighted potential therapeutic targets for pharmacological management of GC-OHT/glaucoma.
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Oouchi Y, Watanabe M, Ida Y, Ohguro H, Hikage F. Rosiglitasone and ROCK Inhibitors Modulate Fibrogenetic Changes in TGF-β2 Treated Human Conjunctival Fibroblasts (HconF) in Different Manners. Int J Mol Sci 2021; 22:ijms22147335. [PMID: 34298955 PMCID: PMC8307967 DOI: 10.3390/ijms22147335] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/16/2021] [Accepted: 07/02/2021] [Indexed: 02/08/2023] Open
Abstract
Purpose: The effects of Rho-associated coiled-coil containing protein kinase (ROCK) 1 and 2 inhibitor, ripasudil hydrochloride hydrate (Rip), ROCK2 inhibitor, KD025 or rosiglitazone (Rosi) on two-dimension (2D) and three-dimension (3D) cultured human conjunctival fibroblasts (HconF) treated by transforming growth factor (TGFβ2) were studied. Methods: Two-dimension and three-dimension cultured HconF were examined by transendothelial electrical resistance (TEER, 2D), size and stiffness (3D), and the expression of the extracellular matrix (ECM) including collagen1 (COL1), COL4 and COL6, fibronectin (FN), and α-smooth muscle actin (αSMA) by quantitative PCR (2D, 3D) in the presence of Rip, KD025 or Rosi. Results: TGFβ2 caused a significant increase in (1) the TEER values (2D) which were greatly reduced by Rosi, (2) the stiffness of the 3D organoids which were substantially reduced by Rip or KD025, and (3) TGFβ2 induced a significant up-regulation of all ECMs, except for COL6 (2D) or αSMA (3D), and down-regulation of COL6 (2D). Rosi caused a significant up-regulation of COL1, 4 and 6 (3D), and down-regulation of COL6 (2D) and αSMA (3D). Most of these TGFβ2-induced expressions in the 2D and αSMA in the 3D were substantially inhibited by KD025, but COL4 and αSMA in 2D were further enhanced by Rip. Conclusion: The findings reported herein indicate that TGFβ2 induces an increase in fibrogenetic changes on the plane and in the spatial space, and are inhibited by Rosi and ROCK inhibitors, respectively.
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TGFβ2-induced formation of lipid droplets supports acidosis-driven EMT and the metastatic spreading of cancer cells. Nat Commun 2020; 11:454. [PMID: 31974393 PMCID: PMC6978517 DOI: 10.1038/s41467-019-14262-3] [Citation(s) in RCA: 166] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Accepted: 12/23/2019] [Indexed: 11/10/2022] Open
Abstract
Acidosis, a common characteristic of the tumor microenvironment, is associated with alterations in metabolic preferences of cancer cells and progression of the disease. Here we identify the TGF-β2 isoform at the interface between these observations. We document that acidic pH promotes autocrine TGF-β2 signaling, which in turn favors the formation of lipid droplets (LD) that represent energy stores readily available to support anoikis resistance and cancer cell invasiveness. We find that, in cancer cells of various origins, acidosis-induced TGF-β2 activation promotes both partial epithelial-to-mesenchymal transition (EMT) and fatty acid metabolism, the latter supporting Smad2 acetylation. We show that upon TGF-β2 stimulation, PKC-zeta-mediated translocation of CD36 facilitates the uptake of fatty acids that are either stored as triglycerides in LD through DGAT1 or oxidized to generate ATP to fulfill immediate cellular needs. We also address how, by preventing fatty acid mobilization from LD, distant metastatic spreading may be inhibited. The tumour microenvironment is known to have an acidic pH but how this influences cancer cell phenotype is unclear. Here, the authors show that tumour cells upregulate TGF-β2 under acidosis, which leads to the increased formation of lipid droplets allowing for invasiveness and metastases.
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Ashworth Briggs EL, Toh T, Eri R, Hewitt AW, Cook AL. Uteroglobin and FLRG concentrations in aqueous humor are associated with age in primary open angle glaucoma patients. BMC Ophthalmol 2018; 18:57. [PMID: 29482497 PMCID: PMC5828060 DOI: 10.1186/s12886-018-0723-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 02/19/2018] [Indexed: 11/22/2022] Open
Abstract
Background The pathophysiological changes occurring in the trabecular meshwork in primary open angle glaucoma are poorly understood, but are thought to include increased extracellular matrix deposition, trabecular meshwork cell apoptosis, inflammation, trabecular meshwork calcification and altered protein composition of the aqueous humor. Although many proteins are present in aqueous humor, relatively few have been studied extensively, and their potential roles in primary open angle glaucoma are unknown. Methods Analyte concentrations in aqueous humor from 19 primary open angle glaucoma and 18 cataract patients were measured using a multiplex immunoassay. Fisher’s exact test was used to assess statistical significance between groups, and correlations of analyte concentrations with age, intraocular pressure, pattern standard deviation, mean deviation, cup-to-disc ratio and disease duration since commencing treatment were tested by Spearman’s method. Results CHI3L1, FLRG, HGF, MIF, P-selectin and Uteroglobin were detected in more than 50% of samples of one or both patient groups, some of which have not previously been quantified in aqueous humor. In the glaucoma but not the cataract group, significant correlations were determined with age for Uteroglobin/SCGB1A1 (rs = 0.805, p < 0.0001) and FLRG (rs = 0.706, p = 0.0007). Furthermore, HGF correlated significantly with disease duration (rs = − 0.723, p = 0.0007). There were no differences in analyte concentrations between groups, and no other significant associations with clinical descriptors that passed correction for multiple testing. Conclusions The correlations of uteroglobin and FLRG with age in primary open angle glaucoma but not cataract may suggest a heightened requirement for anti-inflammatory (uteroglobin) or anti-calcification (FLRG) activity in the ageing glaucomatous trabecular meshwork. Electronic supplementary material The online version of this article (10.1186/s12886-018-0723-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Tze'Yo Toh
- Launceston Eye Institute and Launceston Eye Doctors, Launceston, Australia
| | - Rajaraman Eri
- School of Health Sciences, University of Tasmania, Launceston, Australia
| | - Alex W Hewitt
- School of Health Sciences, University of Tasmania, Launceston, Australia.,Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
| | - Anthony L Cook
- School of Health Sciences, University of Tasmania, Launceston, Australia. .,Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, 7001, Australia.
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Abstract
Transforming growth factor-β (TGF-β) may play a role in the pathogenesis of primary open-angle glaucoma (POAG). Elevated levels of TGF-β are found in the aqueous humor and in reactive optic nerve astrocytes in patients with glaucoma. In POAG, aqueous humor outflow resistance at the trabecular meshwork (TM) leads to increased intraocular pressure and retinal ganglion cell death. It is hypothesized that TGF-β increases outflow resistance by altering extracellular matrix homeostasis and cell contractility in the TM through interactions with other proteins and signaling molecules. TGF-β may also be involved in damage to the optic nerve head. Current available therapies for POAG focus exclusively on lowering intraocular pressure without addressing extracellular matrix homeostasis processes in the TM. The purpose of this review is to discuss possible therapeutic strategies targeting TGF-β in the treatment of POAG. Herein, we describe the current understanding of the role of TGF-β in POAG pathophysiology, and examine ways TGF-β may be targeted at the levels of production, activation, downstream signaling, and homeostatic regulation.
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Raghunathan VK, Morgan JT, Park SA, Weber D, Phinney BS, Murphy CJ, Russell P. Dexamethasone Stiffens Trabecular Meshwork, Trabecular Meshwork Cells, and Matrix. Invest Ophthalmol Vis Sci 2015; 56:4447-59. [PMID: 26193921 PMCID: PMC4509060 DOI: 10.1167/iovs.15-16739] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/22/2015] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Treatment with corticosteroids can result in ocular hypertension and may lead to the development of steroid-induced glaucoma. The extent to which biomechanical changes in trabecular meshwork (TM) cells and extracellular matrix (ECM) contribute toward this dysfunction is poorly understood. METHODS Primary human TM (HTM) cells were cultured for either 3 days or 4 weeks in the presence or absence of dexamethasone (DEX), and cell mechanics, matrix mechanics and proteomics were determined, respectively. Adult rabbits were treated topically with either 0.1% DEX or vehicle over 3 weeks, and mechanics of the TM were determined. RESULTS Treatment with DEX for 3 days resulted in a 2-fold increase in HTM cell stiffness, and this correlated with activation of extracellular signal-related kinase 1/2 (ERK1/2) and overexpression of α-smooth muscle actin (αSMA). Further, the matrix deposited by HTM cells chronically treated with DEX is approximately 4-fold stiffer, more organized, and has elevated expression of matrix proteins commonly implicated in glaucoma (decorin, myocilin, fibrillin, secreted frizzle-related protein [SFRP1], matrix-gla). Also, DEX treatment resulted in a 3.5-fold increase in stiffness of the rabbit TM. DISCUSSION This integrated approach clearly demonstrates that DEX treatment increases TM cell stiffness concurrent with elevated αSMA expression and activation of the mitogen-activated protein kinase (MAPK) pathway, stiffens the ECM in vitro along with upregulation of Wnt antagonists and fibrotic markers embedded in a more organized matrix, and increases the stiffness of TM tissues in vivo. These results demonstrate glucocorticoid treatment can initiate the biophysical alteration associated with increased resistance to aqueous humor outflow and the resultant increase in IOP.
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Affiliation(s)
- Vijay Krishna Raghunathan
- Department of Surgical and Radiological Sciences School of Veterinary Medicine, University of California Davis, Davis, California, United States
| | - Joshua T. Morgan
- Department of Surgical and Radiological Sciences School of Veterinary Medicine, University of California Davis, Davis, California, United States
| | - Shin Ae Park
- Department of Surgical and Radiological Sciences School of Veterinary Medicine, University of California Davis, Davis, California, United States
| | - Darren Weber
- University of California Davis Genome Center Proteomics Core Facility, University of California Davis, Davis, California, United States
| | - Brett S. Phinney
- University of California Davis Genome Center Proteomics Core Facility, University of California Davis, Davis, California, United States
| | - Christopher J. Murphy
- Department of Surgical and Radiological Sciences School of Veterinary Medicine, University of California Davis, Davis, California, United States
- Department of Ophthalmology and Vision Sciences, School of Medicine, University of California Davis, Davis, California, United States
| | - Paul Russell
- Department of Surgical and Radiological Sciences School of Veterinary Medicine, University of California Davis, Davis, California, United States
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Raghunathan VK, Morgan JT, Chang YR, Weber D, Phinney B, Murphy CJ, Russell P. Transforming Growth Factor Beta 3 Modifies Mechanics and Composition of Extracellular Matrix Deposited by Human Trabecular Meshwork Cells. ACS Biomater Sci Eng 2015; 1:110-118. [PMID: 30882039 DOI: 10.1021/ab500060r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Pseudoexfoliation syndrome is a systemic disorder of the extracellular matrix (ECM) with ocular manifestations in the form of chronic open angle glaucoma. Elevated levels of TGFβ3 in the aqueous humor of individuals with pseudoexfoliation glaucoma (PEX) have been reported. The influence of TGFβ3 on the biochemical composition and biomechanics of ECM of human trabecular meshwork (HTM) cells was investigated. HTM cells from eye bank donor eyes were isolated, plated on aminosilane functionalized glass substrates and cultured in the presence or absence of 1 ng/mL TGFβ3 for 4 weeks. After incubation, samples were decellularized and decellularization was verified by immunostaining. The mechanics of the remaining ECM that was deposited by the treated or the control cells were measured by atomic force microscopy (AFM). Imaged by AFM, the surface features of the ECM from both sets of samples had a similar roughness/topography (as determined by RMS values) suggesting surface features of the ECM were similar in both cases; however, the ECM from the HTM cells treated with TGFβ3 was between 3- and 5-fold stiffer than that produced by the control HTM cells. Proteins present in the ECM were solubilized and analyzed using liquid chromatography tandem mass spectroscopy (LC-MS/MS). Data indicate that multiple proteins previously reported to be altered in glaucoma were changed in the ECM as a result of the presence of TGFβ3, including inhibitors of the BMP and Wnt signaling pathways. Gremlin1and 4, SERPINE1 and 2, periostin, secreted frizzled related protein (SFRP) 1 and 4, and ANGPTL4 were among those proteins that were overexpressed in the ECM after TGFβ3 treatment.
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Affiliation(s)
- Vijay Krishna Raghunathan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California 95616, United States
| | - Joshua T Morgan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California 95616, United States
| | - Yow-Ren Chang
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California 95616, United States
| | - Darren Weber
- UC Davis Genome Center Proteomics Core Facility, University of California, Davis, California 95616, United States
| | - Brett Phinney
- UC Davis Genome Center Proteomics Core Facility, University of California, Davis, California 95616, United States
| | - Christopher J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California 95616, United States.,Department of Ophthalmology and Vision Sciences, School of Medicine, University of California, Davis, California 95616, United States
| | - Paul Russell
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California 95616, United States
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Li X, Wang J, Liu H, Wang H, Sun L, Yang C, Li L, Zheng Y. Construction of a eukaryotic expression vector for pEGFP-FST and its biological activity in duck myoblasts. ELECTRON J BIOTECHN 2014. [DOI: 10.1016/j.ejbt.2014.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Fazilaty H, Mehdipour P. Genetics of breast cancer bone metastasis: a sequential multistep pattern. Clin Exp Metastasis 2014; 31:595-612. [PMID: 24493024 DOI: 10.1007/s10585-014-9642-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/26/2014] [Indexed: 02/05/2023]
Abstract
Bone metastasis accounts for the vast majority of breast cancer (BC) metastases, and is related to a high rate of morbidity and mortality. A number of seminal studies have uncovered gene expression signatures involved in BC development and bone metastasis; each of them points at a distinct step of the 'invasion-metastasis cascade'. In this review, we provide most recently discovered functions of sets of genes that are selected from widely accepted gene signatures that are implicate in BC progression and bone metastasis. We propose a possible sequential pattern of gene expression that may lead a benign primary breast tumor to get aggressiveness and progress toward bone metastasis. A panel of genes which primarily deal with features like DNA replication, survival, proliferation, then, angiogenesis, migration, and invasion has been identified. TGF-β, FGF, NFκB, WNT, PI3K, and JAK-STAT signaling pathways, as the key pathways involved in breast cancer development and metastasis, are evidently regulated by several genes in all three signatures. Epithelial to mesenchymal transition that is also an important mechanism in cancer stem cell generation and metastasis is evidently regulated by these genes. This review provides a comprehensive insight regarding breast cancer bone metastasis that may lead to a better understanding of the disease and take step toward better treatments.
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Affiliation(s)
- Hassan Fazilaty
- Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Pour Sina Street, P.O. Box: 14176-13151, Keshavarz Boulevard, Tehran, Iran
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Rao PV. Bioactive lysophospholipids: role in regulation of aqueous humor outflow and intraocular pressure in the context of pathobiology and therapy of glaucoma. J Ocul Pharmacol Ther 2014; 30:181-90. [PMID: 24283588 PMCID: PMC3991961 DOI: 10.1089/jop.2013.0194] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 10/23/2013] [Indexed: 01/21/2023] Open
Abstract
Homeostasis of aqueous humor (AH) outflow and intraocular pressure (IOP) is essential for normal vision. Impaired AH outflow through the trabecular meshwork (TM) and a resultant elevation in IOP are common changes in primary open-angle glaucoma (POAG), which is the most prevalent form of glaucoma. Although elevated IOP has been recognized as a definitive risk factor for POAG and lowering elevated IOP remains a mainstay for glaucoma treatment, little is known about the molecular mechanisms, especially external cues and intracellular pathways, involved in the regulation of AH outflow in both normal and glaucomatous eyes. In addition, despite the recognition that increased resistance to AH outflow via the conventional pathway consisting of TM and Schlemm's canal is the main cause for elevated IOP, there are no clinically approved drugs that target the conventional pathway to lower IOP in glaucoma patients. The aim of this article is to briefly review published work on the importance of bioactive lysophospholipids (eg, lysophosphatidic acid and sphingosine-1-phosphate), their receptors, metabolism, signaling, and role in the regulation of AH outflow via the TM and IOP, and to discuss pharmacological targeting of key proteins in the lysophospholipid signaling pathways to lower IOP in glaucoma patients.
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Affiliation(s)
- Ponugoti Vasantha Rao
- Department of Ophthalmology, Duke University School of Medicine, Durham, North Carolina
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina
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Wordinger RJ, Sharma T, Clark AF. The role of TGF-β2 and bone morphogenetic proteins in the trabecular meshwork and glaucoma. J Ocul Pharmacol Ther 2014; 30:154-62. [PMID: 24517218 DOI: 10.1089/jop.2013.0220] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Primary open-angle glaucoma (POAG) is the second leading cause of blindness worldwide. Elevated intraocular pressure (IOP) is a primary risk factor associated with POAG. Increased aqueous humor (AH) outflow resistance through the trabecular meshwork (TM) results in elevated IOP in POAG patients. Resistance to AH outflow is associated with increased accumulation of extracellular matrix (ECM) proteins in the TM. In addition, levels of transforming growth factor-beta2 (TGF-β2) are elevated in the AH and TM tissue of POAG patients. Elevated levels of TGF-β2 in other tissues have been associated with fibrosis and increased tissue stiffness. However, locally produced effectors that maintain homeostatic relationships must also be present. Bone morphogenetic proteins (BMPs) serve this purpose in the TM as they inhibit TGF-β2-induced ECM changes in TM cells. This review article first describes the TGF-β superfamily of growth factors including BMPs and their canonical and noncanonical signaling pathways. The article then addresses the role of TGF-β2 in the pathophysiology of POAG as related to the ECM and ECM crosslinking enzymes. This is followed by a discussion of potential homeostatic control mechanisms of TGF-β2 signaling in the TM including the inhibitory role of BMP-4 and BMP-7. We then describe the relationship of TGF-β2 and BMPs in TM fibrosis including the role of antagonists. Lastly, in future directions, we identify potential future studies that explore new and unique cellular interactions within the TM for potential therapeutic interventions.
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Affiliation(s)
- Robert J Wordinger
- 1 North Texas Eye Research Institute, University of North Texas Health Science Center , Fort Worth, Texas
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