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Patil SV, Kaipa BR, Ranshing S, Sundaresan Y, Millar JC, Nagarajan B, Kiehlbauch C, Zhang Q, Jain A, Searby CC, Scheetz TE, Clark AF, Sheffield VC, Zode GS. Lentiviral mediated delivery of CRISPR/Cas9 reduces intraocular pressure in a mouse model of myocilin glaucoma. Sci Rep 2024; 14:6958. [PMID: 38521856 PMCID: PMC10960846 DOI: 10.1038/s41598-024-57286-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/16/2024] [Indexed: 03/25/2024] Open
Abstract
Mutations in myocilin (MYOC) are the leading known genetic cause of primary open-angle glaucoma, responsible for about 4% of all cases. Mutations in MYOC cause a gain-of-function phenotype in which mutant myocilin accumulates in the endoplasmic reticulum (ER) leading to ER stress and trabecular meshwork (TM) cell death. Therefore, knocking out myocilin at the genome level is an ideal strategy to permanently cure the disease. We have previously utilized CRISPR/Cas9 genome editing successfully to target MYOC using adenovirus 5 (Ad5). However, Ad5 is not a suitable vector for clinical use. Here, we sought to determine the efficacy of adeno-associated viruses (AAVs) and lentiviruses (LVs) to target the TM. First, we examined the TM tropism of single-stranded (ss) and self-complimentary (sc) AAV serotypes as well as LV expressing GFP via intravitreal (IVT) and intracameral (IC) injections. We observed that LV_GFP expression was more specific to the TM injected via the IVT route. IC injections of Trp-mutant scAAV2 showed a prominent expression of GFP in the TM. However, robust GFP expression was also observed in the ciliary body and retina. We next constructed lentiviral particles expressing Cas9 and guide RNA (gRNA) targeting MYOC (crMYOC) and transduction of TM cells stably expressing mutant myocilin with LV_crMYOC significantly reduced myocilin accumulation and its associated chronic ER stress. A single IVT injection of LV_crMYOC in Tg-MYOCY437H mice decreased myocilin accumulation in TM and reduced elevated IOP significantly. Together, our data indicates, LV_crMYOC targets MYOC gene editing in TM and rescues a mouse model of myocilin-associated glaucoma.
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Affiliation(s)
- Shruti V Patil
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Balasankara Reddy Kaipa
- Department of Ophthalmology and Center for Translational Vision Research, University of California, 829 Health Sciences Rd, Irvine, CA, 92617, USA
| | - Sujata Ranshing
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Yogapriya Sundaresan
- Department of Ophthalmology and Center for Translational Vision Research, University of California, 829 Health Sciences Rd, Irvine, CA, 92617, USA
| | - J Cameron Millar
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Bhavani Nagarajan
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Charles Kiehlbauch
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Qihong Zhang
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
| | - Ankur Jain
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
| | - Charles C Searby
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
| | - Todd E Scheetz
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, 52242, USA
| | - Abbot F Clark
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX, 76107, USA
| | - Val C Sheffield
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, 52242, USA
| | - Gulab S Zode
- Department of Ophthalmology and Center for Translational Vision Research, University of California, 829 Health Sciences Rd, Irvine, CA, 92617, USA.
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2
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Patil SV, Kaipa BR, Ranshing S, Sundaresan Y, Millar JC, Nagarajan B, Kiehlbauch C, Zhang Q, Jain A, Searby CC, Scheetz TE, Clark AF, Sheffield VC, Zode GS. Lentiviral mediated delivery of CRISPR/Cas9 reduces intraocular pressure in a mouse model of myocilin glaucoma. RESEARCH SQUARE 2023:rs.3.rs-3740880. [PMID: 38196579 PMCID: PMC10775399 DOI: 10.21203/rs.3.rs-3740880/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Mutations in myocilin (MYOC) are the leading known genetic cause of primary open-angle glaucoma, responsible for about 4% of all cases. Mutations in MYOC cause a gain-of-function phenotype in which mutant myocilin accumulates in the endoplasmic reticulum (ER) leading to ER stress and trabecular meshwork (TM) cell death. Therefore, knocking out myocilin at the genome level is an ideal strategy to permanently cure the disease. We have previously utilized CRISPR/Cas9 genome editing successfully to target MYOC using adenovirus 5 (Ad5). However, Ad5 is not a suitable vector for clinical use. Here, we sought to determine the efficacy of adeno-associated viruses (AAVs) and lentiviruses (LVs) to target the TM. First, we examined the TM tropism of single-stranded (ss) and self-complimentary (sc) AAV serotypes as well as LV expressing GFP via intravitreal (IVT) and intracameral (IC) injections. We observed that LV_GFP expression was more specific to the TM injected via the IVT route. IC injections of Trp-mutant scAAV2 showed a prominent expression of GFP in the TM. However, robust GFP expression was also observed in the ciliary body and retina. We next constructed lentiviral particles expressing Cas9 and guide RNA (gRNA) targeting MYOC (crMYOC) and transduction of TM cells stably expressing mutant myocilin with LV_crMYOC significantly reduced myocilin accumulation and its associated chronic ER stress. A single IVT injection of LV_crMYOC in Tg-MYOCY437H mice decreased myocilin accumulation in TM and reduced elevated IOP significantly. Together, our data indicates, LV_crMYOC targets MYOC gene editing in TM and rescues a mouse model of myocilin-associated glaucoma.
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Affiliation(s)
- Shruti V Patil
- University of North Texas Health Science Center at Fort Worth
| | | | - Sujata Ranshing
- University of North Texas Health Science Center at Fort Worth
| | | | | | | | | | | | | | | | | | - Abbot F Clark
- University of North Texas Health Science Center at Fort Worth
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Pant A, Dakal TC, Moar K, Dhabhai B, Arora TK, Sharma NK, Ranga V, Maurya PK. Assessment of MMP14, CAV2, CLU and SPARCL1 expression profiles in endometriosis. Pathol Res Pract 2023; 251:154892. [PMID: 37898038 DOI: 10.1016/j.prp.2023.154892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/10/2023] [Accepted: 10/12/2023] [Indexed: 10/30/2023]
Abstract
Endometriotic cells exhibit a notable degree of invasiveness and some characteristics of tissue remodeling underlying lesion formation. In this regard, do matrix metalloproteinases 14 (MMP14) and other related genes such as SPARC-like protein 1 (SPARCL1), caveolin 2 (CAV2), and clusterin (CLU) exert any significant influence in the processes of endometriosis development and pathophysiology is not apparent. We aim to assess whether these genes could serve as potential diagnostic biomarkers in endometriosis. Microarray-based gene expression analysis was performed on total RNA extracted from endometriotic tissue samples treated with and without gonadotropin-releasing hormone agonist (GnRHa). The GnRHa untreated patients were considered the control group. The validation of genes was performed using quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR analysis showed significant downregulation in the expression of MMP14 (p = 0.024), CAV2 (p = 0.017), and upregulation of CLU (p = 0.005) in endometriosis patients treated with GnRHa. SPARCL1 did not show any significant (p = 0.30) change in the expression compared to the control group. These data have the potential to contribute to the comprehension of the molecular pathways implicated in the remodeling of the extracellular matrix, which is a vital step for the physiology of the endometrium. Based on the result, it is concluded that changes in the expression of MMP14, CAV2, and CLU post-treatment imply their role in the pathophysiology of endometriosis and may serve as a potential diagnostic biomarker of endometriosis in response to GnRHa treatment in patients with ovarian endometrioma.
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Affiliation(s)
- Anuja Pant
- Department of Biochemistry, Central University of Haryana, Mahendergarh 123031, India
| | - Tikam Chand Dakal
- Genome and Computational Biology Lab, Department of Biotechnology, Mohanlal Sukhadia University, Udaipur 313001, Rajasthan, India
| | - Kareena Moar
- Department of Biochemistry, Central University of Haryana, Mahendergarh 123031, India
| | - Bhanupriya Dhabhai
- Genome and Computational Biology Lab, Department of Biotechnology, Mohanlal Sukhadia University, Udaipur 313001, Rajasthan, India
| | - Taruna K Arora
- Reproductive Biology and Maternal Child Health Division, Indian Council of Medical Research, New Delhi 110029, India
| | - Narendra Kumar Sharma
- Department of Bioscience and Biotechnology, Banasthali Vidyapith, Tonk 304022, Rajasthan, India
| | - Vipin Ranga
- Department of Biotechnology-North East Centre for Agricultural Biotechnology (DBT-NECAB), Assam Agricultural University, Jorhat 785013, Assam, India
| | - Pawan Kumar Maurya
- Department of Biochemistry, Central University of Haryana, Mahendergarh 123031, India.
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4
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Transgenic Overexpression of Myocilin Leads to Variable Ocular Anterior Segment and Retinal Alterations Associated with Extracellular Matrix Abnormalities in Adult Zebrafish. Int J Mol Sci 2022; 23:ijms23179989. [PMID: 36077382 PMCID: PMC9456529 DOI: 10.3390/ijms23179989] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/18/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Myocilin is an enigmatic glaucoma-associated glycoprotein whose biological role remains incompletely understood. To gain novel insight into its normal function, we used transposon-mediated transgenesis to generate the first zebrafish line stably overexpressing myocilin [Tg(actb1:myoc-2A-mCherry)]. qPCR showed an approximately four-fold increased myocilin expression in transgenic zebrafish embryos (144 hpf). Adult (13 months old) transgenic animals displayed variable and age-dependent ocular anterior segment alterations. Almost 60% of two-year-old male, but not female, transgenic zebrafish developed enlarged eyes with severe asymmetrical and variable abnormalities in the anterior segment, characterized by corneal limbus hypertrophy, and thickening of the cornea, iris, annular ligament and lens capsule. The most severe phenotype presented small or absent ocular anterior chamber and pupils, due to iris overgrowth along with dysplastic retinal growth and optic nerve hypertrophy. Immunohistochemistry revealed increased presence of myocilin in most altered ocular tissues of adult transgenic animals, as well as signs of retinal gliosis and expanded ganglion cells and nerve fibers. The preliminary results indicate that these cells contributed to retinal dysplasia. Visual impairment was demonstrated in all old male transgenic zebrafish. Transcriptomic analysis of the abnormal transgenic eyes identified disrupted expression of genes involved in lens, muscular and extracellular matrix activities, among other processes. In summary, the developed transgenic zebrafish provides a new tool to investigate this puzzling protein and provides evidence for the role of zebrafish myocilin in ocular anterior segment and retinal biology, through the influence of extracellular matrix organization and cellular proliferation.
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Keller KE, Peters DM. Pathogenesis of glaucoma: Extracellular matrix dysfunction in the trabecular meshwork-A review. Clin Exp Ophthalmol 2022; 50:163-182. [PMID: 35037377 DOI: 10.1111/ceo.14027] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/19/2021] [Accepted: 11/26/2021] [Indexed: 12/11/2022]
Abstract
The trabecular meshwork regulates aqueous humour outflow from the anterior chamber of the eye. It does this by establishing a tunable outflow resistance, defined by the interplay between cells and their extracellular matrix (ECM) milieu, and the molecular interactions between ECM proteins. During normal tissue homeostasis, the ECM is remodelled and trabecular cell behaviour is modified, permitting increased aqueous fluid outflow to maintain intraocular pressure (IOP) within a relatively narrow physiological pressure. Dysfunction in the normal homeostatic process leads to increased outflow resistance and elevated IOP, which is a primary risk factor for glaucoma. This review delineates some of the changes in the ECM that lead to gross as well as some more subtle changes in the structure and function of the ECM, and their impact on trabecular cell behaviour. These changes are discussed in the context of outflow resistance and glaucoma.
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Affiliation(s)
- Kate E Keller
- Casey Eye Institute, Oregon Health &Science University, Portland, Oregon, USA
| | - Donna M Peters
- Department of Pathology & Laboratory Medicine, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, USA
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Liang X, Li N, Rong Y, Wang J, Zhang H. Identification of proteomic changes for dexamethasone-induced ocular hypertension using a tandem mass tag (TMT) approach. Exp Eye Res 2021; 216:108914. [PMID: 34979099 DOI: 10.1016/j.exer.2021.108914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 12/10/2021] [Accepted: 12/23/2021] [Indexed: 11/29/2022]
Abstract
Glaucoma, characterized by ocular hypertension, is the second most common cause of vision loss worldwide. The potential mechanism, however, has yet to be elucidated. This study aimed to assess the proteomic changes in the trabecular meshwork (TM) in an observational animal model of Dexamethasone (DEX)-induced OHT. OHT was induced in Wistar rats by applying DEX topically to both eyes for 28 days. Intraocular pressure (IOP) was evaluated and TM protein expressions and protein identification were performed by a TMT-based method for comparing the changes in proteins between DEX-induced OHT and the control group. The results showed that average IOP was elevated significantly in rats of the DEX-induced OHT group compared to controls. Further, a total of 4,804 proteins in the control and DEX-induced OHT group were determined and 4,064 proteins were quantified via TMT proteomics. In total, 292 significantly abundant proteins (173 downregulated and 119 upregulated) were identified between the two groups. Proteins associated with vision, including Crystallin related proteins, filensin, rhodopsin, recoverin, phosducin were lowered in the DEX-induced OHT group relative to the control group. In summary, DEX induced extensive changes in the protein expression of TM tissue. These proteins were found to be candidate biomarkers for personalized treatment and diagnostic research in the future for improving visual health.
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Affiliation(s)
- Xin Liang
- Department of Ophthalmology, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ning Li
- Department of Ophthalmology, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Yan Rong
- Department of Ophthalmology, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Junming Wang
- Department of Ophthalmology, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China.
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Martin MD, Huard DJ, Guerrero-Ferreira RC, Desai IM, Barlow BM, Lieberman RL. Molecular architecture and modifications of full-length myocilin. Exp Eye Res 2021; 211:108729. [DOI: 10.1016/j.exer.2021.108729] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/26/2021] [Accepted: 08/12/2021] [Indexed: 01/06/2023]
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Sharma R, Grover A. Myocilin-associated Glaucoma: A Historical Perspective and Recent Research Progress. Mol Vis 2021; 27:480-493. [PMID: 34497454 PMCID: PMC8403517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/18/2021] [Indexed: 10/29/2022] Open
Abstract
Glaucoma a debilitating disease, is globally the second most common kind of permanent blindness. Primary open-angle glaucoma (POAG) is its most prevalent form and is often linked with alterations in the myocilin gene (MYOC). MYOC encodes the myocilin protein, which is expressed throughout the body, but primarily in trabecular meshwork (TM) tissue in the eyes. TM is principally involved in regulating intraocular pressure (IOP), and elevated IOP is the main risk factor associated with glaucoma. The myocilin protein's function remains unknown; however, mutations compromise its folding and processing inside TM cells, contributing to the glaucoma phenotype. While glaucoma is a complex disease with various molecules and factors as contributing causes, the role played by myocilin has been the most widely studied. The current review describes the present understanding of myocilin and its association with glaucoma and aims to shift the focus toward developing targeted therapies for treating glaucoma patients with variations in MYOC.
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Hatayama K, Chen RH, Hanson J, Teshigawara K, Qiu J, Santoso A, Disdier C, Nakada S, Chen X, Nishibori M, Lim YP, Stonestreet BS. High-mobility group box-1 and inter-alpha inhibitor proteins: In vitro binding and co-localization in cerebral cortex after hypoxic-ischemic injury. FASEB J 2021; 35:e21399. [PMID: 33559227 DOI: 10.1096/fj.202002109rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/09/2021] [Accepted: 01/12/2021] [Indexed: 12/17/2022]
Abstract
The high-mobility group box-1 (HMGB1) protein is a transcription-regulating protein located in the nucleus. However, it serves as a damage-associated molecular pattern protein that activates immune cells and stimulates inflammatory cytokines to accentuate neuroinflammation after release from damaged cells. In contrast, Inter-alpha Inhibitor Proteins (IAIPs) are proteins with immunomodulatory effects including inhibition of pro-inflammatory cytokines. We have demonstrated that IAIPs exhibit neuroprotective properties in neonatal rats exposed to hypoxic-ischemic (HI) brain injury. In addition, previous studies have suggested that the light chain of IAIPs, bikunin, may exert its anti-inflammatory effects by inhibiting HMGB1 in a variety of different injury models in adult subjects. The objectives of the current study were to confirm whether HMGB1 is a target of IAIPs by investigating the potential binding characteristics of HMGB1 and IAIPs in vitro, and co-localization in vivo in cerebral cortices after exposure to HI injury. Solid-phase binding assays and surface plasmon resonance (SPR) were used to determine the physical binding characteristics between IAIPs and HMGB1. Cellular localizations of IAIPs-HMGB1 in neonatal rat cortex were visualized by double labeling with anti-IAIPs and anti-HMGB1 antibodies. Solid-phase binding and SPR demonstrated specific binding between IAIPs and HMGB1 in vitro. Cortical cytoplasmic and nuclear co-localization of IAIPs and HMGB1 were detected by immunofluorescent staining in control and rats immediately and 3 hours after HI. In conclusion, HMGB1 and IAIPs exhibit direct binding in vitro and co-localization in vivo in neonatal rats exposed to HI brain injury suggesting HMGB1 could be a target of IAIPs.
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Affiliation(s)
- Kazuki Hatayama
- Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University, Providence, RI, USA
| | - Ray H Chen
- Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University, Providence, RI, USA
| | - Jordan Hanson
- Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University, Providence, RI, USA
| | - Kiyoshi Teshigawara
- Department of Pharmacology, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Joseph Qiu
- ProThera Biologics, Inc., Providence, RI, USA
| | | | - Clémence Disdier
- Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University, Providence, RI, USA
| | - Sakura Nakada
- Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University, Providence, RI, USA
| | - Xiaodi Chen
- Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University, Providence, RI, USA
| | - Masahiro Nishibori
- Department of Pharmacology, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Yow-Pin Lim
- ProThera Biologics, Inc., Providence, RI, USA.,Department Pathology and Laboratory Medicine, Alpert Medical School of Brown University, Providence, RI, USA
| | - Barbara S Stonestreet
- Women & Infants Hospital of Rhode Island, Alpert Medical School of Brown University, Providence, RI, USA
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Knockout of myoc Provides Evidence for the Role of Myocilin in Zebrafish Sex Determination Associated with Wnt Signalling Downregulation. BIOLOGY 2021; 10:biology10020098. [PMID: 33573230 PMCID: PMC7912607 DOI: 10.3390/biology10020098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/16/2022]
Abstract
Myocilin is a secreted glycoprotein with a poorly understood biological function and it is mainly known as the first glaucoma gene. To explore the normal role of this protein in vivo we developed a myoc knockout (KO) zebrafish line using CRISPR/Cas9 genome editing. This line carries a homozygous variant (c.236_239delinsAAAGGGGAAGGGGA) that is predicted to result in a loss-of-function of the protein because of a premature termination codon p.(V75EfsX60) that resulted in a significant reduction of myoc mRNA levels. Immunohistochemistry showed the presence of myocilin in wild-type embryonic (96 h post-fertilization) anterior segment eye structures and caudal muscles. The protein was also detected in different adult ocular and non-ocular tissues. No gross macroscopic or microscopic alterations were identified in the KO zebrafish, but, remarkably, we observed absence of females among the adult KO animals and apoptosis in the immature juvenile gonad (28 dpf) of these animals, which is characteristic of male development. Transcriptomic analysis showed that adult KO males overexpressed key genes involved in male sex determination and presented differentially expressed Wnt signalling genes. These results show that myocilin is required for ovary differentiation in zebrafish and provides in vivo support for the role of myocilin as a Wnt signalling pathway modulator. In summary, this myoc KO zebrafish line can be useful to investigate the elusive function of this protein, and it provides evidence for the unexpected function of myocilin as a key factor in zebrafish sex determination.
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Moazzeni H, Khani M, Elahi E. Insights into the regulatory molecules involved in glaucoma pathogenesis. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:782-827. [PMID: 32935930 DOI: 10.1002/ajmg.c.31833] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/26/2020] [Accepted: 07/28/2020] [Indexed: 12/19/2022]
Abstract
Glaucoma is an important cause of irreversible blindness, characterized by optic nerve anomalies. Increased intraocular pressure (IOP) and aging are major risk factors. Retinal ganglion cells and trabecular meshwork cells are certainly involved in the etiology of glaucoma. Glaucoma is usually a complex disease, and various genes and functions may contribute to its etiology. Among these may be genes that encode regulatory molecules. In this review, regulatory molecules including 18 transcription factors (TFs), 195 microRNAs (miRNAs), 106 long noncoding RNAs (lncRNAs), and two circular RNAs (circRNAs) that are reasonable candidates for having roles in glaucoma pathogenesis are described. The targets of the regulators are reported. Glaucoma-related features including apoptosis, stress responses, immune functions, ECM properties, IOP, and eye development are affected by the targeted genes. The targeted genes that are frequently targeted by multiple regulators most often affect apoptosis and the related features of cell death and cell survival. BCL2, CDKN1A, and TP53 are among the frequent targets of three types of glaucoma-relevant regulators, TFs, miRNAs, and lncRNAs. TP53 was itself identified as a glaucoma-relevant TF. Several of the glaucoma-relevant TFs are themselves among frequent targets of regulatory molecules, which is consistent with existence of a complex network involved in glaucoma pathogenesis.
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Affiliation(s)
- Hamidreza Moazzeni
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Marzieh Khani
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Elahe Elahi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
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12
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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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Abstract
Many diseases are related to age, among these neurodegeneration is particularly important. Alzheimer's disease Parkinson's and Glaucoma have many common pathogenic events including oxidative damage, Mitochondrial dysfunction, endothelial alterations and changes in the visual field. These are well known in the case of glaucoma, less in the case of neurodegeneration of the brain. Many other molecular aspects are common, such as the role of endoplasmic reticulum autophagy and neuronal apoptosis while others have been neglected due to lack of space such as inflammatory cytokine or miRNA. Moreover, the loss of specific neuronal populations, the induction of similar mechanisms of cell injury and the deposition of protein aggregates in specific anatomical areas are very similar events between these diseases. Intracellular and/or extracellular accumulation of protein aggregates is a key feature of many neurodegenerative disorders. The existence of abnormal protein aggregates has been documented in the RGCs of glaucomatous patients such as the anomalous Tau protein or the β-amyloid accumulations. Intra-cell catabolic processes also appear to be common in both glaucoma and neurodegeneration. They also help us to understand how the basis between these diseases is common and how the visual aspects can be a serious problem for those who are affected.
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Affiliation(s)
- Sergio Claudio Saccà
- Department of Head/Neck Pathologies, St Martino Hospital, Ophthalmology Unit, Genoa, Italy.
| | - Carlo Alberto Cutolo
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Science, University of Genoa, Policlinico San Martino Hospital, Eye Clinic Genoa, Genoa, Italy
| | - Tommaso Rossi
- Department of Head/Neck Pathologies, St Martino Hospital, Ophthalmology Unit, Genoa, Italy
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Aroca-Aguilar JD, Fernández-Navarro A, Ontañón J, Coca-Prados M, Escribano J. Identification of myocilin as a blood plasma protein and analysis of its role in leukocyte adhesion to endothelial cell monolayers. PLoS One 2018; 13:e0209364. [PMID: 30557320 PMCID: PMC6296516 DOI: 10.1371/journal.pone.0209364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 12/04/2018] [Indexed: 12/27/2022] Open
Abstract
Myocilin is an extracellular glycoprotein with a poorly understood biological function and typically known because of its association with glaucoma. In this study, we analyzed the expression and biological activity of human myocilin in some non-ocular tissues. Western immunoblot showed the presence of myocilin in blood plasma as well as in liver and lymphoid tissues (thymus and lymph node). Quantitative PCR confirmed the expression of MYOC in these lymphoid organs and revealed that its mRNA is also present in T-lymphocytes and leukocytes. In addition, detection of 30 kDa C-terminal myocilin fragments in thymus and liver suggested that myocilin undergoes an in vivo proteolytic processing that might regulate its biological activity. The presence of myocilin in blood was further corroborated by peptide mass fingerprinting of the HPLC-isolated protein, and gross estimation of its concentration by Western immunoblot indicated that it is a medium-abundance serum protein with an approximate concentration of 0.85 mg/ml (15.5 μM). Finally, in vitro analyses indicated that myocilin acts as an anti-adhesive protein for human circulating leukocytes incubated with endothelial cell monolayers. Altogether, these data provide insightful information on new biological properties of myocilin and suggest its putative role as a blood matricellular protein.
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Affiliation(s)
- José-Daniel Aroca-Aguilar
- Laboratorio de Genética Molecular Humana, Facultad de Medicina/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
- Cooperative Research Network on Prevention, Early Detection and Treatment of Prevalent Degenerative and Chronic Ocular Pathology (OftaRed), Instituto de Salud Carlos III, Madrid, Spain
| | - Ana Fernández-Navarro
- Laboratorio de Genética Molecular Humana, Facultad de Medicina/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
| | - Jesús Ontañón
- Servicio de Inmunología, Complejo Hospitalario Universitario de Albacete, Castilla la Mancha, Spain
| | - Miguel Coca-Prados
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT, United States of America
- Fundación de Investigación Oftalmológica Instituto Oftalmológico Fernández-Vega, Oviedo, Spain
| | - Julio Escribano
- Laboratorio de Genética Molecular Humana, Facultad de Medicina/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
- Cooperative Research Network on Prevention, Early Detection and Treatment of Prevalent Degenerative and Chronic Ocular Pathology (OftaRed), Instituto de Salud Carlos III, Madrid, Spain
- * E-mail:
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15
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Wang H, Li M, Zhang Z, Xue H, Chen X, Ji Y. Physiological function of myocilin and its role in the pathogenesis of glaucoma in the trabecular meshwork (Review). Int J Mol Med 2018; 43:671-681. [PMID: 30483726 PMCID: PMC6317685 DOI: 10.3892/ijmm.2018.3992] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 11/16/2018] [Indexed: 12/26/2022] Open
Abstract
Myocilin is highly expressed in the trabecular meshwork (TM), which plays an important role in the regulation of intraocular pressure (IOP). Myocilin abnormalities may cause dysfunction of the TM, potentially leading to increased IOP. High IOP is a well‑known primary risk factor for glaucoma. Myocilin mutations are common among glaucoma patients, and they are implicated in juvenile‑onset open‑angle glaucoma (JOAG) and adult‑onset primary open‑angle glaucoma (POAG). Aggregation of aberrant mutant myocilins is closely associated with glaucoma pathogenesis. The aim of the present review was to discuss the recent findings regarding the major physiological functions of myocilin, such as intra‑ and extracellular proteolytic processes. We also aimed to discuss the risk factors associated with myocilin and the development of glaucoma, such as misfolded/mutant myocilin, imbalance of myocilin and extracellular proteins, and instability of mutant myocilin associated with temperature. Finally, we further outlined certain issues that are yet to be resolved, which may represent the basis for future studies on the role of myocilin in glaucoma.
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Affiliation(s)
- Hongwei Wang
- Department of Ophthalmology, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Mingzhe Li
- Department of Ophthalmology, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai 201399, P.R. China
| | - Zhenzhen Zhang
- Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, P.R. China
| | - Haifeng Xue
- Public Health School, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Xing Chen
- Department of Science and Education, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
| | - Yong Ji
- Department of General Surgery, Jingjiang People's Hospital, Jingjiang, Jiangsu 214500, P.R. China
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Lynch JM, Li B, Katoli P, Xiang C, Leehy B, Rangaswamy N, Saenz-Vash V, Wang YK, Lei H, Nicholson TB, Meredith E, Rice DS, Prasanna G, Chen A. Binding of a glaucoma-associated myocilin variant to the αB-crystallin chaperone impedes protein clearance in trabecular meshwork cells. J Biol Chem 2018; 293:20137-20156. [PMID: 30389787 DOI: 10.1074/jbc.ra118.004325] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/19/2018] [Indexed: 01/09/2023] Open
Abstract
Myocilin (MYOC) was discovered more than 20 years ago and is the gene whose mutations are most commonly observed in individuals with glaucoma. Despite extensive research efforts, the function of WT MYOC has remained elusive, and how mutant MYOC is linked to glaucoma is unclear. Mutant MYOC is believed to be misfolded within the endoplasmic reticulum, and under normal physiological conditions misfolded MYOC should be retro-translocated to the cytoplasm for degradation. To better understand mutant MYOC pathology, we CRISPR-engineered a rat to have a MYOC Y435H substitution that is the equivalent of the pathological human MYOC Y437H mutation. Using this engineered animal model, we discovered that the chaperone αB-crystallin (CRYAB) is a MYOC-binding partner and that co-expression of these two proteins increases protein aggregates. Our results suggest that the misfolded mutant MYOC aggregates with cytoplasmic CRYAB and thereby compromises protein clearance mechanisms in trabecular meshwork cells, and this process represents the primary mode of mutant MYOC pathology. We propose a model by which mutant MYOC causes glaucoma, and we propose that therapeutic treatment of patients having a MYOC mutation may focus on disrupting the MYOC-CRYAB complexes.
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Affiliation(s)
- Jeffrey M Lynch
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139.
| | - Bing Li
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Parvaneh Katoli
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Chuanxi Xiang
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Barrett Leehy
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Nalini Rangaswamy
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Veronica Saenz-Vash
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Y Karen Wang
- Analytical Sciences and Imaging, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Hong Lei
- Laboratory Animal Services, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Thomas B Nicholson
- Chemical Biology and Therapeutics, and Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Erik Meredith
- Global Developmental Chemistry, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Dennis S Rice
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Ganesh Prasanna
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
| | - Amy Chen
- From Ophthalmology, Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139
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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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Saccà SC, Gandolfi S, Bagnis A, Manni G, Damonte G, Traverso CE, Izzotti A. From DNA damage to functional changes of the trabecular meshwork in aging and glaucoma. Ageing Res Rev 2016; 29:26-41. [PMID: 27242026 DOI: 10.1016/j.arr.2016.05.012] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/25/2016] [Accepted: 05/26/2016] [Indexed: 12/24/2022]
Abstract
Glaucoma is a degenerative disease of the eye. Both the anterior and posterior segments of the eye are affected, extensive damage being detectable in the trabecular meshwork and the inner retina-central visual pathway complex. Oxidative stress is claimed to be mainly responsible for molecular damage in the anterior chamber. Indeed, oxidation harms the trabecular meshwork, leading eventually to endothelial cell decay, tissue malfunction, subclinical inflammation, changes in the extracellular matrix and cytoskeleton, altered motility, reduced outflow facility and (ultimately) increased IOP. Moreover, free radicals are involved in aging and can be produced in the brain (as well as in the eye) as a result of ischemia, leading to oxidation of the surrounding neurons. Glaucoma-related cell death occurs by means of apoptosis, and apoptosis is triggered by oxidative stress via (a) mitochondrial damage, (b) inflammation, (c) endothelial dysregulation and dysfunction, and (d) hypoxia. The proteomics of the aqueous humor is significantly altered in glaucoma as a result of oxidation-induced trabecular damage. Those proteins whose aqueous humor levels are increased in glaucoma are biomarkers of trabecular meshwork impairment. Their diffusion from the anterior to the posterior segment of the eye may be relevant in the cascade of events triggering apoptosis in the inner retinal layers, including the ganglion cells.
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Affiliation(s)
- Sergio Claudio Saccà
- IRCCS San Martino University Hospital, Department of Neuroscience and Sense Organs, San Martino Hospital, Ophthalmology Unit, Viale Benedetto XV, 16132 Genoa, Italy.
| | - Stefano Gandolfi
- Ophthalmology Unit, Department of Biological, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | - Alessandro Bagnis
- University of Genoa, Eye Clinic, Department of Neuroscience and Sense Organs, Viale Benedetto XV, 5, 16148 Genoa, Italy
| | - Gianluca Manni
- Dept. of Clinical Science and Translational Medicine, University Tor Vergata, Rome, Italy
| | - Gianluca Damonte
- Dept. of Experimental Medicine, Section of Biochemistry and Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV 1, 16132 Genoa, Italy
| | - Carlo Enrico Traverso
- University of Genoa, Eye Clinic, Department of Neuroscience and Sense Organs, Viale Benedetto XV, 5, 16148 Genoa, Italy
| | - Alberto Izzotti
- Mutagenesis Unit, IRCCS San Martino University Hospital, IST National Institute for Cancer Research, Department of Health Sciences, University of Genoa, Via A. Pastore 1, Genoa I-16132, Italy
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19
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Extracellular calcium-binding peptide-modified ceramics stimulate regeneration of calvarial bone defects. Tissue Eng Regen Med 2015; 13:57-65. [PMID: 30603385 DOI: 10.1007/s13770-015-9066-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 08/24/2015] [Accepted: 08/27/2015] [Indexed: 12/26/2022] Open
Abstract
Secreted protein, acidic, cysteine-rich (SPARC)-related modular calcium binding 1 (SMOC1) has been implicated in the regulation of osteogenic differentiation of human bone marrow mesenchymal stem cells (BMSCs). In this study, we found that a peptide (16 amino acids in length), which is located in the extracellular calcium (EC) binding domain of SMOC1, stimulated osteogenic differentiation of human BMSCs in vitro and calvarial bone regeneration in vivo. Treatment of BMSCs with SMOC1-EC peptide significantly stimulated their mineralization in a dose-dependent manner without changing their rate of proliferation. The expression of osteogenic differentiation marker genes, including type 1 collagen and osteocalcin, also increased in a dose-dependent manner. To examine the effect of the SMOC1-EC peptide on bone formation in vivo, the peptide was covalently immobilized onto hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) particles. X-ray photoelectron spectroscopy analysis showed that the peptide was successfully immobilized onto the surface of HA/β-TCP. Implantation of the SMOC1-EC peptide-immobilized HA/β-TCP particles into mouse calvarial defects and subsequent analyses using microcomputed tomography and histology showed significant bone regeneration compared with that of calvarial defects implanted with unmodified HA/β-TCP particles. Collectively, our data suggest that a peptide derived from the EC domain of SMOC1 induces osteogenic differentiation of human BMSCs in vitro and efficiently enhances bone regeneration in vivo.
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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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Chatterjee A, Villarreal G, Rhee DJ. Matricellular proteins in the trabecular meshwork: review and update. J Ocul Pharmacol Ther 2014; 30:447-63. [PMID: 24901502 DOI: 10.1089/jop.2014.0013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Abstract Primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide, and intraocular pressure (IOP) is an important modifiable risk factor. IOP is a function of aqueous humor production and aqueous humor outflow, and it is thought that prolonged IOP elevation leads to optic nerve damage over time. Within the trabecular meshwork (TM), the eye's primary drainage system for aqueous humor, matricellular proteins generally allow cells to modulate their attachments with and alter the characteristics of their surrounding extracellular matrix (ECM). It is now well established that ECM turnover in the TM affects outflow facility, and matricellular proteins are emerging as significant players in IOP regulation. The formalized study of matricellular proteins in TM has gained increased attention. Secreted protein acidic and rich in cysteine (SPARC), myocilin, connective tissue growth factor (CTGF), and thrombospondin-1 and -2 (TSP-1 and -2) have been localized to the TM, and a growing body of evidence suggests that these matricellular proteins play an important role in IOP regulation and possibly the pathophysiology of POAG. As evidence continues to emerge, these proteins are now seen as potential therapeutic targets. Further study is warranted to assess their utility in treating glaucoma in humans.
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Affiliation(s)
- Ayan Chatterjee
- Department of Ophthalmology and Visual Sciences, University Hospitals Eye Institute, Case Western Reserve University School of Medicine , Cleveland, Ohio
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22
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Abstract
Background Myocilin (MYOC) is a gene linked directly to juvenile- and adult-onset open angle glaucoma. Mutations including Pro370Leu (P370L) and Gln368stop (Q368X) have been identified in patients. In the present study, we investigated the processing of myocilin in human trabecular meshwork (TM) cells as well as in inducible, stable RGC5 cell lines. Methodology/Principal Findings The turnover and photoactivation experiments revealed that the endogenous myocilin in human trabecular meshwork (TM) cells was a short-lived protein. It was found that the endogenous myocilin level in TM cells was increased by treatment of lysosomal and proteasomal inhibitors, but not by autophagic inhibitor. Multiple bands immunoreactive to anti-ubiquitin were seen in the myocilin pull down, indicating that myocilin was ubiquitinated. In inducible cell lines, the turnover rate of overexpressed wild-type and mutant P370L and Q368X myocilin-GFP fusion proteins was much prolonged. The proteasome function was compromised and autophagy was induced. A decreased PSMB5 level and an increased level of autophagic marker, LC3, were demonstrated. Conclusions/Significance The current study provided evidence that in normal homeostatic situation, the turnover of endogenous myocilin involves ubiquitin-proteasome and lysosomal pathways. When myocilin was upregulated or mutated, the ubiquitin-proteasome function is compromised and autophagy is induced. Knowledge of the degradation pathways acting on myocilin can help in design of novel therapeutic strategies for myocilin-related glaucoma.
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Joe MK, Kwon HS, Cojocaru R, Tomarev SI. Myocilin regulates cell proliferation and survival. J Biol Chem 2014; 289:10155-67. [PMID: 24563482 DOI: 10.1074/jbc.m113.547091] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Myocilin, a causative gene for open angle glaucoma, encodes a secreted glycoprotein with poorly understood functions. To gain insight into its functions, we produced a stably transfected HEK293 cell line expressing myocilin under an inducible promoter and compared gene expression profiles between myocilin-expressing and vector control cell lines by a microarray analysis. A significant fraction of differentially expressed genes in myocilin-expressing cells was associated with cell growth and cell death, suggesting that myocilin may have a role in the regulation of cell growth and survival. Increased proliferation of myocilin-expressing cells was demonstrated by the WST-1 proliferation assay, direct cell counting, and immunostaining with antibodies against Ki-67, a cellular proliferation marker. Myocilin-containing conditioned medium also increased proliferation of unmodified HEK293 cells. Myocilin-expressing cells were more resistant to serum starvation-induced apoptosis than control cells. TUNEL-positive apoptotic cells were dramatically decreased, and two apoptotic marker proteins, cleaved caspase 7 and cleaved poly(ADP-ribose) polymerase, were significantly reduced in myocilin-expressing cells as compared with control cells under apoptotic conditions. In addition, myocilin-deficient mesenchymal stem cells exhibited reduced proliferation and enhanced susceptibility to serum starvation-induced apoptosis as compared with wild-type mesenchymal stem cells. Phosphorylation of ERK1/2 and its upstream kinases, c-Raf and MEK, was increased in myocilin-expressing cells compared with control cells. Elevated phosphorylation of ERK1/2 was also observed in the trabecular meshwork of transgenic mice expressing 6-fold higher levels of myocilin when compared with their wild-type littermates. These results suggest that myocilin promotes cell proliferation and resistance to apoptosis via the ERK1/2 MAPK signaling pathway.
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Affiliation(s)
- Myung Kuk Joe
- From the Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, NEI, National Institutes of Health, Bethesda, Maryland 20892 and
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24
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Tian Q, Zhao S, Liu C. A solid-phase assay for studying direct binding of progranulin to TNFR and progranulin antagonism of TNF/TNFR interactions. Methods Mol Biol 2014; 1155:163-72. [PMID: 24788181 DOI: 10.1007/978-1-4939-0669-7_14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The discovery that TNF receptors (TNFR) serve as the binding receptors for progranulin (PGRN) reveals the significant role of PGRN in inflammatory and autoimmune diseases, including inflammatory arthritis. Herein we describe a simple, antibody-free analytical assay, i.e., a biotin-based solid-phase binding assay, to examine the direct interaction of PGRN/TNFR and the PGRN inhibition of TNF/TNFR interactions. Briefly, a 96-well high-binding microplate is first coated with the first protein (protein A), and after blocking, the coated microplate is incubated with the biotin-labeled second protein (protein B) in the absence or presence of the third protein (protein C). Finally the streptavidin conjugated with a detecting enzyme is added, followed by a signal measurement. Also discussed in this chapter are the advantages of the strategy, key elements to obtain reliable results, and discrepancies among various PGRN proteins in view of the binding activity with TNFR.
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Affiliation(s)
- Qingyun Tian
- Department of Orthopaedic Surgery, New York University Medical Center, Rm 1608, HJD, 301 East 17th Street, New York, NY, 10003, USA
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25
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Kwon HS, Johnson TV, Tomarev SI. Myocilin stimulates osteogenic differentiation of mesenchymal stem cells through mitogen-activated protein kinase signaling. J Biol Chem 2013; 288:16882-16894. [PMID: 23629661 DOI: 10.1074/jbc.m112.422972] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Myocilin is a secreted glycoprotein that is expressed in ocular and non-ocular tissues. Mutations in the MYOCILIN gene may lead to juvenile- and adult-onset primary open-angle glaucoma. Here we report that myocilin is expressed in bone marrow-derived mesenchymal stem cells (MSCs) and plays a role in their differentiation into osteoblasts in vitro and in osteogenesis in vivo. Expression of myocilin was detected in MSCs derived from mouse, rat, and human bone marrow, with human MSCs exhibiting the highest level of myocilin expression. Expression of myocilin rose during the course of human MSC differentiation into osteoblasts but not into adipocytes, and treatment with exogenous myocilin further enhanced osteogenesis. MSCs derived from Myoc-null mice had a reduced ability to differentiate into the osteoblastic lineage, which was partially rescued by exogenous extracellular myocilin treatment. Myocilin also stimulated osteogenic differentiation of wild-type MSCs, which was associated with activation of the p38, Erk1/2, and JNK MAP kinase signaling pathways as well as up-regulated expression of the osteogenic transcription factors Runx2 and Dlx5. Finally, cortical bone thickness and trabecular volume, as well as the expression level of osteopontin, a known factor of bone remodeling and osteoblast differentiation, were reduced dramatically in the femurs of Myoc-null mice compared with wild-type mice. These data suggest that myocilin should be considered as a target for improving the bone regenerative potential of MSCs and may identify a new role for myocilin in bone formation and/or maintenance in vivo.
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Affiliation(s)
- Heung Sun Kwon
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Thomas V Johnson
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Stanislav I Tomarev
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892.
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Aroca-Aguilar JD, Martínez-Redondo F, Martín-Gil A, Pintor J, Coca-Prados M, Escribano J. Bicarbonate-dependent secretion and proteolytic processing of recombinant myocilin. PLoS One 2013; 8:e54385. [PMID: 23342144 PMCID: PMC3547000 DOI: 10.1371/journal.pone.0054385] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 12/11/2012] [Indexed: 01/28/2023] Open
Abstract
Myocilin is an extracellular glycoprotein of poorly understood function. Mutations of this protein are involved in glaucoma, an optic neuropathy characterized by a progressive and irreversible visual loss and frequently associated with elevated intraocular pressure. We previously showed that recombinant myocilin undergoes an intracellular proteolytic processing by calpain II which cleaves the central region of the protein, releasing one N- and one C-terminal fragment. Myocilin cleavage is reduced by glaucoma mutations and it has been proposed to participate in intraocular pressure modulation. To identify possible factors regulating the proteolytic processing of recombinant myocilin, we used a cellular model in which we analyzed how different culture medium parameters (i.e., culture time, cell density, pH, bicarbonate concentration, etc.) affect the presence of the extracellular C-terminal fragment. Extracellular bicarbonate depletion associated with culture medium acidification produced a reversible intracellular accumulation of full-length recombinant myocilin and incremented its intracellular proteolytic processing, raising the extracellular C-terminal fragment percentage. It was also determined that myocilin intracellular accumulation depends on its N-terminal region. These data suggest that aqueous humor bicarbonate variations could also modulate the secretion and cleavage of myocilin present in ocular tissues.
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Affiliation(s)
- José-Daniel Aroca-Aguilar
- Laboratorio de Genética Molecular Humana, Facultad de Medicina/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
| | - Francisco Martínez-Redondo
- Laboratorio de Genética Molecular Humana, Facultad de Medicina/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
| | - Alba Martín-Gil
- Departamento de Bioquímica y Biología Molecular IV, E.U. Óptica, Universidad Complutense de Madrid, Madrid, Spain
| | - Jesús Pintor
- Departamento de Bioquímica y Biología Molecular IV, E.U. Óptica, Universidad Complutense de Madrid, Madrid, Spain
| | - Miguel Coca-Prados
- Fundación de Investigación Oftalmológica Instituto Oftalmológico Fernández-Vega, Oviedo, Spain
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Julio Escribano
- Laboratorio de Genética Molecular Humana, Facultad de Medicina/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
- * E-mail:
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Ying H, Shen X, Yue BYJT. Establishment of inducible wild type and mutant myocilin-GFP-expressing RGC5 cell lines. PLoS One 2012; 7:e47307. [PMID: 23082156 PMCID: PMC3474840 DOI: 10.1371/journal.pone.0047307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 09/11/2012] [Indexed: 11/22/2022] Open
Abstract
Background Myocilin is a gene linked directly to juvenile- and adult-onset open angle glaucoma. Mutations including Gln368stop (Q368X) and Pro370Leu (P370L) have been identified in patients. The exact role of myocilin and its functional association with glaucoma are still unclear. In the present study, we established tetracycline-inducible (Tet-on) wild type and mutant myocilin-green fluorescence protein (GFP) expressing RGC5 stable cell lines and studied the changes in cell migration and barrier function upon induction. Methodology/Principal Findings After several rounds of selection, clones that displayed low, moderate, or high expression of wild type, Q368X or P370L myocilin-GFP upon doxycycline (Dox) induction were obtained. The levels of wild type and mutant myocilin-GFP in various clones were confirmed by Western blotting. Compared to non-induced controls, the cell migration was retarded, the actin stress fibers were fewer and shorter, and the trypsinization time needed for cells to round up was reduced when wild type or mutant myocilin was expressed. The barrier function was in addition aberrant following induced expression of wild type, Q368X or P370L myocilin. Immunoblotting further showed that tight junction protein occludin was downregulated in induced cells. Conclusions/Significance Tet-on inducible, stable RGC5 cell lines were established. These cell lines, expressing wild type or mutant (Q368X or P370L) myocilin-GFP upon Dox induction, are valuable in facilitating studies such as proteomics, as well as functional and pathogenesis investigations of disease-associated myocilin mutants. The barrier function was found impaired and the migration of cells was hindered with induced expression of wild type and mutant myocilin in RGC5 cell lines. The reduction in barrier function might be related to the declined level of occludin. The retarded cell migration was consistent with demonstrated myocilin phenotypes including the loss of actin stress fibers, lowered RhoA activities and compromised cell-matrix adhesiveness.
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Affiliation(s)
- Hongyu Ying
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine, Chicago, Illinois, United States of America
| | - Xiang Shen
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine, Chicago, Illinois, United States of America
| | - Beatrice Y. J. T. Yue
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine, Chicago, Illinois, United States of America
- * E-mail:
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Thomasy SM, Wood JA, Kass PH, Murphy CJ, Russell P. Substratum stiffness and latrunculin B regulate matrix gene and protein expression in human trabecular meshwork cells. Invest Ophthalmol Vis Sci 2012; 53:952-8. [PMID: 22247475 DOI: 10.1167/iovs.11-8526] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
PURPOSE To determine the impact of substratum stiffness and latrunculin-B (Lat-B), on the expression of several matrix proteins that are associated with glaucoma. METHODS Human trabecular meshwork (HTM) cells were cultured on hydrogels possessing stiffness values mimicking those found in normal (5 kPa) and glaucomatous meshworks (75 kPa), or tissue culture polystyrene (TCP; >1 GPa). Cells were treated with 2.0 μM Lat-B in dimethyl sulfoxide (DMSO) or DMSO alone. RT-PCR was used to determine the impact of substratum stiffness and/or Lat-B treatment on the expression of secreted protein, acidic, cysteine rich (SPARC), myocilin, angiopoietin-like factor (ANGPTL)-7, and transglutaminase (TGM)-2. Immunofluorescence was used to assess changes in protein expression. RESULTS SPARC and myocilin mRNA expression were dramatically increased on the 75 kPa hydrogels and decreased on the 5 kPa hydrogels in comparison to TCP. In contrast, ANGPTL-7 mRNA and TGM-2 mRNA was decreased on the 75 kPa and 5 kPa hydrogels, respectively, in comparison with TCP. Treatment with Lat-B dramatically downregulated both SPARC and myocilin on 75 kPa hydrogels. In contrast, cells grown on TCP produced greater or similar amounts of SPARC and myocilin mRNA after Lat-B treatment. SPARC and myocilin protein expression paralleled changes in mRNA expression. CONCLUSIONS Substratum stiffness impacts HTM matrix gene and protein expression and modulates the impact of Lat-B treatment on the expression of these matrix proteins. Integrating the use of biologically relevant substratum stiffness in the conduction of in vitro experiments gives important insights into HTM cell response to drugs that may more accurately predict responses observed in vivo.
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Affiliation(s)
- Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, CA 95616, USA
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Current concepts on primary open-angle glaucoma genetics: a contribution to disease pathophysiology and future treatment. Eye (Lond) 2011; 26:355-69. [PMID: 22173078 DOI: 10.1038/eye.2011.309] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Glaucoma is a common, complex, heterogenous disease and it constitutes the major cause of irreversible blindness worldwide. Primary open-angle glaucoma (POAG) is the most common type of glaucoma in all populations. Most of the molecular mechanisms leading to POAG development are still unknown. Gene mutations in various populations have been identified by genetic studies and a genetic basis for glaucoma pathogenesis has been established. Linkage analysis and association studies are genetic approaches in the investigation of the genetic basis of POAG. Genome-wide association studies (GWAS) are more powerful compared with linkage analysis in discovering genes of small effect that might contribute to the development of the disease. POAG links to at least 20 genetic loci, but only 2 genes identified in these loci, myocilin and optineurin, are considered as well-established glaucoma-causing genes, whereas the role of other loci, genes, and variants implicated in the development of POAG remains controversial. Gene mutations associated with POAG result in retinal ganglion cell death, which is the common outcome of pathogenetic mechanisms in glaucoma. In future, if the sensitivity and specificity of genotyping increases, it may be possible to screen individuals routinely for disease susceptibility. This review is an update on the latest progress of genetic studies associated with POAG. It emphasizes the correlation of recent achievements in genetics with glaucoma pathophysiology, glaucoma treatment perspectives, and the possibility of future prevention of irreversible visual loss caused by the disease.
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Yue BYJT. Myocilin and Optineurin: Differential Characteristics and Functional Consequences. Taiwan J Ophthalmol 2011; 1:6-11. [PMID: 24163790 DOI: 10.1016/j.tjo.2011.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Myocilin and optineurin are two genes linked to glaucoma, a major blinding disease characterized by progressive loss of retinal ganglion cells and their axons. This review describes the characteristics of myocilin and optineurin protein products and summarizes the consequences of ectopically expressed wild type and mutant myocilin and optineurin in trabecular meshwork and/or neuronal cells. Myocilin and optineurin exhibit differential characteristics and have divergent functional consequences. They contribute to the development of glaucoma likely via distinct mechanisms.
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Affiliation(s)
- Beatrice Y J T Yue
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
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Menaa F, Braghini CA, Vasconcellos JPCD, Menaa B, Costa VP, Figueiredo ESD, Melo MBD. Keeping an eye on myocilin: a complex molecule associated with primary open-angle glaucoma susceptibility. Molecules 2011; 16:5402-21. [PMID: 21709622 PMCID: PMC6264709 DOI: 10.3390/molecules16075402] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 06/21/2011] [Indexed: 02/04/2023] Open
Abstract
MYOC encodes a secretary glycoprotein of 504 amino acids named myocilin. MYOC is the first gene to be linked to juvenile open-angle glaucoma (JOAG) and some forms of adult-onset primary open-angle glaucoma (POAG). The gene was identified as an up-regulated molecule in cultured trabecular meshwork (TM) cells after treatment with dexamethasone and was originally referred to as trabecular meshwork-inducible glucocorticoid response (TIGR). Elevated intraocular pressure (IOP), due to decreased aqueous outflow, is the strongest known risk factor for POAG. Increasing evidence showed that the modulation of the wild-type (wt) myocilin protein expression is not causative of glaucoma while some misfolded and self-assembly aggregates of mutated myocilin may be associated with POAG in related or unrelated populations. The etiology of the disease remains unclear. Consequently, a better understanding of the molecular mechanisms underlyingPOAG is required to obtain early diagnosis, avoid potential disease progression, and develop new therapeutic strategies. In the present study, we review and discuss the most relevant studies regarding structural characterizations, expressions, molecular interactions, putative functions of MYOC gene and/or its corresponding protein in POAG etiology.
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Affiliation(s)
- Farid Menaa
- Laboratory of Human Genetics, Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas-SP 13083-875, Brazil; (C.A.B.); (M.B.D.M.)
- Author to whom correspondence should be addressed; ; or ; Tel.: +55-19-3521-1138; Fax: +55-19-3521-1089
| | - Carolina Ayumi Braghini
- Laboratory of Human Genetics, Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas-SP 13083-875, Brazil; (C.A.B.); (M.B.D.M.)
| | - Jose Paulo Cabral De Vasconcellos
- Department of Ophthalmology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas-SP 13083-888, Brazil; (J.P.C.D.V.); (V.P.C.); (E.S.D.F.)
| | - Bouzid Menaa
- Department of Chemistry and Nanobiotechnology, Fluorotronics, Inc., San Diego, CA 92081, USA; (B.M.)
| | - Vital Paulino Costa
- Department of Ophthalmology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas-SP 13083-888, Brazil; (J.P.C.D.V.); (V.P.C.); (E.S.D.F.)
| | - Eugênio Santana De Figueiredo
- Department of Ophthalmology, Faculty of Medical Sciences, University of Campinas (UNICAMP), Campinas-SP 13083-888, Brazil; (J.P.C.D.V.); (V.P.C.); (E.S.D.F.)
| | - Monica Barbosa De Melo
- Laboratory of Human Genetics, Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas-SP 13083-875, Brazil; (C.A.B.); (M.B.D.M.)
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