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Yan X, Wu S, Liu Q, Cheng Y, Teng Y, Ren T, Zhang J, Wang N. Serine to proline mutation at position 341 of MYOC impairs trabecular meshwork function by causing autophagy deregulation. Cell Death Discov 2024; 10:21. [PMID: 38212635 PMCID: PMC10784477 DOI: 10.1038/s41420-024-01801-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 12/24/2023] [Accepted: 01/04/2024] [Indexed: 01/13/2024] Open
Abstract
Glaucoma is a highly heritable disease, and myocilin was the first identified causal and most common pathogenic gene in glaucoma. Serine-to-proline mutation at position 341 of myocilin (MYOCS341P) is associated with severe glaucoma phenotypes in a five-generation primary open-angle glaucoma family. However, the underlying mechanisms are underexplored. Herein, we established the MYOCS341P transgenic mouse model and characterized the glaucoma phenotypes. Further, we systematically explored the functional differences between wild-type and MYOCS341P through immunoprecipitation, mass spectrometry, and RNA-seq analyses. We found that MYOCS341P transgenic mice exhibit glaucoma phenotypes, characterized by reduced aqueous humor outflow, elevated intraocular pressure, decreased trabecular meshwork (TM) cell number, narrowed Schlemm's canal, retinal ganglion cell loss, and visual impairment. Mechanistically, the secretion of dysfunctional MYOCS341P accumulated in the endoplasmic reticulum (ER), inducing ER stress and dysregulation of autophagy, thereby promoting TM cell death. We describe an effective transgenic model for mechanistic studies and the screening of therapeutic targets. Our data generated from high-throughput analyses help elucidate the mechanism underlying mutant MYOC-related glaucoma.
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Affiliation(s)
- Xuejing Yan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Shen Wu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Qian Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Ying Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Yufei Teng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Tianmin Ren
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China
| | - Jingxue Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, 100730, China.
- Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China.
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Beard DC, Zhang X, Wu DY, Martin JR, Hamagami N, Swift RG, McCullough KB, Ge X, Bell-Hensley A, Zheng H, Lawrence AB, Hill CA, Papouin T, McAlinden A, Garbow JR, Dougherty JD, Maloney SE, Gabel HW. Distinct disease mutations in DNMT3A result in a spectrum of behavioral, epigenetic, and transcriptional deficits. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.27.530041. [PMID: 36909558 PMCID: PMC10002657 DOI: 10.1101/2023.02.27.530041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Phenotypic heterogeneity is a common feature of monogenic neurodevelopmental disorders that can arise from differential severity of missense variants underlying disease, but how distinct alleles impact molecular mechanisms to drive variable disease presentation is not well understood. Here, we investigate missense mutations in the DNA methyltransferase DNMT3A associated with variable overgrowth, intellectual disability, and autism, to uncover molecular correlates of phenotypic heterogeneity in neurodevelopmental disease. We generate a DNMT3A P900L/+ mouse model mimicking a disease mutation with mild-to-moderate severity and compare phenotypic and epigenomic effects with a severe R878H mutation. We show that the P900L mutation leads to disease-relevant overgrowth, obesity, and social deficits shared across DNMT3A disorder models, while the R878H mutation causes more extensive epigenomic disruption leading to differential dysregulation of enhancers elements. We identify distinct gene sets disrupted in each mutant which may contribute to mild or severe disease, and detect shared transcriptomic disruption that likely drives common phenotypes across affected individuals. Finally, we demonstrate that core gene dysregulation detected in DNMT3A mutant mice overlaps effects in other developmental disorder models, highlighting the importance of DNMT3A-deposited methylation in neurodevelopment. Together, these findings define central drivers of DNMT3A disorders and illustrate how variable disruption of transcriptional mechanisms can drive the spectrum of phenotypes in neurodevelopmental disease.
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Affiliation(s)
- Diana C. Beard
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Xiyun Zhang
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Dennis Y. Wu
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jenna R. Martin
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Nicole Hamagami
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Raylynn G. Swift
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Katherine B. McCullough
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Xia Ge
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Austin Bell-Hensley
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63110, USA
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Hongjun Zheng
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Austin B. Lawrence
- Department of Pathology and Anatomical Science, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Cheryl A. Hill
- Department of Pathology and Anatomical Science, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Thomas Papouin
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Audrey McAlinden
- Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joel R. Garbow
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Joseph D. Dougherty
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Susan E. Maloney
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Harrison W. Gabel
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA
- Intellectual and Developmental Disabilities Research Center, Washington University School of Medicine, St. Louis, MO 63110, USA
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Yan X, Wu S, Liu Q, Cheng Y, Zhang J, Wang N. Myocilin Gene Mutation Induced Autophagy Activation Causes Dysfunction of Trabecular Meshwork Cells. Front Cell Dev Biol 2022; 10:900777. [PMID: 35615698 PMCID: PMC9124892 DOI: 10.3389/fcell.2022.900777] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/08/2022] [Indexed: 12/12/2022] Open
Abstract
Trabecular meshwork dysfunction is the main cause of primary open angle glaucoma (POAG) associated with elevated intraocular pressure (IOP). Mutant myocilin causes glaucoma mainly via elevating IOP. Previously we have found that accumulated Asn 450 Tyr (N450Y) mutant myocilin impairs human trabecular meshwork (TM) cells by inducing chronic endoplasmic reticulum (ER) stress response in vitro. However, it is unclear how ER stress leads to TM damage and whether N450Y myocilin mutation is associated with POAG in vivo. Here we found that N450Y mutant myocilin induces autophagy, which worsens cell viability, whereas inhibition of autophagy increases viability and decreases cell death in human TM cells. Furthermore, we construct a transgenic mouse model of N450Y myocilin mutation (Tg-MYOCN450Y) and Tg-MYOCN450Y mice exhibiting glaucoma phenotypes: IOP elevation, retinal ganglion cell loss and visual impairment. Consistent with our published in vitro studies, mutant myocilin fails to secrete into aqueous humor, causes ER stress and actives autophagy in Tg-MYOCN450Y mice, and aqueous humor dynamics are altered in Tg-MYOCN450Y mice. In summary, our studies demonstrate that activation of autophagy is correlated with pathogenesis of POAG.
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Affiliation(s)
- Xuejing Yan
- Beijing Tongren Eye Center, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
- Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Shen Wu
- Beijing Tongren Eye Center, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
- Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Qian Liu
- Beijing Tongren Eye Center, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
- Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| | - Ying Cheng
- Beijing Tongren Eye Center, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
| | - Jingxue Zhang
- Beijing Tongren Eye Center, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
- Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- *Correspondence: Ningli Wang, ; Jingxue Zhang,
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Hospital, Beijing Institute of Ophthalmology, Capital Medical University, Beijing, China
- Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
- *Correspondence: Ningli Wang, ; Jingxue Zhang,
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Panganiban CH, Barth JL, Tan J, Noble KV, McClaskey CM, Howard BA, Jafri SH, Dias JW, Harris KC, Lang H. Two distinct types of nodes of Ranvier support auditory nerve function in the mouse cochlea. Glia 2021; 70:768-791. [DOI: 10.1002/glia.24138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 11/12/2021] [Accepted: 12/17/2021] [Indexed: 11/09/2022]
Affiliation(s)
- Clarisse H. Panganiban
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
- Wolfson Centre for Age‐Related Diseases King's College London London UK
| | - Jeremy L. Barth
- Department of Regenerative Medicine and Cell Biology Medical University of South Carolina Charleston South Carolina USA
| | - Junying Tan
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - Kenyaria V. Noble
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - Carolyn M. McClaskey
- Department of Otolaryngology & Head and Neck Surgery Medical University of South Carolina Charleston South Carolina USA
| | - Blake A. Howard
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - Shabih H. Jafri
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - James W. Dias
- Department of Otolaryngology & Head and Neck Surgery Medical University of South Carolina Charleston South Carolina USA
| | - Kelly C. Harris
- Department of Otolaryngology & Head and Neck Surgery Medical University of South Carolina Charleston South Carolina USA
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
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Investigation of Key Signaling Pathways Associating miR-204 and Common Retinopathies. BIOMED RESEARCH INTERNATIONAL 2021; 2021:5568113. [PMID: 34646884 PMCID: PMC8505061 DOI: 10.1155/2021/5568113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 06/15/2021] [Accepted: 09/08/2021] [Indexed: 02/07/2023]
Abstract
MicroRNAs are a large group of small noncoding RNAs that work in multiple cellular pathways. miR-204, as one of the key axes in the development, maintenance, and pathogenesis of the retina, plays several roles by modulating its target genes. This study was aimed at evaluating the target genes of miR-204 involved in the development and progression of common retinopathies such as glaucoma, retinoblastoma, and age-related macular degeneration. In this study, three datasets related to retinopathies (GSE50195, GSE27276, and GSE97508) were selected from Gene Expression Omnibus. miR-204 target genes were isolated from TargeScan. The shares between retinopathy and miR-204 target genes were then categorized. Using Enrichr and STRING, we highlighted the signaling pathways and the relationships between the proteins. SHC1 events in ERBB2, adherent junction's interactions, NGF signaling via TRKA from the plasma membrane, IRF3-mediated activation of type 1 IFN, pathways in upregulated genes and G0 and early G1, RORA-activated gene expression, PERK-regulated gene expression, adherent junction's interactions, and CREB phosphorylation pathways in downregulated genes were identified in glaucoma, retinoblastoma, and age-related macular degeneration. WEE1, SMC2, HMGB1, RRM2, and POLA1 proteins were also observed to be involved in the progression and invasion of retinoblastoma; SLC24A2 and DTX4 in age-related macular degeneration; and EPHB6, EFNB3, and SHC1 in glaucoma. Continuous bioinformatics analysis has shown that miR-204 has a significant presence and expression in retinal tissue, and approximately 293 genes are controlled and regulated by miR-204 in this tissue; also, target genes of miR-204 have the potential to develop various retinopathies; thus, a study of related target genes can provide appropriate treatment strategies in the future.
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Jejunal Transcriptomic Profiling for Differences in Feed Conversion Ratio in Slow-Growing Chickens. Animals (Basel) 2021; 11:ani11092606. [PMID: 34573572 PMCID: PMC8470203 DOI: 10.3390/ani11092606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/27/2021] [Accepted: 09/02/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary The slow-growing Korat chicken (KR) is economically attractive, as KR meat has a high selling price and has thus been used in Thailand to support smallholder farmers. However, low feed efficiency in KR stockbreeding makes the product less competitive and improving KR feed efficiency is central to increasing KR profitability. Using RNA sequencing, we compared the jejunal transcriptomic profiles of low- and high-feed conversion ratio (FCR) KR chickens, to identify FCR-related transcriptional variation and biological pathways. Gene Ontology and Kyoto Encyclopedia of Gene and Genome analysis revealed that the main pathways involved in KR FCR variation are related to immune response, glutathione metabolism, vitamin transport and metabolism, lipid metabolism, and neuronal and cardiac maturation, development, and growth. This is the first study to investigate, in the jejunum, the molecular genetic mechanisms affecting the FCR of slow-growing chickens. These findings will be useful in line-breeding programs to improve feed efficiency and profitability in slow-growing chicken stockbreeding. Abstract Improving feed efficiency is an important breeding target for the poultry industry; to achieve this, it is necessary to understand the molecular basis of feed efficiency. We compared the jejunal transcriptomes of low- and high-feed conversion ratio (FCR) slow-growing Korat chickens (KRs). Using an original sample of 75 isolated 10-week-old KR males, we took jejunal samples from six individuals in two groups: those with extremely low FCR (n = 3; FCR = 1.93 ± 0.05) and those with extremely high FCR (n = 3; FCR = 3.29 ± 0.06). Jejunal transcriptome profiling via RNA sequencing revealed 56 genes that were differentially expressed (p < 0.01, FC > 2): 31 were upregulated, and 25 were downregulated, in the low-FCR group relative to the high-FCR group. Functional annotation revealed that these differentially expressed genes were enriched in biological processes related to immune response, glutathione metabolism, vitamin transport and metabolism, lipid metabolism, and neuronal and cardiac maturation, development, and growth, suggesting that these are important mechanisms governing jejunal feed conversion. These findings provide an important molecular basis for future breeding strategies to improve slow-growing chicken feed efficiency.
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Park K, Shin Y, Lee G, Park H, Choi Y. Dabrafenib Promotes Schwann Cell Differentiation by Inhibition of the MEK-ERK Pathway. Molecules 2021; 26:2141. [PMID: 33917810 PMCID: PMC8068149 DOI: 10.3390/molecules26082141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/04/2021] [Accepted: 04/07/2021] [Indexed: 11/16/2022] Open
Abstract
Schwann cell differentiation involves a dynamic interaction of signaling cascades. However, much remains to be elucidated regarding the function of signaling molecules that differ depending on the context in which the molecules are engaged. Here, we identified a small molecule, dabrafenib, which promotes Schwann cell differentiation in vitro and exploited this compound as a pharmacological tool to understand the molecular mechanisms regulating Schwann cell differentiation. The results indicated that dabrafenib inhibited ERK phosphorylation and enhanced ErbB2 autophosphorylation and Akt phosphorylation, and the effects of dabrafenib on ErbB2 and Akt phosphorylation were phenocopied by pharmacological inhibition of the MEK-ERK signaling pathway. However, the small molecule inhibitors of MEK and ERK had no effect on the expression of Oct6 and EGR2, which are key transcription factors that drive Schwann cell differentiation. In addition, pharmacological inhibition of phosphatidylinositol-3-kinase (PI3K) almost completely interfered with dabrafenib-induced Schwann cell differentiation. These results suggest that the ErbB2-PI3K-Akt axis is required for the induction of Schwann cell differentiation by dabrafenib in vitro. Although additional molecules targeted by dabrafenib remain to be identified, our data provides insights into the crosstalk that exists between the MEK-ERK signaling pathway and the PI3K-Akt axis in Schwann cell differentiation.
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Affiliation(s)
- Kyuhee Park
- Biocenter, Gyeonggido Business and Science Accelerator, Suwon 16229, Korea; (K.P.); (G.L.)
| | - Yoonkyoung Shin
- Department of Physiology, Peripheral Neuropathy Research Center, Donga University Medical School, Busan 49201, Korea; (Y.S.); (H.P.)
| | - Gyeongbeen Lee
- Biocenter, Gyeonggido Business and Science Accelerator, Suwon 16229, Korea; (K.P.); (G.L.)
| | - Hwantae Park
- Department of Physiology, Peripheral Neuropathy Research Center, Donga University Medical School, Busan 49201, Korea; (Y.S.); (H.P.)
| | - Yongmun Choi
- Biocenter, Gyeonggido Business and Science Accelerator, Suwon 16229, Korea; (K.P.); (G.L.)
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Miyazaki D, Shimizu D, Fukushima A, Ebihara N, Uchio E, Shoji J, Namba K, Inoue Y, Ohashi Y, Okamoto S, Takamura E, Fujishima H. Reduced steroid-induced intraocular pressure elevation in tacrolimus-treated refractory allergic ocular diseases. Jpn J Ophthalmol 2020; 64:568-576. [PMID: 33026594 DOI: 10.1007/s10384-020-00774-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/16/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE To determine whether topical tacrolimus can lessen steroid-induced intraocular pressure (IOP) elevation. STUDY DESIGN Open cohort post hoc analysis study. METHODS Five hundred eleven patients with vernal keratoconjunctivitis or atopic keratoconjunctivitis (mean age 17.0 ± 9.2 years) were studied. All 511 patients were treated with topical tacrolimus with or without topical steroids, and the changes in IOP were measured monthly for 3 months. The elevation in IOP induced by use of topical steroids was calculated using mixed linear regression analyses. The relationship between the elevation in IOP within 4 weeks and the use or nonuse of tacrolimus reported in published data was analyzed using metaregression analysis to estimate the effects of tacrolimus on the IOP in eyes treated with topical steroids. RESULTS The mean topical steroid-induced IOP elevation in tacrolimus-treated eyes was lower, by 5.2 mmHg (P = 0.04), than that in earlier published data without tacrolimus as the control. In the tacrolimus-treated eyes, the mean betamethasone-induced IOP elevation was 1.3 mmHg without discontinuation of the steroid. Metaregression analysis indicated that glaucoma history and younger age had significant effects on topical steroid-induced IOP elevation, by 4.0 mmHg (P = 0.002) and 3.9 mmHg (P = 0.01), respectively. In tacrolimus-treated eyes, the most significant effect on the IOP was associated with glaucoma history or medication; however, its effect on the IOP was limited to 1.7 mmHg elevation (P = 0.006). CONCLUSIONS Topical tacrolimus may lessen the steroid-induced elevation in IOP in younger individuals and may be a good adjunctive therapy to avoid IOP elevation in refractory cases.
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Affiliation(s)
- Dai Miyazaki
- Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori, 683-8504, Japan.
| | - Daisuke Shimizu
- Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori, 683-8504, Japan
| | | | - Nobuyuki Ebihara
- Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan
| | - Eiichi Uchio
- Department of Ophthalmology, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Jun Shoji
- Division of Ophthalmology, Department of Visual Sciences, Nihon University School of Medicine, Tokyo, Japan
| | - Kenichi Namba
- Department of Ophthalmology, Hokkaido University Graduate School of Medicine, Hokkaido, Japan
| | - Yoshitsugu Inoue
- Division of Ophthalmology and Visual Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori, 683-8504, Japan
| | - Yuichi Ohashi
- Department of Ophthalmology, Ehime University School of Medicine, Toon, Ehime, Japan
| | | | - Etsuko Takamura
- Department of Ophthalmology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Hiroshi Fujishima
- Department of Ophthalmology, Tsurumi University Dental Hospital, Yokohama, Kanagawa, Japan
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Folkesson E, Turkiewicz A, Rydén M, Hughes HV, Ali N, Tjörnstrand J, Önnerfjord P, Englund M. Proteomic characterization of the normal human medial meniscus body using data-independent acquisition mass spectrometry. J Orthop Res 2020; 38:1735-1745. [PMID: 31989678 PMCID: PMC7610686 DOI: 10.1002/jor.24602] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 01/02/2020] [Accepted: 01/21/2020] [Indexed: 02/04/2023]
Abstract
Recent research suggests an important role of the meniscus in the development of knee osteoarthritis. We, therefore, aimed to analyze the proteome of the normal human meniscus body, and specifically to gain new knowledge on global protein expression in the different radial zones. Medial menisci were retrieved from the right knees of 10 human cadaveric donors, from which we cut a 2 mm radial slice from the mid-portion of the meniscal body. This slice was further divided into three zones: inner, middle, and peripheral. Proteins were extracted and prepared for mass spectrometric analysis using data-independent acquisition. We performed subsequent data searches using Spectronaut Pulsar and used fixed-effect linear regression models for statistical analysis. We identified 638 proteins and after statistical analysis, we observed the greatest number of differentially expressed proteins between the inner and peripheral zones (163 proteins) and the peripheral and middle zones (136 proteins), with myocilin being the protein with the largest fold-change in both comparisons. Chondroadherin was one of eight proteins that differed between the inner and middle zones. Functional enrichment analyses showed that the peripheral one-third of the medial meniscus body differed substantially from the two more centrally located zones, which were more similar to each other. This is probably related to the higher content of cells and vascularization in the peripheral zone, whereas the middle and inner zones of the meniscal body appear to be more similar to hyaline cartilage, with high levels of extracellular matrix proteins such as aggrecan and collagen type II.
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Affiliation(s)
- Elin Folkesson
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology UnitLund UniversityLund Sweden
- Faculty of Medicine, Department of Clinical Sciences Lund, Rheumatology and Molecular Skeletal BiologyLund UniversityLund Sweden
| | - Aleksandra Turkiewicz
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology UnitLund UniversityLund Sweden
| | - Martin Rydén
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology UnitLund UniversityLund Sweden
- Faculty of Medicine, Department of Clinical Sciences Lund, Rheumatology and Molecular Skeletal BiologyLund UniversityLund Sweden
| | - Harini Velocity Hughes
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology UnitLund UniversityLund Sweden
| | - Neserin Ali
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology UnitLund UniversityLund Sweden
| | - Jon Tjörnstrand
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology UnitLund UniversityLund Sweden
- Department of OrthopaedicsSkåne University HospitalLund Sweden
| | - Patrik Önnerfjord
- Faculty of Medicine, Department of Clinical Sciences Lund, Rheumatology and Molecular Skeletal BiologyLund UniversityLund Sweden
| | - Martin Englund
- Faculty of Medicine, Department of Clinical Sciences Lund, Orthopaedics, Clinical Epidemiology UnitLund UniversityLund Sweden
- Clinical Epidemiology Research and Training UnitBoston University School of MedicineBoston Massachusetts
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Abstract
Peripheral nerves contain axons and their enwrapping glia cells named Schwann cells (SCs) that are either myelinating (mySCs) or nonmyelinating (nmSCs). Our understanding of other cells in the peripheral nervous system (PNS) remains limited. Here, we provide an unbiased single cell transcriptomic characterization of the nondiseased rodent PNS. We identified and independently confirmed markers of previously underappreciated nmSCs and nerve-associated fibroblasts. We also found and characterized two distinct populations of nerve-resident homeostatic myeloid cells that transcriptionally differed from central nervous system microglia. In a model of chronic autoimmune neuritis, homeostatic myeloid cells were outnumbered by infiltrating lymphocytes which modulated the local cell-cell interactome and induced a specific transcriptional response in glia cells. This response was partially shared between the peripheral and central nervous system glia, indicating common immunological features across different parts of the nervous system. Our study thus identifies subtypes and cell-type markers of PNS cells and a partially conserved autoimmunity module induced in glia cells.
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Xiao X, Huang C, Cao Y, Chen S, Xu Y, Chen H, Pang C, Zhang M. Exome Sequencing Reveals a Heterozygous OAS3 Mutation in a Chinese Family With Juvenile-Onset Open-Angle Glaucoma. Invest Ophthalmol Vis Sci 2019; 60:4277-4284. [PMID: 31618764 DOI: 10.1167/iovs.19-27545] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Juvenile-onset open-angle glaucoma (JOAG), if left untreated, will lead to severe visual disability. The purpose of this study was to identify the disease-causing mutations in a Chinese JOAG family. Methods We recruited a Chinese JOAG family and unrelated primary open-angle glaucoma (POAG) patients (270, Chinese), and performed whole-exome sequencing (WES) to screen the sequence variations. Variants identified by WES were validated by Sanger sequencing. Subsequently, qPCR and Western blotting were used to determine the expression of wild-type (WT) and its mutated-type (MT) of 2'-5'-oligoadenylate synthetase 3 (OAS3) genes. Results Seventeen heterozygous candidate variants were revealed in the JOAG family based on the screening of WES data. Of those, the heterozygous variant exon11:c.2299C>T: p.Arg767Cys in OAS3, a gene used to synthesize 2'-5'-oligoadenylate (2-5A), co-segregates with the disease phenotype. One unrelated POAG patient also carried this variant, but this variant was absent in 200 nonglaucoma healthy controls. Analysis of the Arg767Cys mutation with PolyPhen2, CADD, and SIFT all suggest that it is pathogenic. This arginine residue is highly conserved in all selected OAS3 orthologs. On the other hand, in peripheral blood samples, the mRNA expression of OAS3 in patients significantly decreased compared with unaffected controls. Moreover, the expression level of recombinant OAS3 protein (mutated Arg767Cys) also observably reduced compared with level of WT protein in HEK293T cells. Conclusions Our study revealed a heterozygous mutation in OAS3 from a Chinese JOAG family. And this mutation showed a deleterious effect to the expression of OAS3.
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Affiliation(s)
- Xiaoqiang Xiao
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - Chukai Huang
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - Yingjie Cao
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - Shaowan Chen
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - Yanxuan Xu
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - Haoyu Chen
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - Chipui Pang
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China.,Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - Mingzhi Zhang
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
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12
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Cheng YC, Tsai RY, Sung YT, Chen IJ, Tu TY, Mao YY, Wong CS. Melatonin regulation of transcription in the reversal of morphine tolerance: Microarray analysis of differential gene expression. Int J Mol Med 2018; 43:791-806. [PMID: 30569162 PMCID: PMC6317689 DOI: 10.3892/ijmm.2018.4030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 12/11/2018] [Indexed: 12/21/2022] Open
Abstract
Tolerance and associated hyperalgesia induced by long‑term morphine administration substantially restrict the clinical use of morphine in pain treatment. Melatonin, a neurohormone released by the pineal gland, has been demonstrated to attenuate anti‑nociceptive morphine tolerance. The present study investigates differentially expressed genes in the process of morphine tolerance and altered gene expression subsequent to melatonin treatment in chronic morphine‑infused ratspinal cords. Morphine tolerance was induced in male Wistar rats by intrathecal morphine infusion (the MO group). Melatonin (the MOMa group) was administered to overcome the effects derived by morphine. The mRNA collected from L5‑S3 of the spinal cord was extracted and analysed by rat expression microarray. Principal component analysis and clustering analysis revealed that the overall gene profiles were different in morphine and melatonin treatments. Subsequent to Gene Ontology analysis, the biological processes of differentially expressed genes of MO and MOMa compared with the control group were constructed. Furthermore, a panel of genes exclusively expressed following melatonin treatment and another panel of genes with inverse expression between the MO and MOMa group were also established. Subsequent to PANTHER pathway analysis, a group of genes with inverse expression following melatonin administrated compared with morphine alone were identified. The expression levels of genes of interest were also confirmed using a reverse transcription‑quantitative polymerase chain reaction. The gene panel that was constructed suggests a potential signaling pathway in morphine tolerance development and is valuable for investigating the mechanism of morphine tolerance and the regulatory gene profiles of melatonin treatment. These results may contribute to the discovery of potential drug targets in morphine tolerance treatments in the future.
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Affiliation(s)
- Yu-Che Cheng
- Proteomics Laboratory, Department of Medical Research, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Ru-Yin Tsai
- College of Nursing and Health Sciences, Da‑Yeh University, Changhua 51591, Taiwan, R.O.C
| | - Yen-Tseng Sung
- Proteomics Laboratory, Department of Medical Research, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Ing-Jung Chen
- Department of Anesthesiology, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Tzu-Yi Tu
- Proteomics Laboratory, Department of Medical Research, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Ya-Yuan Mao
- Proteomics Laboratory, Department of Medical Research, Cathay General Hospital, Taipei 10630, Taiwan, R.O.C
| | - Chih-Shung Wong
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan, R.O.C
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13
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Joe MK, Lieberman RL, Nakaya N, Tomarev SI. Myocilin Regulates Metalloprotease 2 Activity Through Interaction With TIMP3. Invest Ophthalmol Vis Sci 2017; 58:5308-5318. [PMID: 29049729 PMCID: PMC5644706 DOI: 10.1167/iovs.16-20336] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose To elucidate functions of wild-type myocilin, a secreted glycoprotein associated with glaucoma. Methods Lysates of mouse eyes were used for immunoprecipitation with affinity-purified antibodies against mouse myocilin. Shotgun proteomic analysis was used for the identification of proteins interacting with myocilin. Colocalization of myocilin and tissue inhibitor of metalloproteinases 3 (TIMP3) in different eye structures was investigated by a multiplex fluorescent in situ hybridization and immunofluorescent labeling with subsequent confocal microscopy. Matrix metalloproteinase 2 (MMP2) activity assay was used to test effects of myocilin on TIMP3 inhibitory action. Results TIMP3 was identified by a shotgun proteomic analysis as a protein that was coimmunoprecipitated with myocilin from eye lysates of wild-type and transgenic mice expressing elevated levels of mouse myocilin but not from lysates of transgenic mice expressing mutated mouse myocilin. Interaction of myocilin and TIMP3 was confirmed by coimmunoprecipitation of myocilin and TIMP3 from HEK293 cells transiently transfected with cDNAs encoding these proteins. The olfactomedin domain of myocilin is essential for interaction with TIMP3. In the eye, the main sites of myocilin and TIMP3 colocalization are the trabecular meshwork, sclera, and choroid. Using purified proteins, it has been shown that myocilin markedly enhanced the inhibitory activity of TIMP3 toward MMP2. Conclusions Myocilin may serve as a modulator of TIMP3 activity via interactions with the myocilin olfactomedin domain. Our data imply that in the case of MYOCILIN null or some glaucoma-causing mutations, inhibitory activity of TIMP3 toward MMP2 might be reduced, mimicking deleterious mutations in the TIMP3 gene.
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Affiliation(s)
- Myung Kuk Joe
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Raquel L Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Naoki Nakaya
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - 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, United States
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14
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Scekic-Zahirovic J, Oussini HE, Mersmann S, Drenner K, Wagner M, Sun Y, Allmeroth K, Dieterlé S, Sinniger J, Dirrig-Grosch S, René F, Dormann D, Haass C, Ludolph AC, Lagier-Tourenne C, Storkebaum E, Dupuis L. Motor neuron intrinsic and extrinsic mechanisms contribute to the pathogenesis of FUS-associated amyotrophic lateral sclerosis. Acta Neuropathol 2017; 133:887-906. [PMID: 28243725 PMCID: PMC5427169 DOI: 10.1007/s00401-017-1687-9] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/08/2017] [Accepted: 02/16/2017] [Indexed: 12/11/2022]
Abstract
Motor neuron-extrinsic mechanisms have been shown to participate in the pathogenesis of ALS-SOD1, one familial form of amyotrophic lateral sclerosis (ALS). It remains unclear whether such mechanisms contribute to other familial forms, such as TDP-43 and FUS-associated ALS. Here, we characterize a single-copy mouse model of ALS-FUS that conditionally expresses a disease-relevant truncating FUS mutant from the endogenous murine Fus gene. We show that these mice, but not mice heterozygous for a Fus null allele, develop similar pathology as ALS-FUS patients and a mild motor neuron phenotype. Most importantly, CRE-mediated rescue of the Fus mutation within motor neurons prevented degeneration of motor neuron cell bodies, but only delayed appearance of motor symptoms. Indeed, we observed downregulation of multiple myelin-related genes, and increased numbers of oligodendrocytes in the spinal cord supporting their contribution to behavioral deficits. In all, we show that mutant FUS triggers toxic events in both motor neurons and neighboring cells to elicit motor neuron disease.
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15
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Liu Y, Allingham RR. Major review: Molecular genetics of primary open-angle glaucoma. Exp Eye Res 2017; 160:62-84. [PMID: 28499933 DOI: 10.1016/j.exer.2017.05.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/29/2017] [Accepted: 05/07/2017] [Indexed: 12/13/2022]
Abstract
Glaucoma is a leading cause of irreversible blindness worldwide. Primary open-angle glaucoma (POAG), the most common type, is a complex inherited disorder that is characterized by progressive retinal ganglion cell death, optic nerve head excavation, and visual field loss. The discovery of a large, and growing, number of genetic and chromosomal loci has been shown to contribute to POAG risk, which carry implications for disease pathogenesis. Differential gene expression analyses in glaucoma-affected tissues as well as animal models of POAG are enhancing our mechanistic understanding in this common, blinding disorder. In this review we summarize recent developments in POAG genetics and molecular genetics research.
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Affiliation(s)
- Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, United States; James & Jean Culver Vision Discovery Institute, Augusta University, Augusta, GA, United States; Center for Biotechnology and Genomic Medicine, Augusta University, Augusta, GA, United States
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States; Duke - National University of Singapore (Duke-NUS), Singapore.
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16
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Rao SNR, Pearse DD. Regulating Axonal Responses to Injury: The Intersection between Signaling Pathways Involved in Axon Myelination and The Inhibition of Axon Regeneration. Front Mol Neurosci 2016; 9:33. [PMID: 27375427 PMCID: PMC4896923 DOI: 10.3389/fnmol.2016.00033] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/02/2016] [Indexed: 01/06/2023] Open
Abstract
Following spinal cord injury (SCI), a multitude of intrinsic and extrinsic factors adversely affect the gene programs that govern the expression of regeneration-associated genes (RAGs) and the production of a diversity of extracellular matrix molecules (ECM). Insufficient RAG expression in the injured neuron and the presence of inhibitory ECM at the lesion, leads to structural alterations in the axon that perturb the growth machinery, or form an extraneous barrier to axonal regeneration, respectively. Here, the role of myelin, both intact and debris, in antagonizing axon regeneration has been the focus of numerous investigations. These studies have employed antagonizing antibodies and knockout animals to examine how the growth cone of the re-growing axon responds to the presence of myelin and myelin-associated inhibitors (MAIs) within the lesion environment and caudal spinal cord. However, less attention has been placed on how the myelination of the axon after SCI, whether by endogenous glia or exogenously implanted glia, may alter axon regeneration. Here, we examine the intersection between intracellular signaling pathways in neurons and glia that are involved in axon myelination and axon growth, to provide greater insight into how interrogating this complex network of molecular interactions may lead to new therapeutics targeting SCI.
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Affiliation(s)
- Sudheendra N R Rao
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine Miami, FL, USA
| | - Damien D Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of MedicineMiami, FL, USA; The Department of Neurological Surgery, University of Miami Miller School of MedicineMiami, FL, USA; The Neuroscience Program, University of Miami Miller School of MedicineMiami, FL, USA; The Interdisciplinary Stem Cell Institute, University of Miami Miller School of MedicineMiami, FL, USA; Bruce W. Carter Department of Veterans Affairs Medical CenterMiami, FL, USA
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Su WF, Gu Y, Wei ZY, Shen YT, Jin ZH, Yuan Y, Gu XS, Chen G. Rab27a/Slp2-a complex is involved in Schwann cell myelination. Neural Regen Res 2016; 11:1830-1838. [PMID: 28123429 PMCID: PMC5204241 DOI: 10.4103/1673-5374.194755] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Myelination of Schwann cells in the peripheral nervous system is an intricate process involving myelin protein trafficking. Recently, the role and mechanism of the endosomal/lysosomal system in myelin formation were emphasized. Our previous results demonstrated that a small GTPase Rab27a regulates lysosomal exocytosis and myelin protein trafficking in Schwann cells. In this present study, we established a dorsal root ganglion (DRG) neuron and Schwann cell co-culture model to identify the signals associated with Rab27a during myelination. First, Slp2-a, as the Rab27a effector, was endogenously expressed in Schwann cells. Second, Rab27a expression significantly increased during Schwann cell myelination. Finally, Rab27a and Slp2-a silencing in Schwann cells not only reduced myelin protein expression, but also impaired formation of myelin-like membranes in DRG neuron and Schwann cell co-cultures. Our findings suggest that the Rab27a/Slp2-a complex affects Schwann cell myelination in vitro.
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Affiliation(s)
- Wen-Feng Su
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Yun Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Zhong-Ya Wei
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Yun-Tian Shen
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Zi-Han Jin
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Ying Yuan
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China; Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiao-Song Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Gang Chen
- Jiangsu Key Laboratory of Neuroregeneration, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
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Itakura T, Peters DM, Fini ME. Glaucomatous MYOC mutations activate the IL-1/NF-κB inflammatory stress response and the glaucoma marker SELE in trabecular meshwork cells. Mol Vis 2015; 21:1071-84. [PMID: 26396484 PMCID: PMC4575906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 09/15/2015] [Indexed: 11/14/2022] Open
Abstract
PURPOSE Activation of the IL-1/NF-κB inflammatory stress pathway and induction of SELE expression in the trabecular meshwork (TBM) is a marker for high-tension glaucomas of diverse etiology. Pathway activation stimulates aqueous outflow and protects against oxidative stress, but may be damaging in the long-term. MYOC mutations have been causally linked to high-tension forms of primary open angle glaucoma (POAG). This study investigated a possible link between MYOC mutations and activation of the IL-1/NF-κB pathway and expression of SELE. METHODS We constructed MYOC expression vectors with mutations at sites that cause POAG. Mutations (Q368X, Y437H, A427T) were selected to represent proteins with differing POAG-causing potency (Q368X > Y437H > A427T) and intracellular retention behavior (Q368X and Y437H retained, A427T released). The constructs were made in two different kinds of vectors; one a plasmid designed for transient transfection (pCMV6), and one a doxycycline-inducible lentiviral vector (pSLIK) for stable cell transduction. The immortalized human trabecular meshwork line TM-1 was used for all expression studies. Expression of IL1A mRNA was determined by reverse transcription (RT)-PCR, as well as a set of five other genes associated with signaling pathways linked to glaucoma: IL1B and IL6 (NF-κB pathway), TGFB2 and ACTA2 (TGF-β pathway) and FOXO1 (E2F1 apoptotic pathway). An ELISA was used to quantify IL1A protein released into culture media. To quantify intracellular NF-κB activity, we transiently transfected stably transduced cell lines with a luciferase expression vector under control of the IL8 promoter (containing an NF-κB response element). RESULTS Transiently expressed wild-type MYOC was released into cell culture media, whereas mutant MYOCs Q368X and Y437H remained within cells. Both mutant MYOCs activated the IL-1/ NF-κB pathway, significantly stimulating expression of IL1A and IL1B. However Y437H, which causes a severe glaucoma phenotype, was less effective than Q368X, which causes a moderate glaucoma phenotype. In addition, the retained mutants stimulated expression of stress response genes ACTA2 and FOXO1. Unexpectedly, wild-type MYOC significantly decreased expression of IL6 and TGFB2, to approximately half of the control levels, and expression of IL1B and ACTA2 was also slightly decreased. Induction of MYOC mutants Q368X and Y437H in stably transduced cell lines significantly stimulated the level of IL1A protein released into culture media. Once again however, the effect of the severe MYOC mutant Y437H was less than the effect of the moderate MYOC mutant Q368X. In contrast, induced expression of the intracellularly retained mutant MYOC A427T or wild-type MYOC did not change the amount of IL1A protein in culture media. Induction of Y437H MYOC plus IL1A treatment increased NF-κB activity by 25% over IL1A alone. In contrast, induction of Q368X or A427T plus IL1A treatment did not significantly affect NF-κB activity over IL1A alone. However, wild-type MYOC expression inhibited IL1A-stimulated NF-κB activity. We also observed that endogenous MYOC expression was induced by IL1A in TM-1 cells and primary TBM cell cultures. SELE was co-expressed with MYOC in the primary cell lines. CONCLUSIONS These results indicate that POAG-causing MYOC mutants activate the IL-1/NF-κB pathway, with activation levels correlated with intracellular retention of the protein, but not POAG-causing potency. Unexpectedly, it was also discovered that wild-type MYOC inhibits activation of the IL-1/NF-κB pathway, and that activation of the IL-1/NF-κB pathway stimulates expression of MYOC. This is the first evidence that glaucoma-causing MYOC mutants can activate the inflammatory response and that wild-type MYOC has anti-inflammatory activity.
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Affiliation(s)
- Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA
| | - Donna M. Peters
- Departments of Pathology & Laboratory Medicine and Ophthalmology & Visual Sciences, University of Wisconsin, Madison, WI
| | - M. Elizabeth Fini
- USC Institute for Genetic Medicine, USC Eye Institute, and Departments of Cell & Neurobiology and Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA
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Rasband MN, Peles E. The Nodes of Ranvier: Molecular Assembly and Maintenance. Cold Spring Harb Perspect Biol 2015; 8:a020495. [PMID: 26354894 DOI: 10.1101/cshperspect.a020495] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Action potential (AP) propagation in myelinated nerves requires clustered voltage gated sodium and potassium channels. These channels must be specifically localized to nodes of Ranvier where the AP is regenerated. Several mechanisms have evolved to facilitate and ensure the correct assembly and stabilization of these essential axonal domains. This review highlights the current understanding of the axon intrinsic and glial extrinsic mechanisms that control the formation and maintenance of the nodes of Ranvier in both the peripheral nervous system (PNS) and central nervous system (CNS).
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Affiliation(s)
- Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Elior Peles
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel
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20
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Stothert AR, Fontaine SN, Sabbagh JJ, Dickey CA. Targeting the ER-autophagy system in the trabecular meshwork to treat glaucoma. Exp Eye Res 2015; 144:38-45. [PMID: 26302411 DOI: 10.1016/j.exer.2015.08.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/23/2015] [Accepted: 08/18/2015] [Indexed: 12/19/2022]
Abstract
A major drainage network involved in aqueous humor dynamics is the conventional outflow pathway, which is gated by the trabecular meshwork (TM). The TM acts as a molecular sieve, providing resistance to aqueous outflow, which is responsible for regulating intraocular pressure (IOP). If the TM is damaged, aqueous outflow is impaired, IOP increases and glaucoma can manifest. Mutations in the MYOC gene cause hereditary primary open-angle glaucoma (POAG) by promoting the abnormal amyloidosis of the myocilin protein in the endoplasmic reticulum (ER), leading to ER stress-induced TM cell death. Myocilin accumulation is observed in approximately 70-80% of all glaucoma cases suggesting that environmental or other genetic factors may also promote myocilin toxicity. For example, simply preventing myocilin glycosylation is sufficient to promote its abnormal accretion. These myocilin amyloids are unique as there are no other known pathogenic proteins that accumulate within the ER of TM cells and cause toxicity. Moreover, this pathogenic accumulation only kills TM cells, despite expression of this protein in other cell types, suggesting that another modifier exclusive to the TM participates in the proteotoxicity of myocilin. ER autophagy (reticulophagy) is one of the pathways essential for myocilin clearance that can be impacted dramatically by aging and other environmental factors such as nutrition. This review will discuss the link between myocilin and autophagy, evaluating the role of this degradation pathway in glaucoma as well as its potential as a therapeutic target.
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Affiliation(s)
- Andrew R Stothert
- Department of Molecular Medicine, Byrd Alzheimer's Research Institute, University of South Florida, Tampa, FL 33613, USA
| | - Sarah N Fontaine
- Department of Molecular Medicine, Byrd Alzheimer's Research Institute, University of South Florida, Tampa, FL 33613, USA
| | - Jonathan J Sabbagh
- Department of Molecular Medicine, Byrd Alzheimer's Research Institute, University of South Florida, Tampa, FL 33613, USA
| | - Chad A Dickey
- Department of Molecular Medicine, Byrd Alzheimer's Research Institute, University of South Florida, Tampa, FL 33613, USA.
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Transcriptome and histopathological changes in mouse brain infected with Neospora caninum. Sci Rep 2015; 5:7936. [PMID: 25604996 PMCID: PMC4300462 DOI: 10.1038/srep07936] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/23/2014] [Indexed: 11/15/2022] Open
Abstract
Neospora caninum is a protozoan parasite that causes neurological disorders in dogs and cattle. It can cause nonsuppurative meningoencephalitis and a variety of neuronal symptoms are observed, particularly in dogs. However, the pathogenic mechanism, including the relationship between the parasite distribution and the clinical signs, is unclear. In this study, to understand the pathogenic mechanism of neosporosis, parasite distribution and lesions were assessed in the brain of mice infected with N. caninum (strain Nc-1). Host gene expression was also analyzed with RNA sequencing (RNA-Seq). The histopathological lesions in the frontal lobe and the medulla oblongata were significantly more severe in symptomatic mice than in asymptomatic mice, although no association between the severity of the lesions and parasite numbers was found. In infected mice, the expression of 772 mouse brain genes was upregulated. A GOstat analysis predicted that the upregulated genes were involved in the host immune response. Genes whose expression correlated positively and negatively with parasite numbers were involved in the host immune response, and neuronal morphogenesis and lipid metabolic processes, respectively. These results suggest that changes in the gene expression profile associated with neuronal functions as well as immune responses can contribute to the pathogenesis in N. caninum-infected animals.
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22
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Donegan RK, Hill SE, Freeman DM, Nguyen E, Orwig SD, Turnage KC, Lieberman RL. Structural basis for misfolding in myocilin-associated glaucoma. Hum Mol Genet 2014; 24:2111-24. [PMID: 25524706 DOI: 10.1093/hmg/ddu730] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Olfactomedin (OLF) domain-containing proteins play roles in fundamental cellular processes and have been implicated in disorders ranging from glaucoma, cancers and inflammatory bowel disorder, to attention deficit disorder and childhood obesity. We solved crystal structures of the OLF domain of myocilin (myoc-OLF), the best studied such domain to date. Mutations in myoc-OLF are causative in the autosomal dominant inherited form of the prevalent ocular disorder glaucoma. The structures reveal a new addition to the small family of five-bladed β-propellers. Propellers are most well known for their ability to act as hubs for protein-protein interactions, a function that seems most likely for myoc-OLF, but they can also act as enzymes. A calcium ion, sodium ion and glycerol molecule were identified within a central hydrophilic cavity that is accessible via movements of surface loop residues. By mapping familial glaucoma-associated lesions onto the myoc-OLF structure, three regions sensitive to aggregation have been identified, with direct applicability to differentiating between neutral and disease-causing non-synonymous mutations documented in the human population worldwide. Evolutionary analysis mapped onto the myoc-OLF structure reveals conserved and divergent regions for possible overlapping and distinctive functional protein-protein or protein-ligand interactions across the broader OLF domain family. While deciphering the specific normal biological functions, ligands and binding partners for OLF domains will likely continue to be a challenging long-term experimental pursuit, atomic detail structural knowledge of myoc-OLF is a valuable guide for understanding the implications of glaucoma-associated mutations and will help focus future studies of this biomedically important domain family.
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Affiliation(s)
- Rebecca K Donegan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Shannon E Hill
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Dana M Freeman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Elaine Nguyen
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Susan D Orwig
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Katherine C Turnage
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | - Raquel L Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
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Han H, Kursula P. The olfactomedin domain from gliomedin is a β-propeller with unique structural properties. J Biol Chem 2014; 290:3612-21. [PMID: 25525261 DOI: 10.1074/jbc.m114.627547] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
All members of the olfactomedin (OLF) family have a conserved extracellular OLF domain, for which a structure has not been available. We present here the crystal structure of the OLF domain from gliomedin. Gliomedin is a protein expressed by Schwann cells in peripheral nerves, important for the formation of the nodes of Ranvier. Gliomedin interacts with neuronal cell adhesion molecules, such as neurofascin, but the structural details of the interaction are not known. The structure of the OLF domain presents a five-bladed β-propeller fold with unusual geometric properties. The symmetry of the structure is not 5-fold, but rather reveals a twisted arrangement. The conserved top face of the gliomedin OLF domain is likely to be important for binding to neuronal ligands. Our results provide a structural basis for the functions of gliomedin in Schwann cells, enable the understanding of the role of the gliomedin OLF domain in autoimmune neuropathies, and unravel the locations of human disease-causing mutations in other OLF family members, including myocilin.
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Affiliation(s)
- Huijong Han
- From the Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, 90014 Oulu, Finland, the German Electron Synchrotron (DESY), 22607 Hamburg, Germany, and
| | - Petri Kursula
- From the Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, 90014 Oulu, Finland, the German Electron Synchrotron (DESY), 22607 Hamburg, Germany, and the Department of Biomedicine, University of Bergen, N-5020 Bergen, Norway
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24
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Faralli JA, Clark RW, Filla MS, Peters DM. NFATc1 activity regulates the expression of myocilin induced by dexamethasone. Exp Eye Res 2014; 130:9-16. [PMID: 25450062 DOI: 10.1016/j.exer.2014.11.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/24/2014] [Accepted: 11/17/2014] [Indexed: 10/24/2022]
Abstract
Mutations in the myocilin gene (MYOC) account for 10% of juvenile open-angle glaucoma cases and 3-4% of adult onset primary open-angle glaucoma cases. It is a secreted glycoprotein found in many ocular and non-ocular tissues and has been linked to elevated intraocular pressure. In human trabecular meshwork (HTM) cells, MYOC expression can be induced by the glucocorticoid dexamethasone (DEX). In this study we examined the role of the calcineurin/NFATc1 (Nuclear Factor of Activated T-cells) pathway in the DEX induction of MYOC in HTM cells. In post-confluent HTM cells treated with either 500 nM DEX or 0.1% ethanol (EtOH; vehicle control) for 0-6 days both protein and mRNA levels of MYOC were increased while DEX was present. The protein and mRNA levels remained elevated for an additional 12 days after the removal of DEX. Only 1 day of DEX treatment was sufficient to trigger a sustained increase in MYOC mRNA that lasted for 4 days after the removal of DEX. Similar to other studies, myocilin protein expression was not seen until the second day of DEX treatment while mRNA increased within one day of DEX indicating that this is a secondary glucocorticoid response. To determine if MYOC gene expression was regulated by calcineurin/NFATc1, HTM cells were pre-treated for 1 h with the calcineurin inhibitors cyclosporin A or INCA-6 prior to the addition of DEX or EtOH for 2 days. NFATc1 siRNA was used to determine if NFATc1 was required for MYOC mRNA expression. Cells were also treated with the ionophone ionomycin to determine if increased cytosolic calcium affected MYOC expression. These studies showed that the DEX induced increase in MYOC mRNA could be inhibited with either cyclosporin A or INCA-6 or by transfection with NFATc1 siRNA and that ionomycin was unable to increase MYOC mRNA. Immunofluorescence microscopy was also performed to determine if DEX caused the nuclear translocation of NFATc1. Immunostaining showed that NFATc1 relocated to the nucleus within 15 min of DEX treatment and remained there for up to 2 h. The data suggest that the DEX-induced increase in MYOC expression activates a calcineurin and NFATc1 pathway in a calcium independent mechanism.
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Affiliation(s)
- Jennifer A Faralli
- Departments of Pathology & Laboratory Medicine, University of Wisconsin, Madison, WI 53706, USA.
| | - Ross W Clark
- Departments of Pathology & Laboratory Medicine, University of Wisconsin, Madison, WI 53706, USA
| | - Mark S Filla
- Departments of Ophthalmology & Visual Sciences, University of Wisconsin, Madison, WI 53706, USA
| | - Donna M Peters
- Departments of Pathology & Laboratory Medicine, University of Wisconsin, Madison, WI 53706, USA; Departments of Ophthalmology & Visual Sciences, University of Wisconsin, Madison, WI 53706, USA
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25
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Sultana A, Nakaya N, Dong L, Abu-Asab M, Qian H, Tomarev SI. Deletion of olfactomedin 2 induces changes in the AMPA receptor complex and impairs visual, olfactory, and motor functions in mice. Exp Neurol 2014; 261:802-11. [PMID: 25218043 DOI: 10.1016/j.expneurol.2014.09.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/21/2014] [Accepted: 09/02/2014] [Indexed: 12/19/2022]
Abstract
Olfactomedin 2 (Olfm2) is a secretory glycoprotein belonging to the family of olfactomedin domain-containing proteins. A previous study has shown that a mutation in OLFM2 is associated with primary open angle glaucoma in Japanese patients. In the present study, we generated Olfm2 deficient mice by replacing the Olfm2 gene with the LacZ gene. The loss of Olfm2 resulted in no gross abnormalities. However, Olfm2 null mice showed reduced exploration, locomotion, olfactory sensitivity, abnormal motor coordination, and anxiety related behavior. The pattern of the Olfm2 gene expression was studied in the brain and eye using β-galactosidase staining. In the brain, Olfm2 was mainly expressed in the olfactory bulb, cortex, piriform cortex, olfactory trabeculae, and inferior and superior colliculus. In the eye expression was detected mainly in retinal ganglion cells. In Olfm2 null mice, the amplitude of the first negative wave in the visual evoked potential test was significantly reduced as compared with wild-type littermates. Olfm2, similar to Olfm1, interacted with the GluR2 subunit of the AMPAR complexes and Olfm2 co-segregated with the AMPA receptor subunit GluR2 and other synaptic proteins in the synaptosomal membrane fraction upon biochemical fractionation of the adult mice cortex and retina. Immunoprecipitation from the synaptosomal membrane fraction of the Olfm2 null mouse brain cortex using the GluR2 antibody showed reduced levels of several components of the AMPAR complex in the immunoprecipitates including Olfm1, PSD95 and CNIH2. These results suggest that heterodimers of Olfm1 and Olfm2 interact with AMPAR more efficiently than Olfm2 homodimers and that Olfm2 plays a role in the organization of the AMPA receptor complexes.
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Affiliation(s)
- Afia Sultana
- Section on Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Naoki Nakaya
- Section on Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Lijin Dong
- Genetic Engineering Facility, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Mones Abu-Asab
- Histopathology Core Facility, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Stanislav I Tomarev
- Section on Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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26
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Myocilin is involved in NgR1/Lingo-1-mediated oligodendrocyte differentiation and myelination of the optic nerve. J Neurosci 2014; 34:5539-51. [PMID: 24741044 DOI: 10.1523/jneurosci.4731-13.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Myocilin is a secreted glycoprotein that belongs to a family of olfactomedin domain-containing proteins. Although myocilin is detected in several ocular and nonocular tissues, the only reported human pathology related to mutations in the MYOCILIN gene is primary open-angle glaucoma. Functions of myocilin are poorly understood. Here we demonstrate that myocilin is a mediator of oligodendrocyte differentiation and is involved in the myelination of the optic nerve in mice. Myocilin is expressed and secreted by optic nerve astrocytes. Differentiation of optic nerve oligodendrocytes is delayed in Myocilin-null mice. Optic nerves of Myocilin-null mice contain reduced levels of several myelin-associated proteins including myelin basic protein, myelin proteolipid protein, and 2'3'-cyclic nucleotide 3'-phosphodiesterase compared with those of wild-type littermates. This leads to reduced myelin sheath thickness of optic nerve axons in Myocilin-null mice compared with wild-type littermates, and this difference is more pronounced at early postnatal stages compared with adult mice. Myocilin also affects differentiation of oligodendrocyte precursors in vitro. Its addition to primary cultures of differentiating oligodendrocyte precursors increases levels of tested markers of oligodendrocyte differentiation and stimulates elongation of oligodendrocyte processes. Myocilin stimulation of oligodendrocyte differentiation occurs through the NgR1/Lingo-1 receptor complex. Myocilin physically interacts with Lingo-1 and may be considered as a Lingo-1 ligand. Myocilin-induced elongation of oligodendrocyte processes may be mediated by activation of FYN and suppression of RhoA GTPase.
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27
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Koch MA, Rosenhammer B, Koschade SE, Braunger BM, Volz C, Jägle H, Tamm ER. Myocilin modulates programmed cell death during retinal development. Exp Eye Res 2014; 125:41-52. [PMID: 24837143 DOI: 10.1016/j.exer.2014.04.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/03/2014] [Accepted: 04/18/2014] [Indexed: 11/20/2022]
Abstract
Mutations in the myocilin gene (MYOC) are causative for 10% of cases with juvenile open-angle glaucoma and 3-4% of those with primary open-angle glaucoma. Myocilin is a secreted protein with relatively ill-defined matricellular properties. Despite its high expression in the eye, myocilin-deficient mice have originally been reported to have no obvious ocular phenotype. Here we revisited the ocular phenotype of myocilin-deficient mice and detected a higher number of neurons in their inner (INL) and outer (ONL) nuclear layers, as well as a higher number of retinal ganglion cells (RGC) and their axons. The increase in retinal neurons appears to be caused by a decrease in programmed developmental cell death, as apoptosis of retinal neurons between postnatal days 4 and 10 was found to be attenuated when compared to that of wildtype littermates. In contrast, when Myoc(-/-) mice were crossed with βB1-crystallin-MYOC mice with ectopic overexpression of myocilin in the eye, no differences in developmental apoptosis, RGC number and INL thickness were observed when compared to wildtype littermates. The amounts of the anti-apoptotic Bcl-2-like protein 1 (BCL2L1, Bcl-xL) and its mRNA were increased in retinae of Myoc(-/-) mice, while lower amounts of BCL2L1 and its mRNA were detected in mixed Myoc(-/-)/βB1-crystallin-MYOC mice. The structural differences between Myoc(-/-) mice and wildtype littermates did not result in functional differences as measured by electroretinography. Noteworthy though mixed Myoc(-/-)/βB1-crystallin-MYOC mice with ocular overexpression of myocilin had significant cone function deficits. Myocilin appears to modulate apoptotic death of retinal neurons likely by interacting with the intrinsic apoptotic pathway.
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Affiliation(s)
- Marcus A Koch
- Institute of Human Anatomy and Embryology, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Bernd Rosenhammer
- Institute of Human Anatomy and Embryology, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Sebastian E Koschade
- Institute of Human Anatomy and Embryology, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Barbara M Braunger
- Institute of Human Anatomy and Embryology, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | - Cornelia Volz
- Department of Ophthalmology, University of Regensburg, Regensburg, Germany
| | - Herbert Jägle
- Department of Ophthalmology, University of Regensburg, Regensburg, Germany
| | - Ernst R Tamm
- Institute of Human Anatomy and Embryology, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany.
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28
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Amor V, Feinberg K, Eshed-Eisenbach Y, Vainshtein A, Frechter S, Grumet M, Rosenbluth J, Peles E. Long-term maintenance of Na+ channels at nodes of Ranvier depends on glial contact mediated by gliomedin and NrCAM. J Neurosci 2014; 34:5089-98. [PMID: 24719088 PMCID: PMC3983794 DOI: 10.1523/jneurosci.4752-13.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Clustering of Na(+) channels at the nodes of Ranvier is coordinated by myelinating glia. In the peripheral nervous system, axoglial contact at the nodes is mediated by the binding of gliomedin and glial NrCAM to axonal neurofascin 186 (NF186). This interaction is crucial for the initial clustering of Na(+) channels at heminodes. As a result, it is not clear whether continued axon-glial contact at nodes of Ranvier is required to maintain these channels at the nodal axolemma. Here, we report that, in contrast to mice that lack either gliomedin or NrCAM, absence of both molecules (and hence the glial clustering signal) resulted in a gradual loss of Na(+) channels and other axonal components from the nodes, the formation of binary nodes, and dysregulation of nodal gap length. Therefore, these mice exhibit neurological abnormalities and slower nerve conduction. Disintegration of the nodes occurred in an orderly manner, starting with the disappearance of neurofascin 186, followed by the loss of Na(+) channels and ankyrin G, and then βIV spectrin, a sequence that reflects the assembly of nodes during development. Finally, the absence of gliomedin and NrCAM led to the invasion of the outermost layer of the Schwann cell membrane beyond the nodal area and the formation of paranodal-like junctions at the nodal gap. Our results reveal that axon-glial contact mediated by gliomedin, NrCAM, and NF186 not only plays a role in Na(+) channel clustering during development, but also contributes to the long-term maintenance of Na(+) channels at nodes of Ranvier.
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Affiliation(s)
- Veronique Amor
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Konstantin Feinberg
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Yael Eshed-Eisenbach
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Anya Vainshtein
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Shahar Frechter
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Martin Grumet
- 2 W.M. Keck Center for Collaborative Neuroscience, Rutgers University, Piscataway, New Jersey 08854; and
| | - Jack Rosenbluth
- 3Department of Neuroscience and Physiology, New York University School of Medicine, New York, New York 10016
| | - Elior Peles
- 1Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel;
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29
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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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