1
|
Ganekal P, Vastrad B, Kavatagimath S, Vastrad C, Kotrashetti S. Bioinformatics and Next-Generation Data Analysis for Identification of Genes and Molecular Pathways Involved in Subjects with Diabetes and Obesity. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59020309. [PMID: 36837510 PMCID: PMC9967176 DOI: 10.3390/medicina59020309] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/19/2023] [Accepted: 01/29/2023] [Indexed: 02/10/2023]
Abstract
Background and Objectives: A subject with diabetes and obesity is a class of the metabolic disorder. The current investigation aimed to elucidate the potential biomarker and prognostic targets in subjects with diabetes and obesity. Materials and Methods: The next-generation sequencing (NGS) data of GSE132831 was downloaded from Gene Expression Omnibus (GEO) database. Functional enrichment analysis of DEGs was conducted with ToppGene. The protein-protein interactions network, module analysis, target gene-miRNA regulatory network and target gene-TF regulatory network were constructed and analyzed. Furthermore, hub genes were validated by receiver operating characteristic (ROC) analysis. A total of 872 DEGs, including 439 up-regulated genes and 433 down-regulated genes were observed. Results: Second, functional enrichment analysis showed that these DEGs are mainly involved in the axon guidance, neutrophil degranulation, plasma membrane bounded cell projection organization and cell activation. The top ten hub genes (MYH9, FLNA, DCTN1, CLTC, ERBB2, TCF4, VIM, LRRK2, IFI16 and CAV1) could be utilized as potential diagnostic indicators for subjects with diabetes and obesity. The hub genes were validated in subjects with diabetes and obesity. Conclusion: This investigation found effective and reliable molecular biomarkers for diagnosis and prognosis by integrated bioinformatics analysis, suggesting new and key therapeutic targets for subjects with diabetes and obesity.
Collapse
Affiliation(s)
- Prashanth Ganekal
- Department of General Medicine, Basaveshwara Medical College, Chitradurga 577501, Karnataka, India
| | - Basavaraj Vastrad
- Department of Pharmaceutical Chemistry, K.L.E. College of Pharmacy, Gadag 582101, Karnataka, India
| | - Satish Kavatagimath
- Department of Pharmacognosy, K.L.E. College of Pharmacy, Belagavi 590010, Karnataka, India
| | - Chanabasayya Vastrad
- Biostatistics and Bioinformatics, Chanabasava Nilaya, Bharthinagar, Dharwad 580001, Karnataka, India
- Correspondence: ; Tel.: +91-9480073398
| | - Shivakumar Kotrashetti
- Biostatistics and Bioinformatics, Chanabasava Nilaya, Bharthinagar, Dharwad 580001, Karnataka, India
| |
Collapse
|
2
|
Quan Y, Wu Y, Zhan Z, Yang Y, Chen X, Wu K, Yu M. Inhibition of the leucine-rich repeat protein lingo-1 enhances RGC survival in optic nerve injury. Exp Ther Med 2019; 19:619-629. [PMID: 31885701 PMCID: PMC6913235 DOI: 10.3892/etm.2019.8250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 03/26/2019] [Indexed: 01/02/2023] Open
Abstract
Leucine-rich repeat and immunoglobulin-like domain-containing nogo receptor-interacting protein 1 (lingo-1) is selectively expressed on neurons and oligodendrocytes in the central nervous system and acts as a negative regulator in neural repair, implying a potential role in optic neuropathy. The aim of the present study was to determine whether adeno-associated virus serotype 2 (AAV2) vector-mediated transfer of lingo-1 short hairpin RNA could reduce nerve crush-induced axonal degeneration and enhance axonal regeneration following optic nerve (ON) injury in vivo. The expression of lingo-1 was knocked down in vivo using a green fluorescent protein (GFP)-tagged AAV2 encoding lingo-1 shRNA via intravitreal injection in adult Sprague-Dawley rats. Silencing effects of AAV2-lingo-1-shRNA were confirmed by detecting GFP labelling of RGCs, and by quantifying lingo-1 expression levels with reverse transcription-quantitative polymerase chain reaction and western blotting. Rats received an intravitreal injection of AAV2-lingo-1-shRNA or negative control shRNA. The ON crush (ONC) injury was performed 2 weeks after the intravitreal injection. RGC density, lesion volume of the injured ON and the visual electrophysiology [flash visual evoked potential (F-VEP)] at different time points post-injury were determined. Transduction with lingo-1-shRNA decreased lingo-1 expression levels and promoted RGC survival following ONC. Lingo-1-shRNA promoted ON tissue repair and functional recovery. The mechanism underlying the effect of AAV2-lingo-1-shRNA on RGCs may be the phosphorylation of protein kinase B (Akt) at Ser473 and activation of the Akt signaling pathway acting downstream of lingo-1. The results of the current study indicate that the inhibition of lingo-1 may enhance RGC survival and facilitate functional recovery following ON injury, representing a promising potential strategy for the repair of optic neuropathy.
Collapse
Affiliation(s)
- Yadan Quan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yali Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Zongyi Zhan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yangfan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xiaotao Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Kaili Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| |
Collapse
|
3
|
Huang LJ, Li G, Ding Y, Sun JH, Wu TT, Zhao W, Zeng YS. LINGO-1 deficiency promotes nerve regeneration through reduction of cell apoptosis, inflammation, and glial scar after spinal cord injury in mice. Exp Neurol 2019; 320:112965. [PMID: 31132364 DOI: 10.1016/j.expneurol.2019.112965] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/14/2019] [Accepted: 05/23/2019] [Indexed: 12/16/2022]
Abstract
Leucine-rich repeat and immunoglobulin domain-containing protein 1 (LINGO-1) is a transmembrane protein that negatively regulates neural regeneration in the central nervous system. LINGO-1 expression is up-regulated after central nerve injury, and is accompanied by cell death. Both LINGO-1 and cell death in the injury microenvironment are thought to limit neural regeneration, but the relationship between LINGO-1 and cell death has not been characterized. To investigate whether LINGO-1 deletion improves the spinal cord microenvironment after spinal cord injury (SCI) and contributes to cell survival, we generated LINGO-1 knockout (KO) mice. These mice and wild-type control mice were subjected to spinal cord transection. Fourteen days after spinal cord transection, cell apoptosis, inflammation, glial scar, and growth of nerve fibers were evaluated by immunostaining. The results showed that LINGO-1 KO mice demonstrated a profound reduction in expression of caspase-3, transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL), ionized calcium binding adapter molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), and chondroitin sulfate proteoglycans (CSPGs) compared to controls. In contrast, expression of neurofilament (NF) at the SCI site in LINGO-1 KO mice was markedly increased compared to that in wild-type mice. These results suggested that LINGO-1 plays a critical role in the injury microenvironment in processes such as cell death, inflammatory response, and glial scar formation. Importantly, LINGO-1 deletion and a positive microenvironment may exert synergistic effects to promote nerve fiber regeneration. Therefore, inhibition of LINGO-1 may be a therapeutic strategy to promote neural regeneration following SCI.
Collapse
Affiliation(s)
- Li-Jun Huang
- Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China; Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Ge Li
- Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China; Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Ying Ding
- Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China
| | - Jia-Hui Sun
- Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China; Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Ting-Ting Wu
- Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Wei Zhao
- Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China; Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Yuan-Shan Zeng
- Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou 510080, China; Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou 510120, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
| |
Collapse
|
4
|
Chitranshi N, Dheer Y, Abbasi M, You Y, Graham SL, Gupta V. Glaucoma Pathogenesis and Neurotrophins: Focus on the Molecular and Genetic Basis for Therapeutic Prospects. Curr Neuropharmacol 2018; 16:1018-1035. [PMID: 29676228 PMCID: PMC6120108 DOI: 10.2174/1570159x16666180419121247] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 04/10/2018] [Accepted: 04/18/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Retinal ganglion cell (RGC) degeneration is a major feature of glaucoma pathology. Neuroprotective approaches that delay or halt the progression of RGC loss are needed to prevent vision loss which can occur even after conventional medical or surgical treatments to lower intraocular pressure. OBJECTIVE The aim of this review was to examine the progress in genetics and cellular mechanisms associated with endoplasmic reticulum (ER) stress, RGC dysfunction and cell death pathways in glaucoma. MATERIALS AND METHODS Here, we review the involvement of neurotrophins like brain derived neurotrophic factor (BDNF) and its high affinity receptor tropomyosin receptor kinase (TrkB) in glaucoma. The role of ER stress markers in human and animal retinas in health and disease conditions is also discussed. Further, we analysed the literature highlighting genetic linkage in the context of primary open angle glaucoma and suggested mechanistic insights into potential therapeutic options relevant to glaucoma management. RESULTS The literature review of the neurobiology underlying neurotrophin pathways, ER stress and gene associations provide critical insights into association of RGCs death in glaucoma. Alteration in signalling pathway is associated with increased risk of misfolded protein aggregation in ER promoting RGC apoptosis. Several genes that are linked with neurotrophin signalling pathways have been reported to be associated with glaucoma pathology. CONCLUSION Understanding genetic heterogeneity and involvement of neurotrophin biology in glaucoma could help to understand the complex pathophysiology of glaucoma. Identification of novel molecular targets will be critical for drug development and provide neuroprotection to the RGCs and optic nerve.
Collapse
Affiliation(s)
- Nitin Chitranshi
- Address correspondence to this author at the Faculty of Medicine and Health Sciences, 75, Talavera Road, Macquarie University, Sydney, NSW 2109, Australia; Tel: +61-298502760; E-mail:
| | | | | | | | | | | |
Collapse
|
5
|
Rajendran R, Giraldo-Velásquez M, Stadelmann C, Berghoff M. Oligodendroglial fibroblast growth factor receptor 1 gene targeting protects mice from experimental autoimmune encephalomyelitis through ERK/AKT phosphorylation. Brain Pathol 2017; 28:212-224. [PMID: 28117910 DOI: 10.1111/bpa.12487] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 01/18/2017] [Indexed: 01/17/2023] Open
Abstract
Fibroblast growth factors (FGFs) exert diverse biological effects by binding and activation of specific fibroblast growth factor receptors (FGFRs). FGFs and FGFRs have been implicated in demyelinating pathologies including multiple sclerosis. In vitro activation of the FGF2/FGFR1 pathway results in downregulation of myelin proteins. FGF1, 2 and 9 have been shown to be involved in the pathology of multiple sclerosis. Recent studies on the function of oligodendroglial FGFR1 in a model of toxic demyelination showed that deletion of FGFR1 led to increased remyelination and preservation of axonal density and an increased number of mature oligodendrocytes. In the present study the in vivo function of oligodendroglial FGFR1 was characterized using an oligodendrocyte-specific genetic approach in the most frequently used model of multiple sclerosis the MOG35-55 -induced EAE. Oligodendroglial FGFR1 deficient mice (referred to as Fgfr1ind-/- ) showed a significantly ameliorated disease course in MOG35-55 -induced EAE. Less myelin and axonal loss, and reduced lymphocyte and macrophage/microglia infiltration were found in Fgfr1ind-/- mice. The reduction in disease severity in Fgfr1ind-/- mice was accompanied by ERK/AKT phosphorylation, and increased expression of BDNF and TrkB. Reduced proinflammatory cytokine and chemokine expression was seen in Fgfr1ind-/- mice compared with control mice. Considering that FGFR inhibitors are used in cancer trials, the oligodendroglial FGFR1 pathway may provide a new target for therapy in multiple sclerosis.
Collapse
Affiliation(s)
- Ranjithkumar Rajendran
- Department of Neurology, University of Giessen, Klinikstrasse 33, Giessen, 35385, Germany
| | | | - Christine Stadelmann
- Institute of Neuropathology, University of Göttingen, Robert-Koch-Strasse 40, Göttingen, 37099, Germany
| | - Martin Berghoff
- Department of Neurology, University of Giessen, Klinikstrasse 33, Giessen, 35385, Germany
| |
Collapse
|
6
|
LINGO-1 Regulates Oligodendrocyte Differentiation through the Cytoplasmic Gelsolin Signaling Pathway. J Neurosci 2017; 37:3127-3137. [PMID: 28193690 DOI: 10.1523/jneurosci.3722-16.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 01/19/2017] [Accepted: 02/06/2017] [Indexed: 01/07/2023] Open
Abstract
Differentiation and maturation of oligodendrocyte progenitor cells (OPCs) involve the assembly and disassembly of actin microfilaments. However, how actin dynamics are regulated during this process remains poorly understood. Leucine-rich repeat and Ig-like domain-containing Nogo receptor interacting protein 1 (LINGO-1) is a negative regulator of OPC differentiation. We discovered that anti-LINGO-1 antibody-promoted OPC differentiation was accompanied by upregulation of cytoplasmic gelsolin (cGSN), an abundant actin-severing protein involved in the depolymerization of actin filaments. Treating rat OPCs with cGSN siRNA reduced OPC differentiation, whereas overexpression of cGSN promoted OPC differentiation in vitro and remyelination in vivo Furthermore, coexpression of cGSN and LINGO-1 blocked the inhibitory effect of LINGO-1. Our study demonstrates that cGSN works downstream of LINGO-1 signaling pathway, which enhances actin dynamics and is essential for OPC morphogenesis and differentiation. This finding may lead to novel therapeutic approaches for the treatment of demyelinating diseases such as multiple sclerosis (MS).SIGNIFICANCE STATEMENT Myelin loss and subsequent axon degeneration contributes to a variety of neurological diseases, such as multiple sclerosis (MS). Understanding the regulation of myelination by oligodendrocytes is therefore critical for developing therapies for the treatment of MS. We previously demonstrated that leucine-rich repeat and Ig-like domain-containing Nogo receptor interacting protein 1 (LINGO-1) is a negative regulator of oligodendrocyte differentiation and that anti-LINGO-1 promotes remyelination in preclinical animal models for MS and in a phase II acute optic neuritis clinical trial (RENEW). The mechanism by which LINGO-1 regulates oligodendrocyte differentiation is unknown. Here, we demonstrate that LINGO-1 regulates oligodendrocyte differentiation and maturation through the cytoplasmic gelsolin signaling pathway, providing new drug targets for the treatment of demyelination diseases.
Collapse
|
7
|
Abstract
Demyelination of central nervous system axons, associated with traumatic injury and demyelinating diseases such as multiple sclerosis, causes impaired neural transmission and ultimately axon degeneration. Consequently, extensive research has focused on signaling systems that promote myelinating activity of oligodendrocytes or promote production of new oligodendrocytes from oligodendrocyte progenitor cells. Many receptor systems, notably including growth factor receptors and G protein-coupled receptors, control myelination. A number of recent clinical trials target these receptor signaling pathways.
Collapse
Affiliation(s)
- Mark Bothwell
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195;
| |
Collapse
|
8
|
Ledda F, Paratcha G. Assembly of Neuronal Connectivity by Neurotrophic Factors and Leucine-Rich Repeat Proteins. Front Cell Neurosci 2016; 10:199. [PMID: 27555809 PMCID: PMC4977320 DOI: 10.3389/fncel.2016.00199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/29/2016] [Indexed: 11/13/2022] Open
Abstract
Proper function of the nervous system critically relies on sophisticated neuronal networks interconnected in a highly specific pattern. The architecture of these connections arises from sequential developmental steps such as axonal growth and guidance, dendrite development, target determination, synapse formation and plasticity. Leucine-rich repeat (LRR) transmembrane proteins have been involved in cell-type specific signaling pathways that underlie these developmental processes. The members of this superfamily of proteins execute their functions acting as trans-synaptic cell adhesion molecules involved in target specificity and synapse formation or working in cis as cell-intrinsic modulators of neurotrophic factor receptor trafficking and signaling. In this review, we will focus on novel physiological mechanisms through which LRR proteins regulate neurotrophic factor receptor signaling, highlighting the importance of these modulatory events for proper axonal extension and guidance, tissue innervation and dendrite morphogenesis. Additionally, we discuss few examples linking this set of LRR proteins to neurodevelopmental and psychiatric disorders.
Collapse
Affiliation(s)
- Fernanda Ledda
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET, School of Medicine-University of Buenos Aires (UBA) Buenos Aires, Argentina
| | - Gustavo Paratcha
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET, School of Medicine-University of Buenos Aires (UBA) Buenos Aires, Argentina
| |
Collapse
|
9
|
Li X, Zhang Y, Yan Y, Ciric B, Ma CG, Chin J, Curtis M, Rostami A, Zhang GX. LINGO-1-Fc-Transduced Neural Stem Cells Are Effective Therapy for Chronic Stage Experimental Autoimmune Encephalomyelitis. Mol Neurobiol 2016; 54:4365-4378. [PMID: 27344330 DOI: 10.1007/s12035-016-9994-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 06/14/2016] [Indexed: 12/11/2022]
Abstract
The chronic stage multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS), remains refractory to current treatments. This refractory nature may be due to the fact that current treatments are primarily immunomodulatory, which prevent further demyelination but lack the capacity to promote remyelination. Several approaches, including transplantation of neural stem cells (NSCs) or antagonists to LINGO-1, a key part of the receptor complex for neuroregeneration inhibitors, have been effective in suppressing the acute stage of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, their effect on the chronic stage EAE is not known. Here, we show that transplantation of NSCs had only a slight therapeutic effect when treatment started at the chronic stage of EAE (e.g., injected at day 40 postimmunization). However, NSCs engineered to produce LINGO-1-Fc, a soluble LINGO-1 antagonist, significantly promoted neurological recovery as demonstrated by amelioration of clinical signs, improvement in axonal integrity, and enhancement of oligodendrocyte maturation and neuron repopulation. Significantly enhanced NAD production and Sirt2 expression were also found in the CNS of mice treated with LINGO-1-Fc-producing NSC. Moreover, differentiation of LINGO-1-Fc-producing NSCs into oligodendrocytes in vitro was largely diminished by an NAMPT inhibitor, indicating that LINGO-1-Fc enhances the NAMPT/NAD/Sirt2 pathway. Together, our study establishes a CNS-targeted, novel LINGO-1-Fc delivery system using NSCs, which represents a novel and effective NSC-based gene therapy approach for the chronic stage of MS.
Collapse
Affiliation(s)
- Xing Li
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.,College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yuan Zhang
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.,College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Yaping Yan
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.,College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Bogoljub Ciric
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Cun-Gen Ma
- Institute of Brain Science, Department of Neurology, Shanxi Datong University Medical School, Datong, China
| | - Jeannie Chin
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Mark Curtis
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Guang-Xian Zhang
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
10
|
Meabon JS, de Laat R, Ieguchi K, Serbzhinsky D, Hudson MP, Huber BR, Wiley JC, Bothwell M. Intracellular LINGO-1 negatively regulates Trk neurotrophin receptor signaling. Mol Cell Neurosci 2015; 70:1-10. [PMID: 26546150 DOI: 10.1016/j.mcn.2015.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 10/08/2015] [Accepted: 11/02/2015] [Indexed: 11/30/2022] Open
Abstract
Neurotrophins, essential regulators of many aspects of neuronal differentiation and function, signal via four receptors, p75, TrkA, TrkB and TrkC. The three Trk paralogs are members of the LIG superfamily of membrane proteins, which share extracellular domains consisting of leucine-rich repeat and C2 Ig domains. Another LIG protein, LINGO-1 has been reported to bind and influence signaling of p75 as well as TrkA, TrkB and TrkC. Here we examine the manner in which LINGO-1 influences the function of TrkA, TrkB and TrkC. We report that Trk activation promotes Trk association with LINGO-1, and that this association promotes Trk degradation by a lysosomal mechanism. This mechanism resembles the mechanism by which another LIG protein, LRIG1, promotes lysosomal degradation of receptor tyrosine kinases such as the EGF receptor. We present evidence indicating that the Trk/LINGO-1 interaction occurs, in part, within recycling endosomes. We show that a mutant form of LINGO-1, with much of the extracellular domain deleted, has the capacity to enhance TrkA signaling in PC12 cells, possibly by acting as an inhibitor of Trk down-regulation by full length LINGO-1. We propose that LINGO-1 functions as a negative feedback regulator of signaling by cognate receptor tyrosine kinases including TrkA, TrkB and TrkC.
Collapse
Affiliation(s)
- James S Meabon
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA; Mental Illness Research Education and Clinical Center, VA Medical Center, Seattle, WA 98108, USA
| | | | - Katsuaki Ieguchi
- Department of Pharmacology, Tokyo Women's Medical University, Tokyo, Japan
| | | | - Mark P Hudson
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA
| | - B Russel Huber
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA
| | - Jesse C Wiley
- Department of Comparative Medicine, University of Washington, Seattle, WA 98195, USA
| | - Mark Bothwell
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
11
|
Li N, Leung GKK. Oligodendrocyte Precursor Cells in Spinal Cord Injury: A Review and Update. BIOMED RESEARCH INTERNATIONAL 2015; 2015:235195. [PMID: 26491661 PMCID: PMC4600489 DOI: 10.1155/2015/235195] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/19/2015] [Accepted: 06/25/2015] [Indexed: 12/20/2022]
Abstract
Spinal cord injury (SCI) is a devastating condition to individuals, families, and society. Oligodendrocyte loss and demyelination contribute as major pathological processes of secondary damages after injury. Oligodendrocyte precursor cells (OPCs), a subpopulation that accounts for 5 to 8% of cells within the central nervous system, are potential sources of oligodendrocyte replacement after SCI. OPCs react rapidly to injuries, proliferate at a high rate, and can differentiate into myelinating oligodendrocytes. However, posttraumatic endogenous remyelination is rarely complete, and a better understanding of OPCs' characteristics and their manipulations is critical to the development of novel therapies. In this review, we summarize known characteristics of OPCs and relevant regulative factors in both health and demyelinating disorders including SCI. More importantly, we highlight current evidence on post-SCI OPCs transplantation as a potential treatment option as well as the impediments against regeneration. Our aim is to shed lights on important knowledge gaps and to provoke thoughts for further researches and the development of therapeutic strategies.
Collapse
Affiliation(s)
- Ning Li
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
| | - Gilberto K. K. Leung
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
| |
Collapse
|
12
|
Anti-tumor activity of phenoxybenzamine hydrochloride on malignant glioma cells. Tumour Biol 2015; 37:2901-8. [PMID: 26409450 DOI: 10.1007/s13277-015-4102-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 09/14/2015] [Indexed: 12/18/2022] Open
Abstract
Phenoxybenzamine hydrochloride (PHEN) is a selective antagonist of both α-adrenoceptor and calmodulin that exhibits anticancer properties. The aim of this study was to explore the anti-tumor function of PHEN in glioma. Cell proliferation assay was used to assess glioma cell growth. Migration and invasion capacity of glioma cells was monitored by wound-healing and transwell assay, respectively. Neurosphere formation test was adopted for the tumorigenesis of glioma cells, which was also confirmed by soft agar cloning formation test in vitro and a nude mouse model in vivo. Finally, we explored the potential pathway utilized by PHEN using Western blot and immunofluoresce staining. PHEN exhibited a significant inhibitory effect on the proliferation of both U251 and U87MG glioma cell lines in a positive dose-dependent manner. PHEN apparently attenuated the malignancy of glioma in terms of migration and invasion and also suppressed the tumorigenic capacity both in vitro and in vivo. Mechanism study showed that PHEN promoted tumor suppression by inhibiting the TrkB-Akt pathway. The results of the present study demonstrated that PHEN suppressed the proliferation, migration, invasion, and tumorigenesis of glioma cells, induced LINGO-1 expression, and inhibited the TrkB-Akt pathway, which may prove to be the mechanisms underlying the anti-tumor effect of PHEN on glioma cells.
Collapse
|
13
|
Seiler S, Di Santo S, Widmer HR. Non-canonical actions of Nogo-A and its receptors. Biochem Pharmacol 2015; 100:28-39. [PMID: 26348872 DOI: 10.1016/j.bcp.2015.08.113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/31/2015] [Indexed: 12/13/2022]
Abstract
Nogo-A is a myelin associated protein and one of the most potent neurite growth inhibitors in the central nervous system. Interference with Nogo-A signaling has thus been investigated as therapeutic target to promote functional recovery in CNS injuries. Still, the finding that Nogo-A presents a fairly ubiquitous expression in many types of neurons in different brain regions, in the eye and even in the inner ear suggests for further functions besides the neurite growth repression. Indeed, a growing number of studies identified a variety of functions including regulation of neuronal stem cells, modulation of microglial activity, inhibition of angiogenesis and interference with memory formation. Aim of the present commentary is to draw attention on these less well-known and sometimes controversial roles of Nogo-A. Furthermore, we are addressing the role of Nogo-A in neuropathological conditions such as ischemic stroke, schizophrenia and neurodegenerative diseases.
Collapse
Affiliation(s)
- Stefanie Seiler
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Stefano Di Santo
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland
| | - Hans Rudolf Widmer
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland.
| |
Collapse
|
14
|
Andrews JL, Fernandez-Enright F. A decade from discovery to therapy: Lingo-1, the dark horse in neurological and psychiatric disorders. Neurosci Biobehav Rev 2015; 56:97-114. [PMID: 26143511 DOI: 10.1016/j.neubiorev.2015.06.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 05/15/2015] [Accepted: 06/02/2015] [Indexed: 01/19/2023]
Abstract
Leucine-rich repeat and immunoglobulin domain-containing protein (Lingo-1) is a potent negative regulator of neuron and oligodendrocyte survival, neurite extension, axon regeneration, oligodendrocyte differentiation, axonal myelination and functional recovery; all processes highly implicated in numerous brain-related functions. Although playing a major role in developmental brain functions, the potential application of Lingo-1 as a therapeutic target for the treatment of neurological disorders has so far been under-estimated. A number of preclinical studies have shown that various methods of antagonizing Lingo-1 results in neuronal and oligodendroglial survival, axonal growth and remyelination; however to date literature has only detailed applications of Lingo-1 targeted therapeutics with a focus primarily on myelination disorders such as multiple sclerosis and spinal cord injury; omitting important information regarding Lingo-1 signaling co-factors. Here, we provide for the first time a complete and thorough review of the implications of Lingo-1 signaling in a wide range of neurological and psychiatric disorders, and critically examine its potential as a novel therapeutic target for these disorders.
Collapse
Affiliation(s)
- Jessica L Andrews
- Faculty of Science, Medicine and Health, University of Wollongong, Wollongong 2522, NSW, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong 2522, NSW, Australia; Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst 2010, NSW, Australia.
| | - Francesca Fernandez-Enright
- Faculty of Science, Medicine and Health, University of Wollongong, Wollongong 2522, NSW, Australia; Faculty of Social Sciences, University of Wollongong, Wollongong 2522, NSW, Australia; Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong 2522, NSW, Australia; Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst 2010, NSW, Australia.
| |
Collapse
|
15
|
Agúndez JA, Jiménez-Jimenez FJ, Alonso-Navarro H, García-Martín E. The potential of LINGO-1 as a therapeutic target for essential tremor. Expert Opin Ther Targets 2015; 19:1139-48. [PMID: 25862159 DOI: 10.1517/14728222.2015.1028360] [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] [Indexed: 01/01/2023]
Abstract
INTRODUCTION LINGO-1 is a negative regulator of neuronal survival, oligodendrocyte differentiation and axonal outgrowth and regeneration, because it interacts with diverse growth factor receptors blocking or inhibiting their action. Consistent findings obtained in vitro and in animal models suggest that anti-LINGO-1 therapy may be useful in neurodegenerative disorders such as multiple sclerosis (MS), Parkinson's disease or essential tremor (ET). Moreover, genetic and pathological evidence provide a robust link between LINGO-1 and ET. AREAS COVERED In this review, we present an overview of current knowledge on findings linking LINGO-1 and ET, with a special focus on genetic linkage, we include an overview of LINGO1 gene variations according to the 1000 genomes catalog, and we identify potential gene areas where common changes occur because, as well as the risk developing ET, LINGO1 genetic changes may influence the response to anti-LINGO-1 therapy. EXPERT OPINION The goal of anti-LINGO-1 therapy in neurodegenerative diseases is to ease the brakes of neuronal growth and recovery. An anti-LINGO-1 antibody is under clinical trials for MS patients. Before planning trials with ET patients, refinement on the genetic link between LINGO1 and ET, and a detailed genetic and phenotypic assessment of ET patients to be enrolled, should be carried out.
Collapse
Affiliation(s)
- José Ag Agúndez
- University of Extremadura, Department of Pharmacology , Avda. de la Universidad s/n, E-10071, Cáceres , Spain +34927257000 Ext 86897 ; +34924289676 ;
| | | | | | | |
Collapse
|
16
|
Li HY, Ruan YW, Ren CR, Cui Q, So KF. Mechanisms of secondary degeneration after partial optic nerve transection. Neural Regen Res 2014; 9:565-74. [PMID: 25206855 PMCID: PMC4146235 DOI: 10.4103/1673-5374.130093] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2014] [Indexed: 01/23/2023] Open
Abstract
Secondary degeneration occurs commonly in the central nervous system after traumatic injuries and following acute and chronic diseases, including glaucoma. A constellation of mechanisms have been shown to be associated with secondary degeneration including apoptosis, necrosis, autophagy, oxidative stress, excitotoxicity, derangements in ionic homeostasis and calcium influx. Glial cells, such as microglia, astrocytes and oligodendrocytes, have also been demonstrated to take part in the process of secondary injury. Partial optic nerve transection is a useful model which was established about 13 years ago. The merit of this model compared with other optic nerve injury models used for glaucoma study, including complete optic nerve transection model and optic nerve crush model, is the possibility to separate primary degeneration from secondary degeneration in location. Therefore, it provides a good tool for the study of secondary degeneration. This review will focus on the research progress of the mechanisms of secondary degeneration using partial optic nerve transection model.
Collapse
Affiliation(s)
- Hong-Ying Li
- Department of Ophthalmology, the University of Hong Kong, Hong Kong Special Administrative Region, China ; State Key Laboratory of Brain and Cognitive Science, the University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Yi-Wen Ruan
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China ; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province, China
| | - Chao-Ran Ren
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China ; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province, China
| | - Qi Cui
- GHM Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China ; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province, China
| | - Kwok-Fai So
- Department of Ophthalmology, the University of Hong Kong, Hong Kong Special Administrative Region, China ; GHM Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China ; Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province, China ; State Key Laboratory of Brain and Cognitive Science, the University of Hong Kong, Hong Kong Special Administrative Region, China
| |
Collapse
|
17
|
Winther M, Walmod PS. Neural cell adhesion molecules belonging to the family of leucine-rich repeat proteins. ADVANCES IN NEUROBIOLOGY 2014; 8:315-95. [PMID: 25300143 DOI: 10.1007/978-1-4614-8090-7_14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Leucine-rich repeats (LRRs) are motifs that form protein-ligand interaction domains. There are approximately 140 human genes encoding proteins with extracellular LRRs. These encode cell adhesion molecules (CAMs), proteoglycans, G-protein-coupled receptors, and other types of receptors. Here we give a brief description of 36 proteins with extracellular LRRs that all can be characterized as CAMs or putative CAMs expressed in the nervous system. The proteins are involved in multiple biological processes in the nervous system including the proliferation and survival of cells, neuritogenesis, axon guidance, fasciculation, myelination, and the formation and maintenance of synapses. Moreover, the proteins are functionally implicated in multiple diseases including cancer, hearing impairment, glaucoma, Alzheimer's disease, multiple sclerosis, Parkinson's disease, autism spectrum disorders, schizophrenia, and obsessive-compulsive disorders. Thus, LRR-containing CAMs constitute a large group of proteins of pivotal importance for the development, maintenance, and regeneration of the nervous system.
Collapse
|
18
|
Yin W, Hu B. Knockdown of Lingo1b protein promotes myelination and oligodendrocyte differentiation in zebrafish. Exp Neurol 2013; 251:72-83. [PMID: 24262204 DOI: 10.1016/j.expneurol.2013.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 10/29/2013] [Accepted: 11/08/2013] [Indexed: 12/23/2022]
Abstract
Demyelinating diseases include multiple sclerosis, which is a neurodegenerative disease characterized by immune attacks on the central nervous system (CNS), resulting in myelin sheath damage and axonal loss. Leucine-rich repeat and immunoglobulin domain-containing neurite outgrowth inhibitory protein (Nogo) receptor-interacting protein-1 (LINGO-1) have been identified as a negative regulator of oligodendrocytes differentiation. Targeted LINGO-1 inhibition promotes neuron survival, axon regeneration, oligodendrocyte differentiation, and remyelination in diverse animal models. Although studies in rodent models have extended our understanding of LINGO-1, its roles in neural development and myelination in zebrafish (Danio rerio) are not yet clear. In this study, we cloned the zebrafish homolog of the human LINGO-1 and found that lingo1b regulated myelination and oligodendrocyte differentiation. The expression of lingo1b started 1 (mRNA) and 2 (protein) days post-fertilization (dpf) in the CNS. Morpholino oligonucleotide knockdown of lingo1b resulted in developmental abnormalities, including less dark pigment, small eyes, and a curly spinal cord. The lack of lingo1b enhanced myelination and oligodendrocyte differentiation during embryogenesis. Furthermore, immunohistochemistry and movement analysis showed that lingo1b was involved in the axon development of primary motor neurons. These results suggested that Lingo1b protein functions as a negative regulator of myelination and oligodendrocyte differentiation during zebrafish development.
Collapse
Affiliation(s)
- Wu Yin
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Bing Hu
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China.
| |
Collapse
|
19
|
Abstract
LINGO-1 is a leucine-rich repeat and Ig domain-containing, Nogo receptor interacting protein, selectively expressed in the CNS on both oligodendrocytes and neurons. Its expression is developmentally regulated, and is upregulated in CNS diseases and injury. In animal models, LINGO-1 expression is upregulated in rat spinal cord injury, experimental autoimmune encephalomyelitis, 6-hydroxydopamine neurotoxic lesions and glaucoma models. In humans, LINGO-1 expression is increased in oligodendrocyte progenitor cells from demyelinated white matter of multiple sclerosis post-mortem samples, and in dopaminergic neurons from Parkinson's disease brains. LINGO-1 negatively regulates oligodendrocyte differentiation and myelination, neuronal survival and axonal regeneration by activating ras homolog gene family member A (RhoA) and inhibiting protein kinase B (Akt) phosphorylation signalling pathways. Across diverse animal CNS disease models, targeted LINGO-1 inhibition promotes neuron and oligodendrocyte survival, axon regeneration, oligodendrocyte differentiation, remyelination and functional recovery. The targeted inhibition of LINGO-1 function presents a novel therapeutic approach for the treatment of CNS diseases.
Collapse
|
20
|
TrkB receptor signalling: implications in neurodegenerative, psychiatric and proliferative disorders. Int J Mol Sci 2013; 14:10122-42. [PMID: 23670594 PMCID: PMC3676832 DOI: 10.3390/ijms140510122] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 04/27/2013] [Accepted: 04/28/2013] [Indexed: 02/06/2023] Open
Abstract
The Trk family of receptors play a wide variety of roles in physiological and disease processes in both neuronal and non-neuronal tissues. Amongst these the TrkB receptor in particular has attracted major attention due to its critical role in signalling for brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT3) and neurotrophin-4 (NT4). TrkB signalling is indispensable for the survival, development and synaptic plasticity of several subtypes of neurons in the nervous system. Substantial evidence has emerged over the last decade about the involvement of aberrant TrkB signalling and its compromise in various neuropsychiatric and degenerative conditions. Unusual changes in TrkB signalling pathway have also been observed and implicated in a range of cancers. Variations in TrkB pathway have been observed in obesity and hyperphagia related disorders as well. Both BDNF and TrkB have been shown to play critical roles in the survival of retinal ganglion cells in the retina. The ability to specifically modulate TrkB signalling can be critical in various pathological scenarios associated with this pathway. In this review, we discuss the mechanisms underlying TrkB signalling, disease implications and explore plausible ameliorative or preventive approaches.
Collapse
|
21
|
Zhang Z, Xu X, Xiang Z, Yu Z, Feng J, He C. LINGO-1 receptor promotes neuronal apoptosis by inhibiting WNK3 kinase activity. J Biol Chem 2013; 288:12152-60. [PMID: 23482566 DOI: 10.1074/jbc.m112.447771] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
LINGO-1 is a functional component of the Nogo receptor 1 · p75(NTR) · LINGO-1 and Nogo receptor 1 · TAJ (TNFRSF19/TROY)·LINGO-1 signaling complexes. It has recently been shown that LINGO-1 antagonists significantly improve neuronal survival after neural injury. However, the mechanism by which LINGO-1 signaling influences susceptibility to apoptosis remains unknown. In an effort to better understand how LINGO-1 regulates these signaling pathways, we used an established model of serum deprivation (SD) to induce neuronal apoptosis. We demonstrate that treatment either with a construct containing the intracellular domain of LINGO-1 or with Nogo66, a LINGO-1 receptor complex agonist, resulted in an enhanced rate of apoptosis in primary cultured cortical neurons under SD. Reducing the expression levels of the serine/threonine kinase WNK3 using shRNA or inhibiting its kinase activity had similar effects on the survival of serum-deprived neurons. Consistent with these observations, we found that LINGO-1 and WNK3 co-localized and co-precipitated in cultured cortical neurons and brain tissue. Significantly, this co-association was enhanced by Nogo66 treatment. Binding of WNK3 to the intracellular domain of LINGO-1 led to a reduction in WNK3 kinase activity, as did Nogo66 stimulation. Moreover, in vitro and in vivo evidence indicates that endogenous WNK3 suppresses SD-induced neuronal apoptosis in a kinase-dependent manner, as the expression of either a WNK3 RNAi construct or a kinase-dead N-terminal fragment of WNK3 led to increased apoptosis. Taken together, our results show that LINGO-1 potentiates neuronal apoptosis, likely by inhibiting WNK3 kinase activity.
Collapse
Affiliation(s)
- Zhaohuan Zhang
- Institute of Neuroscience and MOE Key Laboratory of Molecular Neurobiology, Neuroscience Research Center of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China
| | | | | | | | | | | |
Collapse
|
22
|
Jepson S, Vought B, Gross CH, Gan L, Austen D, Frantz JD, Zwahlen J, Lowe D, Markland W, Krauss R. LINGO-1, a transmembrane signaling protein, inhibits oligodendrocyte differentiation and myelination through intercellular self-interactions. J Biol Chem 2012; 287:22184-95. [PMID: 22514275 DOI: 10.1074/jbc.m112.366179] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Overcoming remyelination failure is a major goal of new therapies for demyelinating diseases like multiple sclerosis. LINGO-1, a key negative regulator of myelination, is a transmembrane signaling protein expressed in both neurons and oligodendrocytes. In neurons, LINGO-1 is an integral component of the Nogo receptor complex, which inhibits axonal growth via RhoA. Because the only ligand-binding subunit of this complex, the Nogo receptor, is absent in oligodendrocytes, the extracellular signals that inhibit myelination through a LINGO-1-mediated mechanism are unknown. Here we show that LINGO-1 inhibits oligodendrocyte terminal differentiation through intercellular interactions and is capable of a self-association in trans. Consistent with previous reports, overexpression of full-length LINGO-1 inhibited differentiation of oligodendrocyte precursor cells (OPCs). Unexpectedly, treatment with a soluble recombinant LINGO-1 ectodomain also had an inhibitory effect on OPCs and decreased myelinated axonal segments in cocultures with neurons from dorsal root ganglia. We demonstrated LINGO-1-mediated inhibition of OPCs through intercellular signaling by using a surface-bound LINGO-1 construct expressed ectopically in astrocytes. Further investigation showed that the soluble LINGO-1 ectodomain can interact with itself in trans by binding to CHO cells expressing full-length LINGO-1. Finally, we observed that soluble LINGO-1 could activate RhoA in OPCs. We propose that LINGO-1 acts as both a ligand and a receptor and that the mechanism by which it negatively regulates OPC differentiation and myelination is mediated by a homophilic intercellular interaction. Disruption of this protein-protein interaction could lead to a decrease of LINGO-1 inhibition and an increase in myelination.
Collapse
Affiliation(s)
- Scott Jepson
- Department of Cell and Molecular Biology, Vertex Pharmaceuticals, Inc., Cambridge, Massachusetts 02139, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Neurotrophic factors and the regeneration of adult retinal ganglion cell axons. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2012; 106:1-33. [PMID: 23211458 DOI: 10.1016/b978-0-12-407178-0.00002-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The adult central nervous system (CNS) has only a limited capacity to regenerate axons after injury. This is due to a number of factors including the presence of extrinsic inhibitory factors that limit plasticity, lack of effective trophic support, and intrinsic changes in neuronal responsiveness. In this review, we describe the expression and role of neurotrophins in retinal ganglion cells (RGCs) during development and adulthood, and the receptors and miscellaneous signaling systems that influence axonal regeneration after injury. The impact of exogenous neurotrophic factors on adult RGCs injured at different sites in the visual pathway is described for several modes of delivery, including recombinant factors, viral vectors, cell transplantation, as well as combinatorial treatments involving other pharmacotherapeutic agents. Indirect, off-target effects of neurotrophic factors on RGC axonal regeneration are also considered. There remain unresolved issues relating to optimal delivery of neurotrophic factors, and we emphasize the need to develop safe, reliable methods for the regulation of exogenous supply of these factors to the injured CNS.
Collapse
|
24
|
The Expression Patterns of Nogo-A, Myelin Associated Glycoprotein and Oligodendrocyte Myelin Glycoprotein in the Retina After Ocular Hypertension. Neurochem Res 2011; 36:1955-61. [DOI: 10.1007/s11064-011-0518-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2011] [Indexed: 10/18/2022]
|